HMGB1 - TLR9 - MyD88 - TRAF6 - NF - κB信号通路在急性胰腺炎肠粘膜屏障损伤中的作用

目的 探讨雨蛙素和脂多糖诱导的小鼠重症急性胰腺炎（severe acute pancreatitis, SAP）模型中肠道粘膜屏障损伤的机制。方法 采用雨蛙素和脂多糖诱导小鼠SAP模型。将雄性C57BL/6J小鼠随机分为对照组和SAP组,每组12只。每组分为6 h和12 h两个时间点。HE染色观察胰腺及回肠病理学,ELISA法检测TNF - α、IL - 1β、IL - 6、DAO和EndoCAb的表达水平,Western blot检测HMGB1、TLR9、MyD88、TRAF6、NF - κB p65、p - NF - κB p65和occludin表达水平,TUNEL法检测肠上皮细胞凋亡情况。采用单因素方差分析比较不同处理组之间的结果,组间差异进一步采用LSD - t多重比较。结果 与对照组相比,SAP组血清中 IL - 1β、IL - 6、TNF - α、DAO 和EndoCAb水平升高（F = 104.50,P＜0.05;F = 140.36,P＜0.05;F = 328.21,P＜0.05;F = 372.23,P＜0.05;F = 80.67,P＜0.05）;HMGB1、TLR9、MyD88、TRAF6和p - NF - κB p65蛋白表达升高（F = 65.95,P＜0.05;F = 84.16,P＜0.05;F = 58.27,P＜0.05;F = 122.26,P＜0.05;F = 178.38,P＜0.05）,occludin的表达降低（F = 456.91,P＜0.05）、小鼠肠上皮细胞凋亡增加(F = 400.47,P＜0.05)。与12 h SAP组相比,6 h SAP组血清IL - 1β、IL - 6和TNF - α水平及p - NF - κB p65蛋白表达升高更明显(ｔ = 4.95,P＜0.05;ｔ = 4.57,P＜0.05;ｔ = 3.32,P＜0.05;ｔ =2.93,P＜0.05)。与6 h SAP组相比,12 h SAP组回肠组织中occludin水平降低更明显（ｔ = - 3.52,P＜0.05）,血清DAO、EndoCAb水平、HMGB1、TLR9、MyD88、TRAF6蛋白表达水平更高（ｔ=6.55,P＜0.05;ｔ = 4.96,P＜0.05;ｔ = 6.88,P＜0.05;ｔ = 8.52,P＜0.05;ｔ = 7.37,P＜0.05;ｔ = 7.78,P＜0.05）,肠上皮细胞出现细胞凋亡更明显 (ｔ = 3.10,P＜0.05)。结论 HMGB1 - TLR9 - MyD88 - TRAF6 - NF - κB信号通路可能参与了SAP肠粘膜屏障损伤。     

不同剂量流感病毒感染小鼠模型免疫应答的比较性研究

目的 比较不同剂量流感病毒感染小鼠后肺组织急性损伤情况,初步探讨感染剂量与机体抗病毒的固有、适应性免疫应答的关系。方法 用流感病毒A/PR/8/34（PR8;H1N1）构建小鼠感染102 PFU和103 PFU剂量模型,HE法检测肺组织损伤情况,HA法和免疫荧光染色法检测肺组织病毒滴度和感染程度,RT - PCR法检测肺组织炎性因子干扰素α（interferon - α, IFN - α）、干扰素β（interferon - α, IFN - β）、白细胞介素1β（interleukin - 1β, IL - 1β）、白细胞介素6（interleukin - 6, IL - 6）、肿瘤坏死因子α（tumor necrosis factor - α, TNF - α）及Toll样受体7（Toll - like receptor - 7, TLR7）、髓样分化因子88（myeloid differentiation primary response gene 88, MyD88）、肿瘤坏死因子受体相关蛋白6（TNF receptor associated factor 6, TRAF6）和核因子κB（nuclear factor κB, NF - κB）mRNA水平,免疫组化法对肺组织TLR7、MyD88、TRAF6和NF - κB蛋白定位。流式细胞术检测肺组织、支气管肺泡灌洗液（bronchoalveolar lavage fluid, BALF）和淋巴结中CD4+、CD8+T细胞比例。结果 与102 PFU组比较,103 PFU组小鼠肺组织病毒滴度显著升高（t = 3.071,P = 0.008）,炎症因子IFN - α、IFN - β、IL - 1β、IL - 6、TNF - α mRNA水平上升（t = 4.816,P = 0.003;t = 4.104,P = 0.006;t = 3.992,P = 0.007;t = 4.049,P = 0.007;t = 3.737,P = 0.009）,TLR7、MyD88、TRAF6和NF - κB mRNA水平有不同程度的升高（t = 2.905,P = 0.027;t = 3.854,P = 0.008;t = 3.760,P = 0.009;t = 4.312,P = 0.005）及蛋白表达显著增加（t = 4.712,P = 0.003;t = 4.008,P = 0.007;t = 4.398,P = 0.005;t = 4.564,P = 0.004）,BALF、肺组织和淋巴结中CD4+T细胞比例呈上升趋势（t = 3.771,P = 0.009;t = 2.463,P = 0.049;t = 3.386,P = 0.015）,BALF和肺组织CD8+T细胞比例上调（t = 5.297,P = 0.002;t = 3.502,P = 0.013）。结论 病毒载量影响机体固有和适应性免疫应答状态,通过上调 TLR7 - MyD88 - TRAF6 - NF - κB信号通路促进下游炎症反应,并启动CD4+T和CD8+T细胞发挥抗病毒效应。     

基于TLR4信号通路探讨熊果酸改善大鼠酒精性肝损伤的作用机制

目的 探讨熊果酸对酒精性肝损伤大鼠TLR4信号通路的影响及其作用机制。方法 雄性SPF级SD大鼠40只,随机分为4组,每组10只,包括正常对照组、酒精模型组、熊果酸干预组和抑制剂干预组。干预7周,末次灌胃后,禁食不禁水12 h,处死大鼠,采用酶学实验检测肝脏生物标志物水平,HE染色进行肝组织病理学观察,ELISA法检测TNF - a、IL - 6、IL - Iβ水平,western blot法测定肝脏组织中TLR4、NF - κB p65和pNF - κB p65蛋白的表达水平。结果 酒精模型组大鼠血清内ALT、AST、CHE、TNF - α、IL - 6（34.95±2.03,128.76±10.91,137.85±17.31,70.37±20.30,31.52±3.95）水平均明显高于正常对照组（28.65±0.76,56.47±1.46,117.45±8.04,16.80±9.19,22.65±2.17）,熊果酸干预组与酒精模型组相比数值均有不同程度的下降(P＜0.05)。肝脏病理学观察结果显示酒精模型组肝索排列紊乱且肝细胞出现大量炎性因子浸润和脂肪空泡,熊果酸干预组和抑制剂干预组脂肪变性和炎性因子浸润状况均有减轻。与正常组相比酒精模型组大鼠肝脏组织TLR4、NF - κB p65、pNF - κB p65蛋白的表达水平有不同程度的升高(P＜0.05),熊果酸和抑制剂干预后都有不同程度的降低(P＜0.05)。结论 熊果酸对大鼠酒精性肝损伤具有保护作用,其机制可能是通过调控TLR4信号通路来实现的。     

共轭亚油酸对小鼠巨噬细胞杀伤肿瘤能力的影响

目的　研究c9,t11 共轭亚油酸 (CLA)对C5 7小鼠巨噬细胞杀伤黑色素瘤 (B16 MB)细胞能力的影响并探讨其可能机制。方法　用 0、2 5、5 0、75、10 0 μmol/LCLA处理巨噬细胞 2 4h后 ,分别用四甲基偶氮唑盐法检测CLA处理的巨噬细胞对B16 MB细胞的杀伤能力 ;逆转录聚合酶链式反应方法检测C5 7小鼠巨噬细胞细胞因子IL 6、TNF α和iNOSmRNA表达 ;免疫印迹法 (Westernblot)检测细胞外信号调节蛋白激酶 (Erk)的表达情况。结果　c9,t11 CLA处理后 ,巨噬细胞对肿瘤抑制率随剂量的升高而升高 ,同时 ,白细胞介素 (IL 6 )、肿瘤坏死因子 (TNF α)和一氧化氮合酶 (iNOS)mRNA表达增加 ;Erk的表达下降。结论　c9,t11 CLA增强C5 7小鼠巨噬细胞对B16 MB细胞的杀伤能力 ,并与其诱导IL 6、TNF α和iNOSmRNA的表达有关。推测CLA发挥抗肿瘤作用可能与其参与机体免疫调节作用有关 ,并且CLA对小鼠巨噬细胞IL 6的影响与促裂原活化蛋白激酶 细胞外信号调节蛋白激酶途径无关     

新橙皮苷对葡聚糖硫酸钠致小鼠溃疡性结肠炎的保护作用及其机制

目的 探讨新橙皮苷（neohesperidin, NHP）对葡聚糖硫酸钠（dextran sulfate sodium, DSS）诱导的小鼠溃疡性结肠炎（ulcerative colitis,UC）的保护作用及机制。方法 将28只小鼠随机均分为:对照组、DSS组、低剂量NHP组（L - NHP,50 mg/kg）和高剂量NHP组（H - NHP,100 mg/kg）。对照组小鼠正常饮水,其他组小鼠通过自由饮水摄入质量分数为3% DSS的水溶液,持续饮用7 d,诱导小鼠UC模型。每天记录小鼠体重,NHP灌胃治疗10 d后采用脊椎脱臼的方式处死小鼠,收集结肠组织并记录其长度。HE染色观察小鼠结肠组织病理变化,免疫荧光法检测结肠组织中炎症细胞的浸润情况,实时荧光定量PCR和免疫组织化学染色法检测小鼠结肠组织中促炎因子的表达水平,免疫印迹法检测小鼠结肠组织中核转录因子 - κB（NF - κB p65）和信号传导及转录激活蛋白3（STAT3）的磷酸化水平。结果 与DSS组相比,L - NHP和H - NHP处理均减少了UC炎症期间小鼠的体重下降（P＜0.05）和结肠长度缩短（P＜0.01）,给药后小鼠结肠黏膜组织病理损伤程度降低（P＜0.01）,中性粒细胞表面黏附分子CD11b和巨噬细胞标志物F4 - 80阳性的炎症细胞浸润减少,结肠组织中促炎因子TNF - α、IL - 6、IL - 1β、IL - 17 A、MCP - 1和MIP - 2的表达水平降低（P＜0.05）,NF - κB P65和STAT3蛋白磷酸化水平降低（P＜0.05）,而两者的总蛋白水平却没有变化。结论 NHP能够有效的改善DSS诱导的UC症状,其保护作用机制可能与抑制NF - κB P65和STAT3信号通路的活化有关。     

表没食子儿茶素没食子酸酯对短肠综合征大鼠肠道代偿和肠道屏障的影响

目的 观察研究表没食子儿茶素没食子酸酯（EGCG）对空肠切除后的短肠综合征（SBS）模型大鼠剩余肠道代偿功能和肠道屏障的影响。方法 32只SPF级健康雄性SD大鼠,平均随机分为4组,每组8只,分别为假手术组、手术对照组、低剂量EGCG手术组和高剂量EGCG手术组。假手术组进行空肠横断吻合,其余手术组均切除中段小肠,形成SBS模型。假手术组和手术对照组术后2～14天灌胃生理盐水,低剂量和高剂量EGCG手术组分别灌胃等体积50 mg/kg和100 mg/kg EGCG,术后第15 d处死大鼠。测定各组大鼠术后各组大鼠体重变化;血清超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和丙二醛（MDA）水平;ELISA法检测回肠组织肿瘤坏死因子（TNF - α）和白细胞介素6（IL - 6）的水平;分析小肠病理切片的绒毛长度和隐窝深度评估肠道代偿功能;采用免疫荧光法检测紧密连接蛋白claudin - 1和occludin的分布和平均荧光强度（MFI）;RT - qPCR方法检测大鼠回肠组织TLR4、MyD88和NF - κB p65 mRNA相对表达量。结果 与手术对照组比较,各剂量EGCG手术组大鼠体重均增加（P＜0.05）;血清SOD、CAT的活性和MDA含量增加（P＜0.05）;小肠绒毛高度和隐窝深度增加（P＜0.05）;回肠组织TNF - α和IL - 6的水平减少（P＜0.05）;回肠黏膜紧密连接蛋白claudin - 1和occludin的MFI增加（P＜0.05）,回肠组织TLR4、MyD88 和NF - κB p65 mRNA相对表达量减少（P＜0.05）。结论 EGCG可以通过抑制TLR4/NF - κB信号通路的活化,减轻SBS大鼠的氧化应激和组织炎症,促进小肠功能恢复和保护肠道屏障,加快术后的肠适应和肠康复。     

内毒素、TNF-α及IL-6在诱导生长激素不敏感中的作用

目的：在受体和受体后水平探讨内毒素（LPS）、TNF－α及IL－6在诱导生长激素不敏感中的作用。方法：采用雄性SD大鼠，分别静注LPS、TNF－α及IL－6，不同时相处死大鼠。应用RT－PCR法测定肝组织IGF－1、GHR和SOCS－3mRNA的表达；应用放射免疫法测定血清GH水平；应用酶联免疫吸附法测定血清TNF－α和IL－6水平。结果：静注LPS后，各时间点血清GH水平与对照组无明显差异，血清TNF－α和IL－6迅速升高，但TNF－α很快即恢复至正常水平。肝组织IGF－1和GHR mRNA的表达分别在注射LPS后12h和8h下调最多。正常大鼠肝组织SOCS－3mRNA微弱表达，但在注射LPS后立即上调，在1h时即上升了7．84倍，线性回归分析显示IL－6水平与SOCS－3mRNA的表达呈高度正相关。静注TNF－α后，肝组织SOCS－3 mRNA的表达无明显变化，但可明显下调GHR mRNA的表达。静注IL－6后，肝组织GHR mRNA的表达无明显变化，但SOCS－3 mRNA的表达却明显上调。结论：静注LPS可以诱导生长激素的不敏感，在受体水平与GHR mRNA的表达下调有关，在受体后水平与SOCS－3mRNA的表达上调有关。体内LPS的生物活性主要是由TNF－α和IL－6介导的，TNF－α和IL－6分别在受体和受体后水平发挥作用，但TNF－α的作用具有滞后性。     

生长抑素对脂多糖刺激的大鼠库普弗细胞抑制作用的观察

目的探讨生长抑素（SST）对脂多糖（LPS）刺激的原代培养大鼠库普弗细胞NO、TNFα和5-脂氧合酶（5-LO）表达的影响。方法分离培养SD大鼠库普弗细胞,分为对照组、LPS刺激组、SST干预组;于12、24、48h收集不同实验组细胞培养上清液,硝酸还原酶法测定NO水平,ELISA法检测TNFα含量,半定量RT-PCR法检测细胞5-LO mRNA的表达。结果分离的库普弗细胞产生低水平的NO、TNFα和5-LO mRNA,LPS刺激后各时间点NO、TNFα和5-LO mRNA含量均明显高于对照组（P〈0.05）;SST干预后各时间点NO、TNFα和5-LO mRNA含量低于LPS刺激组（P〈0.05）,其中NO、TNFα含量在各时间点均高于对照组（P〈0.05）,5-LO mRNA表达在12、24h时间点高于对照组（P〈0.05）,而在48h时间点与对照组相比,差异无统计学意义（P〉0.05）。结论生长抑素能抑制LPS诱导的库普弗细胞NO,TNFα和5-LO的表达。     

肠道菌群失调对流感病毒感染小鼠急性肺损伤的影响

目的 探讨肠道菌群失调对流感病毒感染小鼠急性肺损伤的影响及作用机制。方法 BALB/c小鼠随机分为正常对照组、流感病毒对照组、甲硝唑模型组,每组12只。甲硝唑模型组小鼠用甲硝唑（18 mg/mL）连续灌胃8 d,于d9滴鼻甲型流感病毒A/PR/8/4稀释液（103pfu/鼠）,构建肠道菌群失调小鼠感染流感病毒的模型。观察各组小鼠肺组织及盲肠的病理变化,检测肺组织中脂多糖LPS及炎性相关因子肿瘤坏死因子 - α（Tumor necrosis factor - α,TNF - α）、白介素 - 1β（Interleukin - 1β, IL - 1β）、白介素 - 6（Interleukin - 6,IL - 6）、干扰素 - β（Interferon - β,IFN - β）水平,并采用免疫组织化学染色法定位肺组织Toll样受体4（Toll - like receptor 4, TLR4）表达情况。结果 甲硝唑模型组小鼠肺及盲肠组织炎症损伤和病理改变情况较比病毒对照组更加严重,同时小鼠肺组织中LPS含量显著增加,差异有统计学意义（P＜0.05）,TNF - α、IL - 1β、IL - 6、IFN - β水平明显升高（P＜0.05）。TLR4在甲硝唑模型组小鼠肺组织中的表达明显高于病毒对照组,差异有统计学意义（P＜0.05）。结论 肠道菌群失调引起LPS/TLR4通路激活,从而上调小鼠肺组织流感病毒所致的炎性风暴,进一步加重流感病毒引起的组织病理改变。     

噪声对小鼠血糖、炎症因子及肠道菌群的影响

目的 探讨噪声对小鼠血糖、炎症因子及肠道菌群的影响。方法 32只雄性 C57BL/6J小鼠,每组8只,随机分为15 d对照组、15 d噪声组、30 d对照组和30 d噪声组。干预结束后进行腹腔注射葡萄糖耐量试验,用ELISA法检测血清TNF - α、TNF - γ、IL - 6、IL - 1β、IFN - γ水平,16S rRNA高通量测序技术检测粪便菌群。结果 与对照组相比,噪声组的体重变化无明显差异（P＞0.05）;葡萄糖耐量试验曲线下面积（AUC）显著升高（P＜0.05）,糖耐量减退;血清TNF - α、TNF - γ、IL - 6、IL - 1β、IFN - γ水平也明显升高（P＜0.05）。肠道菌群结果显示,与各对照组相比,各噪声组小鼠肠道菌群的α多样性均降低（P＜0.05）,β多样性的主成分分析（PCoA）图明显的区分。所有组别均以拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）为主,噪声组的Bacteroidetes、普雷沃菌属（Prevotella）增加,Firmicutes、疣微菌门（Verrucomicrobia）、阿克曼菌属（Akkermansia）和瘤胃球菌属（Ruminococcus）减少。α多样性指数chao1、faith_pd、shannon与AUC均呈负相关,Bacteroidetes与TNF - α呈正相关,Firmicutes与AUC、TNF - α、IL - 6呈负相关,Prevotella与AUC、TNF - α呈正相关。结论 噪声暴露能引起小鼠炎症反应增强和肠道菌群改变,导致糖耐量减退。     

黄绿青霉素对肿瘤坏死因子α诱导的血管内皮细胞表达单核细胞趋化蛋白1和白细胞介素的影响

目的观察黄绿青霉素(CIT)对血管内皮细胞表达单核细胞趋化蛋白1(MCP-1)、白细胞介素1β(IL-lβ)、IL-6和IL-8等细胞因子的影响,以及CIT上调肿瘤坏死因子α(TNF-α)诱导的内皮细胞表达MCP-1、IL-lβ、IL-6和IL-8的作用。方法体外原代培养人脐静脉内皮细胞(HUVECs),选择第5～6代进行试验,待细胞融合80%后随机分组,加入TNF-α(10μg/L)、CIT(2μmol/L)建立TNF-α组、CIT组、TNF-α+CIT联合处理组和空白对照组,处理时间24h。用酶联免疫吸附法(ELISA)检测细胞上清液IL-lβ、IL-6、IL-8及MCP-1的含量;免疫荧光染色法测定细胞核转录因子κB(NF-κB)的激活表达;RT-PCR检测各组MCP-1 mRNA表达。结果在TNF-α组和TNF-α+CIT组,细胞上清液IL-lβ、IL-6、IL-8、MCP-1浓度,细胞MCP-1 mRNA表达量,NF-κB P65蛋白表达量均高于空白对照组(P<0.05);且TNF-α+CIT组均高于TNF-α组(P<0.05)。结论 CIT可明显上调TNF-α诱导的内皮细胞MCP-1、IL-lβ、IL-6、IL-8表达和NF-κB的激活。     

白藜芦醇对脂多糖诱导小鼠腹腔巨噬细胞炎性因子生成的调控

目的探讨白藜芦醇(Res)对脂多糖(LPS)诱导小鼠腹腔巨噬细胞核因子-κB(NF-κB)活化及炎性细胞因子[肿瘤坏死因子(TNF-α)、白介素-1β(IL-1β)、白介素-6(IL-6)]基因表达的调节。方法分别用1mg/LLPS或25mmol/LRes+1mg/LLPS处理体外培养的小鼠巨噬细胞,采用电泳迁移率改变分析法(EMSA)检测细胞中NF-κB活性,逆转录-聚合酶链反应(RT-PCR)和酶联免疫吸附法(ELISA)检测细胞中TNF-α、IL-1β、IL-6mRNA和蛋白的表达。结果LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量在刺激后6～12h明显高于正常对照组(P<0.001),而Res+LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量均显著低于LPS组(P<0.005)。结论LPS可诱导巨噬细胞NF-κB活化,导致TNF-α、IL-1β、IL-6基因表达增强,而Res能抑制NF-κB活化而调节TNF-α、IL-1β、IL-6基因的表达。     

Physiogenomic comparison of human fat loss in response to diets restrictive of carbohydrate or fat

Background

Adipocytes express inflammatory mediators that contribute to the low-level, chronic inflammation found in obese subjects and have been linked to the onset of cardiovascular disorders and insulin resistance associated with type 2 diabetes mellitus. A reduction in inflammatory gene expression in adipocytes would be expected to reverse this low-level, inflammatory state and improve cardiovascular function and insulin sensitivity. The natural products, curcumin and resveratrol, are established anti-inflammatory compounds that mediate their effects by inhibiting activation of NF-κB signaling. In the present study, we examined if these natural products can inhibit NF-κB activation in adipocytes and in doing so reduce cytokine expression.

Methods

Cytokine (TNF-α, IL-1β, IL-6) and COX-2 gene expression in 3T3-L1-derived adipocytes was measured by quantitative real-time PCR (qRT-PCR) with or without TNFα-stimulation. Cytokine protein and prostaglandin E₂ (PGE₂) expression were measured by ELISA. Effects of curcumin and resveratrol were evaluated by treating TNFα-stimulated adipocytes with each compound and 1) assessing the activation state of the NF-κB signaling pathway and 2) measuring inflammatory gene expression by qRT-PCR and ELISA.

Results

Both preadipocytes and differentiated adipocytes express the genes for TNF-α, IL-6, and COX-2, key mediators of the inflammatory response. Preadipocytes were also found to express IL-1β; however, IL-1β expression was absent in differentiated adipocytes. TNF-α treatment activated NF-κB signaling in differentiated adipocytes by inducing IκB degradation and NF-κB translocation to the nucleus, and as a result increased IL-6 (6-fold) and COX-2 (2.5-fold) mRNA levels. TNF-α also activated IL-1β gene expression in differentiated adipocytes, but had no effect on endogenous TNF-α mRNA levels. No detectable TNFα or IL-1β was secreted by adipocytes. Curcumin and resveratrol treatment inhibited NF-κB activation and resulted in a reduction of TNF-α, IL-1β, IL-6, and COX-2 gene expression (IC₅₀ = 2 μM) and a reduction of secreted IL-6 and PGE₂ (IC₅₀ ~ 20 μM).

Conclusion

Curcumin and resveratrol are able to inhibit TNFα-activated NF-κB signaling in adipocytes and as a result significantly reduce cytokine expression. These data suggest that curcumin and resveratrol may provide a novel and safe approach to reduce or inhibit the chronic inflammatory properties of adipose tissue.     

脂多糖经MyD88/NF-κB信号途径抑制Bewo细胞中乙型肝炎病毒复制

目的 探讨Toll样受体4(TLR4)配体脂多糖(LPS)抑制人滋养层细胞Bewo中乙型肝炎病毒( HBV)复制的作用机制,为防治HBV宫内感染提供依据.方法 首先将2μg 1.3倍HBV全基因重组质粒pcDNA3.1(+)-HBV1.3转染Bewo细胞12h后,以TLR4配体LPS处理3d.尔后用LPS处理Bewo细胞,观察IFN-β、TNF-α表达的动力学、NF-κB拮抗剂二硫代氨基甲酸吡咯烷( PDTC)对LPS诱导Bewo细胞产生细胞因子的作用.采用微粒子酶免疫分析法(MEIA)和荧光定量PCR法分别检测HBsAg、HBeAg和HBV DNA水平,并以ELISA和RT-PCR分别检测IFN-β、TNF-α水平及TIR结构域的转接蛋白(TRIF)、髓样分化蛋白(MyD88)表达.结果 与对照组比较,LPS可显著抑制Bewo细胞中HBV复制(P＜0.01),且LPS可显著诱导Bewo细胞产生TNF-α(P＜0.05),呈时间和剂量依赖性.PDTC可抑制LPS诱导细胞产生TNF-α,显著低于对照组(P＜0.01),但对IFN-β无显著作用(P＞0.05).与对照组比较,LPS可诱导HBV重组质粒转染的Bewo细胞表达MyD88(P＜0.01).结论 通过MyD88/NF-κB信号途径诱导Bewo细胞产生TNF-α,TLR4配体LPS可显著抑制HBV复制.     

Trans-10, cis-12-conjugated linoleic acid modulates NF-κB activation and TNF-α production in porcine peripheral blood mononuclear cells via a PPARγ-dependent pathway

The activation of PPARγ by ligands, including conjugated linoleic acid (CLA) isomers, plays an important role in the immune response. Among CLA isomers, trans-10, cis-12 (t10c12)-CLA is known to participate in the modulation of pro-inflammatory cytokine secretion. The aim of the present study was to assess the effect of t10c12-CLA on PPARγ activation, NF-κB activation and TNF-α expression in lipopolysaccharide (LPS)-naive and LPS-stimulated porcine peripheral blood mononuclear cells (PBMC). In addition, the effect of PPARγ inhibition on NF-κB activation and TNF-α expression in porcine PBMC was examined. t10c12-CLA was found to increase TNF-α expression and NF-κB activity in LPS-naive porcine PBMC. In contrast, t10c12-CLA decreased TNF-α expression and NF-κB activity in LPS-stimulated porcine PBMC. t10c12-CLA up-regulated PPARγ activity and mRNA expression in both LPS-naive and LPS-stimulated porcine PBMC. GW9662, a PPARγ antagonist, completely negated the modulating effects of t10c12-CLA on TNF-α expression and NF-κB activity in both LPS-naive and LPS-stimulated porcine PBMC. These results suggest that t10c12-CLA can modulate TNF-α production and NF-κB activation by a PPARγ-dependent pathway in porcine PBMC.     

Cross-talk of the related bioactivity mediators in serum after injection of soluble TNF-α receptor on silicosis model of rats

This study investigates cross-talk of the related bioactivity mediators in silica-induced pulmonary inflammatory and fibrosis on rats, which contributes to the preventive and therapeutic effect of soluble TNF-α receptor. Wistar rats received saline or 50 mg of quartz by intratracheal instillation. Rats in drug-treated groups were given soluble tumor necrosis factor-α (TNF-α) receptor (500 μg) by hypodermic injection on days 1, 5 and 8 after operation. At 7 days or 14 days after instillation, rats were killed to observe the degree of injury and expression of the related bioactivity mediators including nuclear factor KB (NF-KB), nitric oxide, interleukin-1β, interleukin-10, transforming growth factor beta 1 (TGF-β1), TNF-α, interferon-Y (IFN-Y) and granulocyte macrophage colony-stimulating factor (GM-CSF). The area percentages of type I and III collagens in intervention group were lower than those in silica group. The expression of NF-κB, TGF-β1, and COL I were lower in intervention group than in silica group(p < 0.05) and GM-CSF was significantly higher (p < 0.05) at 7 days after instillation, however, NF-κB, TGF-β1, and COL I were identically lower in intervention group than in silica group, and TNF-α, IFN-γ, and GM-CSF were higher at 14 days after instillation. It may be concluded that soluble TNF-α receptor upregulating or downregulating the expression of the related bioactivity mediators results in decreasing lung injury induced by silica.     

外源性瘦素通过抑制NF-κB活性降低大鼠重症急性胰腺炎促炎因子的表达

目的探讨外源性瘦素（1eptin）对重症急性胰腺炎（SAP）大鼠胰腺组织NF-κB活性及血清炎症因子的影响。方法Wister大鼠36只,分为假手术组、SAP动物模型组、瘦素治疗组,各12只。采用5％牛磺胆酸钠胰胆管顺行注射胰胆管制模,治疗组行外源性瘦素腹腔注射,6h后采血、取胰腺标本,检测各组动物血淀粉酶、瘦素、肿瘤坏死因子α、白细胞介素1β的含量,采用免疫组织化学法测定NF-κB活性,并对大鼠胰腺组织进行病理学评分。结果制模6h后血淀粉酶、leptin、TNF-α、IL-κB水平均升高,胰腺组织NF-κB活性增高,胰腺组织出血坏死明显,外源性瘦素干预组可显著降低血淀粉酶、TNF-α及IL-1β水平,NF-κB活性降低,胰腺组织出血坏死程度减轻,NF-κB活性与炎症因子水平呈正相关。结论外源性瘦素可能通过通过抑制NF-κB活性,降低促炎性因子TNF-α、IL—1β的产生,从而达到对SAP大鼠的保护作用。     

Dietary supplementation with geranylgeraniol suppresses lipopolysaccharide-induced inflammation via inhibition of nuclear factor-κB activation in rats

Purpose

The isoprenoid geranylgeraniol (GGOH) inhibits nuclear factor-kappa B (NF-κB) activation in the liver, yet the mechanism remains unclear. We investigated the modulation and inhibition of lipopolysaccharide (LPS)-induced NF-κB signaling in the liver of rats fed a GGOH-supplemented diet.

Methods

Rats were fed a diet supplemented with or without GGOH for 10 days. Rats were then intraperitoneally injected with 0.5 mg/kg LPS or vehicle (sterilized saline) and fasted for 18 h. Plasma levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, and the liver damage indicators alanine and aspartate aminotransferases (ALT and AST) were assessed. Liver mRNA and proteins were assayed for changes in NF-κB target genes and signal transduction genes.

Results

Rats fed a high-dose, GGOH-supplemented diet showed significantly lower levels of plasma inflammatory cytokines and ALT and AST activities. In the liver, GGOH significantly suppressed NF-κB activation and mRNA expression of its pro-inflammatory target genes. Furthermore, GGOH supplementation substantially suppressed mRNA expression of signal transducer genes upstream of the IκB kinase complex. Western blotting of liver extracts further demonstrated the substantial decrease in total IL-1 receptor-associated kinase 1 (IRAK1) and TNF receptor-associated factor 6 (TRAF6), leading to lower signal transduction and inhibition of NF-κB after LPS.

Conclusion

A 10-day, high-dose, GGOH-supplemented diet was sufficient to inhibit LPS-induced inflammation and activation of NF-κB in rat livers. GGOH significantly modulated NF-κB signaling molecules, inhibiting its signal transduction and activation in the liver, thus protecting against liver damage.     

PM2.5不同成分致冠状动脉粥样硬化大鼠炎症作用的探讨

[目的]探讨大气细颗粒物（PM2.5）标准品的水溶性及酸溶性成分对冠状动脉粥样硬化大鼠的致炎作用。[方法]48只Wistar大鼠随机分为对照组和冠状动脉粥样硬化模型组（模型组）,每组各24只。对照组饲喂正常饲料,模型组饲喂高胆固醇饲料,12周后冠脉病理切片示模型成功建立。提取PM2.5的水溶性成分（WSC）及酸溶性成分（ASC）。将对照组和模型组再各自随机分为3组,分别为正常对照组、WSC对照组、ASC对照组;以及模型对照组、WSC模型组、ASC模型组,每组8只。WSC对照组和WSC模型组（均称WSC组）尾静脉注射WSC（40mg/kg）染毒,ASC对照组和ASC模型组（均称ASC组）尾静脉注射ASC（40mg/kg）染毒,而正常对照组和模型对照组（均称空白组）则以尾静脉注射生理盐水。染毒24h后处死大鼠,测定血清中的白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）的含量及心肌中的核转录因子-κB（NF-κB）活性。[结果]WSC组血清TNF-α水平为（2.83±0.97）ng/mL,高于空白组（2.53±0.76）ng/mL;心肌NF-κB活性为（14.56±10.58）%,高于空白组（7.33±3.97）%。ASC组心肌NF-κB活性为（18.80±17.04）﹪,也高于空白组。冠状动脉粥样硬化模型在升高IL-6、激活心肌NF-κB方面,与WSC、ASC分别存在协同作用。[结论]WSC具有升高TNF-α水平、激活心肌NF-κB活性的作用;ASC也具有激活心肌NF-κB活性的作用。冠状动脉粥样硬化模型还与WSC、ASC染毒具有交互作用,主要表现在升高IL-6水平,激活心肌NF-κB活性的作用上,表明PM2.5水溶性成分及酸溶性成分均可致冠状动脉粥样硬化大鼠的炎症作用。     

Toll样受体7激动剂对荷瘤小鼠肾癌的抑制作用及免疫机制

目的　研究Toll样受体7激动剂Imiquimod对荷瘤小鼠肾癌的抑制作用及免疫机制。方法　用Renca肾癌细胞构建BABL/c小鼠肾癌模型,实验分为control组、imiquimod组和sorafenib组。观察3组小鼠肿瘤体积及重量、抑瘤率,qPCR法检测肿瘤组织中炎性相关因子肿瘤坏死因子α（Tumor necrosis factor-α,TNF-α）、白细胞介素1β（Interleukin-1β,IL-1β）、白细胞介素6（Interleukin-6,IL-6）、干扰素α（Interferon-α,IFN-α）、干扰素β（Interferon-β,IFN-β）、干扰素γ（Interferon-γ,IFN-γ）及Toll样受体通路相关因子Toll样受体7（Toll-like receptor 7,TLR7）、髓样分化因子88（Myeloid differentiation primary response gene 88,MyD88）、核因子κB （Nuclear factor κB,NF-κB）mRNA表达,Western blot法检测瘤组织中TLR7、MyD88、NF-κB蛋白表达。流式细胞术检测脾脏中CD4+T、CD8+T、CD4+IFN-γ和CD8+IFN-γ细胞比例。结果　与control组比较,imiquimod组和sorafenib组小鼠的肿瘤体积及瘤体重量降低（P＜0.05）;与control组相比,imiquimod组TNF-α、IL-6、IL-1β、IFN-α、IFN-β、IFN-γ及TLR7、MyD88、NF-κB mRNA水平升高（P＜0.05）,而sorafenib组各因子略有上升（P＞0.05）;与control组和sorafenib组比较,imiquimod组CD4+T、CD8+T细胞比例有不同程度的升高（P＞0.05）,CD4+IFN-γ和CD8+IFN-γ细胞比例增加（P＜0.05）。结论　Toll样受体7激动剂通过活化TLR7-MyD88-NF-κB信号刺激多种炎性细胞因子分泌,并上调CD4+T、CD8+T比例及功能,对荷瘤小鼠肾癌发挥抑制作用。