Proteomic Analysis of Apoptotic Signaling Networks

描述(申请人提供)：细胞凋亡是一种生理性的细胞死亡机制，已被证明与人类的生理和病理事件有关。细胞凋亡的失控与人类冠状动脉疾病、血管重塑和血管炎症的发病机制有关。我们对血管细胞凋亡的分子生物学进行了研究，并做出了两项重要贡献：我们发现，血管平滑肌细胞的大量凋亡反应在血管壁上引发了深刻的炎症反应，而一般的凋亡细胞，包括血管平滑肌细胞，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。第一个内源性蛋白质配体Annexin I及其受体磷脂酰丝氨酸受体(PSR)的发现是通过高通量蛋白质组学技术实现的，该技术被称为三维同位素编码亲和标签和质谱学。尽管在识别一个重要的配体：控制血管细胞中的凋亡细胞吞噬的受体对方面已经取得了重大进展，但对与细胞凋亡的识别和内化相关的信号机制还缺乏全面的了解。这一竞争性更新应用的长期目标是研究PSR的分子生物学及其相关功能、其调控机制、其相互作用的蛋白质复合体以及PSR结合蛋白的功能特性。我们将利用实验室建立的蛋白质组学技术，以及传统的生化、免疫学、成像、血管细胞组织培养模型和遗传学模型系统。具体地说，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诱导剂的相互作用，PSR与胞浆信号分子的信号依赖相互作用，并阐明PSR如何介导整个凋亡细胞吞噬的机制。拟议的研究有望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.