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Immune-mediated inflammatory diseases are characterized by variability in disease presentation and severity but studying it is a challenging task. Defining the limits of a healthy immune system is therefore a prior step to capture variability in disease conditions. The goal of this study is to characterize the global immune cell composition along with their influencing factors. Blood samples were collected from 2 independent cohorts of respectively 389 (exploratory) and 208 (replication) healthy subjects. Twelve immune cells were measured in blood together with biological parameters. Three complementary clustering approaches were used to evaluate if variability related to the immune cells could be characterized as clusters or as a continuum. Large coefficients of variation confirmed the inter-individual variability of immune cells. Considering all subset variations in an overall analysis, it appeared that the immune makeup was organized as a continuum through the two cohorts. Some intrinsic and environmental factors affected the inter-individual variability of cells but without unveiling separable groups with similar features. This study provides a framework based on complementary clustering approach for analyzing inter-individual variability of immune cells. Our analyses support the absence of clusters in our two healthy cohorts. Also, our study reports some influence of age, gender, BMI, cortisol, season and CMV infection on immune variability.

Background: Acetaminophen overdose is the most frequent cause of drug-induced liver failure in developed countries. Substantial progress has been made in understanding the mechanism of hepatocellular injury, but N-acetylcysteine remains the only effective treatment despite its short therapeutic window. Thus, other hepatoprotective drugs are needed for the delayed treatment of acetaminophen-induced hepatotoxicity. Our interest focused on glycyrrhizin for its role as an inhibitor of high mobility group box 1 (HMGB1) protein, a member of the family of damage-associated molecular pattern, known to play an important pathological role in various diseases., Aim: To investigate the efficacy of the N-acetylcysteine/glycyrrhizin combination compared to N-acetylcysteine alone in the prevention of liver toxicity., Methods: Eight-week-old C57BL/6J wild-type female mice were used for all our experiments. Mice fasted for 15 h were treated with acetaminophen (500 mg/kg) or vehicle (phosphate-buffered saline) by intraperitoneal injection and separated into the following groups: Glycyrrhizin (200 mg/kg); N-acetylcysteine (150 mg/kg); and N-acetylcysteine/glycyrrhizin. In all groups, mice were sacrificed 12 h following acetaminophen administration. The assessment of hepatotoxicity was performed by measuring plasma levels of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase. Hepatotoxicity was also evaluated by histological examination of hematoxylin and eosin-stained tissues sections. Survival rates were compared between various groups using Kaplan-Meier curves., Results: Consistent with data published in the literature, we confirmed that intraperitoneal administration of acetaminophen (500 mg/kg) in mice induced severe liver injury as evidenced by increases in alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase but also by liver necrosis score. Glycyrrhizin administration was shown to reduce the release of HMGB1 and significantly decreased the severity of liver injury. Thus, the co-administration of glycyrrhizin and N-acetylcysteine was investigated. Administered concomitantly with acetaminophen, the combination significantly reduced the severity of liver injury. Delayed administration of the combination of drugs, 2 h or 6 h after acetaminophen, also induced a significant decrease in hepatocyte necrosis compared to mice treated with N-acetylcysteine alone. In addition, administration of N-acetylcysteine/glycyrrhizin combination was associated with an improved survival rate compared to mice treated with only N-acetylcysteine., Conclusion: We demonstrate that, compared to N-acetylcysteine alone, co-administration of glycyrrhizin decreases the liver necrosis score and improves survival in a murine model of acetaminophen-induced liver injury. Our study opens a potential new therapeutic pathway in the prevention of acetaminophen hepatotoxicity., (©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.)

Extracellular release of HMGB1 contributes to acetaminophen-induced liver injury. HMGB1 acts as a danger-associated molecular patterns during this toxic process but the mechanisms of action and targeted cells are incompletely defined. Here we studied, in vitro, the role of HMGB1 in amplifying the acetaminophen-induced hepatocyte necrosis process. Using cultured HepaRG cells, primary human hepatocytes and selective chemical inhibitors we evaluated acetaminophen-induced toxicity. We confirmed that addition of acetaminophen induced HepaRG cell death and HMGB1 release. We showed that inhibition of HMGB1 decreased acetaminophen-induced HepaRG cell death, suggesting a feedforward effect. We provide the first evidence that exposure of HepaRG cells to recombinant human HMGB1 (rhHMGB1) also resulted in cell death. Moreover, we found that both acetaminophen and rhHMGB1 induced programmed HepaRG cell necrosis through a RIPK3-dependent mechanism. By using TLR4 blocking antibody, we demonstrated the reduction of the HepaRG cell death induced by acetaminophen and rhHMGB1. Furthermore, inhibition of TRIF, known to induce a RIPK3-dependent cell death, reduced rhHMGB1-induced HepaRG cell death. Our data support that released HMGB1 from acetaminophen-stressed hepatocytes induced necrosis of neighboring hepatocytes by TLR4-TRIF-RIPK3- pathway. This in vitro study gives new insights in the role of HMGB1 in the amplification of acetaminophen-induced toxicity.

Background: Vedolizumab (VDZ) is effective as an induction and maintenance treatment for Crohn's disease and ulcerative colitis, but, as observed with antitumour necrosis factor-α (anti-TNFα) agents, some patients are nonetheless experiencing loss of response., Objective: The aim of this study was to investigate the impact of the pharmacokinetics of VDZ during induction on long-term treatment response., Patients and Methods: This study focused on a single cohort of 103 inflammatory bowel disease patients treated with VDZ. VDZ trough levels (TLs) were measured by enzyme-linked immunosorbent assay (n=536 samples), and thereafter correlated to clinical, biological, endoscopic and serological data. For patients exposed previously to infliximab, antibodies to infliximab were measured at baseline. On the basis of the outcome at the end of follow-up, patients were then categorized into long-term response, optimized and treatment failure groups., Results: During VDZ induction, at week 6, inflammatory bowel disease patients with long-term response had higher TLs compared with patients in the treatment failure group (33 vs. 24 µg/ml, P=0.02). A cut-off TL of 28 µg/ml predicted a sustained response in the follow-up with an area under curve of 0.723 (95% confidence interval=0.567-0.878, P=0.02). Patients with mucosal healing in maintenance had higher TLs at week 6 (41.65 µg/ml) compared with patients with mild (26 µg/ml) or severe endoscopic activity (20.8 µg/ml), P=0.009. Positive perinuclear antineutrophil cytoplasmic antibody serology was associated with lower TLs. Patients previously exposed to anti-TNFα had lower TLs than naive patients (22.5 vs. 36 µg/ml, P=0.03) without any impact of detectable antibodies to infliximab. Finally, the presence of an immunomodulator at induction did not impact on VDZ TLs at induction., Conclusion: We confirmed that a drug exposure-efficacy association was found early on at induction. This study emphasizes that previous exposure to anti-TNFα and positive perinuclear antineutrophil cytoplasmic antibody serology are important factors influencing VDZ TLs at induction.

Background & Aims: Genomic studies have revealed subtypes of pancreatic ductal adenocarcinoma (PDA) based on their molecular features, but different studies have reported different classification systems. It is a challenge to obtain high-quality, freshly frozen tissue for clinical analysis and determination of PDA subtypes. We aimed to redefine subtypes of PDA using a large number of formalin-fixed and paraffin-embedded PDA samples, which are more amenable to routine clinical evaluation., Methods: We collected PDA samples from 309 consecutive patients who underwent surgery from September 1996 through December 2010 at 4 academic hospitals in Europe; nontumor tissue samples were not included. Samples were formalin fixed and paraffin embedded. DNA and RNA were isolated; gene expression, targeted DNA sequencing, and immunohistochemical analyses were performed. We used independent component analysis to deconvolute normal, tumor, and microenvironment transcriptome patterns in samples. We devised classification systems from an unsupervised analysis using a consensus clustering approach of our data set after removing normal contamination components. We associated subtypes with overall survival and disease-free survival of patients using Cox proportional hazards regression with estimation of hazard ratios and 95% confidence interval. We used The Cancer Genome Consortium and International Cancer Genome Consortium PDA data sets as validation cohorts., Results: We validated the previously reported basal-like and classical tumor-specific subtypes of PDAs. We identified features of the PDA, including microenvironment gene expression patterns, that allowed tumors to be categorized into 5 subtypes, called pure basal like, stroma activated, desmoplastic, pure classical, and immune classical. These PDA subtypes have features of cancer cells and immune cells that could be targeted by pharmacologic agents. Tumor subtypes were associated with patient outcomes, based on analysis of our data set and the International Cancer Genome Consortium and The Cancer Genome Consortium PDA data sets. We also observed an exocrine signal associated with acinar cell contamination (from pancreatic tissue)., Conclusions: We identified a classification system based on gene expression analysis of formalin-fixed PDA samples. We identified 5 PDA subtypes, based on features of cancer cells and the tumor microenvironment. This system might be used to select therapies and predict patient outcomes. We found evidence that the previously reported exocrine-like (called ADEX) tumor subtype resulted from contamination with pancreatic acinar cells. ArrayExpress accession number: E-MTAB-6134., (Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Infliximab (IFX) is indicated for the treatment of inflammatory bowel diseases (IBD). Nevertheless, loss of response (LOR) to IFX is reported in up to 10% to 30% of patients within the first year of treatment. Our objective was to evaluate the impact of the pharmacokinetics of IFX at induction on treatment failure., Methods: This is a longitudinal cohort study on 269 patients with IBD treated with IFX in a single center. A total of 2331 blood samples were prospectively collected from 2007 until March 2015 with a retrospective analysis of clinical data. IFX trough levels (TLs) were measured by enzyme-linked immunosorbent assay. Antibodies to IFX were measured by drug-sensitive bridging assay., Results: During follow-up, patients were defined according to treatment outcome. At week 6, median IFX TL in patients requiring a switch to another treatment due to LOR (LOR switched group) (2.32 μg/mL [0.12-19.93 μg/mL]) was lower than in patients with long-term response (long-term responders) (8.66 μg/mL [0.12-12.09 μg/mL], P = 0.007) and in patients responding to optimization (LOR optimized group) (7.28 μg/mL [0.17-14.91 μg/mL], P = 0.021). At week 2, median IFX TL was lower in the LOR switched group (5.7 μg/mL [0.15-12.09 μg/mL]) compared with the long-term responders (11.92 μg/mL [0.14-19.93 μg/mL], P = 0.041) but no significant difference was reached with the LOR optimized group (11.91 μg/mL [0.23-12.09 μg/mL], P = 0.065). In the LOR switched group, median IFX TL at induction (weeks 2 and 6) was significantly lower when patients had been previously exposed to anti-tumor necrosis factor compared with naive patients (0.91 μg/mL [0.12-4.4 μg/mL] versus 6.6 μg/mL [0.15-19.93 μg/mL], P = 0.044)., Conclusions: This study suggests that patients who do not respond to any optimization strategy have lower IFX TLs during induction at week 6. IFX TLs measured early on at induction might predict treatment failure to IFX during maintenance.

Background & Aims: Patients with alcoholic liver disease (ALD) have vitamin A (VA) deficiency and an enhanced immune response associated with disease severity. All-trans retinoic acid (ATRA), a VA-active metabolite, has anti-inflammatory effects and its deficiency could contribute to the exacerbated proinflammatory reaction. The aim of this study was to investigate the effects of ATRA/VA deficiency and supplementation on the monocyte response in ALD., Methods: Vitamin A and ATRA plasma levels were quantified in ALD patients and healthy subjects (HS). The in vitro effect of ATRA on lipopolysaccharide (LPS)-induced TNF-α production by human peripheral blood mononuclear cells (PBMC) was assessed by ELISA and RT-PCR. The activation pattern of peritoneal macrophages (PerMΦ) and circulating monocytes isolated from VA-deficient mice and ALD patients, respectively, was evaluated by flow cytometry, quantification of TNF-α and NO2 production., Results: Alcoholic liver disease patients (n = 85) showed plasmatic VA deficiency that was correlated with scores of severity and with the hepatic venous pressure gradient. ATRA levels correlated significantly with VA levels. In vitro, ATRA pretreatment decreased the overproduction of TNF-α by LPS-stimulated PBMC of ALD patients. In vivo, VA deficiency in mice was associated with increased activation of PerMΦ, while oral ATRA supplementation normalized it., Conclusion: For the first time, we show that VA/ATRA deficiencies in ALD patients are associated with disease severity. Furthermore, our data strongly suggest that the VA deficiency observed in ALD patients might participate in the pathophysiology of the disease by priming immune cells, and that ATRA supplementation could downregulate the deleterious proinflammatory state in cirrhosis and might thus be of therapeutic use., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background & Aims: Vitamin D deficiency has been frequently reported in advanced liver disease. However, its influence on alcoholic liver disease (ALD) has been poorly elucidated. We investigated the association of vitamin D with clinical, biological, and histological parameters and survival in ALD patients. Furthermore, we explored the effect of vitamin D treatment on ALD patient peripheral blood mononuclear cells (PBMCs), and in a murine experimental model of ALD., Methods: Serum levels of 25-hydroxyvitamin D [25(OH)D] were determined in 324 Caucasian ALD patients and 201 healthy controls. In vitro experiments on vitamin D pre-treated PBMCs evaluated TNFα production by ELISA in culture supernatants. Mice were submitted to an ethanol-fed diet and some of them were orally supplemented three times per week with 1,25(OH)2D., Results: Severe deficiency in 25(OH)D (<10 ng/ml) was significantly associated with higher aspartate aminotransferase levels (p=1.00 × 10(-3)), increased hepatic venous pressure gradient (p=5.80 × 10(-6)), MELD (p=2.50 × 10(-4)), and Child-Pugh scores (p=8.50 × 10(-7)). Furthermore, in multivariable analysis, a low 25(OH)D concentration was associated with cirrhosis (OR=2.13, 95% CI=1.18-3.84, p=0.013) and mortality (HR=4.33, 95% CI=1.47-12.78, p=7.94 × 10(-3)) at one year. In addition, in vitro, 1,25(OH)2D pretreatment decreased TNFα production by stimulated PBMCs of ALD patients (p=3.00 × 10(-3)), while in vivo, it decreased hepatic TNFα expression in ethanol-fed mice (p=0.04)., Conclusions: Low 25(OH)D levels are associated with increased liver damage and mortality in ALD. Our results suggest that vitamin D might be both a biomarker of severity and a potential therapeutic target in ALD., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Acute pancreatitis (AP) is an inflammatory disease in which the regulatory pathways are not clearly elucidated. Activation of interleukin 1β (IL-1β) and immunomodulation via MyD88, the first signaling molecule in the ST2 pathway, seem to be involved. Because IL-33, the ST2 ligand, is an IL-1 family member and acts as an alarmin, we explored the ST2 pathway in human and mouse AP. Soluble ST2 was assayed by enzyme-linked immunosorbent assay (ELISA) in plasma of 44 patients admitted for AP. The levels of soluble ST2 increased early during AP and correlated with parameters of severity. Under two different experimental models of AP (ie, choline-deficient-ethionine-supplemented diet and cerulein injections), ST2-deficient mice (Il1rl1(-/-)) presented with more severe disease than wild-type mice, with increased activation of mast cells. In vitro, Il1rl1(-/-) bone-marrow-derived mast cells exhibited exacerbated degranulation, compared with the wild type. Flow cytometry identified mast cells as the main peritoneal population expressing ST2. Using immunohistochemistry and ELISA, we showed constitutive expression of IL-33 in murine pancreas and its release during experimental AP. Correlated with AP severity, increased soluble ST2 levels evoke involvement of the ST2 pathway in human AP. Furthermore, our experimental data suggest a protective role for ST2 during AP, highlighting the potential regulatory role of mast cells and the possibility of the ST2 pathway as a new therapeutic target in AP., (Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Background & Aims: A recent genome-wide association study identified genetic polymorphism (rs738409 C>G) in the PNPLA3/adiponutrin gene associated with liver steatosis. This variant has also been linked to increased risk of alcoholic liver disease (ALD) and cirrhosis in Mestizo Mexicans with excessive alcohol intake. Our aim was to study the influence of this polymorphism on European Caucasian patients with histologically suggestive ALD., Methods: Three-hundred-and-twenty-eight healthy controls and 330 ALD patients, among whom 265 had cirrhosis, were genotyped for the rs738409 polymorphism. We studied the impact of rs738409 on clinical and biological parameters, together with histological staging of steatosis and fibrosis. PNPLA3 messenger RNA (mRNA) levels were measured by quantitative real-time PCR according to the patient's phenotype., Results: The G-allele was significantly more frequent in ALD patients than in controls (odds ratio [OR] = 1.54, 95% confidence interval [CI] = 1.12-2.11 p = 0.008) and was, among ALD patients, significantly associated with steatosis (p = 0.048), fibrosis (p = 0.001), and greater risk of cirrhosis (p = 0.001). In multivariate analysis, rs738409 remained the strongest independent factor associated with risk of cirrhosis (OR = 2.08; 95% CI = 1.15-3.77; p = 0.02). Furthermore, the PNPLA3 mRNA liver expression level was significantly lower in patients with more advanced fibrosis (p = 0.03) and negatively correlated with the hepatic venous pressure gradient (r = -0.41, p = 0.006)., Conclusions: In European Caucasians, the rs738409 variant is associated with increased risk of ALD, liver damage, and cirrhosis. Further prospective studies are required to confirm these results and to evaluate the potential of PNPLA3 as both a predictor and a therapeutic target in ALD., (Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Unlabelled: Only 20% of patients with chronic hepatitis C (CHC) will develop cirrhosis, and fibrosis progression remains highly unpredictable. A recent genome-wide association study identified a genetic variant in the patatin-like phospholipase-3 (PNPLA3) gene (rs738409 C>G) associated with steatosis that was further demonstrated to influence severity of fibrosis in nonalcoholic fatty liver disease. The aim of this study was to assess the impact of this polymorphism on histological liver damage and response to antiviral therapy in CHC. We recruited 537 Caucasian CHC patients from three European centers (Brussels, Belgium [n = 229]; Hannover, Germany [n = 171]; Lyon, France [n = 137]); these patients were centrally genotyped for the PNPLA3 (rs738409 C>G) polymorphism. We studied the influence of rs738409 and other variants in the PNPLA3 region on steatosis and fibrosis assessed both in a cross-sectional and longitudinal manner. Seven other variants previously associated with fibrosis progression were included. Finally, we explored the impact of rs738409 on response to standard antiviral therapy using the interferon lambda 3 (IL28B) [rs12979860 C>T] variant both as a comparator and as a positive control. After adjustment for age, sex, body mass index, alcohol consumption, and diabetes, rs738409 mutant G allele homozygote carriers remained at higher risk for steatosis (odds ratio [OR] 2.55, 95% confidence interval [CI] 1.08-6.03, P = 0.034), fibrosis (OR 3.13, 95% CI 1.50-6.51, P = 0.002), and fibrosis progression (OR 2.64, 95% CI 1.22-5.67, P = 0.013). Conversely, rs738409 was not independently associated with treatment failure (OR 1.07, 95% CI 0.46-2.49, P = 0.875) and did not influence clinical or biological variables., Conclusion: The PNPLA3 (rs738409 C>G) polymorphism favors steatosis and fibrosis progression in CHC. This polymorphism may represent a valuable genetic predictor and a potential therapeutic target in CHC liver damage., (Copyright © 2011 American Association for the Study of Liver Diseases.)

Unlabelled: Immune dysregulations in alcoholic liver diseases are still unclear, especially regarding alcoholic hepatitis inflammatory burst. Interleukin-17 (IL-17) is known to enhance neutrophil recruitment. We studied the IL-17 pathway in alcoholic cirrhosis and alcoholic hepatitis. Patients with alcoholic liver disease were compared with patients with chronic hepatitis C virus (HCV) infection or autoimmune liver disease and with healthy controls. IL-17 plasma levels and peripheral blood mononuclear cell secretion were assessed by enzyme-linked immunosorbent assay (ELISA) and T cell phenotype by flow cytometry. IL-17 staining and co-staining with CD3 and myeloperoxidase were performed on liver biopsy specimens. IL-17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL-17 by chemotaxis assays. IL-17 plasma levels were dramatically increased in alcoholic liver disease patients. Peripheral blood mononuclear cells of patients with alcoholic liver disease produced higher amounts of IL-17, and their CD4(+) T lymphocytes disclosed an IL-17-secreting phenotype. In the liver, IL-17-secreting cells contributed to inflammatory infiltrates in alcoholic cirrhosis, and alcoholic hepatitis foci disclosed many IL-17(+) cells, including T lymphocytes and neutrophils. In alcoholic liver disease, liver IL-17(+) cells infiltrates correlated to model for end-stage liver disease score, and in alcoholic hepatitis to modified discriminant function. IL-17 receptor was expressed in alcoholic liver disease by hepatic stellate cells, and these cells recruited neutrophils after IL-17 stimulation in a dose-dependent manner through IL-8 and growth related oncogen alpha (GRO-alpha) secretion in vitro., Conclusion: Human alcoholic liver disease is characterized by the activation of the IL-17 pathway. In alcoholic hepatitis, liver infiltration with IL-17-secreting cell infiltrates is a key feature that might contribute to liver neutrophil recruitment. (Clinical trials number NCT00610597).

Unlabelled: Hyperammonemia is a common complication of acute and chronic liver diseases. Often accompanied with side effects, therapeutic interventions such as antibiotics or lactulose are generally targeted to decrease the intestinal production and absorption of ammonia. In this study, we aimed to modulate hyperammonemia in three rodent models by administration of wild-type Lactobacillus plantarum, a genetically engineered ammonia hyperconsuming strain, and a strain deficient for the ammonia transporter. Wild-type and metabolically engineered L. plantarum strains were administered in ornithine transcarbamoylase-deficient Sparse-fur mice, a model of constitutive hyperammonemia, in a carbon tetrachloride rat model of chronic liver insufficiency and in a thioacetamide-induced acute liver failure mice model. Constitutive hyperammonemia in Sparse-fur mice and hyperammonemia in a rat model of chronic hepatic insufficiency were efficiently decreased by Lactobacillus administration. In a murine thioacetamide-induced model of acute liver failure, administration of probiotics significantly increased survival and decreased blood and fecal ammonia. The ammonia hyperconsuming strain exhibited a beneficial effect at a lower dose than its wild-type counterpart. Improved survival in the acute liver failure mice model was associated with lower blood ammonia levels but also with a decrease of astrocyte swelling in the brain cortex. Modulation of ammonia was abolished after administration of the strain deficient in the ammonium transporter. Intestinal pH was clearly lowered for all strains and no changes in gut flora were observed., Conclusion: Hyperammonemia in constitutive model or after acute or chronic induced liver failure can be controlled by the administration of L. plantarum with a significant effect on survival. The mechanism involved in this ammonia decrease implicates direct ammonia consumption in the gut.

Adenosine triphosphate-sensitive K(++) (K(ATP)) channels are poorly characterized in the reproductive tract. The present study was designed to evaluate the putative expression of K(ATP) channel subunits (Kir6.x and SURx) in the epididymis from different mammalian species. Immunohistochemical, Western blot, and RT-PCR techniques were used. A positive immunostaining for Kir6.2 (KCNJ11) and SUR2 (ABCC9) was observed by immunoenzymatic and immunofluorescent approaches in the principal epithelial cells throughout all regions of the rat and mouse epididymis. Double labeling with anti-aquaporin 9 (AQP9) and anti-Kir6.2 (KCNJ11) confirmed their colocalization in the principal cells. No immunostaining could be demonstrated for Kir6.1 (KCNJ8) and SUR1 (ABCC8) subunits. Under higher magnification, the immunostaining for Kir6.2 (KCNJ11) exhibited a cytoplasmic labeling that was more intense at the level of the Golgi apparatus along the whole epididymis. A similar pattern was observed for SUR2 (ABCC9), although in the latter case, the Golgi labeling appeared to be region specific. Spermatozoa in epididymal tubules from rodents also immunostained for Kir6.2 (KCNJ11) and SUR2 (ABCC9). Western blot analysis of epididymal total protein and crude membrane extracts from adult and prepubertal rats confirmed the presence of Kir6.2 (KCNJ11). SUR2 (ABCC9) protein expression was detected in adult epididymal extracts. Furthermore, RT-PCR established the presence of Kir6.2 (KCNJ11) and SUR2 (ABCC9) mRNA in prepubertal and adult mouse epididymis. Indirect immunofluorescence also documented the presence of Kir6.2 (KCNJ11) and SUR2 (ABCC9) in the epididymal epithelium, as well as in spermatozoa, of canine, feline, bovine, and human origin. These data demonstrate the presence of the K(ATP) channel subunits, Kir6.2 (KCNJ11) and SUR2 (ABCC9), in epididymal epithelial cells and spermatozoa from several mammalian species. Although their physiological roles need to be fully characterized, it is tempting to propose that such types of K(++) channels might be involved in protein secretion and fluid-electrolyte transport occurring along the epididymal epithelium, leading to spermatozoa maturation.

Acute pancreatitis (AP) is an inflammatory disease involving the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands [the CC chemokines CCL3/MIP-1alpha, CCL4/MIP-1beta, and CCL5/regulated upon activation, normal T cell expressed and secreted (RANTES)] regulate leukocyte chemotaxis and activation, we investigated the expression of CCR5 ligands and the role of CCR5 and its ligands in experimental AP in mice. AP was induced by hourly intraperitoneal injections of cerulein in CCR5-deficient (CCR5(-/-)) or wild-type (WT) mice. Induction of AP by cerulein resulted in an early increase of pancreatic CCL2, CCL3, and CCL4 mRNA expression, whereas CCL5 mRNA expression occurred later. CCR5(-/-) mice developed a more severe pancreatic injury than WT mice during cerulein-induced AP, as assessed by a more pronounced increase in serum amylase and lipase levels and by more severe pancreatic edema, inflammatory infiltrates (mainly neutrophils), and necrosis. CCR5(-/-) mice also exhibited increased production of CCL2/MCP-1, CCL3/MIP-1alpha, and CCL4/MIP-1beta during the course of cerulein-induced AP. In vivo simultaneous neutralization of CC chemokines with monoclonal antibodies in CCR5(-/-) mice reduced the severity of cerulein-induced AP, indicating a role of CC chemokines in exacerbating the course of AP in the absence of CCR5. Moreover, simultaneous neutralization of CCR5 ligands in WT mice also reduced the severity of cerulein-induced AP. In conclusion, lack of the chemokine receptor CCR5 exacerbates experimental cerulein-induced AP and leads to increased levels of CC chemokines and a more pronounced pancreatic inflammatory infiltrate, suggesting that CCR5 expression can modulate severity of AP.

Gut-derived, endotoxin-mediated hepatocellular damage has been postulated to play a crucial role in the pathogenesis of alcohol-induced liver injury in rodents. Endotoxins induce production of tumor necrosis factor alpha (TNF-alpha) by Kupffer cells via Toll-like receptor (TLR) 4 and contribute to liver injury. This study addressed the contribution of other TLRs and ligands to alcoholic fatty liver. C57Bl6/J mice were fed a modified Lieber-DeCarli diet. Serum aminotransferase measurements, histological analysis, and quantification of liver TNF-alpha and TLR1-9 messenger RNA (mRNA) were performed. The effect of TLR ligands on liver injury was assessed in vivo. Neomycin and metronidazole or diphenyleneiodonium sulfate (DPI) were administered to evaluate the role of gut bacteria and NADPH oxidase activity, respectively, in hepatic TLR expression. Enteral ethanol (EtOH) exposure induced steatosis and increased liver weight, aminotransferase levels, and expression of TLR1, 2, 4, 6, 7, 8, and 9 liver mRNA. Injection of lipoteichoic acid, peptidoglycan (PGN), lipopolysaccharide (LPS), loxoribine, and oligonudeotide containing CpG (ISS-ODN) increased TNF-alpha mRNA expression more in the livers of EtOH-fed mice than in control mice. PGN, LPS, flagellin, and ISS-ODN induced liver inflammatory infiltrate in EtOH-fed mice but not control mice. Addition of antibiotics reduced the severity of alcoholic fatty liver without affecting TLR expression, whereas daily DPI injections reduced the EtOH-mediated upregulation of TLR2, 4, 6, and 9 mRNA. In conclusion, EtOH-fed mice exhibited an oxidative stress dependent on upregulation of multiple TLRs in the liver and are sensitive to liver inflammation induced by multiple bacterial products recognized by TLRs.

Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A-induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/- mice also exhibited increased production of interleukin 4, tumor necrosis factor alpha, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5-/- mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell-mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immuno-mediated liver injury.

Objectives: In mice, body weight is regulated by adipocyte-derived leptin. TNFalpha is a critical mediator of inflammation-induced cachexia in Crohn's disease (CD). The regulation of leptin by TNFalpha is poorly understood in CD. Pharmacological neutralization of TNFalpha with infliximab offers a unique opportunity to study TNFalpha-mediated regulation of leptin in CD patients., Methods: We prospectively followed up CD patients treated with infliximab (n = 20). Body composition was assessed before and after treatment at 1 and 4 wk. Serum leptin, IL-6, soluble TNF receptor type II, and soluble intercellular antiadhesion molecule-1 levels were measured as well as cholesterol levels and free urinary cortisol. Because methylprednisolone (MP) increases leptin production in vivo, CD patients treated with MP (n = 9) were studied separately as a positive control group., Results: Infliximab induced clinical remission and a significant decrease in C-reactive protein (P < 0.01) and IL-6 (P < 0.05) levels in all CD patients and increased body weight (P = 0.013) at 4 wk. Leptinemia was significantly increased after infliximab administration at 1 wk (P = 0.014) and 4 wk (P < 0.001). This increase in serum leptin occurred early at 1 wk, when no significant weight and fat mass changes could be observed and was associated with the down-regulation of TNFalpha-regulated mediators, soluble TNF receptor type II (P = 0.015), and soluble intercellular antiadhesion molecule-1 (P = 0.007). Moreover, infliximab increased cholesterol levels at 1 wk (P = 0.001). Twenty-four-hour cortisol secretion was not altered by infliximab. Leptinemia increased at 1 wk after MP administration (P = 0.028)., Conclusion: Infliximab increases leptinemia in CD. This study suggests that TNFalpha exerts major inhibitory actions on leptin production in CD patients.

Background/aims: Alcohol sensitizes the liver to several injuries. The mechanisms leading to this sensitization are poorly defined. In the present study, we developed a mouse model of chronic exposure to alcohol vapours that sensitize mice to galactosamine (GAL) liver injury., Methods: C57BL/6 mice were exposed to ethanol vapours for 10 days. Liver injury was induced by intraperitoneal injection of GAL (1 g/kg) and mice were killed 24 h later., Results: GAL challenge after ethanol pre-treatment significantly raised serum alanine aminotransaminase (ALT) levels and enhanced liver inflammation when compared with the controls (GAL alone). Serum keratinocyte chemoattractant (KC) and monocyte chemoattractant protein-1 (MCP-1) levels were significantly increased in the GAL+ethanol group. On the contrary, serum interleukin 10 (IL-10) levels were lower than in controls. Anti-KC, anti-tumour necrosis factor alpha antibodies and intestinal decontamination significantly protected mice from liver injury. In GAL+ethanol-treated mice, IL-10 treatment reduced ALT release, KC and MCP-1 serum and hepatic mRNA levels, and improved liver inflammation., Conclusions: Enhancement of GAL-induced liver injury by ethanol is associated with an imbalance between proinflammatory cytokines and the anti-inflammatory cytokine IL-10 and depends on gut bacterial flora.

Background: Graft ischemia-reperfusion injury (IRI) resulting from postreperfusion inflammatory reaction remains a major cause of complications after liver transplantation. In this article, the authors investigated the effect of anti-inflammatory cytokine interleukin (IL)-10 on IRI, in a preclinical model of liver transplantation in pigs., Methods: Donor pigs received IL-10 or saline at the start of liver graft harvesting. After 5 hr of cold ischemia, liver grafts were transplanted into untreated recipient pigs. IRI severity was measured in recipients by transaminase release and by cellular infiltration and necrosis on liver biopsy specimens., Results: Donor IL-10 administration attenuated IRI, as indicated by significant reduction of mean peak of transaminase in recipients of grafts from IL-10-treated donors. In contrast, no significant differences in cell infiltration or amount of necrosis were observed on liver biopsy specimens between groups., Conclusions: Donor preconditioning with IL-10 may constitute an interesting pharmacologic approach to reduce IRI severity after liver transplantation.

Background & Aims: Eosinophils are observed in several liver diseases, but their contribution in the pathogenesis of these disorders remains poorly investigated. Concanavalin A (Con A)-induced hepatitis is an experimental model of immune-mediated liver injury in which natural killer T (NKT) cells play a critical role through the production of interleukin (IL)-4 and the expression of Fas ligand (FasL). Because activated NKT cells also produce IL-5, a critical cytokine for eosinophil maturation and function, the role of IL-5 was investigated in this model., Methods: IL-5-deficient mice, eosinophil depletion in wild-type (WT) mice, and NKT cell transfer from WT- or IL-5-deficient mice into NKT cell-deficient mice were used to assess the role of IL-5 and eosinophils., Results: Liver eosinophil infiltrate and IL-5 production were observed after Con A challenge. Liver injury was dramatically reduced in IL-5-deficient or eosinophil-depleted mice. In addition, residual hepatitis observed in Fas-deficient mice was abolished after IL-5 neutralization. Finally, we showed that NKT cells constituted a critical source of IL-5. Indeed, transfer of WT NKT cells to mice lacking NKT cells restored liver injury, whereas transfer of IL-5-deficient NKT cells did not., Conclusions: These observations highlight the pathologic role of IL-5 and eosinophils in experimental immune-mediated hepatitis.

Interleukin (IL)-10, a potent anti-inflammatory cytokine, limits the severity of acute pancreatitis and downregulates transforming growth factor (TGF)-beta release by inflammatory cells on stimulation. Proinflammatory mediators, reactive oxygen species, and TGF-beta can activate pancreatic stellate cells and their synthesis of collagen I and III. This study evaluates the role of endogenous IL-10 in the modulation of the regeneration phase following acute pancreatitis and in the development of pancreatic fibrosis. IL-10 knockout (KO) mice and their C57BL/6 controls were submitted to repeated courses (3/wk, during 6 wk, followed by 1 wk of recovery) of cerulein-induced acute pancreatitis. TGF-beta(1) release was measured on plasma, and its pancreatic expression was assessed by quantitative RT-PCR and immunohistochemistry. Intrapancreatic IL-10 gene expression was assessed by semiquantitative RT-PCR, and intrapancreatic collagen content was assessed by picrosirius staining. Activated stellate cells were detected by immunohistochemistry. S phase intrapancreatic cells were marked using tritiated thymidine labeling. After repeated acute pancreatitis, IL-10 KO mice had more severe histological lesions and fibrosis (intrapancreatic collagen content) than controls. TGF-beta(1) plasma levels, intrapancreatic transcription, and expression by ductal and interstitial cells, as well as the number of activated stellate cells, were significantly higher. IL-10 KO mice disclosed significantly fewer acinar cells in S phase, whereas the opposite was observed for pseudotubular cells. Endogenous IL-10 controls the regeneration phase and limits the severity of fibrosis and glandular atrophy induced by repeated episodes of acute pancreatitis in mice.

Kupffer cells are thought to mediate most of the deleterious effects of liver ischemia-reperfusion injury. The role of liver T cells and the impact of resident cell deactivation by interleukin 10 (IL-10) have never been addressed. Using a model of ex vivo liver cold ischemia and reperfusion, we assessed liver injury, tumor necrosis factor (TNF) and interferon gamma (IFN-gamma) release from livers of balb/c mice, nude mice, nude mice reconstituted with T cells, and gadolinium balb/c pretreated mice. The anti-inflammatory cytokine IL-10 was then used to define the best strategy of administration potentially able to modulate ischemia-reperfusion injury. For this purpose IL-10 was administered to the donor before liver harvesting, in the preservation medium during cold ischemia or during reperfusion. TNF and IFN-gamma were released time dependently and paralleled liver injury after reperfusion of cold preserved livers. Reperfused livers from nude or gadolinium pretreated mice disclosed a dramatic decrease in TNF and IFN-gamma release. Tissue injury was reduced by 51% in the absence of T cells and by 88% when Kupffer cells were deactivated. This effect was reverted by T-cell transfer to nude mice. Only donor pretreatment with IL-10 or IL-10 infusion during reperfusion led to a significant decrease in liver injury, TNF, and IFN-gamma release (-66% or -41%, -95% or -94%, and -70% or -70%, respectively). In conclusion, liver resident T cells are critically involved in cold ischemia-reperfusion injury and pretreatment of the donor with IL-10 decreases liver injury and the release of T-cell- and macrophage-dependent cytokines.

Oxidative stress plays a major role in the early stage of acute pancreatitis. This study assessed the effects of N-acetylcysteine (NAC), a reduced glutathione (GSH) provider and a direct scavenger of reactive oxygen intermediates, in the course of acute pancreatitis in mice. Acute pancreatitis (AP) was induced by intraperitoneal (i.p.) injections of cerulein. Mice received NAC (1,000 mg/kg, i.p.) every 3 h, starting either 1 h before the first cerulein injection (prophylactic group) or 1 h after the first cerulein injection (therapeutic group), or i.p. saline injections for controls. Severity of AP was evaluated by histology, serum hydrolase levels, and serum and intrapancreatic levels of MCP-1 and interleukin 6 (IL-6). Pancreatic conjugated dienes and intrapancreatic and intrahepatic GSH levels were measured to assess the local and systemic oxidative processes. Acute pancreatitis was also induced with a CDE diet in controls and mice receiving either both NAC ad libidum in drinking water and 1,000 mg/kg i.p. injection once daily. The severity of pulmonary lesions was assessed by arterial blood gases (pO2) and intrapulmonary myeloperoxidase (MPO content) measurements as well as the survival of mice. The severity of cerulein-induced AP was significantly decreased in the prophylactic group compared with the therapeutic and control groups. Prophylactic administration of NAC also decreased the intrapancreatic levels of conjugated dienes compared with controls. The intrapancreatic and systemic release of MCP- 1 and IL-6 was also decreased in the prophylactic group 3 and 6 hours after AP induction. In addition, NAC pretreatment also reduced hepatic IL-6 production at 3 and 6 hours after starting cerulein challenge. In CDE-induced AP, the severity of lung injury (hypoxemia, MPO content) was decreased, and survival was improved by NAC. NAC administered in a prophylactic protocol limits the severity of experimental acute pancreatitis in mice, as well as its systemic complications and related mortality.

Background & Aims: Few data are available on the potential role of T lymphocytes in experimental acute pancreatitis. The aim of this study was to characterize their role in the inflammatory cascade of acute pancreatitis., Methods: To type this issue, acute pancreatitis was induced by repeated injections of cerulein in nude mice and in vivo CD4(+) or CD8(+) T cell-depleted mice. The role of T lymphocyte-costimulatory pathways was evaluated using anti-CD40 ligand or anti-B7-1 and -B7-2 monoclonal blocking antibodies. The role of Fas-Fas ligand was explored using Fas ligand-targeted mutant (generalized lymphoproliferative disease) mice. Severity of acute pancreatitis was assessed by serum hydrolase levels and histology. Intrapancreatic interleukin 12, interferon gamma, Fas ligand, and CD40 ligand messenger RNA were detected by reverse-transcription polymerase chain reaction. Intrapancreatic T lymphocytes were identified by immunohistochemistry., Results: In control mice, T cells, most of them CD4(+) T cells, are present in the pancreas and are recruited during acute pancreatitis. In nude mice, histological lesions and serum hydrolase levels are significantly decreased. T-lymphocyte transfer into nude mice partially restores the severity of acute pancreatitis and intrapancreatic interferon gamma, interleukin 12, and Fas ligand gene transcription. The severity of pancreatitis is also reduced by in vivo CD4(+) (but not CD8(+)) T-cell depletion and in Fas ligand-targeted mutant mice. Blocking CD40-CD40 ligand or B7-CD28 costimulatory pathways has no effect on the severity of pancreatitis., Conclusions: T lymphocytes, particularly CD4(+) T cells, play a pivotal role in the development of tissue injury during acute experimental pancreatitis in mice.

Weekly injections of Concanavalin A (Con A) were performed in BALB/c mice to evaluate the pattern of cytokine production and liver injury. High serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin 2 (IL-2), IL-4, and interferon gamma (IFN-gamma) were found in the serum after the first 2 injections of Con A but rapidly decreased from the third injection. Conversely, IL-10 serum levels after repeated Con A challenge increased by 7 times from week 1 to 20. In vivo depletion studies indicated that CD4(+) T cells are essential in IL-10 production. Hepatocyte necrosis was only observed after the first injections of Con A whereas centrilobular inflammatory infiltrates persisted up to 20 weeks. Perisinusoidal liver fibrosis was also increasingly detected in BALB/c mice, whereas no fibrous change was observed in nude mice after 6 weeks of Con A challenge. The number of stellate cells, detected by immunostaining, increased after 20 weeks of Con A injections. Liver cytokine messenger RNA (mRNA) expression after 20 weeks showed expression of transforming growth factor beta1 (TGF-beta1), IL-10, and IL-4 whereas IL-2 was no more expressed. The present study shows that mice repeatedly injected with Con A develop liver fibrosis. The cytokine-release pattern observed after 1 injection of Con A is rapidly shifted towards an immunomodulatory phenotype characterized by the systemic production of large amounts of IL-10.

Background/aim: Adenosine is an endogenous nucleoside that is released under metabolically unfavourable circumstances such as ischaemia or infection. It exerts potent anti-inflammatory effects by decreasing tumour necrosis factor release and costimulating interleukin-10 production by human monocytes. The aim of this study was to assess the cytokine response to adenosine in whole blood cultures from alcoholic cirrhotic patients., Methods: Whole blood from 17 patients and 17 healthy controls stimulated with lipopolysaccharide was cultured in the presence of adenosine at different concentrations and, in some experiments, with the adenosine deaminase inhibitor deoxycoformycin. Peripheral blood mononuclear cell response was compared to whole blood, and plasma adenosine deaminase activity was measured., Results: Adenosine (100 microM) significantly inhibited TNF release and increased IL-10 production in whole blood cultures from controls stimulated with lipopolysaccharide, but not from cirrhotic patients. However, the response to adenosine was restored in peripheral mononuclear cells of patients in the absence of autologous plasma. To test the hypothesis that plasma adenosine deaminase, which was increased in the patients' plasma, was actually involved in this blunted response to adenosine in alcoholic cirrhosis, we performed adenosine dose-response experiments and pharmacologically blocked adenosine deaminase activity with deoxycoformycin. In both kinds of experiment, adenosine-induced inhibition of TNF release could be restored in alcoholic cirrhotic patients., Conclusions: These data indicate that increased circulating adenosine deaminase activity blunts the anti-inflammatory properties of adenosine in alcoholic cirrhotic patients.