DYNAMIC MICROMECHANICAL PROPERTIES OF CULTURED RAT ATRIAL MYOCYTES MEASURED BY ATOMIC-FORCE MICROSCOPY
DYNAMIC MICROMECHANICAL PROPERTIES OF CULTURED RAT ATRIAL MYOCYTES MEASURED BY ATOMIC-FORCE MICROSCOPY
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DOI：
10.1152/ajpcell.1995.269.1.c286
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发表时间：
1995-07-01
影响因子：
5.5
通讯作者：
LAL, R
中科院分区：
文献类型：
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作者：
SHROFF, SG;SANER, DR;LAL, R
原子力显微镜（AFM）用于量化微机械性能（即，定位于类似于0.015 μ m（2）的区域）的培养的大鼠心房肌细胞。无钙溶液中的静止细胞在核区域上是相当可压缩的，例如，3-4 nN的力产生180-225 nm的单元压痕。静止细胞的横向刚度增加了类似的2倍后，细胞外钙从0到5 mM的增加和类似的16倍后，固定与福尔马林。有五至八倍的变化，在细胞表面的静止细胞的刚度，这样的刚度是最低的核区域，并增加对细胞周边。这些区域的变化与细胞骨架的异质性所揭示的原子力显微镜和荧光成像。局部收缩活动的跳动细胞可以监测的表面变形与高横向空间（类似于1-3 nm）和时间（60-100 μ s）的分辨率。可以观察到细胞收缩活动的变化与生理扰动和细胞刚度的动态变化在一个单一的收缩。这些结果证明了基于原子力显微镜表征高度局部化的细胞微观力学性能的可行性。局部细胞力学行为和潜在的生化和/或结构环境之间的关系，理解细胞（dys）功能的一个重要方面，现在可以直接检查。
The atomic force microscope (AFM) was used to quantify micromechanical properties (i.e., localized to an area of similar to 0.015 mu m(2)) of cultured rat atrial myocytes. Quiescent cells in calcium-free solution were quite compressible over the nuclear region, e.g., a force of 3-4 nN produced 180-225 nm cell indentation. Transverse stiffness of quiescent cells increased by similar to 2-fold after an increase in extracellular calcium from 0 to 5 mM and by similar to 16-fold after fixation with Formalin. There was five- to eightfold variation in stiffness of quiescent cells over the cell surface, such that stiffness was lowest over the nuclear region, and it increased toward the cell periphery. These regional variations correlated with the cytoskeletal heterogeneity as revealed by the AFM and fluorescence imaging. Localized contractile activity of beating cells could be monitored in terms of the surface deformation with high transverse spatial (similar to 1-3 nm) and temporal (60-100 mu s) resolutions. Alterations in cell contractile activity with physiological perturbations and dynamic changes in cell stiffness during a single contraction could be observed. These results demonstrate the feasibility of AFM-based characterization of highly localized cellular micromechanical properties. Relationships among localized cell mechanical behavior and the underlying biochemical and/or structural environment, a crucial aspect in understanding cellular (dys)function, can now be directly examined.