Schmidt W, Pöll-Jordan G, Löffler G
Department of Biochemistry, Microbiology, and Genetics, University of Regensburg, Federal Republic of Germany.
J Biol Chem. 1990 Sep 15;265(26):15489-95.
A culture system for 3T3-L1 preadipocytes based on a serum-free chemically defined medium containing fetuin, transferrin, and pantothenate is described. In this system, adipose conversion depends on the following conditions. 1) In the presence of high insulin concentrations (1 microM), addition of corticosterone together with 1-methyl-3-isobutylxanthine (MIX) for not more than the first 4 days after confluence to the culture medium induces maximal adipose conversion within 12-14 days. MIX may be replaced by forskolin or permeable analogues of cAMP, indicating that its effect is due to elevated cellular cAMP levels. 2) At low insulin concentrations (1 nM), adipose conversion is reduced. Growth hormone or insulin-like growth factor I together with epidermal growth factor have to be present as a medium supplement together with corticosterone and MIX to get maximal adipose conversion. 3) The induction of adipose conversion by corticosterone and MIX in the presence of either high insulin concentrations or insulin-like growth factor I together with epidermal growth factor is accompanied by post-confluent mitoses. Inhibitors of DNA replication markedly reduce adipose conversion. Fibroblast growth factor and platelet-derived growth factor, although acting as potent mitogens on 3T3-L1 cells, do not support adipose conversion induced by corticosterone and MIX.
描述了一种基于含有胎球蛋白、转铁蛋白和泛酸盐的无血清化学限定培养基的3T3-L1前脂肪细胞培养系统。在该系统中，脂肪转化取决于以下条件。1）在高胰岛素浓度（1 microM）存在的情况下，在汇合后最初4天内将皮质酮与1-甲基-3-异丁基黄嘌呤（MIX）添加到培养基中，可在12-14天内诱导最大程度的脂肪转化。MIX可用福斯高林或cAMP的可渗透类似物替代，这表明其作用是由于细胞内cAMP水平升高。2）在低胰岛素浓度（1 nM）下，脂肪转化减少。生长激素或胰岛素样生长因子I与表皮生长因子必须作为培养基补充剂与皮质酮和MIX一起存在，以实现最大程度的脂肪转化。3）在高胰岛素浓度或胰岛素样生长因子I与表皮生长因子存在的情况下，皮质酮和MIX诱导的脂肪转化伴随着汇合后有丝分裂。DNA复制抑制剂显著降低脂肪转化。成纤维细胞生长因子和血小板衍生生长因子虽然对3T3-L1细胞起强效促有丝分裂作用，但不支持皮质酮和MIX诱导的脂肪转化。
