Liu Xueyan, Wei Yuhui, Li Wei, Li Bin, Liu Lin
Key Laboratory of Medicine, School of Laboratory Medicine and Life Sciences, Ministry of Education of China, Wenzhou Medical University, Wenzhou, China.
Division of Physical Biology and Bioimaging Centre, Shanghai Synchrotron Radiation Facility, CAS Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai, China.
J Cell Physiol. 2021 May;236(5):3725-3733. doi: 10.1002/jcp.30110. Epub 2020 Nov 10.
The cytoskeleton acts as a scaffold for membrane protrusion, such as microvilli. However, the relationship between the characteristics of microvilli and cytoskeleton remains poorly understood under the physiological state. To investigate the role of the cytoskeleton in regulating microvilli and cellular mechanical properties, atomic force microscopy (AFM) was used to detect the dynamic characteristics of microvillus morphology and elastic modulus of living HeLa cells. First, HeLa and MCF-7 cell lines were stained with Fluor-488-phalloidin and microtubules antibody. Then, the microvilli morphology was analyzed by high-resolution images of AFM in situ. Furthermore, changes in elastic modulus were investigated by the force curve of AFM. Fluorescence microscopy and AFM results revealed that destroyed microfilaments led to a smaller microvilli size, whereas the increase in the aggregation and number of microfilaments led to a larger microvilli size. The destruction and aggregation of microfilaments remarkably affected the mechanical properties of HeLa cells. Microtubule-related drugs induced the change of microtubule, but we failed to note significant differences in microvilli morphology and mechanical properties of cells. In summary, our results unraveled the relationship between microfilaments and the structure of microvilli and Young's modulus in living HeLa cells, which would contribute to the further understanding of the physiological function of the cytoskeleton in vivo.
细胞骨架作为膜突出结构（如微绒毛）的支架。然而，在生理状态下，微绒毛特征与细胞骨架之间的关系仍知之甚少。为了研究细胞骨架在调节微绒毛和细胞力学特性中的作用，采用原子力显微镜（AFM）检测活HeLa细胞微绒毛形态的动态特征和弹性模量。首先，用荧光素-488-鬼笔环肽和微管抗体对HeLa和MCF-7细胞系进行染色。然后，通过AFM原位高分辨率图像分析微绒毛形态。此外，通过AFM力曲线研究弹性模量的变化。荧光显微镜和AFM结果显示，微丝破坏导致微绒毛尺寸变小，而微丝聚集和数量增加导致微绒毛尺寸变大。微丝的破坏和聚集显著影响HeLa细胞的力学性能。微管相关药物诱导微管变化，但我们未注意到细胞微绒毛形态和力学性能的显著差异。总之，我们的结果揭示了活HeLa细胞中微丝与微绒毛结构及杨氏模量之间的关系，这将有助于进一步了解体内细胞骨架的生理功能。
