Nevo Z, Beit-Or A, Eilam Y
Department of Chemical Pathology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Mech Ageing Dev. 1988 Nov 14;45(2):157-65. doi: 10.1016/0047-6374(88)90105-4.
Cultured epiphyseal-chondrocytes from embryonic chick may serve as a useful in vitro model to study aging processes in cartilage. The accelerated aging process in cultured chondrocytes is completed within a month and is manifested by typical changes in both cellular and extracellular compartments. Under common maintenance conditions, cells show a gradual loss of replicative capacity, increase in the rate of proteoglycan synthesis and age-dependent changes in the structure and composition of proteoglycan. An environmental factor--reduced oxygen tension--was found to slow down aging processes and preserve the young features of chondrocytes for a longer duration in culture. Cultures maintained under lower oxygen tension had higher proliferation rate, smaller cell size, lower rate of proteoglycan synthesis, and lower content of keratan sulfate side chains in the proteoglycan. In addition higher concentrations of free cytosolic calcium [Ca2+]in as compared to control cultures, was found. It is suggested that the increased proliferation rate and the decrease in proteoglycan synthesis caused by low oxygen tension may be signalled by the higher [Ca2+]in in these cells.
来自胚胎鸡的培养骨骺软骨细胞可作为研究软骨衰老过程的有用体外模型。培养的软骨细胞加速衰老过程在一个月内完成，并表现为细胞内和细胞外区室的典型变化。在常规维持条件下，细胞显示出复制能力逐渐丧失、蛋白聚糖合成速率增加以及蛋白聚糖结构和组成的年龄依赖性变化。发现一种环境因素——降低的氧张力——可减缓衰老过程，并在培养中更长时间地保持软骨细胞的年轻特征。在较低氧张力下维持的培养物具有较高的增殖率、较小的细胞大小、较低的蛋白聚糖合成速率以及蛋白聚糖中硫酸角质素侧链的较低含量。此外，与对照培养物相比，发现这些细胞中的游离胞质钙[Ca2+]浓度更高。有人认为，低氧张力引起的增殖率增加和蛋白聚糖合成减少可能由这些细胞中较高的[Ca2+]浓度发出信号。
