AG490对氯化锂-匹罗卡品致癫大鼠星形胶质细胞活化及癫的影响

目的探讨匹罗卡品致癫大鼠海马肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的表达、星形胶质细胞活化及JAK/STAT信号转导通路在颞叶癫发作中的作用。方法应用腹腔注射氯化锂-匹罗卡品(PILO)的方法建立颞叶癫模型,应用JAK/STAT信号转导通路特异性抑制剂AG490进行腹腔注射建立干预模型组;用Western blotting方法测定大鼠海马匀浆后TNF-α表达水平的变化,用免疫荧光观察AG-490阻滞JAK/STAT通路后对大鼠海马TNF-α表达水平与星形胶质细胞活化及癫发作的影响。结果 (1)PILO致癫模型组有80.00%(32/40)的大鼠达Racine分级Ⅳ级以上发作;10.00%(4/40)的雄性大鼠死亡;10.00%(4/40)的雄性大鼠未达Racine分级Ⅳ级发作,模型成功率为80.00%;1月后有自发发作者8只(25.00%8/32)。AG490干预组雄性大鼠Ⅳ级以上发作的发生率为75.00%(30/40);病死率为7.50%(3/40);17.50%(7/40)的雄性大鼠未达Ⅳ级发作,模型成功率为75%;1月后有自发发作者1只(3.3%1/30),AG490组Ⅳ级及以上发作及自发发作数与PILO致癫模型组比较,有显著性差异(P<0.05);(2)PILO致癫模型组TNF-α表达水平较对照组开始增高,AG490干预组TNF-α表达水平均较PILO致癫模型组明显降低(P<0.05);(3)PILO癫模型组可见阳性颗粒在星形胶质细胞内的空间分布,AG490腹腔注射建立干预后阳性颗粒的星形胶质细胞明显减少(P<0.05)。结论癫发作后TNF-α表达水平明显增高,提示星形胶质细胞增生。AG490可阻断JAK/STAT信号转导通路进而抑制星形胶质细胞活化,同时也可以影响癫大鼠的行为学变化,提示AG490对癫的发作可能有一定的抑制作用,其机制可能与其抑制星形胶质细胞增生有关。

Effects of AG490 on reactive astrocytes and onset following in lithium-pilocarpine-induced rat model of seizure

Objective To investigate the spatiotemporal distribution pattern of tumor necrosis factor(TNF-α) and proliferation reactive astrocytes in hippocampus of rats following p Lithium-pilocarpine-induced seizures,and the role of JAK/STAT signaling pathway in gliosis of rats with epilepsy.Methods Temporal lobe epilepsy models were established on rats by intraperitoneal injection of Lithium-pilocarpine(PILO),and specific JAK/STAT inhibitor-AG490 was used to set up pretreated models,and saline was injected in the normal control group.The expression of TNF-α and astrocytes in hippocampus were measured with western blotting and immunofluorescence assay before and after blockage of the JAK/STAT pathway in rats presenting seizures.Results(1) No seizure attack was observed in the Saline control group.Among the Lithium-pilocarpine-treated rats,80.00%(32/40) of animals suffered up to grade Ⅳ and above seizure attack according to Racine Scale,10%(4/40) of male rats died,and 10%(4/40) of male rats below the grade Ⅳ attack were expelled.Success rate of model was 90.00%,and one month later,8 rats in the group still has two spontaneous seizures.For male rats AG490 intervention groups,Ⅳ level and above attack rate was 75.00%(30/40),mor-tality rate was 17.50%(7/40) and 2.50% were expelled,there is still a spontaneous attack,and 3.3%(1/ 30),Ⅳ level and higher onset epilepsy model induced with PILO group(P<0.05).(2) In PILO model group,the level of TNF-α was higher than that in the control group.In AG490 intervention groups,the expression of TNF-α significantly reduced compared with that in PILO group(p<0.01).(3) Yellow-green particles were positive staining.Positive cell can be seen in the astrocytes.In AG490 intervention groups,the number of astrocytes with positive staining was significantly reduced(P<0.05).Conclusions AG490 can block the JAK/STAT signaling pathway and inhibit proliferation of astrocytes,and can change the behavior.AG490 reduces the oneset of epilepsy with the inhibiting effect on the proliferation of astrocytes through JAK/STAT pathway.