黄连素下调细胞周期蛋白依赖性激酶2活性抑制血管紧张素Ⅱ诱导的心肌纤维化

Berberine attenuates angiotensinⅡ-induced cardiac fibrosis by inhibition of cyclin-dependent protein kinases-2 activity

目的探讨黄连素对血管紧张素诱导的心肌纤维化的抑制作用是否是通过蛋白依赖性激酶2(CDK2)起作用。方法在SD大鼠体内用血管紧张素Ⅱ灌注,构建心肌纤维化模型,然后用黄连素灌胃,观察心肌纤维化程度及CDK2-T160磷酸化水平。在体外用血管紧张素Ⅱ刺激大鼠心脏成纤维细胞,用黄连素处理,观察细胞分化、增殖及CDK2-T160磷酸化水平。结果体内实验表明,黄连素浓度依赖性地减轻Ang-Ⅱ所诱导的大鼠心脏功能不全及心肌纤维化,并降低心室组织CDK2-T160磷酸化水平;体外实验表明,黄连素浓度依赖性地抑制Ang-Ⅱ所诱导的心脏成纤维细胞增殖,使细胞周期停滞于G 0/G 1期,并降低成纤维细胞CDK2-T160的磷酸化水平。体外超表达CDK2-T160D,可逆转黄连素对心脏成纤维细胞增殖的抑制作用及对CDK2磷酸化水平的降低作用。结论黄连素通过CDK2-T160活性依赖性显著抑制心肌纤维化、心脏成纤维细胞增殖及保护心脏功能。

Objective To explore the effect of berberine on angiotensinⅡ-induced cardiac fibrosis and the underlying mechanism.Methods SD rats were primed with angiotensinⅡto establish a cardiac fibrosis model,and then treated with berberine by gavage to observe the degree of cardiac fibrosis and the level of CDK2-T160 phosphorylation.AngiotensinⅡwas used in vitro to stimulate rat cardiac fibroblasts with and without pretreatment of berberine to observe cell differentiation,proliferation and the level of CDK2-T160 phosphorylation.Results In vivo,berberine decreased cardiac dysfunction and myocardial fibrosis induced by Ang-Ⅱ,and decreased the phosphorylation level of CDK2-T160 in ventricular tissue in a dose-dependent manner.In vitro,berberine inhibited Ang-Ⅱ-induced proliferation of cardiac fibroblast,which resulted in cell cycle stopping at G 0/G 1 phase,and decreased phosphorylation of CDK2-T160 in fibroblasts.In vitro,overexpression of CDK2-T160D can reverse the inhibitory effect of berberine on cardiac fibroblast proliferation and the reduction of CDK2 phosphorylation level.Conclusion Berberine may inhibit cardiac fibrosis,fibroblast proliferation,and preserve the cardiac function through CDK2-T160 inactivation-dependent mechanism.