Comparison of cellular strain with applied substrate strain in vitro.
Comparison of cellular strain with applied substrate strain in vitro.
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DOI：
10.1016/j.jbiomech.2005.10.032
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发表时间：
2007
影响因子：
2.4
通讯作者：
M. Wall;P. Weinhold;T. Siu;T. Brown;A. Banes
中科院分区：
文献类型：
--
作者：
M. Wall;P. Weinhold;T. Siu;T. Brown;A. Banes
肌腱细胞内的应变幅度经历基板拉伸应变没有很好地定义。据推测，在细胞水平上的应变幅度将反映所施加的基板（等双轴或单轴）应变。采用真空操作装置对腱细胞单层培养的柔性基底施加等双轴或单轴张力。在应变之前和施加静态应变期间20分钟拍摄用Fura-2标记以检测游离细胞内钙离子和用MitoFluor™绿色标记以检测线粒体的腱细胞的图像。一个定制的，纹理相关程序计算应变幅度的基础上的变化，在像素模式之间的非应变和应变细胞的图像位移的细胞。平均而言，细胞应变分别约为施加的等双轴和单轴基底应变的37±8%和63±11%。最大的细胞应变中检测到的细胞定向平行于所施加的单轴拉伸应变的方向。然而，细胞内的应变大小是异质的。腱细胞内和腱细胞之间的应变幅度的变化取决于细胞取向、细胞刚度、细胞骨架组织、亚细胞器或细胞-基质接触的位置和类型。本研究的结果表明，培养的肌腱细胞经历了适度的分数所施加的基板应变。
Strain magnitudes within tenocytes undergoing substrate tensile strain are not well defined. It was hypothesized that strain magnitudes at the cellular level would reflect those of the applied substrate (equibiaxial or uniaxial) strain. A vacuum-operated device was used to apply equibiaxial or uniaxial tension to a flexible substrate upon which tenocytes were cultured in monolayer. Images of tenocytes labeled with Fura-2, to detect free intracellular calcium ions, and MitoFluor™ Green, to detect mitochondria, were taken prior to strain and for 20min during application of static strain. A custom-written, texture correlation program computed strain magnitudes in the cell based on the change in pixel pattern displacements between images of non-strained and strained cells. On average, cellular strain was approximately 37±8% and 63±11% of the applied equibiaxial and uniaxial substrate strain, respectively. The largest cell strains were detected in cells oriented parallel to the direction of applied uniaxial tensile strain. However, strain magnitudes within a cell were heterogeneous. The variance in strain magnitude within and among tenocytes is dependent on cell orientation, cell stiffness, cytoskeleton organization, subcellular organelles, or placement and type of cell-substrate contacts. Results of the present study indicate that cultured tenocytes experience a moderate fraction of the applied substrate strain.