The alteration of a mechanical property of bone cells during the process of changing from osteoblasts to osteocytes
The alteration of a mechanical property of bone cells during the process of changing from osteoblasts to osteocytes
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DOI：
10.1016/j.bone.2008.02.020
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发表时间：
2008-07-01
期刊：
影响因子：
4.1
通讯作者：
Takano-Yarnamoto, Teruko
中科院分区：
文献类型：
--
作者：
Sugawara, Yasuyo;Ando, Ryoko;Takano-Yarnamoto, Teruko
骨细胞是在骨中由成骨细胞向成骨细胞转化的过程中获得其星状形状的。在整个过程中，细胞骨架发生动态变化。一般来说，细胞骨架的变化影响细胞的力学性能。活细胞的力学性质与其生物学功能和生理过程有关。在这项研究中，我们首次分析了弹性模量，骨细胞的力学性质。用荧光标记的鬼笔环肽和鸡骨细胞特异性单克隆抗体OB7.3对鸡胚颅骨和分离培养的骨细胞进行鉴定，然后用共聚焦激光扫描显微镜进行观察。用原子力显微镜分析活细胞的弹性模量。为了检查粘着斑形成对弹性模量的影响，用GRGDS和GRGES预处理细胞，然后分析细胞的弹性模量。黏着斑蛋白的免疫荧光显示细胞中的粘着斑。从荧光图像中，我们可以区分成骨细胞，类骨细胞和成熟的骨细胞在体内和体外。在所有三个群体中的细胞的周边区域的弹性模量显着高于在其核区域。成骨细胞周围区域的弹性模量为12053 +/- 934 Pa，骨样骨细胞为7971 +/- 422 Pa，成熟骨细胞为4471 +/- 198 Pa。这些结果表明，骨细胞的弹性模量水平与成骨细胞向骨细胞转化的阶段成正比。成骨细胞的粘着斑面积明显大于骨细胞。GRGDS处理后，成骨细胞的粘着斑面积减少，而骨细胞的粘着斑面积没有减少。GRGDS处理后成骨细胞和骨样骨细胞的弹性模量降低。而成熟骨细胞则无明显变化。骨细胞的弹性模量力学性能和局部粘附情况呈动态变化。(C)2008年爱思唯尔公司All rights reserved.
Osteocytes acquire their stellate shape during the process of changing from osteoblasts in bone. Throughout this process, dynamic cytoskeletal changes occur. In general, changes of the cytoskeleton affect cellular mechanical properties. Mechanical properties of living cells are connected with their biological functions and physiological processes. In this study, we for the first time analyzed elastic modulus, a mechanical property of bone cells. Bone cells in embryonic chick calvariae and in isolated culture were identified using fluorescently labeled phalloidin and OB7.3, a chick osteocyte-specific monoclonal antibody, and then observed by confocal laser scanning microscopy. The elastic modulus of living cells was analyzed with atomic force microscopy. To examine, the consequences of focal adhesion formation on the elastic modulus, cells were pretreated with GRGDS and GRGES, and then the elastic modulus of the cells was analyzed. Focal adhesions in the cells were visualized by immunofluorescence of vinculin. From fluorescence images, we could distinguish osteoblasts, osteoid osteocytes and mature osteocytes both in vivo and in vitro. The elastic modulus of peripheral regions of cells in all three populations was significantly higher than in their nuclear regions. The elastic modulus of the peripheral region of osteoblasts was 12053 +/- 934 Pa, that of osteoid osteocytes was 7971 +/- 422 Pa and that of mature osteocytes was 4471 +/- 198 Pa. These results suggest that the level of elastic modulus of bone cells was proportional to the stage of changing from osteoblasts to osteocytes. The focal adhesion area of osteoblasts was significantly higher than that of osteocytes. The focal adhesion area of osteoblasts was decreased after treatment with GRGDS, however, that of osteocytes was not. The elastic modulus of osteoblasts and osteoid osteocytes were decreased after treatment with GRGDS. However, that of mature osteocytes was not changed. There were dynamic changes in the mechanical property of elastic modulus and in focal adhesions of bone cells. (C) 2008 Elsevier Inc. All rights reserved.