Downregulation of Long Noncoding RNA Gas5 Affects Cell Cycle and Insulin Secretion in Mouse Pancreatic β Cells.

BACKGROUND: Evidence shows that long non-coding RNAs (lncRNAs) are involved in individual development, cell differentiation, cell cycle processes and other important life processes and are closely related to major human diseases, including diabetes. Recent studies have reported that lncRNAs are involved in β cell functions and that lncRNA Gas5 levels decreased in T2DM patients' serum. The purpose of this study was to clarify the role of lncRNA Gas5 in mouse β cell functions in vitro and in vivo.

METHODS: lncRNA Gas5 expression in T2DM and normal mouse tissues was analyzed using qRT-PCR. RNAi, qRT-PCR, Annexin V-FITC assays, western blot, GSIS and RIA were performed to detect the effects of lncRNA Gas5 on insulin synthesis and secretion in vitro and in vivo.

RESULTS: The lncRNA Gas5 level was significantly decreased in db/db mice. However, lncRNA Gas5 expression was relatively high in the pancreas of normal mice. Knockdown of lncRNA Gas5 expression led to cell cycle G1 arrest and impaired insulin synthesis and secretion in Min6 cells. Further, knockdown of lncRNA Gas5 expression in primary isolated islets resulted in decreased expression of insulin gene and transcription factors, Pdx1 and MafA. These results indicate that lncRNA Gas5 might perform as a new regulator, maintaining β cell identity and function by affecting insulin synthesis and secretion.