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1.
目的

研究靛蓝对葡聚糖硫酸钠(DSS)诱导的溃疡性结肠炎(UC)模型小鼠的干预作用,并分析对小鼠肠道菌群的影响。

方法

实验小鼠分为对照组、模型组、柳氮磺胺吡啶组(125 mg/kg)和靛蓝组(50 mg/kg),每组小鼠各9只。观察给药后小鼠体征并进行疾病活动指数(DAI)评分,通过苏木素―伊红(HE)染色观察小鼠结肠组织切片形态变化,ELISA法检测小鼠血清中IL-6、TNF-α、IL-1β、IL-8和IL-10水平;针对16S rRNA基因V4‒V5区进行高通量测序,分析小鼠肠道内容物的菌群变化。

结果

与模型组相比,靛蓝组小鼠DAI评分降低,病理切片结果显示靛蓝可改善UC小鼠结肠黏膜损伤,减少炎性细胞浸润,血清中促炎因子IL-6、IL-8、IL-1β和TNF-α水平显著降低(t = 4.377 0、5.374 0、12.140 0、5.508 0,P = 0.011 9、0.005 8、0.000 3、0.005 3),抑炎因子IL-10水平显著升高(t = 3.716 0,P = 0.020 5)。16S rRNA基因测序结果显示,模型组小鼠肠道菌群多样性降低,靛蓝组小鼠肠道菌群多样性升高。

结论

给予靛蓝干预后可有效缓解UC小鼠结肠炎症状,通过降低炎症因子水平和调节UC小鼠肠道菌群平衡达到治疗UC的效果。

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2.
Pituitary adenylate cyclase-activating polypeptide (PACAP) plays a crucial role in immunity and inflammation. Our aim was to obtain insight in the role of PACAP in experimental colitis in mice and thus its possible role in inflammatory bowel disease. PACAP-deficient (PACAP-/-) mice and wild-type control mice were challenged by colitis-inducing agent, dextran sulfate sodium (DSS). We monitored clinical symptoms, intestinal morphology, and difference of cytokine production in the proximal and distal colon. After DSS administration, mortality was more severe in PACAP-/- mice versus wild-type control mice. The histological score and the disease activity index of PACAP-/- mice were significantly higher than those of wild-type control mice. In proximal colon, production of IL-1beta and IL-6 in PACAP-/- mice were significantly upregulated on day 8 after DSS administration, compared to wild-type control mice. In distal colon, furthermore, production of IFNgamma, IL-1beta, IL-6, IL-12, and KC were significantly higher in PACAP-/- mice than in wild-type control mice on day 4. Our findings indicate that PACAP regulates the production of pro-inflammatory cytokine in the experimental colitis.  相似文献   

3.
There is increasing evidence that IL-12 and Th1-cytokines play an important role in intestinal inflammation. We therefore examined the role of IL-12 and interferon-gamma (IFN-gamma) in our model of dextran sulfate-induced acute colitis in mice. Treatment of mice with rmIL-12 during colitis induction resulted in severe aggravation as demonstrated by a greater loss of body weight, an increase of the histological parameters, and reduction of myeloperoxidase activity in colonic biopsies. Depletion of neutrophils in mice also led to aggravation of colitis. Neutralization of IFN-gamma in IL-12-treated mice with colitis inhibited these effects of IL-12. Neutralization of endogenous IFN-gamma or IL-12 with specific antibodies in DSS-treated mice, however, had only weak ameliorating effects. Since IL-12 and IFN-gamma have been shown to mediate experimental chronic colitis we conclude that the transition from a macrophage/neutrophil determined response to a Th-cell response promotes chronic intestinal inflammation.  相似文献   

4.
Hesperidin, a flavanone-type flavonoid, is abundant in citrus fruit and has a wide range of pharmacological effects. Here we investigated the effect of Hesperidin on dextran sulphate sodium (DSS)-induced experimental ulcerative colitis in mice. Sulfasalazine (positive control) and Hesperidin in doses of 10, 40 and 80 mg/kg were administered orally once a day for 7 days, beginning concurrently with exposure to DSS. The symptom of ulcerative colitis was evaluated by disease activity index (DAI) and the wet weight of colon. Myeloperoxidase (MPO) activity, malondialdehyde (MDA) content and the levels of interleukin-4 (IL-4) and interleukin-6 (IL-6) in serum were measured to observe the possible mechanisms. Oral administration of Hesperidin significantly decreased DAI, MPO activity, MDA content and the level of IL-6 in serum (p<0.01), while there was no significantly effect on the level of IL-4 in serum. These results demonstrate that Hesperidin can ameliorate DSS-induced experimental colitis, and may be useful in the prevention and treatment of colitis.  相似文献   

5.
In this study we examined changes in colonic mucosal permeability induced by dextran sulfate sodium (DSS) during the acute phase of mouse colitis. To induce colitis, the mice were given drinking water containing 5% (w/v) DSS (MW = 40,000) ad libitum. Colonic mucosal permeability was evaluated by the permeation of Evans blue (EB) from the lumen into the wall of the colon on 1, 2, 3 and 7 days postadministration of DSS. Mucosal changes were also histologically examined daily for 7 days postadministration. The permeation of EB increased significantly by days 3 and 7 postadministration. Histological analysis showed that crypt loss was the initial change, with no inflammatory process and the surface mucosal epithelial cells remained morphologically intact. These histological changes developed on 2 to 3 days postadministration. Erosion was first recognized at 5 days postadministration. These findings indicated that the increase in colonic mucosal permeability may have occurred in 3 days postadministration, and the increase in mucosal permeability occurred before the appearance of the inflammatory process. This suggests that an increase in colonic mucosal permeability, leading to the destruction of mucosal barrier function, may play an important role in the induction of DSS-induced murine colitis.  相似文献   

6.
Sphingosine kinase (SphK)-catalyzed production of sphingosine-1-phosphate (S1P) regulates cell growth, survival and proliferation as well as inflammatory status in animals. In recent study we reported the N′-(3-(benzyloxy)benzylidene)-3,4,5-trihydroxybenzohydrazide scaffold as a potent SphK inhibitor. As a continuation of these efforts, 51 derivatives were synthesized and evaluated by SphK1/2 inhibitory activities for structure–activity relationship (SAR) study. Among them, 33 was identified as the most potent SphK inhibitor. Potency of 33 was also observed to efficiently decrease SphK1/2 expression in human colorectal cancer cells (HCT116) and significantly inhibit dextran sodium sulfate (DSS)-induced colitis as well as the decreased expression of interleukin (IL)-6 and cyclooxygenase-2 (COX-2) in mouse models. Collectively, 33 was validated as an effective SphK inhibitor, which can be served as anti-inflammatory agent to probably treat inflammatory bowel diseases in human.  相似文献   

7.
Oil of mustard (OM) is a potent neuronal activator that is known to elicit visceral hyperalgesia when given intracolonically, but the full extent to which OM is also proinflammatory in the gastrointestinal tract is not known. We have previously shown that male CD-1 mice given a single administration of 0.5% OM develop a severe colitis that is maximum at day 3 and that gradually lessens until essentially absent by day 14. OM-induced neuronal stimulation is reported to be reduced by cannabinoid agonists, and cannabinoid receptor 1 (CB1R)-/- mice have exacerbated experimental colitis. Therefore, we examined the role of cannabinoids in this OM-induced 3-day model of colitis in CD-1 mice and in a 7-day dextran sulfate sodium (DSS) colitis model in BALB/c mice. In OM colitis, the CB1R-selective agonist ACEA and the CB2R-selective agonist JWH-133 reduced (P < 0.05) colon weight gain (means +/- SE; 82 +/- 13% and 47 +/- 15% inhibition, respectively), colon shrinkage (98 +/- 24% and 42 +/- 12%, respectively), colon inflammatory damage score (49 +/- 11% and 40 +/- 12%, respectively), and diarrhea (58 +/- 12% and 43 +/- 11%, respectively). Histological damage was similarly reduced by these treatments. Likewise, CBR agonists attenuated DSS colitis, albeit at higher doses; ACEA at 10 mg/kg, twice daily, inhibited (P < 0.05) macroscopic and microscopic scores (46 +/- 9% and 63 +/- 7%, respectively); whereas 20 mg/kg, twice daily, of JWH-133 was required to diminish (P < 0.05) macroscopic and microscopic scores (29 +/- 7% and 43 +/- 5%, respectively). CB1R and CB2R immunostaining of colon sections revealed that CB1R in enteric neurons was more intense in colitic vs. control mice; however, CB1R was also increased in the endothelial layer in OM colitis only. CB2R immunostaining was more marked in infiltrated immune cells in OM colitis. These findings validate the OM colitis model with respect to the DSS model and provide strong support to the emerging idea that cannabinoid receptor activation mediates protective mechanisms in experimental colitis. The demonstration of CB1R agonist effects in colitis support the neurogenic nature of the OM-induced colitis model and reinforce the importance of neuronal activation in intestinal inflammation.  相似文献   

8.
Inflammatory bowel disease (IBD) is a continual ailment condition which engrosses the entire alimentary canal. The IBD can be primarily distinguished into two forms, ulcerative colitis, and Crohn's disease. The major symptoms of IBD include pustules or abscesses, severe abdominal pain, diarrhea, fistula, and stenosis, which may directly affect the patient's quality of life. A variety of mediators can stimulate the circumstances of IBD, some examples include infections by microbes such as bacteria, perturbation of the immune system and the surrounding environment of the intestines. Severe colitis was stimulated in the experimental animals through administering 4% dextran sulfate sodium (DSS) which is mixed in water ad libitum for 6 days. Eriocitrin (30 mg/kg) was then administered to the experimental animals followed by the induction of severe colitis to evaluate the therapeutic prospective of eriocitrin against the colon inflammation stimulated by DSS. In this study, eriocitrin (30 mg/kg) demonstrated significant (P < .05) attenuation activity against the DSS‐stimulated severe colitis in experimental animals. Eriocitrin counteracted all of the clinical deleterious effects induced by DSS, such as body‐weight loss, colon shortening, histopathological injury, accretion of infiltrated inflammatory cells at the inflamed region and the secretion of inflammatory cytokines. The results clearly showed that eriocitrin effectively attenuated DSS‐induced acute colitis in experimental animals.  相似文献   

9.
Inflammatory bowel disease (IBD), consisting of Crohn's disease and ulcerative colitis (UC), results in substantial morbidity and is difficult to treat. New strategies for adjunct therapies are needed. One candidate is the semi-essential amino acid, L-arginine (L-Arg), a complementary medicine purported to be an enhancer of immunity and vitality in the lay media. Using dextran sulfate sodium (DSS) as a murine colonic injury and repair model with similarities to human UC, we assessed the effect of L-Arg, as DSS induced increases in colonic expression of the y(+) cationic amino acid transporter 2 (CAT2) and L-Arg uptake. L-Arg supplementation improved the clinical parameters of survival, body weight loss, and colon weight, and reduced colonic permeability and the number of myeloperoxidase-positive neutrophils in DSS colitis. Luminex-based multi-analyte profiling demonstrated that there was a marked reduction in proinflammatory cytokine and chemokine expression with L-Arg treatment. Genomic analysis by microarray demonstrated that DSS-treated mice supplemented with L-Arg clustered more closely with mice not exposed to DSS than to those receiving DSS alone, and revealed that multiple genes that were upregulated or downregulated with DSS alone exhibited normalization of expression with L-Arg supplementation. Additionally, L-Arg treatment of mice with DSS colitis resulted in increased ex vivo migration of colonic epithelial cells, suggestive of increased capacity for wound repair. Because CAT2 induction was sustained during L-Arg treatment and inducible nitric oxide (NO) synthase (iNOS) requires uptake of L-Arg for generation of NO, we tested the effect of L-Arg in iNOS(-/-) mice and found that its benefits in DSS colitis were eliminated. These preclinical studies indicate that L-Arg supplementation could be a potential therapy for IBD, and that one mechanism of action may be functional enhancement of iNOS activity.  相似文献   

10.
Dendritic cells (DCs) are essential mediators of the host immune response to surrounding microbes. In this study, we investigate the role of DCs in the pathogenesis of a widely used colitis model, dextran sulfate sodium-induced colitis. The effect of dextran sulfate sodium on the production of proinflammatory cytokines and chemokines by bone marrow-derived DCs (BM-DCs) was analyzed. BM-DCs were adoptively transferred into C57BL/6 mice or DCs were ablated using transgenic CD11c-DTR/GFP mice before treatment with 5% dextran sulfate sodium in drinking water. We found that dextran sulfate sodium induced production of proinflammatory cytokines (IL-12 and TNF-alpha) and chemokines (KC, MIP-1alpha, MIP-2, and MCP-1) by DCs. Adoptive transfer of BM-DCs exacerbated dextran sulfate sodium colitis while ablation of DCs attenuated the colitis. We conclude that DCs are critical in the development of acute dextran sulfate sodium colitis and may serve a key role in immune balance of the gut mucosa.  相似文献   

11.
Macrophages are essential for the maintenance of intestinal homeostasis, and their activation has been proposed to be critical to the pathogenesis of inflammatory bowel disease (IBD). Although there are many recognized mediators of macrophage activation, increasing evidence suggests that macrophages respond to exosome stimulation. Exosomes are 40–150 nm microvesicles released from different cell types and are found in a variety of physiological fluids, including serum. As studies have shown that circulating exosomes participate in intercellular communication and can mediate the immune response, we hypothesized that exosomes may play a role in the pathogenesis of IBD though modulation of macrophage activity. In this study, we used the dextran sulfate sodium (DSS) induced acute colitis mice model to investigate the effect of serum exosomes on macrophages and identify exosome proteins potentially involved in macrophage activation. We treated RAW264.7 macrophages with serum exosomes isolated from dextran sulfate sodium induced mice and found that treatment induced phosphorylation of p38 and ERK and production of tumor necrosis factor α when compared to treatment with exosomes isolated from control mice. Subsequent proteomic analysis identified 56 differentially expressed proteins, a majority of which were acute‐phase proteins and immunoglobulins. Bioinformatics analysis suggested these proteins were mainly involved in the complement and coagulation cascade, which has been implicated in macrophage activation. Our findings provide new insight into the role of circulating serum exosomes in acute colitis and contribute to the understanding of macrophage activation in the pathogenesis of IBD.  相似文献   

12.
Lactic acid bacteria are generally sensitive to hydrogen peroxide (H2O2). Lactobacillus plantarum ATCC14431 is one of the few lactic acid bacteria able to degrade H2O2 through the action of a manganese-dependent catalase (containing the katA gene). However, it is not a natural inhabitant of the intestinal tract and its bio-efficacy and survival in the gastrointestinal tract have never been tested. In this study, we successfully expressed the katA gene from L. plantarum ATCC14431 in L. fermentum I5007 and the recombinant L. fermentum exhibited almost 20-fold higher catalase activity than the empty vector control. The anti-oxidative properties of this catalase-producing L. fermentum were evaluated using a dextran sodium sulphate (DSS) induced colitis mice model. Compared with the control, mice receiving DSS alone had increased diarrhea and mucosa histological scores (P < 0.05), as well as lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05), and active NF-κB in colonic tissue (P < 0.05). Similar to vitamin E, treatment with recombinant L. fermentum mitigate these effects accompanied by a improvement in mucosa histological scores in the proximal colon (P < 0.05) and decreased lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05) and active NF-κB in colonic tissue (P < 0.05). In conclusion, the expression of catalase in L. fermentum increased its ability to survive when exposed to aerated environment in vitro and conferred the anti-oxidative and anti-inflammatory effects in the DSS induced colitis model.  相似文献   

13.
The dextran sulfate sodium (DSS) model of colitis has been commonly utilized in mice to assess novel treatments for ulcerative colitis. Recent studies have indicated that morphological and biochemical changes extend to the small intestine (SI). This study aimed to characterize histological and biochemical changes in the SI during DSS colitis in wild‐type (WT) and DPIV knock‐out (DPIV?/?) mice treated with saline or the DPIV inhibitors, Ile‐Pyrr‐(2‐CN)*TFA or Ile‐Thia. Groups (n = 10) of DPIV?/? and WT mice were orally gavaged twice daily with saline, Ile‐Pyrr‐(2‐CN)*TFA or Ile‐Thia. Mice consumed 2% DSS in drinking water for 6 days to induce colitis. Small intestinal tissue was assessed for histological changes, sucrase, and DPIV activity and neutrophil infiltration. Jejunal villus length was increased in all groups after 6 days DSS consumption (P < 0.05). Jejunal DPIV activity was significantly lower by 35% in WT mice receiving Ile‐Pyrr‐(2‐CN)*TFA compared to saline controls. Jejunal MPO activity was significantly increased in the WT + saline and DPIV?/? + saline groups following DSS consumption, compared to WT and DPIV?/? controls at day 0. Increased sucrase activity was apparent at day 0 in DPIV?/? compared to WT mice (P < 0.05). We conclude that DSS‐induced damage is not restricted to the colon, but also extends to the small intestine. Furthermore, reduced or absent DPIV activity resulted in functional adaptations to brush border enzyme activity. DPIV inhibitors are now a recognized therapy for type‐II diabetes. The work presented here highlights the need to delineate any long‐term effects of DPIV inhibitors on SI function, to further validate their safety and tolerability. J. Cell. Physiol. 226: 3219–3224, 2011. © 2011 Wiley Periodicals, Inc.  相似文献   

14.
15.
The role of serotonin in the pathogenesis of inflammatory bowel disease has not been fully studied. We examined the changes in the serotonin level and the density of serotonin-containing enterochromaffin (EC) and mast cells in the intestinal mucosa of dextran sodium sulfate (DSS)-induced colitis in rats. Rats were treated with 1.5% DSS for 1 month. Serotonin levels were biochemically measured and the density of epithelial EC cells and mucosal mast cells was quantified by serotonin immunohistochemistry. DSS caused malnutrition due to chronic diarrhea. Infiltrated inflammatory cells were microscopically observed in the colonic wall with intact epithelium. The serotonin content in the mucosa/submucosa tissue was increased in the proximal and distal colon in DSS-treated rats, compared to that in control rats. The density of EC cells in the epithelium also increased in the proximal and distal colon in DSS-treated rats. In contrast, the density of mast cells in the lamina propria dramatically increased in the distal, but not in the proximal colon in DSS-treated rats. This discrepancy implies the serotonin released from EC cells and from mast cells may play different roles in the pathogenesis of DSS-induced colitis. Accepted: 30 July 1999  相似文献   

16.
Inflammatory bowel disease (IBD) is a chronic lifelong disease characterized by inflammation of the gastrointestinal tract.Although more and more treatment opti...  相似文献   

17.
In this study, we investigated the influence of zearalenone (ZEA) on the dextran sulfate sodium (DSS)‐induced colitis model both in vitro and in vivo. Our results show that the mRNA levels of IL‐1β, IL‐18, NLRP3, ASC, and caspase‐1 in the DSS+ZEA‐treated group are lower than those in either the DSS or ZEA group, and the protein expression trends are similar. Furthermore, colitis, which is characterized by body weight loss, stool consistency, and the presence of bloody feces, was significantly alleviated in the DSS+ZEA group when compared with that in the DSS group. In addition, histological analysis showed that inflammatory cell infiltration and tissue damage of the colon in the DSS+ZEA group were recovered compared with that in the DSS‐treated group. These results suggest that, instead of aggravating DSS‐induced colitis, ZEA relieves the inflammatory reaction in colon tissue, which may be related to its estrogenic activity.  相似文献   

18.
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.  相似文献   

19.
We previously examined wogonin, isolated from Scutellaria baicalensis, chemical mediators, and IgE by mesenteric lymph node (MLN) lymphocytes in rats. The present study explores the effect of wogonin on the MLN lymphocyte function of mice given orally at 20 mg/kg for 2 weeks with dextran sulfate sodium (DS)-induced colitis. The results indicate that IgA levels in MLN lymphocytes were high, while IgE was low, in mice given wogonin compared to those given water. Also, fecal IgA concentration of DS in the wogonin group mice was significantly higher than in the DS group. Concentrations of interferon-gamma and interleukin (IL)-2 of T cells by concanavalin A treatment was significantly higher in the wogonin fed group than in the normal group. Activation-induced IL-4, IL-5 and IL-10 secretion was lower in wogonin fed mice compared control mice after DS-induced colitis. For these reasons, we conclude that wogonin can alleviate the inflammation in DS-induced colitis brought about by an abnormal Th(2) response.  相似文献   

20.
Conventional therapies for the treatment of inflammatory bowel disease (IBD) have demonstrated limited efficacy and potential toxicity; therefore, there is a need for novel therapies that can safely and effectively treat IBD. Recent evidence has indicated that amino acids may play a role in maintaining gut health. l-Tryptophan has been shown to reduce oxidative stress and improve neurological states. The objective of this study was to assess the therapeutic effects of l-tryptophan in a porcine model of dextran sodium sulfate (DSS)-induced colitis. DSS was administered to piglets via intragastric catheter for 5 days followed by tryptophan administration at 80% of the daily recommended intake. The severity of colitis was assessed macroscopically and histopathologically, and intestinal permeability was monitored in vivo by d-mannitol analysis. The effect of tryptophan on the local expression of key mediators of inflammation and IBD pathogenesis was examined at the protein and gene expression levels. Supplementation with tryptophan ameliorated clinical symptoms and improved weight gain to feed intake conversion ratios. Histological scores and measurements were also improved, and gut permeability was notably reduced in tryptophan-supplemented animals. Moreover, tryptophan reduced the expression of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, interferon (IFN)-γ, IL-12p40, IL-1β and IL-17, as well as IL-8 and intracellular adhesion molecule-1, and resulted in increased expression of apoptosis initiators caspase-8 and Bax. These results demonstrate that l-tryptophan supplementation can reduce inflammation and enhance the rate of recovery in DSS-induced colitis and may be an effective immunomodulating agent for the treatment of IBD.  相似文献   

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