罗格列酮抑制糖基化终产物诱导心肌成纤维细胞增殖和结缔组织生长因子及Smad的表达

目的 探讨糖基化终产物(AGE)对培养乳鼠心肌成纤维细胞增殖、结缔组织生长因子(CTGF)和Smad2、Smad4蛋白表达的影响及罗格列酮的干预作用.方法 采用胰酶消化法和差速贴壁分离法获取心肌成纤维细胞,应用MTT法、流式细胞仪法分别观察不同浓度AGE及罗格列酮对心肌成纤维细胞的细胞增殖、细胞周期的影响,ELISA方法 检测细胞培养上清中TGF-β1水平,Westem印迹技术检测CTGF及Smad2、Smad4蛋白质表达.结果 在一定浓度范围内,AGE干预心肌成纤维细胞,随浓度的增加,细胞增殖更加显著,TGF-β1分泌增加,CTGF蛋白表达增加.罗格列酮(0.1、1、10μmoVL)干预后,随浓度的增加,抑制心肌成纤维细胞增殖(分别为0.823±0.072、0.785±0.060、0.601±0.081对0.981±0.049,P<0.05)、抑制心肌成纤维细胞分泌TGF-β1(分别为257.77±9.09、230.29±6.56、200.84±10.26对300,68±8.56,P<0.01)、抑制CTGF蛋白表达的作用都更加显著(分别为0.769±O.108、0.590±0.095、0.534±0.115对1.021±0.113,P<0.01).罗格列酮(1和10μmol/L)干预后可显著减少AGE诱导的Smad2的蛋白表达(分别为0.424±0.059对0.572±0.073,P<0.05;0.396±0.080对0.572±0.073,P<0.01),同时可显著减少AGE诱导的Smad4的蛋白表达(分别为0.580±0.063对0.672±0.059,P<0.05;0.556±0.051对0.672±0.059,P<0.01).结论 AGE刺激心肌成纤维细胞增殖及分泌TGF-β1,同时诱导CTGF、Smad2及Smad4蛋白表达,罗格列酮在一定程度上抑制AGE上述作用,表明罗格列酮抑制心肌成纤维细胞增殖的效应与CTGF/Smad通路密切相关.

Inhibition of rosiglitazone on the proliferation, connective tissue growth factor and Smad expression in cultured cardiac fibroblasts induced by advanced glycosylation end-products

Objective To investigate the effects of rosiglitazone on the proliferation,connective tissue growth factor and Smad expression in cultured cardiac fibroblasts induced by advanced glycosylation end-products (AGEs).Methods After being treated with various amounts of rosiglitazone,the cultured neonatal rat cardiac fibroblasts were incubated with AGEs.The status of cardiac fibroblasts proliferation and cell cycle were detected by 3-(4,5-dimethyhhiazol-2-yl) -2,5-diphenyl tetrazolium bromide (MTI) assay and flow cytometry.Furthermore,ELISA technique was applied to identify the level of TGF-β1.The protein expressions of CTGF and Smad in cardiac fibroblasts of neonatal SD rats were detected with Western blotting.Results The exposure of cardiac fibroblasts to AGEs at doses of 0-200 mg/L induced a dose-dependent increase in cell proliferation.At the concentration of rosiglitazooe (0.1,1,and 10 μmol/L),the cell proliferation was reduced compared with 200 mg/L AGEs group by O.823±0.072,0.785±0.060,0.601±0.081 vs 0.981±0.049,respectively (P < 0.05).The increased levels of TGF-β1 in supematants of cultured cardiac fibroblasts stimulated by AGEs were inhibited by rosiglitazone at the concentrations of 0.1,1,10μmol/L by 257.77±9.09,230.29±6.56,200.84±10.26 vs 300.68±8.56,respectively (vs 200 mg/L AGEs,P<0.01).Western blot indicated that pretreatment with rosiglitazone (0.1,1,and 10 μmol/L) inhibited CTGF protein production in a dose-dependent by 0.769±0.108,0.590±0.095,0.534±0.115 vs 1.021±0.113,respectively (vs 200 mg/L AGEs,P<0.01).It was also demonstrated that pretreatment with rosiglitazone (1 and 10 μmol/L) inhibited Smad2 protein production by 0.424±0.059,0.396±O.080 vs 0.572±0.073,respectively (vs 200 mg/L AGEs,P < 0.05 or P < 0.01).Meanwhile pretreatment with rosiglitazone (1 and 10 μmol/L) inhibited Smad4 protein production by 0.580±0.063,0.556±0.051 vs 0.672±0.059,respectively (vs 200 mg/L AGEs,P < 0.05 or P < 0.01).Conclusions The findings suggest that AGEs promote the proliferation of cardiac fibroblasts and stimulate the protein production of Smad and CTGF of cardiac fibroblasts.Rosiglitazone inhibits the above reaction.These results indicate that CTGF/Smad pathway may play an important role in the protective effect of rosiglitazone on myocardial fibrosis.