N6-methyladenosine mediates Nrf2 protein expression involved in PM2.5-induced pulmonary fibrosis

作者：Ding Ji, Chenxi Hu, Jie Ning, Xiaoling Ying, Haiqing Zhang, Bohan Zhang, Bixia Liu, Qingping Liu, Weidong Ji, Rong Zhang · 发表于：Ecotoxicology and Environmental Safety · 年份：2023 · DOI：10.1016/j.ecoenv.2023.114755 · 被引用次数：34 · 研究领域：RNA modifications and cancer、HVDC Systems and Fault Protection、Energy and Environment Impacts

It has been reported that particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) could induce epithelial–mesenchymal transition (EMT)- and extracellular matrix (ECM)-related pulmonary fibrosis (PF). The transcription factor Nrf2 alleviated PM2.5-induced PF by antagonizing oxidative stress. The N6-methyladenosine (m6A) modification plays a significant role in the stress response. However, the effect of m6A modification on the mechanisms of Nrf2-mediated defense against PM2.5-induced PF remained unknown. Here, we explored the role and the underlying molecular mechanisms of m6A methylation of Nrf2 mRNA in PM2.5-induced PF. We established filtered air (FA), unfiltered air (UA), and concentrated PM2.5 air (CA) group mice model and 0, 50, and 100 μg/mL PM2.5-treated 16HBE cell models. The extent of lung fibrosis in mice and fibrosis indicators were detected by histopathological analysis, immunohistochemical staining and western blotting. The molecular mechanism of m6A-modified Nrf2 was demonstrated by m6A-methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation (RIP), qRT-PCR and T3 ligase-based PCR. Our data showed that PM2.5 exposure for 16 weeks could induce pulmonary fibrosis and activate Nrf2 signaling pathway. m6A methyltransferase METTL3 was upregulated after PM2.5 treatment in vivo and in vitro. Moreover, METTL3 mediated m6A modification of Nrf2 mRNA and promoted Nrf2 translation in mice and 16HBE cells after PM2.5 exposure. Mechanistically, three m6A...