Development of Rac-Targeted Therapeutic Strategy for Treatment of Calcific Atherosclerosis

钙化动脉粥样硬化 Rac 靶向治疗策略的开发

• 批准号: 10064634
• 负责人: Alan Ross Morrison
• 金额: $ 37.67万
• 依托单位: OCEAN STATE RESEARCH INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-15 至 2022-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10064634
• 关键词: Aorta; Apolipoprotein E; Arterial Fatty Streak; Arteries; Atherosclerosis; Biological Process; Blood Vessels; Bone Marrow Transplantation; Calcium; Cardiovascular system; Cells; Cessation of life; Cholesterol; Chronic; Clinical; Coronary Arteriosclerosis; Coronary artery; Data; Deposition; Development; Disease; Effectiveness; Evaluation; Event; Evolution; Experimental Animal Model; Experimental Models; Family; GTP Binding; Gene Deletion; Genetic Transcription; Goals; Growth Factor; Guanine Nucleotide Exchange Factors; Hematopoietic; High Fat Diet; Histology; Human; Immune signaling; Inflammasome; Inflammation; Inflammatory; Interleukin-1 Receptors; Interleukin-1 beta; Laboratories; Macrophage Activation; Mediator of activation protein; Medicine; Modeling; Molecular; Monomeric GTP-Binding Proteins; Morbidity - disease rate; Mus; Myocardial Infarction; Osteogenesis; Pathway interactions; Patient-Focused Outcomes; Patients; Predictive Value; Prevention; Prevention strategy; Process; Production; Reactive Oxygen Species; Risk; Role; Sampling; Serum; Signal Pathway; Signal Transduction; Signaling Molecule; Smooth Muscle Myocytes; Source; Time; Transducers; Vascular Smooth Muscle; Vascular calcification; acute coronary syndrome; calcification; cardiovascular risk factor; coronary artery calcification; coronary event; cytokine; disability; in vivo; mRNA Expression; macrophage; member; mortality; mouse model; novel therapeutic intervention; osteogenic; prevent; programs; promoter; protein complex; rho; small molecular inhibitor; stressor; sudden cardiac death; targeted treatment; transcription factor; treatment strategy

PROJECT SUMMARY/ABSTRACT: Coronary artery disease (CAD) from calcific atherosclerosis is the single leading cause of morbidity and mortality worldwide. The calcium composition of atherosclerotic plaque has predictive value in terms of cardiovascular events. Inflammation is likely a key mediator of vascular calcification, but immune signaling mechanisms that promote this process are minimally understood. Recently, the small GTPase, Rac2, was identified as a major inflammatory regulator of signaling that directs plaque osteogenesis. Atherosclerotic aortas from ApoE-/- mice fed a high fat diet supplemented with cholesterol demonstrated dynamic expression of Rac2 mRNA expression over time. Moreover, decreased Rac2 expression correlated with increased atherosclerotic calcification, both in the experimental animal model and in human coronary artery plaques. Rac2 -/-ApoE -/- mice helped to define a protective role of Rac2, which prevented progressive calcification through its suppression of Rac1-dependent macrophage IL-1β expression. Plaque and serum from mice with calcified plaque demonstrated increased expression of IL-1β, and moreover, treatment with the IL-1 receptor antagonist inhibited the enhanced atherosclerotic calcification. IL-1β expression was a key driver of vascular smooth muscle cell calcium deposition by its ability to promote osteogenic transcriptional programs, including expression of the osteogenic transcription factors, RUNX2, SOX9, OSX and MSX2. Bone marrow transplantation confirmed the progressive calcification of plaque attributable to Rac2 gene deletion was dependent on the hematopoietic compartment. Several key questions remain: 1) what is the role of macrophage Rac1 in plaque development and atherosclerotic calcification in standard experimental models; 2) are macrophages the key cellular source of plaque IL-1β; 3) how does Rac2 suppress Rac1-dependent macrophage IL-1β expression; and 4) are these signaling mechanisms relevant to calcified atherosclerotic plaque from patients with coronary artery disease? The overall objective of the proposed studies is to thoroughly answer these questions. Preliminary data demonstrate that Rac1 can be a key promoter of macrophage IL-1β expression and that Rac2 and Rac1 may antagonize each other through competition for a similar guanine nucleotide exchange factor, Tiam1, which is upregulated under conditions that activate IL-1β expression. The hypothesis is that macrophage Rac signaling determines atherosclerotic plaque IL-1β expression and consequent inflammatory atherosclerotic calcification, and thus disrupting this pathway can be an effective strategy for the prevention and treatment of CAD. Aim1 will define the role of macrophage Rac1 in plaque IL-1β expression and atherosclerotic calcification. Aim2 will confirm that Rac1 and Rac2 compete for Tiam1, a critical Rac-GEf that is upregulated during macrophage inflammatory activation as well as during experimental atherosclerosis, and that IL-1β expression and inflammatory atherosclerotic calcification are dependent on Tiam1 expression. Finally, Aim3 will confirm the validity of these macrophage signaling mechanisms in atherosclerotic plaque samples from patients with known coronary artery disease. Confirming that a macrophage Rac-IL-1β signaling axis is a central mechanism in inflammatory atherosclerotic calcification paves the way for developing a novel therapeutic strategy for treating coronary artery disease, as small molecular inhibitors of Rac1 and Rac1-Tiam1 interactions have been developed and are incorporated into a number of the proposed studies.

项目摘要/摘要： 钙化性动脉粥样硬化引起的冠状动脉疾病(CAD)是发病率和 全球范围内的死亡率。动脉粥样硬化斑块的钙成分在以下方面具有预测价值 心血管事件。炎症可能是血管钙化的关键介质，但免疫信号 人们对促进这一过程的机制知之甚少。最近，小的GTPase，rac2，被 被认为是引导斑块成骨的信号的主要炎症调节因子。动脉粥样硬化 高脂饮食补充胆固醇的ApoE-/-小鼠的主动脉呈现动态表达 随着时间的推移，Rac2mRNA的表达。此外，Rac2表达的减少与增加相关 实验性动物模型和人冠状动脉中的动脉粥样硬化性钙化 斑块。Rac2-/-ApoE-/-小鼠帮助确定了rac2的保护作用，从而阻止了进行性 通过抑制RAC1依赖的巨噬细胞IL-1β的表达而发生钙化。斑块和血清 显示有钙化斑块的小鼠的IL-1β表达增加，而且 IL-1受体拮抗剂可抑制动脉粥样硬化钙化的增强。IL-1β的表达是一个关键驱动因素 通过其促进成骨转录程序的能力来影响血管平滑肌细胞的钙沉积， 包括成骨转录因子RUNX2、SOX9、OSX和MSX2的表达。骨髓 移植证实斑块的进行性钙化可归因于rac2基因缺失 依赖于造血室。几个关键问题仍然存在：1)政府的作用是什么 标准实验模型中巨噬细胞rac1在斑块形成和动脉粥样硬化钙化中的作用 巨噬细胞是斑块IL-1β的主要细胞来源吗？3)Rac2是如何抑制Rac1依赖的 巨噬细胞IL-1β表达；以及4)这些信号机制是否与钙化动脉粥样硬化有关 冠状动脉疾病患者的斑块？拟议研究的总体目标是 彻底回答这些问题。初步数据表明，rac1可能是一个关键的启动子 巨噬细胞IL-1β表达与Rac2、Rac1可能通过竞争A蛋白相互拮抗 类似的鸟嘌呤核苷酸交换因子，TIAM1，在激活IL-1β的条件下上调 表情。假设巨噬细胞Rac信号决定动脉粥样硬化斑块IL-1β 表达和随之而来的炎性动脉粥样硬化性钙化，从而扰乱这一途径 防治冠心病的有效策略。Aim1将定义巨噬细胞rac1在 斑块IL-1β表达与动脉粥样硬化性钙化AIM2将确认rac1和rac2竞争 Tiam1，一种关键的RAC-Global，在巨噬细胞炎症激活过程中以及在 实验性动脉粥样硬化，IL-1β表达和炎性动脉粥样硬化性钙化 依赖于Tiam1的表达。最后，Aim3将确认这些巨噬细胞信号的有效性 已知冠状动脉疾病患者的动脉粥样硬化斑块样本的机制。正在确认 巨噬细胞Rac-IL-1β信号轴是炎症性动脉粥样硬化的中心机制 钙化为开发治疗冠状动脉疾病的新治疗策略铺平了道路，AS Rac1和Rac1-Tiam1相互作用的小分子抑制剂已经被开发出来，并被并入 纳入了一些拟议的研究。