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

基本信息

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
项目类别：
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

项目摘要

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) 是发病率和死亡率的唯一主要原因动脉粥样硬化斑块的钙成分对全球死亡率具有预测价值。心血管事件可能是血管钙化的关键介质，但免疫信号传导。最近，人们对促进这一过程的机制知之甚少。被确定为指导斑块成骨的信号传导的主要炎症调节剂。饲喂补充胆固醇的高脂肪饮食的 ApoE-/- 小鼠的主动脉表现出动态表达 Rac2 mRNA 表达随时间的变化。此外，Rac2 表达的减少与增加相关。实验动物模型和人类冠状动脉中的动脉粥样硬化钙化 Rac2 -/-ApoE -/- 小鼠有助于确定 Rac2 的保护作用，防止进展。通过抑制 Rac1 依赖性巨噬细胞 IL-1β 斑块和血清的表达来抑制钙化。来自具有钙化斑块的小鼠的实验表明 IL-1β 的表达增加，而且，用 IL-1受体拮抗剂抑制动脉粥样硬化钙化增强，IL-1β表达是关键驱动因素。通过其促进成骨转录程序的能力来影响血管平滑肌细胞钙沉积，包括成骨转录因子 RUNX2、SOX9、OSX 和 MSX2 的表达。移植证实了由于 Rac2 基因缺失导致的斑块进行性钙化取决于造血室，仍然存在几个关键问题：1）其作用是什么。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 的关键细胞来源吗？ 3) Rac2 如何抑制 Rac1 依赖性？巨噬细胞 IL-1β 表达；4) 这些信号传导机制与钙化动脉粥样硬化相关吗？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的初步数据表明 Rac1 可以成为关键的促进者。巨噬细胞 IL-1β 的表达以及 Rac2 和 Rac1 可能通过竞争相互拮抗类似的鸟嘌呤核苷酸交换因子 Tiam1，在激活 IL-1β 的条件下上调假设巨噬细胞 Rac 信号传导决定动脉粥样硬化斑块 IL-1β 的表达。表达和随后的炎症动脉粥样硬化钙化，从而破坏该途径可以预防和治疗 CAD 的有效策略 Aim1 将明确巨噬细胞 Rac1 在其中的作用。斑块IL-1β表达和动脉粥样硬化钙化Aim2将证实Rac1和Rac2竞争。 Tiam1 是一种关键的 Rac-GEf，在巨噬细胞炎症激活期间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钙化最后，Aim3 将确认这些巨噬细胞信号传导的有效性。确认患有已知冠状动脉疾病的患者的动脉粥样硬化斑块样本的机制。巨噬细胞 Rac-IL-1β 信号轴是炎症性动脉粥样硬化的核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 Rac1 和 Rac1-Tiam1 相互作用的小分子抑制剂已被开发并纳入纳入一些拟议的研究。