Downregulation of uncoupling protein-2 by genipin exacerbates diabetes-induced kidney proximal tubular cells apoptosis.

Renal tubular epithelial cell injury is a major pathological event that contributes to the development of diabetic kidney disease (DKD). Uncoupling protein-2 (UCP2), a mitochondrial membrane protein, has been reported to participate in the regulation of reactive oxygen species (ROS) generation, which contributes to tubular cell apoptosis induced by hyperglycemia. In this study, we found that genipin, a UCP2 inhibitor, dramatically boosted oxidative stress, attenuated antioxidative capacity, and exacerbated cell apoptosis accompanied with caspase-3 activation in rat renal proximal tubular cells (NRK-52E) incubated with high glucose. The present study results suggest that manipulation of UCP2 could be important in the prevention of oxidative stress damage in renal tubular epithelial cells induced by hyperglycemia in vitro.