胎肝Sca-1+细胞在体外向神经元分化研究

目的:观察胚胎肝Sca-1⁺细胞能否在体外向神经组织细胞分化。方法: 免疫磁珠法分离孕14.5 d C57BL/6J小鼠的胚胎肝的Sca-1⁺细胞, 以DMEM/F12+10%胎牛血清培养液培养, 当细胞融合达80%, 按1∶3比例传代。第5代细胞用BME和RA先后诱导24 h, 再用无血清培养基培养5 h至5 d。免疫细胞化学检测细胞特点。结果: 胚胎肝Sca-1⁺细胞经诱导后表现神经元形态, 并表达神经元特异蛋白如神经元特异性核蛋白(NeuN)、神经丝蛋白M、神经元特异性微管蛋白1(TuJ-1), 但是无微管相关蛋白Tau、MAP-2和星形胶质细胞特异酸性蛋白(GFAP)表达。结论: 胚胎肝Sca-1⁺细胞(主要为造血干细胞)具有可塑性, 在体外能分化为早期未成熟的神经元样细胞。这提示胚胎肝细胞可能用于神经系统疾病的细胞治疗和基因治疗。

Sca-1+ cells from mouse fetal liver can differentiate into neurons in vitro

AIM: To study whether Sca-1+ cells from fetal liver can be induced to differentiate into neuronal cells in vitro. METHODS: Sca-1+ cells from 14.5-days-old murine fetal liver were isolated with a magnetic cell sorting kit, and were cultured in Dulbecco's modified Eagle's medium (DMEM)/F12 supplemented with 10% fetal bovine serum (FBS), and passaged at a ratio of 1∶3 when cells reached more than 80% confluence. The 5 passage cells were induced by 10-3 mol/L β-mercaptoethanol (β-ME) and 5 ×10-7 mol/L all-trans-retinoic acid (RA) for 24 hours, and then incubated in serum-free medium for 5 hours to 5 days. The characteristics of treated cells were assayed by immunocytochemistry staining analysis at 5 hours, or 5 days.RESULTS: Cells treated with β-ME and RA exhibited neuronal phenotype and expressed neuron-specific protein such as neuron-specific nuclear protein (NeuN), neuronfilament-M, and neuron-specific tubulin-1 (TuJ-1) but not tau, MAP-2, or the astrocyte-specific marker glial fibrillary acidic protein (GFAP).CONCLUSION: Sca-1+ cells from fetal liver, of which most are regarded as hematopoietic stem cells, could differentiate into early immature neuronal cells in vitro. These findings suggest that Sca-1+ cells from fetal liver may be an alternative source in cell therapy and gene therapy of neural dysfunction.