Secretory Mechanisms of aP2: an Adipokine Integrating Adipose Depots with Metabolism

Abstract

Adipose Fatty Acid Binding Protein 4 (FABP4) or aP2, plays an important role in several immunometabolic pathologies such as type 2 diabetes, atherosclerosis, fatty liver disease, asthma, and cancer. Long considered to be a cytosolic protein, aP2 has recently been detected in conditioned media of adipocytes. Interestingly, there is a growing body of literature showing association of increased circulating levels of aP2 with cardiovascular disease and metabolic syndrome. Our lab has discovered a role for aP2 secreted from adipocytes in regulating liver glucose output and blood glucose levels in diabetes. The emerging biology of this novel adipokine makes it critical to understand the route and mechanisms that lead to its secretion.