Advanced Image-Based Approach to Assess How Fibrillar Collagen Modulates Airway Reactivity

先进的基于图像的方法来评估纤维状胶原蛋白如何调节气道反应性

• 批准号: 9272433
• 负责人: Harikrishnan Parameswaran
• 金额: $ 19.63万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9272433
• 关键词: Acetylcholine; Address; Agonist; Asthma; Back; Breathing; Caliber; Cattle; Cell Communication; Cells; Chronic; Collagen; Collagen Fiber; Communities; Critical Pathways; Deposition; Descriptor; Development; Devices; Dimensions; Disease; Elements; Environment; Etiology; Exhibits; Extracellular Matrix; Fibrillar Collagen; Filament; Focal Adhesions; Fresh Tissue; Functional disorder; Generations; Glean; Image; Imaging Techniques; Inflammation; Intuition; Label; Lasers; Light; Link; Maps; Measurement; Measures; Mechanics; Methods; Microscope; Microscopy; Microtubules; Muscle Cells; Muscle Contraction; Myosin ATPase; Organizational Change; Pathway interactions; Periodicity; Play; Process; Property; Protocols documentation; Research; Research Proposals; Role; Signal Transduction; Smooth Muscle; Stress; Stretching; Structure; System; Techniques; Technology; Testing; Thinking; Time; Tissue Sample; Translating; Weight-Bearing state; airway hyperresponsiveness; airway remodeling; base; constriction; extracellular; image processing; imaging system; in vivo; innovation; novel; portability; public health relevance; respiratory smooth muscle; response; second harmonic; time use; tissue fixing; transmission process

 DESCRIPTION (provided by applicant): The airway smooth muscle (ASM) has traditionally been the focus of research into the etiology of airway hyperresponsiveness (AHR) in asthma. However, it is becoming increasingly clear that critical mechanisms leading to AHR cannot be gleaned by only understanding the ASM in isolation from its native environment. When the ASM cells constrict, their force/deformation has to propagate around the circumference of the airway in order for the airway to narrow. This is typically thought to occur through cell-cell contacts between ASM cells, with each ASM cell pulling on another ASM cell attempting to narrow the airway. However, in addition to the cell-cell interactions, it is well established that the ASM cels can form focal adhesions with the ECM. Therefore, it is possible that the ASM force can be transmitted around the airway wall through elements of the ECM such as fibrillar collagen that surround the ASM cells. A fundamental question that emerges from this line of thinking is: how does the ASM contraction in response to an agonist translate into the eventual narrowing of an airway and what role do the collagen fibers play, if any, in modulating airway caliber during the narrowing process. At present, it is impossible to address this question as nothing is known about what happens to the collagen fibers in the airway wall during a muscle contraction. Our proposal will advance an innovative and powerful approach that will use second harmonic generation (SHG) microscopy, a novel imaging technique, to link collagen fiber organization to stress transmission within the airway and consequently the response of airways. Our preliminary results indicate that SHG can be a viable technology to map out the changes in collagen fiber organization as a result of ASM activation or cyclic stretching. Further, when we exposed a freshly dissected airway segment to 10-5M acetylcholine (ACh) while imaging it real time using SHG, we found that counter intuitive to our present understanding of how an ASM force is transmitted around an airway, wavy collagen fibers at baseline appear to straighten in the post ACh image as the airway constricted. Such straightening is consistent with collagen fibers starting to carry tension when the airway is exposed to agonist and the ASM develops active force. If confirmed, this means that airway wall collagen plays a more direct role in transmitting force around the airway during an ASM contraction. Through this exploratory research proposal, we will provide the community with a quantitative understanding of changes in collagen organization caused by an ASM contraction or dynamic stretch and changes in airway wall stress that be mapped back to understand the process by which airways narrow.

 描述（由申请人提供）：气道平滑肌（ASM）传统上一直是哮喘气道高反应性（AHR）病因学研究的焦点，然而，越来越清楚的是，无法通过气道平滑肌（ASM）收集导致AHR的关键机制。仅了解 ASM 与其原生环境的分离情况。当 ASM 细胞收缩时，它们的力/变形必须沿着气道圆周传播，以使气道收缩。这通常被认为是通过 ASM 细胞之间的细胞接触而发生的，每个 ASM 细胞拉动另一个 ASM 细胞试图缩小气道。然而，除了细胞间相互作用之外，ASM 细胞也已被证实。因此，ASM 力可能通过 ECM 的元件（例如 ASM 细胞周围的纤维状胶原）在气道壁周围传递。人们的想法是：ASM 对激动剂的反应如何导致气道最终变窄，以及胶原纤维在变窄过程中在调节气道口径方面发挥什么作用（如果有的话），目前尚无法解决。这个问题是因为我们对肌肉收缩期间气道壁中的胶原纤维发生的情况一无所知，我们的建议将提出一种创新且强大的方法，该方法将使用二次谐波发生（SHG）显微镜（一种新型成像技术）来连接胶原蛋白。我们的初步结果表明，SHG 可以成为绘制 ASM 激活或循环拉伸导致的胶原纤维组织变化的可行技术。将新鲜解剖的气道段与 10-5M 乙酰胆碱 (ACh) 进行比较，同时使用 SHG 对其进行实时成像，我们发现这与我们目前对 ASM 力如何在气道、波状胶原蛋白周围传递的理解背道而驰当气道收缩时，基线处的纤维似乎变直，当气道暴露于激动剂且 ASM 产生主动力时，这种变直与胶原纤维一致，这意味着气道壁胶原。在 ASM 收缩期间在气道周围传递力方面发挥更直接的作用通过这项探索性研究提案，我们将为社区提供对 ASM 收缩或动态拉伸引起的胶原组织变化和变化的定量了解。将气道壁应力映射回以了解气道狭窄的过程。