五味子乙素介导Traf6/NF-κB信号通路抑制心肌细胞肥大实验研究

Experimental Research on Inhibitory Effects of Schisandrin B on Cardiomyocyte Hypertrophy through Mediating Traf6/NF-κB Signal Channel

目的:研究五味子乙素抑制脂多糖(lipopolysaccharide,LPS)诱导心肌细胞肥大的作用及其机制。方法:原代培养心肌细胞,用LPS(1 mg/L)诱导心肌细胞肥大,考察IκBα抑制剂BAY11-7082和不同剂量五味子乙素对心肌细胞肥大的影响。采用计算机图像分析系统观察细胞大小;考马斯亮蓝法分析细胞总蛋白量;ELISA试剂盒检测白细胞介素6(interleukin-6,IL-6)和肿瘤坏死因子α(tumor necrosis factorα,TNF-α)表达量;免疫印迹技术检测心房钠尿肽(atrial natriuretic peptide,ANP)和Traf6/NF-κB信号通路蛋白表达水平。结果:与LPS诱导组相比,五味子乙素和BAY11-7082均可以抑制LPS诱导的心肌细胞肥大,体现在蛋白含量降低,细胞体积减小,ANP蛋白表达降低(P<0.05);五味子乙素还能够降低炎症反应,表现在细胞外液中炎症因子IL-6和TNF-α水平降低(P<0.05),Traf6、p65蛋白表达量降低(P<0.05)及IκBα蛋白水平升高(P<0.05),且呈浓度依赖性。此外,高剂量五味子乙素与BAY11-7082对心肌细胞肥大的保护作用相近。结论:五味子乙素能抑制LPS诱导原代心肌细胞肥大,对心肌细胞的保护作用主要通过抑制Traf6/NF-κB信号通路的活化来实现。

Objective:To investigate the effects and mechanism of schisandrin B on cardiomyocyte hypertrophy induced by lipopolysaccharide(LPS).Methods:Cardiomyocyte hypertrophy was induced by LPS(1 mg/L)after culturing primary cardiomyocyte,to investigate the influence of IκBα inhibitor BAY11-7082 and different dosages of schisandrin B on cardiomyocyte hypertrophy.Computer image analysis system was used to observe the size of the cells;coomassie blue staining to analyze total protein contents of the cells;ELISA kit to detect the expressions of IL-6 and TNF-α;immunoblot assay to measure the expressions of atrial natriuretic peptide(ANP)and Traf6/NF-κB signal channel protein.Results:Compared with LPS-induced group,schisandrin B and BAY11-7082 could inhibit LPS-induced cardiomyocyte hypertrophy,it reflected in protein contents reduction and cellular volume decrease,and ANP protein expressions reduction(P<0.05);schisandrin B could relieve inflammatory reaction,and it perfomed in reducing the levels of IL-6 and TNF-α in extracellular fluid(P<0.05);lowering the expressions of Traf6 and p65 protein(P<0.05)and lifting the levels of IκBα protein(P<0.05),in the concentration dependent maner.Besides,high dose of schisandrin B showed similar protective effects in cardiomyocyte hypertrophy to BAY11-7082.Conclusion:Schisandrin B could inhibit LPS-induced primary cardiomyocyte hypertrophy,its protection for cardiomyocyte is realized mainly through inhibiting Traf6/NF-κB signal channel activation.