Proteomic Analysis of Apoptotic Signaling Networks

描述（由申请人提供）：细胞凋亡是一种生理细胞死亡机制，已被证明参与人体的生理和病理事件。细胞凋亡的失调与人类冠状动脉疾病的发病机制、血管重构和血管炎症有关。我们研究了血管细胞凋亡的分子生物学，并做出了两个重要贡献；我们发现血管平滑肌细胞的大量凋亡反应引起血管壁的深刻炎症反应，包括血管平滑肌细胞在内的凋亡细胞一般利用一种新的内源性吞噬配体受体系统来促进凋亡细胞的吞噬。第一个内源性蛋白配体膜联蛋白I及其受体磷脂酰丝氨酸受体（PSR）的发现是通过使用高通量蛋白质组学分析技术（称为三维同位素编码亲和标签和质谱法）实现的。尽管在血管细胞中控制凋亡细胞吞噬的关键配体受体对的鉴定方面取得了重大进展，但对凋亡细胞如何被识别和内化的信号传导机制的全面理解尚缺乏。这项竞争性更新申请的长期目标是研究PSR的分子生物学和相关功能，其控制机制，其相互作用的蛋白复合物以及PSR相关蛋白的功能特性。我们将利用实验室建立的蛋白质组学技术，结合传统的血管细胞生化、免疫学、影像学、组织培养模型和遗传学模型系统。具体而言，我们将研究PSR介导的凋亡细胞识别的基本机制，PSR介导的信号事件，PSR与其他受体对凋亡细胞和凋亡细胞分泌的化学引诱剂的相互作用，PSR与胞质信号分子的信号依赖相互作用，并阐明PSR如何介导凋亡细胞的整体吞噬机制。这些拟议的研究预计将为如何识别和清除血管壁中的凋亡细胞以防止血管炎症的分子生物学提供新的见解。

DESCRIPTION (provided by applicant): Apoptosis is a physiological cell death mechanism that has been shown to be involved in physiological and pathological events in man. Deregulation of apoptosis has been implicated in pathogenesis of human coronary artery disease, vascular remodeling, and vascular inflammation. We have investigated molecular biology of vascular cell apoptosis and made two significant contributions; we have discovered that massive apoptotic responsive in vascular smooth muscle cells invoke profound inflammatory response in the vessel wall, and apoptotic cells in general including the vascular smooth muscle cells utilize a novel endogenous engulfment ligand receptor system to facilitate engulfment of apoptotic cells. The discovery of the first endogenous protein ligand, annexin I, and its receptor, the phosphatidylserine receptor (PSR), was achieved by the use of high-throughput proteomic profiling technology, termed the 3-Dimensional Isotope-Coded Affinity Tags and mass spectrometry. Although significant progress has been made in the identification of a crucial ligand: receptor pair that controls apoptotic cell engulfment in the vascular cells, comprehensive understanding of signaling mechanisms associated with how apoptotic cells are recognized and internalized is lacking. The long-term objectives of this competitive renewal application is to study the molecular biology and associated functions of PSR, its control mechanisms, its interacting protein complexes, and the function properties of PSR associating proteins. We will utilize proteomics technologies that are established in the laboratory together with traditional biochemical, immunological, imaging, tissue culture models of vascular cells, and genetics model system. Specifically, we will study the basic mechanisms of PSR mediated apoptotic cell recognition, PSR mediated signaling events, interactions of PSR and other receptors in response to apoptotic cells and to chemo-attractants secreted by the apoptotic cells, signaling-dependent interactions of PSR and cytosolic signaling molecules, and elucidate the mechanisms of how PSR mediates the overall apoptotic cell engulfment. The proposed studies are anticipated to provide novel insights into the molecular biology of how apoptotic cells are recognized and cleared in the vessel wall to prevent vascular inflammation.