脓毒症相关性脑病易感小鼠海马的基因差异性  

Genetic differences in hippocampus of mice susceptible to sepsis-associated encephalopathy

作　　者：刘宇[1,2,3] 吴伟伟 傅迪 LIU Yu;WU Weiwei;FU Di(Department of Anesthesiology,Xiangya Hospital,Central South University,Changsha 410008;Department of Anesthesiology,Second Xiangya Hospital,Central South University,Changsha 410011;Department of Human Anatomy,School of Basic Medical Sciences,Central South University,Changsha 410013,China)

机构地区：[1]中南大学湘雅医院麻醉科,长沙410008 [2]中南大学湘雅二医院麻醉科,长沙410011 [3]中南大学基础医学院人体解剖学系,长沙410013

出　　处：《中南大学学报(医学版)》2024年第11期1777-1789,共13页Journal of Central South University :Medical Science

基　　金：湖南省自然科学基金(2023JJ30875)。

摘　　要：目的:脓毒症相关性脑病(sepsis-associated encephalopathy,SAE)属常见的脓毒症并发症,可使患者长期存在认知障碍及焦虑情绪,并可导致脓毒症患者死亡。SAE的发病情况和病情严重程度存在显著的个体差异,而调控SAE易感性差异的机制尚不清楚。海马损伤程度与SAE患者认知障碍程度和精神状况直接相关。本研究探讨SAE模型小鼠海马中差异表达基因对SAE易感性的影响。方法:将6~8周龄无特定病原体(specific pathogen free,SPF)级C57BL/6雄性小鼠随机分为生理盐水对照组(Con组)与SAE模型组(SAE组)。通过腹腔注射10mg/kg脂多糖(lipopolysaccharide,LPS)建立SAE模型,Con组腹腔注射等剂量的生理盐水。采用旷场实验(open field test,OFT)、新物体识别实验(novel object recognition,NOR)及Y迷宫实验比较2组小鼠认知功能及焦虑情绪的差异。以Con组OFT、NOR、Y迷宫实验的行为学数据的均数±标准差为基线,将SAE组小鼠分为SAE高敏(high sensitivity for SAE,HS)组和SAE低敏(low sensitivity for SAE,LS)组。采用免疫组织化学染色法观察即刻早期基因家族成员细胞原癌基因(cellular proto-oncogene Fos,c-Fos)、成熟神经元标志物神经元核蛋白(neuronal nuclei,NeuN)的表达,结合尼氏染色观察并分析小鼠海马齿状回(dentate gyrus,DG)、海马角(cornu ammonis,CA)1、CA3亚区的神经元激活程度与功能受损情况。采用高通量转录组RNA测序(RNA sequencing,RNA-seq)技术对HS组与LS组小鼠组织进行全转录组生物信息学分析,并验证2组的差异表达基因。结果:与Con组小鼠比较,SAE组小鼠认知行为和情绪行为均未表现出显著的易感性差异。进一步分析发现,HS组小鼠较LS组小鼠存在更为严重的认知障碍和焦虑情绪。免疫组织化学染色结果显示,与HS组小鼠比较,LS组小鼠海马c-Fos表达显著增加(P<0.05)。尼氏染色与NeuN染色结果显示,与HS组小鼠比较,LS组小鼠海马神经元功能受损程度显Objective:Sepsis-associated encephalopathy(SAE)is a common complication of sepsis,which can lead to long-term cognitive impairment and anxiety in patients,and may even contribute to mortality in septic individuals.There is substantial individual variability in the incidence and severity and susceptibility of SAE,but the mechanisms regulating susceptibility remain unclear.Previous studies have shown that hippocampal damage is directly associated with cognitive and emotional disturbances in SAE.This study aims to explore the impact of hippocampal differentially expressed genes on SAE susceptibility in a mouse model.Methods:Male specific pathogen-free(SPF)-grade C57BL/6 mice(6−8 weeks old)were randomly divided into a saline control group(Con group)and an SAE model group.SAE was induced by intraperitoneal injection of 10 mg/kg lipopolysaccharide(LPS),while control mice received an equivalent volume of saline.Cognitive and anxiety-like behaviors were assessed using the open field test(OFT),novel object recognition(NOR),and Y-maze test.Based on mean±standard deviation of behavioral results from the Con group,SAE mice were further classified into high-sensitivity(HS)and low-sensitivity(LS)subgroups.Immunohistochemistry was performed to detect the expression of immediate early gene c-Fos and neuronal marker neuronal nuclei(NeuN).Nissl staining was used to assess neuronal injury in the dentate gyrus(DG),cornu ammonis 1(CA1),and cornu ammonis 3(CA3)regions of the hippocampus.RNA sequencing(RNA-seq)was conducted on hippocampal tissues from HS and LS mice to identify differentially expressed genes,followed by pathway enrichment analysis.Results:No significant behavioral susceptibility differences were observed between the overall SAE group and controls.However,HS mice showed severer cognitive deficits and anxiety-like behavior compared to LS mice.Immunohistochemistry revealed significantly higher expression of c-Fos in the hippocampus of LS mice(P<0.05),while Nissl and NeuN staining revealed milder neuronal damage in the

关 键 词：脓毒症相关性脑病 易感性 差异表达基因 海马 遗传因素 

分 类 号：R74[医药卫生—神经病学与精神病学]