pubmed_id
stringlengths 39
43
| abstract
stringlengths 3
18k
|
|---|---|
http://www.ncbi.nlm.nih.gov/pubmed/19561403 | 1. Exp Mol Med. 2009 Oct 31;41(10):695-706. doi: 10.3858/emm.2009.41.10.076.
Negative feedback regulation of Wnt signaling by Gbetagamma-mediated reduction
of Dishevelled.
Jung H(1), Kim HJ, Lee SK, Kim R, Kopachik W, Han JK, Jho EH.
Author information:
(1)Department of Life Science, The University of Seoul, Seoul 130-743, Korea.
Wnt signaling is known to be important for diverse embryonic and post-natal
cellular events and be regulated by the proteins Dishevelled and Axin. Although
Dishevelled is activated by Wnt and involved in signal transduction, it is not
clear how Dishevelled-mediated signaling is turned off. We report that guanine
nucleotide binding protein beta 2 (Gnb2; Gbeta2) bound to Axin and Gbeta2
inhibited Wnt mediated reporter activity. The inhibition involved reduction of
the level of Dishevelled, and the Gbeta2gamma2 mediated reduction of Dishevelled
was countered by increased expression of Axin. Consistent with these effects in
HEK293T cells, injection of Gbeta2gamma2 into Xenopus embryos inhibited the
formation of secondary axes induced either by XWnt8 or Dishevelled, but not by
beta-catenin. The DEP domain of Dishevelled is necessary for both interaction
with Gbeta2gamma2 and subsequent degradation of Dishevelled via the lysosomal
pathway. Signaling induced by Gbeta2gamma2 is required because a mutant of
Gbeta2, Gbeta2 (W332A) with lower signaling activity, had reduced ability to
downregulate the level of Dishevelled. Activation of Wnt signaling by either of
two methods, increased Frizzled signaling or transient transfection of Wnt, also
led to increased degradation of Dishevelled and the induced Dishevelled loss is
dependent on Gbeta1 and Gbeta2. Other studies with agents that interfere with
PLC action and calcium signaling suggested that loss of Dishevelled is mediated
through the following pathway: Wnt/Frizzled-->Gbetagamma-->PLC-->Ca(+2)/PKC
signaling. Together the evidence suggests a novel negative feedback mechanism in
which Gbeta2gamma2 inhibits Wnt signaling by degradation of Dishevelled.
DOI: 10.3858/emm.2009.41.10.076
PMCID: PMC2772972
PMID: 19561403 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/9395081 | 1. FEBS Lett. 1997 Nov 3;417(1):89-91. doi: 10.1016/s0014-5793(97)01263-5.
Generation and characterization of transgenic mice expressing a human mutant
alpha-galactosidase with an R301Q substitution causing a variant form of Fabry
disease.
Shimmoto M(1), Kase R, Itoh K, Utsumi K, Ishii S, Taya C, Yonekawa H, Sakuraba
H.
Author information:
(1)Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical
Science, Japan.
Transgenic mice expressing a human mutant alpha-galactosidase with an R301Q
substitution, which was found in a patient with a variant form of Fabry disease,
were established. The mice transcribed a sufficient amount of
alpha-galactosidase mRNA, but the steady-state levels of the enzyme protein were
decreased in liver, kidney and heart, only residual activity being detected in
these tissues. The mice will be useful for the clarification of the defective
regulation of the structurally altered enzyme protein expressed by the mutant
gene at the organ or individual level as well as for the evaluation of drugs
that stabilize and/or activate the mutant alpha-galactosidase.
DOI: 10.1016/s0014-5793(97)01263-5
PMID: 9395081 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19904272 | 1. Br J Cancer. 2009 Dec 1;101(11):1833-8. doi: 10.1038/sj.bjc.6605422. Epub 2009
Nov 10.
Overdetection, overtreatment and costs in prostate-specific antigen screening
for prostate cancer.
Heijnsdijk EA(1), der Kinderen A, Wever EM, Draisma G, Roobol MJ, de Koning HJ.
Author information:
(1)Department of Public Health, Erasmus MC, University Medical Centre Rotterdam,
PO Box 2040, 3000 CA Rotterdam, The Netherlands. [email protected]
BACKGROUND: Prostate cancer screening with prostate-specific antigen (PSA) has
shown to reduce prostate cancer mortality in the European Randomised study of
Screening for Prostate Cancer (ERSPC) trial. Overdetection and overtreatment are
substantial unfavourable side effects with consequent healthcare costs. In this
study the effects of introducing widespread PSA screening is evaluated.
METHODS: The MISCAN model was used to simulate prostate cancer growth and
detection in a simulated cohort of 100,000 men (European standard population)
over 25 years. PSA screening from age 55 to 70 or 75, with 1, 2 and
4-year-intervals is simulated. Number of diagnoses, PSA tests, biopsies,
treatments, deaths and corresponding costs for 100,000 men and for United
Kingdom and United States are compared.
RESULTS: Without screening 2378 men per 100,000 were predicted to be diagnosed
with prostate cancer compared with 4956 men after screening at 4-year intervals.
By introducing screening, the costs would increase with 100% to 60,695,000 euro.
Overdetection is related to 39% of total costs (23,669,000 euro). Screening
until age 75 is relatively most expensive because of the costs of overtreatment.
CONCLUSION: Introduction of PSA screening will increase total healthcare costs
for prostate cancer substantially, of which the actual screening costs will be a
small part.
DOI: 10.1038/sj.bjc.6605422
PMCID: PMC2788248
PMID: 19904272 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22188924 | 1. Mol Pharmacol. 2012 Mar;81(3):488-97. doi: 10.1124/mol.111.075226. Epub 2011
Dec 21.
Characterization of the substituted N-triazole oxindole TROX-1, a
small-molecule, state-dependent inhibitor of Ca(V)2 calcium channels.
Swensen AM(1), Herrington J, Bugianesi RM, Dai G, Haedo RJ, Ratliff KS, Smith
MM, Warren VA, Arneric SP, Eduljee C, Parker D, Snutch TP, Hoyt SB, London C,
Duffy JL, Kaczorowski GJ, McManus OB.
Author information:
(1)Department of Ion Channels, Merck Research Laboratories, Rahway, New Jersey,
USA.
Biological, genetic, and clinical evidence provide validation for N-type calcium
channels (Ca(V)2.2) as therapeutic targets for chronic pain. A state-dependent
Ca(V)2.2 inhibitor may provide an improved therapeutic window over ziconotide,
the peptidyl Ca(V)2.2 inhibitor used clinically. Supporting this notion, we
recently reported that in preclinical models, the state-dependent Ca(V)2
inhibitor
(3R)-5-(3-chloro-4-fluorophenyl)-3-methyl-3-(pyrimidin-5-ylmethyl)-1-(1H-1,2,4-triazol-3-yl)-1,3-dihydro-2H-indol-2-one
(TROX-1) has an improved therapeutic window compared with ziconotide. Here we
characterize TROX-1 inhibition of Cav2.2 channels in more detail. When channels
are biased toward open/inactivated states by depolarizing the membrane potential
under voltage-clamp electrophysiology, TROX-1 inhibits Ca(V)2.2 channels with an
IC(50) of 0.11 μM. The voltage dependence of Ca(V)2.2 inhibition was examined
using automated electrophysiology. TROX-1 IC(50) values were 4.2, 0.90, and 0.36
μM at -110, -90, and -70 mV, respectively. TROX-1 displayed use-dependent
inhibition of Ca(V)2.2 with a 10-fold IC(50) separation between first (27 μM)
and last (2.7 μM) pulses in a train. In a fluorescence-based calcium influx
assay, TROX-1 inhibited Ca(V)2.2 channels with an IC(50) of 9.5 μM under
hyperpolarized conditions and 0.69 μM under depolarized conditions. Finally,
TROX-1 potency was examined across the Ca(V)2 subfamily. Depolarized IC(50)
values were 0.29, 0.19, and 0.28 μM by manual electrophysiology using matched
conditions and 1.8, 0.69, and 1.1 μM by calcium influx for Ca(V)2.1, Ca(V)2.2,
and Ca(V)2.3, respectively. Together, these in vitro data support the idea that
a state-dependent, non-subtype-selective Ca(V)2 channel inhibitor can achieve an
improved therapeutic window over the relatively state-independent
Ca(V)2.2-selective inhibitor ziconotide in preclinical models of chronic pain.
DOI: 10.1124/mol.111.075226
PMID: 22188924 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/16815302 | 1. Biochem Biophys Res Commun. 2006 Aug 18;347(1):226-31. doi:
10.1016/j.bbrc.2006.06.083. Epub 2006 Jun 22.
Aptamer selection based on inhibitory activity using an evolution-mimicking
algorithm.
Noma T(1), Ikebukuro K.
Author information:
(1)Department of Life Science and Biotechnology, Tokyo University of Agriculture
and Technology, Koganei, Japan.
In order to efficiently select aptamers that bind to and inhibit proteins, we
developed a method that involves screening DNA aptamers based on their
inhibitory activities using an evolution-mimicking algorithm after the
pre-selection by SELEX. The value of this method was demonstrated by the
identification of an inhibitor of Taq DNA polymerase in a unique single-stranded
DNA library, which was expected to form a G-quartet structure. This method
consists of selection via an inhibition assay, sequence shuffling, and mutation
in silico. After six rounds of selection, the inhibitory activities of the
aptamers had evolved significantly. This demonstrates the utility of this
strategy for screening aptamers based on their inhibitory actions.
DOI: 10.1016/j.bbrc.2006.06.083
PMID: 16815302 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22403243 | 1. Circulation. 2012 Apr 10;125(14):1765-73, S1-7. doi:
10.1161/CIRCULATIONAHA.111.079699. Epub 2012 Mar 8.
Regulation of cardiac microRNAs by bone marrow mononuclear cell therapy in
myocardial infarction.
Iekushi K(1), Seeger F, Assmus B, Zeiher AM, Dimmeler S.
Author information:
(1)Institute for Cardiovascular Regeneration, Centre of Molecular Medicine,
Frankfurt 60590, Germany.
BACKGROUND: Cell therapy with bone marrow-derived mononuclear cells (BMCs) can
improve recovery of cardiac function after ischemia; however, the molecular
mechanisms are not yet fully understood. MicroRNAs (miRNAs) are key regulators
of gene expression and modulate the pathophysiology of cardiovascular diseases.
METHODS AND RESULTS: We demonstrated that intramyocardial delivery of BMCs in
infarcted mice regulates the expression of cardiac miRNAs and significantly
downregulates the proapoptotic miR-34a. In vitro studies confirmed that the
supernatant of BMC inhibited the expression of H(2)O(2)-induced miR-34a and
cardiomyocytes apoptosis. These effects were blocked by neutralizing antibodies
directed against insulin-like growth factor-1 (IGF-1). Indeed, IGF-1
significantly inhibited H(2)O(2)-induced miR-34a expression, and miR-34a
overexpression abolished the antiapoptotic effect of IGF-1. Likewise, inhibition
of IGF-1 signaling in vivo abolished the BMC-mediated inhibition of miR-34
expression and the protective effect on cardiac function and increased apoptosis
and cardiac fibrosis. IGF-1 specifically blocked the expression of the precursor
and the mature miR-34a, but did not interfere with the transcription of the
primary miR-34a demonstrating that IGF-1 blocks the processing of miR-34a.
CONCLUSIONS: Together, our data demonstrate that the paracrine regulation of
cardiac miRNAs by transplanted BMCs contributes to the protective effects of
cell therapy. BMCs release IGF-1, which inhibits the processing of miR-34a,
thereby blocking cardiomyocyte apoptosis.
DOI: 10.1161/CIRCULATIONAHA.111.079699
PMID: 22403243 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22533554 | 1. Anal Chem. 2012 Jun 5;84(11):4746-53. doi: 10.1021/ac3001918. Epub 2012 May 8.
Aptameric peptide for one-step detection of protein kinase.
Xu X(1), Zhou J, Liu X, Nie Z, Qing M, Guo M, Yao S.
Author information:
(1)State Key Laboratory of Chemo/Biosensing and Chemometrics, College of
Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's
Republic of China.
Protein kinases are significant regulators in the cell signal pathway, and it is
difficult to achieve quick kinase detection because traditional kinase assays
normally rely on a time-consuming kinase phosphorylation process. Herein, we
present a novel one-step strategy to detect protein kinase by using a
kinase-specific aptameric peptide-functionalized quartz crystal microbalance
(QCM) electrode, in which the detection can be finished in less than 10 min. A
peptide kinase inhibitor (IP(20)) was used as the aptameric peptide because of
its selective and strong interaction with the target protein kinase (cyclic
adenosine monophosphate-dependent protein kinase A, PKA), high stability, and
ease of inexpensive synthesis, presenting a new direct recognition element for
kinase. The aptameric peptide was immobilized on the Au-coated quartz electrode
through dual-thiol anchoring and the binding of His-tagged peptide with a
nitrilotriacetic acid/Ni(II) complex, fabricating a highly specific and stable
detection platform. The interaction of aptameric peptide with kinase was
monitored with the QCM in real time, and the concentration of protein kinase was
sensitively measured by the frequency response of the QCM with the low detection
limit for PKA at 0.061 mU μL(-1) and a linear range from 0.64 to 22.33 mU
μL(-1). This method is rapid and reagentless and does not require a
phosphorylation process. The versatility of our aptameric peptide-based strategy
has also been demonstrated by the application in kinase assay using
electrochemical impedance spectroscopy. Moreover, this method was successfully
applied to detect the forskolin/3-isobutyl-1-methylxanthine-stimulated
activation of PKA in cell lysate.
DOI: 10.1021/ac3001918
PMID: 22533554 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/17053055 | 1. Blood. 2007 Mar 1;109(5):1817-24. doi: 10.1182/blood-2006-08-019166. Epub 2006
Oct 19.
Neutrophil elastase in cyclic and severe congenital neutropenia.
Horwitz MS(1), Duan Z, Korkmaz B, Lee HH, Mealiffe ME, Salipante SJ.
Author information:
(1)Division of Medical Genetics, Department of Medicine, University of
Washington School of Medicine, Seattle, WA 98195, USA. [email protected]
Mutations in ELA2 encoding the neutrophil granule protease, neutrophil elastase
(NE), are the major cause of the 2 main forms of hereditary neutropenia, cyclic
neutropenia and severe congenital neutropenia (SCN). Genetic evaluation of other
forms of neutropenia in humans and model organisms has helped to illuminate the
role of NE. A canine form of cyclic neutropenia corresponds to human
Hermansky-Pudlak syndrome type 2 (HPS2) and results from mutations in AP3B1
encoding a subunit of a complex involved in the subcellular trafficking of
vesicular cargo proteins (among which NE appears to be one). Rare cases of SCN
are attributable to mutations in the transcriptional repressor Gfi1 (among whose
regulatory targets also include ELA2). The ultimate biochemical consequences of
the mutations are not yet known, however. Gene targeting of ELA2 has thus far
failed to recapitulate neutropenia in mice. The cycling phenomenon and origins
of leukemic transformation in SCN remain puzzling. Nevertheless, mutations in
all 3 genes are capable of causing the mislocalization of NE and may also induce
the unfolded protein response, suggesting that there might a convergent
pathogenic mechanism focusing on NE.
DOI: 10.1182/blood-2006-08-019166
PMCID: PMC1801070
PMID: 17053055 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21738127 | 1. Nat Biotechnol. 2011 Jul 7;29(8):731-4. doi: 10.1038/nbt.1927.
Genetic engineering of human pluripotent cells using TALE nucleases.
Hockemeyer D(1), Wang H, Kiani S, Lai CS, Gao Q, Cassady JP, Cost GJ, Zhang L,
Santiago Y, Miller JC, Zeitler B, Cherone JM, Meng X, Hinkley SJ, Rebar EJ,
Gregory PD, Urnov FD, Jaenisch R.
Author information:
(1)The Whitehead Institute for Biomedical Research, Cambridge, Massachusetts,
USA.
Targeted genetic engineering of human pluripotent cells is a prerequisite for
exploiting their full potential. Such genetic manipulations can be achieved
using site-specific nucleases. Here we engineered transcription activator-like
effector nucleases (TALENs) for five distinct genomic loci. At all loci tested
we obtained human embryonic stem cell (ESC) and induced pluripotent stem cell
(iPSC) clones carrying transgenic cassettes solely at the TALEN-specified
location. Our data suggest that TALENs employing the specific architectures
described here mediate site-specific genome modification in human pluripotent
cells with similar efficiency and precision as do zinc-finger nucleases (ZFNs).
DOI: 10.1038/nbt.1927
PMCID: PMC3152587
PMID: 21738127 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19389625 | 1. Chem Biol. 2009 Apr 24;16(4):391-400. doi: 10.1016/j.chembiol.2009.02.006.
Aptamer-derived peptides as potent inhibitors of the oncogenic RhoGEF Tgat.
Bouquier N(1), Fromont S, Zeeh JC, Auziol C, Larrousse P, Robert B, Zeghouf M,
Cherfils J, Debant A, Schmidt S.
Author information:
(1)Université Montpellier 2 et 1, Centre de Recherche en Biochimie
Macromoléculaire, IFR 122, Montpellier, France.
Guanine nucleotide exchange factors (GEFs) activate the Rho GTPases by
accelerating their GDP/GTP exchange rate. Some RhoGEFs have been isolated based
on their oncogenic potency, and strategies to inhibit their activity are
therefore actively being sought. In this study we devise a peptide inhibitor
screening strategy to target the GEF activity of Tgat, an oncogenic isoform of
the RhoGEF Trio, based on random mutations of the Trio inhibitor TRIP alpha,
which we previously isolated using a peptide aptamer screen. This identifies one
peptide, TRIP(E32G), which specifically inhibits Tgat GEF activity in vitro and
significantly reduces Tgat-induced RhoA activation and foci formation.
Furthermore, subcutaneous injection of cells expressing Tgat and TRIP(E32G) into
nude mice reduces the formation of Tgat-induced tumors. Our approach thus
demonstrates that peptide aptamers are potent inhibitors that can be used to
interfere with RhoGEF functions in vivo.
DOI: 10.1016/j.chembiol.2009.02.006
PMID: 19389625 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24293099 | 1. Neuropediatrics. 2014 Apr;45(2):129-31. doi: 10.1055/s-0033-1360481. Epub 2013
Nov 29.
Everolimus for the treatment of subependymal giant cell astrocytoma probably
causing seizure aggravation in a child with tuberous sclerosis complex: a case
report.
Wiemer-Kruel A(1), Woerle H(2), Strobl K(1), Bast T(1).
Author information:
(1)Epilepsy Center Kork, Kehl-Kork, Germany.
(2)Klinikum Stuttgart, Olgahospital, Stuttgart, Germany.
We are reporting on a 13.5-year-old girl with tuberous sclerosis complex (TSC)
who was treated with everolimus because of giant cell astrocytoma and bilateral
angiomyolipoma. She suffered from pharmacoresistant partial epilepsy with
clusters of tonic and tonic-clonic seizures. Treatment with carbamazepine and
sulthiame had led to a stable situation for more than 2.5 years. The dosage of
everolimus had to be increased and refractory status epilepticus followed after
12 days. In the absence of any other possible cause, we believe that the status
epilepticus was provoked by everolimus. So far, only a few cases of possible
seizure aggravation by everolimus have been reported. The clinical relevance of
possible negative effects in epileptic patients remains unclear. Similar
observations should be documented and reported.
Georg Thieme Verlag KG Stuttgart · New York.
DOI: 10.1055/s-0033-1360481
PMID: 24293099 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/14962902 | 1. Blood. 2004 Jun 1;103(11):4119-25. doi: 10.1182/blood-2003-10-3518. Epub 2004
Feb 12.
Mutations in the ELA2 gene correlate with more severe expression of neutropenia:
a study of 81 patients from the French Neutropenia Register.
Bellanné-Chantelot C(1), Clauin S, Leblanc T, Cassinat B, Rodrigues-Lima F,
Beaufils S, Vaury C, Barkaoui M, Fenneteau O, Maier-Redelsperger M, Chomienne C,
Donadieu J.
Author information:
(1)Hôpital Saint-Antoine, Laboratoire de d'Embryologie Pathologique et de
Cytogénétique, 184 rue du fbg Saint-Antoine, 75012 Paris, France.
[email protected]
Heterozygous mutations of the gene encoding neutrophil elastase (ELA2) have been
associated with cyclic neutropenia (CN) and severe congenital neutropenia (SCN).
To date, 30 different mutations have been reported, but no correlation has been
found with the degree of neutropenia. To address this issue, we analyzed the
clinical, hematologic, and molecular characteristics of 81 unrelated patients
with SCN (n = 54) or CN (n = 27). We identified mutations in 31 patients, two
thirds of whom had sporadic forms. Familial cases were consistent with dominant
inheritance. Seventeen novel mutations were identified, showing that the
mutational spectrum encompasses not only the region encoding the mature enzyme
but also the prodomains and promoter region. Genotype-phenotype analysis
strongly suggested that ELA2 mutations correlate with more severe expression of
neutropenia, specifically in patients diagnosed with SCN. This study underlines
the importance of ELA2 molecular screening to identify patients who may be at
particular risk of severe bacterial infections and/or acute myeloid
leukemia/myelodysplasia. By phenotypic analysis of affected relatives and
carriers of the same ELA2 mutations, we showed that the expression of
neutropenia in CN and SCN may be either homogeneous or variable according to the
type of mutations, suggesting different pathogenetic mechanisms.
DOI: 10.1182/blood-2003-10-3518
PMID: 14962902 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19057199 | 1. Curr Opin Hematol. 2009 Jan;16(1):9-13. doi: 10.1097/MOH.0b013e32831952de.
Genetic and molecular diagnosis of severe congenital neutropenia.
Ward AC(1), Dale DC.
Author information:
(1)School of Medicine, Deakin University, Geelong, Victoria, Australia.
[email protected]
PURPOSE OF REVIEW: Severe congenital neutropenia has been a well known
hematological condition for over 50 years. Over this long period of time, the
variable genetic causes and associated sequelae of the disease have been
ascertained, and successful treatment strategies developed. Over the past 2
years, however, new studies have added greatly to our understanding of the
molecular basis of the disease, details of which are presented in this review.
RECENT FINDINGS: Recent studies have elucidated a role for the unfolded protein
response in mediating the pathogenic effects of ELA2 mutations, the most common
mutation in severe congenital neutropenia (SCN) as well as cyclic neutropenia.
Genetic lesions in HAX1 have also been identified in the original Kostmann
pedigree representing the autosomal recessive form of SCN. An emerging theme is
the convergence of these and other genetic lesions underlying SCN in enhancing
neutrophil apoptosis. Other studies have revealed the importance of multiple
independent mutations in these and other genes in SCN. Finally, the key role for
signal transducer and activator of transcription 5 in mediating the effects of
granulocyte colony-stimulating factor receptor truncation mutations in the
development of myelodysplastic syndrome/acute myeloid leukemia following SCN has
been elucidated.
SUMMARY: As the full spectrum of molecular mutations causing neutropenia
emerges, it is becoming possible to differentiate patients into subtypes with
different prognoses, for whom tailored therapies are indicated.
DOI: 10.1097/MOH.0b013e32831952de
PMCID: PMC2720320
PMID: 19057199 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/16581027 | 1. Biochem Biophys Res Commun. 2006 May 19;343(4):1165-70. doi:
10.1016/j.bbrc.2006.03.029. Epub 2006 Mar 20.
Suppression of receptor-mediated apoptosis by death effecter domain recruiting
domain binding peptide aptamer.
Kim GS(1), Park YA, Choi YS, Choi YH, Choi HW, Jung YK, Jeong S.
Author information:
(1)Department of Molecular Biology, Institute of Nanosensor and Biotechnology,
Dankook University, Seoul 140-714, Republic of Korea.
FLASH protein is a component of death-inducing signaling complex and might be
involved in death receptor-mediated extrinsic apoptosis. Here we developed the
peptide aptamer against death effecter domain recruiting domain (DRD) of FLASH
protein and showed that the peptide bound to FLASH protein in vitro.
Intracellular expression of the DRD-binding peptide aptamer specifically
suppressed receptor-mediated extrinsic apoptosis but not intrinsic pathway,
which was recapitulated by the antisense oligonucleotides for FLASH. These data
suggest that DRD-binding peptide is not only a novel inhibitor modulating
receptor-mediated apoptosis but also a tool for elucidating the roles of FLASH
in apoptosis.
DOI: 10.1016/j.bbrc.2006.03.029
PMID: 16581027 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19150354 | 1. J Mol Biol. 2009 Apr 17;387(5):1186-98. doi: 10.1016/j.jmb.2008.12.028. Epub
2008 Dec 24.
Development of systemic in vitro evolution and its application to generation of
peptide-aptamer-based inhibitors of cathepsin E.
Kitamura K(1), Yoshida C, Kinoshita Y, Kadowaki T, Takahashi Y, Tayama T,
Kawakubo T, Naimuddin M, Salimullah M, Nemoto N, Hanada K, Husimi Y, Yamamoto K,
Nishigaki K.
Author information:
(1)Rational Evolutionary Design of Advanced Biomolecules, Saitama (REDS),
Saitama Small Enterprise Promotion Corporation, #552, Saitama Industrial
Technology Center, 3-12-18 Kami-Aoki, Kawaguchi, Saitama 333-0844, Japan.
Proteases are involved in various biological functions. Thus, inhibition of
their activities is scientifically interesting and medically important. However,
there is no systematic method established to date to generate endopeptidase
inhibitory peptides. Here, we report a general system to identify endopeptidase
inhibitory peptides based on the use of in vitro evolution. Using this system,
we generated peptides that inhibit cathepsin E (CE) specifically at a
submicromolar IC(50). This system generates protease inhibitor peptides
utilizing techniques of cDNA display, selection-by-function, Y-ligation-based
block shuffling, and others. We further demonstrated the importance and
effectiveness of a secondary library for obtaining small-sized and active
peptides. CE inhibitory peptides generated by this method were characterized by
a small size (8 to 12 aa) and quite different sequences, suggesting that they
bind to different sites on CE. Typical CE inhibitory peptide aptamers obtained
here (P(i)101; SCGG IIII SCIA) have half an inhibition activity (K(i); 5 nM) of
pepstatin A (potent CE inhibitor) without inhibiting cathepsin D (structurally
similar to CE). The general applicability of this system suggests that it may be
useful to identify inhibitory peptides for various kinds of proteases and that
it may therefore contribute to protein science and drug discovery. The peptide
binding to a protein is discussed in comparison with the antibody binding to an
antigen.
DOI: 10.1016/j.jmb.2008.12.028
PMID: 19150354 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24965068 | 1. Pflugers Arch. 2015 Jan;467(1):141-55. doi: 10.1007/s00424-014-1558-3. Epub
2014 Jun 26.
Non-channel mechanosensors working at focal adhesion-stress fiber complex.
Hirata H(1), Tatsumi H, Hayakawa K, Sokabe M.
Author information:
(1)Mechanobiology Institute, National University of Singapore, 117411,
Singapore, Singapore.
Mechanosensitive ion channels (MSCs) have long been the only established
molecular class of cell mechanosensors; however, in the last decade, a variety
of non-channel type mechanosensor molecules have been identified. Many of them
are focal adhesion-associated proteins that include integrin, talin, and actin.
Mechanosensors must be non-soluble molecules firmly interacting with relatively
rigid cellular structures such as membranes (in terms of lateral stiffness),
cytoskeletons, and adhesion structures. The partner of MSCs is the membrane in
which MSC proteins efficiently transduce changes in the membrane tension into
conformational changes that lead to channel opening. By contrast, the integrin,
talin, and actin filament form a linear complex of which both ends are typically
anchored to the extracellular matrices via integrins. Upon cell deformation by
forces, this structure turns out to be a portion that efficiently transduces the
generated stress into conformational changes of composite molecules, leading to
the activation of integrin (catch bond with extracellular matrices) and talin
(unfolding to induce vinculin bindings). Importantly, this structure also serves
as an "active" mechanosensor to detect substrate rigidity by pulling the
substrate with contraction of actin stress fibers (SFs), which may induce talin
unfolding and an activation of MSCs in the vicinity of integrins. A recent study
demonstrates that the actin filament acts as a mechanosensor with unique
characteristics; the filament behaves as a negative tension sensor in which
increased torsional fluctuations by tension decrease accelerate ADF/cofilin
binding, leading to filament disruption. Here, we review the latest progress in
the study of those non-channel mechanosensors and discuss their activation
mechanisms and physiological roles.
DOI: 10.1007/s00424-014-1558-3
PMID: 24965068 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23246482 | 1. Cell Stem Cell. 2013 Feb 7;12(2):238-51. doi: 10.1016/j.stem.2012.11.011. Epub
2012 Dec 13.
A TALEN genome-editing system for generating human stem cell-based disease
models.
Ding Q(1), Lee YK, Schaefer EA, Peters DT, Veres A, Kim K, Kuperwasser N, Motola
DL, Meissner TB, Hendriks WT, Trevisan M, Gupta RM, Moisan A, Banks E, Friesen
M, Schinzel RT, Xia F, Tang A, Xia Y, Figueroa E, Wann A, Ahfeldt T, Daheron L,
Zhang F, Rubin LL, Peng LF, Chung RT, Musunuru K, Cowan CA.
Author information:
(1)Department of Stem Cell and Regenerative Biology, Harvard University,
Cambridge, MA 02138, USA.
Transcription activator-like effector nucleases (TALENs) are a new class of
engineered nucleases that are easier to design to cleave at desired sites in a
genome than previous types of nucleases. We report here the use of TALENs to
rapidly and efficiently generate mutant alleles of 15 genes in cultured somatic
cells or human pluripotent stem cells, the latter for which we differentiated
both the targeted lines and isogenic control lines into various metabolic cell
types. We demonstrate cell-autonomous phenotypes directly linked to
disease-dyslipidemia, insulin resistance, hypoglycemia, lipodystrophy,
motor-neuron death, and hepatitis C infection. We found little evidence of TALEN
off-target effects, but each clonal line nevertheless harbors a significant
number of unique mutations. Given the speed and ease with which we were able to
derive and characterize these cell lines, we anticipate TALEN-mediated genome
editing of human cells becoming a mainstay for the investigation of human
biology and disease.
Copyright © 2013 Elsevier Inc. All rights reserved.
DOI: 10.1016/j.stem.2012.11.011
PMCID: PMC3570604
PMID: 23246482 [Indexed for MEDLINE]
Conflict of interest statement: A.M. is a fulltime employee of Roche
Pharmaceuticals; the other authors report no relevant conflicts of interest. |
http://www.ncbi.nlm.nih.gov/pubmed/24011800 | 1. J Prosthet Dent. 2013 Nov;110(5):349-55. doi: 10.1016/j.prosdent.2013.05.002.
Epub 2013 Sep 5.
Association between sleep bruxism and gastroesophageal reflux disease.
Mengatto CM(1), Dalberto Cda S, Scheeren B, Barros SG.
Author information:
(1)Professor, Department of Conservative Dentistry, Federal University of Rio
Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address:
[email protected].
STATEMENT OF PROBLEM: Rhythmic masticatory muscle activity, including sleep
bruxism (SB), can be induced in healthy individuals by experimental esophageal
acidification, which plays an important role in the pathogenesis of
gastroesophageal reflux disease (GERD). However, no robust evidence supports the
association between SB and GERD.
PURPOSE: The purpose of this study was to investigate the association between SB
and GERD.
MATERIAL AND METHODS: Forty-five individuals were eligible to participate in
this observational transversal study at the Gastroenterology Service of the
Clinical Hospital of Porto Alegre, Brazil. The participants were classified into
2 groups, those with and without GERD, according to the Montreal Criteria and
pH-metry/endoscopy findings. The diagnosis of SB was not assessed in a sleep
laboratory but was based on self-report plus clinical inspection, according to
the minimal diagnostic criteria of the American Academy of Sleep Medicine. The
Lipp Stress Symptom Inventory was used to evaluate self-perceived stress.
Univariate and multiple logistic regression analyses were performed with SB as
dependent variable and GERD, sex, age, body mass index, and stress as predictors
(α=.05; 90% power).
RESULTS: The study population included individuals with SB without GERD (13.3%)
and individuals with SB with GERD (31.1%). In participants with GERD, the
prevalence of SB was 73.7%. Only the variable GERD was significantly associated
with SB (P=.017; odds ratio 6.58; 95% confidence interval 1.40-30.98), although
adjusted for stress and age.
CONCLUSIONS: Sleep bruxism is prevalent in GERD patients, and GERD is highly
associated with SB.
Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry.
Published by Mosby, Inc. All rights reserved.
DOI: 10.1016/j.prosdent.2013.05.002
PMID: 24011800 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/15899965 | 1. Genome Res. 2005 Jun;15(6):800-8. doi: 10.1101/gr.3545105. Epub 2005 May 17.
Ultraconserved elements in insect genomes: a highly conserved intronic sequence
implicated in the control of homothorax mRNA splicing.
Glazov EA(1), Pheasant M, McGraw EA, Bejerano G, Mattick JS.
Author information:
(1)ARC Special Research Centre for Functional and Applied Genomics, Institute
for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072,
Australia.
Recently, we identified a large number of ultraconserved (uc) sequences in
noncoding regions of human, mouse, and rat genomes that appear to be essential
for vertebrate and amniote ontogeny. Here, we used similar methods to identify
ultraconserved genomic regions between the insect species Drosophila
melanogaster and Drosophila pseudoobscura, as well as the more distantly related
Anopheles gambiae. As with vertebrates, ultraconserved sequences in insects
appear to occur primarily in intergenic and intronic sequences, and at
intron-exon junctions. The sequences are significantly associated with genes
encoding developmental regulators and transcription factors, but are less
frequent and are smaller in size than in vertebrates. The longest identical,
nongapped orthologous match between the three genomes was found within the
homothorax (hth) gene. This sequence spans an internal exon-intron junction,
with the majority located within the intron, and is predicted to form a highly
stable stem-loop RNA structure. Real-time quantitative PCR analysis of different
hth splice isoforms and Northern blotting showed that the conserved element is
associated with a high incidence of intron retention in hth pre-mRNA, suggesting
that the conserved intronic element is critically important in the
post-transcriptional regulation of hth expression in Diptera.
DOI: 10.1101/gr.3545105
PMCID: PMC1142470
PMID: 15899965 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19014335 | 1. J Interferon Cytokine Res. 2009 Jan;29(1):55-67. doi: 10.1089/jir.2008.0013.
The proinflammatory cytokine-induced IRG1 protein associates with mitochondria.
Degrandi D(1), Hoffmann R, Beuter-Gunia C, Pfeffer K.
Author information:
(1)Institute of Medical Microbiology and Hospital Hygiene,
Heinrich-Heine-University of Duesseldorf, Germany.
Erratum in
J Interferon Cytokine Res. 2009 Sep;29(9):643.
Interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) are essential
cytokines for successful clearance of microbial infections. Activation of
macrophages by synergistic effects of these cytokines leads to induction of
antimicrobial effector systems like reactive oxygen and reactive nitrogen
intermediates. Strikingly, IFN-gammaR(-/-) and TNFRp55(-/-) mice are
considerably more susceptible to infections than inducible nitric oxide
synthase(-/-) and p47phox(-/-) mice. Thus we applied transcriptome-profiling
studies to identify genes synergistically upregulated by IFN-gamma and TNF in
macrophages which are potentially involved in the defense against intracellular
pathogens. From a total of 234 regulated genes we found 35 genes that were
upregulated by combined effects of IFN-gamma and TNF and were at least 2-fold
induced. The majority of these genes are involved in signal transduction and
transcriptional regulation. However, we found several genes were poorly
characterized with regard to immunological functions. As a prototypic TNF- and
IFN-gamma-coregulated gene we characterized the expression and the subcellular
localization of immunoresponsive gene 1 (IRG1) in murine macrophages. IRG1 is
highly upregulated in murine ANA-1 macrophages by several proinflammatory
cytokines and Toll-like receptor (TLR) agonists, as well as in spleen and lung
of Listeria monocytogenes or Toxoplasma gondii infected mice, respectively.
Furthermore, this study identifies 35 genes that constitute the
IFN-gamma/TNF-triggered effector program in innate immunity.
DOI: 10.1089/jir.2008.0013
PMID: 19014335 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24188027 | 1. Protein Pept Lett. 2014;21(2):132-9. doi: 10.2174/09298665113206660116.
The PA207 peptide inhibitor of LIM-only protein 2 (Lmo2) targets Zinc Finger
domains in a non-specific manner.
Wilkinson-White L, Matthews JM(1).
Author information:
(1)School of Molecular Bioscience, University of Sydney, NSW 2006, Australia.
[email protected].
Peptide aptamers of LIM-only protein 2 (Lmo2) were previously used to
successfully treat Lmo2-induced tumours in a mouse model of leukaemia. Here we
show that the Lmo2 aptamer PA207, either as a free peptide or fused to
thioredoxin Trx-PA207, causes purified Lmo2 to precipitate rather than binding
to a defined surface on the protein. Stabilisation of Lmo2 through interaction
with LIM domain binding protein 1 (Ldb1), a normal binding partner of Lmo2,
abrogates this effect. The addition of free zinc causes Trx-PA207 to self
associate, suggesting that PA207 destabilises Lmo2 by modulating normal
zinc-coordination in the LIM domains. GST-pulldown experiments with other Lmo
and Gata proteins indicates that PA207 can bind to a range of zinc finger
proteins. Thus, PA207 and other cysteine-containing peptide aptamers for Lmo2
may form a class of general zinc finger inhibitors.
DOI: 10.2174/09298665113206660116
PMID: 24188027 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24276039 | 1. J Pediatr Hematol Oncol. 2014 Oct;36(7):e448-51. doi:
10.1097/MPH.0000000000000005.
Response of subependymal giant cell astrocytoma with spinal cord metastasis to
everolimus.
Aguilera D(1), Flamini R, Mazewski C, Schniederjan M, Hayes L, Boydston W,
Castellino RC, MacDonald TJ.
Author information:
(1)*Aflac Cancer and Blood Disorders Center ‡Department of Pathology, Children's
Healthcare of Atlanta, Emory University School of Medicine Departments of
†Neurology §Radiology ∥Neurosurgery, Children's Healthcare of Atlanta, Atlanta,
GA.
BACKGROUND: Brain subependymal giant cell astrocytomas (SEGAs) in patients with
tuberous sclerosis have been reported to respond to everolimus.
METHODS: A 15-year-old male patient with intractable seizures and multiple SEGAs
of the brain developed leptomeningeal enhancement and multiple metastatic,
histologically confirmed SEGAs of the spinal cord. He received daily everolimus
at a dose of 3 mg/m for 6 weeks, which was then increased to 6 mg/m.
RESULTS: Magnetic resonance image of the brain and spine showed significant
reduction in the size of SEGAs after 6 weeks of treatment. The patient has
remained free of progression for 24 months. Additional benefits included:
excellent seizure control, decrease in the size of cardiac rhabdomyomas, and
improved quality of life.
CONCLUSIONS: We describe a rare case of metastatic SEGA, which was successfully
treated with everolimus.
DOI: 10.1097/MPH.0000000000000005
PMCID: PMC4009394
PMID: 24276039 [Indexed for MEDLINE]
Conflict of interest statement: The remaining authors declare no conflict of
interest. |
http://www.ncbi.nlm.nih.gov/pubmed/26029690 | 1. Front Bioeng Biotechnol. 2015 May 11;3:62. doi: 10.3389/fbioe.2015.00062.
eCollection 2015.
Matrix-Immobilized BMP-2 on Microcontact Printed Fibronectin as an in vitro Tool
to Study BMP-Mediated Signaling and Cell Migration.
Hauff K(1), Zambarda C(2), Dietrich M(3), Halbig M(2), Grab AL(3), Medda R(2),
Cavalcanti-Adam EA(2).
Author information:
(1)Department of Biophysical Chemistry, Institute of Physical Chemistry,
University of Heidelberg , Heidelberg , Germany ; Applied Chemistry, University
of Reutlingen , Reutlingen , Germany.
(2)Department of Biophysical Chemistry, Institute of Physical Chemistry,
University of Heidelberg , Heidelberg , Germany ; Department of New Materials
and Biosystems, Max Planck Institute for Intelligent Systems , Stuttgart ,
Germany.
(3)Department of Biophysical Chemistry, Institute of Physical Chemistry,
University of Heidelberg , Heidelberg , Germany.
During development, growth factors (GFs) such as bone morphogenetic proteins
(BMPs) exert important functions in several tissues by regulating signaling for
cell differentiation and migration. In vivo, the extracellular matrix (ECM) not
only provides support for adherent cells, but also acts as reservoir of GFs.
Several constituents of the ECM provide adhesive cues, which serve as binding
sites for cell trans-membrane receptors, such as integrins. In conveying
adhesion-mediated signaling to the intracellular compartment, integrins do not
function alone but rather crosstalk and cooperate with other receptors, such as
GF receptors. Here, we present a strategy for the immobilization of BMP-2 onto
cellular fibronectin (cFN), a key protein of the ECM, to investigate GF-mediated
signaling and migration. Following biotinylation, BMP-2 was linked to
biotinylated cFN using NeutrAvidin as cross-linker. Characterization with quartz
crystal microbalance with dissipation monitoring and enzyme-linked immunosorbent
assay confirmed the efficient immobilization of BMP-2 on cFN over a period of
24 h. To validate the bioactivity of matrix-immobilized BMP-2 (iBMP-2), we
investigated short- and long-term responses of C2C12 myoblasts, which are an
established in vitro model for BMP-2 signaling, in comparison to soluble BMP-2
(sBMP-2) or in absence of GFs. Similarly to sBMP-2, iBMP-2 triggered Smad 1/5
phosphorylation and translocation of the complex to the nucleus, corresponding
to the activation of BMP-mediated Smad-dependent pathway. Additionally,
successful suppression of myotube formation was observed after 6 days in sBMP-2
and iBMP-2. We next implemented this approach in the fabrication of cFN
micropatterned stripes by soft lithography. These stripes allowed cell-surface
interaction only on the patterned cFN, since the surface in between was
passivated, thus serving as platform for studies on directed cell migration.
During a 10-h observation time, the migratory behavior, especially the cells'
net displacement, was increased in presence of BMP-2. As such, this versatile
tool retains the bioactivity of GFs and allows the presentation of ECM adhesive
cues.
DOI: 10.3389/fbioe.2015.00062
PMCID: PMC4426815
PMID: 26029690 |
http://www.ncbi.nlm.nih.gov/pubmed/25886986 | 1. BMC Cell Biol. 2015 Feb 27;16:3. doi: 10.1186/s12860-015-0051-y.
α6β1- and αV-integrins are required for long-term self-renewal of murine
embryonic stem cells in the absence of LIF.
Cattavarayane S(1), Palovuori R(2), Tanjore Ramanathan J(3)(4), Manninen A(5).
Author information:
(1)Biocenter Oulu, Oulu Center for Cell-Matrix Research, Faculty of Biochemistry
and Molecular Medicine, University of Oulu, Aapistie 5, Oulu, 90220, Finland.
[email protected].
(2)Biocenter Oulu, Oulu Center for Cell-Matrix Research, Faculty of Biochemistry
and Molecular Medicine, University of Oulu, Aapistie 5, Oulu, 90220, Finland.
[email protected].
(3)Biocenter Oulu, Oulu Center for Cell-Matrix Research, Faculty of Biochemistry
and Molecular Medicine, University of Oulu, Aapistie 5, Oulu, 90220, Finland.
[email protected].
(4)Current address: Université de Lorraine, CS 25233, Nancy, cedex, 54052,
France. [email protected].
(5)Biocenter Oulu, Oulu Center for Cell-Matrix Research, Faculty of Biochemistry
and Molecular Medicine, University of Oulu, Aapistie 5, Oulu, 90220, Finland.
[email protected].
BACKGROUND: The growth properties and self-renewal capacity of embryonic stem
(ES) cells are regulated by their immediate microenvironment such as the
extracellular matrix (ECM). Integrins, a central family of cellular ECM
receptors, have been implicated in these processes but their specific role in ES
cell self-renewal remains unclear.
RESULTS: Here we have studied the effects of different ECM substrates and
integrins in mouse ES cells in the absence of Leukemia Inhibitory Factor (LIF)
using short-term assays as well as long-term cultures. Removal of LIF from ES
cell culture medium induced morphological differentiation of ES cells into
polarized epistem cell-like cells. These cells maintained epithelial morphology
and expression of key stemness markers for at least 10 passages in the absence
of LIF when cultured on laminin, fibronectin or collagen IV substrates. The
specific functional roles of α6-, αV- and β1-integrin subunits were dissected
using stable lentivirus-mediated RNAi methodology. β1-integrins were required
for ES cell survival in long-term cultures and for the maintenance of stem cell
marker expression. Inhibition of α6-integrin expression compromised self-renewal
on collagen while αV-integrins were required for robust ES cell adhesion on
laminin. Analysis of the stemness marker expression revealed subtle differences
between α6- and αV-depleted ES cells but the expression of both was required for
optimal self-renewal in long-term ES cell cultures.
CONCLUSIONS: In the absence of LIF, long-term ES cell cultures adapt an epistem
cell-like epithelial phenotype and retain the expression of multiple stem cell
markers. Long-term maintenance of such self-renewing cultures depends on the
expression of β1-, α6- and αV-integrins.
DOI: 10.1186/s12860-015-0051-y
PMCID: PMC4348401
PMID: 25886986 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22262746 | 1. Neurology. 2012 Feb 21;78(8):526-31. doi: 10.1212/WNL.0b013e318247ca8d. Epub
2012 Jan 18.
Everolimus alters white matter diffusion in tuberous sclerosis complex.
Tillema JM(1), Leach JL, Krueger DA, Franz DN.
Author information:
(1)Department of Neurology, Cincinnati Children's Hospital Medical Center,
Cincinnati, OH, USA.
Comment in
Neurology. 2012 Feb 21;78(8):520-1. doi: 10.1212/WNL.0b013e318248a232.
OBJECTIVE: Diffusion tensor imaging (DTI) analysis was performed on patients
with tuberous sclerosis complex (TSC) to investigate potential changes in
normal-appearing white matter after treatment with everolimus, a mammalian
target of rapamycin (mTOR) inhibitor.
METHODS: Recently, a phase I/II trial of everolimus demonstrated significant
reductions in subependymal giant cell astrocytoma (SEGA) volume and decreased
seizure frequency. Subgroup analysis was performed on DTI data available from
this study. TSC patients with SEGA received everolimus, titrated to tolerability
to achieve target trough concentrations of 5-15 ng/mL. DTI (1.5 T, 15
directions) was used to calculate fractional anisotropy (FA) and axial, radial,
and mean diffusivity within regions of interest (ROIs). Baseline scans were
compared to 12-18 months post-treatment and compared to a TSC age- and
gender-matched nontreatment control cohort.
RESULTS: Of 28 enrolled patients, 20 had sufficient DTI data. Comparing baseline
values with those acquired 12-18 months after treatment, a significant change in
FA was observed in the corpus callosum, internal capsule, and geniculo-calcarine
region (p < 0.05). Mean change in FA was 0.04 (p < 0.01), driven primarily by a
significant decrease in radial diffusivity. Mean diffusivity of the combined
ROIs decreased slightly (p < 0.05), axial diffusivity remained stable. The
control group showed no change over time.
CONCLUSION: Significant changes in FA and radial diffusivity were observed after
treatment with everolimus in patients with TSC, suggesting that the genetic
defect of TSC in the brain may be modified pharmacologically, even in
normal-appearing white matter.
DOI: 10.1212/WNL.0b013e318247ca8d
PMID: 22262746 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/12123800 | 1. FEBS Lett. 2002 Jul 17;523(1-3):35-42. doi: 10.1016/s0014-5793(02)02928-9.
Identification of the first Rho-GEF inhibitor, TRIPalpha, which targets the
RhoA-specific GEF domain of Trio.
Schmidt S(1), Diriong S, Méry J, Fabbrizio E, Debant A.
Author information:
(1)CRBM-CNRS, UPR 1086 CNRS, 1919 Route de Mende, 34293 Cedex 5, Montpellier,
France.
The Rho-guanine nucleotide exchange factors (Rho-GEFs) remodel the actin
cytoskeleton via their Rho-GTPase targets and affect numerous physiological
processes such as transformation and cell motility. They are therefore
attractive targets to design specific inhibitors that may have therapeutic
applications. Trio contains two Rho-GEF domains, GEFD1 and GEFD2, which activate
the Rac and RhoA pathways, respectively. Here we have used a genetic screen in
yeast to select in vivo peptides coupled to thioredoxin, called aptamers, that
could inhibit GEFD2 activity. One aptamer, TRIAPalpha (TRio Inhibitory APtamer),
specifically blocks GEFD2-exchange activity on RhoA in vitro. The corresponding
peptide sequence, TRIPalpha, inhibits TrioGEFD2-mediated activation of RhoA in
intact cells and specifically reverts the neurite retraction phenotype induced
by TrioGEFD2 in PC12 cells. Thus TRIPalpha is the first Rho-GEF inhibitor
isolated so far, and represents an important step in the design of inhibitors
for the expanding family of Rho-GEFs.
DOI: 10.1016/s0014-5793(02)02928-9
PMID: 12123800 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23567018 | 1. Eur J Paediatr Neurol. 2013 Sep;17(5):479-85. doi: 10.1016/j.ejpn.2013.03.002.
Epub 2013 Apr 6.
Long-term effect of everolimus on epilepsy and growth in children under 3 years
of age treated for subependymal giant cell astrocytoma associated with tuberous
sclerosis complex.
Kotulska K(1), Chmielewski D, Borkowska J, Jurkiewicz E, Kuczyński D, Kmieć T,
Łojszczyk B, Dunin-Wąsowicz D, Jóźwiak S.
Author information:
(1)Department of Science, The Children's Memorial Health Institute, Warsaw,
Poland. [email protected]
BACKGROUND: Tuberous sclerosis complex (TSC) is a genetic disorder characterized
by increased mammalian target of rapamycin (mTOR) activation and growth of
benign tumors in several organs throughout the body. In young children with TSC,
drug-resistant epilepsy and subependymal giant cell astrocytomas (SEGAs) present
the most common causes of mortality and morbidity. There are also some reports
on the antiepileptic and antiepileptogenic potential of mTOR inhibitors in TSC.
However, the data on everolimus efficacy and safety in young children are very
limited.
AIMS: To show the long-term safety data and the effect of everolimus treatment
on epilepsy in children under the age of 3 who received everolimus for SEGAs
associated with TSC.
METHODS: We present the results of everolimus treatment in 8 children under the
age of 3 who participated in EXIST-1 study. Five patients presented with active,
drug-resistant epilepsy at baseline. The mean follow-up is 35 months (33-38
months) and all children are still on treatment.
RESULTS: In 6 out of 8 children, at least a 50% reduction in SEGA volume was
observed. In 1 child with drug-resistant epilepsy, everolimus treatment resulted
in cessation of seizures and in 2 other children, at least a 50% reduction in
the number of seizures was noted. The incidence of adverse events (AE) was
similar to that observed in older children and adults.
CONCLUSIONS: This study suggests that everolimus is effective and safe in
infants and young children with epilepsy and SEGA associated with TSC and offers
a valuable treatment option.
Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier
Ltd. All rights reserved.
DOI: 10.1016/j.ejpn.2013.03.002
PMID: 23567018 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24667713 | 1. Ann Oncol. 2014 Apr;25(4):763-773. doi: 10.1093/annonc/mdu021.
Adverse event management in patients with advanced cancer receiving oral
everolimus: focus on breast cancer.
Aapro M(1), Andre F(2), Blackwell K(3), Calvo E(4), Jahanzeb M(5), Papazisis
K(6), Porta C(7), Pritchard K(8), Ravaud A(9).
Author information:
(1)Multidisciplinary Oncology Institute, Clinique de Genolier, Genolier,
Switzerland. Electronic address: [email protected].
(2)French National Institute of Health and Medical Research (INSERM), Université
Paris Sud, Orsay; Department of Medical Oncology, Institut Gustave Roussy,
Villejuif, France.
(3)Department of Medicine/Medical Oncology, Duke University Medical Center,
Durham, USA.
(4)Melanoma Program, Centro Integral Oncológico Clara Campal and Clinical
Research, START Madrid, Madrid, Spain.
(5)Sylvester Comprehensive Cancer Center, Miller School of Medicine, University
of Miami, Miami, USA.
(6)Department of Medical Oncology, Euromedica General Clinic, Thessaloniki,
Greece.
(7)Department of Medical Oncology, IRCCS, San Matteo University Hospital
Foundation, Pavia, Italy.
(8)Sunnybrook Odette Cancer Centre and the University of Toronto, Toronto,
Canada.
(9)Department of Medical Oncology, Hôpital Saint-Andre, Bordeaux University
Hospital, Bordeaux, France.
Comment in
Ann Oncol. 2014 Oct;25(10):2096-2098. doi: 10.1093/annonc/mdu373.
Ann Oncol. 2014 Oct;25(10):2096. doi: 10.1093/annonc/mdu371.
Ann Oncol. 2015 Jan;26(1):248-249. doi: 10.1093/annonc/mdu492.
BACKGROUND: Everolimus, an orally administered rapamycin analogue, inhibits the
mammalian target of rapamycin (mTOR), a highly conserved intracellular
serine-threonine kinase that is a central node in a network of signaling
pathways controlling cellular metabolism, growth, survival, proliferation,
angiogenesis, and immune function. Everolimus has demonstrated substantial
clinical benefit in randomized, controlled, phase III studies leading to
approval for the treatment of advanced renal cell carcinoma, advanced
neuroendocrine tumors of pancreatic origin, renal angiomyolipoma and
subependymal giant-cell astrocytoma associated with tuberous sclerosis complex,
as well as advanced hormone-receptor-positive (HR(+)) and human epidermal growth
factor receptor-2-negative advanced breast cancer.
MATERIALS AND METHODS: We discuss clinically relevant everolimus-related adverse
events from the phase III studies, including stomatitis, noninfectious
pneumonitis, rash, selected metabolic abnormalities, and infections, with focus
on appropriate clinical management of these events and specific considerations
in patients with breast cancer.
RESULTS: The majority of adverse events experienced during everolimus therapy
are of mild to moderate severity. The safety profile and protocols for toxicity
management are well established. The class-effect adverse event profile observed
with everolimus plus endocrine therapy in breast cancer is (as expected)
distinct from that of endocrine therapy alone, but is similar to that observed
with everolimus in other solid tumors. Information gained from the experience in
other carcinomas on prompt diagnosis and treatments to optimize drug exposure,
treatment outcomes, and patients' quality of life also applies to the patient
population with advanced breast cancer.
CONCLUSIONS: As with all orally administered agents, education of both
physicians and patients in the management of adverse events for patients
receiving everolimus is critical to achieving optimal exposure and clinical
benefit. Active monitoring for early identification of everolimus-related
adverse events combined with aggressive and appropriate intervention should lead
to a reduction in the severity and duration of the event.
DOI: 10.1093/annonc/mdu021
PMID: 24667713 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24669905 | 1. BMC Genomics. 2014 Mar 26;15:120. doi: 10.1186/1471-2164-15-120.
Chromatin states reveal functional associations for globally defined
transcription start sites in four human cell lines.
Rye M(1), Sandve GK, Daub CO, Kawaji H, Carninci P, Forrest AR, Drabløs F;
FANTOM consortium.
Author information:
(1)Department of Cancer Research and Molecular Medicine, Norwegian University of
Science and Technology, P,O, Box 8905, NO-7491 Trondheim, Norway.
[email protected].
BACKGROUND: Deciphering the most common modes by which chromatin regulates
transcription, and how this is related to cellular status and processes is an
important task for improving our understanding of human cellular biology. The
FANTOM5 and ENCODE projects represent two independent large scale efforts to map
regulatory and transcriptional features to the human genome. Here we investigate
chromatin features around a comprehensive set of transcription start sites in
four cell lines by integrating data from these two projects.
RESULTS: Transcription start sites can be distinguished by chromatin states
defined by specific combinations of both chromatin mark enrichment and the
profile shapes of these chromatin marks. The observed patterns can be associated
with cellular functions and processes, and they also show association with
expression level, location relative to nearby genes, and CpG content. In
particular we find a substantial number of repressed inter- and intra-genic
transcription start sites enriched for active chromatin marks and Pol II, and
these sites are strongly associated with immediate-early response processes and
cell signaling. Associations between start sites with similar chromatin patterns
are validated by significant correlations in their global expression profiles.
CONCLUSIONS: The results confirm the link between chromatin state and cellular
function for expressed transcripts, and also indicate that active chromatin
states at repressed transcripts may poise transcripts for rapid activation
during immune response.
DOI: 10.1186/1471-2164-15-120
PMCID: PMC3986914
PMID: 24669905 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22025602 | 1. Circulation. 2011 Nov 29;124(22):2411-22. doi:
10.1161/CIRCULATIONAHA.111.040071. Epub 2011 Oct 24.
Distinct epigenomic features in end-stage failing human hearts.
Movassagh M(1), Choy MK, Knowles DA, Cordeddu L, Haider S, Down T, Siggens L,
Vujic A, Simeoni I, Penkett C, Goddard M, Lio P, Bennett MR, Foo RS.
Author information:
(1)Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's
Centre for Clinical Investigation, Level 6, Hills Rd, Cambridge, CB2 0QQ UK.
BACKGROUND: The epigenome refers to marks on the genome, including DNA
methylation and histone modifications, that regulate the expression of
underlying genes. A consistent profile of gene expression changes in end-stage
cardiomyopathy led us to hypothesize that distinct global patterns of the
epigenome may also exist.
METHODS AND RESULTS: We constructed genome-wide maps of DNA methylation and
histone-3 lysine-36 trimethylation (H3K36me3) enrichment for cardiomyopathic and
normal human hearts. More than 506 Mb sequences per library were generated by
high-throughput sequencing, allowing us to assign methylation scores to ≈28
million CG dinucleotides in the human genome. DNA methylation was significantly
different in promoter CpG islands, intragenic CpG islands, gene bodies, and
H3K36me3-enriched regions of the genome. DNA methylation differences were
present in promoters of upregulated genes but not downregulated genes. H3K36me3
enrichment itself was also significantly different in coding regions of the
genome. Specifically, abundance of RNA transcripts encoded by the DUX4 locus
correlated to differential DNA methylation and H3K36me3 enrichment. In vitro,
Dux gene expression was responsive to a specific inhibitor of DNA
methyltransferase, and Dux siRNA knockdown led to reduced cell viability.
CONCLUSIONS: Distinct epigenomic patterns exist in important DNA elements of the
cardiac genome in human end-stage cardiomyopathy. The epigenome may control the
expression of local or distal genes with critical functions in myocardial stress
response. If epigenomic patterns track with disease progression, assays for the
epigenome may be useful for assessing prognosis in heart failure. Further
studies are needed to determine whether and how the epigenome contributes to the
development of cardiomyopathy.
DOI: 10.1161/CIRCULATIONAHA.111.040071
PMCID: PMC3634158
PMID: 22025602 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/17509680 | 1. Cell Calcium. 2007 Oct-Nov;42(4-5):503-12. doi: 10.1016/j.ceca.2007.04.002.
Epub 2007 May 16.
Analysis of cellular calcium fluxes in cardiac muscle to understand calcium
homeostasis in the heart.
Dibb KM(1), Graham HK, Venetucci LA, Eisner DA, Trafford AW.
Author information:
(1)Unit of Cardiac Physiology, University of Manchester, 3.08 Core Technology
facility, 46 Grafton Street, Manchester M13 9PT, United Kingdom.
Central to controlling intracellular calcium concentration ([Ca(2+)](i)) are a
number of Ca(2+) transporters and channels with the L-type Ca(2+) channel,
Na(+)-Ca(2+) exchanger and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) being of
particular note in the heart. This review concentrates on the regulation of
[Ca(2+)](i) in cardiac muscle and the homeostatic mechanisms employed to ensure
that the heart can operate under steady-state conditions on a beat by beat
basis. To this end we discuss the relative importance of various sources and
sinks of Ca(2+) responsible for initiating contraction and relaxation in cardiac
myocytes and how these can be manipulated to regulate the Ca(2+) content of the
major Ca(2+) store, the sarcoplasmic reticulum (SR). We will present a simple
feedback system detailing how such control can be achieved and highlight how
small perturbations to the steady-state operation of the feedback loop can be
both beneficial physiologically and underlie changes in systolic Ca(2+) in
ageing and heart disease. In addition to manipulating the amplitude of the
normal systolic Ca(2+) transient, the tight regulation of SR Ca(2+) content is
also required to prevent the abnormal, spontaneous or diastolic release of
Ca(2+) from the SR. Such diastolic events are a major factor contributing to the
genesis of cardiac arrhythmias in disease situations and in recently identified
familial mutations in the SR Ca(2+) release channel (ryanodine receptor, RyR).
How such diastolic release arises and potential mechanisms for controlling this
will be discussed.
DOI: 10.1016/j.ceca.2007.04.002
PMID: 17509680 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23527730 | 1. Int J Immunopathol Pharmacol. 2013 Jan-Mar;26(1):251-7. doi:
10.1177/039463201302600127.
Systemic nickel allergy: oral desensitization and possible role of cytokines
interleukins 2 and 10.
Ricciardi L, Carni A, Loschiavo G, Gangemi S, Tigano V, Arena E, Mannucci C,
Calapai G.
Nickel ingested with food can elicit either systemic cutaneous or
gastrointestinal symptoms causing a systemic nickel allergy syndrome (SNAS) that
can be treated with tolerance by oral ingestion of the metal. It has been
suggested that interleukins 2 (IL-2) and 10 (IL-10) are involved in the
mechanisms underlying oral tolerance. We evaluated the clinical efficacy of oral
desensitization therapy in SNAS consisting in the administration of nickel
sulphate. Because nickel allergy prevalently affects women, only female subjects
(N = 22) were recruited. Oral nickel desensitizing therapy was associated with
low-nickel diet for three months. Before and after therapy, clinical conditions
were evaluated, and circulating cytokines IL-2 and IL-10 were measured. After
the two-year treatment, visual analogue scale (VAS) scores for symptoms were
significantly reduced (P less than 0.001). Patients were released by either
cutaneous or gastrointestinal symptoms and by tolerating nickel-containing food.
At the end of the treatment, nickel oral challenge test was negative in 18
patients, and IL-2 level in the serum was significantly reduced while IL-10 was
increased, although this datum was not statistically significant. Our study
confirms the clinical efficacy of nickel oral immunotherapy and focuses on the
mechanisms triggered by oral tolerance indicating that reduction of IL-2 can be
associated with success of oral nickel desensitizing therapy.
DOI: 10.1177/039463201302600127
PMID: 23527730 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/2611499 | 1. Br J Pharmacol. 1989 Dec;98(4):1413-9. doi:
10.1111/j.1476-5381.1989.tb12691.x.
Selective antagonism to succinylcholine-induced depolarization by
alpha-bungarotoxin with respect to the mode of action of depolarizing agents.
Chang CC(1), Chiou LC, Hwang LL.
Author information:
(1)Department of Pharmacology, College of Medicine, National Taiwan University,
Taipei.
1. The interactions of alpha-bungarotoxin or tubocurarine with the neuromuscular
block and endplate depolarization induced by succinylcholine (SCh) in the
phrenic nerve-diaphragm preparation of mice were studied in order to elucidate
the role of depolarization by SCh in the neuromuscular blockade. 2. The SCh
concentrations required to depress the indirect twitch response by 20% and the
evoked endplate potential in cut muscle preparations by 80% were 10 microm and 6
microM, respectively, while only 2 microM SCh was needed to induce maximal
endplate depolarization from -80 mV to about -60 mV. 3. SCh blocked the
neuromuscular transmission synergistically with either alpha-bungarotoxin or
tubocurarine. There was an initial partial reversal of the neuromuscular
inhibition caused by tubocurarine, but not that by alpha-bungarotoxin. 4.
alpha-Bungarotoxin (0.025 microM) antagonized SCh (10 microM)-induced
depolarization more effectively than it depressed miniature endplate potentials
and the antagonism was insurmountable by increasing SCh concentration. By
contrast, tubocurarine preferentially depressed miniature endplate potentials
and antagonized SCh-depolarization competitively. 5. The above difference was
attributed to the irreversible nature of alpha-bungarotoxin binding to
acetylcholine receptors, to the slow diffusion of the toxin molecule into the
synaptic cleft and thus to the more rapid binding with perijunctional receptors
compared with junctional ones. 6. It is concluded that the sustained
depolarization of the endplate by SCh results largely from an action on the
perijunctional receptor in mice and, unlike cats, the neuromuscular block by SCh
is not due to the depolarization per se but rather to a direct attenuation of
endplate potential.
DOI: 10.1111/j.1476-5381.1989.tb12691.x
PMCID: PMC1854799
PMID: 2611499 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21424586 | 1. Mol Cell Biochem. 2011 Jul;353(1-2):177-87. doi: 10.1007/s11010-011-0784-7.
Epub 2011 Mar 20.
Expression profile of human immune-responsive gene 1 and generation and
characterization of polyclonal antiserum.
Xiao W(1), Wang L, Xiao R, Wu M, Tan J, He Y.
Author information:
(1)Department of Immunology, Wuhan University School of Medicine, Wuhan
University, Dong Hu Road 115, Wuchang, 430071 Wuhan, China.
Murine immune-responsive gene 1 (IRG1) plays significant roles in embryonic
implantation and neurodegeneration. The expression pattern of the human IRG1
gene, however, has not yet been established, and the predicted gene sequence has
been revised several times according to computed expressed sequence tags (ESTs).
To determine the human IRG1 gene expression profile, human fetal tissue samples,
peripheral blood mononuclear cells (PBMCs) from normal healthy subjects, and the
human leukemia cell lines THP-1 and K-562 challenged with lipopolysaccharide
(LPS) were subjected to RT-PCR using degenerate primers. The results indicated
that the IRG1 gene is differentially expressed in human fetal PBMCs and
LPS-stimulated adult PBMCs. The amplified gene fragment was cloned into the
pET32a(+) vector and fusion-expressed with a His-tag in a prokaryotic system.
After affinity chromatography, human IRG1h fusion proteins were isolated by
SDS-PAGE and identified by mass spectrometric analysis for use as an immunogen
to immunize rabbits. The titer and specificity of the purified rabbit antiserum
were sufficient to measure human IRG1 gene expression in various tissues and
cultures. This purified polyclonal antiserum will allow us to initiate studies
to elucidate the biological roles of the human IRG1 gene.
DOI: 10.1007/s11010-011-0784-7
PMID: 21424586 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/20875630 | 1. Int Rev Cell Mol Biol. 2010;284:113-79. doi: 10.1016/S1937-6448(10)84003-1.
What causes a broken heart--molecular insights into heart failure.
Barry SP(1), Townsend PA.
Author information:
(1)Institute of Molecular Medicine, St. James's Hospital, Trinity College
Dublin, Dublin 8, Ireland.
Our understanding of the molecular processes which regulate cardiac function has
grown immeasurably in recent years. Even with the advent of β-blockers,
angiotensin inhibitors and calcium modulating agents, heart failure (HF) still
remains a seriously debilitating and life-threatening condition. Here, we review
the molecular changes which occur in the heart in response to increased load and
the pathways which control cardiac hypertrophy, calcium homeostasis, and immune
activation during HF. These can occur as a result of genetic mutation in the
case of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) or as
a result of ischemic or hypertensive heart disease. In the majority of cases,
calcineurin and CaMK respond to dysregulated calcium signaling and adrenergic
drive is increased, each of which has a role to play in controlling blood
pressure, heart rate, and left ventricular function. Many major pathways for
pathological remodeling converge on a set of transcriptional regulators such as
myocyte enhancer factor 2 (MEF2), nuclear factors of activated T cells (NFAT),
and GATA4 and these are opposed by the action of the natriuretic peptides ANP
and BNP. Epigenetic modification has emerged in recent years as a major
influence cardiac physiology and histone acetyl transferases (HATs) and histone
deacetylases (HDACs) are now known to both induce and antagonize hypertrophic
growth. The newly emerging roles of microRNAs in regulating left ventricular
dysfunction and fibrosis also has great potential for novel therapeutic
intervention. Finally, we discuss the role of the immune system in mediating
left ventricular dysfunction and fibrosis and ways this can be targeted in the
setting of viral myocarditis.
© 2010 Elsevier Inc. All rights reserved.
DOI: 10.1016/S1937-6448(10)84003-1
PMID: 20875630 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/18172603 | 1. Pflugers Arch. 2008 Jun;456(3):479-87. doi: 10.1007/s00424-007-0420-2. Epub
2008 Jan 3.
Maladaptation of calcium homoeostasis in aging cardiac myocytes.
Goldspink P(1), Ruch S, Los T, Buttrick P, García J.
Author information:
(1)Department of Medicine, University of Illinois at Chicago, Chicago, IL 60607,
USA.
With aging, the heart develops myocyte hypertrophy associated with impaired
relaxation indices. To define the cellular basis of this adaptation, we examined
the physiological changes that arise in calcium handling in the aging heart and
contrasted the adaptations that occur following the imposition of a stimulus
that alters calcium homeostasis in a young and an old heart. We utilized a
cardiac-specific conditional transgenic approach to "switch on" protein kinase
(PKC)-beta II expression in mice at different stages of adult life (3 and 12
months) and characterized alterations in ICa and calcium release in wild-type
(WT) and PKC-beta II-expressing cells. Amplitude or voltage dependence of ICa
were not significantly altered by expression of PKC-beta II at any age. No
significant differences in calcium-release properties were seen with age. Upon
activation of PKC-beta II, the amplitude of the calcium transient was larger,
and the calcium spark frequency was greater in PKC-beta II mice compared to WT
at both 3 and 12 months. Spark amplitude increased only in the 12-month PKC-beta
II mice. These changes occurred in parallel with an increase in cell size (as
determined by capacitance measurements) in the 12-month PKC-beta II mice but not
the 3-month PKC-beta II mice. These data suggest that alterations in the
calcium-handling machinery of the cardiocyte differ in the context of age and as
such may predispose the older heart to the development of a hypertrophic
phenotype.
DOI: 10.1007/s00424-007-0420-2
PMID: 18172603 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21750914 | 1. Mol Biol Rep. 2012 Apr;39(4):3847-52. doi: 10.1007/s11033-011-1163-x. Epub
2011 Jul 13.
Analysis of Na(+)/Ca (2+) exchanger (NCX) function and current in murine cardiac
myocytes during heart failure.
Xu L(1), Chen J, Li XY, Ren S, Huang CX, Wu G, Li XY, Jiang XJ.
Author information:
(1)Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060,
People's Republic of China. [email protected]
Na(+)/Ca(2+) exchanger (NCX) plays important roles in cardiac electrical
activity and calcium homeostasis. NCX current (I(NCX)) shows transmural gradient
across left ventricle in many species. Previous studies demonstrated that NCX
expression was increased and transmural gradient of I(NCX) was disrupted in
failing heart, but the mechanisms underlying I(NCX) remodeling still remain
unknown. In present study, we used patch clamp technique to record I(NCX) from
subepicardial (EPI) myocytes and subendocardial (ENDO) myocytes isolated from
sham operation (SO) mice and heart failure (HF) mice. Our results showed that
I(NCX) was higher in normal EPI cells compared with that in ENDO, whatever for
forward mode or reverse mode. In HF group, I(NCX) was significantly
up-regulated, but EPI-ENDO difference was disrupted because of a more increase
of I(NCX) in ENDO myocytes. In order to explore the molecular mechanism
underlying remodeling of I(NCX) in failing heart, we detected the protein
expression of NCX1 and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) by
Western blot. We found that CaMKII activity was dramatically enhanced and
parallel with the expression of NCX1 in failing heart. Our study demonstrated
that transmural gradient of I(NCX) existed in murine left ventricle, and
increased activity of CaMKII should account for I(NCX) remodeling in failing
heart.
DOI: 10.1007/s11033-011-1163-x
PMID: 21750914 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/16415166 | 1. J Leukoc Biol. 2006 Mar;79(3):628-38. doi: 10.1189/jlb.0905520. Epub 2006 Jan
13.
Mycobacterium paratuberculosis, Mycobacterium smegmatis, and lipopolysaccharide
induce different transcriptional and post-transcriptional regulation of the IRG1
gene in murine macrophages.
Basler T(1), Jeckstadt S, Valentin-Weigand P, Goethe R.
Author information:
(1)Institut fuer Mikrobiologie, Zentrum fuer Infektionsmedizin, Stiftung
Tieraerztliche Hochschule Hannover, Bischofsholer Damm 15, 30173 Hannover,
Germany.
Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic enteritis
in ruminants. In addition, MAP is presently the most favored pathogen linked to
Crohn's disease. In this study, we were interested in dissecting the molecular
mechanisms of macrophage activation or deactivation after infection with MAP. By
subtractive hybridization of cDNAs, we identified the immune-responsive gene 1
(IRG1), which was expressed substantially higher in lipopolysaccharide
(LPS)-stimulated than in MAP-infected murine macrophage cell lines. A nuclear
run-on transcription assay revealed that the IRG1 gene was activated
transcriptionally in LPS-stimulated and MAP-infected macrophages with higher
expression in LPS-stimulated cells. Analysis of post-transcriptional regulation
demonstrated that IRG1 mRNA stability was increased in LPS-stimulated but not in
MAP-infected macrophages. Furthermore, IRG1 gene expression of macrophages
infected with the nonpathogenic Mycobacterium smegmatis differed from those of
LPS-stimulated and MAP-infected macrophages. At 2 h postinfection, M.
smegmatis-induced IRG1 gene expression was as low as in MAP-infected, and 8 h
postinfection, it increased nearly to the level in LPS-stimulated macrophages.
Transient transfection experiments revealed similar IRG1 promoter activities in
MAP- and M. smegmatis-infected cells. Northern analysis demonstrated increased
IRG1 mRNA stability in M. smegmatis-infected macrophages. IRG1 mRNA
stabilization was p38 mitogen-activated protein kinase-independent. Inhibition
of protein synthesis revealed that constitutively expressed factors seemed to be
responsible for IRG1 mRNA destabilization. Thus, our data demonstrate that
transcriptional and post-transcriptional mechanisms are responsible for a
differential IRG1 gene expression in murine macrophages treated with LPS, MAP,
and M. smegmatis.
DOI: 10.1189/jlb.0905520
PMID: 16415166 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/25537627 | 1. Cancer Chemother Pharmacol. 2015 Feb;75(2):373-80. doi:
10.1007/s00280-014-2654-y. Epub 2014 Dec 24.
A phase 1 multiple-dose study of orteronel in Japanese patients with
castration-resistant prostate cancer.
Suzuki K(1), Ozono S, Yamaguchi A, Koike H, Matsui H, Nagata M, Takubo T,
Miyashita K, Matsushima T, Akaza H.
Author information:
(1)Department of Urology, Gunma University Graduate School of Medicine, Gunma,
Japan, [email protected].
PURPOSE: Orteronel (TAK-700) is a non-steroidal, selective, reversible inhibitor
of 17,20-lyase. We evaluated the safety, tolerability, pharmacokinetics,
pharmacodynamics, and antitumor effect of orteronel with or without prednisolone
in Japanese patients with castration-resistant prostate cancer (CRPC).
METHODS: We conducted a phase 1 study in men with progressive and
chemotherapy-naïve CRPC. Patients received orteronel orally at doses of 200-400
mg twice daily (BID) with or without oral prednisolone (5 mg BID). Dose-limiting
toxicity (DLT) was assessed during Cycle 1 (28 days). Patients could continue
study treatment until any of criteria for treatment discontinuation were met.
Gonadotropin-releasing hormone therapy was continued in patients without prior
orchidectomy.
RESULTS: Fifteen patients were enrolled and administered at least one dose of
orteronel. No DLTs were reported during Cycle 1 in this study. Adverse events
(AEs) were reported in all 15 patients. Most common AEs (>30%) were
hyperlipasemia (47%), hyperamylasemia (40%), and constipation (33%). Acute
pancreatitis (Grades 2 and 3) and pancreatitis (Grade 1) were complicated in
three patients during the study. Dose-dependent increase in plasma orteronel
concentrations was indicated over the 200-400 mg BID dose range. Prednisolone
coadministered did not alter PK of orteronel. Serum testosterone was rapidly
suppressed below the lower limit of quantification across all doses. Of 15
subjects, 13 achieved at least a 50% reduction from baseline in
prostate-specific antigen.
CONCLUSIONS: Orteronel at doses up to 400 mg BID was tolerable in Japanese CRPC
patients. The present results support further evaluation of orteronel with or
without prednisolone.
DOI: 10.1007/s00280-014-2654-y
PMCID: PMC4305367
PMID: 25537627 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/18045502 | 1. BMC Genomics. 2007 Nov 29;8:441. doi: 10.1186/1471-2164-8-441.
TFCONES: a database of vertebrate transcription factor-encoding genes and their
associated conserved noncoding elements.
Lee AP(1), Yang Y, Brenner S, Venkatesh B.
Author information:
(1)Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673,
Singapore. [email protected]
BACKGROUND: Transcription factors (TFs) regulate gene transcription and play
pivotal roles in various biological processes such as development, cell cycle
progression, cell differentiation and tumor suppression. Identifying
cis-regulatory elements associated with TF-encoding genes is a crucial step in
understanding gene regulatory networks. To this end, we have used a comparative
genomics approach to identify putative cis-regulatory elements associated with
TF-encoding genes in vertebrates.
DESCRIPTION: We have created a database named TFCONES (Transcription Factor
Genes & Associated COnserved Noncoding ElementS) (http://tfcones.fugu-sg.org)
which contains all human, mouse and fugu TF-encoding genes and conserved
noncoding elements (CNEs) associated with them. The CNEs were identified by
gene-by-gene alignments of orthologous TF-encoding gene loci using MLAGAN. We
also predicted putative transcription factor binding sites within the CNEs. A
significant proportion of human-fugu CNEs contain experimentally defined binding
sites for transcriptional activators and repressors, indicating that a majority
of the CNEs may function as transcriptional regulatory elements. The TF-encoding
genes that are involved in nervous system development are generally enriched for
human-fugu CNEs. Users can retrieve TF-encoding genes and their associated CNEs
by conducting a keyword search or by selecting a family of DNA-binding proteins.
CONCLUSION: The conserved noncoding elements identified in TFCONES represent a
catalog of highly prioritized putative cis-regulatory elements of TF-encoding
genes and are candidates for functional assay.
DOI: 10.1186/1471-2164-8-441
PMCID: PMC2148067
PMID: 18045502 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/16931985 | 1. Anesthesiology. 2006 Sep;105(3):521-33. doi: 10.1097/00000542-200609000-00016.
Distinct pharmacologic properties of neuromuscular blocking agents on human
neuronal nicotinic acetylcholine receptors: a possible explanation for the
train-of-four fade.
Jonsson M(1), Gurley D, Dabrowski M, Larsson O, Johnson EC, Eriksson LI.
Author information:
(1)Department of Anesthesiology and Intensive Care Medicine, Karolinska
University Hospital and Karolinska Institutet, Sweden.
[email protected]
Comment in
Anesthesiology. 2007 Jun;106(6):1243; author reply 1243-4. doi:
10.1097/01.anes.0000265457.47797.4c.
BACKGROUND: Nondepolarizing neuromuscular blocking agents (NMBAs) are
extensively used in the practice of anesthesia and intensive care medicine.
Their primary site of action is at the postsynaptic nicotinic acetylcholine
receptor (nAChR) in the neuromuscular junction, but their action on neuronal
nAChRs have not been fully evaluated. Furthermore, observed adverse effects of
nondepolarizing NMBAs might originate from an interaction with neuronal nAChRs.
The aim of this study was to examine the effect of clinically used
nondepolarizing NMBAs on muscle and neuronal nAChR subtypes.
METHODS: Xenopus laevis oocytes were injected with messenger RNA encoding for
the subunits included in the human alpha1beta1epsilondelta, alpha3beta2,
alpha3beta4, alpha4beta2, and alpha7 nAChR subtypes. The interactions between
each of these nAChR subtypes and atracurium, cisatracurium, d-tubocurarine,
mivacurium, pancuronium, rocuronium, and vecuronium were studied using an
eight-channel two-electrode voltage clamp setup. Responses were measured as peak
current and net charge.
RESULTS: All nondepolarizing NMBAs inhibited both muscle and neuronal nAChRs.
The neuronal nAChRs were reversibly and concentration-dependently inhibited in
the low micromolar range. The mechanism (i.e., competitive vs. noncompetitive)
of the block at the neuronal nAChRs was dependent both on subtype and the NMBA
tested. The authors did not observe activation of the nAChR subtypes by any of
the NMBAs tested.
CONCLUSIONS: The authors conclude that nondepolarizing NMBAs
concentration-dependently inhibit human neuronal nAChRs. The inhibition of the
presynaptic alpha3beta2 nAChR subtype expressed at the motor nerve ending
provides a possible molecular explanation for the tetanic and train-of-four fade
seen during a nondepolarizing neuromuscular block.
DOI: 10.1097/00000542-200609000-00016
PMID: 16931985 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24670763 | 1. Nature. 2014 Mar 27;507(7493):455-461. doi: 10.1038/nature12787.
An atlas of active enhancers across human cell types and tissues.
Andersson R(#)(1), Gebhard C(#)(2), Miguel-Escalada I(3), Hoof I(1), Bornholdt
J(1), Boyd M(1), Chen Y(1), Zhao X(1)(4), Schmidl C(2), Suzuki T(5)(6), Ntini
E(7), Arner E(5)(6), Valen E(1)(8), Li K(1), Schwarzfischer L(2), Glatz D(2),
Raithel J(2), Lilje B(1), Rapin N(1)(9), Bagger FO(1)(9), Jørgensen M(1),
Andersen PR(7), Bertin N(5)(6), Rackham O(5)(6), Burroughs AM(5)(6), Baillie
JK(10), Ishizu Y(5)(6), Shimizu Y(5)(6), Furuhata E(5)(6), Maeda S(5)(6),
Negishi Y(5)(6), Mungall CJ(11), Meehan TF(12), Lassmann T(5)(6), Itoh
M(5)(6)(13), Kawaji H(5)(13), Kondo N(5)(13), Kawai J(5)(13), Lennartsson A(14),
Daub CO(5)(6)(14), Heutink P(15), Hume DA(10), Jensen TH(7), Suzuki H(5)(6),
Hayashizaki Y(5)(13), Müller F(3), Forrest ARR(5)(6), Carninci P(5)(6), Rehli
M(#)(2), Sandelin A(#)(1).
Collaborators: Forrest AR, Kawaji H, Rehli M, Baillie JK, de Hoon MJ, Haberle V,
Lassmann T, Kulakovskiy IV, Lizio M, Itoh M, Andersson R, Mungall CJ, Meehan TF,
Schmeier S, Bertin N, Jørgensen M, Dimont E, Arner E, Schmid C, Schaefer U,
Medvedeva YA, Plessy C, Vitezic M, Severin J, Semple CA, Ishizu Y, Young RS,
Francescatto M, Alam I, Albanese D, Altschuler GM, Arakawa T, Archer JA, Arner
P, Babina M, Rennie S, Balwierz PJ, Beckhouse AG, Pradhan-Bhatt S, Blake JA,
Blumenthal A, Bodega B, Bonetti A, Briggs J, Brombacher F, Burroughs AM,
Califano A, Cannistracti CV, Carbajo D, Chen Y, Chierici M, Ciani Y, Clevers HC,
Dalla E, Davis CA, Detmar M, Diehl AD, Dohi T, Drabløs F, Edge AS, Edinger M,
Ekwall K, Endoh M, Enomoto H, Fagiolini M, Fairbairn L, Fang H, Farach-Carson
MC, Faulkner GJ, Favorov AV, Fisher ME, Frith MC, Fujita R, Fukuda S, Furlanello
C, Furuno M, Furusawa J, Geijtenbeek TB, Gibson AP, Gingeras T, Goldowitz D,
Gough J, Guhl S, Guler R, Gustincich S, Ha TJ, Hamaguchi M, Hara M, Harbers M,
Harshbarger J, Hasegawa A, Hasegawa Y, Hashimoto T, Herlyn M, Hitchens KJ, Ho
Sui SJ, Hofman OM, Hoof I, Hori F, Huminiecki L, Iida K, Ikawa T, Jankovic BR,
Jia H, Joshi A, Jurman G, Kaczkowski B, Kai C, Kaida K, Kaiho A, Kajiyama K,
Kanamori-Katayama M, Kasianov AS, Kasukawa T, Katayama S, Kato S, Kawaguchi S,
Kawamoto H, Kawamura YI, Kawashima T, Kempfle JS, Kenna TJ, Kere J, Khachigian
LM, Kitamura T, Klinken SP, Knox AJ, Kojima M, Kojima S, Kondo N, Koseki H,
Koyasu S, Krampitz S, Kubosaki A, Kwon AT, Laros JF, Lee W, Lennartsson A, Li K,
Lilje B, Lipovich L, Mackay-Sim A, Manabe R, Mar JC, Marchand B, Mathelier A,
Mejhert N, Meynert A, Mizuno Y, de Lima Morais DA, Morikawa H, Morimoto M, Moro
K, Motakis E, Motohashi H, Mummery CL, Murata M, Nagao-Sato S, Nakachi Y,
Nakahara F, Nakamura T, Nakamura Y, Nakazato K, van Nimwegen E, Ninomiya N,
Nishiyori H, Noma S, Nozaki T, Ogishima S, Ohkura N, Ohmiya H, Ohno H, Onshima
M, Okada-Hatakeyama M, Okazaki Y, Orlando V, Ovchinnikov DA, Pain A, Passier R,
Patrikakis M, Persson H, Piazza S, Prendergast JG, Rackham OJ, Ramilowski JA,
Rashid M, Ravasi T, Rizzu P, Roncador M, Roy S, Rye MB, Saijyo E, Sajantila A,
Saka A, Sakaguchi S, Sakai M, Sato H, Satoh H, Savvi S, Saxena A, Schneider C,
Schultes EA, Schultz-Tanzil GG, Schwegmann A, Sengstag T, Sheng G, Shimoji H,
Shimoni Y, Shin JW, Simon C, Sugiyama D, Sugiyama T, Suzuki M, Suzuki N, Swoboda
RK, 't Hoen PA, Tagami M, Takahashi N, Takai J, Tanaka H, Tatsukawa H, Tatum Z,
Thompson M, Toyoda H, Toyodo T, Valen E, van de Wetering M, van den Berg LM,
Verardo R, Vijayan D, Vorontsov IE, Wasserman WW, Watanabe S, Wells CA,
Winteringham LN, Wolvetang E, Wood EJ, Yamaguchi Y, Yamamoto M, Yoneda M,
Yonekura Y, Yoshida S, Zabierowski SE, Zhang PG, Zhao X, Zucchelli S, Summers
KM, Suzuki H, Daub CO, Kawai J, Heutink P, Hide W, Freeman TC, Lenhard B, Bajic
VB, Taylor MS, Makeev VJ, Sandelin A, Hume DA, Carninci P, Hayashizaki Y.
Author information:
(1)The Bioinformatics Centre, Department of Biology & Biotech Research and
Innovation Centre, University of Copenhagen, Ole Maaloes Vej 5, DK-2200
Copenhagen, Denmark.
(2)Department of Internal Medicine III, University Hospital Regensburg,
Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany.
(3)School of Clinical and Experimental Medicine, College of Medical and Dental
Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
(4)Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel
Hill, NC 27599, USA.
(5)RIKEN OMICS Science Centre, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho,
Tsurumi-ku, Yokohama City, Kanagawa, 230-0045, Japan.
(6)RIKEN Center for Life Science Technologies (Division of Genomic
Technologies), RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku,
Yokohama City, Kanagawa, 230-0045, Japan.
(7)Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology
and Genetics, C.F. Møllers Alle 3, Bldg. 1130, DK-8000 Aarhus, Denmark.
(8)Department of Molecular and Cellular Biology, Harvard University, USA.
(9)The Finsen Laboratory, Rigshospitalet and Danish Stem Cell Centre (DanStem),
University of Copenhagen, Ole Maaloes Vej 5, DK-2200, Denmark.
(10)Roslin Institute, Edinburgh University, Easter Bush, Midlothian, EH25 9RG
Scotland, UK.
(11)Genomics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road
MS 64-121, Berkeley, CA 94720, USA.
(12)EMBL Outstation - Hinxton, European Bioinformatics Institute, Wellcome Trust
Genome Campus, Hinxton, Cambridge, CB10 1SD.
(13)RIKEN Preventive Medicine and Diagnosis Innovation Program, RIKEN Yokohama
Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa, 230-0045,
Japan.
(14)Department of Biosciences and Nutrition, Karolinska Institutet, 14183
Huddinge, Stockholm, Sweden.
(15)Department of Clinical Genetics, VU University Medical Center, van der
Boechorststraat 7, 1081 BT Amsterdam, Netherlands.
(#)Contributed equally
Enhancers control the correct temporal and cell-type-specific activation of gene
expression in multicellular eukaryotes. Knowing their properties, regulatory
activity and targets is crucial to understand the regulation of differentiation
and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority
of human tissues and cell types, to produce an atlas of active, in
vivo-transcribed enhancers. We show that enhancers share properties with
CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive,
relatively short unspliced RNAs, the generation of which is strongly related to
enhancer activity. The atlas is used to compare regulatory programs between
different cells at unprecedented depth, to identify disease-associated
regulatory single nucleotide polymorphisms, and to classify cell-type-specific
and ubiquitous enhancers. We further explore the utility of enhancer redundancy,
which explains gene expression strength rather than expression patterns. The
online FANTOM5 enhancer atlas represents a unique resource for studies on
cell-type-specific enhancers and gene regulation.
DOI: 10.1038/nature12787
PMCID: PMC5215096
PMID: 24670763 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19349584 | 1. J Cell Biol. 2009 Apr 6;185(1):147-61. doi: 10.1083/jcb.200809008.
Integrin-linked kinase is required for radial sorting of axons and Schwann cell
remyelination in the peripheral nervous system.
Pereira JA(1), Benninger Y, Baumann R, Gonçalves AF, Ozçelik M, Thurnherr T,
Tricaud N, Meijer D, Fässler R, Suter U, Relvas JB.
Author information:
(1)Institute of Cell Biology, Department of Biology, Eidgenössische Technische
Hochschule Zurich, Zurich, Switzerland.
During development, Schwann cells (SCs) interpret different extracellular cues
to regulate their migration, proliferation, and the remarkable morphological
changes associated with the sorting, ensheathment, and myelination of axons.
Although interactions between extracellular matrix proteins and integrins are
critical to some of these processes, the downstream signaling pathways they
control are still poorly understood. Integrin-linked kinase (ILK) is a focal
adhesion protein that associates with multiple binding partners to link
integrins to the actin cytoskeleton and is thought to participate in integrin
and growth factor-mediated signaling. Using SC-specific gene ablation, we report
essential functions for ILK in radial sorting of axon bundles and in
remyelination in the peripheral nervous system. Our in vivo and in vitro
experiments show that ILK negatively regulates Rho/Rho kinase signaling to
promote SC process extension and to initiate radial sorting. ILK also
facilitates axon remyelination, likely by promoting the activation of downstream
molecules such as AKT/protein kinase B.
DOI: 10.1083/jcb.200809008
PMCID: PMC2700520
PMID: 19349584 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/9788777 | 1. Eur J Pharmacol. 1998 Sep 11;357(1):83-92. doi: 10.1016/s0014-2999(98)00542-1.
The actions of muscle relaxants at nicotinic acetylcholine receptor isoforms.
Garland CM(1), Foreman RC, Chad JE, Holden-Dye L, Walker RJ.
Author information:
(1)Pharmacology Group, Division of Cell Sciences, University of Southampton, UK.
The pharmacological diversity of the different isoforms of the nicotinic
acetylcholine receptor arises from the diversity of the subunits that assemble
to form the native receptors. The aim of this study was to investigate the
actions of the muscle relaxants d-tubocurarine, pancuronium and vecuronium on
different isoforms of nicotinic acetylcholine receptors (mouse foetal muscle,
mouse adult muscle and a rat neuronal), using the Xenopus oocyte expression
system. Oocytes were injected with cRNAs for alpha, beta, gamma, delta subunits
(the native foetal muscle subunit combination), or with cRNAs for alpha, beta,
epsilon, delta subunits (the native adult muscle subunit combination), or with
cRNAs for alpha4beta2 subunits (a putative native neuronal subunit combination).
Acetylcholine had a similar potency at all three subunit combinations (EC50
11.6, 17.4 and 19.1 microM, respectively). At all three receptor types,
d-tubocurarine and pancuronium blocked the responses elicited by acetylcholine
in a reversible manner. Furthermore, the inhibition of the acetylcholine
currents for the foetal and adult nicotinic acetylcholine receptor by
pancuronium and d-tubocurarine was independent of the holding voltage over the
range -100 to -40 mV. In oocytes expressing the foetal muscle nicotinic
acetylcholine receptors the inhibition of the current in response to 100 microM
acetylcholine by 10 nM d-tubocurarine was 29 +/- 5% (mean +/- S.E.M.; n = 7),
and the inhibition by 10 nM pancuronium was 39 +/- 6% (mean +/- S.E.M.; n = 8; P
> 0.05 vs. d-tubocurarine). However, in the adult form of the muscle nicotinic
acetylcholine receptor, 10 nM d-tubocurarine and 10 nM pancuronium were both
more effective at blocking the response to 100 microM acetylcholine compared to
the foetal muscle nicotinic acetylcholine receptor, with values of 55 +/- 5% (P
< 0.01; n = 12) and 60 +/- 4% (P < 0.001; n = 10), respectively. Thus the
developmental switch from the gamma to the epsilon subunit alters the antagonism
of the nicotinic acetylcholine receptor for both pancuronium and d-tubocurarine.
Vecuronium was more potent than pancuronium. One nM vecuronium reduced the
response to 100 microM acetylcholine by 71 +- 6% (n = 10) for foetal and 63 +/-
5% (n = 4) for adult nicotinic acetylcholine receptors. In the alpha4beta2
neuronal nicotinic acetylcholine receptor combination, 10 nM pancuronium was a
more effective antagonist of the response to 100 microM acetylcholine (69 +/-
6%, n = 6) than 10 nM d-tubocurarine (30 +/- 5%; n = 6; P < 0.05 compared to
pancuronium). This is in contrast to the adult muscle nicotinic acetylcholine
receptor, where pancuronium and d-tubocurarine were equieffective. The
expression of the beta2 subunit with muscle alpha, epsilon and delta subunits
formed a functional receptor which was blocked by pancuronium and d-tubocurarine
in a similar manner to the alphabeta1epsilondelta subunit consistent with the
hypothesis that the beta subunit is not a major determinant in the action of
this drug at the adult muscle nicotinic acetylcholine receptor.
DOI: 10.1016/s0014-2999(98)00542-1
PMID: 9788777 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24067467 | 1. Int J Immunopathol Pharmacol. 2013 Jul-Sep;26(3):707-16. doi:
10.1177/039463201302600314.
Systemic nickel allergy syndrome: nosologic framework and usefulness of diet
regimen for diagnosis.
Braga M(1), Quecchia C, Perotta C, Timpini A, Maccarinelli K, Di Tommaso L, Di
Gioacchino M.
Author information:
(1)Allergy and Clinical Immunology, University of Medicine, Brescia, Italy.
Systemic (gastrointestinal and skin) reactions to ingestion of nickel rich foods
in patients with nickel allergic contact dermatitis characterize Systemic Nickel
Allergy Syndrome (SNAS). The objective of the study was to describe the
nosologic framework of the syndrome and to compare sensibility and specificity
for SNAS diagnosis between two different low nickel diets - BraMa-Ni and the
usually prescribed list of forbidden foods - along with patient adherence to
diet. One hundred forty-five patients with suspected SNAS (by history and
benefit from nickel dietary restrictions) were selected and orally challenged
with nickel for a definite diagnosis. Specificity and sensibility of the diets
were calculated in relation to the results of nickel challenges. The nosologic
framework of SNAS was deduced from the clinical pictures of 98 patients with
positive nickel challenge and characterized essentially by skin and
gastrointestinal symptoms, whereas all other symptoms (dizziness, headache etc.)
were never elicited by the oral nickel challenge. The specificity and
sensibility of BraMa-Ni in detecting SNAS were significantly higher than the
forbidden food list diet, with an excellent patient adherence. Therefore,
BraMa-Ni diet can be prescribed for the treatment of the syndrome other than for
the diagnosis, the gold standard of which remains the oral nickel challenge.
DOI: 10.1177/039463201302600314
PMID: 24067467 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21658331 | 1. Int J Immunopathol Pharmacol. 2011 Apr-Jun;24(2):535-7. doi:
10.1177/039463201102400230.
Lactose intolerance in systemic nickel allergy syndrome.
Cazzato IA, Vadrucci E, Cammarota G, Minelli M, Gasbarrini A.
Some patients affected by nickel-contact allergy present digestive symptoms in
addition to systemic cutaneous manifestations, falling under the condition known
as systemic nickel allergy syndrome (SNAS). A nickel-related pro-inflammatory
status has been documented at intestinal mucosal level. The aim of the present
study is to evaluate the prevalence of lactose intolerance in patients affected
by SNAS compared to a healthy population. Consecutive patients affected by SNAS
referring to our departments were enrolled. The control population consisted of
healthy subjects without gastrointestinal symptoms. All subjects enrolled
underwent lactose breath test under standard conditions. One hundred and
seventy-eight SNAS patients and 60 healthy controls were enrolled. Positivity of
lactose breath test occurred in 74.7% of the SNAS group compared to 6.6% of the
control group. Lactose intolerance is highly prevalent in our series of patients
affected by SNAS. Based on our preliminary results, we can hypothesize that in
SNAS patients, the nickel-induced pro-inflammatory status could temporarily
impair the brush border enzymatic functions, resulting in hypolactasia. Further
trials evaluating the effect of a nickel-low diet regimen on lactase activity,
histological features and immunological pattern are needed.
DOI: 10.1177/039463201102400230
PMID: 21658331 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23405604 | 1. G Ital Med Lav Ergon. 2012 Jul-Sep;34(3 Suppl):147-9.
[Nickel dermatitis, systemic nickel allergy syndrome, immuno-genesis,
immune-tolerance: an Italian study].
[Article in Italian]
Cirla AM(1), Cirla PE.
Author information:
(1)Divisione Malattie Allergiche CIMAL (DIMAC), Centro Italiano Medicina
Ambiente Lavoro (Gruppo CIMAL), Cremona-Milano, Italy.
[email protected]
Subjects with Nickel sensitization proved by patch test may suffer of contact
eczema, but also of a Sistemic Nickel Allergy Syndrome (SNAS) consisting of
urticaria-like troubles, itch, erythema, cutaneous rush, headache, intestinal
symptoms, recurrent vesicular palmar dermatitis. 160 subjects (130 F, 30 M) were
classified into three groups and underwent dosage of Nickel in urines (U-Ni) and
blood (B-Ni). The two groups with SNAS showed an higher indicators of Nickel
absorption, while the only-eczema group did not. 95 subjects with SNAS were
enrolled for a Nickel-scanty diet: most of them improved. 24 ones again
symptomatic were admitted to an experimental treatment, by a schedule of oral
increasing microdose (nanograms) of Nickel sulphate: all of them improved. In
conclusion Nickel pathology is changing, allergy seems to be due to different
mechanism, dietary intake is important, an immune-tolerance can be induced.
PMID: 23405604 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/6141831 | 1. Br J Pharmacol. 1984 Mar;81(3):519-31. doi:
10.1111/j.1476-5381.1984.tb10105.x.
The interaction between hexamethonium and tubocurarine on the rat neuromuscular
junction.
Rang HP, Rylett RJ.
The ability of hexamethonium (C6) to reverse the neuromuscular blocking action
of tubocurarine (Tc) has been reinvestigated at the voltage clamped endplate of
the omohyoid muscle of rat. The possibility that a weak anticholinesterase
action of C6 could contribute to the paradoxical potentiation of the peak
amplitude of the endplate response has been examined. C6 (50-200 microM) caused
an increase in the amplitude of nerve-evoked endplate currents (e.p.cs) recorded
in the presence of 0.6 microM Tc. The effect decreased with hyperpolarization of
the muscle fibre. Irreversible inhibition of acetylcholinesterase resulted in a
loss of the anti-curare effect of C6. C6 did not cause an increase in e.p.c.
amplitude when acetylcholine (ACh) receptors were blocked irreversibly by
alpha-bungaratoxin. When transmission was blocked by increased Mg2+
concentration, C6 (50-400 microM) reduced the amplitude of e.p.cs without
appreciably affecting their time course. C6 caused a decrease in the amplitude
of miniature endplate currents (m.e.p.cs) the effect being slightly increased
when the fibre was hyperpolarized. An e-fold increase in the effectiveness of C6
occurred with approximately 58 mV hyperpolarization. High concentrations
(greater than 400 microM) affected the time course of m.e.p.cs in a manner
suggestive of open channel block, but this was not evident at 200 microM, the
concentration that was most effective in reversing Tc block. When tested against
responses to short ionophoretic pulses of agonists, C6 was less effective
against ACh (EC50ca. 300 microM) than against carbachol (CCh) (EC50 100 microM).
When cholinesterase was irreversibly inhibited, C6 blocked responses to both
agonists equally (EC50ca. 100 microM). The effectiveness of C6 in blocking the
action of CCh was reduced 10 fold in the presence of 0.6 microM Tc, implying
that the two antagonists compete for the same binding site. C6 (50-200 microM)
in the presence of Tc (0.6 microM) increased the response to ionophoretically
applied ACh but not that to CCh. C6 was equipotent in blocking m.e.p.cs and
responses to ionophoretically applied ACh whereas Tc was more potent against the
exogenously applied agonist. C6 was a weak inhibitor of acetylcholinesterase
activity in rat muscle homogenates (EC50 1.5 mM). The results are discussed in
terms of the kinetic hypothesis advanced by Ginsborg & Stephenson (1974) to
account for the Tc reversal phenomenon. It is concluded that this theory can
explain most of the effect on e.p.cs, but that the weak anticholinesterase
action of C6 is also a factor, particularly in the reversal of Tc block of
ionophoretic responses.
DOI: 10.1111/j.1476-5381.1984.tb10105.x
PMCID: PMC1986851
PMID: 6141831 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23204437 | 1. Proc Natl Acad Sci U S A. 2012 Dec 18;109(51):21081-6. doi:
10.1073/pnas.1219280110. Epub 2012 Nov 30.
CTCF/cohesin-mediated DNA looping is required for protocadherin α promoter
choice.
Guo Y(1), Monahan K, Wu H, Gertz J, Varley KE, Li W, Myers RM, Maniatis T, Wu Q.
Author information:
(1)Key Laboratory of Systems Biomedicine, Ministry of Education, Center for
Comparative Biomedicine, Institute of Systems Biomedicine, Shanghai Jiao Tong
University, Shanghai 200240, China.
The closely linked human protocadherin (Pcdh) α, β, and γ gene clusters encode
53 distinct protein isoforms, which are expressed in a combinatorial manner to
generate enormous diversity on the surface of individual neurons. This diversity
is a consequence of stochastic promoter choice and alternative pre-mRNA
processing. Here, we show that Pcdhα promoter choice is achieved by DNA looping
between two downstream transcriptional enhancers and individual promoters
driving the expression of alternate Pcdhα isoforms. In addition, we show that
this DNA looping requires specific binding of the CTCF/cohesin complex to two
symmetrically aligned binding sites in both the transcriptionally active
promoters and in one of the enhancers. These findings have important
implications regarding enhancer/promoter interactions in the generation of
complex Pcdh cell surface codes for the establishment of neuronal identity and
self-avoidance in individual neurons.
DOI: 10.1073/pnas.1219280110
PMCID: PMC3529044
PMID: 23204437 [Indexed for MEDLINE]
Conflict of interest statement: The authors declare no conflict of interest. |
http://www.ncbi.nlm.nih.gov/pubmed/11562442 | 1. Mol Pharmacol. 2001 Oct;60(4):790-6.
The kinetics of inhibition of nicotinic acetylcholine receptors by
(+)-tubocurarine and pancuronium.
Wenningmann I(1), Dilger JP.
Author information:
(1)Klinik für Anästhesiologie, Universität Bonn, Bonn, Germany.
Erratum in
Mol Pharmacol 2002 Nov;62(5):1258.
Equilibrium conditions of neurotransmitter concentration and receptor binding
are never achieved during synaptic transmission at the neuromuscular junction.
Thus, it is important to determine the binding kinetics of drugs that act this
synapse. Previous determinations of the dissociation rate of (+)-tubocurarine
have produced inconsistent results ranging from 0.1 to 4000/s. Here, we used a
direct approach to measure association (l(on)) and dissociation (l(on)) rates
for two competitive antagonists (clinically used as nondepolarizing muscle
relaxants), pancuronium and (+)-tubocurarine, at nicotinic acetylcholine
receptors (nAChR). We made macroscopic current recordings from outside-out
patches of BC3H-1 cells expressing embryonic mouse muscle nAChR. We used a
three-tube rapid perfusion system to make timed applications of antagonists and
acetylcholine to the patch. We made independent measurements of the equilibrium
inhibition (IC(50)) and the kinetics of onset and recovery of antagonist
inhibition at 20 to 23 degrees C. Rate constants were calculated from the
predictions of a single (high-affinity) site model of competitive inhibition.
For pancuronium: IC(50) = 5.5 +/- 0.5 nM (mean +/- S.D.), l(on) = 2.7 +/- 0.9 x
10(8) M(-1) s(-1), l(off) = 2.1 +/- 0.7/s [corrected] x 10(8)/s. For
(+)-tubocurarine: IC(50) = 41 +/- 2 nM, l(on) = 1.2 +/- 0.2 x 10(8) M(-1) s(-1),
l(off) = 5.9 +/- 1.3/s. The kinetic results are consistent with the equilibrium
results in that l(off)/l(on) is in good agreement with the IC(50) values. All
differences between the antagonists are significant at the p < 0.001 level. The
higher affinity of pancuronium is caused by a faster association rate (2.2-fold)
coupled with a slower dissociation rate (2.8-fold). The association rates of
both antagonists are comparable with or greater than the association rate for
acetylcholine binding to nAChR.
PMID: 11562442 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22801375 | 1. Mol Cell Biol. 2012 Oct;32(19):3814-22. doi: 10.1128/MCB.05938-11. Epub 2012
Jul 16.
A novel complex, RUNX1-MYEF2, represses hematopoietic genes in erythroid cells.
van Riel B(1), Pakozdi T, Brouwer R, Monteiro R, Tuladhar K, Franke V, Bryne JC,
Jorna R, Rijkers EJ, van Ijcken W, Andrieu-Soler C, Demmers J, Patient R, Soler
E, Lenhard B, Grosveld F.
Author information:
(1)Department of Cell Biology and Center for Biomedical Genetics, Erasmus
Medical Center, Rotterdam, Netherlands.
RUNX1 is known to be an essential transcription factor for generating
hematopoietic stem cells (HSC), but much less is known about its role in the
downstream process of hematopoietic differentiation. RUNX1 has been shown to be
part of a large transcription factor complex, together with LDB1, GATA1, TAL1,
and ETO2 (N. Meier et al., Development 133:4913-4923, 2006) in erythroid cells.
We used a tagging strategy to show that RUNX1 interacts with two novel protein
partners, LSD1 and MYEF2, in erythroid cells. MYEF2 is bound in undifferentiated
cells and is lost upon differentiation, whereas LSD1 is bound in differentiated
cells. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and
microarray expression analysis were used to show that RUNX1 binds approximately
9,000 target sites in erythroid cells and is primarily active in the
undifferentiated state. Functional analysis shows that a subset of the target
genes is suppressed by RUNX1 via the newly identified partner MYEF2. Knockdown
of Myef2 expression in developing zebrafish results in a reduced number of HSC.
DOI: 10.1128/MCB.05938-11
PMCID: PMC3457535
PMID: 22801375 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19468253 | 1. Pathobiology. 2009 May;76(3):136-40. doi: 10.1159/000209391. Epub 2009 May 19.
Immunolocalization of DNMT1 and DNMT3a in salivary gland neoplasms.
Cavaliéri Gomes C(1), da Silveira e Oliveira C, Santos Pimenta LG, De Marco L,
Santiago Gomez R.
Author information:
(1)School of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo
Horizonte, Brazil.
OBJECTIVE: Salivary gland neoplasms pathogenesis has not been well established.
DNA methylation occurs when methyl groups are added to cytosine nucleotides in
specific areas of the gene by the enzyme DNA methyltransferase (DNMT). This
chemical modification can alter gene expression without altering DNA sequence.
While DNMT3a is mostly involved in de novo methylation, DNMT1 acts as a
maintenance methyltransferase. We aimed to investigate the immunoexpression of
DNMT3a and DNMT1 in minor salivary gland neoplasms, comparing it with normal
tissue.
MATERIAL: Forty-four formalin-fixed and paraffin-embedded samples of pleomorphic
adenoma, adenoid cystic carcinoma, mucoepidermoid carcinoma and polymorphous
low-grade adenocarcinoma were included in the study. The DNMT1 and DNMT3a
proteins were identified by using a highly sensitive polymer-based system.
RESULTS: Positive nuclear and cytoplasmic labeling for DNMT1 was observed in all
samples, including the controls. Positive nuclear labeling for DNMT3a was found
only in few neoplasms: 1 pleomorphic adenoma (9.0%), 2 adenoid cystic carcinoma
(16.6%) and 1 mucoepidermoid (9.0%) cases.
CONCLUSION: Our results were not able to demonstrate a clear correlation between
DNMT1 and DNMT3a immunoexpression and salivary gland neoplasms development.
Copyright 2009 S. Karger AG, Basel.
DOI: 10.1159/000209391
PMID: 19468253 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/20466982 | 1. Circ Res. 2010 Jul 9;107(1):45-55. doi: 10.1161/CIRCRESAHA.109.213983. Epub
2010 May 13.
The Rac1 regulator ELMO1 controls vascular morphogenesis in zebrafish.
Epting D(1), Wendik B, Bennewitz K, Dietz CT, Driever W, Kroll J.
Author information:
(1)Center for Biomedicine and Medical Technology Mannheim, Research Division
Vascular Biology of the Medical Faculty Mannheim, Heidelberg University and the
German Cancer Research Center (DKFZ-ZMBH Alliance) Heidelberg, Mannheim,
Germany.
RATIONALE: Angiogenesis is regulated by the small GTPase Rac1. The ELMO1/DOCK180
complex forms a guanine nucleotide exchange factor for Rac1, regulating its
activation during cell migration in different biological systems.
OBJECTIVE: To investigate the function of ELMO1/DOCK180 in vascular development.
METHODS AND RESULTS: In situ hybridization studies for elmo1 identified a
vascular and neuronal expression in zebrafish. Morpholino-based expression
silencing of elmo1 severely impaired the formation of the vasculature, including
intersomitic vessels, the dorsal longitudinal anastomotic vessel, the
parachordal vessel, and the development of the thoracic duct in tg(fli1:EGFP)
embryos. Mechanistically, we identified Netrin-1 and its receptor Unc5B as
upstream activators of the ELMO1/DOCK180 complex, regulating its functional
interaction and leading to Rac1 activation in endothelial cells and vessel
formation in zebrafish.
CONCLUSIONS: Our data have identified a novel signaling cascade regulating
vasculature formation in zebrafish.
DOI: 10.1161/CIRCRESAHA.109.213983
PMID: 20466982 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22658851 | 1. Leuk Res. 2012 Sep;36(9):1165-71. doi: 10.1016/j.leukres.2012.05.005. Epub
2012 Jun 1.
Integrin-linked kinase is dispensable for multiple myeloma cell survival.
Steinbrunn T(1), Siegmund D, Andrulis M, Grella E, Kortüm M, Einsele H, Wajant
H, Bargou RC, Stühmer T.
Author information:
(1)Department of Internal Medicine II, Comprehensive Cancer Center Mainfranken,
University Hospital of Würzburg, Würzburg, Germany.
We investigated the utility of integrin-linked kinase (ILK) as a target for
therapeutic intervention in multiple myeloma (MM). ILK (over-)expression was
assessed in primary samples and MM cell lines, and the molecular and
physiological consequences of siRNA-mediated ILK ablation were compared to
treatment with the small molecule inhibitor QLT0267. Whereas ILK expression was
ubiquitous, overexpression was only rarely observed in patient biopsies. ILK
knockdown had no effect on the viability or survival pathway activity pattern of
MM cells. Conversely, QLT0267 induced cell death in MM cell lines and most
primary tumor samples via the intrinsic apoptotic pathway. Although this effect
was largely tumor cell-specific it is unlikely to have been mediated via ILK. We
conclude that ILK does not play a prominent role in the promotion or sustenance
of established MM.
Copyright © 2012 Elsevier Ltd. All rights reserved.
DOI: 10.1016/j.leukres.2012.05.005
PMID: 22658851 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24228714 | 1. J Med Chem. 2014 Apr 24;57(8):3161-85. doi: 10.1021/jm401343c. Epub 2013 Nov
14.
MT1 and MT2 melatonin receptors: ligands, models, oligomers, and therapeutic
potential.
Zlotos DP(1), Jockers R, Cecon E, Rivara S, Witt-Enderby PA.
Author information:
(1)Department of Pharmaceutical Chemistry, The German University in Cairo , New
Cairo City, 11835 Cairo, Egypt.
Numerous physiological functions of the pineal gland hormone melatonin are
mediated via activation of two G-protein-coupled receptors, MT1 and MT2. The
melatonergic drugs on the market, ramelteon and agomelatine, as well as the most
advanced drug candidates under clinical evaluation, tasimelteon and TIK-301, are
high-affinity nonselective MT1/MT2 agonists. A great number of MT2-selective
ligands and, more recently, several MT1-selective agents have been reported to
date. Herein, we review recent advances in the field focusing on high-affinity
agonists and antagonists and those displaying selectivity toward MT1 and MT2
receptors. Moreover, the existing models of MT1 and MT2 receptors as well as the
current status in the emerging field of melatonin receptor oligomerization are
critically discussed. In addition to the already existing indications, such as
insomnia, circadian sleep disorders, and depression, new potential therapeutic
applications of melatonergic ligands including cardiovascular regulation,
appetite control, tumor growth inhibition, and neurodegenerative diseases are
presented.
DOI: 10.1021/jm401343c
PMID: 24228714 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/19736520 | 1. Epigenetics. 2009 Aug 16;4(6):357-61. doi: 10.4161/epi.4.6.9711. Epub 2009 Aug
31.
Transcriptional regulation by TAL1: a link between epigenetic modifications and
erythropoiesis.
Hu X(1), Ybarra R, Qiu Y, Bungert J, Huang S.
Author information:
(1)Edmond H. Fischer Signal Transduction Laboratory, College of Life Science,
Jilin University, Changchun, China.
TAL1/SCL (hereafter referred to as TAL1) is a critical transcription factor
required for hematopoiesis in which hematopoietic stem cells commit and
differentiate to different lineages. During this process, transcription of many
genes is turned on and off in part by epigenetic mechanisms. TAL1 has recently
been shown to differentially recruit LSD1 and other histone modifying complexes
to regulate its target genes. Here, we focus primarily on epigenetic mechanisms
that are regulated by TAL1 during normal and malignant hematopoiesis. We discuss
how different histone modifying enzymes are recruited by TAL1 and how these
enzymatic activities mediate the activating or repressive function of TAL1.
Finally, we further explore the possible mechanisms by which dysregulation of
the recruitment and activity of histone modifying enzymes contribute to
leukemogenesis.
DOI: 10.4161/epi.4.6.9711
PMID: 19736520 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/8051940 | 1. J Inherit Metab Dis. 1994;17(1):85-8. doi: 10.1007/BF00735401.
The N370S mutation in the glucocerebrosidase gene of Portuguese type 1 Gaucher
patients: linkage to the PvuII polymorphism.
Lacerda L(1), Amaral O, Pinto R, Aerts J, Sá Miranda MC.
Author information:
(1)Instituto de Genética Médica Jacinto de Magalhaes, Porto, Portugal.
Comment in
J Inherit Metab Dis. 1995;18(1):103. doi: 10.1007/BF00711395.
The mutation N370S accounts for 63% of the mutated glucocerebrosidase alleles of
Portuguese type 1 Gaucher patients. It has been shown previously that this
mutation is linked to the Pv1.1- form of the PvuII polymorphism and suggested
that the N370S mutation in glucocerebrosidase alleles has an Ashkenazi Jewish
origin. We have found that in Portuguese type 1 Gaucher patients this mutation
is also invariably associated with the Pv1.1- haplotype, despite the fact that
there is no evidence of Ashkenazi Jewish background in this population.
DOI: 10.1007/BF00735401
PMID: 8051940 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22490330 | 1. Blood. 2012 Jun 14;119(24):5824-31. doi: 10.1182/blood-2011-07-367961. Epub
2012 Apr 5.
Mutant DNMT3A: a marker of poor prognosis in acute myeloid leukemia.
Ribeiro AF(1), Pratcorona M, Erpelinck-Verschueren C, Rockova V, Sanders M,
Abbas S, Figueroa ME, Zeilemaker A, Melnick A, Löwenberg B, Valk PJ, Delwel R.
Author information:
(1)Department of Hematology, Erasmus University Medical Center, Rotterdam, The
Netherlands.
Comment in
Blood. 2012 Jun 14;119(24):5615-7. doi: 10.1182/blood-2012-04-423905.
The prevalence, the prognostic effect, and interaction with other molecular
markers of DNMT3A mutations was studied in 415 patients with acute myeloid
leukemia (AML) younger than 60 years. We show mutations in DNMT3A in 96 of 415
patients with newly diagnosed AML (23.1%). Univariate Cox regression analysis
showed that patients with DNMT3A(mutant) AML show significantly worse overall
survival (OS; P = .022; hazard ratio [HR], 1.38; 95% confidence interval [CI],
1.04-1.81), and relapse-free survival (RFS; P = .005; HR, 1.52; 95% CI,
1.13-2.05) than DNMT3A(wild-type) AMLs. In a multivariable analysis, DNMT3A
mutations express independent unfavorable prognostic value for OS (P = .003; HR,
1.82; 95% CI, 1.2-2.7) and RFS (P < .001; HR, 2.2; 95% CI, 1.4-3.3). In a
composite genotypic subset of cytogenetic intermediate-risk AML without FLT3-ITD
and NPM1 mutations, this association is particularly evident (OS: P = .013; HR,
2.09; 95% CI, 1.16-3.77; RFS: P = .001; HR, 2.65; 95% CI, 1.48-4.89). The effect
of DNMT3A mutations in human AML remains elusive, because DNMT3A(mutant) AMLs
did not express a methylation or gene expression signature that discriminates
them from patients with DNMT3A(wild-type) AML. We conclude that DNMT3A mutation
status is an important factor to consider for risk stratification of patients
with AML.
DOI: 10.1182/blood-2011-07-367961
PMID: 22490330 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/8389441 | 1. Nucleic Acids Res. 1993 May 25;21(10):2383-8. doi: 10.1093/nar/21.10.2383.
Isolation and identification by sequence homology of a putative cytosine
methyltransferase from Arabidopsis thaliana.
Finnegan EJ(1), Dennis ES.
Author information:
(1)CSIRO, Division of Plant Industry, Canberra, ACT, Australia.
A plant cytosine methyltransferase cDNA was isolated using degenerate
oligonucleotides, based on homology between prokaryote and mouse
methyltransferases, and PCR to amplify a short fragment of a methyltransferase
gene. A fragment of the predicted size was amplified from genomic DNA from
Arabidopsis thaliana. Overlapping cDNA clones, some with homology to the PCR
amplified fragment, were identified and sequenced. The assembled nucleic acid
sequence is 4720 bp and encodes a protein of 1534 amino acids which has
significant homology to prokaryote and mammalian cytosine methyltransferases.
Like mammalian methylases, this enzyme has a C terminal methyltransferase domain
linked to a second larger domain. The Arabidopsis methylase has eight of the ten
conserved sequence motifs found in prokaryote cytosine-5 methyltransferases and
shows 50% homology to the murine enzyme in the methyltransferase domain. The
amino terminal domain is only 24% homologous to the murine enzyme and lacks the
zinc binding region that has been found in methyltransferases from both mouse
and man. In contrast to mouse where a single methyltransferase gene has been
identified, a small multigene family with homology to the region amplified in
PCR has been identified in Arabidopsis thaliana.
DOI: 10.1093/nar/21.10.2383
PMCID: PMC309536
PMID: 8389441 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/8891947 | 1. J Comp Neurol. 1996 Oct 7;374(1):70-83. doi:
10.1002/(SICI)1096-9861(19961007)374:1<70::AID-CNE5>3.0.CO;2-K.
Atypical and typical neuroleptic treatments induce distinct programs of
transcription factor expression in the striatum.
Hiroi N(1), Graybiel AM.
Author information:
(1)Department of Brain and Cognitive Sciences, Massachusetts Institute of
Technology, Cambridge 02139, USA.
Atypical and typical neuroleptics, when administered chronically, can bring
about profound but contrasting changes in schizophrenic symptoms and motor
activation and dramatically modulate brain neurochemistry. To explore the
transcriptional events that might be involved in this neurochemical regulation,
we used immunohistochemistry and immunoblotting to examine the expression
patterns of two bZip transcription factors, c-Fos and FosB, in the striatum of
rats treated acutely and chronically with neuroleptic drugs of different
classes. Typical and atypical neuroleptic drugs produced contrasting regulatory
effects on a FosB-like protein of ca. 36-39 kDa, the molecular weight of
truncated FosB (delta FosB). Chronic treatments with two typical neuroleptics,
haloperidol and metoclopramide, but not with the atypical neuroleptic clozapine,
led to markedly enhanced FosB-like immunoreactivity in the caudoputamen.
Further, c-Fos-like protein in the striatum, considered a marker for the
induction of antipsychotic actions by neuroleptic treatments, was downregulated
by chronic treatment with the two potent antipsychotic drugs tested, but not by
chronic treatment with metoclopramide, which has low antipsychotic efficacy but
induces extrapyramidal side effects. These results suggest that chronic
treatments with neuroleptics having different effects on cognitive and motor
behavior induce different long-term changes in transcription factor expression
in the striatum. Nevertheless, we found that neuroleptics of both classes
regulated transcription factor expression in overlapping populations of striatal
neurons expressing enkephalin or DARPP-32. Contrasting patterns of
transcriptional regulation in these neurons may thus contribute to the distinct
neurochemical and behavioral effects that characterize neuroleptics of different
classes.
DOI: 10.1002/(SICI)1096-9861(19961007)374:1<70::AID-CNE5>3.0.CO;2-K
PMID: 8891947 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/18639561 | 1. Mutat Res. 2008 Sep 26;644(1-2):17-23. doi: 10.1016/j.mrfmmm.2008.06.009. Epub
2008 Jul 1.
Mechanisms of peroxisome proliferator-induced DNA hypomethylation in rat liver.
Pogribny IP(1), Tryndyak VP, Boureiko A, Melnyk S, Bagnyukova TV, Montgomery B,
Rusyn I.
Author information:
(1)Division of Biochemical Toxicology, National Center for Toxicological
Research, 3900 NCTR Road, Jefferson, AR 72079, USA. [email protected]
Genomic hypomethylation is a consistent finding in both human and animal tumors
and mounting experimental evidence suggests a key role for epigenetic events in
tumorigenesis. Furthermore, it has been suggested that early changes in DNA
methylation and histone modifications may serve as sensitive predictive markers
in animal testing for carcinogenic potency of environmental agents. Alterations
in metabolism of methyl donors, disturbances in activity and/or expression of
DNA methyltransferases, and presence of DNA single-strand breaks could
contribute to the loss of cytosine methylation during carcinogenesis; however,
the precise mechanisms of genomic hypomethylation induced by chemical
carcinogens remain largely unknown. This study examined the mechanism of DNA
hypomethylation during hepatocarcinogenesis induced by peroxisome proliferators
WY-14,643 (4-chloro-6-(2,3-xylidino)-pyrimidynylthioacetic acid) and DEHP
(di-(2-ethylhexyl)phthalate), agents acting through non-genotoxic mode of
action. In the liver of male Fisher 344 rats exposed to WY-14,643 (0.1% (w/w), 5
months), the level of genomic hypomethylation increased by approximately 2-fold,
as compared to age-matched controls, while in the DEHP group (1.2% (w/w), 5
months) DNA methylation did not change. Global DNA hypomethylation in livers
from WY-14,643 group was accompanied by the accumulation of DNA single-strand
breaks, increased cell proliferation, and diminished expression of DNA
methyltransferase 1, while the metabolism of methyl donors was not affected. In
contrast, none of these parameters changed significantly in rats fed DEHP. Since
WY-14,643 is much more potent carcinogen than DEHP, we conclude that the extent
of loss of DNA methylation may be related to the carcinogenic potential of the
chemical agent, and that accumulation of DNA single-strand breaks coupled to the
increase in cell proliferation and altered DNA methyltransferase expression may
explain genomic hypomethylation during peroxisome proliferator-induced
carcinogenesis.
DOI: 10.1016/j.mrfmmm.2008.06.009
PMCID: PMC2571982
PMID: 18639561 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23177624 | 1. Cell Rep. 2012 Nov 29;2(5):1411-24. doi: 10.1016/j.celrep.2012.10.017. Epub
2012 Nov 21.
Linking DNA methyltransferases to epigenetic marks and nucleosome structure
genome-wide in human tumor cells.
Jin B(1), Ernst J, Tiedemann RL, Xu H, Sureshchandra S, Kellis M, Dalton S, Liu
C, Choi JH, Robertson KD.
Author information:
(1)Cancer Research Center, Georgia Health Sciences University, Augusta, GA
30912, USA.
DNA methylation, mediated by the combined action of three DNA methyltransferases
(DNMT1, DNMT3A, and DNMT3B), is essential for mammalian development and is a
major contributor to cellular transformation. To elucidate how DNA methylation
is targeted, we mapped the genome-wide localization of all DNMTs and
methylation, and examined the relationships among these markers, histone
modifications, and nucleosome structure in a pluripotent human tumor cell line
in its undifferentiated and differentiated states. Our findings reveal a strong
link between DNMTs and transcribed loci, and that DNA methylation is not a
simple sum of DNMT localization patterns. A comparison of the epigenomes of
normal and cancerous stem cells, and pluripotent and differentiated states shows
that the presence of at least two DNMTs is strongly associated with loci
targeted for DNA hypermethylation. Taken together, these results shed important
light on the determinants of DNA methylation and how it may become disrupted in
cancer cells.
Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.
DOI: 10.1016/j.celrep.2012.10.017
PMCID: PMC3625945
PMID: 23177624 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21045206 | 1. Sci Signal. 2010 Nov 2;3(146):ra80. doi: 10.1126/scisignal.2001462.
DNMT1 stability is regulated by proteins coordinating deubiquitination and
acetylation-driven ubiquitination.
Du Z(1), Song J, Wang Y, Zhao Y, Guda K, Yang S, Kao HY, Xu Y, Willis J,
Markowitz SD, Sedwick D, Ewing RM, Wang Z.
Author information:
(1)Department of Genetics, Case Western Reserve University, Cleveland, OH 44106,
USA.
DNA methyltransferase 1 (DNMT1) is the primary enzyme that maintains DNA
methylation. We describe a previously unknown mode of regulation of DNMT1
protein stability through the coordinated action of an array of DNMT1-associated
proteins. DNMT1 was destabilized by acetylation by the acetyltransferase Tip60,
which triggered ubiquitination by the E3 ligase UHRF1, thereby targeting DNMT1
for proteasomal degradation. In contrast, DNMT1 was stabilized by histone
deacetylase 1 (HDAC1) and the deubiquitinase HAUSP (herpes virus-associated
ubiquitin-specific protease). Analysis of the abundance of DNMT1 and Tip60, as
well as the association between HAUSP and DNMT1, suggested that during the cell
cycle the initiation of DNMT1 degradation was coordinated with the end of DNA
replication and the need for DNMT activity. In human colon cancers, the
abundance of DNMT1 correlated with that of HAUSP. HAUSP knockdown rendered colon
cancer cells more sensitive to killing by HDAC inhibitors both in tissue culture
and in tumor xenograft models. Thus, these studies provide a mechanism-based
rationale for the development of HDAC and HAUSP inhibitors for combined use in
cancer therapy.
DOI: 10.1126/scisignal.2001462
PMCID: PMC3116231
PMID: 21045206 [Indexed for MEDLINE]
Conflict of interest statement: Competing interests: The authors declare that
they have no competing interests. A materials transfer agreement (MTA) is
required by Case Western Reserve University for DNMT1, DNMT3B, Tip60 3xFlag
knock-in cell lines, the HAUSP knockout cell line, the HDAC1-inducible knockdown
cells, and the plasmids generated for this study. |
http://www.ncbi.nlm.nih.gov/pubmed/22503503 | 1. Curr Biol. 2012 May 8;22(9):830-6. doi: 10.1016/j.cub.2012.03.027. Epub 2012
Apr 12.
Apoptotic cells are cleared by directional migration and elmo1- dependent
macrophage engulfment.
van Ham TJ(1), Kokel D, Peterson RT.
Author information:
(1)Cardiovascular Research Center and Division of Cardiology, Department of
Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown,
MA 02129, USA. [email protected]
Apoptotic cell death is essential for development and tissue homeostasis.
Failure to clear apoptotic cells can ultimately cause inflammation and
autoimmunity. Apoptosis has primarily been studied by staining of fixed tissue
sections, and a clear understanding of the behavior of apoptotic cells in living
tissue has been elusive. Here, we use a newly developed technique to track
apoptotic cells in real time as they emerge and are cleared from the zebrafish
brain. We find that apoptotic cells are remarkably motile, frequently migrating
several cell diameters to the periphery of living tissues. F-actin remodeling
occurs in surrounding cells, but also within the apoptotic cells themselves,
suggesting a cell-autonomous component of motility. During the first 2 days of
development, engulfment is rare, and most apoptotic cells lyse at the brain
periphery. By 3 days postfertilization, most cell corpses are rapidly engulfed
by macrophages. This engulfment requires the guanine nucleotide exchange factor
elmo1. In elmo1-deficient macrophages, engulfment is rare and may occur through
macropinocytosis rather than directed engulfment. These findings suggest that
clearance of apoptotic cells in living vertebrates is accomplished by the
combined actions of apoptotic cell migration and elmo1-dependent macrophage
engulfment.
Copyright © 2012 Elsevier Ltd. All rights reserved.
DOI: 10.1016/j.cub.2012.03.027
PMCID: PMC3597770
PMID: 22503503 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23742986 | 1. Microsc Microanal. 2013 Aug;19(4):842-54. doi: 10.1017/S1431927613001633. Epub
2013 Jun 7.
Zyxin regulates cell migration and differentiation in EMT during chicken AV
valve morphogenesis.
Li N(1), Goodwin RL, Potts JD.
Author information:
(1)Department of Cell Biology and Anatomy, School of Medicine, University of
South Carolina, Columbia, SC 29209, USA.
During heart valve development, epithelial-mesenchymal transformation (EMT) is a
key process for valve formation. EMT leads to the generation of mesenchymal
cells that will eventually become the interstitial cells (fibroblasts) of the
mature valve. During EMT, cell architecture and motility change markedly;
significant changes are also observed in various signaling pathways. Here we
systematically examined the expression, localization, and function of zyxin, a
focal adhesion protein, in EMT during atrioventricular (AV) valve morphogenesis.
Expression and localization studies showed that zyxin was expressed in the AV
canal region during crucial stages of valve development. An in vitro 3D collagen
gel culture system was used to determine zyxin function either after siRNA gene
knockdown or after overexpression. Our studies revealed that zyxin
overexpression inhibited endocardial cell migration and cell differentiation and
also led to a decrease in the number of migrating mesenchymal cells. Moreover,
correlative cytoskeletal changes were apparent in response to both
overexpression and knockdown treatments. Thus, zyxin appears to play a role as a
regulator of cell migration and differentiation during EMT in chicken AV valve
formation.
DOI: 10.1017/S1431927613001633
PMID: 23742986 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/25400662 | 1. Adv Bioinformatics. 2014;2014:502618. doi: 10.1155/2014/502618. Epub 2014 Oct
20.
Computational Analysis Reveals the Association of Threonine 118 Methionine
Mutation in PMP22 Resulting in CMT-1A.
Kumar CV(1), Swetha RG(1), Anbarasu A(1), Ramaiah S(2).
Author information:
(1)School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu
632014, India.
(2)Bioinformatics Division, School of Biosciences & Technology (SBST), VIT
University, Vellore 632014, India.
The T118M mutation in PMP22 gene is associated with Charcot Marie Tooth, type 1A
(CMT1A). CMT1A is a form of Charcot-Marie-Tooth disease, the most common
inherited disorder of the peripheral nervous system. Mutations in CMT related
disorder are seen to increase the stability of the protein resulting in the
diseased state. We performed SNP analysis for all the nsSNPs of PMP22 protein
and carried out molecular dynamics simulation for T118M mutation to compare the
stability difference between the wild type protein structure and the mutant
protein structure. The mutation T118M resulted in the overall increase in the
stability of the mutant protein. The superimposed structure shows marked
structural variation between the wild type and the mutant protein structures.
DOI: 10.1155/2014/502618
PMCID: PMC4220619
PMID: 25400662 |
http://www.ncbi.nlm.nih.gov/pubmed/21223590 | 1. BMC Genomics. 2011 Jan 11;12:20. doi: 10.1186/1471-2164-12-20.
Global gene expression profile progression in Gaucher disease mouse models.
Xu YH(1), Jia L, Quinn B, Zamzow M, Stringer K, Aronow B, Sun Y, Zhang W,
Setchell KD, Grabowski GA.
Author information:
(1)The Division of Human Genetics, Cincinnati Children's Hospital Research
Foundation, Cincinnati, OH 45229-3039, USA. [email protected]
BACKGROUND: Gaucher disease is caused by defective glucocerebrosidase activity
and the consequent accumulation of glucosylceramide. The pathogenic pathways
resulting from lipid laden macrophages (Gaucher cells) in visceral organs and
their abnormal functions are obscure.
RESULTS: To elucidate this pathogenic pathway, developmental global gene
expression analyses were conducted in distinct Gba1 point-mutated mice
(V394L/V394L and D409 V/null). About 0.9 to 3% of genes had altered expression
patterns (≥ ± 1.8 fold change), representing several categories, but
particularly macrophage activation and immune response genes. Time course
analyses (12 to 28 wk) of INFγ-regulated pro-inflammatory (13) and
IL-4-regulated anti-inflammatory (11) cytokine/mediator networks showed tissue
differential profiles in the lung and liver of the Gba1 mutant mice, implying
that the lipid-storage macrophages were not functionally inert. The time course
alterations of the INFγ and IL-4 pathways were similar, but varied in degree in
these tissues and with the Gba1 mutation.
CONCLUSIONS: Biochemical and pathological analyses demonstrated direct
relationships between the degree of tissue glucosylceramides and the gene
expression profile alterations. These analyses implicate IFNγ-regulated
pro-inflammatory and IL-4-regulated anti-inflammatory networks in differential
disease progression with implications for understanding the Gaucher disease
course and pathophysiology.
DOI: 10.1186/1471-2164-12-20
PMCID: PMC3032697
PMID: 21223590 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21678477 | 1. J Cell Biochem. 2011 Oct;112(10):3044-53. doi: 10.1002/jcb.23229.
Vorinostat, SAHA, represses telomerase activity via epigenetic regulation of
telomerase reverse transcriptase in non-small cell lung cancer cells.
Li CT(1), Hsiao YM, Wu TC, Lin YW, Yeh KT, Ko JL.
Author information:
(1)Institute of Medical and Molecular Toxicology, Chung Shan Medical University,
Taichung, Taiwan.
Vorinostat (suberoylanilide hydroxamic acid), a class of histone deacetylase
inhibitors, represents an emerging class of anticancer agents currently
progressing in clinical trials. It causes cell growth inhibition,
differentiation, and apoptosis of many tumor types in vitro and in vivo.
Recently, it was reported that hTERT is one of the targets for cancer therapy in
cancer cells. Telomerase repeat amplification protocol assay was used to analyze
the expression of hTERT after vorinostat treatment in the A549 lung cancer
cells. Vorinostat inhibited telomerase activity by reducing the expression of
human telomerase reverse transcriptase (hTERT) in A549 human lung cancer cells.
The epigenetic regulation mechanism is responsible for the repression of hTERT
by vorinostat, analyzed through the methylation-specific PCR and bisulfite
sequencing of the hTERT promoter. Vorinostat induced the demethylation of
site-specific CpGs on the promoter region of hTERT, which was caused by the
down-regulation of DNA methyltransferases. DNA methyltransferases (DNMT1 and
DNMT3b) were also decreased in vorinostat-treated A549 cancer cells.
Furthermore, chromatin immunoprecipitation analysis of the hTERT promoter
revealed that vorinostat decreased the level of inactive chromatin markers
dimethyl-H3K9, and the declined binding of DNMT1 and DNMT3b were associated. The
novel insights showed that vorinostat down-regulated telomerase via epigenetic
alteration in lung cancer to vorinostat-mediated cancer-specific therapies.
Copyright © 2011 Wiley-Liss, Inc.
DOI: 10.1002/jcb.23229
PMID: 21678477 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/20658796 | 1. CNS Drugs. 2010 Aug;24(8):625-38. doi: 10.2165/11535940-000000000-00000.
Awakenings and awareness recovery in disorders of consciousness: is there a role
for drugs?
Pistoia F(1), Mura E, Govoni S, Fini M, Sarà M.
Author information:
(1)Hospital San Raffaele, Cassino, Italy. [email protected]
Disorders of consciousness (DOC) include coma, vegetative state (VS) and
minimally conscious state (MCS). Coma is a condition of unarousability with a
complete absence of wakefulness and awareness, whereas VS is characterized by a
lack of awareness despite a preserved wakefulness. Patients in coma are
unconscious because they lack both wakefulness and awareness. Patients in a VS
are unconscious because, although they are wakeful, they lack awareness.
Patients in a MCS show minimal but definite behavioural evidence of self and
environmental awareness. Coma results from diffuse bilateral hemispheric lesions
or selective damage to the ascending reticular system (which is functionally
connected to the cerebral cortex by intralaminar thalamic nuclei). VS is a
syndrome that is considered to be the result of a disconnection of different
cortical networks rather than a dysfunction of a single area or a global
reduction in cortical metabolism. As revealed by functional imaging studies,
clinical recovery is often associated with a functional restoration of
cortico-thalamo-cortical connections. Depending on the amount of network
restored, patients may regain full consciousness or remain in a MCS. Molecular
and neural mediators may indirectly contribute to the above restoration
processes owing to their role in the phenomenon of neural synaptic plasticity.
Therefore, there is growing interest in the possible effects of drugs that act
at the level of the CNS in promoting emergence from DOC. Sporadic cases of
dramatic recovery from DOC after the administration of various pharmacological
agents, such as baclofen, zolpidem and amantadine, have been recently supported
by intriguing scientific observations. Analysis of the reported cases of
recovery, with particular attention paid to the condition of the patients and to
the association of their improvement with the start of drug administration,
suggests that these treatments might have promoted the clinical improvement of
some patients. These drugs are from various and diverging classes, but can be
grouped into two main categories, CNS stimulants and CNS depressants. Some of
these treatments seem to directly encourage a consciousness restoration, while
others play a more determinant role in improving cognitive domains, especially
in patients with residual cognitive impairment, than in the field of
consciousness. Given the great interest recently generated in the scientific
community by the increasing number of papers addressing this issue, further
investigation of the above treatments, with particular attention paid to their
mechanisms of action, the neurotransmitters involved and their effects on
cortico-thalamo-cortical circuitry, is needed.
DOI: 10.2165/11535940-000000000-00000
PMID: 20658796 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/17965599 | 1. Epigenetics. 2007 Apr-Jun;2(2):80-5. doi: 10.4161/epi.2.2.3692. Epub 2006 Dec
7.
DNA methylation profile at the DNMT3L promoter: a potential biomarker for
cervical cancer.
Gokul G(1), Gautami B, Malathi S, Sowjanya AP, Poli UR, Jain M, Ramakrishna G,
Khosla S.
Author information:
(1)Laboratory of Mammalian Genetics, Centre for DNA Fingerprinting and
Diagnostics (CDFD), Nacharam, Hyderabad, India.
Epigenetic events play a prominent role during cancer development. This is
evident from the fact that almost all cancer types show aberrant DNA
methylation. These abnormal DNA methylation levels are not restricted to just a
few genes but affect the whole genome. Previous studies have shown genome-wide
DNA hypomethylation and gene-specific hypermethylation to be a hallmark of most
cancers. Molecules like DNA methyltransferase act as effectors of epigenetic
reprogramming. In the present study we have examined the possibility that the
reprogramming genes themselves undergo epigenetic modifications reflecting their
changed transcriptional status during cancer development. Comparison of DNA
methylation status between the normal and cervical cancer samples was carried
out at the promoters of a few reprogramming molecules. Our study revealed
statistically significant DNA methylation differences within the promoter of
DNMT3L. A regulator of de novo DNA methyltransferases DNMT3A and DNMT3B, DNMT3L
promoter was found to have lost DNA methylation to varying levels in 14 out of
15 cancer cervix samples analysed. The present study highlights the importance
of DNA methylation profile at DNMT3L promoter not only as a promising biomarker
for cervical cancer, which is the second most common cancer among women
worldwide, but also provides insight into the possible role of DNMT3L in cancer
development.
DOI: 10.4161/epi.2.2.3692
PMCID: PMC2080824
PMID: 17965599 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23591873 | 1. Nat Commun. 2013;4:1706. doi: 10.1038/ncomms2680.
Association between Gαi2 and ELMO1/Dock180 connects chemokine signalling with
Rac activation and metastasis.
Li H(1), Yang L, Fu H, Yan J, Wang Y, Guo H, Hao X, Xu X, Jin T, Zhang N.
Author information:
(1)Tianjin Medical University Cancer Institute and Hospital and Research Center
of Basic Medical Sciences, He Xi District, Tianjin 300060, China.
The chemokine CXCL12 and its G-protein-coupled receptor CXCR4 control the
migration, invasiveness and metastasis of breast cancer cells. Binding of CXCL12
to CXCR4 triggers activation of heterotrimeric Gi proteins that regulate actin
polymerization and migration. However, the pathways linking chemokine
G-protein-coupled receptor/Gi signalling to actin polymerization and cancer cell
migration are not known. Here we show that CXCL12 stimulation promotes
interaction between Gαi2 and ELMO1. Gi signalling and ELMO1 are both required
for CXCL12-mediated actin polymerization, migration and invasion of breast
cancer cells. CXCL12 triggers a Gαi2-dependent membrane translocation of ELMO1,
which associates with Dock180 to activate small G-proteins Rac1 and Rac2. In
vivo, ELMO1 expression is associated with lymph node and distant metastasis, and
knocking down ELMO1 impairs metastasis to the lung. Our findings indicate that a
chemokine-controlled pathway, consisting of Gαi2, ELMO1/Dock180, Rac1 and Rac2,
regulates the actin cytoskeleton during breast cancer metastasis.
DOI: 10.1038/ncomms2680
PMCID: PMC3644068
PMID: 23591873 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/15289832 | 1. Oncol Rep. 2004 Sep;12(3):527-31.
Inhibition of DNA methyltransferase by antisense oligodeoxynucleotide modifies
cell characteristics in gastric cancer cell lines.
Saikawa Y(1), Kubota T, Maeda S, Otani Y, Kumai K, Kitajima M.
Author information:
(1)Department of Surgery, School of Medicine, Keio University, 35 Shinanomachi,
Shinjuku-ku, Tokyo 160, Japan. [email protected]
DNA (cytosine-5-)-methyltransferase 1 (DNMT1) plays an important role in the
maintenance of DNA methylation patterns via complicated networks including
signaling pathways and transcriptional factors, relating to cell differentiation
or carcinogenesis. In the present study, we designed an antisense
oligodeoxynucleotide of DNMT1 (AS/MT: 5'-CGGTAC GCGCCGGCATCT-3') and
demonstrated successful inhibition of DNMT1 expression by AS/MT at the protein
level, using gastric cancer cell lines in vitro. E-cadherin protein expression
was increased, and both cyclin D1 and PCNA were decreased by AS/MT treatment.
AS/MT also induced suppression of cell growth as determined by BrDU uptake
incorporation, in a dose-dependent manner, suggesting specificity of AS/MT.
Simultaneously, morphological alterations were observed in both TMK-1 and MKN-45
cells after 24 h incubation with 2 micro M of AS/MT. The cells changed shape
from their original forms to dispersed, fibroblast-like cells with neurite-like
processes, accompanied by an increased adhesive potential of the cells. An in
vivo model of peritoneal dissemination using the nude mouse system showed an
increased malignant potential of AS/MT treated TMK-1 cells as demonstrated by a
greater number of peritoneal tumor nodules in the AS/MT as compared to the NS/MT
treated group, 34.8+/-4.3 vs. 22.4+/-3.0 nodules, respectively (p=0.0039). The
total wet tumor weight in the AS/MT group (350+/-47.4 g) was significantly
greater than that in the NS/MT group (248+/-41.5 g) (p=0.0065). In conclusion,
the inhibition of DNA methylation by DNMT1 by an antisense oligodeoxynucleotide
influences cell morphology and adhesion, as well as cell growth in gastric
cancer cells in vitro. Moreover, these alterations in the characteristics of
cancer cells resulted in an increased ability to attach onto the peritoneum in
the nude mouse system in vivo, suggesting that strict clinical guidelines will
be necessary to utilize such a DNA methylation inhibitor, since it does not
always mean a therapeutic antitumor strategy.
PMID: 15289832 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/1733098 | 1. Virology. 1992 Feb;186(2):481-8. doi: 10.1016/0042-6822(92)90013-f.
Characterization of RNAs specific to avocado sunblotch viroid synthesized in
vitro by a cell-free system from infected avocado leaves.
Marcos JF(1), Flores R.
Author information:
(1)Unidad de Biología Molecular y Celular de Plantas, Instituto de Agroquímica y
Tecnología de Alimentos (CSIC), Valencia, Spain.
Analysis by molecular hybridization of the RNAs transcribed by a cell-free
fraction from avocado infected with avocado sunblotch viroid (ASBV) demonstrated
the presence of newly synthesized viroid-specific sequences, most of which were
of the same polarity as the mature infectious viroid RNA. Treatment of the
cell-free fraction with DNase reduced the total synthesis of RNA considerably,
but it did not influence that of the ASBV-specific RNAs, indicating that the
latter were transcribed on an RNA template. Inhibition studies with
alpha-amanitin showed that the synthesis of ASBV-specific RNAs was not affected
by concentrations of 1 and 200 micrograms/ml of the drug, which typically
inhibit RNA polymerase II and III, respectively, from most animal and plant
systems. These results suggest that either RNA polymerase I or an unidentified
RNA polymerase activity resistant to alpha-amanitin, acting on an RNA template,
plays a role in the replication of ASBV, whereas for the rest of the viroids
studied so far it appears that RNA polymerase II is involved. Analysis by
polycrylamide gel electrophoresis under partially and fully denaturing
conditions of the ASBV-specific RNAs synthesized in vitro showed that they
contain unit and longer than unit length viroid strands, probably associated in
complexes with single- and double-stranded regions. The structural properties of
these complexes are similar to those of the RNAs accumulating in vivo in
viroid-infected tissues, which are the postulated replicative intermediates of
the rolling-circle mechanism proposed for viroid synthesis.
DOI: 10.1016/0042-6822(92)90013-f
PMID: 1733098 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/14742272 | 1. Am J Pathol. 2004 Feb;164(2):689-99. doi: 10.1016/S0002-9440(10)63156-2.
Increased DNA methyltransferase 1 (DNMT1) protein expression correlates
significantly with poorer tumor differentiation and frequent DNA
hypermethylation of multiple CpG islands in gastric cancers.
Etoh T(1), Kanai Y, Ushijima S, Nakagawa T, Nakanishi Y, Sasako M, Kitano S,
Hirohashi S.
Author information:
(1)Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
We evaluated the significance of aberrant DNA methyltransferase 1 (DNMT1)
protein expression during gastric carcinogenesis. The protein expression of
DNMT1, Muc2, human gastric mucin, E-cadherin, and proliferating cell nuclear
antigen was examined immunohistochemically in gastric cancers and corresponding
noncancerous mucosae from 134 patients. The DNA methylation status of the CpG
islands of the p16, human MutL homologue 1 (hMLH1), E-cadherin, and
thrombospondin-1 (THBS-1) genes and the methylated in tumor (MINT)-1, -2, -12,
and -31 clones was examined by methylation-specific polymerase chain reaction
and combined bisulfite restriction enzyme analysis. Epstein-Barr virus (EBV)
infection was detected by in situ hybridization. Nuclear immunoreactivity for
DNMT1 was not detected in any of the noncancerous epithelia, except in
proliferative zones (positive internal control), but was found in 97 (72%) of
the gastric cancers. DNMT1 overexpression correlated significantly with poorer
tumor differentiation (P < 0.001), but not with the phenotype (gastric type
versus intestinal type) of the cancer cells. It also correlated significantly
with DNA hypermethylation of the CpG islands of the hMLH1 (P = 0.024) and THBS-1
genes (P = 0.043), and with the CpG island methylator phenotype in the gastric
cancers (P = 0.007). Reduced E-cadherin expression correlated significantly with
poorer tumor differentiation (P = 0.002), DNA hypermethylation of the E-cadherin
gene (P < 0.001) and DNMT1 overexpression (P = 0.014). DNMT1 overexpression was
also associated with EBV infection (a potential etiological factor in gastric
carcinogenesis) but not with the proliferative activity of the cancer cells as
indicated by the proliferating cell nuclear antigen-labeling index. These
results suggest that DNMT1 overexpression may not be just a secondary effect of
increased cancer cell proliferative activity, but may be associated with EBV
infection and other etiological factors during gastric carcinogenesis.
Furthermore, DNMT1 may play a significant role in the development of poorly
differentiated gastric cancers by inducing frequent DNA hypermethylation of
multiple CpG islands.
DOI: 10.1016/S0002-9440(10)63156-2
PMCID: PMC1602280
PMID: 14742272 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/3133104 | 1. Cancer Genet Cytogenet. 1988 Jul 15;33(2):175-83. doi:
10.1016/0165-4608(88)90027-1.
Fanconi's anemia--chromosome breakage studies in homozygotes and heterozygotes.
Rosendorff J(1), Bernstein R.
Author information:
(1)Department of Human Genetics, School of Pathology, South African Institute
for Medical Research, Johannesburg.
The in vitro enhancement of chromosome breakage by diepoxybutane (DEB) and
mitomycin C (MMC) was studied in 24 Fanconi's anemia (FA) homozygotes and 28
heterozygotes. Both drugs were shown to enhance chromosome breakage
significantly in the homozygotes. In the great majority of cases, DEB and MMC
stressing are reliable techniques for the definitive cytogenetic diagnosis of FA
homozygosity. However, the present study provides no evidence that individual FA
heterozygotes can be differentiated from normal individuals on the basis of
spontaneous, DEB- or MMC-induced chromosome breakage.
DOI: 10.1016/0165-4608(88)90027-1
PMID: 3133104 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/15831539 | 1. J Physiol. 2005 Jun 15;565(Pt 3):731-41. doi: 10.1113/jphysiol.2004.081620.
Epub 2005 Apr 14.
In vivo and in vitro functional characterization of Andersen's syndrome
mutations.
Bendahhou S(1), Fournier E, Sternberg D, Bassez G, Furby A, Sereni C, Donaldson
MR, Larroque MM, Fontaine B, Barhanin J.
Author information:
(1)Université de Nice Sophia Antipolis, UMR 6097 CNRS, Institut de Pharmacologie
Moléculaire et Cellulaire, 660 Route des Lucioles, Sophia-Antipolis, 06560
Valbonne, France. [email protected]
The inward rectifier K(+) channel Kir2.1 carries all Andersen's syndrome
mutations identified to date. Patients exhibit symptoms of periodic paralysis,
cardiac dysrhythmia and multiple dysmorphic features. Here, we report the
clinical manifestations found in three families with Andersen's syndrome.
Molecular genetics analysis identified two novel missense mutations in the KCNJ2
gene leading to amino acid changes C154F and T309I of the Kir2.1 open reading
frame. Patch clamp experiments showed that the two mutations produced a loss of
channel function. When co-expressed with Kir2.1 wild-type (WT) channels, both
mutations exerted a dominant-negative effect leading to a loss of the inward
rectifying K(+) current. Confocal microscopy imaging in HEK293 cells is
consistent with a co-assembly of the EGFP-fused mutant proteins with WT channels
and proper traffick to the plasma membrane to produce silent channels alone or
as hetero-tetramers with WT. Functional expression in C2C12 muscle cell line of
newly as well as previously reported Andersen's syndrome mutations confirmed
that these mutations act through a dominant-negative effect by altering channel
gating or trafficking. Finally, in vivo electromyographic evaluation showed a
decrease in muscle excitability in Andersen's syndrome patients. We hypothesize
that Andersen's syndrome-associated mutations and hypokalaemic periodic
paralysis-associated calcium channel mutations may lead to muscle membrane
hypoexcitability via a common mechanism.
DOI: 10.1113/jphysiol.2004.081620
PMCID: PMC1464553
PMID: 15831539 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/20609799 | 1. Ann Thorac Surg. 2010 Jul;90(1):285-7. doi: 10.1016/j.athoracsur.2009.12.045.
Cardiac surgery for a patient with Andersen-Tawil syndrome.
Nagashima M(1), Higaki T, Seike Y, Yokoyama Y.
Author information:
(1)Department of Cardiovascular Surgery, Ehime Prefectural Central Hospital,
Matsuyama City, Ehime, Japan. [email protected]
Andersen-Tawil syndrome is an uncommon inherited autosomal disorder
characterized by a prolonged QT interval, periodic paralysis, and dysmorphic
features. The deleterious effects of cardioplegia on periodic paralysis and
cardiac arrhythmia are unknown, and no studies have reported the performance of
cardiac surgery in patients with Andersen-Tawil syndrome. We present a case of
successful cardiac surgery in a patient with Andersen-Tawil syndrome, without
using cardioplegia.
Copyright 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All
rights reserved.
DOI: 10.1016/j.athoracsur.2009.12.045
PMID: 20609799 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/25352393 | 1. Drugs. 2014 Nov;74(17):2065-78. doi: 10.1007/s40265-014-0317-2.
Riociguat: a review of its use in patients with chronic thromboembolic pulmonary
hypertension or pulmonary arterial hypertension.
Garnock-Jones KP(1).
Author information:
(1)Springer, Private Bag 65901, Mairangi Bay, 0754, Auckland, New Zealand,
[email protected].
Riociguat (Adempas(®)), a soluble guanylate cyclase stimulator, is a new,
first-in-class drug approved for the treatment of patients with chronic
thromboembolic pulmonary hypertension (CTEPH) [inoperable or
persistent/recurrent following surgery] or pulmonary arterial hypertension
(PAH). It has been designated an orphan medicine by the European Medicines
Agency and the US FDA. This article reviews the available pharmacological
properties of oral riociguat and its clinical efficacy and tolerability in
adults with CTEPH or PAH. Riociguat is effective and well tolerated in patients
with inoperable CTEPH or persistent/recurrent CTEPH following pulmonary
endarterectomy, and in patients with PAH. It has a positive result on exercise
capacity and pulmonary haemodynamics, and improves WHO functional class. Most
adverse events can be attributed to the vasodilatory mechanism of riociguat;
however, there is a potential for serious bleeding and fetal harm, and riociguat
use is contraindicated in pregnant patients. Pulmonary endarterectomy remains
the first treatment of choice for CTEPH, as it is potentially curative.
Head-to-head trials comparing riociguat with the approved phosphodiesterase type
5 inhibitors in patients with PAH would be of value for the placement of
riociguat in the management of this disease. Riociguat is a promising addition
to the treatment options for patients with CTEPH or PAH.
DOI: 10.1007/s40265-014-0317-2
PMID: 25352393 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24253240 | 1. Toxins (Basel). 2013 Nov 18;5(11):2212-26. doi: 10.3390/toxins5112212.
A monoclonal antibody based capture ELISA for botulinum neurotoxin serotype B:
toxin detection in food.
Stanker LH(1), Scotcher MC, Cheng L, Ching K, McGarvey J, Hodge D, Hnasko R.
Author information:
(1)Foodborne Toxin Detection and Prevention Unit, United States Department of
Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA
94510, USA. [email protected].
Botulism is a serious foodborne neuroparalytic disease, caused by botulinum
neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum.
Seven toxin serotypes (A-H) have been described. The majority of human cases of
botulism are caused by serotypes A and B followed by E and F. We report here a
group of serotype B specific monoclonal antibodies (mAbs) capable of binding
toxin under physiological conditions. Thus, they serve as capture antibodies for
a sandwich (capture) ELISA. The antibodies were generated using recombinant
peptide fragments corresponding to the receptor-binding domain of the toxin
heavy chain as immunogen. Their binding properties suggest that they bind a
complex epitope with dissociation constants (KD's) for individual antibodies
ranging from 10 to 48 × 10-11 M. Assay performance for all possible combinations
of capture-detector antibody pairs was evaluated and the antibody pair resulting
in the lowest level of detection (L.O.D.), ~20 pg/mL was determined. Toxin was
detected in spiked dairy samples with good recoveries at concentrations as low
as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the
sandwich ELISA described here uses mAb for both the capture and detector
antibodies (binding different epitopes on the toxin molecule) and readily
detects toxin in those food samples tested.
DOI: 10.3390/toxins5112212
PMCID: PMC3847722
PMID: 24253240 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24524094 | 1. Drugs Today (Barc). 2013 Dec;49(12):761-8. doi:
10.1358/dot.2013.49.12.2086995.
Riociguat for the management of pulmonary arterial hypertension and chronic
thromboembolic pulmonary hypertension.
Larche NE(1), Mousa SA(2).
Author information:
(1)The Pharmaceutical Research Institute, Albany College of Pharmacy and Health
Sciences, Rensselaer, New York, USA.
(2)The Pharmaceutical Research Institute, Albany College of Pharmacy and Health
Sciences, Rensselaer, New York, USA. [email protected].
Pulmonary hypertension (PH) is a progressive disease that is accompanied by a
poor prognosis. Pulmonary vasoconstriction is facilitated through multiple
pathways and results in increased pulmonary vascular pressure leading to cell
proliferation, vascular remodeling, right ventricular hypertrophy/failure, and
ultimately death. Until recently, just six medications were approved -all for
one subclass of PH. On October 8, 2013, riociguat (Adempas®) became the first
medication approved for multiple etiologies of PH. Preclinical studies have
demonstrated safety and efficacy with significant clinical trials supporting its
advancement into phase IV trials. Although long-term safety and efficacy and
place in therapy remain to be established, riociguat presents as an exciting new
option for the treatment of PH and potentially has additional indications in the
near future.
Copyright 2013 Prous Science, S.A.U. or its licensors. All rights reserved.
DOI: 10.1358/dot.2013.49.12.2086995
PMID: 24524094 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24391396 | 1. P T. 2013 Dec;38(12):747-54.
Pharmaceutical approval update.
Goldenberg MM.
Duavee, an oral contraceptive; riociguat (Adempas) for two types of pulmonary
hypertension; and macitentan (Opsumit) for pulmonary arterial hypertension.
PMCID: PMC3875264
PMID: 24391396 |
http://www.ncbi.nlm.nih.gov/pubmed/23229562 | 1. J Cardiovasc Transl Res. 2013 Feb;6(1):22-30. doi: 10.1007/s12265-012-9423-2.
Epub 2012 Nov 15.
A review of human pluripotent stem cell-derived cardiomyocytes for
high-throughput drug discovery, cardiotoxicity screening, and publication
standards.
Mordwinkin NM(1), Burridge PW, Wu JC.
Author information:
(1)Department of Medicine (Division of Cardiology), Stanford University, 265
Campus Drive G1120B, Stanford, CA, 94305-5454, USA.
Drug attrition rates have increased in past years, resulting in growing costs
for the pharmaceutical industry and consumers. The reasons for this include the
lack of in vitro models that correlate with clinical results and poor
preclinical toxicity screening assays. The in vitro production of human cardiac
progenitor cells and cardiomyocytes from human pluripotent stem cells provides
an amenable source of cells for applications in drug discovery, disease
modeling, regenerative medicine, and cardiotoxicity screening. In addition, the
ability to derive human-induced pluripotent stem cells from somatic tissues,
combined with current high-throughput screening and pharmacogenomics, may help
realize the use of these cells to fulfill the potential of personalized
medicine. In this review, we discuss the use of pluripotent stem cell-derived
cardiomyocytes for drug discovery and cardiotoxicity screening, as well as
current hurdles that must be overcome for wider clinical applications of this
promising approach.
DOI: 10.1007/s12265-012-9423-2
PMCID: PMC3556463
PMID: 23229562 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/25274302 | 1. Nature. 2014 Dec 11;516(7530):263-6. doi: 10.1038/nature13769. Epub 2014 Sep
28.
Programmable RNA recognition and cleavage by CRISPR/Cas9.
O'Connell MR(1), Oakes BL(1), Sternberg SH(2), East-Seletsky A(1), Kaplan M(3),
Doudna JA(4).
Author information:
(1)Department of Molecular and Cell Biology, University of California, Berkeley,
California 94720, USA.
(2)Department of Chemistry, University of California, Berkeley, California
94720, USA.
(3)1] Howard Hughes Medical Institute, University of California, Berkeley,
California 94720, USA [2] Department of Agricultural and Biological Engineering,
University of Florida, Gainesville, Florida 32611, USA.
(4)1] Department of Molecular and Cell Biology, University of California,
Berkeley, California 94720, USA [2] Department of Chemistry, University of
California, Berkeley, California 94720, USA [3] Howard Hughes Medical Institute,
University of California, Berkeley, California 94720, USA [4] Physical
Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley,
California 94720, USA.
Comment in
Nat Methods. 2014 Nov;11(11):1090. doi: 10.1038/nmeth.3164.
The CRISPR-associated protein Cas9 is an RNA-guided DNA endonuclease that uses
RNA-DNA complementarity to identify target sites for sequence-specific
double-stranded DNA (dsDNA) cleavage. In its native context, Cas9 acts on DNA
substrates exclusively because both binding and catalysis require recognition of
a short DNA sequence, known as the protospacer adjacent motif (PAM), next to and
on the strand opposite the twenty-nucleotide target site in dsDNA. Cas9 has
proven to be a versatile tool for genome engineering and gene regulation in a
large range of prokaryotic and eukaryotic cell types, and in whole organisms,
but it has been thought to be incapable of targeting RNA. Here we show that Cas9
binds with high affinity to single-stranded RNA (ssRNA) targets matching the
Cas9-associated guide RNA sequence when the PAM is presented in trans as a
separate DNA oligonucleotide. Furthermore, PAM-presenting oligonucleotides
(PAMmers) stimulate site-specific endonucleolytic cleavage of ssRNA targets,
similar to PAM-mediated stimulation of Cas9-catalysed DNA cleavage. Using
specially designed PAMmers, Cas9 can be specifically directed to bind or cut RNA
targets while avoiding corresponding DNA sequences, and we demonstrate that this
strategy enables the isolation of a specific endogenous messenger RNA from
cells. These results reveal a fundamental connection between PAM binding and
substrate selection by Cas9, and highlight the utility of Cas9 for programmable
transcript recognition without the need for tags.
DOI: 10.1038/nature13769
PMCID: PMC4268322
PMID: 25274302 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/8052312 | 1. Nature. 1994 Aug 18;370(6490):571-5. doi: 10.1038/370571a0.
Crystal structure of Yersinia protein tyrosine phosphatase at 2.5 A and the
complex with tungstate.
Stuckey JA(1), Schubert HL, Fauman EB, Zhang ZY, Dixon JE, Saper MA.
Author information:
(1)Department of Biological Chemistry, University of Michigan, Ann Arbor
48109-1055.
Comment in
Nature. 1994 Aug 18;370(6490):506-7. doi: 10.1038/370506a0.
Protein tyrosine phosphatases (PTPases) and kinases coregulate the critical
levels of phosphorylation necessary for intracellular signalling, cell growth
and differentiation. Yersinia, the causative bacteria of the bubonic plague and
other enteric diseases, secrete an active PTPase, Yop51, that enters and
suppresses host immune cells. Though the catalytic domain is only approximately
20% identical to human PTP1B, the Yersinia PTPase contains all of the invariant
residues present in eukaryotic PTPases, including the nucleophilic Cys 403 which
forms a phosphocysteine intermediate during catalysis. We present here
structures of the unliganded (2.5 A resolution) and tungstate-bound (2.6 A)
crystal forms which reveal that Cys 403 is positioned at the centre of a
distinctive phosphate-binding loop. This loop is at the hub of several
hydrogen-bond arrays that not only stabilize a bound oxyanion, but may activate
Cys 403 as a reactive thiolate. Binding of tungstate triggers a conformational
change that traps the oxyanion and swings Asp 356, an important catalytic
residue, by approximately 6 A into the active site. The same anion-binding loop
in PTPases is also found in the enzyme rhodanese.
DOI: 10.1038/370571a0
PMID: 8052312 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24244333 | 1. PLoS One. 2013 Nov 11;8(11):e78648. doi: 10.1371/journal.pone.0078648.
eCollection 2013.
Profiling of Parkin-binding partners using tandem affinity purification.
Zanon A(1), Rakovic A, Blankenburg H, Doncheva NT, Schwienbacher C, Serafin A,
Alexa A, Weichenberger CX, Albrecht M, Klein C, Hicks AA, Pramstaller PP,
Domingues FS, Pichler I.
Author information:
(1)Center for Biomedicine, European Academy Bozen/Bolzano (EURAC), Bolzano,
Italy, Affiliated Institute of the University of Lübeck, Lübeck, Germany.
Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting
approximately 1-2% of the general population over age 60. It is characterized by
a rather selective loss of dopaminergic neurons in the substantia nigra and the
presence of α-synuclein-enriched Lewy body inclusions. Mutations in the Parkin
gene (PARK2) are the major cause of autosomal recessive early-onset
parkinsonism. The Parkin protein is an E3 ubiquitin ligase with various cellular
functions, including the induction of mitophagy upon mitochondrial
depolarizaton, but the full repertoire of Parkin-binding proteins remains poorly
defined. Here we employed tandem affinity purification interaction screens with
subsequent mass spectrometry to profile binding partners of Parkin. Using this
approach for two different cell types (HEK293T and SH-SY5Y neuronal cells), we
identified a total of 203 candidate Parkin-binding proteins. For the candidate
proteins and the proteins known to cause heritable forms of parkinsonism,
protein-protein interaction data were derived from public databases, and the
associated biological processes and pathways were analyzed and compared.
Functional similarity between the candidates and the proteins involved in
monogenic parkinsonism was investigated, and additional confirmatory evidence
was obtained using published genetic interaction data from Drosophila
melanogaster. Based on the results of the different analyses, a prioritization
score was assigned to each candidate Parkin-binding protein. Two of the top
ranking candidates were tested by co-immunoprecipitation, and interaction to
Parkin was confirmed for one of them. New candidates for involvement in cell
death processes, protein folding, the fission/fusion machinery, and the
mitophagy pathway were identified, which provide a resource for further
elucidating Parkin function.
DOI: 10.1371/journal.pone.0078648
PMCID: PMC3823883
PMID: 24244333 [Indexed for MEDLINE]
Conflict of interest statement: Competing Interests: The authors have read the
journal's policy and have the following conflicts: Peter P. Pramstaller received
honoraria for serving on scientific boards and speaking from Novartis,
Boehringer, GlaxoSmithKline, Lundbeck and UCB. Christine Klein is a member of
the editorial board of “Neurology” and has served as editor of the “Continuum
Issue Neurogenetics 2008” and as faculty at the Annual Meetings of the American
Academy of Neurology since 2004. She is a consultant to Centogene and received
honoraria for speaking from Boehringer Ingelheim and Orion Pharma. Dr. Klein is
the recipient of a career development award from the Hermann and Lilly Schilling
Foundation. She is funded by the Volkswagen Foundation, the Deutsche
Forschungsgemeinschaft, the Possehl Foundation and received institutional
support from the University of Luebeck for genetics research. This does not
alter the authors' adherence to all the PLOS ONE policies on sharing data and
materials. Also, the current affiliation of Adrian Alexa, one of the co-authors
of the paper, to Illumina, Cambridge Ltd, UK (stated on the first page of the
manuscript) does not alter the authors' adherence to all the PLOS ONE policies
on sharing data and materials. |
http://www.ncbi.nlm.nih.gov/pubmed/25398342 | 1. Methods Enzymol. 2014;546:193-213. doi: 10.1016/B978-0-12-801185-0.00010-6.
Adapting CRISPR/Cas9 for functional genomics screens.
Malina A(1), Katigbak A(1), Cencic R(1), Maïga RI(1), Robert F(1), Miura H(1),
Pelletier J(2).
Author information:
(1)Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
(2)Department of Biochemistry, McGill University, Montreal, Quebec, Canada;
Department of Oncology, McGill University, Montreal, Quebec, Canada; The
Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal,
Quebec, Canada. Electronic address: [email protected].
The use of CRISPR/Cas9 (clustered regularly interspaced short palindromic
repeats/CRISPR-associated protein) for targeted genome editing has been widely
adopted and is considered a "game changing" technology. The ease and rapidity by
which this approach can be used to modify endogenous loci in a wide spectrum of
cell types and organisms makes it a powerful tool for customizable genetic
modifications as well as for large-scale functional genomics. The development of
retrovirus-based expression platforms to simultaneously deliver the Cas9
nuclease and single guide (sg) RNAs provides unique opportunities by which to
ensure stable and reproducible expression of the editing tools and a broad cell
targeting spectrum, while remaining compatible with in vivo genetic screens.
Here, we describe methods and highlight considerations for designing and
generating sgRNA libraries in all-in-one retroviral vectors for such
applications.
DOI: 10.1016/B978-0-12-801185-0.00010-6
PMID: 25398342 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24085367 | 1. Dtsch Med Wochenschr. 2013 Oct;138(41):2104-6. doi: 10.1055/s-0033-1349501.
Epub 2013 Oct 1.
[Chemotherapy-free treatment of chronic lymphocytic leukemia?].
[Article in German]
Wendtner CM(1).
Author information:
(1)Klinikum Schwabing, Klinik für Hämatologie, Onkologie, Immunologie,
Palliativmedizin, Infektiologie und Tropenmedizin, Akademisches Lehrkrankenhaus
der Ludwig-Maximilians- Universität München.
Treatment of CLL patients with conventional cytotoxic agents is often combined
with significant toxicity that prevents broad application especially in elderly
patients. In addition, relapse frequently occurs after application of
conventional chemotherapy in CLL. Recently several new chemo-free treatment
options have been introduced within clinical trials. Among them are monoclonal
antibodies, most of them targeting the CD20 molecule: besides the licensed drugs
rituximab and ofatumumab obinutuzumab, although in combination with
chemotherapy, has recently shown high clinical efficacy in front-line treatment
of elderly patients with CLL. Lenalidomide as monotherapy has demonstrated
clinical efficacy in patients with relapsed disease and first data within
clinical trials have been generated in the front-line setting. A promising class
of novel agents has been designed to block aberrant signaling from the B-cell
receptor. Ibrutinib acts by inhibiting the Bruton's tyrosine kinase (BTK) while
idelalisib represents a first-in-class specific inhibitor of the
phosphoinositol-3 kinase (PI3K) delta isoform. Another class of drugs with
potential impact for chemo-free treatment strategies in CLL are the BH3-mimetic
inhibitors of the Bcl-2 family of pro-survival proteins. Other interesting
candidate drugs that are currently explored for CLL patients include small
modular immunopharmaceutical (SMIP) proteins (e. g. TRU-016), CDK inhibitors (e.
g. dinaciclib), HDAC inhibitors and others. Given all these novel agents and
targets, chemo-free or at least chemo-reduced concepts may become reality in the
near future for our patients suffering from CLL.
© Georg Thieme Verlag KG Stuttgart · New York.
DOI: 10.1055/s-0033-1349501
PMID: 24085367 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/25395817 | 1. P T. 2014 Nov;39(11):749-58.
Riociguat (adempas): a novel agent for the treatment of pulmonary arterial
hypertension and chronic thromboembolic pulmonary hypertension.
Khaybullina D, Patel A, Zerilli T.
Riociguat (Adempas): a novel agent for the treatment of pulmonary arterial
hypertension and chronic thromboembolic pulmonary hypertension.
PMCID: PMC4218670
PMID: 25395817 |
http://www.ncbi.nlm.nih.gov/pubmed/24009233 | 1. Blood. 2013 Nov 7;122(19):3308-16. doi: 10.1182/blood-2013-05-504597. Epub
2013 Sep 5.
Lymphocyte cytosolic protein 1 is a chronic lymphocytic leukemia
membrane-associated antigen critical to niche homing.
Dubovsky JA(1), Chappell DL, Harrington BK, Agrawal K, Andritsos LA, Flynn JM,
Jones JA, Paulaitis ME, Bolon B, Johnson AJ, Byrd JC, Muthusamy N.
Author information:
(1)Division of Hematology, Department of Internal Medicine.
Comment in
Blood. 2013 Nov 7;122(19):3241-2. doi: 10.1182/blood-2013-09-526376.
Membrane antigens are critical to the pathogenesis of chronic lymphocytic
leukemia (CLL) as they facilitate microenvironment homing, proliferation, and
survival. Targeting the CLL membrane and associated signaling patterns is a
current focus of therapeutic development. Many tumor membrane targets are
simultaneously targeted by humoral immunity, thus forming recognizable
immunoglobulin responses. We sought to use this immune response to identify
novel membrane-associated targets for CLL. Using a novel strategy, we
interrogated CLL membrane-specific autologous immunoglobulin G reactivity. Our
analysis unveiled lymphocyte cytosolic protein 1 (LCP1), a lymphocyte-specific
target that is highly expressed in CLL. LCP1 plays a critical role in B-cell
biology by crosslinking F-actin filaments, thereby solidifying cytoskeletal
structures and providing a scaffold for critical signaling pathways. Small
interfering RNA knockdown of LCP1 blocked migration toward CXCL12 in transwell
assays and to bone marrow in an in vivo xenotransplant model, confirming a role
for LCP1 in leukemia migration. Furthermore, we demonstrate that the Bruton's
tyrosine kinase inhibitor ibrutinib or the PI3K inhibitor idelalisib block
B-cell receptor induced activation of LCP1. Our data demonstrate a novel
strategy to identify cancer membrane target antigens using humoral anti-tumor
immunity. In addition, we identify LCP1 as a membrane-associated target in CLL
with confirmed pathogenic significance. This clinical trial was registered at
clinicaltrials.gov; study ID number: OSU-0025 OSU-0156.
DOI: 10.1182/blood-2013-05-504597
PMCID: PMC3953089
PMID: 24009233 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22488303 | 1. Pharmacotherapy. 2012 May;32(5):408-19. doi: 10.1002/j.1875-9114.2012.01029.x.
Epub 2012 Apr 9.
Evaluation of vancomycin dosing regimens in preterm and term neonates using
Monte Carlo simulations.
Mehrotra N(1), Tang L, Phelps SJ, Meibohm B.
Author information:
(1)Department of Pharmaceutical Sciences, College of Pharmacy, University of
Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
Comment in
Pharmacotherapy. 2012 Sep;32(9):e174; discussion e175. doi:
10.1002/j.1875-9114.2012.01180.x.
STUDY OBJECTIVE: To compare four common dosing regimens for vancomycin in
preterm and term neonates by assessing the probability that each regimen would
achieve the widely used therapeutic target serum trough concentrations of 5-15
mg/L and the newly suggested target of 15-20 mg/L.
DESIGN: Retrospective population pharmacokinetic analysis using therapeutic drug
monitoring data obtained from 1990-2007, with a subsequent simulation study
performed on the pharmacokinetic model.
SETTING: Tertiary-care children's hospital.
PATIENTS: One hundred thirty-four preterm (66%) and term (34%) neonates, with a
postnatal age of 1-121 days and postmenstrual age of 24.6-44 weeks.
MEASUREMENTS AND MAIN RESULTS: Therapeutic drug monitoring data for vancomycin
were used to develop a population pharmacokinetic model in the target
population. Parameter estimates for the derived pharmacostatistical model were
used to perform Monte Carlo simulations for four recommended dosing regimens: a
standard dose for all neonates, postmenstrual age-based dosing, postmenstrual
and postnatal age-based dosing, and serum creatinine-based dosing. Multivariate
age-weight distributions were established for term and preterm neonates using
Centers for Disease Control and Prevention growth charts and intrauterine and
postnatal growth charts from the literature, respectively. Each dosing regimen
was treated as a separate scenario in which 200 replicates with 100
patients/replicate were simulated. The 5-15-mg/L target trough serum
concentration was achieved in 34% (90% confidence interval [CI] 20-53%), 42%
(90% CI 31-55%), 52% (90% CI 43-60%), and 63% (90% CI 54-72%) of patients
receiving the standard dose, postmenstrual age-based dose, postmenstrual and
postnatal age-based dose, and serum creatinine-based dose, respectively. Serum
creatinine-based dosing produced trough concentrations predominantly in the
5-15-mg/L target range, with the smallest variability in both term and preterm
neonates. As expected, when the target range was narrow and higher (15-20 mg/L),
only 13-21% of patients were within the range across the four dosing regimens.
CONCLUSION: Monte Carlo simulations based on our population pharmacokinetic
model suggest that vancomycin dosing guidelines based on serum creatinine
concentration have a greater likelihood of achieving trough concentrations in
the 5-15-mg/L range compared with other evaluated dosing regimens. None of the
four dosing regimens is suitable to produce target trough concentration of 15-20
mg/L in an acceptable number of patients.
© 2012 Pharmacotherapy Publications, Inc.
DOI: 10.1002/j.1875-9114.2012.01029.x
PMID: 22488303 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21989257 | 1. Mol Pharmacol. 2012 Jan;81(1):53-62. doi: 10.1124/mol.111.074740. Epub 2011
Oct 11.
Designing calcium release channel inhibitors with enhanced electron donor
properties: stabilizing the closed state of ryanodine receptor type 1.
Ye Y(1), Yaeger D, Owen LJ, Escobedo JO, Wang J, Singer JD, Strongin RM,
Abramson JJ.
Author information:
(1)Department of Physics, Portland State University, Portland, Oregon 97207,
USA.
New drugs with enhanced electron donor properties that target the ryanodine
receptor from skeletal muscle sarcoplasmic reticulum (RyR1) are shown to be
potent inhibitors of single-channel activity. In this article, we synthesize
derivatives of the channel activator 4-chloro-3-methyl phenol (4-CmC) and the
1,4-benzothiazepine channel inhibitor 4-[-3{1-(4-benzyl)
piperidinyl}propionyl]-7-methoxy-2,3,4,5-tetrahydro-1,4-benzothiazepine (K201,
JTV519) with enhanced electron donor properties. Instead of activating channel
activity (~100 μM), the 4-methoxy analog of 4-CmC [4-methoxy-3-methyl phenol
(4-MmC)] inhibits channel activity at submicromolar concentrations (IC(50) =
0.34 ± 0.08 μM). Increasing the electron donor characteristics of K201 by
synthesizing its dioxole congener results in an approximately 16 times more
potent RyR1 inhibitor (IC(50) = 0.24 ± 0.05 μM) compared with K201 (IC(50) =
3.98 ± 0.79 μM). Inhibition is not caused by an increased closed time of the
channel but seems to be caused by an open state block of RyR1. These alterations
to chemical structure do not influence the ability of these drugs to affect
Ca(2+)-dependent ATPase activity of sarcoplasmic/endoplasmic reticulum
Ca(2+)-ATPase type 1. Moreover, the FKBP12 protein, which stabilizes RyR1 in a
closed configuration, is shown to be a strong electron donor. It seems as if
FKBP12, K201, its dioxole derivative, and 4-MmC inhibit RyR1 channel activity by
virtue of their electron donor characteristics. These results embody strong
evidence that designing new drugs to target RyR1 with enhanced electron donor
characteristics results in more potent channel inhibitors. This is a novel
approach to the design of new, more potent drugs with the aim of functionally
modifying RyR1 single-channel activity.
DOI: 10.1124/mol.111.074740
PMCID: PMC3250111
PMID: 21989257 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/11077457 | 1. Epilepsia. 2000 Nov;41(11):1436-43. doi: 10.1111/j.1528-1157.2000.tb00119.x.
Teratogenic effects of antiepileptic drugs: use of an International Database on
Malformations and Drug Exposure (MADRE).
Arpino C(1), Brescianini S, Robert E, Castilla EE, Cocchi G, Cornel MC, de Vigan
C, Lancaster PA, Merlob P, Sumiyoshi Y, Zampino G, Renzi C, Rosano A,
Mastroiacovo P.
Author information:
(1)International Centre for Birth Defects, Rome, Italy.
PURPOSE: The study goal was to assess teratogenic effects of antiepileptic drugs
(AEDs) through the use of a surveillance system (MADRE) of infants with
malformations.
METHODS: Information on all malformed infants (1990-1996) with maternal
first-trimester drug exposure was collected by the International Clearinghouse
for Birth Defects and Monitoring Systems (ICBDMS). Cases were defined as infants
presenting with a specific malformation, and controls were defined as infants
presenting with any other birth defect. Exposure was defined by the use of AEDs
during the first trimester of pregnancy. The association of AEDs with
malformations was then estimated by calculating the odds ratios with 95%
confidence intervals and testing their homogeneity among registries.
RESULTS: Among 8005 cases of malformations, 299 infants were exposed in utero to
AEDs. Of those exposed to monotherapy, 65 were exposed to phenobarbital, 10 to
methylphenobarbital, 80 to valproic acid, 46 to carbamazepine, 24 to phenytoin,
and 16 to other AEDs. Associations were found for spina bifida with valproic
acid. Infants exposed to phenobarbital and to methylphenobarbital showed an
increased risk of oral clefts. Cardiac malformations were found to be associated
with phenobarbital, methylphenobarbital, valproic acid, and carbamazepine.
Hypospadias was associated with valproic acid. Porencephaly and other specified
anomalies of brain, anomalies of face, coarctation of aorta, and limb reduction
defects were found to be associated with valproic acid.
CONCLUSIONS: Using the MADRE system, we confirmed known teratogenic effects of
AEDs. We also found increased risks for malformations that had never been
reported associated with AEDs or for which the association was suggested by case
reports.
DOI: 10.1111/j.1528-1157.2000.tb00119.x
PMID: 11077457 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/20064468 | 1. Mol Cell. 2009 Dec 25;36(6):1034-47. doi: 10.1016/j.molcel.2009.11.021.
SH3 domains from a subset of BAR proteins define a Ubl-binding domain and
implicate parkin in synaptic ubiquitination.
Trempe JF(1), Chen CX, Grenier K, Camacho EM, Kozlov G, McPherson PS, Gehring K,
Fon EA.
Author information:
(1)Department of Biochemistry, McGill University, Montréal, Québec, Canada.
Mutations in the parkin gene are responsible for a common inherited form of
Parkinson's disease (PD). Parkin is a RING-type E3 ubiquitin ligase with an
N-terminal ubiquitin-like domain (Ubl). We report here that the parkin Ubl binds
SH3 domains from endocytic BAR proteins such as endophilin-A with an affinity
comparable to proline-rich domains (PRDs) from well-established SH3 partners.
The NMR structure of the Ubl-SH3 complex identifies the PaRK extension, a unique
C-terminal motif in the parkin Ubl required for SH3 binding and for
parkin-mediated ubiquitination of endophilin-A in vitro. In nerve terminals,
conditions that promote phosphorylation enhance the interaction between parkin
and endophilin-A and increase the levels of ubiquitinated proteins within
PRD-associated synaptic protein complexes in wild-type but not parkin knockout
brain. The findings identify a pathway for the recruitment of synaptic
substrates to parkin with the potential to explain the defects in synaptic
transmission observed in recessive forms of PD.
2009 Elsevier Inc.
DOI: 10.1016/j.molcel.2009.11.021
PMID: 20064468 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/21766433 | 1. Am J Med Genet C Semin Med Genet. 2011 Aug 15;157C(3):234-46. doi:
10.1002/ajmg.c.30306. Epub 2011 Jul 15.
Influencing clinical practice regarding the use of antiepileptic medications
during pregnancy: modeling the potential impact on the prevalences of spina
bifida and cleft palate in the United States.
Gilboa SM(1), Broussard CS, Devine OJ, Duwe KN, Flak AL, Boulet SL, Moore CA,
Werler MM, Honein MA.
Author information:
(1)National Center on Birth Defects and Developmental Disabilities, Centers for
Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA.
[email protected]
Selected antiepileptic drugs (AEDs) increase the risk of birth defects. To
assess the impact of influencing AED prescribing practices on spina bifida and
cleft palate we searched the literature for estimates of the association between
valproic acid or carbamazepine use during pregnancy and these defects and
summarized the associations using meta-analyses. We estimated distributions of
the prevalence of valproic acid and carbamazepine use among women of
childbearing age based on analyses of four data sets. We estimated the
attributable fractions and the number of children born with each defect that
could be prevented annually in the United States if valproic acid and
carbamazepine were not used during pregnancy. The summary odds ratio estimate
for the association between valproic acid and spina bifida was 11.9 (95%
uncertainty interval (UI): 4.0-21.2); for valproic acid and cleft palate 5.8
(95% UI: 3.3-9.5); for carbamazepine and spina bifida 3.6 (95% UI: 1.3-7.8); and
for carbamazepine and cleft palate 2.4 (95% UI: 1.1-4.5) in the United States.
Approximately 40 infants (95% UI: 10-100) with spina bifida and 35 infants (95%
UI: 10-70) with cleft palate could be born without these defects each year if
valproic acid were not used during pregnancy; 5 infants (95% UI: 0-15) with
spina bifida and 5 infants (95% UI: 0-15) with cleft palate could be born
without these defects each year if carbamazepine were not used during pregnancy.
This modeling approach could be extended to other medications to estimate the
impact of translating pharmacoepidemiologic data to evidence-based prenatal care
practice.
Published 2011 Wiley-Liss, Inc.
DOI: 10.1002/ajmg.c.30306
PMID: 21766433 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/24710347 | 1. PLoS One. 2014 Apr 7;9(4):e93806. doi: 10.1371/journal.pone.0093806.
eCollection 2014.
Targeted genome editing of sweet orange using Cas9/sgRNA.
Jia H(1), Wang N(1).
Author information:
(1)Citrus Research and Education Center, Department of Microbiology and Cell
Science, University of Florida, Lake Alfred, Florida, United States of America.
Genetic modification, including plant breeding, has been widely used to improve
crop yield and quality, as well as to increase disease resistance. Targeted
genome engineering is expected to contribute significantly to future varietal
improvement, and genome editing technologies using zinc finger nucleases (ZFNs),
transcription activator-like effector nucleases (TALENs), and clustered
regularly interspaced short palindromic repeat (CRISPR)/Cas9/single guide RNA
(sgRNA) have already been successfully used to genetically modify plants.
However, to date, there has been no reported use of any of the current genome
editing approaches in sweet orange, an important fruit crop. In this study, we
first developed a novel tool, Xcc-facilitated agroinfiltration, for enhancing
transient protein expression in sweet orange leaves. We then successfully
employed Xcc-facilitated agroinfiltration to deliver Cas9, along with a
synthetic sgRNA targeting the CsPDS gene, into sweet orange. DNA sequencing
confirmed that the CsPDS gene was mutated at the target site in treated sweet
orange leaves. The mutation rate using the Cas9/sgRNA system was approximately
3.2 to 3.9%. Off-target mutagenesis was not detected for CsPDS-related DNA
sequences in our study. This is the first report of targeted genome modification
in citrus using the Cas9/sgRNA system-a system that holds significant promise
for the study of citrus gene function and for targeted genetic modification.
DOI: 10.1371/journal.pone.0093806
PMCID: PMC3977896
PMID: 24710347 [Indexed for MEDLINE]
Conflict of interest statement: Competing Interests: The authors have declared
that no competing interests exist. |
http://www.ncbi.nlm.nih.gov/pubmed/17313373 | 1. Biochem J. 2007 Jun 15;404(3):431-8. doi: 10.1042/BJ20070135.
K201 (JTV519) suppresses spontaneous Ca2+ release and [3H]ryanodine binding to
RyR2 irrespective of FKBP12.6 association.
Hunt DJ(1), Jones PP, Wang R, Chen W, Bolstad J, Chen K, Shimoni Y, Chen SR.
Author information:
(1)Department of Physiology and Biophysics, University of Calgary, Calgary, AB,
Canada T2N 4N1.
K201 (JTV519), a benzothiazepine derivative, has been shown to possess
anti-arrhythmic and cardioprotective properties, but the mechanism of its action
is both complex and controversial. It is believed to stabilize the closed state
of the RyR2 (cardiac ryanodine receptor) by increasing its affinity for the
FKBP12.6 (12.6 kDa FK506 binding protein) [Wehrens, Lehnart, Reiken, Deng, Vest,
Cervantes, Coromilas, Landry and Marks (2004) Science 304, 292-296]. In the
present study, we investigated the effect of K201 on spontaneous Ca2+ release
induced by Ca2+ overload in rat ventricular myocytes and in HEK-293 cells (human
embryonic kidney cells) expressing RyR2 and the role of FKBP12.6 in the action
of K201. We found that K201 abolished spontaneous Ca2+ release in cardiac
myocytes in a concentration-dependent manner. Treating ventricular myocytes with
FK506 to dissociate FKBP12.6 from RyR2 did not affect the suppression of
spontaneous Ca2+ release by K201. Similarly, K201 was able to suppress
spontaneous Ca2+ release in FK506-treated HEK-293 cells co-expressing RyR2 and
FKBP12.6. Furthermore, K201 suppressed spontaneous Ca2+ release in HEK-293 cells
expressing RyR2 alone and in cells co-expressing RyR2 and FKBP12.6 with the same
potency. In addition, K201 inhibited [3H]ryanodine binding to RyR2-wt
(wild-type) and an RyR2 mutant linked to ventricular tachycardia and sudden
death, N4104K, in the absence of FKBP12.6. These observations demonstrate that
FKBP12.6 is not involved in the inhibitory action of K201 on spontaneous Ca2+
release. Our results also suggest that suppression of spontaneous Ca2+ release
and the activity of RyR2 contributes, at least in part, to the anti-arrhythmic
properties of K201.
DOI: 10.1042/BJ20070135
PMCID: PMC1896290
PMID: 17313373 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/22325148 | 1. Cell. 2012 Feb 17;148(4):664-78. doi: 10.1016/j.cell.2011.12.029. Epub 2012
Feb 9.
RYBP-PRC1 complexes mediate H2A ubiquitylation at polycomb target sites
independently of PRC2 and H3K27me3.
Tavares L(1), Dimitrova E, Oxley D, Webster J, Poot R, Demmers J, Bezstarosti K,
Taylor S, Ura H, Koide H, Wutz A, Vidal M, Elderkin S, Brockdorff N.
Author information:
(1)Department of Biochemistry, University of Oxford, South Parks Road, Oxford
OX1 3QU, UK.
Erratum in
Cell. 2012 Jun 22;149(7):1647-8.
Polycomb-repressive complex 1 (PRC1) has a central role in the regulation of
heritable gene silencing during differentiation and development. PRC1
recruitment is generally attributed to interaction of the chromodomain of the
core protein Polycomb with trimethyl histone H3K27 (H3K27me3), catalyzed by a
second complex, PRC2. Unexpectedly we find that RING1B, the catalytic subunit of
PRC1, and associated monoubiquitylation of histone H2A are targeted to closely
overlapping sites in wild-type and PRC2-deficient mouse embryonic stem cells
(mESCs), demonstrating an H3K27me3-independent pathway for recruitment of PRC1
activity. We show that this pathway is mediated by RYBP-PRC1, a complex
comprising catalytic subunits of PRC1 and the protein RYBP. RYBP-PRC1 is
recruited to target loci in mESCs and is also involved in Xist RNA-mediated
silencing, the latter suggesting a wider role in Polycomb silencing. We discuss
the implications of these findings for understanding recruitment and function of
Polycomb repressors.
Copyright © 2012 Elsevier Inc. All rights reserved.
DOI: 10.1016/j.cell.2011.12.029
PMCID: PMC3281992
PMID: 22325148 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/23318260 | 1. Cell Rep. 2013 Jan 31;3(1):92-102. doi: 10.1016/j.celrep.2012.12.009. Epub
2013 Jan 10.
Chd5 requires PHD-mediated histone 3 binding for tumor suppression.
Paul S(1), Kuo A, Schalch T, Vogel H, Joshua-Tor L, McCombie WR, Gozani O,
Hammell M, Mills AA.
Author information:
(1)Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Chromodomain Helicase DNA binding protein 5 (CHD5) is a tumor suppressor mapping
to 1p36, a genomic region that is frequently deleted in human cancer. Although
CHD5 belongs to the CHD family of chromatin-remodeling proteins, whether its
tumor-suppressive role involves an interaction with chromatin is unknown. Here
we report that Chd5 binds the unmodified N terminus of H3 through its tandem
plant homeodomains (PHDs). Genome-wide chromatin immunoprecipitation studies
reveal preferential binding of Chd5 to loci lacking the active mark H3K4me3 and
also identify Chd5 targets implicated in cancer. Chd5 mutations that abrogate H3
binding are unable to inhibit proliferation or transcriptionally modulate target
genes, which leads to tumorigenesis in vivo. Unlike wild-type Chd5, Chd5-PHD
mutants are unable to induce differentiation or efficiently suppress the growth
of human neuroblastoma in vivo. Our work defines Chd5 as an N-terminally
unmodified H3-binding protein and provides functional evidence that this
interaction orchestrates chromatin-mediated transcriptional programs critical
for tumor suppression.
Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.
DOI: 10.1016/j.celrep.2012.12.009
PMCID: PMC3575599
PMID: 23318260 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/10339792 | 1. Rev Neurol (Paris). 1999 Mar;155(3):220-4.
[Should folic acid be given to women treated with valproic acid and/or
carbamazepine? Folic acid and pregnancy in epilepsy].
[Article in French]
Champel V(1), Radal M, Moulin-Vallez M, Jonville-Béra AP, Autret-Leca E.
Author information:
(1)Service de Pharmacologie Clinique et Centre Régional de Pharmacovigilance et
de Renseignements sur le Médicament du C.H.U. de Tours.
Fetal exposure to valproic acid or carbamazepine increases the risk of neural
tube defect (NTD). The risk of a mother having a baby with spina bifida has been
estimated at 1-2 p. 100, close to the rate of risk of recurrent cases. No study
has evaluated the effect of folic acid in neonates of women treated with
valproic acid or carbamazepine although the protective effect against NTD has
been proven in other populations. Periconceptional folic acid supplementation,
0.4 to 1 mg/day, for at least one month prior to conception and until the date
of the second missed menstrual period or later decreases the incidence of a
first occurrence of neural tube defect. Periconceptional folic acid
supplementation, 4 mg/day, decreases the recurrence of NTD in women who had
previously had a child with NTD. It seems pertinent to recommend
periconceptional folic acid supplementation in women treated with carbamazepine
or valporic acid. There are very few data in women on which to base a decision
to advise taking 4 mg/day (as used in recurrence prevention) or low doses of 0.4
mg/day (used in primary prevention).
PMID: 10339792 [Indexed for MEDLINE] |
http://www.ncbi.nlm.nih.gov/pubmed/10864882 | 1. Br J Pharmacol. 2000 Jun;130(4):767-76. doi: 10.1038/sj.bjp.0703373.
JTV-519, a novel cardioprotective agent, improves the contractile recovery after
ischaemia-reperfusion in coronary perfused guinea-pig ventricular muscles.
Ito K(1), Shigematsu S, Sato T, Abe T, Li Y, Arita M.
Author information:
(1)Department of Physiology, Oita Medical University, 1-1 Idaigaoka, Hasama,
Oita 879-5593, Japan.
A newly synthesized benzothiazepine derivative, JTV-519 (JT) has been reported
to be cardioprotective. However, the precise mechanism underlying the
cardioprotective effect of this drug is unknown. Coronary-perfused guinea-pig
ventricular muscles were subjected to 20-min no-flow ischaemia followed by
60-min reperfusion (I/R). I/R significantly decreased the contraction in
untreated preparations (control group, 34+/-4% of baseline value, n=6). Brief
administration of JT (1.0 microM) prior to ischaemia significantly improved the
postischaemic contractile recovery (63+/-5% of baseline value, n=4), as compared
to the control group. JT (1.0 microM) slightly prolonged action potential
duration before ischaemia and induced conduction disturbance (2 : 1 block) after
the initiation of ischaemia. The cardioprotective effect of JT was antagonized
by chelerythrine (CH, 5.0 microM), an inhibitor of protein kinase C (PKC) or by
5-hydroxydecanoic acid (5-HD, 400 microM), an inhibitor of mitochondrial
ATP-sensitive K(+) (K(ATP)) channels. These results suggest that the protective
effect of JT is due to the opening of mitochondrial K(ATP) channels, which, in
turn, is linked to PKC activation.
DOI: 10.1038/sj.bjp.0703373
PMCID: PMC1572131
PMID: 10864882 [Indexed for MEDLINE] |