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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.)

Non-alcoholic steatohepatitis (NASH) is the progressive phenotype of non-alcoholic fatty liver disease associated with the metabolic syndrome. The existence of autoimmune features in NASH has been reported, but its significance remains unclear. We herein report the autoantibody profile of 54 patients with histologically proven NASH and further determined the development of autoimmunity in three different murine NASH models (monosodium glutamate, CDAA (choline-deficient L-amino acid-defined), and TSOD (Tsumura Suzuki, Obese Diabetes)) at 48 weeks of age. Forty-eight percent (26/54) of NASH cases were positive for antinuclear (ANA) or antimitochondrial antibody and manifested histological signs of overlap with autoimmune hepatitis and primary biliary cirrhosis, respectively. These patients were significantly older (60 ± 10 versus 50 ± 16 years), more frequently women (81 % versus 43 %), and with more severe portal inflammatory infiltrate compared with patients without autoimmunity. In one third of mice, regardless of the model, we observed a marked lymphoid infiltrate with non-suppurative cholangitis, and several cases were ANA-positive, but none AMA-positive. Our data suggest that autoimmunity may share some pathogenetic traits with the chronic inflammation of NASH, possibly related to advanced age.

Background: Visfatin is a proinflammatory and insulin-mimetic adipokine contributing to whole body glucose and lipid metabolism. Studies to date are conflicting regarding the relationship between visfatin and non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to evaluate the relationship of circulating visfatin with NAFLD., Material and Methods: The study included 114 NAFLD patients and 60 healthy non-diabetic controls. Plasma visfatin, adiponectin, tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) levels were measured by ELISA. High sensitive C-reactive protein (hsCRP) levels were measured by immunoturbidimetric fixed rate method. Insulin sensitivity determined by homeostasis model assessment (HOMA-IR) index., Results: TNF-α, IL-6 and hsCRP levels were higher and, Adiponectin levels were lower in NAFLD group when compared to healthy controls (p < 0.001, for all). However, no difference was found regarding to visfatin levels between two groups. Different histologic subgroups of NAFLD had a significantly higher TNF-α, IL-6 and hsCRP, and lower adiponectin levels than those with controls (p < 0.001, for all). On the other hand, no statistically significant difference was found regarding to visfatin levels among different histologic groups. Visfatin was found to be negatively correlated with TNF-α (r = -0.236, p = 0.011) in NAFLD group. However, no association was found between visfatin and histological findings., Conclusion: Our findings show that plasma visfatin levels are not altered in the early stages of NAFLD. However, it is inversely associated with TNF-α. These findings suggest a role for visfatin in protection against liver injury in this widespread disease.

Inflammation is an integral part of non-alcoholic fatty liver disease (NAFLD), the most prevalent form of hepatic pathology found in the general population. In this context, recently we have examined the potential role of Glutaminyl Cyclases (QC and isoQC), and their inhibitors, in the maturation of chemokines, for example, monocyte chemoattractant protein 1 (MCP-1, CCL2), to generate their bioactive conformation. Catalysis by isoQC leads to the formation of an N-terminal pyroglutamate residue protecting CCL2 against degradation by aminopeptidases. This is of importance because truncated forms possess a reduced potential to attract immune cells. Since liver inflammation is characterized by the up-regulation of different chemokine pathways, and within this CCL2 is known to be a prominent example, we hypothesised that application of QC/isoQC inhibitors may alleviate liver inflammation by destabilizing CCL2. Therefore, we investigated the role of QC/isoQC inhibition, in comparison with the angiotensin receptor blocker Telmisartan, during development of pathology in a mouse model of non-alcoholic fatty liver disease. Application of a QC/isoQC inhibitor led to a significant reduction in circulating alanine aminotransferase and NAFLD activity score accompanied by an inhibitory effect on hepatocyte ballooning. Further analysis revealed a specific reduction of inflammation by decreasing the number of F4/80-positive macrophages, which is in agreement with the proposed CCL2-related mechanism of action of QC/isoQC inhibitors. Finally, QC/isoQC inhibitor application attenuated liver fibrosis as characterized by reduced collagen deposition in the liver parenchyma. Thus in conclusion, QC/isoQC inhibitors are a promising novel class of anti-non-alcoholic steatohepatitis drugs which have a comparable disease-modifying effect to that of Telmisartan, which is probably mediated via specific interference with a comparable monocyte/macrophage infiltration that occurs under inflammatory conditions., (© 2013 The Authors. International Journal of Experimental Pathology © 2013 International Journal of Experimental Pathology.)

Unlabelled: In nonalcoholic fatty liver disease, the pathogenesis of progression from simple steatosis to steatohepatitis has not been fully clarified. Many factors, including oxidative stress and hepatic immune regulation, contribute to the inflammation in steatosis. Because regulatory T cells (Tregs) are important components of immune regulation, we have now investigated their role in the pathogenesis of nonalcoholic steatohepatitis. Wild-type C57BL/6 mice were fed a high-fat (HF) diet to induce steatosis, and the hepatic lymphocyte population was analyzed by flow cytometry. HF-induced steatosis was associated with the depletion of hepatic Tregs and led to up-regulation of the inflammatory tumor necrosis factor-alpha signaling pathway. When challenged by exogenous lipopolysaccharide, the HF-fed mice developed liver inflammation. In contrast, the adoptive transfer of Tregs decreased inflammation in HF-fed mice. In comparison with effector T cells, Tregs had a lower expression of Bcl-2 and, therefore, increased susceptibility to oxidative stress-induced apoptosis. The treatment of mice with the antioxidant Mn(III)tetrakis(4-benzoic acid)porphyrin chloride reduced Treg apoptosis, increased the number of hepatic Tregs, and decreased hepatic inflammation in HF-fed mice., Conclusion: Our results indicate that increased oxidative stress in a fatty liver causes the apoptosis of Tregs, reduces the number of hepatic Tregs, and leads to a lowered suppression of inflammatory responses. This scenario is likely one of the pathogenetic mechanisms that facilitate the transformation of simple steatosis into steatohepatitis when a fatty liver is exposed to second or third hits.

Background and Aims: Endotoxin-responsive monocytes/macrophages (CD14-positive) are potential sources of profibrogenic factors. The aims of this study were to determine (1) whether hepatic CD14-positive cells are present in various forms of chronic liver disease, and (2) the relationship between CD14-positive cells, myofibroblasts, and fibrosis in these diseases., Methods: Liver specimens from control subjects (n = 12) and those with primary biliary cirrhosis (n = 18), chronic hepatitis C (n = 13), or nonalcoholic steatohepatitis (n = 13) were immunostained for CD14, CD68, and alpha-smooth muscle actin (SMA) and the number of cells expressing these antigens was determined. Fibrosis and inflammation were also assessed., Results: The total number of hepatic CD68-positive cells was similar in diseased and control livers. The number of CD14-positive cells was increased in advanced fibrosis in primary biliary cirrhosis and hepatitis C but not in nonalcoholic steatohepatitis. The number of CD14-positive cells was also increased in hepatitis C specimens with high inflammatory activity. CD14-positive cells were often associated with alpha-SMA-positive myofibroblasts in fibrous septa., Conclusions: The number of hepatic CD14-positive cells is increased in advanced fibrosis in subjects with primary biliary cirrhosis and hepatitis C but not in nonalcoholic steatohepatitis. In primary biliary cirrhosis and hepatitis C, CD14-positive macrophages are found in close proximity to fibrous septa and myofibroblasts. In hepatitis C, an increased number of CD14-positive cells are associated with high inflammatory activity.

Non-alcoholic steatohepatitis (NASH) is a common cause of cryptogenic cirrhosis in the Western world. In an animal model of NASH, leptin-deficient ob/ob mice present with alterations in number and function of hepatic NKT and peripheral CD4 lymphocytes. Oral immune regulation is a method to alter the immune response towards orally administered antigens. To determine the effect of oral immune regulation towards liver-extracted proteins on the metabolic disorders in ob/ob mice, ob/ob mice and their lean littermates were orally administered liver extracts from wild-type or ob/ob mice or bovine serum albumin for 1 month. The effect of treatment on hepatic fat content was measured by magnetic resonance imaging (MRI) and using a histological steatohepatitis grading scale. Glucose tolerance was measured by an oral glucose tolerance test (GTT). T lymphocyte subpopulations were assessed by flow cytometry analysis. Induction of immune regulation by oral presentation of liver-extracted proteins resulted in a significant 18% reduction of the hepatic fat content in ob/ob mice fed with either wild-type or ob/ob liver extracts for 1 month. The MRI signal intensity index in treated mice decreased to 0.48 and 0.51, respectively, compared with 0.62 in BSA-fed controls (p = 0.037 and p = 0.019, respectively), while the histological steatohepatitis score decreased in both treated groups to 2.0, compared with 2.4 in BSA-fed controls (p = 0.05). A significant improvement in GTT was noted in treated ob/ob mice. These changes were accompanied by a marked increase in the intrahepatic NKT lymphocyte population in mice fed with proteins extracted from both wild-type and ob/ob mice (46.96% and 56.72%, respectively, compared with 26.21% in BSA-fed controls; p < 0.05) and a significant elevation in serum IL-10 levels. Oral immune regulation towards liver extracted proteins in leptin-deficient mice resulted in a marked reduction in hepatic fat content and improved glucose tolerance. This effect was associated with a significant increase in the intrahepatic NKT lymphocyte population and serum IL-10 levels, suggesting a Th1 to Th2 immune shift. Immune regulation towards disease-associated antigens holds promise as a new mode of therapy for NASH., (Copyright 2005 Pathological Society of Great Britain and Ireland.)

Background & Aims: We explored the roles of nuclear factor-kappaB (NF-kappaB) and tumor necrosis factor (TNF) alpha (TNF-alpha) as mediators of inflammation in a nutritional model of steatohepatitis., Methods: Wild-type (wt), TNF null -/-, and TNF receptor (R)-1-/- mice were fed a methionine- and choline-deficient (MCD) diet for up to 5 weeks. Liver injury (serum alanine aminotransferase [ALT]), hepatic inflammation, triglycerides, and lipid peroxide levels were determined. Hepatic NF-kappaB activation and expression of TNF and intercellular adhesion molecule-1 (ICAM-1) were assayed., Results: Irrespective of genotype, MCD diet-fed mice developed hepatic lipid peroxidation and serum ALT elevation; at day 10, livers from wt, TNF-/-, and TNFR-1-/- mice showed equivalent steatohepatitis. NF-kappaB/DNA binding was enhanced in hepatic nuclear fractions from MCD diet-fed wt mice compared with dietary controls; there were corresponding increases of ICAM-1 and TNF messenger RNA (mRNA). Likewise, NF-kappaB activation and ICAM-1 expression were enhanced by MCD dietary feeding in TNF-/- and TNFR-1-/- mice compared with respective controls. To establish whether NF-kappaB is a primary mediator of inflammation in experimental steatohepatitis, we over-expressed a mutant, nondegradable IkappaB (mIkappaB), delivered by adenovirus in vivo. As expected, hepatic mIkappaB expression reduced NF-kappaB/DNA binding induced by MCD dietary feeding, with resultant abrogation of ICAM-1 and TNF synthesis. Such blockade of NF-kappaB transcriptional activation substantially protected against development of steatohepatitis, with significant reductions in liver injury and hepatic inflammation., Conclusions: In the MCD dietary model of steatohepatitis, NF-kappaB is activated early and is an important proinflammatory mediator of lesion development, but steatohepatitis occurs independently of TNF synthesis and TNFR-1 activation.

The authors investigated the presence of antifibrinogen antibodies (PFb) in the blood of patients with chronic liver diseases (n = 75) and in healthy persons (n = 24). PFb was determined by means of passive haemagglutination reaction of human group 0, Rh minus blood cells enveloped by fibrinogen cleared chromatographically. PFb were directed against fragments D of fibrinogen (immunoblotting method). In hepatocirrhosis PFb appeared in 52% of cases, in chronic hepatitis--in 40.6%, in simple fatty degeneration of the liver--in 33.3%, and in control group only in one person (4.2%). Average concentration of PFb increased as hepatic damage increased. No correlation was found between the presence of PFb and the concentration of fibrinogen and fibrinolytic activity of the plasma. PFb were found significantly more common and in higher concentrations in patients with positive test results of EGT, SDPS and SCT, which indicates to a connection between a latent syndrome of intravascular clotting and the presence of PFb in liver diseases. The results of the examination confirm a hypothesis about the importance of antigenic neodeterminants revealing as a result of proteolytic fibrinogen degradation (fragments D) in inducing PFb.

Studies were undertaken to evaluate the cytotoxicity of peripheral lymphocytes obtained from patients with alcoholic hepatitis. Lymphocyte cytotoxicity to Chang liver cells was investigated by a microcytotoxicity test, and that to autologous liver cells obtained by percutaneous liver biopsy was studied using a 51Cr release assay. Lymphocytes from patients with alcoholic hepatitis were found to be highly cytotoxic to Chang liver cells and autologous liver cells when compared to those of healthy subjects (P is less than 0.001). Cell-free supernatant fluid of lymphocytes from patients with alcoholic hepatitis incubated with purified alcoholic hyalin for 5 days was significantly cytotoxic to Chang liver cells (P is less than 0.01), indicating that a cytotoxic factor is elaborated by sensitized lymphocytes. A significant reduction in cytotoxicity was noted with disappearance of clinical features or direct addition of a purified isolate of alcoholic hyalin or its preincubation with lymphocytes. Preincubation of sensitized lymphocytes with acetaldehyde increased cytotoxicity for autologous liver beyond that obtained by the combined effects of lymphocytes alone and acetaldehyde alone (P is less than 0.001), interpreted as evidence that ethanol toxicity and hyperactivity of lymphocytes independently and collectively contribute to development of cirrhosis in patients with alcoholic hepatitis who continue to imbibe alcohol.