氯喹在血管紧张素Ⅱ诱导的小鼠血管重塑中的作用

Effect of chloroquine in angiotensin Ⅱ induced vascular remodeling in mice

目的:探讨氯喹(chloroquine,CQ)对血管紧张素Ⅱ(angiotensin Ⅱ,Ang Ⅱ)诱导的小鼠血管重塑的作用及可能机制。方法:将32只8周龄雄性C57 BL/6小鼠随机分为4组,分别为对照组、Ang Ⅱ处理组、Ang Ⅱ+CQ低剂量组及Ang Ⅱ+CQ高剂量组,每组8只。对照组不做任何处理,Ang Ⅱ组通过皮下埋置微渗透泵持续给予Ang Ⅱ,剂量为490 ng/(kg·min)。Ang Ⅱ+CQ低剂量及高剂量组小鼠在接受Ang Ⅱ基础上,按10mg/(kg·d)及50mg/(kg·d)剂量每天腹腔注射CQ。各组处理时间均为28d。分别在第0,3,7,14,21及28天用尾套法测定各组小鼠血压及心率。在第28天时处死小鼠,取主动脉,采用HE染色及Masson染色评价主动脉血管重塑情况。采用Western印迹检测主动脉I型、Ⅲ型胶原蛋白(collagen Ⅰ/Ⅲ)及自噬通路分子(LC3B-Ⅱ与P62)表达。结果:与对照组相比,Ang Ⅱ处理组小鼠血压升高,主动脉管壁增厚,主动脉发生明显纤维化,collagen Ⅰ/Ⅲ表达增加,自噬发生标志LC3B-Ⅱ表达增加,自噬底物P62表达降低。与Ang Ⅱ处理组相比,CQ低剂量及高剂量处理组小鼠血压降低,主动脉管壁变薄,纤维化减轻,collagen Ⅰ/Ⅲ表达减少,LC3B-Ⅱ及P62表达均增加;并且CQ高剂量组较低剂量组上述各指标的改变程度更大。结论:CQ可剂量依赖性地抑制Ang Ⅱ诱导的小鼠主动脉重塑,其机制可能与抑制自噬过度激活有关。

Objective： To investigate the effect and potential mechanism of chloroquine（CQ） in angiotensin Ⅱ（Ang Ⅱ） induced murine vascular remodeling. Methods： A total of 32 male C57 BL/6 mice aged 8 weeks were randomly divided into a control group, an Ang Ⅱ group, an Ang Ⅱ ＋ low-dose CQ and an Ang Ⅱ ＋ high-dose CQ（8 mice for each）. Control group was left untreated. Ang Ⅱ group received 490 ng/（kg·min） Ang Ⅱ by subcutaneously imbedded osmotic pump. Ang Ⅱ ＋ low-dose and Ang Ⅱ high-dose CQ group were injected intraperitoneally with 10 mg/（kg·d） and 50 mg/（kg·d） CQ respectively based on Ang Ⅱ treatment for 28 days. Mouse blood pressure and heart rate were monitored by using tail-cuff method on day 0, 3, 7, 14, 21 and 28. On day 28, all the mice were sacrificed to collect aortas for HE and Masson＇s staining to access aortic remodeling. Western bolt was performed to detect expression of collagen I/Ⅲ and autophagy related molecules（LC3B-Ⅱ and P62）. Results： Compared with control group, Ang Ⅱ group presented with elevated blood pressure, thickened aortic vessel wall, significant aortic fibrosis, increased collagen Ⅰ/Ⅲ expression, increased autophagic indicator LC3B-Ⅱ expression and decreased autophagy substance P62. In contrast to Ang Ⅱ group, both low-dose and high dose CQ treatment produced lower blood pressure, thinned aortic vessel, alleviated fibrosis, lowered collagen Ⅰ/Ⅲ, more LC3B-Ⅱ and P62 abundance. Moreover, high-dose CQ treatment showed better improvement than low-dose CQ treatment in terms of all the measurements mentioned above. Conclusion： CQ inhibited Ang Ⅱ induced murine aortic remodeling in a dose dependent manner, which might be mediated through inhibiting over-activated autophagy.