Bacteriophage Prevents Alcoholic Liver Disease.

Alcoholic hepatitis is a severe alcohol-associated liver disease with minimal treatment options. A recent study by Duan et al. uncovers that the exotoxin-secreting gut bacterium Enterococcus faecalis is a critical contributor to alcoholic hepatitis. This bacterium can now be eliminated with a bacteriophage, suggesting a new way to treat this life-threatening disease.

An artificial intelligence-generated model predicts 90-day survival in alcohol-associated hepatitis: A global cohort study.

BACKGROUND AND AIMS: Alcohol-associated hepatitis (AH) poses significant short-term mortality. Existing prognostic models lack precision for 90-day mortality. Utilizing artificial intelligence in a global cohort, we sought to derive and validate an enhanced prognostic model. APPROACH AND RESULTS: The Global AlcHep initiative, a retrospective study across 23 centers in 12 countries, enrolled patients with AH per National Institute for Alcohol Abuse and Alcoholism criteria. Centers were partitioned into derivation (11 centers, 860 patients) and validation cohorts (12 centers, 859 patients). Focusing on 30 and 90-day postadmission mortality, 3 artificial intelligence algorithms (Random Forest, Gradient Boosting Machines, and eXtreme Gradient Boosting) informed an ensemble model, subsequently refined through Bayesian updating, integrating the derivation cohort's average 90-day mortality with each center's approximate mortality rate to produce posttest probabilities. The ALCoholic Hepatitis Artificial INtelligence Ensemble score integrated age, gender, cirrhosis, and 9 laboratory values, with center-specific mortality rates. Mortality was 18.7% (30 d) and 27.9% (90 d) in the derivation cohort versus 21.7% and 32.5% in the validation cohort. Validation cohort 30 and 90-day AUCs were 0.811 (0.779-0.844) and 0.799 (0.769-0.830), significantly surpassing legacy models like Maddrey's Discriminant Function, Model for End-Stage Liver Disease variations, age-serum bilirubin-international normalized ratio-serum Creatinine score, Glasgow, and modified Glasgow Scores ( p < 0.001). ALCoholic Hepatitis Artificial INtelligence Ensemble score also showcased superior calibration against MELD and its variants. Steroid use improved 30-day survival for those with an ALCoholic Hepatitis Artificial INtelligence Ensemble score > 0.20 in both derivation and validation cohorts. CONCLUSIONS: Harnessing artificial intelligence within a global consortium, we pioneered a scoring system excelling over traditional models for 30 and 90-day AH mortality predictions. Beneficial for clinical trials, steroid therapy, and transplant indications, it's accessible at: https://aihepatology.shinyapps.io/ALCHAIN/ .

Recurrent alcohol-associated hepatitis is common and is associated with increased mortality.

BACKGROUND AND AIMS: Alcohol relapse after surviving an episode of alcohol-associated hepatitis (AH) is common. However, the clinical features, risk factors, and prognostic implications of recurrent alcohol-associated hepatitis (RAH) are not well described. APPROACH AND RESULTS: A registry-based study was done of patients admitted to 28 Spanish hospitals for an episode of AH between 2014 and 2021. Baseline demographics and laboratory variables were collected. Risk factors for RAH were investigated using Cox regression analysis. We analyzed the severity of the index episodes of AH and compared it to that of RAH. Long-term survival was assessed by Kaplan-Meier curves and log-rank tests. A total of 1118 patients were included in the analysis, 125 (11%) of whom developed RAH during follow-up (median: 17 [7-36] months). The incidence of RAH in patients resuming alcohol use was 22%. The median time to recurrence was 14 (8-29) months. Patients with RAH had more psychiatric comorbidities. Risk factors for developing RAH included age <50 years, alcohol use >10 U/d, and history of liver decompensation. RAH was clinically more severe compared to the first AH (higher MELD, more frequent ACLF, and HE). Moreover, alcohol abstinence during follow-up was less common after RAH (18% vs. 45%, p <0.001). Most importantly, long-term mortality was higher in patients who developed RAH (39% vs. 21%, p = 0.026), and presenting with RAH independently predicted high mortality (HR: 1.55 [1.11-2.18]). CONCLUSIONS: RAH is common and has a more aggressive clinical course, including increased mortality. Patients surviving an episode of AH should undergo intense alcohol use disorder therapy to prevent RAH.

Serum aryl hydrocarbon receptor activity is associated with survival in patients with alcohol-associated hepatitis.

BACKGROUND AND AIMS: Patients with alcohol-associated hepatitis (AH) have an altered fecal metabolome, including reduced microbiota-derived tryptophan metabolites, which function as ligands for aryl hydrocarbon receptor (AhR). The aim of this study was to assess serum AhR ligand activity in patients with AH. APPROACH AND RESULTS: The study included 74 controls without AUD, 97 patients with AUD, and 330 patients with AH from 2 different multicenter cohorts (InTeam: 134, AlcHepNet: 196). Serum AhR activity was evaluated using an AhR reporter assay with HepG2-Lucia cells incubated with serum for 24 hours. Serum AhR activity was significantly higher in patients with AH compared with both controls (1.59 vs. 0.96-fold change, p < 0.001) and patients with AUD (1.59 vs. 0.93, p < 0.001). In both AH cohorts, patients with AhR activity ≥ 2.09 had significantly lower cumulative survival rates at 30, 60, 90, and 180 days compared to those with AhR activity < 2.09. When serum AhR activity was used to further stratify patients with severe AH, the cumulative 30, 60, 90, and 180-day survival rates for patients with severe AH and the AhR activity ≥ 2.09 group were all significantly lower than those with an AhR activity < 2.09 group. CONCLUSIONS: Serum AhR activity was significantly higher in patients with AH compared with controls and individuals with AUD, and this increased activity was associated with higher mortality. Consequently, serum AhR activity holds potential as a prognostic marker.

Bacteriophage targeting of gut bacterium attenuates alcoholic liver disease.

Chronic liver disease due to alcohol-use disorder contributes markedly to the global burden of disease and mortality1-3. Alcoholic hepatitis is a severe and life-threatening form of alcohol-associated liver disease. The gut microbiota promotes ethanol-induced liver disease in mice4, but little is known about the microbial factors that are responsible for this process. Here we identify cytolysin-a two-subunit exotoxin that is secreted by Enterococcus faecalis5,6-as a cause of hepatocyte death and liver injury. Compared with non-alcoholic individuals or patients with alcohol-use disorder, patients with alcoholic hepatitis have increased faecal numbers of E. faecalis. The presence of cytolysin-positive (cytolytic) E. faecalis correlated with the severity of liver disease and with mortality in patients with alcoholic hepatitis. Using humanized mice that were colonized with bacteria from the faeces of patients with alcoholic hepatitis, we investigated the therapeutic effects of bacteriophages that target cytolytic E. faecalis. We found that these bacteriophages decrease cytolysin in the liver and abolish ethanol-induced liver disease in humanized mice. Our findings link cytolytic E. faecalis with more severe clinical outcomes and increased mortality in patients with alcoholic hepatitis. We show that bacteriophages can specifically target cytolytic E. faecalis, which provides a method for precisely editing the intestinal microbiota. A clinical trial with a larger cohort is required to validate the relevance of our findings in humans, and to test whether this therapeutic approach is effective for patients with alcoholic hepatitis.

Randomized trial of anakinra plus zinc vs. prednisone for severe alcohol-associated hepatitis.

BACKGROUND & AIMS: Severe alcohol-associated hepatitis (SAH) is associated with high 90-day mortality. Glucocorticoid therapy for 28 days improves 30- but not 90-day survival. We assessed the efficacy and safety of a combination of anakinra, an IL-1 antagonist, plus zinc (A+Z) compared to prednisone using the Day-7 Lille score as a stopping rule in patients with SAH. METHODS: In this phase IIb double-blind randomized trial in adults with SAH and MELD scores of 20-35, participants were randomized to receive either daily anakinra 100 mg subcutaneously for 14 days plus daily zinc sulfate 220 mg orally for 90 days, or daily prednisone 40 mg orally for 30 days. Prednisone or prednisone placebo was stopped if Day-7 Lille score was >0.45. All study drugs were stopped for uncontrolled infection or ≥5 point increase in MELD score. The primary endpoint was overall survival at 90 days. RESULTS: Seventy-three participants were randomized to prednisone and 74 to A+Z. The trial was stopped early after a prespecified interim analysis showed prednisone was associated with higher 90-day overall survival (90% vs. 70%; hazard ratio for death = 0.34, 95% CI 0.14-0.83, p = 0.018) and transplant-free survival (88% vs. 64%; hazard ratio for transplant or death = 0.30, 95% CI 0.13-0.69, p = 0.004) than A+Z. Acute kidney injury was more frequent with A+Z (45%) than prednisone (22%) (p = 0.001), but rates of infection were similar (31% in A+Z vs. 27% in prednisone, p = 0.389). CONCLUSIONS: Participants with SAH treated with prednisone using the Day-7 Lille score as a stopping rule had significantly higher overall and transplant-free 90-day survival and lower incidence of acute kidney injury than those treated with A+Z. IMPACT AND IMPLICATIONS: There is no approved treatment for severe alcohol-associated hepatitis (SAH). In this double-blind randomized trial, patients with SAH treated with prednisone using the Lille stopping rule on Day 7 had higher 90-day overall and transplant-free survival and lower rates of acute kidney injury compared to patients treated with a combination of anakinra and zinc. The data support continued use of glucocorticoids for patients with SAH, with treatment discontinuation for those with a Lille score >0.45 on Day 7. TRIAL REGISTRATION: NCT04072822.

Alcoholic Foamy Degeneration, an Entity Resembling Alcohol-Associated Hepatitis: Diagnosis, Prognosis, and Molecular Profiling.

BACKGROUND & AIMS: Alcoholic foamy degeneration (AFD) is a condition with similar clinical presentation to alcohol-associated hepatitis (AH), but with a specific histologic pattern. Information regarding the prevalence and prognosis of AFD is scarce and there are no tools for a noninvasive diagnosis. METHODS: A cohort of patients admitted to the Hospital Clinic of Barcelona for clinical suspicion of AH who underwent liver biopsy was included. Patients were classified as AFD, AH, or other findings, according to histology. Clinical features, histology, and genetic expression of liver biopsy specimens were analyzed. The accuracy of National Institute on Alcohol Abuse and Alcoholism criteria and laboratory parameters for differential diagnosis were investigated. RESULTS: Of 230 patients with a suspicion of AH, 18 (8%) met histologic criteria for AFD, 184 (80%) had definite AH, and 28 (12%) had other findings. In patients with AFD, massive steatosis was more frequent and the fibrosis stage was lower. AFD was characterized by down-regulation of liver fibrosis and inflammation genes and up-regulation of lipid metabolism and mitochondrial function genes. Patients with AFD had markedly better long-term survival (100% vs 57% in AFD vs AH; P = .002) despite not receiving corticosteroid treatment, even in a model for end-stage liver disease-matched sensitivity analysis. Serum triglyceride levels had an area under the receiver operating characteristic of 0.886 (95% CI, 0.807-0.964) for the diagnosis of AFD, whereas the National Institute on Alcohol Abuse and Alcoholism criteria performed poorly. A 1-step algorithm using triglyceride levels of 225 mg/dL (sensitivity, 0.77; specificity, 0.90; and Youden index, 0.67) is proposed for differential diagnosis. CONCLUSIONS: AFD in the setting of suspicion of AH is not uncommon. A differential diagnosis is important because prognosis and treatment differ largely. Triglyceride levels successfully identify most patients with AFD and may be helpful in decision making.

Safety, Pharmacokinetics, and Efficacy Signals of Larsucosterol (DUR-928) in Alcohol-Associated Hepatitis.

INTRODUCTION: This study is to evaluate the safety and pharmacokinetics (PK) of larsucosterol (DUR-928 or 25HC3S) in subjects with alcohol-associated hepatitis (AH), a devastating acute illness without US Food and Drug Administration-approved therapies. METHODS: This phase 2a, multicenter, open-label, dose escalation study evaluated the safety, PK, and efficacy signals of larsucosterol in 19 clinically diagnosed subjects with AH. Based on the model for end-stage liver disease (MELD) score, 7 subjects were considered to have moderate AH and 12 to have severe AH. All subjects received 1 or 2 intravenous infusions (72 hours apart) of larsucosterol at a dose of 30, 90, or 150 mg and were followed up for 28 days. Efficacy signals from a subgroup of subjects with severe AH were compared with those from 2 matched arms of those with severe AH treated with standard of care (SOC), including corticosteroids, from a contemporaneous study. RESULTS: All 19 larsucosterol-treated subjects survived the 28-day study. Fourteen (74%) of all subjects including 8 (67%) of the subjects with severe AH were discharged ≤72 hours after receiving a single infusion. There were no drug-related serious adverse events nor early terminations due to the treatment. PK profiles were not affected by disease severity. Biochemical parameters improved in most subjects. Serum bilirubin levels declined notably from baseline to day 7 and day 28, and MELD scores were reduced at day 28. The efficacy signals compared favorably with those from 2 matched groups treated with SOC. Lille scores at day 7 were <0.45 in 16 of the 18 (89%) subjects with day 7 samples. Lille scores from 8 subjects with severe AH who received 30 or 90 mg larsucosterol (doses used in phase 2b trial) were statistically significantly lower ( P < 0.01) than those from subjects with severe AH treated with SOC from the contemporaneous study. DISCUSSION: Larsucosterol was well tolerated at all 3 doses in subjects with AH without safety concerns. Data from this pilot study showed promising efficacy signals in subjects with AH. Larsucosterol is being evaluated in a phase 2b multicenter, randomized, double-blinded, placebo-controlled (AHFIRM) trial.

ACG Clinical Guideline: Alcohol-Associated Liver Disease.

ABSTRACT: Alcohol-associated liver disease (ALD) is the most common cause of advanced hepatic disease and frequent indication for liver transplantation worldwide. With harmful alcohol use as the primary risk factor, increasing alcohol use over the past decade has resulted in rapid growth of the ALD-related healthcare burden. The spectrum of ALD ranges from early asymptomatic liver injury to advanced disease with decompensation and portal hypertension. Compared with those with other etiologies of liver disease, patients with ALD progress faster and more often present at an advanced stage. A unique phenotype of advanced disease is alcohol-associated hepatitis (AH) presenting with rapid onset or worsening of jaundice, and acute on chronic liver failure in severe forms conveying a 1-month mortality risk of 20%-50%. The model for end stage disease score is the most accurate score to stratify AH severity (>20 defined as severe disease). Corticosteroids are currently the only available therapeutic with proven efficacy for patients with severe AH, providing survival benefit at 1 month in 50%-60% of patients. Abstinence of alcohol use, a crucial determinant of long-term outcomes, is challenging to achieve in ALD patients with concurrent alcohol use disorder (AUD). As patients with ALD are rarely treated for AUD, strategies are needed to overcome barriers to AUD treatment in patients with ALD and to promote a multidisciplinary integrated care model with hepatology, addiction medicine providers, and social workers to comprehensively manage the dual pathologies of liver disease and of AUD. Liver transplantation, a definitive treatment option in patients with advanced cirrhosis, should be considered in selected patients with AH, who are unresponsive to medical therapy and have a low risk of relapse to posttransplant alcohol use. Level of evidence and strength of recommendations were evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations system. This guideline was developed under the American College of Gastroenterology Practice Parameters Committee.

Expansion of effector regulatory T cells in steroid responders of severe alcohol-associated hepatitis.

While steroid therapy is the preferred treatment for severe alcohol-associated hepatitis, the role of effector regulatory T (eTreg) cells and their association with steroid response and clinical outcomes in these patients remains to be elucidated. We prospectively enrolled 47 consecutive patients with alcohol-associated hepatitis, consisting of severe alcohol-associated hepatitis treated with steroids (n=18; steroid-treated group) and mild alcohol-associated hepatitis (n=29; nontreated group). After isolating peripheral blood mononuclear cells from the patients at enrollment and again 7 days later, the frequency of eTreg cells was examined using flow cytometry. Single-cell RNA sequencing analysis was conducted using paired peripheral blood mononuclear cells. In vitro experiments were also performed to assess phenotype changes and the suppressive function of Treg cells following steroid treatment. The steroid-treated group exhibited significantly higher Model for End-Stage Liver Disease scores than the nontreated group ( p < 0.01). Within the steroid-treated group, the proportion of eTreg cells significantly expanded in the steroid responders (n=13; p = 0.01). Furthermore, a significant positive correlation was observed between the decrease in the Model for End-Stage Liver Disease score and the increase in eTreg cells ( p < 0.05). Single-cell RNA sequencing using paired peripheral blood mononuclear cells (pre-steroid and post-steroid therapy) from a steroid responder revealed gene expression changes in T cells and monocytes, suggesting enhancement of Treg cell function. In vitro results showed an elevation in the proportion of eTreg cells after steroid therapy. In conclusion, our findings suggest that the efficacy of steroid therapy in patients with severe alcohol-associated hepatitis is mediated by an increase in the number of eTreg cells.

Alcohol use disorder in alcohol-associated liver disease: Two sides of the same coin.

Alcohol-associated liver disease (ALD) has emerged as the leading indication for liver transplantation (LT) worldwide, with 40% of LTs in the United States performed for ALD in 2019. The ALD-related health care burden accelerated during the COVID-19 pandemic, especially in young individuals. Alcohol use disorder (AUD), which focuses on the negative effects of alcohol on psychosocial, physical, and mental health, is present in the majority of patients with ALD, with moderate to severe AUD in 75%-80%. During the last decade, early liver transplantation (eLT) has emerged as a lifesaving treatment for selected patients with alcohol-associated hepatitis; these patients may have a higher risk of using alcohol after LT. The risk of alcohol use recurrence may be reduced during the pretransplant or post-transplant period with AUD treatment using behavioral and/or pharmacological therapies and with regular monitoring for alcohol use (self-reported and complemented with biomarkers like phosphatidylethanol). However, AUD treatment in patients with ALD is challenging due to patient, clinician, and system barriers. An integrated model to provide AUD and ALD care by hepatologists and addiction experts in a colocated clinic starting from LT evaluation and selection to monitoring listed candidates and then to following up on recipients of LT should be promoted. However, the integration of addiction and hepatology teams in an LT program in the real world is often present only during evaluation and candidate selection for LT. Data are emerging to show that a multidisciplinary integrated AUD treatment within an LT program reduces recurrent alcohol use after LT. If we want to continue using early liver transplantation for patients with severe alcohol-associated hepatitis, LT programs should focus on building integrated multidisciplinary care teams for the integrated treatment of both AUD and ALD.

IgY antibodies against cytolysin reduce ethanol-induced liver disease in mice.

BACKGROUND AND AIMS: Patients with severe alcohol-associated hepatitis have high morbidity and mortality. Novel therapeutic approaches are urgently needed. The aims of our study were to confirm the predictive value of cytolysin-positive Enterococcus faecalis ( E. faecalis ) for mortality in patients with alcohol-associated hepatitis and to assess the protective effect of specific chicken immunoglobulin Y (IgY) antibodies against cytolysin in vitro and in a microbiota-humanized mouse model of ethanol-induced liver disease. APPROACH AND RESULTS: We investigated a multicenter cohort of 26 subjects with alcohol-associated hepatitis and confirmed our previous findings that the presence of fecal cytolysin-positive E. faecalis predicted 180-day mortality in those patients. After combining this smaller cohort with our previously published multicenter cohort, the presence of fecal cytolysin has a better diagnostic area under the curve, better other accuracy measures, and a higher odds ratio to predict death in patients with alcohol-associated hepatitis than other commonly used liver disease models. In a precision medicine approach, we generated IgY antibodies against cytolysin from hyperimmunized chickens. Neutralizing IgY antibodies against cytolysin reduced cytolysin-induced cell death in primary mouse hepatocytes. The oral administration of IgY antibodies against cytolysin decreased ethanol-induced liver disease in gnotobiotic mice colonized with stool from cytolysin-positive patients with alcohol-associated hepatitis. CONCLUSIONS: E. faecalis cytolysin is an important mortality predictor in alcohol-associated hepatitis patients, and its targeted neutralization through specific antibodies improves ethanol-induced liver disease in microbiota-humanized mice.

Multicentered study of patient outcomes after declined for early liver transplantation in severe alcohol-associated hepatitis.

BACKGROUND: Early liver transplantation for alcohol-associated hepatitis is controversial in part because patients may recover, and obviate the need for liver transplantation. METHODS: In this retrospective study among 5 ACCELERATE-AH sites, we randomly sampled patients evaluated and then declined for liver transplantation for alcohol-associated hepatitis. All had Model of End-Stage Liver Disease (MELD) >20 and <6 months of abstinence. Recompensation was defined as MELD <15 without variceal bleeding, ascites, or overt HE requiring treatment. Multilevel mixed effects linear regression was used to calculate probabilities of recompensation; multivariable Cox regression was used for mortality analyses. RESULTS: Among 145 patients [61% men; median abstinence time and MELD-Na was 33 days (interquartile range: 13-70) and 31 (interquartile range: 26-36), respectively], 56% were declined for psychosocial reasons. Probability of 30-day, 90-day, 6-month, and 1-year survival were 76% (95% CI, 68%-82%), 59% (95% CI, 50%-66%), 49% (95% CI, 40%-57%), and 46% (95% CI, 37%-55%), respectively. Probability of 1-year recompensation was low at 10.0% (95% CI, 4.5%-15.4%). Among patients declined because of clinical improvement, 1-year probability of recompensation was 28.0% (95% CI, 5.7%-50.3%). Among survivors, median MELD-Na at 30 days, 90 days, and 1-year were 29 (interquartile range: 22-38), 19 (interquartile range : 14-29), and 11 (interquartile range : 7-17). Increased MELD-Na (adjusted HR: 1.13, p <0.001) and age (adjusted HR: 1.03, p <0.001) were associated with early (≤90 d) death, and only history of failed alcohol rehabilitation (adjusted HR: 1.76, p =0.02) was associated with late death. CONCLUSIONS: Liver recompensation is infrequent among severe alcohol-associated hepatitis patients declined for liver transplantation. Higher MELD-Na and age were associated with short-term mortality, whereas only history of failed alcohol rehabilitation was associated with long-term mortality. The distinction between survival and liver recompensation merits further attention.

Mapping the hepatic immune landscape identifies monocytic macrophages as key drivers of steatohepatitis and cholangiopathy progression.

BACKGROUND AND AIMS: The progression of chronic liver diseases towards liver cirrhosis is accompanied by drastic tissue changes. This study combines elaborate transcriptomic and histological methods aiming at spatially resolving the hepatic immune microenvironment in NAFLD (including NASH, primary sclerosing cholangitis, primary biliary cholangitis, and severe alcoholic hepatitis). APPROACH AND RESULTS: Human liver samples were subjected to RNA-sequencing (n=225) and imaging cytometry (n=99) across 3 independent patient cohorts. Liver samples from alcoholic hepatitis and primary biliary cholangitis patients were used for comparison. Myeloid populations were further characterized in corresponding mouse models. Imaging, clinical, and phenotypical data were combined for multidimensional analysis. NAFLD/NASH and primary sclerosing cholangitis disease stages were associated with loss of parenchymal areas, increased ductular cell accumulation, and infiltration of immune cells. NASH patients predominantly exhibited myeloid cell accumulation, whereas primary sclerosing cholangitis patients additionally had pronounced lymphoid cell responses. Correlating to disease stage, both etiologies displayed intense IBA1 + CD16 low CD163 low macrophage aggregation in nonparenchymal areas, with a distinct spatial proximity to ductular cells. Mouse models revealed that disease-associated IBA1 + hepatic macrophages originated from bone marrow-derived monocytes. Using an unbiased, machine learning-based algorithm, IBA1 in combination with hepatocyte and ductular cell immunostaining-predicted advanced cirrhosis in human NASH, primary sclerosing cholangitis, and alcoholic hepatitis. CONCLUSIONS: Loss of hepatocytes and increased ductular reaction are tightly associated with monocyte-derived macrophage accumulation and represent the most prominent common immunological feature revealing the progression of NAFLD, primary sclerosing cholangitis, primary biliary cholangitis, and alcoholic hepatitis, suggesting IBA1 + CD163 low macrophages are key pathogenic drivers of human liver disease progression across diverse etiologies.

Emergence of highly profibrotic and proinflammatory Lrat+Fbln2+ HSC subpopulation in alcoholic hepatitis.

BACKGROUND AND AIMS: Relative roles of HSCs and portal fibroblasts in alcoholic hepatitis (AH) are unknown. We aimed to identify subpopulations of collagen type 1 alpha 1 (Col1a1)-expressing cells in a mouse AH model by single-cell RNA sequencing (scRNA-seq) and filtering the cells with the HSC (lecithin retinol acyltransferase [Lrat]) and portal fibroblast (Thy-1 cell surface antigen [Thy1] and fibulin 2 [Fbln2]) markers and vitamin A (VitA) storage. APPROACH AND RESULTS: Col1a1-green fluorescent protein (GFP) mice underwent AH, CCl 4 , and bile duct ligation (BDL) procedures to have comparable F1-F2 liver fibrosis. Col1a1-expressing cells were sorted via FACS by VitA autofluorescence and GFP for single-cell RNA sequencing. In AH, approximately 80% of Lrat+Thy1-Fbln2- activated HSCs were VitA-depleted (vs. ~13% in BDL and CCl 4 ). Supervised clustering identified a subset co-expressing Lrat and Fbln2 (Lrat+Fbln2+), which expanded 44-fold, 17-fold, and 1.3-fold in AH, BDL, and CCl 4 . Lrat+Fbln2+ cells had 3-15-times inductions of profibrotic, myofibroblastic, and immunoregulatory genes versus Lrat+Fbln2- cells, but 2-4-times repressed HSC-selective genes. AH activated HSCs had up-regulated inflammatory (chemokine [C-X-C motif] ligand 2 [Cxcl2], chemokine [C-C motif] ligand 2), antimicrobial (Il-33, Zc3h12a), and antigen presentation (H2-Q6, H2-T23) genes versus BDL and CCl 4 . Computational deconvolution of AH versus normal human bulk-liver RNA-sequencing data supported an expansion of LRAT+FBLN2+ cells in AH; AH patient liver immunohistochemistry showed FBLN2 staining along fibrotic septa enriched with LRAT+ cells; and in situ hybridization confirmed co-expression of FBLN2 with CXCL2 and/or human leukocyte antigen E in patient AH. Finally, HSC tracing in Lrat-Cre;Rosa26mTmG mice detected GFP+FBLN2+ cells in AH. CONCLUSION: A highly profibrotic, inflammatory, and immunoregulatory Lrat+Fbln2+ subpopulation emerges from HSCs in AH and may contribute to the inflammatory and immunoreactive nature of AH.

Persistent mTORC1 activation due to loss of liver tuberous sclerosis complex 1 promotes liver injury in alcoholic hepatitis.

BACKGROUND AND AIMS: The aim of the study was to investigate the role and mechanisms of tuberous sclerosis complex 1 (TSC1) and mechanistic target of rapamycin complex 1 (mTORC1) in alcohol-associated liver disease. APPROACH AND RESULTS: Liver-specific Tsc1 knockout (L- Tsc1 KO) mice and their matched wild-type mice were subjected to Gao-binge alcohol. Human alcoholic hepatitis (AH) samples were also used for immunohistochemistry staining, western blot, and quantitative real-time PCR (q-PCR) analysis. Human AH and Gao-binge alcohol-fed mice had decreased hepatic TSC1 and increased mTORC1 activation. Gao-binge alcohol markedly increased liver/body weight ratio and serum alanine aminotransferase levels in L- Tsc1 KO mice compared with Gao-binge alcohol-fed wild-type mice. Results from immunohistochemistry staining, western blot, and q-PCR analysis revealed that human AH and Gao-binge alcohol-fed L- Tsc1 KO mouse livers had significantly increased hepatic progenitor cells, macrophages, and neutrophils but decreased HNF4α-positive cells. Gao-binge alcohol-fed L- Tsc1 KO mice also developed severe inflammation and liver fibrosis. Deleting Tsc1 in cholangiocytes but not in hepatocytes promoted cholangiocyte proliferation and aggravated alcohol-induced ductular reactions, fibrosis, inflammation, and liver injury. Pharmacological inhibition of mTORC1 partially reversed hepatomegaly, ductular reaction, fibrosis, inflammatory cell infiltration, and liver injury in alcohol-fed L- Tsc1 KO mice. CONCLUSIONS: Our findings indicate that persistent activation of mTORC1 due to the loss of cholangiocyte TSC1 promotes liver cell repopulation, ductular reaction, inflammation, fibrosis, and liver injury in Gao-binge alcohol-fed L- Tsc1 KO mice, which phenocopy the pathogenesis of human AH.

Alcohol-induced extracellular ASC specks perpetuate liver inflammation and damage in alcohol-associated hepatitis even after alcohol cessation.

BACKGROUND AIMS: Prolonged systemic inflammation contributes to poor clinical outcomes in severe alcohol-associated hepatitis (AH) even after the cessation of alcohol use. However, mechanisms leading to this persistent inflammation remain to be understood. APPROACH RESULTS: We show that while chronic alcohol induces nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in the liver, alcohol binge results not only in NLRP3 inflammasome activation but also in increased circulating extracellular apoptosis-associated speck-like protein containing a caspase recruitment domain (ex-ASC) specks and hepatic ASC aggregates both in patients with AH and in mouse models of AH. These ex-ASC specks persist in circulation even after the cessation of alcohol use. Administration of alcohol-induced-ex-ASC specks in vivo in alcohol-naive mice results in sustained inflammation in the liver and circulation and causes liver damage. Consistent with the key role of ex-ASC specks in mediating liver injury and inflammation, alcohol binge failed to induce liver damage or IL-1ß release in ASC-deficient mice. Our data show that alcohol induces ex-ASC specks in liver macrophages and hepatocytes, and these ex-ASC specks can trigger IL-1ß release in alcohol-naive monocytes, a process that can be prevented by the NLRP3 inhibitor, MCC950. In vivo administration of MCC950 reduced hepatic and ex-ASC specks, caspase-1 activation, IL-1ß production, and steatohepatitis in a murine model of AH. CONCLUSIONS: Our study demonstrates the central role of NLRP3 and ASC in alcohol-induced liver inflammation and unravels the critical role of ex-ASC specks in the propagation of systemic and liver inflammation in AH. Our data also identify NLRP3 as a potential therapeutic target in AH.

Macrophage-derived MLKL in alcohol-associated liver disease: Regulation of phagocytosis.

BACKGROUND AND AIMS: Mixed lineage kinase domain-like pseudokinase (MLKL), a key terminal effector of necroptosis, also plays a role in intracellular vesicle trafficking that is critical for regulating liver inflammation and injury in alcohol-associated liver disease (ALD). Although receptor interacting protein kinase 3 (Rip3)-/- mice are completely protected from ethanol-induced liver injury, Mlkl-/- mice are only partially protected. Therefore, we hypothesized that cell-specific functions of MLKL may contribute to ethanol-induced injury. APPROACH AND RESULTS: Bone marrow transplants between Mlkl-/- mice and littermates were conducted to distinguish the role of myeloid versus nonmyeloid Mlkl in the Gao-binge model of ALD. Ethanol-induced hepatic injury, steatosis, and inflammation were exacerbated in Mlkl-/- →wild-type (WT) mice, whereas Mlkl deficiency in nonmyeloid cells (WT→ Mlkl-/- ) had no effect on Gao-binge ethanol-induced injury. Importantly, Mlkl deficiency in myeloid cells exacerbated ethanol-mediated bacterial burden and accumulation of immune cells in livers. Mechanistically, challenging macrophages with lipopolysaccharide (LPS) induced signal transducer and activator of transcription 1-mediated expression and phosphorylation of MLKL, as well as translocation and oligomerization of MLKL to intracellular compartments, including phagosomes and lysosomes but not plasma membrane. Importantly, pharmacological or genetic inhibition of MLKL suppressed the phagocytic capability of primary mouse Kupffer cells (KCs) at baseline and in response to LPS with/without ethanol as well as peripheral monocytes isolated from both healthy controls and patients with alcohol-associated hepatitis. Further, in vivo studies revealed that KCs of Mlkl-/- mice phagocytosed fewer bioparticles than KCs of WT mice. CONCLUSION: Together, these data indicate that myeloid MLKL restricts ethanol-induced liver inflammation and injury by regulating hepatic immune cell homeostasis and macrophage phagocytosis.

5S rRNA pseudogene transcripts are associated with interferon production and inflammatory responses in alcohol-associated hepatitis.

BACKGROUND AND AIMS: Interferon (IFN) signaling is critical to the pathogenesis of alcohol-associated hepatitis (AH), yet the mechanisms for activation of this system are elusive. We hypothesize that host-derived 5S rRNA pseudogene (RNA5SP) transcripts regulate IFN production and modify immunity in AH. APPROACH AND RESULTS: Mining of transcriptomic datasets revealed that in patients with severe alcohol-associated hepatitis (sAH), hepatic expression of genes regulated by IFNs was perturbed and gene sets involved in IFN production were enriched. RNA5SP transcripts were also increased and correlated with expression of type I IFNs. Interestingly, inflammatory mediators upregulated in sAH, but not in other liver diseases, were positively correlated with certain RNA5SP transcripts. Real-time quantitative PCR demonstrated that RNA5SP transcripts were upregulated in peripheral blood mononuclear cells (PBMCs) from patients with sAH. In sAH livers, increased 5S rRNA and reduced nuclear MAF1 (MAF1 homolog, negative regulator of RNA polymerase III) protein suggested a higher activity of RNA polymerase III (Pol III); inhibition of Pol III reduced RNA5SP expression in monocytic THP-1 cells. Expression of several RNA5SP transcript-interacting proteins was downregulated in sAH, potentially unmasking transcripts to immunosensors. Indeed, siRNA knockdown of interacting proteins potentiated the immunostimulatory activity of RNA5SP transcripts. Molecular interaction and cell viability assays demonstrated that RNA5SP transcripts adopted Z-conformation and contributed to ZBP1-mediated caspase-independent cell death. CONCLUSIONS: Increased expression and binding availability of RNA5SP transcripts was associated with hepatic IFN production and inflammation in sAH. These data identify RNA5SP transcripts as a potential target to mitigate inflammation and hepatocellular injury in AH.

Alcohol use disorder in community management of chronic liver diseases.

Rising rates of alcohol use disorder (AUD) combined with increases in alcohol-related liver disease (ALD) and other liver disease have resulted in the need to develop alcohol management strategies at all levels of patient care. For those with pre-existing liver disease, whether ALD or others, attention to alcohol use treatment and abstinence becomes critical to avoiding worsening liver-related consequences. Modalities to help patients reduce or stop alcohol include screening/brief intervention/referral to treatment, various therapeutic modalities including cognitive behavioral therapy, motivational enhancement therapy and 12-step facilitation, and alcohol relapse prevention medications. Harm reduction approaches versus total abstinence may be considered, but for those with existing ALD, particularly advanced ALD (cirrhosis or acute alcoholic hepatitis), total abstinence from alcohol is the recommendation, given clear data that ongoing alcohol use worsens mortality and liver-related morbidity. For certain populations, alcohol cessation is even more critically important. For those with hepatitis C or NAFLD, alcohol use accelerates negative liver-related outcomes. In women, alcohol use accelerates liver damage and results in worsened liver-related mortality. Efforts to integrate AUD and liver disease care are urgently needed and can occur at several levels, with establishment of multidisciplinary ALD clinics for fully integrated co-management as an important goal.