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

描述(申请人提供)：囊性纤维化(CF)是由囊性纤维化跨膜电导调节因子(CFTR)突变引起的，CFTR是氯离子和碳酸氢盐的阴离子转运体。CFTR缺陷或缺陷会导致严重的黏液阻塞性肺疾病，以及因肺部感染而导致的严重发病率和早期死亡。尽管我们对CF发病机制的认识已经取得了实质性的进展，但我们仍然不完全了解导致CF患者粘液纤毛清除(MCC)降低的病理生理学机制。在这一障碍下有两个关键障碍：1)目前还没有工具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，2)在感染和炎症等继发性现象发生之前，很难研究年轻的CF患者来确定这种疾病的基本缺陷，这些现象扰乱了CF发病机制的研究。在这笔赠款中，我们将通过一种名为1-？M OCT(？OCT)的新横断面光学显微镜技术克服这些障碍，该技术已在初步研究中显示，可以清楚地显示体外支气管上皮细胞和气管的结构和功能显微解剖。有了？OCT，我们能够同时定量监测呼吸道表面液体(ASL)和纤毛层(PCL)深度、纤毛搏动和粘液纤毛运输，同时还可以通过本地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，这将使？OCT能够用于活体受试者的呼吸道。此外，电位差(PD)电极将集成在？OCT导管的鞘内，从而能够对CFTR离子通道活动进行共同定位测量。然后，在结构性肺部疾病发作之前，该设备将被用来调查患有CF的幼儿的呼吸道。我们的实验旨在定义启动CF发病机制的最早事件，包括ASL调节与粘液纤毛运输(MCT)和粘液生物发生的关系，同时还确定氯和碳酸氢盐运输在调节这些途径中的作用。通过实现这些目标，我们将能够解决关键的假说，并解决该领域的争议，即CFTR离子传输缺陷与ASL/PCL深度、睫毛功能和粘液的物理性质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。这项研究的最终成果将扩大关于CF基本病理生理学的知识基础，从而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。这项工作还将使未来活体人类患者的肺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肺部疾病的进展和抗粘液淤积药物的疗效，从而显著影响那些CF患者。(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)