Amphotericin B Restoration of Anion Secretion in Cystic Fibrosis Airways

计划2 项目摘要 囊性纤维化（CF）是由编码囊性纤维化的基因的功能丧失突变引起的 跨膜传导调节因子（CFTR）顶端膜阴离子通道。CFTR损失- 呼吸道上皮介导的HCO3-和Cl-分泌损害呼吸道宿主防御，引起细菌 感染、炎症、粘液积聚和呼吸衰竭。一种恢复负离子的策略 将CFTR通道功能传递到顶端膜的目的是增加突变CFTR通道的功能。具有 对于有特定CFTR突变的人来说是成功的。然而，约10%的CF患者 突变不响应CFTR调节剂或它们不能服用调节剂。另一 策略是提供另一个渠道。为此，我们研究了阿替霉素B（AmB）; 工作表明AmB形成阴离子通道。我们发现，顶端AmB增加HCO3-， 培养的CF气道上皮细胞中的Cl-分泌，包括具有CFTR无效突变的那些。amb 增加ASL pH、高度和抗菌活性。AmB在临床上被批准用于治疗真菌感染， 而非适应症肺雾化有着令人印象深刻的安全记录。因此，AmB可能提供一种 CF肺病的新突变不可知疗法。然而，许多问题仍然没有答案， 我们缺乏重要的体内数据。因此，我们的首要目标是了解 AmB诱导的气道上皮细胞阴离子分泌，并验证AmB可以恢复气道上皮细胞阴离子分泌的假设。 CF宿主体内防御。为了实现这一目标，我们将回答三个目标的问题。目标1.什么 分子和细胞机制引起AmB介导的阴离子分泌？无cAMP依赖性 AmB的阴离子选择性只有CFTR的一半，是CFTR的不完全替代品。我们将 测试关于AmB如何在气道上皮中发挥作用的关键假设。目标2.哪些上皮细胞 AmB目标以及AmB如何改变它们？这些研究将揭示AmB在大、小细胞中的功能。 气道上皮和不同的细胞类型，测试AmB在气道上皮重塑炎症，并测试 补偿性的变化。目标3。AmB在体内逆转CF宿主防御缺陷吗？使用CF猪， 我们将测试雾化的AmB是否增加ASL pH，增加ASL抗微生物活性和高度， 增加粘膜纤毛转运，增强S.从肺部根除金黄色葡萄球菌。的结果 这些研究将对开发一种新的基因型不可知的治疗方法有直接的意义。 CF，并将告知项目1和3中其他疗法的开发。我们的提案成功了 通过威尔士（爱荷华州）和伯克（伊利诺伊州）实验室之间的持续合作， 利用优秀的核心，并通过该计划的项目之间的合作环境 和调查员。有了这样的背景，我们的跟踪记录和我们的承诺，我们相信这项研究 可以改变CF患者的生活。

PROJECT 2 PROJECT SUMMARY Cystic fibrosis (CF) is caused by loss-of-function mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) apical membrane anion channel. Loss of CFTR- mediated HCO3- and Cl- secretion by airway epithelia impairs respiratory host defenses, causing bacterial infection, inflammation, mucus accumulation, and respiratory failure. One strategy for restoring anion channel function to the apical membrane is to increase the function of mutant CFTR channels. That has proven successful for people with specific CFTR mutations. However, ~10% of people with CF have mutations that do not respond to CFTR modulators or they are not able to take modulators. Another strategy is to provide an alternative channel. Toward this end, we studied amphotericin B (AmB); earlier work showed that AmB forms anion channels. We discovered that apical AmB increased HCO3- and Cl- secretion in cultured CF airway epithelia, including those with CFTR-null mutations. AmB increased ASL pH, height, and antibacterial activity. AmB is clinically approved to treat fungal infections, and off-label lung aerosolization has an impressive safety record. Thus, AmB could potentially provide a new mutation-agnostic therapy for CF lung disease. However, many questions remain unanswered and we lack important in vivo data. Therefore, our overarching goal is to understand the mechanisms of AmB-induced anion secretion in airway epithelia and to test the hypothesis that AmB can restore CF host defenses in vivo. To achieve this goal, we will answer questions in three aims. Aim 1. What molecular and cellular mechanisms elicit AmB-mediated anion secretion? Without cAMP-dependent regulation and with half the anion selectivity of CFTR, AmB is an imperfect substitute for CFTR. We will test key hypotheses about how AmB functions in airway epithelia. Aim 2. Which epithelial cells does AmB target and how does AmB alter them? These studies will reveal AmB function in large and small airway epithelia and diverse cell-types, test AmB in airway epithelia remodeled by inflammation, and test for compensatory changes. Aim 3. Does AmB reverse CF host defense defects in vivo? Using CF pigs, we will test if nebulized AmB increases ASL pH, increases ASL antimicrobial activity and height, increases mucociliary transport, and enhances S. aureus eradication from the lungs. The results of these studies will have direct implications for developing a new genotype agnostic approach to treating CF, and will inform development of other therapies in Projects 1 and 3. Our proposal’s success is enhanced by an ongoing collaboration between the labs of Welsh (Iowa) and Burke (Illinois), by utilization of outstanding cores, and by an environment of cooperation between the Program’s projects and investigators. With this background, our track record, and our commitment, we believe this research can change the lives of people with CF.