REM睡眠剥夺对小鼠海马IL-21介导的炎症反应及Fas/FasL介导的神经元凋亡的影响

The effect of REM sleep deprivation on interleukin-21 mediated inflammation and Fas/FasL mediated neuronal apoptosis in mice hippocampus

目的探讨REM睡眠剥夺(sleep deprivation,SD)对小鼠海马白细胞介素21(IL-21)、Fas/Fas配体(FasL)表达及神经元细胞凋亡的影响。方法将54只C57BL/6J雄性小鼠随机分为对照组、SD模型组及信号转导和转录激活因子-3抑制剂STA-21干预组,每组18只。采用改良多平台水环境法(MMPM)建立小鼠REM-SD模型。STA-21干预组于造模前按体重0.5 mg/kg腹腔注射STA-21,1次/d,共14 d。对照组分笼饲养3 d后、SD模型组和STA-21干预组于SD 3 d后灌注处死小鼠。采用组织免疫荧光染色测定小鼠海马神经元数量;TUNEL染色方法测定海马凋亡神经元数量;Western blot测定海马区IL-21及Fas/FasL、Caspase-8、Bcl-2蛋白表达水平。结果与对照组比较,SD模型组小鼠海马神经元数量未见明显减少,且未发现凋亡神经元。与对照组比较,SD模型组小鼠海马IL-21、Fas/FasL、Caspase-8蛋白表达水平升高(P<0.01),Bcl-2蛋白表达水平降低(P<0.01);STAT-3抑制剂STA-21可抑制SD小鼠海马IL-21、Fas/FasL、Caspase-8蛋白表达(P<0.01),促进Bcl-2蛋白表达(P<0.01)。结论REM-SD可促进小鼠海马IL-21介导的炎症反应,继而影响Fas/FasL介导的死亡受体通路为主的凋亡调控因子的表达。

Objective To investigate the effects of REM sleep deprivation(SD)on the expression of proinflammatory cytokine interleukin-21(IL-21)and apoptotic effectors Fas/Fas ligand(FasL),and the neuronal apoptosis in the hippocampus of mice.Methods Fifty-four male C57BL/6J mice were randomly divided into a cage control group,an SD model group and an STA-21 intervention group;there were 18 mice in each group.The REM-SD model was established by applying the modified multiple platforms method(MMPM).The STA-21 intervention group was injected with STA-21 intraperitoneally at a dose of 0.5 mg/kg,once a day for 14 consecutive days before establishing the model.The cage control group was executed after 3 days in separate cages.The SD model group and the STA-21 intervention group were executed after SD for 3 days.Immunofluorescent was used to determine the number of neurons in mice hippocampus.TUNEL staining was used to determine the number of apoptotic neurons.Western blot analysis was used to determine the IL-21,Fas/FasL,Caspase-8 and Bcl-2 protein levels in mice hippocampus.Results Compared with the cage control group,the number of hippocampal neurons in the mice in the SD model group was not significantly decreased,and no apoptotic neuron was observed in the SD model group.Compared with the controls,the SD model group showed upregulation of IL-21,Fas/FasL,and Caspase-8 and downregulation of Bcl-2 expression(P<0.01)in the hippocampus.In addition,signal transducer and activator of transcription-3(STAT-3)inhibitor STA-21 could inhibit the expression of IL-21,Fas/FasL,and Caspase-8(P<0.01),and promote the expression of Bcl-2(P<0.01).Conclusions REM-SD may promote IL-21 mediated inflammation in mice hippocampus,and then affect the expression of apoptosis regulatory factors dominated by Fas/FasL mediated death receptor pathway.