脓毒症相关性脑病大鼠海马区神经细胞自噬  

Autophagy in hippocampal nerve cells from rats with sepsis-associated encephalopathy

作　　者：李雅斐[1] 苏云洁[1] 屈艺[1] 母得志[1] 李熙鸿[1] 

机构地区：[1]四川大学华西第二医院儿童重症医学科,成都610041

出　　处：《中南大学学报（医学版）》2016年第6期571-577,共7页Journal of Central South University ：Medical Science

摘　　要：目的:探讨脓毒症相关性脑病(sepsis-associated encephalopathy,SAE)大鼠海马区神经细胞自噬现象及微管相关蛋白1轻链3(LC3)的表达。方法:盲肠结扎穿孔术(cecal ligation and puncture,CLP)建立脓毒症大鼠模型。60只30日龄健康雄性Wistar大鼠被随机分为假手术组(10只)和CLP组(50只)。CLP后12 h监测大鼠脑电图(electroencephalogram,EEG)及体感诱发电位(somatosensory evoked potential,SEP),并进行神经生物学评分。根据大鼠是否发生SAE将CLP组大鼠再分为SAE(+)组和SAE(–)组。HE染色观察大鼠海马区病理学改变;电子显微镜观察大鼠海马区神经细胞自噬的超微结构;Western印迹检测LC3-I和LC3-II蛋白的表达。结果:50只大鼠在CLP后12 h内死亡5只,存活45只大鼠中有16只出现神经行为学、EEG及SEP改变,诊断为SAE,其发病率为35.56%(16/45)。与假手术组和SAE(–)组比较,SAE(+)组大鼠在CLP后12 h时α波的频率明显减少,δ波增加,P1振幅下降,P1波和N1波潜伏期延长(P<0.05)。CLP后12 h时SAE(+)组大鼠海马区细胞明显水肿,锥体细胞明显减少,甚至溶解,细胞排列紊乱,而假手术组和SAE(–)组大鼠海马区细胞形态正常、层次清楚。透射电子显微镜观察表明:SAE(+)组大鼠海马区细胞结构紊乱,可见自噬泡、颗粒状基质和方形或长方形晶体,自噬泡内含有溶酶体等细胞器,假手术组和SAE(–)组大鼠海马区组织细胞无自噬泡形成。SAE(+)组大鼠在CLP后12 h,海马区神经细胞LC3-II/LC3-I值明显高于假手术组和SAE(–)组(P<0.05)。结论:SAE大鼠海马区神经细胞存在细胞自噬现象,LC3-II/LC3-I值明显升高。Objective： To show evidence of the autophagy in hippocampal nerve cells from rats with sepsis- associated encephalopathy （SAE） in vivo and to investigate the expression of microtubule- associated protein 1 light chain 3 （LC3）. Methods： A rat model of sepsis was established by the cecal ligation and puncture （CLP）. A total of 60 male Wistar rats （30 days old） were randomly divided into a sham group （n=10） and a CLP group （n=50）. At 12 hours after CLP, the electroencephalogram （EEG） and somatosensory evoked potential （SEP） changes in rats were monitored and the neurobehavioral score was measured. According to the occurrence of SAE, the CLP group was further divided into an SAE（＋） group and an SAE（-） group. Histopathological changes in hippocampus were observed by hematoxylin-eosin staining. An electron microscope was used to observe autophagosome formation and lysosome activation in the hippocampal nerve cells. Expressions of LC3-I and LC3-II protein were measured by Western blot. Results： Five of 50 rats in CLP group died in 12 hours after CLP. According to the low neurobehavioral score and abnormal EEG and SEP, 16 rats were diagnosed as SAE. The incidence of SAE was 35.56% （16/45）. Compared with the sham group or the SAE（-） group, the frequency of a wave in SAE（＋） group was significantly decreased at 12 hours after CLP, the 8 wave increased, the Pl amplitude decreased, and the latency of SEP waves （Pl and N1） was prolonged （P〈0.05）. The morphology of hippocampal nerve cells was obvious in a status of edema. Pyramidal cells decreased significantly, even dissolved, and cell arrangement was in disorder in the SAE（＋） group. But these cells were normal in the sham group and the SAE（-） group. The structure ofhippocampal nerve cells was disordered, and the autophagy, granular matrix and square or rectangular crystals were found in the SAE（＋） group. However, there was no autophagy both in the sham group and the SAE（-） group. LC3-I

关 键 词：脓毒症相关性脑病 海马 自噬 微管相关蛋白1轻链3 

分 类 号：R459.7[医药卫生—急诊医学]