A Study On The Expression And Role Of Nucleolin In Type2Diabetic Cardiomyopathy

Objective Diabetic cardiomyopathy is one of the most common complications of diabetes characterized by cardiac myocyte apoptosis, myocardial interstitial collagen accumulation and cardiomyocyte hypertrophy. Nucleolin is a multifunctional RNA-binding protein, and is closely associated with apoptosis. In this study, a type2diabetes model was prepared in mice with cardiac-specific overexpression of nucleolin to elucidate the role of nucleolin in diabetic cardiomyopathy.Methods To prepare a mouse model of type2diabetes, nucleolin transgenic mice were fed high fat and high sucrose diets for20weeks plus small dose streptozotocin by intraperitoneal injection (beginning from fifth week, dose60mg/Kg, qw×2). The mice were divided into four groups:wild type mice in the control group, nucleolin transgenic mice in the control group, wild type mice in the diabetes group, nucleolin transgenic mice in the diabetes group. Diabetes-related indicators were detected at eighth weekend. At twelfth weekend, levels of myocardial nucleolin protein expression were detected by immunoblotting and immunohistochemistry. And then HE staining, Masson staining, TUNEL staining, WGA staining were used to observe myocardial morphological changes, myocardial fibrosis, cardiac myocyte apoptosis and cardiac myocyte hypertrophy; At twentieth weekend, mouse cardiac hemodynamic parameters were detected with a Powerlab system.Results Fasting blood glucose levels significantly increased in diabetic mice than in control group. Levels of myocardial nucleolin protein in WT diabetes mice were significantly higher than in WT control. In WT diabetes group, myocardial disarrangement, fragmentation and dissolution; myocardial fibrosis; cardiac myocyte apoptosis; cardiomyocyte hypertrophy were respectively showed by HE staining, Masson staining, TUNEL staining and WGA staining; and cardiac function were declined; in TG diabetes group, the above situations were significantly improved.Conclusions Myocardial nucleolin protein expression was increased in diabetic cardiomyopathy; nucleolin overexpression affected the occurrence and development of diabetic cardiomyopathy by inhibiting myocardial fibrosis, cardiac myocyte apoptosis and cardiomyocyte hypertrophy, and improved cardiac function.