Nur77在深低温停循环对大鼠脑保护中作用  

Role of Nur77in cerebral protection of deep hypothermic circulatory arrest in rats

作　　者：朱耀斌[1] 闫道乐 李志强[1] ZHU Yao-bin;YAN Dao-le;LI Zhi-qiang(Department of Cardiac Surgery,Beijing Children's Hospital Affiliated to Capital Medical University,Beijing 100056,China)

机构地区：[1]首都医科大学附属北京儿童医院心外科,北京100056

出　　处：《中华实用诊断与治疗杂志》2022年第12期1204-1209,共6页Journal of Chinese Practical Diagnosis and Therapy

基　　金：北京市教育委员会科技计划一般项目(KM201910025010)。

摘　　要：目的观察深低温停循环下大鼠海马组织Nur77表达情况,探讨Nur77在深低温停循环对大鼠脑保护中的作用及可能机制。方法45只SD大鼠均建立体外循环模型,随机分为对照组(常温不停循环20min)15只,常温停循环组(常温10min、停循环10min)15只,深低温停循环组(深低温10min、停循环10min)15只。术后取3组大鼠海马组织行组织病理检查,采用DAPI染色测定神经细胞凋亡情况,应用透射电镜观察线粒体改变情况,采用Western blot法检测Nur77、Bcl-2、Bax、caspase-3、caspase-9、细胞色素C(cytochrome C,CytC)蛋白相对表达量及细胞核、细胞质Nur77蛋白相对表达量,采用实时荧光定量PCR法检测Nur77mRNA相对表达量,采用免疫荧光法观察Nur77蛋白在细胞中的定位情况。结果对照组海马组织神经细胞及线粒体形态结构正常,细胞核周边连续,染色分布均匀;常温停循环组大量神经细胞变性坏死,凋亡小体出现,线粒体肿胀,数量减少,嵴扭曲变形断裂;深低温停循环组少量神经细胞变性坏死,线粒体轻微肿胀,膜较完整。3组大鼠海马组织Nur77mRNA和蛋白相对表达量比较差异均无统计学意义(P>0.05)。对照组海马区Nur77主要分布于细胞核,细胞质表达较少;常温停循环组细胞质Nur77表达较对照组和深低温停循环组增加。常温停循环组海马组织细胞核Nur77(0.34±0.07)及海马组织Bcl-2(0.11±0.02)蛋白相对表达量均低于对照组(2.12±0.18、0.86±0.09)、深低温停循环组(1.79±0.11、0.34±0.04)(P<0.05),深低温停循环组均低于对照组(P<0.05);常温停循环组细胞质Nur77(0.74±0.05)及海马组织Bax(0.74±0.08)、caspase-3(0.86±0.09)、caspase-9(0.98±0.11)、CytC(0.92±0.08)蛋白相对表达量均高于对照组(0.12±0.02、0.13±0.03、0.13±0.02、0.17±0.03、0.14±0.02)、深低温停循环组(0.21±0.03、0.22±0.04、0.31±0.05、0.43±0.07、0.36±0.06)(P<0.05),深低温停循环组均高于对照组(P<0.05)。结论Nur77�Objective To observe the expression of Nur77in the hippocampus in rats after deep hypothermic circulatory arrest(DHCA),and to investigate the role and potential mechanism of Nur77in cerebral protection after DHCA.Methods Forty-five SD rats were established the models of CPB,and were randomly divided into control group(non-stop circulation for 20min at room temperature),normothermic circulatory arrest group(normal temperature for 10min and circulatory arrest for 10min),and DHCA group(deep hypothermia for 10min and circulatory arrest for 10min),with 15rats in each group.After operation,the hippocampus tissues of three groups were taken for histopathological examination.Apoptosis in the neurons was determined by DAPI staining.The mitochondrial changes were observed by transmission electron microscopy.Western blot was used to measure the relative expressions of Nur77,Bcl-2,Bax,caspase-3,caspase-9and cytochrome C(CytC)proteins in the hippocampus,and Nur77proteins in the nucleus and cytoplasm.Real-time fluorescence quantitative PCR was used to detect the relative expression of Nur77mRNA.The localization of Nur77protein was determined by immunofluorescence.Results In control group,the morphology and structure of the neurons and mitochondria in the hippocampus were normal,the periphery of the nucleus was continuous,and the staining was evenly distributed.In normothermic circulatory arrest group,the degeneration and necrosis of neurons increased,the apoptotic bodies appeared,the mitochondria swelled and decreased,and the cristae twisted and broken.In DHCA group,a few neurons were necrotic,the mitochondria were slightly swollen and the membrane was intact.There were no significant differences in the relative expressions of Nur77mRNA and protein among three groups(P>0.05).In control group,Nur77was mainly distributed in the nucleus and less in the cytoplasm.The expression of Nur77in the cytoplasm was higher in normothermic circulatory arrest group than that in control group and DHCA group.The relative expressions of Nur77in

关 键 词：Nur77 深低温 停循环 凋亡 线粒体 海马组织 大鼠 

分 类 号：R318.52[医药卫生—生物医学工程]