摘要
观察了ConA对培养软骨细胞PG合成代谢的影响。证实ConA能够使培养的软骨细胞高分子硫酸化PG的合成增加3~4倍,其分子量、硫酸化部位和硫酸化程度与对照组相比无明显差异,是具有正常结构的软骨型PG。ConA对低分子型PG的合成未见明显的影响。ConA促进PG合成的作用可由MeMan完全解除,比具有同样效应的激素、生长因子都强,并有明显的凝集素特异性。推测ConA的作用可能与软骨细胞膜或细胞内的分化诱导因子的受体或软骨中存在的ConA软骨细胞分化因子有关。
The effect of concanavalin A(ConA)on proteoglycan synthesis by rabbit costal chondrocyte was examined. Chondrocytes were seeded at low density and grown in MEM medium containing 10 % fetal bovine serum, 50 μg/ml of ascorbic acid and antibiotics at 37℃ under 5 % CO_2 in air. At the 0. 3% of serum concentration, addition of ConA to the culture medium increased by 3 to 4 fold the incorporation of [ ̄(35)S] sulfate,[ ̄3H] glucosamine and [ ̄3H] serine into large cartilagespecific proteoglycan that characteristically found in cartilage. Chemical analysis showed a 4 fold increase in the accumulation of macromolecular containing hexuronic acid in ConA-maintained cultures. However, ConA had less effects on [ ̄(35)S] sulfate incorporation into small proteoglycan and [ ̄3H] glucosamine incorporation into hyaluronic acid and chondroitinase resistant glycosaminoglycans. The effect of ConA on [ ̄(35)S] sulfate incorporation into proteoglycan was greater than that of various growth factor or hormones. Methyl-D-mannopyranoside reversed the effect of ConA on [(35)S] sulfate incorporation into proteoglycan. Since other lectins, such as wheat germ agglutinin, lentil lectin, phytohemagglutinin, Ulex europeasu agglutinin and garden pea lectin had been tested to have little effect on [ ̄(35)S] sulfate incorporation into proteoglycans, the ConA action on chondrocytes seems specific. These results indicate that ConA is a potent modulator of proteoglycan synthesis by chondrocyte.