Functional Anatomic Imaging of CF Patients with Early Lung Disease Using microOCT

描述（由申请人提供）：囊性纤维化（CF）是由囊性纤维化跨膜传导调节因子（CFTR）突变引起的，CFTR是氯离子和碳酸氢根的阴离子转运蛋白。CFTR缺陷或不足导致严重的粘膜阻塞性肺病和严重的发病率以及由于肺部感染导致的早期死亡率。尽管我们对CF发病机制的理解已经取得了实质性进展，但我们仍然没有完全理解导致CF患者粘膜纤毛清除率（MCC）降低的病理生理机制。这一障碍背后有两个关键障碍：1）没有可用于可视化体内呼吸道粘膜和粘液的重要微观结构、功能和生物力学特征的工具，以及2）难以研究年轻CF患者以确定这种疾病的基本缺陷，在继发现象如感染和炎症的发生之前，这些继发现象混淆了CF发病机制的研究。在这项补助金，我们将克服这些障碍，通过一种新的横截面光学显微镜技术，称为1-？m OCT（？OCT），其已在初步研究中显示出清楚地可视化离体支气管上皮细胞和气管的结构和功能显微解剖。用什么？OCT，我们已经能够同时和定量监测气道表面液体（ASL）和睫状体层（PCL）的深度，纤毛跳动，和粘液纤毛运输，同时还测量粘液粘度的本地粒子跟踪技术。我们建议通过建立一种改进的成像系统和一种新型的肺导管来推进这项技术，这将使？OCT用于活体人类受试者的气道。此外，电位差（PD）电极将集成在鞘内？OCT导管，能够对CFTR离子通道活性进行共定位测量。然后，在结构性肺病发作之前，该装置将用于研究患有CF的幼儿的气道。我们的实验旨在确定启动CF发病机制的最早事件，包括ASL调节与粘液纤毛转运（MCT）和粘液生物发生的关系，同时确定氯离子和碳酸氢盐转运对调节这些途径的作用。通过实现这些目标，我们将能够解决关键的假设和解决有关CFTR离子转运缺陷和ASL/PCL深度，纤毛功能和粘液的物理性质的规定之间的相互关系，以及新的CFTR调节剂对这些途径的影响的领域的争议。这项研究的最终产品将扩展有关CF基本病理生理学的知识库，为专门针对离子转运、粘液生物发生或CF发病机制的其他主要途径的药物的研究和开发开辟新的途径。这项工作还将使未来人类患者肺的功能显微解剖成像成为可能，这将通过提供评估CF肺病进展的成像模式和用于对抗粘液淤积的药物的疗效来显著影响CF患者。 (End摘要）

DESCRIPTION (provided by applicant): Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an anion transporter of chloride and bicarbonate. Defective or deficient CFTR leads to severe mucoobstructive lung disease and severe morbidity and early mortality due to lung infections. Even though substantial advances in our understanding of CF pathogenesis have been made, we still do not fully understand the pathophysiologic mechanisms that lead to decreased mucociliary clearance (MCC) in CF patients. Two critical barriers underlie this roadblock: 1) there have been no tools available for visualizing the important microstructural, functional, and biomechanical features of the respiratory mucosa and mucus in vivo, and 2) it has been difficult to study young CF patients to determine the fundamental defects of this disease, prior to the occurrence of secondary phenomena such as infection and inflammation that confound the study of CF pathogenesis. In this grant, we will overcome these barriers through a novel cross-sectional optical microscopy technology termed 1-?m OCT (?OCT), that has been shown in preliminary studies to clearly visualize the structural and functional microanatomy of bronchial epithelial cells and trachea ex vivo. With ?OCT, we have been able to simultaneously and quantitatively monitor airway surface liquid (ASL) and periciliary layer (PCL) depths, ciliary beating, and mucociliary transport while also measuring mucus viscosity by native particle tracking techniques. We propose to advance this technology by building an improved imaging system and a novel pulmonary catheter that will enable ?OCT to be used in the airways of living human subjects. In addition, potential difference (PD) electrodes will be integrated within the sheath of the ?OCT catheter, enabling co-localized measurements of CFTR ion channel activity. This device will then be employed to investigate the airways of young children with CF, prior to the onset of structural lung disease. Our experiments are intended to define the earliest events that initiate CF pathogenesis, including the relationship of ASL regulation to mucociliary transport (MCT) and mucus biogenesis while also determining the roles of chloride and bicarbonate transport towards regulating these pathways. By accomplishing these objectives, we will be able to address key hypotheses and resolve controversies in the field regarding the interrelationships between the CFTR ion transport defect and the regulations of ASL/PCL depth, ciliary function, and the physical properties of mucus, and the impact of novel CFTR modulators on these pathways. The end product of this research will expand the knowledgebase regarding the fundamental pathophysiology of CF, resulting in new avenues for research and development of pharmacologic agents that specifically target ion transport, mucus biogenesis, or other primary pathways underlying CF pathogenesis. This work will also enable imaging of the functional microanatomy of the lung in living human patients in the future, which will significantly impact those with CF by providing an imaging modality for assessing the progression of CF lung disease and the efficacy of drugs administered to combat mucus stasis. (End of Abstract)