硫酸软骨素酶ABC对脑损伤后胶质瘢痕影响的实验研究

Effect of chondroitin sulfate enzyme ABC on glial scar in brain injury models

目的探讨硫酸软骨素酶ABC（chABC）对脑损伤后胶质瘢痕组织的影响。方法38只Wistar大鼠按随机数字表法分成5组：正常对照组（n=2）、模型组（n=9）、1．0U／mLchABC治疗组m=9）、2．5U／mLchABC治疗组（n=9）、5．0U／mLchABC治疗组（n=9），后4组采用自由落体撞击法制作大鼠脑损伤模型，造模后即刻在后3组大鼠局部脑皮层下1mm处注射不同浓度chABC2μL，正常对照组不做任何处理。造模后1、2、4周取脑组织标本行HE染色．分别应用免疫组化染色和Western blotting检测硫酸软骨素多聚蛋白糖（CSPGs）的表达。结果HE染色显示损伤后2周模型组大鼠脑皮层大量星形胶质细胞聚集．不同浓度chABC治疗组损伤部位的星形胶质细胞聚集较模型组减少，以5．0U／mL chABC治疗组明显。免疫组化染色显示模型组，1．0、2．5、5．0U／mLchABC治疗组损伤后2周大鼠脑组织CSPGs分泌均较正常对照组增加，差异有统计学意义（职0．05）；与模型组比较，5．0U／mLchABC治疗组大鼠脑组织CSPGs分泌减少．差异有统计学意义（P〈0．05）。Westem blotting检测显示造模后1、2、4周不同浓度chABC治疗组CSPGs表达均较模型组低．差异有统计学意义（p〈0．05）；模型组和2．5、5．0U／mLchABC治疗组大鼠脑组织中CSPGs的表达在造模后1、2、4周逐渐降低，差异有统计学意义（P〈0．05）。结论chABC能降解胶质瘢痕中主要抑制分子CSPGs，改善脑损伤后局部轴突再生的抑制性微环境．且高浓度（5．0U／mL）chABC表现最明显。

Objective To explore the effect ofchondroitin sulfate enzyme ABC （chABC） on glial scar in rat models of brain traumatic injury （TBI）. Methods Thirty-eight Wistar rats were randomly divided into 5 groups, including normal control group （n=2）, model group （rat models of TBI, n=9）, 1.0 U/mL chABC treatment group （n=9）, 2.5 U/ml chABC treatment group （n=9） and 5.0 U/ml chABC treatment group （n=9）. After performing TBI by free falling in the later 4 groups, rats of the model group were given no treatment, while those of the other 3 groups were administrated with different concentrations of chABC by local injection respectively. One, 2 and 4 w after TBI, HE staining was performed on the brain tissues of these rat models; and immunohistochemical assay and Western blotting were employed to evaluate the secreting of chondroitin sulfate proteoglycans （CSPGs） and the therapeutic effect ofchABC on glial scar. Data were statistically analyzed using t-test. Results Pathological test revealed the scars in the treatment groups were significantly fewer than those in the model group 2 w after TBI, with 5.0 U/mL chABC treatment group enjoying the fewest level （P〈0.05）. Immunohistochemical assay showed that the secreting of CSPGs in the treatment groups and model group was significantly increased than that in normal control group 2 w after TBI （P〈0.05）; the 5.0 U/ml chABC treatment group showed an obvious reduction of CSPGs secreting as compared with the model group （P〈0.05）. Western blotting indicated that the treatment groups showed an obvious reduction of CSPGs secreting as compared with the model group 1, 2 and 4 w after TBI （P〈0.05）; an obvious gradual reduction of CSPGs secreting in the model group, 2.5 and 5.0 U/ml chABC treatment groups was noted 1, 2 and 4 w after TBI （P〈0.05）. Conclusion ChABC could degrade the glial scar by degrading the CSPGs molecules and improve the microenvironment of local axonal regeneration after TBI; In this experiment, the highest concentration of chABC （5U/ml） shows the best effect on removing the glial scar.