BDNF对大鼠胚胎神经干细胞诱导分化的影响

【目的】脑源性神经营养因子（BDNF）对体外培养大鼠神经干细胞（NSCs）诱导分化的影响。【方法】体外克隆化培养获得的NSCs中分别加入不同浓度的BDNF,采用倒置光显微镜观察细胞克隆形成,透射电子显微镜观察细胞超微结构的变化,免疫组化的方法检测胶质纤维酸性蛋白（GFAP）的表达。【结果】在倒置光显微镜下可见细胞接种后5 d形成小细胞球,7 d成为大小不等的细胞克隆。在电镜下可见具有典型的神经干细胞和神经胶质样细胞特征。经BDNF处理7 d后星形胶质样细胞增多,且突起的长度随浓度的增加逐渐延长,尤以40 ng/ml组突起最为显著（P〈0.05）。免疫细胞化学检测GFAP的阳性颗粒位于细胞浆中,经40 ng/mlBDNF诱导后阳性率可达86.1%,与对照组（13.1%）比较有显著性差异。【结论】BDNF可诱导神经干细胞分化为星形胶质细胞。

The inducing effects of BDNF on the differentiation of the rat fetal neural stem cells

Objective] To investigate the inducing effects of brain derived neurotrophic factor （BDNF） on the differentiation of the rat fetal neural stem cells （rNSCs）. Methods] The rat fetal neural stem cells （rNSCs） were obtained by clonal culture and recuhured on the medium containing different dosage of BDNF to induce the rNSCs to different descendants. Formation of cell clone was observed by inverted optical microscope, the ultrastructure of the cells were observed by transmission electron microscope and the expression of the glial fibrillary acidic protein （GFAP） were detected by immunocytochemical method. Results] Small cell spheres were observed by the inverted optical microscope after 5 d culturing and the cell clones in different sizes were formed after 7 d culturing. Results obtained by the transmission electron microscope indicated that the descendant cells with the characteristics of neural stem cells and gliacyte-like cells. There were more astrocyte-like cells after the cells induced by BDNF for 7 d, the length of their processes was increased by a progressively increased dosage of BDNF, the effects were most prominent in 40 ng/ml BDNF （P 〈 0.05）. Immunocytochemical analysis indicated that the GFAP granules were expressed in cytoplasm, and the positive rates were reached 86.1% in 40 ng/ml BDNF group. Conclusions] The NSCs would be differentiated to astrocyte-like cells under the induction of BDNF.