|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Fomina-Yadlin, D, Kubicek, S, Vetere, A, He, KHui Hu, He, KHu, Schreiber, SL, Wagner, BK|
|Keywords||Animals, Cell Cycle, Cell Line, Glucagon-Secreting Cells, Humans, Indoles, Insulin, Mice, Middle Aged, Models, Biological, Protein Processing, Post-Translational, Proto-Oncogene Proteins c-mdm2, Response Elements, Signal Transduction, Transcription, Genetic, Transcriptional Activation, Tumor Suppressor Protein p53|
BACKGROUND: Expression of insulin in terminally differentiated non-beta cell types in the pancreas could be important to treating type-1 diabetes. Previous findings led us to hypothesize involvement of kinase inhibition in induction of insulin expression in pancreatic alpha cells.
METHODOLOGY/PRINCIPAL FINDINGS: Alpha (αTC1.6) cells and human islets were treated with GW8510 and other small-molecule inhibitors for up to 5 days. Alpha cells were assessed for gene- and protein-expression levels, cell-cycle status, promoter occupancy status by chromatin immunoprecipitation (ChIP), and p53-dependent transcriptional activity. GW8510, a putative CDK2 inhibitor, up-regulated insulin expression in mouse alpha cells and enhanced insulin secretion in dissociated human islets. Gene-expression profiling and gene-set enrichment analysis of GW8510-treated alpha cells suggested up-regulation of the p53 pathway. Accordingly, the compound increased p53 transcriptional activity and expression levels of p53 transcriptional targets. A predicted p53 response element in the promoter region of the mouse Ins2 gene was verified by chromatin immunoprecipitation (ChIP). Further, inhibition of Jun N-terminal kinase (JNK) and p38 kinase activities suppressed insulin induction by GW8510.
CONCLUSIONS/SIGNIFICANCE: The induction of Ins2 by GW8510 occurred through p53 in a JNK- and p38-dependent manner. These results implicate p53 activity in modulation of Ins2 expression levels in pancreatic alpha cells, and point to a potential approach toward using small molecules to generate insulin in an alternative cell type.
|Alternate Journal||PLoS ONE|
|PubMed Central ID||PMC3252286|
|Grant List||R37 GM038627 / GM / NIGMS NIH HHS / United States |
DP2 DK083048 / DK / NIDDK NIH HHS / United States
R01 GM038627 / GM / NIGMS NIH HHS / United States
GM38627 / GM / NIGMS NIH HHS / United States
DP2-DK083048 / DK / NIDDK NIH HHS / United States