Korhonen Rami K, Han Sang-Kuy, Herzog Walter
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, Alberta, T2N 1N4 Canada.
Mol Cell Biomech. 2010 Sep;7(3):125-34.
Changes in the osmotic environment cause changes in volume of isolated cells and cells in tissue explants, and the osmotic environment becomes hypotonic in cartilage diseases such as osteoarthritis (OA). However, it is not known how cells respond to a hypotonic osmotic challenge when situated in the fully intact articular cartilage. A confocal laser scanning microscope was used to image chondrocytes of intact rabbit patellae in an isotonic (300 mOsm) and hypotonic (172 mOsm) immersion medium. Cell volumes were calculated before and 5, 15, 60, 120 and 240 minutes after the change in saline concentration. Local tissue strains and swelling of the entire tissue were estimated from the relative movements of cells and displacements of single cells, respectively. Cell volumes increased rapidly (< or = 5 minutes, p<0.05) by approximately 22%, after which they remained constant for an hour (p>0.05). However, two and four hours post the hypotonic challenge, cell volumes were statistically greater (p<0.05) than those at all earlier time points, and swelling of the entire tissue continued throughout the four hour loading period. The results of our study suggest that osmotic loading induced volume changes of in situ chondrocytes in their native environment occur quickly and continue for hours. Understanding the behaviour of cells in their native environment provides novel insigth into the cell mechanics in ostearthritic joints and so may help understand the onset and progression of this disease.
渗透环境的变化会导致分离细胞以及组织外植体中细胞的体积发生变化，在骨关节炎（OA）等软骨疾病中，渗透环境会变成低渗状态。然而，尚不清楚当细胞处于完全完整的关节软骨中时，它们如何应对低渗渗透挑战。使用共聚焦激光扫描显微镜对处于等渗（300 mOsm）和低渗（172 mOsm）浸泡介质中的完整兔髌骨软骨细胞进行成像。在盐水浓度变化之前以及变化后5、15、60、120和240分钟计算细胞体积。分别根据细胞的相对运动和单个细胞的位移估计局部组织应变和整个组织的肿胀情况。细胞体积在<或 = 5分钟内迅速增加（p<0.05）约22%，此后一小时内保持恒定（p>0.05）。然而，在低渗挑战后两小时和四小时，细胞体积在统计学上大于所有早期时间点（p<0.05），并且在整个四小时加载期内整个组织的肿胀持续存在。我们的研究结果表明，在其天然环境中，渗透加载诱导的原位软骨细胞体积变化迅速发生并持续数小时。了解细胞在其天然环境中的行为为骨关节炎关节中的细胞力学提供了新的见解，因此可能有助于理解这种疾病的发病和进展。
