JHEP Reports

Background & AimsHepatitis B virus (HBV) drives hepatocellular carcinoma in part through the activity of its X protein (HBx), yet the mechanisms by which HBx alters hepatocyte function remain incompletely understood. Progress has been limited by the lack of relevant human models that support controlled HBx expression in mature hepatocytes. Here, we use an improved hepatocyte-like organoid (HLO) platform that supports enhanced hepatocyte maturation to investigate HBx function in a differentiated hepatocyte context. MethodsAdult stem cell-derived HLOs were differentiated using an optimized protocol to generate hepatocyte-like cells with enhanced maturation and transcriptional similarity to primary liver tissue. HBx function was interrogated using both cognate promoter-driven expression and doxycycline-inducible systems across multiple donor-derived organoid lines. Transcriptomic, pathway, and single-cell imaging analyses were performed to assess the impact of HBx expression on hepatocytes. ResultsHBx expression consistently suppressed apoptosis-associated transcripts and reduced expression of core hepatocyte identity genes, including CYP3A4. Pathway analysis revealed downregulation of liver-specific functions, including metabolism, detoxification, complement, and coagulation. At the single-cell level, higher HBx expression was associated with reduced caspase 3/7 activation following apoptotic challenge and decreased hepatocyte marker expression. Functionally, HBx expression increased resistance to apoptosis and enhanced the ability of differentiated hepatocyte-like cells to revert to a proliferative, less differentiated state. ConclusionsHBx expression in differentiated human liver organoids reduces apoptosis and impairs hepatocyte identity, consistently across donors and expression systems. These findings support a model in which HBx promotes a survival-permissive less differentiated state that may contribute to early HBV-driven tumorigenesis. This HLO platform provides a relevant system to dissect HBV-host interactions and reveals a mechanism by which HBV may prime the liver for malignant transformation. Impact and implicationsUnderstanding how HBV promotes hepatocellular carcinoma remains a critical challenge, partly due to the lack of physiologically relevant human derived model systems to study HBx function. Using a differentiated adult human liver organoid system, we show that HBx simultaneously suppresses apoptosis and disrupts hepatocyte identity, providing a mechanistic framework for how HBV may prime hepatocytes for malignant transformation. These findings are particularly relevant for researchers studying HBV pathogenesis and liver cancer, as well as for clinicians aiming to better understand early disease progression. While further validation in more complex multicellular systems is needed, this platform can support the identification of HBx-targeted therapeutic strategies and guide the development of improved adult human derived models for virus-host interaction studies.

Purpose Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major cause of chronic liver disease and liver-related morbidity worldwide. Although dietary factors may influence MASLD progression, the long-term liver-specific implications of artificially sweetened beverage (ASB) intake remain unclear. We aimed to examine the association between ASB intake and the risk of liver-related adverse events and liver-related death among individuals with MASLD. Methods This prospective cohort study included 50,562 participants with MASLD from the UK Biobank. ASB intake was assessed using 24-hour dietary recalls and categorized as 0, >0-1, and >1 serving/day. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for liver-related adverse events and liver-related death. Restricted cubic spline models were used to assess dose-response patterns, and competing-risk analyses were performed by treating liver-related death as a competing event for liver-related adverse events. Additional substitution, subgroup and sensitivity analyses were conducted to evaluate the robustness of the findings. Results During a median follow-up of 12.8 years, 292 liver-related adverse events and 91 liver-related deaths occurred. Compared with participants reporting no ASB intake, those consuming >1 serving/day had a higher risk of liver-related adverse events in the fully adjusted model (HR 1.40, 95% CI 1.02-1.93; P = 0.039), whereas the association for >0-1 serving/day was not statistically significant (HR 1.26, 95% CI 0.92-1.71; P = 0.149). The risk of liver-related adverse events increased across ASB intake categories (P for trend = 0.023). Restricted cubic spline analysis indicated a positive linear association between ASB intake and liver-related adverse events (P-overall <0.001; P-nonlinearity = 0.72). In competing-risk analysis, the association for >1 serving/day remained consistent after accounting for liver-related death as a competing event (sub-HR 1.40, 95% CI 1.02-1.93; P = 0.038; Gray test P = 0.006). The association was robust in sensitivity analyses. ASB intake was not significantly associated with liver-related death, and beverage substitution analyses showed no significant associations. Conclusion Among individuals with MASLD, high ASB intake, particularly >1 serving/day, was associated with an increased risk of liver-related adverse events, but not liver-related death. This association was consistent across dose-response, competing-risk, and sensitivity analyses, suggesting that high ASB intake may represent a potential dietary risk marker for adverse liver outcomes in MASLD.

Introduction: The overlap between chronic hepatitis B (CHB) and metabolic dysfunction-associated steatotic liver disease (MASLD) is an emerging global health challenge. We investigated the impact of MASLD and metabolic comorbidity in a diverse London viral hepatitis clinic. Methods: This retrospective cross-sectional study (May 2018-Feb 2024) included adults with CHB having controlled attenuation parameter (CAP) measurements. MASLD was defined as CAP >264 dB/m plus [&ge;]1 cardiometabolic factor (CMF). We used univariable and multivariable models to examine MASLD's relationship with liver stiffness and hepatitis B viral load (HBV VL). Results: Among 323 individuals (67% male, median age 36), most were from Black (35%) or non-white British/Irish (29%) backgrounds. Overall, 64% had [&ge;]1 CMF, and 20% had MASLD. The CHB/MASLD group was significantly older (median 43 vs 35 years, p<0.001) with higher median alanine transaminase (35 vs 30 IU/L, p=0.02) and liver stiffness (5.3 vs 4.7 kPa, p<0.001). Following adjustment for covariates, MASLD remained significantly associated with liver stiffness ({beta} = 0.48 kPa, p=0.03). While univariable analysis showed significantly lower HBV VL in people with MASLD (median 54 vs 417 IU/ml, p=0.004), adjusted multivariable analysis revealed no significant association between MASLD and log10 HBV VL (p=0.2). Conclusions: Although adjusted analysis does not support an independent association between MASLD and HBV VL, the data highlight a substantial cardiometabolic burden in this CHB population and clearly link MASLD to more severe liver disease. Holistic consideration of metabolic comorbidities is crucial in comprehensive CHB management.

Background and aimsAlcohol-associated hepatitis (AH) is characterized by excessive inflammation and blunted antiviral interferon (IFN) responses. We hypothesized that specific gut microbiome-derived metabolites could selectively enhance interferon signaling while limiting NF-{kappa}B mediated inflammation, thereby restoring immune balance in AH. Our goal is to identify microbiome-derived metabolites that differentially regulate the NF-{kappa}B and IFN signaling pathways. Methods and resultsWe used human monocytic THP1-Dual cells, which secrete reporters for NF-{kappa}B and IFN signaling, to model innate immune responses and screened a library of 152 gut microbiome-derived metabolites. From the metabolite screen, 4-hydroxyphenylacetic acid (4-HPAA) emerged as a unique immunomodulator: in LPS-challenged cells, 4-HPAA selectively increased IFN signaling with minimal NF-{kappa}B activation. 4-HPAA was evaluated in vivo using a NIAAA-model, with 4-HPAA supplementation (0.4mg/ml) added to the diet. In the NIAAA-model, dietary 4-HPAA did not induce liver injury and was associated with enhanced interferon-stimulated gene expression. Simultaneously, 4-HPAA reduced pro-inflammatory markers such as Il1{beta}, Ly6g and F4/80 compared to the group exposed to ethanol alone. Metabolomic profiling of mouse cecal contents revealed 4-HPAA supplementation counteracted ethanols metabolic effects, selectively reducing triglyceride-associated lipids that had accumulated with ethanol feeding. Conclusions4-HPAA enhances interferon signaling and antiviral gene induction while dampening NF-{kappa}B-driven inflammation in the presence of LPS, both in vitro and in vivo. In an acute-on-chronic alcohol injury model, 4-HPAA attenuated hepatic inflammation, reduced immune cell recruitment, and activated antioxidant defenses, reflecting a shift toward a more hepatoprotective effect. 4-HPAA treatment was associated with reduced pro-inflammatory markers and modest attenuation of ethanol-induced liver injury. Additionally, 4-HPAA reversed ethanol-induced lipid-dysregulation, particularly triglyceride accumulation, highlighting its metabolic benefit in alcohol-fed mice. In conclusion, 4-HPAA rebalances immune and metabolic pathways by enhancing IFN signaling, suppressing NF-{kappa}B inflammation, and reversing alcohol-induced hepatic injury and lipid accumulation.

miRNA-based transcriptomic analysis of extracellular vesicles (EVs) provide a promising strategy for identifying non-invasive biomarkers and understanding complex pathological mechanisms. Recently, however, urinary extracellular vesicles (uEVs) have emerged as a valuable window into molecular alterations. Despite the high morbidity and mortality associated with alcohol use disorder (AUD), the molecular mechanisms underlying its sex-specific differences remain poorly understood. To address this, we characterize for the first time the uEV miRNome in AUD, revealing its sexually dimorphic profile. We employed uEVs from actively drinking AUD patients of both sexes who did not have advanced liver disease, alongside matched controls. Deep sequencing revealed 14 differentially expressed miRNAs in females (e.g., hsa-miR-197-3p, hsa-miR-19b-3p, hsa-miR-505-3p, hsa-miR-625-5p, and hsa-miR-27a-5p) and 6 in males (e.g., hsa-miR-1290, hsa-miR-1246, hsa-miR-450a-5p, and miR-590-5p). Notably, whereas hsa-miR-4787-5p was consistently overexpressed in uEVs from both sexes, it was absent in plasma-derived EVs, highlighting the specificity of the urinary compartment. Remarkably, the miRNA signatures we uncovered reflect the multiorgan impact of AUD. For instance, hsa-miR-1290 and hsa-miR-197-3p point to alcohol-related liver injury and systemic inflammation, whereas hsa-miR-19b-3p and hsa-miR-1246 signal neuroinflammation and neuronal stress. A subset, including hsa-miR-1290, hsa-miR-1246, and hsa-miR-27a-5p, has been implicated in cancer contexts. Collectively, these findings support the uEV miRNome as a promising sex-informed molecular signature of AUD with biomarker and mechanistic relevance.

Overnutrition-related liver dysfunction and cancer are increasingly prevalent and highly resistant to immunotherapy. While metabolic dysregulation is a hallmark of hepatocellular carcinoma (HCC), how nutrient overload impairs antitumor immunity remains unclear. Here, we show that short-term Western diet (WD) exposure drives near-complete loss of CD8 T cell infiltration and antitumor function in HCC. We identify dietary linoleic acid (LA), the most abundant {omega}-6 fatty acid, as the dominant immunosuppressive driver. Cancer cell-restricted FADS2-mediated desaturation of LA to longer-chain {omega}-6 PUFAs drives their accumulation in the tumor interstitial fluid, suppressing infiltrating CD8 T cells via lipid peroxidation. FADS2 inhibition restores CD8 T cell function and sensitizes WD-driven HCC to PD-1-based immunotherapy. Further, the Parkinsons disease-associated deglycase DJ-1 protects LA-handling proteins from methylglyoxal-mediated glycation, sustaining tumoral immunosuppressive PUFA production. Across multiple independent human MASLD-HCC cohorts, LA metabolic activity correlates with CD8 T cell impairment, immune exclusion, and immunotherapy resistance. Overall, these studies identify a dietary lipid axis as a therapeutically actionable vulnerability in WD-associated HCC.

Autoimmune hepatitis (AIH) is a chronic progressive liver disease that despite suggestive serum autoantibodies or plasma cell enrichment, remains functionally a diagnosis of exclusion. Whether the broader cellular composition of the liver might enable improved specificity of diagnosis has not been systematically tested. We prospectively recruited patients undergoing a clinically-indicated liver biopsy for suspected AIH and performed single-nucleus RNA sequencing (snRNA-seq) on biopsy tissue to map the cellular landscape of AIH and its diagnostic mimics. Unsupervised clustering on cell-type abundances alone largely separated AIH from non-AIH samples. Among individual populations, a subset of CD8 T-cells marked by high TOX and PD1 expression was the most discriminating feature: its enrichment perfectly distinguished AIH by both snRNA-seq and in situ density (AUC = 1.00), outperforming plasma cell abundance (AUC = 0.83). CD8TOX T-cell enrichment may therefore be the histologic lesion that marks the diagnosis of AIH.

Chronic infection with hepatitis B virus (HBV) is characterized by persistent expression of hepatitis B surface antigen (HBsAg), which is associated with profound immune tolerance. Although nucleos(t)ide analogue therapy effectively suppresses viral replication, it neither eliminates HBV nor reverses virus-specific immune dysfunction. Here, we report the results of two parallel first-in-human, dose-escalation studies evaluating a single infusion of mAb19-LS, a long-acting IgG1 monoclonal antibody targeting HBsAg, in individuals with chronic HBV infection receiving nucleos(t)ide analogue therapy. mAb19-LS was generally safe and well tolerated and induced a mean 11-fold increase in antigen clearance. The magnitude and duration of HBsAg suppression were dependent on both baseline antigen levels and mAb19-LS dose, with suppression maintained for more than 36 weeks in individuals receiving the highest dose. Reduction of circulating HBsAg was associated with uptake of HBsAg-IgG immune complexes by monocytes and dendritic cells and inflammatory reprogramming of these antigen-presenting cells. Notably, proliferation of both CD4+ and CD8+ T cells, as well as interferon-{gamma}; and TNF-; production in response to HBV antigens, were significantly increased 24 weeks after infusion. Together, these findings demonstrate that mAb19-LS is generally safe and effectively accelerates HBsAg clearance while activating antigen presenting cells and enhancing antiviral T cell responses.

Background: Pediatric chronic pancreatitis (CP) carries an elevated lifetime risk of pancreatic ductal adenocarcinoma (PDAC), yet the cellular and molecular mechanisms driving disease progression and early neoplastic transformation remain undefined. Methods: We performed single-nucleus RNA sequencing (snRNA-seq) on pancreatic tissue from 15 pediatric CP individuals and 6 healthy controls (HC). Findings were integrated with peripheral blood flow cytometry immunophenotyping of 8 CP and 7 HC individuals and validated by histopathological assessment. Findings: We identified 15 distinct cell populations and profound cellular remodeling in CP, including a 46% reduction in acinar cells and emergence of inflammatory fibroblasts as the dominant stromal population. Acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) populations bearing early PDAC-associated transcriptional signatures were detected in most CP samples. Cell-cell interaction analysis revealed that 68% of CP-specific ligand-receptor interactions converged on ADM and PanIN populations via ECM-integrin and inflammatory pathways. Peripheral blood flow cytometry demonstrated concordant systemic immune activation, including elevated monocyte CCR2 and CD80, increased CD69 on T cells, and upregulated ROR{gamma}t in regulatory T cells. Interpretation: This atlas defines the cellular landscape and intercellular signaling networks underlying pediatric CP, identifying inflammatory fibroblasts and early neoplastic cell states as central features. These findings provide a molecular foundation for understanding cancer risk in pediatric CP and provide a resource to prioritize studies into potential therapeutic targets and biomarkers. Funding: This work was supported by the Network for Pancreatic Organ donors with Diabetes (nPOD) and The Leona M. & Harry B. Helmsley Charitable Trust.

Background & AimsSystemic metabolic dysfunction promotes degenerative diseases in many organs, including liver and kidney. The liver is a master regulator of systemic metal ion homeostasis. Hepatic copper deficiency is increasingly observed in metabolic dysfunction associated steatotic liver disease (MASLD) and is associated with greater disease severity and poor outcomes. However, mechanisms linking copper dysregulation to MASLD and its co-morbidities remain poorly defined. We investigated whether impaired mitochondrial copper homeostasis contributes to MASLD-related pathobiology and represents a modifiable therapeutic axis. Methods & ResultsUsing dietary mouse models of MASLD and in vitro systems, we found that dietary copper deficiency induces lipotoxicity and suppresses mitochondrial metabolic programs. MASLD livers exhibited marked depletion of copper, impaired cytochrome c oxidase integrity, and bioenergetic failure. Targeted restoration of mitochondrial copper with the copper ionophore elesclomol normalized copper-handling programs, improved mitochondrial function, and suppressed ferroptotic stress, hepatocyte senescence, and fibroinflammatory remodeling. Mechanistically, reduced expression of the mitochondrial copper transporter SLC25A3 and MT-CO1 disrupted the SLC25A3-SCO1-MT-CO1-CTR1 axis, limited copper uptake and destabilized copper-iron balance, promoting maladaptive cell fate changes. Across multiple human cohorts and mouse models, copper-iron imbalance tracks with MASLD progression, clinical outcomes, and multiple extrahepatic comorbidities; restoring copper homeostasis in mice with MASLD attenuates both liver and kidney inflammation and fibrosis. ConclusionsMitochondrial copper deficiency is a mechanistically actionable driver of MASLD that promotes bioenergetic failure, ferroptosis, senescence and fibroinflammatory damage in the liver and other organs. Targeting copper-centered mitochondrial regulation represents a novel biomarker and therapeutic strategy for MASLD and its systemic complications.

Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) and associated dyslipidemia is a growing health issue that gives rise to cardiovascular risk. Men are more prone to development of MASLD than women. Understanding mechanisms underlying sex differences in MASLD may lead to improved prevention and treatment approaches. Cholesteryl ester transfer protein (CETP) is a lipid transfer protein that shuttles triglycerides and cholesteryl esters between blood lipoproteins and tissues. In this study investigate the impact of hepatic CETP expression on MASLD. Hepatic CETP expression (L-HuCETP) was achieved by injecting liver-targeted CETP-expressing adeno-associated virus into C57BL/6J mice. In females, L-HuCETP improved glucose tolerance, consistent with our prior clamp results in global human CETP transgenic mice. Whereas in males, L-HuCETP worsened glucose metabolism and impaired insulin signaling. Correspondingly, L-HuCETP expression reduced the expression of gluconeogenic pathway genes in females but upregulated these genes in males. In males, L-HuCETP mice exhibited increased hepatic lipid droplet accumulation, lipogenesis proteins and these changes were not observed in females. L-HuCETP expression resulted in sex-specific hepatic responses, with increased expression of inflammation and fibrosis related genes in male, but decreased expression of these genes in females. Mechanistic studies indicate that L-HuCETP had sex specific effects on transcription factors ChREBP and HNF4, which are important for glucose and lipid metabolism. Our studies suggest that sex-specific roles of L-HuCETP with regard to liver metabolic adaptation and MASLD risk in obesity, highlighting CETP-mediated pathways as potential targets for sex-specific precision medicine approaches to improve MASLD.

An acetaminophen (APAP) overdose is the leading cause of drug-induced hepatotoxicity and acute liver failure (ALF) in the United States. While N-acetylcysteine (NAC), is highly effective when administered early after an overdose, its efficacy decreases with delayed administration. Since most patients present late to the clinic, there is an urgent need for novel late-acting therapeutic options to prevent progression to ALF. We previously demonstrated the benefit of delayed activation of the Adenosine A2B Receptor (A2BAR) in attenuating APAP-induced hepatotoxicity and this study focuses on its effects on liver recovery after injury. Fasted male C57BL/6J mice were treated with 300 mg/kg APAP, followed by activation of A2BAR 6 or 9 h later and sacrifice 24, 48 or 72 h post-APAP with evaluation of liver injury, the innate immune response and liver regeneration. Delayed activation of A2BAR significantly enhanced liver recovery, with accelerated repopulation of the liver by Kupffer cells, increased macrophage migration to the necrotic areas and their faster resolution. A2BAR activation also upregulated lipid metabolism related genes in non-parenchymal cells and cell proliferation and metabolism genes in hepatocytes. Remarkably, genes such as Cidec and Plin2, crucial for lipid droplet formation, were upregulated, indicating that A2ABR activation enhances lipid metabolism which plays a key role in providing energy for liver regeneration. Overall, these findings highlight the potential of A2BAR activation not only in protecting against liver injury, but also in promoting and accelerating liver regeneration by modulating the innate immune responses and metabolic pathways.

Wolman disease (WD), the severe infantile form of lysosomal acid lipase deficiency, is a rare metabolic disorder caused by inactivating mutations in the LIPA gene. Although WD is characterized by profound hepatic dysfunction, experimental human systems capable of modelling multicellular liver pathology and supporting therapeutic testing remain limited. Here, we generated an isogenic human model of WD by introducing LIPA loss-of-function mutations into induced pluripotent stem cells and differentiating them into multicellular human liver organoids (HLO). LIPA-deficient HLO preserved hepatic lineage specification while recapitulating key biochemical and cellular features of WD, including loss of LIPA activity, lysosomal expansion, lipid accumulation, and activation of inflammatory and fibrogenic programs. Single-cell RNA sequencing resolved cell-type-specific disease states across hepatocyte-, stromal-, and biliary-like populations, revealing the emergence of a reactive biliary program consistent with ductular reaction, a complex tissue response associated with chronic liver injury. Importantly, this reactive biliary phenotype was supported by targeted gene-expression analysis in WD liver organoids and independently validated in liver tissue from mouse models and WD patients. Isolated LIPA-deficient cholangiocyte organoids failed to reproduce the DR-associated program, indicating that this response depends on multicellular interactions within the hepatic microenvironment rather than on biliary cell-autonomous dysfunction alone. Consistently, hepatocyte-directed AAV-mediated restoration of LIPA expression attenuated metabolic stress, inflammatory and fibrogenic programs, and suppressed ductular reaction both in organoids and in vivo. Together, these findings establish multicellular human liver organoids as a physiologically relevant platform for modelling emergent tissue-level responses in WD and for evaluating therapeutic rescue strategies in a human context.

BACKGROUNDMetabolic dysfunction-associated steatotic liver disease (MASLD) is a systemic immunometabolic disorder rapidly increasing worldwide, affecting nearly 38% of adults. Gut dysbiosis and host genetic factors, such as PNPLA3 I148M variant, modulate disease development and progression. Through the gut-liver axis, increased intestinal permeability enables microbial translocation to the liver, promoting inflammation and metabolic disruption. However, the composition and functional potential of the hepatic microbiome remain poorly characterized. Understanding its relationship with histological injury and genetic susceptibility may provide novel mechanistic insights. We hypothesized that the hepatic microbiome composition and function are associated with histological severity and PNPLA3 genotype in this disease. AIMTo characterize the hepatic microbiome and assess its association with histological severity and PNPLA3 genotype. METHODSThis cross-sectional observational study included 30 patients with MASLD from a tertiary care hospital. Liver tissue underwent shotgun metagenomic sequencing. Histological severity was assessed using the NAFLD Activity Score (NAS). PNPLA3 genotype was determined by PCR. Differential abundance and functional enrichment analyses were performed using MaAsLin2. Somatic variants were identified using Mutect2. Correlation networks were constructed using Spearmans correlation coefficients. RESULTSPatients with advanced histological injury (NAS [&ge;]5) and PNPLA3 I148M carriers showed a trend toward higher somatic mutational load and a markedly reduced microbial abundance. Analyses revealed broad compositional shifts across bacterial, fungal, viral, and eukaryotic taxa, affecting both commensal and context-dependent pathobiont lineages. Pseudomonas species were enriched, whereas Siphoviridae phages were depleted in advanced disease and PNPLA3 I148M carriers. Functional analysis revealed enrichment of pathways related to nutrient transport and metabolic stress adaptation, while TonB-associated functions were enriched in advanced liver injury but depleted in PNPLA3 I148M carriers. Network analysis identified Sphingomonas leidyi as a keystone node associated with hexosamine metabolism. Salmonella enterica abundance positively correlated with somatic variant burden, suggesting a link between microbial signatures and genomic instability. Histological progression and the risk PNPLA3 genotype were accompanied by marked topological simplification, reflecting less resilient community structures. CONCLUSIONSThe hepatic microbiome in MASLD is a low-biomass, polymicrobial ecosystem shaped by the host genetic background. Its functional activity, taxonomic composition and system architecture bidirectionally relate to liver DNA instability and the severity of histological damage. Core tipThis study characterizes the multi-kingdom hepatic microbiome in MASLD using FFPE-derived metagenomics. We demonstrate that microbial abundance-including bacteria, fungi, protozoa, and viruses- significantly decreases with increased histological severity and the PNPLA3 risk genotype. Rather than global diversity shifts, results showed that disease progression could be linked to specific functional adaptations and simplified microbial network connectivity. In addition, we described associations between specific taxa and somatic mutational burden, suggesting a link between microbial signals and genomic instability. These findings indicate that changes in the liver microbiome as a whole, rather than specific taxonomic modifications, influence MASLD pathophysiology.

Nicotine accumulates in the gut and drives non-alcoholic steatohepatitis (NASH) via the gut-liver axis, yet no effective clinical intervention is currently available. To address this challenge, the probiotic Escherichia coli Nissle 1917 (EcN) was engineered for in situ nicotine clearance in the gut. Mutational screening of nicotine oxidoreductase 2 (PpNicA2) identified a highly active variant, PpNicA2A107R. Its incorporation into EcN together with an electron transfer protein (CycN) and a newly identified transporter (T3/T7) yielded 80% nicotine-degrading activity. Chromosomal integration of this module generated a stable strain, EcN-N12, which in NASH mouse models depleted intestinal nicotine, rescued hepatic lipid metabolism, alleviated tissue damage, and intercepted the nicotine-mediated gut-liver axis pathological progression. This work thus offers an effective and clinically translatable approach for nicotine-associated diseases.

Background: Sepsis-associated liver injury (SALI) is commonly assessed using static laboratory values, although liver dysfunction during sepsis is dynamic.Methods: This retrospective cohort study included 162 ICU patients with SALI. Early trajectories of alanine aminotransferase, total bilirubin, and albumin during the first 7 days after ICU admission were identified using group-based multi-trajectory modeling. Landmark analysis and Cox regression were used to evaluate 60-day mortality.Results: Twenty-five patients died within 60 days. Four trajectory classes were identified. Between-class separation was driven mainly by alanine aminotransferase and total bilirubin, whereas albumin showed limited short-term variation. After the landmark time point, Class 3 (HR, 4.374; 95% CI, 1.960-9.759; P <0 .001) and Class 4 (HR, 7.451; 95% CI, 3.649-15.212; P <0 .001) had higher mortality risk than Class 1.Conclusions: Early joint trajectories of liver-related laboratory biomarkers may identify clinically meaningful SALI subphenotypes and support risk stratification in critically ill patients.

The human liver is composed of a heterogeneous mix of cell types. How these distinct populations contribute individually and collectively to liver function remains poorly understood. Although single-cell technologies have advanced our understanding of liver biology, individual studies have often been limited by small donor cohorts and inconsistent cell type annotations. Integrating multiple datasets can overcome these challenges and better capture biological variability. We present the Human Liver Cell Atlas (HLiCA), an integrated reference of non-disease liver cells assembled from eight datasets across six research centers, encompassing more than 525,000 cells from 110 donors. Developed in collaboration with the Human Cell Atlas Liver Bionetwork, the HLiCA incorporates expert-curated cell annotations refined through community feedback and dedicated cell type annotation meetings. The HLiCA classifies cells into six lineages and expands the cell type resolution to include 47 distinct cell types. Starting from raw sequencing reads, we realigned all data and performed rigorous benchmarking to ensure robust integration across technical and biological variables. Genetic ancestry was inferred for all samples to evaluate the range of ancestral backgrounds represented in the atlas. The expanded cell type annotation enabled identification of previously unrecognized liver cell types, including NRXN1+ stromal cells. Their presence was validated using spatial transcriptomics, which localized NRXN1+ stromal cells to periportal regions. With the number of donors included in the HLiCA we were able to examine cell type specific associations with demographic covariates. In hepatocytes, drug metabolism genes showed differential expression between sexes, and in cholangiocytes, mucus-production genes varied with age. As the largest and most genetically diverse human liver cell atlas to date, the HLiCA provides a comprehensive, well-annotated reference for the field, annotated by expert consensus. This resource will enable deeper interrogation of liver cellular diversity, architecture, and function in the healthy human liver and serve as a reference to understand changes that occur with disease.

How an organism detects organ injury to initiate regeneration remains one of the central unresolved questions in regenerative biology. The liver is the only solid organ in mammals capable of complete regeneration, a process initiated by hepatocyte growth factor (Hgf) upregulation, yet the mechanism linking liver injury to Hgf induction has been unknown. Here we identify an albumin-based sensing mechanism that continuously reports the livers functional status to hepatic stellate cells to gate the regenerative program. Using single-molecule RNA FISH, parabiosis, and an ex vivo plasma assay, we show that stellate cells are the predominant source of Hgf and that a circulating, protein-dependent signal suppresses Hgf expression when the liver is functional. Biochemical fractionation, immunodepletion, and albumin knockout mice together demonstrate that this suppressive signal is a molecule carried by albumin rather than albumin itself. Untargeted metabolomics identified retinol as the albumin-associated suppressive molecule, which we confirm is sufficient to restore Hgf suppression in injured liver plasma. Conversely, long-chain fatty acids that rise after hepatectomy, specifically palmitate and linoleate, which compete for the same albumin binding site, are sufficient to derepress Hgf in healthy plasma. These data support a dual-input model in which albumin functions as an AND gate, integrating retinol loss and fatty acid gain as coincident indicators of liver injury before permitting Hgf derepression. Consistent with this model, acute in vivo knockdown of albumin is sufficient to derepress Hgf in stellate cells and drive liver overgrowth. These findings establish albumin as an active integrator of physiological signals that governs tissue-scale regenerative decisions and reveal that the liver is constitutively poised to regenerate, gatekept by signals that directly reflect its own functional status.

Background & Aims: Liver transplantation improves outcomes in hepatocellular carcinoma (HCC), yet treatment options for patients with tumor recurrence remain limited to tyrosine kinase inhibitors. Glypican-3 (GPC3)-targeted CAR T cells offer a tumor-directed immune-based therapeutic strategy, but their efficacy may be limited by post-transplant immunosuppression. We developed a CAR T cell platform combining CRISPR/Cas9-mediated FKBP1A disruption to confer resistance to FKBP12-dependent immunosuppressive agents, including tacrolimus, everolimus, and sirolimus, with TRAC knockout to eliminate endogenous T cell receptor expression and reduce alloreactivity. Methods: Human T cells were edited using Cas9 ribonucleoprotein complexes targeting FKBP1A and TRAC, expanded, and transduced with an anti-GPC3 CAR construct. Cytokine production and cytotoxicity were assessed in vitro. Antitumor activity under tacrolimus treatment was evaluated in a Hep G2 xenograft model, and xenoreactivity was assessed in a graft-versus-host disease model. FKBP1A/TRAC double-knockout T cells were enriched using mTOR inhibitor selection combined with CD3-based MACS depletion. PBMCs from liver transplant recipients were used to evaluate feasibility for clinical translation during the early post-transplant period. Results: Tacrolimus suppressed wild-type CAR T cell function but not FKBP1A/TRAC double-knockout CAR T cells, which retained cytokine production, cytotoxicity, and in vivo antitumor activity. Cyclosporine A remained suppressive, enabling its potential use as a pharmacologic control strategy. TRAC disruption reduced xenoreactivity. CD3-based MACS depletion and mTOR inhibition achieved functional double-knockout efficiencies greater than 98%, without compromising cell viability. Functional FKBP1A/TRAC knockout CAR T cells were generated from patient PBMC samples 30 days post-transplant. Conclusions: Dual-edited GPC3 CAR T cells resist tacrolimus-based immunosuppression while limiting alloreactivity, supporting their use for recurrent HCC after liver transplantation. Sequential, high-viability selection in a modular cellular engineering framework enables adaptation to alternative tumor targets and next-generation CAR T cell designs.

Sex differences strongly influence susceptibility to metabolic dysfunction-associated steatotic liver disease (MASLD), yet the regulatory mechanisms underlying these differences remain incompletely understood. To examine sex-specific hepatic adaptation to a high-fat (HF) diet mouse model of MASLD, we integrated proteomics, transcriptomics, and Oxford Nanopore direct RNA sequencing for transcriptome-wide m6A profiling in male and female mouse livers. Female mice were relatively protected from HF diet-induced hepatic steatosis and exhibited distinct proteome remodeling enriched for peroxisomal pathways. In contrast, transcriptomic responses in females were dominated by inflammatory signatures and did not recapitulate the metabolic adaptations observed at the protein level, revealing extensive RNA-protein discordance and post-transcriptional remodeling. Integrated RNA-protein analyses identified female-specific amplification of peroxisomal proteins despite modest transcript-level changes. HF diet also induced sex-specific remodeling of m6A RNA methylation and altered regulation of the m6A methylation system. Notably, reduced 3' UTR m6A methylation of peroxisomal transcripts inversely correlated with increased protein abundance relative to RNA expression in female mice. Together, these findings implicate m6A-associated post-transcriptional regulation in sex-specific hepatic adaptation to HF diet exposure and the basis for discordance between many of the mRNAs and proteins in the liver.