Metabolic dysfunction-associated steatohepatitis reduces interferon and macrophage liver gene signatures in patients with chronic hepatitis B.
Journal of hepatology
BACKGROUND & AIMS:Chronic HBV patients with concomitant metabolic dysfunction-associated steatohepatitis (MASH) have been shown to develop more advanced fibrosis faster with more severe liver disease as compared to patients with chronic HBV alone. However, our understanding of the underlying mechanisms is limited. Here we study how MASH co-morbidity impact immune activity in the liver of patients with chronic HBV infection. METHODS:Bulk RNA sequencing was performed on liver biopsies from patients with only MASH (n=10), only HBeAg-negative chronic HBV (ENEG; n=11), combined MASH/ENEG (n=9) and healthy controls (n=9). Biopsies with no or minimal fibrosis (≤F2) were selected to avoid confounding effects of fibrosis. We compared whole transcriptome data from patients with MASH/ENEG to those with ENEG alone to determine the impact of MASH co-morbidity on chronic hepatitis B. RESULTS:There is a high degree of overlap of liver gene expression profiles in patients with only ENEG versus those with only MASH compared to healthy controls, suggesting a largely shared mechanism of liver dysfunction and immune activity for these distinct conditions. In patients with ENEG, MASH co-morbidity significantly reduced interferon pathway activity (NES=2.03, p.adj=0.0251), the expression of ISGs (e.g., IFIT2, IFI27, IFITM1, IFI6), and macrophage gene signatures (e.g., MARCO, CD163, CD5L, CD63), when compared to patients with ENEG alone. CONCLUSIONS:Transcriptomic profiling of the liver suggests that MASH negatively impacts ISGs expression in the liver of patients with ENEG, which may affect antiviral immune pathways, viral replication and inflammatory responses resulting in an increased risk of advanced fibrosis in patients with chronic hepatitis B. Our study provides valuable insights for guiding future research aimed at developing effective, tailored strategies for managing patients with both conditions. IMPACT AND IMPLICATIONS:In recent decades, obesity and associated health issues have reached epidemic levels, with steatotic liver disease affecting up to 30% of adults in developed countries, and this trend is also observed among chronic hepatitis B patients. Given the high and rising prevalence of steatotic liver disease and its frequent co-occurrence in chronic hepatitis B patients, it is essential to understand how conditions such as metabolic dysfunction-associated steatohepatitis (MASH) impact immune responses in the liver. This study provides unique insights into the impact of MASH on HBV antiviral immune activity in the liver of patients with chronic hepatitis B. The rising number of patients with both conditions affects treatment outcomes and highlights the urgent need for novel, tailored therapeutic strategies. Our study holds significant relevance for guiding future research on developing treatment strategies for patients with both MASH and chronic hepatitis B.
10.1016/j.jhep.2024.10.032
Multi-Modal Analysis of human Hepatic Stellate Cells identifies novel therapeutic targets for Metabolic Dysfunction-Associated Steatotic Liver Disease.
Journal of hepatology
BACKGROUND AND AIMS:Metabolic dysfunction-associated steatotic liver disease (MASLD) ranges from Metabolic dysfunction-associated steatotic liver (MASL) to Metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis. Activation of Hepatic Stellate Cells (HSCs) into fibrogenic myofibroblasts plays a critical role in the pathogenesis of MASH liver fibrosis. We compared transcriptome and chromatin accessibility of human HSCs from NORMAL, MASL, and MASH livers at single cell resolution. We aimed to identify genes that are upregulated in activated HSCs and to determine which of these genes are key in the pathogenesis of MASH fibrosis. METHODS:18 human livers were profiled using single-nucleus (sn)RNA-seq and snATAC-seq. High priority targets were identified, then tested in 2D human HSC cultures, 3D human liver spheroids, and HSC-specific gene knockout mice. RESULTS:MASH-enriched activated (A) HSC subclusters are the major source of extracellular matrix proteins. We identified a set of concurrently upregulated and more accessible core genes (GAS7, SPON1, SERPINE1, LTBP2, KLF9, EFEMP1) that drive activation of (A) HSC subclusters. Expression of these genes was regulated via crosstalk between lineage-specific (JUNB/AP1), cluster-specific (RUNX1/2) and signal-specific (FOXA1/2) transcription factors. The pathological relevance of the selected targets, such as SERPINE1 (PAI-1), was demonstrated using dsiRNA-based HSC-specific gene knockdown or pharmacological inhibition of PAI-1 in 3D human MASH liver spheroids, and HSC-specific Serpine1 knockout mice. CONCLUSION:This study identified novel gene targets and regulatory mechanisms underlying activation of MASH fibrogenic HSCs and demonstrated that genetic or pharmacological inhibition of select genes suppressed liver fibrosis. IMPACT AND IMPLICATIONS:Here we present snRNA-seq and snATAC-seq analysis of human HSCs from NORMAL, MASL, and MASH livers. We identified additional subclusters that were not detected by previous studies and characterized the mechanism by which HSCs activate in the MASH livers, including the transcriptional machinery that activates HSCs into myofibroblasts. For the first time, we described the pathogenic role of activated HSC-derived PAI-1 (a product of SERPINE1 gene) in the development of MASH liver fibrosis. Targeting of RUNX1/2-SERPINE1 axis may provide a novel strategy for treatment of liver fibrosis in patients.
10.1016/j.jhep.2024.10.044
Genetic study of intrahepatic cholestasis of pregnancy in Chinese women unveils East Asian etiology linked to historic HBV epidemic.
Journal of hepatology
BACKGROUND & AIMS:Intrahepatic cholestasis of pregnancy (ICP) is the most common and high-risk liver disorder during pregnancy, with varying prevalence across populations. Our understanding of the mechanisms underlying ICP and its population difference remains limited. This study delves into the genetic etiology of ICP in East Asians, drawing comparisons with Europeans to comprehend ICP etiology in the context of genetic background and evolution. METHODS:We conducted the hitherto largest-scale genome-wide association studies (GWAS) on fasting total serum bile acids (TBA) and ICP in 98,269 Chinese pregnancies. The findings were replicated in three cohorts and compared with European populations. Additionally, phenome-wide association and spatio-temporal evolution analyses were employed to investigate the function and evolutionary patterns of ICP-associated loci. RESULTS:We identified eight loci for fasting TBA and four for ICP, including ten novel loci. Notably, we discovered an East-Asian-specific locus within a 0.4Mbp region at 14q24.1, which increases fasting TBA by 6.12 μmol/L and ICP risk by 16.56-fold per risk allele (95% CI: 16.43 to 16.69, P = 7.06×10). Phenome-wide association and spatial-temporal evolution analyses revealed that this 14q24.1 ICP risk locus confers resistance to hepatitis B and has become prevalent in East and Southeast Asia within the last 3,000 years. CONCLUSIONS:We uncovered a distinct genetic etiology of ICP in East Asians, likely linked to a historic HBV epidemic in East and Southeast Asia within the last 3,000 years. These findings enhance our understanding of ICP pathophysiology and offer potential for more precise detection, assessment, and treatment of the disorder. IMPACT AND IMPLICATIONS:This study provides novel insights into the genetic basis of intrahepatic cholestasis of pregnancy (ICP) in East Asian populations, where little was previously known. The identification of the East-Asian-specific 14q24.1 locus, associated with both fasting TBA and ICP, and its connection to a historical hepatitis B epidemic emphasize the importance of incorporating population-specific history into disease research. These findings are crucial for researchers studying pregnancy-related liver disorders and clinicians providing care to pregnant women, enabling more accurate screening, risk assessment, and targeted interventions for ICP.
10.1016/j.jhep.2024.11.008
Towards more consistent models and consensual terminology in preclinical research for Steatotic Liver Disease.
Journal of hepatology
Steatotic liver disease (SLD) is one of the most prevalent liver conditions globally and a leading cause of liver transplantation, yet therapeutic advancements have not kept pace with its major impact on global morbidity and mortality. This underscores the critical importance of developing and refining relevant preclinical animal models. However, preclinical research has faced significant challenges, with concerns about the translational validity of animal models, as findings often fail to accurately reflect human disease. With the recent adoption of new nomenclature for SLD in humans, questions have arisen about how to integrate these changes into preclinical models. Here, we offer suggestions on how to improve preclinical models, including the incorporation of factors such as diet, alcohol, and other metabolic stressors, to better replicate the complexity of human disease. While implementing these improvements presents logistical challenges, doing so is essential to enhancing the translational relevance and reproducibility of animal studies, and advancing therapeutic discoveries. Furthermore, we address the persisting inconsistency in terminology used in animal studies and propose clinically meaningful terms that can be applied consistently to preclinical research.
10.1016/j.jhep.2024.11.025