骨髓间充质干细胞移植联合孕酮应用对脊髓损伤的修复作用

目的 探讨骨髓间充质干细胞(BMSCs)移植联合孕酮应用对大鼠脊髓损伤修复的协同作用及其可能的分子机制.方法 将60只雄性SD大鼠随机分为假手术组、模型组、孕酮组、BMSCs组、BMSCs+孕酮组,除假手术组外其余各组均为采用改良的Allen法建立的脊髓损伤(SCI)模型鼠.按上述分组分别在脊髓损伤后立即将BMSCs移植到损伤部位,和(或)在脊髓损伤后第1～5天腹腔注射孕酮(8 mg/kg).脊髓损伤术后第0、3、7、14、21、28天用BBB评分法评价后肢运动功能的恢复情况;RT-PCR和Western blot检测脊髓损伤后第0天和第28天局部组织脑源性神经营养因子(BDNF)、髓磷脂碱性蛋白(MBP)和生长相关蛋白GAP-43的mRNA和蛋白表达水平.结果 孕酮或BMSCs移植单独应用均可以有效促进大鼠后肢功能的恢复,二者联合运用效果更好.Real-time PCR和Western blot结果显示脊髓损伤后第0天各脊髓损伤组局部组织BDNF、MBP和GAP-43的表达水平均较假手术组明显降低;第28天孕酮组、BMSCs组和BMSCs+孕酮组上述指标较模型组明显升高,孕酮+BMSCs组的表达水平最高.结论 单纯孕酮或BMSCs移植均能促进SCI大鼠后肢运动功能的恢复,其机制之一可能是上调损伤局部BDNF、MBP和GAP-43的表达水平,促进髓鞘和神经元再生,两者联合应用具有协同作用.

Effects of Progeterone Combined with BMSCs Transplantation on Recovery of Motor Function after Spinal Cord Injury in Rats

Objective To investigate the synergistic effects of progesterone combined with bone borrow mesenchymal stem cells(BMSCs)transplantation on the recovery of motor function after spinal cord injury(SCI)in rats,and explore the possible molecular mechanism.Methods Sixty male Sprague-Dawley(SD)rats were randomly divided into sham operation group,SCI group,progesterone treatment group,BMSCs transplantation group,BMSCs transplantation combined with progesterone therapy group.The SCI model was established according to the modified Allen’s contusion method.Progesterone(8 mg/kg)was administrated by intraperitoneal injection on the day 1-5 after SCI.BMSCs were transplanted into the injured sites of spinal cord immediately after SCI.At 0,3,7,14,21 and 28 days after SCI,functional outcome measurements were evaluated by the BBB score.The mRNA and protein levels of BDNF,MBP and GAP-43 were detected by using real-time PCR and Western blot after SCI at the day 0 and 28.Results The functional recovery of hind limb in combined treatment group was the best among the five groups.The RT-PCR and Western blot results showed that the mRNA and protein levels of BDNF,MBP and GAP-43 in SCI group,progesterone group,BMSCs transplantation group and combined treatment group were obviously lower than those in sham operation group,those in progesterone group,BMSCs transplantation group and combined treatment group were obviously higher than those in SCI group,and those were higher in the combined treatment group than in the progesterone or BMSCs group(P<0.05).Conclusion Both progesterone and BMSCs can facilitate the recovery of motor function after SCI probably by enhancing the expression of BDNF,MBP and GAP-43 in the injured tissue.Meanwhile,the combined use of progesterone with BMSCs transplantation exerts the synergetic effects.