MicroRNA-145-5p Protects Human Melanocytes Against Oxidative Damage by Targeting Transient Receptor Potential Melastatin 2 (TRPM2)

Background: Oxidative stress was reported to be involved in the progression of vitiligo. microRNAs (miRNAs) have been confirmed to display critical roles in vitiligo. In this study, we conjectured that miR-145-5p might be related to the development of vitiligo by regulating the key genes expression in melanocytes. Methods: H2O2 was used to induce the dysfunction of melanocytes. The levels of TRPM2 and miR-145-5p in H2O2-induced human primary melanocytes were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). TargetScan and Dual luciferase reporter gene assay were conducted to confirm the correlation between miR-145-5p and TRPM2. Cell viability and apoptosis were determined using MTT and Flow cytometry analysis. Reactive oxygen species (ROS), antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were determined using specific assay kits. The levels of cleaved caspase-3 and pro-Caspase3 were measure by western blotting. Results: TRPM2 was upregulated while miR-145-5p was downregulated in H2O2-induced human primary melanocytes. Dual luciferase reporter assay confirmed that TRPM2 was a target gene of miR-145-5p. miR-145-5p mimic transfection significantly increased cell viability and inhibited cell apoptosis in H2O2-treated melanocytes. In addition, overexpression of miR-145-5p enhanced the antioxidant activity of SOD and CAT, and decreased intracellular ROS accumulation. Notably, these findings were abolished by TRPM2-plasmid. Conclusions: Taken together, our study demonstrated that oxidative stress induced up-regulation of TRPM2 and down-regulation of miR-145-5p in melanocytes. In addition, overexpression of miR-145-5p alleviated melanocytes destruction via targeting TRPM2. These results indicated that miR-145-5p might serve as a potential target for anti-oxidative therapy in vitiligo.