Hedgehog Signaling Antagonist Promotes Regression of Both Liver Fibrosis and Hepatocellular Carcinoma in a Murine Model of Primary Liver Cancer

Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3) develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC) emerges spontaneously in such mice by 50–60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2−/− mice to investigate the hypothesis that activation of the hedgehog (Hh) signaling pathway promotes development of both liver fibrosis and HCC

Whole‐Exome Sequencing Study of Extreme Phenotypes of NAFLD

Abstract Nonalcoholic fatty liver disease (NAFLD) is a heterogeneous disease with highly variable outcomes. Patients with simple steatosis typically experience a benign course, whereas those with more advanced liver injury, nonalcoholic steatohepatitis (NASH), and advanced stage fibrosis suffer increased risk for complications such as cirrhosis, hepatic decompensation, and liver cancer. Genetic variants in patatin‐like phospholipase domain‐containing 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) and clinical factors including diabetes, obesity, and older age increase a patient's risk for NASH, advanced fibrosis, and worse outcomes. Despite substantial investigation and identification of some common variants associated with NAFLD and advanced fibrosis, the genetics and functional mechanisms remain poorly understood. This study aimed to identify genetic variants by whole‐exome sequencing of NAFLD phenotypes to provide novel insights into mechanisms behind NAFLD pathogenesis and variability. We sequenced 82 patients with liver biopsy–confirmed NAFLD and 4455 population controls. NAFLD patients were divided into extreme phenotypes based on liver fibrosis stage and clinical risk factors to investigate rare variants that might predispose to or protect from advanced NAFLD fibrosis. We compared NAFLD extremes to each other and individually to population controls, exploring genetic variation at both the single‐variant and gene‐based level. We replicated known associations with PNPLA3 and TM6SF2 and advanced fibrosis, despite sample‐size limitations. We also observed enrichment of variation in distinct genes for progressor or protective NAFLD phenotypes, although these genes did not reach statistical significance. Conclusion: We report the first whole‐exome sequencing study of genetic variation in liver biopsy–confirmed NAFLD susceptibility and severity, using a small cohort of extreme NAFLD phenotypes and a large cohort of population controls

Prescribing of evidence-based diabetes pharmacotherapy in patients with metabolic dysfunction-associated steatohepatitis

Introduction Metabolic dysfunction-associated steatohepatitis (MASH) is highly prevalent in type 2 diabetes (T2D). Pioglitazone and glucagon-like peptide-1 receptor agonists (GLP-1RA) are medications used in T2D that can resolve MASH and should be considered in all patients with T2D and MASH. We assessed prescription rates of evidence-based T2D pharmacotherapy (EBP) in MASH, and ascertained racial/ethnic disparities in prescribing.Research design and methods We conducted a cross-sectional study on patients in Duke University Health System with diagnosis codes for T2D and MASH between January 2019 and January 2021. Only patients with ≥1 primary care or endocrinology encounter were included. The primary outcome was EBP, defined as ≥1 prescription for pioglitazone and/or a GLP-1RA during the study period. A multivariable logistic regression model was used to examine the primary outcome.Results A total of 847 patients with T2D and MASH were identified; mean age was 59.7 (SD 12) years, 61.9% (n=524) were female, and 11.9% (n=101) and 4.6% (n=39) were of Black race and Latino/a/x ethnicity, respectively. EBP was prescribed in 34.8% (n=295). No significant differences were noted in the rates of EBP use across racial/ethnic groups (Latino/a/x vs White patients: adjusted OR (aOR) 1.82, 95% CI 0.78 to 4.28; Black vs White patients: aOR 0.76, 95% CI 0.44 to 1.33, p=0.20).Conclusions EBP prescriptions, especially pioglitazone, are low in patients with T2D and MASH, regardless of race/ethnicity. These data underscore the need for interventions to close the gap between current and evidence-based care

Serum Metabolites Are Associated With HFpEF in Biopsy‐Proven Nonalcoholic Fatty Liver Disease

Background Nonalcoholic fatty liver disease (NAFLD) and heart failure with preserved ejection fraction (HFpEF) share common risk factors, including obesity and diabetes. They are also thought to be mechanistically linked. The aim of this study was to define serum metabolites associated with HFpEF in a cohort of patients with biopsy‐proven NAFLD to identify common mechanisms. Methods and Results We performed a retrospective, single‐center study of 89 adult patients with biopsy‐proven NAFLD who had transthoracic echocardiography performed for any indication. Metabolomic analysis was performed on serum using ultrahigh performance liquid and gas chromatography/tandem mass spectrometry. HFpEF was defined as ejection fraction >50% plus at least 1 echocardiographic feature of HFpEF (diastolic dysfunction, abnormal left atrial size) and at least 1 heart failure sign or symptom. We performed generalized linear models to evaluate associations between individual metabolites, NAFLD, and HFpEF. Thirty‐seven out of 89 (41.6%) patients met criteria for HFpEF. A total of 1151 metabolites were detected; 656 were analyzed after exclusion of unnamed metabolites and those with >30% missing values. Fifty‐three metabolites were associated with the presence of HFpEF with unadjusted P value <0.05; none met statistical significance after adjustment for multiple comparisons. The majority (39/53, 73.6%) were lipid metabolites, and levels were generally increased. Two cysteine metabolites (cysteine s‐sulfate and s‐methylcysteine) were present at significantly lower levels in patients with HFpEF. Conclusions We identified serum metabolites associated with HFpEF in patients with biopsy‐proven NAFLD, with increased levels of multiple lipid metabolites. Lipid metabolism could be an important pathway linking HFpEF to NAFLD

Branched chain amino acid transaminase 1 (BCAT1) is overexpressed and hypomethylated in patients with non-alcoholic fatty liver disease who experience adverse clinical events: A pilot study.

BACKGROUND AND OBJECTIVES:Although the burden of non-alcoholic fatty liver disease (NAFLD) continues to increase worldwide, genetic factors predicting progression to cirrhosis and decompensation in NAFLD remain poorly understood. We sought to determine whether gene expression profiling was associated with clinical decompensation and death in patients with NAFLD, and to assess whether altered DNA methylation contributes to these changes in gene expression. METHODS:We performed a retrospective analysis of 86 patients in the Duke NAFLD Clinical Database and Biorepository with biopsy-proven NAFLD whose liver tissue was previously evaluated for gene expression and DNA methylation using array based technologies. We assessed the prospective development of liver and cardiovascular disease related outcomes, including hepatic decompensation as identified by the development of ascites, hepatic encephalopathy, hepatocellular carcinoma, or variceal bleeding as well as stroke and myocardial infarction via medical chart review. RESULTS:Of the 86 patients, 47 had F0-F1 fibrosis and 39 had F3-F4 fibrosis at index liver biopsy. Gene expression probe sets (n = 54,675) were analyzed; 42 genes showed significant differential expression (p<0.05) and a two-fold change in expression between patients with and without any outcome. Two expression probes of the branched chain amino-acid transaminase 1 (BCAT1) gene were upregulated (p = 0.02; fold change 2.1 and 2.2 respectively) in patients with a clinical outcome. Methylation of three of the 34 BCAT1 CpG methylation probes were significantly inversely correlated with BCAT1 expression specific to the probes predictive of clinical deterioration. CONCLUSION:We found differential gene expression, correlated to changes in DNA methylation, at multiple BCAT1 loci in patients with cardiovascular outcomes and/or hepatic decompensation. BCAT1 catalyzes the transformation of alpha-ketoglutarate to glutamate and has been linked to the presence and severity of NAFLD, possibly through derangements in the balance between glutamate and alpha-ketoglutarate. Given the potential for BCAT1 to identify patients at risk for poor outcomes, and the potential therapeutic implications, these results should be validated in larger prospective studies