Vivien D, Galera P, Loyau G, Pujol J P
Laboratoire de Biochemie du Tissu Conjonctif, Université de Caen, France.
Eur J Cell Biol. 1991 Apr;54(2):217-23.
We show that addition of TGF-beta (0.01-10 ng/ml) to proliferating rabbit articular chondrocytes in presence of low level of fetal calf serum (FCS, 2%) results in a sustained decrease of cell number and DNA synthesis up to 72 h. In contrast, incubation with high serum concentration (10% FCS) induces a transient increase of cell number after 48 h without elevation of DNA synthesis. Moreover, when the factor is added in 10% FCS-containing medium, a differential effect is observed at 48 h (either increase or decrease of cell number) depending on the serum level (2 or 10%) present between 24 and 48 h. Recruitment of cells in late S-phase occurred under TGF-beta-treatment in both 2 and 10% FCS. These arrested cells may then be released by further exposure to 10% FCS-containing medium. The data show that factor(s) from the serum modulate(s) the action of TGF-beta on chondrocyte proliferation. Addition of epidermal growth factor (EGF) to the cultures in presence of 2% FCS mimicks the effects observed with 10% serum, suggesting that the serum component(s) involved in the mechanism could be of EGF type.
我们发现，在低水平胎牛血清（FCS，2%）存在的情况下，向增殖的兔关节软骨细胞中添加TGF-β（0.01 - 10 ng/ml）会导致细胞数量和DNA合成持续减少，长达72小时。相比之下，在高血清浓度（10% FCS）下孵育48小时后会诱导细胞数量短暂增加，但DNA合成无升高。此外，当在含10% FCS的培养基中添加该因子时，在48小时观察到不同的效应（细胞数量增加或减少），这取决于24至48小时之间存在的血清水平（2%或10%）。在2%和10% FCS中，TGF-β处理均导致细胞在S期晚期募集。这些停滞的细胞随后可能通过进一步暴露于含10% FCS的培养基而被释放。数据表明，血清中的因子调节TGF-β对软骨细胞增殖的作用。在含2% FCS的培养物中添加表皮生长因子（EGF）可模拟在10%血清中观察到的效应，这表明该机制中涉及的血清成分可能是EGF类型。
