[Mechanisms of HNE mediated NLRP3 promoting EMT in chronic rhinosinusitis with polyps]

Objective:The mucosa of Chronic rhinosinusitis with nasal polyps（CRSwNP） is accompanied by tissue remodeling. Epithelial-mesenchymal transition（EMT） plays an important role in tissue remodeling, but the mechanism of EMT is not yet clear. The purpose of this study is to further clarify the pathogenesis of CRSwNP and provide another idea and theoretical basis for the treatment of CRSwNP. Methods:①The expression of NLRP3 and EMT-related protein（E-cadherin, Vimentin） in the nasal mucosa of the CRSwNP group and the normal control group were detected by immunohistochemistry（IHC）. ②Primary human nasal epithelial cells（HNECs） were cultured in vitro, and HNE-intervened cells with different concentrations（0, 10, 25, 50, 100 ng/mL） were used. After stimulation for 24 h, mRNA and protein expressions of E-cadherin, Vimentin, NLRP3 were detected by qRT-PCR and western blotting. ③Cells were collected at 0, 24, 36, 48 and 72 hours later after incubation with HNE with the optimal concentration, and the mRNA and protein expressions of E-cadherin, Vimentin and NLRP3 were detected by qRT-PCR and western blotting. ④Primary human nasal epithelial cells were pretreated with NLRP3 inhibitor MCC950, then stimulated with HNE, and EMT-related proteins（E-cadherin, Vimentin） and NLRP3 expression were detected by qRT-PCR and western blotting. Results:①The expression levels of NLRP3 and Vimentin in nasal polyps of CRSwNP patients were higher than those of control group, and the expression of E-cadherin was lower（P<0.05）. The mRNA and protein expression levels of NLRP3 and Vimentin increased when HNE stimulated primary human nasal epithelial cells, while the expression of E-cadherin decreased. ②The effect was most significant when the HNE stimulated nasal mucosal epithelial cells were exposed to 50 ng/mL（P<0.05）. The primary human nasal epithelial cells were stimulated with 50 ng/ml HNE, and the effect was most significant when the duration of HNE exposure was 36 h（P<0.05）. ③Primary human nasal epithelial cells were pretreated with MCC950 and then stimulated with HNE. The mRNA and protein expression levels of E-cadherin in the NLRP3 inhibitor pretreated group were increased, while the mRNA and protein expression levels of Vimentin and NLRP3 were decreased（P<0.05）. Conclusion:ln CRSwNP, HNE promotes EMT in human nasal mucosal epithelial cells by activating NLRP3.