Stepp M A, Kindy M S, Franzblau C, Sonenshein G E
J Biol Chem. 1986 May 15;261(14):6542-7.
Cultured bovine aortic smooth muscle cells display an increase in production of type I and type III collagen as a function of the number of days in second passage (Beldekas, J. C., Gerstenfeld, L. C., Sonenshein, G. E., and Franzblau, C. (1982) J. Biol. Chem. 257, 12552-12556). In this study, we report that the regulation of these events is highly complex and relates to the growth state of the cells. Cultures, seeded at 1.5 X 10(6) cells/75-cm2 flask, produced very little collagenous protein early when the cells were proliferating rapidly. As they approached confluence at day 6, collagen synthesis began to increase. Maximal collagen synthesis was observed at day 14. In contrast, the levels of the mRNAs for type I and type III collagen increased only up to the 10th day and thereafter decreased. Cell-free translation analyses indicated that the translational activity of the collagen mRNAs was increasing over the time course. These results suggest that both translational and pretranslational sites are involved in the control of collagen production by aortic smooth muscle cells, and that collagen synthesis is inversely related to the proliferative state of the cells in culture.
培养的牛主动脉平滑肌细胞中，I型和III型胶原蛋白的产生量随着第二次传代天数的增加而增加（Beldekas, J. C., Gerstenfeld, L. C., Sonenshein, G. E., and Franzblau, C. (1982) J. Biol. Chem. 257, 12552 - 12556）。在本研究中，我们报告这些事件的调控高度复杂，且与细胞的生长状态有关。接种于75平方厘米培养瓶、密度为1.5×10⁶个细胞/瓶的细胞培养物，在细胞快速增殖的早期产生的胶原蛋白很少。在第6天接近汇合时，胶原蛋白合成开始增加。在第14天观察到胶原蛋白合成达到最大值。相比之下，I型和III型胶原蛋白的mRNA水平仅在第10天之前增加，此后下降。无细胞翻译分析表明，胶原蛋白mRNA的翻译活性在整个时间进程中不断增加。这些结果表明，翻译和翻译前位点均参与主动脉平滑肌细胞胶原蛋白产生的控制，且胶原蛋白合成与培养细胞的增殖状态呈负相关。
