HSP22在高脂血症致内皮损伤中的作用及他汀的干预研究

Hyperlipidemia is the initiating factor of endothelial damage. Statins has a protective effect on endothelial injury. Studies show that heat shock protein (HSP) 70 expression was up-regulated in endothelial cells of the hyperlipidemic environment and played a protective effect. HSP22 is a new discovered small molecular HSP, our previous studies found that HSP22 expression was significantly increased and play a protective role in injury of human umbilical vein endothelial cells (HUVEC) induced by hypoxia. And we also found that expression of HSP22 was up-regulated by hyperlipidemic intervention in HUVEC. Therefore we hypothesize that HSP22 maybe play a protective role in endothelial injury induced by hyperlipidemia, and the protective effect on endothelial may be via increasing expression of HSP22. In this study we will observe the level of HSP22 expression in hyperlipidemic mice and the impact of statin intervention. In the 2nd part of study we establish the hyperlipidemic HSP22 transgenic mice model and administrated them with high-fat diet, then the relationship of HSP22 and atherosclerosis will be studied. The 3rd part is in vitro experiment: we will use ox -LDL to culture HUVEC and intervention by statins at the same time, the HSP22 recombinant plasmids and RNAi plasmid were used to increased and inhibition of HSP22 expression, then the role of HSP22 in the injury of endothelial induced by hyperlipidemia and its mechanism will be clarified.

高脂是内皮损伤始动因素，他汀对内皮损伤具有保护作用。研究表明热休克蛋白(HSP)70在高脂环境的内皮细胞中表达升高并具保护作用。HSP22为新发现小分子HSP，我们前期研究发现HSP22在缺氧后人脐静脉内皮细胞（HUVEC)中表达明显升高并起保护作用，我们还发现HSP22在高脂干预的HUVEC中表达亦明显升高。据此我们提出假设：HSP22在高脂致内皮损伤中起保护作用，而他汀可能通过HSP22对内皮产生保护作用。本研究首先观察高脂血症小鼠主动脉HSP22水平及他汀干预的影响；然后建立HSP22过表达转基因鼠并行高脂饮食干预，观察其与动脉粥样硬化关系；离体实验部分我们将使用ox-LDL培养HUVEC，同时进行他汀干预，利用HSP22 重组质粒及RNAi质粒分别增加及抑制HSP22表达，以进一步探讨其机制。从而阐明HSP22在高脂所致内皮损伤中的作用和他汀干预的影响及其机制。

高脂是内皮损伤始动因素，他汀对内皮损伤具有保护作用。HSP22 为新发现小分子 HSP，我们的前期研究发现HSP22在缺氧后人脐静脉内皮细胞（HUVEC）中表达明显升高并起保护作用，还发现HSP22在高脂干预的HUVEC中表达亦明显升高。经本课题研究我们发现，HSP22在高脂致内皮损伤中起保护作用，而他汀对内皮细胞的保护作用可能和HSP22无关。本研究首先观察高脂血症小鼠主动脉HSP22水平及他汀干预的影响，发现高脂血症老鼠其主动脉中HSP22表达较正常小鼠升高，而他汀的干预可降低其主动脉中HSP22的表达。然后分别建立HSP22-/-APOE-/-基因双敲除小鼠（双敲小鼠）和HSP22+APOE-/-转基因小鼠（过表达小鼠），并行高脂饮食干预，发现双敲小鼠其主动脉斑块形成较APOE-/-明显增多，过表达小鼠的斑块则显著减少，证实了HSP22对高脂致内皮损伤确有保护作用。离体实验部分我们使用ox-LDL培养HUVEC，同时进行他汀干预，利用HSP22重组质粒及RNAi质粒分别增加和抑制HSP22表达，发现使用ox-LDL可损伤内皮细胞，诱导HSP22表达；用RNAi处理的细胞和对照组相比，其p38MAPK和TNF-a表达上调、erk和eNOS下调，用HSP22重组质粒处理的细胞，其p38MAPK和TNF-α表达下调、erk和eNOS上调，提示在ox-LDL诱导环境下HSP22的保护作用可能与下调p38MAPK、上调erk抗凋亡有关，与TNF-α抗炎有关，与eNOS改善内皮功能有关；使用阿托伐他汀干预后HSP22表达下降，p38MAPK、erk、TNF-α下调，eNOS上调，提示他汀的保护作用可能与HSP22无关，可能与下调p38MAPK、erk、TNF-α抗炎有关，与eNOS改善内皮功能有关。