The Role of Adenine Nucleotide Translocase in Mitochondrial Dysfunction Associated Senescence in Chronic Obstructive Pulmonary Disease (COPD)

项目总结 慢性阻塞性肺疾病(COPD)是美国第四大死因， 目前还没有显著改变疾病进展的治疗方法。香烟烟雾(CS)是主要的致病因素 在慢性阻塞性肺疾病中，这会导致线粒体功能障碍和活性氧(ROS)。肺泡上皮2型 细胞(AEC2)是正常肺内稳态(细胞更新)和上皮修复所必需的祖细胞。 CS损伤和慢性阻塞性肺疾病。线粒体功能障碍和细胞衰老是细胞周期停滞的一种状态 与COPD有关，可能会降低AEC2细胞的祖细胞功能和上皮修复。致使性 线粒体功能障碍对AEC2衰老及功能的影响 慢性阻塞性肺疾病的上皮修复仍然是主要的知识空白，并可能为 治疗方法的发展。这项提议的主要目标是确定线粒体如何 腺嘌呤核苷酸转移酶2(ANT2)介导的功能障碍参与细胞衰老和 慢性阻塞性肺疾病(COPD)中的异常上皮细胞修复腺嘌呤核苷酸转位酶 2(ANT2)是一种线粒体ATP转运蛋白，对细胞的新陈代谢和命运至关重要。我们已经证明了ANT2 COPD患者肺组织中基因表达减少及人类ANT2基因被敲除 支气管上皮细胞导致线粒体呼吸减少(Kliment等人，J Cell Sci2021)。我们的 初步数据显示，人类ANT2在COPD肺AEC2中特异性减少。击倒 在体外培养的上皮细胞中，ANT2导致p21和p16(衰老的标志物)增加。在小鼠CS模型中 在COPD中，肺泡上皮细胞ANT2的缺失导致肺破坏(肺气肿)增加 P21和p16在AEC2细胞中的表达，并增加ROS。该提案将决定ANT2如何防范 肺气肿对AEC2细胞ROS生成、线粒体代谢和衰老的调节作用 CS术后上皮修复。我们的研究将确定以下几点：1)检验以下假设 AEC2细胞中的ANT2通过增加ROS和DNA损伤反应(DDR)来推动衰老。2)测试 该假说认为ANT2的缺失改变了AEC2的代谢，降低了修复能力，从而促进了COPD。3) 为了验证ANT2的治疗性修复或去除衰老细胞可以预防 肺气肿。这项提议的结果将定义线粒体功能障碍和 ANT2缺失引起的糖酵解代谢转变会导致衰老和失调的上皮修复 在COPD的AEC2细胞中。ANT2是肺上皮细胞修复和衰老的主要调节因子 线粒体功能障碍提供了连接这些过程的关键知识，并将为这一发现提供信息 新的慢性阻塞性肺病治疗方法。

PROJECT SUMMARY Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death in the United States with no current therapies that significantly alter disease progression. Cigarette smoke (CS) is a major causative factor in COPD that results in mitochondrial dysfunction and reactive oxygen species (ROS). Alveolar epithelial type 2 cells (AEC2s) are essential progenitor cells for normal lung homeostasis (cell renewal) and epithelial repair after CS injury and in COPD. Mitochondrial dysfunction and cell senescence, a state of cell cycle arrest, have been implicated in COPD and may reduce AEC2 cell progenitor function and epithelial repair. The causative mechanisms and functional consequences of mitochondrial dysfunction on AEC2 senescence and epithelial repair in COPD remain major knowledge gaps and may provide new insights for the development of therapeutic approaches. The major goal of this proposal is to determine how mitochondrial dysfunction mediated by adenine nucleotide translocase 2 (ANT2) contributes to cellular senescence and abnormal epithelial cell repair in chronic obstructive pulmonary disease (COPD). Adenine nucleotide translocase 2 (ANT2) is a mitochondrial ATP transporter critical for cell metabolism and fate. We have shown that ANT2 gene expression is reduced in lung tissue from patients with COPD and that ANT2 knockdown in human bronchial epithelial cells results in reduced mitochondrial respiration (Kliment et al, J Cell Sci 2021). Our preliminary data show that human ANT2 is specifically reduced in AEC2s from COPD lungs. Knockdown of ANT2 in epithelial cells in vitro results in increased p21 and p16 (markers of senescence). In a mouse CS model of COPD, loss of ANT2 in alveolar epithelial cells results in enhanced lung destruction (emphysema), increased p21 and p16 in AEC2s, and increased ROS. This proposal will determine how ANT2 protects against emphysema by modulating ROS production, mitochondrial metabolism and senescence in AEC2 cells and epithelial repair after CS. Our study will determine the following: 1) To test the hypothesis that loss of ANT2 in AEC2 cells drives senescence by increasing ROS and the DNA damage response (DDR). 2) To test the hypothesis that loss of ANT2 shifts AEC2 metabolism and decreases repair capacity to promote COPD. 3) To test the hypothesis that therapeutic restoration of ANT2 or removal of senescent cells can protect against emphysema. The outcome of this proposal will define the mechanisms by which mitochondrial dysfunction and shifts towards glycolytic metabolism due to loss of ANT2 drives senescence and dysregulated epithelial repair in AEC2 cells in COPD. Elucidation of ANT2 as a major regulator of lung epithelial repair and senescence through mitochondrial dysfunction provides critical knowledge connecting these processes and will inform the discovery of new COPD therapies.