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.

项目概要： 抗磷脂抗体综合征 (APS) 的特点是复发性动脉和静脉血栓形成 在小血管和大血管中，伴有持续阳性的抗磷脂抗体测试。这个条件 经常影响年轻患者（尤其是育龄妇女），并且与显着的 发病率和死亡率。传统上，血栓形成的研究主要集中在血小板（动脉血栓）、红色 血细胞（静脉血栓）和凝血因子。然而，过去收集的数据越来越多 十年支持炎症和血栓形成之间的密切联系，从而引发炎症 血栓形成和血栓形成会放大炎症反应。具体而言，中性粒细胞活化和 中性粒细胞胞外陷阱（NET）的产生已被证明有助于血栓形成 抗磷脂抗体。此外，NETs 还负责巨噬细胞的炎症小体激活和释放 细胞因子和组织因子涉及骨髓系统成员之间的串扰，以产生 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来控制的 治疗效果有限且出血风险较高，表明替代或 需要采取新的方法。这些观察结果为以下观点提供了动力：靶向治疗 骨髓谱系可能对动脉和静脉血栓形成都有潜在影响。然而， 骨髓细胞激活协调血栓炎症反应的分子机制 人们对此知之甚少。 我们的观察（已发表的和新生的）证实转录因子 KLF2 是一种有效的补品 骨髓细胞活化和炎症的抑制因子，也是动脉和动脉粥样硬化的重要决定因素 静脉血栓形成。从机制上讲，KLF2被发现调节两个保守的古代程序——生成 中性粒细胞胞外陷阱（NET）和炎症小体的激活。具体到这个提案，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 降低 KLF2 表达和巨噬细胞炎症小体激活，并增加 NET 生成 中性粒细胞； (iii) KLF2 的骨髓特异性过度表达在 APLA 存在的情况下提供血栓保护。 最后，我们发现抗癌药物揭示了靶向 KLF2 的治疗潜力 硼替佐米 (BZ) 在低无毒剂量下可诱导骨髓 KLF2 并赋予有效的抗血栓作用 （不改变止血）在依赖 KLF2 的动脉和静脉床中。这些观察 为髓系 KLF2 是髓系细胞的核心决定因素这一中心假设提供了基础 APS 中的血管血栓形成可以作为治疗增益的目标。为了探索这个假设， 提出以下目标：（1）研究改变骨髓KLF2对APLA诱导的影响 大血管和微血管中的血栓形成，(2) 阐明所涉及的分子机制 KLF2 在 APLA 背景下调节 NET 形成和炎性体激活的能力，以及 (3) 了解 BZ 抗血栓作用的分子基础 APLA 治疗。这些研究将揭示改变的分子基础和功能后果 骨髓 KLF2 对 APLA 中血栓形成的影响。此外，他们将阐明骨髓细胞的重要性 KLF2 在这种情况下 BZ 的抗血栓/抗炎作用。总的来说，结果不仅 提供深入的生物学见解，但可能会刺激临床研究评估 BZ 在 APS 中的功效 改变这种毁灭性疾病的护理标准的潜力。