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.

Critical interactions between race and the highly granular area deprivation index in liver transplant evaluation.

Neighborhood socioeconomic deprivation may have important implications on disparities in liver transplant (LT) evaluation. In this retrospective cohort study, we constructed a novel dataset by linking individual patient-level data with the highly granular Area Deprivation Index (ADI), which is advantageous over other neighborhood measures due to: specificity of Census Block-Group (versus Census Tract, Zip code), scoring, and robust variables. Our cohort included 1377 adults referred to our center for LT evaluation 8/1/2016-12/31/2019. Using modified Poisson regression, we tested for effect measure modification of the association between neighborhood socioeconomic status (nSES) and LT evaluation outcomes (listing, initiating evaluation, and death) by race and ethnicity. Compared to patients with high nSES, those with low nSES were at higher risk of not being listed (aRR = 1.14; 95%CI 1.05-1.22; p < .001), of not initiating evaluation post-referral (aRR = 1.20; 95%CI 1.01-1.42; p = .03) and of dying without initiating evaluation (aRR = 1.55; 95%CI 1.09-2.2; p = .01). While White patients with low nSES had similar rates of listing compared to White patients with high nSES (aRR = 1.06; 95%CI .96-1.17; p = .25), Underrepresented patients from neighborhoods with low nSES incurred 31% higher risk of not being listed compared to Underrepresented patients from neighborhoods with high nSES (aRR = 1.31; 95%CI 1.12-1.5; p < .001). Interventions addressing neighborhood deprivation may not only benefit patients with low nSES but may address racial and ethnic inequities.

Global burden of disease: acute-on-chronic liver failure, a systematic review and meta-analysis.

BACKGROUND AND AIMS: Acute-on-chronic liver failure (ACLF) is characterised by acute decompensation of cirrhosis associated with organ failures. We systematically evaluated the geographical variations of ACLF across the world in terms of prevalence, mortality, aetiology of chronic liver disease (CLD), triggers and organ failures. METHODS: We searched EMBASE and PubMed from 3/1/2013 to 7/3/2020 using the ACLF-EASL-CLIF (European Association for the Study of the Liver-Chronic Liver Failure) criteria. Two investigators independently conducted the abstract selection/abstraction of the aetiology of CLD, triggers, organ failures and prevalence/mortality by presence/grade of ACLF. We grouped countries into Europe, East/South Asia and North/South America. We calculated the pooled proportions, evaluated the methodological quality using the Newcastle-Ottawa Scale and statistical heterogeneity, and performed sensitivity analyses. RESULTS: We identified 2369 studies; 30 cohort studies met our inclusion criteria (43 206 patients with ACLF and 140 835 without ACLF). The global prevalence of ACLF among patients admitted with decompensated cirrhosis was 35% (95% CI 33% to 38%), highest in South Asia at 65%. The global 90-day mortality was 58% (95% CI 51% to 64%), highest in South America at 73%. Alcohol was the most frequently reported aetiology of underlying CLD (45%, 95% CI 41 to 50). Infection was the most frequent trigger (35%) and kidney dysfunction the most common organ failure (49%). Sensitivity analyses showed regional estimates grossly unchanged for high-quality studies. Type of design, country health index, underlying CLD and triggers explained the variation in estimates. CONCLUSIONS: The global prevalence and mortality of ACLF are high. Region-specific variations could be explained by the type of triggers/aetiology of CLD or grade. Health systems will need to tailor early recognition and treatment of ACLF based on region-specific data.

Urine DNA biomarkers for hepatocellular carcinoma screening.

BACKGROUND: Hepatocellular carcinoma (HCC) occurs in a well-defined high-risk patient population, but better screening tests are needed to improve sensitivity and efficacy. Therefore, we investigated the use of urine circulating tumour DNA (ctDNA) as a screening test. METHODS: Candidate markers in urine were selected from HCC and controls. We then enrolled 609 patients from five medical centres to test the selected urine panel. A two-stage model was developed to combine AFP and urine panel as a screening test. RESULTS: Mutated TP53, and methylated RASSF1a, and GSTP1 were selected as the urine panel markers. Serum AFP outperformed the urine panel among all cases of HCC, but the urine panel identified 49% of HCC cases with low AFP < 20 ng/ml. Using the two-stage model, the combined AFP and urine panel identified 148 of the 186 HCC cases (79.6% sensitivity at 90% specificity), which was 30% more than the cases detected with serum AFP alone. It also increased early-stage HCC detection from 62% to 92% (BCLC stage 0), and 40% to 77% (BCLC stage A). CONCLUSION: Urine ctDNA has promising diagnostic utility in patients in HCC, especially in those with low AFP and can be used as a potential non-invasive HCC screening test.

HOPE in action: A prospective multicenter pilot study of liver transplantation from donors with HIV to recipients with HIV.

Liver transplantation (LT) from donors-with-HIV to recipients-with-HIV (HIV D+/R+) is permitted under the HOPE Act. There are only three international single-case reports of HIV D+/R+ LT, each with limited follow-up. We performed a prospective multicenter pilot study comparing HIV D+/R+ to donors-without-HIV to recipients-with-HIV (HIV D-/R+) LT. We quantified patient survival, graft survival, rejection, serious adverse events (SAEs), human immunodeficiency virus (HIV) breakthrough, infections, and malignancies, using Cox and negative binomial regression with inverse probability of treatment weighting. Between March 2016-July 2019, there were 45 LTs (8 simultaneous liver-kidney) at 9 centers: 24 HIV D+/R+, 21 HIV D-/R+ (10 D- were false-positive). The median follow-up time was 23 months. Median recipient CD4 was 287 cells/µL with 100% on antiretroviral therapy; 56% were hepatitis C virus (HCV)-seropositive, 13% HCV-viremic. Weighted 1-year survival was 83.3% versus 100.0% in D+ versus D- groups (p = .04). There were no differences in one-year graft survival (96.0% vs. 100.0%), rejection (10.8% vs. 18.2%), HIV breakthrough (8% vs. 10%), or SAEs (all p > .05). HIV D+/R+ had more opportunistic infections, infectious hospitalizations, and cancer. In this multicenter pilot study of HIV D+/R+ LT, patient and graft survival were better than historical cohorts, however, a potential increase in infections and cancer merits further investigation.

Multicenter study of racial and ethnic inequities in liver transplantation evaluation: Understanding mechanisms and identifying solutions.

Racial and ethnic disparities persist in access to the liver transplantation (LT) waiting list; however, there is limited knowledge about underlying system-level factors that may be responsible for these disparities. Given the complex nature of LT candidate evaluation, a human factors and systems engineering approach may provide insights. We recruited participants from the LT teams (coordinators, advanced practice providers, physicians, social workers, dieticians, pharmacists, leadership) at two major LT centers. From December 2020 to July 2021, we performed ethnographic observations (participant-patient appointments, committee meetings) and semistructured interviews (N = 54 interviews, 49 observation hours). Based on findings from this multicenter, multimethod qualitative study combined with the Systems Engineering Initiative for Patient Safety 2.0 (a human factors and systems engineering model for health care), we created a conceptual framework describing how transplant work system characteristics and other external factors may improve equity in the LT evaluation process. Participant perceptions about listing disparities described external factors (e.g., structural racism, ambiguous national guidelines, national quality metrics) that permeate the LT evaluation process. Mechanisms identified included minimal transplant team diversity, implicit bias, and interpersonal racism. A lack of resources was a common theme, such as social workers, transportation assistance, non-English-language materials, and time (e.g., more time for education for patients with health literacy concerns). Because of the minimal data collection or center feedback about disparities, participants felt uncomfortable with and unadaptable to unwanted outcomes, which perpetuate disparities. We proposed transplant center-level solutions (i.e., including but not limited to training of staff on health equity) to modifiable barriers in the clinical work system that could help patient navigation, reduce disparities, and improve access to care. Our findings call for an urgent need for transplant centers, national societies, and policy makers to focus efforts on improving equity (tailored, patient-centered resources) using the science of human factors and systems engineering.

Targeted inactivation of copper transporter Atp7b in hepatocytes causes liver steatosis and obesity in mice.

Copper-transporting ATPase 2 (ATP7B) is essential for mammalian copper homeostasis. Mutations in ATP7B result in copper accumulation, especially in the liver, and cause Wilson disease (WD). The major role of hepatocytes in WD pathology is firmly established. It is less certain whether the excess Cu in hepatocytes is solely responsible for development of WD. To address this issue, we generated a mouse strain for Cre-mediated deletion of Atp7b and inactivated Atp7b selectively in hepatocytes. Atp7bΔHep mice accumulate copper in the liver, have elevated urinary copper, and lack holoceruloplasmin but show no liver disease for up to 30 wk. Liver inflammation is muted and markedly delayed compared with the age-matched Atp7b-/- null mice, which show a strong type1 inflammatory response. Expression of metallothioneins is higher in Atp7bΔHep livers than in Atp7b-/- mice, suggesting better sequestration of excess copper. Characterization of purified cell populations also revealed that nonparenchymal cells in Atp7bΔHep liver maintain Atp7b expression, have normal copper balance, and remain largely quiescent. The lack of inflammation unmasked metabolic consequences of copper misbalance in hepatocytes. Atp7bΔHep animals weigh more than controls and have higher levels of liver triglycerides and 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase. By 45 wk, all animals develop liver steatosis on a regular diet. Thus copper misbalance in hepatocytes dysregulates lipid metabolism, whereas development of inflammatory response in WD may depend on copper status of nonparenchymal cells. The implications of these findings for the cell-targeting WD therapies are discussed.NEW & NOTEWORTHY Targeted inactivation of copper-transporting ATPase 2 (Atp7b) in hepatocytes causes steatosis in the absence of inflammation.

Activation of liver X receptor/retinoid X receptor pathway ameliorates liver disease in Atp7B(-/-) (Wilson disease) mice.

UNLABELLED: Wilson disease (WD) is a hepatoneurological disorder caused by mutations in the copper-transporter, ATP7B. Copper accumulation in the liver is a hallmark of WD. Current therapy is based on copper chelation, which decreases the manifestations of liver disease, but often worsens neurological symptoms. We demonstrate that in Atp7b(-/-) mice, an animal model of WD, liver function can be significantly improved without copper chelation. Analysis of transcriptional and metabolic changes in samples from WD patients and Atp7b(-/-) mice identified dysregulation of nuclear receptors (NRs), especially the liver X receptor (LXR)/retinoid X receptor heterodimer, as an important event in WD pathogenesis. Treating Atp7b(-/-) mice with the LXR agonist, T0901317, ameliorated disease manifestations despite significant copper overload. Genetic markers of liver fibrosis and inflammatory cytokines were significantly decreased, lipid profiles normalized, and liver function and histology were improved. CONCLUSIONS: The results demonstrate the major role of an altered NR function in the pathogenesis of WD and suggest that modulation of NR activity should be explored as a supplementary approach to improving liver function in WD. (Hepatology 2016;63:1828-1841).

Systemic PEGylated TRAIL treatment ameliorates liver cirrhosis in rats by eliminating activated hepatic stellate cells.

UNLABELLED: Liver fibrosis is a common outcome of chronic liver disease that leads to liver cirrhosis and hepatocellular carcinoma. No US Food and Drug Administration-approved targeted antifibrotic therapy exists. Activated hepatic stellate cells (aHSCs) are the major cell types responsible for liver fibrosis; therefore, eradication of aHSCs, while preserving quiescent HSCs and other normal cells, is a logical strategy to stop and/or reverse liver fibrogenesis/fibrosis. However, there are no effective approaches to specifically deplete aHSCs during fibrosis without systemic toxicity. aHSCs are associated with elevated expression of death receptors and become sensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death. Treatment with recombinant TRAIL could be a potential strategy to ameliorate liver fibrosis; however, the therapeutic application of recombinant TRAIL is halted due to its very short half-life. To overcome this problem, we previously generated PEGylated TRAIL (TRAILPEG ) that has a much longer half-life in rodents than native-type TRAIL. In this study, we demonstrate that intravenous TRAILPEG has a markedly extended half-life over native-type TRAIL in nonhuman primates and has no toxicity in primary human hepatocytes. Intravenous injection of TRAILPEG directly induces apoptosis of aHSCs in vivo and ameliorates carbon tetrachloride-induced fibrosis/cirrhosis in rats by simultaneously down-regulating multiple key fibrotic markers that are associated with aHSCs. CONCLUSION: TRAIL-based therapies could serve as new therapeutics for liver fibrosis/cirrhosis and possibly other fibrotic diseases. (Hepatology 2016;64:209-223).

Deregulation of energy metabolism promotes antifibrotic effects in human hepatic stellate cells and prevents liver fibrosis in a mouse model.

Liver fibrosis and cirrhosis result from uncontrolled secretion and accumulation of extracellular matrix (ECM) proteins by hepatic stellate cells (HSCs) that are activated by liver injury and inflammation. Despite the progress in understanding the biology liver fibrogenesis and the identification of potential targets for treating fibrosis, development of an effective therapy remains elusive. Since an uninterrupted supply of intracellular energy is critical for the activated-HSCs to maintain constant synthesis and secretion of ECM, we hypothesized that interfering with energy metabolism could affect ECM secretion. Here we report that a sublethal dose of the energy blocker, 3-bromopyruvate (3-BrPA) facilitates phenotypic alteration of activated LX-2 (a human hepatic stellate cell line), into a less-active form. This treatment-dependent reversal of activated-LX2 cells was evidenced by a reduction in α-smooth muscle actin (α-SMA) and collagen secretion, and an increase in activity of matrix metalloproteases. Mechanistically, 3-BrPA-dependent antifibrotic effects involved down-regulation of the mitochondrial metabolic enzyme, ATP5E, and up-regulation of glycolysis, as evident by elevated levels of lactate dehydrogenase, lactate production and its transporter, MCT4. Finally, the antifibrotic effects of 3-BrPA were validated in vivo in a mouse model of carbon tetrachloride-induced liver fibrosis. Results from histopathology & histochemical staining for collagen and α-SMA substantiated that 3-BrPA promotes antifibrotic effects in vivo. Taken together, our data indicate that sublethal, metronomic treatment with 3-BrPA blocks the progression of liver fibrosis suggesting its potential as a novel therapeutic for treating liver fibrosis.

Differential methylation of the promoter and first exon of the RASSF1A gene in hepatocarcinogenesis.

AIM: Aberrant methylation of the promoter, P2, and the first exon, E1, regions of the tumor suppressor gene RASSF1A, have been associated with hepatocellular carcinoma (HCC), albeit with poor specificity. This study analyzed the methylation profiles of P1, P2 and E1 regions of the gene to identify the region of which methylation most specifically corresponds to HCC and to evaluate the potential of this methylated region as a biomarker in urine for HCC screening. METHODS: Bisulfite DNA sequencing and quantitative methylation-specific polymerase chain reaction assays were performed to compare methylation of the 56 CpG sites in regions P1, P2 and E1 in DNA isolated from normal, hepatitic, cirrhotic, adjacent non-HCC, and HCC liver tissue and urine samples for the characterization of hypermethylation of the RASSF1A gene as a biomarker for HCC screening. RESULTS: In tissue, comparing HCC (n = 120) with cirrhosis and hepatitis together (n = 70), methylation of P1 had an area under the receiver operating characteristics curve (AUROC) of 0.90, whereas methylation of E1 and P2 had AUROC of 0.84 and 0.72, respectively. At 90% sensitivity, specificity for P1 methylation was 72.9% versus 38.6% for E1 and 27.1% for P2. Methylated P1 DNA was detected in urine in association with cirrhosis and HCC. It had a sensitivity of 81.8% for α-fetoprotein negative HCC. CONCLUSION: Among the three regions analyzed, methylation of P1 is the most specific for HCC and holds great promise as a DNA marker in urine for screening of cirrhosis and HCC.