LONG-CHAIN ACYL-COA SYNTHETASES IN VASCULAR CELLS

描述（由申请人提供）：甘油三酯导致糖尿病患者心血管死亡率增加。在动脉粥样硬化病变中，长链脂肪酸从甘油三酯中释放出来，并通过长链acyI-CoA合成酶（ACS1-5）催化的反应被酯化成辅酶a，供血管细胞利用。油酸（OA）是甘油三酯中最常见的脂肪酸，在血管细胞中具有重要的促动脉粥样硬化作用。将解决四个问题：1。哪些ACS亚型在原代平滑肌细胞（SMCs）和巨噬细胞中表达，它们是否受葡萄糖和脂质调节？我们假设原代SMCs和巨噬细胞表达多种ACS亚型，并且它们的表达在体外和体内受到葡萄糖和脂质的不同调节。在体内研究方面，我们开发了一种新的糖尿病加速动脉粥样硬化转基因小鼠模型。2. 在SMCs中，生长因子刺激后OA并入磷脂酰胆碱和生成富含OA的1,2-二酰基甘油是否需要ACS2 ？在生长因子刺激磷脂酶d后，OA通过生成富含OA的1,2-二酰基甘油（1,2- dag）增强SMCs中生长因子的有丝分裂作用。我们假设ACS2介导OA并入磷脂酰胆碱，并在生长因子刺激后生成富含OA的1,2- dag。我们建议使用ACS抑制剂和RNAi来抑制ACS2。3. ACS2对于OA增强SMCs中生长因子诱导的增殖能力是必要的吗？我们假设ACS2是OA增强SMCs中生长因子诱导的增殖能力所必需的。ACS亚型和RNAi抑制剂将用于抑制oa介导的增强生长因子的有丝分裂作用。4. 哪个特定的ACS亚型对oa诱导的巨噬细胞死亡和抑制胆固醇外排是必需的？OA诱导巨噬细胞死亡，抑制胆固醇外排。我们假设特定的ACS异构体对这些事件是必要的。ACS抑制剂和RNAi将用于确定介导oa诱导的巨噬细胞死亡、胆固醇外排和脂质代谢的ACS亚型。迄今为止，血管细胞中的ACS亚型尚未被研究过。我们期望在原发平滑肌和巨噬细胞中鉴定OA重要生物学效应所需的ACS亚型。

DESCRIPTION (provided by applicant): Triglycerides contribute to the increased cardiovascular mortality in people with diabetes. Long-chain fatty acids are released from triglycerides in lesions of atherosclerosis, and are esterified to CoA in order to be utilized by vascular cells through a reaction that is catalyzed by long-chain acyI-CoA synthetases (ACS1-5). Oleic acid (OA), the most common fatty acid in triglycerides, has important pro-atherosclerotic effects in vascular cells. Four questions will be addressed: 1. Which ACS isoforms are expressed in primary smooth muscle cells (SMCs) and macrophages, and are they regulated by glucose and lipids? We hypothesize that primary SMCs and macrophages express several ACS isoforms, and that their expression is differentially regulated by glucose and lipids in vitro and in vivo. For the in vivo studies, we have developed a new transgenic mouse model of diabetes-accelerated atherosclerosis. 2. Is ACS2 necessary for OA incorporation into phosphatidylcholine and generation of OA-enriched 1,2-diacylglycerol following growth factor stimulation in SMCs? OA enhances the mitogenic effects of growth factors in SMCs by generation of OA-enriched 1,2-diacylglycerol (1,2-DAG) following growth factor-stimulation of phospholipase D. We hypothesize that ACS2 mediates OA-incorporation into phosphatidylcholine and generation of OA-enriched 1,2-DAG following growth factor stimulation. We propose to inhibit ACS2 by using ACS inhibitors and RNAi. 3. Is ACS2 necessary for the ability of OA to enhance growth factor-induced proliferation in SMCs? We hypothesize that ACS2 is necessary for the ability of OA to enhance growth factor-induced proliferation in SMCs. Inhibitors of ACS isoforms and RNAi will be used to inhibit OA-mediated potentiation of mitogenic effects of growth factors. 4. Which specific ACS isoform(s) is necessary for OA-induced macrophage death and inhibition of cholesterol efflux? OA induces macrophage death and inhibits cholesterol efflux. We hypothesize that a specific ACS isoform is necessary for these events. ACS inhibitors and RNAi will be used to determine the ACS isoform that mediates OA-induced effects on macrophage death, cholesterol efflux and lipid metabolism. The ACS isoforms in vascular cells have not been studied to date. We expect to identify ACS isoforms required for important biological effects of OA in primary smooth muscle and macrophages.