注射用神经节苷脂钠对癫痫持续状态大鼠认知功能障碍及神经炎症的改善作用及机制

Improvement effects and mechanism of Ganglioside Sodium Injection on cognitive dysfunction and neuroinflammation in rats with status epilepticus

目的探讨注射用神经节苷脂钠对癫痫持续状态大鼠认知功能障碍和神经炎症的改善作用及其可能机制。方法将60只SD大鼠随机分为空白组、模型组、阳性对照组及神经节苷脂钠组,每组15只,除空白组外,其他3组采用腹腔注射氯化锂-毛果芸香碱建立大鼠癫痫持续状态模型。建模成功后,阳性对照组给予腹腔注射以丙戊酸钠,神经节苷脂钠组给予侧脑室注射神经节苷脂钠,空白组、模型组给予侧脑室注射无菌生理盐水。于给药第40天开始,采用Morris水迷宫实验评估各组大鼠学习记忆能力。于给药第45天,采用Nissl染色观察大鼠海马组织形态,并检测血清白细胞介素(IL)-1、IL-6、肿瘤坏死因子α(TNF-α)含量和海马组织Toll样受体4(TLR-4)、核因子κB (NF-κB) p65、髓样分化因子88(MyD88)蛋白表达水平。结果与空白组大鼠相比,在水迷宫实验期间,其他3组大鼠逃避潜伏期均延长,游泳距离增加,在原平台象限探索有效时间比率及游泳距离比率及穿越原平台次数减少;与模型组相比,阳性对照组及神经节苷脂钠组大鼠逃避潜伏期时间及游泳距离均缩短,在原平台象限探索有效时间及游泳距离比率及穿越原平台次数增多(均P<0.05)。与空白组大鼠相比,模型组大鼠海马CA3区可见神经元损伤;与模型组相比,阳性对照组及神经节苷脂钠组大鼠神经元损伤减轻。与空白组大鼠比较,其他3组大鼠血清IL-1β、TNF-α、IL-6的含量及海马组织TLR4、NF-κB p65、MyD88蛋白表达水平升高;与模型组相比,阳性对照组、神经节苷脂钠组IL-1β、TNF-α、IL-6含量及海马组织TLR4、NF-κB p65、MyD88蛋白表达水平降低(均P<0.05)。结论神经节苷脂钠能减轻癫痫持续状态大鼠神经炎症,并改善认知功能障碍,其作用机制可能与抑制TLR4-MyD88信号通路的激活有关。

Objective To investigate the improvement effects of Ganglioside Sodium Injection on cognitive dysfunction and neuroinflammation in rats with status epilepticus and its possible mechanism. Methods Sixty SD rats were randomly divided into blank group, model group, positive control group and ganglioside sodium group, with 15 rats in each group. Except the blank group, the other three groups undertook an intraperitoneal injection of lithium-pilocarpine to establish rat models of status epilepticus. After successful modeling, the positive control group was given an intraperitoneal injection of sodium valproate, the ganglioside sodium group was given a lateral ventricle injection of ganglioside sodium, and the blank and model groups were given a lateral ventricle injection of sterile normal saline. From the 40 th day of the administration, Morris water maze test was used to assess the learning and memory ability of rats in each group. On the 45 th day of the administration, Nissl staining was used to observe the morphology of rat hippocampal tissues, and serum contents of interleukin(IL)-1, IL-6, and tumor necrosis factor α(TNF-α), as well as the expression levels of Toll-like receptor 4(TLR-4), nuclear factor κB(NF-κB) p65, and myeloid differentiation factor 88(MyD88) proteins in hippocampal tissues, were detected. Results Compared with the blank group, during the Morris water maze test, rats in the other three groups exhibited a prolonged escape latency period, an increased swimming distance, a declined ratio of effective duration of exploring the original platform quadrant, a lower ratio of swimming distance in the original platform quadrant, and decreased number of crossing original platform;compared with the model group, rats in the positive control and ganglioside sodium groups exhibited shorter escape latency period and swimming distance, an increased ratio of effective duration of exploring the original platform quadrant, an increased ratio of swimming distance in the original platform quadrant, and increased number of crossing original platform(all P<0.05). Rats in the model group saw neuron damage in hippocampal CA3 region versus rats in the blank group;rats in the positive control and ganglioside sodium groups manifested reduced neuron damage over the model group. Compared with rats in the blank group, rats in the remaining three groups exhibited elevated serum contents of IL-1β, TNF-α, and IL-6, along with higher hippocampal expression levels of TLR4, NF-κB p65, and MyD88 proteins;the positive control and ganglioside sodium groups reported lower contents of IL-1β, TNF-α, and IL-6 as well as lower hippocampal expression levels of TLR4, NF-κB p65, and MyD88 proteins in comparison with the model group(all P<0.05).Conclusion Ganglioside sodium can reduce neuroinflammation and improve cognitive dysfunction in rats with status epilepticus, of which the mechanism may correlate with the inhibition of TLR4-MyD88 signaling pathway activation.