Prolyl Endopeptidase-Mediated Matrix Remodeling and Inflammation in COPD

描述（由申请人提供）： 新描述的胶原片段脯氨酸-甘氨酸-脯氨酸（PGP）驱动慢性嗜酸性炎症反应，似乎在COPD发病机制中发挥作用。脯氨酰内肽酶（PE）是一种特别重要的丝氨酸蛋白酶，因为它已被证明催化从胶原蛋白产生PGP所需的蛋白水解级联中的最后一步。因此，PE似乎是未来COPD相关治疗的一个非常有吸引力的新靶点。然而，由于认识到PE在慢性炎症中的作用是如此之新，在肺部疾病的背景下，这种蛋白酶的调节的某些基本方面仍然知之甚少。本修订提案将通过强调PI实验室的新证据来填补这一知识空白，这些新证据证明PE通过外泌体从气道上皮细胞释放。本申请集中于香烟烟雾（CS）暴露和COPD中PE表达和PGP产生的独特前馈途径，特别强调内源性CXCR配体信号传导。本提案中的目标在主题上相互关联（通过高质量的体外、体内模型和离体临床标本），并经过精心设计，以提高我们对该途径及其与COPD肺部疾病相关性的理解。具体目标1a将通过CXC配体检查PE从原代气道上皮细胞的调节和释放，突出显示PE通过外泌体释放的潜力，鉴定参与释放的细胞内途径，并确定这种释放对胶原蛋白离体产生PGP的影响。具体目标1b将确定香烟烟雾（CS）对PE和PGP产生的调节的影响，用新型治疗化合物特异性靶向CXC受体和PE。该资助的第二个目的将集中在PE抑制作为慢性CS COPD模型的治疗方法。这将利用PE的遗传缺失（PREP-/-小鼠）来检查，以检查慢性CS暴露是否改善了观察到的炎症反应和表型。该模型还将在测试一种新的PE抑制剂S- 17092时进行检查，该抑制剂目前正处于神经退行性疾病的临床试验中，作为该COPD肺病模型中的主要抗炎治疗药物。最终目标将涉及通过支气管镜检查从COPD患者中收集临床生物样本，以确定与无肺部疾病的个体相比是否存在富含PE的外泌体和PGP肽。这些目标的成功完成将导致增加对PE在细胞外环境中的调节和释放以及其不受约束的蛋白酶活性的下游效应的理解。在这样做的过程中，这些研究可能会导致COPD的新生物标志物和治疗靶点的开发。

DESCRIPTION (provided by applicant): The newly described collagen fragment proline-glycine-proline (PGP) drives chronic neutrophilic inflammatory responses and appears to play a role in COPD pathogenesis. Prolyl endopeptidase (PE) is a particularly important serine protease because it has been shown to catalyze the final step in a proteolytic cascade required to generate PGP from collagen. Consequently, PE would seem to represent a very attractive new target for future therapeutics related to COPD. However because recognition of the role of PE in chronic inflammation is so new, certain fundamental aspects of the regulation of this protease in the context of lung disease remains poorly understood. This revised proposal will fill in this void of knowledge by highlighting new evidence from the PI's laboratory demonstrating that PE is released from airway epithelial cells via exosomes. This application focuses on a unique feed-forward pathway of PE expression and PGP generation in cigarette smoke (CS) exposure and COPD with particular emphasis on endogenous CXCR ligand signaling. The aims in this proposal are thematically linked to each other (through high quality in vitro, in vivo models and ex vivo clinicl specimens) and are carefully crafted to improve our understanding of this pathway and its relevance to COPD lung disease. Specific aim 1a will examine the regulation and release of PE from primary airway epithelial cells by CXC ligands, highlighting the potential of PE release via exosomes, identifying the intracellular pathways involved in the release, and determining the impact of this release on ex vivo PGP generation from collagen. Specific aim 1b will determine the impact of cigarette smoke (CS) on the regulation of PE and PGP production, with specific targeting of CXC receptors and PE with novel therapeutic compounds. The second aim of this grant will focus on PE inhibition as a therapeutic approach in a chronic CS model of COPD. This will be examined utilizing a genetic deletion of PE (the PREP-/- mouse) to examine if there is amelioration of the observed inflammatory response and phenotype with chronic CS exposure. This model will also be examined in testing a new PE inhibitor S- 17092, currently in clinical trials for neurodegenerative disease, as a lead anti-inflammatory therapeutic in this model of COPD lung disease. The final aim will involve the collection of clinical biospecimens via bronchoscopy from patients with COPD to determine the presence of PE-rich exosomes and PGP peptides compared to individuals without lung disease. The successful completion of these aims will lead to an increased understanding of the regulation and release of PE in the extracellular environment and the downstream effects of its unfettered protease activity. In doing so, these studies may result in the development of a new biomarker and therapeutic target for COPD.