Fine particulate matter exacerbates childhood asthma via DNMT3A-mediated modulation of GPX4 DNA methylation.

Fine particulate matter measuring less than 2.5 μm in diameter (PM(2.5)) is a significant risk factor for acute asthma episodes in children. Nevertheless, the biological mechanism that underpins this correlation remains unclear. Here, we found that PM(2.5)-induced inflammatory cell infiltration and aggravated childhood asthma in a ferroptosis-dependent manner. GPX4 overexpression could reverse the PM(2.5)-induced increase in reactive oxygen species (ROS), malondialdehyde (MDA), and inflammatory factors, as well as the decrease in mitochondrial membrane potential. Mechanistically, PM(2.5) elevated DNMT3A expression and hypermethylated the promoter region of GPX4, leading to reduced GPX4 expression and promoting ferroptosis. Furthermore, the status of GPX4 DNA methylation was significantly associated with IL-6/8 levels in mild/moderate and severe childhood asthma patients. In conclusion, our research highlights the critical interplay between PM(2.5) exposure, DNA methylation, and ferroptosis in asthma exacerbation, providing clues for the treatment of childhood asthma.