鼠尾草酸通过上调Nrf2治疗动脉粥样硬化的实验研究

Atherosclerosis (AS) is common, but harmful greatly. Nuclear factor-erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway plays a key role against oxidative stress which is an important mechanism in AS. Evidence indicated that carnosic acid (CA) could increase the activity of Nrf2/ARE signaling pathway to play a role against oxidative stress. Therefore, we speculate that hopefully CA can be used to treat AS. In our preliminary experiment, we found that CA could prevent occurrence and development of AS. In order to study the therapeutical effect of CA on atherosclerosis, this project intends to treat the high-fat diet ApoE-/- mice (atherosclerosis model) with CA, and then to observe the changes of aortic pathology and injury to evaluate the therapeutical effect of CA on AS. Next, we will up-regulate or down-regulate Nrf2 expression in human aortic endothelium under hyperlipidemia environment, and discuss the mechanisms how CA relieving the aortic injury in vitro. Finally, we will verify that CA treat AS mainly through Nrf2/ARE signaling pathway by choosing ApoE-/-Nrf2-/- mice as objects. The completion of this project will provide a new way of treating AS, and have great significance to the whole society.

动脉粥样硬化（AS）不仅常见，且危害性大。核因子E2相关因子2（Nrf2）/抗氧化反应元件（ARE）信号通路对抗氧化应激反应，而后者是AS的重要发病机制。证据表明，鼠尾草酸（CA）可通过增强Nrf2/ARE信号通路活性而发挥抗氧化作用。因此我们推测CA可用于AS的防治。预实验结果表明，在小鼠发生AS之前给予CA干预可有效预防AS发生。为进一步探讨CA对AS的治疗作用，本项目拟采用高脂饮食喂养ApoE-/-小鼠的方法建立AS模型，并应用CA治疗已发生AS的小鼠，通过检测主动脉病理改变及损伤指标评价其疗效；然后应用CA干预高脂环境的人主动脉内皮细胞，分别上调和下调Nrf2表达，观察内皮细胞损伤指标及Nrf2/ARE信号通路组分的变化；最后利用ApoE-/-Nrf2-/-小鼠建立AS模型，体内进一步验证Nrf2在CA治疗AS中的核心作用。本课题的完成将为AS的治疗开辟新途径，具有重要的社会意义。

动脉粥样硬化（atherosclerosis，AS）是导致心血管疾病的首要原因，而后者是发达国家致死率最高的疾病。以往研究发现，CA可通过上调Nrf2发挥抗氧化作用而对神经系统、心脏和肝脏起到保护作用，但尚未见CA上调Nrf2防治AS的相关报道。因此，我们推测CA可通过其上调Nrf2防止并治疗AS的发生、发展。首先，以ApoE-/-小鼠（背景为C57BL/6J）为研究对象，给予HFD喂养10周建立AS模型，然后给予CA（1.0mg/Kg）干预12周，同时以LFD喂养同龄C57BL/6J野生型小鼠作为对照。结果发现，AS模型组较LFD组血脂水平增高、动脉内膜厚度增宽，主动脉损伤指标ICAM-1、VCAM-1、4-HNE也明显增高。AS+CA组较AS组动脉平滑肌细胞显著增生，ICAM-1、VCAM-1、4-HNE明显下降，并且Nrf2、NQO1转录水平明显升高。另外，通过细胞实验，验证了鼠尾草酸通过上调Keap1/Nrf2信号通路，抑制由棕榈酸钠刺激的hVSMCs表型转变、迁移作用及泡沫化能力。综上，通过这些体内、体外实验结果说明CA可通过其上调Nrf2治疗AS。