Quantitative optical imaging of cilia-driven fluid flow

纤毛驱动流体流动的定量光学成像

• 批准号: 8849968
• 负责人: Michael Andrew Choma
• 金额: $ 41万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8849968
• 关键词: Accounting; Allergens; Animal Model; Asthma; Biological; Biological Assay; Biological Markers; Biology; Biomechanics; Biomimetics; Cells; Child; Childhood; Cilia; Clinical; Cues; Defect; Detection; Development; Devices; Diagnosis; Diagnostic; Diffusion; Disease; Embryo; Embryonic Development; Frequencies; Genes; Health; Human; Image; Imaging technology; Impairment; Lead; Light; Lighting; Liquid substance; Lung; Lung diseases; Magnetic Resonance Imaging; Measurement; Measures; Mechanics; Methods; Microfluidics; Molecular Genetics; Molecular Motors; Morbidity - disease rate; Mucous body substance; Mus; Nature; Neonatal; Newborn Infant; Optical Coherence Tomography; Optical Methods; Optics; Pattern; Performance; Phenotype; Physiology; Predisposition; Primary Ciliary Dyskinesias; Process; Property; Public Health; Research; Role; Severities; Shapes; Signal Transduction; Signaling Protein; Skin; Speed; Structure; Surface; Tadpoles; Technology; Testing; Time; Translating; Velocimetries; Viscosity; Work; Xenopus; base; clinical care; clinically significant; density; detector; digital; extracellular; fluid flow; genetic manipulation; imaging system; improved; interest; lens; mortality; mouse model; notch protein; novel; optical imaging; optical switch; particle; pathogen; planar cell polarity; quantitative imaging; respiratory; vector

DESCRIPTION (provided by applicant): Respiratory diseases are major causes of pediatric morbidity and mortality. These diseases are incompletely understood, which is a barrier to improving clinical care. Therefore, new mechanisms of disease need to be discovered. Optical imaging (e.g. optical coherence tomography [OCT]) will enable these discoveries since traditional imaging (e.g. x-ray, CT, MRI) cannot visualize structures smaller than ~1 mm. Microfluidic-scale cilia-driven fluid flow clears pathogen and allergen-containing mucus out of the lungs, yet we currently lack quantitative imaging technologies to characterize their flow performance. Moreover, while ciliary defects are traditionally considered a feature of rare but severe diseases (e.g. primary ciliary dyskinesia), development of biomechanical biomarkers extracted from quantitative flow imaging will allow us to test a paradigm-shifting hypothesis: intermediate defects in ciliary performance that are undetectable by current diagnostics are major modifiers of clinical severity in common respiratory diseases (e.g. asthma). Our research therefore has three aims. First, we will develop high-speed, cosine ambiguity-free Doppler OCT imaging systems. Cilia-driven fluid flow is three-dimensional in nature and not amenable to simplifying geometric assumptions such as parabolic flow profile. Traditional Doppler imaging suffers from cosine ambiguity that precludes the measurement of three-component flow velocities (v=vxi+vyj+vzk). We will develop a novel class of OCT interferometers that will enable three-dimensional, three-component flow imaging that will be demonstrated using the ciliated skin of Xenopus (tadpole) embryos, an important animal model in ciliary biology. Second, we will develop quantitative imaging assays of ciliary function that exploit cilia-driven microfluidic mixing. Taking a cue from work in biomimetic cilia, we have (a) demonstrated that ciliated biological surfaces can drive microfluidic mixing and (b) developed a novel microfluidic chip that uses a ciliated biological surface as a microfluidic "component." Building on these results, we will demonstrate that our microfluidic mixing-based assay can quantify biologically relevant perturbations to ciliary physiology including increased fluid viscosity and altered planar cell polarity. Third, we will demonstrate intermediate defects in Xenopus and mouse ciliary function using quantitative imaging. We will target two different classes of genes relevant in the performance of a ciliated surface in Xenopus embryos: ciliary molecular motors and notch signaling proteins (notch signaling controls the density of ciliated cells on the embryo skin). Given the importance of mouse models of pediatric respiratory disease, it is critical to demonstrate that our optical methods can be used to quantify the performance of mouse respiratory cilia. Moreover, this is an important step towards translating our diagnostic technologies to use in humans. We propose to use flow imaging to quantify performance modified by increased fluid viscosity (mechanical perturbation to decrease ciliary beat frequency) and increased extracellular ATP (pharmacological perturbation to increase ciliary beat frequency).

描述（由申请人提供）：呼吸系统疾病是儿科发病和死亡的主要原因。这些疾病尚不完全了解，这是改善临床护理的障碍。因此，需要发现新的疾病机制。光学成像（例如光学相干断层扫描 [OCT]）将使这些发现成为可能，因为传统成像（例如 X 射线、CT、MRI）无法可视化小于约 1 毫米的结构。微流体规模的纤毛驱动的流体流动可将含有病原体和过敏原的粘液清除出肺部，但我们目前缺乏定量成像技术来表征其流动性能。此外，虽然纤毛缺陷传统上被认为是罕见但严重的疾病（例如原发性纤毛运动障碍）的一个特征，但从定量血流成像中提取的生物力学生物标志物的开发将使我们能够测试范式转换的假设：当前诊断无法检测到的纤毛性能的中间缺陷是常见呼吸系统疾病（例如，慢性呼吸道疾病）临床严重程度的主要修饰因素。 哮喘）。因此，我们的研究有三个目标。首先，我们将开发高速、无余弦模糊的多普勒 OCT 成像系统。纤毛驱动的流体流动本质上是三维的，不适合简化几何假设，例如抛物线流动剖面。传统的多普勒成像存在余弦模糊性，无法测量三分量流速 (v=vxi+vyj+vzk)。我们将开发一类新型 OCT 干涉仪，该干涉仪将实现三维、三分量流成像，并将使用爪蟾（蝌蚪）胚胎的纤毛皮肤（纤毛生物学中的重要动物模型）进行演示。其次，我们将开发利用纤毛驱动的微流体的纤毛功能的定量成像测定法 混合。受仿生纤毛研究的启发，我们（a）证明了纤毛生物表面可以驱动微流体混合，并且（b）开发了一种新型微流体芯片，该芯片使用纤毛生物表面作为微流体“组件”。基于这些结果，我们将证明我们的基于微流体混合的测定可以量化对纤毛生理学的生物学相关扰动，包括增加的流体粘度和改变的平面细胞极性。第三，我们将使用定量成像来证明非洲爪蟾和小鼠纤毛功能的中间缺陷。我们将针对与非洲爪蟾胚胎纤毛表面性能相关的两类不同基因：纤毛分子马达和缺口信号蛋白（缺口信号控制胚胎皮肤上纤毛细胞的密度）。鉴于小儿呼吸道疾病小鼠模型的重要性，证明我们的光学方法可用于量化小鼠呼吸道纤毛的性能至关重要。此外，这是将我们的诊断技术应用于人类的重要一步。我们建议使用流成像来量化通过增加流体粘度（机械扰动以降低纤毛跳动频率）和增加细胞外 ATP（药理学扰动以增加纤毛跳动频率）而改变的性能。