Chondrocyte deformation within compressed agarose constructs at the cellular and sub-cellular levels
Chondrocyte deformation within compressed agarose constructs at the cellular and sub-cellular levels
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DOI：
10.1016/s0021-9290(99)00160-8
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发表时间：
2000-01-01
影响因子：
2.4
通讯作者：
Bader, DL
中科院分区：
文献类型：
--
作者：
Lee, DA;Knight, MM;Bader, DL
关节软骨中的机械转导事件可以分解为细胞外组分，随后是细胞内信号传导事件，其最终导致改变的细胞反应。细胞变形是前者的组成部分之一，这已被检查使用的模型涉及牛软骨细胞接种在琼脂糖结构。活荧光标记和共聚焦激光扫描显微镜用于检查细胞和亚细胞形态。据观察，细胞大小增加到第6天的文化，与蛋白多糖和胶原蛋白的含量增加。此外，组织的细胞骨架组件，使用一个简单的评分尺度，揭示了时间的变化，肌动蛋白纤维，微管和波形蛋白中间丝。第1天的结构也经受无侧限压缩应变。通过单个细胞中心的一系列共聚焦扫描显示了从球形到椭圆形形态的变化。直径比从0%应变时的平均值1.00变为25%应变时的平均值0.60，证明了这一点。使用简单的方程，体积和表面积也从扫描中估计。虽然前者显示随着结构应变的增加几乎没有变化，但表面积似乎显著增加。然而，进一步的检查，使用透射电子显微镜，以揭示在细胞周边的超微结构细节，表明这种增加可能是由于在细胞膜的折叠解开。细胞变形与核直径的减少，在所施加的应变的方向。在随后的时间点压缩的结构中，一个方向上产生的核应变增加，尽管其在所有三个评估时间的值均小于细胞应变的相应值。有人建议，核的行为可能是一个直接的结果，观察到的组织中的细胞骨架的时间变化。该研究表明，软骨细胞-琼脂糖模型提供了一个有用的系统，在细胞和亚细胞水平上的压缩事件的检查。(C)1999 Elsevier Science Ltd.保留所有权利。
Mechanotransduction events in articular cartilage may be resolved into extracellular components followed by intracellular signalling events, which finally lead to altered cell response. Cell deformation is one of the former components, which has been examined using a model involving bovine chondrocytes seeded in agarose constructs. Viable fluorescent labels and confocal laser scanning microscopy were used to examine cellular and sub-cellular morphology. It was observed that cell size increased up to day 6 in culture, associated with an increase in the contents of proteoglycan and collagen. In addition, the organisation of the cytoskeleton components, described using a simple scoring scale, revealed temporal changes for actin fibres, microtubules and vimentin intermediate filaments. The constructs on day 1 were also subjected to unconfined compressive strains. A series of confocal scans through the centre of individual cells revealed a change from a spherical to an elliptical morphology. This was demonstrated by a change in diameter ratio, from a mean value of 1.00 at 0% strain to 0.60 at 25% strain. Using simple equations, the volume and surface areas were also estimated from the scans. Although the former revealed little change with increasing construct strain, surface area appeared to increase significantly. However further examination, using transmission electron microscopy to reveal fine ultrastructural detail at the cell periphery, suggest that this increase may be due to an unravelling of folds at the cell membrane. Cell deformation was associated with a decrease in the nuclear diameter, in the direction of the applied strain. The resulting nuclear strain in one direction increased in constructs compressed at later time points, although its values at all three assessment times were less than the corresponding values for cell strain. It is suggested that the nuclear behaviour may be a direct result of temporal changes observed in the organisation of the cytoskeleton. The study demonstrated that the chondrocyte-agarose model provides a useful system for the examination of compression events at both cellular and sub-cellular levels. (C) 1999 Elsevier Science Ltd. All rights reserved.