Gillery P, Leperre A, Maquart F X, Borel J P
Laboratory of Biochemistry, CNRS URA 610, Faculty of Medicine, University of Reims, Champagne-Ardenne, France.
J Cell Physiol. 1992 Aug;152(2):389-96. doi: 10.1002/jcp.1041520221.
Fibroblasts cultivated in three-dimensional tissue-like matrices are characterized by a slowed metabolism and a decrease of protein synthesis, unless they are submitted to physical tensions. We checked the effects of insulin like growth factor-I (IGF-I), known as a potent stimulator of mitogenesis and protein synthesis for many cell types, in various models of cultures: confluent monolayers, collagen lattices, non-retracting or retracting fibrin lattices. IGF-I (1-100 ng.ml-1) had no effect on cell divisions in lattice cultures. It was able to stimulate collagen lattice retraction when the medium was supplemented with low concentrations of serum. IGF-I at 10 or 100 ng.ml-1 stimulated collagen and non-collagen syntheses in all culture systems, but stimulation of collagen synthesis only began at the highest concentration (100 ng.ml-1) in retracted lattices. Northern blot and dot-blot analyses of mRNAs extracted from monolayer cultures of fibroblasts showed that IGF-I stimulated pro alpha 1(I) collagen synthesis at the pretranslational level. Cycloheximide (7.5 micrograms.ml-1) completely inhibited pro alpha 1(I) collagen gene expression induced by IGF-I. These results show that IGF-I is a potent stimulus for protein synthesis and collagen gene expression in monolayers and tridimensional cultures of fibroblasts, but that it exerts no mitogenic activity in tridimensional lattices. Synergistic associations of IGF-I with other growth factors will have to be found in order to reverse the quiescent status of fibroblasts in lattices.
在三维组织样基质中培养的成纤维细胞的特点是代谢减缓、蛋白质合成减少，除非它们受到物理张力作用。我们在多种培养模型中检测了胰岛素样生长因子-I（IGF-I）的作用，IGF-I是许多细胞类型有丝分裂和蛋白质合成的有效刺激剂，这些模型包括汇合单层培养、胶原晶格培养、非收缩或收缩的纤维蛋白晶格培养。IGF-I（1 - 100 ng.ml-1）对晶格培养中的细胞分裂没有影响。当培养基中添加低浓度血清时，它能够刺激胶原晶格收缩。10或100 ng.ml-1的IGF-I在所有培养系统中均能刺激胶原和非胶原的合成，但在收缩晶格中，仅在最高浓度（100 ng.ml-1）时才开始刺激胶原合成。对从成纤维细胞单层培养物中提取的mRNA进行Northern印迹和斑点印迹分析表明，IGF-I在翻译前水平刺激α1（I）型前胶原的合成。放线菌酮（7.5微克.ml-1）完全抑制了IGF-I诱导的α1（I）型胶原基因表达。这些结果表明，IGF-I是成纤维细胞单层培养和三维培养中蛋白质合成和胶原基因表达的有效刺激剂，但在三维晶格中它没有促有丝分裂活性。为了逆转晶格中成纤维细胞的静止状态，必须找到IGF-I与其他生长因子的协同组合。
