壳寡糖促进神经细胞PC-12的分化

Yang, Y., M. Liu, et al. (2009). "Effect of chitooligosaccharide on neuronal differentiation of PC-12 cells." Cell Biology International In Press

译者：乔莹

    江苏省南通大学的神经再生重点实验室09年最新在Cell Biology International上发表的文章表明，壳寡糖具有很好的神经细胞亲和力（nerve cell affinity），可支持神经细胞粘附，促进神经元分化，及轴突的外向生长。
    很多研究有关外周神经再生的文章已经证实，利用壳聚糖为原料的神经导管来桥连神经缺损部位获得了较大的成功。这种导管不仅仅起到导向神经生长的支架作用，而且可以增强神经细胞的存活及神经元轴突的外向生长。
    在植入壳聚糖导管之后，未降解的壳聚糖与可能降解了的壳聚糖（壳寡糖）共同存在于再生神经周围。尽管很多研究报导壳聚糖在体外显示出神经细胞亲和力，但有关壳寡糖是否具此功能还鲜为人知。因此，作者利用具有神经细胞特性的PC-12细胞为模型来研究壳寡糖对神经细胞的作用。
    经过2周左右的培养，与对照组相比，壳寡糖处理组的PC-12细胞显示出神经元样（neuron-like）的表型。并且一定浓度的壳寡糖，具有与阳性对照—NGF（神经生长因子）类似的性质，可增加PC-12细胞的存活力。更为重要的是，0.1mg/ml的壳寡糖可显著提高NF-H和N-cadherins的表达。神经元中大部分结构蛋白是神经丝（Neurofilaments，NF），NF-H是神经丝的一种亚单位，可通过调整微管组装来调控轴突的伸长。N-钙粘附素（N-cadherin）在神经元发育过程中起到重要作用，包括初始轴突萌发（initial neurite sprouting）、轴突特化（axon specification）、后期树状细化（dendritic elaboration）过程。由此，作者认为壳寡糖可支持神经细胞粘附，促进神经元细胞分化，以及通过调控NF-H和N-cadherin等因子来促进轴突生长。

Abstract：
　　Chitosan is now being widely used biomaterial in the tissue engineering field, and has great potential as a candidate material for preparing nerve guidance conduits due to its various favorable properties, especially that of good nerve cell affinity. Chitosan can be degraded in vivo into chitooligosaccharide. We have investigated the in vitro effects of chitooligosaccharide on neuronal differentiation of PC-12 cells to see what effects chitooligosaccharide have on certain functions in the regenerating neurons. The morphologic observation and assessment using the specific reagent of tetrazolium salt WST-8 indicated that neurite outgrowths from PC-12 cells and the viability of PC-12 cells were enhanced by treatment of chitooligosaccharide. The real-time quantitative RT-PCR and Western blot analysis revealed showed that chitooligosaccharide could upregulate the expression of neurofilament-H mRNA or protein and N-cadherin protein in PC-12 cells. The maximum effect of 0.1mg/ml chitooligosaccharide was obtained after 2 week culture. All the data suggest that chitooligosaccharide possesses good nerve cell affinity by supporting nerve cell adhesion and promoting neuronal differentiation and neurite outgrowth.