Lipopolysaccharides transport during fat absorption in rodent small intestine.

Lipopolysaccharides (LPS) are potent pro-inflammatory molecules that enter the systemic circulation from the intestinal lumen by uncertain mechanisms. We investigated these mechanisms and the effect of exogenous glucagon-like peptide-2 (GLP-2) on LPS transport in the rodent small intestine. Transmucosal LPS transport was measured in Ussing-chambered rat jejunal mucosa. In anesthetized rats, the appearance of fluorescein isothiocyanate (FITC)-LPS into the portal vein (PV) and the mesenteric lymph was simultaneously monitored after intraduodenal perfusion of FITC-LPS with oleic acid and taurocholate (OA/TCA). In vitro, luminally applied LPS rapidly appeared in the serosal solution only with luminal OA/TCA present, inhibited by the lipid raft inhibitor methyl-ß-cyclodextrin (MßCD) and the CD36 inhibitor sulfosuccinimidyl oleate (SSO), or by serosal GLP-2. In vivo, perfusion of FITC-LPS with OA/TCA rapidly increased FITC-LPS appearance into the PV, followed by a gradual increase of FITC-LPS into the lymph. Rapid PV transport was inhibited by the addition of MßCD or by SSO, whereas transport into the lymph was inhibited by chylomicron synthesis inhibition. Intraveous injection of the stable GLP-2 analog teduglutide acutely inhibited FITC-LPS transport into the PV, yet accelerated FITC-LPS transport into the lymph via Nω-nitro-l-arginine methyl ester (l-NAME)- and PG97-269-sensitive mechanisms. In vivo confocal microscopy in mouse jejunum confirmed intracellular FITC-LPS uptake with no evidence of paracellular localization. This is the first direct demonstration in vivo that luminal LPS may cross the small intestinal barrier physiologically during fat absorption via lipid raft- and CD36-mediated mechanisms, followed by predominant transport into the PV, and that teduglutide inhibits LPS uptake into the PV in vivo.NEW & NOTEWORTHY We report direct in vivo confirmation of transcellular lipopolysaccharides (LPS) uptake from the intestine into the portal vein (PV) involving CD36 and lipid rafts, with minor uptake via the canonical chylomicron pathway. The gut hormone glucagon-like peptide-2 (GLP-2) inhibited uptake into the PV. These data suggest that the bulk of LPS absorption is via the PV to the liver, helping clarify the mechanism of LPS transport into the PV as part of the "gut-liver" axis. These data do not support the paracellular transport of LPS, which has been implicated in the pathogenesis of the "leaky gut" syndrome.

GLP-2 Acutely Prevents Endotoxin-Related Increased Intestinal Paracellular Permeability in Rats.

BACKGROUND: Circulating endotoxin (lipopolysaccharide, LPS) increases the gut paracellular permeability. We hypothesized that glucagon-like peptide-2 (GLP-2) acutely reduces LPS-related increased intestinal paracellular permeability by a mechanism unrelated to its intestinotrophic effect. METHODS: We assessed small intestinal paracellular permeability in vivo by measuring the appearance of intraduodenally perfused FITC-dextran 4000 (FD4) into the portal vein (PV) in rats 1-24 h after LPS treatment (5 mg/kg, ip). We also examined the effect of a stable GLP-2 analog teduglutide (TDG) on FD4 permeability. RESULTS: FD4 movement into the PV was increased 6 h, but not 1 or 3 h after LPS treatment, with increased PV GLP-2 levels and increased mRNA expressions of proinflammatory cytokines and proglucagon in the ileal mucosa. Co-treatment with a GLP-2 receptor antagonist enhanced PV FD4 concentrations. PV FD4 concentrations 24 h after LPS were higher than FD4 concentrations 6 h after LPS, reduced by exogenous GLP-2 treatment given 6 or 12 h after LPS treatment. FD4 uptake measured 6 h after LPS was reduced by TDG 3 or 6 h after LPS treatment. TDG-associated reduced FD4 uptake was reversed by the VPAC1 antagonist PG97-269 or L-NAME, not by EGF or IGF1 receptor inhibitors. CONCLUSIONS: Systemic LPS releases endogenous GLP-2, reducing LPS-related increased permeability. The therapeutic window of exogenous GLP-2 administration is at minimum within 6-12 h after LPS treatment. Exogenous GLP-2 treatment is of value in the prevention of increased paracellular permeability associated with endotoxemia.

Nicotine treatment ameliorates DSS-induced colitis by suppressing MAdCAM-1 expression and leukocyte recruitment.

The enhanced recruitment of leukocytes to the inflamed colon is a key feature of ulcerative colitis (UC). The gut-specific adhesion molecules involved in leukocyte recruitment have emerged as recent therapeutic targets. Nicotine absorbed from smoking has been reported to work protectively in UC patients. Our hypothesis is that nicotine may suppress the aberrant leukocyte recruitment and colonic inflammation via the suppression of the overexpressed gut-specific adhesion molecules in the inflamed colon. To test this hypothesis, the severity of colitis and the degree of leukocyte recruitment induced by gut-specific adhesion molecules were assessed in dextran sulfate sodium (DSS) colitis mice (C57BL/6J mice treated with 3% DSS) with or without nicotine treatment. We also studied the in vitro changes in the expression of adhesion molecules by using a vascular endothelial cell line. DSS-induced colitis was accompanied by increases in disease activity index (DAI), histological score, recruitment of leukocytes, and the expression of adhesion molecules, mucosal vascular addressin cell adhesion molecule-1 (MAdCAM-1) and VCAM-1. Nicotine treatment significantly attenuated MAdCAM-1 expression, leukocyte recruitment, DAI, and histological score. The expression of ß7-integrin, the ligand for MAdCAM-1, on leukocytes was not affected by nicotine treatment. In vitro study, the TNF-α-enhanced mRNA expression of MAdCAM-1 was reduced by the coadministration of nicotine in a dose-dependent manner, possibly via nicotinic receptor activation. These results supported our hypothesis that nicotine treatment ameliorated colitis through the suppression of MAdCAM-1 expression on the microvessels in the inflamed colon. Further investigation is warranted on the role of nicotine in the treatment of UC.

Amelioration of colitis through blocking lymphocytes entry to Peyer's patches by sphingosine-1-phosphate lyase inhibitor.

BACKGROUND AND AIM: Sphingosine-1-phosphate (S1P) receptor 1, a therapeutic target of the S1P1 agonist FTY720, plays a crucial role in lymphocyte migration and is expressed in several cells including naïve T lymphocytes and endothelial cells. 2-Acetyl-4-tetrahydroxybutyl imidazole (THI), an inhibitor of S1P lyase, exhibits immunomodulatory activity through increasing the S1P concentration in the secondary lymphoid organs, but its effects on colitis remain unclear. This study aimed to clarify how THI affects colitis and migration of naïve T lymphocytes in Peyer's patches (PPs). METHODS: The effect of THI on gut immunity was investigated by analyzing the dextran sulfate sodium (DSS)-induced murine colitis model, lymphocyte components in thoracic duct lymphocytes (TDLs), and microscopic movement of TDLs in PPs. RESULTS: 2-Acetyl-4-tetrahydroxybutyl imidazole ameliorated DSS-induced colitis histologically by causing a significant decrease in colonic lymphocyte infiltration and expression of mucosal pro-inflammatory cytokines. THI suppressed the inflow of naïve T lymphocytes into the thoracic duct. Microscopic observation of PPs in control animals revealed that many TDLs egressed to the stroma and migrated to lymph capillaries after attaching to the high endothelial venules (HEVs). THI or FTY720 treatment in recipient animals blocked lymphocyte egression from the HEVs to the stroma. CONCLUSIONS: This is the first study to clarify the ameliorating effects of THI on DSS-induced colitis. Microscopic observations demonstrated the involvement of HEVs in the egression of S1P-dependent gut-tropic T lymphocytes to lymph capillaries. This S1P lyase inhibitor might become a novel immunosuppressant for inflammatory bowel disease therapy by blocking infiltration of lymphocytes through HEVs into the stroma in PPs.

Evaluation by MR Enterocolonography of Lansoprazole-induced Collagenous Colitis Accompanied with Protein-losing Enteropathy.

We herein describe a 69-year-old man suffering from chronic diarrhea caused by lansoprazole (LPZ)-induced collagenous colitis (CC) accompanied with protein-losing enteropathy (PLE), diagnosed by increased fecal alpha-1 antitrypsin clearance and the findings of leakage from the descending colon to the sigmoid colon on scintigraphy. MR enterocolonography (MREC) was also performed for differentiating digestive diseases, and inflamed findings were observed around the same portion as those on scintigraphy, suggesting that this region was responsible for protein loss in this case. The MREC findings improved after the cessation of LPZ, and hypoalbuminemia also improved simultaneously. This case suggests that MREC may be a new and useful diagnostic tool for CC with PLE.

Vitamin A-coupled liposome system targeting free cholesterol accumulation in hepatic stellate cells offers a beneficial therapeutic strategy for liver fibrosis.

AIM: Liver fibrosis is a life-threatening disorder for which no approved therapy is available. Recently, we reported that mouse hepatic stellate cell (HSC) activation increased free cholesterol (FC) accumulation, partly by enhancing signaling through sterol regulatory element-binding protein 2 (SREBP2) and microRNA-33a (miR-33a), which resulted in HSC sensitization to transforming growth factor-ß (TGFß)-induced activation in a "vicious cycle" of liver fibrosis. METHODS: Human HSCs were isolated from surgical liver specimens from control patients and patients with liver fibrosis. C57BL/6 mice were treated with carbon tetrachloride for 4 weeks and concurrently given SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes. RESULTS: In human activated HSCs obtained from patients with liver fibrosis, FC accumulation was enhanced independently of serum cholesterol levels through increased signaling by both SREBP2 and miR-33a. This increased FC accumulation enhanced Toll-like receptor 4 (TLR4) protein levels and lowered the TGFß-pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor) mRNA levels in HSCs. Notably, in a mouse liver fibrosis model, reduction of FC accumulation, specifically in activated HSCs by suppression of SREBP2 or miR-33a expression using SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes, downregulated TLR4 signaling, increased Bambi expression, and consequently ameliorated liver fibrosis. CONCLUSIONS: Our results suggest that FC accumulation in HSCs, as an intracellular mediator promoting HSC activation, contributes to a vicious cycle of HSC activation in human and mouse liver fibrosis independent of serum cholesterol levels. Targeting FC accumulation-related molecules in HSCs through a vitamin A-coupled liposomal system represents a favorable therapeutic strategy for liver fibrosis.

FFA3 Activation Stimulates Duodenal Bicarbonate Secretion and Prevents NSAID-Induced Enteropathy via the GLP-2 Pathway in Rats.

BACKGROUND: Therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with enteropathy in humans and experimental animals, a cause of considerable morbidity. Unlike foregut NSAID-associated mucosal lesions, most treatments for this condition are of little efficacy. We propose that the endogenously released intestinotrophic hormone glucagon-like peptide-2 (GLP-2) prevents the development of NSAID-induced enteropathy. Since the short-chain fatty acid receptor FFA3 is expressed on enteroendocrine L cells and on enteric nerves in the gastrointestinal tract, we further hypothesized that activation of FFA3 on L cells protects the mucosa from injury via GLP-2 release with enhanced duodenal HCO3- secretion. We thus investigated the effects of synthetic selective FFA3 agonists with consequent GLP-2 release on NSAID-induced enteropathy. METHODS: We measured duodenal HCO3- secretion in isoflurane-anesthetized rats in a duodenal loop perfused with the selective FFA3 agonists MQC or AR420626 (AR) while measuring released GLP-2 in the portal vein (PV). Intestinal injury was produced by indomethacin (IND, 10 mg/kg, sc) with or without MQC (1-10 mg/kg, ig) or AR (0.01-0.1 mg/kg, ig or ip) treatment. RESULTS: Luminal perfusion with MQC or AR (0.1-10 µM) dose-dependently augmented duodenal HCO3- secretion accompanied by increased GLP-2 concentrations in the PV. The effect of FFA3 agonists was inhibited by co-perfusion of the selective FFA3 antagonist CF3-MQC (30 µM). AR-induced augmented HCO3- secretion was reduced by iv injection of the GLP-2 receptor antagonist GLP-2(3-33) (3 nmol/kg), or by pretreatment with the cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 (1 mg/kg, ip). IND-induced small intestinal ulcers were dose-dependently inhibited by intragastric administration of MQC or AR. GLP-2(3-33) (1 mg/kg, ip) or CF3-MQC (1 mg/kg, ig) reversed AR-associated reduction in IND-induced enteropathy. In contrast, ip injection of AR had no effect on enteropathy. CONCLUSION: These results suggest that luminal FFA3 activation enhances mucosal defenses and prevents NSAID-induced enteropathy via the GLP-2 pathway. The selective FFA3 agonist may be a potential therapeutic candidate for NSAID-induced enteropathy.

FFA2 activation combined with ulcerogenic COX inhibition induces duodenal mucosal injury via the 5-HT pathway in rats.

Serotonin (5-HT), predominantly synthesized and released by enterochromaffin cells, is implicated in gastrointestinal symptoms such as emesis, abdominal pain, and diarrhea. Because luminal short-chain fatty acids (SCFAs) release 5-HT from enterochromaffin cells, which express the SCFA receptor free fatty acid receptor 2 (FFA2) in rat duodenum, we examined the effects of the selective FFA2 agonist phenylacetamide-1 (PA1) on duodenal 5-HT release with consequent bicarbonate secretion [duodenal bicarbonate secretion (DBS)] and on indomethacin (IND)-induced enteropathy. Intestinal injury was induced by IND (10 mg/kg sc) with or without PA1. We measured DBS in vivo in a duodenal loop perfused with PA1 while measuring 5-HT released in the portal vein. Duodenal blood flow was measured by laser-Doppler flowmetry. IND induced small intestinal ulcers with duodenal sparing. PA1 given with IND (IND + PA1) dose dependently induced duodenal erosions. IND + PA1-induced duodenal lesions were inhibited by the FFA2 antagonist GLPG-0974, ondansetron, or omeprazole but not by RS-23597 or atropine. Luminal perfusion of PA1 augmented DBS accompanied by increased portal blood 5-HT concentrations with approximately eight times more release at 0.1 mM than at 1 µM, with the effects inhibited by coperfusion of GLPG-0974. Luminal PA1 at 1 µM increased, but at 0.1 mM diminished, duodenal blood flow. Cosuperfusion of PA1 (0.1 mM) decreased acid-induced hyperemia, further reduced by IND pretreatment but restored by ondansetron. These results suggest that, although FFA2 activation enhances duodenal mucosal defenses, FFA2 overactivation during ulcerogenic cyclooxygenase inhibition may increase the vulnerability of the duodenal mucosa to gastric acid via excessive 5-HT release and 5-HT3 receptor activation, implicated in foregut-related symptoms such as emesis and epigastralgia.NEW & NOTEWORTHY Luminal free fatty acid receptor 2 agonists stimulate enterochromaffin cells and release serotonin, which enhances mucosal defenses in rat duodenum. However, overdriving serotonin release with high luminal concentrations of free fatty acid 2 ligands such as short-chain fatty acids injures the mucosa by decreasing mucosal blood flow. These results are likely implicated in serotonin-related dyspeptic symptom generation because of small intestinal bacterial overgrowth, which is hypothesized to generate excess SCFAs in the foregut, overdriving serotonin release from enterochromaffin cells.

Uric acid ameliorates indomethacin-induced enteropathy in mice through its antioxidant activity.

BACKGROUND AND AIM: Uric acid is excreted from blood into the intestinal lumen, yet the roles of uric acid in intestinal diseases remain to be elucidated. The study aimed to determine whether uric acid could reduce end points associated with nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy. METHODS: A mouse model of NSAID-induced enteropathy was generated by administering indomethacin intraperitoneally to 8-week-old male C57BL/6 mice, and then vehicle or uric acid was administered orally. A group of mice treated with indomethacin was also concurrently administered inosinic acid, a uric acid precursor, and potassium oxonate, an inhibitor of uric acid metabolism, intraperitoneally. For in vitro analysis, Caco-2 cells treated with indomethacin were incubated in the presence or absence of uric acid. RESULTS: Oral administration of uric acid ameliorated NSAID-induced enteropathy in mice even though serum uric acid levels did not increase. Intraperitoneal administration of inosinic acid and potassium oxonate significantly elevated serum uric acid levels and ameliorated NSAID-induced enteropathy in mice. Both oral uric acid treatment and intraperitoneal treatment with inosinic acid and potassium oxonate significantly decreased lipid peroxidation in the ileum of mice with NSAID-induced enteropathy. Treatment with uric acid protected Caco-2 cells from indomethacin-induced oxidative stress, lipid peroxidation, and cytotoxicity. CONCLUSIONS: Uric acid within the intestinal lumen and in serum had a protective effect against NSAID-induced enteropathy in mice, through its antioxidant activity. Uric acid could be a promising therapeutic target for NSAID-induced enteropathy.

Xenin Augments Duodenal Anion Secretion via Activation of Afferent Neural Pathways.

Xenin-25, a neurotensin (NT)-related anorexigenic gut hormone generated mostly in the duodenal mucosa, is believed to increase the rate of duodenal ion secretion, because xenin-induced diarrhea is not present after Roux-en-Y gastric bypass surgery. Because the local effects of xenin on duodenal ion secretion have remained uninvestigated, we thus examined the neural pathways underlying xenin-induced duodenal anion secretion. Intravenous infusion of xenin-8, a bioactive C-terminal fragment of xenin-25, dose dependently increased the rate of duodenal HCO3- secretion in perfused duodenal loops of anesthetized rats. Xenin was immunolocalized to a subset of enteroendocrine cells in the rat duodenum. The mRNA of the xenin/NT receptor 1 (NTS1) was predominantly expressed in the enteric plexus, nodose and dorsal root ganglia, and in the lamina propria rather than in the epithelium. The serosal application of xenin-8 or xenin-25 rapidly and transiently increased short-circuit current in Ussing-chambered mucosa-submucosa preparations in a concentration-dependent manner in the duodenum and jejunum, but less so in the ileum and colon. The selective antagonist for NTS1, substance P (SP) receptor (NK1), or 5-hydroxytryptamine (5-HT)3, but not NTS2, inhibited the responses to xenin. Xenin-evoked Cl- secretion was reduced by tetrodotoxin (TTX) or capsaicin-pretreatment, and abolished by the inhibitor of TTX-resistant sodium channel Nav1.8 in combination with TTX, suggesting that peripheral xenin augments duodenal HCO3- and Cl- secretion through NTS1 activation on intrinsic and extrinsic afferent nerves, followed by release of SP and 5-HT. Afferent nerve activation by postprandial, peripherally released xenin may account for its secretory effects in the duodenum.

Psychological stress exacerbates NSAID-induced small bowel injury by inducing changes in intestinal microbiota and permeability via glucocorticoid receptor signaling.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are popular painkillers, but they have serious side effects, not only in the upper gastrointestinal tract but also in the small intestine. It is well known that psychological stress may exacerbate various gastrointestinal diseases. The aim of this study was to determine whether psychological stress exacerbates NSAID enteropathy and to determine the possible underlying mechanisms for this. METHODS: Experiment 1: mice were exposed to water avoidance stress (WAS) or sham stress for 1 h per day for 8 consecutive days, and then enteropathy was induced by indomethacin. Experiment 2: cecal contents from stress (-) or (+) mice were transplanted into mice that had received antibiotics and in which NSAID enteropathy had been induced without WAS. Experiment 3: mifepristone, a glucocorticoid receptor antagonist, was injected before WAS for 8 days. Small intestinal injury, mRNA expression of TNFα, intestinal permeability, and the microbial community were assessed. RESULTS: Psychological stress exacerbated NSAID enteropathy and increased intestinal permeability. Psychological stress induced changes in the ileal microbiota that were characterized by increases in the total number of bacteria and the proportion of Gram-negative bacteria. The increased susceptibility to NSAIDs and intestinal permeability due to WAS was transferable via cecal microbiota transplantation. The increased permeability and aggravation of NSAID enteropathy caused by WAS were blocked by the administration of mifepristone. CONCLUSIONS: This study demonstrated a relationship between NSAID enteropathy and psychological stress, and showed the utility of studying the intestinal microbiota in order to elucidate the pathophysiology of NSAID enteropathy. It also showed the impact of stress on the intestinal microbiota and the mucosal barrier in gastrointestinal diseases.

Platelet interaction with lymphatics aggravates intestinal inflammation by suppressing lymphangiogenesis.

Lymphatic failure is a histopathological feature of inflammatory bowel disease (IBD). Recent studies show that interaction between platelets and podoplanin on lymphatic endothelial cells (LECs) suppresses lymphangiogenesis. We aimed to investigate the role of platelets in the inflammatory process of colitis, which is likely to be through modulation of lymphangiogenesis. Lymphangiogenesis in colonic mucosal specimens from patients with IBD was investigated by studying mRNA expression of lymphangiogenic factors and histologically by examining lymphatic vessel (LV) densities. Involvement of lymphangiogenesis in intestinal inflammation was studied by administering VEGF-receptor 3 (VEGF-R3) inhibitors to the mouse model of colitis using dextran sulfate sodium and evaluating platelet migration to LVs. The inhibitory effect of platelets on lymphangiogenesis was investigated in vivo by administering antiplatelet antibody to the colitis mouse model and in vitro by coculturing platelets with lymphatic endothelial cells. Although mRNA expressions of lymphangiogenic factors such as VEGF-R3 and podoplanin were significantly increased in the inflamed mucosa of patients with IBD compared with those with quiescent mucosa, there was no difference in LV density between them. In the colitis model, VEGF-R3 inhibition resulted in aggravated colitis, decreased lymphatic density, and increased platelet migration to LVs. Administration of an antiplatelet antibody increased LV densities and significantly ameliorated colitis. Coculture with platelets inhibited proliferation of LECs in vitro. Our data suggest that despite elevated lymphangiogenic factors during colonic inflammation, platelet migration to LVs resulted in suppressed lymphangiogenesis, leading to aggravation of colitis by blocking the clearance of inflammatory cells. Modulating the interaction between platelets and LVs could be a new therapeutic means for treating IBD.

Recombinant Thrombomodulin Modulates Murine Colitis Possibly via High-Mobility Group Box 1 Protein Inhibition.

BACKGROUND AND AIM: Thrombomodulin (TM) is an anticoagulant cofactor protein. We hypothesized that its recombinant soluble TM (rhTM) form, widely used to treat disseminated intravascular coagulation, might have anti-inflammatory action in inflammatory bowel disease (IBD), possibly through its inhibition of high-mobility group box 1 protein (HMGB1). METHODS: We investigated inflammatory effects of HMGB1 and anti-inflammatory effect of rhTM in dextran sulfate sodium (DSS)-treated mice, some cell lines and ulcerative colitis (UC) patients, particularly focusing on changes of vascular endothelial adhesion molecules. RESULTS: Treatments with rhTM significantly attenuated DSS-treated mice clinically and histologically. The mRNA levels of proinflammatory cytokines and adhesion molecules were decreased by rhTM. Increased inflammatory cells in the colonic mucosa strongly expressed HMGB1 in the cytoplasm in the DSS-treated mice and UC patients' colonic mucosa, which were significantly decreased by rhTM in mice. In in vitro experiments, rhTM significantly decreased the mRNA levels of tumor necrosis factor-alpha (TNF-α) and adhesion molecules increased by endotoxin exposures in RAW 264.7 (macrophage cell line) and bEND.3 cells (endothelial cell line), suggesting the proinflammatory role of HMGB1 in TNF-α production from macrophages. CONCLUSIONS: These findings suggest that rhTM may be useful for the treatment of IBD by attenuating inflammatory cytokine production and adhesion molecule expression, partly because of its inhibition of HMGB1.

Toll-like receptor (TLR) 2 agonists ameliorate indomethacin-induced murine ileitis by suppressing the TLR4 signaling.

BACKGROUND AND AIM: Few drugs have been found satisfactory in the treatment of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy. Toll-like receptor (TLR) 4 and aberrant leukocyte migration to the intestinal mucosa are reported to be involved in the pathology of intestinal enteropathy and TLR2 agonists have been found to evoke hyposensitivity to TLR4 stimulation in vitro. In this study, we investigated whether and how lipoarabinomannan (LAM) or lipoteichoic acid (LTA), TLR2 agonists, attenuated indomethacin (IND)-induced intestinal damage. METHODS: LAM (0.5 mg/kg) or LTA (15 mg/kg) was administered intraperitoneally to mice before IND (10 mg/kg) administration. Disease activity was evaluated macroscopically and histologically. In the migration analysis, fluorescence-labeled leukocyte movement in the intestinal microvessels was observed by intravital microscopy. Expression of P-selectin, MAdCAM-1, TLR2, TLR4, and F4/80 was observed immunohistochemically. In the in vitro analysis, RAW264.7 macrophage cells were preincubated with LAM and stimulated with lipopolysaccharide (LPS), and the mRNA expression levels of TLR4, tumor necrosis factor-α, and interleukin-12p40 were measured. RESULTS: Pretreatment with LAM or LTA significantly decreased IND-induced injury as well as decreased leukocyte infiltration. Pretreatment with LAM decreased IND-induced TLR4 expression on F4/80(+) macrophages, the level of P-selectin expression, and leukocyte migration in the small intestinal vessels. In the in vitro study, a single administration of LAM decreased TLR4 mRNA expression and inhibited the increase in mRNA expression of inflammatory cytokines by LPS in a dose-dependent manner. CONCLUSION: TLR2 agonists attenuated IND-induced small intestinal lesions and leukocyte infiltration probably by suppressing the TLR4 signaling pathway in tissue macrophages.

Beneficial effect of an omega-6 PUFA-rich diet in non-steroidal anti-inflammatory drug-induced mucosal damage in the murine small intestine.

AIM: To investigate the effect of a fat rich diet on non-steroidal anti-inflammatory drug (NSAID)-induced mucosal damage in the murine small intestine. METHODS: C57BL6 mice were fed 4 types of diets with or without indomethacin. One group was fed standard laboratory chow. The other groups were fed a fat diet consisting of 8% w/w fat, beef tallow (rich in SFA), fish oil, (rich in omega-3 PUFA), or safflower oil (rich in omega-6 PUFA). Indomethacin (3 mg/kg) was injected intraperitoneally from day 8 to day 10. On day 11, intestines and adhesions to submucosal microvessels were examined. RESULTS: In the indomethacin-treated groups, mucosal damage was exacerbated by diets containing beef tallow and fish oil, and was accompanied by leukocyte infiltration (P < 0.05). The mucosal damage induced by indomethacin was significantly lower in mice fed the safflower oil diet than in mice fed the beef tallow or fish oil diet (P < 0.05). Indomethacin increased monocyte and platelet migration to the intestinal mucosa, whereas safflower oil significantly decreased monocyte and platelet recruitment (P < 0.05). CONCLUSION: A diet rich in SFA and omega-3 PUFA exacerbated NSAID-induced small intestinal damage via increased leukocyte infiltration. Importantly, a diet rich in omega-6-PUFA did not aggravate inflammation as monocyte migration was blocked.

Magnetic resonance enterocolonography in detecting erosion and redness in intestinal mucosa of patients with Crohn's disease.

BACKGROUND AND AIM: In Crohn's disease (CD), assessment of disease activity and extension is important for clinical management. Endoscopy is the most reliable tool for evaluating disease activity in these patients and it distinguishes between lesions based on ulcer, erosion, and redness. Magnetic resonance imaging (MRI) is less invasive than endoscopy; however, the sensitivity of MRI in detecting lesions is believed to be lower, and whether MRI can detect milder lesions has not been studied. The aim of this study was to compare the detection ability of magnetic resonance enterocolonography (MREC) with ileocolonic endoscopy in patients with CD. METHODS: A total of 27 patients with CD underwent both MREC and ileocolonoscopy. There were 55 lesions (18 ileum and 37 colon) endoscopically detected, and the findings of MREC were compared with each ileocolonoscopic finding to determine sensitivity and specificity. RESULTS: For a positive lesion defined as having at least one of the following: wall thickness, edema, diffusion-weighted imaging (DWI) high intensity and relative contrast enhancement (RCE) on MREC, the sensitivities were 100% for ulcer, 84.6% for erosion, and 52.9% for redness, suggesting an ability to detect milder lesions such as erosion or redness. Moreover, RCE values were well correlated with the severity of endoscopically identified active lesions. CONCLUSION: MREC findings may be useful not only for evaluation of ulcers, but also for detection of endoscopically identified milder lesions in CD, suggesting a clinical usefulness of MREC for disease detection and monitoring.

Pregnant woman with non-comatose autoimmune acute liver failure in the second trimester rescued using medical therapy: A case report.

We present the case of a 25-year-old woman at 16 weeks of gestation who presented with non-comatose autoimmune acute liver failure and was at high risk of developing fulminant hepatitis. Predictive formulas indicated a high probability of developing fulminant hepatitis. Unenhanced computed tomography showed marked hepatic atrophy and broadly heterogeneous hypoattenuating areas. The course of her illness was subacute, and the etiology of liver injury was unclear. Considering all of the above, we predicted a poor prognosis. Plasma exchange (PE) and continuous hemodiafiltration (CHDF) therapy were initiated just after admission. A few days after admission, a high titer (×80) of antinuclear antibody was noted. Because autoimmune hepatitis (AIH) was considered a cause of liver failure, treatment with moderate prednisolone (30 mg/day) doses was administrated, with careful consideration of her pregnancy. Thereafter, her laboratory findings and clinical course gradually improved without the need for liver transplantation. A liver biopsy at 18 days after admission indicated a diagnosis of AIH. She continued the pregnancy and delivered a healthy baby without any complications. Eventually, prednisolone doses were decreased to 10 mg, after which her liver function worsened. The second liver biopsy also indicated a diagnosis of AIH. Accordingly, low-dose prednisolone and azathioprine doses (50 mg/day) were administrated to recover her liver function, after which her liver function regained normalcy. This case illustrates that a pregnant woman with non-comatose autoimmune acute liver failure in the first or second trimester of pregnancy and her fetus can be rescued by PE/CHDF therapy and safe moderate doses of prednisolone.

Phlebosclerotic colitis that was difficult to distinguish from collagenous colitis.

Phlebosclerotic colitis is a rare and recently known disease entity and its etiology is still to be elucidated. Some phlebosclerotic colitis cases are difficult to distinguish from collagenous colitis because of the similarity of pathological findings. In all Japanese case reports of phlebosclerotic colitis in which an association with the use of Chinese herbal medicine is suspected, sansisi (gardenia fruit) was included, suggesting pathogenesis of this disease. We report a case of phlebosclerotic colitis that wasdifficult to be distinguished from collagenous colitis, and an association with the use of Chinese herbal medicine was suspected as the cause of the disease.

Comparison between famciclovir and valacyclovir for acute pain in adult Japanese immunocompetent patients with herpes zoster.

Famciclovir is a guanine analog antiviral drug used commonly for herpes zoster. Efficacy of famciclovir treatment has been reported to be comparable to valacyclovir treatment. Both of these medications reduce the time to complete cessation of zoster-associated pain including post-herpetic neuralgia, as compared to acyclovir. We conducted a multicenter, randomized, open clinical trial in order to evaluate the extent of pain relief afforded by these two antiviral drugs during the acute disease phase of herpes zoster. The study group comprised 86 immunocompetent adult patients suffering from herpes zoster, who were treated with either famciclovir or valacyclovir for 7 days. Of these, 55 patients enrolled in this study within 72 h of the onset of the rash and 31 patients after 72 h of the onset. There was a significant reduction in acute herpes zoster pain with famciclovir on day 7 and at 2-3 weeks in both of these patient groups, while with valacyclovir, there was not significant reduction in pain on day 7. Of patients aged 50 years or older, there was a significantly earlier reduction in pain with famciclovir than with valacyclovir. In addition, a significant reduction in the number of patients with pain was observed as early as days 3-4 with famciclovir treatment as compared with valacyclovir treatment. We conclude that famciclovir was superior to valacyclovir in the relief of acute pain of herpes zoster. Accordingly, famciclovir is recommended for herpes zoster patients with moderate symptoms and a visual analog scale score of under 50 mm.