Autophagy in proximal tubular cells under diabetic conditions.  Proximal tubular cells show low rates of autophagy under basal conditions. Proteinuria renoprotectively elicits autophagy in proximal tubular cells (upper panel). Obesity suppresses proteinuria-induced autophagy via hyperactivation of mTORC1 in proximal tubular cells, leading to obesity-mediated exacerbation of proteinuria-induced tubulointerstitial damage (lower panel).