PPAR gamma as a therapeutic target in COPD

描述（由申请人提供）：需要更好地了解导致COPD发病的机制，以及治疗干预的新靶点。过氧化物酶体增殖激活受体（PPAR） ？已被证明能够调节多个器官的炎症反应。PPAR吗?thaizoladinediones （TZDs）是FDA批准的活性配体。PPAR的监管？使用这些药物的活动与炎症性肺病动物模型的发病率降低有关。然而，该分子在肺上皮细胞和COPD中的重要性尚未确定。我们发现PPAR？在人类COPD组织和吸烟者的上皮细胞中。肺上皮细胞中PPAR？可以调节与肺组织重塑相关的基因。我们之前曾报道过PPAR？特别是在上皮细胞内导致肺成熟缺陷，从而导致小鼠肺结构和功能的变化。在这里，我们提供的数据表明小鼠肺上皮细胞PPAR？同时也表现出长期暴露于香烟烟雾中对肺气肿的易感性增加。这与炎性巨噬细胞（肺气肿发病的关键效应细胞）的积累增加和肺趋化因子基因表达增加有关。我们提出的初步数据表明，激活PPAR？在慢性阻塞性肺病临床前模型中，在小鼠中使用TZDs可降低吸烟相关炎症和趋化因子表达，以及关键的细胞和分子中间表型。在体内，上皮细胞对PPAR？暴露于香烟烟雾中会增加PPAR？表达，支持上皮细胞PPAR？调节烟雾引起的炎症。总的来说，这些数据支持PPAR的作用。作为COPD的易感因素，有可能成为疾病改善治疗的靶点。我们假设降低PPAR？活性增加对烟雾性肺损伤的易感性，外源性激活PPAR？使用TZDs可降低COPD发病率。我们建议上皮性PPAR？功能特异性调节炎症细胞募集，巨噬细胞激活和慢性烟雾暴露组织破坏的上皮来源趋化因子的表达。为了验证这些假设，我们提出：1)在肺上皮细胞PPAR缺失的情况下，确定导致香烟烟雾诱导肺气肿易感性增加的细胞和分子机制。小鼠的功能。2)评估PPAR？-激活治疗配体，以限制暴露于香烟烟雾的小鼠的肺气肿病理。3)调查PPAR的能力？作为II期临床试验的一部分，在人类细胞和COPD受试者中激活抑制烟雾诱导的肺上皮细胞趋化因子表达。总之，这些实验将检验PPAR的机制作用。在COPD的临床前模型中，专门研究上皮细胞PPAR的作用？在调节疾病发病机制中的作用，并评估PPAR的相关性和潜在的治疗益处？在COPD患者中激活

DESCRIPTION (provided by applicant): An improved understanding of the mechanisms leading to COPD pathogenesis, as well as novel targets for therapeutic intervention, are needed. Peroxisome proliferator-activating receptor (PPAR)-? has been previously shown to be capable of regulating inflammatory responses in multiple organs. PPAR?-activating ligands, the thaizoladinediones (TZDs), are FDA approved. Regulation of PPAR? activity, using these drugs, is associated with reduced morbidity in animal models of inflammatory lung disease. However, the importance of this molecule in lung epithelial cells and in COPD has not been determined. We find increased expression of PPAR? in human COPD tissues, and in epithelial cells from smokers. In lung epithelial cells, PPAR? can regulate genes associated with lung tissue remodeling. We have previously reported that deficiency in PPAR? specifically within epithelial cells leads to a defect in lung maturation resulting in variation in lung structure and function in mice. Here, we present data indicating that mice deficient in lung epithelial cell PPAR? also show increased susceptibility to the development of emphysema in response to chronic cigarette smoke exposure. This is associated with an increase in the accumulation of inflammatory macrophages, the critical effector cell for emphysema pathogenesis, and increased lung chemokine gene expression. We present preliminary data indicating that activating PPAR? using TZDs in mice reduces smoke-related inflammation and chemokine expression, critical cellular and molecular intermediate phenotypes in this pre-clinical model of COPD. In vivo, epithelial cells are highly responsive to PPAR? regulators, and exposure to cigarette smoke increased PPAR? expression, supporting the contributions of epithelial cell PPAR? in regulating smoke-induced inflammation. In total, these data support a role for PPAR? as a susceptibility factor in COPD with potential as a target for disease-modifying therapy. We hypothesize that reduced PPAR? activity increases susceptibility to smoke- induced lung injury and that exogenous activation of PPAR? using TZDs will reduce COPD morbidity. We propose that epithelial PPAR? functions specifically to regulate the expression of epithelial-derived chemokines involved in inflammatory cell recruitment, macrophage activation and tissue destruction in response to chronic smoke exposure. In an effort to test these hypotheses we propose to: 1) Define the cellular and molecular mechanisms leading to increased susceptibility to cigarette smoke-induced emphysema in the absence of lung epithelial cell PPAR? function in mice. 2) Evaluate PPAR?-activating therapeutic ligands for the ability to limit emphysema pathology in mice exposed to cigarette smoke. 3) Investigate the ability of PPAR? activation to suppress smoke-induced lung epithelial cell chemokine expression in human cells and in COPD subjects as part of a phase II clinical trial. In total, these experiments will test the mechanistic role of PPAR? in a preclinical model of COPD, specifically address the role of epithelial cell PPAR? in regulating disease pathogenesis, and evaluate relevance and potential therapeutic benefits of PPAR? activation in humans with COPD.