Pathophysiological roles of nutrient-sensing mechanisms in diabetes and its complications

Diabetic nephropathy, which is characterized by increased albuminuria, has been the most common cause of end-stage kidney disease for many years in Japan and many other countries. Although the renal prognosis of the disease has been improving in recent years because of the clinical implementation of strict glucose, blood pressure, and lipid controls, some diabetes patients continue to exhibit treatment-resistant macroalbuminuria leading to end-stage kidney disease. Furthermore, renal function decline without macroalbuminuria in diabetes is an emerging issue in Japan, which might be partly due to aging. Thus, a novel therapeutic strategy is needed to further improve renal outcome in diabetes patients. We have recently reported the involvement of dysregulation of intracellular nutrient-sensing signals and the related cellular process, autophagy, in the pathogenesis of diabetic nephropathy and abnormal insulin secretion pattern in type 2 diabetes. This review discusses potential roles of intracellular nutrient-sensing signals and autophagy as novel therapeutic targets for type 2 diabetes and diabetic nephropathy.