Cell-ECM Interactions: A 3D Micro-Mechanical Perspective

描述（由申请人提供）： 这项研究的长期目标是促进开发更好的方法来克服组织损失和器官衰竭的破坏性问题。该提案的目的是确定3D细胞外基质（ECM）的特定微观结构和机械特性如何定义机械信号向细胞的分布和传递，从而调节其响应并最终有助于整体组织结构/功能。该研究的中心假设是，细胞对3D ECM内的微结构组成和微机械负载的反应部分地由细胞-基质粘附的分布和组成介导。该研究的基本原理是，细胞ECM环境的关键3D结构和机械特征的定义，特别是在微观层面，以及它们影响细胞行为的机制的识别，将使工程生物材料具有特定的材料特性，可预测地诱导细胞反应，加速或改善组织修复。所提出的研究的目的将通过追求三个具体目标来实现：1）确定成纤维细胞在3D ECM中的形态学、表型、细胞-基质粘附和ECM重塑特性，其中微观结构被量化并且可控地变化，并且没有施加外部机械载荷; 2）确定3D ECM内成纤维细胞的形态学、表型、细胞-基质粘附和ECM重塑特性，其中微机械特性（例如，3D微观水平应力和应变场）被量化并且通过施加外部机械载荷可控地改变;以及3）鉴定成纤维细胞感知周围3D ECM的微观结构组成和微观机械状态的机制。ECM生物化学，细胞生物学，生物力学和生物成像领域的专业知识将结合起来，产生以下成果。首先，将定量定义细胞ECM微环境的特定结构-机械属性。反过来，细胞反应对3D ECM的特定微观结构和机械性质的依赖性将在存在和不存在外部施加的机械载荷的情况下建立。第三，将确定其他主要细胞信号对细胞感知和响应这些生物物理线索的能力的影响。第四，将鉴定与细胞-ECM粘附相关的关键事件，所述细胞-ECM粘附为细胞提供感知和响应3D ECM微环境的物理性质的能力。总的来说，这些结果将提供关于细胞-ECM相互作用的物理方面的新信息，并建立细胞-基质粘附在细胞响应ECM提供的3D结构和机械线索的能力中的作用。这项研究对组织工程和医学具有重要意义，因为其结果预计将定义急需的基本原则和设计标准，为受损组织的定向修复奠定基础。

DESCRIPTION (provided by applicant): The long-range goal of the research is to foster development of better approaches to overcome the devastating problems of tissue loss and organ failure. The objective of this proposal is to determine how specific micro-structural and mechanical properties of a 3D extracellular matrix (ECM) define the distribution and transfer of mechanical signals to cells that in turn regulate their response and ultimately contribute to the overall tissue structure/function. The central hypothesis for the research is that the cellular response to micro-structural composition and micro-mechanical loading within a 3D ECM is mediated, in part, by the distribution and composition of cell-matrix adhesions. The rationale for the research is that definition of critical 3D structural and mechanical features of a cell's ECM environment, especially at the micro level, as well as identification of the mechanisms by which they influence cell behavior will make it possible to engineer biomaterials with specific material properties that predictably induce a cellular response that accelerates or improves tissue restoration. The objective of the proposed research will be achieved by pursuing three specific aims: 1) determine the morphological, phenotypic, cell-matrix adhesion, and ECM remodeling properties of fibroblasts within 3D ECMs in which the micro-structure is quantified and controllably varied and no external mechanical loads are applied; 2) determine the morphological, phenotypic, cell-matrix adhesion, and ECM remodeling properties of fibroblasts within 3D ECMs in which the micro-mechanical properties (e.g., 3D micro level stress and strain fields) are quantified and controllably varied by application of external mechanical loads; and 3) identify mechanisms by which fibroblasts perceive the micro-structural composition and micro-mechanical state of the surrounding 3D ECM. Expertise in the areas of ECM biochemistry, cell biology, biomechanics, and bioimaging will be combined to yield the following outcomes. First, specific structural-mechanical attributes of a cell's ECM micro-environment will be quantitatively defined. In turn, the dependence of the cellular response on specific micro-structural and mechanical properties of a 3D ECM will be established in the presence and absence of externally applied mechanical loads. Third, the effect of other major cellular signals on the ability of cells to sense and response to these biophysical cues will be determined. Fourth, key events associated with celI-ECM adhesion that provide cells with the ability to sense and respond to physical properties of a 3D ECM microenvironment will be identified. Collectively, these outcomes will provide new information regarding the physical aspects of celI-ECM interaction and establish the role of cell-matrix adhesions in the ability of cells to respond to 3D structural and mechanical cues provided by the ECM. This research is significant to tissue engineering and medicine because the results are expected to define much needed fundamental principles and design criteria that will lay the foundation for directed repair of damaged tissues.