Fibroblast Cell Signaling in Utero Nicotine-Induced Lung Injury

描述（由申请人提供）：孕妇在怀孕期间吸烟会对胎儿肺部发育产生广泛的影响，严重损害其长期功能和能力。这些作用背后的分子机制尚不清楚。由于正常的肺发育和损伤/修复都利用常见的肺泡上皮-间充质信号通路来维持内环境平衡，我们提出在子宫内尼古丁暴露会破坏关键的内环境平衡上皮-间充质旁分泌信号通路，导致肺泡间质成纤维细胞（AIFs）向肌成纤维细胞（MYFs）的转分化。这种AIF-to-MYF转分化的特征是下调过氧化物酶体增殖物激活受体γ (PPAR)信号通路和上调无翼/Int （Wnt）信号通路。虽然子宫内尼古丁暴露对PPAR信号传导的影响最近已经被描述，但没有关于其对发育中的肺中Wnt信号传导的影响的信息。我们推测，在子宫内尼古丁暴露可上调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，可预防甚至逆转子宫内尼古丁诱导的肺损伤。利用成熟的体外和体内模型，通过实时RT- PCR， Western分析，免疫组织化学，激光捕获显微解剖，代谢组学，反意义和过表达研究，以及体内肺功能测试，我们将确定(1)子宫内尼古丁暴露如何改变肺发育，导致结构和功能的改变，以及(2)PPAR(激动剂和/或Wnt拮抗剂，无论是单独使用还是联合使用，可以预防和/或逆转围产期尼古丁暴露引起的肺间质PPAR(和Wnt信号传导的改变，从而影响肺结构和功能。由于我们使用的范式和模型是基于肺泡腺泡形成、建立和稳态的通用发育模型，因此产生的信息将不仅限于子宫内尼古丁诱导的损伤，而且可能对肺部发育和损伤/修复具有更大的适用性。因此，通过利用功能基因组学，本文提出的研究有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。项目说明：孕妇在怀孕期间吸烟不仅在怀孕期间和刚出生时造成重大风险，而且还可能导致终生的医疗并发症，包括毁灭性的呼吸问题。母亲吸烟对肺部有害影响的潜在机制是复杂的，尚未完全了解。利用新颖和创新的概念，以及最先进的技术，拟议的研究将揭示不仅在子宫内烟雾暴露引起的肺损伤，而且几乎所有其他形式的慢性肺部疾病的机制。

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.