[Atypical clinical presentation of familial Mediterranean fever resembling colonic diverticulitis in an elderly patient:a case report].

A 69-year-old man had been intermittently experiencing abdominal pain from his 30s and was diagnosed with colonic diverticulitis. He further experienced right lower abdominal pain and received treatment. However, his condition did not improve, and he was referred to the National Defense Medical College Hospital. His abdominal pain episodes continued even after treatment for few weeks;subsequently, familial Mediterranean fever (FMF) was suspected based on the clinical course because of elevated inflammatory responses, although his body temperature was ≤38°C. After administrating colchicine as a diagnostic treatment, the repeated abdominal pain disappeared. Considering the other findings and genetic examination that showed the representative gene mutation of MEFV (M694I), he was diagnosed with FMF. This case indicates that high body temperature, one of the primary diagnostic criteria of FMF, is sometimes not evident in elderly patients, thereby causing potential misdiagnosis in some elderly patients with FMF.

Dietary emulsifier polysorbate-80-induced small-intestinal vulnerability to indomethacin-induced lesions via dysbiosis.

BACKGROUND AND AIM: Dietary emulsifiers are widely used in processed foods and officially approved as safe for intake. However, recent studies have demonstrated that some emulsifiers alter the colonic microbiota, leading to colonic low-grade inflammation, in mice. The effect of dietary emulsifiers on small-intestinal microbiota, which is important for gut immunity, has not been studied. We aimed to investigate the effect of a representative dietary emulsifier, polysorbate-80 (P80), on the small-intestinal microbiota in normal mice. METHODS: Some mice were pretreated with P80 for 8 weeks with or without indomethacin administration on the last 2 days, and intestinal damage was evaluated histologically. The ileal and colonic microbiota composition was assessed using 16S rRNA polymerase chain reaction. RESULTS: Polysorbate-80 increased the Gammaproteobacteria abundance and decreased the α-diversity in the small intestine. No decrease in α-diversity was observed in the colon. P80 pretreatment exacerbated the indomethacin-induced small-intestinal lesions and significantly increased the interleukin-1ß expression. Culture of ileal content on deoxycholate hydrogen sulfide lactose agar showed that P80 significantly increased the colonies of the sulfide-producing bacteria Proteus spp. (genetically identified as Proteus mirabilis). Antibiotic pretreatment abolished the P80-induced aggravation of indomethacin-induced ileitis. Motility assay in semisolid agar showed that adding 0.02% P80 to the agar significantly increased the diameter of P. mirabilis colonies but not that of Escherichia coli colonies. CONCLUSIONS: Polysorbate-80 enhances the vulnerability of the small intestine to indomethacin-induced injury by inducing ileal dysbiosis. Direct enhancement of the motility of specific flagellated microbiota by P80 might be related to dysbiosis and intestinal injury.

Lipoprotein Lipase Up-regulation in Hepatic Stellate Cells Exacerbates Liver Fibrosis in Nonalcoholic Steatohepatitis in Mice.

Lipoprotein lipase (LPL) plays a central role in incorporating plasma lipids into tissues and regulates lipid metabolism and energy balance in the human body. Conversely, LPL expression is almost absent in normal adult livers. Therefore, its physiological role in the liver remains unknown. We aimed to elucidate the role of LPL in the pathophysiology of nonalcoholic steatohepatitis (NASH), a hepatic manifestation of obesity. Hepatic stellate cell (HSC)-specific LPL-knockout (LplHSC-KO ) mice, LPL-floxed (Lplfl/fl ) mice, or double-mutant toll-like receptor 4-deficient (Tlr4-/- ) LplHSC-KO mice were fed a high-fat/high-cholesterol diet for 4 weeks to establish the nonalcoholic fatty liver model or an high-fat/high-cholesterol diet for 24 weeks to establish the NASH model. Human samples, derived from patients with nonalcoholic fatty liver disease, were also examined. In human and mouse NASH livers, serum obesity-related factors, such as free fatty acid, leptin, and interleukin-6, dramatically increased the expression of LPL, specifically in HSCs through signal transducer and activator of transcription 3 signaling, as opposed to that in hepatocytes or hepatic macrophages. In the NASH mouse model, liver fibrosis was significantly reduced in LplHSC-KO mice compared with that in Lplfl/fl mice. Nonenzymatic LPL-mediated cholesterol uptake from serum lipoproteins enhanced the accumulation of free cholesterol in HSCs, which amplified TLR4 signaling, resulting in the activation of HSCs and progression of hepatic fibrosis in NASH. Conclusion: The present study reveals the pathophysiological role of LPL in the liver, and furthermore, clarifies the pathophysiology in which obesity, as a background factor, exacerbates NASH. The LPL-mediated HSC activation pathway could be a promising therapeutic target for treating liver fibrosis in NASH.

Chitinase 3-like 1 deficiency ameliorates liver fibrosis by promoting hepatic macrophage apoptosis.

AIM: Chitinase 3-like 1 (CHI3L1), an 18-glycosyl hydrolase-related molecule, is a member of the enzymatically inactive chitinase-like protein family. Serum levels of CHI3L1 are strongly correlated with hepatic fibrosis progression during many liver diseases. Therefore, this protein could be involved in the development of hepatic fibrosis pathology; however, its role has not been elucidated. We aimed to elucidate its role in the pathophysiology of liver fibrosis. METHODS: Chitinase 3-like 1-deficient (Chi3l1-/- ) mice were given carbon tetrachloride twice per week for 4 weeks or fed a methionine choline-deficient diet for 12 weeks to generate mouse liver fibrosis models. Human fibrotic liver tissues were also examined immunohistochemically. RESULTS: In human and mouse fibrotic livers, CHI3L1 expression was mainly localized to hepatic macrophages, and the intrahepatic accumulation of CHI3L1+ macrophages was significantly enhanced compared to that in control livers. In the two mouse models, hepatic fibrosis was significantly ameliorated in Chi3l1-/- mice compared to that in wild-type mice, which was dependent on hepatic macrophages. The accumulation and activation of hepatic macrophages was also significantly suppressed in Chi3l1-/- mice compared to that in wild-type mice. Furthermore, apoptotic hepatic macrophages were significantly increased in Chi3l1-/- mice. Chitinase 3-like 1 was found to inhibit hepatic macrophage apoptosis by suppressing Fas expression and activating Akt signaling in an autocrine manner, which resulted in hepatic macrophage accumulation and activation, exaggerating liver fibrosis. CONCLUSIONS: Chitinase 3-like 1 exacerbates liver fibrosis progression by suppressing apoptosis in hepatic macrophages. Therefore, this might be a potential therapeutic target for the treatment of liver fibrosis.

Crohn's Disease Accompanied with Small Intestinal Extramedullary Plasmacytoma.

We herein present the case of an immunocompetent 63-year-old man who had previously undergone resection of Crohn's disease (CD)-related small intestinal obstruction more than 30 years ago. He had not been receiving any medication for many years, but had recently started to suffer from ileus. A stenosed site of ileo-cecal anastomosis was identified and therefore was surgically resected, which was diagnosed as CD with small intestinal extramedullary plasmacytoma (EMP). The subsequent progression of CD was successfully controlled by anti-TNFα agents without any recurrence of EMP for over 3 years, implying the clinical benefit and safety of the biological therapy. This was the first known case of a patient who received anti-TNFα agents after a resection of small intestinal EMP accompanied with CD.

Depression Promotes the Onset of Irritable Bowel Syndrome through Unique Dysbiosis in Rats.

Background/Aims: Although studies using conventional animal models have shown that specific stressors cause irritable bowel syndrome (IBS), it is unclear whether depression itself causes IBS. Our aim was to establish a rat model to determine if depression itself promotes the onset of IBS and to elucidate the role of gut microbiota in brain-gut axis pathogenesis during coincident depression and IBS. Methods: Rat models of depression were induced using our shuttle box method of learned helplessness. Visceral hypersensitivity was evaluated by colorectal distension (CRD) to diagnose IBS. Gut microbiota compositions were analyzed using high-throughput sequencing. In the subanalysis of rats without depression-like symptoms, rats with posttraumatic stress disorder (PTSD) were also examined. Results: The threshold value of CRD in depressed rats was significantly lower than that in control rats. Microbial community analysis of cecal microbiota showed that the relative abundance of Clostridiales incertae sedis, the most prevalent microbe, was significantly lower in depressed rats than in control rats. The distribution pattern of the microbiota clearly differed between depressed rats and control rats. Neither visceral hypersensitivity nor the composition of gut microbiota was altered in rats with PTSD-like phenotypes. Conclusions: Our rat model of depression is useful for clarifying the effect of depression on IBS and suggests that depression itself, rather than specific stressors, promotes the onset of IBS. Further, we provided evidence that various psychiatric diseases, viz., depression and PTSD, are associated with unique gut microbiota profiles, which could differentially affect the onset and progression of coincident IBS.

Atypical Clinical Presentation of Crohn's Disease with Superior Mesenteric Vein Obstruction and Protein-losing Enteropathy.

We herein report a 44-year-old man suffering from systemic edema due to protein-losing enteropathy (PLE) with superior mesenteric vein (SMV) obstruction and development of collateral veins, which subsequently proved to be a chronic result of thrombosis and a complication of Crohn's disease (CD). PLE was supposedly induced by both intestinal erosion and thrombosis-related lymphangiectasia, which was histologically proven in his surgically-resected ileal stenosis. Elemental diet and anti-TNFα agent improved his hypoalbuminemia after surgery. The rarity of the simultaneous coexistence of SMV obstruction and PLE and the precedence of these complications over typical abdominal symptoms of CD made the clinical course complex.

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.

Aortic carboxypeptidase-like protein, a WNT ligand, exacerbates nonalcoholic steatohepatitis.

Incidence of nonalcoholic steatohepatitis (NASH), which is considered a hepatic manifestation of metabolic syndrome, has been increasing worldwide with the rise in obesity; however, its pathological mechanism is poorly understood. Here, we demonstrate that the hepatic expression of aortic carboxypeptidase-like protein (ACLP), a glycosylated, secreted protein, increases in NASH in humans and mice. Furthermore, we elucidate that ACLP is a ligand, unrelated to WNT proteins, that activates the canonical WNT pathway and exacerbates NASH pathology. In the liver, ACLP is specifically expressed in hepatic stellate cells (HSCs). As fatty liver disease progresses, ACLP expression is enhanced via activation of STAT3 signaling by obesity-related factors in serum. ACLP specifically binds to frizzled-8 and low-density lipoprotein-related receptor 6 to form a ternary complex that activates canonical WNT signaling. Consequently, ACLP activates HSCs by inhibiting PPARγ signals. HSC-specific ACLP deficiency inhibits fibrosis progression in NASH by inhibiting canonical WNT signaling in HSCs. The present study elucidates the role of canonical WNT pathway activation by ACLP in NASH pathology, indicating that NASH can be treated by targeting ACLP-induced canonical WNT pathway activation in HSCs.

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.

Human intestinal spirochetosis mimicking ulcerative colitis.

Human intestinal spirochetosis (HIS) is a colorectal infection caused by the Brachyspira species of intestinal spirochetes, whose pathogenicity in humans remains unclear owing to the lack of or mild symptoms. We monitored the 5-year clinical course of a woman diagnosed with HIS in whom ulcerative colitis (UC) had been suspected. Following a positive fecal occult blood test, she underwent a colonoscopic examination at a local clinic where she was diagnosed with "right-sided" UC concomitant with incidentally detected HIS, and was referred to our hospital. Colonoscopic, histopathological, and cytological examination revealed localized erosive colitis in the ascending and the right transverse colon concomitant with HIS resembling skip lesions of UC. Initially, we chose the wait-and-watch approach; however, she gradually developed bloody diarrhea. Metronidazole improved her abdominal symptoms, as well as her colonoscopic and histopathological findings, suggesting that HIS was responsible for her colorectal inflammation. This case reveals (1) a possible pro-inflammatory role of HIS, (2) difficulties in diagnosing HIS in chronic proctocolitis, and (3) a possible inclusion of some HIS cases in "UC". HIS could mimic UC and might be included in differential diagnoses for UC. Antibiotic administration is necessary following the detection of HIS, particularly in patients demonstrating an atypical presentation of UC.

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.

Novel probiotics isolated from a Japanese traditional fermented food, Funazushi, attenuates DSS-induced colitis by increasing the induction of high integrin αv/ß8-expressing dendritic cells.

BACKGROUND: We isolated two novel probiotics strains (s193 and s292) from Funazushi, which is a traditional Japanese fermented food, and evaluated its effects on DSS-induced colitis to determine the possible underlying mechanisms. METHODS: A single colony from homogenized Funazushi was isolated by its ability to suppress TNF-α in RAW 264.7. Effect of probiotics on colonic inflammation induced by DSS was evaluated. Effect of probiotics on Treg induction by CD11c+ dendritic cells (DCs) of MLNs were analyzed. RESULTS: Two novel probiotics strains classified into the genus Lactobacillus were isolated (s193 and s292), and those strains showed stronger anti-inflammatory effects on DSS-induced colitis than those of L. gasseri isolated from the gut. mRNA expression ß8 integrin in CD11c+DCs of MLNs and the number of Tregs in the large intestine were significantly increased by s193 and s292 administration compared with L. gasseri administration. Bone marrow DCs treated with s193 and s292 highly increased ß8 integrin, and those cells strongly induced differentiation of CD4+ T cells into Tregs. Differentiation of Tregs was remarkably inhibited by anti-ß8 integrin antibody treatment. CONCLUSIONS: Strains s193 and s292 demonstrate strong anti-inflammatory effects on DSS-induced colitis through induction of ß8 integrin expression on DCs. Our results suggested that Japanese traditional fermented foods are valuable sources for probiotics that are effective for IBD therapy and treatment.

Free cholesterol accumulation in liver sinusoidal endothelial cells exacerbates acetaminophen hepatotoxicity via TLR9 signaling.

BACKGROUND & AIMS: Although obesity is a risk factor for acute liver failure, the pathogenic mechanisms are not yet fully understood. High cholesterol (HC) intake, which often underlies obesity, is suggested to play a role in the mechanism. We aimed to elucidate the effect of a HC diet on acetaminophen-induced acute liver injury, the most frequent cause of acute liver failure in the USA. METHODS: C57BL/6 Toll-like receptor 9 (TLR9) knockout (Tlr9-/-) mice and their Tlr9+/+ littermates were fed an HC diet for fourweeks and then treated with acetaminophen. Liver sinusoidal endothelial cells (LSECs) were isolated from the mice for in vivo and in vitro analyses. RESULTS: The HC diet exacerbated acetaminophen-induced acute liver injury in a TLR9/inflammasome pathway-dependent manner. LSECs played a major role in the cholesterol loading-induced exacerbation. The accumulation of free cholesterol in the endolysosomes in LSECs enhanced TLR9-mediated signaling, thereby exacerbating the pathology of acetaminophen-induced liver injury through the activation of the TLR9/inflammasome pathway. The accumulation of free cholesterol in LSEC endolysosomes induced a dysfunction of the Rab7 membrane trafficking recycling mechanism, thus disrupting the transport of TLR9 from late endosomes to the lysosomes. Consequently, the level of active TLR9 in the late endosomes increased, thereby enhancing TLR9 signaling in LSECs. CONCLUSIONS: HC intake exaggerated acetaminophen-induced acute liver injury via free cholesterol accumulation in LSECs, demonstrating a novel role of free cholesterol as a metabolic factor in TLR9 signal regulation and pathologies of acetaminophen-induced liver injury. Therapeutic approaches may target this pathway. Lay summary: High cholesterol intake exacerbated acetaminophen-induced acute liver injury via the accumulation of free cholesterol in the endolysosomes of liver sinusoidal endothelial cells. This accumulation enhanced Toll-like receptor 9 signaling via impairment of its membrane trafficking mechanism. Thus, free cholesterol accumulation, as an underlying metabolic factor, exacerbated the pathology of acetaminophen-induced liver injury through activation of the TLR9/inflammasome pathway.

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.

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.

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.

Acyl-CoA:cholesterol acyltransferase 1 mediates liver fibrosis by regulating free cholesterol accumulation in hepatic stellate cells.

BACKGROUND & AIMS: Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes the conversion of free cholesterol (FC) to cholesterol ester, which prevents excess accumulation of FC. We recently found that FC accumulation in hepatic stellate cells (HSCs) plays a role in progression of liver fibrosis, but the effect of ACAT1 on liver fibrosis has not been clarified. In this study, we aimed to define the role of ACAT1 in the pathogenesis of liver fibrosis. METHODS: ACAT1-deficient and wild-type mice, or Toll-like receptor 4 (TLR4)(-/-)ACAT1(+/+) and TLR4(-/-)ACAT1(-/-) mice were subjected to bile duct ligation (BDL) for 3 weeks or were given carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis. RESULTS: ACAT1 was the major isozyme in mice and human primary HSCs, and ACAT2 was the major isozyme in mouse primary hepatocytes and Kupffer cells. ACAT1 deficiency significantly exaggerated liver fibrosis in the mouse models of liver fibrosis, without affecting the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation. ACAT1 deficiency significantly increased FC levels in HSCs, augmenting TLR4 protein and downregulating expression of transforming growth factor-ß (TGFß) pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor), leading to sensitization of HSCs to TGFß activation. Exacerbation of liver fibrosis by ACAT1 deficiency was dependent on FC accumulation-induced enhancement of TLR4 signaling. CONCLUSIONS: ACAT1 deficiency exaggerates liver fibrosis mainly through enhanced FC accumulation in HSCs. Regulation of ACAT1 activities in HSCs could be a target for treatment of liver fibrosis.