Fibroblast Cell Signaling in Utero Nicotine-Induced Lung Injury

描述(申请人提供)：孕妇在怀孕期间吸烟对胎儿发育中的肺造成广泛的影响，极大地损害其长期的功能和能力。这些效应背后的分子机制尚不清楚。由于正常的肺发育和损伤/修复都使用共同的肺泡上皮-间充质信号通路来维持内稳态，我们认为宫内尼古丁暴露扰乱了关键的内稳态上皮-间充质旁分泌信号通路，导致肺泡间质成纤维细胞(AIF)向肌成纤维细胞(MYF)的转分化。这种从AIF到MYF的转分化的特征是PPAR()信号通路下调和WINT(WINT)信号通路上调。尽管最近已经描述了宫内尼古丁暴露对PPAR(信号转导)的影响，但还没有关于它对发育中的肺中Wnt信号转导的影响的信息。我们假设，宫内尼古丁暴露上调AIF Wnt信号，通过特异性分子靶向下调Wnt信号和/或上调PPAR(信号转导)，可以预防甚至逆转宫内尼古丁所致的肺损伤。我们将利用成熟的体外和体内尼古丁诱导的宫内肺损伤模型，通过实时荧光RT-PCR、Western分析、免疫组织化学、激光捕获显微解剖、代谢组学、反义和过表达研究以及体内肺功能测试，确定(1)宫内尼古丁暴露如何改变肺发育，导致结构和功能改变，以及(2)PPAR激动剂和/或Wnt拮抗剂单独或联合应用是否可以预防和/或逆转围生期尼古丁暴露引起的PPAR(和/或Wnt)信号转导的改变，从而改善肺结构和功能。由于我们使用的范例和模型是基于肺泡腺泡的形成、建立和内稳态的通用发育模型，所产生的信息将不仅限于宫内尼古丁诱导的损伤，而且可能在总体上对肺发育和损伤/修复具有更大的适用性。因此，通过利用功能基因组学，本文提出的研究很可能转化为所有慢性肺部疾病的新颖和创新的分子预防和治疗方法。项目简介：孕妇在怀孕期间吸烟不仅在孕期和新生儿时期造成重大风险，而且还可能导致终生医疗并发症，包括破坏性的呼吸系统问题。母亲吸烟对肺部有害影响的潜在机制是复杂和不完全了解的。利用新颖的创新概念和最先进的技术，拟议的研究将揭开不仅是宫内烟雾暴露导致的肺损伤的机制，而且还包括几乎所有其他形式的慢性肺部疾病。

DESCRIPTION (provided by applicant): Maternal smoking during pregnancy causes a broad range of effects on the developing lung of the fetus that greatly impairs its long-term function and capacity. The molecular mechanisms underlying these effects are not known. Since both normal lung development and injury/repair utilize common alveolar epithelial-mesenchymal signaling pathways to maintain homeostasis, we propose that in utero nicotine exposure disrupts the critical homeostatic epithelial-mesenchymal paracrine signaling pathways, resulting in the transdifferentiation of alveolar intersitial fibroblasts (AIFs) to myofibroblasts (MYFs). This AIF-to-MYF transdifferentiation is characterized by down regulation of the Peroxisome Proliferator Activated Receptor gamma (PPAR() signaling pathway and up regulation of the Wingless/Int (Wnt) signaling pathway. Although the effects of in utero nicotine exposure on PPAR( signaling have recently been described, there is no information on its effect on the Wnt signaling in the developing lung. We hypothesize that in utero nicotine exposure up-regulates AIF Wnt signaling and that by specific molecular targeting to down regulate the Wnt signaling and/or up regulate the PPAR( signaling, in utero nicotine-induced lung injury can be prevented or even reversed. Using well established in vitro and in vivo models of in utero nicotine-induced lung injury, through real-time RT- PCR, Western analysis, immunohistochemistry, laser capture microdissection, metabolomics, antisense and over expression studies, and in vivo pulmonary function tests, we will determine (1) how in utero nicotine exposure alters lung development, resulting in altered structure and function, and (2) if PPAR( agonists and/or Wnt antagonists, either alone or in combination, can prevent and/or reverse perinatal nicotine exposure-induced alterations in PPAR( and Wnt signaling in lung mesenchyme, and hence lung structure and function. Since the paradigm and models used by us are based on a universal developmental model for the formation, establishment, and homeostasis of the alveolar acinus, the information generated will not be limited only to in utero nicotine-induced injury but is likely to have a much larger applicability to lung development and injury/repair in general. Therefore, by utilizing functional genomics, the studies proposed herein are likely to translate into novel and innovative molecular preventive and therapeutic approaches for all chronic lung diseases in general. PROJECT NARRATIVE: Maternal smoking during pregnancy poses significant risks not only during gestation and immediate newborn period, but may also results in life long medical complications including devastating respiratory problems. The mechanisms underlying the harmful effects of maternal smoking on the lung are complex and incompletely understood. Using novel and innovative concepts, and the state-of-the-art technology, the proposed studies will unravel mechanisms that underlie not only the in utero smoke exposure-induced lung injury, but also almost all other forms of chronic lung diseases.