CREB Programming of Alveolar Macrophage Population and Inflammatory Lung Injury

肺泡巨噬细胞群和炎症性肺损伤的 CREB ​​编程

• 批准号: 10491070
• 负责人: DOLLY MEHTA
• 金额: $ 43.74万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-20 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10491070
• 关键词: Acetyl Coenzyme A; Address; Alveolar; Alveolar Macrophages; Anti-Inflammatory Agents; Attenuated; Binding; Cell Nucleus; Cells; Cyclic AMP Response Element; Data; Epigenetic Process; Generations; Genes; Genetic Transcription; Histone Acetylation; Histones; Homeostasis; ITGAM gene; ITGAX gene; Immune; Immune response; Impairment; Individual; Inflammatory; Injury; Lung; Lung infections; Mediating; Metabolism; Mitochondria; Modeling; Mus; Myelogenous; Nuclear; PPAR gamma; Pathway interactions; Phenotype; Play; Population; Production; Property; Pyruvate; Pyruvate Dehydrogenase Complex; Regulator Genes; Resolution; Role; STAT6 gene; Seminal; Sentinel; Signal Transduction; Testing; Up-Regulation; base; cell type; epigenetic regulation; genetic signature; injury and repair; interstitial; lung injury; lung repair; macrophage; monocyte; mortality; prevent; pyruvate dehydrogenase kinase 4; repair function; repair strategy; repaired; tissue repair; tool; transcription factor

PROJECT SUMMARY/ABSTRACT The lung’s ability to recover from severe inflammatory injury depends on its capacity to rapidly mobilize intrinsic tissue repair pathways. Macrophages (Mɸ), the most abundant sentinel immune cell in lungs, have different lineages and functions. A key, but poorly understood, aspect of these cells is their intrinsic property to promote repair after lung injury. In the basal state, the lung contains alveolar Mɸ (AMɸ) (CD11c+/CD11b-/SiglecF+) as well as a population of interstitial Mɸ (IMɸ) (CD11b+/CX3CR1+/SiglecF-). AMɸ are necessary for restoring lung homeostasis after lung injury but the mechanisms regulating reparative AMɸ generation remain elusive. It is clear that a reparative AMɸ population needs to be efficiently and rapidly mobilized, in particular, in the face of sharp decrease in their number during lung infection and injury. In Project 2, we will address this question based on the seminal observation that the transcription factor cAMP Response Element Binding (CREB) plays a key role in giving rise to a reparative AMɸ lineage. In support of this concept, we show that the myeloid-specific deletion of CREB in mice (Creb∆LyzM mice) resulted in the generation of immature AMɸ (CD11c+/CD11b+/SiglecFlo), which give rise to inflammatory AMɸ, thus subverting the anti-inflammatory and reparative function of mature AMɸ. These mice thereby showed clear evidence of lung injury in the basal state due to the increase in inflammatory AMɸ. Furthermore, lung injury in these mice after LPS was prolonged and agonal. They showed significantly greater mortality than controls. By studying flow-sorted Mɸ from Creb∆LyzM lungs, we also found alterations in the expression of regulatory genes such as Pparγ , an essential driver of reparative AMɸ lineage specification, as well as genes regulating AMɸ metabolism and immune responses. Further analysis showed that CREB induced the expression of pyruvate dehydrogenase kinase 4 (PDK4). PDK4 in turn suppressed the translocation of pyruvate dehydrogenase complex (PDC) from mitochondria to the nucleus, thus inhibiting the production of nuclear acetyl-CoA. In the absence of CREB and its target PDK4, PDC activity was markedly increased which resulted in excessive nuclear acetyl-CoA levels, increased histone acetylation, and the generation of AMɸ, that were incapable of promoting lung repair. Based on these observations and with the availability of powerful tools generated by the Cores, in Project 2 we will define the central role of CREB in generating a pro-resolving AMɸ population through the epigenetic regulation of Pparγ expression. Our Specific Aims are (Aim 1): to address the role of CREB in mediating the generation of a lung reparative AMɸ population following lung injury, and (Aim 2): to investigate the role of CREB in signaling the generation of AMɸ by epigenetically upregulating Pparγ expression. Based on the provocative phenotype of Creb∆LyzM mice, we believe understanding how reparative AMɸ are generated and enhancing their generation during injury holds great promise for developing lung repair strategies.

项目概要/摘要 肺部从严重炎症损伤中恢复的能力取决于其快速动员内在能量的能力 巨噬细胞（Mɸ）是肺部最丰富的前哨免疫细胞，具有不同的组织修复途径。 这些细胞的谱系和功能的一个关键但人们知之甚少的方面是它们促进细胞生长的内在特性。 肺损伤后的修复 在基础状态下，肺含有肺泡 Mɸ (AMɸ) (CD11c+/CD11b-/SiglecF+)。 以及间质 Mɸ (IMɸ) (CD11b+/CX3CR1+/SiglecF-) 群体对于恢复肺功能是必需的。 肺损伤后的稳态，但调节修复性 AMɸ 生成的机制仍然难以捉摸。 明确的是，需要有效、迅速地动员修复性 AMɸ 人口，特别是在面临 在肺部感染和损伤期间，它们的数量急剧减少。在项目 2 中，我们将根据这个问题来解决这个问题。 转录因子 cAMP 响应元件结合 (CREB) 发挥关键作用的开创性观察 在产生修复性 AMɸ 谱系中的作用 为了支持这一概念，我们证明了骨髓特异性。 小鼠（CrebΔLyzM小鼠）中CREB的缺失导致了不成熟AMɸ的产生 (CD11c+/CD11b+/SiglecFlo)，产生炎症性 AMɸ，从而破坏抗炎和 这些小鼠在基础状态下显示出明显的肺损伤证据。 此外，由于炎症 AMɸ 的增加，LPS 后这些小鼠的肺损伤时间延长。 通过研究来自 CrebΔLyzM 的流式排序 Mɸ，它们表现出明显高于对照组的死亡率。 在肺部，我们还发现了调节基因（例如 Pparγ）表达的变化，Pparγ 是肺的重要驱动因素。 修复性 AMɸ 谱系规范，以及调节 AMɸ 代谢和免疫反应的基因。 进一步分析表明，CREB ​​诱导丙酮酸脱氢酶激酶 4 (PDK4) 的表达。 反过来又抑制了丙酮酸脱氢酶复合物（PDC）从线粒体到线粒体的易位。 细胞核，从而在缺乏 CREB ​​及其靶标 PDK4、PDC 的情况下抑制核乙酰辅酶 A 的产生。 活性显着增加，导致核乙酰辅酶A水平过高，组蛋白增加 基于这些，乙酰化和 AMɸ 的生成无法促进肺修复。 观察以及核心生成的强大工具的可用性，在项目 2 中，我们将定义 CREB ​​在通过 Pparγ 的表观遗传调控产生促解决 AMɸ 群体中的核心作用 我们的具体目标是（目标 1）：解决 CREB ​​在介导肺生成中的作用。 肺损伤后修复性 AMɸ 群体，以及（目标 2）：研究 CREB ​​在信号传导中的作用 基于表型的激发表型，通过表观遗传上调 Pparγ 表达来产生 AMɸ。 CrebΔLyzM 小鼠，我们相信了解修复性 AMɸ 是如何生成的并增强其生成 损伤期间的肺修复策略具有广阔的前景。