EGF AND TGFA IN DEVELOPING AIRWAY EPITHELIUM

我们的目标是确定增长因素是否与 兔实质内气道发育和损伤反应的生理学研究 人类的肺。在未来，治疗的新生物学策略 新生儿肺部疾病可能涉及使用生长因子。精确 关于生长因子的合成和可获得性的信息 它们的受体可能有助于此类疗法的设计。这个 这个项目的重点是定义合成的细胞位置和 表皮生长因子(EGF)合成的变化，转化 肺组织中生长因子α和表皮生长因子受体的表达 支气管肺的发育和对损伤的扰动反应 发育不良(BPD)。将检验三个主要假设：(1)选择单元格 实质内传导气道的人群产生EGF， TGFα和EGF-R；(2)EGF或EGF-R的类似配体作用于 有助于发育(和修复)的自分泌或旁分泌效应 肺上皮细胞；(3)EGF的产生或生长的变化 EGF-R的因子配体可能发生在肺发育和BPD过程中。这些 假设将通过以下具体目标进行检验。(1)变更 肺组织中呼吸道上皮细胞的形态分化 发展将由光学和电子显微镜来定义。(2) 将使用敏感的免疫细胞化学(IC)来识别特定的 含有EGF、TGFα和EGF-R免疫反应的细胞类型自.以来 神经内分泌细胞可以摄取和储存多肽激素和EGF： 受体复合体在EGF结合后迅速内化和降解 单独不能确定合成(或缺乏合成)的位置 这些产品。(3)更直接的核酸原位测定法 将使用杂交组织化学(IHH)来鉴定细胞 EGF、TGFα和EGF-R的转录位点。单单IHH不能 确定目标信使核糖核酸被翻译和加工成肽。 因此，对多肽的mRNA和免疫反应性的鉴定 相同或形态相同(和表型)的多肽 定义的)细胞增加了该细胞合成 多肽产品。(4)由于EGF可能参与修复反应，因此 在BPD中将确定EGF、TGFα和EGF-R的合成部位 肺部。生长因子基因表达可能处于发育控制之下 和/或在对伤害的反应中改变，因此(5)相对 将确定EGF、TGFα和EGF-R基因表达的变化 通过对正常发育和正常发育过程中肺组织的定量杂交研究 每桶。(6)其他研究将确定该区域的位置和变化 其他有希望的生长相关多肽的合成。这些研究将 确定EGF的体内合成部位并提供体内证据 EGF在肺发育过程中的生理作用及其对 在BPD中发现受伤。

Our objective is to determine if growth factors can be related to the physiology of intraparenchymal airway development and response to injury in the human lung. In the future, new biologial strategies for the treatment of newborn lung disease may involve the use of growth factors. Precise information about the synthesis of growth factors and the availability of their receptors may contribute to the design of such therapies. The emphasis of this project is to define the cellular sites of synthesis and changes in the synthesis of epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha) and the EGF receptor (EGF-R) during lung development and the perturbed response to injury seen in bronchopulmonary dysplasia (BPD). Three major hypotheses will be tested: (1) select cell populations of the intraparenchymal conducting airways produce EGF, TGFalpha and EGF-R; (2) EGF, or a similar ligand for EGF-R, exerts autocrine or paracrine effects contributing to the development (and repair) of pulmonary epithelium; (3) changes in the production of EGF, or growth factor ligands for EGF-R, may occur during lung development and BPD. These hypotheses will be tested with the following specific aims. (1) Changes in the morphological differentiation of airway epithelium during lung development will be defined by light and electron microscopy. (2) Sensitive immunocytochemistry (IC) will be used to identify the specific cell types containing immunoreactive EGF, TGFalpha and EGF-R. Since neuroendocrine cells may uptake and store peptide hormones and the EGF: receptor complex is rapidly internalized and degraded after EGF binding, IC alone does not establish the sites of synthesis (or lack of synthesis) of these products. (3) The more direct method of nucleic acid in situ hybridization histochemistry (IHH) will be used to identify the cellular sites of transcription of EGF, TGFalpha and EGF-R mRNA. IHH alone does not establish that the target mRNA is translated and processed to the peptide. Hence, identification of both the mRNA for a peptide and the immunoreactive peptide in the same or morphologically identical (and phenotypically defined) cell increases the probability that this cell is synthesizing the peptide product. (4) Since EGF may be involved in the repair response, the sites of synthesis of EGF, TGFalpha and EGF-R will be identified in BPD lungs. Growth factor gene expression may be under developmental control and/or altered during the response to injury, therefore (5) relative changes in the gene expression of EGF, TGFalpha and EGF-R will be defined by quantitative hybridization studies of lung during normal development and BPD. (6) Additional studies will identify the sites of and changes in the synthesis of other promising growth-related peptides. These studies will determine the in vivo sites of EGF synthesis and provide in vivo evidence of a physiological role for EGF during lung development and the response to injury found in BPD.