The role of Fli1 in myeloid cells and its contribution to cardiac fibrosis

Fli1在骨髓细胞中的作用及其对心脏纤维化的贡献

• 批准号: 10696077
• 负责人: Andreea Monica Bujor
• 金额: $ 41.25万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10696077
• 关键词: Adult; Angiotensin II; Autoimmune; Autoimmunity; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cardiovascular Diseases; Cause of Death; Cell model; Cells; Cessation of life; Coculture Techniques; Collagen; Complication; Connective Tissue Diseases; Data; Deposition; Echocardiography; Endothelium; Extracellular Matrix; FLI1 Transcription Factor; FRAP1 gene; Family; Fibroblasts; Fibrosis; Functional disorder; Future; Galectin 3; Gene Expression; Genes; Genetic Recombination; Heart; Heart Diseases; Heterozygote; Human; Hypertrophy; Immune; Infiltration; Inflammation; Inflammatory; Inflammatory Infiltrate; Infusion procedures; Injury; Interferon Activation; Investigation; Link; Macrophage; Macrophage Activation; Mediating; Mediator; Molecular; Mus; Muscle Cells; Myelogenous; Myeloid Cells; Nuclear RNA; Pathogenesis; Pathologic; Pathway interactions; Patients; Phenotype; Production; Proteins; Publishing; Reporter; Research; Rodent Model; Role; Scleroderma; Serum; Signal Pathway; Sirolimus; Small Interfering RNA; System; Systemic Scleroderma; Testing; Tissues; Up-Regulation; Work; coronary fibrosis; cytokine; effective therapy; experimental study; gain of function; improved; in vivo; inhibitor; injured; insight; mTOR Inhibitor; mTOR Signaling Pathway; mTOR inhibition; member; migration; monocyte; mortality; new therapeutic target; prevent; recruit; repository; response; single-cell RNA sequencing; targeted treatment; transcription factor; transcriptome sequencing

ABSTRACT Heart disease is the leading cause of death in the USA and fibrosis is a common endpoint for most cardiac diseases. Recent research has shown monocytes and macrophages are important mediators of heart fibrosis. We found reduced levels of the transcription factor Fli1 in monocytes isolated from systemic sclerosis (SSc) patients, an autoimmune connective tissue disease characterized by widespread tissue fibrosis and fibrotic cardiomyopathy. Co-culture of human cardiac fibroblasts and Fli1 depleted monocytes resulted in potent induction of galectin-3, and alternative activation markers in myeloid cells, and abundant collagen deposition by fibroblasts, and this was blocked by the mTOR inhibitor Rapamycin. Preliminary experiments revealed that deletion of Fli1 in monocytes/macrophages via Cre-mediated recombination using LysMCre mice (LysMCre/Fli1fl/fl) predisposed mice to develop myocardial fibrosis. Based on published data and our preliminary results, we hypothesize that Fli1 deficiency in macrophages contributes to SSc fibrosis and cardiomyopathy, and that Rapamycin may block these effects. To test this hypothesis, we propose the following specific aims: Specific aim 1: Determine the molecular mechanism leading to fibrosis following Fli1 depletion in monocytes/macrophages. We expect that decreased Fli1 in monocytes/macrophages will result in enhanced migration, cardiomyocyte hypertrophy, and will promote the production of extracellular matrix via Fli1/galetin- 3/mTOR pathway. Specific aim 2: Determine whether loss of Fli1 in macrophages leads to cardiomyopathy in vivo. We expect that the LysMCre/Fli1fl/fl mice will have enhanced inflammatory infiltrates, heart fibrosis and diastolic dysfunction in response to Angiotensin II, which will be inhibited by Rapamycin. Specific aim 3. Investigate whether myeloid Fli1 has a role in SSc-associated cardiomyopathy. We expect that monocytes and macrophages from SSc patients with cardiomyopathy will display a similar phenotype to the LysMCre/Fli1fl/fl macrophages. The studies proposed should allow us to gain better understanding of the molecular mechanisms of heart fibrosis in SSc, and determine whether future treatments for SSc-cardiomyopathy, should target Fli1 and the myeloid system via Rapamycin, thus providing the basis for potentially safer, more effective therapies.

抽象的 心脏病是美国的首要死因，纤维化是大多数心脏病患者的常见终点 疾病。最近的研究表明单核细胞和巨噬细胞是心脏纤维化的重要介质。 我们发现从系统性硬化症 (SSc) 分离的单核细胞中转录因子 Fli1 水平降低 患者，一种自身免疫性结缔组织疾病，其特征是广泛的组织纤维化和纤维化 心肌病。人心脏成纤维细胞和 Fli1 耗尽的单核细胞共培养产生了有效的 诱导半乳糖凝集素 3 和骨髓细胞中的替代激活标记物，以及丰富的胶原蛋白沉积 成纤维细胞，而这一过程被 mTOR 抑制剂雷帕霉素阻断。初步实验表明 使用 LysMCre 小鼠通过 Cre 介导的重组删除单核细胞/巨噬细胞中的 Fli1 (LysMCre/Fli1fl/fl) 使小鼠易发生心肌纤维化。 根据已发表的数据和我们的初步结果，我们假设巨噬细胞中存在 Fli1 缺陷 导致 SSc 纤维化和心肌病，雷帕霉素可能会阻止这些影响。为了测试这个 假设，我们提出以下具体目标： 具体目标 1：确定 Fli1 缺失后导致纤维化的分子机制 单核细胞/巨噬细胞。我们预计单核细胞/巨噬细胞中 Fli1 的减少将导致 迁移，心肌细胞肥大，并通过 Fli1/galetin- 促进细胞外基质的产生 3/mTOR 途径。 具体目标 2：确定巨噬细胞中 Fli1 的缺失是否会导致体内心肌病。我们 预计 LysMCre/Fli1fl/fl 小鼠的炎症浸润、心脏纤维化和舒张压增强 血管紧张素 II 反应出现功能障碍，血管紧张素 II 会被雷帕霉素抑制。 具体目标 3. 研究髓样 Fli1 是否在 SSc 相关心肌病中发挥作用。我们期望 患有心肌病的 SSc 患者的单核细胞和巨噬细胞将表现出与 LysMCre/Fli1fl/fl 巨噬细胞。 提出的研究应该使我们能够更好地了解心脏纤维化的分子机制 并确定 SSc 心肌病的未来治疗是否应针对 Fli1 和骨髓 系统通过雷帕霉素，从而为潜在更安全、更有效的治疗提供基础。