Role of myeloid KLF2 in antiphospholipid antibody-mediated thrombosis

髓系 KLF2 在抗磷脂抗体介导的血栓形成中的作用

• 批准号: 9753358
• 负责人: Lalitha Nayak
• 金额: $ 46.42万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9753358
• 关键词: Affect; Antibodies; Antibody Therapy; Anticoagulant therapy; Antiinflammatory Effect; Antineoplastic Agents; Antiphospholipid Antibodies; Antiphospholipid Syndrome; Attenuated; Beds; Biological; Biological Assay; Blood Coagulation Factor; Blood Platelets; Blood Vessels; Bortezomib; Carotid Arteries; Cells; Clinical Research; Coagulation Process; Data; Development; Disease; Dose; Erythrocytes; Female of child bearing age; Foundations; Generations; Genetic; Growth; Habitual Abortion; Hemorrhage; Hemostatic function; Immune Targeting; Inferior vena cava structure; Inflammasome; Inflammation; Inflammatory Response; Infusion procedures; Injury; Kruppel-like transcription factors; Laboratories; Lasers; Leukocytes; Ligation; Link; Macrophage Activation; Mediating; Modeling; Molecular; Morbidity - disease rate; Motivation; Mus; Muscle; Myelogenous; Myeloid Cell Activation; Neutrophil Activation; Patients; Pharmacology; Publishing; Recurrence; Reporter Genes; Risk; Role; Site-Directed Mutagenesis; Syndrome; System; Testing; Therapeutic; Thromboplastin; Thrombosis; Thrombus; Venous; Venous Thrombosis; chromatin immunoprecipitation; cytokine; extracellular; high risk; in vivo; insight; intravital microscopy; macrophage; member; mortality; neutrophil; novel; novel strategies; overexpression; prevent; programs; recruit; response; standard of care; targeted treatment; thromboinflammation

Project Summary: The Antiphospholipid Antibody Syndrome (APS) is characterized by recurrent arterial and venous thrombosis in small and large vessels accompanied by persistently positive antiphospholipid antibody tests. This condition often affects young patients (particularly women of child-bearing age) and is associated with significant morbidity and mortality. Classically, studies of thrombosis have focused largely on platelets (arterial clots), red blood cells (venous clots) and the coagulation factors. However a growing body of data gathering over the past decade supports an intimate link between inflammation and thrombosis such that inflammation begets thrombosis and thrombosis amplifies the inflammatory response. Specifically, neutrophil activation and generation of neutrophil extracellular traps (NETs) have been shown to contribute to thrombosis in the setting of antiphospholipid antibodies. Further, NETs prime macrophages for inflammasome activation and release of cytokines and tissue factor implicating cross talk between members of the myeloid system to generate a proinflammatory and prothrombotic milieu. Presently, thrombosis risk is managed with lifelong anticoagulant therapy that is only modestly effective and associated with a high risk of bleeding, suggesting that alternate or novel approaches are necessary. These observations fuel the momentum for the view that therapies targeting the myeloid lineage may have potential impact on both arterial and venous thrombosis. However, the molecular mechanisms underlying myeloid cell activation in orchestrating this thrombo-inflammatory response is poorly understood. Our observations (both published and nascent) establish transcription factor KLF2 as a potent tonic repressor of myeloid cell activation and inflammation as well as an essential determinant of both arterial and venous thrombosis. Mechanistically, KLF2 is found to regulate two conserved ancient programs — generation of neutrophil extracellular traps (NETs) and activation of the inflammasome. Specific to this proposal, we find that (i) APLA infusion increases both arterial and venous thrombosis in mice; (ii) APLA treatment leads to decreased KLF2 expression and inflammasome activation of macrophages and increased NET generation in neutrophils; (iii) myeloid-specific overexpression of KLF2 offers thromboprotection in the presence of APLA. Finally, the therapeutic potential of targeting KLF2 is revealed by our discovery that the anti-cancer agent bortezomib (BZ), at low non-toxic doses, induces myeloid KLF2 and confers potent anti-thrombotic effects (without altering hemostasis) in both arterial and venous beds that are KLF2-dependent. These observations provide the foundation for the central hypothesis that myeloid KLF2 is a central determinant of vascular thrombosis in APS that can be targeted for therapeutic gain. To explore this hypothesis, the following aims are proposed: (1) To investigate the effect of altering myeloid KLF2 on APLA-induced thrombosis in the macro- and microvasculature, (2) To elucidate the molecular mechanisms involved in KLF2’s ability to regulate NET formation and inflammasome activation in the context of APLA, and (3) To understand the molecular basis for the antithrombotic effect noted with BZ in the context of APLA treatment. These studies will reveal the molecular basis and functional consequences of altering myeloid KLF2 on thrombosis in the setting of APLA. Further, they will illuminate the importance of myeloid KLF2 in the antithrombotic/anti-inflammatory effects of BZ in this setting. Collectively, the results will not only provide deep biologic insights but may stimulate clinical studies evaluating the efficacy of BZ in APS with the potential to change standard of care for this devastating illness.

项目摘要： 抗磷脂抗体综合征（AP）的特征是复发性动脉和静脉血栓形成 在大小血管中，通过持续的抗磷脂抗体测试来完成。这种情况 通常会影响年轻患者（尤其是育龄妇女），并且与大量有关 发病率和死亡率。从经典上讲，血栓形成的研究主要集中在血小板上（动脉凝块），红色 血细胞（静脉布）和凝血因子。但是，过去越来越多的数据收集 十年支持炎症与血栓形成之间的紧密联系，以使炎症产生 血栓形成和血栓形成放大器炎症反应。具体而言，中性粒细胞的激活和 嗜中性粒细胞外陷阱（NET）的产生已证明在情况下有助于血栓形成 抗磷脂抗体。此外，网状巨噬细胞用于炎性体激活和释放 细胞因子和组织因子暗示髓样系统成员之间的交叉谈话产生 促炎和促血栓形成环境。目前，血栓形成风险是通过终身抗凝剂管理的 疗法仅适度有效，并且与出血的高风险有关，这表明替代或 新颖的方法是必要的。这些观察结果助长了靶向治疗的观点 髓样谱系可能会对动脉和静脉血栓形成产生潜在的影响。但是， 在编排这种血栓炎症反应时，髓样细胞激活的分子机制 理解很差。 我们的观察结果（均出版和新生）建立转录因子KLF2作为潜在的滋补品 髓样细胞激活和炎症的阻遏物，以及动脉和动脉的基本决定 静脉血栓形成。从机械上讲，发现KLF2可以调节两个保守的古代程序 - 一代 嗜中性粒细胞外陷阱（网）和炎症体的激活。特定于该提议，我们发现 （i）APLA输注会增加小鼠的动脉和静脉血栓形成； （ii）APLA治疗导致 巨噬细胞的KLF2表达和炎症体激活降低，并增加了净产生 中性粒细胞； （iii）KLF2的髓样特异性过表达在存在APLA的情况下提供血栓保护。 最后，我们的发现揭示了靶向KLF2的治疗潜力 硼替佐米（Bz），低无毒剂量，诱导髓样KLF2并承认潜在的抗栓性作用 （不改变止血）在依赖KLF2的动脉和静脉床中。这些观察 为中心假设提供了基础，即髓样KLF2是确定的中心 可以针对治疗性增益的AP中的血管血栓形成。为了探索这一假设， 提出了以下目的：（1）研究改变髓样KLF2对APLA诱导的影响 宏观和微脉管系统中的血栓形成，（2）阐明了涉及的分子机制 KLF2在APLA的背景下调节净形成和炎症体激活的能力以及 （3）了解在BZ中指出的抗强化作用的分子基础 APLA治疗。这些研究将揭示改变的分子基础和功能后果 在APLA的情况下，髓样KLF2在血栓形成上。此外，他们将阐明髓样的重要性 在这种情况下，BZ的抗血栓形成/抗炎作用中的KLF2。总体而言，结果不仅会 提供深厚的生物学见解，但可能会刺激评估BZ在AP中的效率的临床研究 改变这种毁灭性疾病的护理标准的潜力。