The Study On The Effect Of High Glucose On Apoptosis And Proliferation Of Vascular Smooth Muscle Cells

ObjectDiabetes is a clinical syndrome induced by the inheritance and environment, it is the most popular metabolic disease. In the recent years, following the elevation of people's living standard and the change of food and drink, more and more people suffer from diabetes. It's the third most disease just less than hypertension and tumor. In diabetic patients, foot ulcers , coronary artery disease and blindness are higher than nondiabetic patients due to macroangiopathy and microangiopathy caused by diabetes. In the past few years, many studies show that enhanced cell proliferation is a key feature of diabetic vasculopathy, However, more and more studies have demonstrated that dysreglulated apoptosis also plays an important role. Some evidences suggest that vascular remodeling in diabetic patients involves a perturbation of the balance between cell proliferation and cell apoptosis. We investigate VSMCs cultured in normal glucose and high glucose to find whether there is an increase in proliferation and decrease in apoptosis in VSMCs cultured in high glucose . We also investigate the relationship between apoptosis correlated gene and apoptosis of VSMCs.MethodRabbit aorta was isolated, washing the vessel by using cold PBS to prevent inquination of blood cell. Culture VSMCs in vitro using tissue sticking .To study the effect of high glucose on bcl-2 expression, confluent cells were cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10% serum in the presence of 5.5mmol/l glucose (normal glucose), 25mmol/l glucose (high glucose), or 5.5mmol/l glucose plus 19.5 mmol/1mannitol (mannitol) as indicated. Total RNAand protein was isolated from cultured smooth muscle cells, using PCR and Western blotting to analyze bcl-2 expression in the three groups,using flow cytometry to analyze the apoptosis of VSMCs and using MTT to analyze the proliferation of VSMCs.ResultVSMCs treated with high glucose significantly increased bcl-2 expression than in normal glucose; In contrast, mannitol, used as an osmotic control, had no effect on bcl-2 expression.Flow cytometry showed that cell apoptosis was decreased in high glucose than in normal glucose. Mannitol, used as an osmotic control, had no effect on cell apoptosis.MTT test showed that cell proliferation was enhanced in high glucose than in normal glucose.Mannitol, used as an osmotic control, had no effect on cell proliferation.ConclusionWe conclude that high glucose stimulates bcl-2 expression ,leading to decreased apoptosis and increased proliferation in VSMCs, and result in the pathogenesis of diabetic vasculopathy.