Study on the Mechanism of miR-125b-5p Affecting Melanocyte Biological Behavior and Melanogenesis in Vitiligo through Regulation of MITF.

Objective: The goal was to confirm the mechanism by which miR-125b-5p influences melanocyte biological behavior and melanogenesis in vitiligo by regulating MITF. Methods: oe-MITF, sh-MITF, miR-125b-5p mimic, NC-mimic, NC-inhibitor, and miR-125b-5p inhibitor were transfected into cells by cell transfection. Western blotting was used to detect the related protein expression, qRT-PCR was used to detect miR-125b-5p and MITF expression, immunohistochemistry was used to detect the MITF-positive cells in vitiligo patients tissues, and a dual-luciferase reporter system was used to detect the target of miR-125b-5p and MITF. PIG1 and PIG3V cell proliferation by the CCK-8 method, cell cycle progression and apoptosis by flow cytometry, apoptosis was detected by TUNEL, Tyr activity and melanin content were measured using Tyr and melanin content assay kits. Results: Compared with the healthy control group, the expression of miR-125b-5p in the tissues and serum of vitiligo patients was upregulated, and the expression of MITF was downregulated; compared with PIG1 cells, the expression of miR-125b-5p and MITF in the PIG3V group was consistent with the above. Compared with the NC-minic group, the cell proliferation activity of the miR-125b-5p mimic group decreased, apoptosis increased, and the expression levels of melanogenesis-related proteins Tyr, Tyrp1, Tyrp2, and DCT were downregulated. Compared with the NC-inhibitor group, the above indices in the miR-125b-5p inhibitor group were all opposite to those in the miR-125b-5p mimic group. Transfection of oe-MITF into the miR-125b-5p mimic group reversed the effect of the miR-125b-5p mimic, while transfection of sh-MITF enhanced the effect of the miR-125b-5p mimic. Conclusion: miR-125b-5p affects vitiligo melanocyte biological behavior and melanogenesis by downregulating MITF expression.