Role of TRPV1 and TRPA1 in TSLP production in nasal epithelial cells.

ABSTRACT

BACKGROUND: TRP protein is sensitive to external temperature changes, but its pathogenic mechanism in the upper airway mucosa is still unclear. OBJECTIVE: To investigate the mechanism of TRPV1and TRPA1 in regulating the secretion of inflammatory factors in nasal epithelial cells. METHODS: The expression of TRPV1 and TRPA1 in nasal mucosal epithelial cells was investigated using immunofluorescence assays. Epithelial cells were stimulated with TRPV1 and TRPA1 agonists and antagonists, and changes in Ca2+ release and inflammatory factor secretion in epithelial cells were detected. TSLP secretion stimulated with the calcium chelating agent EGTA was evaluated. The transcription factor NFAT was observed by immunofluorescence staining. RESULTS: TRPV1 and TRPA1 expression was detected in nasal epithelial cells, and Ca2+ influx was increased after stimulation with agonists. After the activation of TRPV1 and TRPA1, the gene expression of TSLP, IL-25, and IL-33 and the protein expression levels of TSLP and IL-33 were increased, and only TSLP could be inhibited by antagonists and siRNAs. After administration of EGTA, the secretion of TSLP was inhibited significantly, and the expression of the transcription factor NFAT in the nucleus was observed after activation of the TRPV1 and TRPA1 proteins in epithelial cells. CONCLUSION: Activation of TRPV1 and TRPA1 on nasal epithelial cells stimulates the generation of TSLP through the Ca2+/NFAT pathway. It also induces upregulation of IL-25 and IL-33 gene expression levels and increased levels of IL-33 protein, leading to the development of airway inflammation.