紊流通过内皮细胞12/15-脂氧合酶促进低密度脂蛋白氧化和动脉粥样发生及机制研究

Atherosclerosis is occurred in a non-random pattern. At sites of flow dividers and ostia of branch points, blood flow is disturbed as characterized by a nonunidirectional, nonsteady flow pattern. Disturbed flow (d-flow) significantly promotes the pathogenesis of atherosclerosis, whereas the specific molecular mechanisms are still unclear. By establishing different flow models in vivo and in vitro, we found d-flow promotes the oxidative modification of low-density lipoprotein in the subendothelial space, which is recognized as a key step in atherogenesis. By using RNA sequencing, bioinformatic analysis, and techniques to analyze lipid peroxidation, we showed that increased expression of 12/15-lipoxygenase (LOX) is required for LDL oxidation under d-flow. Luciferase assay further demonstrated that d-flow activated the promoter of 12/15-LOX gene through SREBP pathway in endothelial cells. We further confirmed these findings by establishing partial carotid artery ligation model of 12/15-LOX/ApoE double knockout mice. In our next step, we will investigate the specific mechanisms, potential therapeutic targets and subcellular localization of LDL oxidation in endothelial cells, as well as its role in the pathogenesis of atherosclerosis under d-flow. We believe our findings will aid the design of novel therapeutic strategies to attenuate atherogenesis under d-flow.

动脉粥样硬化发生具有明显规律性，在血管分叉分支处，血流剪切力减低、方向紊乱形成紊流，是粥样硬化斑块的好发部位，但具体机制仍不清楚。我们通过建立多种体内外紊流模型，发现紊流作用下内皮细胞能显著促进低密度脂蛋白（LDL）氧化。通过RNA测序，首次发现紊流促进内皮细胞12/15-脂氧合酶（lipoxygenase，LOX）表达升高并介导LDL氧化。荧光素酶报告基因系统提示紊流通过促进转录因子SREBP与12/15-LOX基因启动子相互作用以激活其转录。我们进一步建立了12/15-LOX/ApoE基因双敲除小鼠，证实12/15-LOX表达缺失能抑制紊流下LDL氧化和粥样斑块发生。我们将完善机制探讨，详细分析内皮细胞SREBP-12/15-LOX通路促进LDL氧化和动脉粥样硬化发生的分子机制、发生部位和干预靶点，为后续制定针对性治疗方案以减少紊流区域动脉粥样硬化发生提供靶点和途径。

动脉粥样硬化发生具有明显规律性，在血管分叉分支处，血流剪切力减低、方向紊乱形成紊流，是粥样硬化斑块的好发部位，但具体机制仍不清楚。我们通过建立多种体内外紊流模型，发现紊流作用下内皮细胞能显著促进低密度脂蛋白（LDL）氧化。通过RNA测序，首次发现紊流促进内皮细胞12/15-脂氧合酶（lipoxygenase，LOX）表达升高并介导LDL氧化。荧光素酶报告基因系统提示紊流通过促进转录因子SREBP与12/15-LOX基因启动子相互作用以激活其转录。我们进一步通过建立12/15-LOX/ApoE基因双敲除小鼠，并应用12/1-5-LOX特异性抑制剂，证实12/15-LOX表达缺失能抑制紊流下LDL氧化和粥样斑块发生。该研究揭示了紊流促进内皮损伤及动脉粥样硬化发生的精确分子机制，为制定针对性治疗方案以减少紊流区域动脉粥样硬化发生提供靶点和途径。受本项目资助以来，本人已发表通讯或第一作者SCI论文11篇，累计影响因子69.2分。作为项目负责人获得国家自然基金面上项目资助1项，2019年获得美国AHA Paul Dudley White最佳研究奖，主编专著1本。