姜黄素通过NF-κB/miR33a通路对ox-LDL刺激THP-1巨噬细胞分泌的影响及机制

为研究姜黄素对ox-LDL刺激的THP-1巨噬细胞炎症因子IL-6、TNF-α的分泌及相关机制。本实验分别予姜黄素、miR33a inhibitor、吡咯烷二硫代甲酸铵(ammonium pyrrolidinedithiocarbamate,PDTC)处理氧化型低密度脂蛋白(oxidized lowdensity lipoprotein,ox-LDL)刺激的人单核细胞白血病细胞(human acute monocytic leukemia cell line,THP-1)型巨噬细胞,RT-qPCR测定微型RNA33a(MicroRNA33a,miR33a)的表达,Western blot检测胞核内NF-κB p65的表达、IκBα和p-IκBα的表达,ELISA测定IL-6、TNF-α的浓度。结果显示与空白对照组相比,ox-LDL组miR33a、NF-κB p65、p-IκBα的表达及p-IκBα/IκBα的比值及IL-6、TNF-α的浓度增加(P 0. 05),IκBα的表达减少(P 0. 05);而与ox-LDL组相比,ox-LDL+姜黄素组miR33a、NF-κB p65、p-IκBα的表达及p-IκBα/IκBα的比值及IL-6、TNF-α的浓度减少(P 0. 05),IκBα的表达增加(P 0. 05)。姜黄素可能抑制ox-LDL刺激的THP-1巨噬细胞IL-6、TNF-α的分泌,其机制可能是通过下调NF-κB/miR33a信号通路。     

肺炎链球菌候选蛋白疫苗DnaJ-△A146Ply通过PI3K/Akt和NF-κB信号通路刺激巨噬细胞诱导免疫应答

本实验目的是研究肺炎链球菌r Dna J-△A146Ply融合蛋白引起小鼠巨噬细胞的免疫应答机制。原核表达r Dna J-△A146Ply重组蛋白,Ni+柱纯化后去除其内毒素。r Dna J-△A146Ply刺激小鼠来源腹腔巨噬细胞6 h后,提取细胞RNA,RT-PCR检测白细胞介素6(interleukin-6,IL-6)、肿瘤坏死因子(tumor necrosis factor-α,TNF-α)m RNA表达水平。24 h后取细胞培养上清,ELISA检测IL-6和TNF-α蛋白表达水平。信号通路抑制剂预处理腹腔巨噬细胞1 h后加蛋白刺激,ELISA检测上清中IL-6、TNF-α蛋白表达水平抑制情况。取不同时间点处理的细胞进行免疫印迹(Western Blot),检测p-Akt和p-NF-κB表达水平。制备获得纯度90%以上、内毒素含量小于0.1 EU/μg的r Dna J-△A146Ply融合蛋白;r Dna J-△A146Ply可刺激腹腔巨噬细胞IL-6、TNF-αm RNA及蛋白水平表达明显上调、增强Akt和NF-κB磷酸化;Akt和NF-κB抑制剂可显著减少IL-6和TNF-α表达。因此,r Dna J-△A146Ply融合蛋白通过Akt和NF-κB信号通路刺激巨噬细胞诱导免疫应答。     

黄芩苷对脂多糖诱导的巨噬细胞NF-κB活化和炎症因子表达的影响

目的:研究黄芩苷对脂多糖(LPS)诱导小鼠巨噬细胞核因子κB(NF-κB)及肿瘤坏死因子α(TNF-α)、白介素6(IL-6)表达的影响.方法:分别用LPS(终浓度1μgomL-1)和LPs+黄芩苷(终浓度10,50,100μmol moloL-1)处理生长良好的小鼠巨噬细胞RAW264.7,用RT-PCR法和Elisa法检测细胞及其上清液中TNF-α、IL-6 mRNA和蛋白的表达变化,用Western Blot法检测细胞核内NF-κB p65蛋白含量变化.结果:LPS刺激RAW264.7细胞可导致NF-κB激活,上调TNF-α、IL-6表达;黄芩苷预处理能降低LPS诱导的NF-κB出活化和TNF-α、IL-6表达.结论:黄芩苷可通过抑制NF-κB活化,下调LPS诱导的巨噬细胞TNF-α、IL-6的生成,发挥抗炎作用.这可能是其抗动脉粥样硬化的作用机制之一.     

齐墩果酸抑制肿瘤坏死因子-α诱导的成纤维细胞样滑膜细胞炎症因子表达及其机制研究

探讨齐墩果酸(Oleanolic acid,OA)对肿瘤坏死因子-α(TNF-α)诱导成纤维细胞样滑膜细胞的炎症因子表达的影响及其机制。首先复苏培养人成纤维细胞样滑膜细胞(FLS),通过RT-PCR检测细胞IL-6及IL-1βmRNA表达,采用Western blot方法检测p38MAPK及NF-κB蛋白表达变化,通过ELISA法检测细胞上清液中IL-6及IL-1β浓度。与对照组比较,TNF-α明显诱导FLS细胞IL-6及IL-1βmRNA的表达及上清液中IL-6及IL-1β的分泌(P0.05),同时磷酸化p38蛋白和核NF-κB明显增加(P0.05),且p38MAPK阻断剂SB203580能抑制TNF-α诱导的核NF-κB增加。OA呈浓度依赖性抑制TNF-α诱导的FLS细胞p38蛋白磷酸化和核NF-κB增加(P0.05)。且OA、p38MAPK通路抑制剂SB203580或NF-κB阻断剂BAY 11-7082均能抑制TNF-α诱导的IL-6及IL-1β分泌增加(P0.05)。综上所述,OA能抑制TNF-α诱导的FLS细胞炎症因子IL-6及IL-1β的产生,其机制可能与抑制p38MAPK/NF-κB信号通路有关。     

红毛五加多糖单一组分AHP-Ⅲ对巨噬细胞的免疫调节作用及其机制

探讨红毛五加多糖(Acanthopanax giraldii Hams polysaccharide)单一组分AHP-Ⅲ(Acanthopanax giraldii Hams polysaccharideⅢ)对小鼠巨噬细胞RAW 264.7的激活作用及机制。不同浓度AHP-Ⅲ作用RAW 264.7细胞,中性红试验检测细胞吞噬能力;ELISA和Griess法检测其IL-6、TNF-α和NO的释放量;RT-qPCR检测iNOS、TNF-α和IL-6 mRNA相对表达水平;Western blot检测NF-κB信号通路相关蛋白磷酸化水平。在实验浓度范围内,AHP-Ⅲ可显著增强RAW 264.7细胞的吞噬能力(P<0.05);促进RAW 264.7分泌NO、TNF-α和IL-6(P<0.05或P<0.001);并显著增加RAW 264.7细胞中IL-6、TNF-α和iNOS mRNA的表达量,呈剂量依赖性;Western blot结果表明,AHP-Ⅲ作用RAW 264.7细胞后,NF-κB中的p65、IKKβ、IκBα磷酸化水平明显升高。结果显示红毛五加多糖AHP-Ⅲ对小鼠巨噬细胞RAW 264.7具有显著激活作用。     

肺炎支原体Msr B经MAPK/NF-κB通路抑制脂质相关膜蛋白诱生促炎细胞因子

蛋氨酸亚砜还原酶B(methionine sulfoxide reductase, MsrB)是一种重要的氧化还原蛋白。该文探究了肺炎支原体(Mycoplasma pneumoniae, Mp) MsrB对Mp脂质相关膜蛋白(lipidassociated membrane proteins, LAMPs)刺激的人髓系白血病单核细胞(THP-1细胞)分泌促炎细胞因子肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)的调节及相关信号通路,以进一步了解Mp的免疫逃避机制。论文构建了pET28a(+)-msr B重组质粒,诱导表达、鉴定、纯化重组蛋白(rMsrB)并制备了多克隆抗体; Western blot检测MsrB、TLR1、TLR2、TLR6和MyD88蛋白表达水平及NF-κB p65、P38、ERK和JNK的总蛋白和磷酸化蛋白水平;间接免疫荧光分析NF-κB核转位; ELISA测定TNF-α和IL-1β分泌水平。结果显示Msr B可表达于Mp胞质和胞膜。rMsrB预处理可抑制LAMPs刺激的THP-1细胞合成TNF-α和IL-1β。Mp rMsrB可抑制LAMPs刺激的TH...     

脂多糖通过核因子-κB途径下调泡沫细胞ATP结合盒转运体A1的表达

脂多糖(LPS)介导的免疫炎症反应与动脉粥样硬化(As)的发生密切相关,ATP结合盒转运体A1(ABCA1)促进细胞内胆固醇流出,具有抗As作用.观察了LPS对THP-1巨噬细胞源性泡沫细胞ABCA1表达及胆固醇流出的影响,并探讨TLR4/NF-κB信号途径和LXRs在此过程中的作用.THP-1巨噬细胞源性泡沫细胞经不同浓度LPS处理或者用LPS作用不同时间,以LPS单独或用NF-κB抑制剂对甲苯磺酰-L-苯丙氨酸氯甲基甲酮(TPCK)预处理细胞后再加入LPS处理.RT-PCR检测ABCA1、TLR4和LXRα mRNA的表达,Western blot检测ABCA1、LXRα及核内NF-κBp65蛋白的表达,液体闪烁计数器检测细胞内胆固醇流出,高效液相色谱分析细胞内总胆固醇、游离胆固醇和胆固醇酯含量.结果表明,LPS呈浓度和时间依赖性抑制ABCA1的表达,而增加TLR4 mRNA和核内NF-κBp65蛋白的表达,LPS使泡沫细胞内胆固醇流出减少,细胞总胆固醇、游离胆固醇与胆固醇酯增加,TPCK预处理后,LPS的这种作用被部分抑制,LXRα的表达不受LPS和TPCK的影响.这一结果提示,TLR4/NF-κB信号...     

幽门螺杆菌感染激活NF-κB信号通路促进胃癌SGC-7901细胞炎症因子释放

为了探讨幽门螺杆菌对胃癌SGC-7901细胞炎症因子释放的影响,本研究将幽门螺杆菌感染SGC-7901细胞后,采用细胞计数盒(CCK-8)检测SGC-7901细胞活力,酶联免疫吸附实验(ELISA)检测炎症因子TNF-α、IL-1β以及IL-8的水平,Real-time PCR检测细胞TNF-α、IL-1β以及IL-8 m RNA的表达,蛋白免疫印迹法(Western blotting)检测NF-κB信号通路相关蛋白NF-κB p65蛋白表达以及IκBα磷酸化水平。研究结果表明,幽门螺杆菌感染后,SGC-7901细胞活力显著增加;幽门螺杆菌感染明显上调SGC-7901细胞TNF-α、IL-1β以及IL-8 mRNA的表达;本研究还进一步发现幽门螺杆菌感染显著增加SGC-7901细胞TNF-α、IL-1β以及IL-8的水平;此外,幽门螺杆菌处理的SGC-7901细胞,其NF-κB p65的蛋白表达以及IκBα磷酸化水平均显著上调。本研究的结论初步表明,幽门螺杆菌感染促进胃癌SGC-7901细胞炎症因子的释放,其机制可能涉及激活NF-κB信号通路。     

低氧对巨噬细胞分泌TNF-α和IL-6的影响及其机制

目的:观察低氧对巨噬细胞(Mφ)前炎症因子TNF-α和IL-6分泌的影响及其机制.方法:收集分离小鼠腹腔Mφ,建立Mφ的低氧(1% O2,5%CO2)培养模型,并用非特异性酯酶染色法进行鉴定;ELISA法检测上清液中TNF-α和IL-6的含量;RT-PCR法检测TNF-α和IL-6的转录物水平;用Western blot法检测Mφ核内NF-κB的激活量;通过在培养液中加入氢化可的松(5 mg/L),观察低氧时TNF-α和IL-6分泌量的变化.结果:TNF-α和IL-6分泌量在低氧12 h时明显增加(P＜0.01);低氧6 h时,TNF-α mRNA和IL-6 mRNA表达量明显高于对照组(P＜0.01);M中核内NF-κB的激活量在低氧2 h时明显增高(P＜0.05),低氧5 h内持续存在;而当培养液中加入氢化可的松抑制NF-κB活性后,TNF-α和IL-6的分泌水平无明显变化.结论:低氧可通过核转录因子NF-κB途径促进细胞因子TNF-α和IL-6基因的表达和分泌.     

Rig-I对LPS诱导的巨噬细胞增殖、凋亡及功能的作用研究

该研究旨在探讨维甲酸诱导基因I(retinoic acid-inducible gene I,Rig-I)对脂多糖(lipopolysaccharide,LPS)诱导的巨噬细胞增殖、凋亡和细胞因子分泌等生物学功能的影响及其作用机制。以不同剂量的LPS刺激Rig-I基因沉默和过表达的小鼠巨噬细胞系Raw264.7细胞,采用CCK-8和流式细胞术检测细胞的生长状态,采用q PCR方法检测细胞因子TNF-α、IL-10、IL-1和IL-6相关基因的表达水平,并采用Western blot方法检测LPS诱导的TLR4信号通路的相关蛋白表达水平。CCK-8和流式细胞术结果显示,Rig-I促进巨噬细胞的增殖并抑制LPS诱导的细胞凋亡;q PCR结果表明,Rig-I促进巨噬细胞中TNF-α、IL-10、IL-1和IL-6基因的表达。进一步的实验证实,Rig-I通过激活AKT及其下游蛋白p-38、NF-κB和Bcl-x L等抑制细胞凋亡并促进细胞因子的表达。该研究首次证实了Rig-I可通过AKT信号通路对LPS诱导的巨噬细胞增殖、凋亡及功能进行调节。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Determination of stoichiometry of radioiodination of proteins

A sensitive method for the detection of small quantities of hydrophobic antioxidant free radical scavengers such as butylatedhydroxytoluene (BHT) and butylatedhydroxyanisole (BHA) in aqueous samples is described. The procedure involves extraction of the hydrophobic free radical scavenger into an organic solvent phase, followed by the subsequent reaction of an aliquot of this extract with the stable cation radical tris(p-bromophenyl)amminium hexachloroantimonate (TBACA). In experiments with BHT and BHA, the loss of TBACA absorbance at 730 nm was found to be linearly proportional to the amount of antioxidant added, with quantities of BHT as small as 200 pmol being easily detectable. In aqueous suspensions of dimyristoylphosphatidylcholine vesicles, assays of the aqueous BHT concentration showed that BHT partitioned strongly into the membrane phase, achieving very high BHT/phospholipid ratios. For a given concentration of BHT, partitioning into the membrane phase was greater in large, multilamellar liposomes than in either small, single-walled vesicles or in purified rat brain synaptic vesicle membranes. Direct assay of BHT and BHA in phospholipid membranes, however, was complicated by a nonspecific interaction between TBACA and the phospholipid.