以脂滴结构蛋白为核心- - 白藜芦醇对泡沫细胞形成的影响和调控机制研究

Atherosclerosis is the major cause of coronary heart disease and stroke and will cause serious harm to human health. A key event in the pathogenesis of atherosclerosis is the transformation of of macrophages into foam cells, a result of massive accumulation of lipid droplets. However, previous studies did not pay enough attention to the lipid droplets. Only more recently has it become apparent that lipid droplet and lipid droplet proteins - particularly the PAT protein family (perilipin, adipophilin, TIP47, S3-12 and LSDP5) and CIDE family (CIDEA, CIDEB and CIDEC) - play an important role in atherosclerotic processes. In order to illustrate the function of LD-associated proteins during the process of atherosclerosis, the foam cell model is induced by oxidized low-density lipoprotein (Ox-LDL) in macrophages originated from the THP-1 cell line, and cDNA microarrays are used to monitor the gene expression profiles of LD-associated proteins. We found that 2% of changed genes are lipid binding genes during the transformation of foam cells. The major candidate genes, the cell death inducing DFF45-like effector (CIDE) family and Perilipin, Adipophilin, and TIP47 (PAT) family, have different alterations during the formation of foam cells. CIDEB, CIDEC, Adipophilin, S3-12 and LSDP5 were up-regulated, while TIP47 was down-regulated. In addition, previous studies have shown that resveratrol could prevent atherosclerosis by suppresses platelet aggregation, alleviating endothelial damage and etc. However, during the formation of foam cells, the effect of resveratrol on lipid droplets and lipid droplet proteins and molecular mechanisms is still unknown. Our preliminary experiment data indicated that resveratrol can not only reduce the relative levels of cholesterol and triglycerides, but also inhibit the maturation of lipid droplets and thus retard the formation of foam cells. Therefore, based on our current data, we intended to further elucidate the effect of resveratrol on lipid droplets and lipid droplet proteins and molecular mechanisms during the formation of foam cells. Moreover, the results of our study will also promote the prevention of coronary heart disease and stroke.

动脉粥样硬化（AS）是严重危害人类健康的一种血管疾病。近期研究表明：脂滴结构蛋白与脂滴形成、脂滴内脂质合成、代谢和细胞内转运密切相关，在AS始动环节泡沫细胞形成过程中发挥了重要作用。课题组前期也证实：单核细胞向泡沫细胞转化过程中，发生变化基因中约2%为脂滴相关分子，主要是脂滴结构蛋白：CIDEB、CIDEC、ADRP、S3-12和LSDP5表达上调，TIP47表达下调。对白藜芦醇（Res）的研究表明，Res能通过抑制血小板聚集和血管内皮损伤等多方面发挥抗AS作用，但对泡沫细胞形成过程中脂滴结构蛋白的影响和调控机制目前尚不明确。且课题组预实验发现：Res具有影响泡沫细胞内脂滴形态和数量，降低泡沫细胞内胆固醇和TG含量，抑制泡沫细胞形成的潜能。因此，本研究拟在已有基础上，进一步明确Res在泡沫细胞形成过程中对脂滴结构蛋白的影响和调控机制，同时研究结果对冠心病、脑卒中等疾病的防治也具有重要意义。

1.研究背景：对白藜芦醇（Res）的研究表明，Res能通过抑制血管内皮损伤和平滑肌细胞增殖等发挥抗动脉粥样硬化作用，但对泡沫细胞形成过程中脂滴及脂滴分子的影响和调控机制目前尚无研究。因此，本研究拟在已有基础上，进一步明确Res在动脉粥样硬化过程中对脂滴分子的影响和调控机制，同时研究结果对冠心病、脑卒中等疾病的防治也具有重要意义。.2.主要研究内容包括三部分：分别为动物实验，动脉粥样硬化患者脂肪细胞分泌因子研究和体外细胞实验。.3.重要结果及关键数据：.3.1动物实验. 将健康雄性小鼠C57BL/6 18只，随机分为3组，分别为对照组，高脂饮食组和白藜芦醇组，对小鼠主动脉根部组织油红染色发现，对照组：主动脉腔壁光滑；高脂组：主动脉壁可见不同程度的粥样斑块形成；白藜芦醇组粥样斑块略有减轻。对小鼠主动脉根部组织电镜结果发现，对照组：正常对照组小鼠核缘光滑，染色质较少，细胞器数量正常；同对照组相比，高脂组小鼠形态肿胀并，细胞核形态不规则，胞浆内空泡增多；而白藜芦醇组细胞形态相对接近正常，细胞核形状大致规则，细胞器未见明显变化。对小鼠血液中脂代谢总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）和高密度脂蛋白（HDL）所进行的检测结果表明：白藜芦醇能够明显降低高脂所导致的总胆固醇、甘油三酯和低密度脂蛋白升高，而对高密度脂蛋白的变化无较大影响。对小鼠血液中氧化应激相关指标丙二醛（MDA）、超氧化物歧化酶（SOD）和谷胱甘肽（GSH）所进行的检测表明，白藜芦醇能够明显升高高脂所导致的SOD降低，降低MDA水平，而同其他两组相比，白藜芦醇对GSH的水平并未见明显影响；.3.2动脉粥样硬化患者脂肪细胞分泌因子研究.对71例怀疑为冠心病的患者(年龄39～80岁)，根据心电图、冠脉造影等将受试者分为冠心病组和非冠心病组，用酶联免疫分析法（ELISA）法测定血浆SFRP5、RPB4、瘦素（Leptin）的水平，对实验数据和临床数据进行统计学分析。结果发现：冠心病组的SFRP5水平明显低于非冠心病组（24.3±15.6 vs 34.5±18.9 ng/ml p＜0.05），Gensini积分反映了冠心病的严重程度，其与血清SFRP5存在负相关，（r= -0.20,p=0.01），SFRP5水平和性别及吸烟史相关，男性SFRP5水平明显低于女性（p＜0.01），在药物方面，血清S