人尿液干细胞对大鼠脊髓损伤神经凋亡的保护作用及相关机制研究

摘要

Objective To explore the effects of bone human urine-derived stem cells(hUSCs)on the spinal cord injury and the potential mechanisms. Methods hUSCs were obtained via adherence method,and the cell phenotype was determined by flow cytometry. Spinal cord injury model was induced by using the modified weight-drop method at T8 level. 42 SD rats were randomly assigned to control group,SCI group and hUSCs+SCI group. The rat hind limb was determined by the BBB(Basso,Beattie,Bresnahan,BBB)at the 7 d,14 d and 21 d. At the day of 21. The spinal cord of all groups were taken out and the HE staining and immunohistochemistry were detected. The protein expression of Bax and Bcl-2 were detected by western blot and the content of caspase-3 were valued by ELISA. Results The CD29 and CD73 expression of hUSCs were (98.92 ± 0.62)% and(99.14 ± 0.86)% respectively,while the CD34 were at(0.47 ± 0.16)%. Compared with the control group. The motor function of the lower limbs of rats in SCI group significantly decreased,the expression of Bax protein,Caspase-3 protein and Bcl-2 protein sig-nificantly decreased. hUSCs could effectively improve the BBB scores of the spinal cord injury. Immunohistochemistry showed that hUSCs could markedly suppress the content of Bax and Caspase-3. Western blot showed that hUSCs could significantly suppress Bax and enhance Bcl-2 pro-tein expression. Elisa showed that hUSCs could markedly down-regulate the content of Caspase-3. Conclusion The anti-neural apoptosis effects of hUSCs on the spinal cord injury via suppressing the Bax and caspase-3 protein expression and improving the Bcl-2 pathway.%目的 探讨人尿液干细胞(hUSCs)对大鼠脊髓损伤(SCI)后神经凋亡的保护作用及其相关机制.方法体外获取hUSCs进行增殖培养,利用流式细胞仪检测hUSCs细胞表型.Allen法制作大鼠脊髓损伤模型,42只大鼠随机等分为3组:对照组,SCI组和hUSCs+SCI组.分别于7 d、14 d和21 d对各组大鼠下肢运动功能评分,21 d后取出各组大鼠损伤脊髓进行组织切片染色,并利用Western blot法检测脊髓Bax/Bcl-2含量,ELISA法检测Caspase-3含量.结果 hUSCs细胞表型CD29表达(98.92 ± 0.62)%,CD73表达(99.14 ± 0.86)%,CD34表达(0.47 ± 0.16)%.与对照组比较,SCI组大鼠下肢运动功能明显下降,Bax蛋白表达、Caspase-3含量明显增加,Bcl-2蛋白表达明显下调.hUSCs在7 d、14 d和21 d可明显改善SCI大鼠下肢运动功能;与SCI组比较,hUSCs+SCI组大鼠损伤脊髓节段Bax蛋白表达、Caspase-3含量得到抑制,Bcl-2蛋白表达显著提高;ELISA结果显示,hUSCs+SCI组可显著降低损伤脊髓中Caspase-3含量.结论 hUSCs对大鼠脊髓损伤神经凋亡具有明显抑制作用,可能是通过抑制Bax、Caspase-3,提高Bcl-2蛋白表达实现的.