Understanding the control of viral infections is of broad importance. Chronic hepatitis C virus (HCV) infection causes decreased expression of the iron hormone hepcidin, which is regulated by hepatic bone morphogenetic protein (BMP)/SMAD signalling. We found that HCV infection and the BMP/SMAD pathway are mutually antagonistic. HCV blunted induction of hepcidin expression by BMP6, probably via tumour necrosis factor (TNF)-mediated downregulation of the BMP co-receptor haemojuvelin. In HCV-infected patients, disruption of the BMP6/hepcidin axis and genetic variation associated with the BMP/SMAD pathway predicted the outcome of infection, suggesting that BMP/SMAD activity influences antiviral immunity. Correspondingly, BMP6 regulated a gene repertoire reminiscent of type I interferon (IFN) signalling, including upregulating interferon regulatory factors (IRFs) and downregulating an inhibitor of IFN signalling, USP18. Moreover, in BMP-stimulated cells, SMAD1 occupied loci across the genome, similar to those bound by IRF1 in IFN-stimulated cells. Functionally, BMP6 enhanced the transcriptional and antiviral response to IFN, but BMP6 and related activin proteins also potently blocked HCV replication independently of IFN. Furthermore, BMP6 and activin A suppressed growth of HBV in cell culture, and activin A inhibited Zika virus replication alone and in combination with IFN. The data establish an unappreciated important role for BMPs and activins in cellular antiviral immunity, which acts independently of, and modulates, IFN.
Background: The improvement of liver fibrosis assessed using transient elastography (TE) by FibroScan® is leading to new insights in the concepts of fibrosis regression. The possibility of using new direct antiviral agents (DAA) in cirrhotic patients, previous excluded from PegInterferon treatment for risk of hepatic failure, has permitted to verify the hypothesis of fibrosis regression in these patients. TE should be interpreted taking into account the inflammatory profile associated with hepatitis.
Objective. Screening for HBV among groups at risk, such as migrant populations, has proved to be a cost-effective strategy. With a view to advising local policy-makers, the cost-consequences of HBV screening was assessed using a modeling approach.Methods. This cost-consequence analysis of an HBV screening strategy was conducted in a cohort of adult migrants in the province of Padua, northern Italy.Results. The population targeted for screening consisted of 65 405 migrants, among whom the weighted rate for the prevalence of HBV was 0.04972, with 3251 people infected. Over a period of 5 years, the screening strategy prevented 565 cases/year of chronic hepatitis, 141 of compensated cirrhosis, 9 of decompensated cirrhosis, 14 hepatocellular carcinomas and 12 deaths. The above data revealed that the incremental cost of the screening strategy compared to no screening strategy was (sic)7 974 959 over the five year period. The cost per life saved amounted to (sic)676 709.Conclusions. The present study provides useful information to policy-makers at local and regional levels.
Transforming growth factor (TGF)-β-activated kinase 1 (TAK1) signaling can mediate inflammatory responses as well as tissue remodeling. Intestinal mucosal myofibroblast (IMF) activation drives gut fibrosis in Crohn's disease (CD); however, the molecular pathways involved are largely unknown. Thus we investigated the yet-unknown expression and function of TAK1 in human CD-associated fibrosis. Ileal surgical specimens, ileal biopsies, and IMF isolated from controls and CD patients were analyzed for TAK1 and its active phosphorylated form (pTAK1) by Western blotting, immunohistochemistry, and real-time quantitative PCR. TAK1 pharmacological inhibition and silencing were used to assess its role in collagen and inflammatory cytokine synthesis in IMF. TAK1 and pTAK1 levels increased in ileum specimens from CD patients compared with controls and correlated to tissue fibrosis. Similarly, TAK1 mRNA in ileal biopsies of CD patients correlated with fibrogenic marker expression but not inflammatory cytokines. CD-derived IMF showed higher TAK1 and pTAK1 expression associated with increased collagen1(α)1 mRNA levels compared with control IMF. TGF-β1 promoted pTAK1 nuclear translocation and collagen synthesis. TAK1 inhibition or silencing significantly reduced TGF-β1-stimulated collagen production and normalized the profibrogenic phenotype of CD-derived IMF. Taken together, these data suggest that TAK1 activation and nuclear translocation induce and maintain a fibrogenic phenotype in the IMF. Thus the TAK1 signaling pathway may represent a suitable target to design new, antifibrotic therapies.
Introduction: The epidemiology of hepatitis B in Europe is changing, with migration causing significant increases in prevalence rates. It is of paramount importance to identify the most effective ways to contain the disease. Systematic screening and treatment of migrants for CHB virus infection is likely to be cost-effective, but it is crucial to take into account the significant associated costs and the considerable net investment by governments.
Introduction: Hepatitis viruses screening is a secondary prevention strategy to detect earlier liver diseases and begin precociously antiviral treatment to prevent liver disease progression. Worldwide HCV prevalence is generally low and only in few countries is higher than 3.5%. Immigrants in Italy come predominantly from Eastern Europe, Asia and Africa. In all these areas HCV prevalence is lower than HBV.
BACKGROUND & AIMS In the intestines, Toll-like receptor 2 (TLR2) mediates immune responses to pathogens and regulates epithelial barrier function; polymorphisms in TLR2 have been associated with inflammatory bowel disease phenotype. We assessed the effects of TLR2 signaling on the enteric nervous system (ENS) in mice. METHODS TLR2 distribution and function in the ileal neuromuscular layer of mice were determined by immunofluorescence, cytofluorimetric analysis, immunoprecipitation, and immunoblot analyses. We assessed morphology and function of the ENS in Tlr2(-/-) mice and in mice with wild-type Tlr2 (wild-type mice) depleted of intestinal microbiota, using immunofluorescence, immunoblot, and gastrointestinal motility assays. Levels and signaling of glial cell line-derived neurotrophic factor (GDNF) were determined using quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, and immunoprecipitation analyses. Colitis was induced by administration of dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid to Tlr2(-/-) mice after termination of GDNF administration. RESULTS TLR2 was expressed in enteric neurons, glia, and smooth muscle cells of the intestinal wall. Tlr2(-/-) mice had alterations in ENS architecture and neurochemical profile, intestinal dysmotility, abnormal mucosal secretion, reduced levels of GDNF in smooth muscle cells, and impaired signaling via Ret-GFRα1. ENS structural and functional anomalies were completely corrected by administration of GDNF to Tlr2(-/-) mice. Wild-type mice depleted of intestinal microbiota had ENS defects and GDNF deficiency, similar to Tlr2(-/-) mice; these defects were partially restored by administration of a TLR2 agonist. Tlr2(-/-) mice developed more severe colitis than wild-type mice after administration of dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid; colitis was not more severe if Tlr2(-/-) mice were given GDNF before dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid. CONCLUSIONS In mice, TLR2 signaling regulates intestinal inflammation by controlling ENS structure and neurochemical coding, along with intestinal neuromuscular function. These findings provide information as to how defective TLR2 signaling in the ENS affects inflammatory bowel disease phenotype in humans.
Cingulin (CGN) is a 140 kDa protein, which is localized to the cytoplasmic region of vertebrate tight junctions (TJ), and regulates gene expression and RhoA signaling in cultured cells. To investigate the function of CGN at the organism level, we generated CGN knockout (CGN(-/-)) mice by homologous recombination. CGN(-/-) mice are viable and fertile, and are born at the expected mendelian ratios. Immunohistochemistry, immunofluorescence, electron microscopy and permeability assays of epithelial tissues of CGN(-/-) mice show no cingulin labeling at junctions, a normal localization of TJ proteins, and normal TJ structure and barrier function. Microarray analysis of intestinal cells does not show significant changes in gene expression between CGN(-/-) and CGN(+/+) mice, whereas immunoblotting analysis shows a twofold increase in the levels of claudin-2 protein in the duodenum and the kidney of CGN(-/-) mice, compared to CGN(+/+) littermates. Furthermore, CGN(-/-) mice show an exacerbated response to the ulcerogenic action of cysteamine, whereas acute injury of the colon by dextran sodium sulfate elicits undistinguishable responses in CGN(-/-) and CGN(+/+) mice. We conclude that at the organism level cingulin is dispensable for the structure and barrier function of TJ, and is embedded in signaling networks that control the expression of claudin-2, and the mucosal response to acute injury in the duodenum.
Background: Coffee is associated with a reduced risk of hepatocellular carcinoma in patients with chronic C hepatitis. This prospective trial was aimed at assessing the mechanisms underlying coffee-related protective effects.Methods: Forty patients with chronic hepatitis C were randomized into two groups: the first consumed 4 cups of coffee/day for 30 days, while the second remained coffee "abstinent". At day 30, the groups were switched over for a second month.Results: At baseline, aspartate aminotransferase and alanine aminotransferase were lower in patients drinking 3-5 (Group B) than 0-2 cups/day (Group A) (56 +/- 6 vs 74 +/- 11/60 +/- 3 vs 73 +/- 7 U/L p = 0.05/p = 0.04, respectively). HCV-RNA levels were significantly higher in Group B [(6.2 +/- 1.5) x 10(5) vs (3.9 +/- 1.0) x 10(5) UI/mL, p = 0.05]. During coffee intake, 8-hydroxydeoxyguanosine and collagen levels were significantly lower than during abstinence (15 +/- 3 vs 44 +/- 16 8-hydroxydeoxyguanosine/10(5) deoxyguanosine, p = 0.05 and 56 + 9 vs 86 + 21 ng/mL, p = 0.04). Telomere length was significantly higher in patients during coffee intake (0.68 +/- 0.06 vs 0.48 +/- 0.04 Arbitrary Units, p = 0.006). Telomere length and 8-hydroxydeoxyguanosine were inversely correlated.Conclusion: In chronic hepatitis C coffee consumption induces a reduction in oxidative damage, correlated with increased telomere length and apoptosis, with lower collagen synthesis, factors that probably mediate the protection exerted by coffee with respect to disease progression. (c) 2012 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.
Following liver injury, the wound-healing process is characterized by hepatic stellate cell (HSC) activation from the quiescent fat-storing phenotype to a highly proliferative myofibroblast-like phenotype. Snail1 is a transcription factor best known for its ability to trigger epithelial-mesenchymal transition, to influence mesoderm formation during embryonic development, and to favor cell survival. In this study, we evaluated the expression of Snail1 in experimental and human liver fibrosis and analyzed its role in the HSC transdifferentiation process. Liver samples from patients with liver fibrosis and from mice treated by either carbon tetrachloride (CCl 4 ) or thioacetamide (TAA) were evaluated for mRNA expression of Snail1. The transcription factor expression was investigated by immunostaining and real-time quantitative RT-PCR (qRT-PCR) on in vitro and in vivo activated murine HSC. Snail1 knockdown studies on cultured HSC and on CCl 4 -treated mice were performed by adenoviral delivery of short-hairpin RNA; activation-related genes were quantitated by real-time qRT-PCR and Western blotting. Snail1 mRNA expression resulted upregulated in murine experimental models of liver injury and in human hepatic fibrosis. In vitro studies showed that Snail1 is expressed by HSC and that its transcription is augmented in in vitro and in vivo activated HSC compared with quiescent HSC. At the protein level, we could observe the nuclear translocation of Snail1 in activated HSC. Snail1 knockdown resulted in the downregulation of activation-related genes both in vitro and in vivo. Our data support a role for Snail1 transcription factor in the hepatic wound-healing response and its involvement in the HSC transdifferentiation process.
s of the A.I.S.F. Annual Meeting 2010 /Digestive and Liver Disease 43S (2011), S65–S108 S81 diographic epicardial fat measurement could represent an easy diagnostic tool to define visceral and cardiac adiposity and could be proposed to better predict the cardiovascular risk.
independent groups of patients.Mir-224_1 has been described upregulated in hepato-cellular carcinomas.Moreover, deregulation of miR-217 has been reported in pancreatic cancers.Mir-23a inhibits both the development of B cells and the production of IL-6.Interestingly, in our study mir-122 is slightly up-regulated in NRs compared to SVRs.The levels of expression of miRNAs involved in tumoral processes were higher in the liver of NRs than in SVRs and RRs.Conclusion: NRs and SVRs present different miRNAs hepatic expression, before treatment.In particular, mir-99a, mir-181a-2*, mir-23a and mir-217 were significantly deregulated in NRs compared to SVRs.Thus, treatment response could be predicted with a molecular miRNAs signature.
Pegylated interferon (PEG-IFN) and ribavirin is the most effective treatment for chronic hepatitis C virus (HCV) hepatitis, but the rate of sustained virological response (SVR) remains approximately 50%, and 15–20% of all treated patients have a virological relapse after completing the treatment. Studies on the SVR have failed to discriminate between non-responders and relapsers.