Study On The Protective Mechanism Of Hydrogen Sulfide On Pulmonary Fibrosis

Objective:To investigate the inhibitory effects of sodium hydrogen sulfide（NaHS）on the activation of human embryonic lung fibroblasts.Methods:The synchronized human embryonic lung fibroblast cells were randomly divided into 5 groups:（1）Control group:no treatment;（2）Model group:5μg/L TGF-β1;（3）Low-dosage group:5μg/L TGF-β1+100μmol/L Na HS;（4）High-dosage group:5μg/L TGF-β1+300μmol/L NaHS;（5）NaHS-blank group:300μmol/L NaHS.NaHS was treated 30mins before the addition of TGF-β1.Cell proliferation was detected by MTT;the expression of miR-21 and miR-155a were detected by qPCR;and the protein expressions of Smad3 in TGF-β1signal pathway and p42/44 and p38 in Mitogen-activated Protein Kinase（MAPK）signal pathway were measured by Western Blot.Results:The MTT method showed that stimulation with fetal bovine serum（1¹0%）for 24 hours increased the number of cells（P<0.005）,and the proliferative effect was most obvious in 10%fetal bovine serum（FBS）group.Pretreatment of NaHS（10¹00μM）decreased the number of cells induced by FBS（P<0.005）and the antiproliferative effect of Na HS was most obvious in the 100μM and 500μM NaHS groups.The results of qPCR showed that the expressions of miR-21 and miR-155a in the cells were increased significantly after stimulation with TGF-β1,but downregulated in the NaHS 30min pretreatment group（P<0.05）.RT-PCR and Western Blot showed that expressions of Fibronecin（FN）,alpha smooth muscle actin（a-SMA）,collagen-I（Col-I）,collagen-III（Col-III）,cystathionine gamma lyase（CSE）,p-Smad3,p-p42/44 in cells were significantly increased after stimulation with TGF-β1（P<0.05）.In addition,Western blot of p-p38showed no obvious trend,the result was not statistically significant.Conclusions:1.Exogenous H₂S is able to reduce the proliferation of human embryonic lung fibroblasts induced by FBS and inhibites the differentiation of those cells induced by TGF-β1.2.H₂S can inhibit the process of fibrosis by regulating the expressions of miR-21 and miR-155a.3.The mechanism of anti pulmonary fibrosis of H₂S is related to its inhibition of TGF-β1-Smad and MAPK signal transduction.