骨形态发生蛋白4体内外诱导脑神经干细胞向胆碱能细胞的分化

目的：了解骨形态发生蛋白－4 (BMP4) 是否具有诱导原代分离培养的大鼠脑神经干细胞（NSCs）向胆碱能细胞分化的效应。方法：将从两月龄大鼠脑海马、纹状体等区域分离的细胞培养于含EGF、bFGF的DMEM/F12培养液中，在光镜下观察细胞的形态特征，并行Nestin细胞化学染色。24h后换成含有BMP4的培养液，培养7d、8d时，行胆碱乙酰转移酶（choline acetyltransferase, ChAT）和神经巢蛋白Nestin双标免疫细胞化学染色及ChAT间接免疫荧光染色，在光镜下观察细胞形态的变化。结果：分离出的大鼠脑海马、纹状体等区的细胞约48%为nestin阳性的NSCs。培养7d、8d时，光镜下见加BMP4组约34%的细胞呈神经元形态特征；免疫双标细胞化学染色见ChAT阳性细胞与Nestin阳性细胞共存，其中ChAT阳性细胞占28%，Nestin阳性细胞占38%；间接免疫荧光染色见呈较强绿色荧光的ChAT阳性细胞较多；FITC标记流式细胞术检测到16％的细胞呈ChAT阳性。而未加BMP4组呈ChAT阳性的细胞约7％，明显少于加BMP4组，且荧光较弱。结论：BMP4可在体外培养条件下诱导大鼠脑神经干细胞向胆碱能细胞分化。

Bone morphogenetic protein 4 induces cholinergic differentiation of brain-derived neural stem cells in vivo and in vitro

In vitro studies have demonstrated that many factors of bone morphogenetic proteins (BMPs) induce cholinergic differentiation of neural stem cells. However, BMP retains the potential to induce increased numbers of cholinergic neurons in central nervous system regions that are rich in cholinergic cells, which is an important determinant of BMP. Therefore, BMP-4 was added to neural stem cell culture medium or the adult rat hippocampal dentate gyrus. Results demonstrated that BMP-4 induced cholinergic differentiation of neural stem cells in vitro and increased the number of cholinergic neurons in the adult rat hippocampal dentate gyrus.