In a new study published in
Journal of Extracellular Vesicles, Chen-Yu Zhang's group and Antonio Vidal-Puig's group at University of Cambridge report that pancreatic β cells secrete miR-29 family members (miR-29a, miR-29b and miR-29c) in response to high levels of free fatty acids (FFAs). These β cell-derived miR-29s are delivered to the liver, promoting insulin resistance and enhancing hepatic glucose output.
Over 100 years after insulin was discovered, it was believed that pancreatic β cells only secreted a single hormone--insulin. Pancreatic β cell-derived insulin regulates glucose homeostasis by binding with the insulin receptors located in the liver, skeletal muscle, adipose tissues and other peripheral organs. The discovery of insulin and its receptor was essential to understand the mechanisms controlling glucose homeostasis and the pathogenesis of type 2 diabetes defined by defective insulin secretion, signal transduction and insulin resistance. However, glucose homeostasis also depends on the integrated coordination of multiple organs, talking to each other to effectively control glucose metabolism. Understanding the crosstalk between organs is still incomplete, which has greatly limited the rational approach to type 2 diabetes treatment.