The protective effect of EGF-activated ROS in human corneal epithelial cells by inducing mitochondrial autophagy via activation TRPM2.

Abstract

Oxidative stress is a major pathogenesis of some ocular surface diseases. Our previous study demonstrated that epidermal growth factor (EGF)-activated reactive oxygen species (ROS) could protect against human corneal epithelial cell (HCE) injury. In the present study, we aimed to explore the role and mechanisms of oxidative stress and mitochondrial autophagy in HCE cells subjected to scratch injury. CCK-8 assays, EdU assays, Western blot analysis, wound-healing assays, and flow cytometry were conducted to determine cell viability, proliferation, protein expression, cell apoptosis, and intracellular ROS levels, respectively. The results showed that EGF could promote damage repair and inhibit cell apoptosis in scratch injured HCE cells by upregulating ROS (**p < .01, ***p < .001). EGF also induced mitochondrial autophagy and alleviated mitochondrial damage. Interestingly, the combination of the mitochondrial autophagy inhibitor and mitochondrial division inhibitor 1 (MDIVI-1) with EGF could reduce cell proliferation, viability, and the ROS level (*p < .05, **p < .01, ***p < .001). Treatment using the ROS inhibitor N-acetyl- l-cysteine abrogated the increase in mitochondrial membrane potential after EGF treatment. (*p < .05). Taken together, these findings indicated that EGF plays an important role in HCE damage repair and could activate ROS to protect against HCE injury by inducing mitochondrial autophagy via activation of TRPM2.