TRPC3 Channels in Molecular and Cellular Events of Atherogenesis

描述（由申请人提供）：瞬时受体电位经典（TRPC）Ca 2+渗透通道在心血管生理学中起关键作用。TRPC现在也被认为是与几种心血管疾病相关的信号传导过程中的关键组分。然而，TRPC在与动脉粥样硬化相关的分子和细胞事件中的潜在功能，在西方社会冠状动脉疾病的主要原因，仍然在很大程度上未被探索。动脉粥样硬化的特征在于发生在内膜下的适应不良的炎症反应，其中内皮炎症信号传导、粘附分子、循环单核细胞的募集和病变巨噬细胞的存活/凋亡都是动脉粥样硬化病变的进展和命运的基本组成部分。提高我们对这些过程中新信号成分的理解和识别对于开发新的和替代的疾病治疗策略至关重要。通过研究通道形成蛋白TRPC 3在与单核细胞募集和巨噬细胞存活相关的机制中的新作用，该提议有助于实现该目标，并且还提供了填补TRPC领域知识的重要空白的机会。我们小组的工作表明，TRPC 3在驱动冠状动脉内皮中VCAM-1表达/功能的信号传导中以及在巨噬细胞存活的潜在机制中是基础的。因此，提出了一般假设，即TRPC 3通道在动脉粥样硬化病变形成的炎症环境中，由于其在VCAM-1的内皮表达/功能和病变巨噬细胞的存活中的作用，是病变进展中所涉及的机制的促成因素。该项目的长期目标是了解TRPC 3活性对内皮炎症信号传导、单核细胞募集和巨噬细胞存活/凋亡的影响。我们希望这些研究的信息可能有助于合理化未来的转化/临床研究，并将激发更多的努力来了解TRPC 3在这种和其他血管疾病中的作用。具体目标1中提出的实验旨在通过在体外研究TRPC 3对与VCAM-1表达和功能相关的信号传导的贡献，以及在体内研究内皮特异性TRPC 3转基因和敲除小鼠动脉粥样硬化模型中动脉粥样硬化病变的特征，来检查内皮TRPC 3在动脉粥样硬化形成中的作用。特定目标2的研究将研究TRPC 3在体外巨噬细胞存活和凋亡中的作用，以及这种作用如何通过使用巨噬细胞特异性TRPC 3缺陷小鼠影响动脉粥样硬化形成。建议使用野生型和TRPC 3缺陷型巨噬细胞进行体外研究，以检查它们对不同促凋亡刺激的反应性、生存信号通路的状态和细胞外红细胞增多症。在体内，纵向研究提出了检查的特点，早期和先进的病变使用致命的照射LDLR-/-小鼠重建与骨髓巨噬细胞特异性TRPC 3-/-动物。 公共卫生相关性：动脉粥样硬化仍然是冠状动脉疾病的主要潜在病因，并且是西方社会发病率/死亡率的主要原因。该提案研究了瞬时受体电位经典3通道（TRPC 3）在动脉粥样硬化形成机制中的作用，即，动脉粥样硬化病变的开始和进展。从这些研究中获得的信息将有助于目前对TRPC通道在心血管疾病中的认识，并确定潜在的新靶点，这些新靶点将来可用于动脉粥样硬化的诊断、预后和/或治疗。

DESCRIPTION (provided by applicant): Transient Receptor Potential Canonical (TRPC) Ca2+permeable channels play critical roles in cardiovascular physiology. TRPCs are now also recognized as critical components in signaling processes associated to several cardiovascular diseases. Nevertheless, the potential function of TRPCs in molecular and cellular events associated to atherosclerosis, the major cause of coronary artery disease in western societies, remains largely unexplored. Atherosclerosis is characterized by a maladaptive inflammatory response that takes place in the subintima, where endothelial inflammatory signaling, adhesion molecules, recruitment of circulating monocytes and survival/apoptosis of lesional macrophages are all fundamental components in progression and fate of the atherosclerotic lesion. Improving our understanding of and identifying new signaling components in those processes is of key importance to develop new and alternative therapeutic strategies for the disease. By examining a novel role of the channel forming protein TRPC3 in the mechanisms associated to monocyte recruitment and macrophage survival, this proposal contributes to that goal and also provides an opportunity to fill an important gap of knowledge in the TRPC field. Work from our group shows that TRPC3 is fundamental in the signaling driving VCAM-1 expression/function in coronary endothelium and in the mechanisms underlying macrophage survival. The general hypothesis is therefore proposed that TRPC3 channel, in the inflammatory setting of atherosclerotic lesion formation, is a contributing factor to the mechanisms involved in lesion progression by virtue of its roles in endothelial expression/function of VCAM-1 and in the survival of lesional macrophages. The long term goal of the project is to understand the impact of TRPC3 activity on endothelial inflammatory signaling, monocyte recruitment and macrophage survival/apoptosis. It is our hope that the information derived from these studies may help rationalize future translational/clinical studies and that they will provoke additional efforts to understand the role of TRPC3 in this and other vascular diseases. The experiments proposed in Specific Aim 1 are designed to examine the role of endothelial TRPC3 in atherogenesis by investigating, in vitro, the contribution of TRPC3 to the signaling associated to VCAM-1 expression and function, and in vivo, the characteristics of atherosclerotic lesions in endothelial-specific TRPC3 transgenic and knockout mouse models of atherosclerosis. Studies in Specific Aim 2 will examine the role of TRPC3 in macrophage survival and apoptosis in vitro, and how such role influences atherogenesis by using macrophage-specific TRPC3 deficient mice. In vitro studies are proposed using wild-type and TRPC3-deficient macrophages to examine their responsiveness to different pro-apoptotic stimuli, status of survival signaling pathways and efferocytosis. In vivo, a longitudinal study is proposed to examine the characteristics of early and advanced lesions using lethally-irradiated LDLR-/- mice reconstituted with bone marrow from macrophage-specific TRPC3-/- animals. PUBLIC HEALTH RELEVANCE: Atherosclerosis remains the main underlying pathogenetic cause of coronary artery disease and is a major cause of morbidity/mortality in western societies. This proposal examines the role of Transient Receptor Potential Canonical 3 channels (TRPC3) in the mechanisms underlying atherogenesis, i.e., initiation and progression of atherosclerotic lesions. The information obtained from these studies will contribute to current knowledge on TRPC channels in cardiovascular disease and to identify potential new targets that can, in the future, be exploited for diagnosis, prognosis and/or treatment of atherosclerosis.