Effects of overexpressing FoxO1 on apoptosis in glomeruli of diabetic mice and in podocytes cultured in high glucose medium.

Podocyte apoptosis induced by high levels of glucose is a key event in the development and prognosis of diabetic nephropathy (DN). Forkhead transcription factor O1 (FoxO1) has been defined as a critical mediator of oxidative stress in animal models of diabetes and is involved in mitophagy. To test the role of FoxO1 in regulating podocyte apoptosis both in vivo and in vitro, we generated FoxO1 overexpression models. High-glucose (HG) induced podocyte apoptosis with decreased mitophagy. These changes were accompanied by mitochondrial dysfunction and more severe podocyte loss in mouse kidney. FoxO1 overexpression prevented the apoptosis induced by HG. Reduction of cell apoptosis and renal damage depended upon the expression of PTEN-induced putative kinase 1 (PINK1). These findings suggest that specific overexpression of renal FoxO1 decreases podocyte apoptosis, which may be explained in part by its regulation of PINK1, and that targeting FoxO1 may represent a novel therapeutic approach for DN.