细胞外基质的程序性应用促进胚胎干细胞的神经分化

Programmed application of extracellular matrix promotes neural differentiation of mouse embryonic stem cells

目的探讨细胞外基质(ECM)在胚胎干细胞(ESCs)诱导分化中特定时期的作用。方法将ESCs悬浮培养形成胚胎小体(Embryonic bodies,EBs),用高浓度维甲酸(RA)诱导,再将EBs接种在GL、FN、LPO基质上进行分化,利用免疫荧光方法比较这些基质对神经分化的影响;进一步检测LPO对神经突起生长的影响。结果高浓度RA启动并加速了nestin阳性的神经前体细胞的分化;FN对ESCs的神经分化具有剂量依赖性的促进作用,可提高神经元的分化率;LPO基质能够促进神经细胞的突起生长,进一步诱导神经细胞的成熟。结论不同基质在分化的特定阶段起到了不同作用,在诱导神经前体分化阶段应用FN以及在诱导神经细胞分化阶段应用LPO的联合作用对ESCs向神经细胞分化作用最显著。

Objective To study the role of extracellular matrix （ECM） in neural differentiation of mouse embryonic stem cells （ESCs）. Methods Mouse ESCs were incubated in the ESC conditioned medium, and the formation of embryonic bodies （EBs） were induced in bacteriological dishes using high-concentration all-trans retinoic acid （RA）. The EBs were seeded on different matrixes （gelatin, fibronectin, and laminin/poly-L-omithine） to test their impact on neural differentiation of the ESCs using immunofluorescence assay. The effect of laminin/poly-L-ornithine on the growth of neurites was evaluated with fluorescence microscopy. Results High-concentration RA activated and accelerated the differentiation of ESCs toward nestin-positive neural progenitor ceils. Fibroncctin supplement in the matrix dose-dependently promoted ESC differentiation into neural progenitor cells, while laminin/poly-L-omithine increased the growth of the neurites and induced the maturation of the differentiated neural cells. Conclusion ECM plays an important role in neural differentiation of mouse ESCs, and application of FN produces the most conspicuous effect during the differentiation of the ESCs into the neural progenitor cells; laminin/poly-L-omithine is the most effective during their differentiation into neural cells.