【摘要】 目的探讨人参总皂苷(TG)对血管紧张素(AngⅡ)所致心肌细胞肥大的抑制作用及其可能的机制。方法培养3 d的乳大鼠心肌细胞加入TG 50,100和200 mg.L-1,同时加入AngⅡ0.1μmo.lL-1,作用48 h后行HE染色测定细胞直径,Bradford法测定蛋白质含量;Fura-2/AM负载检测细胞内游离钙离子浓度([Ca2+]i);实时PCR法检测心肌细胞心房利钠因子(ANF),钙调神经磷酸酶(CaN)和细胞外信号调节激酶1(ERK1)mRNA的表达;Western蛋白质印迹法检测CaN的α-亚基(CnA)和促分裂原活化的蛋白激酶磷酸酶1(MKP1)蛋白的表达。结果在AngⅡ的作用下,心肌细胞直径由(32±8)μm增加至(79±17)μm,蛋白质含量由每个细胞的(416±9)pg增加至(541±16)pg,ANF mRNA表达由34±5上调至268±36;[Ca2+]i明显升高,CaN和ERK1 mRNA以及CnA蛋白表达显著上调。TG 50,100和200 mg.L-1使AngⅡ所诱导增大的细胞直径分别缩小15.3%,37.7%和51.2%(P<0.05),并使AngⅡ所增加的细胞蛋白质含量分别减少4.0%,15.6%和19.4%,[Ca2+]i显著下降以及ANF,CaN和ERK1 mRNA表达和CnA蛋白表达明显下调(P<0.05),而MKP1蛋白表达显著升高(P<0.05)。结论 TG对AngⅡ诱导的心肌细胞肥大具有明显抑制作用,其分子机制可能与抑制CaN和ERK信号转导通路有关。更多还原

【Abstract】 OBJECTIVE To observe the effect of total ginsenosides(TG) on angiotensinⅡ(AngⅡ)-induced cardiomyocyte hypertrophy and its possible mechanisms.METHODS After 3 d,the cultured primary cardiomyocytes were randomly divided into normal control group,model group with AngⅡ 0.1 μmol·L-1 and TG treated groups(AngⅡ+TG 50,100 and 200 mg·L-1,respectively) for 48 h,respectively.The cell diameter was measured by HE staining,and protein content was determined by Bradford method.The intracellular free Ca2+ concentration(i) was assayed by fluorescent determination using Fura-2/AM.The mRNA expression of atrial natriurertic factor(ANF),calcineurin(CaN) and extracellular signal-regulated kinase 1(ERK1) was assayed by real time PCR.The protein expression of α-subunit of CaN(CnA) and mitogen-activated protein kinase phosphatase1(MKP1) was assayed by Western blotting.RESULTS Cell diameter was increased from(32±8)μm to(79±17)μm,protein content per cell from(416±9)pg to(541±16)pg,and ANF mRNA expression from 34±5 to 268±36 by AngⅡ.i and mRNA expressions of CaN and ERK1 were elevated,so was the protein expression of CnA by AngⅡ.However,they were reversed by TG 50,100 and 200 mg·L-1 in a concentration-dependent manner.The cell diameter was reduced by 15.3%,37.7% and 51.2%,and protein content by 4.0%,15.6% and 19.4% by TG 50,100 and 200 mg·L-1,respectively.In addition,TG could also increase the MKP1 protein expression compared with AngⅡ treated-group.CONCLUSION TG can inhibit the AngⅡ-induced cardiomyocyte hypertrophy,which is related to its inhibition on CaN and ERK signalings.更多还原