Micro-Mechanical Characterization of Lung Tissue Using Atomic Force Microscopy
Micro-Mechanical Characterization of Lung Tissue Using Atomic Force Microscopy
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DOI：
10.3791/2911
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发表时间：
2011-08-01
影响因子：
1.2
通讯作者：
Tschumperlin, Daniel J.
中科院分区：
文献类型：
--
作者：
Liu, Fei;Tschumperlin, Daniel J.
基质硬度强烈影响贴壁细胞的生长、分化和功能(1-3)。在宏观尺度上，人体组织和器官的硬度跨越几个数量级(4)。关于组织内硬度如何在空间上变化，以及在导致组织重塑的疾病过程中硬度变化的范围和空间尺度，人们知之甚少。为了更好地了解基质硬度的变化如何影响健康和疾病的细胞生理学，需要在与常驻细胞相关的空间尺度上获得组织硬度的测量。对于肺来说尤其如此，肺是一种高度顺应性和弹性的组织，其中基质重塑是哮喘、肺气肿、高血压和纤维化等疾病的一个显着特征。为了在与常驻细胞相关的空间尺度上表征肺实质的局部机械环境，我们开发了使用原子力显微镜（AFM）微压痕直接测量新鲜小鼠肺组织的局部弹性特性的方法。通过适当选择 AFM 压头、悬臂和压痕深度，这些方法可以与感兴趣区域的相差和荧光成像并行地测量局部组织剪切模量。组织条的系统采样提供了组织机械特性图，揭示了剪切模量的局部空间变化。机械性能与潜在的解剖学和病理学特征之间的相关性说明了刚度如何随纤维化中的基质沉积而变化。这些方法可以扩展到其他软组织和疾病过程，以揭示局部组织机械特性如何随空间和疾病进展而变化。
Matrix stiffness strongly influences growth, differentiation and function of adherent cells(1-3). On the macro scale the stiffness of tissues and organs within the human body span several orders of magnitude(4). Much less is known about how stiffness varies spatially within tissues, and what the scope and spatial scale of stiffness changes are in disease processes that result in tissue remodeling. To better understand how changes in matrix stiffness contribute to cellular physiology in health and disease, measurements of tissue stiffness obtained at a spatial scale relevant to resident cells are needed. This is particularly true for the lung, a highly compliant and elastic tissue in which matrix remodeling is a prominent feature in diseases such as asthma, emphysema, hypertension and fibrosis. To characterize the local mechanical environment of lung parenchyma at a spatial scale relevant to resident cells, we have developed methods to directly measure the local elastic properties of fresh murine lung tissue using atomic force microscopy (AFM) microindentation. With appropriate choice of AFM indentor, cantilever, and indentation depth, these methods allow measurements of local tissue shear modulus in parallel with phase contrast and fluorescence imaging of the region of interest. Systematic sampling of tissue strips provides maps of tissue mechanical properties that reveal local spatial variations in shear modulus. Correlations between mechanical properties and underlying anatomical and pathological features illustrate how stiffness varies with matrix deposition in fibrosis. These methods can be extended to other soft tissues and disease processes to reveal how local tissue mechanical properties vary across space and disease progression.