Overexpression of Ubiquinol-Cytochrome c Reductase Core Protein 1 May Protect H9c2 Cardiac Cells by Binding with Zinc

In several recent studies, proteomics analyses suggest that increase of ubiquinol-cytochrome c reductase core protein 1 (UQCRC1) is cardio-protective. However, direct evidence for this effect has not yet been obtained. Thus, the current study aimed to determine this effect and the mechanism underlying this effect. The results showed that overexpression of UQCRC1 protected H9c2 cardiac cells against in vitro simulated ischemia-reperfusion by maintaining mitochondrial membrane potential and suppressing the expression of caspase-3. These protective effects were significantly enhanced by exogenous Zn(2+) but completely abolished by Zn(2+)-selective chelator TPEN. Furthermore, the upregulation of UQCRC1 reduced the concentration of free Zn(2+) in mitochondria, whereas the downregulation of UQCRC1 increased the concentration of free Zn(2+) in mitochondria. In conclusion, the overexpression of UQCRC1 can protect H9c2 cardiac cells against simulated ischemia/reperfusion, and this cardio-protective effect is likely mediated by zinc binding.