The Centrosome as a master controller of platelet production.

中心体作为血小板生成的主控制器。

• 批准号: 10576942
• 负责人: JOSEPH E ITALIANO
• 金额: $ 106.2万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2029-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10576942
• 关键词: Acceleration; Actins; Alpha Granule; Biogenesis; Biology; Biomedical Engineering; Blood; Blood Platelets; Blood Vessels; Bone Marrow; Cells; Centrosome; Clinical; Coagulation Process; Cytoplasm; Cytoskeleton; Data; Deposition; Dose; Dysmyelopoietic Syndromes; Endothelium; Genetic Diseases; Hemostatic function; Image Analysis; Immune; Immunity; Inflammation; Infusion procedures; Investigation; Isomerase; Knowledge; Laboratories; Leadership; Life; Mechanics; Megakaryocytes; Mentorship; Microfluidics; Microscopy; Microtubules; Molecular Target; Motor; Operative Surgical Procedures; Organelles; Pathway Analysis; Patients; Penetration; Pharmaceutical Preparations; Physiological; Platelet Count measurement; Play; Process; Production; Regulation; Role; Scientist; Signal Pathway; Structure; Sulfhydryl Compounds; Testing; Therapeutic; Thrombocytopenia; Thrombocytopenic Purpura; Time; angiogenesis; base; chemotherapy; experience; improved; new therapeutic target; novel; precursor cell; programs; repaired; response; small molecule; theories; vascular injury

Platelets are specialized anucleate cells that play an essential role in hemostasis, angiogenesis, immunity, and inflammation. Thrombocytopenia (platelet counts <150x109/L) is a major clinical problem encountered across a number of conditions including immune (idiopathic) thrombocytopenic purpura, myelodysplastic syndromes, chemotherapy, surgery, and genetic disorders. The demand for platelets—and for an improved understanding of their mechanistic formation—is at an all-time high. This program will use a multi-prong approach to investigate megakaryocytes (MKs) to discover therapeutic strategies and molecular targets that drive proplatelet formation and increase platelet counts. MKs are precursor cells that generate platelets by remodeling their cytoplasm into beaded proplatelet processes, which function as the assembly lines for platelet production. While we know that cytoskeletal mechanics power platelet production, many questions about platelet biogenesis remain unanswered. We know that microtubule-based forces are critical for proplatelet elongation; however, there is a surprising lack of understanding of the mechanisms that trigger platelet production. We hypothesize that centrosome regulation, via super spindle formation and KIFC1 motor involvement, is critical for the initiation of platelet production. We will use a novel high-content microscopy screen to identify the small molecules and signaling pathways that drive platelet production. Using proplatelet image analysis, we will test thousands of drug molecule candidates for their ability to stimulate or inhibit platelet production; target pathway analysis, secondary screens, and dose-response curves will be established to identify compound “hits.” While we know that proplatelet protrusions extend from bone marrow, breach the endothelial barrier, and deposit platelets into the blood, we do not know how. Therefore, we will employ bio- engineering and a unique microfluidic bone marrow on-a-chip to test the idea that actin-driven megakaryocyte podosomes provide a mechanism to penetrate the endothelium. This chip will also be used to study how organelles are transported into assembling platelets under physiological conditions, and to test the hypothesis that super spindle assembly functions as a major transport hub for distributing these organelles. We will determine if vascular thiol isomerases play a role in new platelet granule biology through investigating how they are packaged, transported, and exocytosed from platelets. We expect that findings from this investigation will 1) advance the understanding of the mechanisms that initiate and regulate platelet formation, and 2) identify novel therapeutic targets and approaches to accelerate platelet production in patients with thrombocytopenia. The R35 structure is necessary given the relative immaturity of the MK field and will provide vital time and focus to expanding the current base of knowledge. This proposal will coordinate a diverse group of collaborators, provide the field with novel data and theory, and support junior scientists with consistent mentorship and proven leadership from a laboratory with broad ranging translational experience.

血小板是一种特殊的无核细胞，在止血、血管生成、免疫和免疫方面发挥着重要作用。 发炎。血小板减少症(血小板计数和150x109/L)是临床上遇到的主要问题。 包括免疫性(特发性)血小板减少性紫癜、骨髓增生异常综合征、 化疗、手术和遗传疾病。对血小板的需求--以及对更好的理解 他们的机械化阵型-处于历史最高水平。该计划将使用多管齐下的方法来 研究巨核细胞(MK)以发现治疗策略和推动 形成原血小板，增加血小板计数。巨噬细胞集落刺激因子是一种前体细胞，通过 将它们的细胞质重塑为珠状的前血小板突起，作为血小板的装配线 制作。虽然我们知道细胞骨架机械能推动血小板的产生，但关于 血小板的生物发生仍然没有答案。我们知道基于微管的力量对血小板原来说是至关重要的 延长；然而，令人惊讶的是，对触发血小板的机制缺乏了解 制作。我们假设中心体调节，通过超纺锤体形成和KIFC马达 参与，是启动血小板产生的关键。我们将使用一种新型的高含量显微镜 筛选以确定驱动血小板产生的小分子和信号通路。使用原血小板 图像分析，我们将测试数千个候选药物分子的刺激或抑制能力 将建立目标途径分析、二次筛选和剂量-反应曲线 来识别复合“命中”。虽然我们知道原血小板突起是从骨髓延伸出来的，但 内皮屏障，并将血小板沉积到血液中，我们不知道是如何做到的。因此，我们将采用生物- 工程和一种独特的微流控骨髓芯片上测试肌动蛋白驱动的巨核细胞的想法 足体提供了一种穿透内皮的机制。这个芯片还将被用来研究如何 细胞器在生理条件下被运送到组装的血小板中，并检验这一假说 这个超级纺锤组件起到了分配这些细胞器的主要运输枢纽的作用。我们会 通过研究血管硫醇异构酶在新的血小板颗粒生物学中的作用 它们被包装、运输和从血小板中排出。我们期待从这一发现中 研究将1)促进对启动和调节血小板的机制的理解 形成，以及2)确定新的治疗靶点和方法，以加速血小板的产生 患有血小板减少症的患者。考虑到MK油田的相对不成熟，R35结构是必要的 并将为扩大目前的知识基础提供重要的时间和重点。这项建议将协调 一群不同的合作者，为该领域提供新的数据和理论，并支持初级科学家 来自具有广泛翻译经验的实验室的始终如一的指导和成熟的领导力。