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: 10196968
• 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/10196968
• 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 Inflammation; 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; 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; genetic variant; 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.

对于患有终末期肺病，特别是特发性肺病的退伍军人来说，肺移植是一种挽救生命的选择 肺纤维化（IPF）。退伍军人似乎不成比例地受到 IPF 的影响，这种疾病已被 被描述为肺部的早期老化。除非通过移植替代肺部，否则 IPF 通常是致命的。甚至 肺移植后的中位生存期不到六年，主要受到慢性同种异体肺移植的限制 功能障碍（CLAD）。新数据表明，端粒是保护染色体的核蛋白帽 在细胞复制过程中，端粒参与 IPF，但尚不清楚端粒是否也在 CLAD 中发挥作用。 如果情况确实如此，那么移植失败的病理生理学也可能是其失败的原因。 我们自己的初步数据表明，同种异体肺移植供者外周血中端粒受损是相关的 降低肺同种异体移植受者的存活率。我们还发现气道干端粒功能障碍 细胞足以在实验小鼠模型中诱导 CLAD 的病理特征。在人类中， 气道祖细胞增殖和分化以恢复损伤后气道上皮的完整性。因此， 端粒功能障碍可能导致气道上皮细胞祖细胞衰竭，导致气道裸露， 随后被纤维化组织取代。在这个优异奖的支持下，我们将测试创新 端粒功能障碍导致 CLAD 的假设。在研究目标 1 中，我们将评估这些关联 在大型多中心肺移植队列中端粒遗传变异与 CLAD 之间的关系 收件人。导致端粒短的常见遗传变异将从供体细胞中进行测序，并且 端粒长度将通过定量PCR确定。我们将使用调整后的 Cox 比例风险 评估供体端粒长度或基因型与移植后存活时间之间联系的模型。 与端粒功能障碍的新基因型关联将在体外得到验证。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果的影响。 研究目标 2 将测试短同种异体移植上皮细胞端粒与无 CLAD 生存之间的关联 在纵向队列中。上皮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 使用调整后的 Cox 模型研究端粒长度与无 CLAD 生存率之间的关联并检查 端粒功能障碍的转录组后遗症。在研究目标 3 中，我们将确定气道上皮是否 在前瞻性入组的研究中，细胞损伤与同种异体移植端粒缩短和表观遗传衰老有关 肺移植受者队列。早期同种异体移植损伤将通过原发性损伤的存在进行临床评估 移植物功能障碍（PGD）。我们还量化了受体血浆游离 DNA 对同种异体移植物上皮细胞的损伤 使用下一代亚硫酸氢盐测序来枚举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 和游离 DNA 测量之间的关联 使用调整后的线性模型，利用基于端粒和同种异体移植老化表观遗传指标的同种异体移植损伤。 这些发现将揭示急性肺损伤和炎症如何发展这一长期存在的问题 进入慢性纤维化。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细胞对慢性移植相关气道损伤的反应受损。 总体而言，这项拟议的研究有可能重塑我们对 CLAD 和 产生可为尖端治疗干预措施提供信息的新型生物标志物。这将是新的 范式，有可能改变我们的方法 CLAD，从而改善退伍军人的最终结果 阶段性肺部疾病。