Effect of Macrolide Treatment on a Novel Pathway of Neutrophilic Inflammation in

描述（由申请人提供）： 我们描述了一种新的信号通路中性粒细胞（PMN）流入和气道损伤，可能在慢性阻塞性肺疾病（COPD）中发挥作用。胶原蛋白的化学或酶分解释放三肽PGP和乙酰化形式（N-？- PGP）对PMN具有趋化性。气道长期暴露于这种肽会导致肺泡扩大和右心室肥大。此外，在暴露于雾化内毒素（LPS）的动物的气道中发现PGP，并且显著地促进PMN内流。PGP的酶促生产是一个逐步的过程，最初涉及基质金属蛋白酶（MMP）-8和/或MMP-9与脯氨酰内肽酶（PE），一种丝氨酸蛋白酶，催化最终反应。我们还发现PGP存在于大多数COPD患者的支气管肺泡灌洗液（BALF）和/或痰液中，但不存在于对照组或哮喘患者中。来自COPD患者而非对照个体的痰液还含有从纯化的胶原蛋白离体产生PGP所必需的所有酶机制，并且这种PGP产生可以被MMP-8或MMP-9抑制剂或PE特异性抑制剂阻断。目前由COPD临床研究网络（CRN）进行的大环内酯试验为研究PGP在COPD气道炎症中的作用提供了一个独特的机会。PGP和N-？-的测量本试验招募的COPD患者队列中的PGP将提供只能通过另一项大规模临床试验获得的信息。本试验目前的入组期提供了一个重要的机会之窗，掩盖了本提案的时间敏感性。痰液中MMP和PE水平和活性的测量将提供关于COPD中PGP生成的新的和重要的信息，并确定针对这种疾病中的气道炎症的可能的新的治疗靶点。重要的是，大环内酯类抗生素已被确定为MMPs的负转录调节因子。这被认为是慢性肺病如COPD的可能治疗活性的基础。最后，这项试验将使我们能够在一个大的COPD患者队列中检验这一假设，无论是服用阿奇霉素还是对照组，从而为大环内酯类药物在COPD中的活性提供科学依据。我们的基本假设是N-？- PGP/PGP和产生它们的酶的活性，特别是MMP和PE，在服用阿奇霉素的COPD患者中低于服用安慰剂的COPD患者，并且这种降低将与这些患者的临床终点的改善相关。具体目标：1.测量N-？-在服用阿奇霉素的COPD患者和服用安慰剂的COPD患者的痰中PGP/PGP和PGP生成酶的活性，特别是MMP和PE。2.比较服用阿奇霉素的COPD患者的痰液与服用安慰剂的COPD患者的痰液从胶原蛋白离体产生N-a- PGP/PGP的能力。3.相关的N-？- COPD患者诱导痰中PGP/PGP和PE活性与血清中的水平和活性。COPD现在是美国第四大死因，预计到2020年将成为第三大死因。这一疾病造成许多人的痛苦以及巨大的经济负担。由于缺乏生物标志物来诊断和用作临床试验中的终点，以及缺乏对疾病过程本身的基本理解，因此对COPD的理解导致成功的治疗受到阻碍。如果成功，目前的提案将产生对疾病过程的基本见解和COPD的新的特异性生物标志物，并提出新的治疗靶点。(End摘要）

DESCRIPTION (provided by applicant): We describe a new pathway signaling neutrophil (PMN) influx and damage to the airways that may play a role in chronic obstructive pulmonary disease (COPD). Chemical or enzymatic breakdown of collagen releases a tripeptide, PGP, and an acetylated form (N-?-PGP) that are chemotactic for PMN. Prolonged airway exposure to this peptide causes alveolar enlargement and right ventricular hypertrophy. Further- more, PGP is found in the airways of animals exposed to aerosolized endotoxin (LPS) and markedly contributes to PMN influx. The enzymatic production of PGP is a stepwise process initially involving matrix metalloproteases (MMP)-8 and/or MMP-9 with prolyl endopeptidase (PE), a serine protease, catalyzing the final reaction. We have also found that PGP is present in bronchoalveolar lavage fluid (BALF) and/or sputum from most COPD patients but not controls or asthmatics. Sputum from COPD patients but not control individuals also contains all the enzymatic machinery necessary for the ex vivo generation of PGP from purified collagen and such PGP production can be blocked by MMP-8 or MMP-9 inhibitors or by a PE- specific inhibitors. The macrolide trial currently being conducted by the COPD Clinical Research Network (CRN) offers a unique opportunity to study the role of PGP in airway inflammation in COPD. Measurement of PGP and N-?-PGP in the cohort of COPD patients recruited for this trial will provide information which could otherwise only be acquired by another large-scale clinical trial. The current period of enrollment for this trial affords an important window of opportunity, belying the time-sensitive nature of this proposal. Measurement of MMP and PE levels and activity in sputum will provide new and important information on the generation of PGP in COPD and identify possible new therapeutic targets against airway inflammation in this disease. Importantly, macrolide antibiotics have been identified as negative transcriptional regulators for MMPs. This is proposed to underly a possible therapeutic activity in chronic lung diseases such as COPD. Finally, this trial will enable us to test this hypothesis in a large cohort of COPD patients, both taking azithromycin and controls, thereby providing a scientific basis for the activity of macrolides in COPD. Our underlying hypothesis is that levels of N-?-PGP/PGP and the activity of enzymes that generate them, specifically MMPs and PE, are lower in patients with COPD taking azithromycin than in COPD patients on placebo and that this reduction will correlate with improvement in clinical endpoints in these patients. Specific aims: 1. Measure levels of N-?-PGP/PGP and activity of PGP-generating enzymes, specifically MMP's and PE, in sputum of COPD patients taking azithromycin and in sputum of COPD patients taking placebo. 2. Compare the ability of sputum from COPD patients taking azithromycin to generate N-a- PGP/PGP ex vivo from collagen with sputum from COPD patients taking placebo. 3. Correlate levels of N-?-PGP/PGP and activity of PE in induced sputum with levels and activity in serum of COPD patients. COPD is now the fourth leading cause of death in the U.S. and is expected to be the third by 2020. This disease causes much human suffering as well as a large monetary burden. An understanding of COPD that leads to successful therapeutics has been hampered by a lack of biomarkers to diagnose and use as endpoints in clinical trials as well as a lack of a fundamental understanding of the disease process itself. If successful, the current proposal will yield fundamental insights into the disease process and a new and specific biomarker for COPD as well as suggesting new therapeutic targets. (End of Abstract)