不同代次大鼠脂肪间充质干细胞增殖及成神经球的能力比较

背景：脂肪间充质干细胞是一组具有多向分化潜能的干细胞，体外在一定条件下可分化为神经干细胞。 目的：观察不同代次大鼠脂肪间充质干细胞体外培养增殖能力及诱导成神经球的潜力。 方法：取SD大鼠脂肪体外分离培养出脂肪间充质干细胞并传代扩增，分别在P3、P6、P10、P20时观察其形态学变化、测定增殖速度。流式细胞仪检测定不同代次细胞表型及细胞周期。将脂肪间充质干细胞诱导为神经球，计数成神经球率。 结果与结论：脂肪间充质干细胞主要呈长梭形，不同代次的脂肪间充质干细胞均具有很强的体外增殖能力；除P3细胞其他代次细胞均高表达CD29、CD44、CD73，低表达CD45、CD34。细胞周期中G0/G1期细胞所占比例P3为93.4%、P6为92.7%、P10为92.4%、P20为86.0%。P6、P10诱导成神经球率均显著高于P20（P〈0.05），P3细胞较难诱导成神经球。提示以脂肪间充质干细胞作为种子细胞时，应注意选择适宜的扩增代数，以便在获得足够纯度细胞的同时保留细胞最佳的分化潜力。

Comparative study of proliferative and neurosphere differentiation capacities of adipose-derived mesenchymal stem cells at different passages

BACKGROUND：Adipose-derived mesenchymal stem cels are a group of pluripotent stem cels, and under certain conditions can differentiate into neural stem celsin vitro.
OBJECTIVE：To investigate the proliferative and differentiation ability of different passage mesenchymal stem cellfrom adipose tissue into neurospheres.
METHODS：The adipose-derived mesenchymal stem cels from Sprague-Dawley rats were separated and culturedin vitro, and morphology and proliferation rate of cels were observed and compared respectively at passages 3, 6, 10 and 20. The cellsurface antigens and cels cycle were identified by flow cytometry. Furthermore, adipose-derived mesenchymal stem cels were induced into neurospheres, and the neurosphere rate was counted.
RESULTS AND CONCLUSION： Adipose-derived mesenchymal stem cels were mainly in long spindle shape, and cels at different passages had highly proliferative capacity in vitro. Except passage 3, adipose-derived mesenchymal stem cels strongly expressed CD29, CD44, CD73 and lowly expressed CD45 and CD34. The proportion of G0/G1 phase in cellcycle was 93.4% at passage 3, 92.7% at passage 6, 92.4% at passage 10, 86.0% at passage 20. Adipose-derived mesenchymal stem cels at passages 6 and 10 were easier to differentiate into neurospheres than those at passage 20 （P 〈 0.05）, but cels at passage 3 were difficult to differentiate into neurospheres. Therefore, when using adipose-derived mesenchymal stem cels as seed cels, we should pay attention to choose the appropriate amplification passage in order to obtain the cels with best differentiation potential and cellpurity.