"Novel roles of the TRPC3 channel in macrophage functions: implications in atherosclerosis"

 描述(由申请人提供)：动脉粥样硬化是美国冠状动脉和颈动脉疾病的主要原因，也是导致发病率/死亡率的主要原因。斑块破裂后的晚期狭窄或血栓栓子事件引起的缺血症状是该病的主要临床表现。该领域的努力旨在减少斑块进展，提高晚期斑块的稳定性或刺激斑块消退。巨噬细胞凋亡和迁移在晚期病变中的特殊影响是深入研究的主题。然而，它们对人类病理学的潜在适用性仍不确定。 辩论。通过承认巨噬细胞多样性对斑块组成和命运的独特影响，以及探索可能选择性地影响一种巨噬细胞类型而不影响其他类型的分子成分，可以实现定义。这项建议的长期目标是在动脉粥样硬化的背景下检查巨噬细胞瞬时受体潜力典范3(TRPC3)在这些机制中的作用。在最近的工作中，我们发现在骨髓中缺失TRPC3的ApoE基因敲除小鼠的晚期斑块比对照小鼠的坏死和巨噬细胞凋亡要少，来自巨噬细胞特异性缺失TRPC3的小鼠骨髓来源的巨噬细胞(MacTRPC3KO)并在体外分化为M1型，减少了内质网应激诱导的凋亡。值得注意的是，M2巨噬细胞没有受到影响。我们在MacTRPC3KOApoEKO小鼠身上的初步研究表明，与对照组相比，高级斑块减少了巨噬细胞的含量，并且TRPC3缺失促进了M1/M2比率的降低，并减少了细胞凋亡。我们还发现，缺乏TRPC3的M1巨噬细胞，而不是M2巨噬细胞，在体外促进了迁移。一般的假设是，由于其在与M1巨噬细胞的凋亡和迁移相关的机制中的作用，TRPC3可以对斑块的组成和完整性产生深远的影响。预计在体内抑制巨噬细胞TRPC3将减少晚期斑块的细胞密度和坏死，并有利于退化条件。在特定的目标1中，我们将检测内质网应激条件下TRPC3的表达和结构功能对极化巨噬细胞炎症信号和迁移的影响。在特定的目标2中，我们将研究巨噬细胞特异性的TRPC3功能丧失或获得对动脉粥样硬化病变特征的影响。在特定的目标3中，我们将在疾病的小鼠模型中检测巨噬细胞特异性的TRPC3功能丧失或获得对巨噬细胞迁移和斑块消退的影响。

 DESCRIPTION (provided by applicant): Atherosclerosis is the main cause of coronary and carotid artery disease and a leading cause of morbidity/mortality in the United States. Ischemic symptoms due to advanced stenosis or thromboembolic events that follow plaque rupture are major clinical manifestations of the disease. Efforts in the field are aimed at reducing plaque progression, improve stability of advanced plaques or stimulate plaque regression. The particular impact that macrophage apoptosis and migration have in advanced lesions is subject of intensive research efforts. Yet, their potential applicability to human pathology is still under debate. Definitions can be achieved by acknowledging the distinctive impact of macrophage diversity in plaque composition and fate, and by exploring molecular components that may selectively affect a macrophage type and not others. The long term goal of this proposal is to examine the contribution of macrophage Transient Receptor Potential Canonical 3 (TRPC3) to these mechanisms in the context of atherosclerosis. In recent work we showed that advanced plaques in ApoE knockout mice with bone marrow deletion of TRPC3 have less necrosis and macrophage apoptosis than controls, and bone marrow derived macrophages from mice with macrophage-specific deletion of TRPC3 (MacTRPC3KO) and differentiated in vitro to the M1 type, have reduced ER stress-induced apoptosis. Remarkably, M2 macrophages were not affected. Our preliminary studies in MacTRPC3KOApoEKO mice show that, compared to controls, advanced plaques have reduced macrophage content and that TRPC3 deletion promotes a reduction in M1/M2 ratios, and decreased apoptosis. We have also found that TRPC3 deficient M1, but not M2 macrophages, have augmented in vitro migration. The general hypothesis is that by virtue of its roles in mechanisms associated to apoptosis and migration of M1 macrophages TRPC3 can exert profound effects on the characteristics of plaque composition and integrity. It is anticipated that suppression of macrophage TRPC3 in vivo will lessen cellularity and necrosis of advanced plaques and favor regressive conditions. In specific aim 1 we will examine the impact of TRPC3 expression and constitutive function on inflammatory signaling and migration of polarized macrophages under conditions of ER stress. In specific aim 2 we will study the impact of macrophage-specific loss or gain of TRPC3 function on the characteristics of atherosclerotic lesions in a mouse model of the disease. In specific aim 3 we will examine the impact of macrophage-specific loss or gain of TRPC3 function on macrophage migration and plaque regression in mouse models of the disease.