Pericellular Brush and Mechanics of Guinea Pig Fibroblast Cells Studied with AFM
Pericellular Brush and Mechanics of Guinea Pig Fibroblast Cells Studied with AFM
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DOI：
10.1016/j.bpj.2016.06.005
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发表时间：
2016-07-12
影响因子：
3.4
通讯作者：
Sokolov, Igor
中科院分区：
文献类型：
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作者：
Dokukin, Maxim;Ablaeva, Yulija;Sokolov, Igor
原子力显微镜（AFM）压痕方法结合刷子模型可以用来分离的细胞体的机械响应从周围的生物细胞的细胞周层的变形。虽然自洽的刷子模型推导出的细胞体的弹性模量已被证明，该模型的能力，表征细胞周围层尚未得到明确的验证。在这里，我们证明了它通过使用酶去除透明质酸内容物的细胞周刷豚鼠成纤维细胞。这种去除的效果在与细胞周围刷层相关的AFM力分离曲线中清楚地看到。我们进一步扩展刷子模型大于AFM探针的高度，这似乎是成纤维细胞的情况下刷。此外，我们证明了刷子模型的扩展（即，双刷模型）能够检测细胞周刷的分级结构，其例如可以由细胞周外套和膜外膜（微脊和微绒毛）组成。它使我们能够定量分离大的软多糖细胞外被从一个相对刚性和致密的膜包被层。这通过比较从在未处理的细胞上（当该波纹膜部分隐藏在细胞周刷层内时）和在酶促去除细胞周外套部分后（当波纹暴露于AFM探针时）在处理的细胞上收集的力曲线导出的膜波纹层的参数来验证。我们的结论是，刷模型不仅能够测量的力学的细胞体，但也的细胞周刷层的参数，包括定量表征的细胞周层结构。
The atomic force microscopy (AFM) indentation method combined with the brush model can be used to separate the mechanical response of the cell body from deformation of the pericellular layer surrounding biological cells. Although self-consistency of the brush model to derive the elastic modulus of the cell body has been demonstrated, the model ability to characterize the pericellular layer has not been explicitly verified. Here we demonstrate it by using enzymatic removal of hyaluronic content of the pericellular brush for guinea pig fibroblast cells. The effect of this removal is clearly seen in the AFM force-separation curves associated with the pericellular brush layer. We further extend the brush model for brushes larger than the height of the AFM probe, which seems to be the case for fibroblast cells. In addition, we demonstrate that an extension of the brush model (i.e., double-brush model) is capable of detecting the hierarchical structure of the pericellular brush, which, for example, may consist of the pericellular coat and the membrane corrugation (microridges and microvilli). It allows us to quantitatively segregate the large soft polysaccharide pericellular coat from a relatively rigid and dense membrane corrugation layer. This was verified by comparison of the parameters of the membrane corrugation layer derived from the force curves collected on untreated cells (when this corrugation membrane part is hidden inside the pericellular brush layer) and on treated cells after the enzymatic removal of the pericellular coat part (when the corrugations are exposed to the AFM probe). We conclude that the brush model is capable of not only measuring the mechanics of the cell body but also the parameters of the pericellular brush layer, including quantitative characterization of the pericellular layer structure.