大鼠脊髓损伤后形态学观察和LIMK1表达的研究

目的通过监测大鼠脊髓损伤后其形态学和LIMK1、GFAP蛋白表达水平的动态改变,对脊髓损伤后LIMKL1是否参与胶质瘢痕的形成及调控进行初步研究。方法 Wistar成年大鼠54只,随机分为3组:对照组、假伤组和SCI组,SCI组采用改良Allen’s致伤装置制作大鼠脊髓损伤模型,采用BBB运动功能评分法观察大鼠后肢功能恢复情况。分别于术后1、2、3、4周取材,通过HE染色、免疫组化、免疫荧光等方法,观察伤后不同时期脊髓的病理变化及LIMK1、GFAP的表达情况。结果 SCI组死亡率33%,BBB评分示SCI组术后2周后肢运动功能有明显恢复(P<0.01)。LIMK1、GFAP的免疫组化和激光共聚焦显微镜分析结果基本一致,两者蛋白水平表达均于伤后1周增高。GFAP表达于3周达峰值,4周时开始下降;LIMK1在伤后1周时出现峰值,2周开始波动下降,3周时达峰值,4周开始下降。结论大鼠脊髓损伤后,LIMK1和GFAP表达密切相关,结合LIMK1蛋白表达谱,提示LIMK1通路参与胶质瘢痕的形成和调控。

Research on Histological Changes and Expression of LIMK1 after Spinal Cord Injury in Rats

Objective To observe the expression of LIMK1, GFAP and the histological changes after SCI, and to explore whether LIMK1 participate in the formation and control of pathological glial scar. Methods Fifty-four adult Wistar rats were randomly divided into 3 groups： one group was made as control group, one group only accepted the pseudo-operation, the others were made as spinal cord injury （SCI） model by the modified Allen＇s impact device. Locomotor capacity was assessed according to the 21-point Basso, Beanie and Bresnahan score; The lesions were observed with light microscopy and confocal laser scanning microscope at 1, 2, 3 and 4 weeks after SCI. The LIMK1 and GFAP were also observed by immunohistochemistry （IHC） and immunofluorescence assay. Results The mortality rate of SCI group was 33%. BBB scale of hind limb movements showed significant recovery of motor function after SCI in rats （P〈0.01）. There is a high degree of concordance between IHC and laser scanning confocal analysis for LIMK1 and GFAP. Both of the protein expression level increased at 1 week after SCI. The expression of GFAP reached the peak at 3 weeks after injury, and began to fail at 4 weeks. The peak of LIMK1 showed immediately at 1 week, then dropped at 2 weeks. But another peak was formed at 3 weeks and began to fail at 4 weeks. Conclusion After spinal cord injury, the expression of LIMK1 and GFAP are closely related. The expression profile of LIMK1 suggests that LIMK1 may play an important role in the glial scar development.