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Metabolic dysfunction-associated steatotic liver disease (MASLD) is common worldwide. Genes and proteins contributing to drug disposition may show altered expression as MASLD progresses. To assess this further, we undertook transcriptomic and proteomic analysis of 137 pharmacogenes in liver biopsies from a large MASLD cohort. We performed sequencing on RNA from 216 liver biopsies (206 MASLD and 10 controls). Untargeted mass spectrometry proteomics was performed on a 103 biopsy subgroup. Selected RNA sequencing signals were replicated with an additional 187 biopsies. Comparison of advanced MASLD (fibrosis score 3/4) with milder disease (fibrosis score 0-2) by RNA sequencing showed significant alterations in expression of certain phase I, phase II and ABC transporters. For cytochromes P450, CYP2C19 showed the most significant decreased expression (30 % of that in mild disease) but significant decreased expression of other CYPs (including CYP2C8 and CYP2E1) also occurred. CYP2C19 also showed a significant decrease comparing the inflammatory form of MASLD (MASH) with non-MASH biopsies. Findings for CYP2C19 were confirmed in the replication cohort. Proteomics on the original discovery cohort confirmed decreased levels of several CYPs as MASLD advanced but this decrease was greatest for CYP2C19 where levels fell to 40 % control. This decrease may result in decreased CYP2C19 activity that could be problematic for prescription of drugs activated or metabolized by CYP2C19 as MASLD advances. More limited decreases for other P450s suggest fewer issues with non-CYP2C19 drug substrates. Negative correlations at RNA level between CYP2C19 and several cytokine genes provided initial insights into the mechanism underlying decreased expression., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ann Daly and Quentin Anstee reports financial support was provided by European Union. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, encompasses steatosis and metabolic dysfunction-associated steatohepatitis (MASH), leading to cirrhosis and hepatocellular carcinoma. Preclinical MASLD research is mainly performed in rodents; however, the model that best recapitulates human disease is yet to be defined. We conducted a wide-ranging retrospective review (metabolic phenotype, liver histopathology, transcriptome benchmarked against humans) of murine models (mostly male) and ranked them using an unbiased MASLD 'human proximity score' to define their metabolic relevance and ability to induce MASH-fibrosis. Here, we show that Western diets align closely with human MASH; high cholesterol content, extended study duration and/or genetic manipulation of disease-promoting pathways are required to intensify liver damage and accelerate significant (F2+) fibrosis development. Choline-deficient models rapidly induce MASH-fibrosis while showing relatively poor translatability. Our ranking of commonly used MASLD models, based on their proximity to human MASLD, helps with the selection of appropriate in vivo models to accelerate preclinical research., (© 2024. The Author(s).)

Objective: Hyperferritinaemia is associated with liver fibrosis severity in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), but the longitudinal implications have not been thoroughly investigated. We assessed the role of serum ferritin in predicting long-term outcomes or death., Design: We evaluated the relationship between baseline serum ferritin and longitudinal events in a multicentre cohort of 1342 patients. Four survival models considering ferritin with confounders or non-invasive scoring systems were applied with repeated five-fold cross-validation schema. Prediction performance was evaluated in terms of Harrell's C-index and its improvement by including ferritin as a covariate., Results: Median follow-up time was 96 months. Liver-related events occurred in 7.7%, hepatocellular carcinoma in 1.9%, cardiovascular events in 10.9%, extrahepatic cancers in 8.3% and all-cause mortality in 5.8%. Hyperferritinaemia was associated with a 50% increased risk of liver-related events and 27% of all-cause mortality. A stepwise increase in baseline ferritin thresholds was associated with a statistical increase in C-index, ranging between 0.02 (lasso-penalised Cox regression) and 0.03 (ridge-penalised Cox regression); the risk of developing liver-related events mainly increased from threshold 215.5 µg/L (median HR=1.71 and C-index=0.71) and the risk of overall mortality from threshold 272 µg/L (median HR=1.49 and C-index=0.70). The inclusion of serum ferritin thresholds (215.5 µg/L and 272 µg/L) in predictive models increased the performance of Fibrosis-4 and Non-Alcoholic Fatty Liver Disease Fibrosis Score in the longitudinal risk assessment of liver-related events (C-indices>0.71) and overall mortality (C-indices>0.65)., Conclusions: This study supports the potential use of serum ferritin values for predicting the long-term prognosis of patients with MASLD., Competing Interests: Competing interests: LM is supported by Investigator Driven Grants: Gilead, Intercept, Siemens Healthineers. Advisor/Consultancy: Alfa-Sigma, Boehringer-Ingelheim, BMS, Echosens, Galmed, Gilead Sciences, IBSA, Intercept, MEDA, MyGenomics, Merck Sharp & Dohme, Novartis, Pfizer, ProLon, Promethera, Resalis, Rottapharm-Madaus, Siemens Healthineers, Synageva. HH’s institutions have received research funding from Astra Zeneca, EchoSens, Gilead, Intercept, MSD, Novo Nordisk and Pfizer. He has served as consultant or on advisory boards for Astra Zeneca, Bristol Myers-Squibb, MSD and Novo Nordisk and has been part of hepatic events adjudication committees for Boehringer Ingelheim, KOWA and GW Pharma., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background & Aims: In non-alcoholic fatty liver disease (NAFLD), monocytes infiltrate visceral adipose tissue promoting local and hepatic inflammation. However, it remains unclear what drives inflammation and how the immune landscape in adipose tissue differs across the NAFLD severity spectrum. We aimed to assess adipose tissue macrophage (ATM) heterogeneity in a NAFLD cohort., Methods: Visceral adipose tissue macrophages from lean and obese patients, stratified by NAFLD phenotypes, underwent single-cell RNA sequencing. Adipose tissue vascular integrity and breaching was assessed on a protein level via immunohistochemistry and immunofluorescence to determine targets of interest., Results: We discovered multiple ATM populations, including resident vasculature-associated macrophages (ResVAMs) and distinct metabolically active macrophages (MMacs). Using trajectory analysis, we show that ResVAMs and MMacs are replenished by a common transitional macrophage (TransMac) subtype and that, during NASH, MMacs are not effectively replenished by TransMac precursors. We postulate an accessory role for MMacs and ResVAMs in protecting the adipose tissue vascular barrier, since they both interact with endothelial cells and localize around the vasculature. However, across the NAFLD severity spectrum, alterations occur in these subsets that parallel an adipose tissue vasculature breach characterized by albumin extravasation into the perivascular tissue., Conclusions: NAFLD-related macrophage dysfunction coincides with a loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver., Impact and Implications: Our study describes for the first time the myeloid cell landscape in human visceral adipose tissue at single-cell level within a cohort of well-characterized patients with non-alcoholic fatty liver disease. We report unique non-alcoholic steatohepatitis-specific transcriptional changes within metabolically active macrophages (MMacs) and resident vasculature-associated macrophages (ResVAMs) and we demonstrate their spatial location surrounding the vasculature. These dysfunctional transcriptional macrophage states coincided with the loss of adipose tissue vascular integrity, providing a plausible mechanism by which tissue inflammation is perpetuated in adipose tissue and downstream in the liver. Our study provides a theoretical basis for new therapeutic strategies to be directed towards reinstating the endogenous metabolic, homeostatic and cytoprotective functions of ResVAMs and MMacs, including their role in protecting vascular integrity., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background and Aims: A complete understanding of disease pathophysiology in advanced liver disease is hampered by the challenges posed by clinical specimen collection. Notably, in these patients, a transjugular liver biopsy (TJB) is the only safe way to obtain liver tissue. However, it remains unclear whether successful sequencing of this extremely small and fragile tissue can be achieved for downstream characterization of the hepatic landscape., Methods: Here we leveraged in-house available single-cell RNA-sequencing (scRNA-seq) and single-nucleus (snRNA-seq) technologies and accompanying tissue processing protocols and performed an in-patient comparison on TJB's from decompensated cirrhosis patients (n = 3)., Results: We confirmed a high concordance between nuclear and whole cell transcriptomes and captured 31,410 single nuclei and 6,152 single cells, respectively. The two platforms revealed similar diversity since all 8 major cell types could be identified, albeit with different cellular proportions thereof. Most importantly, hepatocytes were most abundant in snRNA-seq, while lymphocyte frequencies were elevated in scRNA-seq. We next focused our attention on hepatic myeloid cells due to their key role in injury and repair during chronic liver disease. Comparison of their transcriptional signatures indicated that these were largely overlapping between the two platforms. However, the scRNA-seq platform failed to recover sufficient Kupffer cell numbers, and other monocytes/macrophages featured elevated expression of stress-related parameters., Conclusion: Our results indicate that single-nucleus transcriptome sequencing provides an effective means to overcome complications associated with clinical specimen collection and could sufficiently profile all major hepatic cell types including all myeloid cell subsets., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Van Melkebeke, Verbeek, Bihary, Boesch, Boeckx, Feio-Azevedo, Smets, Wallays, Claus, Bonne, Maleux, Govaere, Korf, Lambrechts and van der Merwe.)

Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is a complex disease, resulting from the interplay between environmental determinants and genetic variations. Single nucleotide polymorphism rs738409 C>G in the PNPLA3 gene is associated with hepatic fibrosis and with higher risk of developing hepatocellular carcinoma. Here, we analyzed a longitudinal cohort of biopsy-proven NAFLD subjects with the aim to identify individuals in whom genetics may have a stronger impact on disease progression., Methods: We retrospectively analyzed 756 consecutive, prospectively enrolled biopsy-proven NAFLD subjects from Italy, United Kingdom, and Spain who were followed for a median of 84 months (interquartile range, 65-109 months). We stratified the study cohort according to sex, body mass index (BMI) 2 ) and age (

Background: NAFLD is associated with activation of fibroblasts and hepatic fibrosis. Substantial patient heterogeneity exists, so it remains challenging to risk-stratify patients. We hypothesized that the amount of fibroblast activity, as assessed by circulating biomarkers of collagen formation, can define a "high-risk, high-fibrogenesis" patient endotype that exhibits greater fibroblast activity and potentially more progressive disease, and this endotype may be more amendable to dietary intervention., Methods: Patients with clinically confirmed advanced NAFLD were prescribed a very low-calorie diet (VLCD) intervention (∼800 kcal/d) to induce weight loss, achieved using total diet replacement. Serum markers of type III (PRO-C3) and IV collagen (PRO-C4) fibrogenesis were assessed at baseline every second week until the end of the VLCD, and 4 weeks post-VLCD and at 9 months follow-up., Results: Twenty-six subjects had a mean weight loss of 9.7% with VLCD. This was associated with significant improvements in liver biochemistry. When stratified by baseline PRO-C3 and PRO-C4 into distinct fibrosis endotypes, these predicted substantial differences in collagen fibrogenesis marker dynamics in response to VLCD. Patients in the high activity group (PRO-C3 >11.4 ng/mL and/or PRO-C4 >236.5 ng/mL) exhibited a marked reduction of collagen fibrogenesis, ranging from a 40%-55% decrease in PRO-C3 and PRO-C4, while fibrogenesis remained unchanged in the low activity group. The biochemical response to weight loss was substantially greater in patients a priori exhibiting a high fibroblast activity endotype in contrast to patients with low activity., Conclusions: Thus, the likelihood of treatment response may be predicted at baseline by quantification of fibrogenesis biomarkers., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

Background & Aims: The progression of non-alcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC., Methods: C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH-inducing diets or standard chow for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and μMT mice (containing B cells only in the gastrointestinal tract) were fed a choline-deficient high-fat diet, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with simple steatosis, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and single-cell RNA-sequencing analysis were performed in liver and gastrointestinal tissue to characterise immune cells in mice and humans., Results: Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B cells; additionally, we observed a positive correlation between IgA levels and activated FcRg+ hepatic myeloid cells, as well the extent of liver fibrosis., Conclusions: Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for the treatment of NASH., Impact and Implications: There is currently no effective treatment for non-alcoholic steatohepatitis (NASH), which is associated with a substantial healthcare burden and is a growing risk factor for hepatocellular carcinoma (HCC). We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we show that the absence of B cells prevented HCC development. B cell-intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets for combinatorial NASH therapies against inflammation and fibrosis., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

It is currently not well known how necroptosis and necroptosis responses manifest in vivo. Here, we uncovered a molecular switch facilitating reprogramming between two alternative modes of necroptosis signaling in hepatocytes, fundamentally affecting immune responses and hepatocarcinogenesis. Concomitant necrosome and NF-κB activation in hepatocytes, which physiologically express low concentrations of receptor-interacting kinase 3 (RIPK3), did not lead to immediate cell death but forced them into a prolonged "sublethal" state with leaky membranes, functioning as secretory cells that released specific chemokines including CCL20 and MCP-1. This triggered hepatic cell proliferation as well as activation of procarcinogenic monocyte-derived macrophage cell clusters, contributing to hepatocarcinogenesis. In contrast, necrosome activation in hepatocytes with inactive NF-κB-signaling caused an accelerated execution of necroptosis, limiting alarmin release, and thereby preventing inflammation and hepatocarcinogenesis. Consistently, intratumoral NF-κB-necroptosis signatures were associated with poor prognosis in human hepatocarcinogenesis. Therefore, pharmacological reprogramming between these distinct forms of necroptosis may represent a promising strategy against hepatocellular carcinoma., Competing Interests: Declaration of interests A.L.S. and J.M.M. contribute to a project developing necroptosis inhibitors in collaboration with Anaxis Pharma., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Non-alcoholic fatty liver disease (NAFLD) is a common, progressive liver disease strongly associated with the metabolic syndrome. It is unclear how progression of NAFLD towards cirrhosis translates into systematic changes in circulating proteins. Here, we provide a detailed proteo-transcriptomic map of steatohepatitis and fibrosis during progressive NAFLD. In this multicentre proteomic study, we characterize 4,730 circulating proteins in 306 patients with histologically characterized NAFLD and integrate this with transcriptomic analysis in paired liver tissue. We identify circulating proteomic signatures for active steatohepatitis and advanced fibrosis, and correlate these with hepatic transcriptomics to develop a proteo-transcriptomic signature of 31 markers. Deconvolution of this signature by single-cell RNA sequencing reveals the hepatic cell types likely to contribute to proteomic changes with disease progression. As an exemplar of use as a non-invasive diagnostic, logistic regression establishes a composite model comprising four proteins (ADAMTSL2, AKR1B10, CFHR4 and TREM2), body mass index and type 2 diabetes mellitus status, to identify at-risk steatohepatitis., (© 2023. The Author(s).)

Background & Aims: Drug-induced liver injury (DILI) due to amoxicillin-clavulanate (AC) has been associated with HLA-A∗02:01, HLA-DRB1∗15:01, and rs2476601, a missense variant in PTPN22. The aim of this study was to identify novel risk factors for AC-DILI and to construct a genetic risk score (GRS)., Methods: Transcriptome-wide association study and genome-wide association study analyses were performed on 444 AC-DILI cases and 10,397 population-based controls of European descent. Associations were confirmed in a validation cohort (n = 133 cases and 17,836 population-based controls). Discovery and validation AC-DILI cases were also compared with 1358 and 403 non-AC-DILI cases., Results: Transcriptome-wide association study revealed a significant association of AC-DILI risk with reduced liver expression of ERAP2 (P = 3.7 × 10 -7 ), coding for an aminopeptidase involved in antigen presentation. The lead eQTL single nucleotide polymorphism, rs1363907 (G), was associated with AC-DILI risk in the discovery (odds ratio [OR], 1.68; 95% CI, 1.23-1.66; P = 1.7 × 10 -7 ) and validation cohorts (OR, 1.2; 95% CI, 1.04-2.05; P = .03), following a recessive model. We also identified HLA-B∗15:18 as a novel AC-DILI risk factor in both discovery (OR, 4.19; 95% CI, 2.09-8.36; P = 4.9 × 10 -5 ) and validation (OR, 7.78; 95% CI, 2.75-21.99; P = .0001) cohorts. GRS, incorporating rs1363907, rs2476601, HLA-B∗15:18, HLA-A∗02:01, and HLA-DRB1∗15:01, was highly predictive of AC-DILI risk when cases were analyzed against both general population and non-AC-DILI control cohorts. GRS was the most significant predictor in a regression model containing known AC-DILI clinical risk characteristics and significantly improved the predictive model., Conclusions: We identified novel associations of AC-DILI risk with ERAP2 low expression and with HLA-B∗15:18. GRS based on the 5 risk variants may assist AC-DILI causality assessment and risk management., (Copyright © 2023 AGA Institute. All rights reserved.)

Introduction: Normothermic machine perfusion (NMP) provides a platform for drug-delivery. However, pharmacological considerations for therapeutics delivered during NMP are scarcely reported. We aimed to demonstrate the ability of NMP as a platform for pharmacological testing, using a drug which increases metabolism (2,4-dinitrophenol; DNP) as an example therapeutic., Methods: We performed 25 h of NMP on human livers which had been declined for transplant due to steatosis (n = 7). Three livers received a DNP bolus, three were controls, and one received a DNP infusion., Results: Toxicity studies revealed DNP delivery was safe, without hepatotoxic effects. The liver surface temperature was increased in the DNP group (p = 0.046), but no livers suffered hyperthermia-the mechanism of DNP toxicity in vivo. Pharmacokinetic studies revealed DNP elimination with first-order kinetics and 7.7 h half-life (95% CI = 5.1-15.9 hrs). The clearance of DNP in bile was negligible. As expected, DNP significantly increased oxygen consumption (p = 0.023); this increase was closely correlated with perfusate DNP concentration (r 2  = 0.975; p = 0.002) and the effect was lost as DNP was eliminated by the liver. A DNP infusion rate, calculated using our pharmacokinetic data, successfully maintained perfusate DNP concentration., Discussion: Detailed pharmacological testing can be performed during NMP. Our therapeutic (DNP) is rapidly eliminated by the ex vivo liver, meaning the drug effect of increased metabolism is only transient. This demonstrates the importance of assessing pharmacokinetics when delivering therapeutics during NMP, especially for prolonged perfusion of organs with established roles in drug elimination. Rigorous pharmacological testing is needed to unlock the potential of NMP as a clinical drug-delivery platform., (© 2022 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent disease that is associated with multiple metabolic disturbances, yet the metabolic pathways underlying its progression are poorly understood. Here, we studied metabolic pathways of the human liver across the full histological spectrum of NAFLD. We analyzed whole liver tissue transcriptomics and serum metabolomics data obtained from a large, prospectively enrolled cohort of 206 histologically characterized patients derived from the European NAFLD Registry and developed genome-scale metabolic models (GEMs) of human hepatocytes at different stages of NAFLD. We identified several metabolic signatures in the liver and blood of these patients, specifically highlighting the alteration of vitamins (A, E) and glycosphingolipids, and their link with complex glycosaminoglycans in advanced fibrosis. Furthermore, we derived GEMs and identified metabolic signatures of three common NAFLD-associated gene variants (PNPLA3 , TM6SF2 , and HSD17B13) . The study demonstrates dysregulated liver metabolic pathways which may contribute to the progression of NAFLD., Competing Interests: J.M.S. declares Consultancy: Boehringer Ingelheim, BMS, Genfit, Gilead Sciences, Intercept Pharmaceuticals, Madrigal, Novartis, Novo Nordisk, Nordic Bioscience, Pfizer, Roche, Sanofi, Siemens Healthcare GmbH. Research Funding: Gilead Sciences, Boehringer Ingelheim. Speakers Bureau: Falk Foundation MSD Sharp & Dohme GmbH. M.A. reports consultancy/advisory with MedImmune/Astra Zeneca and E3Bio, as well as honoraria from Intercept and grant support from GSK and Takeda. E.B. reports advisory/consulting for BMS, Genfit SA, Gilead, Intercept, and Novartis. Q.M.A. reports grants, personal fees and other from Allergan/Tobira, other from E3Bio, other from Eli Lilly & Company Ltd, other from Galmed, grants, personal fees and other from Genfit SA, personal fees and other from Gilead, other from Grunthal, other from Imperial Innovations, grants and other from Intercept Pharma Europe Ltd, other from Inventiva, other from Janssen, personal fees from Kenes, other from MedImmune, other from NewGene, grants, personal fees and other from Pfizer Ltd, other from Raptor Pharma, grants and other from Novartis Pharma AG, grants from Abbvie, personal fees and other from BMS, grants from GSK, other from NGMBio, other from Madrigal, other from Servier, other from EcoR1, other from 89Bio, other from Altimmune, grants and other from AstraZeneca, other from Axcella, other from Blade, other from BNN Cardio, other from Celgene, other from Cirius, other from CymaBay, other from Genentech, other from HistoIndex, other from Indalo, other from IQVIA, other from Metacrine, other from North Sea Therapeutics, personal fees and other from Novo Nordisk, other from Poxel, other from Terns, other from Viking Therapeutics, grants from Glympse Bio, other from PathAI, outside the submitted work. All other authors declare that they have no competing interests., (© 2022 The Author(s).)

Introduction: Heparin sulphate proteoglycans in the liver tumour microenvironment (TME) are key regulators of cell signalling, modulated by sulfatase-2 (SULF2). SULF2 overexpression occurs in hepatocellular carcinoma (HCC). Our aims were to define the nature and impact of SULF2 in the HCC TME., Methods: In liver biopsies from 60 patients with HCC, expression and localization of SULF2 were analysed associated with clinical parameters and outcome. Functional and mechanistic impacts were assessed with immunohistochemistry (IHC), in silico using The Cancer Genome Atlas (TGCA), in primary isolated cancer activated fibroblasts, in monocultures, in 3D spheroids, and in an independent cohort of 20 patients referred for sorafenib. IHC targets included αSMA, glypican-3, β-catenin, RelA-P-ser536, CD4, CD8, CD66b, CD45, CD68, and CD163. SULF2 impact of peripheral blood mononuclear cells was assessed by migration assays, with characterization of immune cell phenotype using fluorescent activated cell sorting., Results: We report that while SULF2 was expressed in tumour cells in 15% (9/60) of cases, associated with advanced tumour stage and type 2 diabetes, SULF2 was more commonly expressed in cancer-associated fibroblasts (CAFs) (52%) and independently associated with shorter survival (7.2 vs. 29.2 months, p = 0.003). Stromal SULF2 modulated glypican-3/β-catenin signalling in vitro, although in vivo associations suggested additional mechanisms underlying the CAF-SULF2 impact on prognosis. Stromal SULF2 was released by CAFS isolated from human HCC. It was induced by TGFβ1, promoted HCC proliferation and sorafenib resistance, with CAF-SULF2 linked to TGFβ1 and immune exhaustion in TGCA HCC patients. Autocrine activation of PDGFRβ/STAT3 signalling was evident in stromal cells, with the release of the potent monocyte/macrophage chemoattractant CCL2 in vitro. In human PBMCs, SULF2 preferentially induced the migration of macrophage precursors (monocytes), inducing a phenotypic change consistent with immune exhaustion. In human HCC tissues, CAF-SULF2 was associated with increased macrophage recruitment, with tumouroid studies showing stromal-derived SULF2-induced paracrine activation of the IKKβ/NF-κB pathway, tumour cell proliferation, invasion, and sorafenib resistance., Conclusion: SULF2 derived from CAFs modulates glypican-3/β-catenin signalling but also the HCC immune TME, associated with tumour progression and therapy resistance via activation of the TAK1/IKKβ/NF-κB pathway. It is an attractive target for combination therapies for patients with HCC., Competing Interests: F.O. is a director and shareholder in Fibrofind Ltd. J.L. is a shareholder in Fibrofind Ltd, all other authors declare no competing interests., (Copyright © 2022 by The Author(s). Published by S. Karger AG, Basel.)

Background & Aims: Obesity-associated inflammation is a key player in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the role of macrophage scavenger receptor 1 (MSR1, CD204) remains incompletely understood., Methods: A total of 170 NAFLD liver biopsies were processed for transcriptomic analysis and correlated with clinicopathological features. Msr1 -/- and wild-type mice were subjected to a 16-week high-fat and high-cholesterol diet. Mice and ex vivo human liver slices were treated with a monoclonal antibody against MSR1. Genetic susceptibility was assessed using genome-wide association study data from 1,483 patients with NAFLD and 430,101 participants of the UK Biobank., Results: MSR1 expression was associated with the occurrence of hepatic lipid-laden foamy macrophages and correlated with the degree of steatosis and steatohepatitis in patients with NAFLD. Mice lacking Msr1 were protected against diet-induced metabolic disorder, showing fewer hepatic foamy macrophages, less hepatic inflammation, improved dyslipidaemia and glucose tolerance, and altered hepatic lipid metabolism. Upon induction by saturated fatty acids, MSR1 induced a pro-inflammatory response via the JNK signalling pathway. In vitro blockade of the receptor prevented the accumulation of lipids in primary macrophages which inhibited the switch towards a pro-inflammatory phenotype and the release of cytokines such as TNF-ɑ. Targeting MSR1 using monoclonal antibody therapy in an obesity-associated NAFLD mouse model and human liver slices resulted in the prevention of foamy macrophage formation and inflammation. Moreover, we identified that rs41505344, a polymorphism in the upstream transcriptional region of MSR1, was associated with altered serum triglycerides and aspartate aminotransferase levels in a cohort of over 400,000 patients., Conclusions: Taken together, our data suggest that MSR1 plays a critical role in lipid-induced inflammation and could thus be a potential therapeutic target for the treatment of NAFLD., Lay Summary: Non-alcoholic fatty liver disease (NAFLD) is a chronic disease primarily caused by excessive consumption of fat and sugar combined with a lack of exercise or a sedentary lifestyle. Herein, we show that the macrophage scavenger receptor MSR1, an innate immune receptor, mediates lipid uptake and accumulation in Kupffer cells, resulting in liver inflammation and thereby promoting the progression of NAFLD in humans and mice., Competing Interests: Conflict of interest The authors have no potential conflicts (financial, professional or personal) directly relevant to the manuscript. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is a progressive liver disease with potentially severe complications including cirrhosis and hepatocellular carcinoma. Previously, we have identified circulating lipid signatures associating with liver fat content and non-alcoholic steatohepatitis (NASH). Here, we develop a metabolomic map across the NAFLD spectrum, defining interconnected metabolic signatures of steatosis (non-alcoholic fatty liver, NASH, and fibrosis)., Methods: We performed mass spectrometry analysis of molecular lipids and polar metabolites in serum samples from the European NAFLD Registry patients (n = 627), representing the full spectrum of NAFLD. Using various univariate, multivariate, and machine learning statistical approaches, we interrogated metabolites across 3 clinical perspectives: steatosis, NASH, and fibrosis., Results: Following generation of the NAFLD metabolic network, we identify 15 metabolites unique to steatosis, 18 to NASH, and 15 to fibrosis, with 27 common to all. We identified that progression from F2 to F3 fibrosis coincides with a key pathophysiological transition point in disease natural history, with n = 73 metabolites altered., Conclusions: Analysis of circulating metabolites provides important insights into the metabolic changes during NAFLD progression, revealing metabolic signatures across the NAFLD spectrum and features that are specific to NAFL, NASH, and fibrosis. The F2-F3 transition marks a critical metabolic transition point in NAFLD pathogenesis, with the data pointing to the pathophysiological importance of metabolic stress and specifically oxidative stress., Clinical Trials Registration: The study is registered at Clinicaltrials.gov (NCT04442334)., Lay Summary: Non-alcoholic fatty liver disease is characterised by the build-up of fat in the liver, which progresses to liver dysfunction, scarring, and irreversible liver failure, and is markedly increasing in its prevalence worldwide. Here, we measured lipids and other small molecules (metabolites) in the blood with the aim of providing a comprehensive molecular overview of fat build-up, liver fibrosis, and diagnosed severity. We identify a key metabolic 'watershed' in the progression of liver damage, separating severe disease from mild, and show that specific lipid and metabolite profiles can help distinguish and/or define these cases., Competing Interests: QMA is Coordinator of the EU IMI-2 LITMUS consortium, which is funded by the EU Horizon 2020 programme and EFPIA. He reports research grant funding: Allergan/Tobira, AstraZeneca, GlaxoSmithKline, Glympse Bio, Novartis Pharma AG, and Pfizer Ltd. Consultancy: 89Bio, Allergan/Tobira, Altimmune, AstraZeneca, Axcella, Blade, BMS, BNN Cardio, Cirius, CymaBay, EcoR1, E3Bio, Eli Lilly & Company Ltd., Galmed, Genentech, Genfit SA, Gilead, Grunthal, HistoIndex, Indalo, Intercept Pharma Europe Ltd., Inventiva, IQVIA, Janssen, Madrigal, MedImmune, Medpace, Metacrine, NGMBio, North Sea Therapeutics, Novartis, Novo Nordisk A/S, PathAI, Pfizer Ltd., Poxel, ProSciento, Raptor Pharma, Roche, Servier, Terns, The Medicines Company, and Viking Therapeutics. Speaker: Abbott Laboratories, Allergan/Tobira, BMS, Clinical Care Options, Falk, Fishawack, Genfit SA, Gilead, Integritas Communications, Kenes, and Medscape. Royalties: Elsevier Ltd. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2022 The Author(s).)

Objective: The full phenotypic expression of non-alcoholic fatty liver disease (NAFLD) in lean subjects is incompletely characterised. We aimed to investigate prevalence, characteristics and long-term prognosis of Caucasian lean subjects with NAFLD., Design: The study cohort comprises 1339 biopsy-proven NAFLD subjects from four countries (Italy, UK, Spain and Australia), stratified into lean and non-lean (body mass index (BMI) 2 ). Liver/non-liver-related events and survival free of transplantation were recorded during the follow-up, compared by log-rank testing and reported by adjusted HR., Results: Lean patients represented 14.4% of the cohort and were predominantly of Italian origin (89%). They had less severe histological disease (lean vs non-lean: non-alcoholic steatohepatitis 54.1% vs 71.2% p<0.001; advanced fibrosis 10.1% vs 25.2% p<0.001), lower prevalence of diabetes (9.2% vs 31.4%, p<0.001), but no significant differences in the prevalence of the PNPLA3 I148M variant (p=0.57). During a median follow-up of 94 months (>10 483 person-years), 4.7% of lean vs 7.7% of non-lean patients reported liver-related events (p=0.37). No difference in survival was observed compared with non-lean NAFLD (p=0.069)., Conclusions: Caucasian lean subjects with NAFLD may progress to advanced liver disease, develop metabolic comorbidities and experience cardiovascular disease (CVD) as well as liver-related mortality, independent of longitudinal progression to obesity and PNPLA3 genotype. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD where the disease manifests at lower overall BMI thresholds., Lay Summary: NAFLD may affect and progress in both obese and lean individuals. Lean subjects are predominantly males, have a younger age at diagnosis and are more prevalent in some geographic areas. During the follow-up, lean subjects can develop hepatic and extrahepatic disease, including metabolic comorbidities, in the absence of weight gain. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background & Aims: Serum microRNA (miRNA) levels are known to change in non-alcoholic fatty liver disease (NAFLD) and may serve as useful biomarkers. This study aimed to profile miRNAs comprehensively at all NAFLD stages., Methods: We profiled 2,083 serum miRNAs in a discovery cohort (183 cases with NAFLD representing the complete NAFLD spectrum and 10 population controls). miRNA libraries generated by HTG EdgeSeq were sequenced by Illumina NextSeq. Selected serum miRNAs were profiled in 372 additional cases with NAFLD and 15 population controls by quantitative reverse transcriptase PCR., Results: Levels of 275 miRNAs differed between cases and population controls. Fewer differences were seen within individual NAFLD stages, but miR-193a-5p consistently showed increased levels in all comparisons. Relative to NAFL/non-alcoholic steatohepatitis (NASH) with mild fibrosis (stage 0/1), 3 miRNAs (miR-193a-5p, miR-378d, and miR378d) were increased in cases with NASH and clinically significant fibrosis (stages 2-4), 7 (miR193a-5p, miR-378d, miR-378e, miR-320b, miR-320c, miR-320d, and miR-320e) increased in cases with NAFLD activity score (NAS) 5-8 compared with lower NAS, and 3 (miR-193a-5p, miR-378d, and miR-378e) increased but 1 (miR-19b-3p) decreased in steatosis, activity, and fibrosis (SAF) activity score 2-4 compared with lower SAF activity. The significant findings for miR-193a-5p were replicated in the additional cohort with NAFLD. Studies in Hep G2 cells showed that following palmitic acid treatment, miR-193a-5p expression decreased significantly. Gene targets for miR-193a-5p were investigated in liver RNAseq data for a case subgroup (n = 80); liver GPX8 levels correlated positively with serum miR-193a-5p., Conclusions: Serum miR-193a-5p levels correlate strongly with NAFLD activity grade and fibrosis stage. MiR-193a-5p may have a role in the hepatic response to oxidative stress and is a potential clinically tractable circulating biomarker for progressive NAFLD., Lay Summary: MicroRNAs (miRNAs) are small pieces of nucleic acid that may turn expression of genes on or off. These molecules can be detected in the blood circulation, and their levels in blood may change in liver disease including non-alcoholic fatty liver disease (NAFLD). To see if we could detect specific miRNA associated with advanced stages of NAFLD, we carried out miRNA sequencing in a group of 183 patients with NAFLD of varying severity together with 10 population controls. We found that a number of miRNAs showed changes, mainly increases, in serum levels but that 1 particular miRNA miR-193a-5p consistently increased. We confirmed this increase in a second group of cases with NAFLD. Measuring this miRNA in a blood sample may be a useful way to determine whether a patient has advanced NAFLD without an invasive liver biopsy., (© 2021 The Author(s).)

Background and Aims: NAFLD is the most common liver disease worldwide. NASH, the progressive form of NAFLD, and advanced fibrosis are associated with poor outcomes. We searched for their noninvasive biomarkers., Approach and Results: Global RNA sequencing of liver tissue from 98 patients with biopsy-proven NAFLD was performed. Unsupervised hierarchical clustering well distinguished NASH from nonalcoholic fatty liver (NAFL), and patients with NASH exhibited molecular abnormalities reflecting their pathological features. Transcriptomic analysis identified proteins up-regulated in NASH and/or advanced fibrosis (stage F3-F4), including matricellular glycoprotein thrombospondin-2 (TSP-2), encoded by the thrombospondin 2 (THBS2) gene. The intrahepatic THBS2 expression level showed the highest areas under the receiver operating characteristic curves (AUROCs) of 0.915 and 0.957 for diagnosing NASH and advanced fibrosis, respectively. THBS2 positively correlated with inflammation and ballooning according to NAFLD activity score, serum aspartate aminotransferase and hyaluronic acid (HA) levels, and NAFLD Fibrosis Score (NFS). THBS2 was associated with extracellular matrix and collagen biosynthesis, platelet activation, caspase-mediated cleavage of cytoskeletal proteins, and immune cell infiltration. Serum TSP-2 expression was measured in 213 patients with biopsy-proven NAFLD, was significantly higher in NASH than in NAFL, and increased parallel to fibrosis stage. The AUROCs for predicting NASH and advanced fibrosis were 0.776 and 0.856, respectively, which were comparable to Fibrosis-4 index, serum HA level, and NFS in advanced fibrosis diagnosis. Serum TSP-2 level and platelet count were independent predictors of NASH and advanced fibrosis. Serum TSP-2 levels could stratify patients with NAFLD according to the risk of hepatic complications, including liver cancer and decompensated cirrhotic events., Conclusions: TSP-2 may be a useful biomarker for NASH and advanced fibrosis diagnosis in patients with NAFLD., (© 2021 The Authors. Hepatology published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Noninvasive detection of nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease, promises to improve patient screening, accelerate drug trials, and reduce health care costs. On the basis of protease dysregulation of the biological pathways of fibrotic NASH, we developed the Glympse Bio Test System (GBTS) for multiplexed quantification of liver protease activity. GBTS-NASH comprises a mixture of 19 mass-barcoded PEGylated peptides that is administered intravenously and senses liver protease activity by releasing mass-barcoded reporters into urine for analysis by mass spectrometry. To identify a protease signature of NASH, transcriptomic analysis of 355 human liver biopsies identified a 13-protease panel that discriminated clinically relevant NASH ≥F2 fibrosis from F0-F1 with high classification accuracy across two independent patient datasets. We screened 159 candidate substrates to identify a panel of 19 peptides that exhibited high activity for our 13-protease panel. In the choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) mouse model, binary classifiers trained on urine samples discriminated fibrotic NASH from simple steatosis and healthy controls across a range of nondisease conditions and indicated disease regression upon diet change [area under receiver operating characteristics (AUROCs) > 0.97]. Using a hepatoprotective triple combination treatment (FXR agonist, ACC and ASK1 inhibitors) in a rat model of NASH, urinary classification distinguished F0-F1 from ≥F2 animals and indicated therapeutic response as early as 1 week on treatment (AUROCs >0.91). Our results support GBTS-NASH to diagnose fibrotic NASH via an infusion of peptides, monitor changes in disease severity, and indicate early treatment response.

Background & Aims: Non-invasive scoring systems (NSS) are used to identify patients with non-alcoholic fatty liver disease (NAFLD) who are at risk of advanced fibrosis, but their reliability in predicting long-term outcomes for hepatic/extrahepatic complications or death and their concordance in cross-sectional and longitudinal risk stratification remain uncertain., Methods: The most common NSS (NFS, FIB-4, BARD, APRI) and the Hepamet fibrosis score (HFS) were assessed in 1,173 European patients with NAFLD from tertiary centres. Performance for fibrosis risk stratification and for the prediction of long-term hepatic/extrahepatic events, hepatocarcinoma (HCC) and overall mortality were evaluated in terms of AUC and Harrell's c-index. For longitudinal data, NSS-based Cox proportional hazard models were trained on the whole cohort with repeated 5-fold cross-validation, sampling for testing from the 607 patients with all NSS available., Results: Cross-sectional analysis revealed HFS as the best performer for the identification of significant (F0-1 vs. F2-4, AUC = 0.758) and advanced (F0-2 vs. F3-4, AUC = 0.805) fibrosis, while NFS and FIB-4 showed the best performance for detecting histological cirrhosis (range AUCs 0.85-0.88). Considering longitudinal data (follow-up between 62 and 110 months), NFS and FIB-4 were the best at predicting liver-related events (c-indices>0.7), NFS for HCC (c-index = 0.9 on average), and FIB-4 and HFS for overall mortality (c-indices >0.8). All NSS showed limited performance (c-indices <0.7) for extrahepatic events., Conclusions: Overall, NFS, HFS and FIB-4 outperformed APRI and BARD for both cross-sectional identification of fibrosis and prediction of long-term outcomes, confirming that they are useful tools for the clinical management of patients with NAFLD at increased risk of fibrosis and liver-related complications or death., Lay Summary: Non-invasive scoring systems are increasingly being used in patients with non-alcoholic fatty liver disease to identify those at risk of advanced fibrosis and hence clinical complications. Herein, we compared various non-invasive scoring systems and identified those that were best at identifying risk, as well as those that were best for the prediction of long-term outcomes, such as liver-related events, liver cancer and death., Competing Interests: Conflict of interest The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

The prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC) is rising, even in the absence of cirrhosis. We aimed to develop a murine model that would facilitate further understanding of NAFLD-HCC pathogenesis. A total of 144 C3H/He mice were fed either control or American lifestyle (ALIOS) diet, with or without interventions, for up to 48 weeks of age. Gross, liver histology, immunohistochemistry (IHC) and RNA-sequencing data were interpreted alongside human datasets. The ALIOS diet promoted obesity, elevated liver weight, impaired glucose tolerance, non-alcoholic fatty liver disease (NAFLD) and spontaneous HCC. Liver weight, fasting blood glucose, steatosis, lobular inflammation and lipogranulomas were associated with development of HCC, as were markers of hepatocyte proliferation and DNA damage. An antioxidant diminished cellular injury, fibrosis and DNA damage, but not lobular inflammation, lipogranulomas, proliferation and HCC development. An acquired CD44 phenotype in macrophages was associated with type 2 diabetes and NAFLD-HCC. In this diet induced NASH and HCC (DINAH) model, key features of obesity associated NAFLD-HCC have been reproduced, highlighting roles for hepatic steatosis and proliferation, with the acquisition of lobular inflammation and CD44 positive macrophages in the development of HCC-even in the absence of progressive injury and fibrosis., (© 2021. The Author(s).)

Hepatocellular carcinoma (HCC) can have viral or non-viral causes 1-5 . Non-alcoholic steatohepatitis (NASH) is an important driver of HCC. Immunotherapy has been approved for treating HCC, but biomarker-based stratification of patients for optimal response to therapy is an unmet need 6,7 . Here we report the progressive accumulation of exhausted, unconventionally activated CD8 + PD1 + T cells in NASH-affected livers. In preclinical models of NASH-induced HCC, therapeutic immunotherapy targeted at programmed death-1 (PD1) expanded activated CD8 + PD1 + T cells within tumours but did not lead to tumour regression, which indicates that tumour immune surveillance was impaired. When given prophylactically, anti-PD1 treatment led to an increase in the incidence of NASH-HCC and in the number and size of tumour nodules, which correlated with increased hepatic CD8 + PD1 + CXCR6 + , TOX + , and TNF + T cells. The increase in HCC triggered by anti-PD1 treatment was prevented by depletion of CD8 + T cells or TNF neutralization, suggesting that CD8 + T cells help to induce NASH-HCC, rather than invigorating or executing immune surveillance. We found similar phenotypic and functional profiles in hepatic CD8 + PD1 + T cells from humans with NAFLD or NASH. A meta-analysis of three randomized phase III clinical trials that tested inhibitors of PDL1 (programmed death-ligand 1) or PD1 in more than 1,600 patients with advanced HCC revealed that immune therapy did not improve survival in patients with non-viral HCC. In two additional cohorts, patients with NASH-driven HCC who received anti-PD1 or anti-PDL1 treatment showed reduced overall survival compared to patients with other aetiologies. Collectively, these data show that non-viral HCC, and particularly NASH-HCC, might be less responsive to immunotherapy, probably owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance. Our data provide a rationale for stratification of patients with HCC according to underlying aetiology in studies of immunotherapy as a primary or adjuvant treatment.

The mechanisms that drive nonalcoholic fatty liver disease (NAFLD) remain incompletely understood. This large multicenter study characterized the transcriptional changes that occur in liver tissue across the NAFLD spectrum as disease progresses to cirrhosis to identify potential circulating markers. We performed high-throughput RNA sequencing on a discovery cohort comprising histologically characterized NAFLD samples from 206 patients. Unsupervised clustering stratified NAFLD on the basis of disease activity and fibrosis stage with differences in age, aspartate aminotransferase (AST), type 2 diabetes mellitus, and carriage of PNPLA3 rs738409 , a genetic variant associated with NAFLD. Relative to early disease, we consistently identified 25 differentially expressed genes as fibrosing steatohepatitis progressed through stages F2 to F4. This 25-gene signature was independently validated by logistic modeling in a separate replication cohort ( n = 175), and an integrative analysis with publicly available single-cell RNA sequencing data elucidated the likely relative contribution of specific intrahepatic cell populations. Translating these findings to the protein level, SomaScan analysis in more than 300 NAFLD serum samples confirmed that circulating concentrations of proteins AKR1B10 and GDF15 were strongly associated with disease activity and fibrosis stage. Supporting the biological plausibility of these data, in vitro functional studies determined that endoplasmic reticulum stress up-regulated expression of AKR1B10 , GDF15 , and PDGFA , whereas GDF15 supplementation tempered the inflammatory response in macrophages upon lipid loading and lipopolysaccharide stimulation. This study provides insights into the pathophysiology of progressive fibrosing steatohepatitis, and proof of principle that transcriptomic changes represent potentially tractable and clinically relevant markers of disease progression., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

With an increase in sedentary lifestyle and dietary over nutrition, obesity has become one of the major public health problems worldwide and is a prevalent predisposing risk factor to non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in Western developed countries. NAFLD represents a series of diseased states ranging from non-alcoholic fatty liver (NAFL) to steatohepatitis (NASH), which can lead to fibrosis and eventually to cirrhosis and hepatocellular carcinoma. Currently, the only effective treatment to cure end-stage liver disease is liver transplantation. Macrophages have been reported to play a crucial role in the progression of NAFLD, thereby are a potential target for therapy. In this review, we discuss the current knowledge on the role of macrophages and inflammatory signalling pathways associated with obesity and chronic liver inflammation, and their contribution to NAFLD development and progression., (© 2020 The Authors. Scandinavian Journal of Immunology published by John Wiley & Sons Ltd on behalf of The Scandinavian Foundation for Immunology.)

Background & Aims: Genetic factors associated with non-alcoholic fatty liver disease (NAFLD) remain incompletely understood. To date, most genome-wide association studies (GWASs) have adopted radiologically assessed hepatic triglyceride content as the reference phenotype and so cannot address steatohepatitis or fibrosis. We describe a GWAS encompassing the full spectrum of histologically characterised NAFLD., Methods: The GWAS involved 1,483 European NAFLD cases and 17,781 genetically matched controls. A replication cohort of 559 NAFLD cases and 945 controls was genotyped to confirm signals showing genome-wide or close to genome-wide significance., Results: Case-control analysis identified signals showing p values ≤5 × 10 -8 at 4 locations (chromosome [chr] 2 GCKR/C2ORF16; chr4 HSD17B13; chr19 TM6SF2; chr22 PNPLA3) together with 2 other signals with p <1 × 10 -7 (chr1 near LEPR and chr8 near IDO2/TC1). Case-only analysis of quantitative traits showed that the PNPLA3 signal (rs738409) had genome-wide significance for steatosis, fibrosis and NAFLD activity score and a new signal (PYGO1 rs62021874) had close to genome-wide significance for steatosis (p = 8.2 × 10 -8 ). Subgroup case-control analysis for NASH confirmed the PNPLA3 signal. The chr1 LEPR single nucleotide polymorphism also showed genome-wide significance for this phenotype. Considering the subgroup with advanced fibrosis (≥F3), the signals on chr2, chr19 and chr22 maintained their genome-wide significance. Except for GCKR/C2ORF16, the genome-wide significance signals were replicated., Conclusions: This study confirms PNPLA3 as a risk factor for the full histological spectrum of NAFLD at genome-wide significance levels, with important contributions from TM6SF2 and HSD17B13. PYGO1 is a novel steatosis modifier, suggesting that Wnt signalling pathways may be relevant in NAFLD pathogenesis., Lay Summary: Non-alcoholic fatty liver disease is a common disease where excessive fat accumulates in the liver and may result in cirrhosis. To understand who is at risk of developing this disease and suffering liver damage, we undertook a genetic study to compare the genetic profiles of people suffering from fatty liver disease with genetic profiles seen in the general population. We found that particular sequences in 4 different areas of the human genome were seen at different frequencies in the fatty liver disease cases. These sequences may help predict an individual's risk of developing advanced disease. Some genes where these sequences are located may also be good targets for future drug treatments., Competing Interests: Conflict of interest Quentin Anstee reports grants from European Commission during the conduct of the study; other from Acuitas Medical, grants, personal fees and other from Allergan/Tobira, other from E3Bio, other from Eli Lilly & Company Ltd, other from Galmed, grants, personal fees and other from Genfit SA, personal fees and other from Gilead, other from Grunthal, other from Imperial Innovations, grants and other from Intercept Pharma Europe Ltd, other from Inventiva, other from Janssen, personal fees from Kenes, other from MedImmune, other from NewGene, grants and other from Pfizer Ltd, other from Raptor Pharma, grants from GlaxoSmithKline, grants and other from Novartis Pharma AG, grants from AbbVie, personal fees from BMS, grants from GSK, other from NGMBio, other from Madrigal, other from Servier, outside the submitted work; Dina Tiniakos reports consultation fees from Intercept Pharmaceuticals Inc, Allergan, Cirius Therapeutics and an educational grant from Histoindex Pte Ltd; Guruprasad P. Aithal reports institutional consultancy income outside the scope of this study from GSK and Pfizer; Michael Allison reports consultancy/advisory with MedImmune/Astra Zeneca, E3Bio, honoraria from Intercept, Grant support from GSK, Takeda; Jean-Francois Dufour reports advisory committees with AbbVie, Bayer, BMS, Falk, Genfit, Genkyotex, Gilead Science, HepaRegenix, Intercept, Lilly, Merck, Novartis and speaking and teaching with Bayer, BMS, Intercept, Genfit, Gilead Science, Novartis; Pietro Invernizzi reports grants from Intercept, Gilead and Bruschettini; Mattias Ekstedt reports personal fees from AbbVie, AstraZeneca, Albireo, Diapharma, Gilead and non-financial support from Echosens (through LITMUS IMI project); Karine Clement has no personal honoraria but has consultancy and scientific collaboration activity for LNC therapeutics, Confotherapeutics and Danone Research; Jörn M. Schattenberg reports grants from Gilead and Boehringer Ingelheim and fees from Gilead, Boehringer Ingelheim, Galmed, Genfit, Intercept, Novartis, Pfizer and AbbVie outside the submitted work. All other authors report no conflicts of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Introduction: We investigated the longitudinal impact of antinuclear antibody (ANA) on clinical outcomes and survival in nonalcoholic fatty liver disease (NAFLD)., Methods: ANA were found in 16.9% of 923 biopsy-proven NAFLD patients, but none of them had histologic autoimmune hepatitis (AIH) or developed AIH after a mean follow-up of 106±50 months., Results: Although ANA-positive cases had a higher prevalence of nonalcoholic steatohepatitis at baseline, the occurrence of liver-related events, hepatocellula carcinoma, cardiovascular events, extrahepatic malignancy, and overall survival were similar to ANA-negative., Discussion: Once AIH has been ruled out, the long-term outcomes and survival are unaffected by the presence of ANA in patients with NAFLD.

Background & Aims: Homozygosity for the Pi∗Z variant of the gene that encodes the alpha-1 antitrypsin peptide (AAT), called the Pi∗ZZ genotype, causes a liver and lung disease called alpha-1 antitrypsin deficiency. Heterozygosity (the Pi∗MZ genotype) is a risk factor for cirrhosis in individuals with liver disease. Up to 4% of Europeans have the Pi∗MZ genotype; we compared features of adults with and without Pi∗MZ genotype among persons without preexisting liver disease., Methods: We analyzed data from the European Alpha-1 Liver Cohort, from 419 adults with the Pi∗MZ genotype, 309 adults with the Pi∗ZZ genotype, and 284 individuals without the variant (noncarriers). All underwent a comprehensive evaluation; liver stiffness measurements (LSMs) were made by transient elastography. Liver biopsies were analyzed to define histologic and biochemical features associated with the Pi∗Z variant. Levels of serum transaminases were retrieved from 444,642 participants, available in the United Kingdom biobank., Results: In the UK biobank database, levels of serum transaminases were increased in subjects with the Pi∗MZ genotype compared with noncarriers. In the Alpha-1 Liver Cohort, adults with Pi∗MZ had lower levels of gamma-glutamyl transferase in serum and lower LSMs than adults with the Pi∗ZZ variant, but these were higher than in noncarriers. Ten percent of subjects with the Pi∗MZ genotype vs 4% of noncarriers had LSMs of 7.1 kPa or more (adjusted odds ratio, 4.8; 95% confidence interval, 2.0-11.8). Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype. AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages. Subjects with the Pi∗MZ genotype did not have increased hepatic levels of AAT, whereas levels of insoluble AAT varied among individuals., Conclusions: Adults with the Pi∗MZ genotype have lower levels of serum transaminases, fewer AAT inclusions in liver, and lower liver stiffness than adults with the Pi∗ZZ genotype, but higher than adults without the Pi∗Z variant. These findings should help determine risk of subjects with the Pi∗MZ genotype and aid in counseling., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Non-alcoholic steatohepatitis (NASH) is characterized by lipotoxicity, inflammation and fibrosis, ultimately leading to end-stage liver disease. The molecular mechanisms promoting NASH are poorly understood, and treatment options are limited. Here, we demonstrate that hepatic expression of bone morphogenetic protein 8B (BMP8B), a member of the transforming growth factor beta (TGFβ)-BMP superfamily, increases proportionally to disease stage in people and animal models with NASH. BMP8B signals via both SMAD2/3 and SMAD1/5/9 branches of the TGFβ-BMP pathway in hepatic stellate cells (HSCs), promoting their proinflammatory phenotype. In vivo, the absence of BMP8B prevents HSC activation, reduces inflammation and affects the wound-healing responses, thereby limiting NASH progression. Evidence is featured in primary human 3D microtissues modelling NASH, when challenged with recombinant BMP8. Our data show that BMP8B is a major contributor to NASH progression. Owing to the near absence of BMP8B in healthy livers, inhibition of BMP8B may represent a promising new therapeutic avenue for NASH treatment.

Precision cut liver slices (PCLSs) retain the structure and cellular composition of the native liver and represent an improved system to study liver fibrosis compared to two-dimensional mono- or co-cultures. The aim of this study was to develop a bioreactor system to increase the healthy life span of PCLSs and model fibrogenesis. PCLSs were generated from normal rat or human liver, or fibrotic rat liver, and cultured in our bioreactor. PCLS function was quantified by albumin enzyme-linked immunosorbent assay (ELISA). Fibrosis was induced in PCLSs by transforming growth factor beta 1 (TGFβ1) and platelet-derived growth factor (PDGFββ) stimulation ± therapy. Fibrosis was assessed by gene expression, picrosirius red, and α-smooth muscle actin staining, hydroxyproline assay, and soluble ELISAs. Bioreactor-cultured PCLSs are viable, maintaining tissue structure, metabolic activity, and stable albumin secretion for up to 6 days under normoxic culture conditions. Conversely, standard static transwell-cultured PCLSs rapidly deteriorate, and albumin secretion is significantly impaired by 48 hours. TGFβ1/PDGFββ stimulation of rat or human PCLSs induced fibrogenic gene expression, release of extracellular matrix proteins, activation of hepatic myofibroblasts, and histological fibrosis. Fibrogenesis slowly progresses over 6 days in cultured fibrotic rat PCLSs without exogenous challenge. Activin receptor-like kinase 5 (Alk5) inhibitor (Alk5i), nintedanib, and obeticholic acid therapy limited fibrogenesis in TGFβ1/PDGFββ-stimulated PCLSs, and Alk5i blunted progression of fibrosis in fibrotic PCLS. Conclusion: We describe a bioreactor technology that maintains functional PCLS cultures for 6 days. Bioreactor-cultured PCLSs can be successfully used to model fibrogenesis and demonstrate efficacy of antifibrotic therapies., (© 2019 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of American Association for the Study of Liver Diseases.)

There is an unmet need for non-invasive biomarkers in non-alcoholic fatty liver disease (NAFLD) that can diagnose advanced disease and identify patients suitable for clinical trials. The PRO-C3 collagen neo-epitope is a putative direct marker of fibrogenesis. We assessed the performance of PRO-C3 in a large, well-characterised international NAFLD cohort and report the development and validation of 2 novel panels for the diagnosis of advanced fibrosis (F≥3) in NAFLD, including a simplified clinical score which eliminates the need for online calculators., Methods: Plasma PRO-C3 levels were determined in a prospectively recruited international cohort of 449 patients with biopsy diagnosed NAFLD across the full disease spectrum (F0: n = 90; F1: 100; F2: 92; F3: 101; F4: 66). The cohort was divided into a discovery group (n = 151) and a validation group (n = 298). Logistic regression was performed to establish complex (FIBC3) and simplified (ABC3D) diagnostic scores that accurately identify advanced fibrosis. Performance for each was compared to established non-invasive fibrosis scoring systems., Results: Plasma PRO-C3 levels correlated with grade of histological steatohepatitis (r s = 0.367, p ≪ 0.0001) and stage of fibrosis (r s = 0.462, p ≪ 0.0001), exhibiting similar performance to current fibrosis scores such as FIB4 for the detection of F≥3 fibrosis. FIBC3 exhibited substantially improved accuracy (AUROC 0.89 and 0.83 in the discovery and validation sets, respectively) and outperformed FIB4 and other similar diagnostic panels. The simplified version, ABC3D, was concurrently developed and had comparable diagnostic accuracy (AUROC 0.88 and 0.81 in the discovery and validation sets, respectively)., Conclusion: Plasma PRO-C3 levels correlate with severity of steatohepatitis and fibrosis stage. The FIBC3 panel is an accurate tool with a single threshold value that maintains both sensitivity and specificity for the identification of F≥3 fibrosis in NAFLD, eliminating indeterminate results and outperforming commonly used non-invasive tools. A greatly simplified version (ABC3D) that is readily amenable to use in the clinic has been validated and shown to perform with similar accuracy, and may prove a useful tool in routine clinical practice., Lay Summary: We performed a comprehensive, independent evaluation of a collagen biomarker (PRO-C3) to detect and quantify liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). We report the development of 2 diagnostic panels using PRO-C3 to identify patients with advanced fibrosis, one optimal but more complex to calculate (FIBC3), the other easier to use (ABC3D) whilst still performing well., (© 2019 The Authors.)

Caloric excess and sedentary lifestyle have led to a global epidemic of obesity and metabolic syndrome. The hepatic consequence of metabolic syndrome and obesity, nonalcoholic fatty liver disease (NAFLD), is estimated to affect up to one-third of the adult population in many developed and developing countries. This spectrum of liver disease ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Owing to the high prevalence of NAFLD, especially in industrialized countries but also worldwide, and the consequent burden of progressive liver disease, there is mounting epidemiological evidence that NAFLD has rapidly become a leading aetiology underlying many cases of hepatocellular carcinoma (HCC). In this Review, we discuss NAFLD-associated HCC, including its epidemiology, the key features of the hepatic NAFLD microenvironment (for instance, adaptive and innate immune responses) that promote hepatocarcinogenesis and the management of HCC in patients with obesity and associated metabolic comorbidities. The challenges and future directions of research will also be discussed, including clinically relevant biomarkers for early detection, treatment stratification and monitoring as well as approaches to therapies for both prevention and treatment in those at risk or presenting with NAFLD-associated HCC.

Ductular reaction (DR) represents the activation of hepatic progenitor cells (HPCs) and has been associated with features of advanced chronic liver disease; yet it is not clear whether these cells contribute to disease progression and how the composition of their micro-environment differs depending on the aetiology. This study aimed to identify HPC-associated signalling pathways relevant in different chronic liver diseases using a high-throughput sequencing approach. DR/HPCs were isolated using laser microdissection from patient samples diagnosed with HCV or primary sclerosing cholangitis (PSC), as models for hepatocellular or biliary regeneration. Key signals were validated at the protein level for a cohort of 56 patients (20 early and 36 advanced stage). In total, 330 genes were significantly differentially expressed between the HPCs in HCV and PSC. Recruitment and homing of inflammatory cells were distinctly different depending on the aetiology. HPCs in PSC were characterised by a response to oxidative stress (e.g. JUN, VNN1) and neutrophil-attractant chemokines (CXCL5, CXCL6, IL-8), whereas HPCs in HCV were identified by T- and B-lymphocyte infiltration. Moreover, we found that communication between HPCs and macrophages was aetiology driven. In PSC, a high frequency of CCL28-positive macrophages was observed in the portal infiltrate, already in early disease in the absence of advanced fibrosis, while in HCV, HPCs showed a strong expression of the macrophage scavenger receptor MARCO. Interestingly, DR/HPCs in PSC showed more deposition of ECM (e.g. FN1, LAMC2, collagens) compared to HCV, where an increase of pro-invasive genes (e.g. PDGFRA, IGF2) was observed. Additionally, endothelial cells in the vicinity of DR/HPCs showed differential immunopositivity (e.g. IGF2 and INHBA expression). In conclusion, our data shine light on the role of DR/HPCs in immune signalling, fibrogenesis and angiogenesis in chronic liver disease. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Liver cancer is a poor prognosis cancer with limited treatment options. To develop a new therapeutic approach, we derived HCC cells from a known model of murine hepatocellular carcinoma (HCC). We treated adiponectin (APN) knock-out mice with the carcinogen diethylnitrosamine, and the resulting tumors were 7-fold larger than wild-type controls. Tumors were disassociated from both genotypes and their growth characteristics evaluated. A52 cells from APN KO mice had the most robust growth in vitro and in vivo, and presented with pathology similar to the parental tumor. All primary tumors and cell lines exhibited activity of the mammalian target of Rapamycin (mTOR) and Src pathways. Subsequent combinatorial treatment, with the mTOR inhibitor Rapamycin and the Src inhibitor Dasatinib reduced A52 HCC growth 29-fold in vivo. Through protein and histological analyzes we observed activation of these pathways in human HCC, suggesting that targeting both mTOR and Src may be a novel approach for the treatment of HCC., Competing Interests: The authors have declared that no competing interests exist.

Primary liver cancer comprises a diverse group of liver tumors. The heterogeneity of these tumors is seen as one of the obstacles to finding an effective therapy. The Hippo pathway, with its downstream transcriptional co-activator Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), has a decisive role in the carcinogenesis of primary liver cancer. Therefore, we examined the expression pattern of YAP and TAZ in 141 patients with hepatocellular carcinoma keratin 19 positive (HCC K19⁺), hepatocellular carcinoma keratin 19 negative (HCC K19 - ), combined hepatocellular⁻cholangiocarcinoma carcinoma (cHCC-CCA), or cholangiocarcinoma (CCA). All cHCC-CCA and CCA patients showed high expression levels for YAP and TAZ, while only some patients of the HCC group were positive. Notably, we found that a histoscore of both markers is useful in the challenging diagnosis of cHCC-CCA. In addition, positivity for YAP and TAZ was observed in the hepatocellular and cholangiocellular components of cHCC-CCA, which suggests a single cell origin in cHCC-CCA. Within the K19 - HCC group, our results demonstrate that the expression of YAP is a statistically significant predictor of poor prognosis when observed in the cytoplasm. Nuclear expression of TAZ is an even more specific and independent predictor of poor disease-free survival and overall survival of K19 - HCC patients. Our results thus identify different levels of YAP/TAZ expression in various liver cancers that can be used for diagnostics.

Background & Aims: Hepatocellular carcinoma (HCC) typically arises in fibrotic or cirrhotic livers, which are characterized by pathogenic angiogenesis. Myeloid immune cells, specifically tumor-associated macrophages (TAMs), may represent potential novel therapeutic targets in HCC, complementing current ablative or immune therapies. However, the detailed functions of TAM subsets in hepatocarcinogenesis have remained obscure., Methods: TAM subsets were analyzed in-depth in human HCC samples and a combined fibrosis-HCC mouse model, established by i.p. injection with diethylnitrosamine after birth and repetitive carbon tetrachloride (CCl 4 ) treatment for 16 weeks. Based on comprehensively phenotyping TAM subsets (fluorescence-activated cell sorter, transcriptomics) in mice, the function of CCR2 + TAM was assessed by a pharmacologic chemokine inhibitor. Angiogenesis was evaluated by contrast-enhanced micro-computed tomography and histology., Results: We show that human CCR2 + TAM accumulate at the highly vascularized HCC border and express the inflammatory marker S100A9, whereas CD163 + immune-suppressive TAM accrue in the HCC center. In the fibrosis-cancer mouse model, we identified 3 major hepatic myeloid cell populations with distinct messenger RNA profiles, of which CCR2 + TAM particularly showed activated inflammatory and angiogenic pathways. Inhibiting CCR2 + TAM infiltration using a pharmacologic chemokine CCL2 antagonist in the fibrosis-HCC model significantly reduced pathogenic vascularization and hepatic blood volume, alongside attenuated tumor volume., Conclusions: The HCC microenvironment in human patients and mice is characterized by functionally distinct macrophage populations, of which the CCR2 + inflammatory TAM subset has pro-angiogenic properties. Understanding the functional differentiation of myeloid cell subsets in chronically inflamed liver may provide novel opportunities for modulating hepatic macrophages to inhibit tumor-promoting pathogenic angiogenesis., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Liver injury results in rapid regeneration through hepatocyte proliferation and hypertrophy. However, after acute severe injury, such as acetaminophen poisoning, effective regeneration may fail. We investigated how senescence may underlie this regenerative failure. In human acute liver disease, and murine models, p21-dependent hepatocellular senescence was proportionate to disease severity and was associated with impaired regeneration. In an acetaminophen injury mouse model, a transcriptional signature associated with the induction of paracrine senescence was observed within 24 hours and was followed by one of impaired proliferation. In mouse genetic models of hepatocyte injury and senescence, we observed transmission of senescence to local uninjured hepatocytes. Spread of senescence depended on macrophage-derived transforming growth factor-β1 (TGFβ1) ligand. In acetaminophen poisoning, inhibition of TGFβ receptor 1 (TGFβR1) improved mouse survival. TGFβR1 inhibition reduced senescence and enhanced liver regeneration even when delivered beyond the therapeutic window for treating acetaminophen poisoning. This mechanism, in which injury-induced senescence impairs liver regeneration, is an attractive therapeutic target for developing treatments for acute liver failure., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Aims: Hepatic progenitor cells (HPCs) are activated in various liver diseases, but their role in the carcinomatous environment remains unknown. We aimed to identify the possible presence and topography of HPCs in liver metastases., Methods and Results: We examined 14 liver resection specimens for colorectal adenocarcinoma (n = 13) and anal squamous cell carcinoma (n = 1) metastases. Immunohistochemical markers of colonic origin (keratin 20 and CDX2) and squamous cell origin (p63), HPC [keratin 19 (K19) and CD56] and stem cell (CD44) markers, and the biliary marker keratin 7 (K7), which may also highlight HPCs, were applied on routinely processed tissue sections. Double immunohistochemistry/immunofluorescence (K7/CDX2) and confocal microscopy were used on selected sections. K7-positive, Κ19-positive and CD56-positive ductular structures were encountered within the metastatic tumour (tumour interior and periphery), and in the immediate peritumoral area. Hybrid structures composed of HPCs and metastatic adenocarcinoma cells were recognised and confirmed by double immunostaining (K7/CDX2). Carcinoma cells were also observed singly or in groups within the epithelium of interlobular bile ducts and/or ductules in portal tracts without evidence of carcinomatous infiltration and at a distance from the metastatic foci., Conclusions: HPCs are observed at the periphery and in the interior of liver metastatic carcinomas. Bile ductules and small interlobular bile ducts may attract carcinoma cells serving as a potential 'metastatic niche', in line with their recognised role as HPC niches in non-neoplastic liver., (© 2017 John Wiley & Sons Ltd.)

Macrophages are key regulators of liver fibrosis progression and regression in nonalcoholic steatohepatitis (NASH). Liver macrophages comprise resident phagocytes, Kupffer cells, and monocyte-derived cells, which are recruited through the chemokine receptor C-C motif chemokine receptor 2 (CCR2). We aimed at elucidating the therapeutic effects of inhibiting monocyte infiltration in NASH models by using cenicriviroc (CVC), an oral dual chemokine receptor CCR2/CCR5 antagonist that is under clinical evaluation. Human liver tissues from NASH patients were analyzed for CCR2 + macrophages, and administration of CVC was tested in mouse models of steatohepatitis, liver fibrosis progression, and fibrosis regression. In human livers from 17 patients and 4 controls, CCR2 + macrophages increased parallel to NASH severity and fibrosis stage, with a concomitant inflammatory polarization of these cluster of differentiation 68 + , portal monocyte-derived macrophages (MoMF). Similar to human disease, we observed a massive increase of hepatic MoMF in experimental models of steatohepatitis and liver fibrosis. Therapeutic treatment with CVC significantly reduced the recruitment of hepatic Ly-6C + MoMF in all models. In experimental steatohepatitis with obesity, therapeutic CVC application significantly improved insulin resistance and hepatic triglyceride levels. In fibrotic steatohepatitis, CVC treatment ameliorated histological NASH activity and hepatic fibrosis. CVC inhibited the infiltration of Ly-6C + monocytes, without direct effects on macrophage polarization, hepatocyte fatty acid metabolism, or stellate cell activation. Importantly, CVC did not delay fibrosis resolution after injury cessation. RNA sequencing analysis revealed that MoMF, but not Kupffer cells, specifically up-regulate multiple growth factors and cytokines associated with fibrosis progression, while Kupffer cells activated pathways related to inflammation initiation and lipid metabolism., Conclusion: Pharmacological inhibition of CCR2 + monocyte recruitment efficiently ameliorates insulin resistance, hepatic inflammation, and fibrosis, corroborating the therapeutic potential of CVC in patients with NASH. (Hepatology 2018;67:1270-1283)., (© 2017 by the American Association for the Study of Liver Diseases.)

Hepatic progenitor cells (HPCs) are small cells with a relative large oval nucleus and a scanty cytoplasm situated in the canals of Hering that express markers of (immature) hepatocytes and cholangiocytes. HPCs are present in large numbers in alcoholic steatohepatitis (ASH), one of the leading causes of chronic liver disease. To date, the mechanisms responsible for proliferation and differentiation of human HPCs are still poorly understood and the role of HPCs in ASH development is unknown. In this study, we aimed to characterise human HPCs and their interactions with other cells through comparison, on both protein and RNA level, of HPC-enriched cell populations from adult human liver tissue using different isolation methods. Fresh human liver tissue was collected from ASH explant livers and HPC-enriched cell populations were obtained via four different isolation methods: side population (SP), epithelial cell adhesion molecule (EpCAM) and trophoblast antigen 2 (TROP-2) membrane marker isolation and laser capture microdissection. Gene expression profiles of fluorescent-activated cell-sorted HPCs, whole liver extracts and laser microdissected HPC niches were determined by RNA-sequencing. Immunohistochemical evaluation of the isolated populations indicated the enrichment of HPCs in the SP, EpCAM + and TROP-2 + cell populations. Pathway analysis of the transcription profiles of human HPCs showed an enrichment and activation of known HPC pathways like Wnt/β-catenin, TWEAK and HGF. Integration of the HPC niche profile suggests autocrine signalling by HPCs (TNFα, PDGFB and VEGFA) as well as paracrine signalling from the surrounding niche cells including MIF and IGF-1. In addition, we identified IL-17 A signalling as a potentially novel pathway in HPC biology. In conclusion, we provide the first RNA-seq-based, comparative transcriptome analysis of isolated human HPCs from ASH patients and revealed active signalling between HPCs and their surrounding niche cells in ASH livers and suggest that HPCs can actively contribute to liver inflammation.

Background: Tumours are not only composed of malignant cells but also consist of a stromal micro-environment, which has been shown to influence cancer cell behaviour. Because the ageing process induces accumulation of senescent cells in the body, this micro-environment is thought to be different in cancers occurring in old patients compared with younger patients. More specifically, senescence-related fibroblastic features, such as the senescence-associated secretory profile (SASP) and the induction of autophagy, are suspected to stimulate tumour growth and progression., Methods: We compared gene expression profiles in stromal fields of breast carcinomas by performing laser capture microdissection of the cancer-associated stroma from eight old (aged ≥80 years at diagnosis) and nine young (aged <45 years at diagnosis) patients with triple-negative breast cancer. Gene expression data were obtained by microarray analysis (Affymetrix). Differential gene expression and gene set enrichment analysis (GSEA) were performed., Results: Differential gene expression analysis showed changes reminiscent of increased growth, de-differentiation and migration in stromal samples of older versus younger patients. GSEA confirmed the presence of a SASP, as well as the presence of autophagy in the stroma of older patients., Conclusions: We provide the first evidence in humans that older age at diagnosis is associated with a different stromal micro-environment in breast cancers. The SASP and the presence of autophagy appear to be important age-induced stromal features.

Background: Cutaneous melanoma is the deadliest skin cancer, with an increasing incidence and mortality rate. Currently, staging of patients with primary melanoma is performed using histological biomarkers such as tumor thickness and ulceration. As disruption of the epigenomic landscape is recognized as a widespread feature inherent in tumor development and progression, we aimed to identify novel biomarkers providing additional clinical information over current factors using unbiased genome-wide DNA methylation analyses., Methods: We performed a comprehensive DNA methylation analysis during all progression stages of melanoma using Infinium HumanMethylation450 BeadChips on a discovery cohort of benign nevi (n = 14) and malignant melanoma from both primary (n = 33) and metastatic (n = 28) sites, integrating the DNA methylome with gene expression data. We validated the discovered biomarkers in three independent validation cohorts by pyrosequencing and immunohistochemistry., Results: We identified and validated biomarkers for, and pathways involved in, melanoma development (e.g., HOXA9 DNA methylation) and tumor progression (e.g., TBC1D16 DNA methylation). In addition, we determined a prognostic signature with potential clinical applicability and validated PON3 DNA methylation and OVOL1 protein expression as biomarkers with prognostic information independent of tumor thickness and ulceration., Conclusions: Our data underscores the importance of epigenomic regulation in triggering metastatic dissemination through the inactivation of central cancer-related pathways. Inactivation of cell-adhesion and differentiation unleashes dissemination, and subsequent activation of inflammatory and immune system programs impairs anti-tumoral defense pathways. Moreover, we identify several markers of tumor development and progression previously unrelated to melanoma, and determined a prognostic signature with potential clinical utility.

Background: Tumour budding, described as the presence of single cells or small clusters of up to five tumour cells at the invasive margin, is established as a prognostic marker in colorectal carcinoma. In the present study, we aimed to investigate the molecular signature of tumour budding cells and the corresponding tumour bulk., Methods: Tumour bulk and budding areas were microdissected and processed for RNA-sequencing. As little RNA was obtained from budding cells, a special low-input mRNA library preparation protocol was used. Gene expression profiles of budding as compared with tumour bulk were investigated for established EMT signatures, consensus molecular subtype (CMS), gene set enrichment and pathway analysis., Results: A total of 296 genes were differentially expressed with an FDR <0.05 and a twofold change between tumour bulk and budding regions. Genes that were upregulated in the budding signature were mainly involved in cell migration and survival while downregulated genes were important for cell proliferation. Supervised clustering according to an established EMT gene signature categorised budding regions as EMT-positive, whereas tumour bulk was considered EMT-negative. Furthermore, a shift from CMS2 (epithelial) to CMS4 (mesenchymal) was observed as tumour cells transit from the tumour bulk to the budding regions., Conclusions: Tumour budding regions are characterised by a phenotype switch compared with the tumour bulk, involving the acquisition of migratory characteristics and a decrease in cell proliferation. In particular, most tumour budding signatures were EMT-positive and switched from an epithelial subtype (CMS2) in the tumour bulk to a mesenchymal subtype (CMS4) in budding cells.

Purpose: Fuchs' endothelial corneal dystrophy (FECD) is a degenerative eye disorder affecting 4% of Americans older than 40. It is the leading indication for corneal endothelial (CE) transplantation for which there is a global donor shortage. This study aimed to gain further insight into the pathophysiology of FECD and identify targets for nonsurgical therapy., Methods: CE from patients with late-onset FECD was compared with that of normal controls using microarray expression analysis (n = 4 FECD, n = 4 normal), reverse transcriptase quantitative PCR (n = 9 FECD, n = 8 normal), and immunohistology (n = 55 FECD, n = 15 normal)., Results: This led to the identification of circulating fibrocytes and their dendritic derivatives in all examined CE samples with FECD (in all clinical stages of symptomatic FECD and independent of prior cataract surgery). These cells were not present in normal CE. In this study we characterize their morphology, protein expression profile, number, and localization within the CE layer of patients with FECD., Conclusions: Circulating fibrocytes and their dendritic derivatives are a new aspect of FECD that deserves further investigation. Because they are known to cause fibrosis in a variety of organs, they may play a similar role in FECD and might be a valuable target for nonsurgical therapy.

The tumor suppressor p53 is a central regulator of signaling pathways that controls the cell cycle and maintains the integrity of the human genome. p53 level is regulated by mouse double minute 2 homolog (Mdm2), which marks p53 for proteasomal degradation. The p53-Mdm2 circuitry is subjected to complex regulation by a variety of mechanisms, including microRNAs (miRNAs). We found a novel effector of this regulatory circuit, namely, miR-122*, the passenger strand of the abundantly expressed liver-specific miR-122. Here, we demonstrate that miR-122* levels are reduced in human hepatocellular carcinoma (HCC). We found that miR-122* targets Mdm2, thus participating as an important player in the p53-Mdm2 circuitry. Moreover, we observed significant negative correlation between levels of miR-122* and Mdm2 in a large set of human HCC samples. In vivo tumorigenicity assays demonstrate that miR-122* is capable of inhibiting tumor growth, emphasizing the tumor-suppressor characteristics of this miRNA. Furthermore, we show that blocking miR-122 in murine livers with an antagomiR-122 (miRNA inhibitor) results in miR-122* accumulation, leading to Mdm2 repression followed by elevated p53 protein levels., Conclusion: miR-122*, the passenger strand of miR-122, regulates the activity of p53 by targeting Mdm2. Importantly, similarly to miR-122, miR-122* is significantly down-regulated in human HCC. We therefore propose that miR-122* is an important contributor to the tumor suppression activity previously attributed solely to miR-122. (Hepatology 2016;64:1623-1636)., (© 2016 by the American Association for the Study of Liver Diseases.)

Acetaminophen (APAP, paracetamol) poisoning is a leading cause of acute liver failure (ALF) in humans and induces hepatocyte necrosis, followed by activation of the innate immune system, further aggravating liver injury. The role of infiltrating monocytes during the early phase of ALF is still ambiguous. Upon experimental APAP overdose in mice, monocyte-derived macrophages (MoMFs) massively accumulated in injured liver within 12-24 hours, whereas the number of tissue-resident macrophages (Kupffer cells) decreased. Influx of MoMFs is dependent on the chemokine receptor, chemokine (C-C motif) receptor 2 (CCR2), given that Ccr2 -/- mice display reduced infiltration of monocytes and attenuated liver injury post-APAP overdose at early time points. As evidenced by intravital multiphoton microscopy of Ccr2 reporter mice, CCR2 + monocytes infiltrate liver as early as 8-12 hours post-APAP overdose and form dense cellular clusters around necrotic areas. CCR2 + MoMFs express a distinct pattern of inflammatory, but also repair-associated, genes in injured livers. Adoptive transfer experiments revealed that MoMFs primarily exert proinflammatory functions early post-APAP, thereby aggravating liver injury. Consequently, early pharmacological inhibition of either chemokine (C-C motif) ligand (CCL2; by the inhibitor, mNOX-E36) or CCR2 (by the orally available dual CCR2/CCR5 inhibitor, cenicriviroc) reduces monocyte infiltration and APAP-induced liver injury (AILI) in mice. Importantly, neither the early nor continuous inhibition of CCR2 hinder repair processes during resolution from injury. In line with this, human livers of ALF patients requiring liver transplantation reveal increased CD68 + hepatic macrophage numbers with massive infiltrates of periportal CCR2 + macrophages that display a proinflammatory polarization., Conclusion: Infiltrating monocyte-derived macrophages aggravate APAP hepatotoxicity, and the pharmacological inhibition of either CCL2 or CCR2 might bear therapeutic potential by reducing the inflammatory reaction during the early phase of AILI. (Hepatology 2016;64:1667-1682)., (© 2016 by the American Association for the Study of Liver Diseases.)

Hepatic inflammation drives hepatic stellate cells (HSC), resulting in liver fibrosis. The Farnesoid-X receptor (FXR) antagonizes inflammation through NF-κB inhibition. We investigated preventive and therapeutic effects of FXR agonist obeticholic acid (OCA) on hepatic inflammation and fibrosis in toxic cirrhotic rats. Cirrhosis was induced by thioacetamide (TAA) intoxication. OCA was given during or after intoxication with vehicle-treated rats as controls. At sacrifice, fibrosis, hemodynamic and biochemical parameters were assessed. HSC activation, cell turn-over, hepatic NF-κB activation, pro-inflammatory and pro-fibrotic cytokines were determined. The effect of OCA was further evaluated in isolated HSC, Kupffer cells, hepatocytes and liver sinusoidal endothelial cells (LSEC). OCA decreased hepatic inflammation and fibrogenesis during TAA-administration and reversed fibrosis in established cirrhosis. Portal pressure decreased through reduced intrahepatic vascular resistance. This was paralleled by decreased expression of pro-fibrotic cytokines (transforming growth-factor β, connective tissue growth factor, platelet-derived growth factor β-receptor) as well as markers of hepatic cell turn-over, by blunting effects of pro-inflammatory cytokines (e.g. monocyte chemo-attractant protein-1). In vitro, OCA inhibited both LSEC and Kupffer cell activation; while HSC remained unaffected. This related to NF-κB inhibition via up-regulated IκBα. In conclusion, OCA inhibits hepatic inflammation in toxic cirrhotic rats resulting in decreased HSC activation and fibrosis.