In a new study published in
Journal of Extracellular Vesicles, Chen-Yu Zhang's group at Nanjing University, School of Life Sciences, and Antonio Vidal-Puig's group at University of Cambridge report that pancreatic β cells secrete miR-29 family members (miR-29s) via exosomes in response to high levels of free fatty acids (FFAs). Theses β cell-derived exosomal miR-29s regulate glucose homeostasis through their manipulations on glucose output in liver.
Previously, Chen-Yu Zhang's group identified extracellular miRNA as a new form of cell-to-cell communication. They are among the first that reported the selective secretion of miRNAs under different physiological or pathological states; also, the uptake and function of secreted miRNAs in recipient cells. In the past decade, intensive studies have revealed the role of extracellular miRNAs in a range of biological processes. Thus, as a newly-emerged secretory factor, more insightful studies are needed to further reveal its relevance to more physiological progresses and diseases. Pancreatic islet has long been identified as critical secretory tissue in term of its role on maintaining glucose homeostasis by releasing conventional hormones, such as glucagon and insulin. Since pancreatic islet is a classic secretory organ, study to identify its secreted miRNAs and their functional implications in the regulation of glucose homeostasis is very needed.