Fig. 6: Schematic model illustrating the molecular mechanism of claudin1 downregulation exacerbates mice asthma.

Our working hypothesis was that claudin1 downregulation exacerbated HDM-triggered airway mucus secretionvia inducing the overexpression of MUC5AC. EGFR activation or transactivation in response to EGFR ligands (such as EGF or HBEGF) or IL-13 reduced expression of claudin1. Erlotinib, which inhibited EGFR signaling, reduced MUC5AC expression via restoring claudin1 expression.