Accelerated Aging as a Cause of Chronic Lung Allograft Dysfunction

加速衰老是慢性同种异体肺移植功能障碍的原因

• 批准号: 10409672
• 负责人: JOHN GREENLAND
• 金额: --
• 依托单位: VETERANS AFFAIRS MED CTR SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10409672
• 关键词: Acute Lung Injury; Affect; Age; Aging; Allografting; Award; Biological Markers; Biopsy; Biopsy Specimen; Bronchiolitis; Cell Aging; Cells; Cessation of life; Characteristics; Chromosomes; Chronic; Clinical; Cohort Studies; Cox Models; Cox Proportional Hazards Models; DNA Methylation; DNA Repair; Data; Development; Diagnostic; Disease; Donor Selection; Donor person; Enrollment; Epigenetic Process; Epithelial; Epithelial Cells; Failure; Fibrosis; Fluorescent in Situ Hybridization; Functional disorder; Genes; Genetic Polymorphism; Genetic Risk; Genetic Variation; Genotype; Hand; Human; Immune; Immune response; Immunofluorescence Immunologic; Immunosuppression; Impairment; In Vitro; Inflammation; Injury; Intervention; Investigation; Lead; Length; Light; Linear Models; Link; Longitudinal cohort; Lung; Lung Transplantation; Lung diseases; Lymphocyte; Measurement; Measures; Mediating; Methylation; Molecular; Mus; Neurodegenerative Disorders; Nucleoproteins; Organ; Outcome; Pathogenesis; Pathologic; Pathway interactions; Perioperative; Peripheral; Peripheral Blood Mononuclear Cell; Phenotype; Plasma; Plasma Cells; Play; Prevalence; Proliferating; Pulmonary Inflammation; RNA; Rapid diagnostics; Rehabilitation therapy; Risk Assessment; Risk Factors; Role; Sampling; Solid; Telomere Shortening; Testing; Therapeutic Intervention; Time; Tissues; Transplant Recipients; Transplantation; Veterans; airway epithelium; airway regeneration; base; bisulfite sequencing; cell free DNA; cell injury; cell type; cohort; constriction; digital; epithelial stem cell; fibrotic lung disease; genetic variant; graft dysfunction; idiopathic pulmonary fibrosis; improved outcome; injured airway; innovation; insight; lung allograft; methylation pattern; mortality risk; mouse model; next generation; novel; novel marker; peripheral blood; post-transplant; prospective; recruit; response; stem cells; technology development; telomere; transcriptomics

Lung transplantation is a lifesaving option for veterans with end-stage lung diseases, in particular idiopathic pulmonary fibrosis (IPF). Veterans appear to be disproportionately affected by IPF, a disease that has been described as early aging of the lung. IPF is usually fatal unless the lungs are replaced by transplant. Even following lung transplantation median survival is less than six years, limited primarily by chronic lung allograft dysfunction (CLAD). Emerging data suggest that telomeres, the nucleoprotein caps that protect chromosomes during cellular replication, are involved in IPF, but it is unknown whether telomeres also play a role in CLAD. Were that to be the case, the same pathophysiology that necessitated transplant might also underlie its failure. Our own preliminary data show that impaired telomeres in peripheral blood of lung allograft donors are linked to decreased survival in lung allograft recipients. We also have found that telomere dysfunction in airway stem cells is sufficient to induce the pathologic hallmarks of CLAD in an experimental murine model. In humans, airway progenitor cells proliferate and differentiate to restore airway epithelial integrity following injury. Thus, telomere dysfunction could lead to airway epithelial cell progenitor failure, resulting in denuded airways that are subsequently replaced by fibrotic tissue. With the support of this Merit Award, we will test the innovative hypothesis that telomere dysfunction leads to CLAD. In Study Aim 1, we will evaluate the associations between telomere genetic variants and CLAD in a large established multi-center cohort of lung transplant recipients. Common genetic variants resulting in short telomeres will be sequenced from donor cells, and telomere length will be determined by quantitative PCR. We will use adjusted Cox proportional hazards models to evaluate the links between donor telomere length or genotype and post-transplant survival time. Novel genotypic associations with telomere dysfunction will be validated in vitro. These findings will help distinguish the contributions of innate and acquired telomere dysfunction to poor post-transplant outcomes. Study Aim 2 will test the association between short allograft epithelial cell telomeres and CLAD-free survival in a longitudinal cohort. Epithelial telomere lengths will be determined by fluorescence-in situ hybridization with a telomere-specific probe (Telo-FISH) on endobronchial and transbronchial biopsy tissues. We will test the association between telomere length and CLAD-free survival using adjusted Cox models and examine transcriptomic sequelae of telomere dysfunction. In Study Aim 3, we will determine whether airway epithelial cell injury is associated with allograft telomere shortening and epigenetic aging in a prospectively enrolled cohort of lung transplant recipients. Early allograft injury will be assessed clinically by the presence of primary graft dysfunction (PGD). We also quantify allograft epithelial cell injury from recipient plasma cell-free DNA using next-generation bisulfite sequencing to enumerate donor-specific polymorphisms and cell-type specific DNA methylation patterns. We will test for associations between PGD and cell-free DNA measurements of allograft injury with telomere-based and epigenetic metrics of allograft aging using adjusted linear models. These findings will shed light on the longstanding question of how acute lung injury and inflammation develop into chronic fibrosis. Further, these studies could establish that CLAD is an evoked phenotype in which telomere dysfunction leads to impaired epithelial responses to chronic transplant-associated airway injury. Overall, this proposed investigation has the potential to reshape our conceptual understanding of CLAD and lead to novel biomarkers that could inform cutting edge therapeutic interventions. This would be new paradigm, potentially transforming our approach CLAD and thus improving outcomes for veterans with end- stage lung disease.

肺移植是一种挽救生命的选择退伍军人与终末期肺部疾病，特别是特发性 肺纤维化（IPF）。退伍军人似乎不成比例地受到IPF的影响，IPF是一种 被描述为肺的早期老化。IPF通常是致命的，除非肺被移植替代。甚至 肺移植后的中位生存期少于6年，主要受慢性肺移植的限制。 功能障碍（CLAD）。新的数据表明，端粒，保护染色体的核蛋白帽， 在细胞复制过程中，参与IPF，但尚不清楚端粒是否也在CLAD中发挥作用。 如果是这样的话，同样的病理生理学，需要移植也可能是其失败的基础。 我们自己的初步数据表明，肺移植供体外周血中受损的端粒与 肺移植受者的存活率降低。我们还发现，气道干细胞中的端粒功能障碍 细胞足以在实验鼠模型中诱导CLAD的病理标志。在人类中， 气道祖细胞增殖并分化以恢复损伤后的气道上皮完整性。因此，在本发明中， 端粒功能障碍可导致气道上皮祖细胞衰竭，导致气道裸露， 随后被纤维化组织取代。在这次优异奖的支持下，我们将测试创新的 端粒功能障碍导致CLAD的假说。在研究目标1中，我们将评估 在一个大型的多中心肺移植队列中端粒遗传变异和CLAD之间的关系 受惠人士导致短端粒的常见遗传变异将从供体细胞中测序， 端粒长度将通过定量PCR测定。我们将使用调整后的考克斯比例风险 模型来评估供体端粒长度或基因型与移植后存活时间之间的联系。 新的基因型与端粒功能障碍的关联将在体外验证。这些发现将有助于 区分先天性和后天性端粒功能障碍对移植后不良结局的影响。 研究目标2将测试短的同种异体移植上皮细胞端粒和无CLAD存活之间的关系。 在纵向队列中。上皮细胞端粒长度将通过荧光原位杂交测定 使用端粒特异性探针（Telo-FISH）对支气管内和经支气管活检组织进行检测。我们将测试 使用调整后考克斯模型研究端粒长度和无CLAD生存率之间的关系， 端粒功能障碍的转录组学后遗症。在研究目标3中，我们将确定气道上皮细胞是否 在一项前瞻性招募的研究中， 肺移植受者队列。早期同种异体移植物损伤将在临床上通过原发性 移植物功能障碍（PGD）。我们还从受体浆细胞游离DNA定量了同种异体移植上皮细胞损伤 使用下一代亚硫酸氢盐测序来计数供体特异性多态性和细胞类型特异性 DNA甲基化模式。我们将测试PGD和细胞游离DNA测量之间的关联， 使用调整的线性模型，用基于端粒的和表观遗传学的同种异体移植物老化指标评估同种异体移植物损伤。 这些发现将阐明急性肺损伤和炎症如何发展的长期问题 变成慢性纤维化此外，这些研究可以确定CLAD是一种诱发表型，其中 端粒功能障碍导致上皮对慢性移植相关气道损伤的反应受损。 总的来说，这项拟议的调查有可能重塑我们对CLAD的概念性理解， 导致新的生物标志物，可以告知尖端的治疗干预。这将是新的 范式，可能会改变我们的方法CLAD，从而改善退伍军人与结束的结果， 阶段性肺病。