METTL3 regulates PM2.5-induced cell injury by targeting OSGIN1 in human airway epithelial cells.

N6-methyladenosine (m6A) is implicated in alteration of cellular biological processes caused by exogenous environmental factors. However, little is known about the role of m6A in airborne fine particulate matter (PM2.5)-induced adverse effects. Thus, we investigated the role of m6A modification in PM2.5-induced airway epithelial cell injury. We observed a methyltransferase-like 3 (METTL3)-dependent induction of m6A modification after PM2.5 treatment in HBE and A549 cells. METTL3 knockdown attenuated PM2.5-induced apoptosis and arrest of cell cycle. mRNA sequencing and RNA N6-methyladenosine binding protein immunoprecipitation (Me-RIP) assay identified m6A-modified oxidative stress induced growth inhibitor 1 (OSGIN1) as the target gene of METTL3. Knockdown of METTL3 resulted a shorter mRNA half-life of OSGIN1 by catalyzing its m6A modification. Knockdown of METTL3 or OSGIN1 attenuated cell apoptosis, arrest of cell cycle and autophagy induced by PM2.5. In conclusion, METTL3 may mediate PM2.5-induced cell injury by targeting OSGIN1 in human airway epithelial cells. Our work uncovered a critical role of METTL3 in PM2.5-induced airway epithelial cell injury and provided insight into the vital role of m6A modification in PM2.5-induced human hazards.