Dinitrobenzene Sulfonic Acid Research Articles

Cytotoxic Activity of Lepidium virginicum L. Methanolic Extract on Human Colorectal Cancer Cells, Caco-2, through p53-Mediated Apoptosis.

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Its treatment options have had a limited impact on cancer remission prognosis. Therefore, there is an ongoing need to discover novel anti-cancer agents. Medicinal plants have gained recognition as a source of anti-cancer bioactive compounds. Recently, ethanolic extract of L. virginicum stems ameliorated dinitrobenzene sulfonic acid (DNBS)-induced colitis by modulating the intestinal immune response. However, no scientific study has demonstrated this potential cytotoxic impact on colon cancer cells. The objective of this study was to evaluate the cytotoxic effect of the methanolic extract of L. virginicum (ELv) on a human colorectal adenocarcinoma cell line (Caco-2) and to identify and quantify the phenolic compounds present in ELv extracts by liquid chromatography-mass spectrometry analysis. The cytotoxic activity was assessed using cell viability assays by reduction in the compound 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH). MTT and LDH assays revealed that the ELv decreases cell viability in the Caco-2 cell line in a concentration-dependent manner. Cell death was a result of DNA fragmentation and p53-mediated apoptosis. Eight phenolic acids and five flavonoids were identified and quantified in the stems. In conclusion, our findings demonstrate that the extract of L. virginicum possesses cytotoxic properties on Caco-2 cell line, suggesting that it could be a potential source of new drugs against CRC.

Mesenteric adipose-derived exosomal TINAGL1 enhances intestinal fibrosis in Crohn's Disease via SMAD4

IntroductionCrohn's Disease (CD) is a chronic inflammatory condition characterized by intestinal fibrosis, severely impacting patient quality of life. The molecular mechanisms driving this fibrosis remain inadequately understood. Recent evidence implicates mesenteric adipose tissue (MAT) in CD pathogenesis, particularly through its exosome secretion, which may influence fibrogenic pathways. Understanding the role of MAT-derived exosomes is crucial for unraveling these molecular processes. ObjectivesThis study aims to elucidate the role of MAT-derived exosomes in CD-related intestinal fibrosis. We focus on investigating their molecular composition and the potential impact on fibrosis progression, with an emphasis on identifying novel therapeutic targets. MethodsWe induced chronic intestinal inflammation in mice using dinitrobenzene sulfonic acid (DNBS), simulating CD-like fibrosis. Exosomes were isolated from DNBS-treated mice (MG) and normal controls (NG) for characterization using electron microscopy and proteomic analysis. Additionally, human colonic fibroblasts were exposed to exosomes from CD patients and healthy individuals, with subsequent assessment of fibrogenesis through proteomic and RNA sequencing analyses. ResultsProteomic analyses revealed a significant activation of the TGF-β signaling pathway in MG-treated mice compared to controls, correlating with enhanced intestinal fibrosis. In vitro experiments demonstrated that colonic fibroblasts exposed to CD patient-derived exosomes exhibited increased fibrogenic activity. Protein docking and co-immunoprecipitation studies suggested a critical interaction between TINAGL1 and SMAD4, enhancing fibrosis. Importantly, in vivo experiments corroborated that recombinant TINAGL1 protein exacerbated DNBS-induced intestinal fibrosis. ConclusionOur findings highlight the pivotal role of MAT-derived exosomes, particularly those carrying TINAGL1, in the progression of intestinal fibrosis in CD. The involvement of the TGF-β signaling pathway, especially the SMAD4 protein, offers new insights into the molecular mechanisms of CD-related fibrosis and presents potential targets for therapeutic intervention.

Screening of probiotic strains to improve visceral hypersensitivity in irritable bowel syndrome by using in vitro and in vivo approaches.

Oral administration of probiotics has been proposed as a promising biotherapy to prevent and treat different diseases related to gastrointestinal disorders, such as irritable bowel syndrome (IBS). Due to the increasing research area on the characterisation of new probiotic bacterial strains, it is necessary to perform suitable in vitro experiments, using pertinent cellular models, in order to establish appropriate readout profiles based on IBS symptoms and subtypes. In this work, a collection of 30 candidate strains, belonging mainly to the Lactobacillus and Bifidobacterium genera, were screened using three different sets of in vitro experiments with different readouts to identify promising probiotic strains with: (1) the ability to inhibit the synthesis of IL-8 production by TNF-α stimulated HT-29 cells, (2) immunomodulatory properties quantified as increased IL-10 levels in peripheral blood mononuclear cell (PBMCs), and (3) the ability to maintain epithelial barrier integrity by increasing the trans-epithelial/endothelial electrical resistance (TEER) values in Caco-2 cells. Based on these criteria, three strains were selected: Lactobacillus gasseri PI41, Lacticaseibacillus rhamnosus PI48 and Bifidobacterium animalis subsp. lactis PI50, and tested in a murine model of low-grade inflammation induced by dinitrobenzene sulfonic acid (DNBS), which mimics some of the symptoms of IBS. Among the three strains, L. gasseri PI41 improved overall host well-being by preventing body weight loss in DNBS-treated mice and restored gut homeostasis by normalising the intestinal permeability and reducing pro-inflammatory markers. Therefore, the potential of this strain was confirmed in a second murine model known to reproduce IBS symptoms: the neonatal maternal separation (NMS) model. The PI41 strain was effective in preventing intestinal permeability and reducing colonic hypersensitivity. In conclusion, the set of in vitro experiments combined with in vivo assessments allowed us to identify a promising probiotic candidate strain, L. gasseri PI41, in the context of IBS.

Attenuation of Colitis-Induced Visceral Hypersensitivity and Pain by Selective Silencing of TRPV1-Expressing Fibers in Rat Colon.

Transient receptor potential vanilloid 1 (TRPV1) cation channels, expressed on nociceptors, are well established as key contributors to abdominal pain in inflammatory bowel disease (IBD). Previous attempts at blocking these channels have been riddled with side effects. Here, we propose a novel treatment strategy, utilizing the large pore of TRPV1 channels as a drug delivery system to selectively inhibit visceral nociceptors. We induced colitis in rats using intrarectal dinitrobenzene sulfonic acid. Visceral hypersensitivity, spontaneous pain, and responsiveness of the hind paws to noxious heat stimuli were examined before and after the intrarectal application of membrane-impermeable sodium channel blocker (QX-314) alone or together with TRPV1 channel activators or blockers. Intrarectal co-application of QX-314 with TRPV1 channel activator capsaicin significantly inhibited colitis-induced gut hypersensitivity. Furthermore, in the model of colitis, but not in naïve rats, QX-314 alone was sufficient to reverse gut hypersensitivity. The blockade of TRPV1 channels prevented this effect of QX-314. Finally, applying QX-314 alone to the inflamed gut inhibited colitis-induced ongoing pain. Selective silencing of gut nociceptors by a membrane-impermeable sodium channel blocker entering via exogenously or endogenously activated TRPV1 channels diminishes IBD-induced gut hypersensitivity. The lack of effect on naïve rats suggests a selective analgesic effect in the inflamed gut. Our results suggest that in the colitis model, TRPV1 channels are tonically active. Furthermore, our results emphasize the role of TRPV1-expressing nociceptive fibers in colitis-induced pain. These findings provide proof of concept for using charged activity blockers for the blockade of IBD-associated abdominal pain.

Polyphenol-Rich Extract from 'Limoncella' Apple Variety Ameliorates Dinitrobenzene Sulfonic Acid-Induced Colitis and Linked Liver Damage.

Inflammatory bowel conditions can involve nearly all organ systems and induce pathological processes through increased oxidative stress, lipid peroxidation and disruption of the immune response. Patients with inflammatory bowel disease (IBD) are at high risk of having extra-intestinal manifestations, for example, in the hepatobiliary system. In 30% of patients with IBD, the blood values of liver enzymes, such as AST and ALT, are increased. Moreover, treatments for inflammatory bowel diseases may cause liver toxicity. Apple polyphenol extracts are widely acknowledged for their potential antioxidant effects, which help prevent damage from oxidative stress, reduce inflammation, provide protection to the liver, and enhance lipid metabolism. The aim of this study was to investigate whether the polyphenol apple extract from Malus domestica cv. 'Limoncella' (LAPE) may be an effective intervention for the treatment of IBD-induced hepatotoxicity. The LAPE was administrated in vivo by oral gavage (3-300 mg/kg) once a day for 3 consecutive days, starting 24 h after the induction of dinitro-benzenesulfonic acid (DNBS) colitis in mice. The results showed that LAPE significantly attenuated histological bowel injury, myeloperoxidase activity, tumor necrosis factor and interleukin (IL-1β) expressions. Furthermore, LAPE significantly improved the serum lipid peroxidation and liver injury in DNBS-induced colitis, as well as reduced the nuclear transcription factor-kappaB activation. In conclusion, these results suggest that LAPE, through its antioxidant and anti-inflammatory properties, could prevent liver damage induced by inflammatory bowel disease.

A240 THE PROTECTIVE EFFECT OF HYMENOLEPIS DIMINUTA INFECTION IN EXPERIMENTAL COLITIS CAN BE INDEPENDENT OF IL-4RΑ SIGNALING

Abstract Background Helminth parasites are potent inducers of Th2 immunity, characterized by the production of IL-4, IL-5, IL-13 and IL-10, and mobilization of regulatory cells. This orchestrated immune response establishes an immunomodulatory and/or immunosuppressive environment that may be protective against colitis and other inflammatory diseases. Earlier studies reveal that infection with the tapeworm parasite Hymenolepis diminuta ameliorates chemical-induced colitis in immunocompetent mice, and highlighted participation of the anti-inflammatory cytokine IL-10 in the mechanisms of protection. Moreover, the IL-4ra/STAT6 signaling pathway plays a pivotal role in promoting the Th2 immune response that is crucial for parasite expulsion: IL-4ra KO mice cannot expel the worm. However, the need for activation of IL-4rasignaling in the suppression of colitis by H. diminuta infection is unknown. Aims To determine if the inhibition of DNBS-induced colitis evoked by infection with H. diminuta requires IL-4ra signaling. Methods IL-4ra KO mice (n=4-8/group) were orally infected with 5 viable cysticercoids of H. diminuta and 8 days post-infection (dpi) were treated with 2.5 mg of dinitrobenzene sulfonic acid (DNBS). Subsequently, mice were assessed 72h post-DNBS. Disease was assessed by macroscopic disease activity score, colon length, weight loss, MPO activity of the colon, and leucocyte profile by blood count. Production of IL-10 by concanavalin-A (con-A; 48h)-stimulated splenocytes was measured by ELISA. Results An increase in blood eosinophilia in H. diminuta infected mice indicated a successful infection. DNBS treatment induced acute colitis in IL-4ra KO mice, and surprisingly prior infection with H. diminuta resulted in significantly less severe colitis, as evidenced by reduction in macroscopic disease activity score, prevention of weight loss, reduced MPO colon levels and maintenance of regular colon length. However, splenocytes from H. diminuta-infected IL-4ra KO mice did not show increased IL-10 production evoked by con-A compared to cells from non-infected mice. Conclusions These results indicate that the protection against DNBS-induced colitis by prior infection with H. diminuta can occur in the absence of IL-4ra signalling. This suggests redundancy in the anti-colitic effect of infection with this helminth parasite, such that absence of IL4ra is compensated for via another, yet to be determined, mechanism. We speculate that this may be via participation of type 2 innate lymphoid cell activity, mobilization of regulatory T cells or innate immunity: all possibilities that need to be rigorously tested. Funding Agencies CIHRBeverly Phillips Rising Star and Cumming School of Medicine (U. Calgary) Fellowships

P116 Gastro-resistant microparticles for the oral delivery of Phycocyanin in the Inflammatory Bowel Disease therapy

Abstract Background Inflammatory Bowel Disease (IBD) is a chronically relapsing inflammation of the gastrointestinal tract, with ambiguous etiology. Oral route is the most common and acceptable approach for drug administration in the IBD treatment. However, it remains a challenge to maintain the stability of the drugs during oral treatment, particularly in the gastric environment, due its harsh conditions. In this context, the antioxidant and antiinflagmmatory properties of various natural compounds, as Phycocyanin (PC), a water-soluble bioactive molecule found in algae, can be strongly affected by factors as pH and temperature, inducing PC degradation and attenuating the curative effects. In this work, we produced a gastro-resistant microparticles (MPs) as controlled release systems for PC, and we aimed to compare its efficacy with free PC effects, on rat model of IBD. Methods The novel pharmaceutical system (SPC) was produced by microencapsulation technique, the spray-drying technique, using soy proteins (SPs) as natural excipients, aiming to improve the stability of the active ingredient and to ensure a modified release profile of PC. Rats were divided into groups and colitis was induced by intracolonic instillation of Dinitrobenzene sulfonic acid (DNBS, 20 mg/rat). Effects of preventive oral treatment of free PC or SPC were investigated, bioavailability was assessed and then body weight loss, stool consistency, colon weight/length index, myeloperoxidase activity (MPO), macroscopic damage and disease activity index (DAI) were determined. Results The SPC microparticle systems showed enhanced bioavailability of Phycocyanin, resulting in increased blood concentrations. The SPC system achieved the maximum AUC value and a modified release profile, particularly for gastro-resistant types, with a delayed Tmax of 5 hours, indicating their potential as a gastro-resistant formulation. Both PC and SPC pretreatments significantly ameliorated the severity of DNBS-induced colitis, however SPC pretreatment demonstrated enhanced activity vs PC. SPC rats showed a reduction of DAI, body weight loss and diarrhea incidence >15%, compared to PC (P<0.05); the ability of preventing the DNBS-induced macroscopic colonic damage and the MPO increase in SPC group were significantly higher than PC group (P<0.05) and also a tendency to improvement of colon weight/length index was observed. Conclusion In conclusion, the results of our research demonstrated that gastro-resistant microparticles (SPC) exhibit significantly improved therapeutic efficacy compared to orally administered free PC and can be developed as an effective new oral drug delivery system with controlled release profile in the treatment of IBD.

CrebH protects against liver injury associated with colonic inflammation via modulation of exosomal miRNA

BackgroundHepatic liver disease, including primary sclerosing cholangitis (PSC), is a serious extraintestinal manifestations of colonic inflammation. Cyclic adenosine monophosphate (cAMP)-responsive element-binding protein H (CrebH) is a transcription factor expressed mostly in the liver and small intestine. However, CrebH’s roles in the gut–liver axis remain unknown.MethodsInflammatory bowel disease (IBD) and PSC disease models were established in wild-type and CrebH−/− mice treated with dextran sulfate sodium, dinitrobenzene sulfonic acid, and diethoxycarbonyl dihydrocollidine diet, respectively. RNA sequencing were conducted to investigate differential gene expression. Exosomes were isolated from plasma and culture media. miRNA expression profiling was performed using the NanoString nCounter Mouse miRNA Panel. Effects of miR-29a-3p on adhesion molecule expression were investigated in bEnd.3 brain endothelial cells.ResultsCrebH−/− mice exhibited accelerated liver injury without substantial differences in the gut after administration of dextran sulfate sodium (DSS), and had similar features to PSC, including enlarged bile ducts, enhanced inflammation, and aberrant MAdCAM-1 expression. Furthermore, RNA-sequencing analysis showed that differentially expressed genes in the liver of CrebH−/− mice after DSS overlapped significantly with genes changed in PSC-liver. Analysis of plasma exosome miRNA isolated from WT and CrebH−/− mice indicates that CrebH can contribute to the exosomal miRNA profile. We also identified miR-29a-3p as an effective mediator for MAdCAM-1 expression. Administration of plasma exosome from CrebH−/− mice led to prominent inflammatory signals in the liver of WT mice with inflammatory bowel disease (IBD).ConclusionsCrebH deficiency led to increased susceptibility to IBD-induced liver diseases via enhanced expression of adhesion molecules and concomitant infiltration of T lymphocytes. Exosomes can contribute to the progression of IBD-induced liver injury in CrebH−/− mice. These study provide novel insights into the role of CrebH in IBD-induced liver injury.

Altered endocannabinoidome bioactive lipid levels accompany reduced DNBS-induced colonic inflammation in germ-free mice

BackgroundGut microbiota are involved in the onset and development of chronic intestinal inflammation. The recently described endocannabinoidome (eCBome), a diverse and complex system of bioactive lipid mediators, has been reported to play a role in various physio-pathological processes such as inflammation, immune responses and energy metabolism. The eCBome and the gut microbiome (miBIome) are closely linked and form the eCBome - miBIome axis, which may be of special relevance to colitis.MethodsColitis was induced in conventionally raised (CR), antibiotic-treated (ABX) and germ-free (GF) mice with dinitrobenzene sulfonic acid (DNBS). Inflammation was assessed by Disease Activity Index (DAI) score, body weight change, colon weight-length ratio, myeloperoxidase (MPO) activity and cytokine gene expression. Colonic eCBome lipid mediator concentrations were measured by HPLC-MS /MS.ResultsGF mice showed increased levels of anti-inflammatory eCBome lipids (LEA, OEA, DHEA and 13- HODE-EA) in the healthy state and higher MPO activity. DNBS elicited reduced inflammation in GF mice, having lower colon weight/length ratios and lower expression levels of Il1b, Il6, Tnfa and neutrophil markers compared to one or both of the other DNBS-treated groups. Il10 expression was also lower and the levels of several N-acyl ethanolamines and 13-HODE-EA levels were higher in DNBS-treated GF mice than in CR and ABX mice. The levels of these eCBome lipids negatively correlated with measures of colitis and inflammation.ConclusionsThese results suggest that the depletion of the gut microbiota and subsequent differential development of the gut immune system in GF mice is followed by a compensatory effect on eCBome lipid mediators, which may explain, in part, the observed lower susceptibility of GF mice to develop DNBS-induced colitis.

Bifidobacterium breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration.

Bifidobacterium breve was the first bacteria isolated in the feces of healthy infants and is a dominant species in the guts of breast-fed infants. Some strains of B. breve have been shown to be effective at relieving intestinal inflammation, but the modes of action have yet to be elucidated. In this study, we investigated the mechanisms of action of B. breve CBT BR3 isolated from South Korean infant feces in relieving colitis in vitro and in vivo. Colitis was induced in mice with dextran sodium sulfate (DSS) and dinitrobenzene sulfonic acid (DNBS). Quantitative reverse-transcription polymerase chain reaction, in vitro FITC-dextran flux permeability assay, and aryl hydrocarbon receptor (AhR) luciferase assay are performed using Caco-2 cells and HT29-Lucia™ AhR cells. B. breve CBT BR3 was orally administered. B. breve CBT BR3 improved colitis symptoms in both DSS- and DNBS-induced colitis models. B. breve CBT BR3 increased the number of goblet cells per crypt. B. breve increased the mRNA expressions of Notch, Spdef, Muc5, and Il22. The mRNA expressions of Occludin, which encodes a membrane tight-junction protein, and Foxo3, which encodes a protein related to butyrate metabolism, were also increased in the DSS- and DNBS-induced colitis models. B. breve CBT BR3 protected inflammation-induced epithelial cell permeability and improved goblet cell function by inducing aryl hydrocarbon receptor in vitro. These results indicate that B. breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration.

A163 INFECTION WITH HYMENOLEPIS DIMINUTA ELICITS A TH2 IMMUNITY AND ALLEVIATES DNBS-COLITIS IN A MOUSE MODEL WITH MINIMAL INTESTINAL MICROBIOTA

Abstract Background Immunocompetent mice infected with the rat tapeworm Hymenolepis diminuta are protected from dinitrobenzene sulphonic-acid (DNBS)-induced colitis that was accompanied by the increased relative abundance of short-chain fatty acid (SCFA)-producing bacteria and fecal SCFA levels at 8 days post-infection (dpi). These changes were not observed in antibiotic-treated BALB/c mice or germ-free mice. To further characterize the host-parasite-microbiota interaction in the control of colitis, experiments have been conducted in a reductionist system in which the H. diminuta anti-colitic response was tested in mice colonized with 12 commensal bacteria representing the major five phyla of the mouse gut. Purpose To identify key bacterial species and microbe-derived mediators involved in the H. diminuta-induced protection from DNBS-induced colitis. Method OligoMM12 (Oligo-Mouse-Microbiota) mice (n=4-8/group) were infected with 10 viable antibiotic-treated H. diminuta cysticercoids eight days prior to challenge with DNBS (3mg, i.r.). Mice were monitored daily and necropsied 72h post-DNBS. Disease was assessed by a macroscopic disease activity score, colon length and histopathology on H&E sections of mid-colon. Production of IL-4, -5, -10 and -13 by concanavalin-A treated spleen cells by ELISA was used as an index of successful helminth infection. Result(s) OligoMM12 mice treated with DNBS developed acute colitis, with 3/8 mice requiring humane euthanization, while all mice infected with H. diminuta survived the DNBS challenge. Successful infection was confirmed by statistically significant increases in splenic output of the Th2-cytokines in response to mitogenic stimulation and efficient expulsion of the worms burden by 11 dpi. The severity of DNBS-induced colitis was reduced in H. diminuta-infected mice (n=4), although additional experiments are required to confirm the statistical significance of these data. Conclusion(s) Reproducible DNBS-induced colitis in mice with the simplified OligoMM12 consortium of bacteria and reduced disease in H. diminuta-infected mice has created a model by which the participation of exact bacterial groups or species in H. diminuta-induced suppression of colitis can be tested. This is of translational value, since the failure of helminth therapy in IBD could be predicated by dysbiosis in the patient, and therefore potentially overcome by combination therapy of ‘probiotic’ and helminth. Please acknowledge all funding agencies by checking the applicable boxes below CIHR, Other Please indicate your source of funding; NSERC-CGS D, Eyes High doctoral Recruitment Scholarship Disclosure of Interest None Declared

Metagenomic analysis of Tongxie Yaofang therapy for rat models of ulcerative colitis with liver depression and spleen deficiency syndrome

Tongxie Yaofang (TXYF) has therapeutic effect on the ulcerative colitis (UC) with liver depression and spleen deficiency syndrome. This study investigated the changes in the gut microbiota of UC rats treated with TXYF. Wistar rats were divided into three groups: Control, dinitrobenzene sulfonic acid (DNBS)-colitis, and DNBS + TXYF (n = 8 per group). UC model was constructed via intrarectally injection of DNBS (25 mg DNBS and 0.25 mL 50% ethanol); rats in DNBS + TXYF group were administered with TXYF (20.8 g/kg) for 21 days. Physiological parameters were measured. Five samples from each group were selected for metagenomic analysis. TXYF treatment significantly reduced disease activity index, colon mucosal damage index, and tumor necrosis factor-alpha level. TXYF treatment prevented DNBS-induced dysregulation of gut microbial communities. Compared with DNBS-colitis group, the abundance of Firmicutes increased significantly and that of Bacteroidetes and Proteobacteria decreased in DNBS + TXYF group. Pathways such as protein processing in the endoplasmic reticulum pathway was enriched in the DNBS-colitis group, whereas it was decreased in the DNBS + TXYF group. Thus, TXYF treatment could effectively restore the dysregulation of intestinal flora induced by UC.

Effect of electroacupuncture on visceral sensitivity and colonic NGF, TrkA, TRPV1 expression in IBS-D rats

To observe the effect of electroacupuncture (EA) at "Tianshu" (ST 25) and "Shangjuxu" (ST 37) on mental state, visceral sensitivity and protein expression of nerve growth factor (NGF), tyrosine kinase receptor A (TrkA) and transient receptor potential vanilloid 1 (TRPV1) of colonic tissue in diarrhea-predominant irritable bowel syndrome (IBS-D) rats, and to explore its possible mechanism on treating IBS-D. A total of 36 male SD rats of SPF grade were randomized into a blank group, a model group, an EA group and a western medication group, 9 rats in each group. In the model group, the EA group and the western medication group, IBS-D model was established by enema of dinitrobenzene sulfonic acid (DNBS) combined with chronic restraint stress method. In the EA group, EA was applied at "Tianshu" (ST 25) and "Shangjuxu" (ST 37), with disperse-dense wave, in frequency of 2 Hz/100 Hz, 20 min each time, once a day for 7 days. In the western medication group, pinaverium bromide suspension was given by gavage (15 mg•kg-1•d-1) for 7 days. Before and after model establishment, and after intervention, the body mass, 24 h food intake and fecal water content were observed, the visceral sensitivity was detected by abdominal withdrawal reflex (AWR); after intervention, the mental state was evaluated by elevated plus maze (EPM) test, the protein expression of NGF, TrkA and TRPV1 was detected by immunohistochemistry and Western blot in the 4 groups. After model establishment, compared with the blank group, the body mass and 24 h food intake were decreased (P<0.05), first systolic latency of AWR was shortened and number of contraction wave of AWR was increased (P<0.05), and fecal water content was increased (P<0.05) in the model group, the EA group and the western medication group. After intervention, compared with the blank group, open arm residence time ratio (OT%) of EPM was decreased (P<0.05) and protein expression of NGF, TrkA, TRPV1 in colonic tissue was increased in the model group (P<0.05); compared with the model group, the body mass and 24 h food intake were increased (P<0.05), first systolic latency of AWR was lengthened and number of contraction wave of AWR was decreased (P<0.05), the fecal water content was decreased (P<0.05), OT% of EPM was increased (P<0.05), and protein expression of NGF, TrkA, TRPV1 in colonic tissue was decreased (P<0.05) in the EA group and the western medication group. Electroacupuncture at "Tianshu" (ST 25) and "Shangjuxu" (ST 37) can relieve the anxiety and depression-like behaviors in IBS-D rats, down-regulate the protein expression of NGF, TrkA, TRPV1 in colonic tissue, so as to reduce the visceral sensitivity and relieve symptoms.

Serpin-positive Bifidobacterium breve CNCM I-5644 improves intestinal permeability in two models of irritable bowel syndrome

Probiotic supplementation can help to mitigate the pathogenesis of irritable bowel syndrome (IBS) by reinforcing the intestinal barrier, and reducing both inflammation and proteolytic activity. Here, a combination of in vitro tests was performed on 33 Bifidobacterium strains as probiotic candidates for IBS. In addition to the classical tests performed, the detection of the serine protease inhibitor (serpin) enzyme capable of decreasing the high proteolytic activity found in IBS patients was included. Three serpin-positive strains were selected: Bifidobacterium breve CNCM I-5644, Bifidobacterium longum subsp. infantis CNCM I-5645 and B. longum CNCM I-5646 for their immunomodulation properties and protection of intestinal epithelial integrity in vitro. Furthermore, we found that B. breve CNCM I-5644 strain prevented intestinal hyperpermeability by upregulating Cingulin and Tight Junction Protein 1 mRNA levels and reducing pro-inflammatory markers. The ability of CNCM I-5644 strain to restore intestinal hyperpermeability (FITC-dextran) was shown in the murine model of low-grade inflammation induced by dinitrobenzene sulfonic acid (DNBS). This effect of this strain was corroborated in a second model of IBS, the neonatal maternal separation model in mice. Altogether, these data suggest that serpin-positive B. breve CNCM I-5644 may partially prevent disorders associated with increased barrier permeability such as IBS.

Tissue imaging reveals disruption of epithelial mitochondrial networks and loss of mitochondria-associated cytochrome-C in inflamed human and murine colon

Mitochondrial dysfunction as defined by transcriptomic and proteomic analysis of biopsies or ultra-structure in transmission electron microscopy occurs in inflammatory bowel disease (IBD); however, mitochondrial dynamics in IBD have received minimal attention, with most investigations relying on cell-based in vitro models. We build on these studies by adapting the epithelial cell immunofluorescence workflow to imaging mitochondrial networks in normal and inflamed colonic tissue (i.e., murine di-nitrobenzene sulphonic acid (DNBS)-induced colitis, human ulcerative colitis). Using antibodies directed to TOMM20 (translocase of outer mitochondrial membrane 20) and cytochrome-C, we have translated the cell-based protocol for high-fidelity imaging to examine epithelial mitochondria networks in intact intestine. In epithelia of non-inflamed small or large intestinal tissue, the mitochondrial networks were dense and compact. This pattern was more pronounced in the basal region of the cell compared to that between the nucleus and apical surface facing the gut lumen. In comparison, mitochondrial networks in inflamed tissue displayed substantial loss of TOMM20+ staining. The remaining networks were less dense and fragmented, and contained isolated spherical mitochondrial fragments. The degree of mitochondrial network fragmentation mirrored the severity of inflammation, as assessed by blinded semi-quantitative scoring. As an indication of poor cell ‘health’ or viability, cytosolic cytochrome-C was observed in enterocytes with highly fragmented mitochondria. Thus, high-resolution and detailed visualization of mitochondrial networks in tissue is a feasible and valuable approach to assess disease, suited to characterizing mitochondrial abnormalities in tissue. We speculate that drugs that maintain a functional remodelling mitochondrial network and limit excess fragmentation could be a valuable addition to current therapies for IBD.

TNF-α enhances sensory DRG neuron excitability through modulation of P2X3 receptors in an acute colitis model.

Previous studies have demonstrated that acute colonic inflammation leads to an increase in dorsal root ganglia (DRG) neuronal excitability. However, the signaling elements implicated in this hyperexcitability have yet to be fully unraveled. Extracellular adenosine 5’-triphosphate (ATP) is a well-recognized sensory signaling molecule that enhances the nociceptive response after inflammation through activation of P2X3 receptors, which are expressed mainly by peripheral sensory neurons. The aim of this study is to continue investigating how P2X3 affects neuronal hypersensitivity in an acute colitis animal model. To achieve this, DNBS (Dinitrobenzene sulfonic acid; 200 mg/kg) was intrarectally administered to C57BL/6 mice, and inflammation severity was assessed according to the following parameters: weight loss, macroscopic and microscopic scores. Perforated patch clamp technique was used to evaluate neuronal excitability via measuring changes in rheobase and action potential firing in T8-L1 DRG neurons. A-317491, a well-established potent and selective P2X3 receptor antagonist, served to dissect their contribution to recorded responses. Protein expression of P2X3 receptors in DRG was evaluated by western blotting and immunofluorescence. Four days post-DNBS administration, colons were processed for histological analyses of ulceration, crypt morphology, goblet cell density, and immune cell infiltration. DRG neurons from DNBS-treated mice were significantly more excitable compared with controls; these changes correlated with increased P2X3 receptor expression. Furthermore, TNF-α mRNA expression was also significantly higher in inflamed colons compared to controls. Incubation of control DRG neurons with TNF-α resulted in similar cell hyperexcitability as measured in DNBS-derived neurons. The selective P2X3 receptor antagonist, A-317491, blocked the TNF-α-induced effect. These results support the hypothesis that TNF-α enhances colon-innervating DRG neuron excitability via modulation of P2X3 receptor activity.

Efficacy of Sishen Wan on dinitrobenzene sulfonic acid-induced ulcerative colitis and its effect on toll-like receptor 2/interleukin-1 receptor-associated kinase-4/nuclear factor-κB signal pathway.

To investigate the therapeutic effect of Sishen Wan (, SSW) on ulcerative colitis (UC) induced by dinitrobenzene sulfonic acid and its effect on toll-like receptor 2/interleukin-1 receptor-associated kinase-4/nuclear factor-κB (TLR2/IRAK4/NF-κB) sig-naling pathway in colonic tissue. In this study, 120 Sprague-Dawley rats were randomly divided into blank and model groups. The experimental UC model in rats was established by subcutaneous injection of hydrocortisone + senna gavage for 21 d + dinitrobenzene sulfonic acid (DNBS)/ ethanol solution enema. The successful model rats were randomly divided into the model group; mesalazine (0.36 g/kg) group; and high-, medium-, and low- dose SSW (24, 12, and 6 g/kg) groups. The model and blank groups were gavaged with equal volumes of distilled water once a day for 21 d. The general condition of the rats was observed, and the body mass, fecal properties, and occult blood were recorded for calculating the disease activity index (DAI) score. The colonic tissue of the rats was collected, and its general morphology and pathological form were noted for obtaining the colonic mucosal injury index (CMDI) score. Hematoxylin-eosin staining was used to view the pathological changes of the colon tissue in each group, apoptosis of the cells was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, and quantitative real-time polymerase chain reaction was used to measure the expressions of TLR2, myeloid differentiation primary response gene 88 (MyD88), IRAK4, and NF-κB p65 mRNA in the colon tissue. The expressions of TLR2, MyD88, IRAK4, and NF-κB p65 protein were detected using western blotting and immunohistochemistry assay, and the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the colon tissue were determined using enzyme linked immunosorbent assay. Compared with the blank group, the general condition of the model group was relatively poor. The DAI and CMDI scores of the model group increased significantly (< 0.01), the glands and intestinal mucosa disappeared partially, and several inflammatory cells infiltrated and gathered in the mucosal layer and base layer of the rats in the model group. Furthermore, the cell apoptosis and expression levels of TLR2, MyD88, IRAK4, and NF-κB p65 mRNA and protein in the colon tissue of rats in the model group increased significantly (< 0.01). The levels of IL-1β and TNF-α increased significantly in the colon tissue of rats in the model group (< 0.01). After treatment with SSW, compared with the model group, the general condition of the UC rats improved. Moreover, the DAI and CMDI scores of the UC rats decreased significantly (< 0.05), and the pathological changes in the colon tissue of the UC rats tended to be normal. The cell apoptosis and expression levels of TLR2, MyD88, IRAK4, and NF-κB p65 mRNA and protein in the colon tissue of the UC rats decreased gradually ( < 0.01), and the levels of IL-1β and TNF-α decreased significantly (< 0.01). SSW can improve the general condition and alleviate the intestinal mucosal injury of UC model rats. Additionally, SSW can inhibit the TLR2/IRAK4/ NF-κB signaling pathway, but further studies are required to confirm it.

Effect of electroacupuncture on colonic motility and RhoA and ROCK protein expression in IBS-D rats

To observe the effect of electroacupuncture (EA) of "Tianshu"(ST25) and "Shangjuxu"(ST37)on gastrointestinal motility, psychological abnormality and expression of RhoA and ROCK protein in rats with diarrhea predominant irritable bowel syndrome (IBS-D), so as to explore its underlying mechanism in improving IBS-D. Thirty-six male rats were randomly and equally divided into control, model, EA and medication groups (n=9 in each group). The IBS-D model with psychological abnormality was established by gavage of dinitrobenzene sulfonic acid (DNBS) + chronic restraint stress. EA (2 Hz/100 Hz, 0.3 mA) was applied to bilateral ST25 and ST37 for 20 min, once a day for 7 days. Rats of the medication group received gavage of pinaverium bromide solution (15 mg/kg), once a day for 7 days. The rats' food intake in 24 h, body mass and colonic contraction waves were recorded. The anhedonia-related behavior was measured using the sucrose consumption test. The elevated plus maze test (the open-arm residence time ratio) was used to assess the anxiety-like behavior. The small intestinal propulsion rate test was used to assess the intestinal motility. The expression levels of RhoA and ROCK proteins in the colonic tissue were measured by Western blot. After modeling, the body mass, food consumption, sucrose preference index, the open-arm residence time ratio andlatency of colonic contraction waves were significantly decreased (P<0.05), and the number of contraction waves, intestinal propulsive rate, and the expression levels of RhoA and ROCK proteins considerably increased (P<0.01，P<0.05) in the model group relevant to the control group. Following the interventions, the decrease of body mass, food consumption, sucrose preference index, open-arm residence time ratio and latency of contraction waves, and the increase of the contraction waves, intestinal propulsive rate, and the expression levels of RhoA and ROCK proteins were all reversed by both EA and medication (P<0.05，P<0.01). The effect of EA was significantly superior to that of medication in increasing the sucrose pre-ference index (P<0.05). EA can improve both colonic motility and psychological disorders in IBS-D rats with psychological disorder, which may be related to its function in down-regulating the expression of colonic RhoA and ROCK proteins.

Aberrant Mesenteric Adipose Extracellular Matrix Remodelling is Involved in Adipocyte Dysfunction in Crohn's Disease: The Role of TLR-4-mediated Macrophages.

Hypertrophic mesenteric adipose tissue [htMAT] is involved in the disease progression of Crohn's disease [CD] through expressing proinflammatory adipokines from dysfunctional adipocytes by unknown mechanism. Adipocyte function is affected by dynamic adipose tissue extracellular matrix [ECM] remodelling that is mainly mediated by macrophages, and our study aimed to reveal whether aberrant ECM remodelling was present in CD-htMAT and its effects on adipocyte dysfunction, as well as the mechanism. ECM remodelling was examined in MAT samples from CD patients and controls. Mice with dinitrobenzene sulphonic acid [DNBS]-induced colitis were used in vivo study, and lipopolysaccharide [LPS]-induced remodelling behaviour in macrophages was examined in vitro. Macrophages or TLR4 inhibition were used to analyse ECM remodelling mechanisms and their effects on adipocyte function. Aberrant ECM remodelling: was observed in CD-htMAT, which was characterised by a widened and deformed ECM structure accompanied by dysregulated matrix synthesis and degradation; served as a reservoir for inflammatory factors/cells dominated by macrophages; and was involved in adipocyte dysfunction. In addition, macrophages were the main source of ECM remodelling regulatory factors with activation of Toll-like receptor 4 [TLR4] in htMAT. In vivo, macrophage depletion or TLR4 inhibition largely attenuated mesenteric ECM remodelling while improving mesenteric adipocyte dysfunction during chronic enteritis. In vitro, antagonizing TLR4 significantly inhibited LPS-induced macrophage ECM remodelling behavior. The aberrant ECM remodelling in CD-htMAT contributed to mesenteric adipocyte dysfunction, which may be caused at least partly by TLR4-mediated macrophage remodelling behavior. Inhibiting ECM remodelling may be a potential therapeutic strategy for CD.

Enteric glia regulates the expression of neutrophil inflammatory factors during acute inflammation

Abstract Inflammation is an event in functional gastrointestinal disorders that has detrimental effects in the enteric nervous system. Recent advances in our understanding of the immune and enteric nervous system indicate that enteric glial cells modulate immune cells in the gastrointestinal tract. Previous single-nuclei multiomic analysis has shown that genes that encode for and influence neutrophil function, Neutrophil cytosolic factor 4 and C-X-C motif chemokine ligand 5, are changed in enteric glia during peak colitis. We hypothesize that enteric glia regulate the expression of neutrophil modulating factors during acute inflammation. We tested this using the acute dinitrobenzene sulfonic acid colitis model. Animal body weight and gross macroscopic damage were recorded as indications of overall inflammation and tissue was harvested for immunohistochemical analysis. Enteric glial cells were labeled with antibodies against Neutrophil cytosolic factor 4 and C-X-C motif chemokine ligand 5. Results suggest no significant difference in labeling for immunological markers in enteric glial cells of dinitrobenzene sulfonic acid treated mice. Results also show labeling in some neurons that may or may not be specific. Further experimentation is needed to elucidate the mechanisms of enteric neurons and glia in gut inflammation. These studies will contribute to further understand how immune responses are regulated in the gut and impact the general knowledge of gut disease processes. This work was supported by the National Institute of Health grants R01DK103723 and R01DK120862 to BDG and DPR was supported by the National Institute of Health Bridge to the Ph.D. in Neuroscience grant 2R25NS090989.