Oxazolone-induced Colitis In Mice Research Articles

Intestinal vitamin D receptor knockout protects from oxazolone-induced colitis

Crohn’s disease (CD) and ulcerative colitis (UC) actually had different pathological mechanisms, as the former was mainly induced by Th1 and Th17 response and the latter by Th2 response. Our previous study found that oxazolone-induced Th2-mediated colitis could not be attenuated by vitamin D supplementation. This study investigated the influence of intestinal vitamin D receptor (VDR) knockout on oxazolone-induced colitis and explored the possible immunological mechanism. Intestinal VDR knockout mice had milder oxazolone-induced colitis than wildtype controls, as demonstrated by less body weight decrease and faster recovery, more intact local structure, reduced cell apoptosis, and better preserved barrier function. Th2-mediated inflammation was significantly inhibited by VDR deficiency. Meanwhile, the percentage of invariant natural killer T (iNKT) cells did not increase as much in intestinal VDR knockout mice as in wild-type controls, nor did the iNKT cells develop normally as in the controls. Intestinal VDR knockout protected against oxazolone-induced colitis in mice by blocking Th2 cell response and reducing the function of intestinal iNKT cells. Vitamin D status had no influence on the severity of colitis. This study may explain the diverse outcomes after vitamin D supplementation in literature and add some clue to the targeted therapy of IBD.

Preventative effects of Lactobacillus plantarum YS-3 on oxazolone-induced BALB/c colitis in mice

In this study, the preventative effects of Lactobacillus plantarum YS-3 (LP-YS3) on colitis were studied using an in vitro animal experiment. Oxazolone was administered to BALB/c mice to induce colitis, and the preventive effects of LP-YS3 were determined using serum- and tissue-related indexes. The mice treated with LP-YS3 showed a significant decrease (p < 0.05) in disease activity index for colitis by inhibiting colon shortening and increasing colon weight/length ratio. The application of LP-YS3 resulted in a significant reduction in myeloperoxidase, nitric oxide, and malondialdehyde activities and a decrease in glutathione activity (p < 0.05) in mouse colon tissues. LP-YS3 also significantly increased serum interleukin-2 and reduced interleukin-10 cytokines levels in mice (p < 0.05). Reverse transcription-polymerase chain reaction and western blot assays showed that LP-YS3 application resulted in a significant increase in neuronal nitric oxide synthase, endothelial nitric oxide synthase, c-Kit, and stem cell factor expressions and a decrease in inducible nitric oxide synthase, interleukin-8, and C-X-C motif chemokine receptor 2 expressions in mouse colonic tissues (p < 0.05). These findings indicate that LP-YS3 imparts preventative effects on oxazolone-induced colitis in mice.

Modified Pulsatilla decoction attenuates oxazolone-induced colitis in mice through suppression of inflammation and epithelial barrier disruption.

Inflammatory bowel diseases (IBDs) are chronic inflammatory gastrointestinal disorders caused by a dysregulated mucosal immune response and epithelial barrier disruption. Conventional treatment of IBD is currently limited to overcoming patient symptoms and is often associated with severe adverse effects from the drugs used. Modified Pulsatilla decoction has been used previously to treat ulcerative colitis (UC) in clinical practice in China, however, the underlying mechanism in the treatment of UC remains to be elucidated. In the present study, the efficiency and mechanisms of modified Pulsatilla decoction in the treatment of oxazolone-induced colitis were investigated. Assessment of clinical colitis and histological examination found that the administration of modified Pulsatilla decoction attenuated the severity of oxazolone-induced colitis in mice. Measurement of cytokine concentration, western blotting and reverse transcription-quantitative polymerase chain reaction demonstrated modified Pulsatilla decoction treatment significantly reduced the secretion of pro-inflammatory cytokines and restored alterations in tight junction proteins in the colon tissues. In addition, modified Pulsatilla decoction suppressed the activation of the nuclear factor-κB signaling pathway. Thus, the findings of the present study demonstrated that modified Pulsatilla decoction offers an effective therapeutic approach for the treatment of IBD and revealed the underlying mechanisms of action offered by modified Pulsatilla decoction.

P036. Colon targeted delivery of tofacitinib inhibits oxazolone-induced colitis in mice, despite low systemic exposure

P036. Colon targeted delivery of tofacitinib inhibits oxazolone-induced colitis in mice, despite low systemic exposure

Therapeutic activity of an interleukin-4/interleukin-13 dual antagonist on oxazolone-induced colitis in mice.

Interleukin-4 (IL-4) and IL-13 are critical drivers of immune activation and inflammation in ulcerative colitis, asthma and other diseases. Because these cytokines may have redundant function, dual targeting holds promise for achieving greater efficacy. We have recently described a bifunctional therapeutic targeting IL-4 and IL-13 developed on a novel protein scaffold, generated by combining specific binding domains in an optimal configuration using appropriate linker regions. In the current study, the bifunctional IL-4/IL-13 antagonist was evaluated in the murine oxazolone-induced colitis model, which produces disease with features of ulcerative colitis. The bifunctional IL-4/IL-13 antagonist reduced body weight loss throughout the 7-day course of the model, and ameliorated the increased colon weight and decreased colon length that accompany disease. Colon tissue gene expression was modulated in accordance with the treatment effect. Concentrations of serum amyloid P were elevated in proportion to disease severity, making it an effective biomarker. Serum concentrations of the bifunctional IL-4/IL-13 antagonist were inversely proportional to disease severity, colon tissue expression of pro-inflammatory genes, and serum amyloid P concentration. Taken together, these results define a panel of biomarkers signifying engagement of the IL-4/IL-13 pathway, confirm the T helper type 2 nature of disease in this model, and demonstrate the effectiveness of dual cytokine blockade.

Pulverized konjac glucomannan ameliorates oxazolone-induced colitis in mice

Pulverized konjac glucomannan (PKGM) is a natural biologically active compound extracted from konjac, a Japanese traditional food. In the present study, we investigated the role of PKGM in intestinal immunity in a mouse model of oxazolone (OXA)-induced colitis. C57BL/6(B6) mice were fed PKGM or control food from 2weeks before the induction of OXA colitis. Body weight change, colon length, and histological change in the colon were examined. The mononuclear cells were purified from colon and stimulated with PMA/ionomycin. The levels of TNF-α, interferon (IFN)-γ, interleukin (IL)-4, and IL-13 from the supernatant were measured by ELISA. Oral administration of PKGM prevented the body weight loss and shortening of colon length associated with OXA-induced colitis. Histological analysis revealed that the colonic inflammation was improved by the administration of PKGM. The levels of IL-4 and IL-13, the critical inflammatory cytokines in OXA colitis, derived from mononuclear cells from the lamina propria of the colon were significantly suppressed by PKGM administration. PKGM-fed mice showed a significantly lower IL-4/IFN-γ ratio in the colonic lamina propria compared with that in control-fed mice. Fluorescence-activated cell sorting analysis revealed that natural killer (NK) 1.1(+) T cells in the liver were significantly decreased in PKGM-fed mice. Finally, the preventive role of PKGM in OXA-induced colitis was not observed in invariant natural killer T cell-deficient mice. PKGM ameliorated OXA-induced colitis in mice. This effect is associated with a decreased population of NK1.1(+) T cells and induction of Th1-polarized immune responses.

CCL25/CCR9 interactions regulate the function of iNKT cells in oxazolone-induced colitis in mice.

BackgroundNatural killer T (NKT) cells share phenotypic and functional properties with both conventional natural killer cells and T cells. These cells might have an important role in the pathogenesis of ulcerative colitis (UC). The interaction of chemokine ligand 25 (CCL25) with chemokine receptor 9 (CCR9) is involved in gut-specific migration of leukocytes and induces regulatory T cells (Tregs) to migrate to the intestine in chronic ileitis.Methodology/FindingsIn UC patients, NKT receptor CD161, CCL25, and CCR9 expression levels were evaluated by qRT-PCR. A murine model of oxazolone-induced colitis was induced in BALB/c mice. The mRNA levels of NK1.1, CCL25 and CCR9, and pro-inflammatory cytokines in mice were evaluated. The CCR9 expression on Type I or invariant NKT (iNKT) cells, and the iNKT cells chemotaxis are observed according to flow cytometry. NKT receptor CD161, CCL25 and CCR9 expression levels were significantly increased in UC patients. And, the mRNA expression levels of NK1.1, CCL25 and CCR9 were increased in oxazolone-induced colitis in mice. The production of pro-inflammatory cytokines was significantly increased, especially interleukin 4 (IL-4), IL-10 and IL-13. We observed significantly increased CCR9 expression on iNKT cells. Furthermore, we found an increased iNKT population and enhanced chemotaxis during oxazolone-induced colitis.Conclusions/SignificanceOur study suggests that CCL25/CCR9 interactions may promote the induction and function of iNKT cells during oxazolone-induced colitis. These findings may have important implications for UC treatment and suggest a role for CCR9 inhibitors.

P094 CCL25/CCR9 interactions promote the induction and function of iNKT cells in oxazolone-induced colitis in mice

P094 CCL25/CCR9 interactions promote the induction and function of iNKT cells in oxazolone-induced colitis in mice

The Rhizome Mixture of Anemarrhena asphodeloides and Coptidis chinensis Ameliorates Acute and Chronic Colitis in Mice by Inhibiting the Binding of Lipopolysaccharide to TLR4 and IRAK1 Phosphorylation.

In the previous study, the mixture of the rhizome of Anemarrhena asphodeloides (AA, family Liliaceae) and the rhizome of Coptidis chinensis (CC, family Ranunculaceae) (AC-mix) improved TNBS- or oxazolone-induced colitis in mice. Therefore, to investigate its anticolitic mechanism, we measured its effect in acute and chronic DSS-induced colitic mice and investigated its anti-inflammatory mechanism in peritoneal macrophages. AC-mix potently suppressed DSS-induced body weight loss, colon shortening, myeloperoxidase activity, and TNF-α, IL-1β, and IL-6 expressions in acute or chronic DSS-stimulated colitic mice. Among AC-mix ingredients, AA, CC, and their main constituents mangiferin and berberine potently inhibited the expression of proinflammatory cytokines TNF-α and IL-1β, as well as the activation of NF-κB in LPS-stimulated peritoneal macrophages. AA and mangiferin potently inhibited IRAK phosphorylation, but CC and berberine potently inhibited the binding of LPS to TLR4 on macrophages, as well as the phosphorylation of IRAK1. AC-mix potently inhibited IRAK phosphorylation and LPS binding to TLR4 on macrophages. Based on these findings, AC-mix may ameliorate colitis by the synergistic inhibition of IRAK phosphorylation and LPS binding to TLR4 on macrophages.

Tu1874 STAT6 Contributes to Sustaining Oxazolone-Induced Colitis in Mice

Tu1874 STAT6 Contributes to Sustaining Oxazolone-Induced Colitis in Mice

Tetramethylpyrazine attenuates PPAR-γ antagonist-deteriorated oxazolone-induced colitis in mice

Tetramethylpyrazine (TMP) is suggested to have anti-inflammatory activity. The aim of this study was to determine the role of peroxisome proliferator activated receptor γ (PPAR-γ) signaling in the pharmacologic effect of TMP on oxazolone (OXZ)-induced colitis. TMP (80 mg/kg/day i.p.) was administered daily 48 h after intrarectal instillation of OXZ, with or without PPAR-γ inhibitor [bisphenol A diglycidyl ether (BADGE) 30 mg/kg] during the 4 days before sacrifice. The inflammatory response was assessed by the disease activity index, macroscopy, histology and myeloperoxidase (MPO) activity. Expression levels of PPAR-γ, NF-κB p65, COX-2, iNOS and TNF-α mRNA in colon mucosa were determined by FQ-PCR, levels of PPAR-γ and NF-κB p65 protein were analyzed by immunohistochemistry, and the total and phosphorylated levels of p38 MAPK were assessed by western blotting. TMP significantly attenuated the damage caused by OXZ and substantially reduced the rise in MPO activity, TNF-α, iNOS, NF-κB p65 and COX-2 expression, as well as the increase in PPAR-γ production; however, no changes in the activation of p38 MAPK were observed. Inhibition of PPAR-γ signaling aggravated inflammation of colon mucosa, and increased p38 phosphrylation. TMP counteracted the effect of inhibition of PPAR-γ. We suggest that the effect of TMP treatment in ulcerative colitis may be related to PPAR-γ signaling, but is independent of PPAR-γ.

B Cells That Produce Immunoglobulin E Mediate Colitis in BALB/c Mice

Induction of colitis in mice by administration of oxazolone is mediated by T-helper (Th) 2 cells and has features of human ulcerative colitis. We investigated whether activation of interleukin (IL)-4Rα on T and B cells determines their effector functions and mediates oxazolone-induced colitis. We studied induction of colitis with oxazolone in wild-type mice and those with CD4(+) T cells that did not express IL-4Rα (Lck(cre)IL-4Rα(-/lox)). We also generated mice with B cells that did not express IL-4Rα (mb1(cre)IL-4Rα(-/lox)) and studied induction of colitis. Lck(cre)IL-4Rα(-/lox) mice did not develop colitis in response to oxazolone, and their levels of IL-4, IL-13, and immunoglobulin (Ig) E were reduced. Adoptive transfer of naïve, wild-type CD4(+) Th cells depleted of natural killer T cells to Lck(cre)IL-4Rα(-/lox) mice restored their susceptibility to colitis. In contrast, Lck(cre)IL-4Rα(-/lox) mice maintained their protection against colitis when IL-13-deficient CD4(+) T cells were transferred. These findings indicate that development of colitis involves not only natural killer T-cell functions, but also requires IL-13 production by CD4(+) T helper cells. Mb1(cre)IL-4Rα(-/lox) mice, which cannot produce IgE, were also protected against oxazolone-induced colitis. Blocking IgE binding significantly reduced mast cell numbers in colons and protected wild-type BALB/c mice from the onset of colitis. IL-4 appears to induce CD4(+) Th2 cells to produce IL-13 and B cells to produce IgE, which together mediate oxazolone-induced colitis in mice.

Tumor development in murine ulcerative colitis depends on MyD88 signaling of colonic F4/80+CD11bhighGr1low macrophages

Patients with prolonged ulcerative colitis (UC) frequently develop colorectal adenocarcinoma for reasons that are not fully clear. To analyze inflammation-associated colonic tumorigenesis, we developed a chronic form of oxazolone-induced colitis in mice that, similar to UC, was distinguished by the presence of IL-13-producing NKT cells. In this model, the induction of tumors using azoxymethane was accompanied by the coappearance of F4/80+CD11b(high)Gr1(low) M2 macrophages, cells that undergo polarization by IL-13 and are absent in tumors that lack high level IL-13 production. Importantly, this subset of macrophages was a source of tumor-promoting factors, including IL-6. Similar to dextran sodium sulfate-induced colitis, F4/80+CD11b(high)Gr1(intermediate) macrophages were present in the mouse model of chronic oxazolone-induced colitis and may influence tumor development through production of TGF-β1, a cytokine that inhibits tumor immunosurveillance. Finally, while robust chronic oxazolone-induced colitis developed in myeloid differentiation primary response gene 88-deficient (Myd88-/-) mice, these mice did not support tumor development. The inhibition of tumor development in Myd88-/- mice correlated with cessation of IL-6 and TGF-β1 production by M2 and F4/80+CD11b(high)Gr1(intermediate) macrophages, respectively, and was reversed by exogenous IL-6. These data show that an UC-like inflammation may facilitate tumor development by providing a milieu favoring development of MyD88-dependent tumor-supporting macrophages.

Effects of Bawei Xilei San on mice with oxazolone-induced colitis and the mechanisms

To investigate the therapeutic effects of Bawei Xilei San (BWXLS), a compound traditional Chinese herbal medicine, on mice with oxazolone-induced colitis and to explore the mechanisms. Thirty-two BALB/c mice were randomly divided into 4 groups (8 for each): normal control group, untreated group, hydrocortisone group and BWXLS group. Except for the mice in the normal control group, all mice were intrarectally administered with 3.0% oxazolone to induce colitis. Then the mice in the normal control group and untreated group were administered with 0.9% carboxymethyl cellulose sodium solution. Mice in the BWXLS group were intrarectally administered with 0.2 mg/g BWXLS and hydrocortisone group with 0.02 mg/g respectively for 5 days. The body weight and stool consistency and occult or gross blood were recorded to calculate the disease activity index (DAI). The mice were sacrificed at the 6th day. The macroscopic and histological changes of the colon were evaluated. The expressions of Toll-like receptor 4 (TLR4), nuclear factor-kappaB (NF-kappaB), and epithelial tight junction protein occludin were assessed by immunohistochemical method. The level of tumor necrosis factor-alpha (TNF-alpha) in colonic mucosa was evaluated by enzyme-linked immunosorbent assay. The DAI, and macroscopic and histological changes in the BWXLS group were improved as compared with those in the untreated group (P<0.05) but were similar to those in the hydrocortisone group. The expression of occludin was significantly increased (P<0.05) while the expressions of TLR4, NF-kappaB and TNF-alpha were significantly decreased in the BWXLS group as compared with the untreated group, and were similar to those in the hydrocortisone group (P>0.05). Up-regulating the expression of occludin and down-regulating the expressions of TLR4 and NF-kappaB, and hence inhibiting TNF-alpha expression and improving the mucosa barrier function may be part of the mechanisms of BWXLS in treating oxazolone-induced colitis in mice.

FTY720 ameliorates oxazolone colitis in mice by directly affecting T helper type 2 functions

The sphingosine-1-phosphate analogue FTY720 is known to alter migration and homing of lymphocytes via sphingosine-1-phosphate receptors. However, several studies indicate that its mode of action is more complex and that FTY720 may also directly influence cytokine effector functions. Therefore, we studied the effect of FTY720 in T helper type (Th2)-mediated oxazolone-induced colitis in mice. Following rectal oxazolone instillation, Th2 cells producing IL-13 induce a progressive colitis resembling human ulcerative colitis. A rectal enema of oxazolone [90 mg/kg body weight] was applied to BALB/c mice. FTY720 was administered i.p. from day 0 to 3 or from day 3 to 5 following the instillation of the haptenating agent. Assessment of severity of colitis was performed daily. FTY720 plasma levels were detected using LC–MS/MS-analysis. Colon tissue was analyzed macroscopically and microscopically, myeloperoxidase activity as well as cytokine levels of lamina propria CD4 + T-cells and T1/ST2 expression were determined. Treatment with FTY720 prominently reduced the clinical and histopathologic severity of oxazolone-induced colitis, abrogating body weight loss, diarrhea, and macroscopic and microscopic intestinal inflammation. The therapeutic effects of FTY720 were associated with a prominent reduction of the key effector Th2 cytokines IL-13, IL-4 and IL-5. Strikingly, FTY720 inhibited GATA3 and T1/ST2 expression which represent highly relevant markers for Th2 differentiation and Th2 effector function, respectively. Our data provide the first evidence that FTY720 exhibits beneficial prophylactic as well as therapeutic effects in Th2-mediated experimental colitis by directly affecting Th2 cytokine profiles probably by reducing T1/ST2, thus offering a new auspicious therapeutic instrument for the treatment of human ulcerative colitis.