Wang Hongxin, Zhang Han, Tamura Ryo, Da Bo, Abdellatef Shimaa A, Watanabe Ikumu, Ishida Nobuyuki, Fujita Daisuke, Hanagata Nobutaka, Nakagawa Tomoki, Nakanishi Jun
Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan.
Center for Basic Research on Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan.
Sci Technol Adv Mater. 2023 Oct 18;24(1):2265434. doi: 10.1080/14686996.2023.2265434. eCollection 2023.
The response of cells to environmental stimuli, under either physiological or pathological conditions, plays a key role in determining cell fate toward either adaptive survival or controlled death. The efficiency of such a feedback mechanism is closely related to the most challenging human diseases, including cancer. Since cellular responses are implemented through physical forces exerted on intracellular components, more detailed knowledge of force distribution through modern imaging techniques is needed to ensure a mechanistic understanding of these forces. In this work, we mapped these intracellular forces at a whole-cell scale and with submicron resolution to correlate intracellular force distribution to the cytoskeletal structures. Furthermore, we visualized dynamic mechanical responses of the cells adapting to environmental modulations in situ. Such task was achieved by using an informatics-assisted atomic force microscope (AFM) indentation technique where a key step was Markov-chain Monte Carlo optimization to search for both the models used to fit indentation force-displacement curves and probe geometry descriptors. We demonstrated force dynamics within cytoskeleton, as well as nucleoskeleton in living cells which were subjected to mechanical state modulation: myosin motor inhibition, micro-compression stimulation and geometrical confinement manipulation. Our results highlight the alteration in the intracellular prestress to attenuate environmental stimuli; to involve in cellular survival against mechanical signal-initiated death during cancer growth and metastasis; and to initiate cell migration.
在生理或病理条件下，细胞对环境刺激的反应在决定细胞命运走向适应性存活或可控死亡方面起着关键作用。这种反馈机制的效率与包括癌症在内的最具挑战性的人类疾病密切相关。由于细胞反应是通过施加在细胞内成分上的物理力来实现的，因此需要通过现代成像技术更详细地了解力的分布，以确保对这些力有一个机械学的理解。在这项工作中，我们在全细胞尺度上以亚微米分辨率绘制了这些细胞内力，以将细胞内力分布与细胞骨架结构相关联。此外，我们原位可视化了细胞适应环境调节的动态力学反应。这项任务是通过使用信息学辅助原子力显微镜（AFM）压痕技术实现的，其中关键步骤是马尔可夫链蒙特卡罗优化，以寻找用于拟合压痕力-位移曲线的模型和探针几何描述符。我们展示了在受到机械状态调节（肌球蛋白运动抑制、微压缩刺激和几何限制操作）的活细胞中，细胞骨架以及核骨架内的力动态。我们的结果突出了细胞内预应力的改变，以减弱环境刺激；参与细胞在癌症生长和转移过程中抵抗机械信号引发的死亡的存活；以及启动细胞迁移。
