Allergen-Induced Epithelial Senescence Drives Airway Inflammation via the AhR-c-Myc Axis

Background: Environmental allergens can induce epithelial cellular senescence, which contributes to airway inflammation. The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor responsive to environmental stimuli, may regulate this process. Objectives: We sought to determine whether epithelial AhR controls cellular senescence and to define its underlying mechanisms in allergic airway inflammation. Methods: Club cell-specific p16 conditional knockout mice (p16ΔScgb1a1) were used to assess the role of epithelial senescence and allergic airway inflammation. AhR regulation of senescence was examined using AhR agonist, antagonist, and Club cell-specific AhR-deficient mice (AhRΔScgb1a1) in both in vitro and in vivo models. Bulk RNA-seq was performed to identify AhR-regulated, senescence-associated genes, and immunoprecipitation (IP) along with ChIP-PCR was employed to validate AhR-target gene interactions. Results: Single-cell transcriptomics revealed epithelial senescence as a key feature of allergen-induced asthma. p16ΔScgb1a1 mice exhibited reduced cockroach allergen–induced airway inflammation and decreased Th2/Th17 cytokines in bronchoalveolar lavage fluids (BALFs). AhR signaling was enhanced in airway epithelial cells of allergen-treated asthmatics and regulated senescence, as indicated by SA-β-gal activity and expression of Cdkn2a, Cdkn1a, and γH2AX. The AhR agonist VAF347 suppressed, whereas AhRΔScgb1a1 deficiency exacerbated, airway inflammation. RNA-seq identified senescence as a major AhR-regulated pathway, highlighting c-Myc, TGF-β2, IGFBP3, and SERPINE1 as key targets. AhR binding to the c-Myc promoter was validated, and c-Myc inhibition with EN4 reduced allergen-induced senescence and inflammation. Conclusions: Epithelial AhR suppresses allergen-induced senescence and airway inflammation through direct regulation of c-Myc. These findings establish the AhR–c-Myc axis as a potential therapeutic target in allergic asthma.