β-mercaptoethanol can induce adipose-derived stromal cells to rapidly and efficiently differentiate into neurons in vitro. However, because of the short survival time of the differentiated cells, clinical applications for this technique are limited. As such, we examined apoptosis of neurons differentiated from adipose-derived stromal cells induced with β-mercaptoethanol in vitro using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and transmission electron microscopy. The results revealed that the number of surviving cells decreased and apoptosis rate increased as induction time extended. Taken together, these results suggest that apoptosis occurring in the process of adipose-derived stromal cells differentiating into neurons is the main cause of cell death. However, the mechanism underlying cellular apoptosis should be researched further to develop methods of controlling apoptosis for clinical applications.

The quantity and survival time of astrocytes, which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine, have thus far been unsatisfactory. The present study investigated the growth and differentiation characteristics of induced astrocytes by observing their growth curves. After induction for 48 hours with an inducer containing 0.5% ethanol, some adult adult adipose-derived stromal cells displayed typical astrocytic morphology. The cell quantity gradually decreased with prolonged induction time. Nestin, glial fibrillary acidic protein, and S-100 expression reached peak levels at 14 days, but neuron-specific enolase was not expressed. These results suggest that the induced astrocytes reached their peak at 14 days. Further optimization of the culture environment may yield mature astrocytes with normal functions, in greater quantity, and prolonged survival time.

骨髓间充质干细胞的体外培养及定向诱导分化

目的:探讨人骨髓间充质干细胞(hMSCs)的体外培养生长特性及其在体外定向分化为神经样细胞的条件.方法:采用Ficoll-paque(1.077g/ml)分离液密度梯度分离hMSCs,显微镜下观察其生长特性,测定生长曲线;取传至3～6代的hMSCs,用阿魏酸钠对其进行诱导培养,并以β-巯基乙醇作对照观察诱导培养后细胞的形态变化,分别在6h、1d、3d和7d通过免疫荧光细胞化学染色方法测定诱导后细胞的神经元烯醇化酶(neuron specific enolase,NSE)和胶质纤维酸性蛋白(glia fiber acid protein,GFAP),进行定量分析.结果:体外培养条件下hMSCs呈长梭形,细胞生长曲线呈S形,细胞倍增时间约为72h.阿魏酸钠诱导培养后6h可见细胞形态明显变化,NSE和GFAP表达阳性.24h后诱导细胞表现为典型的神经细胞样形态.第3天,NSE和GFAP表达高,分别为67±3.5%和39±1.8%.结论:人骨髓间充质干细胞在体外具有自我更新能力及多分化潜能;阿魏酸钠具有诱导体外培养的人骨髓间充质干细胞向神经细胞分化的作用.