DSS与TNBS诱导大鼠实验性结肠炎模型的对比研究

背景:鉴于人体实验受到诸多限制,建立、选择合适的动物模型对于溃疡性结肠炎(UC)的研究具有重要意义。目的:比较葡聚糖硫酸钠(DSS)和三硝基苯磺酸(TNBS)诱导的大鼠实验性结肠炎模型的症状和结肠病理改变,以期为UC相关研究动物模型的选择提供参考。方法:予Sprague-Dawley大鼠自由饮用4%DSS 7 d或予100 mg/kg TNBS-50%乙醇单次灌肠建立实验性结肠炎模型,动态评估疾病活动指数(DAI)。分批取模型大鼠全结肠标本,观察不同时点的结肠损伤评分、髓过氧化物酶(MPO)活性等指标。结果:DSS和TNBS模型组DAI最高值分别出现在实验第7天和第2天,其后呈下降趋势,两组造模过程中分别有6只和1只大鼠死亡。DSS模型组结肠炎症持续时间短,损伤轻,停药后病变逐渐好转,18 d时结肠损伤评分和MPO活性分别为0.25±0.50和(0.80±0.33)U/g,与正常对照组相比无明显差异。TNBS模型组结肠炎症持续时间长,损伤重,21 d时结肠损伤评分和MPO活性分别为3.60±0.55和(1.60±0.39)U/g,组织学上呈现慢性炎症特征。结论:DSS和TNBS均可成功诱导大鼠实验性结肠炎模型,后者可体现急性炎症向慢性转化的动态过程,可能更适用于UC治疗相关研究。     

罗格列酮对大鼠溃疡性结肠炎的疗效及其机制

目的观察罗格列酮对大鼠溃疡性结肠炎的疗效并探讨其可能存在的机制。方法应用三硝基苯磺酸(TNB)/乙醇灌肠制备大鼠溃疡性结肠炎模型。实验设正常对照组、模型对照组、阳性药物组(柳氮磺胺吡啶组,100 mg/kg)、罗格列酮给药组(2 mg、4mg、8 mg/kg),每天灌胃给药1次,给药时间从造模后第2天开始至实验结束共8 d,观察大鼠疾病活动指数(DAI)、结肠黏膜损伤指数(CMDI)及组织学评分(HS)。生化法检测大鼠结肠组织髓过氧化物酶(MPO)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)的含量。结果与正常组相比,模型组大鼠DAI、CMDI、HS明显增加(P<0.01),结肠组织MPO活性、MDA水平显著升高(P<0.01),SOD活性下降(P<0.01)。罗格列酮4 mg、8 mg/kg和SASP可不同程度改善DAI、CMDI和HS(P<0.05,P<0.01),降低MPO活性和MDA水平(P<0.01),增加SOD活性(P<0.01)。结论罗格列酮对大鼠溃疡性结肠炎有保护作用,其机制可能与减少脂质氧化,增加清除氧自由基的能力有关。     

葡聚糖硫酸钠自由饮用与定量灌胃诱导小鼠急性结肠炎模型的比较研究

背景：自由饮用葡聚糖硫酸钠（DSS）诱导的鼠类急性结肠炎模型均一性欠佳,动物死亡率较高。目的：评估2%DSS自由饮用或定量灌胃诱导的小鼠急性结肠炎模型模拟人类溃疡性结肠炎（UC）的效果和均一性。方法：予ICR小鼠2%DSS自由饮用或定量灌胃建立急性结肠炎模型,检测并比较正常对照组和两组模型小鼠的症状出现时间和频率、疾病活动指数（DAI）、DSS消耗量、死亡率、结肠长度、结肠损伤大体评分（MACD）、结肠组织病理学表现以及外周血白细胞计数和分类。结果：两组模型小鼠均出现类似人类UC的症状和组织病理学改变,结肠显著短缩,DAI、MACD以及外周血白细胞计数和中性粒细胞百分比显著高于正常对照组。与DSS自由饮用组相比,DSS定量灌胃组小鼠症状出现时间更为一致,症状出现率显著增高,动物死亡率和DSS消耗量显著减低。结论：2%DSS定量灌胃诱导的小鼠急性结肠炎模型能较稳定地模拟人类UC,均一性高,动物死亡率低。     

维生素D_3对结肠炎大鼠肠黏膜Toll样受体4表达的影响

背景:近年我国溃疡性结肠炎(UC)的患病率明显增高,Toll样受体4(TLR4)与UC的发生、发展可能密切相关。目的:探讨维生素D_3对结肠炎模型大鼠肠黏膜TLR4表达的影响。方法:将30只Sprague-Dawley大鼠随机分为正常对照组、模型组和维生素D_3组。模型组和维生素D_3组大鼠给予三硝基苯磺酸(TNBS)灌肠制备结肠炎模型,维生素D_3组给予胆维丁乳灌肠。行HE染色,评估疾病活动指数(DAI)和组织病理学评分,采用免疫组化法检测结肠组织TLR4表达。结果:与正常对照组相比,模型组DAI、组织病理学评分显著增高(P0.05),结肠组织TLR4表达显著增高(P0.05)。给予维生素D_3干预后,DAI、组织病理学评分显著降低(P0.05),TLR4表达显著降低(P0.05)。结论:结肠炎大鼠结肠组织中TLR4高表达,可能与UC发病有关。维生素D_3可通过抑制TLR4表达减轻结肠炎大鼠的肠道炎症反应,从而发挥辅助治疗UC的作用。     

复方血竭制剂对远端型溃疡性结肠炎小鼠肺、肠白介素-6表达的影响

目的:探讨复方血竭制剂对远端型溃疡性结肠炎(ulcerative colitis,UC)小鼠模型肺与肠的保护作用.方法:60只♂BALB/c小鼠随机分成4组(n=15),正常组、葡聚糖硫酸钠(dextran sulfate sodium,DSS)组、复方血竭制剂组、DSS+复方血竭制剂组.全部小鼠适应环境喂养7 d,第8天,正常组、DSS组小鼠予以生理盐水1 mL灌胃,复方血竭制剂组、DSS+复方血竭制剂组小鼠予以复方血竭制剂[0.075 g/(kg·d)]1 mL灌胃,每只小鼠自由觅食,继续喂养10 d.通过疾病活动指数(disease activity index,DAI)评分、结肠组织病理评分(histopathology score,HI)、肺HI评分、苏木精-伊红(hematoxylin-eosin,HE)染色评价炎症严重程度.通过酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA)、免疫组织化学、实时荧光定量PCR(real-time quantitative PCR,RT-QPCR)测定结肠与肺组织中白介素(interleukin,IL)-6炎性因子的表达量.结果:与正常组、复方血竭制剂组比较,DSS组、DSS+复方血竭制剂组小鼠一般情况、DAI评分、结肠HI评分、肺HI评分均升高(P0.05);与DSS+复方血竭制剂组比较,DSS组小鼠结肠与肺组织炎症程度更重(P0.05);且小鼠肺与结肠组织中IL-6表达量显著升高(P0.05).结论:复方血竭制剂可以下调炎性因子IL-6表达量,缓解小鼠实验性UC及UC肺损伤.     

恶唑酮结肠炎小鼠模型的建立

建立合适的动物模型有助于炎症性肠病(IBD)的研究，然而目前尚缺乏类似人类溃疡性结肠炎(UC)的动物模型。目的：建立恶唑酮诱导的小鼠结肠炎模型，并评估其在IBD研究中的价值。方法：予BALB／c小鼠皮肤涂搽0．2ml3％恶唑酮(溶解于100％乙醇中)2次致敏，5天后予0.15ml1％恶唑酮(溶解于50％乙醇中)灌肠。观察小鼠的疾病活动指数(DAI)和病变结肠的组织学改变，并测定髓过氧化物酶(MPO)活性以及肿瘤坏死因子(TNF)-α干扰素(IFN)-γ和白细胞介素(IL)-4的含量。结果：结肠炎模型小鼠的DAI、组织学损伤评分和MPO活性均较对照组有明显改变，病变结肠组织的IL-4含量显著增高，TNF-α和IFN-γ含量则基本正常；结肠炎症可持续2周左右。结论：恶唑酮诱导的结肠炎是一种IL-4介导的2型辅助性T细胞(Th2)型炎症，其组织学特征和炎症分布均类似人类UC。恶唑酮小鼠结肠炎模型可作为研究UC发病机制和评估药物疗效的有益工具。     

趋化因子SLC在小鼠实验性结肠炎中的表达和意义

背景：次级淋巴组织趋化因子（SLC）是一种CC型趋化因子,主要功能为趋化各种淋巴细胞向外周淋巴组织或器官归巢。既往研究发现结肠组织SLC表达增高可能参与了溃疡性结肠炎（UC）的发病。目的：明确SLC在UC中的作用及其作为UC治疗靶点的可能性。方法：24只雌性BALB/c小鼠随机分为对照组、DSS模型组和地塞米松（DXM）治疗组,后两组饮用5% DSS溶液7 d诱导实验性结肠炎以模拟人类UC,DXM治疗组于造模第3 d起腹腔注射DXM 0.4 mg/kg qd×5 d。实验过程中评估疾病活动指数（DAI）。第8 d处死各组小鼠,行结肠大体形态和组织学评分,以免疫组化染色和RT-PCR检测结肠组织SLC表达。结果：对照组结肠组织SLC表达微弱,DSS模型组SLC mRNA和蛋白表达均较对照组显著上调（P〈0.01）,DXM治疗组SLC表达较DSS模型组显著降低（P〈0.01）,伴DAI以及结肠大体形态和组织学评分改善（P〈0.01）。结论：结肠组织SLC表达增高与UC发病有关,针对SLC的靶向治疗可作为UC的治疗选择。     

Met-RANTES干预实验性小鼠溃疡性结肠炎对MIP-3α及其受体CCR6的影响

目的:探讨MIP-3α及其受体CCR6在实验性小鼠溃疡性结肠炎(UC)发病中的作用,并分析Met-RANTES疗效机制.方法:用葡聚糖硫酸钠(DSS)诱导建立结肠炎小鼠模型,观察Met-RANTES对小鼠结肠炎病活动指数(DAI)、大体形态评分(GMS)、结肠组织学病理评分(HPS)的影响:并通过RT-PCR检测其对小鼠结肠组织MIP-3α、CCR6mRNA的表达变化及Western blot和免疫组织化学方法检测其小鼠结肠组织MIP-3α、CCR6的蛋白表达变化.结果:DAI、GMS和HPS在DSS模型组和生理盐水治疗组中高于空白对照组,MIP-3α和CCR6在小鼠溃疡性结肠炎中表达上调,在小鼠空白对照组中不表达或弱阳性表达,差异有统计学意义(P<0.01):与DSS模型组和生理盐水治疗组相比,Met-RANTES治疗组小鼠DAI、GMS和HPS降低,MIP-3α和CCR6表达下调(mRNA:0.21±0.08 vs 1.09±0.08.1.08±0.07;0.25±0.08 vs 1.11±0.07,1.05±0.08,P<0.01:蛋白:0.28±0.08 vs 0.98±0.07,1.05±0.06;0.25±0.07 vs 1.19±0.07.1.15±0.06.P<0.01):生理盐水治疗组小鼠DAI、GMS和HPS 以及MIP-3α和CCR6表达与DSS模型组相比表达无明显差异(P>0.05).结论:MIP-3α与CCR6参与了小鼠UC的发生、发展;Met-RANTES能下调MIP-3α及CCR6的表达,并能减轻炎症损伤;针对MIP-3α或CCR6的靶向治疗可能是UC一种有效的治疗方法.     

小鼠葡聚糖硫酸钠结肠炎模型结肠黏膜中5-羟色胺及其转运蛋白的变化和意义

背景：小鼠葡聚糖硫酸钠（DSS）结肠炎模型的组织学特点与人类溃疡性结肠炎（UC）类似。5-羟色胺（5-HT）是胃肠道重要的神经递质，其在UC中的变化和意义鲜见报道。目的：测定小鼠DSS结肠炎模型结肠黏膜中5-HT和5-HT转运蛋白（SERT）的变化，探讨UC是否与5-HT信号转导失衡有关。方法：36只C57BL／6小鼠随机分为急、慢性DSS结肠炎组和正常对照组，以免疫组化方法检测5-HT和SERT的表达，以免疫荧光技术检测SERT的免疫反应性。结果：与正常对照组相比，急、慢性DSS结肠炎组远段和近段结肠黏膜5-HT平均灰度值显著降低（含量增加，P〈0．05），远段结肠黏膜SERT平均灰度值显著增高（含量降低，P〈0．05）。正常对照组、慢性和急性DSS结肠炎组结肠黏膜依次发出耀眼、明亮和微弱的黄绿色荧光，提示DSS结肠炎组SERT免疫反应性减弱。结论：DSS诱导的结肠炎促使小鼠结肠黏膜中5-HT含量和SERT的表达发生变化，5-HT和SERT可能参与了UC发生的病理生理机制。     

高迁移率族蛋白B1抗体对结肠炎小鼠结肠黏膜的保护作用

背景:我国溃疡性结肠炎(UC)发病率明显上升,但目前尚无满意的治疗方法,因此研究其发病机制并寻求新的治疗途径具有重要意义。目的:研究高迁移率族蛋白B1(HMGB1)抗体对结肠炎小鼠结肠黏膜的影响。方法:36只BALB/c小鼠随机分为正常对照组、结肠炎模型组和HMGB1抗体治疗组,后两组以3%葡聚糖硫酸钠(DSS)制备小鼠结肠炎模型,HMGB1抗体治疗组小鼠腹腔注射HMGB1抗体。实验第7d,处死小鼠。行结肠组织学评分,测定结肠通透性,分别以RT-PCR和蛋白质印迹法检测结肠组织HMGB1 mRNA和蛋白表达。结果:与正常对照组相比,结肠炎模型组小鼠结肠组织学评分、结肠通透性以及HMGB1 mRNA和蛋白表达显著增高(P0.05)。与结肠炎模型组相比,HMGB1抗体治疗组小鼠结肠组织学评分、结肠通透性和HMGB1蛋白表达显著降低(P0.05)。结论:HMGB1参与了结肠炎小鼠的炎症反应过程,HMGB1抗体可有效抑制结肠炎小鼠结肠组织HMGB1表达,改善肠黏膜屏障功能,从而对UC结肠黏膜损伤起有明显保护作用。     

The Role of Zinc and Metallothionein in the Dextran Sulfate Sodium-Induced Colitis Mouse Model

Zinc (Zn) and its binding protein metallothionien (MT) have been proposed to suppress the disease activity in ulcerative colitis. To determine the role of Zn and MT in the dextran sulfate sodium (DSS)-induced model of colitis in mice, a DSS dose-response study was conducted in male C57BL/6 wild-type (MT+/+) and MT-null (MT−/−) mice by supplementing 2%, 3%, and 4% DSS in the drinking water for 6 days. In the intervention study, colitis was induced with 2% DSS, Zn (24 mg/ml as ZnO) was gavaged (0.1 ml) daily, concurrent with DSS administration, and the disease activity index (DAI) was scored daily. Histology, MT levels, and myeloperoxidase (MPO) activity were determined. DAI was increased (P<0.05) by 16% and 21% with 3% and 4% concentrations of DSS, respectively, compared to 2%, evident after 5 days of DSS administration. MPO activity was increased in MT+/+ compared to MT−/− mice and those receiving DSS. Zn administration had a 50% (P<0.05) lower DAI compared to DSS alone. Zn partially prevented the distal colon of MT+/+ by 47% from DSS-induced damage compared to MT−/− mice. MT did not prevent DSS-induced colitis and Zn was partially effective in amelioration of DSS-induced colitis.     

Polaprezinc (N-(3-aminopropionyl)-L-histidinato zinc) ameliorates dextran sulfate sodium-induced colitis in mice

OBJECTIVE: Polaprezinc (N-(3-Aminopropionyl)-L-histidinato zinc), an anti-ulcer drug, has been reported to have an anti-inflammatory action in several inflammatory diseases. The aim of this study was to investigate the effect of polaprezinc on dextran sulfate (DSS)-induced colitis in mice. MATERIAL AND METHODS: Mice with colitis induced by DSS were intrarectally treated with polaprezinc (15 mg/kg) or zinc sulfate (7.5 mg/kg) every day after the administration of DSS for 7 days. Disease activity index (DAI) and histological tissue damage were assessed. Levels of myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma in the colon were measured. Expression of heat shock protein (HSP) 25 and HSP70 in the colon was analyzed by Western blot analysis. RESULTS: DAI and histological scores were remarkably reduced in polaprezinc-treated mice with DSS-induced colitis. Polaprezinc suppressed the increase of MPO activity and the production of TNF-alpha and IFN-gamma in the colon tissues of mice with DSS-induced colitis. Expression of HSP25 and HSP70 was remarkably up-regulated in the colon tissues of polaprezinc-treated mice during DSS treatment. CONCLUSIONS: Polaprezinc suppresses DSS-induced colitis in mice, partly through inhibition of production of pro-inflammatory cytokine, suppression of neutrophils accumulation and cytoprotection by overexpression of HSPs. Polaprezinc could be useful in the treatment of inflammatory bowel diseases.     

益生菌对实验性结肠炎大鼠肠黏膜TLR2、TLR4表达及NF-κB活性的影响

目的通过检测益生菌对实验性结肠炎大鼠肠黏膜上皮细胞(IECs)Toll样受体(Toll Like recefor,TLR)、TLR4表达及肠黏膜核因子,kappa B活化的影响,探讨益生菌预防与辅助治疗溃疡性结肠炎的作用机制。方法将30只雄性SD大鼠随机分为3组,即正常对照组(N)、模型组(M)、益生菌组(P)。正常对照组正常饲养,不予任何处理;模型组给予含5%葡聚糖硫酸钠dextransulfate sodium的饮用水10 d建立亚急性结肠炎模型,第11 d开始常规饲养观察2周;益生菌组则在建立模型后给予双歧三联活菌500 mg.kg-1.d-1灌胃,1次/d,共2周;2周后处死所有大鼠,观察疾病活动指数(DAI),进行组织学评分(HPS)和分离ICEs并提取ICE中的总RNA,用RT-PCR法检测TLR2、TLR4的表达;采用免疫组织化学方法检测NF-κB的活性情况。结果益生菌组的症状、组织损害程度均较模型组明显减轻;模型组和益生菌组TLR2和TLR4的表达均明显高于正常对照组(P<0.001);与模型组比较,益生菌组TLR2的表达增加(P<0.05),而TLR4的表达则明显下降(P<0.001);模型组NF-κB活性明显高于益生菌组和正常对照组(P<0.001),益生菌组与正常对照组NF-κB活性比较差异无统计学意义(P>0.05)。结论益生菌通过促使TLR2表达进一步增加,并可抑制TLR4的表达,进而控制NF-κB的活性,并在缓解肠道炎症中发挥作用。     

The Effect of Restraint Stress on the Normal Colon and on Intestinal Inflammation in a Model of Experimental Colitis

Stress may induce development of inflammation in animal models of colitis. The effects of restraint stress on oxidative damage and on antioxidants in the normal colonic mucosa were studied. The effect of stress on the severity of indicators of inflammation, as well as the importance of mucosal substance P (SP) as a mediator of this effect were investigated in the TNBS-colitis model. Restraint stress significantly increased malondialdehyde levels and reduced levels of low-molecular-weight-antioxidants in the normal colon. ATP and the mucosal “energy charge” decreased substantially with chronic stress. Chronic stress worsened the extent of inflammation in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. Mucosal SP content was not affected by exposure to chronic stress but increased after induction of colitis. The increase was greater when colitis was induced after exposure to stress. We conclude that chronic restraint stress causes oxidative damage to the normal colon and aggravates intestinal inflammation induced by TNBS. This effect may be mediated by SP. E. Israeli and T. Hershcovici contributed equally to this work.     

复方甘草酸苷对小鼠实验性结肠炎NF-κB、STAT3信号转导通路的影响

背景：溃疡性结肠炎（UC）的病因、发病机制不明,且缺乏有效治愈手段.对相关信号转导通路的研究有助于了解药物干预的作用机制.目的：观察复方甘草酸苷对小鼠实验性结肠炎的治疗作用及其对NF-κB、STAT3信号转导通路的影响.方法：40只健康昆明小鼠随机分为四组,一组为正常对照组,另三组以噁唑酮诱导实验性结肠炎,随后分别腹腔注射0.9%NaCl溶液（模型对照组）、复方甘草酸苷（甘草酸苷组）或予柳氮磺砒啶（SASP）灌胃（SASP组）7 d.观察各组小鼠疾病活动指数（DAI）、结肠组织大体和组织学损伤评分以及髓过氧化物酶（MP0）活性,蛋白质印记法检测结肠黏膜NF-κB、STAT3活化水平.结果：模型对照组DAI、大体和组织学损伤评分、MP0活性以及结肠黏膜固有层单个核细胞中活化NF-κB p65、STAT3的表达均显著高于正常对照组（P＜0.05）,甘草酸苷组和SASP组则较模型对照组显著降低（P＜0.05）,甘草酸苷组与SASP组间仅DAI和组织学损伤评分有显著差异（P＜0.05）.结论：复方甘草酸苷能有效改善小鼠实验性结肠炎的炎症活动水平,其作用机制可能与下调NF-κB、STAT3信号转导通路有关.     

Vanilloid receptor-1 containing primary sensory neurones mediate dextran sulphate sodium induced colitis in rats

BACKGROUND AND AIMS: The role of sensory neurones in colitis was studied by chemical denervation of primary sensory neurones as well as antagonism of the vanilloid receptor-1 (VR-1) in rats prior to administration of dextran sulphate sodium (DSS) to induce colitis. METHODS: Neonatal rats were chemically denervated by subcutaneous administration of capsaicin; controls received capsaicin vehicle only. When animals reached maturity, colitis was induced by administration of 5% DSS in drinking water for seven days. Additionally, normal adult rats were treated with a VR-1 antagonist capsazepine (CPZ) or vehicle twice daily via an enema from day 0 to day 6 of the DSS regimen. Control rats were treated with an enema infusion of vehicle and 5% DSS, or without either an enema infusion or DSS in drinking water. For both groups of rats, severity of inflammation was quantitated by disease activity index (DAI), myeloperoxidase (MPO) activity, and histological examination. RESULTS: DSS induced active colitis in all control rats with resultant epithelial ulceration, crypt shortening, and neutrophil infiltration. Both neonatal capsaicinised rats and normal adult rats treated with CPZ enemas exhibited significantly lower levels of DAI, MPO, and histological damage compared with vehicle treated rats (p< 0.05). CONCLUSIONS: Neonatal capsaicinisation and local administration of CPZ prevents intestinal inflammation in a well established model of colitis indicating that primary sensory neurones possessing VR-1 receptors are required in the propagation of colonic inflammation.     

Toll-like receptor 2 monoclonal antibody or/and Toll-like receptor 4 monoclonal antibody increase counts of Lactobacilli and Bifidobacteria in dextran sulfate sodium-induced colitis in mice

Background and Aim: The accurate pathogenesis of ulcerative colitis (UC) is not yet well understood. Recently, Toll‐like receptor 2 (TLR2), TLR4 and gut microbial flora have been proved as playing important roles in the process of UC. This study was to evaluate the effect of TLR2 and TLR4 monoclonal antibodies on gut microbial flora in dextran sulfate sodium (DSS)‐induced colitis in a mouse model. Methods: We evaluated the effects of the TLR2 and TLR4 monoclonal antibodies on the development of DSS‐induced colitis. Clinical symptoms were evaluated by the disease activity index (DAI), while tissue samples were evaluated by histological scoring (HS). Meanwhile, the mucosal mRNA expressions of TLR2, TLR4, interferon‐γ (IFN‐γ), interleukin‐4 (IL‐4) and IL‐17 were analyzed by Realtime polymerase chain reaction (PCR). The mucosal protein TRAF6, TAB1, P‐IKK, P‐P38α mitogen‐activated protein kinase (MAPL) and c‐jun expressions of the TLR2 and TLR4 signaling pathways were analyzed using Western blot. The mucosal nuclear factor kappa B (NF‐κB) was analyzed using electrophoretic mobility shift assay. Fecal samples were obtained directly from the cecum for microbiological studies. Results: Expressions of TLR2 and TLR4 in colonic epithelial cells on DSS‐induced colitis were much higher than normal ones. After the treatment with TLR2mAb and TLR4mAb, DAI and HS were decreased significantly. The UC model group showed a conspicuous increase of Escherichia coli and decreases of Lactobacillus spp. and Bifidobacterium spp. After being treated with TLR2mAb or/and TLR4mAb, Lactobacillus spp. and Bifidobacterium spp. increased to the normal level. Conclusions: TLR2mAb and TLR4mAb can suppress the development of DSS‐induced colitis and increase counts of Lactobacilli and Bifidobacteria.     

MUC Genes Are Differently Expressed During Onset and Maintenance of Inflammation in Dextran Sodium Sulfate-Treated Mice

Colonic mucosal protection is provided by mucous gel, mainly composed of secreted (Muc2) and membrane-bound (Muc1, Muc3, Muc4) mucins. Our aim was to determine the expression profile of secreted and membrane-bound mucins in experimental dextran sulfate sodium (DSS)-induced colitis. Acute colitis was induced in Balb/C mice by oral administration of 1.0% DSS (5 days) and chronic colitis was maintained by subsequent 0.15% DSS treatment (28 days). Clinical symptoms (mortality, weight gain), stool scores, and MPO activity confirmed the inflammatory state in the two phases of colitis. Muc2 gene expression was not modified by colitis, whereas Muc3 gene expression was increased (×2) only in the cecum and the distal colon of mice after acute colitis. Muc1 and Muc4 mRNA levels were more significantly increased in the cecum (×8–10) than in colonic segments (×4) after acute colitis. TFF3 involved in mucosal repair was up-regulated during colitis induction. These results indicate that Muc and TFF3 genes are regulated early in inflammation and suggest that their mRNA levels could be used as early markers of inflammation.     

A recombinant cystatin from Ascaris lumbricoides attenuates inflammation of DSS‐induced colitis

Helminthiasis may ameliorate inflammatory diseases, such as inflammatory bowel disease and asthma. Information about immunomodulators from Ascaris lumbricoides is scarce, but could be important considering the co‐evolutionary relationships between helminths and humans. We evaluated the immunomodulatory effects of a recombinant cystatin from A. lumbricoides on an acute model of dextran sodium sulphate (DSS)‐induced colitis in mice. From an A. lumbricoides cDNA library, we obtained a recombinant cystatin (rAl‐CPI). Protease activity inhibition was demonstrated on cathepsin B and papain. Immunomodulatory effects were evaluated at two intraperitoneal doses (0.5 and 0.25 μg/G) on mice with DSS‐induced colitis. Body weight, colon length, Disease Activity Index (DAI), histological inflammation score, myeloperoxidase (MPO) activity, gene expression of cytokines and cytokines levels in colon tissue were analysed. Treatment with rAl‐CPI significantly reduced DAI, MPO activity and inflammation score without toxic effects. Also, IL‐10 and TGF‐B gene overexpression was observed in rAl‐CPI‐treated group compared to DSS‐exposed control and healthy mice. Furthermore, a reduction in IL‐6 and TNF‐A expression was found, and this was confirmed by the levels of these cytokines in colonic tissue. In conclusion, rAl‐CPI reduces inflammation in a mouse model of DSS‐induced colitis, probably by increasing the expression of anti‐inflammatory cytokines and reducing pro‐inflammatory ones.