Homocysteine induces mitochondrial dysfunction and oxidative stress in myocardial ischemia/reperfusion injury through stimulating ROS production and the ERK1/2 signaling pathway

Acute oxidative stress and mitochondrial dysfunction are crucial for acute myocardial ischemia-reperfusion (AMI/R) injury, which may induce cell or mitochondrial membrane rupture and myocardial infarction. Plasma homocysteine (Hcy) expression levels are positively associated with risk of cardiovascular disease, and ERK1/2 exert anti-apoptotic and cardioprotective effects on AMI/R injury. However, the precise molecular mechanism of action underlying the effects of Hcy and the ERK1/2 signaling pathway on mitochondrial dysfunction and oxidative stress in AMI/R injury remains unclear. In the present study, AMI/R injury models were established in an animal model treated with Hcy and in H9C2 cells that were treated with hypoxia-reoxygenation. Mitochondrial function and oxidative stress were evaluated. The results demonstrated that Hcy enhanced ERK1/2 protein expression levels and oxidative stress, induced cytochrome c translocation and mitochondria dysfunction, and caused cardiac dysfunction in rats with AMI/R injury. However, an ERK1/2 inhibitor effectively protected AMI/R injury rats from Hcy-induced cardiac dysfunction and oxidative stress. In conclusion, Hcy induced mitochondrial dysfunction and oxidative stress in AMI/R injury through stimulating ROS production and the ERK1/2 signaling pathway. An ERK1/2 inhibitor may be an effective new therapeutic method for treating Hcy-induced cardiac dysfunction in patients with AMI/R injury.