Oxidative stress: One potential factor for arsenite-induced increase of N6-methyladenosine in human keratinocytes.

N6-methyladenosine (m6A) modification is affected by oxidative stress and gets involved in arsenite toxicity. However, whether oxidative stress is one factor in arsenite-induced alteration of m6A levels remains unclear. Here, reactive oxygen species (ROS), product of lipid peroxidation (MDA), antioxidants (GSH and SOD), m6A levels, m6A methyltransferases (METTL3, METTL14, and WTAP) and demethylases (FTO and ALKBH5) were detected in human keratinocytes exposed to different concentrations of arsenite. Antioxidant N-acetylcysteine was used to assess the influence of arsenite-induced oxidative stress on m6A modification. Possible regulations of m6A modification induced by arsenite were explored using bioinformatic analysis. Our results demonstrated that arsenite-induced oxidative stress increased the levels of m6A methylation possibly by mediating m6A methyltransferases and demethylases, especially elevated expressions of WTAP and METTL14, in human keratinocytes. Whereas N-acetylcysteine suppressed the elevated m6A level and its methyltransferases in human keratinocytes exposed to arsenite. Furthermore, arsenite-induced oxidative stress might mediate m6A methyltransferases and demethylases by reducing transcription of 4 genes (HECTD4, ABCA5, SLC22 A17 and KCNQ5) according to our bioinformatic analysis and experiments. Additionally, GO and Pathway analysis further suggested that the increase of m6A modification in arsenite-induced oxidative stress might be involved in some biological processes such as positive regulation of GTPase activity, apoptotic process, and platelet activation. Taken together, our study revealed the significant role of oxidative stress in m6A modification induced by arsenite.