ROLE OF STATHMIN IN MEGAKARYOPOIESIS AND PLATELET PRODUCTION

STATHMIN 在巨核细胞生成和血小板生成中的作用

• 批准号: 7985278
• 负责人: Camelia IancuRubin
• 金额: $ 5.4万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-10 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7985278
• 关键词: Biology; Blood Platelet Disorders; Blood Platelets; Bone Marrow; Cell Line; Complex; Cytoskeleton; Down-Regulation; Event; Future; Goals; Hematological Disease; Investigation; Lead; Mediating; Megakaryocytes; Megakaryocytopoieses; Microtubules; Molecular; Physiological; Ploidies; Process; Production; Regulation; Research; Role; Subfamily lentivirinae; Transduction Gene; Transgenic Mice; Transgenic Organisms; base; career; genetic regulatory protein; in vivo; insight; intervention effect; lentiviral-mediated; overexpression; prevent; stathmin; therapeutic target; tool

DESCRIPTION (provided by applicant): The long-term career goal of the candidate is to understand the as yes undefined mechanisms of megakaryopoiesis and platelet production and to apply the insights to understand and possibly treat hematological disorders. Megakaryopoiesis is a complex process in which bone marrow megakaryocytes give rise to circulating platelets. Microtubule cytoskeleton has a unique organization in megakaryocytes which is essential for normal platelet production. The overall objective of this project is to investigate the role of stathmin, a major microtubule-regulatory protein, in the process of polyploidization (i.e. acquisition of more than 4N DNA content) and platelet production in primary megakaryocytes. Stathmin is physiologically downregulated during megakaryopoiesis and is absent in platelets. The levels of stathmin expression correlate inversely with megakaryocytes polyploidization. Inhibition of stathmin increases ploidy while its overexpression decreases ploidy of megakaryocytic cell lines. Based on this, our hypothesis is that downregulation of stathmin expression is necessary for polyploidization and platelet production during normal megakaryopoiesis. Thus, we propose to prevent physiological downregulation of stathmin in primary megakaryocytes and platelets ex vivo and in vivo in transgenic mice study the effects of this intervention on polyploidization and platelet production. First, we will investigate the effects of lentivirus-mediated overexpression of stathmin on polyploidization and the potential mechanisms underlying this process (Specific Aim 1). Second, we will generate transgenic mice that overexpress stathmin conditionally in megakaryocytes (Specific Aim 2). Third, we will investigate megakaryopoiesis and platelet formation in transgenic megakaryopcytes (Specific Aim 3). These studies should make it possible to better understand the process of normal megakaryopoiesis and provide the basis for the future investigation of the potential role of stathmin and/or microtubules in abnormal megakaryopoiesis and platelet production. They should also make possible to validate the potential use of microtubules as therapeutic targets in platelet disorders.

描述（由申请人提供）： 候选人的长期职业目标是了解巨核细胞生成和血小板产生的未定义机制，并应用这些见解来理解和可能治疗血液疾病。巨核细胞生成是骨髓巨核细胞产生循环血小板的复杂过程。微管细胞骨架在巨核细胞中具有独特的组织，这对于正常血小板的产生至关重要。该项目的总体目标是研究 Stathmin（一种主要的微管调节蛋白）在原代巨核细胞多倍化（即获得超过 4N DNA 含量）和血小板生成过程中的作用。 Stathmin 在巨核细胞生成过程中在生理上下调，并且在血小板中不存在。 Stathmin 表达水平与巨核细胞多倍化成反比。 Stathmin 的抑制会增加巨核细胞系的倍性，而其过度表达则会降低倍性。基于此，我们的假设是，在正常巨核细胞生成过程中，stathmin 表达的下调对于多倍体化和血小板产生是必要的。因此，我们建议防止原代巨核细胞和血小板中stathmin的生理下调，并在转基因小鼠体内离体和体内研究这种干预对多倍化和血小板产生的影响。首先，我们将研究慢病毒介导的 stathmin 过度表达对多倍化的影响以及该过程的潜在机制（具体目标 1）。其次，我们将产生在巨核细胞中有条件地过度表达 stathmin 的转基因小鼠（具体目标 2）。第三，我们将研究转基因巨核细胞中的巨核细胞生成和血小板形成（具体目标 3）。这些研究应该能够更好地理解正常巨核细胞生成的过程，并为未来研究stathmin和/或微管在异常巨核细胞生成和血小板生成中的潜在作用提供基础。它们还应该能够验证微管作为血小板疾病治疗靶点的潜在用途。