Search

Background: Links have been reported between the airflow limitation and both metabolic syndrome (MetS) and fatty liver (FL). Additionally, associations between genetic factors and risks of MetS, FL, and airflow limitation have been identified separately in different studies. Our study aims to simultaneously explore the association between specific single nucleotide polymorphisms (SNPs) of certain genes and the risk of the three associated diseases., Methods: In this retrospective cross-sectional nationwide study, 150,709 participants from the Taiwan Biobank (TWB) were enrolled. We conducted a genotype-phenotype association analysis of nine SNPs on seven genes (ApoE-rs429358, MBOAT7-rs641738, LEPR-rs1805096, APOC3-rs2854116, APOC3-rs2854117, PPP1R3B-rs4240624, PPP1R3B-rs4841132, TM6SF2-rs58542926, and IFNL4-rs368234815) using data from the TWB1.0 and TWB2.0 genotype dataset. Participants underwent a series of assessments including questionnaires, blood examinations, abdominal ultrasounds, and spirometry examinations., Results: MetS was associated with FL and airflow limitation. ApoE-rs429358, LEPR-rs1805096, APOC3-rs2854116, APOC3-rs2854117, PPP1R3B-rs4240624, PPP1R3B-rs4841132, and TM6SF2-rs58542926 were significantly associated with the risk of MetS. The cumulative impact of T alleles of ApoE-rs429358 and TM6SF2-rs58542926 on the risk of FL was observed (p-value for trend < 0.001). Individuals without MetS and airflow limitation carrying LEPR-rs1805096 G&#95;G genotype exhibited a reduction in the forced expiratory volume in 1 s percentage prediction (Coefficient -35, 95 % confidence interval (CI) -69.7- -0.4), low forced vital capacity percentage prediction (Coefficient -41.6, 95 % CI -82.6- -0.6), and low vital capacity percentage prediction (Coefficient -42.2, 95 % CI -84.2- -0.1)., Conclusions: MetS significantly correlated with FL and airflow limitation. Multiple SNPs were notably associated with MetS. Specifically, T alleles of ApoE-rs429358 and TM6SF2-rs58542926 cumulatively increased the risk of FL. LEPR-rs1805096 shows a trend-wise association with pulmonary function, which is significant in patients without MetS or airflow limitation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cell death frequently occurs in the pathogenesis of obesity and metabolic dysfunction-associated fatty liver disease (MAFLD). However, the exact contribution of core cell death machinery to disease manifestations remains ill-defined. Here, we show via the direct comparison of mice genetically deficient in the essential necroptotic regulators, receptor-interacting protein kinase-3 (RIPK3) and mixed lineage kinase domain-like (MLKL), as well as mice lacking apoptotic caspase-8 in myeloid cells combined with RIPK3 loss, that RIPK3/caspase-8 signaling regulates macrophage inflammatory responses and drives adipose tissue inflammation and MAFLD upon high-fat diet feeding. In contrast, MLKL, divergent to RIPK3, contributes to both obesity and MAFLD in a manner largely independent of inflammation. We also uncover that MLKL regulates the expression of molecules involved in lipid uptake, transport, and metabolism, and congruent with this, we discover a shift in the hepatic lipidome upon MLKL deletion. Collectively, these findings highlight MLKL as an attractive therapeutic target to combat the growing obesity pandemic and metabolic disease., (© 2024 Tye et al.)

Background: Metabolic dysfunction associated steatotic liver disease (MASLD), closely linked to excessive lipogenesis, induces chronic liver disease. MASLD often cause other metabolic diseases, such as cardiovascular disease, diabetes and obesity. However, the mechanism of N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) mRNA modification in lipogenesis of MASLD has not been fully elucidated. This study investigated the role of NAT10 in lipogenesis targeting mRNA ac4C modification., Methods: The expression of NAT10 in mouse liver was assessed after a 12-week high-fat diet. In addition, the expression of NAT10 also was detected after AML12 hepatocytes cells were treated with 150 µmol/L palmitic acid (PA). The ac4C mRNA modification was performed by dot blotting. Oil red O staining and the mRNA expression of Srebf1, Acaca and Fasn were used to assess lipogenesis in AML12 cells with NAT10 overexpression or knockdown. acRIP-PCR and NAT10 RIP-PCR were used to verify the Srebf1 and Scap mRNA ac4C modification by NAT10. Furthermore, the liver lipogenesis was evaluated by AAV-mediated target knockdown of NAT10 in mouse liver and treating a specific inhibitor, Remodelin., Results: This study revealed that NAT10 is significantly upregulated in liver lipogenesis after a 12-week high-fat diet. NAT10 and ac4C mRNA modification were also drastically increased in AML12 cells after treated with 150 µmol/L PA. Silencing of NAT10 notably inhibited the lipogenesis in AML12 cells and AAV-mediated target knockdown of NAT10 in mouse liver. The acRIP-PCR and NAT10-RIP-PCR revealed that NAT10 ac4C modified Srebf1 and Scap mRNA, the critical modulator of liver lipogenesis, to regulate liver lipogenesis. Besides, Remodelin strongly inhibited liver lipogenesis, including liver TG, serum ALT, AST, TG and TC level and glucose metabolism., Conclusions: NAT10 mediates ac4C modification of Srebf1 and Scap mRNA, thereby affecting lipogenesis in the liver. This study provided a new target for the treatment of MASLD., Competing Interests: Declarations Ethics approval and consent to participate The animal experiments conducted at The Third Xiangya Hospital of Central South University, Changsha, China adhered to strict ethical guidelines set forth by the Ethical Committee for Animal Experiments. Approval for the experiments was granted under Approval NO: 2023-S027. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

The liver regenerates after injury; however, prolonged injury can lead to chronic inflammation, fatty liver disease, fibrosis, and cancer. The mechanism involving the complex pathogenesis of the progression of liver injury to chronic liver disease remains unclear. In this study, we investigated the dynamics of gene expression associated with the progression of liver disease. We analyzed changes in gene expression over time in a mouse model of carbon tetrachloride (CCl 4 )-induced fibrosis using high-throughput RNA sequencing. Prolonged CCl 4 -induced liver injury increased the expression levels of genes associated with the unfolded protein response (UPR), which correlated with the duration of injury, with substantial, progressive upregulation of muscle, intestine, and stomach expression 1 (Mist1, bhlha15) in the mouse fibrosis model and other liver-damaged tissues. Knockdown of MIST1 in HepG2 cells decreased tribbles pseudokinase 3 (TRIB3) levels and increased apoptosis, consistent with the patterns detected in Mist1-knockout mice. MIST1 expression was confirmed in liver tissues from patients with metabolic dysfunction-associated steatohepatitis and alcoholic steatohepatitis (MASH) and correlated with disease progression. In conclusion, MIST1 is expressed in hepatocytes in response to damage, suggesting a new indicator of liver disease progression. Our results suggest that MIST1 plays a key role in the regulation of apoptosis and TRIB3 expression contributing to progressive liver disease after injury., (© 2024. The Author(s).)

Metabolic associated fatty liver disease (MAFLD) is considered an indicator of metabolic syndrome, which affects millions of people around the world and no effective treatment is currently available. MAFLD involves a wide spectrum of liver damage, that initiates from steatosis (fatty live) and may progress to more complex pathophysiology. Then, details in lipid metabolism controlling should be explored aiming to control the fatty liver. In this context, the miR-1914-5p can be considered a potential biotechnology tool to control lipid metabolism in hepatic cells. This miRNA finds potential mRNA binding sequences in more than 100 molecules correlated with energy production and lipid metabolism pointed in bioinformatic platforms. The present study addressed the miR-1914-5p effects in hepatic HepG2/LX-2 co-cultured cells in a in vitro steatotic environment stablished by the addition of 400 μM of a mixture of oleic and palmitic acids. The analyses demonstrated that the inhibition of the miRNA reduced energetic metabolites such as total lipids, triglycerides, cholesterol and even glucose. In addition, the miR-inhibitor-transfected cells did not present any deleterious effect in cellular environment by controlling reactive oxygen species production (ROS), mitochondrial membrane potential (ΔΨm) and even the pro-inflammatory environment. Moreover, the functional effect of the investigated miR, suggested its close connection to the modulation of Sirt-1-PGC1-α pathway, a master switch metabolic route that controlls cellular energetic metabolism. Our assays also suggested a synergistic effect of this miR-1914-5p in cell metabolism, which should be considered as a strong candidate to control steatotic environment in future clinical trials., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Porto-Barbosa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: The global burden of metabolic dysfunction-associated steatotic liver disease (MASLD) is growing, but its subsequent health consequences have not been thoroughly examined., Methods: A phenome-wide association study was conducted to map the associations of MASLD with 948 unique clinical outcomes among 361,021 Europeans in the UK Biobank. Disease trajectory and comorbidity analyses were applied to visualize the sequential patterns of multiple comorbidities related to the occurrence of MASLD. The associations jointly verified by observational and polygenic phenome-wide analyses were further replicated by two-sample Mendelian randomization analysis using data from the FinnGen study and international consortia., Findings: The observational and polygenic phenome-wide association study revealed the associations of MASLD with 96 intrahepatic and extrahepatic diseases, including circulatory, metabolic, genitourinary, neurological, gastrointestinal, and hematologic diseases. Sequential patterns of MASLD-related extrahepatic comorbidities were primarily found in circulatory, metabolic, and inflammatory diseases. Mendelian randomization analyses supported the causal associations between MASLD and the risk of several intrahepatic disorders, metabolic diseases, cardio-cerebrovascular disease, and ascites but found no associations with neurological diseases., Conclusions: This study elucidated multisystem comorbidities and health consequences of MASLD, contributing to the development of combination interventions targeting distinct pathways for health promotion among patients with MASLD., Funding: X.L. was funded by the Natural Science Fund for Distinguished Young Scholars of Zhejiang Province (LR22H260001) and the National Nature Science Foundation of China (82204019) and Y.D. was funded by the Key Project of Traditional Chinese Medicine Science and Technology Plan of Zhejiang Province (GZY-ZJ-KJ-24077) and the National Natural Science Foundation of China (82001673 and 82272860)., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Nonalcoholic fatty liver disease (NAFLD) causes significant global mortality and healthcare costs with no recommended pharmacological intervention for clinical management. Nuciferine (Nuc) is an alkaloid with aromatic rings, abundantly found in Nelumbo nucifera Gaertn . In this study, we explored the protective mechanisms of Nuc against hepatic steatosis and ferroptosis in NAFLD. High-fat diet (HFD) and healthy male ApoE -/- mice were used to induce NAFLD and a hypercholesterolemia model. Nuc was administered to the mice for four consecutive weeks from the ninth week. Various assessments, including histopathology, RNA sequencing, lipid metabolism, and ferroptosis-related protein expression, showed that Nuc alleviated hepatic steatosis and ferroptosis. We further showed that Nuc improves fatty acid accumulation and ferroptosis through the PPARα signaling pathway in mice and RSL3-treated AML-12 cells. The PPARα inhibitor GW6471 blocked Nuc's protective effects, leading to excess accumulation of iron ions. Thus, Nuc may be a potential therapeutic agent for NAFLD.

Fat accumulation, de novo lipogenesis, and glycolysis are key drivers of hepatocyte reprogramming and the consequent metabolic dysfunction-associated steatotic liver disease (MASLD). Here we report that obesity leads to dysregulated expression of hepatic protein-tyrosine phosphatases (PTPs). PTPRK was found to be increased in steatotic hepatocytes in both humans and mice, and correlates positively with PPARγ-induced lipogenic signaling. High-fat-fed PTPRK knockout male and female mice have lower weight gain and reduced hepatic fat accumulation. Phosphoproteomic analysis in primary hepatocytes and hepatic metabolomics identified fructose-1,6-bisphosphatase 1 and glycolysis as PTPRK targets in metabolic reprogramming. Mechanistically, PTPRK-induced glycolysis enhances PPARγ and lipogenesis in hepatocytes. Silencing PTPRK in liver cancer cell lines reduces colony-forming capacity and high-fat-fed PTPRK knockout mice exposed to a hepatic carcinogen develop smaller tumours. Our study defines the role of PTPRK in the regulation of hepatic glycolysis, lipid metabolism, and tumour development in obesity., (© 2024. The Author(s).)

Background: Exposure to ambient air pollutants has emerged as a risk for metabolic-dysfunction associated steatotic liver disease (MASLD)., Objectives: We sought to examine associations between short-term (prior month) and long-term (prior year) ambient air pollution exposure with hepatic fat fraction (HFF) and liver stiffness in Latino youth with obesity. A secondary aim was to investigate effect modification by patatin-like phospholipase domain-containing protein 3 (PNPLA3) genotype and liver disease severity., Methods: Data was analyzed from 113 Latino youth (age 11-19) with obesity in Southern California. Individual exposure to particulate matter with aerodynamic diameter ≤ 2.5μm (PM 2.5 ), ≤ 10μm (PM 10 ), nitrogen dioxide (NO 2 ), 8-hour maximum ozone (8hrMax-O 3 ), 24-hr O 3 , and redox-weighted oxidative capacity (O x wt ) were estimated using residential address histories and United States Environmental Protection Agency air quality observations. HFF and liver stiffness were measured using magnetic resonance imaging. Linear models were used to determine associations between short-term and long-term exposure to air pollutants with HFF and liver stiffness. Modification by PNPLA3 and liver disease severity was then examined., Results: Short-term exposure to 8hrMax-O 3 was positively associated with HFF. Relationships between air pollution exposure and HFF were not impacted by PNPLA3 genotype or liver disease severity. Long-term exposure to 8hrMax-O 3 and O x wt were positively associated with liver stiffness. Associations between air pollution exposure and liver stiffness depended on PNPLA3 genotype, such that individuals with GG genotypes exhibited stronger, more positive relationships between short-term exposure to PM 10 , 8hrMax-O 3 , 24-hr O 3, and O x wt and liver stiffness than individuals with CC/CG genotypes. In addition, relationships between short-term exposure to NO 2 and liver stiffness were stronger in those with severe liver disease., Discussion: Air pollution exposure may be a risk factor for liver disease among Latino youth with obesity, particularly in those with other preexisting risks for liver damage., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Rohit Kohli reports a relationship with Mirum Biopharma that includes: consulting or advisory. Rohit Kohli reports a relationship with Ipsen that includes: consulting or advisory. Michael Goran reports a relationship with YUMI foods that includes: consulting or advisory. Michael Goran reports a relationship with Bobbie Labs that includes: consulting or advisory. Michael Goran receives royalties from Penguin Random House for Sugarproof If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The primary objective of this study was to examine the association between iron overload (IO), metabolic dysfunction-associated steatotic liver disease (MASLD), and hepatic fibrosis. We hypothesized that there is a significant association. Data from the NHANES (2017-2020) were analyzed to explore IO's impact on MASLD and hepatic fibrosis in U.S. adults. We assessed serum ferritin, controlled attenuation parameter (CAP), liver stiffness measurement (LSM), and various covariates. Gene expression data were sourced from the FerrDb V2 and GEO databases. Differential gene expression analysis, Protein-Protein Interaction (PPI) Network construction, and Gene Ontology (GO) and KEGG pathway enrichment analyses were performed. The study verified the link between MASLD, hepatic fibrosis, and iron overload hub genes. This study of 5927 participants, averaging 46.78 years of age, revealed significant correlations between serum ferritin and CAP, LSM, after adjusting for covariates. Threshold effect analysis indicated nonlinear associations between serum ferritin and CAP, LSM, with distinct patterns observed by age and gender. Moreover, the area under the ROC curve for serum ferritin with MASLD and hepatic fibrosis was 0.8272 and 0.8376, respectively, demonstrating its performance in assessing these conditions. Additionally, molecular analyses identified potential hub genes associated with iron overload and MASLD, and hepatic fibrosis, revealing the underlying mechanisms. Our study findings reveal an association between iron overload, MASLD, and hepatic fibrosis. Additionally, the hub genes may be implicated in iron overload and subsequently contribute to the progression of MASLD and hepatic fibrosis. These findings support precision nutrition strategies., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Regular exercise is believed to suppress cancer progression. However, the precise molecular mechanisms by which exercise prevents cancer development remain unclear. In this study, using a steatosis-associated liver cancer mouse model, we found that regular exercise at a speed of 18 m/min for 20 min daily suppressed liver cancer development. To explore the underlying mechanisms, we examined the gene expression profiles in the livers of the exercise and non-exercise groups. The expressions of circadian genes, such as Per1 and Cry2, were upregulated in the exercise group. As circadian rhythm disruption is known to cause various diseases, including cancer, improving circadian rhythm through exercise could contribute to cancer prevention. We further found that the expression of a series of E2F1 and c-Myc target genes that directly affect the proliferation of cancer cells was downregulated in the exercise group. However, the expression of E2F1 and c-Myc was transcriptionally unchanged but degraded at the post-translational level by exercise. Cry2, which is regulated by the Skp1-Cul1-FBXL3 (SCF FBXL3 ) ubiquitin ligase complex by binding to FBXL3, can form a complex with E2F1 and c-Myc, which we think is the mechanism to degrade them. Our study revealed a previously unknown mechanism by which exercise prevents cancer development., (© 2024 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.)

The dynamic interplay between parenchymal hepatocytes and non-parenchymal cells (NPCs), such as macrophages, is an important mechanism for liver metabolic homeostasis. Although numerous endeavors have been made to identify the mediators of metabolic dysfunction associated steatohepatitis (MASH), the molecular underpinnings of MASH progression remain poorly understood, and therapies to arrest MASH progression remain elusive. Herein, it is revealed that the expression of grancalcin (GCA) is upregulated in the macrophages of patients and rodents with MASH and correlates with MASH progression. Notably, the administration of recombinant GCA aggravates the development of MASH, whereas, Gca deletion in myeloid cells blunts liver steatosis and inflammation in multiple MASH murine models. Mechanistically, GCA activates macrophages via TLR9-NF-κB signaling, and the activated macrophages promote hepatocyte lipid accumulation and apoptosis via secretion of Interleukin-6(IL-6), Tumor Necrosis Factor α (TNFα), and Interleukin-1β(IL-1β), thereby leading to hepatic steatosis and inflammation. Finally, the therapeutic administration of antibody blocking GCA effectively halts the progression of MASH. Collectively, these findings implicate GCA as a crucial mediator of MASH and clarify a new metabolic signaling axis between the hepatocytes and macrophages, implying that GCA can emerge as a particularly interesting putative therapeutic target for reversing MASH progression., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

We previously demonstrated hepatic, cardiac, and skin inflammation in a high-fat diet-induced steatotic liver disease (SLD) model. However, the molecular mechanism in the kidneys in this model remains unclear. It has been recently reported that SGLT2 inhibitors improve chronic kidney disease (CKD). Therefore, we used this model to evaluate the effects of tofogliflozin on renal lipid metabolism and inflammation. Male 8-10-week-old C57Bl/6 mice were fed a high-fat/high-cholesterol/high-sucrose/bile acid (HF/HC/HS/BA) diet with 0.015% tofogliflozin (Tofo group) or an HF/HC/HS/BA diet alone (SLD group). After eight weeks, serum lipid profiles, histology, lipid content, and mRNA/microRNA and protein expression levels in the kidney were examined. The Tofo group showed significant reductions in body (26.9 ± 0.9 vs. 24.5 ± 1.0 g; p < 0.001) and kidney weight compared to those of the SLD group. Renal cholesterol (9.1 ± 1.6 vs. 7.5 ± 0.7 mg/g; p < 0.05) and non-esterified fatty acid (NEFA) (12.0 ± 3.0 vs. 8.4 ± 1.5 μEq/g; p < 0.01) were significantly decreased in the Tofo group. Transmission electron microscopy revealed the presence of fewer lipid droplets. mRNA sequencing analysis revealed that fatty acid metabolism-related genes were upregulated and NFκB signaling pathway-related genes were downregulated in the Tofo group. MicroRNA sequencing analysis indicated that miR-21a was downregulated and miR-204 was upregulated in the Tofo group. Notably, the expression of PPARα, which has been known to be negatively regulated by miR-21, was significantly increased, leading to enhancing β-oxidation genes, Acox1 and Cpt1 in the Tofo group. Tofogliflozin decreased renal cholesterol and NEFA levels and improved inflammation through the regulation of PPARα and miR-21a.

The escalating obesity epidemic and aging population have propelled metabolic dysfunction-associated steatohepatitis (MASH) to the forefront of public health concerns. The activation of FXR shows promise to combat MASH and its detrimental consequences. However, the specific alterations within the MASH-related transcriptional network remain elusive, hindering the development of more precise and effective therapeutic strategies. Through a comprehensive analysis of liver RNA-seq data from human and mouse MASH samples, we identified central perturbations within the MASH-associated transcriptional network, including disrupted cellular metabolism and mitochondrial function, decreased tissue repair capability, and increased inflammation and fibrosis. By employing integrated transcriptome profiling of diverse FXR agonists-treated mice, FXR liver-specific knockout mice, and open-source human datasets, we determined that hepatic FXR activation effectively ameliorated MASH by reversing the dysregulated metabolic and inflammatory networks implicated in MASH pathogenesis. This mitigation encompassed resolving fibrosis and reducing immune infiltration. By understanding the core regulatory network of FXR, which is directly correlated with disease severity and treatment response, we identified approximately one-third of the patients who could potentially benefit from FXR agonist therapy. A similar analysis involving intestinal RNA-seq data from FXR agonists-treated mice and FXR intestine-specific knockout mice revealed that intestinal FXR activation attenuates intestinal inflammation, and has promise in attenuating hepatic inflammation and fibrosis. Collectively, our study uncovers the intricate pathophysiological features of MASH at a transcriptional level and highlights the complex interplay between FXR activation and both MASH progression and regression. These findings contribute to precise drug development, utilization, and efficacy evaluation, ultimately aiming to improve patient outcomes., (© 2024. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

Recent advances in the genetics of metabolic dysfunction-associated steatotic liver disease (MASLD) are gradually revealing the mechanisms underlying the heterogeneity of the disease and have shown promising results in patient stratification. Genetic characterization of the disease has been rapidly developed using genome-wide association studies, exome-wide association studies, phenome-wide association studies, and whole exome sequencing. These advances have been powered by the increase in computational power, the development of new analytical algorithms, including some based on artificial intelligence, and the recruitment of large and well-phenotyped cohorts. This review presents an update on genetic studies that emphasize new biological insights from next-generation sequencing approaches. Additionally, we discuss innovative methods for discovering new genetic loci for MASLD, including rare variants. To comprehensively manage MASLD, it is important to stratify risks. Therefore, we present an update on phenome-wide association study associations, including extreme phenotypes. Additionally, we discuss whether polygenic risk scores and targeted sequencing are ready for clinical use. With particular focus on precision medicine, we introduce concepts such as the interplay between genetics and the environment in modulating genetic risk with lifestyle or standard therapies. A special chapter is dedicated to gene-based therapeutics. The limitations of approved pharmacological approaches are discussed, and the potential of gene-related mechanisms in therapeutic development is reviewed, including the decision to perform genetic testing in patients with MASLD., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to investigate the associations among sex hormone-binding globulin (SHBG), visceral adipose tissue (VAT), liver fat content, and risk of type 2 diabetes (T2D). In the Netherlands Epidemiology of Obesity study, 5,690 women (53%) and men (47%) without preexisting diabetes were included and followed for incident T2D. SHBG concentrations were measured in all participants, VAT was measured using MRI, and liver fat content was measured using proton magnetic resonance spectroscopy in a random subset of 1,822 participants. We examined associations between SHBG and liver fat using linear regression and bidirectional Mendelian randomization analyses and between SHBG and T2D using Cox regression adjusted for confounding and additionally for VAT and liver fat to examine mediation. Mean age was 56 (SD 6) years, mean BMI was 30 (SD 4) kg/m2, median SHBG was 47 (interquartile range [IQR] 34-65) nmol/L in women and 34 (26-43) nmol/L in men, and median liver fat was 3.4% (IQR 1.6-8.2%) in women and 6.0% (2.9-13.5%) in men. Compared with the highest SHBG quartile, liver fat was 2.9-fold (95% CI 2.4, 3.4) increased in women and 1.6-fold (95% CI 1.3, 1.8) increased in men, and the hazard ratio of T2D was 4.9 (95% CI 2.4, 9.9) in women and 1.8 (1.1, 2.9) in men. Genetically predicted SHBG was associated with liver fat content (women: SD -0.45 [95% CI -0.55, -0.35]; men: natural logarithm, -0.25 [95% CI -0.34, -0.16]). VAT and liver fat together mediated 43% (women) and 60% (men) of the SHBG-T2D association. To conclude, in a middle-aged population with overweight, the association between low SHBG and increased risk of T2D was, for a large part, mediated by increased VAT and liver fat., (© 2024 by the American Diabetes Association.)

The purpose of this study is to investigate the mechanism by which 6-shogaol ameliorates hepatic steatosis via miRNA-mRNA interaction analysis. C57BL/6 J mice were fed a high-fat diet (HFD) for 12 weeks, during which 6-shogaol was administered orally. The liver lipid level, liver function and oxidative damage in mice were evaluated. mRNA sequencing, miRNA sequencing, and RT-qPCR were employed to compare the expression profiles between the HFD group and the 6-shogaol-treated group. High-throughput sequencing was used to construct the mRNA and miRNA libraries. Target prediction and integration analysis identified eight potential miRNA-mRNA pairs involved in hepatic steatosis, which were subsequently validated in liver tissues and AML12 cells. The findings revealed that 6-shogaol modulates the miR-3066-5p/Grem2 pathway, thereby improving hepatic steatosis. This study provides new insights into the mechanisms through which 6-shogaol alleviates hepatic steatosis, establishing a foundation for future research on natural active compounds for the treatment of metabolic diseases., Competing Interests: Declaration of competing interest All authors of this work have no relevant conflicts of interest to disclose., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background & Aims: Metabolic dysfunction associated steatotic liver disease (MASLD) has a strong genetic component. The aim of this study was to examine noninvasively the prevalence of MASLD and of advanced fibrosis in relatives of patients with advanced MASLD and the risk factors for liver involvement, with a focus on the contribution of common genetic risk variants., Methods: We prospectively enrolled 98 consecutive probands with advanced fibrosis and/or hepatocellular carcinoma caused by MASLD and 160 nontwin first-degree relatives noninvasively screened for MASLD and advanced fibrosis at 4 Italian centers. We evaluated common genetic determinants and polygenic risk scores of liver disease., Results: Among relatives, prevalence of MASLD was 56.8% overall, whereas advanced fibrosis was observed in 14.4%. At multivariable analysis in relatives, MASLD was associated with body mass index (odds ratio [OR], 1.31 [1.18-1.46]) and tended to be associated with diabetes (OR, 5.21 [0.97-28.10]), alcohol intake (OR, 1.32 [0.98-1.78]), and with female sex (OR, 0.54 [0.23-1.15]), whereas advanced fibrosis was associated with diabetes (OR, 3.13 [1.16-8.45]) and nearly with body mass index (OR, 1.09 [1.00-1.19]). Despite that the PNPLA3 risk variant was enriched in probands (P = .003) and overtransmitted to relatives with MASLD (P = .045), evaluation of genetic risk variants and polygenic risk scores was not useful to guide noninvasive screening of advanced fibrosis in relatives., Conclusions: We confirmed that about 1 in 7 relatives of patients with advanced MASLD has advanced fibrosis, supporting clinical recommendations to perform family screening in this setting. Genetic risk variants contributed to liver disease within families but did not meaningfully improve fibrosis risk stratification., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Casein kinase 1 epsilon (CK1ε), a member of the serine/threonine protein kinase family, phosphorylates a broad range of substrates. However, its role in the development of chronic liver diseases remains elusive. This study aimed to investigate the role of CK1ε in the development and progression of metabolic dysfunction-associated steatohepatitis (MASH). Hepatocyte-specific CK1ε knockout (CK1ε ΔHEP ) mice were generated by crossbreeding mice with floxed CK1ε alleles (CK1ε fl/fl ) and Cre-expressing albumin mice. Mice were fed either a Western diet (WD) or a methionine- and choline-deficient diet to induce MASH. CK1ε ΔHEP was associated with a decreased severity of WD- or methionine- and choline-deficient diet-induced MASH, as confirmed by reduced incidence of hepatic lesions and significantly lower levels of alanine aminotransferase, aspartate aminotransferase, and proinflammatory cytokine tumor necrosis factor (TNF)-α. CK1ε ΔHEP WD-fed mice exhibited significant amelioration of total cholesterol, triglycerides, and de novo lipogenic genes, indicating that CK1ε could influence lipid metabolism. CK1ε ΔHEP WD-fed mice showed significantly down-regulated TNF receptor-associated factor (TRAF) 3, phosphorylated (p) transforming growth factor-β-activated kinase 1, p-TRAF-associated NF-κB activator (TANK)-binding kinase 1 (TBK1), and p-AKT levels, thereby affecting downstream mitogen-activated protein kinase signaling, indicating a potential mechanism for the observed rescue. Finally, pharmacologic inhibition of CK1ε with PF670462 improved palmitic acid-induced steatohepatitis in vitro and attenuated WD-induced metabolic profile in vivo. In conclusion, CK1ε up-regulates TNF receptor-associated factor 3, which, in turn, causes transforming growth factor-β-activated kinase 1-dependent signaling, amplifies downstream mitogen-activated protein kinase signaling, modifies p-c-Jun levels, and exacerbates inflammation, all of which are factors in WD-induced metabolic dysfunction-associated steatotic liver disease., Competing Interests: Disclosure Statement None declared., (Copyright © 2024 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Hepatic steatosis, a common liver disorder, can progress to severe conditions such as nonalcoholic steatohepatitis and cirrhosis. While olfactory receptors are primarily known for detecting odorants, emerging evidence suggests that they also influence liver lipid metabolism. This study generated a mouse model with a specific knockout of olfactory receptor 23 (MOR23) to investigate its role in hepatic steatosis. MOR23 knockout mice on a normal diet showed a slight increase in liver weight compared to wild-type (WT) mice. When fed a high-fat diet (HFD), these knockout mice exhibited accelerated hepatic steatosis, indicated by increased liver weight and hepatic triglyceride levels. Our findings suggest that the cyclic adenosine monophosphate/protein kinase A/AMP-activated protein kinase pathway is involved in the role of MOR23, leading to the upregulation of peroxisome proliferator-activated receptor α, peroxisome proliferator-activated receptor-γ coactivator 1-α, and their target β-oxidation genes in the liver. MOR23 also appeared to regulate lipogenesis and free fatty acid uptake in HFD-fed mice, potentially by influencing sterol regulatory element-binding protein 1 activity. Notably, administering a potential MOR23 ligand, cedrene, attenuated hepatic steatosis in WT mice, but these effects were largely nullified in MOR23 knockout mice. These findings provide valuable insights into the in vivo role of MOR23 in hepatic steatosis development., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Fibroblast growth factor 23 (FGF23) is a bone-secreted protein widely recognized as a critical regulator of skeletal and mineral metabolism. However, little is known about the nonskeletal production of FGF23 and its role in tissues other than bone. Growing evidence indicates that circulating FGF23 levels rise with a high-fat diet (HFD) and they are positively correlated with body mass index (BMI) in humans. In the present study, we show for the first time that increased circulating FGF23 levels in obese humans correlate with increased expression of adipose Fgf23 and both positively correlate with BMI. To understand the role of adipose-derived Fgf23, we generated adipocyte-specific Fgf23 knockout mice (AdipoqFgf23Δfl/Δfl) using the adiponectin-Cre driver, which targets mature white, beige, and brown adipocytes. Our data show that targeted ablation of Fgf23 in adipocytes prevents HFD-fed female mice from gaining body weight and fat mass while preserving lean mass but has no effect on male mice, indicating the presence of sexual dimorphism. These effects are observed in the absence of changes in food and energy intake. Adipose Fgf23 inactivation also prevents dyslipidemia, hyperglycemia, and hepatic steatosis in female mice. Moreover, these changes are associated with decreased respiratory exchange ratio and increased brown fat Ucp1 expression in knockout mice compared to HFD-fed control mice (Fgf23fl/fl). In conclusion, this is the first study highlighting that targeted inactivation of Fgf23 is a promising therapeutic strategy for weight loss and lean mass preservation in humans., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Ghrelin is an orexigenic peptide released by gastric ghrelin cells that contributes to obesity and hepatic steatosis. The mechanosensitive ion channel Piezo1 in gastric ghrelin cells inhibits the synthesis and secretion of ghrelin in response to gastric mechanical stretch. We sought to modulate hepatic lipid metabolism by manipulating Piezo1 in gastric ghrelin cells. Mice with a ghrelin cell-specific deficiency of Piezo1 ( Ghrl-Piezo1 -/- ) had hyperghrelinemia and hepatic steatosis when fed a low-fat or high-fat diet. In these mice, hepatic lipid accumulation was associated with changes in gene expression and in protein abundance and activity expected to increase hepatic fatty acid synthesis and decrease lipid β-oxidation. Pharmacological inhibition of the ghrelin receptor improved hepatic steatosis in Ghrl-Piezo1 -/- mice, thus confirming that the phenotype of these mice was due to overproduction of ghrelin caused by inactivation of Piezo1. Gastric implantation of silicone beads to induce mechanical stretch of the stomach inhibited ghrelin synthesis and secretion, thereby helping to suppress fatty liver development induced by a high-fat diet in wild-type mice but not in Ghrl-Piezo1 -/- mice. Our study elucidates the mechanism by which Piezo1 in gastric ghrelin cells regulate hepatic lipid accumulation, providing insights into potential treatments for fatty liver.

LncRNAs are involved in modulating the individual risk and the severity of progression in metabolic dysfunction-associated fatty liver disease (MASLD), but their precise roles remain largely unknown. This study aimed to investigate the role of lncRNA Snhg3 in the development and progression of MASLD, along with the underlying mechanisms. The result showed that Snhg3 was significantly downregulated in the liver of high-fat diet-induced obesity (DIO) mice. Notably, palmitic acid promoted the expression of Snhg3 and overexpression of Snhg3 increased lipid accumulation in primary hepatocytes. Furthermore, hepatocyte-specific Snhg3 deficiency decreased body and liver weight, alleviated hepatic steatosis and promoted hepatic fatty acid metabolism in DIO mice, whereas overexpression induced the opposite effect. Mechanistically, Snhg3 promoted the expression, stability and nuclear localization of SND1 protein via interacting with SND1, thereby inducing K63-linked ubiquitination modification of SND1. Moreover, Snhg3 decreased the H3K27me3 level and induced SND1-mediated chromatin loose remodeling, thus reducing H3K27me3 enrichment at the Pparg promoter and enhancing PPARγ expression. The administration of PPARγ antagonist T0070907 improved Snhg3 -aggravated hepatic steatosis. Our study revealed a new signaling pathway, Snhg3 /SND1/H3K27me3/PPARγ, responsible for mice MASLD and indicates that lncRNA-mediated epigenetic modification has a crucial role in the pathology of MASLD., Competing Interests: XX, MG, WZ, CL, WZ, JY, YZ, EC, YG, ZG, MZ, EN, HW, XW, YZ, YW, XL, HY, LY, FF, ML, AQ, XL No competing interests declared, (© 2024, Xie et al.)

Background: Metabolic dysfunction-associated steatohepatitis (MASH) is a highly prevalent liver disease globally, with a significant risk of progressing to cirrhosis and even liver cancer. Efferocytosis, a process implicated in a broad spectrum of chronic inflammatory disorders, has been reported to be associated with the pathogenesis of MASH; however, its precise role remains obscure. Thus, we aimed to identify and validate efferocytosis linked signatures for detection of MASH., Methods: We retrieved gene expression patterns of MASH from the GEO database and then focused on assessing the differential expression of efferocytosis-related genes (EFRGs) between MASH and control groups. This analysis was followed by a series of in-depth investigations, including protein-protein interaction (PPI), correlation analysis, and functional enrichment analysis, to uncover the molecular interactions and pathways at play. To screen for biomarkers for diagnosis, we applied machine learning algorithm to identify hub genes and constructed a clinical predictive model. Additionally, we conducted immune infiltration and single-cell transcriptome analyses in both MASH and control samples, providing insights into the immune cell landscape and cellular heterogeneity in these conditions., Results: This research pinpointed 39 genes exhibiting a robust correlation with efferocytosis in MASH. Among these, five potential diagnostic biomarkers- TREM2, TIMD4, STAB1, C1QC, and DYNLT1 -were screened using two distinct machine learning models. Subsequent external validation and animal experimentation validated the upregulation of TREM2 and downregulation of TIMD4 in MASH samples. Notably, both TREM2 and TIMD4 demonstrated area under the curve (AUC) values exceeding 0.9, underscoring their significant potential in facilitating the diagnosis of MASH., Conclusion: Our study comprehensively elucidated the relationship between MASH and efferocytosis, constructing a favorable diagnostic model. Furthermore, we identified potential therapeutic targets for MASH treatment and offered novel insights into unraveling the underlying mechanisms of this disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Cao, Liu, Guo, Weng, Chen, Luo, Wang, Zhu, Liu and Peng.)

Myotonic Dystrophy type 1 (DM1), a highly prevalent form of muscular dystrophy, is caused by (CTG) n repeat expansion in the DMPK gene. Much of DM1 research has focused on the effects within the muscle and neurological tissues; however, DM1 patients also suffer from various metabolic and liver dysfunctions such as increased susceptibility to metabolic dysfunction-associated fatty liver disease (MAFLD) and heightened sensitivity to certain drugs. Here, we generated a liver-specific DM1 mouse model that reproduces molecular and pathological features of the disease, including susceptibility to MAFLD and reduced capacity to metabolize specific analgesics and muscle relaxants. Expression of CUG-expanded (CUG) exp repeat RNA within hepatocytes sequestered muscleblind-like proteins and triggered widespread gene expression and RNA processing defects. Mechanistically, we demonstrate that increased expression and alternative splicing of acetyl-CoA carboxylase 1 drives excessive lipid accumulation in DM1 livers, which is exacerbated by high-fat, high-sugar diets. Together, these findings reveal that (CUG) exp RNA toxicity disrupts normal hepatic functions, predisposing DM1 livers to injury, MAFLD, and drug clearance pathologies that may jeopardize the health of affected individuals and complicate their treatment., (© 2024. The Author(s).)

It is known that both transcriptional and post-transcriptional mechanisms control messenger RNA (mRNA) levels. Compared to transcriptional regulations, our understanding of how post-transcriptional regulations adapt during fatty liver progression at the whole-transcriptome level is unclear. While traditional RNA-seq analysis uses only reads mapped to exons to determine gene expression, recent studies support the idea that intron-mapped reads can be reliably used to estimate gene transcription. In this study, we analyzed differential gene expression at both the exon and intron levels using two liver RNA-seq datasets from mice that were fed a high-fat diet for seven weeks (mild fatty liver) or thirty weeks (severe fatty liver). We found that the correlation between gene transcription and mature mRNA levels was much lower in mice with mild fatty liver as compared with mice with severe fatty liver. This result indicates broad post-transcriptional regulations for early fatty liver and such regulations are compromised for severe fatty liver. Specifically, gene ontology analysis revealed that genes involved in synapse organization and cell adhesion were transcriptionally upregulated, while their mature mRNAs were unaffected in mild fatty liver. Further characterization of post-transcriptionally suppressed genes in early fatty liver revealed that their mRNAs harbor a significantly longer 3' UTR, one of the major features that may subject RNA transcripts to nonsense-mediated RNA decay (NMD). We further show that the expression of representative genes that were post-transcriptionally suppressed were upregulated in mice with a hepatocyte-specific defect of NMD. Finally, we provide data supporting a time-dependent decrease in NMD activity in the liver of a diet-induced metabolic-dysfunction-associated fatty liver disease mouse model. In summary, our study supports the conclusion that NMD is essential in preventing unwanted/harmful gene expression at the early stage of fatty liver and such a mechanism is lost due to decreased NMD activity in mice with severe fatty liver.

GDF15 and FGF21, stress-responsive cytokines primarily secreted from the liver, are promising therapeutic targets for metabolic dysfunction-associated steatotic liver disease (MASLD). However, the interaction between GDF15 and FGF21 remains unclear. We examined the effects of hepatocyte-specific GDF15 or FGF21 overexpression in high-fat diet (HFD)-fed mice for 8 weeks. Hydrodynamic injection of GDF15 or FGF21 sustained high circulating levels of GDF15 or FGF21, respectively, resulting in marked reductions in body weight, epididymal fat mass, insulin resistance, and hepatic steatosis. In addition, GDF15 treatment led to early reduction in body weight despite no change in food intake, indicating the role of GDF15 other than appetite loss. GDF15 treatment increased liver-derived serum FGF21 levels, whereas FGF21 treatment did not affect GDF15 expression. GDF15 promoted eIF2α phosphorylation and XBP1 splicing, leading to FGF21 induction. In murine AML12 hepatocytes treated with free fatty acids (FFAs), GDF15 overexpression upregulated Fgf21 mRNA levels and promoted eIF2α phosphorylation and XBP1 splicing. Overall, continuous exposure to excess FFAs resulted in a gradual increase of β-oxidation-derived reactive oxygen species and endoplasmic reticulum stress, suggesting that GDF15 enhanced this pathway and induced FGF21 expression. GDF15- and FGF21-related crosstalk is an important pathway for the treatment of MASLD., (© 2024. The Author(s).)

The platelet-derived growth factor (PDGF) family contributes to the progression of steatohepatitis; however, changes in and the characteristics of isoform-specific expression remain unclear. Since diabetes is a major driver of metabolic dysfunction-associated steatohepatitis (MASH), we characterized the mouse model of diabetic MASH (dMASH) by focusing on PDGF signaling. Pdgfa-d expression was markedly higher in hepatic stellate cells among flow-sorted cells in control mice and also increased in dMASH. In contrast, a reanalysis of human single-cell RNA-Seq data showed the distinct distribution of each PDGF isoform with disease progression. Furthermore, inflammation and fibrosis in the liver were less severe in diabetic MASH using tamoxifen-induced PDGF receptor β (PDGFRβ)-deficient mice (KO) than in control dMASH using floxed mice (FL) at 12 weeks old. Despite the absence of tumors, the expression of tumor-related genes was lower in KO than in FL. Tumorigenesis was significantly lower in 20-week-old KO. An Ingenuity Pathway Analysis of differentially expressed miRNA between FL and KO identified functional networks associated with hepatotoxicity and cancer. Therefore, PDGFRβ signals play important roles in the progression of steatohepatitis and tumorigenesis in MASH, with the modulation of miRNA expression posited as a potential underlying mechanism., (© 2024. The Author(s).)

The crosstalk between adipose tissue and the liver is finely controlled to maintain metabolic health. Yet, how adipose tissue controls toxic free fatty acid overflow into the liver remains incompletely understood. Here, we show that adipocyte activating transcription factor 3 (ATF3) was induced in human or mouse obesity. Adipocyte Atf3 -/- (Atf3 Adi-/- ) mice developed obesity, glucose intolerance, and metabolic dysfunction-associated steatohepatitis (MASH) in chow diet, high-fat diet, or Western diet-fed mice. Blocking fatty acid flux by inhibiting hepatocyte CD36, but not the restoration of hepatic AMPK signaling, prevented the aggravation of MASH in Atf3 Adi-/- mice. Further studies show that the loss of adipocyte ATF3 increased lipolysis via inducing adipose triglyceride lipase, which in turn induced lipogenesis and inflammation in hepatocytes. Moreover, Atf3 Adi-/- mice had reduced energy expenditure and increased adipose lipogenesis and inflammation. Our data demonstrate that adipocyte ATF3 is a gatekeeper in counteracting MASH development under physiological and pathological conditions., (© 2024. The Author(s).)

The inhibitor-kappaB kinase epsilon (IKKε) represents a non-canonical IκB kinase that modulates NF-κB activity and interferon I responses. Inhibition of this pathway has been linked with atherosclerosis and metabolic dysfunction-associated steatotic liver disease (MASLD), yet the results are contradictory. In this study, we employed a combined model of hepatic PCSK9 D377Y overexpression and a high-fat diet for 16 weeks to induce atherosclerosis and liver steatosis. The development of atherosclerotic plaques, serum lipid concentrations, and lipid metabolism in the liver and adipose tissue were compared between wild-type and IKKε knock-out mice. The formation and progression of plaques were markedly reduced in IKKε knockout mice, accompanied by reduced serum cholesterol levels, fat deposition, and macrophage infiltration within the plaque. Additionally, the development of a fatty liver was diminished in these mice, which may be attributed to decreased levels of multiple lipid species, particularly monounsaturated fatty acids, triglycerides, and ceramides in the serum. The modulation of several proteins within the liver and adipose tissue suggests that de novo lipogenesis and the inflammatory response are suppressed as a consequence of IKKε inhibition. In conclusion, our data suggest that the knockout of IKKε is involved in mechanisms of both atherosclerosis and MASLD. Inhibition of this pathway may therefore represent a novel approach to the treatment of cardiovascular and metabolic diseases.

Background: Fatty liver disease is a metabolic disorder that recently has been classified into two categories: metabolic dysfunction-associated fatty liver disease (MAFLD) and non-MAFLD. TGF-β signaling pathway is likely a significant factor in the pathogenesis of this condition, exerting its effects through its downstream signaling proteins, Smad2/3. Accordingly, this study aimed to investigate the TGF-β signaling pathway in the white blood cells (WBCs) of patients with MAFLD compared to those with non-MAFLD and control groups., Methods and Results: In this study, 41 patients with fatty liver were evaluated, comprising 22 patients with MAFLD and 19 patients with non-MAFLD, and compared to 22 healthy controls. Gene expression of TGF-β1, TGF-β3, and CTGF were quantified using qRT-PCR, and the protein expressions of Smad2/3 and P-Smad2/3 were analyzed using western blotting. Gene expression analysis revealed a significant decrease in the gene expressions of the TGF-β1 and TGF-β3 and an increase in CTGF gene expression in patients with MAFLD and non-MAFLD compared to the control group. Notably, the Smad2/3 protein expression was significantly higher in the non-MAFLD group compared to the control group (P < 0.05). On the other hand, the P-smad2/3 protein expression was significantly elevated in the MAFLD group compared to the control group (P < 0.001)., Conclusions: TGF-β signaling pathway in WBCs of patients with fatty liver are affected by a complex signaling pathway. However, metabolic factors most probably affect TGF-β1 gene expression and its downstream signaling proteins more than TGF-β3., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Liver X receptor-α (LXRα) regulates cellular cholesterol abundance and potently activates hepatic lipogenesis. Here we show that at least 1 in 450 people in the UK Biobank carry functionally impaired mutations in LXRα, which is associated with biochemical evidence of hepatic dysfunction. On a western diet, male and female mice homozygous for a dominant negative mutation in LXRα have elevated liver cholesterol, diffuse cholesterol crystal accumulation and develop severe hepatitis and fibrosis, despite reduced liver triglyceride and no steatosis. This phenotype does not occur on low-cholesterol diets and can be prevented by hepatocyte-specific overexpression of LXRα. LXRα knockout mice exhibit a milder phenotype with regional variation in cholesterol crystal deposition and inflammation inversely correlating with steatosis. In summary, LXRα is necessary for the maintenance of hepatocyte health, likely due to regulation of cellular cholesterol content. The inverse association between steatosis and both inflammation and cholesterol crystallization may represent a protective action of hepatic lipogenesis in the context of excess hepatic cholesterol., (© 2024. The Author(s).)

The production of the omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from alpha-linolenic acid (ALA) relies on the delta-6 desaturase (D6D) enzyme encoded by the Fads2 gene. While EPA and DHA reduce hepatic triacylglycerol (TAG) storage and regulate lipogenesis, the independent impact of ALA is less understood. To address this gap in knowledge, hepatic fatty acid metabolism was investigated in male wild-type (WT) and Fads2 knockout (KO) mice fed diets (16% kcal from fat) containing either lard (no n-3 LCPUFA), flaxseed oil (ALA-rich), or menhaden oil (EPA/DHA rich) for 21 weeks. Fat content and composition, as well as markers of lipogenesis, glyceroneogenesis, and TAG synthesis, were analyzed using histology, gas chromatography, and reverse transcription quantitative PCR (RT-qPCR). Mice fed the menhaden diet had significantly lower hepatic TAG compared to both lard- and flax-fed mice, concomitant with changes in n-3 and n-6 LCPUFA in both TAG and phospholipid (PL) fractions (all P < 0.05). Flax-fed WT mice had lower liver TAG content compared to their KO counterparts. Menhaden-fed mice had significantly lower expression of key lipogenic (Scd1, Srebp-1c, Fasn, Fads1, and Fads2), glyceroneogenic (Pck1), and TAG synthesis (Agpat3) genes compared to lard, with flax-fed mice showing some intermediate effects. Gene expression effects were independent of D6D activity, since no differences were detected between WT and KO mice fed the same diet. This study demonstrates that EPA/DHA and not ALA itself is critical for the prevention of hepatic steatosis., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic liver condition worldwide, demanding further investigation into its pathogenesis. Circular RNAs (circRNAs) are emerging as pivotal regulators in MASLD processes, yet their pathological implications in MASLD remain poorly understood. This study focused on elucidating the role of circular RNA ribonucleotide reductase subunit M2 (circRRM2) in MASLD progression. In this study, we used both in vitro and in vivo MASLD models using long-chain-free fatty acid (FFA)-treated hepatocytes and high-fat diet (HFD)-induced MASLD in mice, respectively. We determined the expression patterns of circRRM2, microRNA-142-5p (miR-142-5p), and neuregulin 1 (NRG1) in livers of MASLD-afflicted mice and MASLD hepatocytes by RT-qPCR. Dual-luciferase reporter assays verified the binding relationships among circRRM2, miR-142-5p, and NRG1. We conducted further analyses of their roles in MASLD hepatocytes and modulated circRRM2, miR-142-5p, and NRG1 expression in vitro by transfection. Our findings were validated in vivo. The results demonstrated reduced levels of circRRM2 and NRG1, along with elevated miR-142-5p expression in MASLD livers and hepatocytes. Overexpression of circRRM2 downregulated lipogenesis-related genes and decreased triglycerides accumulation in livers of MASLD mice. MiR-142-5p, which interacts with circRRM2, effectively counteracted the effects of circRRM2 in MASLD hepatocytes. Furthermore, NRG1 was identified as a miR-142-5p target, and its overexpression mitigated the regulatory impact of miR-142-5p on MASLD hepatocytes. In conclusion, circRRM2, via its role as a miR-142-5p sponge, upregulating NRG1, possibly influenced triglycerides accumulation in both in vitro and in vivo MASLD models. NEW & NOTEWORTHY CircRRM2 expression was downregulated in free fatty acid (FFA)-challenged hepatocytes and high-fat diet (HFD) fed mice. Overexpressed circular RNA ribonucleotide reductase subunit M2 (circRRM2) attenuated metabolic dysfunction-associated steatotic liver disease (MASLD) development by suppressing FFA-induced triglycerides accumulation. CircRRM2 targeted microRNA-142-5p (miR-142-5p), which served as an upstream inhibitor of neuregulin 1 (NRG1) and collaboratively regulated MASLD progression.

Endoplasmic reticulum (ER) stress is a major cause of hepatic steatosis through increasing de novo lipogenesis. Forkhead box O6 (FoxO6) is a transcription factor mediating insulin signaling to glucose and lipid metabolism. Therefore, dysregulated FoxO6 is involved in hepatic lipogenesis. This study elucidated the role of FoxO6 in ER stress-induced hepatic steatosis in vivo and in vitro. Hepatic ER stress responses and β-oxidation were monitored in mice overexpressed with constitutively active FoxO6 allele and FoxO6-null mice. For the in vitro study, liver cells overexpressing constitutively active FoxO6 and FoxO6-siRNA were treated with high glucose, and lipid metabolism alterations were measured. ER stress-induced FoxO6 activation suppressed hepatic β-oxidation in vivo. The expression and transcriptional activity of peroxisome proliferator-activated receptor α (PPARα) were significantly decreased in the constitutively active FoxO6 allele. Otherwise, inhibiting β-oxidation genes were reduced in the FoxO6-siRNA and FoxO6-KO mice. Our data showed that the FoxO6-induced hepatic lipid accumulation was negatively regulated by insulin signaling. High glucose treatment as a hyperglycemia condition caused the expression of ER stress-inducible genes, which was deteriorated by FoxO6 activation in liver cells. However, high glucose-mediated ER stress suppressed β-oxidation gene expression through interactions between PPARα and FoxO6 corresponding to findings in the in vivo study-lipid catabolism is also regulated by FoxO6. Furthermore, insulin resistance suppressed b-oxidation through the interaction between FoxO6 and PPARα promotes hepatic steatosis, which, due to hyperglycemia-induced ER stress, impairs insulin signaling. KEY MESSAGES: Our original aims were to delineate the interrelation between the regulation of PPARα and the transcription factor FoxO6 pathway in relation to lipid metabolism at molecular levels. Evidence on high glucose promoted FoxO6 activation induced lipid accumulation in liver cells. The effect of PPARα activation of the insulin signaling. FoxO6 plays a pivotal role in hepatic lipid accumulation through inactivation of PPARα in FoxO6-overexpression mice., (© 2024. The Author(s).)

Background & Aims: We previously identified subsets of patients with metabolic (dysfunction)-associated steatotic liver disease (MASLD) with different metabolic phenotypes. Here, we aimed to refine this classification based on genetic algorithms implemented in a Python package. The use of these genetic algorithms can help scientists to solve problems which cannot be solved with other methods. We present this package and its capabilities with specific problems. The name, PyGenMet, comes from its main goal, solving problems in Python with Genetic Algorithms and Metabolomics data., Methods: We collected serum from methionine adenosyltransferase 1a knockout (Mat1a-KO) mice, which have chronically low level of hepatic S-adenosylmethionine (SAMe) and the metabolomes of all samples were determined. We also analyzed serum metabolomes of 541 patients with biopsy proven MASLD (182 with simple steatosis and 359 with metabolic (dysfunction)-associated steatohepatitis or MASH) and compared them with the serum metabolomes of this specific MASLD mouse model using Genetic Algorithms in order to select patients with a specific phenotype., Results: By applying genetic algorithms, we have found a subgroup of patients with a lipid profile similar to that observed in the mouse model. When analyzing the two groups of patients, we have seen that patients with a lipid profile reflecting the mouse model characteristics show significant differences in lipoproteins, especially in LDL-4, LDL-5, and LDL-6 associated with atherogenic risk., Conclusion: The results show that the application of genetic algorithms to subclassify patients with MASLD (or other metabolic disease) give consistent results and are a good approximation for the treatment of large volumes of data such as those from omics sciences and patient classification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationship that could have appeared to influence the work reported in this paper. Ibon Martinez-Arranz, Cristina Alonso, Rebeca Mayo and Itziar Mincholé are employees of OWL Metabolomics (Rubió Metabolomics, S.L.U.)., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide. If left untreated, MASLD can progress from simple hepatic steatosis to metabolic dysfunction-associated steatohepatitis, which is characterized by inflammation and fibrosis. Current treatment options for MASLD remain limited, leaving substantial unmet medical needs for innovative therapeutic approaches. Here, we show that PLIN2, a lipid droplet protein inhibiting hepatic lipolysis, serves as a promising therapeutic target for MASLD. Hepatic PLIN2 levels were markedly elevated in multiple MASLD mouse models induced by diverse nutritional and genetic factors. The liver-specific deletion of Plin2 exhibited significant anti-MASLD effects in these models. To translate this discovery into a therapeutic application, we developed a GalNAc-siRNA conjugate with enhanced stabilization chemistry and validated its potent and sustained efficacy in suppressing Plin2 expression in mouse livers. This siRNA therapeutic, named GalNAc-siPlin2, was shown to be biosafe in mice. Treatment with GalNAc-siPlin2 for 6-8 weeks led to a decrease in hepatic triglyceride levels by approximately 60% in high-fat diet- and obesity-induced MASLD mouse models, accompanied with increased hepatic secretion of VLDL-triglyceride and enhanced thermogenesis in brown adipose tissues. Eight-week treatment with GalNAc-siPlin2 significantly improved hepatic steatosis, inflammation, and fibrosis in high-fat/high fructose-induced metabolic dysfunction-associated steatohepatitis models compared to control group. As a proof of concept, we developed a GalNAc-siRNA therapeutic targeting human PLIN2, which effectively suppressed hepatic PLIN2 expression and ameliorated MASLD in humanized PLIN2 knockin mice. Together, our results highlight the potential of GalNAc-siPLIN2 as a candidate MASLD therapeutic for clinical trials., Competing Interests: Conflict of interest A. J. Z., Y. W., M. L., Y. Z., and Q. Y. are named inventors of pending patent applications (2023106233979 to the Chinese Patent Office). The other authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is common worldwide. Genes and proteins contributing to drug disposition may show altered expression as MASLD progresses. To assess this further, we undertook transcriptomic and proteomic analysis of 137 pharmacogenes in liver biopsies from a large MASLD cohort. We performed sequencing on RNA from 216 liver biopsies (206 MASLD and 10 controls). Untargeted mass spectrometry proteomics was performed on a 103 biopsy subgroup. Selected RNA sequencing signals were replicated with an additional 187 biopsies. Comparison of advanced MASLD (fibrosis score 3/4) with milder disease (fibrosis score 0-2) by RNA sequencing showed significant alterations in expression of certain phase I, phase II and ABC transporters. For cytochromes P450, CYP2C19 showed the most significant decreased expression (30 % of that in mild disease) but significant decreased expression of other CYPs (including CYP2C8 and CYP2E1) also occurred. CYP2C19 also showed a significant decrease comparing the inflammatory form of MASLD (MASH) with non-MASH biopsies. Findings for CYP2C19 were confirmed in the replication cohort. Proteomics on the original discovery cohort confirmed decreased levels of several CYPs as MASLD advanced but this decrease was greatest for CYP2C19 where levels fell to 40 % control. This decrease may result in decreased CYP2C19 activity that could be problematic for prescription of drugs activated or metabolized by CYP2C19 as MASLD advances. More limited decreases for other P450s suggest fewer issues with non-CYP2C19 drug substrates. Negative correlations at RNA level between CYP2C19 and several cytokine genes provided initial insights into the mechanism underlying decreased expression., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ann Daly and Quentin Anstee reports financial support was provided by European Union. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Backgrounds/aims: Transmembrane 6 superfamily member 2 (TM6SF2) E167K variant is closely associated with the occurrence and development of metabolic dysfunction-associated steatotic liver disease (MASLD). However, the role and mechanism of TM6SF2 E167K variant during MASLD progression are not yet fully understood., Methods: The Tm6sf2167K knock-in (KI) mice were subjected to high-fat diet (HFD). Hepatic lipid levels of Tm6sf2167K KI mice were detected by lipidomics analysis. Thin-layer chromatography (TLC) was used to measure the newly synthesized triglyceride (TG) and phosphatidylcholine (PC)., Results: The TM6SF2 E167K variant significantly aggravated hepatic steatosis and injury in HFD-induced mice. Decreased polyunsaturated PC level and increased polyunsaturated TG level were found in liver tissue of HFD-induced Tm6sf2167K KI mice. Mechanistic studies demonstrated that the TM6SF2 E167K variant increased the interaction between TM6SF2 and PNPLA3, and impaired PNPLA3-mediated transfer of polyunsaturated fatty acids (PUFAs) from TG to PC. The TM6SF2 E167K variant increased the level of fatty acid-induced malondialdehyde and reactive oxygen species, and decreased fatty acid-downregulated cell membrane fluidity. Additionally, the TM6SF2 E167K variant decreased the level of hepatic PC containing C18:3, and dietary supplementation of PC containing C18:3 significantly attenuated the TM6SF2 E167K-induced hepatic steatosis and injury in HFD-fed mice., Conclusion: The TM6SF2 E167K variant could promote its interaction with PNPLA3 and inhibit PNPLA3-mediated transfer of PUFAs from TG to PC, resulting in the hepatic steatosis and injury during MASLD progression. PC containing C18:3 could act as a potential therapeutic supplement for MASLD patients carrying the TM6SF2 E167K variant.

Background/aims: Blocking the complement system is a promising strategy to impede the progression of metabolic dysfunction-associated steatotic liver disease (MASLD). However, the interplay between complement and MASLD remains to be elucidated. This comprehensive approach aimed to investigate the potential association between complement dysregulation and the histological severity of MASLD., Methods: Liver biopsy specimens were procured from a cohort comprising 106 Korean individuals, which included 31 controls, 17 with isolated steatosis, and 58 with metabolic dysfunction-associated steatohepatitis (MASH). Utilizing the Infinium Methylation EPIC array, thorough analysis of methylation alterations in 61 complement genes was conducted. The expression and methylation of nine complement genes in a murine MASH model were examined using quantitative RT-PCR and pyrosequencing., Results: Methylome and transcriptome analyses of liver biopsies revealed significant (P<0.05) hypermethylation and downregulation of C1R, C1S, C3, C6, C4BPA, and SERPING1, as well as hypomethylation (P<0.0005) and upregulation (P<0.05) of C5AR1, C7, and CD59, in association with the histological severity of MASLD. Furthermore, DNA methylation and the relative expression of nine complement genes in a MASH diet mouse model aligned with human data., Conclusion: Our research provides compelling evidence that epigenetic alterations in complement genes correlate with MASLD severity, offering valuable insights into the mechanisms driving MASLD progression, and suggests that inhibiting the function of certain complement proteins may be a promising strategy for managing MASLD.

Fatty liver disease is a common metabolic disease in chickens. This disease can lead to a decrease in egg production and increase the risk of death in chickens. Long non-coding RNAs (lncRNAs) are involved in fatty liver formation by directly targeting genes or regulating gene expression by competitively binding microRNAs. However, a large proportion of competing endogenous RNA (ceRNA) networks in fatty liver diseases are still unclear. The total of 300 Jingxing-Huang chickens were used for fatty liver model construction. Then, differentially expressed (DE) genes (DEGs) identified through whole-transcriptome sequencing from four chickens with fatty liver and four chickens without fatty liver were chosen from the F1 generation. A total of 953 DEGs were identified between the fatty liver group and the control group, including 26 DE micro (mi)RNAs and 56 DE lncRNAs. Differential expression heatmaps and volcano plots were obtained after clustering expression analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these DEGs were involved in many biological processes and signaling pathways related to fatty acid metabolism and lipid synthesis. Furthermore, cytoscape was used to construct a ceRNA network of the DE miRNAs, DE mRNAs, and DE lncRNAs. Eleven DE lncRNAs, seven DE miRNAs, and 13 DE mRNAs were found to be associated with the pathogenesis of fatty liver disease. An lncRNA-miRNA-mRNA ceRNA network was constructed to elucidate the mechanisms of fatty liver diseases, and the ENSGALT00000079786-miR-140/miR-143/miR-1a/miR-22/miR-375 network was identified. These results provide a valuable resource for further elucidating the posttranscriptional regulatory mechanisms of chicken liver and adipose fat development or deposition., (© 2024 Stichting International Foundation for Animal Genetics.)

Background and Aims: Healthy weight (lean) patients with metabolic dysfunction-associated fatty liver disease (MAFLD) have a more favorable metabolic and histological profile in cross-sectional studies compared with their non-lean counterparts. Paradoxically, they also have higher overall mortality. The underpinning pathophysiology of this paradox is not understood. Telomere attrition is associated with increased mortality in various diseases., Methods: We investigated the role of telomere length in the pathogenesis of lean MAFLD in cohorts with biopsy-proven MAFLD (n = 303). We measured serum malondialdehyde (MDA) levels and hepatic 8-hydroxydeoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) expression (reactive oxygen species (ROS) markers), growth/differentiation factor-15 (GDF-15) and tested the effect of H 2 O 2 on telomere length and activity in hepatocyte cell lines. The association between leukocyte telomere length and mortality was examined., Results: Telomere length was significantly lower in patients with lean MAFLD (p < 0.001). They also demonstrated an increase in ROS levels and decreases in GDF-15. H 2 O 2 induced telomere shortening and reducing telomere activity in hepatocyte cell lines. We subsequently confirmed that telomere length shortening at baseline is associated with increased hazards of all-cause mortality; the deleterious effect was more profound in lean people., Conclusion: Differences in telomere length in part explain the increased mortality of lean compared to non-lean patients with MAFLD. The effect is in part mediated through ROS activation and provide opportunities for therapy., (© 2024. Asian Pacific Association for the Study of the Liver.)

Fatty acid omega hydroxylase P450s consist of enzymes that hydroxylate various chain-length saturated and unsaturated fatty acids (FAs) and bioactive eicosanoid lipids. The human cytochrome P450 gene 4 family (CYP4) consists of 12 members that are associated with several human diseases. However, their role in the progression of metabolic dysfunction-associated fatty liver disease (MASLD) remains largely unknown. It has long been thought that the induction of CYP4 family P450 during fasting and starvation prevents FA-related lipotoxicity through FA metabolism to dicarboxylic acids that are chain-shortened in peroxisomes and then transported to the mitochondria for complete oxidation. Several studies have revealed that peroxisome succinate transported to the mitochondria is used for gluconeogenesis during fasting and starvation, and recent evidence suggests that peroxisome acetate can be utilized for lipogenesis and lipid droplet formation as well as epigenetic modification of gene transcription. In addition, omega hydroxylation of the bioactive eicosanoid arachidonic acid to 20-Hydroxyeicosatetraenoic acid (20-HETE) is essential for activating the GPR75 receptor, leading to vasoconstriction and cell proliferation. Several mouse models of diet-induced MASLD have revealed the induction of selective CYP4A members and the suppression of CYP4F during steatosis and steatohepatitis, suggesting a critical metabolic role in the progression of fatty liver disease. Thus, to further investigate the functional roles of CYP4 genes, we analyzed the differential gene expression of 12 members of CYP4 gene family in datasets from the Gene Expression Omnibus (GEO) from patients with steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. We also observed the differential expression of various CYP4 genes in the progression of MASLD, indicating that different CYP4 members may have unique functional roles in the metabolism of specific FAs and eicosanoids at various stages of fatty liver disease. These results suggest that targeting selective members of the CYP4A family is a viable therapeutic approach for treating and managing MASLD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Non-alcoholic fatty liver disease (NAFLD) has emerged as a prominent global health concern associated with high risk of metabolic syndrome, and has impacted a substantial segment of the population. The disease spectrum ranges from simple fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma (HCC) and is increasingly becoming a prevalent indication for liver transplantation. The existing therapeutic options for NAFLD, NASH, and HCC are limited, underscoring the urgent need for innovative treatment strategies. Insights into gene expression, particularly RNA modifications such as N 6 methyladenosine (m 6 A), hold promising avenues for interventions. These modifications play integral roles in RNA metabolism and cellular functions, encompassing the entire NAFLD-NASH-HCC progression. This review will encompass recent insights on diverse RNA modifications, including m 6 A, pseudouridine (ψ), N 1 -methyladenosine (m 1 A), and 5-methylcytidine (m 5 C) across various RNA species. It will uncover their significance in crucial aspects such as steatosis, inflammation, fibrosis, and tumorigenesis. Furthermore, prospective research directions and therapeutic implications will be explored, advancing our comprehensive understanding of the intricate interconnected nature of these pathological conditions., (© 2024. The Author(s).)

Aim: We aimed to assess the role of FGF21 in metabolic dysfunction-associated steatotic liver disease (MASLD) at a multi-scale level., Methods: We used human MASLD pathology samples for FGF21 gene expression analyses (qPCR and RNAseq), serum to measure circulating FGF21 levels and DNA for genotyping the FGF21 rs838133 variant in both estimation and validation cohorts. A hepatocyte-derived cell line was exposed to free fatty acids at different timepoints. Finally, C57BL/6J mice were fed a high-fat and choline-deficient diet (CDA-HFD) for 16 weeks to assess hepatic FGF21 protein expression and FGF21 levels by ELISA., Results: A significant upregulation in FGF21 mRNA expression was observed in the liver analysed by both qPCR (fold change 5.32 ± 5.25 vs. 0.59 ± 0.66; p = 0.017) and RNA-Seq (3.5 fold; FDR: 0.006; p < 0.0001) in MASLD patients vs. controls. Circulating levels of FGF21 were increased in patients with steatohepatitis vs. bland steatosis (386.6 ± 328.9 vs. 297.9 ± 231.5 pg/mL; p = 0.009). Besides, sex, age, A-allele from FGF21, GG genotype from PNPLA3, ALT, type 2 diabetes mellitus and BMI were independently associated with MASH and significant fibrosis in both estimation and validation cohorts. In vitro exposure of Huh7.5 cells to high concentrations of free fatty acids (FFAs) resulted in overexpression of FGF21 (p < 0.001). Finally, Circulating FGF21 levels and hepatic FGF21 expression were found to be significantly increased (p < 0.001) in animals under CDA-HFD., Conclusions: Hepatic and circulating FGF21 expression was increased in MASH patients, in Huh7.5 cells under FFAs and in CDA-HFD animals. The A-allele from the rs838133 variant was also associated with an increased risk of steatohepatitis and significant and advanced fibrosis in MASLD patients., (© 2024 The Authors. United European Gastroenterology Journal published by Wiley Periodicals LLC on behalf of United European Gastroenterology.)

Hepatic adipogenesis has common mechanisms with adipocyte differentiation such as PPARγ involvement and the induction of adipose tissue-specific molecules. A previous report demonstrated that integrator complex subunit 6 (INTS6) is required for adipocyte differentiation. This study aimed to investigate INTS6 expression and its role in hepatic steatosis progression. The expression of INTS6 and PPARγ was examined in the liver of a mouse model of steatohepatitis and in paired liver biopsy samples from 11 patients with severe obesity and histologically proven metabolic dysfunction associated steatohepatitis (MASH) before and one year after bariatric surgery. To induce hepatocellular steatosis in vitro, an immortalized human hepatocyte cell line Hc3716 was treated with free fatty acids. In the steatohepatitis mouse model, we observed hepatic induction of INTS6, PPARγ, and adipocyte-specific genes. In contrast, β-catenin which negatively regulates PPARγ was reduced. Biopsied human livers demonstrated a strong positive correlation (r 2  = 0.8755) between INTS6 and PPARγ mRNA levels. After bariatric surgery, gene expressions of PPARγ, FABP4, and CD36 were mostly downregulated. In our in vitro experiments, we observed a concentration-dependent increase in Oil Red O staining in Hc3716 cells after treatment with the free fatty acids. Alongside this change, the expression of INTS6, PPARγ, and adipocyte-specific genes was induced. INTS6 knockdown using siRNA significantly suppressed cellular lipid accumulation together with induction of β-catenin and PPARγ downregulation. Collectively, INTS6 expression closely correlates with PPARγ. INTS6 suppression significantly reduced hepatocyte steatosis via β-catenin-PPARγ axis, indicating that INTS6 could be a novel therapeutic target for treating MASH., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic and is the most rapidly rising cause of HCC. Clonal hematopoiesis of indeterminate potential (CHIP) contributes to neoplastic and cardiometabolic disorders and is considered a harbinger of tissue inflammation. CHIP was recently associated with increased risk of liver disease. The aim of this study was to examine whether CHIP is associated with HCC development in patients with SLD., Approach and Results: We considered individuals with MASLD-HCC (n=208) and controls with (n =414) and without (n =259) advanced fibrosis who underwent whole exome sequencing. CHIP was diagnosed when ≥2 variant callers identified a known myeloid mutation with variant allele frequency ≥2%. CHIP was observed in 116 participants (13.1%), most frequently in DNMT3A, TET2, TP53 , and ASXL1 , and correlated with age ( p <0.0001) and advanced liver fibrosis (p=0.001). Higher aspartate aminotransferase levels predicted non- DNMT3A -CHIP, in particular with variant allele frequency ≥10% (OR: 1.14, 1.03 -1.28 and OR: 1.30, 1.12 -1.49, respectively, p <0.05). After adjustment for sex, diabetes, and a polygenic risk, a score of inherited MASLD predisposition CHIP was associated with cirrhosis (2.00, 1.30 -3.15, p =0.02), and with HCC even after further adjustment for cirrhosis (OR: 1.81, 1.11 -2.00, 1.30 -3.15, p =0.002). Despite the strong collinearity among aging and development of CHIP and HCC, non- DNTM3A -CHIP, and TET2 lesions remained associated with HCC after full correction for clinical/genetics covariates and age (OR: 2.45, 1.35 -4.53; OR: 4.8, 1.60 -17.0, p =0.02)., Conclusions: We observed an independent association between CHIP, particularly related to non- DNTM3A and TET2 genetic lesions and MASLD-HCC., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Hepatic steatosis, the first step in the development of nonalcoholic fatty liver disease (NAFLD), is frequently observed in the aging population. However, the underlying molecular mechanism remains largely unknown. In this study, we first employed GSEA enrichment analysis to identify short-chain acyl-CoA dehydrogenase (SCAD), which participates in the mitochondrial β-oxidation of fatty acids and may be associated with hepatic steatosis in elderly individuals. Subsequently, we examined SCAD expression and hepatic triglyceride content in various aged humans and mice and found that triglycerides were markedly increased and that SCAD was upregulated in aged livers. Our further evidence in SCAD-ablated mice suggested that SCAD deletion was able to slow liver aging and ameliorate aging-associated fatty liver. Examination of the molecular pathways by which the deletion of SCAD attenuates steatosis revealed that the autophagic degradation of lipid droplets, which was not detected in elderly wild-type mice, was maintained in SCAD-deficient old mice. This was due to the decrease in the production of acetyl-coenzyme A (acetyl-CoA), which is abundant in the livers of old wild-type mice. In conclusion, our findings demonstrate that the suppression of SCAD may prevent age-associated hepatic steatosis by promoting lipophagy and that SCAD could be a promising therapeutic target for liver aging and associated steatosis., (© 2024 The Author(s). Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.)

Eukaryotic elongation factor 1A1 (EEF1A1), originally identified for its role in protein synthesis, has additional functions in diverse cellular processes. Of note, we previously discovered a role for EEF1A1 in hepatocyte lipotoxicity. We also demonstrated that a 2-wk intervention with the EEF1A1 inhibitor didemnin B (DB) (50 µg/kg) decreased liver steatosis in a mouse model of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) [129S6/SvEvTac mice fed Western diet (42% fat) for 26 wk]. Here, we further characterized the hepatic changes occurring in these mice by assessing lipid droplet (LD) size, bulk differential expression, and cell type-associated alterations in gene expression. Consistent with the previously demonstrated decrease in hepatic steatosis, we observed decreased median LD size in response to DB. Bulk RNA sequencing (RNA-Seq) followed by gene set enrichment analysis revealed alterations in pathways related to energy metabolism and proteostasis in DB-treated mouse livers. Deconvolution of bulk data identified decreased cell type association scores for cholangiocytes, mononuclear phagocytes, and mesenchymal cells in response to DB. Overrepresentation analyses of bulk data using cell type marker gene sets further identified hepatocytes and cholangiocytes as the primary contributors to bulk differential expression in response to DB. Thus, we show that chemical inhibition of EEF1A1 decreases hepatic LD size and decreases gene expression signatures associated with several liver cell types implicated in MASLD progression. Furthermore, changes in hepatic gene expression were primarily attributable to hepatocytes and cholangiocytes. This work demonstrates that EEF1A1 inhibition may be a viable strategy to target aspects of liver biology implicated in MASLD progression. NEW & NOTEWORTHY Chemical inhibition of EEF1A1 decreases hepatic lipid droplet size and decreases gene expression signatures associated with liver cell types that contribute to MASLD progression. Furthermore, changes in hepatic gene expression are primarily attributable to hepatocytes and cholangiocytes. This work highlights the therapeutic potential of targeting EEF1A1 in the setting of MASLD, and the utility of RNA-Seq deconvolution to reveal valuable information about tissue cell type composition and cell type-associated gene expression from bulk RNA-Seq data.