The small RNA miR-375 - a pancreatic islet abundant miRNA with multiple roles in endocrine beta cell function

•The islet-abundant miR-375 regulate multiple functions in the pancreatic beta cell.•Mir-375 regulate expression of genes involved in control of beta cell mass and identity.•Mir-375 regulate expression of genes involved in the regulation of insulin secretion.•Mir-375 is a potential biomarker for diabetes being a better predictor of T1D than T2D.

The pathophysiology of diabetes is complex and recent research put focus on the pancreatic islets of Langerhans and the insulin-secreting beta cells as central in the development of the disease. MicroRNAs (miRNAs), the small non-coding RNAs regulating post-transcriptional gene expression, are significant regulators of beta cell function. One of the most abundant miRNAs in the islets is miR-375. This review focus on the role of miR-375 in beta cell function, including effects in development and differentiation, proliferation and regulation of insulin secretion. It also discusses the regulation of miR-375 expression, miR-375 as a potential circulating biomarker in type 1 and type 2 diabetes, and the need for the beta cell to keep expression of miR-375 within optimal levels. The summed picture of miR-375 is a miRNA with multiple functions with importance in the formation of beta cell identity, control of beta cell mass and regulation of insulin secretion.