骨髓间充质干细胞移植对急性脊髓损伤大鼠神经功能恢复及Nogo-A表达的影响

关键词：骨髓间充质干细胞  脊髓损伤  神经功能  Nogo-A

Keywords:bone marrow-derived mesenchymal stem cells  spinal cord injury  neurological functions  Nogo-A

摘要：

      目的：探讨骨髓间充质干细胞（BMSCs）静脉注射移植对急性脊髓损伤(SCI)大鼠神经功能恢复及Nogo-A表达的影响。方法：采用全贴壁法分离培养大鼠BMSCs, 雌性SD大鼠96只，随机分成4组,假手术组(sham组)、损伤对照组(SCI组)、溶剂对照组（vehicle组）和BMSCs治疗组（BMSCs组），24只/组。采用改良Allen法制作大鼠急性SCI模型，BMSCs移植前用羧基荧光素二醋酸盐琥珀酰亚胺酯（CFSE）标记,BMSCs 组于造模成功10min后自大鼠尾静脉注射BMSCs悬液1ml（5×106个 BMSCs）；vehicle组则注射1ml 0.01m的磷酸盐缓冲液(PBS)。术后第1天、第3天、第7天和第14天通过进行BBB神经行为学评分对神经功能进行评估，观察其恢复状况，免疫组化及RT-PCR法检测Nogo-A表达。结果：BMSCs组损伤周边区脊髓组织中观察到CFSE染色的阳性细胞；BMSCs组术后第7天和第14天神经功能评估明显优于SCI组、vehicle组；BMSCs组术后第3天、第7天和第14天脊髓损伤区周边组织中Nogo-A表达较SCI组和Vehicle组明显降低(P<0.01)。结论：BMSCs移植可以通过下调SCI中Nogo-A的生成来促进脊髓损伤后大鼠神经功能的恢复。

Abstract:

      Objective：To investigate the effects of intravenous administration of bone marrow-derived mesenchymal stem cells（BMSCs）on the recovery of neurological functions and the expressions of Nogo-A after acute spinal cord injury(SCI) in rats. Method: BMSCs were harvested and purified following adherence technique. Briefly 96 female adult Sprague-Dawley rats were randomized into 4 groups (24 in each group)：sham-operated group，SCI group，vehicle group, BMSCs-treated group. Rat′s acute SCI model was established with modified Allen′s method.Soon after SCI，5×106 BMSCs(1ml) were injected into tail vein at 10 min after SCI and 1ml 0.01m(PBS) were given to the vehicle group. BMSCs were labeled by carboxyfluorescein succinimidy ester(CFSE) before transplantation. Before sacrifice and at the 1st d、3rd d，7th d and 14th d after SCI，neurological functions were evaluated by Basso-Beattie-Bresnahan(BBB)scale; The expressions of Nogo-A were detected by reverse transcriptase-polymerase chain reaction(RT-PCR) technigue and immunohistochemical method at the 1st d、3rd d，7th d and 14th d after SCI. Result: CFSE staining positive cells were observed around the SCI area in BMSCs-treated group. Compared with SCI group and vehicle group，neurological functions were better in BMSCs-treated group at the 7th d、14th d after SCI，and the expressions of Nogo-A around the injury area down-regulated significantly at the 3rd d、7th d、14th d after SCI. (all P<0.01). Conclusion: BMSCs transplantation after acute SCI in rats can significantly improve the neurological functions, and its mechanism is related to down-regulation of Nogo-A expressions.