Compound/Combination Selection Core

慢性阻塞性肺疾病和慢性阻塞性肺疾病的发病机制是多因素的，但包括一个共同的致病步骤：粘液纤毛清除减少(MCC)。根据形成tPPG项目I和II的基础的研究，已经观察到正常的粘液清除需要呼吸道表面充分的水化(见计划概述)。然而，慢性阻塞性肺疾病和慢性阻塞性肺疾病患者都表现出气道粘液浓度(固体百分比)的增加，这是由于CFTR功能障碍(1)、粘蛋白高分泌(2)或两者的组合导致的气道水合作用减少的结果。其结果是出现呼吸道粘附性粘液斑块，纤毛和咳嗽依赖的粘液清除减慢，导致慢性呼吸道感染。因此，开发治疗方法以加强对呼吸道粘液的清除可能会使慢性阻塞性肺疾病/慢性阻塞性肺疾病患者受益。Core E的主要目标是通过确定最有效的治疗药物来增强粘液的粘附性和运输性，以支持tPPG的所有项目。作为tPPG项目的一部分，我们已经确定了一些类别的候选治疗剂，预计它们将改变粘液的性质，促进其清除。表1总结了这些潜在试剂的类别和实例。由于粘液的粘弹性是浓度相关的，因此将研究增加粘液水化状态的试剂(称为水化器)(3)。这将包括渗透调节剂(如高渗盐水和甘露醇)以及ENaC介导的液体重吸收的调节剂，包括：ENAC阻滞剂(Parion P552和PI 527)和ENaC活性调节剂(QUB和Splunk)。作为降低粘液浓度的另一种方法，我们还将评估大环内酯类化合物的使用，这已被证明可以减少粘液的表达。除了阿奇霉素，我们还将测试来自Cempra和Gilead的一系列新型大环内酯类药物，这些药物经过优化以提高它们的活性(见支持信)。除了降低粘液的浓度，我们还将通过改变粘蛋白-粘蛋白和粘蛋白-蛋白质的相互作用来寻找降低其粘弹性和粘附性的试剂。二硫基还原剂预计会通过减少粘蛋白单体的头尾链来降低粘液的粘弹性。除了现有的还原剂(如N-乙酰半胱氨酸和DTT)外，我们还将测试新的还原剂，如耶鲁大学Peter Cresswell博士的伽马干扰素诱导溶酶体硫醇还原酶(GILT)和Parion的各种新型重组DTT(DTT-Rs)，它们可以提高作用效率和持续时间(参见计划介绍)。破坏粘液层内蛋白质-蛋白质相互作用的表面活性剂和洗涤剂被认为会降低粘液的粘附性(5-6)。我们还将研究其他一些假定的粘液改变药物(例如，钙离子螯合剂(7)、葡聚糖(8)、肝素(9)、碳酸氢盐(10))，以确定恢复/刺激MCC的新疗法。Core E由三个不同的功能部门组成，将确定潜在用于人体临床试验的有效药物。图1显示了这一核心的总体战略及其与每个tPPG项目的交互作用。总体概念是使用体外粘液筛选方法筛选大量测试试剂，并确定在后续细胞培养和小鼠研究中要研究的最有效的试剂(S)。粘液流变学和水化核心服务的主要目标是为项目I和II的研究人员提供对所有感兴趣的制剂的全面分析，并建立关于(1)粘液粘弹性--粘液“流动性”的衡量标准--和(2)呼吸道水化变化的剂量-效应关系。一旦确定了最有效的候选制剂，这些制剂中的每一种在刺激和恢复人类呼吸道上皮细胞粘液运输方面的效果将在下一项核心服务中进行研究。最后，在第三个核心部分中，先前研究中最有效的药物将在单剂量和多剂量测试方案中在阻塞性呼吸道疾病的小鼠模型中进行测试。 目的是通过组织病理学、形态测量、生化分析和炎性细胞计数来评估药物的疗效和毒性。一旦确定，这些代理(或代理类别)将成为项目III中人体试验的焦点。

The pathogenesis of CF and COPD lung disease is multi-factorial, but includes a common disease-initiating step: the reduction of mucociliary clearance (MCC). Based on studies shaping the foundation of the tPPG Projects I and II, it has been observed that normal mucus clearance requires adequate hydration of the airway surface (see Program Overview). However, both CF and COPD patients exhibit an increase in airway mucus concentration (% solids), as a result of reduced airway hydration, due to CFTR dysfunction (1), mucin hypersecretion (2), or a combination of the two. The result is the appearance of airway-adherent mucus plaques and the slowing of both cilial- and cough-dependent mucus clearance, leading to chronic airway infections. Therefore, developing therapies to enhance the clearance of mucus from the airways is likely to benefit patients with CF/COPD. The primary goal of Core E is to support all the Projects of the tPPG by identifying the most effective therapeutic agents to enhance the dis-adherence and transportability of mucus. As part of this tPPG project, we have identified a number of classes of candidate therapeutic agents, which are predicted to alter the properties of mucus, facilitating its clearance. These classes and examples of potential agents are summarized in Table 1. Because the viscoelasticity of mucus is concentration dependant, agents which increase the hydration state of mucus (called hydrators) will be studied (3). This will include osmolytes (such as hypertonic saline and mannitol) as well as modifiers of ENaC-mediated fluid reabsorption, including: ENaC blockers (Parion P552 and PI 527) and modifiers of ENaC activity (QUB and SPLUNK). As an alternative approach to reduce mucus concentration, we will also evaluate the use of macrolides, which have been shown to reduce mucus expression (4). As well as Azithromycin, we will test a series of novel macrolide agents from Cempra and Gilead which are optimized to improve their activity (see Letters of Support). In addition to lowering the concentration of mucus, we will also seek to identify agents which reduce its viscoelasticity and adhesivity, by altering mucin-mucin and mucin-protein interactions. Di-sulfhydryl reducing agents are predicted to decrease the viscoelasticity of mucus by decreasing the head-to-tail chaining of mucin monomers. In addition to existing reducing agents (e.g. N-acetylcysteine and DTT) we will also test novel reducing agents such as Gamma-interferon-inducible lysosomal thiol reductase (GILT) from Dr. Peter Cresswell (Yale) and a variety of novel recombinant- DTTs (DTT-Rs) from Parion which increase the efficiency and duration of action (see Program Introduction). Surfactants and detergents that disrupt protein-protein interactions within the mucus layer are envisaged to decrease the cohesive properties of mucus (5-6). There are a number of other putative mucus-altering agents (e.g. Ca2+ chelators (7), dextran (8), heparin (9), bicarbonate (10)) that we will study to identify novel therapeutics for restoring/ stimulating MCC. Core E consists of three distinct functional divisions that will identify effective agents for potential use in a human clinical trial. The overall strategy of this Core and its interactions with each tPPG Project is shown in Figure 1. The general concept is to screen a large number of test agents using in vitro mucus screening methodologies and identify the most effective agent(s) to be studied in subsequent cell culture and mouse studies. The primary goal of the mucus rheology and hydration core service is to provide Project I & II investigators with a comprehensive analysis of all agents of interest and establish the dose-effect relationship on changes in (1) mucus viscoelasticity - a measure of the "flowability" the mucus, and (2) the hydration of the airway. Once the most effective candidate agents are identified, the effect of each of these agents on stimulating and restoring mucus transport in human airway epithelial cultures will be studied in the next core service. Finally, in the third core component, the most effective agents from the previous studies will be tested in a mouse model for obstructive airway diseases during a single and multiple dose testing regimens. The goal is to evaluate drug efficacy and toxicity, as assessed by histopathology, morphometric measurements,biochemical analysis and inflammatory cell count. Once identified, these agents (or class of agents) will be the focus of a human trial in Project III.