The roles of abnormal expressions of Caspase-8 and protein kinase C-β of cardiomyocytes in the development of the apoptosis of cardiomyocyte in diabetic rat / 中华老年医学杂志

ABSTRACT

Objective To study the roles of abnormal expressions of Caspase-8 and protein kinase C(PKC)-β of cardiomyocytes in the development of the apoptosis of cardiomyocyte in diabetic rat. Methods Rats were divided into 4 groups(1)normal control (NC, n=37),(2)rats given STZ injection and normal diet(STZ,n= 42), (3) rats fed with high fat and high sngar ( HFS, n= 37), (4)rats given STZ injection and high fat and high sugar diet (type 2 DM, n=64). Plasma glucose, insulin and lipids were detected. At the end of experiment, the animals were sacrificed, and their hearts were examined. Pathological changes were observed and the expressions of Caspase-8, PKC-β mRNA were determined by real time-PCR method; apoptosis was analyzed by flow cytometry. Results (1)The body weight was higher in HFS group than in other three groups, and progressively decreased in type 2 diabetes group. The glucose level was highest in diabetic group, and was similar between groups of HFS and NC. (2)The apoptosis showed tendency to ascend during course of disease in diabetes model group. (3)The expressions of Caspase-8 and PKC-β mRNA were significantly enhanced in diabetes model group than in normal control group, and had a tendency to ascend during the course of disease.(4)The myocardial cells of the diabetic rats were rarified and swelling, fibrosis was observed. (5)At the 16th week, the level of plasma glucose was correlated positively with the expressions of Caspase-8 and PKC-β mRNA. Conclusions The enhancement of expressions of Caspase-8 amd PKC-β may play iportat rols in the pathogenesis of diabetic cardiomyopathy,in which apoptosis of the cardiomyocytes increased.