The F-BAR protein CIP4 in WAS-dependent thrombocytopenia

WAS依赖性血小板减少症中的F-BAR蛋白CIP4

• 批准号: 8202444
• 负责人: Seth Joel Corey
• 金额: $ 24.91万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-20 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8202444
• 关键词: Actins; Address; Affect; Autoimmune Diseases; Autoimmune Process; Autoimmunity; B-Lymphocytes; Biology; Blood Platelet Disorders; Blood Platelets; Cardiovascular Diseases; Cardiovascular system; Cell membrane; Cell physiology; Cytoskeletal Modeling; Cytoskeletal Proteins; Defect; Disease; Dynamin; Eczema; Functional disorder; Genes; Genetic; Goals; Health; Hemorrhage; Human; Immune; Immunologic Deficiency Syndromes; Inflammation; Inflammatory; Knock-out; Knockout Mice; Label; Lead; Link; Lymphoma; Measures; Mediating; Megakaryocytes; Membrane; Metabolic Clearance Rate; Microtubules; Mouse Protein; Mouse Strains; Mus; Myelin P2 Protein; Natural Killer Cells; Neoplasm Metastasis; Pathway interactions; Phenotype; Phospholipids; Play; Production; Protein Binding; Protein Family; Proteins; Reporting; Risk; Role; SH3 Domains; Scaffolding Protein; Signal Pathway; Stroke; T-Lymphocyte; Testing; Thrombocytopenia; Vascular System; Wiskott-Aldrich Syndrome; Work; Yeasts; base; cdc42 GTP-Binding Protein; immune function; improved; insight; member; polymerization; protein function; rho GTP-Binding Proteins; src-Family Kinases; yeast two hybrid system

DESCRIPTION (provided by applicant): Platelets play a central role in cardiovascular, stroke, and bleeding disease through their quantity, activation, and interaction with the inflammatory and vascular systems. The Wiskott -Aldrich syndrome (WAS) is an X- linked disorder characterized by thrombocytopenia, immunodeficiency, eczema and an increased risk of lymphoma and autoimmunity. The affected gene encodes the cytoskeletal protein, WASP. Through the RhoGTPase, Cdc42, WASp undergoes conformational change that leads to actin polymerization. How WASp results in thrombocytopenia, the most common manifestation of WAS, remains unknown. Cdc42, Src kinases, membrane phospholipids, and SH3 domains control WASP function. Our lab has discovered a new regulator of WASP, CIP4 (Cdc42 interacting protein 4), in a yeast two hybrid screen with the Src kinase Lyn as bait. CIP4 is a member of the F-BAR family of proteins, which remodel the plasma membrane and promote actin polymerization. To determine CIP4's function, we created a CIP4-null mouse. We found that CIP4-/- mice display thrombocytopenia, similar to that observed in WASP-/- mice. The mechanism for thrombocytopenia in WAS is not known. Some studies demonstrate an autoimmune basis; others a defect in proplatelet production. Because our mice do not display signs of autoimmune disease, we favor the hypothesis ("defective proplatelet formation hypothesis") that CIP4-WASP forms a signaling pathway that promotes platelet production and that a deficiency of either CIP4 or WASP perturbs actin polymerization in megakaryocytes, which results in defective proplatelet formation. An alternative "immune destruction hypothesis" states that a defect in this CIP4-WASP pathway promotes autoimmunity and immune-mediated destruction of platelets. We propose to address these hypotheses through the following two specific aims: 1) the defective proplatelet hypothesis by culturing megakaryocyte precursors and megakaryocytes from wild-type, CIP4-/-, WASP-/-, and CIP4-/-WASP-/- mice and analyzing their proplatelet formation. We will use these unique mice strains to analyze proplatelet formation, the interaction of CIP4 with microtubules in megakaryocytes, and ultrastructural features of platelets; and 2) Test the immune destruction hypothesis by labeling platelets and measuring their clearance rates in wild-type, CIP4-/-, WASP-/-, and CIP4-/-WASP-/- mice and measuring their T, B, and NK cell functions. We will use these unique mice strains to measure platelet survival and to correlate with altered immune function. PUBLIC HEALTH RELEVANCE: Platelet production is critical for normal control of bleeding. Excessive bleeding and thrombocytopenia characterizes Wiskott - Aldrich syndrome (WAS). We have discovered a protein CIP4 that interacts physically and functionally with WAS Protein (WASP). The mechanism for the thrombocytopenia in WAS is not known. We will study platelet production in CIP4 knockout and CIP4/WASP double knockout mice to determine the precise mechanism that results in thrombocytopenia. Since platelets are involved in cardiovascular, stroke, and inflammatory diseases, our work has the potential to impact more broadly on human health.

描述（由申请人提供）：血小板通过与炎症和血管系统的数量，激活和相互作用，在心血管，中风和出血疾病中起着核心作用。 Wiskott -Aldrich综合征（WAS）是一种X连接疾病，其特征是血小板减少，免疫缺陷，湿疹以及淋巴瘤和自身免疫性的风险增加。受影响的基因编码细胞骨架蛋白WASP。通过RhogTPase Cdc42，黄蜂经历了导致肌动蛋白聚合的构象变化。黄蜂如何导致血小板减少症，这是最常见的WAS表现，仍然未知。 CDC42，SRC激酶，膜磷脂和SH3结构域控制WASP功能。我们的实验室在酵母两种混合筛选中发现了一个新的WASP CIP4（CDC42相互作用蛋白4）的调节剂，并与SRC激酶Lyn作为诱饵。 CIP4是F-BAR蛋白家族的成员，该家族重塑了质膜并促进肌动蛋白聚合。为了确定CIP4的功能，我们创建了一个CIP4-NULL鼠标。我们发现CIP4 - / - 小鼠表现出血小板减少症，类似于在黄蜂 - / - 小鼠中观察到的血小板减少症。血小板减少症的机制尚不清楚。一些研究证明了自身免疫性基础。其他人是预言生产的缺陷。因为我们的小鼠没有显示自身免疫性疾病的迹象，所以我们赞成CIP4-WASP形成信号通路的假设（“有缺陷的PREPLATELT形成假设”），该信号途径可促进血小板的产生，并且CIP4或WASP的缺陷均缺乏巨核细胞中肌动蛋白聚合的肌动蛋白聚合，从而导致缺乏性的eleftectialteletseletteletseletseletseletseletseletseletslettemtletselet。另一种“免疫破坏假设”指出，这种CIP4-WASP途径中的缺陷促进了自身免疫性和免疫介导的血小板破坏。我们建议通过以下两个具体目的解决这些假设：1）通过培养野生型，cip4 - / - / - ，wasp-/ - ，cip4-/cip4-/ - wasp-/ - wasp-/ - - / - - / - - / - - / - 小鼠和分析的巨型细胞前体和巨核细胞来培养有缺陷的预防性假设。我们将使用这些独特的小鼠菌株来分析预言形成，CIP4与巨核细胞中微管的相互作用以及血小板的超微结构特征； 2）通过标记血小板并测量其在野生型，CIP4 - / - ，WASP - / - 以及CIP4-/ - WASP - / - 小鼠以及测量其T，B和NK细胞功能的情况下测量其清除率，并测量其t，b和nk细胞功能。我们将使用这些独特的小鼠菌株测量血小板存活，并与免疫功能改变。 公共卫生相关性：血小板产生对于正常控制出血至关重要。过多的出血和血小板减少症的特征是Wiskott -Aldrich综合征（WAS）。我们发现了一种与蛋白质（WASP）在物理和功能上相互作用的蛋白CIP4。血小板减少症的机制尚不清楚。我们将研究CIP4敲除和CIP4/WASP双基因敲除小鼠中的血小板产生，以确定导致血小板减少症的精确机制。由于血小板参与心血管，中风和炎症性疾病，因此我们的工作有可能对人类健康的影响更广泛。