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，导致AHR的关键机制不能仅仅通过孤立于其原生环境来理解ASM。当ASM细胞收缩时，它们的力/变形必须围绕气道的圆周传播，以便使气道变窄。这通常被认为是通过ASM细胞之间的细胞-细胞接触发生的，每个ASM细胞拉动另一个ASM细胞试图使气道变窄。然而，除了细胞-细胞相互作用之外，已经充分确定的是ASM粘附物可以与ECM形成局灶性粘附。因此，可能的是，ASM力可以通过ECM的元件（诸如围绕ASM细胞的纤维状胶原）围绕气道壁传递。从这一思路中出现的一个基本问题是：响应于激动剂的ASM收缩如何转化为气道的最终狭窄，以及胶原纤维在狭窄过程中调节气道口径中发挥什么作用（如果有的话）。目前，这是不可能解决这个问题，因为没有人知道发生了什么事，在气道壁的胶原纤维在肌肉收缩。我们的提案将推进一种创新的和强大的方法，将使用二次谐波发生（SHG）显微镜，一种新的成像技术，连接胶原纤维组织的压力在气道内的传输，从而气道的反应。我们的初步结果表明，SHG可以是一种可行的技术，以绘制出的胶原纤维组织的变化，作为ASM激活或循环拉伸的结果。此外，当我们将新鲜解剖的气道段暴露于10- 5 M乙酰胆碱（ACh），同时使用SHG对其进行真实的时间成像时，我们发现，与我们目前对ASM力如何在气道周围传递的理解相反，基线处的波状胶原纤维在ACh后图像中随着气道收缩而变直。这种拉直与当气道暴露于激动剂并且ASM产生主动力时胶原纤维开始承载张力一致。如果得到证实，这意味着气道壁胶原蛋白在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的定量了解，以及气道壁应力的变化，这些变化将被映射回来，以了解气道狭窄的过程。