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Background and Aims: Although the majority of patients with non-alcoholic fatty liver disease (NAFLD) have only steatosis without progression, a sizeable fraction develop non-alcoholic steatohepatitis (NASH), which can lead to cirrhosis and hepatocellular carcinoma (HCC). Many established diet-induced mouse models for NASH require 24-52 weeks, which makes testing for drug response costly and time consuming., Methods: We have sought to establish a murine NASH model with rapid progression of extensive fibrosis and HCC by using a western diet (WD), which is high-fat, high-fructose and high-cholesterol, combined with low weekly dose of intraperitoneal carbon tetrachloride (CCl 4 ), which serves as an accelerator., Results: C57BL/6J mice were fed a normal chow diet ± CCl 4 or WD ± CCl 4 for 12 and 24 weeks. Addition of CCl 4 exacerbated histological features of NASH, fibrosis, and tumor development induced by WD, which resulted in stage 3 fibrosis at 12 weeks and HCC development at 24 weeks. Furthermore, whole liver transcriptomic analysis indicated that dysregulated molecular pathways in WD/CCl 4 mice and immunologic features were similar to those of human NASH., Conclusions: Our mouse NASH model exhibits rapid progression of advanced fibrosis and HCC, and mimics histological, immunological and transcriptomic features of human NASH, suggesting that it will be a useful experimental tool for preclinical drug testing., Lay Summary: A carefully characterized model has been developed in mice that recapitulates the progressive stages of human fatty liver disease, from simple steatosis, to inflammation, fibrosis and cancer. The functional pathways of gene expression and immune abnormalities in this model closely resemble human disease. The ease and reproducibility of this model make it ideal to study disease pathogenesis and test new treatments., (Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

The complement system anchors the innate inflammatory response by triggering both cell-mediated and antibody-mediated immune responses against pathogens. The complement system also plays a critical role in sterile tissue injury by responding to damage-associated molecular patterns. The degree and duration of complement activation may be a critical variable controlling the balance between regenerative and destructive inflammation following sterile injury. Recent studies in kidney transplantation suggest that aberrant complement activation may play a significant role in delayed graft function following transplantation, confirming results obtained from rodent models of renal ischemia/reperfusion (I/R) injury. Deactivating the complement cascade through targeting anaphylatoxins (C3a/C5a) might be an effective clinical strategy to dampen reperfusion injury and reduce delayed graft function in liver transplantation. Targeting the complement cascade may be critical in donor livers with mild to moderate steatosis, where elevated lipid burden amplifies stress responses and increases hepatocyte turnover. Steatosis-driven complement activation in the donor liver may also have implications in rejection and thrombolytic complications following transplantation. This review focuses on the roles of complement activation in liver I/R injury, strategies to target complement activation in liver I/R, and potential opportunities to translate these strategies to transplanting donor livers with mild to moderate steatosis.

Liver X receptor (LXR) α expression is mainly localized to metabolic tissues, such as the liver, whereas LXRβ is ubiquitously expressed. LXRα is activated by oxysterols and plays an important role in the regulation of lipid metabolism in metabolic tissues. In macrophages, LXRs stimulate reverse cholesterol transport and regulate immune responses. Although a high-cholesterol diet induces severe steatohepatitis in LXRα-knockout (KO) mice, the underlying mechanisms linking lipid metabolism and immune responses remain largely unknown. In this study, we investigated the role of LXRα in the pathogenesis of steatohepatitis by assessing the effects of a high-fat and high-cholesterol diet (HFCD) on hepatic immune cell proportion and function as well as lipid metabolism in wild-type (WT) and LXRα-KO mice. HFCD feeding induced severe steatohepatitis in LXRα-KO mice compared with WT mice. These mice had higher cholesterol levels in the plasma and the liver and dysregulated expression of LXR target and proinflammatory genes in both whole liver samples and isolated hepatic mononuclear cells. Flow cytometry showed an increase in CD68+CD11b+ Kupffer cells/macrophages and a decrease in invariant natural killer T cells in the liver of HFCD-fed LXRα-KO mice. These mice were more susceptible to lipopolysaccharide-induced liver injury and resistant to inflammatory responses against α-galactosylceramide or concanavalin-A treatment. The findings provide evidence for activation of bone marrow-derived Kupffer cells/macrophages and dysfunction of invariant natural killer T cells in LXRα-KO mouse liver. These findings indicate that LXRα regulates hepatic immune function along with lipid metabolism and protects against the pathogenesis of nonalcoholic steatohepatitis.

Peripheral inflammation contributes to minimal hepatic encephalopathy in chronic liver diseases, which could be mediated by neuroinflammation. Neuroinflammation in cerebellum of patients with chronic liver diseases has not been studied in detail. Our aim was to analyze in cerebellum of patients with different grades of liver disease, from mild steatohepatitis to cirrhosis and hepatic encephalopathy: (a) neuronal density in Purkinje and granular layers; (b) microglial activation; (c) astrocyte activation; (d) peripheral lymphocytes infiltration; (e) subtypes of lymphocytes infiltrated. Steatohepatitis was classified as SH1, SH2 and SH3. Patients with SH1 show Th17 and Tfh lymphocytes infiltration in the meninges, microglia activation in the molecular layer and loss of 16 ± 4% of Purkinje and 19 ± 2% of granular neurons. White matter remains unaffected. With the progression of liver disease to worse stages (SH2, SH3, cirrhosis) activation of microglia and astrocytes extends to white matter, Bergman glia is damaged in the molecular layer and there is a further loss of Purkinje neurons. The results reported show that neuroinflammation in cerebellum occurs at early stages of liver disease, even before reaching cirrhosis. Neuroinflammation occurs earlier in the molecular layer than in white matter, and is associated with infiltration of peripheral Th17 and Tfh lymphocytes.

Gynura bicolor leaf aqueous extract (GAE) is rich in phytochemicals including phenolic acids, flavonoids, carotenoids, and anthocyanins. Effects of GAE upon hepatic injury in mice with chronic ethanol intake were examined. Lieber-DeCarli liquid diet with ethanol was used to induce hepatic lipid accumulation, oxidative, glycative, and inflammatory injury. GAE at 0.25% or 0.5% was added in feeds, and supplied to mice consumed Lieber-DeCarli liquid diet with ethanol for 6 wk. Blood and liver were collected for analyses. Results showed that ethanol increased plasma and hepatic triglyceride and cholesterol content, and affected plasma levels of insulin, adiponectin, leptin, and ghrelin. GAE at both doses decreased lipid accumulation, and at high dose improved hormones abnormality. Histological data revealed that GAE supplement mitigated hepatic lipid deposit. Ethanol increased plasma N ε -(carboxyethymethyl)-lysine and pentosidine levels. GAE at high doses lowered those glycative factors. Ethanol depleted glutathione content, increased CYP2E1 activity and reactive oxygen species production, and reduced the activity of glutathione peroxide, glutathione reductase and catalase in liver. GAE supplement at both doses reversed these alterations and attenuated hepatic oxidative stress. GAE supplement also at both doses decreased hepatic inflammatory cytokines release in ethanol treated mice. These findings support that leaves of G. bicolor is a functional food with liver protective activities against ethanol., (© 2017 Institute of Food Technologists®.)

Background & Aims: Recent studies have shown that patients with manifest non-alcoholic fatty liver disease (NAFLD), e.g. steatosis grade 3 or steatohepatitis with or without beginning fibrosis frequently show altered fecal microbiota composition and elevated bacterial endotoxin levels. However, if these alterations are signs of a progressing disease or are already found in initial disease stages has not yet been clarified., Methods: Twenty children with simple steatosis (grade 1) diagnosed by ultrasound and 29 normal weight healthy control children (age <10 years) were included in the study (mean age 7.6 ± 1.1 years). Metabolic parameters, markers of intestinal barrier function and inflammation were determined., Results: Activity of alanine aminotransferase, concentrations of some markers of inflammation and insulin resistance were significantly higher in plasma of NAFLD children than in controls. When compared to controls, plasma bacterial endotoxin and lipopolysaccharide-binding protein (LBP) levels were significantly higher in NAFLD children (+50% and +24%, respectively), while soluble CD14 serum and D-lactate plasma levels as well as the prevalence of small intestinal bacterial overgrowth did not differ between groups. Plasma endotoxin and LBP levels were positive associated with proinflammatory markers like plasminogen activator inhibitor-1, c-reactive protein, interleukin-6 and leptin while no associations with markers of insulin resistance were found., Conclusions: Taken together, our results indicate that even in juvenile patients with early stages of NAFLD e.g. simple steatosis grade 1, plasma endotoxin concentrations are already elevated further suggesting that intestinal barrier dysfunction might be present already in the initial phases of the disease.

Background and Aim: Enterohepatic immunologic derangement is associated with non-alcoholic steatohepatitis. Here, we investigated whether Clostridium butyricum B1 (CB) would be an effective immune-targeted substance to attenuate steatohepatitis in mice., Methods: Thirty mice were randomized into a control group fed with common forage, a high-fat diet (HFD) group fed an HFD for 16 weeks, and an HFD + CB group treated with CB for the latter 8 weeks. Inflammation-associated or metabolism-associated genes in the liver or epididymal fat tissue were quantified; intrahepatic and intestinal immune factors were detected. Further short-chain fatty acids in the cecal contents or liver were measured, and differentiations of T cells in vitro were analyzed., Results: Characteristics of non-alcoholic steatohepatitis in the HFD group were obvious and were significantly attenuated in the HFD + CB group. The messenger RNA levels of monocyte chemotactic protein-1 and tumor necrosis factor-α in the liver and epididymal fat tissue were increased in the HFD group compared with the control group and were downregulated in the HFD + CB group. Intrahepatic and intestinal interferon-γ and interleukin (IL)-17 were significantly increased, whereas forkhead box P3, IL-4, and IL-22 were significantly decreased in the HFD group compared with the control group. However, these intrahepatic or intestinal immune changes were reversed after CB intervention. Furthermore, butyrate in the cecal content and liver of the HFD + CB group was significantly elevated. An in vitro investigation showed that sodium butyrate promoted CD4 + T cell differentiation into Th2, Th22, or Treg, whereas it inhibited CD4 + T cell differentiation into Th1 or Th17 under a cytokine milieu, which was mimicked by Trichostatin A., Conclusion: Clostridium butyricum B1 could attenuate HFD-induced steatohepatitis in mice partially through butyrate-induced enterohepatic immunoregulation., (© 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNFα), may contribute to hepatic steatosis in the situation of excess lipid accumulation in farmed fish. Pigment epithelium-derived factor (PEDF) is an endogenous anti-inflammatory factor and promotes lipolysis. Accordingly, we isolated PEDF from grass carp and investigated its role in TNFα-induced hepatic steatosis. Sequence analysis showed that PEDF gene, which possesses 8 exons and 7 introns, encodes a protein with 409 amino acids. PEDF was a critical determinant of the transcriptional response to nutrient availability in grass carp. Endogenous PEDF was an intracellular protein with cytoplasmic distribution and directly interacts with adipose triglyceride lipase (ATGL), which might mediate PEDF-induced lipolysis. TNFα significantly promoted lipid accumulation in vivo and in vitro, accompanied with a decrease in mRNA levels of PEDF and peroxisome proliferator-activated receptor alpha (PPARα). Recombinant PEDF and PPARα agonist diminished the TNFα-induced hepatic steatosis. Meanwhile, PPARα agonist caused an increase in PEDF expression, suggesting that TNFα antagonizes the actions of PEDF possibly in a PPARα-dependent manner. These findings suggest that PEDF is an important protective factor against hepatic steatosis induced by TNFα, which provided a new therapeutic target for inflammation-associated hepatic steatosis., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Sodium-glucose cotransporter (SGLT) 2 inhibitors increase urinary glucose excretion (UGE), leading to blood glucose reductions and weight loss. However, the impacts of SGLT2 inhibition on energy homeostasis and obesity-induced insulin resistance are less well known. Here, we show that empagliflozin, a SGLT2 inhibitor, enhanced energy expenditure and attenuated inflammation and insulin resistance in high-fat-diet-induced obese (DIO) mice. C57BL/6J mice were pair-fed a high-fat diet (HFD) or a HFD with empagliflozin for 16weeks. Empagliflozin administration increased UGE in the DIO mice, whereas it suppressed HFD-induced weight gain, insulin resistance, and hepatic steatosis. Moreover, empagliflozin shifted energy metabolism towards fat utilization, elevated AMP-activated protein kinase and acetyl-CoA carbolxylase phosphorylation in skeletal muscle, and increased hepatic and plasma fibroblast growth factor 21 levels. Importantly, empagliflozin increased energy expenditure, heat production, and the expression of uncoupling protein 1 in brown fat and in inguinal and epididymal white adipose tissue (WAT). Furthermore, empagliflozin reduced M1-polarized macrophage accumulation while inducing the anti-inflammatory M2 phenotype of macrophages within WAT and liver, lowering plasma TNFα levels and attenuating obesity-related chronic inflammation. Thus, empagliflozin suppressed weight gain by enhancing fat utilization and browning and attenuated obesity-induced inflammation and insulin resistance by polarizing M2 macrophages in WAT and liver., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Obesity mediates immune inflammatory response and induces IL-17 expression. Adipgenesis can be regulated by IL-17 and it causes TBK1 activation. The inhibition of TBK1 and the inhibition of I IKBKE reduces inflammatory response and improves obesity. It is hypothesized that IL-17 deficiency inhibits obesity progression and inflammation. 3T3-L1 preadipocytes were differentiated in vitro and treated with IL-17. RAW264.7 cells and differentiated 3T3-L1 were pretreated with TBK1 inhibitor and then stimulated with IL-17. Wild-type and IL-17 knock out mice were fed with high-fat diet. IL-17 inhibits adipocyte differentiation from mouse-derived 3T3-L1 preadipocytes and reduces mRNA expression of proadipogenic transcription factors and adipokines in adipocyte cells. IL-17 also showed up-regulation of mRNA levels of inflammatory cytokines in RAW cells. The inhibitor of TBK1 and IKBKE attenuates the effect of IL-17. Loss of IL-17 deficiency improves diet-induced obesity, fatty liver, glucose and lipid metabolism in mice. The expression of TBK1 and IKBKE decreased in the spleen and liver of IL-17 deficiency mice. Moreover, the inflammatory response within the visceral adipose tissue and Th1 cells were inhibited, however, M2 macrophage and Th2 cells increased in IL-17 deficiency mice. IL-17 inhibits adipogenesis where a lack of IL-17 ameliorates glucose metabolism. As well, the inhibition of TBK1 reduces inflammation induced by IL-17. Therefore, IL-17 may be involved in the development of obesity and metabolic dysfunction in a TBK1-dependent manner., (Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.)

Diet-related health issues such as nonalcoholic fatty liver disease and cardiovascular disorders are known to have a major inflammatory component. However, the exact pathways linking diet-induced changes (e.g., hyperlipidemia) and the ensuing inflammation have remained elusive so far. We identified biological processes related to innate immunity and oxidative stress as prime response pathways in livers of low-density lipoprotein receptor-deficient mice on a Western-type diet using RNA sequencing and in silico functional analyses of transcriptome data. The observed changes were independent of the presence of microbiota and thus indicative of a role for sterile triggers. We further show that malondialdehyde (MDA) epitopes, products of lipid peroxidation and markers for enhanced oxidative stress, are detectable in hepatic inflammation predominantly on dying cells and stimulate cytokine secretion as well as leukocyte recruitment in vitro and in vivo. MDA-induced cytokine secretion in vitro was dependent on the presence of the scavenger receptors CD36 and MSR1. Moreover, in vivo neutralization of endogenously generated MDA epitopes by intravenous injection of a specific MDA antibody results in decreased hepatic inflammation in low-density lipoprotein receptor-deficient mice on a Western-type diet., Conclusion: Accumulation of MDA epitopes plays a major role during diet-induced hepatic inflammation and can be ameliorated by administration of an anti-MDA antibody. (Hepatology 2017;65:1181-1195)., (© 2016 by the American Association for the Study of Liver Diseases.)

Strategies for prevention and treatment of nonalcoholic steatohepatitis remain to be established. We evaluated the effect of glycine on metabolic steatohepatitis in genetically obese, diabetic KK-A y mice. Male KK-A y mice were fed a diet containing 5% glycine for 4 wk, and liver pathology was evaluated. Hepatic mRNA levels for lipid-regulating molecules, cytokines/chemokines, and macrophage M1/M2 markers were determined by real-time RT-PCR. Hepatic expression of natural killer (NK) T cells was analyzed by flow cytometry. Body weight gain was significantly blunted and development of hepatic steatosis and inflammatory infiltration were remarkably prevented in mice fed the glycine-containing diet compared with controls. Indeed, hepatic induction levels of molecules related to lipogenesis were largely blunted in the glycine diet-fed mice. Elevations of hepatic mRNA levels for TNFα and chemokine (C-C motif) ligand 2 were also remarkably blunted in the glycine diet-fed mice. Furthermore, suppression of hepatic NK T cells was reversed in glycine diet-fed KK-A y mice, and basal hepatic expression levels of NK T cell-derived cytokines, such as IL-4 and IL-13, were increased. Moreover, hepatic mRNA levels of arginase-1, a marker of macrophage M2 transformation, were significantly increased in glycine diet-fed mice. In addition, dietary glycine improved glucose tolerance and hyperinsulinemia in KK-A y mice. These observations clearly indicate that glycine prevents maturity-onset obesity and metabolic steatohepatitis in genetically diabetic KK-A y mice. The underlying mechanisms most likely include normalization of hepatic innate immune responses involving NK T cells and M2 transformation of Kupffer cells. It is proposed that glycine is a promising immunonutrient for prevention and treatment of metabolic syndrome-related nonalcoholic steatohepatitis., (Copyright © 2016 the American Physiological Society.)

The role of Invariant chain (CD74 or Ii) in antigen presentation via Antigen Presenting Cells (APC), macrophage recruitment as well as survival, T cell activation and B cell differentiation has been well recognized. However, the aspect of CD74 which is involved in the development of hepatic steatosis and the pathways through which it acts remain to be studied. In this study, we investigated the role of CD74 in the inflammatory pathway and its contribution to development of hepatic steatosis. For this, wild type C57BL/6J and CD74 deficient mice (Ii(-/-) mice) were fed with high fat high fructose (HFHF) diet for 12 weeks. Chronic consumption of this feed did not develop hepatic steatosis, glucose intolerance or change in the level of immune cells in Ii(-/-) mice. Moreover, there was relatively delayed expression of genes involved in development of non alcoholic fatty liver disease (NAFLD) in HFHF fed Ii(-/-) mice as compared to that of C57BL/6J phenotype. Taken together, the data suggest that HFHF diet fed Ii(-/-) mice fail to develop hepatic steatosis, suggesting that Ii mediated pathways play a vital role in the initiation and propagation of liver inflammation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Fibroproliferative diseases are driven by dysregulated tissue repair responses and are a major cause of morbidity and mortality because they affect nearly every organ system. Type 2 cytokine responses are critically involved in tissue repair; however, the mechanisms that regulate beneficial regeneration versus pathological fibrosis are not well understood. Here, we have shown that the type 2 effector cytokine interleukin-13 simultaneously, yet independently, directed hepatic fibrosis and the compensatory proliferation of hepatocytes and biliary cells in progressive models of liver disease induced by interleukin-13 overexpression or after infection with Schistosoma mansoni. Using transgenic mice with interleukin-13 signaling genetically disrupted in hepatocytes, cholangiocytes, or resident tissue fibroblasts, we have revealed direct and distinct roles for interleukin-13 in fibrosis, steatosis, cholestasis, and ductular reaction. Together, these studies show that these mechanisms are simultaneously controlled but distinctly regulated by interleukin-13 signaling. Thus, it may be possible to promote interleukin-13-dependent hepatobiliary expansion without generating pathological fibrosis. VIDEO ABSTRACT., (Published by Elsevier Inc.)

Obesity is a chronic inflammatory disease mediated in large part by the activation of inflammatory macrophages. This chronic inflammation underlies a whole host of diseases including atherosclerosis, hepatic steatosis, insulin resistance, type 2 diabetes, and cancer, among others. Macrophages are generally classified as either inflammatory or alternatively activated. Some tissue-resident macrophages are derived from yolk sac erythromyeloid progenitors and fetal liver progenitors that seed tissues during embryogenesis and have the ability to repopulate through local proliferation. These macrophages tend to be anti-inflammatory in nature and are generally involved in tissue remodeling, repair, and homeostasis. Alternatively, during chronic inflammation induced by obesity, bone marrow monocyte-derived macrophages are recruited to inflamed tissues, where they produce proinflammatory cytokines and exacerbate inflammation. The extent to which these two populations of macrophages are plastic in their phenotype remains controversial. We have demonstrated previously that the Ron receptor tyrosine kinase is expressed on tissue-resident macrophages, where it limits inflammatory macrophage activation and promotes a repair phenotype. In this study, we demonstrate that Ron is expressed in a subpopulation of macrophages during chronic inflammation induced by obesity that exhibit a repair phenotype as determined by the expression of arginase 1. In addition, we demonstrate that the Ron receptor plays a protective role in the progression of diet-induced obesity, hepatosteatosis, and atherosclerosis. These results suggest that altering macrophage heterogeneity in vivo could have the potential to alleviate obesity-associated diseases., (Copyright © 2016 by The American Association of Immunologists, Inc.)

Background: Despite the efficacy of orthotopic liver transplantation in the treatment of end-stage liver diseases, its therapeutic utility is severely limited by the availability of donor organs. The ability to rehabilitate marginal organs, such as steatotic allografts, has the potential to address some of the supply limitations of available organs for transplantation. Steatotic livers are more susceptible to ischemia-reperfusion injury (IRI), which is exacerbated by the thrombospondin-1/CD47 pathway through inhibition of nitric oxide signaling. We postulated that CD47 blockade with a monoclonal antibody specific to CD47, clone 400 (CD47mAb400) may reduce the extent of IRI in steatotic liver allografts., Methods: Orthotopic liver transplantation was performed using steatotic liver grafts from Zucker rats transplanted into lean recipients. Control IgG or the CD47mAb400 was administered to the donor livers at procurement. Serum transaminases, histological changes, and animal survival were assessed. Hepatocellular damage, oxidative and nitrosative stress, and inflammation were also quantified., Results: Administration of CD47mAb400 to donor livers increased recipient survival and resulted in significant reduction of serum transaminases, bilirubin, triphosphate nick-end labeling staining, caspase-3 activity, oxidative and nitrosative stresses, and proinflammatory cytokine expression of TNF-α, IL-6 and IL-1β., Conclusions: We conclude that administration of CD47mAb400 to donor grafts may reduce IRI through CD47 blockade to result in improved function of steatotic liver allografts and increased survival of recipients and represent a novel strategy to allow the use of livers with higher levels of steatosis.

Inflammation and hepatocyte injury and death are the hallmarks of nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease (NAFLD), which is a currently burgeoning public health problem. Innate immune activation is a key factor in triggering and amplifying hepatic inflammation in NAFLD/NASH. Thus, identification of the underlying mechanisms by which immune cells in the liver recognize cell damage signals or the presence of pathogens or pathogen-derived factors that activate them is relevant from a therapeutic perspective. In this review, we present new insights into the factors promoting the inflammatory response in NASH including sterile cell death processes resulting from lipotoxicity in hepatocytes as well as into the altered gut-liver axis function, which involves translocation of bacterial products into portal circulation as a result of gut leakiness. We further delineate the key immune cell types involved and how they recognize both damage-associated molecular patterns or pathogen-associated molecular patterns through binding of surface-expressed pattern recognition receptors, which initiate signaling cascades leading to injury amplification. The relevance of modulating these inflammatory signaling pathways as potential novel therapeutic strategies for the treatment of NASH is summarized.

In obesity, adipose tissue (AT) and liver are infiltrated with Th-1 polarized immune cells, which are proposed to play an important role in the pathogenesis of the metabolic abnormalities of obesity. Aging is also associated with increased adiposity, but the effects of this increase on inflammation and associated metabolic dysfunction are poorly understood. To address this issue, we assessed insulin resistance (IR) andATand liver immunophenotype in aged, lean (AL) and aged, obese (AO) mice, all of whom were maintained on a standard chow diet (11% fat diet) throughout their lives. For comparison, these variables were also assessed in young, lean (YL) and young diet-induced obese mice (41% fat diet,YO). Despite similar body weight and fat accumulation,YOmice were substantially moreIRand had greater liver steatosis compared toAOmice.YOalso had elevated infiltration of macrophages/dendritic cells inATand liver, but these increases were absent inAO Furthermore, liver immune cells ofYOwere more Th-1 polarized thenAO Notably, aging was associated with accumulation of T cells, but this occurred independent of obesity. Together, the data suggest that reduced inflammation inAOunderlies the improved insulin sensitivity and lowered steatosis compared toYO., (© 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.)

Artemisia annua L. (AA) is a well-known source of the antimalarial drug artemisinin. AA also has an antibacterial and antioxidant activity. However, the effect of AA extract on hepatic steatosis induced by obesity is unclear. We investigated whether AA extract prevents obesity-induced insulin resistance and hepatic steatosis in high-fat diet (HFD)-fed mice. Mice were randomly divided into groups that received a normal chow diet or HFD with or without AA for 12 weeks. We found that AA extract reduced insulin resistance and hepatic steatosis in HFD-fed mice. Western blot analysis showed that HFD-induced expression of nuclear sterol regulatory element-binding protein 1 and carbohydrate-responsive element-binding protein in the livers was decreased by AA extract. In particular, dietary administration of AA extract decreased hepatic high-mobility group box 1 and cyclooxygenase-2 expression in HFD-fed mice. AA extract also attenuated HFD-induced collagen deposition and fibrosis-related transforming growth factor-β1 and connective tissue growth factor. These data indicate that dietary AA extract has beneficial effects on hepatic steatosis and inflammation in HFD-fed mice.

Background: The fatty liver could increase the risk of serious acute ischemia reperfusion (I/R) injury, and hepatic steatosis is indeed a major risk factor for hepatic failure after grafting a fatty liver., Materials & Methods: Fatty liver models of methionine- and choline-deficient high-fat mice were subjected to I/R injury with or without 5-aminolevulinic acid (5-ALA)/sodium ferrous citrate (SFC) treatment. Levels of hepatic enzymes, lipid peroxidation and apoptosis, inflammatory cytokines and heme oxygenase (HO)-1, and the carbon monoxide (CO) in the liver, and reactive oxygen species (ROS), inflammatory cytokines and members of the signaling pathway in isolated Kupffer were assessed., Results: Alanine aminotransferase and aspartate aminotransferase levels, the number of necrotic areas, thiobarbituric acid reactive substance content, TUNEL-positive cells, infiltrated macrophages, and the inflammatory cytokine expression after I/R injury were dramatically decreased, whereas the endogenous CO concentrations and the HO-1 expression were significantly increased by 5-ALA/SFC treatment. The expression of toll-like receptors 2 and 4, NF-κB and inflammatory cytokines and ROS production in Kupffer cells were significantly decreased with 5-ALA/SFC treatment., Conclusion: 5-ALA/SFC significantly attenuates the injury level in the fatty liver after I/R injury., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This review summarizes our current knowledge of the innate and adaptive immune responses induced by hepatitis C virus, and of the genetic polymorphisms that may determine the outcome of the disease. In addition, the authors discuss the role of reactive oxygen species and oxidative stress in hepatitis C virus-related pathogenic processess, such as hepatitis, fibrosis, hepatocellular carcinoma, steatosis and insulin resistance.

IL-25 or IL-17E is a member of IL-17 cytokine family and has immune-modulating activities. The role of IL-25 in maintaining lipid metabolic homeostasis remains unknown. We investigated the effects of exogenous IL-25 or deficiency of IL-25 on hepatic lipid accumulation. IL-25 expression was examined in paraffin-embedded tissue sections of liver from patients or in the livers from mice. Mouse model of steatosis was induced by feeding a high-fat diet (HFD). Extent of steatosis as well as expression of cytokines, key enzymes for lipid metabolic pathways, markers for Kupffer cells/macrophages, and lipid droplet (LD) proteins, were analyzed. Our results show that hepatic steatosis in mice was accompanied by increased LD proteins, but decreased IL-25 in the liver. Decreased hepatic IL-25 was also observed in patients with fatty liver. Administration of IL-25 to HFD-fed wild-type mice led to a significant improvement in hepatic steatosis. This effect was associated with increased expression of IL-13, development of alternatively activated Kupffer cells/macrophages, and decreased expression of LD proteins in the liver. In contrast, administration of IL-25 to HFD-fed mice deficient in STAT6 or IL-13 had no effects. In addition, stimulation of primary hepatocytes with IL-13, but not IL-25, resulted in downregulation of LD proteins. Finally, mice deficient in IL-25 had exacerbated hepatic lipid accumulation when fed the HFD. These data demonstrate that dysregulated IL-25 expression contributes to lipid accumulation, whereas exogenous IL-25 protects against hepatic steatosis through IL-13 activation of STAT6. IL-25 and IL-13 are potential therapeutic agents for hepatic steatosis and associated pathologies., (Copyright © 2015 by The American Association of Immunologists, Inc.)

Dairy cows with fatty liver are characterized by hepatic lipid accumulation and a severe inflammatory response. Sterol receptor element binding protein-1c (SREBP-1c) and nuclear factor κB (NF-κB) are components of the main pathways for controlling triglyceride (TG) accumulation and inflammatory levels, respectively. A previous study demonstrated that hepatic inflammatory levels are positively correlated with hepatic TG content. We therefore speculated that SREBP-1c might play an important role in the overactivation of the hepatic NF-κB inflammatory pathway in cows with fatty liver. Compared with healthy cows, cows with fatty liver exhibited severe hepatic injury and high blood concentrations of the inflammatory cytokines TNF-α, IL-6 and IL-1β. Hepatic SREBP-1c-mediated lipid synthesis and the NF-κB inflammatory pathway were both overinduced in cows with fatty liver. In vitro, treatment with non-esterified fatty acids (NEFA) further increased SREBP-1c expression and NF-κB pathway activation, which then promoted TG and inflammatory cytokine synthesis. SREBP-1c overexpression overactivated the NF-κB inflammatory pathway in hepatocytes by increasing ROS content and not through TLR4. Furthermore, SREBP-1c silencing decreased ROS content and further attenuated the activation of the NEFA-induced NF-κB pathway, thereby decreasing TNF-α, IL-6 and IL-1β synthesis. SREBP-1c-overexpressing mice exhibited hepatic steatosis and an overinduced hepatic NF-κB pathway. Taken together, these results indicate that SREBP-1c enhances the NEFA-induced overactivation of the NF-κB inflammatory pathway by increasing ROS in cow hepatocytes, thereby further increasing hepatic inflammatory injury in cows with fatty liver., (Copyright © 2015. Published by Elsevier Inc.)

Aging is associated with increased vulnerability to inflammatory challenge. However, the effects of altered inflammatory response on the metabolic status of tissues or organs are not well documented. In this study, we present evidence demonstrating that lipopolysaccharide (LPS)-induced upregulation of the inflammasome/IL-1β pathway is accompanied with an increased inflammatory response and abnormal lipid accumulation in livers of aged rats. To monitor the effects of aging on LPS-induced inflammation, we administered LPS (2 mg kg(-1) ) to young (6-month old) and aged (24-month old) rats and found abnormal lipid metabolism in only aged rats with increased lipid accumulation in the liver. This lipid accumulation in the liver was due to the dysregulation of PPARα and SREBP1c. We also observed severe liver inflammation in aged rats as indicated by increased ALT levels in serum and increased Kupffer cells in the liver. Importantly, among many inflammation-associated factors, the aged rat liver showed chronically increased IL-1β production. Increased levels of IL-1β were caused by the upregulation of caspase-1 activity and inflammasome activation. In vitro studies with HepG2 cells demonstrated that treatment with IL-1β significantly induced lipid accumulation in hepatocytes through the regulation of PPARα and SREBP1c. In summary, we demonstrated that LPS-induced liver inflammation and lipid accumulation were associated with a chronically overactive inflammasome/IL-1β pathway in aged rat livers. Based on the present findings, we propose a mechanism of aging-associated progression of steatohepatitis induced by endotoxin, delineating a pathogenic role of the inflammasome/IL-1β pathway involved in lipid accumulation in the liver., (© 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

Activation of the innate immune system plays a key role in the development of fatty liver disease (FLD). The complement system is a major humoral component of the innate immune response and complement C3 plays a central role, implying that C3 may be a powerful predictor or therapeutic target for FLD. However, few studies have assessed the association between C3 and FLD in a large population. Here we use a cross-sectional study to investigate the link between serum C3 levels and FLD. Participants were recruited from Tianjin Medical University's General Hospital-Health Management Centre. Serum C3 was measured using immunoturbidimetry method and FLD was diagnosed by liver ultrasonography. Multiple logistic regression analysis was used to examine the association between quartiles of C3 and FLD prevalence. The overall prevalence of nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD) were 37.3% and 10.1%, respectively. After adjusting for covariates, the odds ratio of having NAFLD or AFLD (only in males) in the fourth quartile of C3 compared with the first quartile was 4.13 times greater (95% confidence interval, 2.97-5.77) (trend P values < 0.0001) and 2.09 times greater (95% confidence interval, 1.08-4.18) (trend P values = 0.02). This is the first study to demonstrate that serum C3 levels are independently associated with a higher prevalence of NAFLD and AFLD (only in males) in an adult population. Further studies are needed to establish a causal link and determine the precise role of C3 in FLD.

Myeloid cells, particularly macrophages, mediate metabolic inflammation, thus promoting insulin resistance and metabolic disease progression in obesity. Numerous cytokines, toxic metabolites, damage-associated molecular patterns, and pathogen-associated molecular patterns are involved in activating macrophages via their cognate receptors in obesity. TRAF3 (TNF receptor-associated factor 3) is a common signaling molecule for these ligands/receptors and negatively regulates the proinflammatory NF-κB and MAPK pathways, but its metabolic activity is unknown. We here show that myeloid cell TRAF3 is required for metabolic inflammation and metabolic disease progression in obesity. Myeloid cell-specific deletion of TRAF3 significantly attenuated insulin resistance, hyperglycemia, hyperinsulinemia, glucose intolerance, and hepatic steatosis in mice with either genetic (ob/ob) or high-fat diet (HFD)-induced obesity. Myeloid cell-specific deletion of TRAF3 had the opposite effects on metabolic inflammation between obese and lean mice. It decreased the expression of proinflammatory cytokines in the liver and adipose tissue of obese mice and largely prevented HFD-induced inflammation in these metabolic tissues; by contrast, in lean mice, it increased the expression of proinflammatory cytokines in the liver and adipose tissue. These data suggest that, in obesity progression, myeloid TRAF3 functionally switches its activity from anti-inflammatory to proinflammatory modes, thereby coupling overnutrition to metabolic inflammation, insulin resistance, and metabolic disease., (Copyright © 2015 the American Physiological Society.)

Type 2 diabetes (T2D) is a metabolic disease affecting >370 million people worldwide. It is characterized by obesity-induced insulin resistance, and growing evidence has indicated that this causative link between obesity and insulin resistance is associated with visceral adipose tissue inflammation. However, using anti-inflammatory drugs to treat insulin resistance and T2D is not a common practice. We recently applied a bioinformatics methodology to open public data and found that CD44 plays a critical role in the development of adipose tissue inflammation and insulin resistance. In this report, we examined the role of CD44 in T2D by administering daily injections of anti-CD44 monoclonal antibody (mAb) in a high-fat-diet mouse model. Four weeks of therapy with CD44 mAb suppressed visceral adipose tissue inflammation compared with controls and reduced fasting blood glucose levels, weight gain, liver steatosis, and insulin resistance to levels comparable to or better than therapy with the drugs metformin and pioglitazone. These findings suggest that CD44 mAb may be useful as a prototype drug for therapy of T2D by breaking the links between obesity and insulin resistance., (© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

Insulin resistance results from several pathophysiologic mechanisms, including chronic tissue inflammation and defective insulin signaling. We found that liver, muscle and adipose tissue exhibit higher levels of the chemotactic eicosanoid LTB4 in obese high-fat diet (HFD)-fed mice. Inhibition of the LTB4 receptor Ltb4r1, through either genetic or pharmacologic loss of function, led to an anti-inflammatory phenotype with protection from insulin resistance and hepatic steatosis. In vitro treatment with LTB4 directly enhanced macrophage chemotaxis, stimulated inflammatory pathways, reduced insulin-stimulated glucose uptake in L6 myocytes, and impaired insulin-mediated suppression of hepatic glucose output in primary mouse hepatocytes. This was accompanied by lower insulin-stimulated Akt phosphorylation and higher Irs-1/2 serine phosphorylation, and all of these events were dependent on Gαi and Jnk1, two downstream mediators of Ltb4r1 signaling. These observations elucidate a novel role of the LTB4-Ltb4r1 signaling pathway in hepatocyte and myocyte insulin resistance, and they show that in vivo inhibition of Ltb4r1 leads to robust insulin-sensitizing effects.

Background & Aims: Innate immune activation has been postulated as a central mechanism for disease progression from hepatic steatosis to steatohepatitis in obesity-related fatty liver disease. Arginase 2 competes with inducible nitric oxide synthase (iNOS) for its substrate and the balance between these two enzymes plays a crucial role in regulating immune responses and macrophage activation. Our aim was to test the hypothesis that arginase 2 deficiency in mice favours progression from isolated hepatic steatosis, induced by high fat feeding, to steatohepatitis., Methods: Arginase 2-knockout (Arg2(-/-)) mice were studied for changes in liver histology and metabolic phenotype at baseline and after a short term course (7 week) feeding with a high fat (HFAT) diet. In additional experiments, Arg2(-/-) mice received tail vein injections of liposome-encapsulated clodronate (CLOD) over a three-week period to selectively deplete liver macrophages., Results: Unexpectedly, Arg2(-/-) mice showed profound changes in their livers at baseline, characterized by significant steatosis as demonstrated with histological and biochemical analysis. These changes were independent of systemic metabolic parameters and associated with marked mRNA level increases of genes involved in hepatic de novo lipogenesis. Liver injury and inflammation were present with elevated serum ALT, marked infiltration of F4/80 positive cells, and increased mRNA levels of inflammatory genes. HFAT feeding exacerbated these changes. Macrophage depletion after CLOD injection significantly attenuated lipid deposition and normalized lipogenic mRNA profile of livers from Arg2(-/-) mice., Conclusions: This study identifies arginase 2 as a novel link between innate immune responses, hepatic lipid deposition, and liver injury., (Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Aims. Local and systemic inflammation represent a major feature of atherosclerotic cardiovascular disease (CVD) and are also linked to nonalcoholic fatty liver disease (NAFLD). Studies indicate that NAFLD might be a risk factor for CVD whereas low-to-moderate alcohol consumption is associated with lower cardiovascular morbidity and mortality compared to abstainers and heavy drinkers. We hypothesize that FLD interacts with the effect of alcohol intake on markers of inflammation, and thus potentially on cardiovascular risk. Methods and Results. We evaluated alcohol consumption, markers of inflammation and sonographic criteria of FLD in 515 subjects, representing a subsample of a cross-sectional population based study (Echinococcus multilocularis and Internal Diseases in Leutkirch (EMIL) Study). Presence of FLD was markedly reduced in subjects drinking 0-20 g alcohol/d (19%), compared to nondrinkers (35%) and heavy drinkers (34-44.9%). Serum concentrations of inflammatory markers were substantially higher in subjects with FLD. However, presence of FLD showed no effect on the association between alcohol consumption and inflammatory biomarkers. Conclusions. Based on data from a population-based sample, there is no evidence for a link between FLD, alcohol consumption, and inflammatory cardiovascular risk markers. However, larger prospective studies are needed to confirm this.

Objective: Obesity has been demonstrated to be associated with elevated leukocytes in adults and children. This study assessed the associations between peripheral total and differential leukocyte counts and obesity-related complications in young adults., Methods: 12 obese (median age 21.5 (range 19-28) years, median BMI 35.7 (range 32.0-44.9) kg/m(2)) and 11 normal (median age 23 (range 18-27) years, median BMI 19.5 (range 18.1-21.7) kg/m(2)) adults were enrolled. Complete blood count and serum levels of liver enzymes, fasting blood glucose, insulin and lipids were measured, and the homeostasis model assessment of insulin resistance was calculated. Fat mass was calculated using a bioimpedance analysis device, and ultrasonography was performed to measure fat thickness and to detect fatty change of the liver., Results: Total leukocyte and monocyte counts were significantly increased in obese young adults. Total leukocyte count was associated with liver enzyme levels, insulin resistance as well as visceral and subcutaneous fat thickness. Neutrophil count was associated with insulin resistance. Lymphocyte count was associated with serum liver enzymes, insulin resistance, and dyslipidemia. Monocyte count was associated with serum liver enzyme, insulin resistance, visceral and subcutaneous fat thickness, body fat mass, and percentage body fat., Conclusion: The results of this study suggest that chronic low-grade systemic inflammation is associated with obesity-related complications such as nonalcoholic fatty liver disease, insulin resistance, and dyslipidemia in young adults., (© 2015 S. Karger GmbH, Freiburg.)

Prolonged ingestion of a cholesterol- or saturated fatty acid-enriched diet induces chronic, often systemic, auto-inflammatory responses resulting in significant health problems worldwide. In vivo information regarding the local and direct inflammatory effect of these dietary components in the intestine and, in particular, on the intestinal epithelium is lacking. Here we report that both mice and zebrafish exposed to high-fat (HFDs) or high-cholesterol (HCDs) diets develop acute innate inflammatory responses within hours, reflected in the localized interleukin-1β-dependent accumulation of myeloid cells in the intestine. Acute HCD-induced intestinal inflammation is dependent on cholesterol uptake via Niemann-Pick C1-like 1 and inflammasome activation involving apoptosis-associated Speck-like protein containing a caspase recruitment domain, which leads to Caspase-1 activity in intestinal epithelial cells. Extended exposure to HCD results in localized, inflammation-dependent, functional dysregulation as well as systemic pathologies. Our model suggests that dietary cholesterol initiates intestinal inflammation in epithelial cells.

Macrophage infiltration is a critical determinant of high-fat diet induced adipose tissue inflammation and insulin resistance. The precise mechanisms underpinning the initiation of macrophage recruitment and activation are unclear. Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine, displays chemokine-like properties. Circulating MIF levels are elevated during obesity however its role in high-fat diet induced adipose inflammation and insulin resistance remains elusive. Wildtype and MIF-/- C57Bl\6J mice were fed chow or high-fat diet. Body weight and food intake was assessed. Glucose homeostasis was monitored by glucose and insulin tolerance tests. Adipose tissue macrophage recruitment and adipose tissue insulin sensitivity was evaluated. Cytokine secretion from stromal vascular fraction, adipose explants and bone marrow macrophages was measured. Inflammatory signature and insulin sensitivity of 3T3-L1-adipocytes co-cultured with wildtype and MIF-/- macrophage was quantified. Hepatic triacylglyceride levels were assessed. MIF-/- exhibited reduced weight gain. Age and weight-matched obese MIF-/- mice exhibited improved glucose homeostasis coincident with reduced adipose tissue M1 macrophage infiltration. Obese MIF-/- stromal vascular fraction secreted less TNFα and greater IL-10 compared to wildtype. Activation of JNK was impaired in obese MIF-/-adipose, concomitant with pAKT expression. 3T3-L1-adipocytes cultured with MIF-/- macrophages had reduced pro-inflammatory cytokine secretion and improved insulin sensitivity, effects which were also attained with MIF inhibitor ISO-1. MIF-/- liver exhibited reduced hepatic triacyglyceride accumulation, enhanced pAKT expression and reduced NFκB activation. MIF deficiency partially protects from high-fat diet induced insulin resistance by attenuating macrophage infiltration, ameliorating adipose inflammation, which improved adipocyte insulin resistance ex vivo. MIF represents a potential therapeutic target for treatment of high-fat diet induced insulin resistance.

Hepatocellular carcinoma (HCC), the fastest rising cancer in the United States and increasing in Europe, often occurs with nonalcoholic steatohepatitis (NASH). Mechanisms underlying NASH and NASH-induced HCC are largely unknown. We developed a mouse model recapitulating key features of human metabolic syndrome, NASH, and HCC by long-term feeding of a choline-deficient high-fat diet. This induced activated intrahepatic CD8(+) T cells, NKT cells, and inflammatory cytokines, similar to NASH patients. CD8(+) T cells and NKT cells but not myeloid cells promote NASH and HCC through interactions with hepatocytes. NKT cells primarily cause steatosis via secreted LIGHT, while CD8(+) and NKT cells cooperatively induce liver damage. Hepatocellular LTβR and canonical NF-κB signaling facilitate NASH-to-HCC transition, demonstrating that distinct molecular mechanisms determine NASH and HCC development., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected for transplantation because of their increased rate of primary nonfunction (PNF). Lean livers have less I/R-induced damage and inflammation due to Kupffer cells (KC), which are protective after total, warm, hepatic I/R with associated bowel congestion. This protection has been linked to KC-dependent expression of the potent anti-inflammatory cytokine interleukin-10 (IL-10). We hypothesized that pretreatment with exogenous IL-10 would protect the steatotic livers of genetically obese (ob/ob) mice from inflammation and injury induced by I/R. Lean and ob/ob mice were pretreated with either IL-10 or liposomally-encapsulated bisphosphonate clodronate (shown to deplete KC) prior to total, warm, hepatic I/R. IL-10 pretreatment increased survival of ob/ob animals at 24 hrs post-I/R from 30% to 100%, and significantly decreased serum ALT levels. At six hrs post-I/R, IL-10 pretreatment increased IL-10 mRNA expression, but suppressed up-regulation of the pro-inflammatory cytokine IL-1β mRNA. However, ALT levels were elevated at six hrs post-I/R in KC-depleted animals. These data reveal that pretreatment with IL-10 protects steatotic livers undergoing I/R, and that phagocytically active KC retain a hepatoprotective role in the steatotic environment.

Approximately half of all adult burn patients are intoxicated at the time of their injury and have worse clinical outcomes than those without prior alcohol exposure. This study tested the hypothesis that intoxication alters the gut-liver axis, leading to increased pulmonary inflammation mediated by burn-induced IL-6 in the liver. C57BL/6 mice were given 1.2 g/kg ethanol 30 min prior to a 15% total body surface area burn. To restore gut barrier function, the specific myosin light chain kinase inhibitor membrane-permeant inhibitor of kinase (PIK), which we have demonstrated to reduce bacterial translocation from the gut, was administered 30 min after injury. Limiting bacterial translocation with PIK attenuated hepatic damage as measured by a 47% reduction in serum alanine aminotransferase (P < 0.05), as well as a 33% reduction in hepatic IL-6 mRNA expression (P < 0.05), compared with intoxicated and burn-injured mice without PIK. This mitigation of hepatic damage was associated with a 49% decline in pulmonary neutrophil infiltration (P < 0.05) and decreased alveolar wall thickening compared with matched controls. These results were reproduced by prophylactic reduction of the bacterial load in the intestines with oral antibiotics before intoxication and burn injury. Overall, these data suggest that the gut-liver axis is deranged when intoxication precedes burn injury and that limiting bacterial translocation in this setting attenuates hepatic damage and pulmonary inflammation., (Copyright © 2014 the American Physiological Society.)

Insulin resistance and risk of type 2 diabetes are the most important complications following exposure to organophosphorous (OPs) pesticides. Regarding the importance of liver on metabolic pathways regulation, in particular blood glucose homeostasis, we focused on liver inflammation and oxidative damages in a subchronic model of toxicity by malathion. Adult male Wistar rats of body weight 200-250g were used for the study. Malathion (200mg/kg b.w./day) was administered to rats by oral intubation for 28 days. Glycemic and insulin resistance indices, markers of liver injury, markers of inflammation and oxidative stress were assessed. Malathion-treated rats showed increased glycemia, insulinemia and glycated hemoglobin level, HOMA-IR and HOMA-β indices, plasma activities of hepatocellular enzymes, lipid peroxidation index, CD3(+)/CD4(+) and CD3(+)/CD4(+) and pro-inflammatory cytokines when decreased antioxidant status in liver was noted. Most of our study indicates that malathion promotes insulin resistance, inflammation and Hepatosteatosis in subchronic model of exposure. On the basis of biochemical and molecular findings, it is concluded that insulin resistance induced by malathion occurs through oxidative stress and related pro-inflammatory markers in a way to result in a reduced function of insulin in liver cells., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Scope: Increased fat consumption in industrialized countries has resulted in hepatic steatosis that upregulates atherogenic aspirant genes, leading to atherosclerosis and mortality. Although extensive studies have been carried out to elucidate the atheroprotective efficacy of epigallocatechin-3-gallate (EGCG), the effect of EGCG on hepatic steatosis has not been studied comprehensively. Hence, the current study was designed to find out the effect of EGCG on hepatic events that prelude atherosclerosis with special reference to macrophage infiltration., Methods and Results: Male albino rats of Wistar strain were used in this study. Basic biochemical assays along with the protein expression of CAMs, NF-κB, TNF-α and NF-AT were assayed in the current study. EGCG supplementation significantly reverted the alterations in both biochemical and histological parameters and is shown to reduce the TNF-α mediated NF-AT expression and thereby its downstream targets like ICAM-1 and E-selectin expression to a greater extent than NF-κB mediated downstream targets like VCAM-1 and P-selectin in hypercholesterolemic rat liver., Conclusion: Our results suggest that EGCG influences the early events of atherosclerosis that occur; thereby modulating the NF-AT pathway and thereby mitigating the hypercholesterolemic stress., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Unlabelled: Annexin A1 (AnxA1) is an effector of the resolution of inflammation and is highly effective in terminating acute inflammatory responses. However, its role in chronic settings is less investigated. Because changes in AnxA1 expression within adipose tissue characterize obesity in mice and humans, we queried a possible role for AnxA1 in the pathogenesis of nonalcoholic steatohepatitis (NASH), a disease commonly associated with obesity. NASH was induced in wild-type (WT) and AnxA1 knockout (AnxA1 KO) C57BL/6 mice by feeding a methionine-choline deficient (MCD) diet up to 8 weeks. In MCD-fed WT mice, hepatic AnxA1 increased in parallel with progression of liver injury. This mediator was also detected in liver biopsies from patients with NASH and its degree of expression inversely correlated with the extent of fibrosis. In both humans and rodents, AnxA1 production was selectively localized in liver macrophages. NASH in AnxA1 KO mice was characterized by enhanced lobular inflammation resulting from increased macrophage recruitment and exacerbation of the M1 phenotype. Consistently, in vitro addition of recombinant AnxA1 to macrophages isolated from NASH livers down-modulated M1 polarization through stimulation of interleukin-10 production. Furthermore, the degree of hepatic fibrosis was enhanced in MCD-fed AnxA1 KO mice, an effect associated with augmented liver production of the profibrotic lectin, galectin-3. Accordingly, AnxA1 addition to isolated hepatic macrophages reduced galectin-3 expression., Conclusions: Macrophage-derived AnxA1 plays a functional role in modulating hepatic inflammation and fibrogenesis during NASH progression, suggesting the possible use of AnxA1 analogs for therapeutic control of this disease., (© 2014 The Authors. Hepatology published by Wiley on behalf of the American Association for the Study of Liver Diseases.)

Background & Aims: HCV infection in haemodialysis (HD) patients is still a matter of investigation. The aim of this study was to determine the histology of chronic hepatitis C (CHC) in HCV-infected HD patients within the context of a comparative analysis including non-uraemic patients with CHC. The relative importance of virological, demographic and clinical parameters on disease manifestation was examined., Methods: Sixty-one consecutive liver biopsies from HD patients and 326 from non-uraemic patients with chronic HCV infection were comparatively evaluated., Results: Haemodialysis patients with CHC were older than control subjects (P = 0.031), showing a similar HCV genotype distribution (P = 0.328) and lower viral load (P = 0.001). CHC in HD patients was significantly milder according to stage (P = 0.033), grade and its parameters (periportal activity, portal inflammation and lobular activity) (P < 0.001). The frequency of lymphoid aggregates (10.2% vs. 50%, P < 0.001), bile duct lesions (1.7% vs. 22.1%, P < 0.001) and extent of steatosis (P = 0.022) in HD group was significantly reduced. Multivariate analysis showed that non-uraemic patients had 2.3 times higher risk of developing steatosis independently of genotype distribution and age. In HD group, genotype 3, longer HD duration and age at infection were significantly associated with steatosis, while older age at infection correlated with advanced fibrosis., Conclusions: Chronic hepatitis C in HD patients is usually very mild, losing its diagnostic histological features while patient's age and age at infection retain their prognostic significance. The weak inflammatory response, probably because of immunocompromised status and low viral load, may present a beneficial factor in the natural course of the disease., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Unlabelled: Obesity and adiponectin depletion have been associated with the occurrence of nonalcoholic fatty liver disease (NAFLD). The goal of this study was to identify the relationship between weight gain, adiponectin signaling, and development of nonalcoholic steatohepatitis (NASH) in an obese, diabetic mouse model. Leptin-receptor deficient (Lepr(db/db) ) and C57BL/6 mice were administered a diet high in unsaturated fat (HF) (61%) or normal chow for 5 or 10 weeks. Liver histology was evaluated using steatosis, inflammation, and ballooning scores. Serum, adipose tissue, and liver were analyzed for changes in metabolic parameters, messenger RNA (mRNA), and protein levels. Lepr(db/db) HF mice developed marked obesity, hepatic steatosis, and more than 50% progressed to NASH at each timepoint. Serum adiponectin level demonstrated a strong inverse relationship with body mass (r = -0.82; P < 0.0001) and adiponectin level was an independent predictor of NASH (13.6 μg/mL; P < 0.05; area under the receiver operating curve (AUROC) = 0.84). White adipose tissue of NASH mice was characterized by increased expression of genes linked to oxidative stress, macrophage infiltration, reduced adiponectin, and impaired lipid metabolism. HF lepr (db/db) NASH mice exhibited diminished hepatic adiponectin signaling evidenced by reduced levels of adiponectin receptor-2, inactivation of adenosine monophosphate activated protein kinase (AMPK), and decreased expression of genes involved in mitochondrial biogenesis and β-oxidation (Cox4, Nrf1, Pgc1α, Pgc1β and Tfam). In contrast, recombinant adiponectin administration up-regulated the expression of mitochondrial genes in AML-12 hepatocytes, with or without lipid-loading., Conclusion: Lepr(db/db) mice fed a diet high in unsaturated fat develop weight gain and NASH through adiponectin depletion, which is associated with adipose tissue inflammation and hepatic mitochondrial dysfunction. We propose that this murine model of NASH may provide novel insights into the mechanism for development of human NASH., (© 2014 by the American Association for the Study of Liver Diseases.)

Chrysin (5,7-di-OH-flavone), a widely distributed natural flavonoid, has been well documented for involving in various biological activities, especially in regulation of peroxisome proliferator activated receptor γ (PPARγ) activity as a modest modulator. However, the exact molecular mechanism is still unrevealed. In the current study, for the first time, we discovered that, chrysin not only significantly attenuated inflammation in high-fat feeding mice, but also alleviated high fat diet-induced hepatic, muscular steatosis in obese mice without altering the body weight. Chrysin decreases the infiltration of macrophages into adipose tissue in obese mice. In addition, chrysin was also found to induce an anti-inflammatory M2 phenotype and decreases M1 phenotype, both in peritoneal macrophages of obese mice and cultured macrophages in vitro, and thereby, chrysin changed the M1/M2 status. Our data further showed that chrysin regulated the phenotype of macrophages through enhancing the transcriptional activation of PPARγ and the expression of its target genes. Taken together, we conclude that chrysin may serve as an effective modulator of PPARγ during the pathogenesis of inflammation, thereby our findings shed light on the potential therapeutic feature of chrysin in recovering inflammatory diseases via regulating M1/M2 status., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Isoniazid (INH) treatment can cause serious liver injury and autoimmunity. There are now several lines of evidence that INH-induced liver injury is immune mediated, but this type of liver injury has not been reproduced in animals, possibly because immune tolerance is the dominant response of the liver. In this study, we immunized mice with isonicotinic acid (INA)-modified proteins and Freund's adjuvant, which led to mild experimental autoimmune hepatitis (EAH) with an increase in cells staining positive for F4/80, CD11b, CD8, CD4, CD45R, and KI67. We expected that subsequent treatment of mice with oral INH would lead to more serious immune-mediated liver injury, but paradoxically it markedly attenuated the EAH caused by immunization with INA-modified hepatic proteins. In addition, patients of the slow acetylator phenotype are at increased risk of INH-induced liver injury. Treatment of arylamine N-acetyltransferase-deficient Nat1/2(-/-) mice with INH for up to 5 weeks produced mild increases in glutamate and sorbitol dehydrogenase activities, but not severe liver injury. Female Nat1/2(-/-) mice treated with INH for 1, 3, or 7 days developed steatosis, an increase in Oil Red O staining, and abnormal mitochondrial morphology in the liver. A decrease in M1 and an increase in M2a and M2b macrophages was observed in female Nat1/2(-/-) mice treated with INH for 1, 3, or 7 days; these changes returned to baseline levels by day 35. These data indicate that INH has immunosuppressive effects, even though it is also known to induce autoantibody production and a lupus-like autoimmune syndrome in humans.

A prerequisite for establishment of mutualism between the host and the microbial community that inhabits the large intestine is the stringent mucosal compartmentalization of microorganisms. Microbe-loaded dendritic cells trafficking through lymphatics are arrested at the mesenteric lymph nodes, which constitute the firewall of the intestinal lymphatic circulation. We show in different mouse models that the liver, which receives the intestinal venous blood circulation, forms a vascular firewall that captures gut commensal bacteria entering the bloodstream during intestinal pathology. Phagocytic Kupffer cells in the liver of mice clear commensals from the systemic vasculature independently of the spleen through the liver's own arterial supply. Damage to the liver firewall in mice impairs functional clearance of commensals from blood, despite heightened innate immunity, resulting in spontaneous priming of nonmucosal immune responses through increased systemic exposure to gut commensals. Systemic immune responses consistent with increased extraintestinal commensal exposure were found in humans with liver disease (nonalcoholic steatohepatitis). The liver may act as a functional vascular firewall that clears commensals that have penetrated either intestinal or systemic vascular circuits., (Copyright © 2014, American Association for the Advancement of Science.)

Primary liver cancer has several well-recognized risk factors, such as HBV and HCV infection, alcohol abuse and aflatoxin. Recent studies show that nonalcoholic fatty liver disease (NAFLD), especially its aggressive form nonalcoholic steatohepatitis (NASH) is associated with an increased risk of liver cancer, mainly hepatocellular carcinoma (HCC). On the other hand, clinical and epidemiological data have showed that HCC has rarely been found in a "pure" fatty liver in human. Thus, the question we need to ask is do we have sufficient evidence to support a causative role of NAFLD in liver cancer? Furthermore, if NAFLD is indeed a causative factor for liver cancer, what is the mechanism? Perhaps at this stage, fatty liver and NASH can be regarded as a definite risk factor for liver cancer, but to conclude that NAFLD induces HCC requires more robust in vitro and in vivo data., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. Hepatocellular carcinoma (HCC) accounts for around 90% of primary liver cancers. Chronic infection with hepatitis B and hepatitis C viruses are two of most common causes of liver cancer. However, there are non-viral factors that are associated with liver cancer development. Numerous population studies have revealed strong links between obesity and the development of liver cancer. Obesity can alter hepatic pathology, metabolism and promote inflammation, leading to nonalcoholic fatty liver disease (NAFLD) and the progression to the more severe form, non-alcoholic steatohepatitis (NASH). NASH is characterised by prominent steatosis and inflammation, and can lead to HCC. Here, we discuss the role of obesity in inflammation and the principal signalling mechanisms involved in HCC formation., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The mechanisms that regulate disease progression during hepatitis C virus (HCV) infection and the response to treatment are not clearly identified. Numerous studies have demonstrated that a strong host immune response against HCV favors HCV clearance. In addition, genetic factors and metabolic machinery, particularly cholesterol modulation, are involved in HCV infection. It is likely that the interplay between all of these factors contributes to the outcome of HCV infection. In recent years, the world has experienced its largest epidemic of obesity. Mexico and the United States are the leading sufferers from this epidemic at the global level. Obesity is associated with the development of numerous pathologies including hypercholesterolemia which is one of the eight most important risk factors for mortality in Mexico. This may be related to the course of HCV infection in this population. Here, we focus on the urgent need to study the progression of HCV infection in relation to ethnic characteristics. Discoveries are discussed that hold promise in identifying immune, metabolic and genetic factors that, in conjunction, could be therapeutic targets or predictors of the progression of HCV infection.

The present study was undertaken to evaluate the hepatoprotective effect mechanisms of Nelumbo nucifera leaves extract (NLE) in experimental alcoholic steatohepatitis animal models. We found that the NLE contained polyphenols (phenolic acids and flavonoids), and more than 70% of the main functional components in NLE could potentially provide benefits for alcoholic liver disease. The parameters of histopathology, immunohistochemistry, antioxidant defense, proinflammatory mediator and lipid synthesis-related proteins demonstrated the inhibitory effect of NLE on alcoholic steatohepatitis. Plasma and hepatic content analysis showed that NLE inhibited lipid accumulation by altering the levels of triglycerides (TG) and cholesterol (TC). Treatment with NLE increased the expression of the p-AMPK/AMPK ratio and PPAR-α. Furthermore, fatty acid oxidation and transport via carnitine palmitoyltransferase-1 (CPT1) and microsomal triglyceride transfer protein (MTP) were through the activation of the AMPK and PPAR-α signal. These results revealed that the polyphenol-rich component of NLE prevents alcoholic steatohepatitis by multiple pathways, including reduced lipid synthesis, enhanced fatty acid oxidation and transport responses, inhibited oxidative stress and facilitated anti-inflammation. Suggesting that NLE might be regarded as a beneficial food that has the potential to be developed as a natural agent for preventing alcoholic steatohepatitis.