FTY720改善颅脑损伤大鼠神经功能的机制研究

目的探讨FTY720对颅脑损伤大鼠神经功能的影响及其相关机制研究。 方法60只大鼠分成假手术组、模型组和治疗组，每组20只，采用改进的Feeney自由落体损伤装置建立大鼠颅脑损伤模型。治疗组大鼠按1 mg/kg剂量予FTY720腹腔注射，假手术组及模型组大鼠予以腹腔注射1 ml生理盐水。术后24 h，每组各取10只大鼠断头处死，分离海马组织，采用Western-blotting检测核因子κB表达水平，采用免疫组织化学染色法检测大鼠小胶质细胞OX-42表达水平。同时采用前肢放置试验评分、平衡实验评分及改良神经功能缺损程度评分进行神经功能评估。 结果三组大鼠海马组织核因子κB蛋白表达水平（F=95.962，P<0.001）及小胶质细胞（F=108.853，P<0.001）比较，差异均有统计学意义。且模型组核因子κB蛋白及小胶质细胞OX-42表达水平较假手术组及治疗组明显增加（P均< 0.05）。同时，模型组大鼠术后7、14、21、28 d前肢放置试验评分（7.0 ± 0.7）分vs.（6.3 ± 0.5）分，（5.9 ± 0.7）分vs.（5.0 ± 0.8）分，（4.9 ± 1.0）分vs.（3.8 ± 0.8）分，（3.7 ± 1.1）分vs.（2.3 ± 0.7）分；t=2.689、2.586、2.741、3.525，P=0.015、0.019、0.013、0.002]、平衡实验评分（4.3 ± 0.7）分vs.（3.6 ± 0.7）分，（3.5 ± 1.1）分vs.（2.6 ± 0.7）分，（2.9 ± 0.9）分vs.（1.9 ± 0.7）分，（2.5 ± 0.7）分vs.（1.8 ± 0.6）分；t=2.278、2.212、2.762、2.333，P=0.035、0.040、0.013、0.031]及改良神经功能缺损程度评分（10.1 ± 1.0）分vs.（8.7 ± 1.6）分，（8.8 ± 0.8）分vs.（7.5 ± 1.5）分，（7.3 ± 1.0）分vs.（5.6 ± 1.3）分，（5.7 ± 1.3）分vs.（4.1 ± 1.4）分；t=2.385、2.414、3.400、2.726，P=0.028、0.027、0.003、0.014]均明显高于治疗组。 结论FTY720可显著改善颅脑损伤大鼠神经功能，其作用机制可能与FTY720的中枢炎症抑制作用有关。

Mechanism of FTY720 on neural function improvement of rats with traumatic brain injury

ObjectiveTo investigate the effect of FTY720 on neurological function in rats with traumatic brain injury and the related mechanism. MethodsA total of 60 rats were randomly divided to the sham-operation group, model group and treatment group, 20 rats in each group. Modified Feeney free fall injury device was used to build rat craniocerebral injury model. Rats in the treatment group were administrated intraperitoneally with 1 mg/kg FTY720. Rats in the sham-operation group and model group were given 1 ml normal saline by intraperitoneal injection. After 24 hours, 10 rats in each group were sacrifice and their hippocampus tissues were used to determine the expression of nuclear factor-kappa B and microglial OX-42 by Western blotting and immunohistochemistry respectively. Additionally, the forelimb-placement test, balance test and modified neurological severity scores were used to assess the neurological function in each group. ResultsThe expression of nuclear factor-kappa B (F=95.962, P<0.001) and microglial OX-42 (F=108.853, P<0.001) were all showed significant differences among the three groups, and were higher in the model group than those in the sham-operation group and treatment group (all P<0.05). Meanwhile, the forelimb-placement test (7.0 ± 0.7) vs. (6.3 ± 0.5), (5.9 ± 0.7) vs. (5.0 ± 0.8), (4.9 ± 1.0) vs. (3.8 ± 0.8), (3.7 ± 1.1) vs. (2.3 ± 0.7); t=2.689, 2.586, 2.741, 3.525, P=0.015, 0.019, 0.013, 0.002], balance test (4.3 ± 0.7) vs. (3.6 ± 0.7), (3.5 ± 1.1) vs. (2.6 ± 0.7), (2.9 ± 0.9) vs. (1.9 ± 0.7), (2.5 ± 0.7) vs. (1.8 ± 0.6); t=2.278, 2.212, 2.762, 2.333, P=0.035, 0.040, 0.013, 0.031] and modified neurological severity scores (10.1 ± 1.0) vs. (8.7 ± 1.6), (8.8 ± 0.8) vs. (7.5 ± 1.5), (7.3 ± 1.0) vs. (5.6 ± 1.3), (5.7 ± 1.3) vs. (4.1 ± 1.4); t=2.385, 2.414, 3.400, 2.726, P=0.028, 0.027, 0.003, 0.014] on 7, 14, 21, 28 d after operation in the model group were higher as compared with the treatment group. ConclusionFTY720 could markedly improve the neurological function of rats with trauma brain injury and its mechanism might be related to the inhibition of FTY720 on central nervous system inflammation.