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：钙化动脉粥样硬化的冠状动脉疾病（CAD）是发病率和全球死亡率。动脉粥样硬化斑块的钙组成在心血管事件。炎症可能是血管钙化的关键介体，但免疫信号传导促进这一过程的机制是最少理解的。最近，小型GTPase Rac2是被确定为指导斑块成骨的信号传导的主要炎症调节剂。动脉粥样硬化 ApoE - / - 小鼠的主动脉喂养的高脂饮食中补充了胆固醇表达动态表达 Rac2 mRNA的表达随着时间的流逝。此外，Rac2表达降低与增加在实验动物模型和人类冠状动脉中，动脉粥样硬化钙化斑块。 RAC2 - / - APOE-/ - 小鼠有助于定义Rac2的受保护作用，从而阻止了进步通过抑制Rac1依赖性巨噬细胞IL-1β表达钙化。牌匾和串行来自具有计算斑块的小鼠表明IL-1β表达增加，此外，用 IL-1受体拮抗剂抑制了增强的动脉粥样硬化钙化。 IL-1β表达是关键驱动力血管平滑肌细胞钙沉积的沉积能够促进成骨转录程序的能力，包括成骨转录因子的表达，runx2，sox9，osx和msx2。骨髓移植证实了可归因于Rac2基因缺失的斑块的进行性计算是取决于造血室。仍然存在几个关键问题：1）巨噬细胞Rac1在标准实验模型中的斑块发育和动脉粥样硬化计算中； 2）巨噬细胞是斑块IL-1β的关键细胞来源； 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的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可以是巨噬细胞IL-1β的表达，Rac2和Rac1可能会通过竞争A彼此对抗类似的鸟嘌呤核交换因子TIAM1，在激活IL-1β的条件下进行更新表达。假设是巨噬细胞RAC信号确定动脉粥样硬化斑块IL-1β 表达和随之而来的炎症性动脉粥样硬化钙化，因此可以破坏该途径预防和治疗CAD的有效策略。 AIM1将定义巨噬细胞Rac1的作用斑块IL-1β表达和动脉粥样硬化钙化。 AIM2将确认Rac1和Rac2竞争 tiam1，一种关键的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表达和炎症性动脉粥样硬化钙化是取决于tiam1表达。最后，AIM3将确认这些巨噬细胞信号的有效性来自已知冠状动脉疾病患者的动脉粥样硬化斑块样品的机制。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制定一种新的治疗冠状动脉疾病的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经开发出来并合并进入许多拟议的研究。