Endogenous programmed alveolar turnover in adult lung

描述（由申请人提供）：我们的长期目标是解释 最近公认的生理程序的分子和细胞基础 成年哺乳动物肺部肺泡的周转（损失和再生）； 并且，利用这些信息来诱导疾病中肺泡的形成。成人时 小鼠，热量限制（CR）增加了个体肺泡的体积 减少肺泡数量和表面积而不改变肺容量。 CR 导致 72 小时内肺 DNA 减少 20%，至少部分原因是 细胞凋亡。重新喂养（RF）可以逆转这些结构和细胞的变化。 因此，成年哺乳动物具有内源性程序来 a) 消除肺泡和 肺泡壁细胞和 b) 引起肺泡壁细胞的复制和 肺泡再生。我们的假设是基因表达分析 在热量限制再喂食 (CR-RF) 诱导的细胞复制过程中 肺泡再生将识别负责的基因和信号通路 肺泡形成。为了检验我们的假设和我们的具体目标，使用成年小鼠 接受 CR-RF 的方法是： 1) 使用形态测量程序来检测 肺泡再生和肺泡壁细胞的复制，识别 复制肺泡壁细胞，并确定它们之间是否存在差异 复制开始时的细胞类型。 2) 评估肺基因表达 使用微阵列进行肺泡壁细胞复制和肺泡再生 技术。 3) 使用 Northern 分析 (N)、核糖核酸酶保护测定 (RPA) 和 蛋白质印迹 (W)，以确认肺部的微阵列结果。对于选定的 基因和信号通路，使用N、RPA或W来确定是否相同的CR-RF 诱导的基因表达发生在 a) 同一小鼠的其他器官中（较少 重要基因），或b）在其他三种模型中以肺特异性方式 肺泡形成。那些在肺泡形成过程中在肺中表达的基因 将考虑四种不同的肺泡形成模型之间的共享 最重要的是。 4) 操纵选定的基因和信号通路 在可能的情况下进行药理学，或通过敲除，并确定对 a) 的影响 CR-RF 诱导小鼠肺泡再生或 b) 对小鼠肺泡形成的影响 使用形态测定法随意饲喂未经治疗的成年野生型小鼠 程序。

DESCRIPTION (provided by applicant): Our long-term goal is to explicate the molecular and cellular basis for the recently recognized physiologic programmed turnover (loss and regeneration) of alveoli present in lungs of adult mammals; and, use this information to induce alveolus formation in disease. In adult mice, calorie restriction (CR) increases the volume of individual alveoli and diminishes alveolar number and surface area without altering lung volume. CR causes, within 72 h, a 20 percent decrease in lung DNA due, at least partly, to apoptosis. Refeeding (RF) reverses these architectural and cellular changes. Thus, adult mammals have endogenous programs to a) eliminate alveoli and alveolar wall cells and b) cause replication of alveolar wall cells and regeneration of alveoli. Our hypothesis is that an analysis of gene expression during calorie restriction-refeeding (CR-RF) induced cell replication and alveolar regeneration will identify genes and signal pathways responsible for alveolus formation. To test our hypothesis, our Specific Aims, using adult mice subjected to CR-RF, are: 1) Use morphometric procedures to detect the onset of alveolar regeneration and replication of alveolar wall cells, identify the replicating alveolar wall cells, and determine if there are differences among cell types in the onset of replication. 2) Assess lung gene expression during alveolar wall cell replication and alveolar regeneration using microarray technology. 3) Use Northern analysis (N), Rnase protection assay (RPA), and Western blotting (W), to confirm microarray results in the lung. For selected genes and signal pathways, use N, RPA, or W to determine if the same CR-RF induced gene expression occurs a) in other organs of the same mice (less important genes), or b) in a lung specific manner in three other models of alveolus formation. Those genes whose lung expression during alveolus formation is shared among four different models of alveolus formation will be considered most important. 4) Manipulate selected genes and signal pathways pharmacologically when possible, or by knockout, and determine the effect on a) CR-RF-induced alveolar regeneration in mice or b) on alveolus formation in adult otherwise untreated wild-type mice fed ad libitum using morphometric procedures.