Mechanisms of foamy monocyte formation in atherosclerosis

动脉粥样硬化中泡沫单核细胞形成的机制

基本信息

批准号：
10707022
负责人：
WonMo Ahn
金额：
$ 4.77万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-17 至 2025-08-16
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10707022
关键词：
Academic Training Adhesions Affinity Arteries Atherosclerosis Attenuated Biology Blood Vessels CD36 gene Cardiovascular system Cause of Death Chemical Stimulation Chemicals Consensus Data Development Endothelium FDA approved Foam Cells Funding Genetic Goals Health Human In Vitro Inflammatory Ischemic Stroke Knockout Mice Lipids Liquid substance Low-Density Lipoproteins Macrophage Mediating Membrane Mentorship Methodology Mus Myeloid Cells Myocardial Infarction NHE1 Pathogenesis Pathway interactions Patients Peripheral arterial disease Pharmaceutical Preparations Phase Phenotype Physiological Plasma Play Pre-Clinical Model Process Publishing Recording of previous events Research Role Secure Stroke Technical Expertise Testing Tetradecanoylphorbol Acetate Time Training United States Universities Woman cost cytokine health care delivery hypercholesterolemia improved in vivo inflammatory marker inhibitor insight medical schools men migration monocyte new therapeutic target novel pharmacologic post-doctoral training pre-doctoral receptor receptor mediated endocytosis scavenger receptor skills therapeutic target therapeutically effective uptake

项目摘要

PROJECT SUMMARY Atherosclerosis, the underlying cause of heart attack, stroke and peripheral arterial disease, is the leading cause of death in the United States. A better understanding of the pathomechanisms of atherosclerosis is critical to identify more effective therapeutic strategies to treat atherosclerosis. Recent studies demonstrated that majority of the circulating monocyte pool in patients with atherosclerosis are lipid-laden foamy monocytes and pharmacological depletion of foamy monocytes in hypercholesterolemic mice attenuates atherosclerosis development. Although these studies suggest that monocyte uptake of plasma LDL is a therapeutic target in atherosclerosis, the mechanism of foamy monocyte formation is currently unknown. Preliminary studies demonstrate for the first time that chemical stimulation of macropinocytosis promotes native LDL uptake, leading to foamy monocyte formation in vitro. Moreover, pharmacological inhibition of macropinocytosis and genetic deletion of the macropinocytosis regulator, NHE1, selectively in myeloid cells attenuates atherosclerosis development in hypercholesterolemic mice. The central hypothesis of this proposal is that stimulation of macropinocytosis promotes monocyte lipid uptake and foamy monocyte formation. Aim 1 will test the hypothesis that physiologically relevant stimulators of macropinocytosis increase foamy monocyte formation in vitro. We will assess the ability of human primary and THP1 monocytes to uptake lipids in the presence or absence of physiologically relevant macropinocytosis stimulators and pharmacological inhibitors. The relative contribution of scavenger receptor-mediated lipid uptake vs. macropinocytosis will be quantified using monocytes from wild type, CD36-/-, SRA-/- and CD36-/-/SRA-/- mice. Finally, we will assess phenotypic and functional changes in foamy monocytes relevant to the pathogenesis of atherosclerosis. Aim 2 will test the hypothesis that myeloid cell- specific deletion of the macropinocytosis regulator, NHE1, inhibits foamy monocyte formation in vivo. Monocytes from NHE1f/f Lysm Cre+ and littermate Cre- mice injected with AAV8-PCSK9 will be isolated and analyzed for lipid content, inflammatory cytokine secretion, inflammatory markers, and adhesion ability. Additionally, we will use wild type and CD36-/-/SRA-/- mice to assess the effect of a repurposed FDA-approved drug that inhibits macropinocytosis in attenuating circulating foamy monocyte levels. This project will allow me to develop new technical skills, gain expertise in conducting rigorous, hypothesis-driven research and improve my independent skills. The project will be conducted under the mentorship of Dr. Gabor Csanyi and Dr. Neal Weintraub in the Vascular Biology Center at the Medical College of Georgia, Augusta University, which has a rich history of successful pre- and post-doctoral training. The proposed project is for 3 years of funding with the aims divided amongst the 3 years of funding, culminating with a dissertation defense at the end of the third year. We anticipate that findings from this novel proposal will identify macropinocytosis as a key mechanism by which monocytes internalize lipids and will highlight this pathway as a new therapeutic target in atherosclerosis.

项目摘要动脉粥样硬化是心脏病发作，中风和周围动脉疾病的根本原因，是主要原因在美国死亡。更好地了解动脉粥样硬化的病理机理对确定治疗动脉粥样硬化的更有效的治疗策略。最近的研究表明多数动脉粥样硬化患者的循环单核细胞库是富含脂质的泡沫单核细胞和高胆固醇小鼠中泡沫单核细胞的药理耗竭会减弱动脉粥样硬化发展。尽管这些研究表明血浆LDL的单核细胞摄取是一种治疗靶点动脉粥样硬化，泡沫单核细胞形成的机制目前尚不清楚。初步研究首次证明化学刺激大型细胞增多症促进了天然LDL吸收在体外形成泡沫单核细胞。此外，药理学抑制大型细胞增多症和遗传大型细胞增多症调节剂NHE1在髓样细胞中有选择地减弱动脉粥样硬化高胆固醇小鼠的发育。该提议的中心假设是刺激大型细胞增多症促进单核细胞脂质摄取和泡沫单核细胞的形成。 AIM 1将检验假设大型细胞增多症与生理相关的刺激剂会在体外增加泡沫状的单核细胞形成。我们将在存在或不存在的情况下，评估人类主要和THP1单核细胞摄取脂质的能力生理相关的大型细胞增多症刺激剂和药理学抑制剂。相对贡献将使用野生的单核细胞来定量清道夫受体介导的脂质摄取与大型细胞增多症类型，CD36 - / - ，SRA - / - 和CD36 - / - /SRA - / - 小鼠。最后，我们将评估泡沫状的表型和功能变化与动脉粥样硬化的发病机理有关的单核细胞。 AIM 2将检验髓样细胞的假设大型细胞增多症调节剂NHE1的特异性缺失抑制体内泡沫单核细胞的形成。单核细胞将隔离并分析从NHE1F/f lysm cre++ cremate cre-cre-cre-exject in Aav8-pcsk9中含量，炎症细胞因子分泌，炎症标记和粘附能力。此外，我们将使用野生型和CD36 - / - /SRA - / - 小鼠评估抑制FDA批准的药物的效果巨型细胞增多症在衰减循环泡沫单核细胞水平中。这个项目将使我开发新的技术技能，在进行严格的，假设驱动的研究方面获得专业知识，并改善我的独立技能。该项目将在Gabor Csanyi博士和Neal Weintraub博士的指导下进行奥古斯塔大学佐治亚州医学院的血管生物学中心，该学院拥有丰富的历史成功的博士后培训。拟议的项目是为期3年的资金，目的分为在三年的资金中，在第三年末以论文辩护达到顶点。我们期待从这个新建议中的发现将确定大型细胞增多症是单核细胞的关键机制将脂质内化，并将在动脉粥样硬化中强调这一途径是一种新的治疗靶点。