The antiapoptotic effect of insulin against anoxia/reoxygenation injury in cultured cardiomyocyte of neonatal rat

Objective： To study protective effect of insulin against cardiomyocyte apoptosis in anoxia/reoxygenation （A/R） injury of neonatal rat. Methods： The model of A/R injury was finished through receiving anoxia for 2h and reoxygenation for 4h in cultured cardiomyocytes of neonatal rat. The cardiomyocytes were divided randomly into 3 groups： control group （CON）, anoxia/reoxygenation group （A/R） and insulin-treated group （INS）. At the end of reoxygenation of 4 hours, activities of lactate dehydrogenase （LDH）, contents of malondiaidehyde （MDA）, were assessed through spectrophotometric procedures, myocyte apoptosis were detected through TUNEL and DNA Ladder. Results： MDA, LDH, and Apoptosis Index were significantly decreased in INS group compared with A/R group （P〈0.01）. Conclusion： Insulin has a protective effect against A/R injury in cultured cardiomyocyte of neonatal rat; the protective mechanism may contribute to antiapoptosis of insulin.     

Protective effects of erythropoietin pretreatment on myocardium with hypoxia／reoxygenation injury in rats

To establish the rat model with myocardial hypoxia/reoxygenation (H/R) injury, and investigate the protective effect of EPO pretreatment on the myocardium. Methods: Sixty male adult Wistar rats were randondv divided into 3 groups: control group, H/R group, and EPO group, 20 in each group. The rats in EPO group accepted injection of 5000 U/kg recombinant human erythropoietin (RHuEPO) through vein, and the other rats accepted the injection of the same volume of saline. Twenty-four hours after the injection, rats in the EPO and H/R groups were put into the hypoxia environment for 12h and then returned to the nonnoxic environment for 2 h, and then the samples of blood and myocardium were collected. Serum myocardial enzyme activity, apoptosis, ultrastructure, myocardial MDA contents, EPO receptor (EPOR) expression in cardiac myocytes and cardiac functions were tested. Results: EPOR expression was positive in cardiac myocytes of adult rat according to the result of immunohistochemitry assayng. Compared to those in H/R group, rats in EPO group presented lighter injury of myocardial ultrastructure, the reduction of serum myocardial erzyme activity, inhibition of apoptosis, the better recovery of cardiac functions, and the less production of oxygen-derived free radicals. Conclusion: Adult rat cardiac myocytes could express EPOR, and EPO pretreatment produced protective effects on myocardium with H/R injury.     

NF-κB在脑缺血再灌注损伤中的双重作用

核因子-κB(nuclear factor-kappaB，NF-κB)是一种重要的核转录因子，参与许多基因的表达，包括细胞因子、生长因子、急性期蛋白、黏附分子、转录因子、细胞表面受体等。它广泛存在于真核细胞中，在机体免疫、细胞发生与凋亡中起重要作用。近年来发现神经细胞和脑血管内皮细胞中都含有NF-κB位点，其与脑缺血时细胞死亡有密切关系。     

NF-κB在EPO预处理对培养心肌细胞缺氧/复氧损伤保护效应中作用的研究

目的观察促红细胞生成素(erythropoietin, EPO)预处理对培养心肌细胞缺氧/复氧损伤(H/R)的保护效应及其与预处理过程中NF-κB的关系.方法采用培养的新生大鼠心肌细胞建立缺氧/复氧损伤模型,细胞分组为:对照组,EPO预处理组(EPO组)(EPO 10 U/ml),EPO 吡咯烷二硫氨基甲酸盐(PDTC)预处理组(EPO PDTC组)(EPO 10 U/ml PDTC 5 μg/ml),PDTC预处理组(PDTC组)(PDTC 5 μg /ml),共4组,分别于缺氧/复氧损伤前后,检测培养液LDH含量,MTT比色法观察细胞活力及流式细胞仪检测心肌细胞凋亡.采用EMSA检测缺氧复氧损伤前后各组心肌细胞NF-κB活性.结果 EPO预处理显著降低心肌细胞缺氧/复氧损伤后细胞培养液LDH含量,提高细胞存活率,并降低心肌细胞凋亡率,预处理过程中同时加入NF-κB阻断剂PDTC使EPO预处理的以上心肌保护效应显著减弱或消失.EMSA显示EPO预处理使H/R前心肌细胞NF-κB活性较对照组、EPO PDTC组、PDTC组显著升高(P<0.05),EPO PDTC组心肌细胞NF-κB活性与PDTC组和对照组无显著差异(P>0.05).缺氧复氧损伤后各组心肌细胞NF-κB活性较正常对照组显著升高(P<0.01),但EPO组的NF-κB活性低于其余各组(P<0.05),其余各组间无显著差异(P>0.05).结论 EPO预处理对培养心肌细胞缺氧/复氧损伤具有保护效应,这一作用与EPO预处理过程中NF-κB的活化有关,NF-κB的活化可能通过其负反馈调节机制抑制H/R后心肌细胞NF-κB活性的升高.     

新生鼠脑组织缺氧缺血再灌注损伤NF-κB的表达及意义

目的 观察新生鼠窒息后缺氧-缺血-再灌注损伤不同时间脑组织NF-κB动态变化,以探讨NF-κB信号途径在新生儿窒息脑损伤中的作用.方法 出生7 d新生鼠随机分为对照组(A组)和窒息组(B组);制备新生鼠窒息模型,并于窒息后1、3、5和7 d取脑组织行石蜡切片.采用免疫组织化学方法检测窒息新生鼠脑组织NF-κB p65活性表达水平,用苏木精-伊红染色观察窒息后脑组织形态学变化.结果 B组脑组织NF-κB的表达较A组显著增强(P＜0.05),以5 d时升高最明显;并伴有神经细胞坏死及凋亡现象.结论 NF-κB可能通过炎症反应机制介导窒息脑损伤过程.     

NF-κB与心肌缺血／再灌注损伤的相关性

缺血，再灌注损伤（Ischemic reperfusion injury，RPI）指心肌血供中断，一定时间内恢复血供．原缺血心肌发生较血供恢复前更严重的损伤。NF-κB是一种具有多向性调节作用的核转录因子．广泛调控与免疫反应、应激反应和炎症反应相关的基因表达。已经证实。心脏的缺血，再灌注可引起心脏局部某些细胞因子、粘附分子的过度表达。     

缺血再灌注损伤中PC12细胞胞质Ca2+浓度变化和NF-κB的表达

目的:建立大鼠肾上腺嗜络细胞瘤细胞(PC12)的缺血再灌注模型,观察其在缺血再灌注损伤中细胞胞质Ca2+浓度变化和NF-κB表达情况. 方法: 将传代培养的PC12细胞在特制装置中进行缺血再灌注处理,建立研究所需要的细胞模型,运用激光共聚焦显微镜检测不同处理条件下胞质的Ca2+浓度;应用免疫细胞化学、流式细胞术对NF-κB的表达进行检测. 结果: 试验组与对照组相比,胞质Ca2+浓度和NF-κB的表达均有升高,并于再灌注30 min左右达到高峰(P<0.01). 结论: 细胞胞质Ca2+和NF-κB可能在PC12细胞的缺血再灌注损伤机制中起着重要作用.     

Activation of NF-κB and its regulation on IL-6 expression during LPS-induced liver injury

Objective： To explore the kinetics of the activation of nuclear factor-kappa B （NF-κB） and its regulation of interleukin-6 （IL-6） expression during LPS induced liver injury. Methods： Kunming mice were randomly divided into 4 groups in order to observe the does effect relationship at 3h： normal saline solution （control） group, low （1 mg/kg）, middle （5 mg/kg）, and high （10 mg/kg） LPS-induced groups; 6 groups in order to observe the time-effect relationship of 5 mg/kg LPS injection： normal saline solution （control） group, 0.5, 1, 3, 5 and 8 h groups ; pyrrolidine dithiocarbamate （PDTC） intervened groups （3 h）： normal saline solution （control） group, 5 mg/kg LPS, 200 mg/kg PDTC, and 200 mg/kg PDTC＋5 mg/kg LPS groups. NF-κB activities of Kupffer cells were determined with electrophoretic mobility shift assay （EMSA） and expression levels of IL-6 were measured with enzyme-linked immunosorbent assay （ELISA）. Results： Does-effect of NF-κB activities in Kupffer cells after LPS injection 3 h： NF-κB activation could be detected in 1 mg/kg LPS group, reached the highest level in 5 mg/kg LPS group, and persisted in 10 mg/kg LPS group; time-course after 5 mg/kg LPS injection： the DNA-binding activity was observable at 0.5 h after LPS injection, increased significantly at 3 h, and persisted for at least 8 h; in addition, antioxidant PDTC could inhibit the activation of NF-κB significantly. The kinetics of IL-6 level in liver tissues during LPS-induced liver injury were that IL-6 level after 3 h of injection increased first and then reduced; the same trend was observed in the time-course on IL-6 level after LPS injection; PDTC could significantly inhibit the release of IL-6. Correlation analyses revealed that IL-6 level was significantly and positively correlated with the activation of NF-κB. Conclusion ： NF-κB in Kupffer cells can be activitied during LPS-induced liver injury to some extent, and NF-κB may have some regulation on the expression of IL-6.     

核转录因子NF-κB与肾脏缺血-再灌注损伤

核转录因子κB（NF-κB）普遍存在于真核生物细胞内,在免疫反应、炎症反应、细胞凋亡、缺血-再灌注损伤等病理生理改变过程中起着重要的调控作用。NF-κB在肾脏缺血-灌注损伤中的起着重要作用,本文就这方面的研究进展进行综述。     

姜黄素对大鼠脑缺血再灌注损伤时NF-κB、ICAM-1的影响

目的 观察大鼠脑缺血再灌注损伤时海马神经元NF-κB及ICAM-1随再灌注时间表达变化,探讨姜黄素脑保护的分子机制.方法 制作SD大鼠全脑缺血再灌注损伤模型.实验分为S组、IR组、Cur组及SC组.HE染色观察海马锥体细胞形态改变、免疫组化观察海马NF-κB蛋白的表达,酶联免疫吸附试验测定海马组织ICAM-1蛋白含量.结果 IR组细胞轮廓消失,大部分细胞出现核固缩、碎裂.Cur组70%细胞边界基本清楚,核形状基本规则.Cur组海马CA1区在再灌注后各时间NF-κB的表达水平均低于相应时间点IR组(P<0.05).Cur组海马ICAM-1蛋白含量均低于IR组及SC组,其中在1 d和3 d有显著差异(P<0.05).结论 姜黄素可能通过抑制ICAM-1、NF-κB的表达减轻缺血再灌注神经元损伤.     

Study on the protective mechanism of remifentanil on mitochondria in rat hepatocytes subjected to ischemia-reperfusion injury

Objective：To explore the protective effect of remifentanil on mitochondria in rat hepatocytes subjected to ischemia-reperfusion injury and their possible mechanism. Methods：The model of rat hepatic ischemia-reperfusion injury was used and the effect of remifentanil on the ultrastructure of mitochondria, calcium homeostasis, MDA level in mitochondria were observed. Results： In contrast with the control group, mitochondrial matrix calcium concentration, calcium concentration after calcium uptake, and the quantity of calcium uptake in low and high remifentanil concentration groups and 5-HD group are lower （P〈0.01）, and there is no difference in RHD （5-HD＋remifentanil） group. The difference in MDA level between groups is insignificant. Conclusion ：Remifentanil at clinical concentrations exerts a protective effect on mitochondria in rat hepatocytes subjected to ischemia-reperfusion injury, in which activating the KATP channel may be involved.     

Effects of Triptolide on the Expression and Activity of NF-κB in Synovium of Collagen-induced Arthritis Rats

Summary： The expression and activity of NF-kB in the synovium of collagen-induced arthritis （CIA） rats was detected in order to investigate the possible therapeutic effects of triptolide on rheumatoid arthritis （RA）. The experimental Wistar rat model of CIA was set up by intradermal injection of emulsion of bovine collagen 11 and the successful rate of setting-up models was evaluated by arthritis index （AI）. Rats were grouped randomly into three groups： normal, model and treatment group. The expression of TNF-α and IL-6 in synovial fluid was detected by ELISA, and the expression and activity of NF kB in synovium by immunohistochemistry method and by electrophoretic mobility shift assay （EMSA） respectively. As compared with normal group, the expression of TNF a and IL-6 in synovia （P〈0. 05）, and the expression and activity of NF-kB （P〈0.05） in synovium were increased in model group. There was statistical difference in above-mentioned indexes between model group and treatment group. Triptolide may play a protective role in IRA via downregulating the expression and activity of NF-kB in synovium.     

乌司他丁对大鼠全脑缺血再灌注后NF-κB的影响

[目的]观察乌司他丁对急性全脑缺血再灌注损伤大鼠脑组织核转录因子κB(NF-κB)的影响,探讨乌司他丁在全脑缺血再灌注损伤时对大脑皮质的保护作用。[方法]建立大鼠急性全脑缺血再灌注损伤模型,予乌司他丁治疗干预,采用免疫组化法测定脑组织海马CA1区NF-κB含量。石蜡切片HE染色光镜下观察该区神经细胞形态。[结果]再灌注损伤后,脑组织NF-κB表达均增高,与假手术组比较差异显著(P<0.01);NF-κB表达于再灌注6h达到高峰,异常神经细胞数随再灌注时间的延长而逐渐增多。乌司他丁干预后,NF-κB的表达显著下降(P<0.01),异常神经细胞数减少。[结论]①NF-κB参与了全脑缺血再灌注损伤的病理过程;②在脑复苏救治过程中,乌司他丁可通过抑制NF-κB的表达,抑制炎症反应而发挥脑保护作用。     

齐墩果酸预处理对大鼠肝脏缺血再灌注损伤过程中IKK/I-κB/NF-κB通路的影响

目的:探讨齐墩果酸(oleanolic acid,OA)预处理对大鼠肝脏缺血再灌注损伤(hepatic ischemic/reperfusion injury,HIRI)过程中IKK/I-κB/NF-κB信号转导通路的影响?方法:将128只SD大鼠随机分为假手术组(SH组)?缺血再灌注组(IR组)?0.5%羧甲基纤维素钠组(CM组)和齐墩果酸预处理组(OA组)?OA组以100 mg/kg的齐墩果酸混悬液,SH和IR组以相同容积的水,CM组以相同容积的0.5%CMC-Na分别每日灌胃1次,连续7天?第8天建立70%肝脏缺血模型,缺血60 min后再灌注?于术前?再灌注0?3?6 h取肝组织?用Western blot法测定肝脏细胞内IKK2,I-κBα及细胞核内NF-κB p65蛋白含量?结果:术前?0 h,各组胞浆未检测到IKK2,核内仅检测到极少量NF-κB,各组I-κBα蛋白量之间没有统计学差异?3?6 h时,SH组胞浆IKK2和核内NF-κB的蛋白含量均分别明显低于其余3组(P < 0.05);此时OA组该两个蛋白含量分别明显低于CM组和IR组(P < 0.05)?3?6 h时,SH组I-κBα的蛋白含量均分别明显高于其余3组(P < 0.05),OA组此值分别明显高于CM组和IR组(P < 0.05),CM组和IR组各时点之间的细胞内IKK2,I-κBα及细胞核内NF-κB p65蛋白量均无统计学差异(P > 0.05)?结论:HIRI能促进胞浆内IKK2蛋白的表达,使I-κB磷酸化水解,NF-κB活化进入细胞核内介导炎症反应,损伤肝细胞?缺血前使用OA可抑制IKK/I-κB/NF-κB信号传导通路的激活,这可能是OA预处理减轻HIRI的机制之一?     

供肝冷保存再灌注期间核因子NF-κB和抑制蛋白IκBs的变化及其意义

目的:研究肝移植期间供肝组织中核因子NF-κB的激活特征及其活性调控机制.方法:改良Kamada法建立大鼠原位肝脏移植模型,按供肝在4℃乳酸林格液中的冷保存时间,实验分冷保存2 h组和6 h组,凝胶迁移率改变分析法(EMSA)和Western印迹法测定移植期间不同时相供肝组织中NF-κB的活性变化及其主要抑制蛋白IκB-α、IκB-β的表达水平.结果:两组供肝组织在冷缺血保存期间其NF-κB活性与正常肝组织相比无明显差异(P>0.05),再灌注后30 min至6 h两组的NF-κB活性均出现显著的诱导激活(P<0.01),其中冷保存2 h组供肝组织的NF-κB活性高峰出现在再灌注1 h;而冷保存6 h组在再灌注30 min即达到活性高峰,并维持在较高的激活水平;供肝组织中抑制蛋白IκB-α的含量显著高于IκB-β,两组的IκB-α蛋白在再灌注30 min至1 h均有明显降解(P<0.05),而IκB-β蛋白仅在冷保存6 h组有较明显的降解(再灌注30 min).结论:核因子NF-κB仅在供肝的再灌注早期呈诱导性激活,其激活特征与供肝的冷保存再灌注损伤有关,抑制蛋白IκB-α在供肝的NF-κB活性调控中可能起了主要作用.     

Effect of protective myocardium by allitridum from decreasing apoptosis in rats with ischemia／reperfusion injury

INTRODUCTIONI schemic preconditioning (IP) is a powerful protec tive endogenous adaptive response of the heartagainst a prolonged ischemic insult[1,2]. However, theapplication of IP requires a physical cut of the blood sup ply which is difficult or impractical in many clinical situ ations. So a way to circumvent these potential problemsassociated with the clinical application of IP may be pre conditioning by pharmacological preconditioning ( PP)means or manipulation of the…     

The role of NF-κB in hepatocellular carcinoma cell

Objective To evaluate the role of nuclear factor-kappaB (NF-κB) and IκBα in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-κB inhibition in SMMC7721 cells transfected with mutated IκBα (mIκBα) plasmid and the effect of stable inhibition of NF-κB activity in combination with Doxorubicin.Methods Western blot was used to determine the expression of NF-κB and IκBα in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the 32P-labeled tandem κB sequence using electrophoretic mobility shift assay and the expression of NF-κB using Western blot between SMMC7721 cells transfected with mIκBα plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of κB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated.Results Western blot analysis for nuclear extract showed more P50 (NF-κB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IκBα protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-κB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-κB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-κB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P&lt;0.01）.Conclusions The present study demonstrates that upregulation of NF-κB and downregulation of inhibitory kappaB (IκBα) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIκBα in SMMC7721-MT cells can inhibit NF-κB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-κB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-κB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.     

缺血后处理对大鼠肾脏缺血再灌注损伤及NF-κB表达的影响

[目的]探讨缺血后处理对大鼠肾缺血再灌注损伤影响。[方法]夹闭左侧肾动脉60 min后再灌注6 h法制备肾脏缺血再灌注损伤模型。雄性SD大鼠18只随机分为3组：缺血再灌注组（IR组,n=6）,缺血后处理组（IPO组,n=6）,假手术组（Sham组,n=6）。测定血肌酐（Cr）浓度、尿素氮（Bun）,检测肾脏组织中超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量和髓过氧化物酶（MPO）活性;取左肾组织行HE染色,光镜下观察肾组织病理学改变,免疫组化法检测肾组织中NF-κB表达。[结果]与Sham组比较,IR组血Cr浓度和血Bun浓度上升,达到（93.02±13.44）μmol/L和（15.58±0.56）mmol/L（P〈0.01）,SOD活性下降为（185.87±17.68）U/mgprot（P〈0.01）,MDA含量和MPO活性增加分别达到（4.09±0.34）nmol/mgprot、（0.90±0.07）U/g（P〈0.01）。与Sham组比较IPO组血Cr、Bun浓度、MPO活性差异有统计学意义（P〈0.05）,SOD活性和MDA含量差异无统计学意义;病理损伤明显,肾脏组织中NF-κB表达增强。与IR组比较,IPO组血Cr和血Bun浓度降低分别为（58.98±8.02）μmol/L（P〈0.01）、（9.45±1.03）mmol/L（P〈0.01）,SOD活性升高为（230.90±9.19）U/mgprot（P〈0.01）,MDA含量降低为（3.67±0.20）nmol/mgprot（P〈0.01）,MPO活力降低为（0.78±0.06）U/g（P〈0.01）,病理损伤减轻,肾脏组织NF-κB表达减弱。[结论]缺血后处理对肾脏有保护作用,其机制与增强肾脏抗氧化能力,减轻肾脏组织炎性细胞浸润和抑制肾组织NF-κB表达有关。     

利多卡因对脑缺血再灌注损伤大鼠海马组织细胞间NF-κB表达的影响

目的观察利多卡因对大鼠脑缺血再灌注损伤后海马组织细胞间NF-κB基因表达的影响,探讨利多卡因脑保护作用的机制。方法雄性SD大鼠32只,随机分为假手术组(A组)、缺血再灌注组(B组)、利多卡因大剂量组(C组)和利多卡因小剂量组(D组),缺血前10min腹腔注射。脑缺血10min再灌注24h时,断头处死大鼠。用RT-PCR技术检测海马组织NF-κB的表达,用免疫组织化学、蛋白印记(westernblot)方法检测NF-κB蛋白表达情况。结果脑缺血再灌注后海马组织NF-κBmRNA及蛋白表达水平增高,利多卡因可下调NF-κB表达,缺血再灌注后,海马区神经元细胞出现明显坏死,利多卡因可减轻海马区神经元损伤。结论利多卡因可能通过抑制NF-κB基因表达而对脑缺血再灌注损伤起到一定的保护作用。     

促红细胞生成素对脑缺血再灌注大鼠脑内NF-κB表达的影响研究

目的研究促红细胞生成素(EPO)对大鼠缺血再灌注后核因子-κB(NF-κB)表达的影响。方法将45只SD大鼠随机分为假手术组、脑缺血再灌注模型组(模型组)以及EPO治疗组(治疗组)。构建SD大鼠大脑中动脉闭塞脑缺血/再灌注模型,观测缺血再灌注后4、12、24h的神经功能缺损评分;比较脑梗死体积,免疫组织化学检测NF-κB蛋白的表达,TUNEL法检测神经元凋亡率。结果与模型组比较,治疗组12、24h的神经功能缺损评分降低;脑梗死体积显著减小;脑内NF-κB蛋白的表达与神经元凋亡率明显降低。结论 EPO可通过降低NF-κB蛋白表达对大鼠脑缺血再灌注损伤起保护作用。