Aberrant Platelet Mechanisms in Inherited Human Platelet Function Disorders

遗传性人类血小板功能障碍中的异常血小板机制

• 批准号: 7482279
• 负责人: Angara Koneti Rao
• 金额: $ 38.03万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-08 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7482279
• 关键词: Address; Agonist; Antiplatelet Drugs; Bernard-Soulier Syndrome; Biochemical; Blood Platelet Disorders; Blood Platelets; Cardiovascular Diseases; Child; Clinical; Complex; Core-Binding Factor; Cytoplasmic Granules; Defect; Disease; District of Columbia; Family member; Foundations; Functional disorder; GTP-Binding Proteins; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic; Genetic Medicine; Genetics and Medicine; Genome; Genomics; Hematology; Hematopoietic; Hemorrhage; Human; Human Genome Project; Individual; Inherited; Isoenzymes; Knowledge; Laboratories; Lead; Mediating; Medical center; Membrane Glycoproteins; Messenger RNA; Microarray Analysis; Molecular; Molecular Biology; Molecular Profiling; Mutation; Myosin ATPase; Myosin Light Chains; Numbers; Pathway interactions; Patients; Pharmacotherapy; Phospholipase C; Phosphorylation; Physiological; Physiology; Platelet Activation; Platelet Storage Pool Deficiency; Protein Kinase C; Proteins; RUNX1 gene; Reporting; Research; Research Personnel; Selection Bias; Shotguns; Signal Transduction; Signal Transduction Pathway; System; Thrombasthenia; Thrombocytopenia; Thrombosis; Validation; base; concept; experience; human disease; insight; mRNA Expression; novel; novel strategies; phospholipase C beta2; platelet protein P47; programs; protein activation; receptor; receptor function; response; synergism; tool; transcription factor

DESCRIPTION (provided by applicant): Despite tremendous advances in our understanding of platelet physiology, the underlying molecular mechanisms remain unknown in the vast majority of patients with inherited defects in platelet function. Mechanisms, such as deficiencies in membrane glycoproteins and the storage pool deficiency, are commonly considered but occur in a small proportion of patients. Most of these patients are characterized by a bleeding disorder, and impaired aggregation and dense granule secretion on platelet activation, and are currently lumped in a loosely defined group called "platelet secretion/activation defects." The molecular mechanisms in these patients are unknown. Several studies suggest that these patients may have abnormalities in the signal transduction mechanisms. We have documented specific defects in platelet phospholipase C-beta2, Gaq and protein kinase C-theta. Newer approaches are required to define the molecular defects in such patients who constitute an untapped reservoir of new information. We have now applied genome-wide platelet expression profiling using the Affymetrix microarrays to demonstrate a unique decrease in expression of myosin light chain 9 (MYL9, 70 fold decrease) and other genes in a patient with an inherited thrombocytopenia, impaired platelet responses (including myosin and pleckstrin phosphorylation and GPIIb-llla activation), and a heterozygous mutation in transcription factor CBFA2 (Core-binding factor A2), thereby providing proof of concept that expression profiling can indeed be applied to obtain new insights in patients with platelet dysfunction. The microarray technology has hitherto not been applied to such patients. In this project, we propose an integrated approach encompassing, a) detailed biochemical and functional studies on platelet mechanisms, b) platelet expression profiling and c) subsequent validation of the aberrant mechanisms using functional, mutational, biochemical and immunological approaches, to delineate the molecular mechanisms in 15 patients with inherited platelet dysfunction. We have extensive experience in all of the involved approaches. This project is a collaborative effort between two laboratories with strong complementary expertise. It represents application of the recent advances in genomics and the Human Genome Project to a group of patients who are frequently encountered but extremely poorly characterized. Our studies will provide a wealth of information on platelet mechanisms and on potential new targets for antithrombotic therapy.

描述（由申请人提供）：尽管我们对血小板生理学的理解取得了巨大进步，但在绝大多数具有遗传缺陷的血小板功能缺陷的患者中，潜在的分子机制仍然未知。通常考虑使用机制，例如膜糖蛋白缺乏和储存池缺乏蛋白，但发生在少数患者中。这些患者中的大多数的特征是出血障碍，血小板激活的聚集和密集颗粒分泌受损，目前在一个被宽松定义的组中，称为“血小板分泌/激活缺陷”。这些患者的分子机制尚不清楚。几项研究表明，这些患者可能在信号转导机制中具有异常。我们已经记录了血小板磷脂酶C-BetA2，GAQ和蛋白激酶C-theta中的特定缺陷。需要较新的方法来定义构成未开发的新信息库的此类患者的分子缺陷。 We have now applied genome-wide platelet expression profiling using the Affymetrix microarrays to demonstrate a unique decrease in expression of myosin light chain 9 (MYL9, 70 fold decrease) and other genes in a patient with an inherited thrombocytopenia, impaired platelet responses (including myosin and pleckstrin phosphorylation and GPIIb-llla activation), and a heterozygous mutation in转录因子CBFA2（核心结合因子A2），从而提供了概念证明，表达分析确实可以应用于血小板功能障碍患者的新见解。迄今为止，微阵列技术尚未应用于此类患者。在该项目中，我们提出了一种综合方法，a）详细的生化和功能研究有关血小板机制，b）血小板表达分析和c）随后使用功能，突变，生化和免疫学方法的功能性，生化和免疫学方法，以分配15例具有遗传性基质dys的分子机制的异常机制。我们在所有涉及的方法方面都有丰富的经验。该项目是两个具有强大互补专业知识的实验室之间的合作努力。它代表了基因组学和人类基因组项目的最新进展的应用，这些患者经常遇到但表征较差。我们的研究将提供有关血小板机制以及潜在的抗血栓疗法的新靶标的大量信息。