Association between myocardial calpain activation and apoptosis in lipopolysaccharide-induced septic mouse model
10.3760/cma.j.issn.0253-3758.2010.09.017
- VernacularTitle:钙激活中性蛋白酶在脓毒症小鼠心肌半胱氨酸蛋白酶-3活化中的作用及其机制
- Author:
Xiao-Ping LI
1
;
Lang LI
;
Rui-Zhen CHEN
;
Tang-Wei LIU
;
Wei-Feng WU
;
E SHEN
;
Ying-Zhen YANG
;
Hao-Zhu CHEN
Author Information
1. 复旦大学附属中山医院
- Keywords:
Sepsis;
Myocytes,cardiac;
Apoptosis;
Calpain;
Caspase 3
- From:
Chinese Journal of Cardiology
2010;38(9):834-838
- CountryChina
- Language:Chinese
-
Abstract:
Objective In septic mice, myocardial calpain was activated and induced caspase-3 activation, the association between calpain activation and apoptosis was explored in this experiment. Methods In in vivo model, adult C57 mice were injected with lipopolysaccharide (LPS, 4rg/kg, i. p. ) to induce sepsis. Myocardial calpain and caspase-3 activities, protein levels of calpain-1,calpain-2, calpastatin, Bcl-2 and Bid were detected by Western blot analysis and myocardial apoptosis was detected by TUNEL, myocardiac function was evaluated by Langendorff system. In in vitro model, adult rat cardiomyocytes were incubated with LPS (1μg/ml) or co-incubated with calpain inhibitor-Ⅲ (10μmol/L), calpain activity, caspase-3 activity, protein levels of Bcl-2 and Bid, and cardiomyocyte apoptosis were detected. Results In septic mice, myocardial calpain and caspase-3 activity were increased up to 2. 7-and 1.8-folds, respectively. Both calpain inhibitor-Ⅲ and PD150606 significantly attenuated the increase of caspase-3 activity. Myocardial protein levels of calpain-1, calpain-2, calpastatin, Bcl-2 and Bid were similar between control and septic mice, and no cleavage of both Bcl-2 and Bid was found in septic mice. Calpain inhibitor-Ⅲ significantly improved myocardial function in septic mice. In in vitro model, calpain and caspase-3 activities were increased after 4 h LPS treatment, co-treatment with calpain inhibitor-Ⅲ prevented caspase-3 activity increase, protein Bcl-2 and Bid were similar between normal cardiomyocytes and LPS-treated cardiomyocytes. Cardiomyocyte apoptosis was similar in in vivo and in vitro septic models. Conclusion Myocardial calpain activity is increased in LPS induced septic mice, subsequent caspase-3 activation may contribute to myocardial dysfunction in septic mice without aggravating myocardial apoptosis and Bcl-2 and Bid are not involved on calpain induced caspase-3 activation in our model.
