Treatment with IL-27 attenuates experimental colitis through the suppression of the development of IL-17-producing T helper cells

Inflammatory bowel disease (IBD) represents a group of chronic inflammatory diseases characterized by inflammation and relapsing gastrointestinal disorders. Recent studies have shown that Th17 cells, which are well known as key mediators of chronic inflammation, have a pivotal role in onset and development of IBD in humans and mice, alike. In recent years, it has been reported that IL-27, which is an IL-12-related heterodimeric cytokine consisting of EBI3 and p28 subunits, act directly on naive T cells to suppress the differentiation of Th17 cells. However, effects of exogenous IL-27 on the IBD are not well elucidated. To clarify the suppressive effect of IL-27 treatment on IBD, we applied the flexible linking method to EBI3 and p28 subunits and generated a single-chain human IL-27 (scIL-27). scIL-27 inhibited xenogenic mouse Th17 cell differentiation in vitro, indicating that scIL-27 also acts in mouse immune systems. In a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse acute colitis model, subcutaneous scIL-27 treatment significantly improved the colon length, extent of necrosis, and ulceration and thickened epithelium and several pathological scores in a dose-dependent manner. scIL-27 clearly suppressed several inflammatory cytokines, including IL-17, in inflamed colon, except for anti-inflammatory cytokine IL-10. The mesenteric lymph node cells from scIL-27-treated mice also exhibited a reduced inflammatory response and, furthermore, a lower population of Th17 cells than those of PBS-treated mice. Finally, we showed the therapeutic efficacy of scIL-27 on TNBS-induced colitis even after active colitis was established. These results suggest new possible therapeutic approaches for IBD, including disorders such as Crohn's disease and ulcerative colitis.     

益生菌对炎症性肠病幼鼠 Th17细胞的调节作用

目的观察鼠李糖乳杆菌(LGG)对炎症性肠病(IBD)幼鼠结肠白细胞介素-17A (IL-17A)水平的影响,探讨益生菌对Th17细胞的调节作用。方法 36只健康雄性SD幼鼠随机分4组:空白对照组、LGG对照组各8只,IBD组、IBD-LGG组各10只。利用2,4,6-三硝基苯磺酸(TNBS)诱导幼鼠IBD模型,观察一般状况、IBD疾病活动指数评分。第8天处死所有幼鼠,留取结肠标本,观察病理改变并采用免疫组织化学法测定结肠组织IL-17A的表达。结果相比两对照组,IBD组、IBD-LGG组幼鼠一般状态差,IBD-LGG组便性状及隐血较IBD组缓解;IBD组、IBD-LGG组幼鼠结肠组织均见炎症改变,但IBD-LGG组较轻。IBD-LGG组DAI评分、IL-17A水平均低于IBD组,差异有统计学意义(Ps0.05)。结论益生菌可减轻IBD幼鼠肠道炎症,其机制可能与益生菌调节Th17细胞进而调控IL-17A表达有关。     

Therapeutic effects of novel sphingosine-1-phosphate receptor agonist W-061 in murine DSS colitis

Although IL-17 is a pro-inflammatory cytokine reportedly involved in various autoimmune inflammatory disorders, its role remains unclear in murine models of colitis. Acute colitis was induced by 2.5% dextran sodium sulfate (DSS) treatment for 5 days. A novel sphingosine-1-phosphate receptor agonist W-061, a prototype of ONO-4641, was orally administered daily, and histopathological analysis was performed on the colon. The number of lymphocytes and their cytokine production were also evaluated in spleen, mesenteric lymph node, Peyer's patch and lamina propria of the colon. Daily administration of W-061 resulted in improvement of DSS-induced colitis, and significantly reduced the number of CD4+ T cells in the colonic lamina propria. Numbers of both Th17 and Th1 cells were reduced by W-061 treatment. W-061, however, had no influence on the number of Treg cells in lamina propria. Thus, Th17 and Th1 cells in lamina propria were thought to be the key subsets in the pathogenesis of DSS-induced colitis. In conclusion, W-061 may be a novel therapeutic strategy to ameliorate acute aggravation of inflammatory bowel diseases.     

白藜芦醇抑制肠癌细胞焦亡的作用*

目的: 研究白藜芦醇(Res)对肠癌细胞焦亡的影响。方法: ①葡聚糖硫酸钠(DSS)诱发小鼠结肠癌(CRC)实验:30只C57BL/6小鼠随机分为正常对照组(Contro组),氧化偶氮甲烷(AOM)组,AOM/DSS组,AOM/DSS+Res组和Res组,每组6只,造模周期共70 d。第1周第1日对AOM组、AOM/DSS组和AOM/DSS+Res组小鼠AOM(10 mg/kg)腹腔注射一次,无菌水饮水,1% DSS水供AOM/DSS组和AOM/DSS+Res组饮用,对AOM/DSS+Res组和Res组小鼠灌胃给予Res(50 mg/kg),造模结束后,取小鼠结肠组织固定、包埋、切片; IHC和Western blot检测小鼠结肠组织NLRP3、Caspase-1、IL-18蛋白表达情况。②离体实验:HCT 116细胞给予Res(2.4 μg/L)以及转染miR-31,加Res实验分为4组,分别标记0 h、12 h、24 h、48 h组;细胞转染分组为5组,即control组、miR-31 mimic组、miR-31 mimic+Res组、miR-31inhibitor组、miR-31inhibitor+Res组,48 h后收集细胞,每组设置三个复孔,并通过Western blot检测细胞NLRP3、Caspase-1、GSDMD-N、IL-18和IL-1β蛋白表达情况。结果: 动物实验:与control组相比较,AOM/DSS组NLRP3、Caspase-1、IL-18蛋白表达显著升高(P<0.01),AOM/DSS+Res组NLRP3、Caspase-1、IL-18蛋白表达水平相较于AOM/DSS组有显著下降(P<0.01);细胞实验:与control组相比,miR-31 mimic组NLRP3(P<0.01)、GSDMD-N(P<0.05)、IL-18(P<0.01)蛋白表达显著升高, miR-31 inhibitor组NLRP3、GSDMD-N、IL-18蛋白表达显著降低(P<0.05)。结论: Res可通过细胞焦亡抑制结肠癌。     

细胞粘附分子CHL1缺失对炎症性肠病的影响

目的：探讨细胞粘附分子CHL1缺失对炎症性肠病（IBD）的影响。方法：采用葡聚糖硫酸钠（DSS）建立CHL1（-/-）炎症性肠病小鼠模型,将10只C57/BL6为遗传背景的CHL1（+/+）型小鼠分为对照组、DSS模型组（n=5）;将10只C57/BL6为背景的CHL （-/-）型小鼠分为CHL1缺失组、CHL1缺失DSS模型组（n=5）。DSS模型组和CHL1缺失DSS模型组自主饮用7 d含1.5% DSS蒸馏水,随后改用蒸馏水饲喂2 d;对照组和CHL1缺失组连续饮用蒸馏水9 d,观察小鼠体重、血便、生存率及结肠组织长度的变化。结果：CHL1缺失DSS模型组小鼠在炎症性肠病的发生中便血明显,从应激的第7天开始,体重明显减轻,在第9天,CHL1缺失DSS模型组型小鼠死亡率明显增加;结肠长度明显缩短,损伤加重。结论：细胞粘附分子CHL1缺失加重炎症性肠病的发生。     

Interleukin-1beta targets interleukin-6 in progressing dextran sulfate sodium-induced experimental colitis

Inflammatory bowel disease (IBD) is an immunologically mediated disorder that is characterized by chronic, relapsing, and inflammatory responses. Dextran sulfate sodium (DSS)-induced experimental colitis in mice has been recognized as a useful model for human IBD and interleukin (IL)-1beta is a key cytokine in the onset of IBD. The purpose of the present study was to clarify which pro-inflammatory mediators are targeted by IL-1beta in mice with DSS-induced colitis. First, we found that DSS markedly induced IL-1beta production in both dose- and time-dependent manners (P < 0.05 and P < 0.01, respectively) in murine peritoneal macrophages (pMphi), while that of tumor necrosis factor-alpha was insignificant. Further, the expressions of mRNA and protein for IL-1beta were increased in colonic mucosa and pMphi from mice that received drinking water containing 5% DSS for 7 days (P < 0.01, each). In addition, the expressions of IL-6, granulocyte macrophage-colony stimulating factor, inducible nitric oxide synthase, and cyclooxygenase-2 mRNA were also time dependently increased (P < 0.01, each). Furthermore, administration of rIL-1beta (10 microg/kg, i.p.) significantly induced the expressions of IL-1beta and IL-6 mRNA in colonic mucosa from non-treated mice (P < 0.01). Anti-mIL-1beta antibody treatments (50 microg/kg, i.p.) attenuated DSS-induced body weight reduction and shortening of the colorectum (P < 0.05, each), and abrogated the expressions of IL-1beta and IL-6 mRNA in colonic mucosa (P < 0.01, each). Our results evidently support the previous findings that IL-1beta is involved in the development of DSS-induced experimental colitis in mice, and strongly suggest that IL-1beta targets itself and IL-6 for progressing colonic inflammation.     

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。     

Anthocyanin-containing purple potatoes ameliorate DSS-induced colitis in mice

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately three million people suffer from IBD in the United States alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study evaluated the antiinflammatory potential of purple-fleshed potato using a dextran sodium sulfate (DSS) murine model of colitis. Mice were randomly assigned to control (AIN-93G diet), P15 (15% purple-fleshed potato diet) and P25 (25% purple-fleshed potato diet) groups. Colitis was induced by 2% DSS administration in drinking water for six days. The results indicated that purple-fleshed potato supplementation suppressed the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weights. P15 and P25 diets suppressed the elevation in the intestinal permeability, colonic MPO activity, mRNA expression and protein levels of pro-inflammatory interleukins IL-6 and IL-17, the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae, Escherichia coli (E. coli) and pks⁺ E. coli, and the increased flagellin levels induced by DSS treatment. P25 alone suppressed the elevated systemic MPO levels in DSS-exposed mice, and elevated the relative abundance of Akkermansia muciniphila (A. muciniphila) as well as attenuated colonic mRNA expression level of IL-17 and the protein levels of IL-6 and IL-1β. Therefore, the purple-fleshed potato has the potential to aid in the amelioration of UC symptoms.     

Fatty Acid Synthase Inhibitor C75 Ameliorates Experimental Colitis

Abnormalities of lipid metabolism through overexpression of fatty acid synthase (FASN), which catalyzes the formation of long-chain fatty acids, are associated with the development of inflammatory bowel disease (IBD). C75 is a synthetic α-methylene-γ-butyrolactone compound that inhibits FASN activity. We hypothesized that C75 treatment could effectively reduce the severity of experimental colitis. Male C57BL/6 mice were fed 4% dextran sodium sulfate (DSS) for 7 d. C75 (5 mg/kg body weight) or dimethyl sulfoxide (DMSO) (vehicle) was administered intraperitoneally from d 2 to 6. Clinical parameters were monitored daily. Mice were euthanized on d 8 for histological evaluation and measurements of colon length, chemokine, cytokine and inflammatory mediator expression. C75 significantly reduced body weight loss from 23% to 15% on d 8, compared with the vehicle group. The fecal bleeding, diarrhea and colon histological damage scores in the C75-treated group were significantly lower than scores in the vehicle animals. Colon shortening was significantly improved after C75 treatment. C75 protected colon tissues from DSS-induced apoptosis by inhibiting caspase-3 activity. Macrophage inflammatory protein 2, keratinocyte-derived chemokine, myeloperoxidase activity and proinflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1β and IL-6) in the colon were significantly downregulated in the C75-treated group, compared with the vehicle group. Treatment with C75 in colitis mice inhibited the elevation of FASN, cyclooxygenase-2 and inducible nitric oxide synthase expression as well as IκB degradation in colon tissues. C75 administration alleviates the severity of colon damage and inhibits the activation of inflammatory pathways in DSS-induced colitis. Thus, inhibition of FASN may represent an attractive therapeutic potential for treating IBD.     

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。     

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。     

Involvement of IL-17A in the pathogenesis of DSS-induced colitis in mice

To investigate the etiological implication of IL-17A in inflammatory bowel disease (IBD), dextran sodium sulfate (DSS) was administered to the mice deficient for the IL-17A gene. They showed only faint manifestations of colitis, as revealed by body weight loss, shrinkage in the colon length, serum haptoglobin concentration, and disease activity index. Although the mortality rate of WT mice reached approximately 60%, more than 90% of the IL-17A KO mice survived the DSS treatment. Histological change was also marginal in the IL-17A KO intestine, in which epithelial damage and inflammatory infiltrates were not obvious and the myeloperoxidase activity elevated only slightly. G-CSF and MCP-1 were abundantly produced in WT mouse intestine, whereas the production of these chemokines was drastically hampered in IL-17A-null intestine. The present results show that IL-17A plays a pivotal role in the pathogenesis of DSS-induced colitis, while MCP-1 and G-CSF may be crucially involved in the IL-17A-induced inflammation.     

Excretory/Secretory Products from Trichinella spiralis Adult Worms Ameliorate DSS-Induced Colitis in Mice

Background

Many evidences show the inverse correlation between helminth infection and allergic or autoimmune diseases. Identification and characterization of the active helminth-derived products responsible for the beneficial effects on allergic or inflammatory diseases will provide another feasible approach to treat these diseases.

Methods and Findings

Colitis was induced in C57BL/6 mice by giving 3% DSS orally for 7 days. During this period, the mice were treated daily with the excretory/secretory products from T. spiralis adult worms (AES) intraperitoneally. The severity of colitis was monitored by measuring body weight, stool consistency or bleeding, colon length and inflammation. To determine the T. spiralis AES product-induced immunological response, Th1, Th2, Th17 and regulatory cytokine profiles were measured in lymphocytes isolated from colon, mesenteric lymph nodes (MLN), and the spleen of treated mice. The CD4⁺ CD25⁺ FOXP3⁺ regulatory T cells (Tregs) were also measured in the spleens and MLN of treated mice. Mice treated with AES significantly ameliorated the severity of the DSS-induced colitis indicated by the reduced disease manifestations, improved macroscopic and microscopic inflammation correlated with the up-regulation of Treg response (increased regulatory cytokines IL-10, TGF-beta and regulatory T cells) and down-regulation of pro-inflammatory cytokines (IFN-gamma, IL-6 and IL-17) in the spleens, MLN and colon of treated mice.

Conclusions

Our results provide direct evidences that T. spiralis AES have a therapeutic potential for alleviating inflammatory colitis in mice. This effect is possibly mediated by the immunomodulation of regulatory T cells to produce regulatory and anti-inflammatory cytokines and inhibit pro-inflammatory cytokines.     

Overexpression of GATA-3 in T Cells Accelerates Dextran Sulfate Sodium-Induced Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease, and its pathogenesis includes genetic, environmental, and immunological factors, such as T helper cells and their secreted cytokines. T helper cells are classified as Th1, Th2, and Th17 cells. However, it is unclear which T helper cells are important in UC. Dextran sulfate sodium (DSS)-induced colitis is a commonly used model of UC. In this study, we induced DSS colitis in Th1 dominant (T-bet transgenic (Tg)) mice, Th2 dominant (GATA-3 Tg) mice, and Th17 dominant (RORγt Tg) mice to elucidate the roles of T helper cell in DSS colitis. The results showed that GATA-3 Tg mice developed the most severe DSS colitis compared with the other groups. GATA-3 Tg mice showed a significant decreased in weight from day 1 to day 7, and an increased high score for the disease activity index compared with the other groups. Furthermore, GATA-3 Tg mice developed many ulcers in the colon, and many neutrophils and macrophages were detected on day 4 after DSS treatment. Measurement of GATA-3-induced cytokines demonstrated that IL-13 was highly expressed in the colon from DSS-induced GATA-3 Tg mice. In conclusion, GATA-3 overexpression in T-cells and IL-13 might play important roles in the development of DSS colitis.     

Interleukin-23: immunological roles and clinical implications

Increasing evidence has revealed the importance of IL-23, which closely resembles IL-12 both structurally and immunologically, in linking innate and adaptive immunity. IL-23, produced by activated type 1 macrophages and dendritic cells (DC), possesses unique roles in the differentiation and expansion of memory T cells. IL-23 has been associated with several inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease (IBD) and Helicobacter pylori associated gastritis, mainly due to its capacity to induce a strong Th1 type immune response. IL-23 is also associated with Th17 responses and the cytokine produced by the antigen presenting cells (APC), i.e. IL-12 vs IL-23 determines in part if a response is Th1 or Th17. Recent studies have also associated chronic inflammatory diseases such as IBD, psoriasis and myocardial infarction with polymorphisms of the IL-23 receptor complex. The current review focuses on the immunological role of IL-23 and possible therapeutic avenues for inflammatory diseases.     

Genetic deletion of IL-25 (IL-17E) confers resistance to dextran sulfate sodium-induced colitis in mice

Background

IL-25 is emerging as a key regulator of inflammation in the intestinal mucosa because of its ability to promote type 2 while suppressing Th1 and Th17 responses. Several previous studies reported inconsistent results on the role of exogenous IL-25 in development of colonic inflammation and none were performed in animals with a genetic deletion of IL-25. We investigated the contribution of endogenous IL-25 to DSS-induced colitis using mice deficient in IL-25.

Results

Mice were exposed to DSS in drinking water ad libitum either for seven days (acute) or for three cycles of seven days with DSS followed by 14 days without DSS (chronic) to induce colitis, respectively. The loss of body weight, appearance of diarrhea and bloody stools, and shortening of colon length were significantly less pronounced in IL-25^?/? mice compared to WT mice after exposure to acute DSS. Histological examination showed that DSS-treated IL-25^?/? mice had only mild inflammation in the colon, while severe inflammation developed in DSS-treated WT mice. A significant up-regulation of IL-33 was observed in acute DSS-treated WT but not in the IL-25^?/? mice. There was significantly lower expression of pro-inflammatory cytokines in the colon of acute DSS-treated IL-25^?/? compared to WT mice. IL-25^?/? mice were also partially protected from chronic DSS challenge especially during the first 2 cycles of DSS exposure. In contrast to IL-25^?/? mice, IL-13^?/? mice were more susceptible to DSS-induced colitis. Finally, stimulation of T84 colonic epithelial cells with IL-25 up-regulated the expression of IL-33 and several pro-inflammatory cytokines.

Conclusions

These data indicate that endogenous IL-25 acts as a pro-inflammatory factor in DSS-induced colitis, which is unlikely to be mediated by IL-13 but possibly the induction of IL-33 and other pro-inflammatory mediators from colonic epithelial cells. The present study suggests that IL-25 may contribute to the pathogenesis of inflammatory bowel disease in at least a subgroup of patients.