原子力显微镜技术检测几种骨组织细胞力学性能

Investigation of Mechanical Property of Various Bone Cell Lines by Atomic Force Microscopy

为了探究几种骨组织细胞系的力学性能及其与细胞功能的关系,该文采用原子力显微镜压陷法分别检测了前成骨细胞系(2T3和MC3T3-E1)、前骨细胞系(MLO-A5)和骨样细胞系(MLO-Y4)的杨氏模量,利用激光共聚焦显微镜观察了这几种细胞微丝和微管的排布。结果显示,2T3,MC3T3-E1、MLO-A5和MLO-Y4细胞的杨氏模量分别为(7000±2015)Pa、(6600±2024)Pa、(4700±1644)Pa和(4500±1622)Pa,与原代骨组织细胞的杨氏模量及变化趋势保持一致,但两种前成骨细胞的杨氏模量要显著高于前骨细胞和骨细胞。细胞荧光染色结果表明,前成骨细胞细胞核周围的微丝和微管分布密度要高于前骨细胞和骨细胞,而前骨细胞MLO-A5,尤其是骨细胞MLOY4的骨架主要集中于细胞突触和边缘,这可能是导致几种细胞力学性能差异的原因。该研究从生物力学的角度为进一步深入理解骨组织细胞结构与功能的关系提供了实验依据。

In order to investigate the mechanical property of various bone cell lines and its relation with cell function, atomic force microscopy （AFM） was used to probe the Young＇s modulus of pre-osteoblast （2T3 and MC3T3-E1）, pre-osteocyte （MLO-A5） and osteocyte （MLO-Y4）. The fluorescent images of cell cytoskeleton such as F-actin and microtubule were detected by laser confocal microscopy. The results demonstrated that the Young＇s modulus of 2T3, MC3T3-E1, MLO-A5 and MLO-Y4 cell lines were （7 000±2 015） Pa, （6 600±2 024） Pa, （4 700± 1 644） Pa and （4 500±1 622） Pa, respectively. Interestingly, the Young＇s modulus ofpro-osteoblast was significantly higher than those of MLO-A5 and MLO-Y4, and this tendency of change in the Young＇s modulus was consistent with that of primary bone cells in different differentiation states. Meanwhile, the images of cytoskeleton showed that thick bundles of the F-actin and microtubule in 2T3 and MC3T3-E1 were concentrated in peri-nuclear region. But for MLO-A5, especially for the MLO-Y4, the cytoskeletons were mainly distributed in the cell process or cell periphery, which might be one reason to explain the low Young＇s modulus in the MLO-A5 and MLO-Y4 cells. This study, for a biomechanical view, provided a basis interpretation for deeply understanding the relationship between the cell function and their structure.