骨髓间充质干细胞表达神经营养因子及对神经干细胞的保护作用

目的 研究大鼠骨髓间充质干细胞（BMSC）表达脑源性神经营养因子（BDNF）和神经生长因子（NGF）以及BMSC条件培养液对神经干细胞的保护作用。方法 取大鼠骨髓培养BMSC，用CD44、CD45和CD71免疫细胞化学染色进行鉴定。提取BMSCmRNA，RT-PCR检测BDNF和NGF表达，ELISA检测BMSC培养液中BDNF和NGF的含量。原代取材培养新生大鼠皮质神经干细胞，nestin染色鉴定。用不同比例的BMSC条件培养液培养神经干细胞24h后，热休克诱导凋亡，流式细胞仪检测凋亡细胞比率。结果 BMSC贴壁生长，免疫细胞化学染色CD44和CD71阳性表达．CD45阴性表达。BMSC表达BDNF和NGFmRNA，BMSC培养液中含有BDNF和NGF；随培养时间的延长，培养液中BDNF和NGF的浓度增加。BMSC条件培养液可以减少热休克诱导的神经干细胞凋亡比率．并且BMSC条件培养液浓度高者有更好的保护作用。结论 BMSC表达神经营养因子BDNF和NGF，对神绎千细朐凋亡有保护作用．

Bone Marrow Mesenchymal Stem Cells Express Neurotrophic Factores and Protect Neural Stem Cells

ObjectiveTo investigate bone marrow mesenchymal stem cells(BMSC) express brain derived neurotrophic factor(BDNF) and nerve growth factor(NGF) and their protective effect for neural stem cells (NSCs).MethodsBMSC were obtained from rat tibiae and femurs and centrifuged with Ficoll. The passage 3 cells were chosen to make immunocytochemical stain for CD_ 44, CD_ 71 and CD_ 45. The expression of BDNF and NGF was detected in BMSC with RT-PCR, as well as in the media with ELISA. The media that cultured BMSC were collected as BMSC condition media. NSCs were obtained from cerebral cortex of new-born rat and cultured in vitro. After different ratio of BMSC condition midia were added, NSCs were induced to apoptosis with heat-shock, then NSCs were dyed with Annexin V-FITC/PI apoptosis kit and apoptosis rates were tested with flow cytometry. ResultsBMSC were CD_ 44(+), CD_ 45(-), CD_ 71(+) and expressed BDNF and NGF mRNA. BDNF and NGF could be tested in the media of cultured BMSC and increase with cultured time. BMSC condition media could reduce the ratio of heat-induced apoptosis of NSCs, and more BMSC condition media showed better effect. ConclusionBMSC can express neurotrophic factores and protect neural stem cells from heat-induced apoptosis.