Study of the mechanism of methyltransferase 3 regulation of ferroptosis in allergic rhinitis and promotion of allergic rhinitis in an m6A-dependent mechanism.

OBJECTIVE: This study aimed to investigate the regulation of allergic rhinitis (AR) by methyltransferase 3 through an m6A-dependent mechanism, providing a theoretical foundation for its treatment. METHODS: An in vitro experiment was conducted in which HNEpC cells were stimulated with IL-13 (50 ng/mL) to create an AR cell model. After establishing the AR cell model, the cells were treated with DAA (m6A inhibitor) and separated into three groups: Control group, shNC group and shMETTL3 group.m6A-RIP assessed the m6A modification level of PTBP1 mRNA, while RIP was used to analyze the interaction between METTL3 and PTBP1 mRNA. On the shMETTL3 background, PTBP1 or TXNIP was re-expressed with or without the ferroptosis inhibitor ferrostatin-1 (Fer-1). Endpoints included serum cytokines/immunoglobulins (IFN-γ, IL-1β, IL-18, TGF-β, IL-4, IL-10, IgE, IgG2a, IgG1) and oxidative-stress indices (GSH, SOD, MDA) by ELISA, alongside nasal-mucosa western blots for GPX4, Nrf2, MnSOD, ACSL4, METTL3, PTBP1, and TXNIP. RESULTS: In vitro, shMETTL3 reduced m6A on PTBP1 mRNA and lowered PTBP1 expression. In vivo, the AR condition was associated with higher circulating IFN-γ, IL-1β, IL-18, IL-4, IL-10, IgE, IgG1, and IgG2a, together with lower TGF-β, GSH, and SOD, and a ferroptosis-prone protein profile characterized by reduced GPX4, Nrf2, and MnSOD and increased ACSL4, PTBP1, and TXNIP in nasal mucosa. Silencing METTL3 shifted these readouts toward an anti-oxidant, anti-ferroptotic state, normalizing cytokines/immunoglobulins, raising GSH and SOD while lowering MDA, and restoring a protein pattern with higher GPX4, Nrf2, and MnSOD and lower ACSL4, PTBP1, and TXNIP. Re-expression of PTBP1 or TXNIP on the shMETTL3 background attenuated these improvements and reinstated AR-like oxidative and ferroptotic features. Notably, co-administration of ferrostatin-1 with either overexpression condition re-established antioxidant capacity (higher GSH and SOD with lower MDA) and returned the Western-blot profile toward protection, consistent with a METTL3/PTBP1/TXNIP pathway that promotes ferroptotic and oxidative injury and with the capacity of pharmacologic ferroptosis blockade to counteract it. CONCLUSION: Methyltransferase 3 potentially modulates ferroptosis and oxidative stress linked to AR through an m6A-dependent mechanism, thereby alleviating symptoms in AR mice.