降纤酶对脊髓损伤后VEGF的表达及细胞凋亡的作用

Effect of defibrase on the expression of VEGF and apoptosis after spinal cord injury

目的观察降纤酶对大鼠脊髓损伤后血管内皮生长因子(VEGF)的表达及细胞凋亡的影响。方法 SD大鼠随机分为假手术组、对照组、干预组,每组各30只。各组分别于伤后各个时间点进行运动功能(BBB)评分,并随机处死5只,损伤部位取材进行HE染色和免疫组化染色,在光镜下观察、计算VEGF阳性细胞数及凋亡细胞数。结果假手术组的BBB评分为21分,对照组、干预组在各时间点评分明显降低,干预组在5 d及之后的各时间点BBB评分明显高于对照组(P<0.05),尤其7 d、14 d、28 d时间点两组有显著性差异(P<0.01)。脊髓损伤后对照组VEGF在脊髓损伤及损伤周边区高表达,5 d达高峰,7 d、14 d表达仍较明显,28 d见少量表达。干预组各时间点VEGF的表达和对照组相比明显增加(P<0.05),其中3 d、5 d、7 d、14 d时间点差异显著(P<0.01)。凋亡细胞在脊髓损伤后逐渐增多,1 d达高峰,此后逐渐减少;干预组各个时间点凋亡细胞数较对照组明显减少(P<0.05),其中3 d、5 d、7 d时间点差异显著(P<0.01)。相关性分析发现对照组1～5 d时间点VEGF阳性细胞数和细胞凋亡数呈负相关(r=-0.90052,P<0.05)。结论降纤酶可能通过促进VEGF的表达减少细胞凋亡,从而对急性脊髓损伤起治疗作用。

Objective To observe the effect of defibrase on the expression of VEGF and the apoptosis after spinal cord injury.Methods Ninty SD rats were randomly divided into sham operation group,control group,intervention group,with 30 in each group.Motor function assessment（BBB） was performed at each time-point post-injury,and 5 rats were selected randomly for sacrifice.HE staining and immunohistochemical staining were performed.VEGF-positive cells and the apoptotic cells under light microscope were counted.Results BBB scores was 21 in sham group.The scores of control group and intervention group at each time-point were significantly decreased,while the score of intervention group was higher than that of control group at all time points after 5 d（P0.05）.The scores of two groups were significantly different at 7 d,14 d,28 d（P0.01）.In control group,after spinal cord injury VEGF was highly expressed in and around the injured area,which peaked at 5 d,was obviously expressed at 7 d,14 d and was little expressed at 28 d.In intervention group,the expressions of VEGF were significantly increased at each time-point compared to control group（P0.05）.The expressions of VEGF in two groups were significantly different at 3 d,5 d,7 d,14 d（P0.01）.The number of apoptotic cells was gradually increased after injury,peaked at 1 d,and then was decreased gradually.In intervention group the number of apoptotic cells was less at each time-point compared to control group（P0.05）,with 3 d,5 d,7 d the most significant（P0.01）.The correlation between VEGF-positive cells and apoptosis cells at 1 d,3 d,5 d was analyzed.The expression of VEGF in control group was negatively correlated with the number of apoptotic cells at 1~5 d（r=-0.90052,P0.05）.Conclusion Defibrase performed a therapeutic effect on spinal cord injury by promoting the expression of VEGF,which reduces the cell apoptosis in injury.