间充质干细胞聚合体治疗大鼠脊髓损伤的实验研究

The experiment of mesenchymal stem cell aggregates in the treatment of spinal cord injury in rats

目的:探究脱落乳牙牙髓干细胞(SHED)聚合体和脐带间充质干细胞(UCMSCs)聚合体在治疗大鼠脊髓损伤的可行性。方法:68只雌性SD大鼠被随机分成4组:假手术组(sham)、脊髓损伤组(SCI)、SHED聚合体治疗组(SHED)和UCMSCs聚合体治疗组(UCMSCs)。SHED聚合体和UCMSCs聚合体通过特殊的细胞培养获得。之后建立大鼠脊髓全横断损伤模型。SHED聚合体和UCMSCs聚合体分别被移植到脊髓损伤区进行治疗。术后1至8周每周用BBB评分来评定后肢功能恢复情况。第1、3和8周分别检测运动诱发电位(MEP)和感觉诱发电位(SEP)。免疫荧光法检测大鼠脊髓损伤区胶质纤维酸性蛋白(GFAP)、神经微丝蛋白(NF)和人特异性细胞核抗体(HuNu)的表达。结果:SHED组和UCMSCs组的BBB评分均有改善(P <0.05),且SHED组的改善更显著(P <0.05)。SHED组和UCMSCs组的MEP和SEP都能被诱发出来。与SCI组相比,SHED组和UCMSCs组的GFAP表达被下调,但NF表达被上调。GFAP和NF与HuNu的共染几乎都没有共定位现象。结论:SHED聚合体和UCMSCs聚合体均可用于治疗大鼠脊髓损伤。

Objective: To investigate the feasibility of stem cells from human exfoliated deciduous teeth(SHED) aggregates and umbilical cord mesenchymal stem cells(UCMSCs) aggregates in the treatment of spinal cord injury(SCI)in rats.Methods: Forty female SD rats were randomly allocated into four groups: sham-operated group(sham),spinal cord injury group(SCI),SHED aggregates treatment group(SHED),and UCMSCs aggregates treatment group(UCMSCs).The SHED aggregates and UCMSCs aggregates were prepared by cells culture.Then SCI model of rats was established by complete transection injury of spinal cord.SHED aggregates and UCMSCs aggregates were transplanted into the spinal cord injury area respectively.The recovery of motor function of hindlimbs was evaluated by Basso Beattie Bresnahan(BBB) score weekly for 8 weeks.The motor evoked potential(MEP) and sensory evoked potential(SEP)were recorded at weeks 1,3,and 8.The expression of glial fibrillary acidic protein(GFAP),neurofilament(NF),and human nuclei(HuNu) in spinal cord of rats were detected by immunofluorescence staining.Results: The BBB scores of rats in the SHED group and the UCMSCs group were improved(P < 0.05),and the improvement was more significant in the SHED group(P < 0.05).The MEP and SEP of rat spinal cord were induced both in SHED group and UCMSCs group.Compared with SCI group,the expression of GFAP was down-regulated but the expression of NF was up-regulated in both SHED group and UCMSCs group.There is almost no co-localization of GFAP or NF with HuNu in the rat spinal cord of rats of SHED group and UCMSCs group.Conclusion: Both SHED aggregates and UCMSCs aggregates could be used to treat spinal cord injury in rats.