Pulmonary fibrosis is modulated by MCU-mediated macrophage apoptosis resistance

MCU介导的巨噬细胞凋亡抵抗调节肺纤维化

• 批准号: 10754498
• 负责人: A BRENT CARTER
• 金额: --
• 依托单位: BIRMINGHAM VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10754498
• 关键词: Alveolar Macrophages; Apoptosis; Apoptotic; Asbestos; Asbestosis; Attenuated; BCL-2 Protein; BCL2 gene; Binding Proteins; Bioenergetics; Biological; Bleomycin; Bone Marrow; Calcium; Carnitine Palmitoyltransferase I; Cell Survival; Cell physiology; Cells; Chimera organism; Chronic Disease; Cytosol; Data; Development; Disease Progression; Dominant-Negative Mutation; Enzymes; Exhibits; Fibrosis; Generations; Human; Immune response; In Vitro; Induction of Apoptosis; Link; Lipids; Lung; Lung diseases; Macrophage; Macrophage Activation; Mediating; Metabolic; Metabolism; Mitochondria; Molecular; Mus; Pathogenesis; Peroxisome Proliferator-Activated Receptors; Phenotype; Play; Process; Pulmonary Fibrosis; Reactive Oxygen Species; Resistance; Resolution; Role; Testing; Tissues; calcium uniporter; fatty acid oxidation; fibrogenesis; fibrotic lung; fighting; genetic approach; human subject; idiopathic pulmonary fibrosis; injury and repair; lung injury; lung repair; monocyte; mortality; organ injury; prevent; repaired; transcription factor

! In fibrotic disorders of the lung, including idiopathic pulmonary fibrosis (IPF), lung macrophages have a decisive role in fibrotic repair of injured lung. Macrophages play an integral role in the normal resolution of organ injury but also contribute to the pathogenesis of pulmonary fibrosis by initiating an immune response and by generating reactive oxygen species (ROS), particularly mitochondrial ROS (mtROS). Lung remodeling during pulmonary fibrosis is poorly understood; however, changes in mitochondrial bioenergetics in monocyte- derived macrophages are emerging as a critical determinant of fibrotic repair. The generation of mtROS is linked to calcium (Ca2+) influx into the mitochondria, which is regulated, in part, by the mitochondrial Ca2+ uniporter (MCU). Macrophages in chronic disease typically exhibit apoptosis resistance, and their prolonged survival is associated with disease progression. Metabolic reprogramming to fatty acid oxidation (FAO) is a key feature in macrophage activation. The relative efficiency of FAO is well suited to meet the metabolic requirements necessary for the repair of injured tissue. Our preliminary data show that lung macrophages from IPF subjects have increased expression of peroxisome proliferator-activated receptor coactivator-1 (PGC-1a), a transcription factor that leads to increased enzymatic capacity for FAO, carnitine palmitoyltransferase IA (CPT1A), the rate limiting mitochondrial lipid transporter, and mitochondrial Bcl-2 compared to normal subjects. MCU deficiency attenuates PGC-1a expression, and dominant-negative (DN)-MCU expression abrogates FAO. These findings are relevant because by generating reciprocal bone marrow chimeras using WT and MCU+/- mice, we found mice that received MCU+/- bone marrow were protected from bleomycin-induced pulmonary fibrosis. We hypothesize that MCU mediates pulmonary fibrosis by metabolic reprogramming of lung macrophages to induce apoptosis resistance. We will test this hypothesis with three aims. Aim 1 will test if MCU modulates macrophage metabolic reprogramming to FAO and if MCU is required for pulmonary fibrosis utilizing mice harboring expression of a dominant-negative (DN)-MCU in monocyte-derived macrophages. In Aim 2, we will test if MCU mediates apoptosis resistance by inducing metabolic reprogramming to FAO and enhancing expression of anti-apoptotic Bcl-2 proteins that bind to CPT1a using genetic approaches and in mice harboring expression of DN-MCU or a deletion of Bcl-2 in monocyte-derived macrophages. Aim 3 will provide human biological evidence of the importance of MCU in fibrosis development by determining if modulation of MCU in lung macrophages from IPF subjects regulates FAO and resistance to apoptosis. Understanding the role of MCU in lung macrophages may provide an important target for preventing or halting progression of fibrosis.

呢在肺的纤维化疾病中，包括特发性肺纤维化（IPF），肺巨噬细胞具有 肺部纤维化修复中的决定性作用。巨噬细胞在正常分辨率中起着不可或缺的作用 器官损伤，但也通过引发免疫反应和 通过产生活性氧（ROS），尤其是线粒体ROS（MTROS）。肺改造 在肺纤维化期间，人们了解得很糟糕。但是，单核细胞中线粒体生物能学的变化 衍生的巨噬细胞正在成为纤维化修复的关键决定因素。 Mtros的一代是 与钙（Ca2+）涌入到线粒体中的相关，该线粒体部分由线粒体Ca2+部分调节 Uniporter（MCU）。慢性疾病中的巨噬细胞通常表现出凋亡的抗性，其延长 生存与疾病进展有关。代谢重编程对脂肪酸氧化（FAO）是关键 巨噬细胞激活中的特征。粮农组织的相对效率非常适合满足代谢 修复受伤组织所需的要求。我们的初步数据表明，来自 IPF受试者的过氧化物酶体增殖物激活受体共振剂1（PGC-1A）的表达增加， 转录因子，导致粮农组织，肉碱棕榈转移酶IA的酶促能力增加 （CPT1A），与正常受试者相比，线粒体脂质转运蛋白的速率限制了线粒体脂质转运蛋白和线粒体Bcl-2。 MCU缺乏减弱PGC-1A的表达和显性阴性（DN）-MCU表达式消除 刑事。这些发现很重要，因为通过使用WT和 MCU +/-小鼠，我们发现接受MCU +/-骨髓的小鼠免受博来霉素诱导的保护 肺纤维化。 我们假设MCU通过肺巨噬细胞的代谢重编程介导肺纤维化 诱导抗细胞凋亡抗性。我们将以三个目标检验这一假设。 AIM 1将测试MCU是否调节巨噬细胞代谢重新编程对粮农组织以及是否需要MCU的MCU 利用单核细胞衍生中具有显性阴性​​（DN）-MCU表达的小鼠的肺纤维化 巨噬细胞。 在AIM 2中，我们将测试MCU是否通过诱导代谢重编程来介导凋亡抗性 并增强使用遗传方法和在 在单核细胞衍生的巨噬细胞中具有DN-MCU表达或Bcl-2缺失的小鼠。 AIM 3将提供人类的生物学证据，表明MCU在纤维化开发中的重要性 确定来自IPF受试者肺巨噬细胞中MCU是否调节粮农组织和抵抗 凋亡。了解MCU在肺巨噬细胞中的作用可能为防止 或停止纤维化的进展。