Polysulfur-based bulking of dynamin-related protein 1 prevents ischemic sulfide catabolism and heart failure

The presence of redox-active molecules containing catenated sulfur atoms (supersulfide) in living organisms has led to a review of the concepts of redox biology and its translational strategy. Glutathione (GSH) is the body’s primary detoxifier and antioxidant, and its oxidized form (GSSG) has been considered as a marker of oxidative status. However, we report that GSSG, but not reduced GSH, prevents ischemic supersulfide catabolism-associated heart failure in mice by electrophilic modification of dynamin-related protein (Drp1). In healthy exercised hearts, the redox-sensitive Cys644 of Drp1 is highly S-glutathionylated. Nearly 40 % of Cys644 is normally polysulfidated, and Cys644 S-glutathionylation is resistant to Drp1 depolysulfidation-dependent mitochondrial hyperfission and myocardial dysfunction caused by hypoxic or environmental chemical stress. MD simulation of Drp1 structure and site-directed mutagenetic analysis reveals a functional interaction between Cys644 and a critical phosphorylation site Ser637, through Glu640. Bulky modification at Cys644 via polysulfidation or S-glutathionylation reduces Drp1 activity by disrupting Ser637-Glu640-Cys644 interaction. Disruption of Cys644 S-glutathionylation nullifies the cardioprotective effect of GSSG against heart failure after myocardial infarction. Our findings suggest a novel therapeutic potential of polysulfur-based Cys bulking on Drp1 for ischemic heart disease.