Heat Shock Protein 70 Expression Protects Against Sepsis-Associated Cardiomyopathy By Inhibiting Autophagy

Objectives:Increasing evidence suggests that heat shock protein 70 (Hsp70) has a protective effect in sepsis-induced cardiomyopathy; however, the protective mechanism remains unclear.Methods:Previous studies have also implicated autophagy in sepsis-induced cardiomyopathy. The aim of the current study was to reveal the protective mechanisms of Hsp70 in sepsis-induced cardiomyopathy using a cecal ligation and puncture (CLP) rat sepsis model. The roles of Hsp70 and autophagy in sepsis-induced cardiomyopathy were investigated by pretreating rats with the Hsp70 inhibitor quercetin or the autophagy inhibitor 3-methyladenine (3-Ma) before CLP. We also investigated the protective mechanisms of Hsp70 and the relationship between Hsp70 and autophagy in vitro by stimulating H9c2 cells with lipopolysaccharide (LPS) to simulate sepsis.Results:The result show that inhibition of Hsp70 promoted sepsis-induced death in rats, while inhibition of autophagy inhibited sepsis-induced death. These results suggested that both Hsp70 and autophagy were involved in sepsis-induced cardiomyopathy. Overexpression of Hsp70 in H9c2 myocardial cells in vitro suppressed LPS-induced apoptosis, while inhibition of autophagy with 3-Ma also decreased LPS-induced H9c2 cell apoptosis, suggesting that the protective effect of Hsp70 in sepsis-induced cardiomyopathy was related to autophagy regulation.Conclusion:Overall, these results suggested that Hsp70 protected against sepsis-induced cardiac impairment by attenuating sepsis-induced autophagy.