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剂（CFTR）突变引起的，CFTR是氯离子和碳酸氢盐的阴离子转运体。CFTR缺陷或不足可导致严重的黏液梗阻性肺部疾病以及肺部感染导致的严重发病率和早期死亡。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了解导致CF患者粘膜纤毛清除率（mucocile clearance， MCC）下降的病理生理机制。这一障碍背后有两个关键的障碍：1)没有可用的工具来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；2)在继发现象（如感染和炎症）发生之前，很难对年轻CF患者进行研究，以确定该疾病的根本缺陷，这些继发现象混淆了CF发病机制的研究。在这项资助中，我们将通过一种新的横断面光学显微镜技术，称为1-？m OCT (？OCT)，在初步研究中可以清晰地看到体外支气管上皮细胞和气管的结构和功能显微解剖。?OCT，我们已经能够同时定量监测气道表面液体（ASL）和纤毛周层（PCL）深度，纤毛搏动和纤毛粘膜运输，同时通过天然颗粒跟踪技术测量粘液粘度。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。OCT将用于活体受试者的气道。此外，电位差（PD）电极将集成在？OCT导管，使CFTR离子通道活性的共定位测量。然后，该设备将用于调查年幼的CF儿童气道，在结构性肺病发作之前。我们的实验旨在确定启动CF发病机制的最早事件，包括ASL调节与粘膜纤毛运输（MCT）和粘液生物发生的关系，同时确定氯化物和碳酸氢盐运输在调节这些途径中的作用。通过完成这些目标，我们将能够解决CFTR转运缺陷与ASL/PCL深度、纤毛功能和粘液物理性质的调节之间的相互关系以及新型CFTR调节剂对这些途径的影响的关键假设和解决该领域的争议。这项研究的最终成果将扩大CF基本病理生理学的知识库，为研究和开发专门针对离子转运、粘液生物发生或CF发病机制的其他主要途径的药物开辟新的途径。这项工作还将使将来活人肺的功能显微解剖成像成为可能，这将通过提供一种成像方式来评估CF肺病的进展和对抗粘液停滞的药物的疗效，从而对CF患者产生重大影响。（摘要结束）

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)