Novel strategies to prevent FcgRIIA-dependent platelet activation and thrombosis

预防 FcgRIIA 依赖性血小板活化和血栓形成的新策略

基本信息

批准号：
8693003
负责人：
Wolfgang Bergmeier
金额：
$ 37万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-20 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8693003
关键词：
1,2-diacylglycerol 1-Phosphatidylinositol 3-Kinase ADP Receptors Agonist Animal Model Antibodies Blood Platelet Disorders Blood Platelets Calcium Clinical Collagen Cytoplasmic Granules Data Development Diglycerides Disease Fc Receptor Feedback G-Protein-Coupled Receptors Generations Goals Guanosine Triphosphate Phosphohydrolases Hematological Disease Hemorrhage Hemostatic function Heparin Human ITAM Immune Integrins Knockout Mice Link Mediating Minor Modeling Molecular Morbidity - disease rate Mus Pathogenesis Pathologic Pathway interactions Patients Phospholipase C Phosphorylation Phosphotransferases Physiological Platelet Activation Platelet aggregation Play Prevention Protein Isoforms Protein Tyrosine Kinase Regulation Research Risk Role Safety Second Messenger Systems Signal Pathway Signal Transduction Signaling Molecule Surface Syndrome Testing Therapeutic Thrombin Thrombocytopenia Thrombosis Thromboxane A2 Thromboxanes Transgenic Mice Work design improved inhibitor/antagonist mortality mouse model novel novel strategies novel therapeutics pre-clinical prevent receptor receptor coupling release of sequestered calcium ion into cytoplasm second messenger sensor therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Activation of the platelet Fc receptor, Fc?RIIA, is central to the pathogenesis of several immune- mediated thrombocytopenia and thrombosis (ITT) syndromes, including heparin-induced thrombocytopenia/thrombosis. One of the barriers to successful treatment of these thrombotic syndromes is that therapeutic targeting of platelet activation pathways to prevent thrombosis is either not effective or comes with an inherent risk of bleeding complications. The purpose of this proposal is a) to identify critical signaling molecules, which preferentially contribute to Fc?RIIA- mediated platelet activation and b) to develop therapeutic anti-platelet strategies to prevent pathologic thrombosis in ITT while minimizing bleeding complications. Our preliminary studies identify the tyrosine kinase Syk, the Ser/Thr kinase Akt, and the Ca2+ sensor CalDAG-GEFI as promising new targets for antiplatelet therapy in the setting of ITT. Downstream of ITAM-coupled receptors like Fc?RIIA, Syk is important for the activation of phospholipase C?2 and thus the generation of the second messengers Ca2+ and diacylglycerol. CalDAG-GEFI links an increase in intracellular Ca2+ to the signaling pathways regulating integrin activation, thromboxane generation, and granule release. Preliminary studies on Akt demonstrate that it is important for Fc?RIIA-induced calcium flux and integrin activation, thus linking it to Syk and CalDAG-GEFI. Preliminary results as well as work by us and others further demonstrate that Syk, CalDAG- GEFI, and Akt are particularly important for Fc?RIIA/ITAM-mediated platelet activation. With the proposed studies, we will improve our understanding of the molecular mechanisms by which CalDAG-GEFI (aim 1) and Akt (aim 2) contribute to Fc?RIIA-mediated platelet activation. In aim 3, we will validate Syk and Akt and explore CalDAG-GEFI as therapeutic targets in ITT. The safety and efficacy of pharmacologic inhibition of Syk and Akt for the treatment and prevention of ITT will be tested in our established mouse models. The utility of CalDAG-GEFI or Akt2 as therapeutic targets for the treatment of ITT will be evaluated in crosses between mice transgenic for the human Fc?RIIA and mice knockout for CalDAG-GEFI or Akt2. The successful completion of this proposal will accelerate the rational design of novel therapeutics for immune-mediated platelet disorders.

描述（由申请人提供）：血小板Fc受体FcRIIA的激活对于几种免疫介导的血小板减少症和血栓形成（ITT）综合征（包括肝素诱导的血小板减少症/血栓形成）的发病机制至关重要。成功治疗这些血栓综合征的障碍之一是，以血小板激活途径为靶点来预防血栓形成的治疗要么无效，要么存在出血并发症的固有风险。该提案的目的是a) 鉴定关键信号分子，其优先促进FcRIIA 介导的血小板活化；b) 开发治疗性抗血小板策略以预防ITT 中的病理性血栓形成，同时最大限度地减少出血并发症。我们的初步研究确定酪氨酸激酶 Syk、Ser/Thr 激酶 Akt 和 Ca2+ 传感器 CalDAG-GEFI 是 ITT 背景下抗血小板治疗的有希望的新靶点。 ITAM 偶联受体（如 Fc?RIIA）的下游，Syk 对于磷脂酶 C?2 的激活以及第二信使 Ca2+ 和二酰基甘油的生成非常重要。 CalDAG-GEFI 将细胞内 Ca2+ 的增加与调节整合素激活、血栓素生成和颗粒释放的信号通路联系起来。对 Akt 的初步研究表明，它对于 Fc?RIIA 诱导的钙流和整合素激活很重要，因此将其与 Syk 和 CalDAG-GEFI 联系起来。初步结果以及我们和其他人的工作进一步证明 Syk、CalDAG-GEFI 和 Akt 对于 Fc?RIIA/ITAM 介导的血小板活化特别重要。通过拟议的研究，我们将加深对 CalDAG-GEFI（目标 1）和 Akt（目标 2）促进 Fc?RIIA 介导的血小板活化的分子机制的理解。在目标 3 中，我们将验证 Syk 和 Akt 并探索 CalDAG-GEFI 作为 ITT 的治疗靶点。 Syk 和 Akt 的药物抑制治疗和预防 ITT 的安全性和有效性将在我们建立的小鼠模型中进行测试。将在人FcRIIA转基因小鼠与CalDAG-GEFI或Akt2敲除小鼠之间的杂交中评估CalDAG-GEFI或Akt2作为治疗ITT的治疗靶标的效用。该提案的成功完成将加速免疫介导的血小板疾病新疗法的合理设计。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Mice Expressing Low Levels of CalDAG-GEFI Exhibit Markedly Impaired Platelet Activation With Minor Impact on Hemostasis.

表达低水平 CalDAG-GEFI 的小鼠表现出血小板活化明显受损，对止血影响较小。

DOI：
发表时间：
2016
期刊：
影响因子：
0
作者：
Piatt, Raymond;Paul, David S;Lee, Robert H;McKenzie, Steven E;Parise, Leslie V;Cowley, Dale O;Cooley, Brian C;Bergmeier, Wolfgang
通讯作者：
Bergmeier, Wolfgang

CalDAG-GEFI deficiency protects mice from FcγRIIa-mediated thrombotic thrombocytopenia induced by CD40L and β2GPI immune complexes.

CalDAG-GEFI 缺陷保护小鼠免受CD40L 和β2GPI 免疫复合物诱导的FcγRIIa 介导的血栓性血小板减少症。