Animal Model Of Ulcerative Colitis Research Articles

Involvement of PPARγ in the protective action of tropisetron in an experimental model of ulcerative colitis

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal (GI) tract. Tropisetron, a selective 5-HT3 receptor antagonist, is highly used to counteract chemotherapy-induced emesis. Previous studies revealed the anti-inflammatory properties of this drug. The aim of this study was to evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) receptor in the protective effect of tropisetron in an animal model of ulcerative colitis. Experimental colitis was induced by a single intra-colonic instillation of 4% (V/V) acetic acid in male rats. Tropisetron (3 mg/kg) and GW9662 (PPARγ antagonist) (5 mg/kg) were given twice daily for 2 days after colitis induction. Forty-eight hours after induction of colitis, colon was removed and macroscopic and microscopic features were given. Moreover, colonic concentrations of malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, myeloperoxidase (MPO), and PPARγ activity were assessed. Both macroscopic and histopathological features of colonic injury were markedly ameliorated by tropisetron. Likewise, levels of NO, MDA, TNF-α, and IL-1β diminished significantly (p < .05). GW9662 reversed the effect of tropisetron on these markers partially or completely. In addition, tropisetron increased the PPARγ and decreased the MPO activity (p < .05). Tropisetron exerts notable anti-inflammatory effects in acetic acid-induced colitis in rats, which is probably mediated through PPARγ receptors.

Orally available extract from Brassica oleracea var. capitata rubra attenuates experimental colitis in mouse models of inflammatory bowel diseases

Red cabbage is an important source of vitamins, micro- and macroelements and polyphenols. The aim of our study was to evaluate the anti-inflammatory effect of red cabbage extract (RCE) in mouse models of inflammatory bowel disease (IBD). The effect of RCE on experimental colitis was determined using clinical, macro- and microscopic parameters of inflammation. To study the mechanism of RCE action, the expression of pro-inflammatory cytokines and parameters of oxidative stress were assessed. RCE produced a potent anti-inflammatory action in the mouse model of Crohn's disease, as shown by decreased macroscopic damage score in acute (2.70 ± 0.24 vs. 5.78 ± 0.58 for control group) and chronic (1.81 ± 0.38 vs. 2.94 ± 0.29) colitis model. In the animal model of ulcerative colitis, total macroscopic score was decreased after prophylactic and therapeutic administration (11.9 ± 0.5 and 11.2 ± 0.9 vs. 14.2 ± 0.4 in control group, respectively). Red cabbage extract may be applied as a potential dietary supplement in IBD therapy.

Animal models of ulcerative colitis developed with chemicals

Animal models of ulcerative colitis developed with chemicals

The PI3K/Akt pathway in colitis associated colon cancer and its chemoprevention with celecoxib, a Cox-2 selective inhibitor

Oncogenesis and angiogenesis are the two major pathways involved in tumorigenesis. Oncogenesis involves the PI3K/Akt and Wnt/β-catenin pathways, both of which are upregulated in several types of cancers. We established animal model of ulcerative colitis, colon cancer and colitis associated colon cancer by the incorporation of dextran sufate sodium (DSS) and dimethyl hydrazine (DMH), alone as well as in combination. Apart from the gross morphological analysis, we presently explored the role of various components of the oncogenic pathways, including PI3K, p-Akt, PTEN, PDK1, mTOR, GSK-3β, Wnt and β-catenin and found the elevated levels of these proteins, except the tumor suppressors PTEN and GSK-3β, whose levels were downregulated in both inflammatory and carcinogenic conditions. We also studied the protein expression of some major angiogenic agents, such as Vegf, MMP-2, MMP-9 and iNOS. The angiogenic pathway was also upregulated presently in the DSS, DMH and DSS+DMH groups. Also, the reactive oxygen and nitrogen species, which lead to oxidative stress, were found to be elevated in these groups. All these effects were brought towards normal by the co-administration of celecoxib, a second generation non-steroidal anti-inflammatory drug (NSAID), with DSS, DMH and their combinatorial group.

Mesenchymal stem/stromal cell-derived microparticles show anti-inflammatory activity in an animal model of ulcerative colitis

Mesenchymal stem/stromal cell-derived microparticles show anti-inflammatory activity in an animal model of ulcerative colitis

Animal models of ulcerative colitis and their application in drug research.

The specific pathogenesis underlying inflammatory bowel disease is complex, and it is even more difficult to decipher the pathophysiology to explain for the similarities and differences between two of its major subtypes, Crohn’s disease and ulcerative colitis (UC). Animal models are indispensable to pry into mechanistic details that will facilitate better preclinical drug/therapy design to target specific components involved in the disease pathogenesis. This review focuses on common animal models that are particularly useful for the study of UC and its therapeutic strategy. Recent reports of the latest compounds, therapeutic strategies, and approaches tested on UC animal models are also discussed.

Animal models of ulcerative colitis

Animal models of ulcerative colitis

Seeing citrulline: development of a phenylglyoxal-based probe to visualize protein citrullination.

Protein arginine deiminases (PADs) catalyze the hydrolysis of peptidyl arginine to form peptidyl citrulline. Abnormally high PAD activity is observed in a host of human diseases, but the exact role of protein citrullination in these diseases and the identities of specific citrullinated disease biomarkers remain unknown, largely because of the lack of readily available chemical probes to detect protein citrullination. For this reason, we developed a citrulline-specific chemical probe, rhodamine-phenylglyoxal (Rh-PG), which we show can be used to investigate protein citrullination. This methodology is superior to existing techniques because it possesses higher throughput and excellent sensitivity. Additionally, we demonstrate that this probe can be used to determine the kinetic parameters for a number of protein substrates, monitor drug efficacy, and identify disease biomarkers in an animal model of ulcerative colitis that displays aberrantly increased PAD activity.

Cold Spark Discharge Plasma Treatment of Inflammatory Bowel Disease in an Animal Model of Ulcerative Colitis

Cold plasma discharges have been shown to have medically-relevant therapeutic effects when applied to living tissues, including blood coagulation and wound healing; thus, plasma treatment of inflamed tissues in ulcerative colitis disease may be an effective approach to reduce adverse consequences if not cure the disease. Here we discuss results of the first experimental study of cold plasma treatment of ulcerative colitis in a mouse model. As a plasma source, a cold spark discharge has been used. The results show that plasma treatment of experimental model of ulcerative colitis in mice has some beneficial effects by suppressing the progression of the disease while no damage to colon tissues is observed; and these effects are comparable to standard therapy.

Role of anti-angiogenic factor endostatin in the pathogenesis of experimental ulcerative colitis

AimsVascular endothelial growth factor (VEGF) and pathologic angiogenesis have been demonstrated to play a pathogenic role in the development and progression of inflammatory bowel disease. Thus, we hypothesized that the potent anti-angiogenic factor endostatin might play a beneficial role in experimental ulcerative colitis (UC). Main methodsWe used three animal models of UC: (1) induced by 6% iodoacetamide (IA) in rats, or (2) by 3% dextran sulfate sodium (DSS) in matrix metalloproteinase-9 (MMP-9) knockout (KO) and wild-type mice, and (3) interleukin-10 (IL-10) KO mice. Groups of MMP-9 KO mice with DSS-induced UC were treated with endostatin or water for 5days. Key findingsWe found concomitant upregulation of VEGF, PDGF, MMP-9 and endostatin in both rat and mouse models of UC. A positive correlation between the levels of endostatin or VEGF and the sizes of colonic lesions was seen in IA-induced UC. The levels and activities of MMP-9 were also significantly increased during UC induced by IA and IL-10 KO. Deletion of MMP-9 decreased the levels of endostatin in both water- and DSS-treated MMP-9 KO mice. Treatment with endostatin significantly improved DSS-induced UC in MMP-9 KO mice. Significance1) Concomitantly increased endostatin is a defensive response to the increased VEGF in UC, 2) MMP-9 is a key enzyme to generate endostatin which may modulate the balance between VEGF and endostatin during experimental UC, and 3) endostatin treatment plays a beneficial role in UC. Thus, anti-angiogenesis seems to be a new therapeutic option for UC.

You See UC: An Animal Model of Ulcerative Colitis

You See UC: An Animal Model of Ulcerative Colitis

Therapeutic Effect of Lecithinized Superoxide Dismutase against Colitis

Ulcerative colitis (UC) involves intestinal mucosal damage induced by reactive oxygen species (ROS), in particular, superoxide anion. Superoxide dismutase (SOD) catalyzes dismutation of superoxide anion to hydrogen peroxide, which is subsequently detoxified by catalase. Lecithinized SOD (PC-SOD) is a new modified form of SOD that has overcome previous clinical limitations of SOD. In this study, we examined the action of PC-SOD using an animal model of UC, dextran sulfate sodium (DSS)-induced colitis. DSS-induced colitis was ameliorated by daily intravenous administration of PC-SOD. Unmodified SOD produced a similar effect but only at more than 30 times the concentration of PC-SOD. In vivo electron spin resonance analysis confirmed that the increase in the colonic level of ROS associated with development of colitis was suppressed by PC-SOD administration. The dose-response profile of PC-SOD was bell-shaped, but simultaneous administration of catalase restored the ameliorative effect at high doses of PC-SOD. Accumulation of hydrogen peroxide was observed with the administration of high doses of PC-SOD, an effect that was suppressed by the simultaneous administration of catalase. We also found that either a weekly intravenous administration or daily oral administration of PC-SOD conferred protection. These results suggest that PC-SOD achieves its ameliorative effect against colitis through decreasing the colonic level of ROS and that its ineffectiveness at higher doses is because of the accumulation of hydrogen peroxide. Furthermore, we consider that intermittent or oral administration of PC-SOD can be applied clinically to improve the quality of life of UC patients.

MDX-1100, a fully human anti-CXCL10 (IP-10) antibody, is a high affinity, neutralizing antibody that has entered Phase I clinical trials for the treatment of Ulcerative Colitis (UC). (131.20)

Abstract The chemokine, CXCL10 or interferon γ inducible protein-10 (IP-10) is a chemotactic cytokine for activated T cells and monocytes and plays an important role in migration of cells into sites of inflammation. The receptor for CXCL10, CXCR3, is expressed by activated T cells, eosinophils, NK, and endothelial cells. CXCL10 levels are elevated in ulcerative colitis (UC) amongst other inflammatory diseases. In preclinical animal models of UC, antibodies against CXCL10 have been shown to modify disease progression. Medarex, Inc. has developed a fully human monoclonal antibody (MDX-1100) that binds selectively to CXCL10. This antibody binds to the ligand with high affinity and effectively competes for ligand binding to CXCR3 expressing cells. MDX-1100 blocks CXCL10 induced calcium flux and cell migration with an estimated IC50 in the low nM range. In order to identify potential pharmacodynamic markers for CXCL10 activity, gene chip analysis was performed with RNA purified from CXCL10-stimulated human PBMCs. We identified cell surface receptors, intracellular and soluble markers that are CXCL10 responsive and confirmed the induction of a subset of these genes using quantitative RT-PCR. In summary, MDX-1100, an antibody that binds and neutralizes the activity of CXCL10 is predicted to reduce disease severity in patients with UC and thus a Phase I clinical trial has been initiated.

Suppressive effect of non-anaphylactogenic anti-IgE antibody on the development of dextran sulfate sodium-induced colitis

Inflammatory bowel disease (IBD) is a spectrum of immune-mediated chronic disorders of the intestine. Patients with IBD tend to exhibit significantly elevated levels of IgE in their serum. In general, the pathogenesis of IBD exhibits inflammatory events such as immunoglobulin E (IgE)-mediated hypersensitivity. We examined the effect of the non-anaphylactogenic anti-IgE antibody, which has been known to block IgE functions, in an animal model of ulcerative colitis induced by the oral intake of dextran sulfate sodium (DSS) for seven days. The non-anaphylactogenic anti-IgE antibody was subcutaneously injected on day 0 of DSS treatment. The disease activity index (DAI) was calculated by scoring intestinal states, including body weight loss, diarrhea, and rectal bleeding, and the activities of myeloperoxidase (MPO) and chymase were measured in the colon tissue. In addition, the expression of tumor necrosis factor (TNF)-alpha and cyclooxygenase (COX)-2 was determined by Western blotting. Administration of the anti-IgE antibody markedly reduced the histological damage to the colon and the DAI increment exhibited by the DSS-induced colitis. The anti-IgE antibody also significantly suppressed the activities of MPO and chymase as well as the expression of TNF-alpha and COX-2 in the DSS-treated colon tissue. Furthermore, the elevation of IgE levels in serum was induced by DSS and reduced by anti-IgE antibody injection. Thus, these results indicate that the IgE response played an important role in the clinical signs and the expression of inflammatory mediators in a colitis model caused by DSS treatment, suggesting that the non-anaphylactogenic anti-IgE antibody may be a useful therapeutic agent for ulcerative colitis.

Altered angiogenic balance in ulcerative colitis: A key to impaired healing?

Angiogenesis is an essential component of ulcer healing since it assures delivery of oxygen and nutrients to the healing site. Previous studies demonstrated increased serum and tissue levels of vascular endothelial growth factor (VEGF, the most potent angiogenic growth factor) in patients with active ulcerative colitis (UC) and animal models of UC. However, there is no explanation why the healing of UC-related mucosal injury is impaired despite increased expression of VEGF. Expression of angiogenesis inhibitors, angiostatin and/or endostatin, in UC has not been determined before. We examined expression of VEGF, angiostatin, and endostatin in two models of experimental UC. The results revealed that in addition to increased VEGF, both endostatin and angiostatin levels were markedly (2–3-folds) increased in colonic mucosa at early stage of experimental UC. This is the first demonstration that colitis triggers increase in angiostatin and endostatin levels. The results may explain why mucosal lesions heal slowly despite increased VEGF levels, and may provide a novel and mechanistic insight into UC.

Oxidative stress and ulcerative colitis-associated carcinogenesis: studies in humans and animal models.

The chronic inflammatory bowel disease ulcerative colitis (UC) occurs commonly in the US and other Western countries, but its etiology is unknown. An association between UC and an elevated risk for colorectal cancer is well established. UC-associated colorectal carcinogenesis is probably driven by chronic inflammation, but the mechanism is unclear. The morphological development of UC-associated cancer differs from that of its sporadic counterpart. Similarly, detailed molecular analyses have indicated that whereas many of the genetic alterations observed in sporadic colon cancers also occur in UC-associated neoplasms, the timing and frequency of those changes in the setting of UC are different. These histological and molecular signatures may very well be reflective of an inflammation-driven carcinogenesis process in UC patients. Studies in animal models of UC have helped to shed light on the mechanisms of inflammation-driven colorectal carcinogenesis. The available evidence suggests that DNA damage caused by oxidative stress in the characteristic damage-regeneration cycle is a major contributor to colorectal cancer development in UC patients. Based on this concept, iron over-nutrition is proposed as a risk factor and dietary antioxidants as protective factors for UC and associated carcinogenesis.

Interleukin-1 receptor antagonist (IL-1ra) as a probe and as a treatment for IL-1 mediated disease

The natural human IL-1 receptor antagonist (IL-1ra) has been produced in a recombinant organism and has been used to study IL-1 action in vivo. The receptor antagonist mitigates the pathophysiology associated with animal models of ulcerative colitis through reducing IL-1 mediated neutrophil recruitment into the affected tissue. It also reduces joint swelling and damage in an animal model of rheumatoid arthritis, possibly by reducing IL-1 mediated synthesis of proteases by the synovial fibroblasts and chondrocytes of the joint. The receptor antagonist is not immunosuppressive in rodents, indicating that it is working by blocking the inflammatory reaction rather than any underlying defect in specific immunity.