Ivacaftor for Acquired CFTR Dysfunction in Chronic Rhinosinusitis

粘液纤毛清除无效(MCC)是慢性阻塞性肺疾病常见的病理生理过程。 鼻-鼻窦炎(CRS)--一种发病率很高的疾病。我们实验室的证据显示 证明了短暂接触革兰氏阴性细菌的脂多糖(LPS)会导致 人和其他人通过CFTR顶端氯离子通道的阴离子转运减少而导致的MCC功能障碍 哺乳动物物种。在这种情况下，CFTR的抑制是由TLR4介导的活性氧的产生引起的 种(ROS)，但不依赖于NFkB来源的炎症。此外，我们小组已经确认了 在人类鼻窦中存在获得性CFTR功能障碍，并已证明CFTR增强剂可以 当在多个体外和临床前模型中出现部分CFTR功能障碍时，刺激Cl-的分泌。我们的 中心假设是，内毒素诱导的获得性CFTR缺陷，1)在很大程度上导致了 CRS的发病机制，以及2)可以用IVAKAFTOR治疗，这是一种为CF开发的CFTR增强剂 心理治疗。特定目标1将探讨内毒素介导的鼻腔CFTR功能障碍的机制基础 通过1)通过AMP依赖的激酶(一种抑制物)检测氧化剂对CFTR的抑制作用 依赖于PKA的CFTR调节域的磷酸化)，2)评估ROS的影响 (超氧化物、过氧化氢)对CFTR功能(膜片钳分析)和结构(质谱学)的影响 3)测量长期暴露于脂多糖对CFTR表达、成熟过程的影响，以及 回收利用。目的2在临床前兔模型中确定异烟肼改善CFTR功能的有效性 1)建立脂多糖暴露兔上颌窦CFTR的标准数据 功能障碍，2)评估异丙酚对CFTR相关终点的影响，以及3)评估异丙酚作为 兔上颌窦炎铜绿假单胞菌的治疗。Aim 3将进行一项临床研究 1)新的“内窥镜引导下的窦房结电势差”分析与CRS患者的异丙肾上腺素 验证CRS疾病严重程度的措施和2)使用异烟肼治疗CRS进行试点临床试验 难治性革兰阴性杆菌CRS患者。目前的提议将有助于澄清各种机制 负责鼻窦炎的发病机制，但也将我们的实验室发现转化为人类受试者 提供使用异烟肼治疗鼻窦炎的临床试验。我们相信我们的应用程序会回答 关于CRS发病机制的基本问题，并为新的 对一种严重且使人衰弱的慢性病的治疗方法。

Ineffective mucociliary clearance (MCC) is a common pathophysiologic process contributing to chronic rhinosinusitis (CRS) - a highly prevalent disease with substantial morbidity. Evidence from our laboratory has demonstrated that brief exposures to lipopolysaccharide (LPS) from gram-negative bacteria lead to dysfunctional MCC by decreasing anion transport through CFTR apical Cl- channels in humans and other mammalian species. CFTR inhibition in this setting is caused by TLR4-mediated generation of reactive oxygen species (ROS), but independent of NFkB-derived inflammation. Furthermore, our group has confirmed the presence of acquired CFTR dysfunction in human sinuses, and has demonstrated that CFTR potentiators can stimulate Cl- secretion when partial CFTR dysfunction is present in multiple in vitro and preclinical models. Our central hypotheses are that LPS-induced acquired CFTR deficiency, 1) contributes substantially to the pathogenesis of CRS, and 2) can be treated with Ivacaftor, a CFTR potentiator developed for CF therapy. Specific Aim 1 will investigate the mechanistic basis of LPS-mediated CFTR dysfunction in sinonasal epithelium by 1) examining the oxidant-dependent inhibition of CFTR via AMP-dependent kinase (an inhibitor of PKA-dependent phosphorylation of the CFTR regulatory domain), 2) assessing the impact of ROS (superoxide, hydrogen peroxide) on CFTR function (patch clamp analysis) and structure (mass spectrometry), and 3) measuring the effects of longer exposures to LPS on CFTR expression, maturational processing, and recycling. Aim 2 will identify the efficiency of Ivacaftor in improving CFTR function in a pre-clinical rabbit model of acquired CFTR deficiency by 1) developing normative data for LPS-exposed rabbit maxillary sinus CFTR dysfunction, 2) assessing the effects of Ivacaftor on CFTR-related endpoints, and 3) evaluating Ivacaftor as therapy for Pseudomonas aeruginosa rabbit maxillary sinusitis. Aim 3 will conduct a clinical study using Ivacaftor in CRS patients by 1) correlating the novel “endoscopically-directed sinus potential difference” assay to validated measures of CRS disease severity and 2) performing a pilot clinical trial using Ivacaftor for CRS patients with refractory gram-negative bacterial CRS. The current proposal will help clarify mechanisms responsible for sinusitis pathogenesis, but also translates our laboratory findings to human subjects by providing a clinical trial using Ivacaftor for therapy of sinusitis. We believe our application will answer fundamental questions regarding pathomechanisms underlying CRS and establish the foundation for a new therapeutic approach to a serious and debilitating chronic disease.