不同途径下MIMP对 炎症性肠病小鼠肠道菌群结构的影响

目的通过葡聚糖硫酸钠诱导小鼠炎症性肠病(IBD)模型并观察不同途经下乳杆菌微小膜蛋白(MIMP)对炎症性肠病小鼠的紧密连接蛋白及菌群结构的影响。方法 C57BL/6小鼠24只根据DSS和MIMP不同干预组合将其分为4组:MIMP腹腔注射组(n=6)、MIMP灌胃组(n=6)、诱导肠炎组(n=6)和健康对照组(n=6),利用Western blot对各组小鼠肠道中紧密连接蛋白(Occludin、JAM-1和ZO-1)的表达进行检测,采用16SrRNA测序技术检测V4区鉴定细菌,并进行菌群差异分析。结果 MIMP腹腔注射及灌胃均可显著提高IBD小鼠肠道中紧密连接蛋白的表达水平,灌胃组效果更为显著;MIMP干预后小鼠肠道中拟杆菌门(Bacteroidetes)丰度增高、厚壁菌门(Firmicutes)及变形菌门(Proteobacteria)丰度降低,LEfSe分析、PCoA分析和PCA分析提示4组小鼠肠道菌群结构差异显著。结论不同途径下MIMP均可显著提高IBD小鼠肠道中紧密连接蛋白的表达水平,改善肠黏膜屏障功能,纠正小鼠肠道菌群结构紊乱。     

不同浓度葡聚糖硫酸钠对小鼠炎症性肠病模型建立及其致病相关免疫因子表达的影响

目的探讨饮用不同浓度的葡聚糖硫酸钠(dextran sulfate sodium,DSS)对于建立小鼠炎症性肠病(inflammatory bowel disease,IBD)模型及其致病相关免疫因子表达的影响。方法雄性C57BL/6J小鼠随机分为对照组和不同浓度的DSS饮用组(3%、5%、7%)。观察小鼠的大便性状,体重和生存时间。饮用后的第6天处死各组小鼠,观察结肠大体形态并评分;取病变处进行石蜡包埋病理切片,苏木素伊红染色并进行病理组织学评分;定量PCR检测各组脾细胞免疫因子表达情况。结果饮用3%、5%、7%浓度DSS的小鼠在第6天均有不同程度溃疡形成,成模率随着DSS浓度提升而增加,但是小鼠死亡率也相应增加。定量PCR结果表明促炎因子(TNF-α、IFN-γ和IL-17A)的表达水平与DSS浓度成正相关,而抑炎因子(IL-4和IL-10)以及调节性T细胞相关的转录因子Foxp3的表达水平与DSS浓度成负相关关系。结论给予小鼠5%浓度的DSS溶液饮用有助于高效经济地建立小鼠IBD模型,为进一步研究IBD的发病机理、生物学特性、干预因素等打下了重要基础。     

特定双歧杆菌菌株对炎症性肠病小鼠的影响

为了观察特定双歧杆菌菌株对葡聚糖硫酸钠(DSS)诱导的Balb/c小鼠结肠炎的影响,探讨该双歧杆菌菌株对炎症性肠病(IBD)的防治作用及其可能机制。将小鼠分为3组:正常对照组、模型组(DSS组)、实验组(DSS+Bf组)。用已挑选好的双歧杆菌菌株预先处理小鼠4周后,用4%DSS溶液诱导急性结肠炎。实验结束后,检测每组小鼠结肠的长度及结肠炎炎症程度,利用半定量RT-PCR法检测小鼠肠道派伊尔结细胞中IL-10的表达,利用免疫组化实验检测肠道黏膜中IL-10分泌阳性细胞。结果实验组小鼠结肠的平均长度为7.80 cm±0.21 cm,虽较正常对照组(9.10 cm±0.82 cm)缩短,但较模型组(6.80 cm±0.31 cm)其缩短程度减少;结肠炎炎症程度肉眼评分结果:模型组和实验组分别为8.60±0.24分和6.60±0.68分,两组之间均有显著性差异(P<0.05),显微镜下评分结果为实验组(6.80±0.73分)较模型组(8.80±0.37分)明显减少(P<0.05);实验组小鼠肠道派伊尔结细胞IL-10的表达和肠道黏膜IL-10分泌阳性细胞数明显多于模型组。该实验所用的双歧杆菌菌株减轻了DSS诱导的小鼠肠道炎症反应,并且增强了肠道免疫细胞的IL-10的表达及分泌。     

构建表达IL 2的大肠埃希菌对小鼠肠炎的影响

目的以Escherichia coli Nissle 1917为基础建立一种与肠道菌群相关的新型白介素2(IL-2)递送方式,研究其对葡聚糖硫酸钠(DSS)诱导的实验性结肠炎的治疗作用。方法将小鼠随机分为4组(每组10只),以正常小鼠作为空白对照组,实验组小鼠用3%的DSS水诱导小鼠结肠炎模型,分别灌胃表达IL-2的菌株(E.coli 1917/IL-2)、空质粒转化的菌株(E.coli 1917/0)或PBS进行治疗5 d,定期评估各组小鼠的临床体征、疾病活动指数(DAI)、病理和免疫组织学变化。结果构建的益生工程菌E.coli 1917/IL-2可有效缓解DSS诱导的小鼠肠炎,小鼠DAI评分较低,体质量及结肠长度均高于对照组,肠黏膜组织中炎症细胞浸润较少。结论使用工程化益生大肠埃希菌编码免疫调节细胞因子的治疗策略为溃疡性结肠炎提供一种潜在的治疗方法。     

马齿苋多糖对溃疡性结肠炎小鼠肠黏膜细胞因子及肠道菌群的影响

目的观察马齿苋多糖对溃疡性结肠炎小鼠肠黏膜细胞因子及肠道菌群的影响。方法应用硫酸葡聚糖钠(DSS)制备溃疡性结肠炎小鼠模型,随机分成2组:正常对照组、模型组,造模成功后模型组再分为自然恢复组、马齿苋多糖治疗组。分别于造模后、给药7 d后处死小鼠,进行肠黏膜细胞因子测定、肠道菌群检测。结果 DSS造模后模型组小鼠肠黏膜细胞因子TNF-а、IL-6升高,IL-10减少;小鼠肠道菌群失调。马齿苋多糖治疗7 d后治疗组小鼠与模型组小鼠比TNF-α、IL-6下降,IL-10增加;肠道双歧杆菌和乳杆菌数量上升。结论马齿苋多糖可以提高抗炎细胞因子IL-10的水平并降低致炎细胞因子TNF-α、IL-6的水平;可以提高双歧杆菌和乳杆菌数量。马齿苋多糖通过抗炎和降低肠道过度的免疫反应以及调节肠道微生态失调,对溃疡性结肠炎发挥治疗作用。     

低聚果糖对溃疡性结肠炎模型小鼠肠黏膜屏障影响的研究

目的探讨低聚果糖对溃疡性结肠炎(UC)模型小鼠肠黏膜屏障的调节作用及可能机制。方法小鼠随机分成3组:正常对照(NC)组、模型(MD)组和低聚果糖(FOS)组,采用葡聚糖硫酸钠制作UC小鼠模型。造模7d同时给予干预治疗,停用造模药物并后续治疗7d。采用细菌定量测定法检测肠道菌群,放射免疫法检测肠黏膜sIgA,ELISA法检测小鼠肠黏膜IL-10、TNF-α和IL-6水平。结果模型组小鼠存在肠道菌群失调(t=2.088,2.036,2.203,2.109,P0.05),其TNF-α、IL-6水平高于正常对照组(t=1.734,1.801,P0.05),肠黏膜sIgA、IL-10低于正常对照组(t=1.820,1.806,P0.05);低聚果糖组肠道菌群失调状况较模型组有所改善,其TNF-α、IL-6水平低于正常对照组(t=1.980,1.816,1.936,1.920,1.969,1.893,P0.05),肠黏膜sIgA、IL-10高于正常对照组(t=1.801,1.796,P0.05)。结论低聚果糖可改善溃疡性结肠炎模型小鼠肠道菌群屏障功能,可以提高肠黏膜sIgA和抗炎细胞因子IL-10的水平并降低致炎细胞因子TNF-α和IL-6的水平,通过调节肠道过度的免疫反应,使免疫屏障功能得到一定恢复。     

二十碳五烯酸和DHA差异抑制上皮间质转化和胶原沉积并缓解肠纤维化

肠纤维化是炎症性肠病(inflammatory bowel disease, IBD)的严重并发症,然而目前尚未找到针对肠纤维化的治疗方案。ω-3 PUFAs在其他器官中的抗纤维化作用已受到广泛关注,但在肠纤维化中的应用潜力仍有待发掘。本研究旨在探究ω-3 PUFAs对肠纤维化的作用及机制。研究采用TNBS(2,4,6-trinitrobenzene sulfonic acid)诱导的肠纤维化小鼠模型,比较EPA、DHA和鱼油对肠纤维化小鼠不同的抗纤维化作用。将40只8周龄雄性BALB/C小鼠随机分为5组。相较于DHA和鱼油组,EPA干预能更有效缓解小鼠体重丢失,减少结肠长度缩短,降低疾病活动指数评分,并显著改善炎症反应(P<0.05)。ELISA法检测发现,EPA抑制促炎细胞因子TNF-α、IL-6和IL-17的表达,促进抗炎细胞因子IL-10的表达。EPA干预显著减轻了小鼠结肠的纤维化程度,下调了结肠中col1a2、col3a2和羟脯氨酸的表达,并且结肠中EPA含量与肠纤维化评分呈负相关(R²=0.7383,P<0.0004;R²     

过表达白细胞介素10的间充质干细胞对炎症性肠病的治疗作用

炎症性肠病(inflammatory bowel disease,IBD)是一种以T细胞浸润至结肠为特征的难治性炎性自身免疫疾病。间充质干细胞 (mesenchymal stem cells,MSCs) 具有免疫抑制能力,在IBD的治疗中具有一定的潜力。但是由于MSCs在体内的免疫调节能力不稳定,所以其治疗效果会受到影响。本研究构建了过表达白细胞介素10(interleukin 10,IL-10)的工程化MSCs,并对其在IBD小鼠模型中的治疗潜力进行评估。MSCs经编码IL-10的慢病毒(lentivirus,LV)转染后,其表型和细胞增殖率均不发生变化。免疫细胞和 MSCs体外共培养的结果表明,与未修饰的MSCs相比,同过表达IL-10的MSCs共培养的免疫细胞中辅助T细胞1(T helper 1 cells,Th1)和辅助T细胞17(T helper 17 cells,Th17)数量显著性降低(P<0.05),同过表达IL-10的MSCs共培养的巨噬细胞细胞培养上清液,TNF-α含量显著性降低(P<0.0001)。右旋糖酐硫酸钠(dextran sodium sulfate,DSS)诱导IBD小鼠模型中,尾静脉注射过表达IL-10的MSCs与注射未修饰MSCs相比,过表达IL-10的MSCs具有更好的治疗效果,结肠长度、疾病活动指数(disease activity index,DAI)和结肠炎性细胞因子表达共同证明这一差异。实验结果均具有统计学差异(P<0.05)。总体而言,经LV转染过表达IL-10的MSCs可能是IBD的一种有希望的替代治疗选择。     

氯化两面针碱对小鼠溃疡性结肠炎的干预作用及其机制*

目的:探讨氯化两面针碱(NC)通过靶向miR-31对葡聚糖硫酸钠(DSS)诱发小鼠结肠炎的保护作用及其机制。方法:用1%DSS诱发小鼠溃疡性结肠炎(UC)。30只雄性C57BL/6小鼠随机分为正常对照组(Control)(n=7),DSS组(n=8),DSS+NC组(7.27 mg/kg)(n=8)和NC组(n=7),饮水给予DSS,灌胃给予氯化两面针碱。造模周期为3周,分别为Control组和NC组每天饮用无菌水,DSS组和DSS+NC组第一周饮用1% DSS水,第2周正常饮水,第3周1% DSS水。造模最后一周给予Control组和DSS组小鼠0.5% 羧甲基纤维素钠(CMC-Na)灌胃,DSS+NC组和NC组给予NC灌胃。造模完成后,观察小鼠结肠炎相关的疾病活动指数(DAI),HE染色进行结肠组织病理评分,qPCR检测小鼠结肠组织miR-31的表达水平,Western blot检测小鼠结肠组织炎症蛋白NF-κB和COX-2的表达情况。结果:①与DSS组相比,DSS+NC组的 DAI 显著降低(P＜0.01),结肠病理损伤明显改善;②与Control组相比,DSS组小鼠结肠组织miR-31表达显著升高(P＜0.01),DSS+NC组miR-31的表达水平显著低于DSS组(P＜0.05);③与DSS组相比,DSS+NC组中的炎症蛋白NF-κB和COX-2表达水平显著下降(P＜0.05)。结论:氯化两面针碱对DSS诱导的小鼠溃疡性结肠炎有明显的治疗作用,其抗炎机制与下调miR-31的表达有关。     

鼠衣原体改善DSS诱导的小鼠溃疡性结肠炎的作用研究

【目的】探讨鼠衣原体(Chlamydia muridarum)对小鼠溃疡性结肠炎的作用。【方法】取15只雌性C57BL/6J小鼠随机分为3组,每组5只动物,分别为空白对照组(Control)、肠炎模型组(DSS)、实验组(CM+DSS)。选取CM+DSS组小鼠予以2×10⁵ IFU的鼠衣原体灌胃处理,并在其感染后第29天开始,给予DSS组和CM+DSS组的小鼠2%DSS饮水,持续5d,每天监测小鼠体重和肠炎疾病评分,实验结束后检测小鼠结肠长度和结肠组织炎性改变。【结果】肠炎模型组的小鼠均表现出典型的肠炎症状(包括体重减轻、肠炎疾病评分、结肠长度和组织炎性改变);而经鼠衣原体预处理的小鼠(CM+DSS组)肠炎症状显著减轻,表现在肠炎疾病评分降低,体重和结肠长度有所恢复,肠组织炎性损伤减轻。【结论】鼠衣原体对DSS诱导的小鼠溃疡性结肠炎具有改善作用。     

Taurine and inflammatory diseases

Taurine (2-aminoethanesulfonic acid) is the most abundant free amino acid in humans and plays an important role in several essential biological processes such as bile acid conjugation, maintenance of calcium homeostasis, osmoregulation and membrane stabilization. Moreover, attenuation of apoptosis and its antioxidant activity seem to be crucial for the cytoprotective effects of taurine. Although these properties are not tissue specific, taurine reaches particularly high concentrations in tissues exposed to elevated levels of oxidants (e.g., inflammatory cells). It suggests that taurine may play an important role in inflammation associated with oxidative stress. Indeed, at the site of inflammation, taurine is known to react with and detoxify hypochlorous acid generated by the neutrophil myeloperoxidase (MPO)–halide system. This reaction results in the formation of less toxic taurine chloramine (TauCl). Both haloamines, TauCl and taurine bromamine (TauBr), the product of taurine reaction with hypobromous acid (HOBr), exert antimicrobial and anti-inflammatory properties. In contrast to a well-documented regulatory role of taurine and taurine haloamines (TauCl, TauBr) in acute inflammation, their role in the pathogenesis of inflammatory diseases is not clear. This review summarizes our current knowledge concerning the role of taurine, TauCl and TauBr in the pathogenesis of inflammatory diseases initiated or propagated by MPO-derived oxidants. The aim of this paper is to show links between inflammation, neutrophils, MPO, oxidative stress and taurine. We will discuss the possible contribution of taurine and taurine haloamines to the pathogenesis of inflammatory diseases, especially in the best studied example of rheumatoid arthritis.     

Evolution of inflammatory diseases

The association of inflammation with modern human diseases (e.g. obesity, cardiovascular disease, type 2 diabetes mellitus, cancer) remains an unsolved mystery of current biology and medicine. Inflammation is a protective response to noxious stimuli that unavoidably occurs at a cost to normal tissue function. This fundamental trade-off between the cost and benefit of the inflammatory response has been optimized over evolutionary time for specific environmental conditions. Rapid change of the human environment due to niche construction outpaces genetic adaptation through natural selection, leading increasingly to a mismatch between the modern environment and selected traits. Consequently, multiple trade-offs that affect human physiology are not optimized to the?modern environment, leading to increased disease susceptibility. Here we examine the inflammatory response from an evolutionary perspective. We discuss unique aspects of the inflammatory response and its evolutionary history that can help explain the association between inflammation and modern human diseases.     

Cytokine-induced inflammatory liver injuries

IL-18 is a pleiotropic cytokine and is produced by various types of cells including activated macrophages, particularly Kupffer cells. IL-18 has potential to activate inflammatory responses through induction of IFN-gamma production in collaboration with IL-12. Somewhat paradoxically, IL-18 also has the capacity to induce allergic responses via induction of IL-4 production by T helper cells and to activate mast cells and basophils to release atopic effector molecules such as histamine. Indeed, IL-18 is involved in inflammatory tissue injuries, such as Crohn's disease and atherosclerosis, and also in hyper IgE and atopic dermatitis. IL-18 is particularly important for induction of experimental liver diseases. Endotoxin-induced liver injury or Fas ligand-induced hepatitis is caused by endogenous IL-18 in mice. Moreover, patients with liver diseases such as fulminant hepatitis, liver cirrhosis due to hepatitis virus infection and primary biliary cirrhosis show elevation of serum levels of IL-18, that correlates with the corresponding disease severity. Therefore, endogenous IL-18 plays a major role in induction of some types of liver injuries in mice and human. NKT cells that express both T cell receptor and NK cell marker are abundant in the liver of mice and human. Recent studies have revealed that NKT cells participate in some types of liver injuries, such as concanavalin A-induced T cell-mediated hepatitis and malaria hepatitis. In this review article, we focus on IL-18-involving liver damages and NKT-cell-mediated liver injuries.     

Macrophage inflammatory protein-1

Macrophage inflammatory protein-1 (MIP-1) and MIP-1β are highly related members of the CC chemokine subfamily. Despite their structural similarities, MIP-1 and MIP-1β show diverging signaling capacities. Depending on the MIP-1 subtype and its NH₂-terminal processing, one or more of the CC chemokine receptors CCR1, CCR2, CCR3 and CCR5 are recognized. Since both human MIP-1 subtypes (LD78 and LD78β) and MIP-1β signal through CCR5, the major co-receptor for M-tropic HIV-1 strains, these chemokines are capable of inhibiting HIV-1 infection in susceptible cells. In this review, different aspects of human and mouse MIP-1 and MIP-1β are discussed, including their protein and gene structures, their regulated production, their receptor usage and biological activities and their role in several pathologies including HIV-1 infection.     

Galectins as inflammatory mediators

Over the last decade a vast amount of reports have shown that galectin-1 and galectin-3 are important mediators of inflammation. In this review we describe how the galectins may be involved in several parts of the inflammatory process, including the recruitment of neutrophils into an infected tissue and the recognition and killing of bacteria by activation of the tissue destructive phagocytic respiratory burst. During bacterial infection or aseptic inflammatory processes, galectins are produced and released by e.g. infected epithelium, activated tissue-resident macrophages and endothelial cells. These extracellular galectins may facilitate binding of neutrophils to the endothelium by cross-linking carbohydrates on the respective cells. Further the galectins improve binding of the neutrophil to the extracellular matrix proteins laminin and fibronectin, and are potential chemotactic factors, inducing migration through the extracellular matrix towards the inflammatory focus. When the cells encounter bacteria, galectin-3 could function as an opsonin, cross-linking bacterial lipopolysaccharide or other carbohydrate-containing surface structures to phagocyte surface glycoconjugates. Both galectin-1 and galectin-3 have the capacity to induce a respiratory burst in neutrophils, provided that the cells have been primed by degranulation and receptor upregulation. The reactive oxygen species produced may be destructive to the invading micro-organisms as well as to the surrounding host tissue, pointing out the possible role of galectins, not only in defence toward infection, but also in inflammatory-induced tissue destruction. Published in 2004.     

炎症复合体与炎症反应

炎症复合体(inflammasome)是胞浆内一组复杂的多蛋白复合体,是胱天蛋白酶(caspase)-1活化所必需的反应平台,调控白介素(interleukin,IL)-1β、IL-18、IL-33等促炎细胞因子的加工及活化,参与天然免疫系统的激活.核苷酸结合寡聚化结构域样受体(nucleotide-binding and oligomerization domain-like receptors,NLRs)是胞浆内重要的模式识别受体,能感知胞内病原微生物产物及代谢性应激,起始炎症复合体的组装,是构成炎症复合体的核心成分.综述了炎症复合体和NLRs研究现状及其在炎症反应中的作用.