趋炎脂质抑制HSP90与eNOS结合促进动脉粥样硬化形成

We have demonstrated that apolipoprotien A-I(ApoA-I) mimetic peptide can inhibit atherosclerosis(AS) by reducing proinflammatory lipids，and that heat shock protein90（HSP90）can protect vascular endothelial function by regulating endothelial nitric oxide synthase(eNOS). Although AS is related to proinflammatory lipids and endothelial dysfunction, the mechanisms of AS formation is still not entirely clear. Preliminary experiments showed that proinflammatory lipids inhibited the association of HSP90 with eNOS, and at the same time, the association of HSP90 with eNOS reduced on AS. Therefore, we propose that proinflammatory lipids promoted AS by inhibiting the association of HSP90 with eNOS. In this project, vascular endothelial cells will be treated with proinflammaory lipids, and low-density lipoprotein receptor-null(LDLr-/-) mice and LDLr-/-/eNOS-/- mice will be treated with two kinds of peptides: either promoting or inhibiting the association of HSP90 with eNOS. The association of HSP90 with eNOS, proinflammatory levels and the formation of AS will be measured. The aim of this study is to obtain reliable evidence that proinflammatory lipids promote AS by inhibiting the association of HSP90 with eNOS and illustrate the novel mechanism of AS formation. Findings from this study may provide scientific evidence that proinflammatory lipids/HSP90/eNOS is a new target for preventing and treating AS in the future.

我们已证明：1.载脂蛋白A-I (ApoA-I)模拟肽通过减少趋炎脂质而抑制动脉粥样硬化(AS)形成；2. 热休克蛋白90（HSP90）通过调控内皮一氧化氮合酶（eNOS）保护血管内皮功能。尽管AS形成与趋炎脂质及内皮功能失调有关，但其机制未明。初步实验显示趋炎脂质可抑制HSP90与eNOS结合且AS时HSP90与eNOS结合减少。因此，我们提出趋炎脂质可能通过抑制HSP90与eNOS结合促进AS形成。本项目用趋炎脂质处理血管内皮细胞，再分别用促进或抑制HSP90与eNOS结合的两种蛋白肽处理低密度脂蛋白受体缺乏(LDL-/-)和LDLr-/-/eNOS-/-两种小鼠，并检测eNOS与HSP90结合、趋炎脂质变化和AS形成情况，旨在获得趋炎脂质抑制HSP90与eNOS结合促进AS形成的可靠依据，阐明AS形成的新机制，为将来确立趋炎脂质/HSP90/eNOS作为防治AS的新靶点提供科学依据。

血管内皮功能失调是动脉粥样硬化的早期表现，趋炎脂质导致血管内皮功能受损的机制仍未清楚。本项目通过细胞培养和血管舒张功能试验以及建立小鼠动物模型，测定与内皮功能相关的自由基、蛋白活动的变化。项目已按原计划完成。结果发现趋炎脂质POVPC、25—OHC抑制了血管内皮细胞的增殖、迁移、管状形成，抑制NO但促进超氧自由基的产生，损伤血管内皮依赖的血管舒张功能，抑制HSP90与eNOS结合以及抑制Akt和eNOS磷酸化表达, 并增加内皮细胞凋亡小体的产生，促进caspase-9、caspase-3的活性和活化的caspase-9和caspase-3的表达、抑制BCL-2的表达。而POVPC还促进了PKC、P70磷酸化的表达。另外，研究发现冠心病病人的HDL趋炎水平明显升高，这些趋炎HDL中POVPC和25—OHC含量增加，升高的POVPC明显损伤内皮功能。趋炎HDL可引起长链非编码的 RNAs（LncRNA）差异性表达，而某些差异表达的LncRNA可通过调控某些蛋白和HSP90/eNOS/NO通路抑制血管新生。也发现心脏瓣膜病病人体外循环术后HDL的趋炎水平较术前升高更明显，这些HDL明显抑制HSP90/eNOS/NO通路，而且HDL的趋炎水平与肺动脉的压力和病人的住院时间呈正相关。本研究获得了趋炎脂质直接影响内皮和内皮一氧化氮合酶依赖的血管舒张功能的可靠依据，阐明趋炎脂质损伤血管内皮功能促进动脉粥样硬化形成的新机制，为将来确立趋炎脂质作为防治动脉粥样硬化的新靶点提供科学依据。在国际权威期刊Journal of Molecular and Cellular Cardiology、American Journal of Physiology- Endocrinology and Metabolism、The Journal of Thoracic and Cardiovascular Surgery、 Journal of Cardiovascular Pharmacology、Journal of Translational Medicine、Biochemical and Biophysical Research Communications、Plos One等发表8篇SCI文章，发表4篇中文论著，并多次在国内、外会议上交流。3篇论著在送审中。