Ekblom P, Thesleff I, Saxén L, Miettinen A, Timpl R
Proc Natl Acad Sci U S A. 1983 May;80(9):2651-5. doi: 10.1073/pnas.80.9.2651.
Differentiation of the metanephric mesenchyme, which is triggered by an inductive tissue interaction, has been shown to proceed in a chemically defined medium containing transferrin. Here, we report that neither transferrin-depleted serum nor a chemically defined medium devoid of transferrin promote differentiation and that activity can be restored by the addition of transferrin. It thus appears that we have identified the serum factor required for kidney differentiation. Transferrin seems to affect differentiation by stimulating cell proliferation. We show by using an organ-culture model system that only mesenchymes induced to differentiate by the 24-hr tissue interaction respond to transferrin by proliferation and differentiation, whereas uninduced mesenchymes remain unresponsive. The inductor tissue used is not responsive to transferrin. Thus, the data suggest that the short-range cell-mediated tissue interaction acts by making the nephrogenic mesenchyme responsive to the long-range mediator, which is transferrin. Transferrin is suggested to be an important circulating growth factor required for proliferation during embryogenesis.
由诱导性组织相互作用引发的后肾间充质分化，已被证明在含有转铁蛋白的化学限定培养基中进行。在此，我们报告转铁蛋白耗尽的血清或不含转铁蛋白的化学限定培养基均不能促进分化，而添加转铁蛋白可恢复其活性。因此，我们似乎已经确定了肾脏分化所需的血清因子。转铁蛋白似乎通过刺激细胞增殖来影响分化。我们通过使用器官培养模型系统表明，只有经24小时组织相互作用诱导分化的间充质才能通过增殖和分化对转铁蛋白作出反应，而未诱导的间充质则无反应。所使用的诱导组织对转铁蛋白无反应。因此，数据表明短程细胞介导的组织相互作用通过使肾源性间充质对作为远程介质的转铁蛋白产生反应而起作用。转铁蛋白被认为是胚胎发育过程中增殖所需的一种重要循环生长因子。
