FGF-7 (KGF) AND RECEPTORS IN LUNG MORPHOGENESIS AND REPAIR

这个项目是基于观察到的对 成纤维细胞生长因子受体-2-角质形成细胞生长因子 肺中的胰岛素样生长因子(KGF)轴导致严重的分支异常 胎鼠发育过程中的形态发生和肺生长。新生儿 表达显性阴性FGFR-2(FGFR-2dn)的转基因小鼠 原始肺上皮显示严重的肺发育不良 而在发育过程中高水平表达KGF的转基因小鼠 肺死于宫内，伴有大量的呼吸道扩张和肺泡紊乱 队形。这个项目的研究是基于这样一个假设 KGF的表达需要精确的时间/空间调节 用于氧气损伤后肺的成功发育和修复。 KGF在肺内的表达定位将在 胎鼠、新生小鼠和成年小鼠的原位杂交。离体 并利用体内模型来建立控制机制 肺组织特异性KGF基因的表达。KGF的表观遗传调控 表达将使用体外细胞培养模型来确定， 瞬时转染法和转基因小鼠模型。体能 将确定小鼠KGF基因的结构，以便 识别介导KGF表达的顺式和反式活性因子 在肺里。氧对KGF表达的调控机制 新生动物和成年动物的损伤将被识别。转基因 在对照条件下表达嵌合四环素反式激活子的小鼠 将使用SP-C启动子的时间来控制表达 KGF或FGFR-2dn在肺中的表达，从而调节KGF/FGFR-2轴 在整个发展过程中。形态测量和生理学研究将 补充分析小鼠肺组织结构和细胞成分 转基因诱导的背景。这些研究将确定地点 和KGF在肺组织中表达的基础，并测定 与异常的KGF相关的有害和有益的后果 在发育和损伤过程中的表达。与人类疾病的相关性 可能与KGF异常表达相关的状态，如 囊腺瘤样畸形和支气管肺发育不良将促进 对其发病机制的理解和创新的机会 治疗方法。

This project is based upon the observation that disruption of the fibroblast growth factor receptor-2 (FGFR-2)-keratinocyte growth factor (KGF) axis in the lung produces profound abnormalities of branching morphogenesis and lung growth during fetal mouse development. Newborn transgenic mice expressing a dominant negative FGFR-2 (FGFR-2dn) in the primordial pulmonary epithelium display severe pulmonary hypoplasia while transgenic mice expressing high levels of KGF in the developing lung die in utero with massive airway dilatation and disordered alveolar formation. Studies in this project are based upon the hypothesis that the precise temporal/spatial regulation of KGF expression is required for successful lung development and repair following oxygen injury. Localization of KGF expression within the lung will be determined in the fetal, neonatal and adult mouse using in situ hybridization. In vitro and in vivo models are used to establish the mechanisms controlling specific pulmonary KGF mRNA expression. Epigenetic controls of KGF expression will be determined using in vitro cell culture models, transient transfection assays, and transgenic mouse models. The physical structure of the murine KGF locus will be determined in order to identify the cis and trans active factors that mediate KGF expression in the lung. Mechanisms of modulation of KGF expression following oxygen injury in the newborn and adult animal will be identified. Transgenic mice expressing a chimeric tetracycline transactivator under the control of the SP-C promoter will be used to temporally control the expression of KGF or FGFR-2dn in the lung, thus modulating the KGF/FGFR-2 axis throughout development. Morphometric and physiologic studies will complement an analysis of lung structure and cellular composition in the context of transgene induction. These studies will define the location and basis for expression of KGF in the lung and determine the consequences, detrimental and beneficial, associated with aberrant KGF expression during development and injury. Correlation with human disease states likely to be associated with aberrant KGF expression such as cystadenomatoid malformation and bronchopulmonary dysplasia will promote understanding of their pathogenesis and opportunities for novel therapeutic approaches.