再程序化脂肪干细胞移植治疗大鼠脊髓损伤的机制

Mechanism of reprogrammed adipose derived stem cells transplantation promoting recovery of injured spinal cord

目的制备再程序化脂肪干细胞(ADSCs),并在体研究再程序化ADSCs移植入大鼠脊髓损伤模型后促进损伤脊髓神经功能恢复的作用和机制。方法体外培养、纯化和鉴定大鼠ADSCs,并利用慢病毒包装神经元生成素2(Ngn2)基因转染ADSCs制备再程序化干细胞。体内实验将48只雌性SD大鼠随机分成3组:SCI对照(A)组、单纯ADSCs移植(B)组和Ngn2-ADSCs移植(C)组。采用BBB评分评价大鼠运动功能,并通过HE染色、免疫组化和免疫荧光等方法检测脊髓组织学改变和相关蛋白的表达水平,进而观察实验动物脊髓功能恢复情况。结果 Ngn2-ADSCs移植组在运动功能评分、胶质瘢痕的形成、脊髓损伤后病理变化和分泌神经营养因子BDNF和VEGF蛋白含量明显优于其他组。结论 Ngn2-ADSCs移植后能有效地存活,并分化为神经细胞,抑制胶质瘢痕形成,减小脊髓损伤空洞,增加BDNF和VEGF表达,最终促进SCI大鼠的运动功能恢复,较单纯应用ADSCs能更好地促进SCI修复。

Objective To investigate the therapeutic effects of reprogrammed adipose derived stem cell（ ADSCs） in a rat model of spinal cord injury（ SCI）. Methods ADSCs from rats were cultured in vitro and then purified and identified, and genetically modified ADSCs with the neurogenin2（ Ngn2） gene. 48 adult female Sprague-Dawley rats were randomly assigned to three groups,the control,ADSC,and Ngn2-ADSCs groups. The hind-limb motor function of all rats was recorded using the Basso,Beattie,and Bresnahan（ BBB） locomotor rating scale for 8 weeks.Subsequently,haematoxylineosin（ HE） staining,immunohistochemistry were performed. Results Ngn2-ADSCs transplantation group in motor function score,glial scar formation after spinal cord injury and pathological changes in the secretion of neurotrophic factor BDNF and VEGF were significantly better than the other groups. Conclusion Ngn2-ADSCs after transplantation can effectively survive and differentiate into nerve cells,inhibit glial scar formation,reduce spinal cord injury voids,increase BDNF and VEGF expression,and to improve recovery of motor function in SCI rats in a more efficient way than that with ADSCs alone.