In Vitro /In Vivo Approach to Artery Wall Inflammation

动脉壁炎症的体外/体内方法

• 批准号: 6758073
• 负责人: Alan M Fogelman
• 金额: $ 29.73万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6758073
• 关键词: apolipoproteins; atherosclerosis; blood lipoprotein metabolism; cholesterol; clinical research; genetically modified animals; high density lipoproteins; human subject; inflammation; laboratory mouse; lipid transport; low density lipoprotein; mitogen activated protein kinase; oxidized lipid; phospholipids; vascular endothelium

During the current grant period normal HDL was shown to inhibit three steps in the formation of mildly oxidized LDL (MM-LDL). The function of HDL (its ability to prevent LDL oxidation and inactivate oxidized phospholipids (Ox-PAPC) in MM-LDL) was found to better predict atherosclerosis in some patients than HDL-cholesterol. MKP-1 was required for Ox-PAPC to induce endothelial cells to produce MCP-1. Paraoxonase (PON)-2 was found to be an intracellular enzyme capable of inactivating Ox-PAPC while PON-3 was shown to be an HDL associated enzyme that like PON-1 inactivates Ox-PAPC, but unlike PON-1 is not regulated by Ox-PAPC. Ox-PAPC regulated hepatic PON-1 and apoJ, but not MCP-1, via IL-6. Following influenza A infection in mice, HDL lost PON activity and lost the ability to protect LDL against oxidation. When an apoA-I mimetic peptide synthesized from all D-amino acids (D-4F) was given orally to LDL receptor null mice on a Western diet or apoE null mice on a chow diet, there was a dramatic improvement in HDL's ability to inhibit LDL oxidation accompanied by a dramatic decrease in atherosclerotic lesions independent of total plasma or HDL-cholesterol. When D-4F was given to LDL receptor null mice after a Western diet and influenza A infection there was a dramatic reduction in macrophage traffic into the aortic arch and innominate arteries. In the next grant period the mechanisms by which MKP-1 mediates the inflammatory response induced by Ox-PAPC will be determined in genetically engineered mice. A link between reverse cholesterol transport and LDL oxidation will be explored in mice. The mechanisms of action of D-4F will be determined in mouse models of atherosclerosis. The ability of D-4F to promote the formation and cycling of pre-beta HDL-like particles through the reverse cholesterol transport pathway will also be studied. The mechanism by which D-4F inhibits macrophage traffic into arteries after influenza infection will be determined. The mechanisms by which oral administration of a synthetic phospholipid raises HDL and PON levels, and decreases atherosclerosis in mouse models will be determined. Finally we will determine if HDL function is a sensitive indicator of the presence or absence of atherosclerosis in mice and humans. This proposal will identify potential diagnostic and therapeutic targets by elucidating the molecular and genetic mechanisms that enhance or inhibit the inflammatory response to oxidized phospholipids.

在当前的资助期内，正常的 HDL 被证明可以抑制轻度氧化的 LDL (MM-LDL) 形成的三个步骤。研究发现，HDL 的功能（其防止 LDL 氧化和灭活 MM-LDL 中氧化磷脂 (Ox-PAPC) 的能力）比 HDL-胆固醇能更好地预测某些患者的动脉粥样硬化。 Ox-PAPC 需要 MKP-1 才能诱导内皮细胞产生 MCP-1。对氧磷酶 (PON)-2 被发现是一种能够灭活 Ox-PAPC 的细胞内酶，而 PON-3 被证明是一种 HDL 相关酶，与 PON-1 一样灭活 Ox-PAPC，但与 PON-1 不同，不受牛-PAPC。 Ox-PAPC 通过 IL-6 调节肝脏 PON-1 和 apoJ，但不调节 MCP-1。小鼠感染甲型流感后，HDL 失去了 PON 活性，并失去了保护 LDL 的能力 氧化。当将由所有 D-氨基酸 (D-4F) 合成的 apoA-I 模拟肽口服给采用西方饮食的 LDL 受体缺失小鼠或采用食物饮食的 apoE 缺失小鼠时，HDL 抑制的能力显着提高。低密度脂蛋白氧化伴随着动脉粥样硬化病变的显着减少，与总血浆或高密度脂蛋白胆固醇无关。当 LDL 受体缺失小鼠在接受西方饮食并感染甲型流感后给予 D-4F 时，进入主动脉弓和无名动脉的巨噬细胞流量显着减少。在下一个资助期内，将在基因工程小鼠中确定 MKP-1 介导 Ox-PAPC 诱导的炎症反应的机制。我们将在小鼠身上探索胆固醇反向转运和低密度脂蛋白氧化之间的联系。 D-4F 的作用机制将在小鼠动脉粥样硬化模型中确定。 D-4F促进阵型的能力 还将研究前β HDL 样颗粒通过反向胆固醇转运途径的循环。流感感染后 D-4F 抑制巨噬细胞进入动脉的机制将被确定。将确定口服合成磷脂提高 HDL 和 PON 水平并减少小鼠模型动脉粥样硬化的机制。最后，我们将确定高密度脂蛋白功能是否是小鼠和人类是否存在动脉粥样硬化的敏感指标。该提案将通过阐明增强或抑制氧化磷脂炎症反应的分子和遗传机制来确定潜在的诊断和治疗靶点。