LAMININ ALPHA CHAINS IN LUNG DEVELOPMENT AND DISEASE

尽管人们承认肺泡基底膜对正常是至关重要的 肺泡的结构和功能，目前关于肺泡的信息有限。 肺泡基底膜成分的细胞来源与调控 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。每个层粘连蛋白都是一种 由α、β和伽马链组成的杂三聚体。我们将重点关注 最近发现的层粘连蛋白α链、α3A、α3B、α4和 α5，在成年小鼠肺实质中比 Alpha1，层粘连蛋白-1中被广泛研究的阿尔法链。我们将定义 层粘连蛋白α链在小鼠肺组织中的细胞表达 发展。我们将确定层粘连蛋白α链在 用免疫电子显微镜观察肺泡壁。使用字母5“Knokout” 我们制造的小鼠，我们将确定层粘连蛋白α5的作用 对肺部发育的影响。我们将比较层粘连蛋白α5缺乏症与 层粘连蛋白β2缺乏症使用层粘连蛋白β2基因敲除的小鼠，我们 也有。在初步观察中，我们发现TGFbeta1和 KGF上调肺泡上皮细胞层粘连蛋白α5的表达。我们 将这些观察结果扩展到其他层粘连蛋白阿尔法链和其他 肺细胞类型。我们将使用共培养来确定 上皮-间充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α5的表达是通过 TGFbeta1和KGF是转录的，我们将表征 小鼠层粘连蛋白α5基因，包括启动子元件。我们会 实验性肺泡层粘连蛋白α链表达的测定 基底膜损伤及KGF是否影响基底膜成分的表达 在肺泡损伤模型中。我们将评估基底的表达。 使用试剂检测人类肺泡损伤中的膜成分 是专门为人体组织开发的。初步研究显示- 层粘连蛋白α5在人肺纤维化中的调节。我们相信 更好地了解肺泡基底膜生物学将导致 提高了监测和影响肺损伤和修复的能力 ARDS和特发性肺纤维化等情况。

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.