Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2010-12-14
pubmed:abstractText
The calcium-regulated phosphatase calcineurin intersects with both calcium and cAMP-mediated signaling pathways in the pancreatic ?-cell. Pharmacologic calcineurin inhibition, necessary to prevent rejection in the setting of organ transplantation, is associated with post-transplant ?-cell failure. We sought to determine the effect of calcineurin inhibition on ?-cell replication and survival in rodents and in isolated human islets. Further, we assessed whether the GLP-1 receptor agonist and cAMP stimulus, exendin-4 (Ex-4), could rescue ?-cell replication and survival following calcineurin inhibition. Following treatment with the calcineurin inhibitor tacrolimus, human ?-cell apoptosis was significantly increased. Although we detected no human ?-cell replication, tacrolimus significantly decreased rodent ?-cell replication. Ex-4 nearly normalized both human ?-cell survival and rodent ?-cell replication when co-administered with tacrolimus. We found that tacrolimus decreased Akt phosphorylation, suggesting that calcineurin could regulate replication and survival via the PI3K/Akt pathway. We identify insulin receptor substrate-2 (Irs2), a known cAMP-responsive element-binding protein target and upstream regulator of the PI3K/Akt pathway, as a novel calcineurin target in ?-cells. Irs2 mRNA and protein are decreased by calcineurin inhibition in both rodent and human islets. The effect of calcineurin on Irs2 expression is mediated at least in part through the nuclear factor of activated T-cells (NFAT), as NFAT occupied the Irs2 promoter in a calcineurin-sensitive manner. Ex-4 restored Irs2 expression in tacrolimus-treated rodent and human islets nearly to baseline. These findings reveal calcineurin as a regulator of human ?-cell survival in part through regulation of Irs2, with implications for the pathogenesis and treatment of diabetes following organ transplantation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Calcineurin, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/Hypoglycemic Agents, http://linkedlifedata.com/resource/pubmed/chemical/IRS2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Immunosuppressive Agents, http://linkedlifedata.com/resource/pubmed/chemical/Insulin Receptor Substrate Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Irs2 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Irs2 protein, rat, http://linkedlifedata.com/resource/pubmed/chemical/NFATC Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-akt, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Glucagon, http://linkedlifedata.com/resource/pubmed/chemical/Tacrolimus, http://linkedlifedata.com/resource/pubmed/chemical/Venoms, http://linkedlifedata.com/resource/pubmed/chemical/exenatide, http://linkedlifedata.com/resource/pubmed/chemical/glucagon-like peptide receptor
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
17
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40050-9
pubmed:meshHeading
pubmed-meshheading:20943662-Animals, pubmed-meshheading:20943662-Apoptosis, pubmed-meshheading:20943662-Calcineurin, pubmed-meshheading:20943662-Cell Line, Tumor, pubmed-meshheading:20943662-Cell Proliferation, pubmed-meshheading:20943662-Cell Survival, pubmed-meshheading:20943662-Cyclic AMP, pubmed-meshheading:20943662-Diabetes Mellitus, pubmed-meshheading:20943662-Gene Expression Regulation, pubmed-meshheading:20943662-Humans, pubmed-meshheading:20943662-Hypoglycemic Agents, pubmed-meshheading:20943662-Immunosuppressive Agents, pubmed-meshheading:20943662-Insulin Receptor Substrate Proteins, pubmed-meshheading:20943662-Insulin-Secreting Cells, pubmed-meshheading:20943662-Mice, pubmed-meshheading:20943662-NFATC Transcription Factors, pubmed-meshheading:20943662-Organ Transplantation, pubmed-meshheading:20943662-Peptides, pubmed-meshheading:20943662-Phosphatidylinositol 3-Kinases, pubmed-meshheading:20943662-Phosphorylation, pubmed-meshheading:20943662-Proto-Oncogene Proteins c-akt, pubmed-meshheading:20943662-Rats, pubmed-meshheading:20943662-Rats, Sprague-Dawley, pubmed-meshheading:20943662-Receptors, Glucagon, pubmed-meshheading:20943662-Signal Transduction, pubmed-meshheading:20943662-Tacrolimus, pubmed-meshheading:20943662-Venoms
pubmed:year
2010
pubmed:articleTitle
Calcineurin signaling regulates human islet {beta}-cell survival.
pubmed:affiliation
Division of Endocrinology, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural