BDNF联合chABC鞘内注射对大鼠脊髓损伤修复的影响

目的 探究脑源性神经营养因子（BDNF）联合软骨素酶（chABC）鞘内注射对大鼠脊髓损伤后运动感觉功能的影响以及脊髓组织中神经干细胞、神经元、星形胶质细胞、少突胶质细胞的影响。方法 将SD大鼠分为假手术对照组（A组），损伤对照组（B组），chABC治疗组（C组），BDNF治疗组（D组），联合治疗组（E组），采用后肢运动功能评分法（CBS）对大鼠术后1周、2周、4周和2个月后肢运动功能进行评定，苏木精-伊红（HE）染色法观察不同时间点大鼠脊髓组织变化，免疫组化法观察各组大鼠脊髓组织神经干细胞的影响，荧光免疫组化法观察各组大鼠神经元、星形胶质细胞、少突胶质细胞的变化。结果 术前各组大鼠神经功能均正常，术后1~2周，B、C、D、E各组CBS评分降低，但各组间对比差异无统计学意义（P>0.05）；术后4周~2个月，C、D、E组CBS评分逐渐降低，低于B组，差异有统计学意义（P<0.05）。与A组相比，B组不同时间点BrdU阳性细胞数目降低，差异有统计学意义（P<0.05）。脊髓损伤后1周，C、D、E组大鼠脊髓组织BrdU阳性细胞数目与B组比较，差异无统计学意义（P>0.05）；脊髓损伤后第2~4周，C、D、E组BrdU阳性细胞数高于B组，差异有统计学意义（P<0.05）。与空白对照A组比较，B组脊髓损伤后不同时间点Nestin阳性细胞数目均减少，差异有统计学意义（P<0.05）。脊髓损伤后2周、4周、2个月，C、D、E组脊髓组织Nestin阳性细胞数高于B组，差异有统计学意义（P<0.05）。脊髓损伤后1周，A组星形胶质细胞比例逐渐降低，神经元细胞比例逐渐升高。B组细胞3种细胞比例均较低，随着时间延长，神经元细胞比例缓慢升高，星形胶质细胞比例缓慢下降。C、D、E组脊髓受损后脊髓受损后4周~2个月，C、D、E组神经元比例逐渐升高，星形胶质细胞逐渐下降，与B组比较，差异有统计学意义（P<0.05）。结论 BDNF、chABC鞘内注射后对大鼠脊髓损伤后运动、感觉功能恢复具有一定的促进作用，可能与促进神经干细胞增殖以及神经元细胞的分化有关，但两者联合后效果并不显著。

Effect of BDNF Combined with chABC on Repair of Spinal Cord Injury in Rats

Objective To investigate the effects of motor sensory function and the neural stem cells, neurons, astrocytes and oligodendrocytes in the spinal cord tissue after spinal cord injury in rats by intrathecal injection of brain derived neurotrophic factor (BDNF) combined with chondroitin sulfate (chABC). Methods SD rats were divided into sham operation control group (A group), injury control group (B group), chABC treatment group (C group), BDNF treatment group (D group), combined treatment group (group E).Hindlimb motor function score (CBS) was used to assess hindlimb motor function after 1 weeks, 2weeks, 4 weeks and 2 months postoperatively.Immunohistochemical method was used to observe the effect of neural stem cells in spinal cord tissue of rats in each group.The changes of neurons, astrocytes and oligodendrocytes in rats were observed by fluorescence immunohistochemistry. Results The neurological function of rats in each group before operation was normal. After 1-2 weeks, the scores of B, C, D, E and CBS in each group decreased, but there was no significant difference between the groups (P>0.05). After4 weeks -2 months,CBS score of C, D, E group was decreased gradually, lower than the B group, and the difference was statistically significant(P<0.05).Compared with group A, the number of BrdU positive cells in B group decreased at different time points, and the difference was statistically significant (P<0.05).The number of BrdU positive cells in spinal cord tissue of rats in group C, D and E after 1 weeks of spinal cord injury was not significantly different from that of group B (P>0.05).The number of BrdU positive cells in C, D and E groups was higher than that in group B at 2-4 weeks after spinal cord injury, and the difference was statistically significant (P<0.05).Compared with the blank control group A, the number of Nestin positive cells in the B group at different time points after spinal cord injury was decreased, the difference was statistically significant (P<0.05).The number of Nestin positive cells in spinal cord tissue of C, D and E groups was higher than that of group B at 2, 4 and 2 weeks after spinal cord injury, with statistical difference (P<0.05). Conclusion BDNF and chABC after intrathecal injection has a certain role in motor and sensory function recovery after spinal cord injury in rats, and may promote the proliferation of neural stem cells and neuronal differentiation, but the effect is not significant after the combination.At 1 weeks after spinal cord injury, the proportion of astrocytes decreased gradually and the proportion of neurons increased gradually in A group. The proportion of neuronal cells in B group increased slowly, and the proportion of astrocytes decreased slowly. In the C, D and E groups, the proportion of neurons in C, D and E increased gradually and the astrocytes decreased gradually after 4 weeks -2 months after spinal cord injury, and the difference was statistically significant compared with the B group (P<0.05).