| ObjectiveIdiopathic pulmonary fibrosis(IPF)is a kind of pulmonary disease characterized by progressive,restricted to the lung,unexplained etiology,and chronic progressive pulmonary fibrosis with Honeycomb changes.The pathogenesis is still unclear and the prognosis is very poor.There is still no effective treatment in clinical.The main pathological features were the injury of alveolar epithelial cell,massive accumulation of fibroblasts and accumulation of extracellular matrix with usual interstitial pneumonia(UIP).Saikosaponin d(SSd)is the main active ingredient of Bupleurum chinense.Studies have shown that it has anti-inflammatory,anti-tumor and anti-organ fibrosis effects.This study was to investigate the effects of SSd on the proliferation and transformation of human embryonic lung fibroblasts induced by transforming growth factor-beta 1(TGF-β1)and the regulation of signal pathway of TGF-β1/Drosophila mothers against decapentaplegic protein(Smads)family.and further studying the mechanism of SSd in anti-pulmonary fibrosis,so as to provide a potential therapeutic target for the clinical treatment of IPF.MethodsHuman embryonic lung fibroblasts(HELF)were cultured in vitro and divided into 5 groups: a control group,1 ng/mL TGF-β1 induced group,1 ng/mL TGF-β1combined with 0.5 μmol/L SSD treatment group,1 ng/mL TGF-β1 combined with 1μmol/L SSD treatment group,1 ng/mL TGF-β1 combined with 2 μmol/L SSD treatment group.Cell viability of HELF was detected by CCK-8 assay,The expression of Smad2,Smad3 and Smad7 were detected by real-time fluorescence quantitative PCR,The protein levels of α-smooth muscle actin SMA(α-SMA),typeⅠcollagen(Col I),Smad2,Smad3,phosphorylated Smad2(p-smad2),p-smad3 and Smad7 were assessed by Western blot analysis.Results(1)Compared with the control group,the model group apparently increased,the protein levels of Col I and α-SMA increased(P<0.05),the mRNA levels of Smad2 andSmad3 increased significantly(P<0.05),and the mRNA expression of Smad7 decreased significantly(P<0.05),the protein phosphorylation levels of Smad2 and Smad3 increased significantly(P<0.05),and the protein expression of Smad7 decreased significantly(P<0.05).(2)Compared with the TGF-β1 induced group,The cell proliferation of HELFs in different concentrations of SSD treatment groups was reduced(P<0.01),which could reverse the changes of the above indicators,the effect of medium and high concentration group was obvious,showing a dose-effect relationship(P<0.05).ConclusionSSd could play an important role in anti-pulmonary fibrosis by regulating TGF-β1/Smads signaling pathway and inhibiting the proliferation of lung fibroblasts to myofibroblasts and collagen production. |
