白质星形胶质细胞内S100A4蛋白对小鼠背根神经节细胞突起生长的影响

Effects of S100A4 expressed In white matter astrocytes on sensory neurite outgrowth in vitro

目的研究离体条件下白质星形胶质细胞及其表达的S100A4蛋白对小鼠背根神经节(DRG)细胞突起生长的影响。方法用对照siRNA或S100A4 siRNA转染纯的白质星形胶质细胞,3d后与成年小鼠DRG细胞共同培养6,12,18,24h,采用免疫荧光化学方法观察DRG细胞突起的生长情况。结果在多聚-L-赖氨酸包被的盖玻片上,成熟的DRG细胞能较好地存活,但在培养24h内未见有突起长出。与白质星形胶质细胞共培养6h,各组DGR细胞均未长出突起；共同培养12,18,24h,各组DGR细胞长出突起,且突起长度随共同培养时间的延长而增加；S100A4 siRNA转染组DRG细胞突起明显长于培养相同时间的对照siRNA转染组。结论白质星形胶质细胞促进小鼠DRG细胞突起生长．而星形胶质细胞内的S100A4蛋白抑制该作用。

Objective To investigate the role of white matter astrocytes and their specific protein S100A4 in sensory neurite outgrowth in vitro. Methods White matter astrocyte cultures expressing S100A4 were prepared. Dissociated adult dorsal root ganglion （DRG） cells were placed on the top of the astrocytes and co-cultured for 6, 12, 18, 24 hours. Small interfering S100A4 RNA was used to eliminate S100A4 expression. The growth of DRG cell neurites on Sl00A4-silenced and S100A4-expressing astrocytes was compared. Results 12, 18 and 24 hours after the co-culture with Sl00A4-expressing or S100A4-silenced astrocytes, neurite growth from the DRG cells was observed. Neurite outgrowth was significantly greater in S100A4 siRNA treated cultures compared to control siRNA treated white matter astrocyte cultures, Conclusion These findings suggest that white matter astrocytes are able to support axonal regeneration and, furthermore, that administration of small interfering S100A4 RNA provides strong additional support for axon regeneration.