PPAR gamma Signaling and Lung Fibroblast Transdifferentiation

描述（由申请方提供）：异常损伤/修复伴肺泡化截断是“新型支气管肺发育不良（BPD）"的主要组织病理学标志。 我们最近提出，破坏正常的稳态上皮-间充质通信，以及随之而来的肺泡间质成纤维细胞（AIF）到肌成纤维细胞（MYF）的转分化，是其病理生物学的关键事件。 参与这一过程的具体分子机制仍不完全确定。本提案的目的是使用体内和体外模型确定BPD中涉及的特定分子机制，特别是过氧化物酶体激活受体（PPAR）信号传导在高氧诱导的大鼠肺AIF至MYF转分化中的作用，并确定新的分子预防和治疗方法的有效性。 在特定目标1中，使用激光捕获显微切割、形态测定、免疫组织化学、真实的时间PCR、北方和西方分析，我们将在体内新生大鼠模型中确定PPAR激动剂如何预防和/或治疗高氧诱导的AIF至MYF转分化。 在特定目标2中，使用真实的时间-PCR、北方和西方分析、代谢组学、反义和体外转染研究，针对甲状旁腺激素相关蛋白受体、过氧化物酶体增殖物激活受体、C/增强子结合蛋白和脂肪细胞分化相关蛋白的mRNA表达，以及相应蛋白的差异表达和磷酸化，我们将确定参与AIF向MYF转分化的机制。 我们还将确定如何通过有效的PPAR配体如罗格列酮和GW 7845刺激脂肪生成途径来预防或逆转AIF向MYF的转分化。 这项提议除了为BPD的病理生物学提供新的见解外，还具有巨大的潜力，可以开辟新的干预策略来解决一般的慢性肺部疾病，特别是BPD。 事实上，使用功能基因组方法，在我们的建议中采用，即，诱导脂肪生成转录因子，不仅可以预防，而且还可以逆转已建立的慢性肺病。 该提案提出的概念新颖、创新，脱离了传统的氧致肺损伤的范式，可能比单纯理解氧致肺损伤具有更广泛的意义。

DESCRIPTION (provided by applicant): Abnormal injury/repair, with truncation of alveolarization, is the major histopathological hallmark of "The New Bronchopulmonary Dysplasia (BPD)". We have recently proposed that disrupting normal homeostatic epithelial-mesenchymal communications, and the consequent alveolar interstitial fibroblast (AIF)-to-myofibroblast (MYF) transdifferentiation, are the key events in its pathobiology. The specific molecular mechanisms involved in this process remain incompletely defined. The objective of this proposal is to determine the specific molecular mechanisms involved in BPD, particularly the role of Peroxisome Proliferator Activated Receptor (PPAR) signaling in hyperoxia-induced rat lung AIF-to-MYF transdifferentiation, using both in vivo and in vitro models and to determine the effectiveness of a novel molecular preventive and therapeutic approach. In Specific Aim 1, using Laser Capture Microdissection, Morphometry, Immunohistochemistry, Real Time-PCR, Northern, and Western analyses, we will determine, in an in vivo neonatal rat model, how PPAR agonists prevent and/or treat hyperoxia-induced AIF-to-MYF transdifferentiation. In Specific Aim 2, using Real Time -PCR, Northern and Western analyses, Metabolomics, Antisense, and Transfection in vitro studies, for the mRNA expression of Parathyroid Hormone-related Protein Receptor, PPAR, C/Enhancer Binding Protein, and Adipocyte Differentiation Related Protein, coupled with the differential expression and phosphorylation of the corresponding proteins, we will determine the mechanism involved in AIF-to-MYF transdifferentiation. We will also determine how AIF-to-MYF transdifferentiation can be prevented or reversed by stimulating the lipogenic pathway through potent PPAR ligands such as rosiglitazone and GW7845. This proposal, in addition to providing new insights into the pathobiology of BPD, has enormous potential for opening up novel interventional strategies to tackle chronic lung disease in general, and BPD in particular. In fact, using the functional genomic approach, adopted in our proposal, i.e., inducing lipogenic transcription factors, may not only prevent, but may also reverse established chronic lung disease. The concept put forward in this proposal is novel, innovative, and departs from the traditional paradigm of oxygen-induced lung damage, and may have much wider implications than simply understanding oxygen-induced lung injury.