转化生长因子β1/Smad通路调控糜酶诱导的大鼠心脏成纤维细胞增殖

Effect of transforming growth factor-β1/Smad pathway on proliferation of chymase-induced cardiac fibroblasts

目的:探讨转化生长因子β1(TGF-β1)/Smad(线虫Sma分子和果蝇Mad分子的组合)信号通路对糜酶诱导大鼠心脏成纤维细胞(CFs)增殖的影响。方法:用胰酶消化法分离、培养新生SD大鼠的CFs。采用氚标记胸腺嘧啶核苷(3H-TdR)掺入法测定CFs的DNA合成,Westernblot检测TGF-β1、Smad2/3、p-Smad2/3及Smad7的蛋白的表达。结果:①糜酶可以浓度依赖的方式增加CFs的3H-TdR掺入率。15、30和60μg/L组3H-TdR的掺入率分别为(319±29)、(372±43)和(401±47)cpm/孔,均高于对照组[(252±35)cpm/孔,P<0.01]。②随着糜酶作用浓度的增加,CFs中TGF-β1蛋白的表达呈递增趋势。15、30和60μg/L组的TGF-β1蛋白的表达水平分别为0.968±0.069、1.782±0.058和2.656±0.085,均较对照组(0.333±0.023)显著升高(P<0.05或P<0.01)。③糜酶可以浓度依赖的方式上调p-Smad2/3蛋白的表达、下调Smad7蛋白的表达,15、30和60μg/L组的p-Smad2/3蛋白表达的水平均较对照组显著升高(P<0.01),Smad7蛋白表达的水平均较对照组明显降低(P<0.05或P<0.01)。不同浓度的糜酶对Smad2/3蛋白的表达均无明显影响。结论:糜酶具有促进CFs增殖的作用,其机制可能与TGF-β1/Smad信号通路的活化有关。

AIM： To explore the effect of growth factor-β1 （TGF-β1）/Smad pathway on the proliferation of chymase-induced rat cardiac fibroblasts （CFs）. METHODS ： CFs from neonatal Sprague Dawley rats isolated by trypsinization were cultured. DNA synthesis of the CFs was determined by [ 3H ]-TdR incorpo- ration and protein expressions of TGF-I31, p-Smad2/3, Smad2/3 and Smad7 in CFs were determined by Western blot. RESULTS： Chymase increased the [ 3H]-TdR incorporation of CFs in a concentration- dependent manner. The [3H]-TdR incorporations induced by 15, 30 and 60 μg/L chymase were （319 ±29）, （372±43） and （401±47） cpm/well, respectively, significantly higher than in control groups （252 ±35） cpm/well, P 〈0.01 ）. Chymase also increased the expression of TGF-I31 protein in a con- centration-dependent manner. TGF-131 protein expressions in 15, 30 and 60 μg/L chymase groups were 0. 968 ± 0. 069, 1. 782 ± 0. 058 and 2. 656 ± 0. 085, respectively, significantly higher than in control groups （0.333 ±0.023, P 〈0.05 or P 〈0.01）. Also, 15, 30 and 60 μg/L chymase obviously increased the p-Smad2/3 expression and decreased Smad7 protein expression in a concentration-dependent manner as compared with control groups （P 〈 0. 05 or P 〈 0. 01 ） but had no effect on the protein expression of Smad2/3. CONCLUSION： Chymase promotes proliferation of rat CFs and the increase may be related to the activation of TGF-β1/Smad signaling pathway.