NAcM‐OPT protects keratinocytes from H 2 O 2 ‐induced cell damage by promoting autophagy

Abstract This study aimed to investigate the protective effect of NAcM‐OPT, a small molecule inhibitor of defective in cullin neddylation 1 (DCN1), on H 2 O 2 ‐induced oxidative damage in keratinocytes. Immortalized human keratinocytes (HaCaT cells) were treated with NAcM‐OPT and exposed to oxidative stress. CCK‐8 assays were used to measure cell viability. The mGFP‐RFP‐LC3 dual fluorescent autophagy indicator system was utilized to evaluate changes in autophagic flux. Western blotting was used to measure the expression of the autophagy‐related proteins LC3 and Beclin 1. Keratinocytes were treated with the autophagy activator rapamycin, and HaCaT cell supernatant was added to PIG1 cells (immortalized human melanocytes), followed by evaluation of tyrosinase ( TYR ) expression via qRT‐PCR. NAcM‐OPT increased cell viability and cell proliferation. Furthermore, this molecule promoted autophagic flux through increased expression of autophagy‐related proteins under H 2 O 2 ‐induced oxidative stress. Additionally, rapamycin increased the mRNA levels of TYR in PIG1 cells. Moreover, NAcM‐OPT alleviated mitochondrial damage, restored mitochondrial function, and upregulated the expression of NFE2L2 , HO1 , NQO1 , and GCLM . Importantly, NAcM‐OPT also increased epidermal thickness, follicle length, and melanin synthesis under oxidative stress in vivo. These findings suggest that NAcM‐OPT may be a promising small molecule antioxidant drug for the treatment of vitiligo.