Endogenous programmed alveolar turnover in adult lung

描述(由申请人提供)：我们的长期目标是阐明 新近发现的生理学程序化的分子和细胞基础 成年哺乳动物肺泡的周转(丢失和再生)； 并且，利用这些信息在疾病中诱导肺泡的形成。在成人中 小鼠，热量限制(CR)增加了单个肺泡的体积和 减少肺泡数和表面积，而不改变肺体积。Cr 在72小时内导致肺DNA下降20%，至少部分原因是 细胞凋亡。再摄食(RF)逆转了这些结构和细胞的变化。 因此，成年哺乳动物有内源性程序来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，对基因表达的分析 在卡路里限制-再喂养(CR-RF)诱导的细胞复制和 肺泡再生将确定负责的基因和信号通路 肺泡形成。为了验证我们的假设，我们的特定目标，使用成年小鼠 接受CR-RF，有：1)使用形态计量学程序检测发病 肺泡壁细胞的再生和复制，鉴定 复制肺泡壁细胞，并确定 细胞类型在复制的开始。2)评估肺基因的表达 利用微阵列技术进行肺泡壁细胞复制和肺泡再生 技术3)使用Northern分析(N)、核糖核酸酶保护试验(RPA)，以及 Western blotting(W)，以确认肺中的微阵列结果。对于选定的 基因和信号通路，使用N、RPA或W来确定相同的CR-RF 诱导基因表达发生在同一小鼠的其他器官中(较少 重要基因)，或者b)在其他三个模型中以肺特有的方式 肺泡形成。肺泡形成过程中肺组织表达的基因 将考虑在四种不同的肺泡形成模型中共享 最重要的是。4)操纵选定的基因和信号通路 药理上，如果可能，或通过基因敲除，并确定对一个) CR-RF诱导小鼠肺泡再生或b)诱导小鼠肺泡形成 用形态计量学方法随机喂食未处理的成年野生型小鼠 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.