Rejuvenation of the Lung

摘要 我们的总体目标是设计一种临床可翻译的策略来改善老年肺的功能。在这里我们 建议开发一种通过改变细胞外基质(ECM)-支架来恢复老年肺的活力的策略 细胞附着在其上，这会影响细胞的行为、器官结构和机械性能。我们有 有证据表明，老年小鼠的肺中几种层粘连蛋白的水平较低。另外，当人类的肺 在去细胞的老年小鼠肺中培养成纤维细胞，其层粘连蛋白α-4(Lama4)的表达 与在年轻的肺基质中培养时相比显著减少。他们也会改变他们的ECM基因 老年肺ECM暴露时的表达谱(与年轻ECM相比)。同样，正常的人类 肺上皮细胞在老年脱细胞肺上培养时表达较低水平的层粘连蛋白α-3。自.以来 ECM可以指导细胞行为，对年轻化战略产生影响的更全面的方式是 改变陈旧的“景观”，即将ECM重置为更年轻的状态。我们希望测试我们的中心假设 细胞介导的治疗可以用来补充已经衰退的基础支架成分 年龄，导致肺具有年轻肺的特性。在目标1中，我们将使用完整的脱细胞肺基质 (DLm)作为天然的基础支架，将被Lama3和/或 并预期人肺成纤维细胞的行为将与年轻时一样 体外培养的DLm。在目标2中，我们将测试改变肺ECM的可行性和机械性能。 体内转导Lama3/4的基质细胞作为细胞治疗衰老小鼠肺组织的实验研究如果成功，我们的工作 将提供关于老年和年轻肺基质如何影响肺成纤维细胞行为的见解，并将提供 临床前证据表明，细胞介导的治疗可以用来恢复老年肺的活力。ECM的概念 “重置”可能为治疗肺部衰老和肺部疾病开辟一条新的途径，以及 用于其他与衰老有关的器官和血管疾病。

ABSTRACT Our overall goal is to devise a clinically translatable strategy to improve the function of aged lungs. Here we propose to develop a strategy to rejuvenate old lungs by altering the extracellular matrix (ECM) - the scaffold on which cells adhere and that can affect cell behavior, organ structure and mechanical properties. We have evidence that the lungs of aged mice have lower levels of several laminins. In addition, when human lung fibroblasts are cultured in decellularized lungs of aged mice, their expression of laminin alpha-4 (Lama4) is significantly reduced compared to when they are cultured in young lung matrix. They also alter their ECM gene expression profile when exposed to the aged lung ECM (compared to young ECM). Similarly, normal human lung epithelial cells express lower levels of laminin alpha-3 when cultured on aged decellularized lungs. Since ECM can direct cell behavior, a more encompassing way to make an impact on rejuvenation strategies is to alter the aged “landscape”, i.e. reset the ECM to its younger state. We wish to test our central hypothesis that cell-mediated therapy can be used to replenish the foundational scaffold components that have declined with age, resulting in lungs with properties of younger lungs. In Aim 1, we will use intact, decellularized lung matrix (DLM) from aged mouse lungs as the natural foundational scaffolds that will be altered with Lama3 and/or Lama4-transfected stromal cells and anticipate that human lung fibroblasts will behave as they do in young DLM in vitro. In Aim 2, we will test the feasibility of altering the lung ECM and the mechanical properties of lungs of aged mice by using Lama3/4-transduced stromal cells in vivo as cell therapy. If successful, our work will provide insight into how aged versus young lung matrix affects lung fibroblast behavior and will provide preclinical evidence that cell-mediated therapy can be used to rejuvenate old lungs. The concept of an ECM “reset” could open the avenue to a new approach to treat lung aging and lung diseases in general, as well as for other organ and vascular diseases associated with aging.