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Background and Aims Thiazolidinediones (TZDs) and glucagon‐like peptide‐1 (GLP‐1) receptor agonists are potential pharmacological treatment options for patients at risk of NAFLD. Therefore, we examined the association between the risk of NAFLD and the use of TZDs and GLP‐1 receptor agonists compared with the use of sulfonylureas (SUs) and insulins. Additionally, we calculated the incidence of HCC in users of TZDs and GLP‐1 receptor agonists. Approach and Results We conducted a population‐based cohort study using primary care data from the Clinical Practice Research Datalink database (2007‐2018). All patients aged ≥18 with a prescription of an oral glucose‐lowering agent or GLP‐1 receptor agonist were included. The first prescription defined the start of follow‐up. The primary outcome was a new diagnosis of NAFLD. Cox proportional hazards regression was used to estimate HRs and 95% CIs of the primary outcome. Incidence rates of HCC were determined per 1,000 person‐years for all exposures. The study identified 207,367 adults with a prescription for a glucose‐lowering agent. The risk of NAFLD was lower in patients prescribed a TZD than in those prescribed an SU (adjusted HR [aHR], 0.32; 95% CI, 0.20‐0.51). No difference in risk of NAFLD was observed comparing GLP‐1 receptor agonist use with insulin use (aHR, 1.22; 95% CI, 0.91‐1.63). Conclusions Results of our study endorse the use of TZDs for selected patients at risk of NAFLD but do not support previous findings regarding the beneficial effect of GLP‐1 receptor agonists. The low number of events in several subgroups may affect the generalizability of the current findings.

Background and aims Nonalcoholic fatty liver disease, especially nonalcoholic steatohepatitis (NASH), has become a major cause of liver transplantation and liver-associated death. NASH is the hepatic manifestation of metabolic syndrome and is characterized by hepatic steatosis, inflammation, hepatocellular injury, and different degrees of fibrosis. However, there is no US Food and Drug Administration-approved medication to treat this devastating disease. Therapeutic activators of the AMP-activated protein kinase (AMPK) have been proposed as a potential treatment for metabolic diseases such as NASH. Cordycepin, a natural product isolated from the traditional Chinese medicine Cordyceps militaris, has recently emerged as a promising drug candidate for metabolic diseases. Approach and results We evaluated the effects of cordycepin on lipid storage in hepatocytes, inflammation, and fibrosis development in mice with NASH. Cordycepin attenuated lipid accumulation, inflammation, and lipotoxicity in hepatocytes subjected to metabolic stress. In addition, cordycepin treatment significantly and dose-dependently decreased the elevated levels of serum aminotransferases in mice with diet-induced NASH. Furthermore, cordycepin treatment significantly reduced hepatic triglyceride accumulation, inflammatory cell infiltration, and hepatic fibrosis in mice. In vitro and in vivo mechanistic studies revealed that a key mechanism linking the protective effects of cordycepin were AMPK phosphorylation-dependent, as indicated by the finding that treatment with the AMPK inhibitor Compound C abrogated cordycepin-induced hepatoprotection in hepatocytes and mice with NASH. Conclusion Cordycepin exerts significant protective effects against hepatic steatosis, inflammation, liver injury, and fibrosis in mice under metabolic stress through activation of the AMPK signaling pathway. Cordycepin might be an AMPK activator that can be used for the treatment of NASH.

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. ispartof: HEPATOLOGY vol:74 issue:5 pages:2452-2466 ispartof: location:United States status: published

BACKGROUND AND AIMS High serum ferritin is frequent among patients with chronic liver disease and commonly associated with hepatic iron overload. Genetic causes of high liver iron include homozygosity for the p.Cys282Tyr variant in homeostatic iron regulator (HFE) and rare variants in non-HFE genes. The aims of the present study were to describe the landscape and frequency of mutations in hemochromatosis genes and determine whether patient selection by noninvasive hepatic iron quantification using MRI improves the diagnostic yield of next-generation sequencing (NGS) in patients with hyperferritinemia. APPROACH AND RESULTS A cohort of 410 unselected liver clinic patients with high serum ferritin (defined as ≥200 μg/L for women and ≥300 μg/L for men) was investigated by HFE genotyping and abdominal MRI R2*. Forty-one (10%) patients were homozygous for the p.Cys282Tyr variant in HFE. Of the remaining 369 patients, 256 (69%) had high transferrin saturation (TSAT; ≥45%) and 199 (53%) had confirmed hepatic iron overload (liver R2* ≥70 s-1 ). NGS of hemochromatosis genes was carried out in 180 patients with hepatic iron overload, and likely pathogenic variants were identified in 68 of 180 (38%) patients, mainly in HFE (79%), ceruloplasmin (25%), and transferrin receptor 2 (19%). Low spleen iron (R2*

Background and aims Manual histological assessment is currently the accepted standard for diagnosing and monitoring disease progression in NASH, but is limited by variability in interpretation and insensitivity to change. Thus, there is a critical need for improved tools to assess liver pathology in order to risk stratify NASH patients and monitor treatment response. Approach and results Here, we describe a machine learning (ML)-based approach to liver histology assessment, which accurately characterizes disease severity and heterogeneity, and sensitively quantifies treatment response in NASH. We use samples from three randomized controlled trials to build and then validate deep convolutional neural networks to measure key histological features in NASH, including steatosis, inflammation, hepatocellular ballooning, and fibrosis. The ML-based predictions showed strong correlations with expert pathologists and were prognostic of progression to cirrhosis and liver-related clinical events. We developed a heterogeneity-sensitive metric of fibrosis response, the Deep Learning Treatment Assessment Liver Fibrosis score, which measured antifibrotic treatment effects that went undetected by manual pathological staging and was concordant with histological disease progression. Conclusions Our ML method has shown reproducibility and sensitivity and was prognostic for disease progression, demonstrating the power of ML to advance our understanding of disease heterogeneity in NASH, risk stratify affected patients, and facilitate the development of therapies.

BACKGROUND AND AIMS The liver plays a central role in all metabolic processes in the body. However, precise characterization of liver metabolism is often obscured by its inherent complexity. Phosphorylated metabolites occupy a prominent position in all anabolic and catabolic pathways. Here, we develop a 31 P nuclear magnetic resonance (NMR)-based method to study the liver "phosphorome" through the simultaneous identification and quantification of multiple hydrophilic and hydrophobic phosphorylated metabolites. APPROACH AND RESULTS We applied this technique to define the metabolic landscape in livers from a mouse model of the rare disease disorder congenital erythropoietic porphyria (CEP) as well as two well-known murine models of nonalcoholic steatohepatitis: one genetic, methionine adenosyltransferase 1A knockout mice, and the other dietary, mice fed a high-fat choline-deficient diet. We report alterations in the concentrations of phosphorylated metabolites that are readouts of the balance between glycolysis, gluconeogenesis, the pentose phosphate pathway, the tricarboxylic acid cycle, and oxidative phosphorylation and of phospholipid metabolism and apoptosis. Moreover, these changes correlate with the main histological features: steatosis, apoptosis, iron deposits, and fibrosis. Strikingly, treatment with the repurposed drug ciclopirox improves the phosphoromic profile of CEP mice, an effect that was mirrored by the normalization of liver histology. CONCLUSIONS In conclusion, these findings indicate that NMR-based phosphoromics may be used to unravel metabolic phenotypes of liver injury and to identify the mechanism of drug action.

Background and aims Sirtuin 2 (SIRT2), an NAD+ -dependent deacetylase, is involved in various cellular processes regulating metabolic homeostasis and inflammatory responses; however, its role in hepatic steatosis and related metabolic disorders is unknown. Approach and results Integrating the published genomic data on NAFLD samples from humans and rodents available in the Gene Expression Omnibus, we found that SIRT2 was significantly down-regulated in livers from patients with advanced NAFLD and high-fat diet (HFD)-induced NAFLD mice. This study further revealed that SIRT2 was markedly decreased in obese (ob/ob) mice and in palmitate-treated HepG2 cells. Restoration of hepatic SIRT2 expression in ob/ob or HFD-fed mice largely alleviated insulin resistance, hepatic steatosis, and systematic inflammation, whereas SIRT2 liver-specific ablation exacerbated these metabolic dysfunctions in HFD-fed C57BL/6J mice. Mechanistically, SIRT2 stabilized the hepatocyte nuclear factor 4α (HNF4α) protein by binding to and deacetylating HNF4α on lysine 458. Furthermore, HNF4α was sufficient to mediate SIRT2 function, and SIRT2-HNF4α interaction was required for SIRT2 function both in vivo and in vitro. Conclusions Collectively, the present study provided evidence that SIRT2 functions as a crucial negative regulator in NAFLD and related metabolic disorders and that targeting the SIRT2-HNF4α pathway may be a promising strategy for NAFLD treatment.

Background and Aims Whether glycemic control, as opposed to diabetes status, is associated with the severity of NAFLD is open for study. We aimed to evaluate whether degree of glycemic control in the years preceding liver biopsy predicts the histological severity of NASH. Approach and Results Using the Duke NAFLD Clinical Database, we examined patients with biopsy‐proven NAFLD/NASH (n = 713) and the association of liver injury with glycemic control as measured by hemoglobin A1c (HbA1c). The study cohort was predominantly female (59%) and White (84%) with median (interquartile range) age of 50 (42, 58) years; 49% had diabetes (n = 348). Generalized linear regression models adjusted for age, sex, race, diabetes, body mass index, and hyperlipidemia were used to assess the association between mean HbA1c over the year preceding liver biopsy and severity of histological features of NAFLD/NASH. Histological features were graded and staged according to the NASH Clinical Research Network system. Group‐based trajectory analysis was used to examine patients with at least three HbA1c (n = 298) measures over 5 years preceding clinically indicated liver biopsy. Higher mean HbA1c was associated with higher grade of steatosis and ballooned hepatocytes, but not lobular inflammation. Every 1% increase in mean HbA1c was associated with 15% higher odds of increased fibrosis stage (OR, 1.15; 95% CI, 1.01, 1.31). As compared with good glycemic control, moderate control was significantly associated with increased severity of ballooned hepatocytes (OR, 1.74; 95% CI, 1.01, 3.01; P = 0.048) and hepatic fibrosis (HF; OR, 4.59; 95% CI, 2.33, 9.06; P

International audience; Background and aims: Glycogen storage disease (GSD) type 1a is an inborn error of metabolism caused by defective glucose-6-phosphatase catalytic subunit (G6PC) activity. Patients with GSD 1a exhibit severe hepatomegaly due to glycogen and triglyceride (TG) accumulation in the liver. We have shown that the activity of carbohydrate response element binding protein (ChREBP), a key regulator of glycolysis and de novo lipogenesis, is increased in GSD 1a. In the current study, we assessed the contribution of ChREBP to nonalcoholic fatty liver disease (NAFLD) development in a mouse model for hepatic GSD 1a.Approach and results: Liver-specific G6pc-knockout (L-G6pc-/- ) mice were treated with adeno-associated viruses (AAVs) 2 or 8 directed against short hairpin ChREBP to normalize hepatic ChREBP activity to levels observed in wild-type mice receiving AAV8-scrambled short hairpin RNA (shSCR). Hepatic ChREBP knockdown markedly increased liver weight and hepatocyte size in L-G6pc-/- mice. This was associated with hepatic accumulation of G6P, glycogen, and lipids, whereas the expression of glycolytic and lipogenic genes was reduced. Enzyme activities, flux measurements, hepatic metabolite analysis and very low density lipoprotein (VLDL)-TG secretion assays revealed that hepatic ChREBP knockdown reduced downstream glycolysis and de novo lipogenesis but also strongly suppressed hepatic VLDL lipidation, hence promoting the storage of "old fat." Interestingly, enhanced VLDL-TG secretion in shSCR-treated L-G6pc-/- mice associated with a ChREBP-dependent induction of the VLDL lipidation proteins microsomal TG transfer protein and transmembrane 6 superfamily member 2 (TM6SF2), the latter being confirmed by ChIP-qPCR.Conclusions: Attenuation of hepatic ChREBP induction in GSD 1a liver aggravates hepatomegaly because of further accumulation of glycogen and lipids as a result of reduced glycolysis and suppressed VLDL-TG secretion. TM6SF2, critical for VLDL formation, was identified as a ChREBP target in mouse liver. Altogether, our data show that enhanced ChREBP activity limits NAFLD development in GSD 1a by balancing hepatic TG production and secretion.

Background and aims Nonalcoholic fatty liver disease (NAFLD) encompasses a range of conditions, from simple steatosis to nonalcoholic steatohepatitis. Studies in the United States have reported an increased mortality risk among individuals with NAFLD; therefore, the population attributable fractions (PAFs) for mortality were examined. Approach and results A total of 12,253 adult individuals with ultrasound assessment of NAFLD from the Third National Health and Nutrition Examination Survey and mortality follow-up through 2015 were included in the analysis. Cox proportional hazard regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for NAFLD in association with all-cause and cause-specific mortality. Overall, sex- and race/ethnicity-specific PAFs and 95% CIs were estimated. In the current study, presence of NAFLD was associated with a 20% increased risk of all-cause mortality (HR, 1.20; 95% CI, 1.08, 1.34). The overall PAF for all-cause mortality associated with NAFLD was 7.5% (95% CI, 3.0, 12.0). The PAF for diabetes-specific mortality was 38.0% (95% CI, 13.1, 63.0) overall, 40.8% (95% CI, 2.1, 79.6) in men, and 36.8% (95% CI, 6.6, 67.0) in women. The PAF for liver disease (LD)-specific mortality was notably higher in men (68.3%; 95% CI, 36.3, 100.0) than women (3.5%; 95% CI, -39.7, 46.8). In the race-specific analysis, the PAFs of NAFLD for all-cause mortality (9.3%; 95% CI, 4.0, 14.6) and diabetes-specific mortality (44.4%; 95% CI, 10.8, 78.0) were significantly greater than zero only for whites. Conclusions In the United States, approximately 8% of all-cause mortality and more than one-third of LD- and diabetes-specific deaths are associated with NAFLD. With these high percentages, efforts are needed to reduce the burden of NAFLD in the United States.

Background and Aims Vacuolar H+-ATP complex (V-ATPase) is a multisubunit protein complex required for acidification of intracellular compartments. At least five different factors are known to be essential for its assembly in the endoplasmic reticulum (ER). Genetic defects in four of these V-ATPase assembly factors show overlapping clinical features, including steatotic liver disease and mild hypercholesterolemia. An exception is the assembly factor vacuolar ATPase assembly integral membrane protein (VMA21), whose X-linked mutations lead to autophagic myopathy.Approach and Results Here, we report pathogenic variants in VMA21 in male patients with abnormal protein glycosylation that result in mild cholestasis, chronic elevation of aminotransferases, elevation of (low-density lipoprotein) cholesterol and steatosis in hepatocytes. We also show that the VMA21 variants lead to V-ATPase misassembly and dysfunction. As a consequence, lysosomal acidification and degradation of phagocytosed materials are impaired, causing lipid droplet (LD) accumulation in autolysosomes. Moreover, VMA21 deficiency triggers ER stress and sequestration of unesterified cholesterol in lysosomes, thereby activating the sterol response element-binding protein-mediated cholesterol synthesis pathways.Conclusions Together, our data suggest that impaired lipophagy, ER stress, and increased cholesterol synthesis lead to LD accumulation and hepatic steatosis. V-ATPase assembly defects are thus a form of hereditary liver disease with implications for the pathogenesis of nonalcoholic fatty liver disease.

Background and Aims Patients with glycogen storage disease type 1a (GSD-1a) primarily present with life-threatening hypoglycemia and display severe liver disease characterized by hepatomegaly. Despite strict dietary management, long-term complications still occur, such as liver tumor development. Variations in residual glucose-6-phosphatase (G6PC1) activity likely contribute to phenotypic heterogeneity in biochemical symptoms and complications between patients. However, lack of insight into the relationship between G6PC1 activity and symptoms/complications and poor understanding of the underlying disease mechanisms pose major challenges to provide optimal health care and quality of life for GSD-1a patients. Currently available GSD-1a animal models are not suitable to systematically investigate the relationship between hepatic G6PC activity and phenotypic heterogeneity or the contribution of gene-gene interactions (GGIs) in the liver. Approach and Results To meet these needs, we generated and characterized a hepatocyte-specific GSD-1a mouse model using somatic CRISPR/CRISPR-associated protein 9 (Cas9)-mediated gene editing. Hepatic G6pc editing reduced hepatic G6PC activity up to 98% and resulted in failure to thrive, fasting hypoglycemia, hypertriglyceridemia, hepatomegaly, hepatic steatosis (HS), and increased liver tumor incidence. This approach was furthermore successful in simultaneously modulating hepatic G6PC and carbohydrate response element-binding protein, a transcription factor that is activated in GSD-1a and protects against HS under these conditions. Importantly, it also allowed for the modeling of a spectrum of GSD-1a phenotypes in terms of hepatic G6PC activity, fasting hypoglycemia, hypertriglyceridemia, hepatomegaly and HS. Conclusions In conclusion, we show that somatic CRISPR/Cas9-mediated gene editing allows for the modeling of a spectrum of hepatocyte-borne GSD-1a disease symptoms in mice and to efficiently study GGIs in the liver. This approach opens perspectives for translational research and will likely contribute to personalized treatments for GSD-1a and other genetic liver diseases.

To investigate the effect of antidiabetic agents on nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM), 75 patients with T2DM and NAFLD under inadequate glycemic control by metformin were randomized (1:1:1) to receive add‐on liraglutide, sitagliptin, or insulin glargine in this 26‐week trial. The primary endpoint was the change in intrahepatic lipid (IHL) from baseline to week 26 as quantified by magnetic resonance imaging–estimated proton density fat fraction (MRI‐PDFF). Secondary endpoints included changes in abdominal adiposity (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT]), glycated hemoglobin, and body weight from baseline to week 26. We analysed data from intent‐to‐treat population. MRI‐PDFF, VAT, and weight decreased significantly with liraglutide (15.4% ± 5.6% to 12.5% ± 6.4%, P < 0.001; 171.4 ± 27.8 to 150.5 ± 30.8, P = 0.003; 86.6 ± 12.9 kg to 82.9 ± 11.1 kg, P = 0.005, respectively) and sitagliptin (15.5% ± 5.6% to 11.7% ± 5.0%, P = 0.001; 153.4 ± 31.5 to 139.8 ± 27.3, P = 0.027; 88.2 ± 13.6 kg to 86.5 ± 13.2 kg, P = 0.005, respectively). No significant change in MRI‐PDFF, VAT, or body weight was observed with insulin glargine. SAT decreased significantly in the liraglutide group (239.9 ± 69.0 to 211.3 ± 76.1; P = 0.020) but not in the sitagliptin and insulin glargine groups. Changes from baseline in MRI‐PDFF, VAT, and body weight were significantly greater with liraglutide than insulin glargine but did not differ significantly between liraglutide and sitagliptin. Conclusion: Combined with metformin, both liraglutide and sitagliptin, but not insulin glargine, reduced body weight, IHL, and VAT in addition to improving glycemic control in patients with T2DM and NAFLD.

Nonalcoholic fatty liver disease (NAFLD), which has a wide global distribution, includes different stages ranging from simple steatosis to nonalcoholic steatohepatitis, advanced fibrosis, and liver cirrhosis according to the degree of severity. Chronic low‐grade inflammation, insulin resistance, and lipid accumulation are the leading causes of NAFLD. To date, no effective medicine for NAFLD has been approved by governmental agencies. Our study demonstrated that the expression of dual‐specificity phosphatase 26 (Dusp26), a member of the Dusp protein family, was decreased in the liver tissue of mice with hepatic steatosis and genetically obese (ob/ob) mice. In our study, hepatic steatosis, inflammatory responses, and insulin resistance were exacerbated in liver‐specific Dusp26‐knockout (KO) mice but ameliorated in liver‐specific Dusp26‐transgenic mice induced by a high‐fat diet. In addition, the degree of liver fibrosis was aggravated in high‐fat high‐cholesterol diet–induced Dusp26‐KO mice. We further found that the binding of Dusp26 to transforming growth factor beta–activated kinase 1 (TAK1) to block the phosphorylation of TAK1 regulated the TAK1–p38/c‐Jun NH2‐terminal kinase signaling axis to alleviate hepatic steatosis and metabolic disturbance. Conclusion: These findings suggest that Dusp26 is a good TAK1‐dependent therapeutic target for NAFLD.

Primary sclerosing cholangitis (PSC) represents a major unmet medical need. In a phase II double-blind, placebo-controlled study, we tested the safety and efficacy of cilofexor (formerly GS-9674), a nonsteroidal farnesoid X receptor agonist in patients without cirrhosis with large-duct PSC. Patients were randomized to receive cilofexor 100 mg (n = 22), 30 mg (n = 20), or placebo (n = 10) orally once daily for 12 weeks. All patients had serum alkaline phosphatase (ALP) > 1.67 × upper limit of normal and total bilirubin ≤ 2 mg/dL at baseline. Safety, tolerability, pharmacodynamic effects of cilofexor (serum C4 [7α-hydroxy-4-cholesten-3-one] and bile acids), and changes in liver biochemistry and serum fibrosis markers were evaluated. Overall, 52 patients were randomized (median age 43 years, 58% male, 60% with inflammatory bowel disease, 46% on ursodeoxycholic acid). Baseline median serum ALP and bilirubin were 348 U/L (interquartile range 288-439) and 0.7 mg/dL (0.5-1.0), respectively. Dose-dependent reductions in liver biochemistry were observed. At week 12, cilofexor 100 mg led to significant reductions in serum ALP (median reduction -21%; P = 0.029 versus placebo), gamma-glutamyl transferase (-30%; P < 0.001), alanine aminotransferase (ALT) (-49%; P = 0.009), and aspartate aminotransferase (-42%; P = 0.019). Cilofexor reduced serum C4 compared with placebo; reductions in bile acids were greatest with 100 mg. Relative reductions in ALP were similar between ursodeoxycholic acid-treated and untreated patients. At week 12, cilofexor-treated patients with a 25% or more relative reduction in ALP had greater reductions in serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, tissue inhibitor of metalloproteinase 1, C-reactive protein, and bile acids than nonresponders. Adverse events were similar between cilofexor and placebo-treated patients. Rates of grade 2 or 3 pruritus were 14% with 100 mg, 20% with 30 mg, and 40% with placebo. Conclusion: In this 12-week, randomized, placebo-controlled study, cilofexor was well tolerated and led to significant improvements in liver biochemistries and markers of cholestasis in patients with PSC.

Nonalcoholic fatty liver disease (NAFLD) is a major risk factor of many end‐stage liver diseases. Alterations in microRNA expression have been reported in patients with NAFLD. However, the transcriptional mechanism(s) of dysregulated microRNAs under the state of NAFLD is poorly described, and microRNAs that regulate the pathogenesis of NAFLD synergistically with their regulators remain unknown. Here we report that microRNA‐378 expression is significantly increased in fatty livers of mice and patients with NAFLD. Although microRNA‐378 locates within the intron of Ppargc1β (peroxisome proliferator‐activated receptor γ coactivator 1‐beta), there was a significant uncoupling of Ppargc1β mRNA and microRNA‐378 levels in both sources of fatty livers. Further studies identified a full‐length primary transcript of microRNA‐378. LXRα (liver X receptor alpha) functioned as a transcription activator of microRNA‐378 and a repressor of Ppargc1β transcription. It is known that miR‐378 is an inhibitor of fatty acid oxidation (FAO) and the function of Ppargc1β is opposite to that of miR‐378. GW3965 treatment (LXRα agonist) of murine hepatocytes and mice increased microRNA‐378 and reduced Ppargc1β, which subsequently impaired FAO and aggravated hepatosteatosis. In contrast, additional treatment of miR‐378 inhibitor or Ppargc1β, which knocked down increased miR‐378 or recovered expression of Ppargc1β, offset the effects of GW3965. Liver‐specific ablation of Lxrα led to decreased miR‐378 and increased Ppargc1β, which subsequently improved FAO and reduced hepatosteatosis. Conclusion: Our findings indicated that miR‐378 possesses its own transcription machinery, which challenges the well‐established dogma that miR‐378 transcription is controlled by the promoter of Ppargc1β. LXRα selectively activates transcription of miR‐378 and inhibits expression of Ppargc1β, which synergistically impairs FAO. In addition to lipogenesis, impaired FAO by miR‐378 in part contributes to LXRα‐induced hepatosteatosis.

Background and Aims: Gestational diabetes seems to be associated with offspring NAFLD. We hypothesized that maternal glucose concentrations across the full range may have persistent effects on offspring liver fat accumulation. Approach and Results: In a multiethnic, population-based, prospective cohort study among 2,168 women and their offspring, maternal early-pregnancy glucose concentrations were measured at a median of 13.1 weeks’ gestation (95% CI, 9.6-17.2). Liver fat fraction was measured at 10 years by MRI. NAFLD was defined as liver fat fraction ≥5.0%. We performed analyses among all mothers with different ethnic backgrounds and those of European ancestry only. The multiethnic group had a median maternal early-pregnancy glucose concentration of 4.3 mmol/L (interquartile range, 3.9-4.9) and a 2.8% (n = 60) prevalence of NAFLD. The models adjusted for child age and sex only showed that in the multiethnic group, higher maternal early-pregnancy glucose concentrations were associated with higher liver fat accumulation and higher odds of NAFLD, but these associations attenuated into nonsignificance after adjustment for potential confounders. Among mothers of European ancestry only, maternal early-pregnancy glucose concentrations were associated with increased odds of NAFLD (OR, 1.95; 95% CI, 1.32; 2.88, after adjustment for confounders) per 1-mmol/L increase in maternal early-pregnancy glucose concentration. These associations were not explained by maternal prepregnancy and childhood body mass index, visceral fat, and metabolic markers. Conclusions: In this study, maternal early-pregnancy glucose concentrations were only among mothers of European ancestry associated with offspring NAFLD. The associations of higher maternal early-pregnancy glucose concentrations with offspring NAFLD may differ between ethnic groups.

NGM282, an engineered fibroblast growth factor 19 analogue, rapidly and significantly reduced liver fat content in a multicenter, randomized, double‐blind, placebo‐controlled study in patients with biopsy‐confirmed nonalcoholic steatohepatitis (NASH). However, it is unclear whether these changes would be accompanied by histological improvement. In this open‐label study, we assessed the histological efficacy of NGM282 in patients with biopsy‐confirmed nonalcoholic steatohepatitis. Paired liver biopsies from 43 patients who received subcutaneous NGM282 (1 mg, n = 24; 3 mg, n = 19) once daily for 12 weeks were evaluated blinded to time point, subject, and clinical information. At week 12, NGM282 significantly reduced nonalcoholic fatty liver disease activity score (NAS; −1.9; 95% confidence interval, −2.6 to −1.2; P

Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent liver pathology marked by hepatic steatosis and commonly accompanied by systematic inflammation and metabolic disorder. Despite an accumulating number of studies, no pharmacological strategy is available to treat this condition in the clinic. The current work applied extensive gain- and loss-of-function approaches to identify the key immune factor leukocyte immunoglobulin-like receptor B4 (LILRB4) as a negative regulator of NAFLD. The hepatocyte-specific knockout of LILRB4 (LILRB4-HKO) significantly exacerbated high-fat diet (HFD)-induced insulin resistance, glucose metabolic imbalance, hepatic lipid accumulation, and systematic inflammation in mice, whereas LILRB4 overexpression in hepatocytes showed a completely opposite phenotype relative to that of LILRB4-HKO mice when compared to their corresponding controls. Further investigations on molecular mechanism demonstrated that LILRB4 recruit SHP1 for inhibiting TRAF6 ubiquitination and subsequently inactivating NF-κB and MAPK cascades. From a therapeutic perspective, the overexpression of LILRB4 in a genetic model of NAFLD, ob/ob mice, largely reversed the inherent hepatic steatosis, inflammation, and metabolic disorder. Conclusions: Targeting hepatic LILRB4 to improve its expression or activation might represent a promising strategy for the treatment of NAFLD as well as related liver and metabolic diseases. This article is protected by copyright. All rights reserved.

Background: Nonalcoholic fatty liver disease (NAFLD) and resulting nonalcoholic steatohepatitis (NASH) are highly prevalent in the US, where they are a growing cause of cirrhosis and hepatocellular carcinoma (HCC), and increasingly, an indicator for liver transplantation. Methods: A Markov model was used to forecast NAFLD disease progression. Incidence of NAFLD was based on historical and projected changes in adult prevalence of obesity and type 2 diabetes mellitus (DM). Assumptions were derived from published literature where available, and validated using national surveillance data for incidence of NAFLD-related HCC. Projected changes in NAFLD-related cirrhosis, advanced liver disease, and liver-related mortality were quantified through 2030. Results: Prevalent NAFLD cases are forecasted to increase 21%, from 83.1 (2015) to 100.9 million (2030), while prevalent NASH cases will increase 63% from 16.52 to 27.00 million cases. Overall NAFLD prevalence among the adult population (aged ≥15 years) is projected at 33.5% in 2030, and the median age of the NAFLD population will increase from 50 to 55 years during 2015-2030. In 2015, approximately 20% of NAFLD cases were classified as NASH, increasing to 27% by 2030, a reflection of both disease progression and an aging population. Incidence of decompensated cirrhosis will increase 168% to 105,430 cases by 2030, while incidence of HCC will increase by 137% to 12,240 cases. Liver deaths will increase 178% to an estimated 78,300 deaths in 2030. During 2015-2030, there are nearly 800,000 excess liver deaths. Conclusions: With continued high rates of adult obesity and DM, and an aging population, NAFLD-related liver disease and mortality will increase in the US. Strategies to slow the growth of NAFLD cases and therapeutic options are necessary to mitigate disease burden. This article is protected by copyright. All rights reserved.

Ferroptosis is a recently identified iron‐dependent form of nonapoptotic cell death implicated in brain, kidney, and heart pathology. However, the biological roles of iron and iron metabolism in ferroptosis remain poorly understood. Here, we studied the functional role of iron and iron metabolism in the pathogenesis of ferroptosis. We found that ferric citrate potently induces ferroptosis in murine primary hepatocytes and bone marrow–derived macrophages. Next, we screened for ferroptosis in mice fed a high‐iron diet and in mouse models of hereditary hemochromatosis with iron overload. We found that ferroptosis occurred in mice fed a high‐iron diet and in two knockout mouse lines that develop severe iron overload (Hjv–/– and Smad4Alb/Alb mice) but not in a third line that develops only mild iron overload (Hfe –/– mice). Moreover, we found that iron overload–induced liver damage was rescued by the ferroptosis inhibitor ferrostatin‐1. To identify the genes involved in iron‐induced ferroptosis, we performed microarray analyses of iron‐treated bone marrow–derived macrophages. Interestingly, solute carrier family 7, member 11 (Slc7a11), a known ferroptosis‐related gene, was significantly up‐regulated in iron‐treated cells compared with untreated cells. However, genetically deleting Slc7a11 expression was not sufficient to induce ferroptosis in mice. Next, we studied iron‐treated hepatocytes and bone marrow–derived macrophages isolated from Slc7a11–/– mice fed a high‐iron diet. Conclusion: We found that iron treatment induced ferroptosis in Slc7a11–/– cells, indicating that deleting Slc7a11 facilitates the onset of ferroptosis specifically under high‐iron conditions; these results provide compelling evidence that iron plays a key role in triggering Slc7a11‐mediated ferroptosis and suggest that ferroptosis may be a promising target for treating hemochromatosis‐related tissue damage. (Hepatology 2017;66:449–465).

Ferroportin (FPN1) is the sole iron exporter in mammals, but its cell‐specific function and regulation are still elusive. This study examined FPN1 expression in human macrophages, the cells that are primarily responsible on a daily basis for plasma iron turnover and are central in the pathogenesis of ferroportin disease (FD), the disease attributed to lack‐of‐function FPN1 mutations. We characterized FPN1 protein expression and traffic by confocal microscopy, western blotting, gel filtration, and immunoprecipitation studies in macrophages from control blood donors (donor) and patients with either FPN1 p.A77D, p.G80S, and p.Val162del lack‐of‐function or p.A69T gain‐of‐function mutations. We found that in normal macrophages, FPN1 cycles in the early endocytic compartment does not multimerize and is promptly degraded by hepcidin (Hepc), its physiological inhibitor, within 3‐6 hours. In FD macrophages, endogenous FPN1 showed a similar localization, except for greater accumulation in lysosomes. However, in contrast with previous studies using overexpressed mutant protein in cell lines, FPN1 could still reach the cell surface and be normally internalized and degraded upon exposure to Hepc. However, when FD macrophages were exposed to large amounts of heme iron, in contrast to donor and p.A69T macrophages, FPN1 could no longer reach the cell surface, leading to intracellular iron retention. Conclusion: FPN1 cycles as a monomer within the endocytic/plasma membrane compartment and responds to its physiological inhibitor, Hepc, in both control and FD cells. However, in FD, FPN1 fails to reach the cell surface when cells undergo high iron turnover. Our findings provide a basis for the FD characterized by a preserved iron transfer in the enterocytes (i.e., cells with low iron turnover) and iron retention in cells exposed to high iron flux, such as liver and spleen macrophages. (Hepatology 2017;65:1512‐1525)

UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) can progress from simple steatosis (i.e., nonalcoholic fatty liver [NAFL]) to nonalcoholic steatohepatitis (NASH), cirrhosis, and cancer. Currently, the driver for this progression is not fully understood; in particular, it is not known how NAFLD and its early progression affects the distribution of lipids in the liver, producing lipotoxicity and inflammation. In this study, we used dietary and genetic mouse models of NAFL and NASH and translated the results to humans by correlating the spatial distribution of lipids in liver tissue with disease progression using advanced mass spectrometry imaging technology. We identified several lipids with distinct zonal distributions in control and NAFL samples and observed partial to complete loss of lipid zonation in NASH. In addition, we found increased hepatic expression of genes associated with remodeling the phospholipid membrane, release of arachidonic acid (AA) from the membrane, and production of eicosanoid species that promote inflammation and cell injury. The results of our immunohistochemistry analyses suggest that the zonal location of remodeling enzyme LPCAT2 plays a role in the change in spatial distribution for AA-containing lipids. This results in a cycle of AA-enrichment in pericentral hepatocytes, membrane release of AA, and generation of proinflammatory eicosanoids and may account for increased oxidative damage in pericentral regions in NASH. CONCLUSION: NAFLD is associated not only with lipid enrichment, but also with zonal changes of specific lipids and their associated metabolic pathways. This may play a role in the heterogeneous development of NAFLD. (Hepatology 2017;65:1165-1180).

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide. Due to the growing economic burden of NAFLD on public health, it has become an emergent target for clinical intervention. DUSP12 is a member of the dual specificity phosphatase (DUSP) family, which plays important roles in brown adipocyte differentiation, microbial infection, and cardiac hypertrophy. However, the role of DUSP12 in NAFLD has yet to be clarified. Here, we reveal that DUSP12 protects against hepatic steatosis and inflammation in L02 cells after palmitic acid/oleic acid treatment. We demonstrate that hepatocyte specific DUSP12‐deficient mice exhibit high‐fat diet (HFD)–induced and high‐fat high‐cholesterol diet–induced hyperinsulinemia and liver steatosis and decreased insulin sensitivity. Consistently, DUSP12 overexpression in hepatocyte could reduce HFD‐induced hepatic steatosis, insulin resistance, and inflammation. At the molecular level, steatosis in the absence of DUSP12 was characterized by elevated apoptosis signal‐regulating kinase 1 (ASK1), which mediates the mitogen‐activated protein kinase (MAPK) pathway and hepatic metabolism. DUSP12 physically binds to ASK1, promotes its dephosphorylation, and inhibits its action on ASK1‐related proteins, JUN N‐terminal kinase, and p38 MAPK in order to inhibit lipogenesis under high‐fat conditions. Conclusion: DUSP12 acts as a positive regulator in hepatic steatosis and offers potential therapeutic opportunities for NAFLD.

Nonalcoholic fatty liver is associated with obesity-related metabolic disturbances, but little is known about the metabolic perturbations preceding fatty liver disease. We performed comprehensive metabolic profiling to assess how circulating metabolites, such as lipoprotein lipids, fatty acids, amino acids, and glycolysis-related metabolites, reflect the presence of and future risk for fatty liver in young adults. Sixty-eight lipids and metabolites were quantified by nuclear magnetic resonance metabolomics in the population-based Young Finns Study from serum collected in 2001 (n = 1,575), 2007 (n = 1,509), and 2011 (n = 2,002). Fatty liver was diagnosed by ultrasound in 2011 when participants were aged 34-49 years (19% prevalence). Cross-sectional associations as well as 4-year and 10-year risks for fatty liver were assessed by logistic regression. Metabolites across multiple pathways were strongly associated with the presence of fatty liver (P < 0.0007 for 60 measures in age-adjusted and sex-adjusted cross-sectional analyses). The strongest direct associations were observed for extremely large very-low-density lipoprotein triglycerides (odds ratio [OR] = 4.86 per 1 standard deviation, 95% confidence interval 3.48-6.78), other very-low-density lipoprotein measures, and branched-chain amino acids (e.g., leucine OR = 2.94, 2.51-3.44). Strong inverse associations were observed for high-density lipoprotein measures, e.g., high-density lipoprotein size (OR = 0.36, 0.30-0.42) and several fatty acids including omega-6 (OR = 0.37, 0.32-0.42). The metabolic associations were attenuated but remained significant after adjusting for waist, physical activity, alcohol consumption, and smoking (P < 0.0007). Similar aberrations in the metabolic profile were observed already 10 years before fatty liver diagnosis. Conclusion: Circulating lipids, fatty acids, and amino acids reflect fatty liver independently of routine metabolic risk factors; these metabolic aberrations appear to precede the development of fatty liver in young adults. (Hepatology 2017;65:491-500).

The opioid system is widely known to modulate the brain reward system and thus affect the behavior of humans and other animals, including feeding. We hypothesized that the hypothalamic opioid system might also control energy metabolism in peripheral tissues. Mice lacking the kappa opioid receptor (κOR) and adenoviral vectors overexpressing or silencing κOR were stereotaxically delivered in the lateral hypothalamic area (LHA) of rats. Vagal denervation was performed to assess its effect on liver metabolism. Endoplasmic reticulum (ER) stress was inhibited by pharmacological (tauroursodeoxycholic acid) and genetic (overexpression of the chaperone glucose-regulated protein 78 kDa) approaches. The peripheral effects on lipid metabolism were assessed by histological techniques and western blot. We show that in the LHA κOR directly controls hepatic lipid metabolism through the parasympathetic nervous system, independent of changes in food intake and body weight. κOR colocalizes with melanin concentrating hormone receptor 1 (MCH-R1) in the LHA, and genetic disruption of κOR reduced melanin concentrating hormone–induced liver steatosis. The functional relevance of these findings was given by the fact that silencing of κOR in the LHA attenuated both methionine choline–deficient, diet-induced and choline-deficient, high-fat diet–induced ER stress, inflammation, steatohepatitis, and fibrosis, whereas overexpression of κOR in this area promoted liver steatosis. Overexpression of glucose-regulated protein 78 kDa in the liver abolished hypothalamic κOR-induced steatosis by reducing hepatic ER stress. Conclusions: This study reveals a novel hypothalamic–parasympathetic circuit modulating hepatic function through inflammation and ER stress independent of changes in food intake or body weight; these findings might have implications for the clinical use of opioid receptor antagonists. (Hepatology 2016;64:1086-1104)

A sequence variation (I148M) in patatin‐like phospholipase domain‐containing protein 3 (PNPLA3) is strongly associated with fatty liver disease, but the underlying mechanism remains obscure. In this study, we used knock‐in (KI) mice (Pnpla3148M/M) to examine the mechanism responsible for accumulation of triglyceride (TG) and PNPLA3 in hepatic lipid droplets (LDs). No differences were found between Pnpla3148M/M and Pnpla3+/+ mice in hepatic TG synthesis, utilization, or secretion. These results are consistent with TG accumulation in the Pnpla3148M/M mice being caused by impaired TG mobilization from LDs. Sucrose feeding, which is required to elicit fatty liver in KI mice, led to a much larger and more persistent increase in PNPLA3 protein in the KI mice than in wild‐type (WT) mice. Inhibition of the proteasome (bortezomib), but not macroautophagy (3‐methyladenine), markedly increased PNPLA3 levels in WT mice, coincident with the appearance of ubiquitylated forms of the protein. Bortezomib did not increase PNPLA3 levels in Pnpla3148M/M mice, and only trace amounts of ubiquitylated PNPLA3 were seen in these animals. Conclusion: These results are consistent with the notion that the 148M variant disrupts ubiquitylation and proteasomal degradation of PNPLA3, resulting in accumulation of PNPLA3‐148M and impaired mobilization of TG from LDs. (Hepatology 2017;66:1111‐1124).

A variant (148M) in patatin‐like phospholipase domain‐containing protein 3 (PNPLA3) is a major risk factor for fatty liver disease. Despite its clinical importance, the pathogenic mechanism linking the variant to liver disease remains poorly defined. Previously, we showed that PNPLA3(148M) accumulates to high levels on hepatic lipid droplets (LDs). Here we examined the effect of that accumulation on triglyceride (TG) hydrolysis by adipose triglyceride lipase (ATGL), the major lipase in the liver. As expected, overexpression of ATGL in cultured hepatoma (HuH‐7) cells depleted the cells of LDs, but unexpectedly, co‐expression of PNPLA3(wild type [WT] or 148M) with ATGL inhibited that depletion. The inhibitory effect of PNPLA3 was not caused by the displacement of ATGL from LDs. We tested the hypothesis that PNPLA3 interferes with ATGL activity by interacting with its cofactor, comparative gene identification‐58 (CGI‐58). Evidence supporting such an interaction came from two findings. First, co‐expression of PNPLA3 and CGI‐58 resulted in LD depletion in cultured cells, but expression of PNPLA3 alone did not. Second, PNPLA3 failed to localize to hepatic LDs in liver‐specific Cgi‐58 knockout (KO) mice. Moreover, overexpression of PNPLA3(148M) increased hepatic TG levels in WT, but not in Cgi‐58 KO mice. Thus, the pro‐steatotic effects of PNPLA3 required the presence of CGI‐58. Co‐immunoprecipitation and pulldown experiments in livers of mice and in vitro using purified proteins provided evidence that PNPLA3 and CGI‐58 can interact directly. Conclusion: Taken together, these findings are consistent with a model in which PNPLA3(148M) promotes steatosis by CGI‐58‐dependent inhibition of ATGL on LDs.

The role of antiretroviral therapy (ART) in reducing or contributing to liver fibrosis in persons with human immunodeficiency virus (HIV) is unclear. We evaluated participants in the Strategic Timing of AntiRetroviral Treatment (START) trial for liver fibrosis using the AST to Platelet Ratio Index (APRI) and Fibrosis-4 Index (FIB-4), and assessed for a benefit of early versus delayed ART on liver fibrosis progression. ART-naive persons with high CD4 counts (>500 cells/µL) from 222 clinical sites in 35 countries were randomized to receive ART either at study enrollment (immediate treatment arm) or when their CD4 count fell below 350 cells/µL (deferred treatment arm). The following outcomes were evaluated: fibrosis (APRI > 0.5 or FIB-4 > 1.45), significant fibrosis (APRI > 1.5 or FIB-4 > 3.25), hepatic flare, and resolution of elevated APRI and FIB-4 scores. Of the 4,684 enrolled into the START study, 104 did not have APRI or FIB-4 results and were excluded. Among 4,580 participants (2,273 immediate treatment; 2,307 deferred treatment), the median age was 36 years, 26.9% were female, and 30.4% were black. Three percent had an alcoholism or substance abuse history, 6.4% had hepatitis B and/or C, and 1.1% had significant fibrosis at baseline. The median CD4 count was 651, and 5.3% had HIV RNA ≤ 200. Immediate arm participants were at lower risk of developing increased fibrosis scores than deferred arm participants (hazard ratio [HR] = 0.66; 95% confidence interval [CI] = 0.57-0.78; P < 0.001) and more likely to have resolution of elevated baseline scores (HR 1.6; 95% CI 1.3-1.9; P < 0.001). Conclusions: Significant liver fibrosis was rare among ART-naive HIV-positive persons with high CD4 counts. Our findings suggest a benefit of early ART in preventing the development of liver fibrosis.

Nonalcoholic fatty liver disease (NAFLD), ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis (NASH), is the leading cause of chronic liver diseases. Until now, no medications for NAFLD have been approved by relevant governmental agencies. Dual-specificity phosphatase 9 (Dusp9) is a member of the DUSP protein family. Dusp9 is expressed in insulin-sensitive tissues, and its expression may be modified with the development of insulin resistance (IR). However, the molecular targets and mechanisms of Dusp9 action on NAFLD and NASH remain poorly understood. In this study, using conditional liver-specific Dusp9-knockout (Dusp9-CKO) mice and Dusp9-transgenic mice, we showed that Dusp9 was a key suppressor of high-fat diet-induced hepatic steatosis and inflammatory responses and that Dusp9 deficiency aggravated high-fat high-cholesterol diet-induced liver fibrosis. Dusp9 was shown to exert its effects by blocking apoptosis signal-regulating kinase 1 (ASK1) phosphorylation and the subsequent activation of p38 and c-Jun NH2-terminal kinase signaling. Conclusion: Hepatocyte Dusp9 prevents NAFLD and NASH progression in mice, including lipid accumulation, glucose metabolism disorders, and enhanced inflammation and liver fibrosis, in an ASK1-dependent manner; these findings suggest that Dusp9 may be a promising therapeutic target for the treatment of NAFLD and NASH.

The aim of this study was to evaluate cenicriviroc (CVC), a dual antagonist of C-C chemokine receptor types 2 and 5, for treatment of nonalcoholic steatohepatitis (NASH) with liver fibrosis. A randomized, double-blind, multinational phase 2b study enrolled subjects with NASH, a nonalcoholic fatty liver disease activity score [NAS] ≥4, and liver fibrosis (stages 1-3, NASH Clinical Research Network) at 81 clinical sites. Subjects (N = 289) were randomly assigned CVC 150 mg or placebo. Primary outcome was ≥2-point improvement in NAS and no worsening of fibrosis at year 1. Key secondary outcomes were: resolution of steatohepatitis and no worsening of fibrosis; improvement in fibrosis by ≥1 stage and no worsening of steatohepatitis. Biomarkers of inflammation and adverse events were assessed. Full study recruitment was achieved. The primary end point of NAS improvement in the intent-to-treat population and resolution of steatohepatitis was achieved in a similar proportion of subjects on CVC (N = 145) and placebo (N = 144) (16% vs 19%, P = 0.52 and 8% vs 6%, P = 0.49, respectively). However, the fibrosis end point was met in significantly more subjects on CVC than placebo (20% vs 10%; P = 0.02). Treatment benefits were greater in those with higher disease activity and fibrosis stage at baseline. Biomarkers of systemic inflammation were reduced with CVC. Safety and tolerability of CVC were comparable to placebo. Conclusions: After 1 year of CVC treatment, twice as many subjects achieved improvement in fibrosis and no worsening of steatohepatitis compared with placebo. Given the urgent need to develop antifibrotic therapies in NASH, these findings warrant phase 3 evaluation. ClinicalTrials.gov no: NCT02217475 (CENTAUR). This article is protected by copyright. All rights reserved.

Inhibition of apoptosis signal–regulating kinase 1, a serine/threonine kinase, leads to improvement in inflammation and fibrosis in animal models of nonalcoholic steatohepatitis. We evaluated the safety and efficacy of selonsertib, a selective inhibitor of apoptosis signal–regulating kinase 1, alone or in combination with simtuzumab, in patients with nonalcoholic steatohepatitis and stage 2 or 3 liver fibrosis. In this multicenter phase 2 trial, 72 patients were randomized to receive 24 weeks of open‐label treatment with either 6 or 18 mg of selonsertib orally once daily with or without once‐weekly injections of 125 mg of simtuzumab or simtuzumab alone. The effect of treatment was assessed by paired pretreatment and posttreatment liver biopsies, magnetic resonance elastography, magnetic resonance imaging–estimated proton density fat fraction, quantitative collagen content, and noninvasive markers of liver injury. Due to the lack of effect of simtuzumab on histology or selonsertib pharmacokinetics, selonsertib groups with and without simtuzumab were pooled. After 24 weeks of treatment, the proportion of patients with a one or more stage reduction in fibrosis in the 18‐mg selonsertib group was 13 of 30 (43%; 95% confidence interval, 26‐63); in the 6‐mg selonsertib group, 8 of 27 (30%; 95% confidence interval, 14‐50); and in the simtuzumab‐alone group, 2 of 10 (20%; 95% confidence interval, 3‐56). Improvement in fibrosis was associated with reductions in liver stiffness on magnetic resonance elastography, collagen content and lobular inflammation on liver biopsy, as well as improvements in serum biomarkers of apoptosis and necrosis. There were no significant differences in adverse events between the treatment groups. Conclusion: These findings suggest that selonsertib may reduce liver fibrosis in patients with nonalcoholic steatohepatitis and stage 2‐3 fibrosis. (Hepatology 2018;67:549‐559).

The prevalence of diabetes is increasing rapidly in China. However, evidence is limited about its effects on chronic liver diseases and liver cancer. We aimed to examine the associations of diabetes with chronic liver diseases and liver cancer and of random plasma glucose (RPG) with these liver diseases among participants without diabetes in Chinese adults, and to assess the possible interaction by hepatitis B virus (HBV) infection. The prospective China Kadoorie Biobank recruited 512,891 adults. During 10 years of follow-up, 2,568 liver cancer, 2,082 cirrhosis, 1,298 hospitalised non-alcoholic fatty liver disease (NAFLD), and 244 hospitalised alcoholic liver disease (ALD) were recorded among 503,993 participants without prior history of cancer or chronic liver diseases at baseline. Cox regression was used to estimate hazard ratios (HRs) for each disease by diabetes status (previously diagnosed or screen-detected) and, among those without previously diagnosed diabetes, by levels of RPG. Overall 5.8% of participants had diabetes at baseline. Compared with those without diabetes, individuals with diabetes had adjusted HRs of 1.49 (95% CI 1.30-1.70) for liver cancer, 1.81 (1.57-2.09) for cirrhosis, 1.76 (1.47-2.16) for NAFLD, and 2.24 (1.42-3.54) for ALD. The excess risks decreased but remained elevated in those with longer duration. Among those without previously diagnosed diabetes, RPG was positively associated with liver diseases, with adjusted HRs per 1 mmol/L higher RPG of 1.04 (1.03-1.06) for liver cancer, 1.07 (1.05-1.09) for cirrhosis, 1.07 (1.05-1.10) for NAFLD, and 1.10 (1.05-1.15) for ALD. These associations did not differ by HBV infection.In Chinese adults, diabetes and higher blood glucose levels among those without known diabetes are associated with increased risks of liver cancer and major chronic liver diseases. This article is protected by copyright. All rights reserved.

With no approved pharmacological treatment, nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease in Western countries and its worldwide prevalence continues to increase along with the growing obesity epidemic. Here, we show that a high‐fat high‐sucrose (HFHS) diet, eliciting chronic hepatosteatosis resembling human fatty liver, lowers hepatic nicotinamide adenine dinucleotide (NAD+) levels driving reductions in hepatic mitochondrial content, function, and adenosine triphosphate (ATP) levels, in conjunction with robust increases in hepatic weight, lipid content, and peroxidation in C57BL/6J mice. To assess the effect of NAD+ repletion on the development of steatosis in mice, nicotinamide riboside, a precursor of NAD+ biosynthesis, was added to the HFHS diet, either as a preventive strategy or as a therapeutic intervention. We demonstrate that NR prevents and reverts NAFLD by inducing a sirtuin (SIRT)1‐ and SIRT3‐dependent mitochondrial unfolded protein response, triggering an adaptive mitohormetic pathway to increase hepatic β‐oxidation and mitochondrial complex content and activity. The cell‐autonomous beneficial component of NR treatment was revealed in liver‐specific Sirt1 knockout mice (Sirt1hep−/−), whereas apolipoprotein E‐deficient mice (Apoe −/−) challenged with a high‐fat high‐cholesterol diet affirmed the use of NR in other independent models of NAFLD. Conclusion: Our data warrant the future evaluation of NAD+ boosting strategies to manage the development or progression of NAFLD. (Hepatology 2016;63:1190–1204)

Hepatic copper determination is an important test for the diagnosis of Wilson's disease (WD). However, the method has not been standardized, the diagnostic accuracy has not been evaluated prospectively, and the optimal cut‐off value remains controversial. Accordingly, we aimed to prospectively evaluate the diagnostic accuracy of hepatic copper content, as determined using the entire core of a liver biopsy sample. Patients for whom a liver biopsy was indicated were consecutively enrolled. Hepatic copper content was determined with atomic absorption spectroscopy. All assays were performed using careful quality control by a single technician. WD diagnosis was based on WD score or its combination with clinical follow‐up results. A total of 3,350 consecutive patients underwent liver biopsy. Six hundred ninety‐one patients, including 178 with WD, underwent two passes of liver biopsy with hepatic copper determination. Mean hepatic content in WD patients was 770.6 ± 393.2 μg/g dry weight (wt). Sensitivity, specificity, and positive and negative predictive values of hepatic copper content for WD diagnosis in the absence of primary biliary cirrhosis (PBC) or primary sclerosing cholangitis at the cut‐off value of 250 μg/g dry wt. were 94.4%, 96.8%, 91.8%, and 97.8%, respectively. The most useful cut‐off value was 209 μg/g dry wt, with a sensitivity and specificity of 99.4% and 96.1%, respectively. A total of 23.3% of patients without WD and PBC had hepatic copper content >75 μg/g dry wt. Conclusion: A liver biopsy sample of more than 1 mg dry wt may reliably reflect hepatic copper content and should be used for hepatic copper determination. Hepatic copper determination is a very valid procedure for the diagnosis of WD, and the most useful cut‐off value is 209 μg/g dry wt.(Hepatology 2015;62:1731–1741)

Cholesterol synthesis is regulated by the transcription factor sterol regulatory element binding protein 2 (SREBP‐2) and its target gene 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR), which is the rate‐limiting enzyme in cholesterol synthesis. Cyclic adenosine monophosphate–responsive element (CRE) binding protein–regulated transcription coactivator (CRTC) 2 is the master regulator of glucose metabolism. However, the effect of CRTC2 on cholesterol and its potential molecular mechanism remain unclear. Here, we demonstrated that CRTC2 expression and liver cholesterol content were increased in patients with high serum cholesterol levels who underwent resection of liver hemangiomas, as well as in mice fed a 4% cholesterol diet. Mice with adenovirus‐mediated CRTC2 overexpression also showed elevated lipid levels in both serum and liver tissues. Intriguingly, hepatic de novo cholesterol synthesis was markedly increased under these conditions. In contrast, CRTC2 ablation in mice fed a 4% cholesterol diet (18 weeks) showed decreased lipid levels in serum and liver tissues compared with those in littermate wild‐type mice. The expression of lipogenic genes (SREBP‐2 and HMGCR) was consistent with hepatic CRTC2 levels. In vivo imaging showed enhanced adenovirus‐mediated HMGCR‐luciferase activity in adenovirus‐mediated CRTC2 mouse livers; however, the activity was attenuated after mutation of CRE or sterol regulatory element sequences in the HMGCR reporter construct. The effect of CRTC2 on HMGCR in mouse livers was alleviated upon SREBP‐2 knockdown. CRTC2 modulated SREBP‐2 transcription by CRE binding protein, which recognizes the half‐site CRE sequence in the SREBP‐2 promoter. CRTC2 reduced the nuclear protein expression of forkhead box O1 and subsequently increased SREBP‐2 transcription by binding insulin response element 1, rather than insulin response element 2, in the SREBP‐2 promoter. Conclusion: CRTC2 regulates the transcription of SREBP‐2 by interfering with the recognition of insulin response element 1 in the SREBP‐2 promoter by forkhead box O1, thus inducing SREBP‐2/HMGCR signaling and subsequently facilitating hepatic cholesterol synthesis. (Hepatology 2017;66:481–497).

Excess collagen synthesis (fibrogenesis) in the liver plays a causal role in the progression of nonalcoholic fatty liver disease (NAFLD). Methods are needed to identify patients with more rapidly progressing disease and to demonstrate early response to treatment. We describe here a novel method to quantify hepatic fibrogenesis flux rates both directly in liver tissue and non-invasively in blood. Twenty-one patients with suspected NAFLD ingested heavy water (2H2O, 50 ml aliquots) 2-3 times daily for 3 to 5 weeks prior to a clinically indicated liver-biopsy. Liver collagen fractional synthesis rate (FSR) and plasma lumican FSR were measured based on 2H labeling using tandem mass spectrometry. Patients were classified by histology for fibrosis stage (F0-F4) and as having non-alcoholic fatty liver (NAFL) or non-alcoholic steatohepatitis (NASH). Magnetic resonance elastography measurements of liver stiffness were also performed. Hepatic collagen FSR in NAFLD increased with advancing disease stage (e.g. higher in NASH than NAFL, positive correlation with fibrosis score and liver stiffness) and correlated with hemoglobin A1C. In addition, plasma lumican FSR demonstrated a significant correlation with hepatic collagen FSR. Conclusion: Utilizing a well-characterized cohort of patients with biopsy-proven NAFLD, this study demonstrates that hepatic scar in NASH is actively remodeled even in advanced fibrosis, a disease that is generally regarded as static and slowly progressive. Moreover, hepatic collagen FSR correlates with established risks for fibrotic disease progression in NASH and plasma lumican FSR correlates with hepatic collagen FSR, suggesting applications as direct or surrogate markers, respectively, of hepatic fibrogenesis in humans. This article is protected by copyright. All rights reserved.

Obesity is a worldwide health problem and associated with hepatic steatosis and intra-abdominal fat accumulation. Although obesity and hepatic steatosis often coincide, hepatic steatosis can be present in lean subjects and is not present in all obese humans,1 suggesting that factors besides obesity contribute to fat accumulation in the liver. An obvious candidate to be involved is the diet. Caloric content2 and individual macronutrients are associated with hepatic steatosis. Short-term high-fat diets increase intrahepatic triglyceride content (IHTG) in lean and obese humans3,4 and induce robust hepatic steatosis in rodents5 and dietary glucose and fructose stimulate de novo lipogenesis (DNL)6 and increase IHTG, even in lean subjects.7,8 Moreover, cross-sectional studies have identified the consumption of sugar-sweetened soft drinks as a dietary factor predicting hepatic steatosis.9 Recent human studies, however, showed that overfeeding resulted in accumulation of IHTG without a differential effect of fructose, glucose, or fat.10,11 This suggests that macronutrient composition is not the only determining dietary factor in IHTG accumulation. A factor less often considered is the frequency and timing of food intake. This is remarkable, since up to 27% of U.S. children's daily calories come from snacks12 and also in obese women excessive caloric intake mainly comes from snacks between meals.13 Interestingly, when provided with the choice to consume saturated fat and liquid sugar separate from their balanced chow pellets, rats increase their meal frequency, show persistent hyperphagia, and become obese.14 Whether snacking specifically affects IHTG is unknown. Hepatic steatosis increases the risk for nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis and is associated with insulin resistance.15,16 How hepatic steatosis interferes with insulin sensitivity in humans is only in part elucidated. We recently showed in patients with familial hypobetalipoproteinemia, which is characterized by massive IHTG accumulation, that hepatic steatosis per se is not associated with insulin resistance.17 Interference of lipid metabolites with insulin signaling is a general concept in obesity-associated insulin resistance, and macronutrients themselves are able to modulate glucose production and insulin sensitivity independent of obesity.18,19 Rats snacking fat and sugar develop insulin resistance within 1 week,20 and female adolescents who reported consumption of frequent snacks throughout the day have a higher homeostatic model assessment of insulin resistance (HOMA-IR) compared to nonsnacking controls.21 Randomized controlled studies on the effect of increasing meal frequency or meal size with different macronutrient combinations on insulin sensitivity and IHTG are currently unavailable and was the aim of this study. We hypothesized that increasing meal frequency, representing a snacking eating pattern, negatively affects IHTG and insulin sensitivity.

Inflammation plays a central pathogenic role in the pernicious metabolic and end-organ sequelae of obesity. Among these sequelae, nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the developed world. The twinned observations that obesity is associated with increased activation of the interleukin (IL)-17 axis and that this axis can regulate liver damage in diverse contexts prompted us to address the role of IL-17RA signaling in the progression of NAFLD. We further examined whether microbe-driven IL-17A regulated NAFLD development and progression. We show here that IL-17RA−/− mice respond to high-fat diet stress with significantly greater weight gain, visceral adiposity, and hepatic steatosis than wild-type controls. However, obesity-driven lipid accumulation was uncoupled from its end-organ consequences in IL-17RA−/− mice, which exhibited decreased steatohepatitis, nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase enzyme expression, and hepatocellular damage. Neutralization of IL-17A significantly reduced obesity-driven hepatocellular damage in wild-type mice. Further, colonization of mice with segmented filamentous bacteria (SFB), a commensal that induces IL-17A production, exacerbated obesity-induced hepatocellular damage. In contrast, SFB depletion protected from obesity-induced hepatocellular damage. Conclusion: These data indicate that obesity-driven activation of the IL-17 axis is central to the development and progression of NAFLD to steatohepatitis and identify the IL-17 pathway as a novel therapeutic target in this condition. (Hepatology 2014;59:1830–1839)

We report the genetic analysis of a “humanized” hyperlipidemic mouse model for progressive nonalcoholic steatohepatitis (NASH) and fibrosis. Mice carrying transgenes for human apolipoprotein E*3‐Leiden and cholesteryl ester transfer protein and fed a “Western” diet were studied on the genetic backgrounds of over 100 inbred mouse strains. The mice developed hepatic inflammation and fibrosis that was highly dependent on genetic background, with vast differences in the degree of fibrosis. Histological analysis showed features characteristic of human NASH, including macrovesicular steatosis, hepatocellular ballooning, inflammatory foci, and pericellular collagen deposition. Time course experiments indicated that while hepatic triglyceride levels increased steadily on the diet, hepatic fibrosis occurred at about 12 weeks. We found that the genetic variation predisposing to NASH and fibrosis differs markedly from that predisposing to simple steatosis, consistent with a multistep model in which distinct genetic factors are involved. Moreover, genome‐wide association identified distinct genetic loci contributing to steatosis and NASH. Finally, we used hepatic expression data from the mouse panel and from 68 bariatric surgery patients with normal liver, steatosis, or NASH to identify enriched biological pathways. Conclusion: The pathways showed substantial overlap between our mouse model and the human disease.

Genome-wide array studies have associated the patatin-like phospholipase domain-containing 3 (PNPLA3) gene polymorphisms with hepatic steatosis. However, it is unclear whether PNPLA3 functions as a lipase or a lipogenic enzyme and whether PNPLA3 is involved in the pathogenesis of hepatic insulin resistance. To address these questions we treated high-fat-fed rats with specific antisense oligonucleotides to decrease hepatic and adipose pnpla3 expression. Reducing pnpla3 expression prevented hepatic steatosis, which could be attributed to decreased fatty acid esterification measured by the incorporation of [U-13C]-palmitate into hepatic triglyceride. While the precursors for phosphatidic acid (PA) (long-chain fatty acyl-CoAs and lysophosphatidic acid [LPA]) were not decreased, we did observe an ∼20% reduction in the hepatic PA content, ∼35% reduction in the PA/LPA ratio, and ∼60%-70% reduction in transacylation activity at the level of acyl-CoA:1-acylglycerol-sn-3-phosphate acyltransferase. These changes were associated with an ∼50% reduction in hepatic diacylglycerol (DAG) content, an ∼80% reduction in hepatic protein kinase Cε activation, and increased hepatic insulin sensitivity, as reflected by a 2-fold greater suppression of endogenous glucose production during the hyperinsulinemic-euglycemic clamp. Finally, in humans, hepatic PNPLA3 messenger RNA (mRNA) expression was strongly correlated with hepatic triglyceride and DAG content, supporting a potential lipogenic role of PNPLA3 in humans. Conclusion: PNPLA3 may function primarily in a lipogenic capacity and inhibition of PNPLA3 may be a novel therapeutic approach for treatment of nonalcoholic fatty liver disease-associated hepatic insulin resistance. ((Hepatology 2013;57:1763-1772))

Alpha1‐antitrypsin deficiency is a genetic disease that can affect both the lung and the liver. The vast majority of patients harbor a mutation in the serine protease inhibitor 1A (SERPINA1) gene leading to a single amino acid substitution that results in an unfolded protein that is prone to polymerization. Alpha1‐antitrypsin defciency‐related liver disease is therefore caused by a gain‐of‐function mechanism due to accumulation of the mutant Z alpha1‐antitrypsin (ATZ) and is a key example of an disease mechanism induced by protein toxicity. Intracellular retention of ATZ triggers a complex injury cascade including apoptosis and other mechanisms, although several aspects of the disease pathogenesis are still unclear. We show that ATZ induces activation of c‐Jun N‐terminal kinase (JNK) and c‐Jun and that genetic ablation of JNK1 or JNK2 decreased ATZ levels in vivo by reducing c‐Jun–mediated SERPINA1 gene expression. JNK activation was confirmed in livers of patients homozygous for the Z allele, with severe liver disease requiring hepatic transplantation. Treatment of patient‐derived induced pluripotent stem cell‐hepatic cells with a JNK inhibitor reduced accumulation of ATZ. Conclusion: These data reveal that JNK is a key pathway in the disease pathogenesis and add new therapeutic entry points for liver disease caused by ATZ. (Hepatology 2017;65:1865‐1874).

Nonalcoholic fatty liver disease (NAFLD) and insulin resistance have recently been found to be associated with increased plasma concentrations of apolipoprotein CIII (APOC3) in humans carrying single nucleotide polymorphisms within the insulin response element of the APOC3 gene. To examine whether increased expression of APOC3 would predispose mice to NAFLD and hepatic insulin resistance, human APOC3 overexpressing (ApoC3Tg) mice were metabolically phenotyped following either a regular chow or high-fat diet (HFD). After HFD feeding, ApoC3Tg mice had increased hepatic triglyceride accumulation, which was associated with cellular ballooning and inflammatory changes. ApoC3Tg mice also manifested severe hepatic insulin resistance assessed by a hyperinsulinemiceuglycemic clamp, which could mostly be attributed to increased hepatic diacylglycerol content, protein kinase C- activation, and decreased insulin-stimulated Akt2 activity. Increased hepatic triglyceride content in the HFD-fed ApoC3Tg mice could be attributed to a � 70% increase in hepatic triglyceride uptake and � 50% reduction hepatic triglyceride secretion. Conclusion: These data demonstrate that increase plasma APOC3 concentrations predispose mice to diet-induced NAFLD and hepatic insulin resistance. (HEPATOLOGY 2011;54:1650-1660)

A sequence polymorphism (rs738409, I148M) in patatin-like phospholipid domain containing protein 3 (PNPLA3) is strongly associated with nonalcoholic fatty liver disease (NAFLD), but the mechanistic basis for this association remains enigmatic. Neither ablation nor overexpression of wild-type PNPLA3 affects liver fat content in mice, whereas hepatic overexpression of the human 148M transgene causes steatosis. To determine whether the 148M allele causes fat accumulation in the liver when expressed at physiological levels, we introduced a methionine codon at position 148 of the mouse Pnpla3 gene. Knockin mice had normal levels of hepatic fat on a chow diet, but when challenged with a high-sucrose diet their liver fat levels increased 2 to 3-fold compared to wild-type littermates without any associated changes in glucose homeostasis. The increased liver fat in the knockin mice was accompanied by a 40-fold increase in PNPLA3 on hepatic lipid droplets, with no increase in hepatic PNPLA3 messenger RNA (mRNA). Similar results were obtained when the catalytic dyad of PNPLA3 was inactivated by substituting the catalytic serine with alanine (S47A). Conclusion: These data provide the first direct evidence that physiological expression of PNPLA3 148M variant causes NAFLD, and that the accumulation of catalytically inactive PNPLA3 on the surfaces of lipid droplets is associated with the accumulation of TG in the liver. (Hepatology 2015;61:108–118)

© 2014 The Authors. HEPATOLOGY published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases. Ezetimibe inhibits intestinal cholesterol absorption and lowers low-density lipoprotein cholesterol. Uncontrolled studies have suggested that it reduces liver fat as estimated by ultrasound in nonalcoholic steatohepatitis (NASH). Therefore, we aimed to examine the efficacy of ezetimibe versus placebo in reducing liver fat by the magnetic resonance imaging-derived proton density-fat fraction (MRI-PDFF) and liver histology in patients with biopsy-proven NASH. In this randomized, double-blind, placebo-controlled trial, 50 patients with biopsy-proven NASH were randomized to either ezetimibe 10 mg orally daily or placebo for 24 weeks. The primary outcome was a change in liver fat as measured by MRI-PDFF in colocalized regions of interest within each of the nine liver segments. Novel assessment by two-dimensional and three-dimensional magnetic resonance elastography was also performed. Ezetimibe was not significantly better than placebo at reducing liver fat as measured by MRI-PDFF (mean difference between the ezetimibe and placebo arms -1.3%, P = 0.4). Compared to baseline, however, end-of-treatment MRI-PDFF was significantly lower in the ezetimibe arm (15%-11.6%, P < 0.016) but not in the placebo arm (18.5%-16.4%, P = 0.15). There were no significant differences in histologic response rates, serum alanine aminotransferase and aspartate aminotransferase levels, or longitudinal changes in two-dimensional and three-dimensional magnetic resonance elastography-derived liver stiffness between the ezetimibe and placebo arms. Compared to histologic nonresponders (25/35), histologic responders (10/35) had a significantly greater reduction in MRI-PDFF (-4.35 ± 4.9% versus -0.30 ± 4.1%, P < 0.019). Conclusions: Ezetimibe did not significantly reduce liver fat in NASH. This trial demonstrates the application of colocalization of MRI-PDFF-derived fat maps and magnetic resonance elastography-derived stiffness maps of the liver before and after treatment to noninvasively assess treatment response in NASH.

UNLABELLED Wilson disease (WD) is an autosomal recessive disorder that is caused by the toxic accumulation of copper (Cu) in the liver. The ATP7B gene, which is mutated in WD, encodes a multitransmembrane domain adenosine triphosphatase that traffics from the trans-Golgi network to the canalicular area of hepatocytes, where it facilitates excretion of excess Cu into the bile. Several ATP7B mutations, including H1069Q and R778L that are two of the most frequent variants, result in protein products, which, although still functional, remain in the endoplasmic reticulum. Thus, they fail to reach Cu excretion sites, resulting in the toxic buildup of Cu in the liver of WD patients. Therefore, correcting the location of these mutants by leading them to the appropriate functional sites in the cell should restore Cu excretion and would be beneficial to help large cohorts of WD patients. However, molecular targets for correction of endoplasmic reticulum-retained ATP7B mutants remain elusive. Here, we show that expression of the most frequent ATP7B mutant, H1069Q, activates p38 and c-Jun N-terminal kinase signaling pathways, which favor the rapid degradation of the mutant. Suppression of these pathways with RNA interference or specific chemical inhibitors results in the substantial rescue of ATP7B(H1069Q) (as well as that of several other WD-causing mutants) from the endoplasmic reticulum to the trans-Golgi network compartment, in recovery of its Cu-dependent trafficking, and in reduction of intracellular Cu levels. CONCLUSION Our findings indicate p38 and c-Jun N-terminal kinase as intriguing targets for correction of WD-causing mutants and, hence, as potential candidates, which could be evaluated for the development of novel therapeutic strategies to combat WD. (Hepatology 2016;63:1842-1859).

Nonalcoholic fatty liver disease (NAFLD) is characterized by the presence of hepatic steatosis in individuals who consume little or no alcohol and who have no other identifiable secondary cause of steatosis.1–5. NAFLD is associated with features of metabolic syndrome, including obesity, insulin resistance, hypertension, diabetes, and dyslipidemia.1,4,6,7 It is the most common cause of chronic liver disease (CLD) in the United States.2–5 It affects 80-100 million Americans, of whom 10%-22% may have nonalcoholic steatohepatitis (NASH),8–13 a progressive form that may lead to cirrhosis11,14 and hepatocellular carcinoma.11,15–19 Patients with NASH and especially those with advanced fibrosis are at particularly high risk for these outcomes and require more-intense monitoring and therapy. The current diagnostic gold standard to diagnose advanced fibrosis is liver biopsy.20 However, biopsy is invasive and costly and may be complicated by morbidity and even death.21 Accurate noninvasive objective methods to detect advanced fibrosis in patients with NAFLD are needed, but are not yet commercially available. There are no approved noninvasive tests to diagnose advanced fibrosis. Cytokeratin-18,22 NAFLD fibrosis score,23 and Enhanced Liver Fibrosis (ELF™) Test24 are promising, but may not be sufficiently accurate for routine clinical use.1,25 Ultrasound elastography methods have high (21%-50%) failure rates in NAFLD.26–29 Recent retrospective studies demonstrate that two-dimensional magnetic resonance (MR) elastography (2D-MRE) may be useful in noninvasive diagnosis of advanced fibrosis in NAFLD.30 However, prospective studies of 2D-MRE with paired liver biopsies in well-characterized patients with biopsy-proven NAFLD with a clinical indication for a liver biopsy are needed. Utilizing a prospective cohort study design, we aimed to determine the accuracy of 2D-MRE for noninvasive diagnosis of advanced fibrosis in well-characterized patients with biopsy-proven NAFLD. We also aimed to determine the accuracy of 2D-MRE for noninvasive diagnosis of the presence of NASH, as well as dichotomized stages of fibrosis.

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

Sterol regulatory element binding proteins (SREBPs) play key roles in lipid homeostasis from yeast to humans.1,2 In mammals, three different SREBP isoforms, including SREBP1a, SREBP1c (also known as ADD1), and SREBP2, are encoded by two genes: SREBF1 and SREBF2. SREBP1 regulates fatty acid metabolism, whereas SREBP2 controls cholesterol metabolism.3 When the cellular sterol level is low, SREBP cleavage-activating protein (SCAP) escorts the SREBP precursors from the endoplasmic reticulum (ER) to the Golgi, where SREBPs are cleaved by Site-1 and Site-2 proteases.4 Subsequently, the mature forms of SREBPs are translocated into the nucleus and stimulate the expression of target genes.5,6 SREBP1a and SREBP1c are generated through transcription from alternative promoters and splicing from a single SREBF1 gene. In metabolic tissues such as adipose tissue and liver, SREBP1c is the predominant isoform of SREBP1.1,7 SREBP1c governs de novo lipogenesis by stimulating its target genes, including fatty acid synthase (FASN), acetyl-CoA carboxylase1 (ACC1), steroyl-CoA desaturase1 (SCD1), and long-chain fatty acid elongase (ELOVL6).8–10 Furthermore, SREBP1c is sensitively regulated by nutritional and hormonal changes to achieve energy balance. For example, SREBP1c is suppressed by fasting, whereas SREBP1c is activated by feeding in adipose tissue and liver.11,12 In parallel, the expression of most lipogenic genes, including FASN, ACC1, and SCD1, is also modulated in a fashion analogous to that of nutritionally regulated SREBP1c.12–14 Accordingly, it has been reported that various hormones, such as insulin, glucagon, and adrenaline, participate in the regulation of SREBP1c and its target lipogenic genes.15,16 Insulin, a key postprandial hormone, stimulates the expression and activity of SREBP1c to accommodate anabolic processes, such as fatty acid synthesis, upon feeding.12,17 In contrast, glucagon, a key catabolic hormone, suppresses the activity of SREBP1c in fasting states, leading to a decrease in lipogenesis.18 In the nucleus, mature SREBPs are very unstable and are rapidly degraded by the proteasome.19,20 Previous reports have shown that SREBP1 is phosphorylated by glycogen synthase kinase-3 beta (GSK-3β), which leads to F-box and WD repeat domain-containing7 (FBXW7)-dependent ubiquitination of SREBP1.21,22 However, a recent in vivo study revealed that inhibition of FBXW7 does not alter the expression of SREBP1c or lipogenic genes in the liver.23 Although SREBP1c-mediated lipogenic program in liver is rapidly repressed by nutritional deprivations, the factors that are involved in the suppression of SREBP1c activity during fasting have not been thoroughly characterized. The finding that ring finger protein20 (RNF20) ubiquitin ligase was identified as one of the novel SREBP1c-interating proteins led us to test whether fasting signaling would promote SREBP1c degradation in an RNF20-dependent manner. In this study, we demonstrate that RNF20 promotes polyubiquitination and degradation of SREBP1c. Overexpression of RNF20 represses SREBP1c activity, leading to a decrease in the expression of lipogenic genes. In obese db/db mice, RNF20 overexpression alleviates hepatic steatosis by reducing the lipogenic program by way of SREBP1c down-regulation. Furthermore, activated PKA, a major signaling cascade that mediates the fasting state, induces degradation of SREBP1c by increasing RNF20 expression. Taken together, these data suggest that RNF20 plays a critical role in the regulation of hepatic lipid metabolism by modulating the protein stability and transcriptional activity of SREBP1c during hormonal changes.

Bile acid sequestrants (BAS) lower plasma low density lipoprotein levels and improve glycemic control. Colestimide, a BAS, has been claimed by computed tomography to reduce liver fat. Therefore, we examined the efficacy of colesevelam, a potent BAS, to decrease liver fat in patients with biopsy-proven nonalcoholic steatohepatitis (NASH). Liver fat was measured by a novel magnetic resonance imaging (MRI) technique, the proton-density-fat-fraction (PDFF), as well as by conventional MR spectroscopy (MRS). Fifty patients with biopsy-proven NASH were randomly assigned to either colesevelam 3.75 g/day orally or placebo for 24 weeks. The primary outcome was change in liver fat as measured by MRI-PDFF in colocalized regions of interest within each of the nine liver segments. Compared with placebo, colesevelam increased liver fat by MRI-PDFF in all nine segments of the liver with a mean difference of 5.6% (P = 0.002). We cross-validated the MRI-PDFF-determined fat content with that assessed by colocalized MRS; the latter showed a mean difference of 4.9% (P = 0.014) in liver fat between the colesevelam and the placebo arms. MRI-PDFF correlated strongly with MRS-determined hepatic fat content (r2= 0.96, P < 0.0001). Liver biopsy assessment of steatosis, cellular injury, and lobular inflammation did not detect any effect of treatment. Conclusion: Colesevelam increases liver fat in patients with NASH as assessed by MRI as well as MRS without significant changes seen on histology. Thus, MRI and MRS may be better than histology to detect longitudinal changes in hepatic fat in NASH. Underlying mechanisms and whether the small MR-detected increase in liver fat has clinical consequences is not known. © 2012 American Association for the Study of Liver Diseases.