黄芪甲苷通过抑制氯化物细胞内通道蛋白4/ADP核糖基化因子6信号通路改善血管紧张素Ⅱ诱导的高血压大鼠模型的心肌损伤

Astragaloside Ⅳ ameliorates myocardial injury in angiotensin Ⅱ induced hypertension rat model by regulating chloride intracellular channel protein 4/ADP-ribosylation factor 6 signal pathway

目的探究黄芪甲苷在血管紧张素Ⅱ(AngⅡ)诱导的高血压大鼠模型中的心肌保护作用及其机制。方法将60只SD大鼠分随机分为6组,每组10只:对照组,模型组,黄芪甲苷低(10 mg/kg)、中(20 mg/kg)、高剂量(50 mg/kg)组和ADP核糖基化因子6(Arf6)特异性抑制剂(NAV-2729)组。建立AngⅡ诱导高血压心肌损伤大鼠模型后给予不同药物或剂量处理2周后,观察各组大鼠左心室舒张末期内径、心脏射血分数及短轴缩短率、心肌病理损伤、心肌细胞凋亡以及相关凋亡蛋白B细胞淋巴瘤因子-2(Bcl-2)及Bcl-2关联X蛋白(Bax)表达情况。另选30只SD大鼠随机分为3组,每组10只:氯化物细胞内通道蛋白4(CLIC4)过表达联合黄芪甲苷组、腺病毒阴性对照联合黄芪甲苷组及腺病毒阴性对照组。先通过尾静脉注射相应腺病毒,再用AngⅡ诱导高血压模型。2周后观察大鼠左心室舒张末期内径、心脏射血分数及短轴缩短率、心肌病理损伤、心肌细胞凋亡情况。结果与模型组大鼠比较,中剂量和高剂量的黄芪甲苷能够改善AngⅡ诱导的高血压心肌损伤模型大鼠的心脏功能及心肌结构,促进抗凋亡蛋白Bcl-2表达(0.36±0.01比0.22±0.02,0.78±0.01比0.22±0.02;均P<0.05),抑制Bax表达(1.51±0.02比2.13±0.03,1.22±0.01比2.13±0.03;均P<0.05)。黄芪甲苷通过抑制CLIC4/Arf6蛋白表达发挥心肌保护作用,过表达CLIC4则减弱这种保护作用。结论黄芪甲苷能够改善AngⅡ诱导的高血压大鼠模型中的心肌损伤,可能通过抑制CLIC4/Arf6信号通路实现。

Objective To explore the cardioprotective effect and mechanism of astragaloside Ⅳ(AS-Ⅳ)on angiotensin Ⅱ(AngⅡ)induced hypertension rat model.Methods Sixty Sprague-Dawley(SD)rats were randomly divided into 6 groups,with 10 rats in each group:control group,model group,AS-Ⅳ low dose group(10 mg/kg),AS-Ⅳ medium dose group(20 mg/kg),AS-Ⅳ high dose group(50 mg/kg)and specific inhibitor of ADP-ribosylation factor 6(Arf6)(NAV-2729)group.Rats were treated with different drugs or doses after AngⅡ-induced hypertensive myocardial injury models were established.The left ventricular end-diastolic diameter,cardiac ejection fraction and fractional shortening,myocardial pathological injury,myocardial apoptosis and the expression of related apoptotic proteins Bcl-2(B-cell lymphoma-2)and Bax(Bcl-2 associated X)in each group were observed after 2 weeks.The other 30 SD rats were randomly divided into three groups,with 10 rats in each group:chloride intracellular channel protein 4(CLIC4)overexpression combined with AS-Ⅳ group,adenovirus negative control combined with AS-Ⅳ group and adenovirus negative control group.The rats were injected with corresponding adenovirus by tail vein and then AngⅡ-induced hypertensive model was eatablished.The end-diastolic internal diameter of the left ventricle,left ventricular ejection fraction,fractional shortening,myocardial pathological damage,and myocardial apoptosis were observed after 2 weeks.Results Compared with the model group,the middle dose and high dose of AS-Ⅳ could improve the cardiac function and myocardial structure of AngⅡ-induced hypertensive myocardial injury model rats,promote the expression of anti-apoptotic protein Bcl-2(0.36±0.01 vs 0.22±0.02,0.78±0.01 vs 0.22±0.02;both P<0.05)and inhibit the expression of Bax(1.51±0.02 vs 2.13±0.03,1.22±0.01 vs 2.13±0.03;both P<0.05).AS-Ⅳ exerted myocardial protective effect by inhibiting the expression of CLIC4/Arf6 protein,and overexpression of CLIC4 attenuated this protective effect.Conclusion AS-Ⅳ can ameliorate myocardial injury in AngⅡ-induced hypertension rat model,possibly through inhibiting CLIC4/Arf6 signaling pathway.