Sulfur dioxide derivatives aggravated ovalbumin-induced asthma through targeting TRPV1 and tight junctions.

This study aimed to investigate the effects of sulfur dioxide (SO2) derivatives on asthma induced by ovalbumin (OVA). Sprague Dawley rats were sensitized to and challenged with OVA and SO2 derivatives (NaHSO3 and Na2SO3, 1:3 M/M) to establish 28-day (short-term) and 42-day (long-term) asthma models. Exposure to SO2 derivatives aggravated asthma and hence, promoted lung injury in OVA-induced asthma. In addition, it upregulated the protein expression of TRPV1 and downregulated the expression of tight junctions (TJs). These changes were dose-dependent and were more pronounced in the presence of a high concentration of SO2 derivatives. In vitro, SO2 derivatives also increased the calcium influx and TRPV1 protein expression, and decreased TJ expression. Besides, no significant difference in the TJ expression was found between the WT and TRPV1-/- mice. The underlying mechanism might be related to regulating the effects of TRPV1 and TJs.