Expression Of Cyt C And Caspase3in Lens Epithelial Cells Of Streptozotocin-induced Diabetic Rats

ObjectiveTo evaluate the expression of Cyt C and Caspase3in lens epithelial cells ofstreptozotocin-induced diabetic rats, providing new clues for the mechanism ofdiabetic cataract.Methods60healthy SD male rats were randomly divided into control group and diabeticgroup induced by STZ,30in each group. The change of blood glucose weremonitored and lens opacity was observed by slit lamp microscope every4weeks.Anterior lens capsule were sampled at the end of12weeks and the expression ofCyt C and Caspase3in lens epithelial cells was dected by immunohistochemistry andWestern Blot.ResultsThe blood glucose of2groups was stable during the experiment. Slit-lampexamination shows that lens opacification was observed in diabetic group while thelens of control group was transparent at the end of12weeks. Immunohistochemistrydata suggested that the expression of Cyt C and Caspase3in diabetic group waspositive whereas the expression in control group was negative. Cyt C contents bothin the mitochondria and cytosol were dected by Western Blot,indicating that thecytosolic contents of Cyt C in diabetic group were higher than in control group andthe mitochondrial contents of Cyt C in diabetic group were lower than thecontrol’s(P<0.05). Besides, the expression level of Caspase3in diabetic group wassignificantly higher than that of control group by Western Blot (P<0.05).ConclusionCyt C was released from the mitochondria into the cytosol and the expression ofCaspase3increased in lens epithelial cells of streptozotocin-induced diabetic rats,indicating that hyperglycaemia may incite the release of Cyt C and activateCaspase3, inducing apoptosis in lens epithelial cells which results in cataractformation.