Department of Biotechnology, University of NSW, 2052, Sydney, NSW, Australia.
Cytotechnology. 1995 Feb;17(1):13-9. doi: 10.1007/BF00749216.
A Chinese Hamster Ovary (CHO-K1) derived cell line, which expresses human follicle stimulating hormone (hFSH) under the control of a beta actin promoter, was used as a model system to study heterologous glycoprotein expression. It has been shown previously that specific productivities in this cell line were three times higher in the presence of serum than in its absence. In this paper, a systematic study was made of the affects of various serum components of product levels in order to determine if the affect of serum on FSH expression could be duplicated by defined medium supplements. Culture media were supplemented with growth factors, direct activators of secondary messengers, steroids, lipids and various sugars. It was shown that the components with the most stimulatory affect of hFSH expression were sodium butyrate, mevalonate and hydrocortisone. Although butyrate has been shown to elevate transcription of some genes, it was concluded that this could not have been the only mechanism of action, since mevalonate and hydrocortisone are both implicated in the lipid pathway of protein glycosylation, but not with transcriptional activation of the beta actin promoter. Conversely, actual supply of dolichol-linked oligosaccharide for glycosylation was probably not rate limiting, since butyrate has never been reported to affect the supply of this comerabolite, but glycosylation is likely to be implicated in some way.
一种来源于中国仓鼠卵巢（CHO-K1）的细胞系，在β肌动蛋白启动子的控制下表达人促卵泡激素（hFSH），被用作研究异源糖蛋白表达的模型系统。先前已经表明，在存在血清的情况下，该细胞系的特定生产率比不存在血清时高三倍。在本文中，系统研究了各种血清成分对产物水平的影响，以确定血清对 FSH 表达的影响是否可以通过定义的培养基补充来复制。培养基中添加了生长因子、二级信使的直接激活剂、类固醇、脂质和各种糖。结果表明，对 hFSH 表达最具刺激作用的成分是丁酸钠、甲羟戊酸和氢化可的松。尽管丁酸钠已被证明可提高某些基因的转录，但结论是这不可能是唯一的作用机制，因为甲羟戊酸和氢化可的松都与蛋白质糖基化的脂质途径有关，但与β肌动蛋白启动子的转录激活无关。相反，糖基化的实际需要可能不是限速步骤，因为丁酸钠从未被报道过会影响这种共同代谢物的供应，但糖基化可能以某种方式涉及。
