葡聚糖硫酸钠诱导小鼠实验性结肠炎的临床和组织病理学特征研究

目的研究葡聚糖硫酸钠(DSS)诱导小鼠实验性结肠炎的临床和病理特征,以便于指导选择合适的溃疡性结肠炎(ulcerative colitis,UC)小鼠模型。方法予3%DSS溶液喂饲野生型C57BL/6成年小鼠诱导急性结肠炎模型,分别于第0天、第3天、第5天、第7天和第10天麻醉处死小鼠,取结肠观察不同时期结肠病理学特征,造模过程中连续观察并记录小鼠体质量、大便和死亡情况。结果小鼠造模第3天开始出现粪便潜血,第5天开始出现血便,第10天开始出现死亡小鼠,死亡率为30%。DSS诱导小鼠急性结肠炎模型疾病活动指数第3天后与饮用纯净水的小鼠比较明显增高(P0.05)。小鼠结肠炎造模第3天黏膜上皮细胞开始逐渐丧失,第7~10天最为严重;隐窝结构的紊乱从第3天开始发生,第7天出现固有层塌陷;炎性细胞浸润从第3天开始数量逐渐增加,第10天最为严重。DSS诱导小鼠急性结肠炎模型结肠组织病理评分第5天后与饮用纯净水的小鼠比较明显增高(P0.05)。结论 3%DSS诱导野生型C57BL/6成年小鼠急性结肠炎模型可用于UC的实验研究,第3天出现明显的炎症表现,第7天模型较理想,小鼠死亡少。     

New approach of medicinal herbs and sulfasalazine mixture on ulcerative colitis induced by dextran sodium sulfate

BACKGROUND Sulfasalazine has been used as a standard-of-care in ulcerative colitis for decades, however, it results in severe adverse symptoms, such as hepatotoxicity, blood disorders, male infertility, and hypospermia. Accordingly, the new treatment strategy has to enhance pharmacological efficacy and stimultaneously minimize side effects.AIM To compare the anti-inflammatory action of sulfasalazine alone or in combination with herbal medicine for ulcerative colitis in a dextran sodium sulfate(DSS)-induced colitis mouse model.METHODS To induce ulcerative colitis, mice received 5% DSS in drinking water for 7 d. Animals were divided into five groups(n = 9 each) for use as normal(non-DSS), DSS controls, DSS + sulfasalazine(30 mg/kg)-treatment experimentals, DSS + sulfasalazine(60 mg/kg)-treatment experimentals, DSS + sulfasalazine(30 mg/kg) + Citrus unshiu peel and Bupleuri radix mixture(30 mg/kg)(SCPB)-treatment experimentals.RESULTS The SCPB treatment showed an outstanding effectiveness in counteracting the ulcerative colitis, as evidenced by reduction in body weight, improvement in crypt morphology, increase in antioxidant defenses, down-regulation of proinflammatory proteins and cytokines, and inhibition of proteins related to apoptosis.CONCLUSION SCPB may represent a promising alternative therapeutic against ulcerative colitis, without inducing adverse effects.     

瑞巴匹特预防葡聚糖硫酸酯钠诱发的小鼠结肠炎疗效观察及作用机制初探

目的近年氧自由基在溃疡性结肠炎(UC)发病过程中作用受到关注,一种新型的黏膜保护剂瑞巴匹特被认为具有清除氧自由基的作用,有望成为治疗溃疡性结肠炎的新药物。本文观察瑞巴匹特灌肠和灌胃治疗葡聚糖硫酸酯钠(DSS)诱发的小鼠结肠炎效果并探讨可能的作用机制。方法 3%DSS予8周龄雄性BALB/c小鼠自由饮用7 d制成小鼠结肠炎模型。予DSS前5 d开始瑞巴匹特(45 mg/kg/d)灌肠或灌胃治疗直到造模结束,处死小鼠取结肠组织,测量小鼠体重、结肠长度,进行大体和病理评分,分光光度法测定髓过氧化物酶、丙二醛含量,免疫组化法测定核因子κB(NFκB)表达水平,RT-PCR法测定过氧化物酶体增殖体激活受体γ(PPARγ)mRNA表达。结果与安慰剂对照组比较,瑞巴匹特灌肠和灌胃治疗组小鼠大体和病理评分显著改善,髓过氧化物酶活性、丙二醛含量、NFκB活性明显降低,PPARγmRNA的表达显著升高。结论瑞巴匹特可有效预防DSS诱发的小鼠结肠炎,其抑制炎症作用至少部分与清除氧自由基,从而维持局部PPARγ表达和抑制NFκB活性有关。     

Oxidative stress and metabolism in animal model of colitis induced by dextran sulfate sodium

BACKGROUND AND AIM: Ulcerative colitis is a chronic inflammatory disease of the gastrointestinal tract. Its etiology remains unclear, but it appears to result from a dysregulated immune response, with infiltration of phagocytic leukocytes into the mucosal interstitium. The production and release of reactive oxygen species by immune cells seems to play a crucial role in physiopathology of colitis. The aim of this work was to evaluate the effects of N-acetylcysteine (NAC) and deferoxamine (DFX) in the treatment of colitis induced by dextran sulfate sodium (DSS). METHODS: The effects of NAC and DRX on rats with DSS-induced colitis were determined by measuring intestinal parameters of oxidative stress and mitochondrial function, inflammatory response and bowel histopathological alterations. RESULTS: DSS increased white blood cells count and NAC and DFX did not prevent this effect. However, DSS increased mitochondrial respiratory chain complex IV in colon of rats and NAC and DFX prevented this alteration. In addition, thiobarbituric acid reactive substances were increased in colon of DSS-treated rats. NAC and DFX, when taken together, prevented this effect. Complex II and succinate dehydrogenase were not affected by DSS, as protein carbonyl content. CONCLUSIONS: It is speculated that NAC and DFX might be useful for treatment of colitis, but further research is necessary to clarify these effects.     

Th17细胞及IL-23在炎症性肠病中的研究进展

炎症性肠病(IBD)是一种病因和发病机制尚不清楚的发生在胃肠道的慢性非特异性炎症性疾病。大量证据表明先天性和获得性免疫系统的异常均对该疾病起着关键性作用。传统观点认为炎症性肠病与Th1细胞和Th2细胞所介导的免疫应答有关;但最新研究指出,体内Th17细胞以及白细胞介素IL-23的存在,与炎症性肠病的发生息息相关。本文对炎症性肠病中Th17细胞及IL-23的研究进展作一综述。     

Immune response in mouse experimental cholangitis associated with colitis induced by dextran sulfate sodium

BACKGROUND AND AIM: Primary sclerosing cholangitis is frequently complicated by inflammatory bowel disease. Although many colitis models have been reported, little information has been obtained about complicated cholangitis. The aim of the present study was to determine whether hepatobiliary disorders occur in mice experimental colitis, and to clarify the underlying mechanisms. METHODS: The CD-1 mice were fed standard chow with or without dextran sulfate sodium in the drinking water, followed by histological examination of the liver and colon. Mononuclear cells were isolated from these organs, and cytokine production was assessed. The CD4/CD8 ratio and the population of natural killer T (NKT) cells were analyzed by flow cytometry. RESULTS: Inflammatory cell infiltration and focal necrosis in the liver were found in 33% of treated mice. In treated mice, the CD4/CD8 ratio increased in the liver, whereas no such change was found in the colon. Also an increase of interferon-gamma and a decrease of interleukin-4 production were observed. The NKT cell population showed transient changes in the liver and colon. CONCLUSIONS: Hepatobiliary disorders were complicated with experimental colitis in CD-1 mice. Immunological findings indicate a T-helper-1-dominant underlying mechanism, and NKT cells may play a pathogenic role in this model. This model may help to elucidate the relationship between hepatic and colonic inflammations.     

Effect of adiponectin on murine colitis induced by dextran sulfate sodium

BACKGROUND & AIMS: Adiponectin, an adipose tissue-derived hormone, exhibits anti-inflammatory properties and has various biological functions, such as increasing insulin sensitivity, reducing hypertension, and suppressing atherosclerosis, liver fibrosis, and tumor growth. The aim of the present study was to determine the effect of adiponectin on intestinal inflammation. METHODS: We investigated the effect of adiponectin on dextran sulfate sodium (DSS)-induced colitis by using adiponectin-knockout (APN-KO) mice and an adenovirus-mediated adiponectin expression system. We also examined the contribution of adiponectin deficiency to trinitrobenzene sulfonic acid (TNBS)-induced colitis. In vitro, we examined the effect of adiponectin on intestinal epithelial cells. RESULTS: After administration of 0.5% DSS for 15 days, APN-KO mice developed much more severe colitis compared with wild-type mice. The messenger RNA expression levels of chemokines were significantly higher in the colonic tissues of DSS-treated APN-KO mice compared with wild-type mice, accompanied by increased cellular infiltration, including macrophages. Adenovirus-mediated supplementation of adiponectin significantly attenuated the severity of colitis, but there were no differences in the severity of TNBS-induced colitis between the 2 groups. Adiponectin receptors were expressed in intestinal epithelial cells, and adiponectin inhibited lipopolysaccharide-induced interleukin-8 production in intestinal epithelial cells. CONCLUSIONS: Adiponectin is protective against DSS-induced murine colitis, probably due to the inhibition of chemokine production in intestinal epithelial cells and the following inflammatory responses, including infiltration of macrophages and release of proinflammatory cytokines.     

Expression of B7 costimulatory molecules by cells infiltrating the colon in experimental colitis induced by oral dextran sulfate sodium in the mouse

BACKGROUND AND AIM: T-cell activation, mediated by the interaction with major histocompatibility complex (MHC)-peptide complexes and B7 costimulatory molecules on antigen-presenting cells, is an essential event in the pathogenesis of inflammatory bowel disease (IBD). We investigated the expression of B7 costimulatory molecules on cells in the colon in an experimental mouse model of IBD to determine whether the B7/ligand interaction could provide a target for therapeutic intervention in IBD. METHODS: Experimental colitis was induced in mice by oral consumption of water substituted with 5% dextran sulfate sodium (DSS). Mice (n=4) were killed 1, 2, 3, 4 and 7 days after commencing DSS consumption, and colonic tissue was collected and examined immunohistochemically for T cells, B cells, macrophages and cells expressing B7-1 or B7-2. RESULTS: Compared to control mice drinking water, macrophage numbers in the colonic epithelium were elevated sevenfold by day 1 and T cells were elevated threefold by day 3 following commencement of DSS consumption. Numbers of infiltrating B7-positive (B7+) cells were not significantly elevated until day 7 when B7-1+, B7-2+ cells and macrophages were increased 20-fold compared to normal mice. CONCLUSION: These results demonstrate that an initial and rapid infiltration of the colonic epithelium by B7-negative macrophages is followed by an infiltration of T cells and subsequent upregulation of the B7 costimulatory molecules potentiating the inflammatory reaction in this disease model. These results suggest an intervention strategy based on the blockade of the B7-costimulatory axis could find application in the treatment of inflammatory bowel disease.     

半夏泻心汤抑制DMH/DSS诱导的结肠炎相关性结肠癌的发生

目的:观察半夏泻心汤对DMH/DSS诱导的结肠炎向结肠癌转变的抑制作用.方法:♂ICR小鼠65只,随机分为正常组、模型组和半夏泻心汤3个剂量(100,200,400 mg/ kg)给药组.采用腹腔注射1,2-二甲肼20 mg/kg及饮用含20 g/L的右旋葡聚糖苷钠复制结肠炎相关的小鼠结肠癌.除模型组20只小鼠,其余30只存活小鼠在出现第二次便血时分别口服给予半夏泻心汤100,200和400 mg/kg进行治疗,1次/d,共11 wk.实验第20周,乙醚麻醉处死小鼠,截取结肠,称重;记录结肠肿瘤数目,取结肠做HE染色:摘取脾脏、胸腺称重.结果:在实验第20周,40%的模型组小鼠出现脱肛,成癌率为85%.半夏泻心汤3个剂量组则未见脱肛小鼠,100 mg/kg组成癌率为20%,200和400 mg/kg成癌率为10%.DMH/DSS诱导的结肠癌小鼠脾脏指数显著升高(6.50±4.08 mg/g vs 4.25±3.39 mg/g,P<0.01),而胸腺指数则明显降低(0.60±0.33 mg/g vs0.71±0.29 mg/g,P<0.05),与对照组相比有显著性差异.半夏泻心汤可明显的对抗结肠癌小鼠胸腺的萎缩(P<0.05),而对脾脏的增大也有明显的治疗作用(P<0.01).病理结果表明,半夏泻心汤成功的将小鼠结肠停留在炎症状态,阻止了结肠炎向结肠癌的转变.结论:半夏泻心汤能够显著地抑制结肠炎向结肠癌的转变,结肠炎的有效治疗是防止结肠癌发生的重要措施.     

Treg/Th17细胞在不同时期慢性阻塞性肺疾病患者中的改变及意义探讨

目的 探讨CD4+ CD25+ CD127low调节性T细胞(Treg细胞)、Th17细胞特异性分泌因子IL-17在COPD急性加重期(AECOPD)及COPD稳定期中的改变及临床意义.方法 选取住院AECOPD患者26例,随访COPD稳定期患者20例,健康对照患者15例.流式细胞仪检测患者外周血CD4+ CD25+ CD1271.wTreg细胞比例、ELISA检测外周血IL-17浓度.结果 ①AECOPD组患者外周血Treg细胞比例较COPD稳定期组、对照组均明显升高[分别为(10.319±2.154)％,(6.406±1.498)％,(6.307±1.626)％;P＜0.05],COPD稳定期组患者Treg细胞比例高于对照组但差异无统计学意义;②A ECO PD组及COPD稳定期组外周血IL-17水平较对照组明显升高[分别为(0.813±0.233) ng/L,(o.547±0.157) ng/L,(0.408±0.169) ng/L;P＜0.001],AECOPD组IL-17水平高于COPD稳定期组(P＜0.01),COPD稳定期组IL-17水平高于对照组(P=0.046);③各组Treg细胞、IL-17水平与各指标之间未见相关性.结论 Treg细胞、IL-17在AECOPD及COPD稳定期中的水平异常说明在COPD的不同时期存在着不同的炎症,Treg/Th17细胞失衡可能导致COPD的免疫紊乱和慢性炎症持续.     

Sodium chloride exacerbates dextran sulfate sodiuminduced colitis by tuning proinflammatory and antiinflammatory lamina propria mononuclear cells through p38/MAPK pathway in mice

AIM To investigate the influence of high salt on dextran sulfate sodium(DSS)-induced colitis in mice and explore the underlying mechanisms of this effect.METHODS DSS and NaC l were used to establish the proinflammatory animal model. We evaluated the colitis severity. Flow cytometry was employed for detecting the frequencies of Th1, macrophages and Tregs in spleen, mesenteric lymph node and lamina propria. The important role of macrophages in the promotion of DSS-induced colitis by NaCl was evaluated by depleting macrophages with clodronate liposomes. Activated peritoneal macrophages and lamina propria mononuclear cells(LPMCs) were stimulated with NaCl, and proteins were detected by western blotting. Cytokines and inflammation genes were analyzed by enzyme-linked immunosorbent assay and RT-PCR, respectively.RESULTS The study findings indicate that NaC l up-regulates the frequencies of CD11b~+ macrophages and CD4~+IFN-γ~+IL-17~+ T cells in lamina propria in DSS-treated mice. CD3~+CD4~+CD25~+Foxp~3+ T cells, which can secrete high levels of IL-10 and TGF-β, increase through feedback in NaCl-and DSS-treated mice. Furthermore, clodronate liposomes pretreatment significantly alleviated DSSinduced colitis, indicating that macrophages play a vital role in NaCl proinflammatory activity. NaCl aggravates peritoneal macrophage inflammation by promoting the expressions of interleukin(IL)-1, IL-6 and mouse inducible nitric oxide synthase. Specifically, high NaCl concentrations promote p38 phosphorylation in lipopolysaccharide-and IFN-γ-activated LPMCs mediated by SGK1. CONCLUSION Proinflammatory macrophages may play an essential role in the onset and development of NaCl-promoted inflammation in DSS-induced colitis. The underlining mechanism involves up-regulation of the p38/MAPK axis.