MESENCHYMAL CELL DIFFERENTIATION

细胞的增殖、定型和分化过程 间充质细胞将在细胞水平上使用 畸胎瘤衍生的双能细胞系1246和胰岛素- 来源于1246细胞的独立变异细胞系作为模型 系统 1246细胞系具有以下性质：（1）它可以 分化成脂肪细胞或肌肉细胞;（2）它可以 在成分确定的培养基中增殖并经历脂肪分化 而其它成脂细胞系可以在成分确定的培养基中生长 但需要胎牛血清来分化; 3）其生长， 分化严格依赖于 胰岛素;和4）其条件培养基能够代替血清， 刺激几种成脂细胞系的分化。 从1246个细胞中，已经获得了胰岛素非依赖性变异细胞系。 与世隔绝 这种失去分化能力的细胞系 在其培养基中产生脂肪分化抑制剂 具有阻断几种成脂细胞系分化的活性， 大鼠和小鼠脂肪细胞的原代培养物。 实验 提出了表征，纯化和研究两者的表达 两种细胞产生的脂肪分化调节因子的类型 线 这项研究将是我们长期目标的一部分， 与因素特性有关的调查 控制增长，承诺和分化过程 间充质来源的细胞系，并了解其 作用机制。

The processes of proliferation, commitment and differentiation of mesenchymal cells will be studied at the cellular level using the teratoma-derived, bipotential cell line 1246 and an insulin- independent variant cell line derived from 1246 cells as a model system. The 1246 cell line has the following properties; (1) it can differantiate either into adipocytes or into muscle cells; (2) it can proliferate and undergo adipose differentiation in defined medium whereas other adipogenic cell lines can grow in defined medium but require fetal calf serum to differentiate; 3) its growth and differentiation are stringently dependent on the presence of insulin; and 4) its conditioned medium is able to replace serum to stimulate the differentiation of several adipogenic cell lines. From 1246 cells, an insulin-independent variant cell line has been isolated. This cell line which has lost the ability to differentiate produces in its culture medium an adipose differentiation inhibitor active to block differentiation of several adipogenic cell lines and of primary cultures of rat and mouse adipocytes. Experiments are proposed to characterize, purify and study the expression of both types of adipose differentiation regulators produced by both cell lines. This study will be part of the long-term objective of our investigations related to the characterization of factors controlling growth, commitment and differentiation processes of mesenchymal-derived cell lines and to understand their mechanism of action.