Bronchioalveolar Stem Cells Contribute to Alveolar Repair in Emphysema

描述(申请人提供)：慢性阻塞性肺病是一个日益严重的世界性问题。到目前为止，大多数研究都集中在空域发炎和破坏的机制上。人们一直认为修复是不够的，但修复的机制，特别是细胞修复，还没有得到解决。这项建议将支持首席研究员对最近描述的肺中成体干细胞群体的研究，该群体被称为细支气管肺泡干细胞(BASCs)。BASCs同时具有呼吸道和肺泡上皮细胞的特性。已有研究表明，它们在呼吸道和肺泡细胞损伤模型中增殖，并可能有助于呼吸道和肺泡的修复。我们的总体假设是，BASCs对肺泡的维持是必不可少的，而BASCs修复吸烟者受损的肺泡会导致肺气肿。此外，BASCs使用其MMPs，特别是MMP9，重新填充肺泡上皮和基底膜，以解决这一假说，我们建议：(1)应用标记BA$Cs的转基因谱系来解决BASCs在肺气肿模型中迁移到肺泡腔而不是肺泡I型和II型细胞的假说。我们将使用我们实验室培育的谱系标记小鼠(CC10-CreXRosa 26报告小鼠)来评估BASC对实质中两种细胞类型的贡献。(2)建立BASC转基因系消融小鼠，评价BASC促进肺泡结构修复的能力。我们将通过产生一只转基因的cc10-CreXSPCLox-Stop-Lox-TK小鼠来产生一只BASC缺陷小鼠，在其中BASCs(CC-10+和SPC+)将用更昔洛韦处理特异性地缺失。(3)探讨基质金属蛋白酶-9在肺气肿模型基底细胞迁移和肺泡维持中的作用。我们将使用野生型和基质金属蛋白酶-9缺陷的小鼠(在我们实验室中产生)和从它们分离的基底细胞来评估基质金属蛋白酶-9在基底细胞迁移中的作用。职业目标：这项提议和授课学习将使P.I.发展专业和技术技能，成为一名多产的独立科学家。肺干细胞生物学和肺气肿修复的科学重点代表了对公共健康具有重要意义的长期职业重点。值得注意的是，学习如何创造新的转基因工具将对肺科学界特别重要。相关性(见说明)：慢性阻塞性肺病是一种由长期吸入香烟烟雾引起的疾病，这种疾病在全球流行，预计到2020年将成为第三大死亡原因。到目前为止，我们还没有将我们对发病机制的理解转化为疾病修正疗法的发展。此外，关闭炎症和破坏性的过程只能防止肺进一步恶化，但不能恢复肺功能。为了恢复肺功能，我们讨论了肺气肿的修复过程及其失败的基础。(摘要结束)

DESCRIPTION (provided by applicant): COPD Is a growing problem worldwide. Most research to date has focused on the mechanisms of airspace inflammation and destruction. It has been presumed that repair is insufficient, but the mechanisms of repair, particularly cellular repair, have not been addressed. This proposal will support the Principle Investigator in the study of a recently described population of adult stem cells in the lung termed bronchioalveolar stem cells (BASCs). BASCs possess properties of both airway and alveolar epithelial cells. They have been shown to proliferate in airway and alveolar cell injury models and may contribute to both airway and alveolar repair. Our overall hypothesis is that BASCs are essential for alveolar maintenance and failure of BASCs to repair damaged alveoli in smokers contributes to emphysema. Moreover, BASCs use their repertoire of MMPs, particularly MMP-9, to repopulate the alveolar epithelium and basement membrane To address this hypotheses we propose to: (1) Apply transgenic lineage tagged BA$Cs to address the hypothesis that BASCs migrate into the alveolar space replacing alveolar type I and II cells in models of emphysema. We will use lineage tagged mice (CC10-CreXRosa 26 reporter mice) developed in our lab to evaluate BASC contribution to both cells types in the parenchyma. (2) Generate transgenic BASC lineage ablated mice to evaluate BASC ability to promote alveolar structural repair. We will generate a BASC deficient mouse by generating a transgenic CC10-CreXSPCLox-STOP-Lox-TK mouse in which BASCs, (that are CC-10+ and SPC+), will be specifically deleted with gancyclovir treatment. (3) Evaluate the role that MMP-9 plays in BASC migration and alveolar maintenance in models of emphysema. We will use wild type and MMP-9 deficient mice (generated in our lab) and BASC cells isolated from them to evaluate the role of MMP-9 in migration of BASC cells. Career Goals: This proposal and didactic learning will allow the P.I. to develop professional and technical skills to become a productive independent scientist. The scientific focus of lung stem cell biology and repair in emphysema represents a long-term career focus of significant importance to public health. Of note, learning how to create new transgenic tools will be of particular importance to the lung scientific community. RELEVANCE (See Instructions): COPD is a disease caused by the chronic inhalation of cigarette smoke which is epidemic worldwide, and predicted to be 3rd leading cause of death by 2020. To date, we have yet to translate our understanding of the pathogenesis into the development of disease modifying therapy. In addition, turning off the inflammatory, destructive processes can only prevent further lung deterioration but not restore lung function. In order to restore lung function, we address the process of repair and the basis for its failure in emphysema. (End of Abstract)