Amarnani S, Merriman H L, Linkhart T A, Baylink D J, Mohan S
Department of Medicine, Loma Linda University, California.
J Bone Miner Res. 1993 Feb;8(2):157-65. doi: 10.1002/jbmr.5650080206.
MC3T3-E1 cells, a clonal osteoblast-like mouse calvarial cell line, secrete several growth regulating factors. These regulators include insulin-like growth factor (IGF) type I, transforming growth factor beta (TGF-beta), and IGF-II in descending order of abundance. MC3T3-E1 cells in culture also produce two IGF binding proteins (IGFBP), M(r) 25 and 32 kD, having sequence identity with IGFBP-4 and IGFBP-6, respectively. In addition, this is the first observation that osteoblast-like bone cells in culture produce IGFBP-6. To determine if growth factors produced by MC3T3-E1 cells have autocrine actions on these cells, the effects of IGF-I, IGF II, TGF-beta 1, and IGFBP-4 on MC3T3-E1 cell proliferation were determined. Exogenous addition of IGF-I and IGF-II stimulated MC3T3-E1 cell proliferation, but TGF-beta 1 and IGFBP-4 inhibited MC3T3-E1 cell proliferation. Based on these findings, we conclude that MC3T3-E1 cells in culture produce autocrine regulators of MC3T3-E1 cell proliferation and that the actions of IGFs may also be regulated by IGFBPs produced by these same cells.
MC3T3-E1细胞是一种成骨细胞样的小鼠颅盖细胞系，可分泌多种生长调节因子。这些调节因子按丰度递减顺序包括胰岛素样生长因子（IGF）I型、转化生长因子β（TGF-β）和IGF-II。培养中的MC3T3-E1细胞还产生两种IGF结合蛋白（IGFBP），分子量分别为25和32 kD，它们分别与IGFBP-4和IGFBP-6具有序列同源性。此外，这是首次观察到培养中的成骨细胞样骨细胞产生IGFBP-6。为了确定MC3T3-E1细胞产生的生长因子是否对这些细胞具有自分泌作用，研究了IGF-I、IGF II、TGF-β1和IGFBP-4对MC3T3-E1细胞增殖的影响。外源性添加IGF-I和IGF-II可刺激MC3T3-E1细胞增殖，但TGF-β1和IGFBP-4则抑制MC3T3-E1细胞增殖。基于这些发现，我们得出结论，培养中的MC3T3-E1细胞产生MC3T3-E1细胞增殖的自分泌调节因子，并且IGF的作用也可能受到这些相同细胞产生的IGFBP的调节。
