METTL3 Deficiency in Macrophage Aggravates Neutrophilic Asthma by Regulating ZBP1-NLRP3 Inflammasome Activation

N6-methyladenosine (m6A), the most abundant RNA modification, plays the essential role in the immune disorders. Yet, the role of m6A and its master regulator, methyltransferase-like 3 (METTL3) in asthma remain ambiguous. Here, we found that macrophage deficient in METTL3 aggravates the ovalbumin/lipopolysaccharide (OVA/LPS)-induced neutrophilic asthma. Subsequently, we observed that METTL3 deficiency facilitates NLRP3 but not AIM2 and NLRC4-dependent inflammasome activation and IL-1β secretion. Mechanistically, METTL3 deficiency enhanced NLRP3 inflammasome activation were dependent on upregulation of ZBP1 and TRAF1. Lastly, we elucidated that METTL3 negatively regulates ZBP1 expression through m6A modification dependence. In summary, the study unveils the function of m6A in regulating NLRP3 inflammasome activation in macrophage and identifies potential targets in therapeutic intervention of neutrophilic asthma. BMDM cells from Lyz2-Cre-Mettl3fl/fl and Mettl3fl/fl mice were stimulated overnight with LPS (50 ng/ml), and then incubated with nigericin (10 μM) for 1 h or 3 h.