Macrophage AMPK, Inflammation, and Atherosclerosis

巨噬细胞 AMPK、炎症和动脉粥样硬化

• 批准号: 8236575
• 负责人: Bingzhong Xue
• 金额: $ 15.77万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-12-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8236575
• 关键词: 5' -AMP-activated protein kinase; Acute; Address; Adipocytes; Adipose tissue; Antigen Presentation; Apolipoprotein E; Apoptosis; Arterial Fatty Streak; Atherogenic Diet; Atherosclerosis; Body Weight; Cardiac Death; Cells; Cholesterol; Cholesterol Homeostasis; Chronic; Coculture Techniques; Development; Diet; Disease; Dominant-Negative Mutation; Endoplasmic Reticulum; Euglycemic Clamping; Event; Exhibits; Fatty acid glycerol esters; Gene Expression; Genes; Glucose; Glucose Clamp; Goals; Immune; In Vitro; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Insulin; Insulin Resistance; Kinetics; Knock-out; Knockout Mice; Knowledge; Lead; Lesion; Link; Lipids; Lipoproteins; Liver; Low Density Lipoprotein Receptor; Low-Density Lipoproteins; Mediating; Metabolic; Metabolic Diseases; Metabolic Pathway; Mus; Muscle; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Pathogenesis; Pathology; Pathway interactions; Phagocytosis; Phenotype; Plasma; Prevention; Reporting; Role; Saturated Fatty Acids; Signal Pathway; Signal Transduction; Signaling Molecule; Staging; System; Testing; Therapeutic; Tissues; Toxic effect; Transgenic Mice; Up-Regulation; cytokine; endoplasmic reticulum stress; fatty acid oxidation; feeding; glucose metabolism; glucose tolerance; glucose uptake; improved; in vivo; insulin sensitivity; insulin signaling; insulin tolerance; lipid metabolism; macrophage; migration; mouse model; novel; nutrient metabolism; oxidation; oxidized low density lipoprotein; particle; prevent; protective effect; reverse cholesterol transport; sensor

DESCRIPTION (provided by applicant): AMP-activated protein kinase (AMPK) is an evolutionally conserved cellular energy sensor that regulates metabolic pathways in lipid, cholesterol and glucose metabolism. We have reported that macrophage AMPK protects against lipid-induced inflammation and insulin resistance in vitro. In addition, activating AMPK by 5- aminoimidazole-4-carboxamide-1-2-4-ribofuranoside (AICAR) in ApoE-/- mice alleviates atherosclerosis burden. However, the pleiotropic functions of AMPK make it difficult to determine specifically the role of macrophage AMPK in the pathogenesis of inflammation-associated metabolic disorders, including atherosclerosis and insulin resistance. In this proposal, transgenic mice with macrophage-specific over- expression of dominant negative or constitutively active 11AMPK (DN11 and CA11, respectively), and macrophage-specific 11MAPK knockout (MAKO) mice will be used to study the role of macrophage AMPK in these metabolic disorders. We find that macrophages from CA11 mice have significantly lower lipid- and cholesterol-induced ER stress, inflammation and apoptosis, which is associated with up-regulation of genes involved in fatty acid oxidation and cholesterol efflux. We hypothesize that macrophage AMPK regulates macrophage lipid and cholesterol homeostasis by promoting fatty oxidation and cholesterol efflux, thereby preventing lipid- and cholesterol-induced ER stress, inflammation and apoptosis. This may contribute to macrophage AMPK's protective effects against atherosclerosis and insulin resistance. Specific aim 1 will determine mechanisms by which macrophage AMPK prevents lipid- and cholesterol-induced ER stress, inflammation and apoptosis using macrophages from CA11, DN11 and MAKO mice. We will determine: 1) whether AMPK regulates macrophage lipid and cholesterol homeostasis by promoting cholesterol efflux and fatty acid oxidation, and 2) whether these pathways are necessary in mediating AMPK's suppression of lipid- and cholesterol-induced ER stress, inflammation and apoptosis. Specific aim 2 will determine the protective effects of macrophage AMPK against atherosclerosis using CA11, DN11 and MAKO mice crossed with low density lipoprotein receptor knockout mice. We will determine: 1) plasma lipoprotein phenotype, 2) in vivo reverse cholesterol transport from macrophages, 3) atherosclerosis extent, 4) macrophage number, lipid content, ER stress, inflammation and apoptosis in atherosclerotic lesions, and 5) kinetics of macrophage accumulation, ER stress, inflammation and apoptosis development in early and late atherosclerotic lesions in these mice fed an atherogenic diet. Specific aim 3 will determine the protective effects of macrophage AMPK against insulin resistance using CA11, DN11 and MAKO mice. The insulin sensitivity and adipose tissue macrophage infiltration, ER stress and inflammation will be determined in these mice on a high fat diet. Completing these studies will greatly improve our knowledge on the role of macrophage AMPK in the protection against inflammation-associated metabolic disorders, including atherosclerosis and insulin resistance. PUBLIC HEALTH RELEVANCE: The goal of this project is to understand AMPK as a key signaling molecule linking cellular nutrient metabolism to inflammatory responses and to identify mechanisms mediating the protective effects of macrophage AMPK against both atherosclerosis and insulin resistance through suppression of lipid-mediated macrophage endoplasmic reticulum stress, inflammation and apoptosis.

描述（由申请人提供）：AMP活化蛋白激酶（AMPK）是一种进化保守的细胞能量传感器，可调节脂质、胆固醇和葡萄糖代谢中的代谢途径。我们已经报道了巨噬细胞AMPK在体外对脂质诱导的炎症和胰岛素抵抗具有保护作用。此外，在ApoE-/-小鼠中，通过5-氨基咪唑-4-甲酰胺-1-2-4-呋喃核糖苷（AICAR）激活AMPK减轻了动脉粥样硬化负担。然而，AMPK的多效性功能使得很难确定巨噬细胞AMPK在炎症相关代谢紊乱（包括动脉粥样硬化和胰岛素抵抗）发病机制中的作用。在该提议中，将使用具有巨噬细胞特异性显性阴性或组成型活性11 AMPK过表达的转基因小鼠（分别为DN 11和CA 11）和巨噬细胞特异性11 MAPK敲除（MAKO）小鼠来研究巨噬细胞AMPK在这些代谢紊乱中的作用。我们发现，从CA 11小鼠巨噬细胞有显着降低脂质和胆固醇诱导的ER应激，炎症和凋亡，这是与上调基因参与脂肪酸氧化和胆固醇流出。我们推测巨噬细胞AMPK通过促进脂肪氧化和胆固醇流出来调节巨噬细胞脂质和胆固醇稳态，从而防止脂质和胆固醇诱导的ER应激、炎症和细胞凋亡。这可能有助于巨噬细胞AMPK对动脉粥样硬化和胰岛素抵抗的保护作用。具体目标1将使用来自CA 11、DN 11和MAKO小鼠的巨噬细胞确定巨噬细胞AMPK防止脂质和胆固醇诱导的ER应激、炎症和凋亡的机制。我们将确定：1）AMPK是否通过促进胆固醇流出和脂肪酸氧化来调节巨噬细胞脂质和胆固醇稳态，以及2）这些途径是否在介导AMPK抑制脂质和胆固醇诱导的ER应激、炎症和凋亡中是必需的。具体目标2将使用与低密度脂蛋白受体敲除小鼠杂交的CA 11、DN 11和MAKO小鼠来确定巨噬细胞AMPK对动脉粥样硬化的保护作用。我们将确定：1）血浆脂蛋白表型，2）来自巨噬细胞的体内反向胆固醇转运，3）动脉粥样硬化程度，4）动脉粥样硬化病变中的巨噬细胞数量、脂质含量、ER应激、炎症和凋亡，和5）在这些喂食致动脉粥样硬化饮食的小鼠中，早期和晚期动脉粥样硬化病变中的巨噬细胞积累、ER应激、炎症和凋亡发展的动力学。具体目标3将使用CA 11、DN 11和MAKO小鼠确定巨噬细胞AMPK对胰岛素抵抗的保护作用。将在这些高脂肪饮食的小鼠中测定胰岛素敏感性和脂肪组织巨噬细胞浸润、ER应激和炎症。完成这些研究将大大提高我们对巨噬细胞AMPK在预防炎症相关代谢紊乱（包括动脉粥样硬化和胰岛素抵抗）中作用的认识。 公共卫生相关性：本项目的目标是了解AMPK作为连接细胞营养代谢与炎症反应的关键信号分子，并确定介导巨噬细胞AMPK通过抑制脂质介导的巨噬细胞内质网应激、炎症和凋亡对动脉粥样硬化和胰岛素抵抗的保护作用的机制。