vasoactive-intestinal-peptide and Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) which is related to an immunological imbalance of the intestinal mucosa. Many clinical evidences indicate probiotics supplementation appears to be effective and safe in patients with UC. Vasoactive intestinal peptide (VIP) is an endogenous neuropeptide with multiple physiological and pathological effects. In this study, we investigated the protective effect of the combination of Lactobacillus casei ATCC 393 (L. casei ATCC 393) with VIP on dextran sodium sulfate (DSS)-induced UC in mice and the potential mechanism. The results showed that, compared with the control group, DSS treatment significantly shortened the colon length, caused inflammation and oxidative stress, and further resulted in the intestinal barrier dysfunction and gut microbiota dysbiosis. In addition, intervention with L. casei ATCC 393, VIP or L. casei ATCC 393 combined with VIP significantly reduced UC disease activity index. However, compared with L. casei ATCC 393 or VIP, L. casei ATCC 393 combined with VIP effectively relieved symptoms of UC by regulating immune response, enhancing antioxidant capacity, and regulating nuclear factor kappa-B (NF-κB) and nuclear factor erythroid-derived-2-like 2 (Nrf2) signaling pathways. In conclusion, this study suggests that L. casei ATCC 393 combined with VIP can effectively relieve DSS-induced UC, which is a promising treatment strategy for UC.

Topics: Animals; Colitis; Colitis, Ulcerative; Colon; Dextran Sulfate; Dextrans; Disease Models, Animal; Gastrointestinal Diseases; Lacticaseibacillus casei; Mice; Mice, Inbred C57BL; NF-E2-Related Factor 2; NF-kappa B; Signal Transduction; Vasoactive Intestinal Peptide

Atractylodes lancea (Thunb.) DC. is a widely used traditional herb that is well known for treating spleen deficiency and diarrhea. According to traditional Chinese medicine (TCM) theory, diarrhea-predominant irritable bowel syndrome (IBS-D) is caused by cold and dampness, resulting in diarrhea and abdominal pain. Nevertheless, the effect and mechanism of Atractylodes on IBS-D are still unclear.. This study was designed to confirm the therapeutic effect of Atractylodes lanceolata oil (AO) in a rat model of IBS-D, and to determine the mechanisms by which AO protects against the disease.. The chemical components in AO were determined using gas chromatography-mass spectrometry (GC-MS). The expression levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal peptide (VIP), and surfactant protein (SP) in serum and colon tissue were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR), western blotting (WB), immunohistochemistry (IHC), and immunofluorescence (IF) were used to elucidate the mechanism of action of AO toward inflammation and the intestinal barrier in a rat model of IBS-D.. The 15 chemical substances of the highest concentration in AO were identified using GC-MS. AO was effective against IBS-D in the rat model, in terms of increased body weight, diarrhea grade score, levels of interleukin-10 (IL-10), aquaporin 3 (AQP3), and aquaporin 8 (AQP8), and reduced fecal moisture content, levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), 5-HT, VIP, and SP, while also reducing intestinal injury, as observed using hematoxylin-eosin (HE) staining. In addition, the results indicated that AO increased the mRNA and protein expression levels of stem cell factor (SCF) and c-kit and enhanced the levels of zonula occludens-1 (ZO-1) and occludin, as well as decreased the levels of myosin light chain kinase (MLCK) and inhibited the phosphorylation of myosin light chain 2 (p-MLC2).. AO was found to be efficacious in the rat model of IBS-D. AO inhibited the SCF/c-kit pathway, thereby reducing inflammation and protecting against intestinal barrier damage via the MLCK/MLC2 pathway.

Topics: Animals; Aquaporins; Atractylodes; Colitis; Cytokines; Diarrhea; Intestinal Mucosa; Irritable Bowel Syndrome; Myosin Light Chains; Myosin-Light-Chain Kinase; Plant Oils; Proto-Oncogene Proteins c-kit; Rats, Sprague-Dawley; Serotonin; Signal Transduction; Stem Cell Factor; Tight Junction Proteins; Vasoactive Intestinal Peptide

Topics: Animals; Capsules; Colitis; Male; Mice; Mice, Inbred C57BL; Nanomedicine; Vasoactive Intestinal Peptide

To evaluate the efficacy of vasoactive intestinal peptide (VIP) in treating ulcerative colitis (UC), targeting colonic mitochondrial dysfunction by virtue of its free radical scavenging properties for maintenance of colon mucosal integrity.. A murine model was administered with dextran sodium sulfate (DSS) to induce colitis in C57BL/6J mice at 3.5%/g bodyweight for 3 cycles of 5 days each, followed by an intraperitoneal dose of VIP at 0.5 nmol/L per mouse per day for 10 days. The post-treatment mice were sacrificed and their colon samples were utilized for further analysis. To substantiate the in vivo findings and identify the reactive species involved in progression of UC, Caco-2 cells were subjected to DSS (5%) for 24 hours at 37 °C with or without VIP (10 nmol/L) in the presence or absence of specific free radical scavengers and antioxidants.. Treatment with VIP reduced histopathological severity of colitis and cell death markers in murine model, leading to partial recovery of inhibited mitochondrial respiratory complexes, altered mitochondrial membrane potential and lowered adenosine triphosphate generation. Interestingly, in vitro treatment with VIP restored mitochondrial functions and its efficacy was equal to super oxide dismutase and dimethyl sulfoxide, indicating involvement of superoxide free radical (O. By virtue of its free radical scavenging properties VIP can act as a potent anti-colitogenic agent, reversing colonic mitochondrial dysfunction for treating UC.

Topics: Animals; Caco-2 Cells; Colitis; Colitis, Ulcerative; Colon; Dextran Sulfate; Disease Models, Animal; Humans; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Mitochondria; Vasoactive Intestinal Peptide

Citrobacter rodentium infection is a model for infection with attaching and effacing pathogens, such as enteropathogenic Escherichia coli. The vasoactive intestinal peptide (VIP) has emerged as an anti-inflammatory agent, documented to inhibit Th1 immune responses and successfully treat animal models of inflammation. VIP is also a mucus secretagogue. Here, we found that colonic levels of VIP decrease during murine C. rodentium infection with a similar time dependency as measurements reflecting mitochondrial function and epithelial integrity. The decrease in VIP appears mainly driven by changes in the cytokine environment, as no changes in VIP levels were detected in infected mice lacking interferon gamma (IFNγ). VIP supplementation alleviated the reduction of activity and levels of mitochondrial respiratory complexes I and IV, mitochondrial phosphorylation capacity, transmembrane potential and ATP generation caused by IFNγ, TNFα and C. rodentium infection, in an in vitro mucosal surface. Similarly, VIP treatment regimens that included the day 5-10 post infection period alleviated decreases in enzyme complexes I and IV, phosphorylation capacity, mitochondrial transmembrane potential and ATP generation as well as increased apoptosis levels during murine infection with C. rodentium. However, VIP treatment failed to alleviate colitis, although there was a tendency to decreased pathogen density in contact with the epithelium and in the spleen. Both in vivo and in vitro, NO generation increased during C. rodentium infection, which was alleviated by VIP. Thus, therapeutic VIP administration to restore the decreased levels during infection had beneficial effects on epithelial cells and their mitochondria, but not on the overall infection outcome.

Topics: Animals; Citrobacter rodentium; Colitis; Colon; Disease Models, Animal; Electron Transport Complex I; Electron Transport Complex IV; Enterobacteriaceae Infections; Host Microbial Interactions; HT29 Cells; Humans; Interferon-gamma; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Mitochondria; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the intestine, with increasing incidence worldwide. At present, the management of IBD is an unmet medical need due to the ineffectiveness of currently available drugs in treating all patients, and there is strong demand for novel therapeutics. In this regard, vasoactive intestinal peptide, a potent anti-inflammatory endogenous hormone, has shown promise in managing multiple immune disorders in animal models. However, when administered in the free form, VIP undergoes rapid degradation in vivo, and with continuous infusion, it causes severe dose limiting side effects. To overcome these barriers, we have developed a superior mode to deliver VIP in its native form, using sterically stabilized micelles (VIP-SSM). Our previous studies demonstrated that, VIP, when administered in SSM, prevented joint damage and inflammation in a mouse model of rheumatoid arthritis at a significantly lower dose than the free peptide, completely abrogating the serious side effect of hypotension associated with VIP. In the current study, we demonstrate the therapeutic benefit of VIP-SSM over free peptide in reversing severe colitis associated with IBD. First, we conducted preliminary studies with dextran sulfate sodium (DSS) induced colitis in mice, to determine the effectiveness of VIP administered on alternate days in reducing disease severity. Thereafter, a single intra peritoneal injection of VIP-SSM or the free peptide was used to determine its therapeutic effect on the reversal of colitis and associated diarrhea. The results demonstrated that when administered on alternate days, both VIP-SSM and VIP were capable of alleviating DSS colitis in mice. However, when administered as a single dose, in a therapeutic setting, VIP-SSM showed superior benefits compared to the free peptide in ameliorating colitis phenotype. Namely, the loss of solid fecal pellets and increased fluid accumulation in colon resulting from DSS insult was abrogated in VIP-SSM treated mice and not with free VIP. Furthermore, reduced protein and mRNA levels of the major chloride bicarbonate exchanger, down regulated in adenoma (DRA), seen with DSS was reversed with VIP-SSM, but not with the free peptide. Similarly, VIP-SSM treatment significantly reduced the elevated mRNA levels of pro-inflammatory cytokines and showed significant histologic recovery when compared to mice treated with free VIP. Therefore, these results demonstrated that as a si

Topics: Animals; Colitis; Colitis, Ulcerative; Dextran Sulfate; Humans; Inflammatory Bowel Diseases; Mice; Micelles; Nanomedicine; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) is an immunomodulatory neuropeptide with therapeutic properties in multiple murine models of inflammatory disease including the trinitrobenzene-sulfonic acid (TNBS)-colitis model of Crohn's disease. Understanding the spectrum of biological actions of endogenously produced VIP may help us dissect the complex and multifactorial pathogenesis of such inflammatory diseases. Our goal was to determine the contribution of endogenously produced VIP to TNBS-colitis by using VIP knockout (KO) mice.. TNBS was intracolonically administered to wild-type (WT) and VIP KO mice, and weight loss and colitis were assessed over time. Colon histopathological changes and myeloperoxidase activities were analyzed and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in colon and serum quantified. The proliferative response in vitro of splenocytes from TNBS WT and VIP KO administered mice to anti-CD3 and anti-CD28 was determined.. VIP KO mice did not exhibit the predicted exacerbated response to TNBS. Instead, they developed a milder clinical profile than WT mice, with lower TNF-α and IL-6 levels. Such potential defects seem selective, because other parameters such as the histopathological scores and the cytokine levels in the colon did not differ between the two strains of mice. Moreover, splenocytes from TNBS-treated VIP KO mice exhibited an enhanced proliferative response to anti-CD3/CD28 stimulation in vitro.. Chronic loss of VIP in mice leads to a disruption of certain but not all immunological compartments, corroborating recent findings that VIP KO mice exhibit reduced mortality in the lipopolysaccharide-induced endotoxemia model and attenuated clinical development of experimental autoimmune encephalomyelitis while developing robust T-cell responses.

Topics: Animals; Cell Proliferation; Colitis; Colon; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxidase; RNA, Messenger; T-Lymphocytes; Time Factors; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

We previously showed that vasoactive intestinal peptide (VIP) protects against bacterial pathogen-induced epithelial barrier disruption and colitis, although the mechanisms remain poorly defined. The aim of the current study was to identify cellular pathways of VIP-mediated protection with use of pharmacological inhibitors during enteropathogenic Escherichia coli (EPEC) infection of Caco-2 cell monolayers and during Citrobacter rodentium-induced colitis. EPEC-induced epithelial barrier disruption involved the PKC pathway but was independent of functional cAMP, Rho, and NF-κB pathways. VIP mediated its protective effects by inhibiting EPEC-induced PKC activity and increasing expression of the junctional protein claudin-4. Short-term treatment with TPA, which is known to activate PKC, was inhibited by VIP pretreatment, while PKC degradation via long-term treatment with TPA mimicked the protective actions of VIP. Immunostaining for specific PKC isotypes showed upregulated expression of PKCθ and PKCε during EPEC infection. Treatment with specific inhibitors revealed a critical role for PKCε in EPEC-induced barrier disruption. Furthermore, activation of PKCε and loss of barrier integrity correlated with claudin-4 degradation. In contrast, inhibition of PKCε by VIP pretreatment or the PKCε inhibitor maintained membrane-bound claudin-4 levels, along with barrier function. Finally, in vivo treatment with the PKCε inhibitor protected mice from C. rodentium-induced colitis. In conclusion, EPEC infection increases intracellular PKCε levels, leading to decreased claudin-4 levels and compromising epithelial barrier integrity. VIP inhibits PKCε activation, thereby attenuating EPEC-induced barrier disruption.

Topics: Adult; Aged; Animals; Caco-2 Cells; Cells, Cultured; Citrobacter rodentium; Claudin-4; Colitis; Cyclic AMP; Enteropathogenic Escherichia coli; Escherichia coli Infections; Female; HT29 Cells; Humans; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Protein Kinase C-epsilon; rho-Associated Kinases; Vasoactive Intestinal Peptide

To investigate the vasoactive intestinal peptides (VIP) expression in irritable bowel syndrome (IBS) and trinitrobenzene sulfonic acid (TNBS) induced colitis.. The VIP gene expression and protein plasma levels were measured in adult participants (45.8% male) who met Rome III criteria for IBS for longer than 6 mo and in a rat model of colitis as induced by TNBS. Plasma and colons were collected from naïve and inflamed rats. Markers assessing inflammation (i.e., weight changes and myeloperoxidase levels) were assessed on days 2, 7, 14 and 28 and compared to controls. Visceral hypersensitivity of the rats was assessed with colo-rectal distension and mechanical threshold testing on hind paws. IBS patients (n = 12) were age, gender, race, and BMI-matched with healthy controls (n = 12). Peripheral whole blood and plasma from fasting participants was collected and VIP plasma levels were assayed using a VIP peptide-enzyme immunoassay. Human gene expression of VIP was analyzed using a custom PCR array.. TNBS induced colitis in the rats was confirmed with weight loss (13.7 ± 3.2 g) and increased myeloperoxidase activity. Visceral hypersensitivity to colo-rectal distension was increased in TNBS treated rats up to 21 d and resolved by day 28. Somatic hypersensitivity was also increased up to 14 d post TNBS induction of colitis. The expression of an inflammatory marker myeloperoxidase was significantly elevated in the intracellular granules of neutrophils in rat models following TNBS treatment compared to naïve rats. This confirmed the induction of inflammation in rats following TNBS treatment. VIP plasma concentration was significantly increased in rats following TNBS treatment as compared to naïve animals (P < 0.05). Likewise, the VIP gene expression from peripheral whole blood was significantly upregulated by 2.91-fold in IBS patients when compared to controls (P < 0.00001; 95%CI). VIP plasma protein was not significantly different when compared with controls (P = 0.193).. Alterations in VIP expression may play a role in IBS. Therefore, a better understanding of the physiology of VIP could lead to new therapeutics.

Topics: Adult; Animals; Biomarkers; Case-Control Studies; Colitis; Colon; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Hyperalgesia; Inflammation Mediators; Irritable Bowel Syndrome; Male; Middle Aged; Pain Threshold; Peroxidase; Pilot Projects; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Time Factors; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide; Visceral Pain; Weight Loss; Young Adult

Inflammatory bowel disease is a chronic gastrointestinal inflammatory disorder associated with changes in neuropeptide expression and function, including vasoactive intestinal peptide (VIP). VIP regulates intestinal vasomotor and secretomotor function and motility; however, VIP's role in development and maintenance of colonic epithelial barrier homeostasis is unclear. Using VIP deficient (VIPKO) mice, we investigated VIP's role in epithelial barrier homeostasis, and susceptibility to colitis. Colonic crypt morphology and epithelial barrier homeostasis were assessed in wildtype (WT) and VIPKO mice, at baseline. Colitic responses were evaluated following dinitrobenzene sulfonic acid (DNBS) or dextran-sodium sulfate (DSS) exposure. Mice were also treated with exogenous VIP. At baseline, VIPKO mice exhibited distorted colonic crypts, defects in epithelial cell proliferation and migration, increased apoptosis, and altered permeability. VIPKO mice also displayed reduced goblet cell numbers, and reduced expression of secreted goblet cell factors mucin 2 and trefoil factor 3. These changes were associated with reduced expression of caudal type homeobox 2 (Cdx2), a master regulator of intestinal function and homeostasis. DNBS and DSS-induced colitis were more severe in VIPKO than WT mice. VIP treatment rescued the phenotype, protecting VIPKO mice against DSS colitis, with results comparable to WT mice. In conclusion, VIP plays a crucial role in the development and maintenance of colonic epithelial barrier integrity under physiological conditions and promotes epithelial repair and homeostasis during colitis.

Topics: Animals; CDX2 Transcription Factor; Cell Count; Colitis; Dinitrofluorobenzene; Disease Susceptibility; Epithelial Cells; Goblet Cells; Homeodomain Proteins; Homeostasis; Intestines; Male; Mice, Inbred C57BL; Mice, Knockout; Protective Agents; Real-Time Polymerase Chain Reaction; Signal Transduction; Transcription Factors; Vasoactive Intestinal Peptide

VIP is highly expressed in the colon and regulates motility, vasodilatation, and sphincter relaxation. However, its role in the development and progress of colitis is still controversial. Our aim was to determine the participation of VIP on dextran sodium sulfate (DSS)-induced colonic mucosal inflammation using VIP(-/-) and WT mice treated with VIP antagonists. Colitis was induced in 32 adult VIP(-/-) and 14 age-matched WT litter-mates by giving 2.5 % DSS in the drinking water. DSS-treated WT mice were injected daily with VIP antagonists, VIPHyb (n = 22), PG 97-269 (n = 9), or vehicle (n = 31). After euthanasia, colons were examined; colonic cytokines mRNA were quantified. VIP(-/-) mice were remarkably resistant to DSS-induced colitis compared to WT. Similarly, DSS-treated WT mice injected with VIPHyb (1 μM) or PG 97-269 (1 nM) had significantly reduced clinical signs of colitis. Furthermore, colonic expression of IL-1ϐ, TNF-α, and IL-6 was significantly lower in VIP(-/-) and VIPHyb or PG 97-269 compared to vehicle-treated WT. Genetic deletion of VIP or pharmacological inhibition of VIP receptors resulted in resistance to colitis. These data demonstrate a pro-inflammatory role for VIP in murine colitis and suggest that VIP antagonists may be an effective clinical treatment for human inflammatory bowel diseases.

Topics: Animals; Colitis; Cytokines; Dextran Sulfate; Gene Deletion; Interleukins; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Neurotensin; Recombinant Fusion Proteins; RNA, Messenger; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

To clarify the role of mast cells and neuropeptides substance P (SP), somatostatin (SS), and vasoactive intestinal peptide (VIP) in dextran sulfate sodium (DSS)-induced colitis in rats.. Experimental colitis was induced in Sprague-Dawley rats (180-200 g, n=20) by oral ingestion of 4% (w/v) DSS in drinking water for 7 days. Control rats (n=5) drank water and were sacrificed on day 0. Mast cell number, histamine levels in whole blood and tissue, tissue levels of SP, SS and, VIP in the distal colon of the rats were measured on day 8, day 13, and day 18 of experimentation.. Oral administration of 4% DSS solution for 7 days resulted in surface epithelial loss and crypt loss in the distal colon. Mast cell count increased on day 8 (1.75±1.09/mm vs. 0.38±0.24/mm, P<0.05) and day 13 (1.55±1.01/mm vs. 0.38±0.24/mm, P<0.05) after DSS treatment. Whole blood histamine levels were increased on day 8 (266.93±35.62 ng/mL vs. 76.87±32.28 ng/mL, P<0.01) and gradually decreased by day 13 and day 18 after DSS treatment. Histamine levels in the distal colon were decreased on day 8 (1.77±0.65 ng/mg vs. 3.06±0.87 ng/mg, P<0.05) and recovered to control levels by day 13 after DSS treatment. SP level in the distal colon gradually increased and were raised significantly by day 13 (8777.14±3056.14 pg/mL vs. 4739.66±3299.81 pg/mL, P<0.05) after DSS treatment. SS and VIP levels in the distal colon were not changed.. Mast cell degranulation followed by histamine release may play an important role in the pathogenesis of colitis induced by DSS. SP may be a significant substance in the progression of inflammation and the recovery process of DSS-induced colitis.

Topics: Animals; Colitis; Dextran Sulfate; Histamine; Male; Mast Cells; Neuropeptides; Rats; Rats, Sprague-Dawley; Somatostatin; Substance P; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) regulates various functions including motility and immune homeostasis in colon. The VIP system including its receptors has been established to control the development of ulcerative colitis, but the functional changes of the system-regulated motility in colon with ulcerative colitis are not well understood. In this study, we investigated VIP-related contractile responses in distal colon from mice with dextran sulfate sodium (DSS)-induced acute colitis. Electrical stimulation (ES) under our conditions caused relaxation during ES and contraction after withdrawal of ES in a tetrodotoxin-sensitive manner. Pharmacological analyses showed two phases of ES-induced relaxation: a transient neuronal nitric oxide (NO) synthase-dependent phase (I), and a continued VIP receptor-mediated phase (II). Inhibition of VIP receptors and protein kinase A decreased both phases. In colon from DSS-treated mice, ES-induced phase II (also phase I) and VIP-induced, but not cyclic AMP analog-induced, relaxation were decreased. Stimulation with VIP significantly increased cyclic AMP formation in colon preparations from control but not DSS-treated mice. In colon from DSS-treated mice, the basal cyclic AMP level was markedly greater without changes in the level of VIP receptor VPAC(2). Isoprenaline- and forskolin-induced relaxation and cyclic AMP formation were not changed by DSS treatment. These findings suggest that dysfunction of VIP receptors in muscles, in addition to loss of the neuronal VIP and NO pathways, are involved in abnormal motility in mouse colon with DSS-induced colitis.

Topics: Animals; Colitis; Colon; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Dextran Sulfate; Electric Stimulation; Mice; Muscle Contraction; Muscle Relaxation; Muscle, Smooth; Nitric Oxide Synthase Type I; Receptors, Vasoactive Intestinal Peptide; Vasoactive Intestinal Peptide

Neuroinflammation driven by the vanilloid-type ion channel receptor transient receptor potential vanilloid type 1 (TRPV-1) is suspected to play a role in the pathophysiology of inflammatory bowel disease. Because inflammatory bowel disease is known to elevate the risk of colon cancer, we examined postulated roles for TRPV-1-driven neuroinflammation in promoting colitis-associated and spontaneous colon cancer development. Using a well-established model of colitis-associated cancer (CAC), we found that mice genetically deficient in TRPV-1 showed a higher incidence and number of tumors in the distal colon. In like manner, genetic deficiency of TRPV-1 in the APC(Min/+) model of spontaneous colon cancer accentuated the number of colonic adenomas formed. Mechanistic analyses in the CAC model revealed an increased infiltration of inflammatory cells into the tumors along with elevated expression of interleukin (IL)-6 and IL-11 and activation of the STAT3 and NF-κB signaling pathways. Notably, TPRV-1-deficient mice exhibited a defect in expression of the anti-inflammatory neuropeptides, vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase-activating peptide (PACAP) which contributed to the generation of a local proinflammatory environment. Together, our findings argue that by limiting neuroinflammatory processes, TRPV-1 exerts a protective role that restricts the initiation and progression of colon cancer.

Topics: Animals; Colitis; Colonic Neoplasms; Cytokines; Genes, APC; Mice; Mice, Inbred C57BL; Mutation; Neurogenic Inflammation; NF-kappa B; Pituitary Adenylate Cyclase-Activating Polypeptide; RNA, Messenger; STAT3 Transcription Factor; TRPV Cation Channels; Vasoactive Intestinal Peptide

Distinct roles of the two T cell G protein-coupled receptors for vasoactive intestinal peptide (VIP), termed VPAC1 and VPAC2, in VIP regulation of autoimmune diseases were investigated in the dextran sodium sulfate (DSS)-induced murine acute colitis model for human inflammatory bowel diseases. In mice lacking VPAC2 (VPAC2-KO), DSS-induced colitis appeared more rapidly with greater weight loss and severe histopathology than in wild-type mice. In contrast, DSS-induced colitis in VPAC1-KO mice was milder than in wild-type mice and VPAC2-KO mice. Tissues affected by colitis showed significantly higher levels of myeloperoxidase, IL-6, IL-1β and MMP-9 in VPAC2-KO mice than wild-type mice, but there were no differences for IL-17, IFN-γ, IL-4, or CCR6. Suppression of VPAC1 signals in VPAC2-KO mice by PKA inhibitors reduced the clinical and histological severity of DSS-induced colitis, as well as tissue levels of IL-6, IL-1β and MMP-9. Thus VIP enhancement of the severity of DSS-induced colitis is mediated solely by VPAC1 receptors.

Topics: Animals; Body Weight; Colitis; Colon; Cyclic AMP-Dependent Protein Kinases; Dextran Sulfate; Disease Models, Animal; Female; Forkhead Transcription Factors; Gene Expression; Interleukin-17; Interleukin-1beta; Interleukin-6; Intestinal Mucosa; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Peroxidase; Protein Kinase Inhibitors; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Signal Transduction; T-Lymphocytes, Regulatory; Vasoactive Intestinal Peptide

Hand2 is a basic helix-loop-helix transcription factor required for terminal differentiation of enteric neurons. We studied Hand2 haploinsufficient mice, to determine whether reduced expression of Hand2 allows sufficient enteric neurogenesis for survival, but not for development of a normal enteric nervous system (ENS).. Enteric transcripts that encode Hand2 and the neuron-specific embryonic lethal abnormal vision proteins HuB, HuC, and HuD were quantified. Immunocytochemistry was used to identify and quantify neurons. Apoptosis was analyzed with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling procedure. Intracellular microelectrodes were used to record inhibitory junction potentials. Gastrointestinal transit and colonic motility were measured in vivo.. Levels of of enteric Hand2 transcripts were associated with genotypes of mice, in the following order: Hand2(+/+) > Hand2(LoxP/+) > Hand2(+/-) > Hand2(LoxP/-). Parallel reductions were found in expression of HuD and in regional and phenotypic manners. Numbers of neurons, numbers of neuronal nitric oxide synthase(+) and calretinin(+), but not substance P(+) or vasoactive intestinal peptide(+) neurons, decreased. No effects were observed in stomach or cecum. Apoptosis was not detected, consistent with the concept that Hand2 inhibits neuronal differentiation, rather than regulates survival. The amplitude of inhibitory junction potentials in colonic circular muscle was similar in Hand2 wild-type and haploinsufficient mice, although in haploinsufficient mice, the purinergic component was reduced and a nitrergic component appeared. The abnormal ENS of haploinsufficient mice slowed gastrointestinal motility but protected mice against colitis.. Reduced expression of factors required for development of the ENS can cause defects in the ENS that are subtle enough to escape detection yet cause significant abnormalities in bowel function.

Topics: Animals; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Calbindin 2; Cell Count; Colitis; Colon; ELAV Proteins; ELAV-Like Protein 2; ELAV-Like Protein 3; ELAV-Like Protein 4; Enteric Nervous System; Gastrointestinal Motility; Genotype; Intercellular Junctions; Mice; Muscle, Smooth; Neuroglia; Neurons; Nitric Oxide Synthase; S100 Calcium Binding Protein G; Substance P; Synaptic Transmission; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Causal connections between dipeptidyl peptidase IV, also known as CD26 molecule (DPP IV/CD26) and inflammatory bowel disease (IBD) have been shown, but mechanisms of these interactions are unclear. Our hypothesis was that DPP IV/CD26 could affect the neuroimmune response during inflammatory events. Therefore, we aimed to evaluate its possible role and the relevance of the gut-brain axis in a model of IBD in mice. Trinitrobenzenesulfonic acid-induced (TNBS) colitis was induced in CD26-deficient (CD26(-/-) ) and wild-type (C57BL/6) mice. Pathohistological and histomorphometrical measurements were done. Concentrations and protein expressions of DPP IV/CD26 substrates neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) were determined. Concentrations of IL-6 and IL-10 were evaluated. Investigations were conducted at systemic and local levels. Acute inflammation induced increased serum NPY concentrations in both mice strains, more enhanced in CD26(-/-) mice. Increased NPY concentrations were found in colon and brain of C57BL/6 mice, while in CD26(-/-) animals only in colon. VIP and IL-6 serum and tissue concentrations were increased in both mice strains in acute inflammation, more pronouncedly in CD26(-/-) mice. IL-10 concentrations, after a decrease in serum of both mice strains, increased promptly in CD26(-/-) mice. Decreased IL-10 concentration was found in brain of C57BL/6 mice, while it was increased in colon of CD26(-/-) mice in acute inflammation. DPP IV/CD26 deficiency affects the neuroimmune response at systemic and local levels during colitis development and resolution in mice. Inflammatory changes in the colon reflected on investigated parameters in the brain, suggesting an important role of the gut-brain axis in IBD pathogenesis.

Topics: Animals; Blotting, Western; Colitis; Dipeptidyl Peptidase 4; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Interleukins; Mice; Mice, Knockout; Neuropeptide Y; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Inflammatory bowel diseases (IBD) can involve widespread gastrointestinal dysfunction, even in cases in which inflammation is localized to a single site. The underlying pathophysiology of dysfunction in noninflamed regions is unclear. We examined whether colitis is associated with altered electrogenic ion transport in the ileal mucosa and/or changes in the properties of ileal submucosal neurons. Colitis was induced by administration of trinitrobenzene sulfonic acid (TNBS), and the uninflamed ileum from animals was examined 3, 7, and 28 days later. Electrogenic ion transport was assessed in Ussing chambers. Intracellular microelectrode recordings were used to examine the neurophysiology of the submucosal plexus of the ileum in animals with colitis. Noncholinergic secretion was reduced by 33% in the ileum from animals 7 days after the induction of colitis. The epithelial response to vasoactive intestinal peptide (VIP) was unaltered in animals with colitis, but the response to carbachol was enhanced. Slow excitatory synaptic transmission was dramatically reduced in VIP-expressing, noncholinergic secretomotor neurons. This change was detected as early as 3 days following TNBS treatment. No changes to fast synaptic transmission or the number of VIP neurons were observed. In addition, cholinergic secretomotor neurons fired more action potentials during a given stimulus, and intrinsic primary afferent neurons had broader action potentials in animals with colitis. These findings implicate changes to enteric neural circuits as contributing factors in inflammation-induced secretory dysfunction at sites proximal to a localized inflammatory insult.

Topics: Animals; Colitis; Guinea Pigs; Ileum; Intestinal Mucosa; Male; Neurons; Signal Transduction; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Attaching and effacing bacterial pathogens attach to the apical surface of epithelial cells and disrupt epithelial barrier function, increasing permeability and allowing luminal contents access to the underlying milieu. Previous in vitro studies demonstrated that the neuropeptide vasoactive intestinal peptide (VIP) regulates epithelial paracellular permeability, and the high concentrations and close proximity of VIP-containing nerve fibers to intestinal epithelial cells would support such a function in vivo. The aim of this study was to examine whether VIP treatment modulated Citrobacter rodentium-induced disruption of intestinal barrier integrity and to identify potential mechanisms of action. Administration of VIP had no effect on bacterial attachment although histopathological scoring demonstrated a VIP-induced amelioration of colitis-induced epithelial damage compared with controls. VIP treatment prevented the infection-induced increase in mannitol flux a measure of paracellular permeability, resulting in levels similar to control mice, and immunohistochemical studies demonstrated that VIP prevented the translocation of tight junction proteins: zonula occludens-1, occludin, and claudin-3. Enteropathogenic Escherichia coli (EPEC) infection of Caco-2 monolayers confirmed a protective role for VIP on epithelial barrier function. VIP prevented EPEC-induced increase in long myosin light chain kinase (MLCK) expression and myosin light chain phosphorylation (p-MLC). Furthermore, MLCK inhibition significantly attenuated bacterial-induced epithelial damage both in vivo and in vitro. In conclusion, our results indicate that VIP protects the colonic epithelial barrier by minimizing bacterial-induced redistribution of tight junction proteins in part through actions on MLCK and MLC phosphorylation.

Topics: Animals; Anti-Inflammatory Agents; Azepines; Bacterial Adhesion; Bacterial Translocation; Caco-2 Cells; Citrobacter rodentium; Claudin-3; Colitis; Colon; Disease Models, Animal; Enterobacteriaceae Infections; Humans; Injections, Intraperitoneal; Intestinal Mucosa; Mannitol; Membrane Proteins; Mice; Mice, Inbred C57BL; Myosin Light Chains; Myosin-Light-Chain Kinase; Naphthalenes; Occludin; Permeability; Phosphoproteins; Phosphorylation; Protein Kinase Inhibitors; Tight Junctions; Time Factors; Vasoactive Intestinal Peptide; Zonula Occludens-1 Protein

We tested the hypothesis that spontaneous release of vasoactive intestinal peptide (VIP) from enteric neurons maintains homeostasis in smooth muscle function in mild inflammatory insults and that infusion of exogenous VIP has therapeutic effects on colonic smooth muscle dysfunction in inflammation. In vitro experiments were performed on human colonic circular smooth muscle tissues and in vivo on rats. The incubation of human colonic circular smooth muscle strips with TNF-alpha suppressed their contractile response to ACh and the expression of the pore-forming alpha(1C) subunit of Ca(v)1.2 channels. VIP reversed both effects by blocking the translocation of NF-kappaB to the nucleus and its binding to the kappaB recognition sites on halpha(1C)1b promoter. The translocation of NF-kappaB was inhibited by blocking the degradation of IkappaBbeta. Induction of inflammation by a subthreshold dose of 17 mg/kg trinitrobenzene sulfonic acid (TNBS) in rats moderately decreased muscularis externa concentration of VIP, and it had little effect on the contractile response of circular smooth muscle strips to ACh. The blockade of VIP and pituitary adenylate cyclase-activating peptide receptors 1/2 during mild inflammatory insult significantly worsened the suppression of contractility and the inflammatory response. The induction of more severe inflammation by 68 mg/kg TNBS induced marked suppression of colonic circular muscle contractility and decrease in serum VIP. Exogenous infusion of VIP by an osmotic pump reversed these effects. We conclude that the spontaneous release of VIP from the enteric motor neurons maintains homeostasis in smooth muscle function in mild inflammation by blocking the activation of NF-kappaB. The infusion of exogenous VIP mitigates colonic inflammatory response and smooth muscle dysfunction.

Topics: Acetylcholine; Active Transport, Cell Nucleus; Animals; Binding Sites; Calcium Channels, L-Type; Cells, Cultured; Colitis; Colon; Disease Models, Animal; Dose-Response Relationship, Drug; Enteric Nervous System; Homeostasis; Hormone Antagonists; Humans; I-kappa B Proteins; In Vitro Techniques; Inflammation Mediators; Infusions, Subcutaneous; Muscle Contraction; Muscle, Smooth; Neuroimmunomodulation; NF-kappa B; Promoter Regions, Genetic; Rats; Rats, Sprague-Dawley; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Time Factors; Transfection; Trinitrobenzenesulfonic Acid; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

New diagnostic criteria for different variants of diverticular disease (DD) are considered based on the examination of 110 patients. Patients of group 1 (n = 77) showed no signs of diverticulitis in contrast to group 2 (n = 33). Two control groups comprised 38 patients with chronic hypomotor colitis and 25 practically healthy subjects respectively. Dynamic observations included clinical and endoscopic examination supplemented by morphological and immunohistochemical Studies. It was shown that DD developed in association with undifferentiated dysplasia of connective tissue, increased number of P substance-inducing colonocytes, and lowered density of vasointestinal peptide-reactive cells. Diagnostically significant criteria in patients with diverticulitis were grade II-III intestinal dysbiosis and increased number of mast cells in rectosigmoid nucosa.

Topics: Aged; Biomarkers; Colitis; Colonoscopy; Diagnosis, Differential; Diverticulitis, Colonic; Follow-Up Studies; Humans; Middle Aged; Pancreatic Elastase; Vasoactive Intestinal Peptide

Crohn's disease (CD) is a chronic intestinal inflammatory pathology, which develops as a result of innate immune signals, such as the activation of Toll-like receptors (TLRs), and adaptive immune signals, including Th1 cytokine release. We have recently demonstrated in TNBS-induced colitis, a murine model of CD, that VIP plays a homeostatic role, by reducing TNBS-induced TLR2 and TLR4 expression to control levels. The purpose of this paper is to elucidate for the first time, the physiological relevance of VIP specific control of innate and adaptive immune responses through TLR2 and TLR4 ligands. In addition, we investigated the effect of VIP on regulatory activity of T regulatory (Treg) cells in the TNBS-colitis model. First, we found that VIP downregulated the inflammatory response elicited in mesenteric lymph node cell cultures by treatment with the TLR2 ligand Pam3Cys, or the TLR4 ligand lipopolysaccharide (LPS), reducing the production of the chemokine CXCL1. Also, treatment with VIP impaired the induction of Th1 responses by decreasing p70 interleukin (IL)-12 and interferon gamma (IFN-gamma) levels after TLR2/TLR4 stimulation in culture. Besides, VIP treatment restored in vivo the numbers of TLR2 and TLR4 positive CD4+CD25+ T lymphocytes, augmented by TNBS administration, and increased the expression of molecules involved in regulatory T cell function, such as Foxp3 and TGF-beta. In conclusion, the ability of VIP to down-regulate uncontrolled inflammation by targeting TLR-mediated responses and regulatory T cell activity could be used as a new alternative therapy for intestinal inflammatory/autoimmune disorders.

Topics: Animals; Cells, Cultured; Colitis; Disease Models, Animal; Immunity, Cellular; Immunity, Innate; Lymph Nodes; Male; Mesentery; Mice; Mice, Inbred BALB C; Models, Immunological; Time Factors; Toll-Like Receptor 2; Toll-Like Receptor 4; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Impairment of small intestinal absorption has been described in patients with ulcerative colitis and in animal models of experimental colitis. The pathophysiology of this dysfunction has not been elucidated. The aim of this study was to investigate the effect of chemical colitis on jejunal fluid absorption and determine the role of the enteric nervous system and some putative neurotransmitters. In a rat model of iodoacetamide-induced colitis, jejunal net fluid absorption was evaluated by the in vivo single-pass perfusion technique. The effects of 1) tetrodotoxin (TTX), 2) benzylalkonium chloride (BAC), 3) capsaicin, 4) vasoactive intestinal polypeptide (VIP) antagonism, 5) nitric oxide (NO) synthase (NOS) inhibition, and 6) 5-hydroxytryptamine type 3 and 4 (5-HT(3) and 5-HT(4)) receptor antagonism on the changes in fluid movement were investigated. A significant decrease in jejunal net fluid absorption was found 2 and 4 days after colitis induction: 26 (SD 14) and 28 (SD 19) microl x min(-1) x g dry intestinal wt(-1), respectively [P < 0.0002 compared with sham rats at 61 (SD 6.5) microl x min(-1) x g dry intestinal wt(-1)]. No histological changes were evident in jejunal sections. TTX and BAC reversed this decrease in fluid absorption: 54 (SD 13) and 44 (SD 14) microl x min(-1) x g dry intestinal wt(-1) (P = 0.0005 and P = 0.019, respectively, compared with colitis). Ablation of capsaicin-sensitive primary afferent fibers had a partial effect: 45 (SD 5) microl x min(-1) x g dry intestinal wt(-1) (P = 0.001 and P = 0.003 compared with colitis and sham, respectively). Constitutive and neuronal NOS inhibition and VIP antagonism returned jejunal net fluid absorption to normal values: 66 (SD 19), 61 (SD 5), and 56 (SD 14) microl x min(-1) x g dry intestinal wt(-1), respectively. 5-HT(3) and 5-HT(4) receptor antagonism had no effect. Chemical colitis is associated with a significant decrease in jejunal net fluid absorption. This decrease is neurally mediated and involves VIP- and NO-related mechanisms.

Topics: Animals; Benzalkonium Compounds; Capsaicin; Colitis; Enteric Nervous System; Enzyme Inhibitors; Intestinal Absorption; Iodoacetamide; Jejunum; Male; Myenteric Plexus; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Perfusion; Rats; Rats, Sprague-Dawley; Serotonin; Serotonin Antagonists; Sulfhydryl Reagents; Tetrodotoxin; Ulcer; Vasoactive Intestinal Peptide

Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs), which recognize numerous molecules collectively named pathogen-associated molecular patterns, with an essential role in inflammatory conditions and connecting innate and acquired immune responses. Moreover, a new function of TLRs in the intestinal mucosa has been described. Under homeostatic conditions, TLRs act to protect the intestinal epithelium; but when homeostasis is disrupted, TLRs appear deregulated. Disruption of intestinal homeostasis occurs in disorders, such as Crohn's disease (CD). Trinitrobenzene sulfonic acid (TNBS)-induced colitis is a murine model of human CD and vasoactive intestinal polypeptide (VIP) exerts a beneficial effect, by decreasing both inflammatory and autoimmune components of the disease. Recently, we have demonstrated the constitutive expression of TLR2 and TLR4 at mRNA and protein levels in colon extracts and their upregulation in TNBS-treated mice as well as the effect of VIP treatment, approaching control levels. However, the systemic effect is little known. The present results demonstrate a beneficial role of VIP, restoring homeostatic conditions through the regulation of both lymphoid cell traffic and TLR2/4 expression on macrophages (MØ), dendritic cells (DCs), and CD4 and CD8 T lymphocytes.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Movement; Colitis; Dendritic Cells; Disease Models, Animal; Lymph Nodes; Macrophages; Mice; Toll-Like Receptor 2; Toll-Like Receptor 4; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Crohn's disease is a chronic debilitating disease characterized by severe T helper cell (Th)1-driven inflammation of the colon partially caused by a loss of immune tolerance against mucosal antigens. The use of regulatory dendritic cells (DCs) with the capacity to induce regulatory T cells has been proposed recently for the treatment of Crohn's disease in a strategy to restore immune tolerance. Vasoactive intestinal peptide is an immunomodulatory neuropeptide that induces regulatory DCs. The aim of this study was to investigate the therapeutic effect of vasoactive intestinal peptide-induced regulatory DCs (DC(VIP)) in a murine model of colitis.. We examined the therapeutic action of DC(VIP) in the colitis induced by intracolonic administration of trinitrobenzene sulfonic acid, evaluating diverse clinical signs of the disease including weight loss, diarrhea, colitis, and histopathology. We also investigated the mechanisms involved in the potential therapeutic effect of DC(VIP), such as inflammatory cytokines and chemokines, Th1-type response, and the generation of regulatory T cells.. DC(VIP) injection significantly ameliorated the clinical and histopathologic severity of colitis, abrogating body weight loss, diarrhea, and inflammation, and increasing survival. The therapeutic effect was associated with down-regulation of both inflammatory and Th1-driven autoimmune response, by regulating a wide spectrum of inflammatory mediators directly through activated macrophages, and by generating interleukin-10-secreting regulatory T cells with suppressive capacity on autoreactive T cells.. The possibility to generate/expand ex vivo regulatory DC(VIP) opens new therapeutic perspectives for the treatment of Crohn's disease in human beings, and may minimize the dependence on nonspecific immunosuppressive drugs used currently for autoimmune disorders.

Topics: Animals; Autoimmunity; CD4-Positive T-Lymphocytes; Cell Transplantation; Cells, Cultured; Colitis; Dendritic Cells; Disease Models, Animal; Immune Tolerance; Immunotherapy; Interleukin-10; Mice; Mice, Inbred BALB C; Th1 Cells; Transforming Growth Factor beta; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Inflammatory bowel diseases are chronic inflammatory disorders of the gastrointestinal tract. Vasoactive intestinal peptide (VIP) is a neuropeptide with known anti-inflammatory activity. We have demonstrated previously that administration of VIP inhibits leucocyte migration in a murine model of delayed-type hypersensitivity, and anti-inflammatory efficacy is supported by other studies. The aim of this study was to investigate the VIP effects in a murine model of intestinal inflammation. Colitis was induced in BALB/c mice by a 2.5 mg enema of 2,4,6-trinitrobenzenesulphonic acid (TNBS) and the mice were killed on day 7. Mice were administered either a 3-day (therapeutic) or 7-day (prophylactic) constant infusion of VIP by subcutaneously implanted mini-osmotic pumps, or intraperitoneal (i.p.) injection of VIP on alternate days over 7 days. Clinical disease scores, weight changes, histopathology of colon tissues, plasma VIP levels, cytokine levels and chemotaxis of peripheral blood mononuclear cells were evaluated. After administration of TNBS, mice quickly developed severe colitis accompanied by dramatic body weight loss (20% by day 6) and high mortality (30%). Prophylactic treatment using high-dose VIP abrogated leucocyte chemotaxis; however, it failed to ameliorate the weight loss and mortality. Moreover, VIP delivered either by constant infusion or i.p. failed to modify the clinical, histological or cytokine markers of disease. Our studies show that, despite an ability to inhibit chemokine-induced chemotaxis of mononuclear cells, VIP was unable to modulate TNBS-induced colitis. This contrasts with the efficacy of VIP in models of mild inflammatory disease and suggests that VIP is unlikely to provide a useful model for novel anti-IBD therapy.

Topics: Acute Disease; Animals; Chemotaxis, Leukocyte; Colitis; Infusion Pumps, Implantable; Injections, Intraperitoneal; Male; Mice; Mice, Inbred BALB C; Models, Animal; Treatment Failure; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Endothelin (ET)-2, an ET family peptide, is highly expressed in intestine. However, the specific distribution and function of ET-2 remain unknown. We elucidated the expression profile and localization of ET-2 in mouse gastrointestinal tract. Real-time PCR analysis revealed that ET-2 gene expression in the gastrointestinal tract of healthy animals was relatively high in the colon. Immunohistochemical analysis revealed ET-2-like immunoreactivity mainly in epithelial cells of the mucosa throughout the intestinal tract of healthy animals. Intracellularly, ET-2 was concentrated close to the basement membrane of intestinal epithelial cells. A weak ET-2-like immunoreactivity was also localized to some neurofibers and the myenteric plexus of the muscle layer, coexpressing with vasoactive intestinal peptide. ET-2-like immunoreactivity was also detected at Brunner's glands of the duodenum and follicle-associated epithelium of Peyer's patch. In contrast, ET-1-like immunoreactivity was uniformly distributed in epithelial cells. In dextran sulfate sodium (DSS)-induced colitis, colonic ET-2 was upregulated during the late stage of DSS treatment. These results suggest that in intestinal epithelial cells ET-2 could be secreted into the lamina propria and the dome region in Peyer's patch, and that it might modulate immune cells in these sites for mucosal defense.

Topics: Animals; Colitis; Dextran Sulfate; Endothelin-1; Endothelin-2; Gene Expression Profiling; Humans; Immunohistochemistry; In Situ Hybridization; Indicators and Reagents; Intestinal Mucosa; Intestines; Male; Mice; Polymerase Chain Reaction; Protein Isoforms; Up-Regulation; Vasoactive Intestinal Peptide

Crohn's disease (CD) is a chronic debilitating disease of unknown etiology that is characterized by severe inflammation of the colon. Vasoactive intestinal peptide (VIP) has recently emerged as a promising candidate for treatment of inflammatory Th1-driven diseases. We studied the effect of VIP in trinitrobenzene sulfonic acid (TNBS)-induced colitis, which has clinical and molecular features in common with CD.. A 3-mg enema of TNBS was given to BALB/c mice, and VIP (1 nmol) was given either as a single dose at 12 hours or every other day. Weight loss, histopathology, and chemokine and cytokine levels in serum and colon extracts were assessed. VIP was also tested given 5 days after the onset of TNBS-induced colitis, and its effect was analyzed given a second dose of TNBS.. Treatment with VIP reduced the clinical and histopathologic severity of TNBS-induced colitis, abrogating body weight loss, diarrhea, and macroscopic and microscopic intestinal inflammation. The therapeutic effects of VIP were associated with down-regulation of both inflammatory and Th1-driven autoimmune responses, including tumor necrosis factor alpha, interleukin 1, and interleukin 6 in colon extracts and serum as well as interferon gamma by splenic and lamina propria CD4(+) T cells. VIP reduced disease severity when given after disease onset and dramatically reduced disease recurrence given a second dose of TNBS.. Our data suggest that VIP has beneficial prophylactic and therapeutic effects in TNBS-induced colitis and is a promising candidate to test for potential benefits in CD.

Topics: Animals; Colitis; Crohn Disease; Cytokines; Disease Models, Animal; Down-Regulation; Gastrointestinal Agents; Male; Mice; Mice, Inbred BALB C; Receptors, Vasoactive Intestinal Peptide; Receptors, Vasoactive Intestinal Polypeptide, Type I; Th1 Cells; Th2 Cells; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide; Wasting Syndrome

The aim of this work was to determine the alterations in the absorptive and secretory functions of the rat colon after abdominal irradiation and to compare the effects of abdominal and whole-body irradiation. Rats received an abdominal irradiation with 8 to 12 Gy and were studied at 1, 4 and 7 days after exposure. Water and electrolyte absorption was measured in vivo by insertion of an agarose cylinder into the colons of anesthetized rats. In vitro measurements of potential difference, short-circuit current and tissue conductance were performed in Ussing chambers under basal and agonist-stimulated conditions. Most of the changes appeared at 4 days after abdominal irradiation. At this time, a decrease in water and electrolyte absorption in the colon was observed for radiation doses > or = 9 Gy. The response to secretagogues (VIP, 5-HT and forskolin) was attenuated after 10 and 12 Gy. Epithelial integrity, estimated by potential difference and tissue conductance, was altered from 1 to 7 days after 12 Gy abdominal irradiation. These results show that the function of the colon was affected by abdominal irradiation. Comparison with earlier results for total-body irradiation demonstrated a difference of 2 Gy in the radiation dose needed to induce changes in the function of the colon.

Topics: Abdomen; Animals; Carbachol; Colforsin; Colitis; Colon; Dose-Response Relationship, Drug; Electric Conductivity; Electrolytes; Epithelial Cells; Intestinal Absorption; Male; Radiation Injuries, Experimental; Radiation Tolerance; Rats; Rats, Wistar; Serotonin; Vasoactive Intestinal Peptide; Water; Whole-Body Irradiation

Knowledge of the neurochemical coding of submucosal neurones in the human gut is important to assess neuronal changes under pathological conditions. We therefore investigated transmitter colocalization patterns in rectal submucosal neurones in normal tissue (n=11) and in noninflamed tissue of Crohn's disease (CD) patients (n=17). Neurone-specific enolase (NSE), choline acetyltransferase (ChAT), vasoactive intestinal polypeptide (VIP), substance P (SP), nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) were detected immunohistochemically in whole-mount preparations from rectal biopsies. The neuronal marker NSE revealed no differences in the number of cells per ganglion (controls 5.0; CD 5.1). Four cell populations with distinct neurochemical codes were identified. The sizes of the populations ChAT/VIP (58% vs. 55%), ChAT/SP (8% vs. 8%), and ChAT/- (22% vs. 22%) were similar in control and CD. The population VIP/- was significantly increased in CD (12% vs. 2% in controls). Unlike in controls, all NOS neurones colocalized ChAT in CD. Thickened CGRP-fibres occurred in CD. We identified neurochemically distinct populations in the human submucous plexus. The increase in the VIP/- population, extensive colocalization of ChAT and NOS and hypertrophied CGRP fibres indicated adaptive changes in the enteric nervous system in noninflamed rectum of CD patients.

Topics: Adolescent; Adult; Aged; Biopsy; Calcitonin Gene-Related Peptide; Choline O-Acetyltransferase; Colitis; Crohn Disease; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neurons; Nitric Oxide Synthase; Phosphopyruvate Hydratase; Rectum; Submucous Plexus; Substance P; Vasoactive Intestinal Peptide

With its abundance of neurons and immunocytes, the gut is a potentially important site for the study of the interaction between the nervous and immune systems. In this electron microscopic study we have investigated the distribution of substance P (SP)- and vasoactive intestinal polypeptide (VIP)-immunoreactive (IR) nerve terminals and the immunocytes during experimental colitis in the rat. A mild colitis was induced by a luminal enema containing trinitrobenzene sulfonic acid. The most severe inflammation was detected after 2 days and the density and the distribution of the SP- and VIP-IR nerve terminals as well as the immunocompetent cells were studied at that time. Many SP- and VIP-IR nerve terminals were observed in a very close situation to the inflammatory cells. The number of VIP-IR nerve terminals slightly increased in the inflamed area. The gap between the axolemma of the nerve terminals and immunocytes was 20-200 nm. Some lymphocytes and plasma cells were also IR for SP in the inflamed area, whereas no IR immunocytes were observed in the control and in noninflamed area from the same animal. The very close apposition of the SP- and VIP-IR nerve terminals to the inflammatory cells as well as the presence of SP-IR immunocytes in inflamed area support the suggestion that bidirectional neuroimmunomodulation exists in the colon.

Topics: Animals; Cell Communication; Cell Count; Colitis; Colon; Enteric Nervous System; Immunohistochemistry; Lymphocytes; Male; Microscopy, Electron; Neuroimmunomodulation; Plasma Cells; Presynaptic Terminals; Rats; Rats, Wistar; Substance P; Synaptic Vesicles; Vasoactive Intestinal Peptide

To study functional morphology of a total population of endocrine cells of colon mucosa, mast and enterochromaffine cells.. Light and electrone microscopy, immunohistochemical methods, morphometry were used to study endocrine and mast cells of the sigmoid colon in inflammation.. Changes of functional morphology and size of endocrine and mast cell population as well as apudocytes producing serotonin, melatonin, vasointestinal peptides were stated. Apudocyte and mass cell functional morphology, clinical symptoms and mucosal structural changes correlated. Specificity of some parameters in Chron's disease is shown.. The results may provide additional criteria in diagnosis of different variants of chronic colitis.

Topics: Adolescent; Adult; APUD Cells; Biopsy; Colitis; Crohn Disease; Humans; Intestinal Mucosa; Mast Cells; Melatonin; Middle Aged; Prognosis; Serotonin; Sigmoid Diseases; Vasoactive Intestinal Peptide

Immunohistochemistry was used to examine the distribution of calcitonin gene-related peptide (CGRP), substance P, somatostatin and vasoactive intestinal polypeptide (VIP) in experimental colitis induced with trinitrobenzene sulphonic acid (TNBS) in rats. CGRP immunoreactivity was observed throughout the colonic wall. A significant reduction of CGRP-immunoreactive (IR) nerve fibres was observed in the mucosa after the induction of colitis. After TNBS treatment substance P immunoreactivity was reduced throughout the colon; however, after 7 days there was a marked re-innervation of the circular muscle. Somatostatin immunoreactivity was distributed sparsely within the colonic wall, and was comparatively less affected by colitis. VIP immunoreactivity was abundantly distributed in the colonic wall and underwent an immediate reduction in the mucosa after TNBS treatment. After 2 days, there was a consistent and progressive increase in the number and density of VIP-IR nerve fibres in the inflamed colon, particularly the circular muscle. This change was associated with a proliferation of nerve fibres within the muscle layers. It was concluded that the early decrease in these neuropeptides was consistent with release from peripheral nerve terminals or the loss of nerves during the initial stages of colonic inflammation, which may be an essential condition for the development of colitis in this model. The observation that the intensity and density of substance P and VIP-IR nerve fibres increased in the circular muscle 7 days after the induction of colitis suggests their possible involvement in tissue repair.

Topics: Animals; Biomarkers; Calcitonin Gene-Related Peptide; Colitis; Ethanol; Immunohistochemistry; Male; Neurons; Neuropeptides; Rats; Rats, Wistar; Somatostatin; Substance P; Vasoactive Intestinal Peptide

We investigated whether platelet-activating factor (PAF) alters colonic tissue levels of substance P and vasoactive intestinal peptide (VIP), two neuropeptides that regulate colonic motility. Left colons were harvested from NZ White Rabbits and underwent vascular perfusion via the inferior mesenteric artery. Strain gauge transducers were sewn onto the serosal surface of the colon to evaluate colonic motility. Colons were perfused with either buffered saline alone or with 5.0 x 10(-5) M PAF. PAF administration increased tissue VIP and substance P levels and decreased the force of colonic contractions. Pretreatment with WEB-2170 or alprazolam decreased concentrations of both tissue neuropeptides, and decreased the force of colonic contractions and minute motility index. These results suggest that both VIP and substance P are stimulated by PAF and may participate in colonic dysmotility during inflammatory states.

Topics: Alprazolam; Animals; Azepines; Colitis; Colon; Gastrointestinal Motility; In Vitro Techniques; Iodine Radioisotopes; Neuropeptides; Platelet Activating Factor; Rabbits; Substance P; Triazoles; Vasoactive Intestinal Peptide

7-Nitroindazole induced concentration-dependent relaxation of precontracted rabbit aorta, dog middle cerebral artery, rat anococcygeus muscle and rat stomach fundus. Relaxations to 7-nitroindazole in rabbit aorta were unaffected by nitric oxide synthase blockade or endothelial removal. 6-Nitroindazole also caused concentration-dependent relaxation in dog middle cerebral artery and rabbit aorta, being equipotent with 7-nitroindazole in both tissues. These data suggest that indazole derivatives can induce an endothelium- and nitric oxide synthase-independent relaxation of smooth muscle in vitro.

Topics: Alprazolam; Animals; Azepines; Colitis; Colon; Gastrointestinal Motility; In Vitro Techniques; Iodine Radioisotopes; Neuropeptides; Platelet Activating Factor; Rabbits; Substance P; Triazoles; Vasoactive Intestinal Peptide

The present in vitro study was conducted to investigate possible alterations in the control of colonic electrolyte transport in an experimental model of colitis. Intrarectal administration of trinitrobenzenesulfonic acid induced a colitis-like inflammation in the rabbit distal colon. Responses to amiloride and residual short-circuit current after this treatment were unchanged, suggesting that the absorptive and secretory mechanisms remained intact. Electrical field stimulation and vasoactive intestinal polypeptide, a candidate secretomotor neurotransmitter, both elicited similar responses in control and colitic tissue. This suggests that communication at the neuroepithelial junction was unimpaired. In untreated tissue, the effects of prostaglandin E2 (PGE2) and of acetylcholine were attenuated by tetrodotoxin, suggesting, therefore, that both play a role in the modulation of secretomotor neurons. In addition, PGE2 had an appreciable direct epithelial effect. Responses to both of these agonists were absent in colitis. The effects of N6,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate were unchanged in colitis, suggesting that altered PGE2 responsiveness may involve changes in epithelial receptor number, affinity, or in their ability to mediate an increase in adenosine 3',5'-cyclic monophosphate levels. It is concluded that this rabbit model of colitis exhibits 1) defects in the modulation of secretomotor neurons by acetylcholine and PGE2 and 2) an attenuated epithelial response to PGE2.

Topics: Acetylcholine; Amiloride; Animals; Bucladesine; Colitis; Colon; Dinoprostone; Disease Models, Animal; Epithelium; Inflammation; Male; Membrane Potentials; Motor Neurons; Muscle, Smooth; Rabbits; Tetrodotoxin; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

The present study investigated the effect of vasoactive intestinal peptide and prostaglandin E2 on cyclic adenosine monophosphate levels in isolated colonocytes during experimental colitis. Intra-rectal trinitrobenzenesulfonic acid induced a colitis-like inflammation in the rabbit distal colon. Basal levels of cyclic adenosine monophosphate were similar in control and colitic colonocytes. Levels were increased by prostaglandin E2 and vasoactive intestinal peptide in control cells. Colonocytes from colitic tissue responded to vasoactive intestinal peptide normally, but exhibited an attenuated response to prostaglandin E2. We conclude during colitis the epithelium exhibits a specific alteration in prostaglandin E2 receptor number, affinity or adenylate cyclase coupling.

Topics: Animals; Colitis; Colon; Cyclic AMP; Dinoprostone; Epithelium; In Vitro Techniques; Male; Rabbits; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide

Acute inflammation of the colonic wall was induced by perendoscopic injection of formalin in rats. As compared to control animals (no endoscopy, no injection), the procedure was followed by a marked reduction of immunoreactive substance P, calcitonin gene-related peptide and vasoactive intestinal peptide concentrations in rectosigmoid wall. Tissue substance P concentration in the spinal cord, at the level of afferent projection, increased at the same time. The three peptides tested are thus likely to be involved in the pathophysiology of acute intestinal inflammation. In addition, substance P may play a role in the transmission of nociceptive signals from the inflamed colonic segment.

Topics: Animals; Calcitonin Gene-Related Peptide; Colitis; Colon, Sigmoid; Colonoscopy; Female; Formaldehyde; Neuropeptides; Radioimmunoassay; Rats; Rats, Inbred Strains; Spinal Cord; Substance P; Vasoactive Intestinal Peptide

The vasoactive intestinal peptide concentration was examined in the colonic wall and portal venous plasma of rats with chemical colitis by radioimmunoassay, and the colonic localization was determined with immunocytochemistry. Colonic acetylcholine esterase activity was also measured, and the response of vasoactive intestinal peptide to acetylcholine administration was determined. Colitis was induced by administration of dextran sulfate for three months. The chemical colitis was histologically similar to active human ulcerative colitis. We observed a significant increase of immunostained neurons and nerve fibers and a significant rise in the colonic wall vasoactive intestinal peptide content in chemical colitis rats, while plasma concentrations of the peptide did not change significantly. Colonic acetylcholine esterase activity was significantly elevated in colitis rats compared with control rats. Systemic administration of acetylcholine significantly increased the colonic and plasma vasoactive intestinal peptide concentrations in colitis rats. These findings demonstrated a positive association between colitis activity and an increase of vasoactive intestinal peptide and suggested that increased vagal tone promoted the peptide's release.

Topics: Acetylcholine; Acetylcholinesterase; Animals; Colitis; Colon; Dextran Sulfate; Immunohistochemistry; Intestinal Mucosa; Male; Radioimmunoassay; Rats; Rats, Wistar; Vasoactive Intestinal Peptide

Topics: Colitis; Crohn Disease; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Neurotensin; Rectum; Somatostatin; Vasoactive Intestinal Peptide