Malondialdehyde-induced Endothelial Dysfunction in Atherosclerosis

丙二醛诱导的动脉粥样硬化内皮功能障碍

• 批准号: 10449472
• 负责人: Xiaoli Sun
• 金额: $ 24.9万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10449472
• 关键词: Alzheimer' s Disease; Amino Acids; Anti-Inflammatory Agents; Antibodies; Area; Atherosclerosis; Award; Binding; Blood; Blood Vessels; Cell physiology; Cells; Cellular biology; Cholesterol; Coronary artery; Coronary heart disease; Data; Disease; Electron Transport; Endothelial Cells; Endothelium; Environment; Enzymes; Equilibrium; Event; Exhibits; Faculty; Fc domain; Free Radicals; Functional disorder; Gene Expression; Goals; Heme; Homeostasis; Human; Hyperlipidemia; Immunoglobulin G; Immunoglobulin M; Impairment; In Vitro; Infiltration; Inflammation; Inflammatory; Intercellular Junctions; Knockout Mice; Knowledge; Lesion; Lesion by Morphology; Libraries; Lipid Peroxidation; Lipoproteins; Malondialdehyde; Measures; Mediating; Mentors; Metabolism; Molecular; Mus; Necrosis; Outcome; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Permeability; Phage Display; Phase; Physiological; Plant Roots; Plasma; Polyunsaturated Fatty Acids; Positioning Attribute; Proteins; Research; Research Personnel; Resources; Role; Site; Sp1 Transcription Factor; Stains; Steatohepatitis; Stimulus; Synthetic Genes; Transgenic Mice; Vascular Permeabilities; activating transcription factor; atherogenesis; base; drug metabolism; endothelial dysfunction; experimental study; feeding; heme biosynthesis; improved; in silico; in vivo; macrophage; mouse model; new therapeutic target; novel therapeutic intervention; oxidation; oxidized lipid; oxygen transport; prevent; promoter; protein function; protein structure; synthetic enzyme; tenure track; therapeutic target; therapeutically effective; transcriptome; vascular endothelial dysfunction; vascular inflammation; western diet

PROJECT SUMMARY/ABSTRACT Malondialdehyde (MDA) is a ubiquitous and highly reactive end product of non-enzymatic lipid peroxidation, which is a central event in atherogenesis. MDA can covalently modify proteins, and is thought to be pro- inflammatory and atherogenic. It was shown that blood MDA level is correlated to coronary heart disease. However, its exact roles in atherogenesis are unknown as there were no in vivo strategies to specifically neu- tralize it. We recently generated IK17-scFv transgenic mice, which express a single chain variable fragment (scFv) of the human IK17 antibody that targets MDA. My preliminary studies found that IK17-scFv ameliorated Western diet (WD)-induced atherosclerosis in Ldlr-/- mice. MDA staining of lesion cross-sections showed that MDA is enriched in the intima, indicating endothelial cells (ECs) as a major target of MDA. My proposed stud- ies will uncover the mechanisms by which neutralizing MDA decreases atherosclerosis, with an emphasis on EC biology. As the innermost lining of blood vessels, normal ECs are critical for vascular homeostasis and functions. Under physiological conditions, intact ECs maintain an optimal balance between vessel integrity and permeability, exhibit anti-inflammatory function, and maintain normal vascular metabolism. My preliminary studies found that MDA induced excess heme accumulation in EC in vivo, and this was associated with induc- tion in EC of expression of genes encoding heme synthesis enzymes. Unlike its normal functions for oxygen transport and storage, electron transfer or drug metabolism, excess heme causes inflammation and EC dys- function, and increases vascular permeability. Based on my preliminary data, I hypothesize that MDA induces heme accumulation, which promotes endothelial dysfunction during atherogenesis. My proposal will as- sess the pathological effects of the MDA-heme axis on EC dysfunction during atherosclerosis. In Specific Aim1 (K99 phase), I will dissect roles of MDA in EC dysfunction and atherosclerosis using the IK17-scFvLdlr-/- mice. I will also systematically characterize the effects of MDA on EC transcriptome. In Specific Aim2 (R00 phase), I will characterize the effects of MDA on endothelial heme synthesis, and elucidate the underlying mechanisms. In specific Specific Aim3 (K99 and R00 phase), I will generate a new inducible endothelial cell-specific Alas1 (rate-limiting enzyme for heme synthesis) knockout mouse model to study the impact of excess heme on endo- thelial dysfunction and atherosclerosis. The roles of MDA-heme axis in EC dysfunction will be defined in vitro and in vivo. These studies will uncover mechanisms by which targeting MDA and heme can prevent EC dys- function and define novel therapeutic strategies to improve endothelial function and atherogenesis. The out- standing resources and stimulating research environment at UCSD will provide exemplary support for the ap- plicant’s goal of becoming a successful and independent investigator, and the candidate’s mentor has a suc- cessful track record of transitioning trainees into independent faculty. This K99/R00 award will support the ap- plicant toward a tenure track faculty position.

项目概要/摘要 丙二醛 (MDA) 是一种普遍存在且高度反应性的非酶脂质过氧化最终产物， 这是动脉粥样硬化形成的核心事件。 MDA 可以共价修饰蛋白质，并被认为是亲 炎症和动脉粥样硬化。研究表明，血液MDA水平与冠心病相关。 然而，它在动脉粥样硬化形成中的确切作用尚不清楚，因为没有体内策略来特异性地中和 分析它。我们最近生成了 IK17-scFv 转基因小鼠，其表达单链可变片段 靶向 MDA 的人类 IK17 抗体（scFv）。我的初步研究发现 IK17-scFv 改善了 西方饮食 (WD) 诱导 Ldlr-/- 小鼠动脉粥样硬化。病灶横截面的 MDA 染色表明 MDA 在内膜中富集，表明内皮细胞 (EC) 是 MDA 的主要靶标。我提议的研究- 他们将揭示中和 MDA 减少动脉粥样硬化的机制，重点是 EC生物学。作为血管的最内层，正常的 EC 对于血管稳态和维持至关重要。 功能。在生理条件下，完整的内皮细胞在血管完整性和 通透性，具有抗炎功能，维持正常的血管代谢。我的初步 研究发现，MDA 会诱导 EC 体内过量血红素积累，这与诱导 EC 中编码血红素合成酶的基因的表达。与氧气的正常功能不同 运输和储存、电子转移或药物代谢，过量的血红素会导致炎症和 EC 失调 功能，并增加血管通透性。根据我的初步数据，我假设 MDA 会诱导 血红素积累，在动脉粥样硬化形成过程中促进内皮功能障碍。我的建议将是—— 评估动脉粥样硬化期间 MDA-血红素轴对 EC 功能障碍的病理影响。具体目标1 （K99 阶段），我将使用 IK17-scFvLdlr-/- 小鼠剖析 MDA 在 EC 功能障碍和动脉粥样硬化中的作用。我 还将系统地表征 MDA 对 EC 转录组的影响。在特定目标2（R00阶段）中，我 将描述 MDA 对内皮血红素合成的影响，并阐明其潜在机制。 在特定的Specific Aim3（K99和R00期）中，我将生成新的可诱导内皮细胞特异性Alas1 （血红素合成限速酶）敲除小鼠模型，研究过量血红素对内源性的影响 皮细胞功能障碍和动脉粥样硬化。 MDA-血红素轴在 EC 功能障碍中的作用将在体外得到确定 和体内。这些研究将揭示靶向 MDA 和血红素可以预防 EC 失调的机制。 功能并确定改善内皮功能和动脉粥样硬化形成的新治疗策略。输出- 加州大学圣地亚哥分校的常备资源和令人兴奋的研究环境将为应用程序提供模范支持 申请人的目标是成为一名成功的独立研究者，并且候选人的导师取得了成功 将受训者转变为独立教师的成功记录。该 K99/R00 奖项将支持 ap- 申请终身教授职位。