A Molecular Mechanism Coordinating Proliferation and Differentiation of Neural Precursor Cells

Wnt信号对神经前体细胞的作用存在争议：据报道，它要么促进细胞增殖，要么加速分化成为有丝分裂后的神经元。为了了解Wnt规范途径的这种不同作用，我们将Wnt3a应用于胚胎第15天小鼠海马区的原代培养。WNT3a可增加细胞总数、增殖细胞数和分化神经元数。这一结果在现象学上表明，WNT3a既能诱导神经前体细胞增殖，又能诱导神经元分化。值得注意的是，培养后的神经元数量与总细胞数量的比率几乎是相似的。WNT3a对细胞对称分裂和不对称分裂的比例没有显著影响，但通过缩短细胞周期而加速细胞周期进程，从而导致增殖细胞和分化神经元的增加。

The effects of Wnt signaling on neural progenitor cells were controversial: it was reported to either promote their cell proliferation or accelerate differentiation to become postmitotic neurons. To understand this discrepant role of the Wnt canonical pathway, we applied Wnt3a on the primary culture prepared from embryonic day 15 mouse hippocampus. Wnt3a increased the numbers of total cells, proliferating cells and differentiated neurons. This result phenomenologically suggests that Wnt3a induces both neural progenitor cell proliferation and neuronal differentiation. Notably, the ratio of the number of neurons to total cells after the culture was almost comparable. Wnt3a did not significantly affect the ratio of symmetric and asymmetric cell divisions, but accelerated cell cycle progression by shortening the cell cycle duration, which could result in increases of both proliferative cells and differentiated neurons.