The exclusion of other chronic liver diseases including "excess" alcohol intake has until now been necessary to establish a diagnosis of metabolic dysfunction-associated fatty liver disease (MAFLD). However, given our current understanding of the pathogenesis of MAFLD and its rising prevalence, "positive criteria" to diagnose the disease are required. In this work, a panel of international experts from 22 countries propose a new definition for the diagnosis of MAFLD that is both comprehensive and simple, and is independent of other liver diseases. The criteria are based on evidence of hepatic steatosis, in addition to one of the following three criteria, namely overweight/obesity, presence of type 2 diabetes mellitus, or evidence of metabolic dysregulation. We propose that disease assessment and stratification of severity should extend beyond a simple dichotomous classification to steatohepatitis vs. non-steatohepatitis. The group also suggests a set of criteria to define MAFLD-associated cirrhosis and proposes a conceptual framework to consider other causes of fatty liver disease. Finally, we bring clarity to the distinction between diagnostic criteria and inclusion criteria for research studies and clinical trials. Reaching consensus on the criteria for MAFLD will help unify the terminology (e.g. for ICD-coding), enhance the legitimacy of clinical practice and clinical trials, improve clinical care and move the clinical and scientific field of liver research forward. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Few studies have been conducted to compare the efficacies of stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA). Thus, in this multinational study, we compared the effectiveness of SBRT and RFA in patients with unresectable HCC. Methods: The retrospective study cohort included 2,064 patients treated in 7 hospitals: 1,568 and 496 in the RFA and SBRT groups, respectively. More than half of the patients (56.5%) developed recurrent tumors, mainly after transarterial chemoembolization (44.8%). Propensity score matching was performed to adjust for clinical factors (n = 313 in each group). Results: At baseline, the SBRT group had unfavorable clinical features compared to the RFA group, including BCLC stage (B-C 65% vs. 16%), tumor size (median 3.0 cm vs. 1.9 cm), and frequent history of liver-directed treatment (81% vs. 49%, all p<0.001). With a median follow-up of 27.7 months, the 3-year cumulative local recurrence rates in the SBRT and RFA groups were 21.2% and 27.9%, respectively (p<0.001). After adjusting for clinical factors, SBRT was related to a significantly lower risk of local recurrence than RFA in both the entire (hazard ratio [HR] 0.45, p<0.001) and matched (HR 0.36, p<0.001) cohorts. In subgroup analysis, SBRT was associated with superior local control in small tumors (<= 3 cm) irrespective of location, large tumors located in the subphrenic region, and those that progressed after transarterial chemoembolization. Acute grade >= 3 toxicities occurred in 1.6% and 2.6% of the SBRT and RFA patients, respectively (p = 0.268). Conclusions: SBRT could be an effective alternative to RFA for unresectable HCC, particularly for larger tumors (>3 cm) in a subphrenic location and tumors that have progressed after transarterial chemoembolization. Lay summary: It is currently not known what the best treatment option is for patients with unresectable hepatocellular carcinoma. Here, we show that stereotactic body radiation therapy provides better local control than radiofrequency ablation, with comparable toxicities. Stereotactic body radiation therapy appears to be an effective alternative to radiofrequency ablation that should be considered when there is a higher risk of local recurrence or toxicity after radiofrequency ablation. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Toll-like receptor 4 (TLR4) plays an essential role in mediating organ injury in acute liver failure (ALF) and acute-on-chronic liver failure (ACLF). Herein, we assess whether inhibiting TLR4 signaling can ameliorate liver failure and serve as a potential treatment. Methods: Circulating TLR4 ligands and hepatic TLR4 expression were measured in plasma samples and liver biopsies from patients with cirrhosis. TAK-242 (TLR4 inhibitor) was tested in vivo (10 mg/kg intraperitoneally) in rodent models of ACLF (bile duct ligation + lipopolysaccharide [LPS]; carbon tetrachloride + LPS) and ALF (galactosamine + LPS) and in vitro on immortalized human monocytes (THP-1) and hepatocytes (HHL5). The in vivo therapeutic effect was assessed by coma-free survival, organ injury and cytokine release and in vitro by measuring IL-6, IL-1 beta or cell injury (TUNEL), respectively. Results: In patients with cirrhosis, hepatic TLR4 expression was upregulated and circulating TLR4 ligands were increased (p<0.001). ACLF in rodents was associated with a switch from apoptotic cell death in ALF to non-apoptotic forms of cell death. TAK-242 reduced LPS-induced cytokine secretion and cell death (p = 0.002) in hepatocytes and monocytes in vitro. In rodent models of ACLF, TAK-242 administration improved coma-free survival, reduced the degree of hepatocyte cell death in the liver (p<0.001) and kidneys (p = 0.048) and reduced circulating cytokine levels (IL-1 beta, p<0.001). In a rodent model of ALF, TAK-242 prevented organ injury (p<0.001) and systemic inflammation (IL-1 beta, p<0.001). Conclusion: This study shows that TLR4 signaling is a key factor in the development of both ACLF and ALF; its inhibition reduces the severity of organ injury and improves outcome. TAK-242 may be of therapeutic relevance in patients with liver failure. Lay summary: Toll-like receptor 4 (or TLR4) mediates endotoxin-induced tissue injury in liver failure and cirrhosis. This receptor sensitizes cells to endotoxins, which are produced by gram-negative bacteria. Thus, inhibiting TLR4 signaling with an inhibitor (TAK-242) ameliorates organ injury and systemic inflammation in rodent models of acute and acute-on-chronic liver failure. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Mutations in ABCB11 can cause deficiency of the bile salt export pump (BSEP), leading to cholestasis and end-stage liver disease. Owing to the rarity of the disease, the associations between genotype and natural history, or outcomes following surgical biliary diversion (SBD), remain elusive. We aimed to determine these associations by assembling the largest genetically defined cohort of patients with severe BSEP deficiency to date. Methods: This multicentre, retrospective cohort study included 264 patients with homozygous or compound heterozygous pathological ABCB11 mutations. Patients were categorized according to genotypic severity (BSEP1, BSEP2, BSEP3). The predicted residual BSEP transport function decreased with each category. Results: Genotype severity was strongly associated with native liver survival (NLS, BSEP1 median 20.4 years; BSEP2, 7.0 years; BSEP3, 3.5 years; p<0.001). At 15 years of age, the proportion of patients with hepatocellular carcinoma was 4% in BSEP1, 7% in BSEP2 and 34% in BSEP3 (p = 0.001). SBD was associated with significantly increased NLS (hazard ratio 0.50; 95% CI 0.27-0.94: p = 0.03) in BSEP1 and BSEP2. A serum bile acid concentration below 102 mu mol/L or a decrease of at least 75%, each shortly after SBD, reliably predicted NLS of >= 15 years following SBD (each p<0.001). Conclusions: The genotype of severe BSEP deficiency strongly predicts long-term NLS, the risk of developing hepatocellular carcinoma, and the chance that SBD will increase NLS. Serum bile acid parameters shortly after SBD can predict long-term NLS. Lay summary: This study presents data from the largest genetically defined cohort of patients with severe bile salt export pump deficiency to date. The genotype of patients with severe bile salt export pump deficiency is associated with clinical outcomes and the success of therapeutic interventions. Therefore, genotypic data should be used to guide personalized clinical care throughout childhood and adulthood in patients with this disease. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Apoptosis signal-regulating kinase 1 (ASK1) plays a key role in hepatocyte injury, inflammation, and fibrosis in non-alcoholic steatohepatitis (NASH). We evaluated the safety and antifibrotic effect of selonsertib, a selective inhibitor of ASK1, in patients with advanced fibrosis due to NASH. Methods: We conducted 2 randomized, double-blind, placebo-controlled, phase III trials of selonsertib in patients with NASH and bridging fibrosis (F3, STELLAR-3) or compensated cirrhosis (F4, STELLAR-4). Patients were randomized 2:2:1 to receive selonsertib 18 mg, selonsertib 6 mg, or placebo once daily for 48 weeks. Liver biopsies were performed at screening and week 48 and non-invasive tests of fibrosis (NITs) were evaluated. The primary efficacy endpoint was the proportion of patients with >=-1-stage improvement in fibrosis without worsening of NASH at week 48. Additional endpoints included changes in NITs, progression to cirrhosis (in STELLAR-3), and liver-related clinical events. Results: Neither trial met the primary efficacy endpoint. In STELLAR-3, fibrosis improvement without worsening of NASH was observed in 10% (31/322, p = 0.49 vs. placebo), 12% (39/321, p = 0.93 vs. placebo), and 13% (21/159) of patients in the selonsertib 18 mg, selonsertib 6 mg, and placebo groups, respectively. In STELLAR-4, the primary endpoint was achieved in 14% (51/354; p = 0.56), 13% (45/351; p = 0.93), and 13% (22/172) of patients, respectively. Although selonsertib led to dose-dependent reductions in hepatic phospho-p38 expression indicative of pharmacodynamic activity, it had no significant effect on liver biochemistry, NITs, progression to cirrhosis, or adjudicated clinical events. The rates and types of adverse events were similar among selonsertib and placebo groups. Conclusions: Forty-eight weeks of selonsertib monotherapy had no antifibrotic effect in patients with bridging fibrosis or compensated cirrhosis due to NASH. Lay summary: Patients with non-alcoholic steatohepatitis (NASH) can develop scarring of the liver (fibrosis), including cirrhosis, which increases the risks of liver failure and liver cancer. We tested whether 48 weeks of treatment with selonsertib reduced fibrosis in patients with NASH and advanced liver scarring. We did not find that selonsertib reduced fibrosis in these patients. (C) 2020 Published by Elsevier B.V. on behalf of European Association for the Study of the Liver.
Background & Aims: Circulating peptides and G protein-coupled receptors (GPCRs) have gained much attention because of their biofunctions in metabolic disorders including obesity and non-alcoholic fatty liver disease (NAFLD). Herein, we aimed to characterize the role and therapeutic potential of a newly identified peptide hormone in NAFLD. Methods: Using bioinformatics, we identified a murine circulating pentadecapeptide flanked by potential convertase cleavage sites of osteocalcin (OCN), which we named 'metabolitin (MTL)'. We used ligand-receptor binding, receptor internalization, bioluminescence resonance energy transfer and Nano isothermal titration calorimetry assays to study the binding relationship between MTL and GPRC6A. For in vivo biological studies, wild-type mice kept on a high-fat diet (HFD) were injected or gavaged with MTL to study its function in NAFLD. Results: We confirmed that MTL binds to GPRC6A and OCN interacts with GPRC6A using in vitro biological studies. Both intraperitoneal and oral administration of MTL greatly improved NAFLD and insulin resistance in a mouse model. Interacting with GPRC6A expressed in intestines, MTL can significantly inhibit intestinal neurotensin secretion, which in turn inhibits triglyceride but not cholesterol gut absorption, mediated by the 5'AMP-activated protein kinase pathway. In addition, glucagon like peptide-1 secretion was induced by MTL treatment. Conclusions: Oral or intraperitoneal MTL significantly improves the symptoms of NAFLD by inhibiting lipid absorption and insulin resistance. MTL could be a potential therapeutic candidate for the treatment of NAFLD. Lay summary: A novel murine peptide hormone, herein named 'metabolitin', inhibits fatty acid absorption and improves systemic insulin resistance in a murine model of obesity and non-alcoholic fatty liver disease. Thus, metabolitin has therapeutic potential for the treatment of patients with non-alcoholic fatty liver disease. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: RNA G-quadruplexes (RG4s) appear to be important in post-transcriptional gene regulation, but their pathophysiological functions remain unknown. MicroRNA-26a (miR-26a) is emerging as a therapeutic target for various human diseases, however the mechanisms underlying endogenous miR-26a regulation are poorly understood. Herein, we study the role of RG4 in miR-26a expression and function in vitro and in vivo. Methods: Putative RG4s within liver-enriched miRNAs were predicted by bioinformatic analysis, and the presence of an RG4 structure in the miR-26a-1 precursor (pre-miR-26a-1) was further analyzed by biophysical and biochemical methods. RG4 stabilizers, pre-miR-26a-1 overexpression plasmids, and luciferase reporter assays were used to assess the effect of RG4 on pre-miR-26a-1 maturation. Both miR-26a knock-in and knockout mouse models were employed to investigate the influence of this RG4 on miR-26a expression and function. Moreover, the interaction between RG4 in pre-miR-26a-1 and DEAH-box helicase 36 (DHX36) was determined by biophysical and molecular methods. Finally, miR-26a processing and DHX36 expression were quantified in the livers of obese mice. Results: We identify a guanine-rich sequence in pre-miR-26a-1 that can fold into an RG4 structure. This RG4 impairs pre-miR-26a-1 maturation, resulting in a decrease in miR-26a expression and subsequently an increase in miR-26a cognate targets. In line with known miR-26a functions, this RG4 can regulate hepatic insulin sensitivity and lipid metabolism in vitro and in vivo. Furthermore, we reveal that DHX36 can bind and unwind this RG4 structure, thereby enhancing miR-26a maturation. Intriguingly, there is a concordant decrease of miR-26a maturation and DHX36 expression in obese mouse livers. Conclusions: Our findings define a dynamic DHX36/RG4/miR-26a regulatory axis during obesity, highlighting an important role of RG4 in physiology and pathology. Lay summary: Specific RNA sequences called G-quadruplexes (or RG4) appear to be important in post-transcriptional gene regulation. Obesity leads to the formation of these RG4 structures in pre-miR-26a-1 molecules, impairing the maturation and function of miR-26a, which has emerged as a therapeutic target in several diseases. This contributes to hepatic insulin resistance and the dysregulation of liver metabolism. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Obesity is a well-established risk factor for type 2 diabetes (T2D) and non-alcoholic steatohepatitis (NASH), but the underlying mechanisms remain incompletely understood. Herein, we aimed to identify novel pathogenic factors (and possible therapeutic targets) underlying metabolic dysfunction in the liver. Methods: We applied a tandem quantitative proteomics strategy to enrich and identify transcription factors (TFs) induced in the obese liver. We used flow cytometry of liver cells to analyze the source of the induced TFs. We employed conditional knockout mice, shRNA, and small-molecule inhibitors to test the metabolic consequences of the induction of identified TFs. Finally, we validated mouse data in patient liver biopsies. Results: We identified PU.1/SPI1, the master hematopoietic regulator, as one of the most upregulated TFs in livers from diet-induced obese (DIO) and genetically obese (db/db) mice. Targeting PU.1 in the whole liver, but not hepatocytes alone, significantly improved glucose homeostasis and suppressed liver inflammation. Consistently, treatment with the PU.1 inhibitor DB1976 markedly reduced inflammation and improved glucose homeostasis and dyslipidemia in DIO mice, and strongly suppressed glucose intolerance, liver steatosis, inflammation, and fibrosis in a dietary NASH mouse model. Furthermore, hepatic PU.1 expression was positively correlated with insulin resistance and inflammation in liver biopsies from patients. Conclusions: These data suggest that the elevated hematopoietic factor PU.1 promotes liver metabolic dysfunction, and may be a useful therapeutic target for obesity, insulin resistance/T2D, and NASH. Lay summary: Expression of the immune regulator PU.1 is increased in livers of obese mice and people. Blocking PU.1 improved glucose homeostasis, and reduced liver steatosis, inflammation and fibrosis in mouse models of non-alcoholic steatohepatitis. Inhibition of PU.1 is thus a potential therapeutic strategy for treating obesity-associated liver dysfunction and metabolic diseases. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Background & Aims: Non-alcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D) and obesity are epidemiologically correlated with each other but the causal inter-relationships between them remain incompletely understood. We aimed to explore the causal relationships between the 3 diseases. Methods: Using both UK Biobank and publicly available genome-wide association study data, we performed a 2-sample bidirectional Mendelian randomization analysis to test the causal interrelationships between NAFLD, T2D, and obesity. Transgenic mice expressing the human PNPLA3-I148M isoforms (TghPNPLA3-I148M) were used as an example to validate causal effects and explore underlying mechanisms. Results: Genetically driven NAFLD significantly increased the risk of T2D and central obesity but not insulin resistance or generalized obesity, while genetically driven T2D, body mass index and WHRadjBMI causally increased NAFLD risk. The animal study focusing on PNPLA3 corroborated these causal effects: compared to the TghPNPLA3-I148I controls, the TghPNPLA3-I148M mice developed glucose intolerance and increased visceral fat, but maintained normal insulin sensitivity, reduced body weight, and decreased circulating total cholesterol. Mechanistically, the TghPNPLA3-I148M mice demonstrated decreased pancreatic insulin but increased glucagon secretion, which was associated with increased pancreatic inflammation. In addition, transcription of hepatic cholesterol biosynthesis pathway genes was significantly suppressed, while transcription of thermogenic pathway genes was activated in subcutaneous and brown adipose tissues but not in visceral fat in TghPNPLA3-I148M mice. Conclusions: Our study suggests that lifelong, genetically driven NAFLD causally promotes T2D with a late-onset type 1-like diabetic subphenotype and central obesity; while genetically driven T2D, obesity, and central obesity all causally increase the risk of NAFLD. This causal relationship revealed new insights into how nature and nurture drive these diseases, providing novel hypotheses for disease subphenotyping. Lay summary: Non-alcoholic fatty liver disease, type 2 diabetes and obesity are epidemiologically correlated with each other, but their causal relationships were incompletely understood. Herein, we identified causal relationships between these conditions, which suggest that each of these closely related diseases should be further stratified into subtypes. This is important for accurate diagnosis, prevention and treatment of these diseases. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.