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: 10351290
• 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/10351290
• 关键词: Actins; Alpha Granule; Biogenesis; Biology; Biomedical Engineering; Blood; Blood Platelets; Blood Vessels; Bone Marrow; Cells; Centrosome; Clinical; Coagulation Process; Cytoplasm; Data; Deposition; Dose; Dysmyelopoietic Syndromes; Endothelium; Genetic Diseases; Hemostatic function; Idiopathic Thrombocytopenic Purpura; Image Analysis; Immune; Immunity; Inflammation; Infusion procedures; Investigation; Isomerase; Knowledge; Laboratories; Lead; Leadership; Life; Mechanics; Megakaryocytes; Mentorship; Microfluidics; Microscopy; Microtubules; Molecular Target; Motor; Operative Surgical Procedures; Organelles; Pathway Analysis; Patients; Pharmaceutical Preparations; Physiological; Platelet Count measurement; Play; Process; Production; Regulation; Role; Scientist; Signal Pathway; Structure; Sulfhydryl Compounds; Testing; Therapeutic; Thrombocytopenia; 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.

血小板是专门的无核细胞，在止血、血管生成、免疫和免疫系统中发挥着重要作用。 炎症是临床上遇到的一个主要问题。 多种疾病，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、手术和遗传性疾病的需求——以及对血小板的进一步了解。 他们的机械形成 - 处于历史最高水平。该计划将使用多管齐下的方法来实现。 研究巨核细胞 (MK) 以发现治疗策略和驱动的分子靶点 前血小板形成和增加血小板计数 MK 是产生血小板的前体细胞。 将其细胞质重塑为珠状前血小板过程，充当血小板的装配线 虽然我们知道细胞骨架力学为血小板的生成提供动力，但关于血小板生成的许多问题仍然存在。 我们知道，基于微管的力对于前血小板至关重要。 然而，令人惊讶的是，人们对触发血小板的机制缺乏了解。 我们通过超纺锤体形成和 KIFC1 马达来追求中心体的调节。 参与，对于血小板生成的启动至关重要，我们将使用一种新型的高内涵显微镜。 使用前血小板筛选来识别驱动血小板产生的小分子和信号通路。 图像分析，我们将测试数千种候选药物分子的刺激或抑制能力 将建立血小板产生；目标途径分析、二次筛选和剂量反应曲线 虽然我们知道前血小板突出物是从骨髓中延伸出来的，但它却破坏了 内皮屏障，并将血小板沉积到血液中，我们不知道如何，因此，我们将采用生物-。 工程和独特的微流控骨髓芯片来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，该芯片也将用于研究如何穿透内皮。 细胞器在生理条件下转运至组装血小板，并检验该假设 超级纺锤体组件充当分配这些细胞器的主要运输枢纽。 通过研究如何确定血管硫醇异构酶是否在新的血小板颗粒生物学中发挥作用 它们被包装、运输并从血小板中胞吐出来，我们期待由此得出的结论。 研究将 1) 促进对血小板启动和调节机制的理解 形成，2) 确定新的治疗靶点和加速血小板生成的方法 鉴于 MK 场相对不成熟，R35 结构是必要的。 并将为扩展当前的知识基础提供重要的时间和重点。该提案将进行协调。 多元化的合作者群体，为该领域提供新颖的数据和理论，并为初级科学家提供支持 来自具有广泛转化经验的实验室的持续指导和久经考验的领导力。