Molecular hydrogen attenuates sepsis-induced cardiomyopathy in mice by promoting autophagy.

BACKGROUND: Approximately 40 to 60% of patients with sepsis develop sepsis-induced cardiomyopathy (SIC), which is associated with a substantial increase in mortality. We have found that molecular hydrogen (H2 ) inhalation improved the survival rate and cardiac injury in septic mice. However, the mechanism remains unclear. This study aimed to explore the regulatory mechanism by which hydrogen modulates autophagy and its role in hydrogen protection of SIC.

METHODS: Cecal ligation and puncture (CLP) was used to induce sepsis in adult C57BL/6J male mice. The mice were randomly divided into 4 groups: Sham, Sham + 2% hydrogen inhalation (H2 ), CLP, and CLP + H2 group. The 7-day survival rate was recorded. Myocardial pathological scores were calculated. Myocardial troponin I (cTnI) levels in serum were detected, and the levels of autophagy- and mitophagy-related proteins in myocardial tissue were measured. Another four groups of mice were also studied: CLP, CLP + Bafilomycin A1 (BafA1), CLP + H2 , and CLP + H2  + BafA1 group. Mice in the BafA1 group received an intraperitoneal injection of the autophagy inhibitor BafA1 1 mg/kg 1 h after operation. The detection indicators remained the same as before.

RESULTS: The survival rate of septic mice treated with H2 was significantly improved, myocardial tissue inflammation was improved, serum cTnI level was decreased, autophagy flux was increased, and mitophagy protein content was decreased (P < 0.05). Compared to the CLP + H2 group, the CLP + H2  + BafA1 group showed a decrease in autophagy level and 7-day survival rate, an increase in myocardial tissue injury and cTnI level, which reversed the protective effect of hydrogen (P < 0.05).

CONCLUSION: Hydrogen exerts protective effect against SIC, which may be achieved through the promotion of autophagy and mitophagy.