The effects of osmotic stress on the viscoelastic and physical properties of articular chondrocytes
The effects of osmotic stress on the viscoelastic and physical properties of articular chondrocytes
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DOI：
10.1016/s0006-3495(02)75434-9
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发表时间：
2002-02-01
影响因子：
3.4
通讯作者：
Ting-Beall, HP
中科院分区：
文献类型：
--
作者：
Guilak, F;Erickson, GR;Ting-Beall, HP
关节软骨中软骨细胞的代谢活性受到组织渗透环境改变的影响，这种改变继发于机械压迫。渗透胁迫调节细胞生理的机制尚不完全清楚，可能涉及膜或细胞骨架物理性质的改变。本研究的目的是确定渗透环境对软骨细胞的机械和物理性质的影响。在等渗培养基中，软骨细胞呈球形，有许多膜褶。规范化的细胞体积与细胞外渗透压（Boyle van't Hoff关系）的倒数线性相关，渗透活性的细胞内水分数为61%。在去离子水中，软骨细胞单调膨胀直至溶解，平均表观膜面积为初始面积的234 +/- 49%。生物力学上，软骨细胞表现为粘弹性固体行为。细胞的瞬时弹性模量、平衡弹性模量和表观黏度在低渗胁迫下显著降低，而在高渗胁迫下基本不变。粘弹性的变化与皮层肌动蛋白在低渗应激下的快速解离和重塑是平行的。这些发现表明，物理化学环境对软骨细胞的粘弹性和物理特性有很强的影响，可能通过改变肌动蛋白细胞骨架。
The metabolic activity of chondrocytes in articular cartilage is influenced by alterations in the osmotic environment of the tissue, which occur secondary to mechanical compression. The mechanism by which osmotic stress modulates cell physiology is not fully understood and may involve changes in the physical properties of the membrane or the cytoskeleton. The goal of this study was to determine the effect of the osmotic environment on the mechanical and physical properties of chondrocytes. In isoosmotic medium, chondrocytes exhibited a spherical shape with numerous membrane ruffles. Normalized cell volume was found to be linearly related to the reciprocal of the extracellular osmolality (Boyle van't Hoff relationship) with an osmotically active intracellular water fraction of 61%. In deionized water, chondrocytes swelled monotonically until lysis at a mean apparent membrane area 234 +/- 49% of the initial area. Biomechanically, chondrocytes exhibited viscoelastic solid behavior. The instantaneous and equilibrium elastic moduli and the apparent viscosity of the cell were significantly decreased by hypoosmotic stress, but were unchanged by hyperosmotic stress. Changes in the viscoelastic properties were paralleled by the rapid dissociation and remodeling of cortical actin in response to hypoosmotic stress. These findings indicate that the physicochemical environment has a strong influence on the viscoelastic and physical properties of the chondrocyte, potentially through alterations in the actin cytoskeleton.