Intracellular and extracellular adenosine triphosphate in regulation of insulin secretion from pancreatic β cells

Adenosine triphosphate (ATP) synthesis and release in mitochondria play critical roles in regulating insulin secretion in pancreatic cells. Mitochondrial dysfunction is mainly characterized by a decrease in ATP production, which is a central event in the progression of pancreatic cell dysfunction and diabetes. ATP has been demonstrated to regulate insulin secretion via several pathways: (i) Intracellular ATP directly closes ATP-sensitive potassium channel to open L-type calcium channel, leading to an increase in free cytosolic calcium levels and exocytosis of insulin granules; (ii) A decrease in ATP production is always associated with an increase in production of reactive oxygen species, which exerts deleterious effects on pancreatic cell survival and insulin secretion; and (iii) ATP can be co-secreted with insulin from pancreatic cells, and the released ATP functions as an autocrine signal to modulate insulin secretory process via P2 receptors on the cell membrane. In this review, the recent findings regarding the role and mechanism of ATP synthesis and release in regulation of insulin secretion from pancreatic cells will be summarized and discussed.