芬戈莫德改善蛛网膜下腔出血大鼠认知功能及其机制研究

Protective effects of fingolimod on cognitive function in rats with subarachnoid hemorrhage and its mechanism

目的探讨芬戈莫德对蛛网膜下腔出血大鼠认知功能的影响及相关机制。方法96只大鼠分成对照组、假手术组、模型组和治疗组,每组24只。对照组仅予0.9%氯化钠注射液1 m L腹腔注射。模型组与治疗组大鼠采用枕大池二次注血建立蛛网膜下腔出血大鼠模型,假手术组大鼠两次均注入等量生理盐水。此外,治疗组大鼠模型形成前0.5 h按1 mg/kg剂量予芬戈莫德腹腔注射,假手术组与模型大鼠均予以腹腔注射0.9%氯化钠溶液1 mL。同时,每组取12只大鼠采用Morris水迷宫实验分别于建模成功后8 d及22 d记录大鼠逃避潜伏期,每次历时5 d。另每组取12只大鼠建模24 h后处死,取大鼠海马组织观察炎性细胞浸润,并采用酶联免疫吸附测定法检测海马组织白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)和IL-6浓度。结果四组大鼠在建模后8、9、10、11、12、22、23、24、25、26 d逃避潜伏期比较差异均有统计学意义(F=171.147、59.363、104.145、91.132、67.732、25.580、21.809、26.693、22.254、24.319,P均<0.001),模型组与治疗组逃避潜伏期均显著长于对照组和假手术组,且治疗组逃避潜伏期均较模型组显著缩短(P均<0.001)。模型组与治疗组大鼠海马组织炎性细胞浸润明显增加,四组大鼠海马组织IL-1β、TNF-α和IL-6浓度比较,差异均有统计学意义(F=231.650、165.281、158.320,P均<0.001),模型组与治疗组大鼠较对照组和假手术组均显著升高,且治疗组较模型组均显著下降(均P<0.001)。结论芬戈莫德可显著改善蛛网膜下腔出血大鼠认知功能,其作用机制可能与芬戈莫德的中枢炎症抑制作用有关。

Objective To investigate the effect of fingolimod on cognitive function in rats with subarachnoid hemorrhage and its mechanism. Methods A total of 96 rats were randomly assigned to the control group, sham-operation group, model group and treatment group, 24 rats in each group. Rats in the control group only received 1 m L 0.9% sodium chloride injection by intraperitoneal injection. The rats in the model group and treatment group were established subarachnoid hemorrhage model via double autologous blood injection into cisterna magna, and rats in the sham-operation group were injected amount of saline twice. Moreover, rats in the treatment group were administrated intraperitoneally with 1 mg/kg fingolimod at 0.5 h before model establishment, and rats in the sham-operation group and model group were given 1 m L0.9% sodium chloride injection by intraperitoneal injection at the same time. On 8 and 22 d after model establishment, 12 rats from each group were continuously recorded escape latency 5 d by using Morris water maze. The rest rats were sacrificed at 24 h after model establishment. The hippocampus tissues were used to observe the inflammatory cell infiltration and determine the levels of interleukin-1beta（IL-1β）, tumor necrosis factor-alpha（TNF-α） and IL-6 by enzyme linked immunosorbent assay. Results The escape latency among the four groups on 8, 9, 10,11, 12, 22, 23, 24, 25, and 26 d after model establishment were all showed significant differences（F = 171.147, 59.363, 104.145, 91.132, 67.732, 25.580, 21.809, 26.693, 22.254, 24.319; all P〈0.001）. The escape latency in the model group and treatment group were longer than those in the control group and sham-operation group, and were longest in the model group（all P〈0.001）.Meanwhile, inflammatory cellular infiltration of hippocampus tissues in the model group and treatment group increased. The levels of IL-1β, TNF-α and IL-6 among the four groups also showed significant differences（F = 231.650, 165.281, 158.320; all P〈0.001）, and these levels in the model group and treatment group were higher than those in the control group and sham-operation group, and were highest in the model group（all P〈0.001）. Conclusion Fingolimod can markedly improve the cognitive function of rats with subarachnoid hemorrhage and its mechanism might be related to the inhibition of fingolimod on central nervous system inflammation.