Citrullination of ApoA1 as a Novel Contributor to Inflammatory Atherogenesis

ApoA1 的瓜氨酸化作为炎症性动脉粥样硬化形成的新贡献者

• 批准号: 9130424
• 负责人: Jeremy B Sokolove
• 金额: $ 35.81万
• 依托单位: PALO ALTO VETERANS INSTIT FOR RESEARCH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-04 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9130424
• 关键词: Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Apolipoprotein A-I; Arginine; Arginine deiminase; Arterial Fatty Streak; Atherosclerosis; Biological Assay; Blood Vessels; Cardiovascular Diseases; Cardiovascular system; Cause of Death; Cells; Cholesterol; Citrulline; Coronary; Coronary Arteriosclerosis; Coronary heart disease; Data; Development; Diagnostic tests; Diet; Due Process; Electron Beam; Enzymes; Event; Excision; Family; Genetic; Goals; Health; Heart; High Density Lipoproteins; Human; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Lead; Leukocytes; Link; Mass Spectrum Analysis; Mediating; Modeling; Modification; Mus; Mutation; Pathologic; Pattern; Peroxidases; Physiological; Plasma; Prevention; Process; Proteins; Risk Factors; Role; Severities; Site; Tissues; Translations; Ultrasonography; Work; atherogenesis; base; cardiovascular disorder risk; cardiovascular risk factor; case control; cohort; inhibitor/antagonist; insight; macrophage; monocyte; neutrophil; novel; prevent; success; therapeutic target; vascular inflammation

 DESCRIPTION (provided by applicant): Citrullination is the post-translational conversion of peptidyl-arginine to peptidyl-citrulline and is mediated by a family of enzymes known as peptidyl-arginine deiminases (PADs). Citrullination has been demonstrated to be an inflammation-dependent process due to the constitutive expression of the enzymes PAD2 and PAD4 by polymorphonuclear leukocytes as well as cells of the monocytes/macrophage lineage. The link between inflammation and atherosclerosis is well established with numerous mechanisms implicated including oxidative modification of protective HDL proteins induced by the enzyme myeloperoxidase. However, another post- translation modification recently identified within the atherosclerotic plaque is protein citrullination. We have identified several citrullinated plaque proteins including prominently, the HDL-associated protein ApoA-I . ApoA-I facilitates removal of excess cellular cholesterol thus impeding atherogenesis. Additionally, ApoA-I has been demonstrated to have direct anti-inflammatory effects thus limiting vascular inflammation. We propose to study citrullination as a novel mediator of inflammation induced atherosclerotic progression. This work represents a scientific progression of our previous studies demonstrating citrullination within the atherosclerotic plaque. The proposed studies will provide new insights into how a group of enzymes ubiquitously carried by white blood cells, peptidyl arginine-deiminases (PADs), contributes to the effect of pathologic inflammation within the atherosclerotic plaque. The main goal of this application is to investigate the role of ApoA-I citrullination as a risk factor for atherosclerotic development and progression. Specifically, we propose to: 1. Define the sites of ApoA-I citrullination from in-vitro citrullinated ApoA-I as wellas ApoA-I isolated from human plasma, and from within the atherosclerotic plaque; 2. Confirm and characterize citrullination-dependent abrogation of ApoA-I cholesterol efflux capacity and to identify residues critical for mediating this abrogation; 3. Use pharmacologic and genetic animal models to define the role of citrullination in atherosclerosis progression, and 4. Quantitate citrullination of plasma ApoA-I and correlate with subclinical atherosclerosis as well as atherosclerotic events. Success of these studies could identify novel mechanisms contributing to inflammation-driven atherosclerosis and have the potential to both contribute to the development of diagnostic tests for cardiovascular risk prediction, as well as identifying potentia therapeutic targets for the treatment and/or prevention of coronary artery disease.

 描述（由申请人提供）：瓜氨酸化是肽基精氨酸到肽基瓜氨酸的翻译后转化，并且由称为肽基精氨酸脱亚氨酶（PAD）的酶家族介导。由于多形核白细胞以及单核细胞/巨噬细胞谱系的细胞 PAD2 和 PAD4 酶的组成型表达，瓜氨酸化已被证明是炎症依赖性过程。炎症和动脉粥样硬化之间的联系已得到充分证实，涉及多种机制，包括由髓过氧化物酶诱导的保护性 HDL 蛋白的氧化修饰。然而，最近在动脉粥样硬化斑块内发现的另一种翻译后修饰是蛋白质瓜氨酸化。我们已经鉴定了几种瓜氨酸斑块蛋白，其中最突出的是 HDL 相关蛋白 ApoA-I。 ApoA-I 有助于去除多余的细胞胆固醇，从而阻止动脉粥样硬化形成。此外，ApoA-I 已被证明具有直接抗炎作用，从而限制血管炎症。我们建议研究瓜氨酸化作为炎症诱导的动脉粥样硬化进展的新型介质。这项工作代表了我们先前研究的科学进展，证明了动脉粥样硬化斑块内的瓜氨酸化。拟议的研究将为白细胞普遍携带的一组酶——肽基精氨酸脱亚胺酶（PAD）——如何影响动脉粥样硬化斑块内的病理性炎症提供新的见解。本申请的主要目标是研究 ApoA-I 瓜氨酸化作为动脉粥样硬化发生和进展的危险因素的作用。具体来说，我们建议： 1. 定义体外瓜氨酸化 ApoA-I 以及从人血浆和动脉粥样硬化斑块内分离的 ApoA-I 的 ApoA-I 瓜氨酸化位点； 2. 确认并表征瓜氨酸依赖性的 ApoA-I 胆固醇流出能力的消除，并确定介导这种消除的关键残基； 3. 使用药理学和遗传动物模型来确定瓜氨酸化在动脉粥样硬化进展中的作用，以及 4. 定量血浆 ApoA-I 的瓜氨酸化并与亚临床动脉粥样硬化以及动脉粥样硬化事件相关联。这些研究的成功可以确定导致炎症驱动的动脉粥样硬化的新机制，并有可能有助于开发心血管风险预测的诊断测试，以及确定治疗和/或预防冠状动脉疾病的潜在治疗靶点。