大鼠不同程度脊髓损伤后再生基因蛋白-2的表达变化

Expression changes of regeneration gene protein-2 in rats after different degrees of spinal cord injury

目的比较大鼠不同程度脊髓损伤(SCI)后再生基因蛋白(Reg)-2的表达差异。方法 30只SPF级Wistar大鼠随机分为正常组、假手术组、轻伤组(致伤能量25 g·cm)、中度损伤组(50 g·cm)和重伤组(75 g·cm)。各损伤组大鼠采用自制打击装置建立SCI动物模型,并于伤后1、3、5和7 d采用联合行为评分(CBS)检查大鼠神经功能恢复情况。伤后7 d处死动物,取损伤节段脊髓组织,采用RT-PCR和免疫组织化学SABC法检测Reg-2 mRNA和Reg-2的表达。结果各损伤组大鼠CBS较正常组显著升高(P<0.05),并随损伤时间的延长而逐渐降低,各损伤组组内比较,差异具有统计学意义(P<0.05);Reg-2 mRNA表达量和Reg-2阳性细胞数在各损伤组均显著高于正常组(P<0.05),并且随损伤程度的加重而升高,各损伤组之间比较,差异具有统计学意义(P<0.05)。轻伤组Reg-2阳性细胞以神经元为主,而在重伤组以神经胶质细胞为主。结论 SCI后Reg-2表达开始升高,其表达水平具有一定的损伤程度依赖性。

Objective To detect expression changes of regeneration gene protein （Reg）-2 in rats with different degrees of spinal cord injury （SCI）. Methods Thirty SPF Wistar rats were randomly divided into 5 groups： normal control group, sham operation group, slight injury group （injury energy： 25 g.cm）, moderate injury group （injury energy： 50 g-cm）, and severe injury group （injury energy： 75 g. cm）. The SCI model rats were established with own-made device by umdified Allen＇s crush method. The combine behavioral score （CBS） of injury groups rats were assessed in 1, 3, 5, and 7 d after injury. The rats were sacrificed at 7 d after surgery, then the content of Reg-2 mRNA and expression of Reg-2 were detected with RT-PCR and immunohistochemistry assay, respectively. Results The results of CBS in injury groups, which were higher than that in normal control group, declined gradually with the lapse of injury time, and the differences in every injury group were statistically significant （P 〈 0.05）. The contents of Reg-2 mRNA and Reg-2 in injury groups, which were higtier than that in normal control group （ P 〈 0.05）, elevated with the severity of injury. The differences of Reg-2 mRNA and Reg- 2 among every injury group were statistically significant （P 〈 0.05）. In slight injury group, the Reg-2 positive cells were mainly neurons, but in severe injury group they were mainly neurogliocytes. Conclusion Reg-2 could improve the function of neurons after SCI, which was dependent on the injury degree.