Effect of Dietary Fatty Acids on Adipose Tissue Inflammation

膳食脂肪酸对脂肪组织炎症的影响

• 批准号: 8903548
• 负责人: ALAN CHAIT
• 金额: $ 43.5万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8903548
• 关键词: Address; Adipocytes; Adipose tissue; Adverse effects; Affect; Anti-Inflammatory Agents; Anti-inflammatory; Apolipoprotein A-I; Apolipoproteins; Atherosclerosis; Back; Biology; Blood Vessels; Body Weight decreased; Bone Marrow; Cardiovascular Diseases; Cell membrane; Cells; Chemotactic Factors; Cholesterol; Conjugated Linoleic Acids; Cyclodextrins; Data; Diet; Dietary Fatty Acid; Excision; Exposure to; Fatty Acids; Funding; Generations; Genes; Grant; Health; High Density Lipoproteins; Human; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Insulin Resistance; Isomerism; Laurates; Lead; Link; Lipids; Mediating; Metabolic; Metabolic syndrome; Mitochondria; Myristates; NADPH Oxidase; Nutritional; Obesity; Oxidative Stress; Palmitates; Pathway interactions; Prevention; Process; Production; Protein translocation; Proteins; Reactive Oxygen Species; Role; Saturated Fatty Acids; Signal Transduction; Supplementation; Testing; Transgenic Mice; Transplantation; Triglycerides; adipocyte differentiation; base; cardiovascular disorder risk; cholesterol transporters; dietary excess; disorder control; fatty acid oxidation; in vivo; macrophage; monocyte; mouse model; novel; overexpression; prevent

DESCRIPTION (provided by applicant): Adipose tissue inflammation is associated with insulin resistance and an increased risk of cardiovascular disease. Excess dietary saturated fatty acids (SFA) such as palmitate stimulate the production of reactive oxygen species (ROS) by a NOX4-dependent mitochondria-independent pathway, and increase the generation of monocyte chemotactic factors and inflammatory signals in adipocytes. Conversely, an isomer of conjugated linoleic acid (CLA) that is used as a weight loss supplement, decreases triglyceride accumulation and stimulates ROS production by mitochondria rather than NOX4. This too leads to adipocyte chemotactic factor generation and inflammation. On the basis of our preliminary data, we hypothesize that SFA such as palmitate stimulate adipose tissue inflammation by NOX4-dependent generation of ROS by adipocytes. This process involves transfer of key cellular proteins such as NOX4 to the plasma membrane, and can be blocked by removing cholesterol from plasma membranes by exposure to HDL. Conversely, we hypothesize that CLA stimulates adipose tissue inflammation by a distinct pathway that involves generation of ROS by mitochondria, is associated with reduced triglyceride accumulation in adipocytes, is not associated with translocation of proteins to the cell membrane, and is not blocked by HDL. To determine whether NOX expression by adipocytes is required for SFA-induced adipose tissue inflammation, we will specifically delete NOX4 in adipocytes. We also will determine mechanisms by which HDL and its major apolipoprotein, apoA-I, exert anti-inflammatory effects on adipocytes and adipose tissue in vitro and in vivo. Our in vivo studies will focus on the role o the cholesterol transporter, ABCG1, which we have shown in preliminary data to be a likely candidate for the removal of cholesterol from plasma membranes. Since ABCG1 is likely to be produced by adipose tissue macrophages rather than adipocytes, we will transplant either wild type or ABCG1-deficient bone marrow into apoA-I transgenic mice, in which SFA-mediated adipose tissue inflammation is blunted. We will identify differences in how adipocytes metabolize CLA versus palmitate, and determine why CLA leads to triglyceride reduction and fatty acid utilization by mitochondria rather than storage of triglycerides as occurs with other SFA. We also will investigate how this metabolic switch is linked to the generation of mitochondrial ROS, chemotactic factors and inflammatory molecules. Findings from this grant have important implications for preventing diet-induced adipose tissue inflammation and the accompanying insulin resistance and cardiovascular disease risk.

描述（由申请人提供）：脂肪组织炎症与胰岛素抵抗和心血管疾病风险增加有关。过量的膳食饱和脂肪酸（SFA）如棕榈酸盐通过nox4依赖的线粒体独立途径刺激活性氧（ROS）的产生，并增加脂肪细胞中单核细胞趋化因子和炎症信号的产生。相反，共轭亚油酸（CLA）的异构体被用作减肥补充剂，减少甘油三酯的积累，刺激线粒体而不是NOX4产生ROS。这也会导致脂肪细胞趋化因子的产生和炎症。根据我们的初步数据，我们假设棕榈酸酯等SFA通过脂肪细胞产生nox4依赖性ROS来刺激脂肪组织炎症。这一过程涉及到关键细胞蛋白（如NOX4）向质膜的转移，并且可以通过暴露于HDL来去除质膜上的胆固醇来阻止。相反，我们假设CLA通过一种独特的途径刺激脂肪组织炎症，该途径涉及线粒体产生ROS，与脂肪细胞中甘油三酯积累减少有关，与蛋白质向细胞膜的易位无关，并且不被HDL阻断。为了确定sfa诱导的脂肪组织炎症是否需要脂肪细胞表达NOX，我们将特异性地删除脂肪细胞中的NOX4。我们还将确定HDL及其主要载脂蛋白apoA-I在体外和体内对脂肪细胞和脂肪组织发挥抗炎作用的机制。我们的体内研究将集中在胆固醇转运体ABCG1的作用上，我们已经在初步数据中表明，ABCG1可能是去除质膜胆固醇的候选者。由于ABCG1可能是由脂肪组织巨噬细胞而不是脂肪细胞产生的，我们将把野生型或ABCG1缺失的骨髓移植到apoA-I转基因小鼠中，sfa介导的脂肪组织炎症被减弱。我们将确定脂肪细胞代谢CLA与棕榈酸酯的差异，并确定为什么CLA会导致甘油三酯减少和线粒体利用脂肪酸，而不是像其他SFA那样导致甘油三酯储存。我们还将研究这种代谢开关如何与线粒体ROS、趋化因子和炎症分子的产生相关联。这项研究的发现对于预防饮食引起的脂肪组织炎症以及伴随的胰岛素抵抗和心血管疾病风险具有重要意义。