磷脂酶A2活性与慢性常压低氧性肺动脉高压关系的研究

目的:研究磷脂酶A₂(PLA₂)活性及其相关炎症介质在大鼠慢性常压低氧性肺动脉高压形成中的作用。方法:29只健康SD大鼠随机分为正常对照组、单纯低氧组和低氧加白藜芦醇苷(PD)组。右心导管法检测大鼠肺动脉压力(mPAP),观察右室/左室+室间隔比值(R/L+S)、血浆和肺匀浆中PLA₂、血栓素B₂(TXB₂)、6-酮-前列腺素F_1α(6-k-PGF_1α)、丙二醛(MDA)、超氧化物歧化酶(SOD)水平的变化。结果:低氧3周后大鼠mPAP、R/L+S、血浆及肺匀浆中PLA₂活性、TXB₂、MDA含量显著升高;6-k-PGF_1α、SOD水平下降。用PD预处理后可减轻上述变化。结论:PLA₂通过相关炎症介质及与自由基的相互作用在慢性低氧性肺动脉高压的形成中起着重要的介导作用。     

脂氧素A4抑制内毒素诱导的人支气管上皮细胞环氧合酶2及前列腺素E2的表达

目的: 探讨脂氧素A₄对人支气管上皮细胞(HBECs)环氧合酶2(COX-2)表达的影响。方法: 应用不同浓度(0.1、1、10 mg/L)的内毒素(LPS)刺激HBECs 9 h,或者用1 mg/L LPS分别刺激HBECs不同时点(3 h、6 h、9 h)后,测定HBECs的COX-2 mRNA表达和细胞上清液前列腺素E₂(PGE₂)水平。应用不同浓度 (0、100、400 μmol/L) 的脂氧素A₄作用于经过LPS(1 mg/L)刺激培养9 h的HBECs,采用酶联免疫吸附法(ELISA)检测细胞上清液PGE₂的水平, 同时分别应用RT-PCR和Western blotting分别检测HBECs COX-2 mRNA及蛋白的表达。结果: LPS刺激培养条件下HBECs的COX-2 mRNA表达及其上清液PGE₂水平增加,并呈时间、剂量依赖性。脂氧素A₄能抑制LPS刺激培养HBECs COX-2蛋白和mRNA的表达及上清液PGE₂的水平,并呈剂量依赖性。结论: 脂氧素A₄能抑制LPS诱导的HBECs COX-2表达及上清液PGE₂的水平。     

小檗碱对流感病毒感染肺泡巨噬细胞炎性细胞因子的影响及其分子机制研究

目的:探讨小檗碱对流感病毒感染大鼠肺泡巨噬细胞(NR8383)后TNF-α、MCP-1转录、表达的影响及与TLR7介导的MyD88依赖性信号通路的关系。方法:流感病毒感染NR8383细胞1小时后,加入含小檗碱的培养基(终浓度5μg/ml),药物作用后6、12、24小时,ELISA检测细胞上清中TNF-α、MCP-1的含量;24小时,Real time PCR检测细胞内TNF-α、MCP-1的mRNA水平,RT-PCR检测TLR7、MyD88、NF-κB P65 mRNA水平;4、6、24小时,免疫组化法检测NF-κB P65核转位情况,并做半定量分析;24小时,Western blot检测NF-κB P65表达水平。结果:小檗碱抑制了流感病毒感染NR8383细胞后TNF-α、MCP-1的转录和表达(P<0.05),降低了TLR7、MyD88、NF-κB P65 mRNA水平(P<0.05、P<0.05、P<0.01),抑制了流感病毒感染后NF-κB P65的核转位及表达(P<0.01)。结论:小檗碱通过抑制TLR7介导的MyD88依赖性信号通路,抑制了NF-κB P65的核转位及表达,从而减少流感病毒感染巨噬细胞后炎性细胞因子TNF-α、MCP-1的产生,在流感治疗中发挥抗炎作用。     

白细胞介素-10抑制人肾系膜细胞环氧化酶-2表达及其催化的前列腺素E2释放的实验研究

目的:观察IL-10对IL-1β诱导的人系膜细胞(HMC)前列腺素E₂(PGE₂)释放及环氧化酶-2(cyclooxygenase-2,COX-2)基因和蛋白表达的影响。方法:应用放射免疫测定法检测HMC培养上清中PGE₂,应用RT-PCR和Westernblot分别检测COX-2mRNA和蛋白水平。结果:①IL-1β显著上调PGE₂释放及COX-2基因和蛋白的表达(P均＜0.01);②IL-10对基础状态下PGE₂释放及COX-2基因和蛋白表达无明显影响(P＞0.05);③IL-10可呈剂量依赖性地下调IL-1β诱导的PGE₂释放及COX-2mRNA和蛋白表达(P＜001)。结论:IL-10抑制IL-1β诱导的HMCPGE₂释放及COX-2表达,提示IL-10对HMC具有多方面抗炎作用。     

糖尿病大鼠肾脏细胞因子基因表达初步研究

目的:研究糖尿病大鼠肾脏细胞因子mRNA的表达。方法:大鼠随机分成2组:单肾切组、糖尿病组。实验第8周,应用RT-PCR技术检测大鼠肾皮质转化生长因子-β₁ (TGF-β₁)、血小板衍化生长因子-B(PDGF-B)、肿瘤坏死因子-α (TNF-α)及Ⅳ型胶原mRNA的表达。 结果: 糖尿病组大鼠肾皮质TGF-β₁ (P＜0.01)、 PDGF-B(P＜0.01)、TNF-α(P＜0.01)及Ⅳ型胶原(P＜0.01)mRNA的表达显著高于单肾切组大鼠。结论: 在实验性大鼠糖尿病肾皮质TGF-β₁、PDGF-B 、TNF-α和Ⅳ型胶原mRNAs表达显著增加。     

PGE2受体EP2和EP4调节CIA小鼠脾B细胞表面分子和细胞因子表达

目的: 探讨前列腺素E₂(PGE₂)受体EP2和EP4在胶原诱导性关节炎(CIA)小鼠脾B细胞免疫调节中的作用。方法: 建立CIA小鼠模型,用CD19⁺ 免疫磁珠分选脾B细胞,流式细胞术检测MHCⅡ、CD80和CD86的表达,实时荧光定量PCR技术检测EPs 和细胞因子IFN-γ、TNF-α、IL-6、IL-4、IL-10和TGF-β的表达。结果: 小鼠脾B细胞表达EP的4个亚型,CIA模型小鼠EP2和EP4表达增加;EP2阻断剂可以降低MHCⅡ、CD80和CD86的表达,而EP4阻断剂对CD80没有明显影响;EP2和EP4阻断剂均可以降低IFN-γ、TNF-α 和IL-6 的表达(P<0.05或P<0.01),促进IL-10的表达(P<0.01或P<0.05),并可以分别促进IL-4和TGF-β的表达(P<0.01)。结论: PGE₂可通过EP2/EP4调节B细胞表面分子和细胞因子参与CIA发病,EP2/EP4有可能成为类风湿关节炎治疗的新靶点。     

曲古抑菌素A对心衰大鼠心脏促炎细胞因子及心功能的影响

目的: 观察组蛋白脱乙酰化酶抑制剂曲古抑菌素A(TSA)对心肌梗死后心衰(HF)大鼠心脏肿瘤坏死因子(TNF-α)、白细胞介素-1β(IL-1β)和诱导型一氧化氮合酶(iNOS)及心功能的影响。方法: 采用冠状动脉左前降支结扎术致心肌梗死制备大鼠HF模型和假手术模型(sham),给予TSA或vehicle处理。给药4周后,测定血流动力学参数,应用免疫组织化学和ELISA检测左室心肌TNF-α、IL-1β和iNOS的水平,并测定右室/体重(RV/BW)、肺重/体重(LW/BW)。结果: 与HF+vehide组相比,给予TSA后可使HF大鼠心肌组织内增高的TNF-α、IL-1β和iNOS含量明显降低(P<0.05),左室舒张末压(LVEDP)和LW/BW降低(P<0.05);降低的左室内压最大上升速率(+dp/dt_max)和左室内压最大下降速率(-dp/dt_max)明显升高(P<0.05)。结论: 组蛋白脱乙酰化酶抑制剂TSA抑制心肌梗死后HF大鼠心肌组织TNF-α、IL-1β及iNOS的产生,并且可能通过该抑制作用改善HF大鼠的心功能,减轻肺淤血。     

氯沙坦钾对2型糖尿病肾病大鼠肾脏TGF-β1、CD68和MCP-1 表达的影响

目的: 探讨氯沙坦钾对2型糖尿病肾病大鼠转化生长因子β₁ (transforming growth factor beta 1, TGF-β₁)、CD68(巨噬细胞标记物)和单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)表达的影响,进一步说明氯沙坦钾对2型糖尿病大鼠肾脏的保护作用。方法: 雄性SD大鼠30只,按随机数字表法分为正常对照组、模型组和治疗组,每组10只。15周后, 观测肾组织形态学、肾功能和24 h尿蛋白定量等指标的变化, 用免疫组化法检测肾脏TGF-β₁、CD68和MCP-1表达水平的变化。结果: (1)与正常对照组相比,模型组及治疗组大鼠体重均降低,血糖、甘油三酯、胆固醇及MCP-1、CD68、TGF-β₁的阳性细胞数升高,模型组24 h尿蛋白和肌酐升高;(2)与模型组相比,治疗组血肌酐、24 h尿蛋白、甘油三酯及MCP-1、CD68、TGF-β₁的阳性细胞数明显降低。结论: 在2型糖尿病肾病大鼠中氯沙坦钾可以通过减少肾组织MCP-1表达,阻止巨噬细胞的浸润,下调TGF-β₁表达,对糖尿病肾病病变起到保护作用。     

阿魏酸钠对结肠炎大鼠结肠巨噬细胞功能的影响

目的:探讨阿魏酸钠在整体水平下对结肠炎大鼠结肠巨噬细胞功能的影响及其机制。方法:建立大鼠免疫性结肠炎模型。阿魏酸钠(SF)灌肠用药21d后检测结肠组织MDA、NO、PGE₂含量,SOD、IL-1、TNF-α、MPO活性及NF-κBp65表达水平。结果:阿魏酸钠(200、400、800mg/kg)灌肠用药剂量依赖性降低模型组大鼠显著升高的MDA、NO、PGE₂含量,IL-1、TNF-α、MPO活性及NF-κBp65表达水平,同时升高显著降低的SOD活性。结论:SF整体水平下减弱结肠炎大鼠结肠活化巨噬细胞的生物活性,缓解结肠炎症反应,机制可能与抑制NF-κB表达有关。     

人工晶体植入术后房水白介素-2和肿瘤坏死因子-α水平及其与一氧化氮的关系

目的：探讨人工晶体植入术后房水中白介素-2（IL-2）和肿瘤坏死因子-α（TNF-α）水平及其与一氧化氮（NO）的关系。方法：将新西兰白兔随机分成3组：(1) 正常对照组;(2) 晶体囊外摘除术组（ECCE）;(3) 晶体囊外摘除术+人工晶体囊袋内植入术组（ECCE +IOL）。于术后0、1、3、7、14、30 d观察各组动物眼内炎症反应的同时,测定房水中IL-2和TNF-α水平及NO₂^-/NO₃^-含量。结果：(1) 术后1-14 d ECCE+IOL组房水中IL-2、TNF-α和NO₂^-/NO₃^-含量均明显高于ECCE组和对照组,该含量于术后3-7 d达到高峰,2周后逐渐减少;(2) 各组房水IL-2、TNF-α和NO₂^-/NO₃^-含量变化的规律一致,房水IL-2和TNF-α水平与NO含量变化密切相关（P<0.01）。结论：NO和IL-2、TNF-α在人工晶体植入术后眼内炎症反应中可能均起重要的作用。     

Phospholipase A2 activation by interleukin 1: Release and metabolism of arachidonic acid by IL 1-stimulated rabbit chondrocytes

Treatment of rabbit chondrocytes with natural or recombinant human IL 1 results in a dramatic dose-dependent increase in intracellular phospholipase A₂ (PLA₂) activity and subsequent secretion of this enzyme into the intracellular millieu. PLA₂ activity is detectable as early as 1 hr after IL 1 stimulation and is maximal by 24 hr. In the present study, we have characterized more fully the relationship between PLA₂ activation and arachidonate metabolism in these cells. IL 1 treatment of chondrocytes which had been prelabeled with [¹⁴C] arachidonic acid resulted in an enhanced release of free arachidonic acid identified by thin-layer chromatography. Moreover, the arachidonic acid liberated was subsequently metabolized exclusively to PGE₂; no significant increases in the production of 6-keto PGF₁, LTB₄, LTC₄, 12-HETE or 15-HETE were observed following IL 1 stimulation.     

MicroRNA-132转染对脂多糖诱导的肺泡巨噬细胞炎症反应的作用

 目的:探讨转染微小RNA-132（miR-132）对肺泡巨噬细胞炎症反应的作用。方法: 将体外去致热源培养的大鼠肺泡巨噬细胞株NR8383分为空白对照组、阴性对照组和转染组,分别采用miR-132增敏剂、错义链和PBS作用。转染24 h后,CCK-8法检测细胞増殖;实时荧光定量PCR检测细胞中miR-132的表达;用脂多糖（LPS）作用细胞后,凝胶电泳迁移率实验（EMSA）检测细胞中NF-κB活性;Western blotting法检测细胞中肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）的表达。结果: 与空白对照组和阴性对照组相比较,转染组细胞中miR-132的表达明显升高;转染组细胞増殖被明显抑制,与空白对照组相比较,差异有统计学意义（P<0.05）;LPS作用后,转染组NF-κB、TNF-α和IL-6表达量显著下降,与空白对照组和阴性对照组相比较,差异均有统计学意义（P<0.05）。结论: 转染miR-132可抑制NR8383细胞増殖,并抑制LPS诱导的NR8383细胞的炎症反应。     

miR-181a参与调控香烟提取物诱导的NR8383肺泡巨噬细胞自噬紊乱与促炎因子的生成

目的:探讨微小RNA-181a(miR-181a)对香烟提取物(CSE)诱导的NR8383大鼠肺泡巨噬细胞自噬紊乱与促炎因子生成的影响。方法:采用5%、10%和20%浓度的CSE刺激NR8383细胞,ELISA法检测肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和IL-8的分泌,RT-qPCR检测miR-181a水平,Cyto-ID染色检测自噬体数量,Western blot法检测LC3-Ⅱ、beclin-1和p62的表达。在20%CSE条件下,采用自噬抑制剂3-甲基腺嘌呤(3-MA)或自噬激动剂雷帕霉素(Rapa)预处理细胞,ELISA检测TNF-α、IL-6和IL-8的分泌;进一步转染miR-181a mimic或miR-181a inhibitor后,分别采用ELISA和Western blot观察在20%CSE条件下,细胞TNF-α、IL-6和IL-8分泌及LC3-Ⅱ、beclin-1和p62表达的情况。结果:CSE浓度依赖性促进NR8383细胞促炎因子生成和自噬紊乱;3-MA促进CSE诱导的NR8383细胞促炎因子释放,而Rapa部分逆转CSE诱导的NR8383细胞促炎因子释放;miR-181a mimic显著抑制CSE诱导的NR8383细胞促炎因子生成,促进自噬,miR-181a inhibitor促进CSE诱导的NR8383细胞促炎因子生成,加剧自噬紊乱。结论:miR-181a调控CSE诱导的NR8383细胞促炎因子释放可能与其调控自噬紊乱有关。     

Influenza virus replication in human alveolar macrophages

Studies with animal models suggest that alveolar macrophages may be important cells in some respiratory virus infections, but little is known about the role of these cells in virus infections in man. In this study human alveolar macrophages were obtained by fibreoptic bronchoscopy and infected in vitro with a variety of influenza viruses. After infection with the NWS strain of influenza virus the haemagglutinin and nucleoprotein viral antigens were demonstrated in >90% of cells at 24 h by immunofluorescence with specific antisera. There was no cytopathic effect at this time, and no virus release was detected by plaque assay of culture fluids on MDCK cells. Alveolar macrophages were also infected with a human vaccine strain (H₁N₁) of influenza virus and with two recent isolates (H₁N₁ and H₃N₂). In each case viral nucleoprotein antigen was produced in 10–20% of the cells by 24 h postinfection, but there was no release of infectious virus. There was no cytopathic effect and the phagocytosis of IgG-coated latex beads was unimpaired 24 h after in vitro infection.     

Dual inhibition of 5-lipoxygenase/cyclooxygenase by a reconstituted homeopathic remedy; possible explanation for clinical efficacy and favourable gastrointestinal tolerability

Objective: In order to elucidate potential anti-inflammatory activities of Zeel comp. N and its constituents, the inhibition of the synthesis of Leukotriene B₄ (LTB₄) and Prostaglandin (PGE₂) by 5-lipoxygenase (5-LOX) and cyclo-oxygenase 1 and 2 (COX 1 and 2) respectively were examined in vitro.Materials: Human HL-60 cells, differentiated for 6–8 days with DMSO (1.2% v/v) were used for the 5-LOX assay. The COX activity assays were carried out with purified enzymes, COX 1 (ram seminal vesicles), COX 2 (sheep placenta) and with human THP-1 cells, differentiated for 24 h with PMA (50 nM).Methods: LTB₄ and PGE₂ production in the 5-LOX and COX assays respectively were determined by enzyme linked immunoassays.Results: A reconstituted Zeel comp. N combination as well as its constituent mother tinctures of Arnica montana, Sanguinaria canadensis and Rhus toxicodendron (Toxicodendron quercifolium) showed distinct inhibitory effects on the production of LTB₄ by 5-LOX (IC₅₀ values of 10, 20, 2 and 5 µg/ml respectively) and on the synthesis of PGE₂ by COX 1 (IC₅₀ values of 50, 80, 40 and 20 µg/ml respectively) and COX 2 enzymes (IC₅₀ values of 60, 110, 50 and 20 µg/ml respectively). The mother tincture of Solanum dulcamara inhibited the production of PGE₂ by COX 1 (IC₅₀ 40 µg/ml) and COX 2 (IC₅₀ 150 µg/ml) but not production of leukotriene LTB₄ by 5-LOX.Conclusions: The observed dual inhibition of both LOX- and COX-metabolic pathways may offer an explanation for the reported clinical efficacy and the favorable gastrointestinal tolerability of the original remedy Zeel comp. N.Received 10 April 2003; returned for revision 27 May 2003; accepted by W. B. van den Berg 24 November 2003     

Eicosanoid production in rheumatoid synovitis

Leukotriene B₄ (LTB₄) synthesis in rheumatoid synovitis was studied using peripheral and synovial fluid polymorphonuclear leukocytes (PMNs) and rheumatic synovial lining cells. No differences were found in LTB₄ synthesis between peripheral PMNs from healthy volunteers and rheumatoid arthritis patients. When peripheral and synovial PMNs from the same RA patient were compared, arachidonic acidinduced LTB₄ synthesis in synovial fluid PMNs was increased 1.7–7.2 fold, whereas the response to Ca ionophore A23187 stimulation was similar. This suggests 5-lipoxygenase stimulating factor(s) in inflamed joints. Rheumatic synovial lining cells in a primary cell culture produced small amounts of LTB₄, the concentrations being less than 0.1 per cent of those of prostaglandin E₂ (PGE₂). PGE₂ synthesis in synovial cells was increased when arachidonic acid or interleukin-1 was added to the culture, whereas LTB₄ production remained unaltered. The present results suggest that in inflamed joints LTB₄ originates mainly from PMNs whereas synovial lining cells are the source for PGE₂.     

Contribution of group II phospholipase A2 to arachidonic acid release and prostaglandin synthesis by mesangial cells

Interleukin 1 (IL-1) and tumour necrosis factor (TNF)α have been found to increase group II phospholipase A₂ (PLA₂) synthesis and secretion by mesangial cells. In all cases 85%–90% of the enzyme is secreted from the cells and a parallel increase in prostaglandin (PGE₂) synthesis is observed. We report here that co-incubation with a monoclonal antibody that specifically binds and neutralizes rat group II PLA₂ attenuates IL-1β and TNFα-stimulated PGE₂ production by 45% and 52%, respectively. CGP43182, a specific inhibitor of group II PLA₂, potently blocks IL-1β- and TNFα-stimulated PGE₂ synthesis in intact mesangial cells with 1C₅₀s of 1.3 and 1.0 μM, respectively.     

Immune cells and mediators involved in the inflammatory responses induced by a P-I metalloprotease and a phospholipase A2 from Bothrops atrox venom

Bothrops envenomations can promote severe inflammatory responses by inducing edema, pain, leukocyte recruitment and release of chemical mediators by local cells. In the present study, two toxins from Bothrops atrox venom (the P-I metalloprotease Batroxase and the acidic phospholipase A₂ BatroxPLA₂) were evaluated in relation to their inflammatory effects induced in vivo and in vitro, mainly focusing on the participation of different immune cells and inflammatory mediators. Both toxins mainly promoted acute inflammatory responses with significant recruitment of neutrophils in the early hours (1–4 h) after administration into the peritoneal cavity of C57BL/6 mice, and increased infiltration of mononuclear cells especially after 24 h. Among the mediators induced by both toxins are IL-6, IL-10 and PGE₂, with Batroxase also inducing the release of L-1β, and BatroxPLA₂ of LTB₄ and CysLTs. These responses pointed to possible involvement of immune cells such as macrophages and mast cells, which were then evaluated in vitro. Mice peritoneal macrophages stimulated with Batroxase produced significant levels of IL-6, IL-1β, PGE₂ and LTB₄, whereas stimulus with BatroxPLA₂ induced increases of IL-6, PGE₂ and LTB₄. Furthermore, both toxins were able to stimulate degranulation of RBL-2H3 mast cells, but with distinct concentration-dependent effects. Altogether, these results indicated that Batroxase and BatroxPLA₂ promoted local and acute inflammatory responses related to macrophages and mast cells and to the production of several mediators. Our findings should contribute for better understanding the different mechanisms of toxicity induced by P-I metalloproteases and phospholipases A₂ after snakebite envenomations.     

白藜芦醇对TNF-α诱导的离体大鼠肺动脉内皮细胞损伤及MCP-1表达的影响

目的:探讨中药单体白藜芦醇(resveratrol,Res)对肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)诱导的离体大鼠肺动脉内皮细胞(rat pulmonary artery endothelial cells,RPAECs)中单核细胞趋化蛋白1(monocyte chemoattractant protein-1,MCP-1)的作用。方法:采用组织贴块法培养RPAECs,随机分为空白对照组(control组)、溶剂对照组(solvent组)、TNF-α(10μmol/L)组和Res(50μmol/L)+TNF-α组(Res组),每组又分成1、4和8 h三个时点(n=6),在8 h增加TNF-α+C1142(MCP-1特异性中和抗体)组(C1142组)。采用Western blot方法检测RPAECs中MCP-1蛋白表达,real-time PCR方法检测MCP-1 mRNA表达。结果:C1142可显著减少TNF-α诱导的RPAECs凋亡(P0.05)。相同时点solvent组的MCP-1蛋白和control组比较差异无统计学显著性;TNF-α组的MCP-1蛋白及mRNA较control组增高(P0.05);Res组的MCP-1蛋白及mRNA表达较TNF-α组降低(P0.05)。结论:MCP-1参与TNF-α诱导的RPAECs损伤;Res可降低TNF-α诱导的RPAECs中MCP-1表达,从而减少内皮细胞损伤。