槲皮素对LPS诱导的中性粒细胞产生白介素6的影响

目的 研究离体培养的人中性粒细胞在被LPS激活的情况下,槲皮素对中性粒细胞产生IL-6的影响。方法 运用ELISA法检测槲皮素对LPS诱导的中性粒细胞分泌IL-6的影响;运用流式细胞术检测槲皮素对LPS活化的中性粒细胞内IL-6的蛋白水平的影响;运用逆转录PCR（RT-PCR）技术检测槲皮素对LPS活化的中性粒细胞表达IL-6 mRNA的影响。结果 在无刺激的情况下中性粒细胞不产生IL-6,LPS（1μg／mL）以时间依赖性的方式诱导中性粒细胞表达IL-6 mRNA,合成并分泌IL-6,并在16h达到高峰。然而,预先用槲皮素（40μmol／L）处理中性粒细胞30min后,LPS诱导的中性粒细胞表达IL-6 mRNA,合成并分泌IL-6则受到了抑制。结论IL-6是炎症早期重要的促炎症因子。因此,槲皮素抑制LPS诱导中性粒细胞产生IL-6,提示槲皮素可能通过对炎症因子负性调控而发挥其抗炎作用。     

PKC在IL-1分泌中的作用

许多细胞可通过PKC 跨膜信号的传递而产生某些生物活性介质。LPS 可促使人单核细胞PKC 从胞浆移位到胞膜,从而诱导细胞产生和分泌IL-1。采用游离LPS,MLV-LPS(多层磷脂泡LPS),Lyo-MLV-LPS(水溶性脂质体表面LPS 经用LPS 重悬后制成)和LPS-脂质体四种不同形式的LPS 以及H7和星状孢子两种PKC 抑制剂,通过IL-1生物学活性方法检测单核细胞IL-1产生水平,应用免疫斑点法和[~3H]PBDu 结合法检测胞质中、胞膜中PKC 分布,研究了PKC在单核细胞IL-1诱导产生过程中的作用。结果表明:(1)游离LPS 或Lyo-MLV-LPS 促使IL-1α、β的产生、分泌及PKC     

LPS和IL-13影响系膜细胞表达IL-12的研究

目的：探讨脂多糖（LPS）及IL-13对系膜细胞表达IL-12的影响作用。方法：用酶联免疫吸附（ELISA）法检测LPS对系膜细胞分泌IL-12的影响，实验分组：①LPS（20μg／ml）对系膜细胞刺激不同时间；②不同剂量LPS刺激系膜细胞24小时。用ELISA法和逆转录聚合酶链反应（RT-PCR）法分别检测IL-13对系膜细胞IL-12蛋白和IL-12p40 mRNA表达的影响，分空白对照组，LPS（10μg／ml）刺激组及实验组（LPS 10μg／ml＋不同浓度的IL-13）。结果：未受LPS刺激的系膜细胞几乎不分泌IL-12，在一定的剂量范围内，LPS诱导系膜细胞显著表达IL-12，但随着LPS刺激时间及浓度的增加，IL-12的表达量反而减少。IL-13在1。100μg／ml浓度范围内呈剂量依赖性抑制LPS诱导的系膜细胞IL-12分泌及其mRNA表达（P〈0．01）。结论：LPS可诱导系膜细胞表达IL-12，但系膜细胞在表达IL-12时对LPS的长期及高浓度刺激产生耐受性。IL-13可能通过抑制LPS诱导系膜细胞分泌IL-12，作为抗炎性细胞因子在肾小球肾炎发病机制中发挥一定作用。 12；系膜细胞     

脂多糖对白细胞介素27的调节作用及其与环氧化酶2及前列腺素E2之间的相关性研究

目的 探讨脂多糖(LPS)在THP-1细胞对白细胞介素27(IL-27)的调节作用,阐明IL-27与环氧化酶2(COX-2)及前列腺素E2(PGE2)之间的关系.方法 采用不同浓度的LPS和IL-27刺激THP-1细胞,并在不同时间采用酶联免疫吸附试验(ELISA)检测细胞上清中IL-27和PGE2的含量,同时采用反转录PCR和Western blot检测COX-2的mRNA和蛋白表达的变化.结果 LPS在THP-1细胞能够诱导IL-27的产生,并呈时间和剂量依赖关系;IL-27能够在mRNA和蛋白水平诱导COX-2的表达,同时诱导PGE2的产生,其诱导作用呈时间和剂量依赖效应.结论 LPS能够在细胞水平刺激IL-27的分泌,同时IL-27能够诱导COX-2的表达和PGE2的产生.     

地塞米松和IL-10对hPBMC促炎细胞因子产生和核转录因子活化的影响

目的:观察地塞米松 (Dex)和白细胞介素 (IL)-10对培养的经脂多糖 (LPS)刺激的人外周血单个核细胞 (hPBMC)释放促炎细胞因子肿瘤坏死因子 (TNF)-α、IL-6及对转录因子核因子-κB(NF-κB)、活化蛋白-1(AP-1)、cAMP反应元件结合蛋白 (CREB)活化的影响。方法:用LPS刺激分离培养的hPBMC,分为正常对照组、LPS刺激组、IL-10和Dex干预组。ELISA法检测培养上清中TNF-α、IL-6含量。凝胶电泳迁移率改变分析法 (EMSA)检测核提取物中NF-κB、AP-1、CREB活性。结果:LPS刺激1h后TNF-α含量显著增加,Dex和IL-10干预后TNF-α含量增加被显著抑制;IL-6含量在LPS刺激后12h显著增加,Dex和IL-10显著抑制IL-6的产生;LPS刺激12h后IL-10含量显著增加,Dex对IL-10产生没有明显影响。LPS刺激1h后NF-κB、AP-1、CREB的DNA结合活性显著增加,Dex和IL-10显著抑制以上三种核因子的活性,但Dex对AP-1、CREB活性的抑制作用强于IL-10。结论:LPS诱导hPBMC释放多种促炎和抗炎细胞因子的产生,并诱导多种转录因子的活化;Dex、IL-10能抑制上述促炎细胞因子的产生和转录因子的活化。Dex对AP-1、CREB活性的抑制作用强于IL-10。     

Notch信号在脂多糖诱导的骨髓间充质干细胞中的作用

目的:探讨Notch信号对脂多糖(lipopolysaccharide,LPS)诱导的小鼠骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)增殖及白细胞介素6(interleukin-6,IL-6)和趋化因子CXCL1分泌的影响。方法:全骨髓培养法制备BMSCs;采用q PCR与Western blot实验比较LPS对BMSCs中Notch信号通路配体、受体及靶基因表达的变化;MTT法和活细胞计数检测Notch信号对细胞增殖的影响;并以ELISA法检测Notch信号通路抑制剂DAPT对IL-6和CXCL1分泌的调节作用。结果:经10μg/L、100μg/L和1 mg/L的LPS刺激后,BMSCs增殖和IL-6分泌呈现上升趋势(P0.05或P0.01)。q PCR与Western blot结果显示Notch信号通路受体和配体在BMSCs中均有表达,但LPS对其mRNA与蛋白水平并无明显影响,然而LPS可显著诱导Notch信号靶基因Hes1与Hey1的蛋白表达。Notch信号通路抑制剂DAPT可以降低LPS诱导的BMSCs活力的上升(P0.01),同时对LPS诱导的BMSCs增殖有抑制作用。另外,LPS显著诱导BMSCs中IL-6与CXCL1的分泌,而抑制Notch信号通路可显著抑制LPS所诱导的IL-6与CXCL1的分泌(P0.05)。结论:抑制Notch信号可以抑制LPS诱导的BMSCs增殖,并抑制IL-6与CXCL1的分泌。     

Fractalkine对脂多糖激活的小胶质细胞炎症相关因子表达的影响

目的:探讨趋化因子Fractalkine对脂多糖(LPS)诱导的小鼠小胶质细胞(N9)激活时所分泌的TNF-α、IL-1β和一氧化氮(NO)表达的影响.方法:用Fractalkine处理经LPS激活的小鼠小胶质细胞24 h,以ELISA法检测细胞培养上清中TNF-α和IL-1β的浓度,以NO试剂盒检测培养上清中NO的浓度.结果:LPS能够激活小胶质细胞,使IL-1 β、TNF-α和NO的表达量与对照组相比明显升高;Fractalkine能够降低LPS激活的小胶质细胞IL-1β、TNF-α和NO的表达.结论:Fractalkine可能通过抑制炎症相关因子的产生而在中枢神经系统中发挥神经保护作用.     

MyD88/PI3-K/NF-κB途径介导脂氧素A4拮抗LPS诱导大鼠内皮细胞的白细胞介素合成

目的研究脂氧素A4（LXA4）对脂多糖（LPS）诱导血管内皮细胞合成白细胞介素（IL）-1β、IL-6、IL-8的影响，并探讨其机制。方法对体外培养大鼠肺微血管内皮细胞（PMVEC），用LXA4孵育，再加入LPS；或单用LPS刺激PMVEC。在孵育后用酶联免疫吸附法（ELISA）检测培养上清中的IL-1β、IL-6、IL-8蛋白表达；用RT-PCR法检测IL-1β、IL-6、IL-8的mRNA表达。应用Western blot法检测磷酸化的磷脂酰肌醇-3-激酶（PI3-K）、髓细胞分化因子88（MyD88）的表达。应用凝胶电泳迁移率试验（EMSA）测定核因子-κB（NF-κB）和活化蛋白-1（AP-1）的DNA结合活性。结果LXA4呈剂量依赖性地抑制LPS诱导的PMVEC的IL-1β、IL-6、IL-8的蛋白合成与mRNA表达，抑制PI-3K的表达，抑制NF-κB和AP-1的DNA结合活性，但不影响LPS诱导的MyD88表达。结论LXA4通过下调PI3-K的表达和NF-κB、AP-1的DNA结合活性，拮抗LPS对PMVEC的IL-1β、IL-6、IL-8合成的诱导作用。     

青藤碱对LPS、IL-4诱导的小鼠RAW264.7巨噬细胞极化的影响

目的:探讨青藤碱(Sinomenine,SIN)对脂多糖(LPS)以及白细胞介素4(IL-4)诱导的RAW264.7细胞向M1、M2型极化的影响。方法:以LPS刺激RAW264.7细胞诱导M1型极化,IL-4刺激RAW264.7细胞诱导M2型极化;青藤碱作用于LPS或IL-4诱导的巨噬细胞后:用酶联免疫法(ELISA)检测不同诱导状态下RAW264.7细胞TNF-α和IL-10的分泌量;荧光定量PCR检测与巨噬细胞极化相关的精氨酸酶-1(Arg-1)、一氧化氮合酶(i NOS)、细胞因子信号转导抑制蛋白-2(SOCS2)和细胞因子信号转导抑制蛋白-3(SOCS3)的mRNA表达水平。结果:青藤碱能抑制LPS诱导下细胞TNF-α的分泌量,抑制细胞i NOS和SOCS3的mRNA表达水平的升高。青藤碱能抑制IL-4诱导下细胞IL-10的分泌量和Arg1的mRNA表达水平的升高,对IL-4诱导下细胞SOCS2的mRNA表达水平的升高没有明显影响。结论:青藤碱对LPS诱导下巨噬细胞向M1型极化具有抑制作用;对IL-4诱导下巨噬细胞向M2型极化具有抑制作用。青藤碱对M1/M2亚型的失衡具有调节作用,有利于维持其动态平衡。     

黄芩苷对NLRP3炎症小体活化和细胞焦亡的抑制作用及其机制研究

目的以LPS致敏的小鼠巨噬细胞(J774A.1或者腹腔巨噬细胞)作为细胞模型,探讨黄芩苷对ATP诱导的炎症小体活化和细胞焦亡的影响及其机制。方法 C57BL/6小鼠腹腔注射30 g·L-1巯基乙酸盐培养基诱导大量腹腔巨噬细胞产生;利用LPS致敏巨噬细胞,再以ATP激活NLRP3炎症小体;采用免疫印迹法检测细胞裂解物和培养上清液中IL-1β、caspase-1、HMGB1等蛋白的表达水平;以基于微球的免疫测定法(CBA)检测细胞培养上清液中IL-1β的水平;碘化丙锭(PI)染色法检测黄芩苷对LPS+ATP诱导的细胞焦亡的影响。结果黄芩苷处理能剂量依赖性地抑制LPS+ATP刺激下巨噬细胞中caspase-1的活化,成熟IL-1β(Mr17 000)和HMGB1的释放;同时,黄芩苷也能明显抑制LPS+ATP诱导的小鼠巨噬细胞发生焦亡。腺苷酸环化酶抑制剂MDL12330A和蛋白激酶A(PKA)抑制剂H89可以明显逆转黄芩苷对ATP诱导的细胞焦亡的抑制作用。结论黄芩苷可能通过影响巨噬细胞中PKA的活性,进而抑制NLRP3炎症小体活化与细胞焦亡。     

Thrombin and factor Xa enhance the production of interleukin-1.

Interleukin-1 (IL-1) plays a major role in inflammatory responses. Activation of coagulation and fibrin deposition typical of these reactions is mediated by macrophage procoagulants induced on stimulated macrophages. IL-1 activity in the supernatant of lipopolysaccharide (LPS)-stimulated guinea-pig macrophages was markedly enhanced by the presence of thrombin during macrophage activation. Although thrombin alone had no effect, inclusion of 1 mU/ml of thrombin with suboptimal levels of LPS produced a 200-fold increase in IL-1 activity, and further enhancement was observed with increasing doses of thrombin. The active site of thrombin was necessary for enhancement, as the serine esterase inhibitor di-isopropyl-fluorophosphate (DIP) and hirudin inhibited the synergy observed with LPS and thrombin. Prothrombin and Factor Xa also enhanced IL-1 production, although not to the same extent as thrombin. Factor Xa-like activity was demonstrated on the surface of LPS-stimulated macrophages. Both the Xa-like activity and IL-1 generated by LPS-stimulated cells were inhibited by heparin. Heparin with a high affinity for antithrombin III (anti-coagulant heparin; HAH) inhibited IL-1 generation, whereas low-affinity heparin (non-anticoagulant; LAH) had no effect. We show that proteases of the extrinsic coagulation cascade enhance IL-1 generation and propose that a Factor Xa-like activity present in activated macrophages, together with thrombin, may be important in IL-1 processing.     

Decreased interleukin 1 activity in culture supernatant of lipopolysaccharide stimulated monocytes from patients with liver cirrhosis and hepatocellular carcinoma.

Immunoregulatory function of peripheral blood monocytes was studied in patients with hepatocellular carcinoma (HCC) and liver cirrhosis (LC), by assaying interleukin 1 (IL-1) and prostaglandin E2 (PGE2) in the culture supernatant of lipopolysaccharide-stimulated monocytes. IL-1 activity of the monocyte culture supernatant without indomethacin was decreased in patients with HCC and LC, compared with that of controls. The activity was lower in patients with HCC than that in those with LC. The PGE2 content of the culture supernatant of monocytes from patients with LC and HCC was increased, compared to normal controls. To avoid the effect of PGE2 on the IL-1 assay, we cultured the monocytes with addition of indomethacin and assayed IL-1 activity in the culture supernatant. As a result, monocyte IL-1 production was increased in patients with HCC and LC, compared with normal controls. The decrease in IL-1 activity of the supernatant without indomethacin of patients with LC and HCC was considered to be due to increased secretion of PGE2 by the monocytes. Therefore, monocytes from patients with HCC and LC had an increased capacity of secreting both IL-1 and PGE2 over normal controls, but the effect of the suppressor function (PGE2 secretion) dominated in these patients.     

Interleukin-1 production by mononuclear cells from patients with scleroderma.

Interleukin-1 (IL-1) production by peripheral blood mononuclear cells (PBMC) from patients with scleroderma and healthy controls was studied. Supernatants from unstimulated PBMC cultures from 10 of 13 patients with progressive systemic sclerosis (PSS) had significantly less IL-1 activity as measured by thymocyte proliferation than controls. IL-1 activity per monocyte/macrophage in both patients and controls was 10 times greater when PBMC were cultured at 10(5) cells/ml compared to 10(6) cells/ml. Five-fold dilution of supernatants from PBMC cultured at 10(6) cells/ml revealed more IL-1 activity than undiluted supernatant and addition of indomethacin increased IL-1 activity primarily of the undiluted supernatant. The results show that IL-1 activity from crude PBMC supernatants from PSS patients is low and may be regulated by non-dialysable inhibitors produced by PBMC and/or cell interactions.     

Influence of cell sources, stimulating agents, and incubation conditions on release of interleukin-1 from chicken macrophages

Experiments were conducted to determine the cell source, stimulating agents, and incubation conditions that maximize interleukin-1 (IL-1) release by chicken macrophages/monocytes. Thymocyte co-mitogen proliferation was used to assay IL-1 activity of conditioned or partially purified supernatants. Monolayers of a transformed chicken macrophage cell line, HD11, released greater amounts of IL-1 than adherent cells isolated from peripheral blood, peritoneal cavity, or spleen. E. coli endotoxin and heat-killed S. aureus induced greater release of IL-1 by HD11 and splenic macrophages than latex or a super induction protocol with mezerien. Blocking macrophage eicosanoid synthesis with indomethacin did not influence IL-1 release from HD11 macrophages. Removing low molecular weight compounds from conditioned supernatants by dialysis did not influence IL-1 activity. IL-1 release was increased by incubating macrophages at 42 C compared to 39 C. Thymocyte co-mitogenic activity of IL-1 was increased by incubating thymocytes at 42 C compared to 39 C. Species cross reactivity between chicken and mammalian IL-1 was also investigated. Chicken IL-1 had slight co-stimulation activity on murine thymocytes, but murine and human IL-1 were without activity on chicken thymocytes.     

Interleukin-1 release by alveolar macrophages in asthmatic patients and healthy subjects

A thymocyte proliferative response assay was used to compare spontaneous and lipopolysaccharide (LPS)-induced interleukin-1 (IL-1) release by alveolar macrophage (AM) in asthmatic patients and normal subjects. Twelve asthmatic patients and seven nonsmoking healthy subjects underwent a bronchoalveolar lavage (BAL). All asthmatic patients had a reversible airway obstruction and 7/12 were allergic. BAL AM were separated by adherence on tissue culture plates in medium RPMI-1640 supplemented with antibiotics and fetal calf serum, and were incubated with or without 10 micrograms/ml LPS for 20 h. Free-cell supernatants were tested by C3H/HeJ mice thymocyte proliferative assay. Unstimulated AM supernatant IL-1 activity was significantly higher in asthmatic patients (mean +/- SEM: 47.8 +/- 11.9 units/10(6) AM) in comparison with healthy subjects (4.8 +/- 2.3 units/10(6) AM; p less than 0.05, Mann-Whitney U test) but did not significantly differ between allergic (42.2 +/- 15.5 units/10(6) AM) and intrinsic asthmatic patients (55.8 +/- 20.7 units/10(6) AM). For healthy subjects, IL-1 activity was significantly higher in LPS-stimulated AM supernatants (85 +/- 20 units/10(6) AM, p less than 0.05; Mann-Whitney U test) in comparison with unstimulated ones; for asthmatic patients, unstimulated and LPS-stimulated AM supernatant IL-1 activity did not significantly differ. This finding is in accordance with previous work suggesting that AM from asthmatic patients have a weak suppressive activity upon lymphocyte proliferation and emphasize the enhanced AM releasability in asthma.     

In vitro modulation of interleukin-1 beta secretion by cultured rat doxorubicin-stimulated whole glomeruli and dissociated mesangial glomerular cells.

Doxorubicin-stimulated whole rat glomeruli and dissociated mesangial and resident glomerular macrophage cells produced the release of interleukin (IL)-1 beta cytokine. This activity increased after the addition of lipopolysaccharide (LPS) or LPS plus indomethacin to the cultures. In the presence of WEB2086 [platelet-activating factor (PAF)-acether antagonist], this activity showed a drastic reduction, without modification after sodium furegrelate (thromboxane synthetase inhibitor) was added to the cultures. Our results also demonstrate that this IL-1 beta activity is mainly produced by glomerular-resident macrophage cells. These findings support the important role by both IL-1 beta and PAF-acether mediator factors, at the cellular level, in the rat model of doxorubicin-induced nephrosis.     

Factors in AMLR culture supernatant which mediate the cytotoxic T-cell response to hapten-altered self: interaction with macrophages

Supernatants from autologous mixed lymphocyte reaction (AMLR) cultures mediated the cytotoxic T-cell response in a system containing T cells and mitomycin C-treated, TNP-modified syngeneic thymocytes. No cytotoxic activity developed in the absence of the AMLR supernatants. The removal of thymic adherent cells abrogated the effect of the AMLR supernatants in the generation of cytotoxic cells. AMLR helper activity was restored following the addition of small numbers of splenic adherent cells. These results led to speculation that the AMLR supernatant interacted with accessory cells. Examination of the supernatant revealed significant levels of colony stimulating factor (CSF), and interferon-gamma (IFN-gamma). Functionally, incubation of the AMLR supernatant with P388D1, a macrophage tumor line, resulted in the production of interleukin 1 (IL-1). CSF is a major inducer of IL-1 synthesis. In addition, the AMLR supernatant induced the expression of Ia antigens on the P388D1 cells. IFN-gamma has been reported to mediate this activity. Although both lymphokines were present and appeared to have an effect on macrophages, it was unknown if both were required for cytotoxic T-cell development in this system. Samples of AMLR supernatant were incubated for 10 min at various temperatures. The ability of the AMLR supernatants to mediate cytotoxic T-cell activation was sensitive to incubation at 80 or 90 degrees C. Interestingly, at these temperatures CSF activity in the bone marrow colony-forming cell assay was enhanced. In separate experiments, AMLR culture supernatant was dialyzed against a pH 2 buffer. The induction of IA antigens by these supernatants was sensitive to dialysis at this pH. The similarity with IFN-gamma provides further evidence that this activity was mediated by IFN-gamma in the AMLR supernatants. The ability of the AMLR supernatants to mediate the cytotoxic T-cell response to altered self was also pH 2 sensitive. In contrast, IL-1 inducing capability and bone marrow colony growth, both CSF activities, were not reduced by pH 2 dialysis. Taken together, these data demonstrate a primary role for an IFN-like molecule, present in the AMLR supernatant, on cytotoxic T-cell activation. CSF involvement in this response is suggested by its IL-1 inducing activity, but cannot be definitively proven in the present study.     

Interferon-gamma (IFN-gamma) and prostaglandin E2 (PGE2) regulate differently IL-12 production in human intestinal lamina propria mononuclear cells (LPMC).

IL-12 modulates Th1 immune response during chronic colitis. Mechanisms regulating IL-12 synthesis in human intestine are poorly understood. The aim of this study was to investigate the effect of IFN-gamma and PGE2 on lipopolysaccharide (LPS)-stimulated LPMC IL-12 production. Normal LPMC cultures were run in the presence or absence of IFN-gamma and/or PGE2 before LPS stimulation. To examine the role of endogenous PGE2 on LPS-stimulated IL-12 release, LPMC cultures were added of indomethacin before LPS stimulation. IL-12, IL-10 and IL-8 were measured by ELISA. No IL-12 was detected in either unstimulated or LPS-stimulated LPMC cultures. In contrast, LPMC released IL-8 (650 +/- 125 pg/ml) and IL-10 (75 +/- 25 pg/ml) in response to LPS. Treatment of LPMC with IFN-gamma facilitated LPS-stimulated IL-12, whereas it completely abrogated IL-10 production. IL-12 release by LPMC stimulated with IFN-gamma and LPS was significantly inhibited by exogenous IL-10. The addition of PGE2 to IFN-gamma-treated LPMC cultures inhibited in a dose-dependent manner LPS-induced IL-12 secretion. Furthermore, IL-12 was detectable (85 +/- 25 pg/ml) in the supernatants of LPMC cultures treated with indomethacin and LPS. In contrast to the effect on IL-12, PGE2 significantly augmented LPS-stimulated LPMC IL-10 production. However, the inhibition of IL-12 by PGE2 was only partially reversed by anti-IL-10. In a simplified model of LPS tolerance, we finally showed that monocyte-derived macrophages exhibited reduced IL-12 production after repeat LPS stimulation. In these cell cultures, indomethacin abrogated the induction of LPS desensitization. IFN-gamma and PGE2 modulate differently the LPMC responsiveness to LPS in terms of IL-12 synthesis.