Amelioration of mitochondrial dysfunction in heart failure through S-sulfhydration of Ca2+/calmodulin-dependent protein kinaseⅡ

摘要

OBJECTIVE To determine the functional role of hydrogen sulfide (H2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca2 +/calmodulin-dependent protein kinaseⅡ (CaMKⅡ) using wild type and CSE knockout mouse models. METHODS Continuous subcutaneous injection isoprenaline (7.5 mg·kg-1·d-1), once a day for 4 weeks to induce heart failure in Male C57BL/6 (6-8 weeks old) mice and CSE-/- mice. 150 μmol·L-1 H2O2 was used to induce oxidative stress in H9c2 cells. Echocardiograph was used to detect cardiac parameters. H&E stain and Masson stain was to observation histopathological changes. Western blot was used to detect protein expression and activity. The siRNA was used to silence protein expression. HPLC was used to detect H2S level. Biotin assay was used to detect the level of S- sulfhydration protein. RESULTS Treatment with S-propyl-L-cysteine (SPRC) or sodium hydrosulfide (NaHS), modulators of blood H2S levels, attenuated the development of heart failure in animals, reduced lipid peroxidation, and preserved mitochondrial function. The inhibition CaMKⅡ phosphorylation by SPRC and NaHS as demonstrated using both in vivo and in vitro models corresponded with the cardioprotective effects of these compounds. Interestingly, CaMKⅡ activity was found to be elevated in CSE-/- mice as compared to wild type animals and the phosphorylation status of CaMKⅡ appeared to relate to the severity of heart failure. Importantly, in wild type mice SPRC was found to promote S-sulfhydration of CaMKII leading to reduced activity of this protein however, in CSE-/- mice S-sulfhydration was abolished following SPRC treatment. CONCLUSION A novel mechanism depicting a role of S-sulfhydration in the regulation of CaMKⅡ is presented. SPRC mediated S-sulfhydration of CaMKII was found to inhibit CaMKⅡ activity and to preserve cardiovascular homeostasis.