Sottile J, Hoyle M, Millis A J
J Cell Physiol. 1987 May;131(2):210-7. doi: 10.1002/jcp.1041310210.
The secretory protein profiles of early and late passage cultures of human fibroblasts were compared using polyacrylamide gel electrophoresis. In comparison with early passage cell cultures (40-50% lifespan completed), late passage (greater than 80% of lifespan completed) cell cultures exhibited enhanced production of several peptides in the Mr range 55-60,000. One of those peptides had an apparent molecular weight of Mr = 55,000 and was constitutively present in the late passage cell conditioned medium. Late passage cell cultures synthesized the Mr = 55,000 peptide in the presence or absence of fetal bovine serum. Serum did not enhance its production by early passage cells. Further, production of the peptide was not induced in early passage cell cultures whose proliferation was arrested either by serum starvation or by contact inhibition. Pulse chase studies demonstrated that the peptide appears in the culture medium within 60 min of labeling. There was no evidence that it is derived via degradation of other proteins present either in early passage or late passage cell conditioned media. Further, the production of the 55,000 dalton peptide did not appear to be regulated by factors present in conditioned media. The peptide was detected in the conditioned media produced by late passage cultures of several different cell strains.
利用聚丙烯酰胺凝胶电泳比较了人成纤维细胞早期传代培养物和晚期传代培养物的分泌蛋白谱。与早期传代细胞培养物（已完成40 - 50%的寿命）相比，晚期传代（已完成超过80%的寿命）细胞培养物在55 - 60,000的Mr范围内几种肽的产量有所增加。其中一种肽的表观分子量为Mr = 55,000，并且在晚期传代细胞条件培养基中持续存在。晚期传代细胞培养物在有或没有胎牛血清的情况下都能合成Mr = 55,000的肽。血清不会增加早期传代细胞对其的产量。此外，在因血清饥饿或接触抑制而增殖停止的早期传代细胞培养物中，该肽的产量不会被诱导。脉冲追踪研究表明，该肽在标记后60分钟内出现在培养基中。没有证据表明它是由早期传代或晚期传代细胞条件培养基中存在的其他蛋白质降解而来。此外，55,000道尔顿肽的产量似乎不受条件培养基中存在的因子调节。在几种不同细胞系的晚期传代培养物产生的条件培养基中检测到了该肽。
