Oxysterol misbalance critically contributes to Wilson disease pathogenesis.

Wilson disease (WD) is a metabolic disorder caused by inactivation of the copper-transporting ATPase 2 (ATP7B) and copper (Cu) overload in tissues. Excess Cu causes oxidative stress and pathologic changes with poorly understood mechanistic connections. In Atp7b-/- mice with established liver disease, Cu overload activates the stress-sensitive transcription factor Nrf2 (nuclear factor erythroid-derived 2-like 2). Nrf2 targets, especially sulfotransferase 1e1 (Sult1e1), are strongly induced and cause elevation of sulfated sterols, whereas oxysterols are decreased. This sterol misbalance results in inhibition of the liver X receptor (LXR) and up-regulation of LXR targets associated with inflammatory responses. Pharmacological inhibition of Sult1e1 partially reverses oxysterol misbalance and LXR inhibition. Contribution of this pathway to advanced hepatic WD was demonstrated by treating mice with an LXR agonist. Treatment decreased inflammation by reducing expression of proinflammatory molecules, diminished fibrosis by down-regulating the noncanonical transforming growth factor-ß signaling pathway, and improved liver morphology and function. Thus, the identified pathway is an important driver of WD.

Hepatic Steatosis in the Mouse Model of Wilson Disease Coincides with a Muted Inflammatory Response.

Wilson disease (WND) is caused by inactivation of the copper transporter ATP7B and copper accumulation in tissues. WND presentations vary from liver steatosis to inflammation, fibrosis, and liver failure. Diets influence the liver phenotype in WND, but findings are inconsistent. To better understand the impact of excess calories on liver phenotype in WND, the study compared C57BL/6J Atp7b-/- and C57BL/6J mice fed for 12 weeks with Western diet or normal chow. Serum and liver metabolites, body fat content, liver histology, hepatic proteome, and copper content were analyzed. Wild-type and Atp7b-/- livers showed striking similarities in their responses to Western diet, most notably down-regulation of cholesterol biosynthesis, altered nuclear receptor signaling, and changes in cytoskeleton. Western diet increased body fat content and induced liver steatosis in males and females regardless of genotype; however, the effects were less pronounced in Atp7b-/- mice compared with those in the wild type mice. Although hepatic copper remained elevated in Atp7b-/- mice, liver inflammation was reduced. The diet diminished signaling by Rho GTPases, integrin, IL8, and reversed changes in cell cycle machinery and cytoskeleton. Overall, high calories decreased inflammatory response in favor of steatosis without improving markers of cell viability. Similar changes of cellular pathways during steatosis development in wild-type and Atp7b-/- mice explain histologic overlap between WND and non-alcoholic fatty liver disease despite opposite copper changes in these disorders.

Systemic deletion of Atp7b modifies the hepatocytes' response to copper overload in the mouse models of Wilson disease.

Wilson disease (WD) is caused by inactivation of the copper transporter Atp7b and copper overload in tissues. Mice with Atp7b deleted either globally (systemic inactivation) or only in hepatocyte recapitulate various aspects of human disease. However, their phenotypes vary, and neither the common response to copper overload nor factors contributing to variability are well defined. Using metabolic, histologic, and proteome analyses in three Atp7b-deficient mouse strains, we show that global inactivation of Atp7b enhances and specifically modifies the hepatocyte response to Cu overload. The loss of Atp7b only in hepatocytes dysregulates lipid and nucleic acid metabolisms and increases the abundance of respiratory chain components and redox balancing enzymes. In global knockouts, independently of their background, the metabolism of lipid, nucleic acid, and amino acids is inhibited, respiratory chain components are down-regulated, inflammatory response and regulation of chromosomal replication are enhanced. Decrease in glucokinase and lathosterol oxidase and elevation of mucin-13 and S100A10 are observed in all Atp7b mutant strains and reflect the extent of liver injury. The magnitude of proteomic changes in Atp7b-/- animals inversely correlates with the metallothioneins levels rather than liver Cu content. These findings facilitate identification of WD-specific metabolic and proteomic changes for diagnostic and treatment.

Lipoprotein and Metabolic Profiles Indicate Similar Cardiovascular Risk of Liver Steatosis and NASH.

BACKGROUND AND AIM: Nonalcoholic fatty liver disease (NAFLD) affects about 25% of the global population, with no reliable noninvasive tests to diagnose nonalcoholic steatohepatitis (NASH) and to differentiate between NASH and nonalcoholic fatty liver (NAFL) (steatosis alone). It is unclear if NAFL and NASH differ in cardiovascular risk for patients. Here, we compared obese NAFLD patients with a healthy cohort to test whether cholesterol compounds could represent potential noninvasive markers and to estimate associated risks. METHOD: Serum samples of 46 patients with histologically confirmed NAFLD (17 NAFL, 29 NASH) who underwent bariatric surgery were compared to 32 (9 males, 21 females) healthy controls (HCs). We analyzed epidemiological data, liver enzymes, cholesterol and lipid profile, and amino acids. The latter were analyzed by nuclear magnetic resonance spectroscopy. RESULTS: Total serum and high-density lipoprotein (HDL) cholesterol were significantly lower in the NAFLD group than in HCs, with a stronger reduction in NASH. Similar observations were made for sub-specification of HDL-p, HDL-s, SHDL-p, and LHDL-p cholesterols. Low-density lipoprotein (LDL)-s and LLDL-p cholesterol were significantly reduced in NAFLD groups. Interestingly, SLDL-p cholesterol was significantly higher in the NAFL group with a stronger elevation in NASH than in HCs. The amino acids alanine, leucin, and isoleucine were significantly higher in the NAFL and NASH groups than in HCs. CONCLUSION: We show in this study that cholesterol profiles, apolipoproteins, and amino acids could function as a potential noninvasive test to screen for NAFLD or even NASH in larger populations. However, few differences in cholesterol profiles were identified between the NAFL and NASH groups, indicating similar cardiovascular risk profiles.

Why Bile Acids Are So Important in Non-Alcoholic Fatty Liver Disease (NAFLD) Progression.

Non-alcoholic fatty liver disease (NAFLD) is a complex disease, affecting not just the liver, but also all other organs in the body. Despite an increasing amount of people worldwide developing NAFLD and having it progress to non-alcoholic steatohepatitis (NASH) and potentially cirrhosis, there is still no approved therapy. Therefore, huge efforts are being made to find and develop a successful treatment. One of the special interests is understanding the liver-gut axis and especially the role of bile acids in the progression of NAFLD. Farnesoid X receptor (FXR)-agonists have been approved und used in other liver diseases, such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), and have shown signs of being able to decrease inflammation and potentially steatosis. This review will mainly focus on targets/ligands that play an important role in bile acid metabolism and give an overview of ongoing clinical as well as pre-clinical trials. With the complexity of the issue, we did not aim at giving a complete review, rather highlighting important targets and potential treatments that could be approved for NAFLD/NASH treatment within the next few years.

Implications of Immunotherapy in Hepatobiliary Tumors.

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related death worldwide. Upon ineligibility for resection, liver transplantation, or locoregional therapies, sorafenib has been the only systemic treatment option of advanced HCC for more than a decade. Immunotherapy is an evolving HCC treatment option that has shown promise in treatment efficacy at an acceptable safety profile during several preceding phase I/II trials. Numerous clinical trials of immune checkpoint inhibitors (ICPIs) alone, in combination of two, or combined with other targeted or locoregional therapies are ongoing. Encouraging results of two-phase III trials testing pembrolizumab or nivolumab versus standard care therapy even resulted in Food and Drug Administration approval for second-line treatment of advanced HCC. ICPIs may open new avenues to the treatment of hepatobiliary tumors, alone or in combination.

Single-Center Retrospective Study of Clinical and Laboratory Features That Predict Survival of Patients With Budd-Chiari Syndrome After Liver Transplant.

OBJECTIVES: Budd-Chiari syndrome is a rare but critical condition that can progress to liver failure and death. For severe cases, orthotopic liver transplant remains the only curative option. The present study aimed to identify predictive parameters to assess outcomes of liver transplant. MATERIALS AND METHODS: Medical records of 33 individuals with Budd-Chiari syndrome who received orthotopic liver transplant were retrospectively assessed. Twenty-seven eligible patients were identified and grouped by outcome (survived/deceased) after transplant for Budd-Chiari syndrome. Demographic, clinical, and serum parameters taken at the time of Budd-Chiari syndrome diagnosis were evaluated for prognostic value. RESULTS: Differences between patients who survived and those who died were found for nausea/vomiting (P < .01) and splenomegaly (P < .01), which were both more common in patients who died after transplant. In addition, patients in the deceased group exhibited significantly lower serum cholinesterase levels (P < .01) and higher alkaline phosphatase levels (P < .01). Scoring systems to assess liver status or Budd-Chiari syndrome severity (Model for End-Stage Liver Disease and Child-Pugh scores, Rotterdam score, and the transjugular intrahepatic portosystemic shunting prognostic index) did not differ between groups. CONCLUSIONS: Nausea/vomiting, splenomegaly, low serum cholinesterase, and high alkaline phosphatase were associated with adverse outcomes after orthotopic liver transplant for Budd-Chiari syndrome. These factors may be surrogate markers for a severely impaired health status at time of diagnosis and should be evaluated prospectively in larger cohorts.

How to Define Acute Liver Failure Patients with Pre-Existing Liver Disease without Signs of Cirrhosis.

BACKGROUND: The definition of acute liver failure (ALF) usually implies no previous liver injury. Though, some patients admitted to liver transplantation centers with the diagnosis of ALF are obese or have diabetes. Elevated liver enzymes were not recorded previously, and no signs of cirrhosis or prior decompensation of the liver function were ever present. Still, these patients differ from the "typical" ALF-patient. GOALS: In this study, we aimed to confirm acute-on-chronic-liver failure (AOCLF) in patients diagnosed with ALF and to identify possible differences between ALF and AOCLF. STUDY: Patients were retrospectively recruited from all patients admitted to the University Hospital Essen with diagnosis of ALF between 2008 and 2015. Data of 163 patients were evaluated, resulting in a reclassification of 32 patients as AOCLF (remaining ALF: 131). Demographic and clinical data as well as serum parameters, including cell death markers, were correlated with clinical outcome. RESULTS: Patients with AOCLF were significantly older, had a higher body mass index (BMI), and were more often male. The cause for liver failure in these patients differed significantly from patients who had an actual ALF. Significant differences were also found for serum liver enzymes. Outcome of patients did not differ between AOCLF and ALF. Though, lower BMI and MELD and higher AST and GLDH were predictors for a beneficial outcome. CONCLUSION: AOCLF is still commonly misdiagnosed as ALF. While clinical outcome does not significantly differ between ALF and AOCLF, risk factors for adverse outcome may significantly differ between these entities.

Nonalcoholic-Fatty-Liver-Disease and Nonalcoholic Steatohepatitis: Successful Development of Pharmacological Treatment Will Depend on Translational Research.

BACKGROUND: Nonalcoholic-fatty-liver-disease/nonalcoholic steatohepatitis (NAFLD/NASH) is expected to become the leading liver disease worldwide. Typical liver-related complications are fibrosis, cirrhosis, and the development of hepatocellular cancer (HCC) with the need for liver transplantation. Up to now there is no approved pharmacotherapy. Indeed, this might be due to the complexity of this disease. While the cheapest therapeutic approach is still a lifestyle change leading to weight loss, the proportion of people achieving sufficient weight reduction without additional support is low. Newly developed drugs are expensive and lack a breakthrough in therapeutic success. One reason might be that drugs developed often derive from murine models. Unfortunately, there is little overlap between genes in human and mice that are responsible for the development of NAFLD/NASH. This review aims at summarizing latest developments as well as stress again that more translational research is necessary. SUMMARY: Therapy of NAFLD/NASH is easy and very complex at the same time, as the current main target is weight reduction. Since this is in fact not easily achieved and maintained by many affected individuals, pharmacotherapy to halt the progression of NAFLD/NASH is urgently warranted. More translational studies are needed to understand the metabolic mechanisms and interactions between the liver, gut, oxidative stress and the processes leading to NAFLD progression and HCC development, even in the absence of cirrhosis.

The Presence and Severity of Nonalcoholic Steatohepatitis Is Associated with Specific Changes in Circulating Bile Acids.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease nowadays with currently no approved therapies for the disease. The liver plays a pivotal role in lipid and glucose metabolism. The interactions of molecular mechanisms on the gut for example influences the development still needs to be understood. Bile acids (BA) have been shown to impact metabolic homeostasis and insulin sensitivity. Here, we comment on a study analyzing BA profiles in NAFLD patients addressing novel pathways involved in NAFLD progression.

RITA displays anti-tumor activity in medulloblastomas independent of TP53 status.

Current therapy of medulloblastoma, the most common malignant brain tumor of childhood, achieves 40-70% survival. Secondary chemotherapy resistance contributes to treatment failure, where TP53 pathway dysfunction plays a key role. MDM2 interaction with TP53 leads to its degradation. Reactivating TP53 functionality using small-molecule inhibitors, such as RITA, to disrupt TP53-MDM2 binding may have therapeutic potential. We show here that RITA decreased viability of all 4 analyzed medulloblastoma cell lines, regardless of TP53 functional status. The decrease in cell viability was accompanied in 3 of the 4 medulloblastoma cell lines by accumulation of TP53 protein in the cells and increased CDKN1A expression. RITA treatment in mouse models inhibited medulloblastoma xenograft tumor growth. These data demonstrate that RITA treatment reduces medulloblastoma cell viability in both in vitro and in vivo models, and acts independently of cellular TP53 status, identifying RITA as a potential therapeutic agent to treat medulloblastoma.