Effects Of Alpha-lipoic Acid On The Proliferation And Collagen Production Of Cardiac Fibroblasts Induced By High Glucose And Its Possible Molecular Machenism

ObjectiveTo study the effect of alpha-lipoic acid（α-LA） on cardiac fibroblastscincrease and Collagen synthesis in high glucose environment, and to futherexplore the effect of α-LA on p38mitogen-aetivated protein kinase（p38MApK）and transforming growthfactor betal（TGF-β₁） Smad3and Smad7.To expoundthe protect effect of α-LA on cardiac.MethodsThe differential adherence method was used to draw2-3postnatal daySprague-Dawley（SD） rats CFb.Then putting into containing10%fetal bovineserum low glucose DMEM medium.Cutured in37℃、5%CO₂constanttemperature incubation box,passage waiting for the CFb growth close to thefusion with1:2.2-3generation was used in the expriment.Mediums were dividedinto five groups according to the different culture media:Normal glucosegroup（NG5.5mmol/L glucose）;High glucose group（25.5mmol/L glucose）;Themedicine intervention group:High glucose+100、200、300μmol/Lα-LA，HG+p38MAPK inhibitor group（HG+10μmol/L SB203580）.each group has6holes.Cell multiplications was detected by Methyl thiazolyl tetrazolium（MTT）.The content of collagen Ⅰ was detected by Elisa.The protein of TGF-β₁、p38MAPKwere detected by Western blots.The mRNA levels of SMAD3、SMAD7weredetected by RT-PCR.Results1. Proliferation action of each group:Compared with normal glucosegroup,high glucose promotes proliferation of cardiac fibroblasts,MTT-ODvalues increased;Compared with high glucose,proliferation of cardiacfibroblasts of α-LA treatment groups were significantly inbited,MTT-ODvalues decreased（P<0.05）, Inhibitory effect of high glucose+200μmol/Lα-LAgroup was lager than high glucose+100μmol/Lα-LA group,highglucose+300μmol/Lα-LA group was lager than high glucose+200μmol/Lα-LA group,and then concentration-dependent（P<0.01）;2. Effect of each group on the expression of collagen Ⅰ:Compared with normalglucose group,the expression of collagen Ⅰon high glucose group wereincreased signficantly（P<0.01）,Cells were offered with differentconcentration α-LA after24h stimulate,compared with high glucose,theprotein levels of collagen Ⅰwas significantly lower.Inhibitory effect of highglucose+200μmol/Lα-LA group was lager than high glucose+100μmol/Lα-LA group,high glucose+300μmol/Lα-LA group was lager than highglucose+200μmol/Lα-LAgroup,and then concentration-dependent（P<0.01）;Compared with high glucose group,the expression of collagen Ⅰ of highglucose+10μmol/L SB203580was significantly decreased（P<0.05）.3. The protein expression of p38MAPK and TGF-β₁on each group:Comparedwith normal glucose,the protein expression of p38MAPK and TGF-β₁wereincreased;compared with high glucose,the protein expression of p38MAPKand TGF-β₁of α-LA treatment groups were decreaced （P<0.05）.4. The mRNA levels of SMAD3、SMAD7on each group:Compared with normalglucose,high glucose promotes the mRNA levels of SMAD3in fibroblast（P<0.01）,the mRNA levels of SMAD7was decreased（P<0.01）.Compared with high glucose,the mRNA levels of SMAD3of α-LA treatment groups weredecreased,the mRNA levels of SMAD7were increased（P<0.01）.ConclusionThe experimental results show that high glucose have proliferation effect onmyocardial fibroblasts; Promote Ⅰtype collagen protein expression increased;Raised the TGF–β₁, p38MAPK protein and SMAD3mRNA expression level;reduceSMAD7mRNA expression level. Alpha-lipoic inhibits collagen productionvia P38MAPK signaling pathway under high glucose condition.