Beneficial effects of metformin on glomerular podocytes in diabetes.

Podocytes and their foot processes form an important cellular layer of the glomerular barrier involved in regulating glomerular permeability. Disturbances in podocyte function play a central role in the development of proteinuria in diabetic nephropathy. The retraction of podocyte foot processes forming a slit diaphragm is a common feature of proteinuria. Metformin is an oral antidiabetic agent of the biguanide class that is widely recommended for the treatment of high blood glucose in patients with type 2 diabetes mellitus. In addition to lowering glucose, several recent studies have reported potential beneficial effects of metformin on diabetic kidney function. Furthermore, a key molecule of the antidiabetic mechanism of action of metformin is adenosine 5'-monophospate-activated protein kinase (AMPK), as the metformin-induced activation of AMPK is well documented. The present review summarizes current knowledge on the protective effects of metformin against pathological changes in podocytes that are induced by hyperglycemia.