RAS阻滞剂及LCZ696对动脉粥样硬化小鼠ACE2-Ang-(1-7)-Mas轴的影响研究

摘要

目的 探讨肾素-血管紧张素系统(RAS)阻滞剂及LCZ696对动脉粥样硬化小鼠ACE2-Ang-(1-7)-Ma s轴的影响及可能的机制.方法 采用6周龄健康雄性ApoE-/-小鼠28只和C57BL/6小鼠7只.ApoE-/-小鼠高脂喂养建模后随机分为4组,分别予以生理盐水、依那普利、缬沙坦和LCZ696灌胃处理,C57BL/6小鼠予以等量0.9％氯化钠溶液灌胃.干预6周后处死取血样及病理标本,应用全自动生化分析仪测定各组血清中LDL-C、TC水平,ELISA法测定血清CRP、IL-6、ACE2、Ang-(1-7)、AngII水平,油红O染色法测斑块脂质含量,RT-qPCR法测定主动脉ACE2 mRNA表达,免疫组化法测定主动脉斑块中ACE2和Ang-(1-7)蛋白表达.结果 与C57BL/6组相比,ApoE-/-对照组LDL-C、TC、CRP、IL-6水平升高(P＜0.01),主动脉斑块明显增加(P＜0.01).与Ap oE-/-对照组相比,依那普利组、缬沙坦组和LCZ696组血清CRP、IL-6、AngII水平显著降低(P＜0.01),ACE2、Ang-(1-7)水平显著升高(P＜0.01),依那普利组、缬沙坦组和LCZ696组斑块显著减少(P＜0.01),依那普利组和LCZ696组的主动脉中ACE2 mRNA表达增加(P＜0.01或0.05),依那普利组、缬沙坦组和LCZ696组主动脉斑块中ACE2和Ang-(1-7)蛋白表达增加(P＜0.01).与依那普利组、缬沙坦组相比,LCZ696组斑块减少更明显(P＜0.05),主动脉斑块中ACE2和Ang-(1-7)蛋白表达增加更明显(P＜0.01或0.05).结论 依那普利、缬沙坦和LCZ696均可以通过ACE2-Ang-(1-7)-Mas轴来抑制动脉粥样硬化的发展,LCZ696抗动脉粥样硬化作用更明显.%Objective To investigate the effect of RAS blockers and LCZ696 on ACE2-Ang- (1-7) -Mas axis in atherosclerotic mice and the possible mechanisms. Methods 28 healthy male ApoE-/-mice aged 6 weeks were fed high-fat diet and randomly divided into 4 groups after animal model established and then treated with saline, Enalapril, Valsartan and LCZ696, respectively. 7C57BL/6 mice were given equal amount of saline. After six-week intervention, all mice were killed and the blood samples and pathological specimens were taken for measurements of serum LDL-C, TC by automatic biochemical analyzer, and serum levels of CRP, IL-6, ACE2, Ang- (1-7) and AngII by ELISA. The lipid content of plaque was measured by Oil Red O staining. The expression of aortic ACE2 m RNA was determined by RT-qPCR. The expression of ACE2 and Ang- (1-7) protein in aortic plaques was determined by immunohistochemistry. Results Compared with C57BL/6 group, LDL-C, TC, CRP and IL-6 as well as aortic plaque size significantly increased in ApoE-/-control group (all P＜0.01). Compared with ApoE-/-control group, serum CRP, IL-6 and AngII decreased, serum ACE2 and Ang- (1-7) increased and the plaque decreased significantly in Enalapril, Valsartan and LCZ696 groups (all P＜0.01), ACE2 m RNA expression increased in the aorta in enalapril group and LCZ696 group (P＜0.01 or 0.05), and ACE2, Ang- (1-7) protein expression increased in aortic plaques in enalapril, valsartan and LCZ696 groups (P ＜0.01). Compared with enalapril and valsartan groups, the reduction of aortic plaque was more significant in LCZ696 group (P＜0.05) and the expression of ACE2 and Ang- (1-7) protein in aortic plaque increased more (P＜0.01 or 0.05). Conclusion Enalapril, valsartan and LCZ696 can all inhibit the development of atherosclerosis through ACE2-Ang- (1-7) -Mas axis, and LCZ696 has more obvious anti-atherosclerosis effect.