LAMININ ALPHA CHAINS IN LUNG DEVELOPMENT AND DISEASE

尽管公认肺泡基底膜对正常的 肺泡的结构和功能，有有限的信息， 肺泡基底膜成分的细胞来源和调节 或关于肺泡细胞对肺泡基底膜损伤的反应。 层粘连蛋白是基底膜的主要成分。每个层粘连蛋白是 由α、β和γ链组成的异源三聚体。我们将专注于 最近鉴定的层粘连蛋白α链，α 3A，α 3B，α 4，和 α 5，其在成年小鼠肺实质中比 alpha 1，研究较多的层粘连蛋白-1中的α链。我们将定义 层粘连蛋白α链在小鼠肺中的细胞表达 发展我们将确定层粘连蛋白α链在 肺泡壁的免疫电镜观察。使用alpha 5“敲除” 我们已经制造了小鼠，我们将确定层粘连蛋白α 5 对肺部发育的影响我们将比较层粘连蛋白α 5缺乏症与 使用层粘连蛋白β 2“敲除”小鼠， 也有。在初步观察中，我们发现TGF β 1和 KGF上调肺泡上皮细胞层粘连蛋白α 5的表达我们 将这些观察扩展到其他层粘连蛋白α链和其他 肺细胞类型。我们将使用共培养来确定 上皮-间质相互作用对层粘连蛋白α链表达的影响。 因为我们假设层粘连蛋白α 5表达的调节是由 TGF β 1和KGF是转录的，我们将表征TGF β 1和KGF的5'端。 小鼠层粘连蛋白α 5基因，包括启动子元件。我们将 测定实验肺泡中层粘连蛋白α链的表达 KGF是否影响基底膜成分的表达 在肺泡损伤的模型中。我们将评估地下室的表达 膜组件在人类肺泡损伤使用的试剂，我们是 专为人体组织而生初步研究显示- 层粘连蛋白α 5在人肺纤维化中的调节。我们认为 更好地了解肺泡基底膜生物学将导致 提高监测和影响肺损伤和修复的能力， 例如ARDS和特发性肺纤维化。

Despite acceptance that alveolar basement membranes are critical to normal alveolar structure and function, there is limited information about the cellular sources and regulation of alveolar basement membrane components or about alveolar cell responses to alveolar basement membrane damage. Laminins are major components of basement membranes. Each laminin is a heterotrimer composed of an alpha, beta, and gamma chain. We will focus on recently-identified laminin alpha chains, alpha3A, alpha3B, alpha4, and alpha5, which are more prominent in adult mouse lung parenchyma than alpha1, the alpha chain in the much studied laminin-1. We will define the cellular expression of laminin alpha chains in lung through mouse development. We will determine the distribution of laminin alpha chains in alveolar walls using immunoelectron microscopy. Using alpha5 "knockout" mice, which we have made, we will determine the effect of laminin alpha5 on lung development. We will compare laminin alpha5-deficiency with laminin beta2-deficiency using laminin beta2 "knockout" mice, which we also have. In preliminary observations, we have found that TGFbeta1 and KGF up-regulate laminin alpha5 expression by alveolar epithelial cells. We will extend these observations to other laminin alpha chains and other lung cell types. We will use co-cultures to determine the effects of epithelial-mesenchymal interactions on laminin alpha chain expression. Because we hypothesize that the regulation of laminin alpha5 expression by TGFbeta1 and KGF is transcriptional, we will characterize the 5' end of the mouse laminin alpha 5 gene, including the promoter elements. We will determine the expression of laminin alpha chains in experimental alveolar damage and whether KGF affects expression of basement membrane components in models of alveolar damage. We will assess expression of basement membrane components in human alveolar damage using reagents we are developing specifically for human tissue. Preliminary studies show up- regulation of laminin alpha5 in human pulmonary fibrosis. We believe that better understanding of alveolar basement membrane biology will lead to improved capacity to monitor and influence lung damage and repair in conditions such as ARDS and idiopathic pulmonary fibrosis.