The effects of caspase-3 in apoptosis of cultured retinal microvascular pericytes induced by advanced glycation end products

Abstract

One of the earliest changes observed in the development of diabetic retinopathy (DR) is the selective loss of pericytes and acellular capillaries. We tested the hypothesis that advanced glycation end products (AGE) might be involved in the disappearance of retinal pericytes by apoptosis and further investigated the activity and effect of caspase-3 at the same time. Cultured bovine retinal microvascular pericytes (BRPs) were exposed to various concentrations of advanced glycation end products-bovine serum albumin (AGE, 0.47, 1.88, 7.50 micromol/L) for 4 days. We assayed the degree of pericytes apoptosis by fluorescence activated cell sorting, and further measured the caspase-3 activity and the effect of selective caspase-3 inhibitor Z-DEVD-fmk on apoptosis and the of ratio Bcl-2/Bax expression. The results showed that AGE could induce significantly the apoptosis of BRPs in a dose-dependent manner compared with controls (r = 0.867, P < 0.01), associated with an increase in intracellular caspase-3 activity. Selective caspase-3 inhibitor Z-DEVD-fmk inhibited pericyte apoptosis induced by AGE. These data suggest that the pericyte loss in DR involves an apoptotic process, and that activation of caspase-3 are associated with apoptotic process, which can provide new therapeutic perspectives in diabetic retinopathy.