Introduction

Cell stretch is a method which can rapidly apply mechanical force through cell-matrix and cell-cell adhesions and can be utilized to better understand underlying biophysical questions related to intracellular force transmission and mechanotransduction.

Methods

3D printable stretching devices suitable for live-cell fluorescent imaging were designed using finite element modeling and validated experimentally. These devices were then used along with FRET based nesprin-2G force sensitive biosensors as well as live cell fluorescent staining to understand how the nucleus responds to externally applied mechanical force in cells with both intact LINC (linker of nucleoskeleton and cytoskeleton) complex and cells with the LINC complex disrupted using expression of dominant negative KASH protein.

Results

The devices were shown to provide a larger strain ranges (300% uniaxial and 60% biaxial) than currently available commercial or academic designs we are aware of. Under uniaxial deformation, the deformation of the nucleus of NIH 3T3 cells per unit of imposed cell strain was shown to be approximately 50% higher in control cells compared to cells with a disrupted LINC complex. Under biaxial deformation, MDCK II cells showed permanent changes in the nuclear morphology as well as actin organization upon unloading, indicating that failure, plastic deformation, or remodeling of the cytoskeleton is occurring in response to the applied stretch.

Conclusion

Development and open distribution of low-cost, 3D-printable uniaxial and biaxial cell stretching devices compatible with live-cell fluorescent imaging allows a wider range of researchers to investigate mechanical influences on biological questions with only a minimal investment of resources.

中文翻译：

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用于活细胞中成像力传输的 3D 打印拉伸装置的表征。

介绍

细胞拉伸是一种可以通过细胞-基质和细胞-细胞粘附快速施加机械力的方法，可用于更好地理解与细胞内力传递和机械转导相关的潜在生物物理问题。

方法

适用于活细胞荧光成像的 3D 打印拉伸装置是使用有限元建模设计的，并经过实验验证。然后将这些设备与基于 FRET 的 nesprin-2G 力敏生物传感器以及活细胞荧光染色一起使用，以了解细胞核如何对具有完整 LINC（核骨架和细胞骨架的接头）复合物的细胞和具有使用显性阴性 KASH 蛋白的表达破坏了 LINC 复合物。

结果

与我们所知道的目前可用的商业或学术设计相比，这些设备被证明可以提供更大的应变范围（300% 单轴和 60% 双轴）。在单轴变形下，每单位施加的细胞应变的 NIH T3 细胞核变形显示在对照细胞中比具有破坏的 LINC 的细胞高约 50%。在双轴变形下，MDCK II 细胞在卸载时显示出核形态和肌动蛋白组织的永久性变化，表明细胞骨架的失效、塑性变形或重塑正在响应施加的拉伸而发生。

结论

与活细胞荧光成像兼容的低成本、可 3D 打印的单轴和双轴细胞拉伸装置的开发和开放分发使更广泛的研究人员能够以最少的资源投资研究对生物问题的机械影响。