Mechanical Point Loading Induces Cortex Stiffening and Actin Reorganization
Mechanical Point Loading Induces Cortex Stiffening and Actin Reorganization
复制标题
机械点加载引起皮层僵硬和肌动蛋白重组
DOI：
10.1016/j.bpj.2019.09.012
复制
发表时间：
2019-10-15
影响因子：
3.4
通讯作者：
Long, Mian
中科院分区：
文献类型：
--
作者：
Hu, Jinrong;Chen, Shenbao;Long, Mian
当细胞暴露于不同的机械刺激时，整体细胞骨架重组已被广泛认识，但细胞特定区域的局部反应仍不清楚。在这项工作中，我们使用原子力显微镜在 PeakForce 定量纳米力学模式下原位绘制了静态点加载这些细胞之前和之后单细胞的细胞表面机械特性。在加载位点附近，细胞表面硬度最高提高了 1.35 倍，表明皮层对细胞的结构保护得到了增强。机械模型还阐明了硬化细胞皮层的结构保护，其中细胞核的最大应力和应变分别降低了 9-15% 和 10-19%。此外，使用平端原子力显微镜探针定量捕获点加载后的细胞骨架重组，发现施加的力越大、加载时间越长，细胞骨架重组越明显。此外，使用微针与实时共聚焦显微镜相结合的点加载揭示了点加载后肌动蛋白染色的活细胞肌动蛋白细胞骨架重组的快速动态（
Global cytoskeleton reorganization is well-recognized when cells are exposed to distinct mechanical stimuli, but the localized responses at a specified region of a cell are still unclear. In this work, we mapped the cell-surface mechanical property of single cells in situ before and after static point loading these cells using atomic force microscopy in PeakForce-Quantitative Nano Mechanics mode. Cell-surface stiffness was elevated at a maximum of 1.35-fold at the vicinity of loading site, indicating an enhanced structural protection of the cortex to the cell. Mechanical modeling also elucidated the structural protection from the stiffened cell cortex, in which 9-15% and 10-19% decrease of maximum stress and strain of the nucleus were obtained. Furthermore, the flat-ended atomic force microscopy probes were used to capture cytoskeleton reorganization after point loading quantitatively, revealing that the larger the applied force and the longer the loading time are, the more pronounced cytoskeleton reorganization is. Also, point loading using a microneedle combined with real-time confocal microscopy uncovered the fast dynamics of actin cytoskeleton reorganization for actin-stained live cells after point loading (