中性粒细胞胞外陷阱与肿瘤的研究进展

中性粒细胞作为机体的第一道防线,在保护宿主免于感染中具有十分重要的作用,是循环中最丰富的白细胞。2004年发现,中性粒细胞在活化后会释放去凝聚的染色质,形成中性粒细胞胞外陷阱,先前研究证明其发生在捕获和杀死细菌和其他病原体的防御机制中。然而越来越多的人认识到其参与恶性疾病的发病和发展。全文综述中性粒细胞胞外陷阱在肿瘤进展、转移和肿瘤相关血栓形成中的作用。     

C5a-C5aR在脓毒症中的作用

脓毒症中补体系统的过度激活导致大量C5a的产生,并诱导其受体(C5aR)在细胞上的表达异常,C5a-C5aR相互作用调节炎症介质的表达、干扰凝血通路和诱导中性粒细胞功能障碍,最终导致器官功能损伤.     

Asthma phenotyping: a necessity for improved therapeutic precision and new targeted therapies

Asthma is a common heterogeneous disease with a complex pathophysiology that carries a significant mortality rate and high morbidity. Current therapies based on inhaled corticosteroids and long‐acting β‐agonists remain effective in a large proportion of patients with asthma, but ~10% (considered to have ‘severe asthma’) do not respond to these treatments even at high doses or with the use of oral corticosteroids. Analytical clustering methods have revealed phenotypes that include dependence on high‐dose corticosteroid treatment, severe airflow obstruction and recurrent exacerbations associated with an allergic background and late onset of disease. One severe phenotype is eosinophilic inflammation‐predominant asthma, with late‐onset disease, rhinosinusitis, aspirin sensitivity and exacerbations. Blood and sputum eosinophilia have been used to distinguish patients with high Th2 inflammation and to predict therapeutic response to treatments targeted towards Th2‐associated cytokines. New therapies in the form of humanized antibodies against Th2 targets, such as anti‐IgE, anti‐IL4Rα, anti‐IL‐5 and anti‐IL‐13 antibodies, have shown encouraging results in terms of reduction in exacerbations and improvement in airflow in patients with a ‘Th2‐high’ expression profile and blood eosinophilia. Research efforts are now focusing on elucidating the phenotypes underlying the non‐Th2‐high (or Th2‐low) group, which constitutes ~50% of severe asthma cases. There is an increasing need to use biomarkers to indicate the group of patients who will respond to a specifically targeted treatment. The use of improved tools to measure activity of disease, a better definition of severe asthma and the delineation of inflammatory pathways with omics analyses using computational tools, will lead to better‐defined phenotypes for specific therapies.     

Neutrophils extracellular traps damage Naegleria fowleri trophozoites opsonized with human IgG

Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack. In this work, we evaluate the capacity of N. fowleri to induce the liberation of NETs by human PMN cells. Neutrophils were cocultured with unopsonized or IgG‐opsonized N. fowleri trophozoites. DNA, histone, myeloperoxidase (MPO) and neutrophil elastase (NE) were stained, and the formation of NETs was evaluated by confocal microscopy and by quantifying the levels of extracellular DNA. Our results showed N. fowleri induce the liberation of NETs including release of MPO and NE by human PMN cells as exposure interaction time is increased, but N. fowleri trophozoites evaded killing. However, when trophozoites were opsonized, they were susceptible to the neutrophils activity. Therefore, our study suggests that antibody‐mediated PMNs activation through NET formation may be crucial for antimicrobial responses against N. fowleri.     

In vitro effects of beetroot juice and chips on oxidative metabolism and apoptosis in neutrophils from obese individuals

Oxidative stress and inflammation are involved in the development of obesity. Beetroot (Beta vulgaris var. rubra) is a food ingredient containing betalain pigments that show antioxidant activity. The in vitro effect of beetroot juice and chips on oxidative metabolism and apoptosis in neutrophils from obese individuals has been investigated. Fifteen obese women (aged 45 +/- 9 years, BMI >30 kg/m2) and nine healthy controls (women, aged 29 +/- 11 years, BMI = 22.2 +/- 1.6 kg/m2) were examined. The investigated products were used as concentrates and after transport and digestion in an artificial gastrointestinal tract. Neutrophil oxidant production, in response to phorbol 12-myristate 13-acetate, was characterized by luminol-dependent chemiluminescence and a flow cytometric dichlorofluorescin oxidation assay. Caspase-3 activity, a marker of apoptosis, was measured by cleavage of the fluorogenic substrate Ac-DEVD-AMC. Neutrophils from obese individuals had a significantly higher ROS production compared with the controls (p < 0.05). Beetroot products inhibited neutrophil oxidative metabolism in a concentration-dependent manner. Also observed were the pro-apoptotic effects of beetroot at a concentration range of 0.1-10% in 24 h culture of stimulated neutrophils. These natural products (in both the liquid and solid state) have antioxidant and antiinflammatory capacity, and could be an important adjunct in the treatment of obesity.     

Attenuation of colitis injury in rats using Garcinia cambogia extract

Inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis are chronic enteropathies that probably result from a dysregulated mucosal immune response. These pathologies are characterized by oxidative and nitrosative stress, leukocyte infiltration and up-regulation of pro-inflammatory substances. Current IBD treatment presents limitations in both efficacy and safety that stimulated the search for new active compounds. Garcinia cambogia extract has attracted interest due to its pharmacological properties, including gastroprotective effects. In this study, the antiinflammatory activity of a garcinia extract was assessed in TNBS-induced colitis rats. The results obtained revealed that garcinia administration to colitic rats significantly improved the macroscopic damage and caused substantial reductions in increases in MPO activity, COX-2 and iNOS expression. In addition, garcinia extract treatment was able to reduce PGE(2) and IL-1beta colonic levels. These antiinflammatory actions could be related to a reduction in DNA damage in isolated colonocytes, observed with the comet assay. Finally, garcinia extract caused neither mortality nor toxicity signals after oral administration. As such, the antiinflammatory effects provided by the Garcinia cambogia extract result in an improvement of several parameters analysed in experimental colitis and could provide a source for the search for new antiinflammatory compounds useful in IBD treatment.     

布洛芬对人离体中性白细胞MyD88-p38MAPK通路的影响

目的：研究布洛芬对脂多糖（LPS）介导人中性白细胞MyD88-p38MAPK通路的影响。方法取正常健康人外周静脉血20 mL。用密度梯度法分离中性白细胞和用免疫磁珠纯化纯化中性白细胞。用Nucleofection转染系统转染MyD88 siRNA基因。用5μmol/L、10μmol/L、50μmol/L和100μmol/L布洛芬和LPS 1μg/mL刺激上述细胞。用Western Blot检测 MyD88和p38MAPK磷酸化水平。结果布洛芬呈剂量依赖性抑制LPS介导的正常人中性白细胞和MyD88基因沉默中性白细胞产生氧自由基。正常人中性白细胞和MyD88基因沉默中性白细胞,浓度为50μmol/L和100μmol/L时,可明显抑制ROS的产生达到50.0%±2.4%和42.5%±4.7%,40.0%±3.7%和30.0%±4.6%,与单纯LPS刺激相比P＜0.01。同时在正常和MyD88基因沉默细胞,50μmol/L布洛芬可明显抑制LPS介导的MyD88和p38MAPK的表达。结论布洛芬通过下调MyD88-p38MAPK通路抑制人中性白细胞细胞内氧自由基的产生。     

系统性红斑狼疮患者外周血RDW-CV和PLT/NEUT%与相关免疫学指标及病情活动度的相关性

目的 探讨红细胞分布宽度变异系数(RDW-CV)和血小板与中性粒细胞百分比比值(PLT/NEUT%)与系统性红斑狼疮(SLE)相关免疫学指标及病情活动度的相关性。方法 回顾性分析128例SLE患者与128例健康对照的资料; 比较两组RDW-CV和PLT/NEUT%水平,分析RDW-CV和PLT/NEUT%与CRP,ESR,C3,C4,IgG和SLEDAI-2000的相关性; 评价RDW-CV,PLT/NEUT%及两者联合检测在诊断SLE疾病的价值。结果 SLE组PLT/NEUT%水平低于对照组,而RDW-CV水平高于对照组; PLT/NEUT%与CRP,ESR和IgG呈负相关(r=-0.258～-0.245,均P<0.01); 与C3和C4呈正相关(r=0.507,0.309,均P<0.01); RDW-CV与CRP,ESR呈正相关(r=0.391,0.306,均P<0.01),与C3呈负相关(r=-0.236,P:0.07); RDW,PLT/NEUT%和C3与SLEDAI-2000有线性回归关系(t=-5.819～3.075,均P<0.01); 两者联合预测值(AUC=0.879)>PLT/NEUT%(AUC=0.861)>RDW-CV(AUC=0.784)。结论 RDW-CV和PLT/NEUT%可作为SLE病情变化的辅助监测指标,与SLE疾病活动度有一定的相关性。     

充血性心力衰竭老年患者中性粒细胞膜脂流动性与心功能状况的关系

目的:观察中性粒细胞膜脂流动性(LFU)在充血性心力衰竭(CHF)中的变化及其与心功能状况的相关性.方法:选择CHF患者40例,正常对照者30例,用荧光分光光度计偏振技术测定外周血中性粒细胞LFU.结果:CHF组中性粒细胞LFU低于正常对照组(P＜0.01);心功能越差,LFU越低,随着心功能的改善而逐渐升高(P＜0.05).结论:中性粒细胞LFU可能参与了CHF的病理过程,在一定程度上反映了心力衰竭程度.     

乌司他丁对中性粒细胞NF—κB活性及血浆TNF—α和IL-8水平的影响

目的观察乌司他丁对体外循环（cardiopulmonary bypass,CPB）患者中性粒细胞（PMN）核因子κB（NF—κB）活性及血浆中TNF—α和IL-8水平的影响。方法选择在体外循环下行心脏直视手术的法洛四联症患儿40例,随机分成乌司他丁组（U组）和对照组（C组）,每组20例。U组于麻醉诱导后给予乌司他丁,C组患者则给予等容积的生理盐水代替。分别于麻醉后手术前（T1）、CPB开始后30min（他）、CPB停止后30min（T3）、CPB停止后4h（T4）和CPB停止后24h（T5）抽血,应用ELISA法检测NF—κB活性及血浆中TNF—α和IL-8水平。结果两组PMNNF—κB活性在CPB开始后逐渐升高,T3时达到峰值,之后逐渐下降,但在T5时点依然高于术前水平;U组在T2、B、T4、rr5时点PMNNF—κB活性均低于C组（P〈0．05）。两组TNF-α和IL-8水平均于手术开始后逐渐升高（P〈0．05）,T3达高峰,之后逐渐下降,在T5时点基本恢复正常;C组TNF—α和IL-8水平在T3、T4时点均显著高于U组（p〈0．05）。U组NF—κB的活性与血浆TNF-仪水平呈正相关,相关系数为0．533（P〈0．05）;NF—κB的活性与血浆IL-8水平亦呈正相关,相关系数为0．528（P〈0．05）。C组NF—κB的活性与血浆TNF—α、IL-8水平亦呈正相关,相关系数分别为0．531、0．512（P〈0．05）。结论乌司他丁可以通过降低CPB患者PMNNF—κB活性进而降低血浆TNF—α和IL-8的表达,抑制体外循环后的炎症反应。