人神经干细胞源施万样细胞微囊泡促进大鼠神经元轴突生长

Microvesicles of Schwann-like cells derived from human neural stem cells promote axonal growth of neurons in vitro

目的:探究人神经干细胞源施万样细胞微囊泡对大鼠神经元轴突生长的影响。方法:选取出生4~5 d的SD大鼠乳鼠,摘取背根神经节(dorsal root ganglion,DRG),获得DRG神经元;用施万样细胞微囊泡刺激DRG神经元,行βⅢ-微管蛋白免疫荧光染色,观察轴突生长情况;分别用0、5、20、40 mg/L施万细胞微囊泡刺激神经元样N2a细胞19 h,用荧光定量PCR检测N2a细胞生长相关蛋白43(growth associated protein 43,GAP43) mRNA表达;分别用0、20、40 mg/L施万细胞微囊泡刺激N2a细胞48 h,行过碘酸-雪夫染色,检测细胞内糖原生成情况。结果:施万样细胞微囊泡组的DRG神经元轴突长度明显长于PBS组(P <0. 05)。施万样细胞微囊泡可被N2a细胞吞噬。与0 mg/L组相比,5 mg/L组GAP43 mRNA表达差异无统计学意义(P> 0. 05);20、40 mg/L组GAP43 mRNA表达量、突起增长率及碘酸-雪夫染色细胞阳性率均明显高于0 mg/L组(P均<0. 05)。结论:施万细胞微囊泡在体外能够促进大鼠神经元轴突生长。

Objective: To explore the effect of microvesicles of Schwann-like cells derived from human neural stem cells on axon growth of neurons. Methods: Dorsal root ganglion( DRG) neurons were obtained from DRG of suckling rats born 4-5 d. DRG neurons were stimulated by microvesicles of Schwann-like cells,and immunofluorescence staining of βⅢ-tubulin was performed to observe the axon growth. After stimulating neuron-like N2 a cells with 0,5,20,40 mg/L microvesicles of Schwann-like cells for 19 h,the expression of growth associated protein 43( GAP43) mRNA in N2 a cells was detected by real-time PCR. After stimulating neuron-like N2 a cells with 0,20,40 mg/L microvesicles of schwannlike cells for 48 h,periodic acid-Schiff( PAS) staining was performed to detect intracellular glycogen production. Results: The axon length of DRG neurons in the Schwann cell microvesicle group was significantly longer than that in the PBS group( P < 0. 05). Microvesicles of Schwann-like cells could be internalized by N2 a cells,and there was no significant difference in GAP43 mRNA expression between 5 mg/L group and 0 mg/L group( P < 0. 05). Compared with 0 mg/L group,20 and 40 mg/L groups showed higher levels of GAP43 mRNA expression,neurite outgrowth rate and PAS staining positive cell rate( all P < 0. 05). Conclusion: Microvesicles of Schwann-like cells derived from human neural stem cells could promote the growth of murine axons in vitro.