The Role Of Relaxin-2 In Tissue Remodeling Of Cultured Nasal Polyps In Vitro

BACKGROUND:Relaxin is a small peptide hormone that regulates extracellular matrix remodeling and reduces fibrosis in a number of organs.However,the role of relaxin in the process of tissue remodeling of chronic rhino sinusitis(CRS)remains unclear,especially in the reconstruction of nasal polyps.OBJECTIVE:The aim of this study was to detect the expression of human H2relaxin(Relaxin-2)in CRS and to detect relaxin-2 and TGF-β1(Transforming Growth Factor-beta 1)in cultured nasal polyps,further explore the role of relaxin-2 in the reconstruction of nasal polyps.MATERIALS AND METHODS:45 patients were collected and divided into 3 groups: chronic rhino sinusitis with nasal polyps(CRSwNP;n = 15),chronic rhino sinusitis without nasal polyps(CRSsNP;n = 15)and controls(n = 10).Tissue samples were detected by Masson trichrome staining for collagen,while the location and expression of relaxin-2,TGF-β1,and phosphorylated(p)Smad2/Smad3 were analyzed by immunohistochemistry and Western blot.The expression of relaxin-2,Smad2,Smad3 and TGF-β1 mRNA was tested by quantitative polymerase chain reaction(qPCR).Ex vivo nasal polyps were treated with relaxin-2(n = 15)or TGF-β1(n = 15).Collagen type I(collagen I),relaxin-2 and TGF-β1 levels in the culture supernatants were examined by enzyme-linked immunosorbent assay(ELISA),while pSmad2/Smad3 in culture pellets was analyzed by Western blot and the expression of Smad2 and Smad3 mRNA was tested by qPCR.RESULTS:The expression levels of collagen,relaxin-2,TGF-β1,and pSmad2/Smad3 were significantly decreased in the CRSwNP group compared with the CRSsNP group and control groups(P < 0.05).The mRNA expression of relaxin-2,Smad2,Smad3 and TGF-β1 in the CRSsNP group was significantly higher than in the CRSwNP and control groups(P < 0.05).Compared with the ex vivo controls,in CRSwNP,the levels of TGF-β1,collagen I,pSmad2/Smad3,Smad2 and Smad3 were significantly decreased after relaxin-2 treatment.However,relaxin-2,collagen I,pSmad2/Smad3,Smad2 and Smad3 were remarkably increased after TGF-β1 treatment.CONCLUSIONS:Tissue level detection and in vitro primary tissue stimulation showed that relaxin-2 plays an important role in the tissue remodeling of CRSwNP,which may be an important cause of collagen reduction and tissue edema innasal polyps.The anti-fibrotic effects of relaxin-2 may play a role in the tissue remodeling of CRSwNP,but the detailed mechanism deserves further study.