D'Souza A L, Masuda K, Otten L M, Nishida Y, Knudson W, Thonar E J
Department of Biochemistry, Rush Medical College at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, 60612, USA.
Arch Biochem Biophys. 2000 Feb 1;374(1):59-65. doi: 10.1006/abbi.1999.1626.
Phenotypically stable young adult bovine articular chondrocytes suspended in beads of alginate gel were first cultured for 5 days, using daily changes of medium containing 10% fetal bovine serum and supplements. The cells in the beads were then maintained in culture for a further 3 days in the presence or absence of interleukin-1alpha at 1 ng/ml in the daily change of medium. The exposure to interleukin-1alpha caused the incorporation of (35)S-sulfate into the predominant cartilage proteoglycan, aggrecan, to decrease by approximately 60%. In addition, proteoglycans that had accumulated into the cell-associated matrix during the first 5 days of culture in the absence of interleukin-1alpha moved into the matrix further removed from the cells and from there into the medium. In contrast, the exposure to interleukin-1alpha was found to markedly promote the rate of synthesis of hyaluronan, especially during the first 24 h. Over the 3 days of culture in the presence of interleukin-1alpha, a large proportion of the newly synthesized hyaluronan molecules, as well as those that had previously become residents of the cell-associated matrix, moved out of this compartment and appeared to become permanent residents of the further removed matrix. These results demonstrate that exposure of young adult articular chondrocytes to interleukin-1alpha has profound effects on the metabolism of hyaluronan, a molecule that plays a critical role in the retention of proteoglycan molecules in the matrix. Importantly, the results suggest that exposure of chondrocytes to interleukin-1 in inflamed joints, such as occurs in rheumatoid arthritis, leads to the rapid loss of coordination of the synthesis of aggrecan and hyaluronan, two of the critical constituents of the proteoglycan aggregate. In addition, we present evidence that these interleukin-1-induced effects differentially alter the metabolism of hyaluronan in the metabolically active cell-associated matrix and the metabolically inactive matrix further removed from the chondrocytes.
将悬浮于藻酸盐凝胶珠中的表型稳定的年轻成年牛关节软骨细胞，首先在含有10%胎牛血清和添加剂的培养基中培养5天，每天更换培养基。然后，在每天更换的培养基中，在有或无1 ng/ml白细胞介素-1α的情况下，将珠中的细胞再培养3天。暴露于白细胞介素-1α导致（35）S-硫酸盐掺入主要的软骨蛋白聚糖聚集蛋白聚糖中减少约60%。此外，在无白细胞介素-1α的情况下培养的前5天内积累到细胞相关基质中的蛋白聚糖，迁移到离细胞更远的基质中，并从那里进入培养基。相反，发现暴露于白细胞介素-1α可显著促进透明质酸的合成速率，尤其是在最初的24小时内。在有白细胞介素-1α存在的3天培养过程中，很大一部分新合成的透明质酸分子，以及那些先前已成为细胞相关基质驻留分子的透明质酸分子，移出了这个隔室，似乎成为更远基质中的永久驻留分子。这些结果表明，年轻成年关节软骨细胞暴露于白细胞介素-1α对透明质酸的代谢有深远影响，透明质酸是一种在基质中保留蛋白聚糖分子方面起关键作用的分子。重要的是，结果表明，软骨细胞暴露于类风湿性关节炎等炎症关节中的白细胞介素-1会导致聚集蛋白聚糖和透明质酸这两种蛋白聚糖聚集体的关键成分的合成迅速失去协调。此外，我们提供的证据表明，这些白细胞介素-1诱导的效应会不同程度地改变代谢活跃的细胞相关基质和离软骨细胞更远的代谢不活跃基质中透明质酸的代谢。
