Regulation of the anti-angiogenic switch by CD36, Thrombospondin, and HRGP

CD36、血小板反应蛋白和 HRGP 调节抗血管生成开关

• 批准号: 7524585
• 负责人: Roy L Silverstein
• 金额: $ 39.25万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-20 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7524585
• 关键词: Address; Angiogenesis Inhibitors; Angiogenic Factor; Angiogenic Proteins; Angiogenic Switch; Binding; Biological; Blood; Blood Vessels; Blood capillaries; CD36 gene; Cell Line; Cells; Development; Diabetes Mellitus; Diabetic Retinopathy; Disease; Down-Regulation; Endothelial Cells; Genes; Goals; Growth; Human; In Vitro; Inflammation; Laboratories; Lead; Ligands; Lysophospholipids; Malignant Neoplasms; Measures; Mediating; Messenger RNA; Mus; Myocardial Infarction; NMR Spectroscopy; Organism; Phospholipids; Phosphorylation; Post-Translational Protein Processing; Process; Protein Kinase C; Protein Overexpression; Proteins; Public Health; Radiation; Regulation; Regulatory Pathway; Role; Signal Transduction; Skin; Stroke; Surface; System; Thrombospondin 1; Thrombospondins; Tissues; Transgenic Mice; Transgenic Organisms; Ultraviolet B Radiation; Ursidae Family; angiogenesis; base; design; histidine-rich glycoprotein; human disease; in vivo; lysophosphatidic acid; novel therapeutics; prognostic; receptor; recombinant peptide; response; tumor growth

DESCRIPTION (provided by applicant): The goal of this proposal is to understand the mechanisms by which angiogenesis (new blood vessel growth) is regulated by a protein receptor called CD36 that is expressed on the surface of microvascular endothelial cells. These are the cells that form the lining of blood capillaries. Angiogenesis is a critically important process in the development of many human diseases, including heart attack stroke, diabetes and cancer. Therefore, understanding how the body normally turns angiogenesis on and off has direct potential to lead to new therapeutic and prognostic approaches to many diseases. CD36 functions by sending a signal to microvascular endothelial cells to halt angiogensesis when it is exposed to any of a group of other proteins that contain a structural domain called the thrombospondin type I repeat (TSR). Our laboratory has recently disovered that a protein circulating in blood, called HRGP, bears structural similarity to CD36 and can act as a "decoy", blocking the activity of TSR-containing anti-angiogenic proteins. These discoveries have led to the hypothesis that angiogenesis is modulated by the fine control of CD36, TSR and HRGP expression in tissues. To address the hypothesis three specific aims have been developed. The first is to identify the structural determinants involved in recognition of TSR domains by CD36 and to characterize modulation of TSR binding by oxidized phospholipids. The approach will involve generating recombinant peptides, studying their interaction, and using NMR spectroscopy to define the mechanisms of the interactions at the atomic level. Aim 2 will characterize expression of CD36 in human microvascular endothelial cells, focusing on the mechanisms by which CD36 expression or function is down-regulated by modified phospholipids via protein kinase C activation and by ecto-domain phosphorylation. Expression will be measured at the mRNA and protein levels. The biological importance of these regulatory pathways in vivo will be determined in aim 3, in which angiogenesis associated with UVB skin radiation and tumor growth will be studied in mice with targeted deletion of the cd36 and hrgp genes and transgenic mice that over-express HRGP in skin. Accomplishing these aims could lead to new therapeutic approaches to modulate angiogenesis through the CD36-mediated anti-angiogenic switch. PUBLIC HEALTH RELEVANCE: Angiogenesis (new blood vessel growth) is a critically important process in the development of many human diseases, including heart attack, stroke, diabetic retinopathy, and cancer. Therefore, understanding how the body normally turns angiogenesis on and off has direct potential to lead to new therapeutic and prognostic approaches to many diseases. This project seeks to understand the cellular mechanisms by which an anti-angiogenic switch on blood vessel lining cells (endothelial cells) is turned on and off. The switch is mediated by a cellular receptor called CD36 which functions by sending a signal to endothelial cells to halt angiogenesis when it is exposed to any of a group of other proteins that contain a structural domain called the thrombospondin type I repeat (TSR). This project will define the structural basis of TSR- CD36 interactions, determine how expression of the key components of the system are regulated, and determine the functional role of the system in regulating angiogenesis during inflammation and tumor growth in vivo.

描述（由申请人提供）：该提案的目的是了解血管生成（新血管生长）受到一种称为CD36的蛋白质受体调节的机制，该蛋白质受体在微血管内皮细胞表面表达。这些是形成血液毛细血管内壁的细胞。血管生成是许多人类疾病的发展，包括心脏病发作，糖尿病和癌症的至关重要的过程。因此，了解人体通常如何打开血管生成的方式有直接的潜力，从而导致许多疾病的新治疗和预后方法。当CD36暴露于任何包含一个称为血小板蛋白I型I型I型（TSR）的结构结构域时，CD36通过向微血管内皮细胞发送信号来停止血管合成。我们的实验室最近拆除了一种称为HRGP的血液循环的蛋白质与CD36具有结构相似性，并且可以充当“诱饵”，从而阻止了含TSR的抗血管生成蛋白的活性。这些发现导致了一个假说，即血管生成是通过组织中CD36，TSR和HRGP表达的精细控制来调节的。为了解决假设，已经开发出三个具体目标。首先是通过CD36识别识别TSR结构域的结构决定因素，并表征通过氧化磷脂对TSR结合的调节。该方法将涉及生成重组肽，研究其相互作用，并使用NMR光谱法来定义原子水平上相互作用的机理。 AIM 2将表征CD36在人类微血管内皮细胞中的表达，重点是通过蛋白激酶C激活和肾上腺磷酸化的磷脂修饰的磷脂下调CD36表达或功能的机制。表达将在mRNA和蛋白质水平下测量。这些调节途径在体内的生物学重要性将在AIM 3中确定，其中将研究与CD36和HRGP基因靶向缺失的小鼠中，将研究与UVB皮肤辐射和肿瘤生长相关的生物发生，而皮肤中过表达HRGP的转基因小鼠则将研究。完成这些目标可能会导致新的治疗方法通过CD36介导的抗血管生成开关调节血管生成。公共卫生相关性：血管生成（新血管生长）是许多人类疾病的发展，包括心脏病发作，中风，糖尿病性视网膜病和癌症至关重要的过程。因此，了解人体通常如何打开血管生成的方式有直接的潜力，从而导致许多疾病的新治疗和预后方法。该项目旨在了解抗血管内膜细胞（内皮细胞）抗血管生成的细胞机制打开和关闭。该开关是由称为CD36的细胞受体介导的，该细胞受体通过向内皮细胞发送信号来阻止血管生成，当它暴露于任何其他包含称为血栓素蛋白I型I型重复的结构结构域的蛋白质中时，它会停止血管生成。该项目将定义TSR-CD36相互作用的结构基础，确定系统的关键成分的表达如何受到调节，并确定系统在调节体内炎症和肿瘤生长过程中调节血管生成中的功能作用。