prostaglandin-d2 and Colitis

Nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin are one of the most frequently used classes of drug worldwide and inhibit prostaglandin (PG) production by inhibiting cyclooxygenase activity. Although NSAIDs are broadly used against inflammatory diseases, they have side effects including alimentary canal disorders, kidney damage, infection and cardiovascular disorders. Thus, it is necessary to elucidate the pathophysiological role of each PG in various diseases to develop better therapies with fewer and milder side effects. PGD

Topics: Acute Lung Injury; Animals; Capillary Permeability; Colitis; Dermatitis; Inflammation; Mice; Neoplasms; Neovascularization, Pathologic; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin

Uncontrolled macrophage functions cause failure to resolve gut inflammation and has been implicated in the pathogenesis of inflammatory bowel disease (IBD). 15-Deoxy-Δ

Topics: Animals; Anti-Inflammatory Agents; Biomarkers; Colitis; Dextran Sulfate; Disease Models, Animal; Immunologic Factors; Intestinal Mucosa; Macrophages; Male; Mice; Prostaglandin D2; STAT3 Transcription Factor; Treatment Outcome

The selenoprotein glutathione peroxidase 2 (GPx2) is highly expressed in the gastrointestinal epithelium. During inflammatory bowel disease and colorectal cancer, GPx2 expression is enhanced.. We analyzed GPx2 expression and transcriptional regulation during the different phases of dextran sulfate sodium (DSS)-induced colitis in mice and in cytokine-treated colorectal cancer cells.. In the colon of DSS-treated mice, GPx2 was upregulated during the acute and recovery phase. In the latter, it was specifically localized in regenerating ki67-positive crypts next to ulcerations. In cultured cells, endogenous GPx2 expression and GPx2 promoter activity were enhanced by the anti-inflammatory mediators 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2) and interleukin-22 (IL-22), while it was unaffected by classical proinflammatory cytokines like IL-1β. Induction of GPx2 expression by 15d-PGJ2 was mediated through Nrf2. In contrast, in DSS-treated Nrf2-KO mice GPx2 expression remained upregulated during recovery, which appeared to be independent of Nrf2. IL-22 activates transcription factors of the signal transducers and activators of transcription (STAT) family. Therefore, we analyzed the GPx2 promoter for putative STAT-responsive elements and identified 4 of them. Point mutation of the binding element next to the transcription start completely abolished promoter activation after IL-22 treatment and after cotransfection of STAT expression plasmids. To show in vivo relevance of the obtained results, we performed immunohistochemistry for phospho-STAT3 and GPx2. Especially during acute colitis, GPx2 and nuclear STAT3 colocalized in inflamed areas.. GPx2 is a novel target of STAT transcription factors. The upregulation of GPx2 by IL-22 indicates that GPx2 might be important for the resolution of inflammation.

Topics: Animals; Caco-2 Cells; Colitis; Colon; Cytokines; Dextran Sulfate; Glutathione Peroxidase; Humans; Immunologic Factors; Interleukin-22; Interleukins; Ki-67 Antigen; Mice; NF-E2-Related Factor 2; Promoter Regions, Genetic; Prostaglandin D2; STAT Transcription Factors; Up-Regulation

Bone marrow mesenchymal stem cells (BMMSCs) have been used to treat a variety of autoimmune diseases in clinics. However, the therapeutic effects are largely dependent on the immunomodulatory capacity of culture-expanded BMMSCs. In the present study, we show that aspirin (acetylsalicylic acid, ASA)-treated BMMSCs have significantly improved immunomodulatory function, as indicated by upregulation of regulatory T cells (Tregs) and downregulation of Th17 cells via the 15d-PGJ2/PPARγ/TGF-β1 pathway. Furthermore, the therapeutic effect of ASA-pretreated BMMSCs was confirmed in a dextran sodium sulfate-induced experimental colitis mouse model, in which systemic infusion of ASA-pretreated BMMSCs significantly ameliorated disease activity index and colonic inflammation, along with an increased number of Tregs and decreased number of Th17 cells. Taken together, our results suggest that aspirin treatment is a feasible strategy to promote BMMSC-based immunomodulation.

Topics: Animals; Apoptosis; Aspirin; Cell Proliferation; Cells, Cultured; Coculture Techniques; Colitis; Dinoprostone; Female; Immunomodulation; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice, Inbred C57BL; PPAR gamma; Prostaglandin D2; Signal Transduction; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta1

Compared with prostaglandin E2, which has an established role in cancer, the role of the COX metabolite prostaglandin D2 (PGD2) in chronic inflammation leading to tumorigenesis is uncertain. In this study, we investigated the role of PGD2 in colitis and colitis-associated colon cancer (CAC) using genetically modified mice and an established model of inflammatory colon carcinogenesis. Systemic genetic deficiency in hematopoietic PGD synthase (H-PGDS) aggravated colitis and accelerated tumor formation in a manner associated with increased TNFα expression. Treatment with a TNFα receptor antagonist attenuated colitis regardless of genotype. Histologic analysis revealed that infiltrated mast cells strongly expressed H-PGDS in inflamed colons. Mast cell-specific H-PGDS deficiency also aggravated colitis and accelerated CAC. In contrast, treatment with a PGD2 receptor agonist inhibited colitis and CAC. Together, our results identified mast cell-derived PGD2 as an inhibitor of colitis and CAC, with implications for its potential use in preventing or treating colon cancer.

Topics: Animals; Colitis; Colonic Neoplasms; Genotype; Intramolecular Oxidoreductases; Lipocalins; Mast Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Signal Transduction; Tumor Necrosis Factor-alpha

Proresolution functions were reported for PGD2 in colitis, but the role of its two receptors, D-type prostanoid (DP) and, in particular, chemoattractant receptor homologous molecule expressed on Th2 cells (CRTH2), is less well defined. We investigated DP and CRTH2 expression and function during human and murine ulcerative colitis (UC). Expression of receptors was measured by flow cytometry on peripheral blood leukocytes and by immunohistochemistry and immunoblotting in colon biopsies of patients with active UC and healthy individuals. Receptor involvement in UC was evaluated in a mouse model of dextran sulfate sodium colitis. DP and CRTH2 expression changed in leukocytes of patients with active UC in a differential manner. In UC patients, DP showed higher expression in neutrophils but lower in monocytes as compared with control subjects. In contrast, CRTH2 was decreased in eosinophils, NK, and CD3(+) T cells but not in monocytes and CD3(+)/CD4(+) T cells. The decrease of CRTH2 on blood eosinophils clearly correlated with disease activity. DP correlated positively with disease activity in eosinophils but inversely in neutrophils. CRTH2 internalized upon treatment with PGD2 and 11-dehydro TXB2 in eosinophils of controls. Biopsies of UC patients revealed an increase of CRTH2-positive cells in the colonic mucosa and high CRTH2 protein content. The CRTH2 antagonist CAY10595 improved, whereas the DP antagonist MK0524 worsened inflammation in murine colitis. DP and CRTH2 play differential roles in UC. Although expression of CRTH2 on blood leukocytes is downregulated in UC, CRTH2 is present in colon tissue, where it may contribute to inflammation, whereas DP most likely promotes anti-inflammatory actions.

Topics: Adolescent; Adult; Animals; Blotting, Western; CD3 Complex; Colitis; Colitis, Ulcerative; Colon; Dextran Sulfate; Female; Flow Cytometry; Humans; Immunohistochemistry; Indoles; Killer Cells, Natural; Male; Mice; Mice, Inbred C57BL; Middle Aged; Neutrophils; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; T-Lymphocytes; Th2 Cells; Young Adult

Psychological stress has been implicated in the clinical course of several gastrointestinal diseases, but the mechanisms implicated and the effects of stress on the normal colon are not yet fully understood.. Male Wistar rats were exposed to various immobilization periods as a stress paradigm. Colon was processed to assess myeloperoxidase activity, nitric oxide synthase 2, cyclooxygenase 2, and peroxisome proliferator-activated receptor gamma (PPARgamma) expression and production of prostaglandins. Colonic permeability, bacterial translocation, tight junctions ultrastructure, and immunoglobulin (Ig) A levels were also evaluated.. Exposure to acute (6 hours) immobilization stress produced an increase in myeloperoxidase activity and nitric oxide synthase 2 and cyclooxygenase 2 expression. All these parameters remained increased after 5 days of repeated stress exposure, showing a trend to normalize after 10 days. Levels of the anti-inflammatory eicosanoid 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) and expression of PPARgamma run parallel with these changes. Colonic epithelial barrier was altered after stress exposure, and a significant decrease in colonic IgA levels after acute stress exposure was observed. Pretreatment with PPARgamma agonists 15d-PGJ(2) and rosiglitazone prevented colonic inflammation and barrier dysfunction as well as the decrease of IgA production induced after acute stress; PPARgamma specific antagonist T0070907 reverted these effects.. Activation of PPARgamma in rat colon in vivo seems to counteract colonic inflammation and dysfunction induced by stress. On the other hand, PPARgamma ligands may be therapeutically useful in conditions in which inflammation and barrier dysfunction takes place in colon after exposure to stress.

Topics: Animals; Bacterial Translocation; Benzamides; Colitis; Colon; Corticosterone; Cyclooxygenase 2; Gene Expression Regulation, Enzymologic; Homeostasis; Intestinal Absorption; Ligands; Male; Nitric Oxide Synthase Type II; Peroxidase; PPAR gamma; Prostaglandin D2; Pyridines; Rats; Rats, Wistar; Restraint, Physical; Rosiglitazone; Stress, Physiological; Thiazolidinediones

Neutrophil infiltration, proinflammatory cytokines, eicosanoid generation and oxidative stress have been implicated in colitis. Resveratrol is a polyphenolic compound found in grapes and wine, with multiple pharmacological actions, including anti-inflammatory, antioxidant, antitumour and immunomodulatory activities. In a previous report, we documented that resveratrol decreases the degree of inflammation associated with acute experimental colonic inflammation, but its effects on chronic experimental colitis remain undetermined. The aim of this research was to investigate the effects of resveratrol on the chronic colonic injury caused by intracolonic instillation of trinitrobenzenesulphonic acid (TNBS) in rats. The inflammatory response was assessed by histology and myeloperoxidase activity. Tumour necrosis factor alpha (TNF-alpha) production, histological and histochemical analysis of the lesions were also carried out. We determined the production of prostaglandin (PG) E2 and D2 in colon mucosa, as well as cyclooxygenase (COX)-1 and -2 and nuclear transcription factor NF-kappa B (NF-kappaB) p65 protein expression. Finally, since resveratrol has been found to modulate apoptosis, we intended to elucidate its effects on colonic mucosa under chronic inflammatory conditions. Resveratrol (10 mg kg(-1) day(-1)) significantly attenuated the damage score and corrected the disturbances in morphology associated to injury. In addition, the degree of neutrophil infiltration and the levels of TNF-alpha were significantly ameliorated. Resveratrol did not modify PGD2 levels but returned the decreased PGE2 values to basal levels and also reduced COX-2 and the NF-kappaB p65 protein expression. Furthermore, treatment of rats with resveratrol caused a significant increase of TNBS-induced apoptosis in colonic cells. In conclusion, resveratrol reduces the damage in chronic experimentally induced colitis, alleviates the oxidative events, returns PGE2 production to basal levels and stimulates apoptosis in colonic cells.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Colitis; Colon; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Gene Expression Regulation; Inflammation; Male; Membrane Proteins; NF-kappa B; Peroxidase; Phytoalexins; Prostaglandin D2; Rats; Rats, Wistar; Resveratrol; Sesquiterpenes; Stilbenes; Terpenes; Trinitrobenzenesulfonic Acid; Tumor Necrosis Factor-alpha; Wine

Curcumin is a widely used spice with anti-inflammatory and anti-cancer properties. It has been reported that curcumin held therapeutic effects on experimental colitis by inhibition of nuclear factor kappa B (NF-kappaB). The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor with anti-tumor and anti-inflammatory effects and its activation may inhibit the nuclear translocation of NF-kappaB. Several studies have shown that PPARgamma ligands had an important therapeutic effect in colitis. However there is no report about the alteration of PPARgamma in trinitrobenzene sulphonic acid (TNBS)-induced colitis treated with curcumin. In this study, we administered curcumin (30 mg/kg/day) by intraperitoneal injection immediately after colitis was induced and the injection lasted for two weeks. have evaluated the effects of curcumin on the colitis induced by trinitrobenzene sulphonic acid (TNBS). Curcumin (30 mg/kg d) was administered by intraperitoneal just after colitis was induced and lasted for two weeks. Therapeutic effects of dexamethasone (Dex, 2 mg/kg d) alone and the combined effects of curcumin+Dex were also examined. We found that curcumin improved long-term survival rate of disease-bearing rats, promoted rat body weight recovery, and decreased macroscopic scores of the colitis. The expression levels of PPARgamma, 15-deoxy-D12,14-prostaglandin J(2) (15d-PGJ(2)) and prostaglandin E(2) (PGE(2)) were all increased, but the expression level of cyclooxygenase-2 (COX-2) was decreased in rats after administration of curcumin. Treatment with Dex improved PPARgamma expression and inhibited the expression of COX-2, 15d-PGJ(2) and PGE(2). Combined effects of curcumin+Dex were similar to that of Dex. In summary, curcumin showed therapeutic effects on TNBS-induced colitis and the mechanisms by which curcumin exerts its effects may involve activation of PPARgamma and its ligands.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Colitis; Colon; Curcumin; Cyclooxygenase 2; Cytokines; Dexamethasone; Dinoprostone; Drug Therapy, Combination; Enzyme-Linked Immunosorbent Assay; Gene Expression; PPAR gamma; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Specific Pathogen-Free Organisms; Time Factors; Trinitrobenzenesulfonic Acid; Weight Loss

Colitis involves immune cell-mediated tissue injuries, but the contribution of epithelial cells remains largely unclear. Vanin-1 is an epithelial ectoenzyme with a pantetheinase activity that provides cysteamine/cystamine to tissue. Using the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-colitis model we show here that Vanin-1 deficiency protects from colitis. This protection is reversible by administration of cystamine or bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor (PPAR)gamma antagonist. We further demonstrate that Vanin-1, by antagonizing PPARgamma, licenses the production of inflammatory mediators by intestinal epithelial cells. We propose that Vanin-1 is an epithelial sensor of stress that exerts a dominant control over innate immune responses in tissue. Thus, the Vanin-1/pantetheinase activity might be a new target for therapeutic intervention in inflammatory bowel disease.

Topics: Active Transport, Cell Nucleus; Amidohydrolases; Animals; Benzhydryl Compounds; Body Weight; Cell Adhesion Molecules; Cell Line; Cell Nucleus; Chemokine CCL2; Chemokine CXCL2; Chemokines; Colitis; Colon; Cyclooxygenase 2; Cystamine; Cytokines; Epithelial Cells; Epoxy Compounds; Gene Expression Regulation; GPI-Linked Proteins; Interleukin-1beta; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, SCID; PPAR gamma; Prostaglandin D2; Survival Analysis; Trinitrobenzenesulfonic Acid

We have evaluated the efficacy of the selective cyclo-oxygenase (COX)-2 inhibitor, rofecoxib, for the prevention of experimental colitis.. To induce colitis BALB/c mice received 5% dextran sulphate sodium (DSS) in their drinking water continuously for 7 days. Rofecoxib (2.5-10 mg/kg body weight, p.o.) was administered throughout the treatment period with DSS. Colitis was quantified by a clinical damage score, colon length, weight loss, stool consistency and rectal bleeding. Inflammatory response was assessed by neutrophil infiltration, determined by histology and myeloperoxidase (MPO) activity. Interleukin (IL)-1beta, prostaglandin (PG)E2 and PGD2 levels in colon mucosa and the immunohistochemical expression of COX-1 and -2 were also studied.. The COX-2 inhibitor ameliorated severe colitis, reduced the degree of inflammation through reduction of neutrophil infiltration and IL-1beta levels. PGE2, and PGD2 synthesis were significantly reduced in DSS-treated groups. Indeed, treatment with rofecoxib diminished the lost of COX-1 caused by DSS in the crypt epithelium whereas expression of COX-2 remained unaffected.. Rofecoxib is protective in acute DSS-induced colitis, probably by reducing neutrophil infiltration, inhibiting up-regulation of IL-1beta and returning to normal COX-1 expression in the inflamed colonic mucosa.

Topics: Animals; Colitis; Cyclooxygenase 1; Cyclooxygenase Inhibitors; Dextran Sulfate; Dinoprostone; Immunohistochemistry; Lactones; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Prostaglandin D2; Sulfones

Colitis markedly increases the risk of developing colon cancer, but the underlying mechanisms are not fully understood. In a rat model of colitis, alterations in epithelial secretion, proliferation, and barrier function persist long after healing has occurred. In the present study, we examined whether rats that have recovered from a bout of colitis are more susceptible to preneoplastic lesions and whether this susceptibility is mediated by cyclooxygenase (COX)-2-derived prostaglandin (PG) D2. Colitis was induced by intracolonic administration of trinitrobenzenesulfonic acid. Six weeks later, weekly treatment with the carcinogen azoxymethane was initiated. Postcolitis rats exhibited significantly more aberrant crypt foci after azoxymethane treatment than controls. The postcolitis rats also exhibited markedly increased colonic PGD2 synthesis and elevated COX-2, H-PGD synthase, and beta-catenin expression. Treatment for 1 week with a selective COX-2 inhibitor or with a selective PGD2 receptor (DP1) antagonist significantly reduced susceptibility of postcolitis rats to aberrant crypt foci development, beta-catenin expression, and mucosal thickness. The results from this animal model suggest that prolonged elevation of COX-2-derived PGD2 synthesis after resolution of colitis may contribute significantly to colitis-associated increases in colon cancer incidence. PGD2 may therefore represent a rational target for therapies directed at reducing the incidence of colitis-associated colorectal cancer.

Topics: Animals; Azoxymethane; beta Catenin; Colitis; Colon; Colorectal Neoplasms; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Disease Susceptibility; Intramolecular Oxidoreductases; Lipocalins; Male; Prostaglandin D2; Rats; Rats, Wistar; Receptors, Immunologic; Receptors, Prostaglandin; Trinitrobenzenesulfonic Acid

1. Inflammatory bowel disease (IBD) is characterized by oxidative and nitrosative stress, leukocyte infiltration, and increased expression of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) in the colon. Recent evidence also suggests that the cyclopentenone prostaglandin (PG) 15-deoxy-delta(12,14)-PGJ(2) (15d- PGJ(2)) functions as an early anti-inflammatory signal. 2. The aim of the present paper is to investigate the effects of 15d-PGJ(2) in rats subjected to experimental colitis. 3. Colitis was induced in rats by intra-colonic instillation of dinitrobenzene sulphonic acid (DNBS). 15d-PGJ(2) was administered daily as intraperitoneal injection (20 or 40 microg kg(-1)). On day 4, animals were sacrificed and tissues were taken for histological and biochemical analysis. 4. 15d-PGJ(2) significantly reduced the degree of haemorrhagic diarrhoea and weight loss caused by administration of DNBS. 15d-PGJ(2) also caused a substantial reduction of (i) the degree of colonic injury, (ii) the rise in myeloperoxidase (MPO) activity (mucosa), (iii) the increase in the tissue levels of malondialdehyde (MDA) and (iv) of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta). 5. Furthermore, 15d-PGJ(2) reduced the increase in immunohistochemical staining for (i) inducible nitric oxide synthase (iNOS), (ii) nitrotyrosine and (iii) poly (ADP-ribose) polymerase (PARP), as well as (iv) the increased expression of ICAM-1 caused by DNBS in the colon. 6. Electrophoresis mobility shift assay (EMSA) of inflamed colon revealed that 15d- PGJ(2) also caused a substantial reduction of the activation of nuclear factor-kappaB (NF-kappaB). Furthermore, 15d-PGJ(2) stimulates the activation of heat shock protein 72 (hsp72) in the inflamed colon, as assessed by Western blot analysis. 7. In conclusion, 15d-PGJ(2) reduces the development of experimental colitis.

Topics: Animals; Benzenesulfonates; Colitis; Colon; Male; Prostaglandin D2; Rats; Rats, Sprague-Dawley

The colonic epithelium plays a key role in host defence. During colitis, epithelial function is impaired, leading to elevated bacterial translocation and exacerbation of inflammation. We previously documented perturbation of epithelial function, in terms of secretion and as a barrier to bacterial translocation, that persisted long after resolution of a bout of colitis in the rat. The mechanisms underlying the epithelial dysfunction are not completely understood.. Given the ability of prostaglandin (PG) D2 to suppress colonic epithelial secretion, we investigated the potential roles of this eicosanoid and of cyclooxygenase 2 (COX-2) in mediating post-colitis epithelial secretory and barrier dysfunction.. Six weeks after induction of colitis with trinitrobenzene sulphonic acid, there was marked elevated synthesis of PGD2 and elevated COX-2 expression. Selective COX-2 inhibition abolished the increase in PGD2 synthesis. Colonic chloride secretory responses (in vitro) were significantly diminished relative to those in controls, a defect that was reversed by pre-exposure to a selective COX-2 inhibitor (celecoxib) but not to a selective COX-1 inhibitor (SC-560). The hyporesponsiveness was mimicked by pre-exposure of normal colonic tissue to PGD2, but not to its metabolite, 15-deoxy-Delta(12-14)PGJ2. The post-colitis rats exhibited a 10-fold increase in bacterial colonisation of the colon, and >3-fold increase in bacterial translocation. Twice daily treatment for one week with a selective COX-2 inhibitor (rofecoxib) did not affect bacterial colonisation but abolished the increase in bacterial translocation.. These studies demonstrate an important role for COX-2, possibly via generation of PGD2, in mediating the prolonged epithelial secretory and barrier dysfunction after a bout of colitis in the rat.

Topics: Animals; Bacterial Translocation; Colitis; Colon; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Intestinal Mucosa; Isoenzymes; Male; Membrane Proteins; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar

The ability of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors to exacerbate inflammatory bowel disease suggests that prostaglandins are important anti-inflammatory mediators in this context. Prostaglandin D(2) has been suggested to exert anti-inflammatory effects. We investigated the possibility that prostaglandin D(2) derived from cyclooxygenase-2 plays an important role in downregulating colonic inflammation in rats. Colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid. At various times thereafter (from 1 h to 7 days), colonic prostaglandin synthesis and myeloperoxidase activity (index of granulocyte infiltration) were measured. Prostaglandin D(2) synthesis was elevated >4-fold above controls within 1-3 h of induction of colitis, preceding significant granulocyte infiltration. Treatment with a selective cyclooxygenase-2 inhibitor abolished the increase in prostaglandin D(2) synthesis and caused a doubling of granulocyte infiltration. Colonic granulocyte infiltration was significantly reduced by administration of prostaglandin D(2) or a DP receptor agonist (BW-245C). These results demonstrate that induction of colitis results in a rapid increase in prostaglandin D(2) synthesis via cyclooxygenase-2. Prostaglandin D(2) downregulates granulocyte infiltration into the colonic mucosa, probably through the DP receptor.

Topics: Animals; Blotting, Western; Celecoxib; Colitis; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Hydantoins; Indomethacin; Intramolecular Oxidoreductases; Isoenzymes; Lipocalins; Male; Necrosis; Neutrophils; Peroxidase; Peroxisomes; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Pyrazoles; Rats; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Receptors, Immunologic; Receptors, Prostaglandin; RNA, Messenger; Sulfonamides; Transcription Factors

Peroxisome proliferator-activated receptor gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily originally shown to play a critical role in adipocyte differentiation and glucose homeostasis, has recently been implicated as a regulator of cellular proliferation and inflammatory responses. Colonic epithelial cells, which express high levels of PPAR-gamma protein, have the ability to produce inflammatory cytokines that may play a role in inflammatory bowel disease (IBD). We report here that PPAR-gamma ligands dramatically attenuate cytokine gene expression in colon cancer cell lines by inhibiting the activation of nuclear factor-kappaB via an IkappaB-alpha-dependent mechanism. Moreover, thiazolidinedione ligands for PPAR-gamma markedly reduce colonic inflammation in a mouse model of IBD. These results suggest that colonic PPAR-gamma may be a therapeutic target in humans suffering from IBD.

Topics: Animals; Caco-2 Cells; Colitis; Cytokines; DNA-Binding Proteins; Epithelium; Gene Expression; HT29 Cells; Humans; I-kappa B Proteins; Inflammation; Inflammatory Bowel Diseases; Interleukin-8; Ligands; Mice; Microbodies; NF-kappa B; NF-KappaB Inhibitor alpha; Prostaglandin D2; Receptors, Cytoplasmic and Nuclear; Rosiglitazone; Thiazoles; Thiazolidinediones; Transcription Factors