The desumoylating enzyme sentrin-specific protease 3 contributes to myocardial ischemia reperfusion injury

Sentrin-specific protease 3 (SENP3), a member of the desumoylating enzyme family, is known as a redox sensor and could regulate multiple cellular signaling pathways. However, its implication in myocardial ischemia reperfusion (MIR) injury is unclear. Here, we observed that SENP3 was expressed and upregulated in the mouse heart depending on reactive oxygen species (ROS) production in response to MIR injury. By utilizing siRNA-mediated cardiac specific gene silencing, SENP3 knockdown was demonstrated to significantly reduce MIR-induced infarct size and improve cardiac function. Mechanistic studies indicated that SENP3 silencing ameliorated myocardial apoptosis mainly via suppression of endoplasmic reticulum (ER) stress and mitochondrial-mediated apoptosis pathways. By contrast, adenovirus-mediated cardiac SENP3 overexpression significantly exaggerated MIR injury. Further molecular analysis revealed that SENP3 promoted mitochondrial translocation of dynamin-related protein 1 (Drp1) in reperfused myocardium. In addition, mitochondrial division inhibitor-1 (Mdivi-1), a pharmacological inhibitor of Drp1, significantly attenuated the exaggerated mitochondrial abnormality and cardiac injury by SENP3 overexpression after MIR injury. Taken together, we provide the first direct evidence that SENP3 upregulation pivotally contributes to MIR injury in a Drp1-dependent manner, and suggest that SENP3 suppression may hold therapeutic promise for constraining MIR injury.