奈诺沙星对脂多糖诱导炎性反应的免疫调控作用

目的通过体外细胞学实验和体内动物实验来研究奈诺沙星是否对脂多糖(LPS)诱导的炎性反应具有调控作用。方法 (1)体外细胞学实验检测奈诺沙星对LPS诱导小鼠单核巨噬细胞RAW264.7产生炎性反应的调控作用。RAW264.7细胞液中先加入奈诺沙星,后加入LPS,在不同时间点收集奈诺沙星+LPS组和LPS组等各组细胞上清液,酶联免疫吸附测定(ELISA)方法检测白介素(IL)-6、IL-10以及肿瘤坏死因子(TNF)-α等细胞因子的含量;(2)低剂量LPS诱导小鼠炎性反应及奈诺沙星干预实验。小鼠先腹腔注射奈诺沙星再注射低剂量LPS(5 mg/kg),ELISA方法检测小鼠血清中IL-6、IL-10以及TNF-α等细胞因子的含量;(3)奈诺沙星对注射高剂量LPS小鼠保护作用的实验:小鼠腹腔注射高剂量的LPS(12.5mg/kg),2 h后开始腹腔注射奈诺沙星40 mg/kg,1次/12 h,记录0～72 h实验组和对照组小鼠的死亡率。结果 (1)体外细胞学实验显示奈诺沙星对LPS诱导RAW264.7产生的炎性反应有抑制作用,表现为奈诺沙星抑制IL-6、TNF-α等促炎因子的分泌,促进IL-10等抑炎因子的分泌;(2)体内动物实验结果显示奈诺沙星对低剂量LPS诱导小鼠的炎性反应也有抑制作用;(3)奈诺沙星能降低因高剂量LPS引起严重内毒素血症小鼠的死亡率。奈诺沙星+LPS组总体死亡率为0/5,而LPS组总体死亡率为3/5。结论奈诺沙星对宿主感染LPS具有免疫调节作用,可以抑制宿主产生的过度免疫反应,对宿主具有保护作用。     

重组表达的猪溶素及其突变体诱导小鼠巨噬细胞的细胞毒性和IL-1β释放

目的观察猪溶素(Suilysin,SLY)及其无溶血活性的突变体诱导小鼠腹腔巨噬细胞(peritoneal macrophage,PM)释放IL-1β和细胞毒的差异,为进一步研究SLY诱导炎性体激活通路奠定基础。方法重组表达纯化SLY及第353氨基酸位点突变体rSLY353L,体外和小鼠PM相互作用,用乳酸脱氢酶释放法检测细胞毒作用,用酶联免疫吸附试验(ELISA)检测IL-1β的水平。结果不同浓度rSLY(0.1~10μg)诱导小鼠PM细胞毒性呈现明显的剂量效应,rSLY(1μg/ml)诱导产生750 pg/ml的IL-1β同时细胞毒20%;rSLY(5μg/ml)可引起最大量的IL-1β释放但细胞毒高达90%。相同剂量的rSLY353L不能诱导可检测到的IL-1β和细胞毒性。rSLY与PM共孵育20 h IL-1β产量最高,20 h后IL-1β产量下降但细胞毒性随孵育时间延长而增大。结论 1μg/ml SLY和PM作用20 h可诱导较高的IL-1β产生同时细胞毒性较低,该实验条件适用于进一步进行SLY激活PM炎性体信号通路的机制研究。     

姜黄素缓解动物急性肺损伤的研究现状

姜黄素是从姜黄中提取的一种活性成分,具有抗炎、抗氧化、抗凋亡和免疫调节等作用。急性肺损伤是以急性重度的肺弥散功能障碍为特征的重症,表现为炎性细胞的浸润、过氧化物的释放、内皮细胞的损伤和大量促炎因子的产生等。研究发现姜黄素能缓解多种因素导致的动物急性肺损伤,本文对该领域的研究现状作一综述。     

EGCG对体外诱导小鼠Th17细胞的产生及促炎因子调控的影响

目的探讨表没食子儿茶素没食子酸酯(EGCG)对体外诱导小鼠Th17细胞的产生及促炎因子白细胞介素(IL)-17和肿瘤抑制因子(TNF)-α的表达和分泌的影响。方法分离小鼠脾脏CD4+T淋巴细胞,加入刺激体系诱导体外培养的淋巴细胞活化分化成Th17细胞。设立对照组和不同剂量EGCG组(100、200、400 ng/mL),分别培养72 h后,采用流式细胞仪检测Th17细胞。分别采用荧光定量PCR和ELISA法检测培养细胞IL-17、TNF-α的基因表达和蛋白分泌水平。结果 EGCG能够抑制体外诱导的Th17细胞的产生,IL-17和TNF-α的基因表达和蛋白分泌水平均受到显著抑制,且其抑制作用呈剂量依赖性。结论 EGCG可抑制体外诱导的小鼠Th17细胞产生,抑制IL-17和TNF-α的表达和分泌。     

副猪链球菌临床分离株引起小鼠大脑炎性反应的特征及机制研究

目的 研究副猪链球菌临床分离株引起小鼠大脑炎性反应的特征及其机制。方法 副猪链球菌临床分离株NN1和BS26及高致病型猪链球菌P1/7感染C57BL/6小鼠后,观察其脑组织中的细菌载量,并提取脑组织RNA,使用实时荧光定量聚合酶链式反应方法明确诱导型一氧化氮合酶（iNOS）、促炎性细胞因子IL-1β以及核苷酸结合寡聚化结构域样受体（NOD1/2）表达的时间动力学特征。副猪链球菌临床分离株NN1和BS26及猪链球菌P1/7分别与小鼠原代星型胶质细胞及小胶质细胞细胞系BV2细胞相互作用后,分别测定细胞上清液中一氧化氮（NO）浓度以及IL-1β和NOD1/2 mRNA转录水平的时间动力学特征。结果 副猪链球菌临床分离株感染小鼠后可在小鼠脑组织中持续存在超过48 h,并在感染早期引起小鼠脑组织中iNOS、IL-1β及NOD1/2受体转录水平的显著升高（P<0.05）。小胶质细胞可能在副猪链球菌临床分离株诱导脑组织产生NO和IL-1β中发挥重要作用。副猪链球菌通过NOD1/2受体激活星形胶质细胞的能力显著强于小胶质细胞（P<0.05）。结论 副猪链球菌临床分离株NN1和BS26在感染...     

白细胞介素-10与静脉血栓形成

与静脉血栓形成相关的静脉壁的炎症是由促炎和抗炎细胞因子的动态平衡调节的,而白细胞介素-10(IL-10)作为一种有力的抗炎细胞因子,在调节与静脉血栓形成相关的炎症中有重要作用[1]。本文就IL-10与静脉血栓形成有关的文献作一综述。1IL-10概述IL-10是1989年Fiorentino等发现的小鼠Th2细胞株D10.G4.1产生一种能抑制Th1细胞株细胞因子mRNA转录的细胞因子,当时被称为细胞因子合成抑制因子(cytokine syn-thesis inhibitory factor,CSIF)。成熟的IL-10分子由160个氨基酸残基组成,在氨基酸序列中含有2个糖基化位点,3个半胱氨酸和9个甲硫氨酸。小鼠和人的IL-10基因都定位于1号染色体,均由5个外显子和4个内含子组成,它们在DNA和氨基酸水平上分别有81%和73%的同源性。人IL-10可作用于小鼠细胞,而小鼠IL-10对人的细胞却无作用。IL-10通过和细胞膜上的IL-10受体(IL-10R)结合而发挥其生物学作用。IL-10主要由单核/巨噬细胞、B细胞、T细胞(包括CD8 细胞、Th1细胞和Th2细胞等)、中性粒细胞、肥大细胞、内皮细胞、血管...     

白细胞介素-10在社区获得性肺炎中的表达

社区获得性肺炎(CAP)是院外发病和死亡主要原因。在大多数CAP患者发生炎症反应综合征和败血症,持续平衡抗炎因子和促炎因子之间的平衡。主要促炎因子有IL-6、TNF,败血症时也产生对抗炎症反应的因子IL-10,从而抑制促炎因子IL-6、IL-1α、IL-1β、IL-8和TNF。不同细胞因子基因水平对应激刺激的反应是不同的。本文旨在探讨诱导基因表达的IL-6和IL-10启动区单核苷酸多肽性与CAP之间的关系。     

薯蓣皂苷对胶原性关节炎大鼠的免疫调节

目的研究薯蓣皂苷(Dioscin)对大鼠胶原性关节炎(CIA)的免疫调节作用。方法将SD大鼠随机分为正常组、CIA模型组、阳性药物组和实验组。连续灌胃给药2周,停药后处死大鼠,足容积法测量继发侧足肿胀度,观察该药对CIA大鼠免疫器官的影响,MTT法检测ConA诱导的小鼠脾淋巴细胞增殖转化,中性红实验测定小鼠腹腔巨噬细胞吞噬功能,酶联免疫吸附测定法(ELISA)测定大鼠血清细胞因子IL-1、和TNF-α的水平。结果从第24天起,薯蓣皂苷(60、120 mg/kg)对CIA大鼠继发性炎症反应有明显的治疗作用。薯蓣皂苷可剂量依赖性降低CIA大鼠胸腺指数,提高淋巴细胞增殖反应及腹腔巨噬细胞吞噬能力,高、中、低剂量组给药大鼠的血清内炎性细胞因子IL-1、TNF-α水平较CIA模型组明显降低(P<0.01)。结论薯蓣皂苷有良好的抗炎及免疫调节作用,对CIA大鼠继发性炎症有治疗作用,其作用机制可能与调节机能依赖性的双向免疫及抑制炎性细胞因子产生有关。     

内毒素致伤大鼠肺组织促炎与抗炎细胞因子mRNA表达的时相性研究

目的 研究不同剂量内毒素致伤大鼠肺组织促炎和抗炎细胞因子mRNA表达的时相性,并探讨这些细胞因子在全身炎症反应失控和急性肺损伤中的可能作用。方法 采用逆转录-聚合酶链反应(RT-PCR)检测不同剂量脂多糖(LPS)致伤大鼠肺组织肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6、IL-4、IL-10和IL-13的mRNA表达。结果 随着LPS剂量增加,TNF-α、IL-1β、IL-6、IL-4、IL-10和IL-13的mRNA表达均增强(与生理盐水对照组比较,P均<0.01);LPS≥6 mg/kg组上述细胞因子表达显著高于此剂量以下组(P均<0.01)。表达峰值时间:TNF-α为1 h,IL-6为4 h,其他均在2 h。结论 内毒素致急性肺损伤中,TNF-α是早期表达的促炎细胞因子,而IL-6在炎症进一步发展中发挥作用;抗炎细胞因子IL-4、IL-10、IL-13高表达亦可能促进炎症的放大而不是起保护作用。     

神经细胞焦亡与麻醉药物相关研究进展

细胞焦亡是继细胞凋亡和细胞坏死后发现的一种程序性、伴有炎性反应的细胞死亡方式。由天冬氨酸特异性半胱氨酸蛋白酶(胱天蛋白酶,caspase)-1介导,并伴有大量炎性因子[白细胞介素(IL)-1β、IL-18等]及促炎因子的释放,诱导其他炎性细胞因子的合成和释放,募集炎性细胞集聚,扩大全身炎性反应,导致细胞焦亡。最近研究显示,细胞焦亡可能参与了麻醉药物作用于脑组织的过程,并对术后认知功能产生影响。因此,本文对细胞焦亡的形态学变化、发生机制及麻醉药物在其中所起作用方面取得的相关研究进展综述如下。     

Human prostate cancer cells induce inflammatory cytokine secretion by peripheral blood mononuclear cells

A substantial number of studies provide evidence that inflammation may play a significant role in the pathogenesis of prostate cancer via increased activity of inflammatory cytokines, particularly IL-6. We have previously shown that peripheral blood mononuclear cells (PBMC) are capable of carrying out an in vitro “immunomodulatory dialog” with colon cancer cells expressed by an increased production of pro-inflammatory cytokines by PBMC. The aim of the current study was to examine the model of cell-to-cell interaction between PBMC and prostate cancer cells from two lines – androgen resistant (PC-3) and androgen-dependent (LNCaP). For that purpose, cancer cells from both lines were incubated with PBMC, and cytokine secretion by PBMC was evaluated. The results showed a cell-concentration dependent increase in secretion of the pro-inflammatory cytokine IL-6 by PBMC induced by cells from both lines, whereas generation of IL-1β and the anti-inflammatory cytokine IL-10 were found to be increased after incubation with PC-3 cells only. The secretion of IL-10 was slightly lower following incubation of PBMC with supernatants derived from PC-3 cells. The results of the study support the possibility that prostate cancer cell-induced cytokine production by PBMC, and particularly IL-6, are involved in prostate cancer development. The discrepancy between the effect of the two prostate cancer cell lines on cytokine secretion by PBMC may be due to their different androgen dependency.     

The interleukin-1 beta-converting enzyme inhibitor pralnacasan reduces dextran sulfate sodium-induced murine colitis and T helper 1 T-cell activation

The proinflammatory cytokines interleukin (IL)-1beta and IL-18 are supposed to play a crucial role in the pathogenesis of human inflammatory bowel disease. To exert biological activity, the precursors of both IL-1beta and IL-18 need to be cleaved by the interleukin-1beta-converting enzyme (ICE). IL-18 induces the synthesis of IFN-gamma in T cells and NK cells. In the present study, we investigated the effect of the specific ICE inhibitor pralnacasan in dextran sulfate sodium-induced murine colitis. Colitis was induced in BALB/c mice by 3.5% dextran sulfate sodium dissolved in drinking water for 10 days. Pralnacasan was administered either intraperitoneally or orally every day. To assess in vivo efficacy, a clinical disease activity score was evaluated daily. Colon length, expression of IL-18 in colonic tissue, expression of interferon-gamma (IFN-gamma) in paraaortal lymphocytes, and systemic production of IFN-gamma in splenocytes were analyzed post mortem. Intraperitoneally administered pralnacasan significantly reduced the clinical score compared with the dextran sulfate sodium control group from day 6 to day 10. Oral administration of pralnacasan also significantly reduced the clinical score at days 8 and 9. Administration of pralnacasan i.p. reduced the expression of intracolonic IL-18 significantly. Furthermore, pralnacasan reduced the number of IFN-gamma-positive lymphocytes in paraaortal lymph nodes. IFN-gamma synthesis in stimulated splenocytes was significantly suppressed in all pralnacasan-treated groups. No side effects of pralnacasan were observed. In conclusion, pralnacasan is effective in the prevention of dextran sulfate sodium-induced colitis. This effect is probably mediated by suppression of the proinflammatory cytokines IL-18, IL-1beta, and IFN-gamma.     

Iron supplementation affects the production of pro-inflammatory cytokines in IL-10 deficient mice

BACKGROUND: Iron supplements may increase disease activity in inflammatory bowel disease through the production of the hydroxyl radical because of its catalytic activity in the Fenton reaction. The purpose of this study was to assess the effect of dietary and locally administered iron in the IL-10 knock-out (-/-) mouse, a model of chronic inflammatory bowel disease. MATERIALS AND METHODS: IL10-/- and wild-type mice received a standard or a high-iron diet (35 mg kg(-1) ferrosulphate vs. 500 mg kg(-1) ferrosulphate) after weaning. After 4 weeks the mice were sacrificed. Furthermore, a group of adult IL-10 knock-out mice was given three iron-containing enema's (0.2 mL of 1 mM ferrous-ammonium sulphate) or phosphate buffered saline. These mice were sacrificed after 1 week. Production of pro-inflammatory cytokines by colon tissue cultures, haematological parameters and histology was determined to assess inflammatory activity. RESULTS: Oral as well as rectal administration of iron resulted in increased pro-inflammatory cytokine production in IL-10-/- mice. Neutrophil counts in IL10-/- on a high iron diet increased as well. No enhanced colonic inflammation was noted on histology after iron supplementation. CONCLUSION: We conclude that dietary or topical administered iron increases pro-inflammatory cytokine production in the colon of IL10-/- mice. No significant increase of histological intestinal inflammation was observed.     

Differential induction of pro- and anti-inflammatory cytokines in whole blood by bacteria: effects of antibiotic treatment.

The in vitro production of interleukin-1beta (IL-1beta), IL-6, and the IL-1 receptor antagonist (IL-1ra) in whole blood upon stimulation with different bacterial strains was measured to study the possible relationship between disease severity and the cytokine-inducing capacities of these strains. Escherichia coli, Neisseria meningitidis, Neisseria gonorrhoeae, Bacteroides fragilis, Capnocytophaga canimorsus, Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, and Streptococcus pyogenes induced the cytokines IL-1beta, IL-6, and IL-1ra. Gram-negative bacteria induced significantly higher levels of proinflammatory cytokine production than gram-positive bacteria. These differences were less pronounced for the anti-inflammatory cytokine IL-1ra. In addition, blood was stimulated with E. coli killed by different antibiotics to study the effect of the antibiotics on the cytokine-inducing capacity of the bacterial culture. E. coli treated with cefuroxime and gentamicin induced higher levels of IL-1beta and IL-6 production but levels of IL-1ra production similar to that of heat-killed E. coli. In contrast, ciprofloxacin- and imipenem-cilastatin-mediated killing showed a decreased or similar level of induction of cytokine production as compared to that by heat-killed E. coli; polymyxin B decreased the level of production of the cytokines.     

Curcumin prevents and reverses cirrhosis induced by bile duct obstruction or CCl4 in rats: role of TGF-beta modulation and oxidative stress

Curcumin is a phytophenolic compound, which is highly efficacious for treating several inflammatory diseases. The aim of this study was to evaluate the efficacy of curcumin in preventing or reversing liver cirrhosis. A 4-week bile duct ligation (BDL) rat model was used to test the ability of curcumin (100 mg/kg, p.o., daily) to prevent cirrhosis. To reverse cirrhosis, CCl₄ was administered chronically for 3 months, and then it was withdrawn and curcumin administered for 2 months. Alanine aminotransferase, γ-glutamyl transpeptidase, liver histopathology, bilirubin, glycogen, reduced and oxidized glutathione, and TGF-β (mRNA and protein) levels were assessed. Curcumin preserved normal values of markers of liver damage in BDL rats. Fibrosis, assessed by measuring hydroxyproline levels and histopathology, increased nearly fivefold after BDL and this effect was partially but significantly prevented by curcumin. BDL increased transforming growth factor-beta (TGF-β) levels (mRNA and proteins), while curcumin partially suppressed this mediator of fibrosis. Curcumin also partially reversed the fibrosis induced by CCl₄. Curcumin was effective in preventing and reversing cirrhosis, probably by its ability of reducing TGF-β expression. These data suggest that curcumin might be an effective antifibrotic and fibrolitic drug in the treatment of chronic hepatic diseases.     

Use of curcumin to decrease nitric oxide production during the induction of antitumor responses by IL-2

Nitric oxide (NO) synthesis is strongly induced during interleukin (IL)-2 treatment of mice and humans. Although this free radical can act as a cytotoxic effector molecule against cancer cells, immunosuppressive effects have also been suggested. We evaluated the effects of curcumin on IL-2-induced NO synthesis and IL-2-induced antitumor responses in a mouse ascites tumor model. Curcumin inhibited inducible nitric oxide synthase (iNOS) expression and NO production, and thereby enhanced the proliferation and cytotoxic activity of cocultured lymphocytes and macrophages during IL-2 stimulation which we earlier established as an in vitro model of IL-2-induced NO synthesis. Curcumin also decreased apoptosis of cocultured lymphocytes and macrophages during IL-2 stimulation. In contrast, the curcumin-induced changes in proliferation and apoptosis were not observed in cultures of lymphocytes alone, macrophages alone, and cocultured lymphocytes/iNOS-knock out macrophages, all of which produced little nitrite during IL-2 stimulation. In conjunction with IL-2 treatment, oral curcumin administration significantly inhibited IL-2 therapy-induced urinary nitrite/nitrate excretion and iNOS expression of tumor tissues, and further increased the IL-2 therapy-induced prolongation of survival in a murine Meth-A ascites tumor model. Curcumin may be useful as an adjunct to increase the antitumor activity of IL-2 therapy.     

Does cardiac surgery in newborn infants compromise blood cell reactivity to endotoxin?

Introduction

Neonatal cardiac surgery is associated with a systemic inflammatory reaction that might compromise the reactivity of blood cells against an inflammatory stimulus. Our prospective study was aimed at testing this hypothesis.

Methods

We investigated 17 newborn infants with transposition of the great arteries undergoing arterial switch operation. Ex vivo production of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), of the regulator of the acute-phase response IL-6, and of the natural anti-inflammatory cytokine IL-10 were measured by enzyme-linked immunosorbent assay in the cell culture supernatant after whole blood stimulation by the endotoxin lipopolysaccharide before, 5 and 10 days after the operation. Results were analyzed with respect to postoperative morbidity.

Results

The ex vivo production of TNF-α and IL-6 was significantly decreased (P < 0.001 and P < 0.002, respectively), whereas ex vivo production of IL-10 tended to be lower 5 days after the operation in comparison with preoperative values (P < 0.1). Ex vivo production of all cytokines reached preoperative values 10 days after cardiac surgery. Preoperative ex vivo production of IL-6 was inversely correlated with the postoperative oxygenation index 4 hours and 24 hours after the operation (P < 0.02). In contrast, postoperative ex vivo production of cytokines did not correlate with postoperative morbidity.

Conclusion

Our results show that cardiac surgery in newborn infants is associated with a transient but significant decrease in the ex vivo production of the pro-inflammatory cytokines TNF-α and IL-6 together with a less pronounced decrease in IL-10 production. This might indicate a transient postoperative anti-inflammatory shift of the cytokine balance in this age group. Our results suggest that higher preoperative ex vivo production of IL-6 is associated with a higher risk for postoperative pulmonary dysfunction.     

Cytokine patterns after tourniquet-induced skeletal muscle ischaemia reperfusion in total knee replacement

OBJECTIVE: Extremity surgery performed under tourniquet control causes one of the most common forms of skeletal muscle ischaemia-reperfusion injury in clinical practice. The aim of this study was to investigate the systemic and local inflammatory response after tourniquet-induced skeletal muscle ischaemia-reperfusion injury in patients undergoing total knee replacement. It was our hypothesis that local inflammatory responses in a surgical wound under tourniquet-induced ischaemia cause an excessive overflow of cytokines to the systemic circulation in the reperfusion phase. MATERIAL AND METHODS: Blood was sampled before and after surgery in nine patients given total knee replacement. Samples from ischaemic and non-ischaemic limbs and from drained blood were analysed for pro-inflammatory and anti-inflammatory cytokines. RESULTS: Surgery induced significant increases of IL-6 (p = 0.007) in the non-ischaemic (systemic) limb and in drained blood (p = 0.032), with highest levels 4 h after operation. The increased IL-6 in the ischaemic limb was non-significant. IL-1 beta was not detectable under surgery, from either the traumatized limb or from the non-traumatized limb, nor were TNFalpha and IL-10 significantly influenced by surgery. CONCLUSIONS: Knee replacement trauma performed under ischaemia, is associated with modest systemic inflammatory reactions with no spillover of increased IL-6 from the traumatized area in the reperfusion phase.