地塞米松对脓毒症相关性脑病大鼠海马区星形胶质细胞哺乳动物雷帕霉素靶蛋白表达的影响  

Effect of Dexamethasone on Mammalian Target of Rapamycin Expression of Astrocytes in Hippocampus of Rats with Sepsis Associated Encephalopathy

作　　者：陈斌[1] 李雅斐[1] 苏云洁[1] 李熙鸿[1] 

机构地区：[1]四川大学华西第二医院急诊医学科,成都610041

出　　处：《华西医学》2016年第6期1013-1018,共6页West China Medical Journal

基　　金：四川省科技厅科技支撑计划项目(2012SZ0012)~~

摘　　要：目的探讨地塞米松对脓毒症相关性脑病(SAE)大鼠海马区星形胶质细胞哺乳动物雷帕霉素靶蛋白(m TOR)表达的影响。方法 90只30日龄健康雄性Wistar大鼠被随机分为假手术组(10只)和盲肠结扎穿孔术(CLP)组(80只)。CLP组采用CLP建立脓毒症大鼠模型。CLP后12 h时如大鼠出现神经行为学评分降低、脑电图和体感诱发电位(SEP)异常,则诊断为SAE。再将SAE大鼠随机分为脑病未治疗组和地塞米松组。地塞米松组行尾静脉注射地塞米松(1 mg/kg),隔天1次,共3次;脑病未治疗组注射同剂量的生理盐水。大鼠40日龄时再次行神经行为学评分、脑电图和SEP检查,然后统一处死大鼠,取大鼠海马组织,蛋白质印迹法检测海马区神经细胞m TOR蛋白的表达,免疫荧光检测海马区星形胶质细胞胶质纤维酸性蛋白(GFAP)和m TOR的表达,图像分析系统软件统计阳性表达的细胞数量。结果 80只CLP大鼠在术后12 h内死亡6只,CLP后12 h时检查发现存活74只大鼠中有28只出现神经行为学评分降低,脑电图和SEP异常,诊断为SAE,其发病率为37.84%(28/74)。大鼠40日龄时,与脑病未治疗组比较,地塞米松组大鼠神经行为学评分降低,脑电图的α波明显减少、δ波增加,SEP的P1振幅下降、P1和N1潜伏期延长(P<0.05)。GFAP免疫荧光染色提示:假手术组大鼠海马区星形胶质细胞胞体小,突起细;而脑病未治疗组星形胶质细胞胞体和突起肥大,与假手术组比较,细胞数量明显增多(P<0.05);与脑病未治疗组比较,地塞米松组星形胶质细胞胞体小,突起细,细胞数量也明显减少(P<0.05)。与假手术组比较,脑病未治疗组表达m TOR的星形胶质细胞数量明显增多(P<0.05),与脑病未治疗组比较,地塞米松组表达m TOR的星形胶质细胞数量明显减少(P<0.05)。结论 SAE时大鼠海马区星形胶质细胞被激活,存在反应性增生,m TOR表达上调,而地塞米松对其具有抑制作用。Objective To investigate the effect of dexamethasone on mammalian target of rapamycin （mTOR） expression of astrocytes in hippocampus of rats with sepsis associated encephalopathy （SAE）. Methods Totally, 90 cases of 30-day-old male Wistar rats were randomly divided into sham-operation group （n=10） and cecal ligation and puncture （CLP） group （n=80）. Models of rats with sepsis were established by CLP. At 12 hours after CLP, if rats appeared lower neurobehavioral scores, abnormal electroencephalogram （EEG） and somatosensory evoked potential （SEP）, they were diagnosed with SAE. And then, they were randomly divided into non-treated group and dexamethasone group. Rats in the dexamethasone group were injected with dexamethasone （1 mg/kg） via tail vein every other day for a total of 3 times. The same dose of saline was used in the non-treated group. The neurobehavioral score was measured, SEP and EEG were examined in the age of 40 days, and then the rats were killed and the hippocampus was taken. Expressions of mTOR protein were measured by Western blot. The glial fibrillary acidic protein （GFAP） and mTOR were detected by immunofluorescence assay, and the number of positive cells was calculated by image analysis system software. Results Six of 80 CLP rats died in 12 hours after operation, and 28 of 74 rats were diagnosed as SAE because they appeared lower neurobehavioral scores, abnormal EEG and SEP at 12 hours after CLP. The incidence of SAE was 37.84% （28/74）. In the age of 40 days, compared with non-treated group, neurobehavioral score of rats in the dexamethasone group was low, the amount of alpha waves in EEG reduced, delta waves increased, the amplitude of P1 waves in SEP was decreased, and the latencies of P1 and N1 waves were prolonged （P 〈 0.05）. GFAP immunofluorescence staining showed astrocytic body and processes were small in the sham operation group. However, astrocytes in the non-treated group had large body and hypertrophic processes, and compared with the sham

关 键 词：脓毒症相关性脑病 海马 胶质纤维酸性蛋白 哺乳动物雷帕霉素靶蛋白 大鼠 

分 类 号：R459.7[医药卫生—急诊医学] R747.9[医药卫生—治疗学]