Role of Nrf2 in Alveolar Epithelial Cell Regeneration During Lung Repair

Nrf2 在肺修复过程中肺泡上皮细胞再生中的作用

• 批准号: 10025798
• 负责人: Sekhar P. Reddy
• 金额: $ 4.08万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-10 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10025798
• 关键词: Acute; Acute Lung Injury; Address; Adult Respiratory Distress Syndrome; Agreement; Air; Bacterial Infections; Cell Cycle Arrest; Cellular Stress; Chronic Obstructive Airway Disease; Clinical; Critical Illness; Cysteine; Cytoprotection; Epithelial; Epithelial Cell Proliferation; Epithelial Cells; Epithelium; Equilibrium; Exhibits; Exposure to; G2/M Arrest; Health; Homeostasis; Hyperoxia; Impairment; Inflammatory Response; Injury; Knockout Mice; Lead; LoxP-flanked allele; Lung; Lung Inflammation; Lung diseases; M cell; Mediating; Modeling; Mus; Oxidative Stress; Pathway interactions; Patients; Proliferating; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Resolution; Role; Signal Transduction; Stress; Structure of parenchyma of lung; Testing; Tissues; alveolar epithelium; cell regeneration; conditional mutant; experimental study; gain of function; improved; in vivo; inhibitor/antagonist; loss of function; lung injury; lung repair; mouse model; regenerative; repaired; response; small molecule; three dimensional cell culture; tissue repair; transcription factor; transdifferentiation

Impaired repair of alveolar epithelium after acute lung injury (ALI) can lead to heightened inflammatory response and tissue repair do not normally resolve. Studies in this application will test the hypothesis that impaired lung repair after injury is the result of GSH/AKT signaling imbalance in type 2 alveolar epithelial cells (AEC2s) regulated by cyto-protection and pro-survival transcription factor, Nrf2. We found that global deletion of Nrf2 impairs lung repair after sub-lethal pro-oxidant (hyperoxia)-induced ALI. Using conditional mutant Nrf2 ("floxed") mouse model to determine the contribution of lung resident cellular stress to acute lung and repair, we found that deletion of Nrf2 in lung epithelium impaired the resolution of ALI in a manner similar to that observed in Nrf2-null mice, suggesting that lung epithelial-Nrf2 signaling regulates pro-resolution response and lung repair. In agreement with this result, we found that primary AEC2s lacking Nrf2 (Nrf2-/-AEC2s) proliferate poorly due to oxidative stress and G2/M (not G1/M) cell cycle arrest. Interestingly, mitigating oxidative stress in Nrf2-/-AEC2s by exogenous N-acetyl-cysteine, but it failed to rescue G2/M arrest. In contrast, exogenous GSH mitigated stress, activated AKT signaling and restored proliferation in Nrf2-/-AEC2s. Preliminary 3D cell culture experiments showed reduced size of "alveolospheres" formation by AEC2s isolated from Nrf2+/+ mice exposed to sub-lethal (48-h) hyperoxia compared to room air counterparts. AEC2s from Nrf2-/- mice exposed to either room air or hyperoxia formed disorganized and reduced number of "alveolospheres". Nrf2-/-AEC2s supplemented with GSH exhibited improved alveolosphere formation, but not efficient AEC2/1 trans-differentiation. In this project, we test hypothesize that AEC2-specific Nrf2 regulated signaling is essential for tipping the equilibrium towards either for optimal GSH/AKT- dependent AEC2 proliferation and GSH/AKT-independent AEC2/1 trans-differentiation. We will use multiple approaches to provide a mechanistic test of this hypothesis including the use of AEC2-tissue- specific loss-of-function (Nrf2-/-AEC2) and gain-of-function (Nrf2 inhibitor Keap1-/-AEC2) mouse models and small molecule Nrf2 activators. The Specific Aims to be pursued are: 1) to determine the mechanisms and role of Nrf2 regulated GSH/AKT-mediated signaling in the mechanisms of optimal AEC2 proliferation and AEC2/1 trans-differentiation, 2) to address in vivo the role of AEC2-specific Nrf2 as a pro-survival and pro-regenerative mechanism after ALI, and 3) to test the postulate that Nrf2 activation will accelerate AEC repair post-injury. Hyperoxia is used widely in the treatment of pulmonary diseases (such as COPD and ARDS), but its effects on the repair lung alveolar epithelium in these patients are not clearly understood. Likewise, abnormal repair of lung alveolar epithelium caused by bacterial infection is a major health concern. Thus, the studies proposed are of major scientific and clinical importance to critically ill ALI/ARDS patients.

急性肺损伤（ALI）后肺泡上皮修复受损可导致炎症加剧 反应和组织修复通常不会解决。本应用中的研究将检验假设 损伤后肺修复受损是 2 型肺泡中 GSH/AKT 信号失衡的结果 上皮细胞 (AEC2) 受细胞保护和促生存转录因子 Nrf2 调节。我们 发现 Nrf2 的整体缺失会损害亚致死性促氧化剂（高氧）诱导后的肺修复 阿里。使用条件突变 Nrf2（“floxed”）小鼠模型来确定肺的贡献 常驻细胞对急性肺应激和修复的影响，我们发现肺上皮中 Nrf2 的缺失 以类似于在 Nrf2 缺失小鼠中观察到的方式损害 ALI 的解决，这表明 肺上皮 Nrf2 信号传导调节促缓解反应和肺修复。对此表示同意 结果，我们发现缺乏 Nrf2 的原代 AEC2（Nrf2-/-AEC2s）由于氧化而增殖不良 应激和 G2/M（非 G1/M）细胞周期停滞。有趣的是，减轻 Nrf2-/-AEC2 的氧化应激 外源性 N-乙酰半胱氨酸的作用，但未能挽救 G2/M 停滞。相比之下，外源GSH 减轻应激、激活 AKT 信号传导并恢复 Nrf2-/-AEC2 的增殖。初步 3D 细胞培养实验表明，AEC2 所形成的“肺泡球”尺寸减小 与室内空气小鼠相比，Nrf2+/+ 小鼠暴露于亚致死（48 小时）高氧环境。 AEC2 来自 暴露于室内空气或高氧的 Nrf2-/- 小鼠会变得混乱且数量减少 “肺泡球”。补充 GSH 的 Nrf2-/-AEC2 表现出改善的肺泡球形成， 但不是有效的 AEC2/1 转分化。在这个项目中，我们测试了 AEC2 特定的假设 Nrf2 调节的信号传导对于将平衡向最佳 GSH/AKT 倾斜至关重要。 依赖的 AEC2 增殖和不依赖 GSH/AKT 的 AEC2/1 转分化。我们将使用 多种方法对该假设进行机械检验，包括使用 AEC2-组织- 特定功能丧失（Nrf2-/-AEC2）和功能获得（Nrf2抑制剂Keap1-/-AEC2）小鼠模型和 小分子 Nrf2 激活剂。要追求的具体目标是： 1) 确定机制 以及 Nrf2 调节 GSH/AKT 介导的信号在最佳 AEC2 机制中的作用 增殖和 AEC2/1 转分化，2) 解决体内 AEC2 特异性 Nrf2 作为 ALI 后的促生存和促再生机制，以及 3) 测试 Nrf2 激活的假设 将加速 AEC 损伤后的修复。高氧治疗广泛用于肺病的治疗 疾病（如慢性阻塞性肺病（COPD）和急性呼吸窘迫综合征（ARDS）），但它对这些疾病中肺泡上皮修复的影响 患者并不清楚。同样，由以下原因引起的肺泡上皮的异常修复 细菌感染是一个主要的健康问题。因此，所提出的研究具有重大科学意义和 对重症 ALI/ARDS 患者的临床重要性。

项目成果

Replacement of a Naphthalene Scaffold in Kelch-like ECH-Associated Protein 1 (KEAP1)/Nuclear Factor (Erythroid-derived 2)-like 2 (NRF2) Inhibitors.

• DOI: 10.1021/acs.jmedchem.8b01133
• 发表时间: 2018-09-13
• 期刊: Journal of medicinal chemistry
• 影响因子: 7.3
• 作者: Richardson BG;Jain AD;Potteti HR;Lazzara PR;David BP;Tamatam CR;Choma E;Skowron K;Dye K;Siddiqui Z;Wang YT;Krunic A;Reddy SP;Moore TW
• 通讯作者: Moore TW

Nrf2 Regulates Anti-Inflammatory A20 Deubiquitinase Induction by LPS in Macrophages in Contextual Manner.

• DOI: 10.3390/antiox10060847
• 发表时间: 2021-05-26
• 期刊: Antioxidants (Basel, Switzerland)
• 作者: Potteti HR;Venkareddy LK;Noone PM;Ankireddy A;Tamatam CR;Mehta D;Tiruppathi C;Reddy SP
• 通讯作者: Reddy SP

Recent advances in dead cell clearance during acute lung injury and repair.

• DOI: 10.12703/r/10-33
• 发表时间: 2021
• 期刊: Faculty reviews
• 作者: Noone PM;Reddy SP
• 通讯作者: Reddy SP