Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that bind to the 3′-UTR of mRNAs and function mainly in post-transcriptional regulation. MiRNAs have been implicated to play roles in organ development, including that of the pancreas. Many miRNAs, such as miR-375, miR-124, miR-7, miR-21 and miR-221, have been shown to regulate insulin production as well as insulin secretion. However, it is not known whether miRNAs can regulate insulin secretion via the control of intracellular Ca2+ in pancreatic beta cells. In this research, expression profiles of miRNAs and mRNAs were investigated using RNA-sequencing and microarray analysis in chicken pancreatic nestin-positive progenitor cells and differentiated pancreatic beta cells. A number of miRNAs were up-regulated after differentiation of progenitors into beta cells, which regulate cell signaling pathways to control cell function. miR-223 and miR146a were shown to promote insulin secretion from pancreatic beta cells by regulating the concentration of intracellular Ca2+ via the down-regulation of their target genes.