REGULATION OF TG RICH LIPOPROTEIN SECRETION BY OXIDIZED LIPIDS

氧化脂质对富含 TG 脂蛋白分泌的调节

• 批准号: 6242220
• 负责人: F JEFFREY FIELD
• 金额: $ 22.2万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-30 至 1998-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6242220
• 关键词: P glycoprotein; apolipoproteins; atherosclerotic plaque; blood lipoprotein metabolism; cell line; dietary lipid; gastrointestinal absorption /transport; gene expression; glycerides; laboratory mouse; laboratory rat; lipid metabolism; lipid transport; low density lipoprotein; low density lipoprotein receptor; northern blottings; nutrition related tag; tissue /cell culture; western blottings

Oxidized lipoproteins are believed to play a crucial role in the development of atherosclerosis. Dietary oxidized lipids likely contribute to the generation of oxidized lipoproteins. Indeed studies in humans and animals suggest that dietary oxidized lipids are taken up by the small intestine and secreted as lipoproteins. Whether oxidized lipids alter the composition of lipoproteins or interfere with the normal assembly and secretion of intestinal lipoproteins is unknown. Because the intestine contributes directly to the plasma pool of atherogenic lipoproteins, information regarding mechanisms by which oxidized lipids might regulate lipoprotein assembly and secretion would be important. MTP, apo b, and the influx of lipids are all recognized mediators of lipoprotein secretion by intestinal cells. Additionally, recent data have implicated p-glycoprotein as a facilitator of cholesterol trafficking and lipoprotein secretion in intestinal cells. This proposal will address, therefore, mechanisms by which oxidized lipids might alter lipoprotein assembly and secretion and secretion by regulating the availability of lipid flux through the intestine or by regulating the activities, mass or gene expression of MTP, apo B, or p-glycoprotein. Experiments will be performed in CaCo-2 cells grown on semi-permeable supports and results supported by experiments performed in everted gut sacs from rats. Cells will be incubated with the oxidized lipid of interest and the incorporation of this lipid into cellular lipids and its eventual secretion in a triacylglycerol-rich lipoprotein particle will be estimated. Moreover, the effect of the oxidized lipid on triacylglycerol-rich lipoprotein assembly and secretion will be determine by estimating the synthesis and secretion of apo B and lipids, translocation efficiency and degradation of apo B, and apo B mRNA. MTP and p-glycoprotein activities and mass will also be estimated in cells during influx of oxidized lipids. The effects of oxidized lipids on the atherogenicity of secreted lipoprotein particles will be addressed by either co-culturing CaCo-2 cells with macrophages or by incubating remnant particles obtained from CaCo-2 cells with mouse peritoneal macrophages and assessing the propensity for foam cell formation.

氧化脂蛋白被认为在 动脉粥样硬化的发展。 饮食中可能存在氧化脂质 有助于氧化脂蛋白的生成。 确实研究过 在人类和动物中表明饮食中的氧化脂质被摄入 由小肠向上并以脂蛋白形式分泌。 无论 氧化脂质改变脂蛋白的组成或干扰 肠道脂蛋白的正常组装和分泌 未知。 因为肠道直接贡献血浆 致动脉粥样硬化脂蛋白库，有关机制的信息 氧化脂质可能通过它调节脂蛋白组装和 分泌很重要。 MTP、apo b 和脂质流入 都是公认的肠道分泌脂蛋白的介质 细胞。 此外，最近的数据表明 p-糖蛋白是 胆固醇运输和脂蛋白分泌的促进剂 肠细胞。 因此，该提案将涉及机制 氧化脂质可能会改变脂蛋白的组装并 通过调节脂质通量的可用性来分泌和分泌 通过肠道或通过调节活动、质量或基因 MTP、apo B 或 p-糖蛋白的表达。实验将是 在半透性支持物上生长的 CaCo-2 细胞中进行 结果得到外翻肠囊实验的支持 来自老鼠。 细胞将与感兴趣的氧化脂质一起孵育 以及将这种脂质掺入细胞脂质及其 最终分泌富含三酰甘油的脂蛋白颗粒 被估计。 此外，氧化脂质对 富含三酰甘油的脂蛋白的组装和分泌 通过估计 apo B 的合成和分泌来确定 脂质、载脂蛋白 B 的易位效率和降解以及载脂蛋白 B mRNA。 MTP 和 p-糖蛋白活性和质量也将 在氧化脂质流入细胞期间估计。 的影响 氧化脂质对分泌脂蛋白颗粒致动脉粥样硬化的影响 将通过与 CaCo-2 细胞共培养来解决 巨噬细胞或通过孵育从获得的残余颗粒 CaCo-2 细胞与小鼠腹腔巨噬细胞并评估 泡沫细胞形成的倾向。