马来酸二乙酯对半乳糖胺/脂多糖致小鼠急性肝损伤发生中核转录因子表达的影响

目的　耗竭肝脏还原型谷胱甘肽 (GSH)导致氧化还原失平衡后 ,是否可通过改变库普弗细胞核转录因子表达而影响肝损伤发生。方法　给小鼠注射马来酸二乙酯 (DEM) ,耗竭 GSH。结果　马来酸二乙酯在一定程度上 ,抑制了半乳糖胺 /脂多糖 (Galn/ L PS)诱导胞质 IκBα的降解和核 NF- κBp6 5的表达。结论　 DEM可能是通过抑制 IκBα降解 ,影响 NF-κBp6 5易位入核 ,从而抑制肿瘤坏死因子 (TNF) -α释放 ,减轻肝损伤     

大鼠心肌缺血缺氧损伤核转录因子-κB与细胞间粘附分子-1的表达

目的　研究异丙肾上腺素致大鼠心肌损伤对心肌核转录因子 κB(NF κB)以及细胞间粘附分子 1(ICAM 1)表达的影响。方法　大鼠皮下注射异丙肾上腺素造成心肌坏死模型,测定血清乳酸脱氢酶(LDH)、肌酸磷酸激酶(CK)活力和丙二醛(MDA)含量,观察心肌坏死程度,免疫组化检测心肌NF κBp65蛋白的表达,Western蛋白质印迹杂交检测IκBα的蛋白质表达,半定量RT PCR检测ICAM 1mRNA含量。观察腹腔注射地塞米松后上述指标的变化。结果　大鼠给予异丙肾上腺素后,血清LDH、CK和MDA含量升高,心肌坏死,NF κBp65蛋白大量表达,IκBα蛋白质表达减弱,ICAM 1mRNA表达上升。地塞米松使升高的LDH、CK和MDA明显下降,减轻心肌坏死程度,显著抑制NF κBp65蛋白和ICAM 1mRNA表达,IκBα蛋白质表达增强。结论　儿茶酚胺大量释放引起的心肌缺血缺氧损伤中,NF κB和ICAM 1mRNA表达增加,表明抑制NF κB激活,减少ICAM 1mRNA的表达及炎性细胞因子产生是减少心肌缺血缺氧损伤的关键点之一。     

丹参对大鼠肝星状细胞核因子-κB活性和肿瘤坏死因子-α的影响

目的 探讨丹参对大鼠肝星状细胞(HSC)的作用机制。方法分离大鼠HSC，采用不同浓度的丹参处理后，分别应用MTT法、凝胶迁移率法、ELISA法和Northern blot检测大鼠HSC的增殖、核转录因子κB(NF κB)活性和肿瘤坏死因子 α(TNF α)蛋白和mRNA的表达。结果 丹参对大鼠HSC生长具有较强的抑制作用。丹参可明显抑制大鼠HSC的NF κB活性，并能下调TNF α蛋白和mRNA的表达，并且呈剂量依赖性。结论丹参对大鼠HSC增殖具有很强的抑制作用，可能与抑制NF κB活性和下调TNF α表达有关。     

染料木黄酮对哮喘患者核因子-kB表达和肿瘤坏死因子-a分泌的影响

目的 :探讨染料木黄酮对支气管哮喘患者外周血单个核细胞 (PBMCs)核因子 κB(NF κB)表达及肿瘤坏死因子 α(TNF α)分泌的作用。方法 :32例支气管哮喘急性发作期患者及 31例健康对照者的PBMCs ,均分空白对照、地塞米松和染料木黄酮 3组进行研究。NF κB表达由免疫组化染色检测 ,TNF α含量由放射免疫法测定。结果 :哮喘患者PBMCsNF κB胞核染色阳性率及培养上清TNF α含量明显高于健康对照者 (P <0 .0 1) ,且二者呈显著正相关(P <0 .0 1)。染料木黄酮抑制哮喘组NF κB高表达及TNF α高分泌 ,与哮喘空白对照组比较二者均有统计学意义 (P <0 .0 1) ,但其抑制作用弱于地塞米松 ,且哮喘染料木黄酮组PBMCsNF κB胞核染色阳性率与TNF α含量呈显著正相关 (P <0 .0 1)。结论 :哮喘患者NF κB表达增高 ,TNF α分泌增多。染料木黄酮可抑制哮喘患者PBMCsNF κB的高表达及TNF α的高分泌 ,对哮喘可能有潜在的治疗作用。     

地塞米松治疗大鼠重症急性胰腺炎肺损伤的实验研究

目的:探讨地塞米松治疗重症急性胰腺炎(SAP)肺损伤的作用机制,观察核因子 κB(NF κB)在SAP时动态表达,探讨NF κB在SAP炎症反应中的信号传导过程以及NF κB的活化与SAP的关系.方法:108只SD大鼠随机分为假手术组(SO组)、SAP组(阻断肝门部胆管,向胰管逆行注入5%牛磺胆酸钠0.001 mL&#8226;g 1)及SAP地塞米松处理组(DEX组,即给SAP大鼠腹腔注射DEX 0.01 mL&#8226;g 1),每组36只.采用免疫组织化学的方法检测肺脏NF κB活性,同时测定血淀粉酶(AMS)及肿瘤坏死因子 α(TNF α)和白细胞介素 6(IL 6)水平,并于光镜下观察胰腺及肺脏病理改变.结果:SAP组术后1 h NF κB开始表达,TNF α和IL 6开始升高,3 h达高峰,6 h后下降.地塞米松明显下调NF κB的表达,抑制TNF α和IL 6的产生,减轻肺组织的损伤程度,使SAP病情明显缓解.结论:信号转录因子NF κB参与了大鼠SAP时肺组织的炎症反应,地塞米松发挥明显的抗炎作用,减轻SAP时肺组织损伤,这与其对NF κB表达的抑制及细胞因子的调节作用密切相关.     

班布特罗对哮喘豚鼠淋巴细胞核因子-kB表达的影响

目的 :探讨 β2 受体激动剂班布特罗 (bambu terol)对哮喘豚鼠支气管肺泡灌洗液 (BALF)淋巴细胞核因子 κB (NF κB)表达的影响。方法 :用卵白蛋白 (ovalbumin ,OA)建立豚鼠哮喘模型 ,BALF分离淋巴细胞 ,采用免疫组化染色方法观察淋巴细胞NF κB表达 ,酶联免疫吸附 (ELISA)法测定淋巴细胞胞浆IκB含量及BALF中白细胞介素 10 (IL 10 )水平。结果 :与模型组相比 ,班布特罗可显著增加BALF中IL 10水平及淋巴细胞胞浆IκB含量 (P <0 .0 5 ) ,降低NF κB胞核阳性细胞百分比 (P <0 .0 5 ) ,而且这一作用可被 β2 受体阻断剂普奈洛尔拮抗 ;但IκB含量及IL 10水平仍低于正常对照组 (P <0 .0 5 ) ,NF κB胞核阳性细胞百分比仍高于正常对照组 (P <0 .0 5 )。Pearson相关分析显示NF κB与IL 10之间呈明显负相关关系 (r =- 0 .5 70 ,P <0 .0 1)。结论 :班布特罗通过抑制IκB降解和增加IL 10水平 ,从而抑制淋巴细胞NF κB表达 ,这可能是其抑制哮喘气道慢性炎症的机制之一。     

NF-κB、细胞凋亡与肿瘤治疗

NF κB是普遍存在于细胞浆中的一种快反应转录因子 ,是由 p5 0和 p6 5 (Rel A)两个亚单位构成的异源二聚体 ,p5 0是核因子与DNA结合的部分 ,p6 5是与抑制蛋白IκB结合的部分。NF κB与抑制蛋白IκB结合以非活性的状态存在于大多数细胞的胞浆中 ,后者阻止NF κB进入胞核与DNA结合。许多刺激 (如细胞因子、蛋白激酶C激活剂、氧化剂、病毒、免疫刺激剂、脂多糖和紫外线等 )可激活NF κB ,使IκB迅速磷酸化和降解 ,被激活的NF κB会进行核转移 ,与DNA启动子上特定的认知序列结合 ,转录靶基因。NF κB调节许多重要的功能 ,如参与…     

复方银黄微型灌肠剂调节细胞因子表达及核因子-κB信号通路的实验研究

目的研究复方银黄微型灌肠剂(Yinhuangmicroenemacompound,YHMEC)的体外抗炎效应并探讨其部分分子作用机制。方法大鼠腹腔巨噬细胞(PMФ)随机分为正常对照组、脂多糖(LPS)刺激组、YHMEC和地塞米松干预组,观察各组细胞形态学的改变,MTT比色法分析PMФ的生长活性,ELISA法检测细胞上清中肿瘤坏死因子(TNFα)和白介素6(IL6)的蛋白表达,细胞免疫化学法分析核因子κB(nuclearfactorkappaB,NFκB)p65的表达及分布变化。结果LPS刺激组TNFα和IL6含量增加,NFκB表达增强且多分布在细胞核;YHMEC干预组TNFα和IL6含量增加被明显抑制,细胞核p65表达减少。结论复方银黄微型灌肠剂通过抑制NFκB核转位,使PMФ分泌TNFα和IL6减少,可能是其发挥抗炎作用的分子作用机制之一。     

Ghrelin通过核因子-κB抑制肿瘤坏死因子-α诱导的HepG2细胞PAI-1 mRNA表达

目的探讨Ghrelin对肿瘤坏死因子-α(TNF-α)诱导的HepG2细胞纤溶酶原激活物抑制剂-1(PAI-1)mRNA表达的影响及核因子-κB(NF-κB)在其中的作用.方法HepG2细胞培养,加入不同浓度TNF-α,采用逆转录-聚合酶链反应测定(RT-PCR)检测PAI-1 mRNA的水平;免疫印迹法检测胞浆胞核NF-κBp65和胞浆κB抑制蛋白(IκB)的表达.给予Ghrelin预处理1 h后,加入TNF-α检测NF-κKBp65和IκB表达的变化.结果TNF-α(0.1,1,10μg·L-1)浓度依赖地增高HepG2细胞PAI-1 mRNA的表达;Ghrelin组的PAI-1 mRNA表达减少.TNF-α组胞核NF-κBp65表达增加,胞浆IκBα的表达减少;Ghrelin组较TNF-α组胞核NF-κBp65减少,胞浆IκBα的表达增加.结论TNF-α通过NF-κB介导HepG2 PAl-1mRNA的表达;Ghrelin通过抑制NF-κB而抑制TNF-α诱导PAI-1mRNA的表达.     

二硫代氨基甲酸吡咯烷对小鼠免疫性肝损伤的抑制作用

目的探讨二硫代氨基甲酸吡咯烷(PDTC)对免疫性肝损伤的抑制作用及其机制。方法设正常对照、脂多糖(LPS)、卡介苗(BCG)、BCG+LPS、PDTC和BCG+PDTC+LPS组。除正常对照、LPS和PDTC组外,其余各组小鼠经尾静脉注射BCG(每只2.5mg)。10d后,LPS和BCG+LPS组分别给予LPS(0.2mg·kg-1,ip),PDTC和BCG+PDTC+LPS组在给予LPS前24和2h分别给予PDTC(100mg·kg-1,ip),对照组给予等体积生理盐水。每组15只小鼠用于观察LPS处理后72h的死亡率;每组6只小鼠于LPS处理后1.5h处死,取肝脏,用RT-PCR检测肝脏组织肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)mRNA表达水平,用凝胶电泳迁移率分析法测定肝脏核因子κB(NF-κB)结合活性;每组12只小鼠于LPS处理后6h取血,处死,留取肝脏,测定血清谷丙转氨酶(GPT)活性、一氧化氮(NO)水平和肝组织还原型谷胱甘肽(GSH)含量,制备肝组织切片进行HE染色,观察组织病理变化。结果与正常对照组比较,BCG和LPS组小鼠肝脏炎症细胞明显增加,血清GPT活性升高,肝脏GSH含量显著下降,肝脏TNF-α与IL-1β mRNA表达增强,各组均未见小鼠死亡;PDTC组除血清GPT活性升高外,上述其他指标均未发生明显改变。与BCG和LPS组比较,BCG+LPS组血清GPT活性进一步升高,并伴有大面积肝脏坏死和大量炎症细胞浸润,肝脏NF-κB结合活性显著升高,TNF-α和IL-1β表达进一步增强,GSH水平下降,血清NO水平增加,小鼠死亡率40%。与BCG+LPS组比较,PDTC预处理明显抑制BCG+LPS引起的肝脏NF-κB活性、TNF-α及IL-1β mRNA表达增强,升高肝脏GSH含量,降低血清GPT活性和NO水平,减轻BCG+LPS引起的肝脏炎症和坏死,未见小鼠死亡。结论PDTC可抑制BCG+LPS引起的小鼠免疫性肝损伤,其机制可能与其抗炎和抗氧化作用有关。     

滨蒿内酯对四氯化碳致小鼠急性肝损伤的保护作用研究

目的:研究滨蒿内酯对四氯化碳(CCl4)致小鼠急性肝损伤的保护作用及潜在分子机制.方法:将50只雄性昆明种小鼠随机分为正常对照组、模型组、水飞蓟素组(阳性对照,120 mg/kg)和滨蒿内酯高、低剂量组(60、30 mg/kg),每组10只.各给药组小鼠均灌胃相应药物,正常对照组和模型组小鼠灌胃等体积0.5％羧甲基纤维...     

β-Ionone attenuates LPS-induced pro-inflammatory mediators such as NO,PGE2 and TNF-α in BV2 microglial cells via suppression of the NF-κB and MAPK pathway

β-Ionone, a precursor of carotenoids, possesses a variety of biological properties such as anti-cancerous, anti-mutagenic and anti-microbial activity. Nevertheless, anti-inflammatory effects of β-ionone remain unknown. In this study, we investigated whether ION attenuates the expression of lipopolysaccharide (LPS)-induced pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E₂ (PGE₂) and tumor necrosis factor-α (TNF-α) in BV2 microglia cells. Our data showed that β-ionone significantly inhibits secretion of NO, PGE₂ and TNF-α. β-Ionone also inhibits the expression of inducible NO synthesis (iNOS), cyclooxygenase-2 (COX-2) and TNF-α protein and their mRNA in LPS-stimulated BV2 microglia cells. In addition, β-ionone significantly reduced DNA-binding activity of nuclear factor-κB (NF-κB) through suppression of nuclear translocation of p50 and p65. We showed that NF-κB inhibitor N-acetyl-L-cysteine (NAC) effectively attenuates the expression of LPS-stimulated iNOS, COX-2 and TNF-α. We also found that LPS-induced NF-κB activation is significantly regulated through inhibition of Akt phosphorylation in the presence of β-ionone. Finally, we showed that β-ionone substantially inhibits the phosphorylation of mitogen-activated protein kinases (MAPKs), including ERK1/2, p38 and JNK, which are closely related to regulation of pro-inflammatory mediator secretion. Taken together, these data imply that β-ionone regulates LPS-induced NF-κB-dependent inflammatory pathways through suppression of Akt and MAPK activation.     

Exopolysaccharide of Laetiporus sulphureus var. miniatus downregulates LPS-induced production of NO, PGE2, and TNF-α in BV2 microglia cells via suppression of the NF-κB pathway

Our previous study showed that the exopolysaccharide (EPS) of Laetiporus sulphureus var. miniatus was well characterized and prevented cell damage in streptozotocin-induced apoptosis. However, little is known about the molecular mechanisms underlying its anti-inflammatory effects. Therefore, we attempted in this study to determine whether EPS induces a significant inhibition of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated murine BV2 microglia cells. Our results showed that EPS significantly inhibited LPS-induced pro-inflammatory mediators, such as nitric oxide (NO), prostaglandin E₂ (PGE₂), and tumor necrosis factor-α (TNF-α), without any significant cytotoxicity. EPS also downregulated mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α in LPS-induced BV2 microglia cells. Our data also revealed that EPS treatment significantly reduced translocation of nuclear factor-κB (NF-κB) subunit p65 and its DNA-binding activity in LPS-stimulated BV2 microglia cells. Furthermore, we confirmed by using proteasome inhibitor N-acetyl-l-cysteine (NAC), that the inhibition of NF-κB activity influenced the expression of pro-inflammatory genes in LPS-induced BV2 microglia cells. As expected, NAC suppressed the expression of iNOS, COX-2, and TNF-α by blocking proteasome-mediated degradation. Taken together, our data indicate that EPS inhibits the expression of pro-inflammatory mediators by suppressing NF-κB activity.     

二硫代氨基甲酸吡咯烷对小鼠急性凋亡性肝损伤的效应

目的探讨二硫代氨基甲酸吡咯烷(PDTC)对氨基半乳糖(GalN)/细菌脂多糖(LPS)诱导小鼠急性凋亡性肝损伤的作用及其分子机制。方法设置生理盐水(NS)组、GalN/LPS组、PDTC+GalN/LPS组和PDTC组。每组10只小鼠被用于观察LPS处理后72h内的动物死亡情况;每组6只小鼠经LPS处理后1.5h被取血、处死并留取肝脏,用RT-PCR检测肝脏组织TNF-αmRNA表达水平,用EMSA分析肝脏NF-κB结合活性,每组12只小鼠于LPS处理后8h取血、处死并留取肝脏,测定血清丙氨酸转氨酶(ALT)活力,用TUNEL技术检测肝脏细胞凋亡,并对肝组织切片行常规HE染色。结果GalN/LPS共处理升高小鼠血清ALT活力;肝脏组织病理学检查发现,GalN/LPS组小鼠肝脏严重充血、坏死并伴有大量炎性细胞浸润,肝脏组织TUNEL阳性细胞增多;在GalN/LPS共处理72h内有90%小鼠发生死亡,所有死亡小鼠均伴有肝脏严重充血。PDTC预处理抑制GalN/LPS诱导的肝脏NF-κB激活和TNF-α表达,但PDTC预处理反而加重GalN/LPS引起的小鼠肝脏细胞凋亡、进一步升高血清ALT活力、加重肝脏充血和坏死并加速小鼠死亡。结论NF-κB抑制剂PDTC通过抑制肝脏实质细胞NF-κB介导的抗凋亡机制加重GalN/LPS诱导的小鼠急性凋亡性肝损伤。     

Salvianic acid A inhibits induction of inflammatory mediators by blocking Nuclear Factor-κB activation in macrophages

Objective To investigate the anti-inflammation effect and possible mechanism of Salvianic acid A(SAA)in mouse peritoneal macrophages.Methods Peritoneal macrophages were obtained from BALB/c mice.LPS induced nitric oxide(NO),tumor necrosis factor-alpha(TNF-α)and interleukin-6(IL-6)in supernatant,protein expression of inducible nitric oxide synthase(iNOS),matrix metalloproteinase-9(MMP-9)and activation of nuclear factor-kappa B(NF-κB)in the extract were measured.Results SAA strongly inhibited the excessive production of NO,TNF-α and IL-6 in LPS-induced peritoneal macrophages in a concentration-dependent manner and blocked the expression of iNOS and MMP-9.Treatment with LPS alone increased the translocation of NF-κB(p65)from cytosol to the nucleus,but the SAA inhibited the translocation of NF-κB(p65).Conclusions The results showed that SAA had strong anti-inflammatory effects in LPS-stimulated peritoneal macrophages.The important mechanism is due to its inhibition of NF-κB activation.     

Dioscin reduces lipopolysaccharide-induced inflammatory liver injury via regulating TLR4/MyD88 signal pathway

We previously reported the effects of dioscin against carbon tetrachloride-, acetaminophen- and alcohol-induced acute liver damage. However, its effect on lipopolysaccharide (LPS)-induced inflammatory liver injury remains unknown. In the present work, liver injury in mice and rats was induced by LPS, and dioscin was intragastrically administered for 7 days. In vitro, the AML-12 cells and HepG-2 cells were treated with LPS after dioscin treatment. The results showed that dioscin not only markedly reduced serum ALT, AST levels and relative liver weights, but also restored cell injury caused by LPS. In mechanism study, dioscin significantly attenuated inflammation through down-regulating the levels of toll-like receptor (TLR) 4, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), phosphorylated inhibitor of nuclear factor κB kinase (p-IKK), phosphorylated inhibitor of nuclear factor κB alpha (p-IκBα), phosphorylated nuclear factor κB p65 (p-NF-κB p65), high-mobility group protein 1 (HMGB-1), interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α). TLR4 overexpression was also decreased by dioscin, leading to the markedly decreased levels of MyD88, IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65 and HMGB-1. Suppression of MyD88 by ST2825 eliminated the inhibitory effects of dioscin on the levels of IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65, HMGB-1, IL-1β, IL-6 and TNF-α. Our results suggested that dioscin exhibited protective effect against LPS-induced liver injury via altering TLR4/MyD88 pathway, which should be developed as one potent candidate for the treatment of acute inflammatory liver injury in the future.