MEMBRANE-CYTOSKELETAL REMODELING IN PLATELET BIOGENESIS

血小板生物发生中的膜细胞骨架重塑

• 批准号: 10067106
• 负责人: Yolande Chen
• 金额: $ 2.64万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-07 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10067106
• 关键词: MEMBRANE; CYTOSKELETAL; REMODELING; PLATELET; BIOGENESIS

 DESCRIPTION (provided by applicant): Project Summary Defects in platelet production and function play substantial roles in cardiovascular, bleeding, and inflammatory diseases. More complete understanding of platelet biogenesis will yield insights and advances in human health. My mentor's lab discovered a new cytoskeletal component, Cdc42-interacting protein 4 (CIP4), in a yeast two-hybrid screen with the Src kinase Lyn as bait. CIP4 is a BAR protein that coordinates membrane and cytoskeletal remodeling. Through its SH3 domain, CIP4 interacts with Wiskott-Aldrich Syndrome Protein (WASP) or dynamin. Wiskott-Aldrich Syndrome is characterized by thrombocytopenia. My lab generated CIP4-knockout (KO) mice that displayed thrombocytopenia. I determined that the mechanism for thrombocytopenia in CIP4-KO mouse megakaryocytes involves decreased proplatelet formation and reduced demarcation membrane system, which are not observed in WASP-KO mouse megakaryocytes. In addition, unlike WASP-KO mice, CIP4 KO mice show decreased platelet-microparticle release into the plasma. I hypothesize that CIP4-dependent thrombocytopenia involves dynamin. Surprisingly, cells with dynamin knockdown showed increased microparticle release. Since dynamin's chief role is to promote endocytic vesicle formation, this variation of membrane scission mediated by dynamin would be novel. The goal of my proposed research is to determine the mechanism by which CIP4-dynamin pathway regulates membrane remodeling in normal platelet biogenesis and how this may impact platelet biogenesis. I hypothesize that loss of dynamin, affects membrane intracellular trafficking in megakaryocytes, resulting in more membrane being available for demarcation membrane system invagination and for microparticle release. To address this hypothesis, I propose the following two specific aims: 1) establish that loss of dynamin promotes formation of the demarcation membrane system and 2) define the thrombogenic potential from microparticles produced by megakaryocytes/platelets with reduced dynamin activity. This proposal combines cell biology, biochemistry, biophysics, and advanced imaging with animal modeling to establish a new pathway of membrane remodeling in platelet biogenesis and thrombogenesis. This K08 award provides me with intensive laboratory training, mentorship, and committee oversight so that I can successfully develop into an independent physician- scientist. Research and training plan will be carried at Northwestern University under the mentorships of Drs. Seth Corey and Susan Quaggin with graduate school coursework in cell biology and advice from a committee of well-established investigators in platelet biogenesis (Joseph Italiano), thrombogenesis (Xiaoping Du) and hematopoiesis (Liz Eklund).

 描述（由申请人提供）： 项目摘要 血小板生成和功能的缺陷在心血管、出血和炎症疾病中发挥着重要作用。对血小板生物发生的更全面的了解将为人类健康带来见解和进步。我导师的实验室在以 Src 激酶 Lyn 作为诱饵的酵母双杂交筛选中发现了一种新的细胞骨架成分，即 Cdc42 相互作用蛋白 4 (CIP4)。 CIP4 是一种协调膜和细胞骨架重塑的 BAR 蛋白。 CIP4 通过其 SH3 结构域与 Wiskott-Aldrich 综合征蛋白 (WASP) 或动力相互作用。威斯科特-奥尔德里奇综合征的特征是血小板减少。我的实验室培育了表现出血小板减少症的 CIP4 敲除 (KO) 小鼠。我确定 CIP4-KO 小鼠巨核细胞血小板减少的机制涉及前血小板形成减少和分界膜系统减少，而在 WASP-KO 小鼠巨核细胞中未观察到这些情况。此外，与 WASP-KO 小鼠不同，CIP4 KO 小鼠表现出向血浆中释放的血小板微粒减少。我推测 CIP4 依赖性血小板减少症与动力有关。令人惊讶的是，动力蛋白敲低的细胞显示出微粒释放增加。由于动力蛋白的主要作用是促进内吞囊泡的形成，因此由动力介导的膜分裂的这种变化将是新颖的。我提出的研究的目标是确定 CIP4-动力途径调节正常血小板生物发生中膜重塑的机制以及这如何影响血小板生物发生。我假设动力的损失会影响巨核细胞的膜细胞内运输，导致更多的膜可用于分界膜系统内陷和微粒释放。为了解决这一假设，我提出以下两个具体目标：1）确定动力的损失促进分界膜系统的形成，2）确定动力活性降低的巨核细胞/血小板产生的微粒的血栓形成潜力。该提案将细胞生物学、生物化学、生物物理学和先进成像与动物模型相结合，在血小板生物发生和血栓形成中建立膜重塑的新途径。这个 K08 奖项为我提供了强化实验室培训、指导和委员会监督，使我能够成功发展成为一名独立的医师科学家。研究和培训计划将在西北大学博士的指导下进行。 Seth Corey 和 Susan Quaggin 完成了细胞生物学研究生课程，并得到了血小板生物发生（Joseph Italiano）、血栓形成（杜小平）和造血作用（Liz Eklund）领域知名研究人员委员会的建议。

项目成果

Dynamin-2 deficiency causes age- and sex-dependent neutropenia and myelodysplasia in mice.

• DOI: 10.1182/bloodadvances.2022008135
• 发表时间: 2023-04-25
• 期刊: BLOOD ADVANCES
• 影响因子: 7.5
• 作者: Willis, Alexander J.;Corey, Seth J.;Murga-Zamalloa, Carlos;Karimi, Saman S.;Khaddour, Karam;Quigley, John;Eklund, Elizabeth A.;Chen, Yolande
• 通讯作者: Chen, Yolande