The Mechanism Of Ginsenoside Rg1 In Alleviation Of Airway Remodeling In COPD

Objective:To investigate the effect and the related mechanism of ginsenoside Rg1 in epithelial mesenchymal transition(EMT)and extracellular matrix(ECM)deposition in chronic obstructive pulmonary disease(COPD).Methods:1.COPD rat models were induced by exposure to cigarette smoke.Ginsenoside Rg1 was intragastrically administered.(1)The pulmonary function test and lung histologic HE staining were used to evaluate emphysema and small airway destruction.(2)The expressions of E-cad and α-SMA were measured using immunohistochemistry assay,real-time PCR and western blot analysis to evaluate the effect of ginsenoside Rg1 on EMT.(3)Masson trichrome staining was used for collagen detection.The protein levels of MMP-9 and TIMP-1 in lung tissue were measured by western blot analysis to estimate the effect of ginsenoside Rg1 on ECM deposition.(4)The concentration of TGF-β1 in serum and Balf was measurd by ELISA.TGF-β1 m RNA and protein of lung tissue were detected by real-time PCR and western blot analysis.2.To investigate the anti-EMT role and underlying mechanism of ginsenoside Rg1 in human bronchial epithelia(HBE)cells stimulated by cigarette smoke extract(CSE).(1)The ultrastructure of HBE cells were detected by electron microscope.Protein levels of E-cad and α-SMA were measured using western blot analysis.(2)The concentration of TGF-β1 in supernatants was determined by ELISA.The expression of TGFβRI and the phosphorylation of Smad2 and Smad3 in HBE cells were detected by western blot analysis.The selective TGFβRI inhibitor SB525334 was used to inhibit the activated TGF-β1/Smad signaling pathway,followed by the detection of E-cad and α-SMA,and compared with the effect of ginsenoside Rg1.On the other hand,HBE cells were transfected with Smad3-plasmid in order to overexpress Smad3.The effect of ginsenoside Rg1 on EMT induced by upregulation of TGF-β1/Smad signaling pathway was determined by western blot analysis.3.To investigate the effect and underlying mechanism of ginsenoside Rg1 on fibroblast/myofibroblast transition and ECM deposition in human embryonic lung fibroblasts(MRC-5 fibroblasts)stimulated by CSE.(1)The ultrastructure of MRC-5 fibroblasts were detected by electron microscope.Protein levels of α-SMA,collagen I,MMP-9 and TIMP-1 were measured using western blot analysis.(2)The concentration of TGF-β1 in supernatants was determined by ELISA.The expression of TGFβRI and the phosphorylation of Smad2 and Smad3 in MRC-5fibroblasts were detected by western blot analysis.SB525334 was used to inhibit the activated TGF-β1/Smad signaling pathway,followed by the detection ofα-SMA,collagen I and MMP-9,and compared with the effect of ginsenoside Rg1.On the other hand,MRC-5 fibroblasts were transfected with Smad3-plasmid to overexpress Smad3.The effect of ginsenoside Rg1 on fibroblast/myofibroblast transition and ECM deposition induced by upregulation of TGF-β1/Smad signaling pathway was determined by western blot analysis.Result:1.Ginsenoside Rg1 ameliorated emphysema and airway destruction in COPD rats,improved pulmonary function,alleviated airway EMT and ECM deposition in lung tissue,and decreased the TGF-β1 expression in serum,Balf and lung tissue.2.Ginsenoside Rg1 alleviatged CSE-induce EMT in HBE cells through inhibition of the activation-associated phosphorylation of Smad2/3.3.Ginsenoside Rg1 suppressed CSE-induce fibroblast/myofibroblast transition and ECM deposition in MRC-5 fibroblasts through inhibition of the activation-associated phosphorylation of Smad2/3.Conclusion:Ginsenoside Rg1 protests against EMT and ECM depositon in lung tissue,which is partly mediated by inhibition of TGF-β1/Smad signaling pathway.This study indicates that ginsenoside Rg1 could act as an potent intervention against small airway fibrosis in COPD.