RESUMO
Objective To investigate the mechanism of matrix metalloproteinase(MMP)-9 involved in epithelial mesenchymal transformation(EMT)in chronic sinusitis(CRS).Methods The expression of MMP-9 from polypoid middle turbinate tissue was detected by immunohistochemical staining qPCR and Western blot assay in 42 patients with CRS and 8 patients underwent septoplasty.Primary human nasal epithelial cells HNEpc were cultured in vitro and divided into the control group,the TGF-β1 group(5 μg/L TGF-β1 intervention)and the TGF-β1+si-MMP-9 group(transfected with si-MMP-9 and 5 μg/L TGF-β1 intervention).The expression of MMP-9 was detected by cell immunofluorescence staining.Expression levels of TGF-β1,MMP-9 and EMT-related proteins E-cadherin,vimentin and α-SMA were detected by Western blot assay.Results(1)The positive expression rate of MMP-9 was significantly higher in the nasal mucosa of CRS with nasal polyps(CRSwNP)group(54.5%,12/22)than that of the CRS without polyps(25.0%,5/20)group and the control group(12.8%,1/8).The relative expression levels of MMP-9 mRNA and protein in nasal mucosa were higher in the CRSwNP group than those in the CRSsNP group and the control group(P＜0.05).(2)Compared with the control group,the expressions levels of TGF-β1,MMP-9,vimentin and α-SMA were increased in the TGF-β1 group,while the expression of E-cadherin was decreased(P＜0.05).Compared with the TGF-β1 group,expression levels of TGF-β1,MMP-9,vimentin and α-SMA were decreased in the TGF-β1+si-MMP-9 group,and the expression of E-cadherin was increased(P＜0.05).Conclusion The expression of MMP-9 is increased in CRS patients,which may be involved in the development of CRS through the regulation of EMT.