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Bile acids (BAs) are significantly altered in the liver and serum of patients with nonalcoholic steatohepatitis (NASH). However, the underlying mechanisms of these changes, particularly BA alternative pathways (BAP) responsible for non12-OH BAs, remain unclear. RNA-seq data were initially analyzed to reveal the changes of gene expression in NASH patients. Targeted metabolomics were conducted on plasma from NASH mice induced by high-fat or western diet with CCl 4 for 10-24 weeks. Liver tissues were examined using proteomics, RT-qPCR, and western blotting. An integrated approach was then employed to analyze protein interactions and network correlations. Analysis of RNA-seq data revealed the inhibition of CYP7B1 in NASH patients, indicating the dysregulation of BAP. In NASH mouse models, dysregulation of BA circulation was observed by increased plasma total BA (TBA) levels and decreased liver TBA, with liver swelling and histopathological changes. Targeted metabolomics revealed suppressed levels of non12-OH BAs, which inversely correlated with increased liver injury markers. The reduced mRNA and protein expression of Fxr and upregulation of Lxr signaling in livers suggested the suppressed BAP was modulated by Fxr-Lxr signaling. Moreover, BAP interactions predominantly implicated multiple metabolism disruptions, involving 7 hub proteins (Hk1, Acadsb, Pklr, Insr, Ldlr, Cyp27a1, and Cyp7b1), offering promising therapeutic targets for NASH. We presented the metabolic and proteomic map of BAP and its regulatory network in NASH progression. Therapeutic targeting of BAP or its co-regulatory proteins holds promise for NASH treatment and metabolic syndrome management., (© 2024 Federation of American Societies for Experimental Biology.)

The relationship between depression and severe non-alcoholic fatty liver disease (NAFLD) has not been clearly defined. We conducted a longitudinal cohort study and a two-sample Mendelian randomization (MR) analysis to assess the association of depression with severe NAFLD risk. We used individual data from the UK Biobank study with 481,181 participants, and summary data from published genome-wide association studies. The association between depression and severe NAFLD was assessed using Cox proportional hazards regression analysis. Two-sample MR for depression with NAFLD was conducted, the principal analysis employed the inverse variance weighted (IVW) approach. In the observational study, after a median follow-up of 13.46 years, 4,563 participants had severe NAFLD. In multivariable-adjusted model, participants with depression had an increased risk of severe NAFLD (hazards ratio:1.21, 95% confidence interval (CI):1.09-1.34), as compared to those without depression. In subgroup analyses, the association between depression and severe NAFLD risk was generally observed across different subgroups. For the MR, result also showed that genetically predicted depression was causally associated with a higher risk of NAFLD (odds ratio:1.55, 95%CI:1.10-2.19) in IVW. Our study revealed a prospective association of depression with severe NAFLD, thus potentially necessitating clinical monitoring of individuals with depression for severe NAFLD., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethical approval The UK Biobank study has approval from the North West Multi-centre Research Ethics Committee, all methods were performed in accordance with the relevant guidelines and regulations, and all participants provided written informed consent. As our MR study was based on publicly available data, no additional ethical approval or consent was required., (© 2024. The Author(s).)

To explore the therapeutic effects along with the molecular mechanisms of epigallocatechin gallate (EGCG) in non-alcoholic fatty liver disease (NAFLD) treatment using network pharmacology as well as animal experiments. Firstly, the Traditional Chinese Medicine (TCM) Systems Pharmacology Database was searched to identify the potential targets of EGCG. The DisGeNET Database was used to screen the potential targets of NAFLD. The GeneCards Database was searched to identify related genes involved in pyroptosis. Subsequently, the intersecting genes of EGCG targeting pyroptosis to regulate NAFLD were obtained using a Venn diagram. Simultaneously, the aforementioned intersecting genes were used to construct a drug-disease target protein-protein interaction (PPI) network. The DAVID database was adopted for Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The main pathway-target network was determined. Next, the potential mechanism of EGCG targeting pyroptosis to regulate NAFLD was investigated and validated through in vivo experiments. 626 potential targets of EGCG, 447 target genes of NAFLD, and 568 potential targets of pyroptosis were identified. The number of common targets between EGCG, NAFLD, and pyroptosis was 266. GO biological process items and 92 KEGG pathways were determined based on the analysis results. Animal experiments demonstrated that EGCG could ameliorate body weight, glucolipid metabolism, steatosis, and liver injury, enhance insulin sensitivity, and improve glucose tolerance in NAFLD mice through the classical pathway of pyroptosis. EGCG could effectively treat NAFLD through multiple targets and pathways. It was concluded that EGCG ameliorates hepatocyte steatosis, pyroptosis, dyslipidemia, and inflammation in NAFLD mice fed a high-fat diet (HFD), and the protective mechanism could be associated with the NLRP3-Caspase-1-GSDMD classical pyroptosis pathway., Competing Interests: Declaration of competing interest The authors declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Metabolic-associated fatty liver disease (MAFLD) is a common chronic condition that poses a significant threat to human health. Mitochondrial dysfunction, particularly involving the mitochondrial Ca 2+ uniporter (MCU), plays a key role in its pathogenesis. This study aimed to investigate the impact of the MCU gene on hepatic lipid metabolism in mice fed a high-fat diet. Using MCU knockout and wild-type mice, subjected to either a high-fat or normal diet for 14 weeks, we observed notable Steatosis and liver weight gain in MCU-deficient mice. Liver function markers, serum triglycerides, very low-density lipoprotein (VLDL) levels, and ApoB protein expression were all significantly elevated. Mechanistic studies revealed that MCU deletion led to mitochondrial dysfunction, increased oxidative stress. These findings highlight the critical role of the MCU gene in maintaining hepatic lipid balance and suggest its potential as a therapeutic target for managing nonalcoholic fatty liver disease., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Evidence has indicated that Enterococcus plays a vital role in non-alcoholic fatty liver disease (NAFLD) development. However, the microbial genetic basis and metabolic potential in the disease are yet unknown. We previously isolated a bacteria Enterococcus faecium B6 (E. faecium B6) from children with NAFLD for the first time. Here, we aim to systematically investigate the potential of strain B6 in lipogenic effects. The lipogenic effects of strain B6 were explored in vitro and in vivo. The genomic and functional characterizations were investigated by whole-genome sequencing and comparative genomic analysis. Moreover, the metabolite profiles were unraveled by an untargeted metabolomic analysis. We demonstrated that strain B6 could effectively induce lipogenic effects in the liver of mice. Strain B6 contained a circular chromosome and two circular plasmids and posed various functions. Compared to the other two probiotic strains of E. faecium, strain B6 exhibited unique functions in pathways of ABC transporters, phosphotransferase system, and amino sugar and nucleotide sugar metabolism. Moreover, strain B6 produced several metabolites, mainly enriched in the protein digestion and absorption pathway. The unique potential of strain B6 in lipogenic effects was probably associated with glycolysis, fatty acid synthesis, and glutamine and choline transport. This study pioneeringly revealed the metabolic characteristics and specific detrimental traits of strain B6. The findings provided new insights into the underlying mechanisms of E. faecium in lipogenic effects, and laid essential foundations for further understanding of E. faecium-related disease., 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.)

Despite public health measures, type 2 diabetes (T2D) is still a significant concern worldwide, given its associated complications, including hepatic alterations. The role of epithelial-to-mesenchymal transition (EMT) in liver fibrosis is well established. However, its effects on the progression of diabetic liver diseases are not well understood. Therefore, this study aims to investigate the mRNA/miRNA axes involved in this process. Bioinformatic analysis revealed new EMT-associated genes (CDH2, ITGB1, COL4A1, COL1A1, TNC, CCN2, and JUN), which showed higher expression in obese T2D and hepatocellular carcinoma (HCC) patients. In addition, six miRNAs (miR-21-5p, miR-26a-5p, miR-34a-5p, miR-106a-5p, miR-320a-3p and miR-424-5p) have been found as potential targets. Among them, miR-26a-5p and miR-424-5p were significantly downregulated in nonalcoholic steatohepatitis (NASH) and HCC (p < 0.05), being considered potential negative regulators of the EMT process. In our hepatic mesenchymal culture model, miR-26a-5p negatively regulated cadherin 2 (also known as N-cadherin, CDH2) and promoted the cadherin 1 (also known as E-cadherin, CDH1) expression. Our results reveal potential molecules involved in liver tumor development. Moreover, we observe that miR-26a-5p impairs EMT in the initial stages of diabetic liver disease by inhibiting CDH2 and could be a valuable target in this pathology., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethical approval All research was conducted in accordance with the Declarations of Helsinki. The research experimental procedure was approved by the Ethics Committee of the Fundeni Clinical Institute (51715/27.09.2022). Informed consent All enrolled patients gave written informed consent., (© 2024. The Author(s).)

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.)

Nonalcoholic fatty liver disease (NAFLD) has become a common health care burden worldwide. The high heterogeneity of NAFLD remains elusive and impairs outcomes of clinical diagnosis and pharmacotherapy. Several NAFLD classifications have been proposed on the basis of clinical, genetic, alcoholic, or serum metabolic analyses. Yet, accurately predicting the progression of NAFLD to cirrhosis or hepatocellular carcinoma (HCC) in patients remains a challenge. Here, on the basis of a Chinese cohort of patients, we classified NAFLD into three distinct molecular subtypes (NAFLD-mSI, NAFLD-mSII, and NAFLD-mSIII) using integrative multiomics including whole-genome sequencing (WGS), proteomics, phosphoproteomics, lipidomics, and metabolomics across a broad range of liver, blood, and urine specimens. We found that NAFLD-mSI had higher expression of CYP1A2 and CYP3A4, which alleviate hepatic steatosis through mediating free fatty acid/bile acid-mTOR-FXR/PPARα signaling. NAFLD-mSII displayed an elevated risk of liver cirrhosis along with increased hepatic infiltration of M1 and M2 macrophages because of lipid-triggered hepatic CCL2 and CRP production. NAFLD-mSIII exhibited a potential risk for HCC development by increased transcription of CEBPB- and ERCC3-regulated oncogenes because of activation of the EGF-EGFR/CHKA/PI3K-PDK1-AKT cascade. Next, we validated the existence of these three NAFLD molecular subtypes in an external cohort comprising 92 patients with NAFLD across three different Chinese hospitals. These findings may aid in understanding the molecular features underlying NAFLD heterogeneity, thereby facilitating clinical diagnosis and treatment strategies with the aim of preventing the development of liver cirrhosis and HCC.

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.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder characterized by fat accumulation in the liver. This leads to aggravated hepatocyte inflammation due to impaired mitochondrial function, mitochondrial double-stranded RNA (mt-dsRNA) release, elevated oxidative stress, and reactive oxygen species (ROS) production. MicroRNA-29a (miR-29a) is used to reduce hepatic fibrosis in cases of cholestatic liver damage and lessen the severity of non-alcoholic steatohepatitis in animal studies by influencing mitochondrial protein balance. However, the effectiveness of miR-29a in diminishing mt-dsRNA-induced exacerbation of NAFLD remains poorly understood, particularly in the context of a Western diet (WD). Our results have found that mice with increased miR-29a levels and fed a WD showed notably decreased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol, and low-density lipoprotein cholesterol levels. They also experienced less weight gain and lower final body and liver weights. In addition, overexpression of miR-29a reduced the severity of fibrosis, alleviated hepatic oxidative stress, misfolded protein aggregates, and the release of mt-dsRNA. Moreover, miR-29a attenuated the innate immune mitochondrial antiviral-signaling protein (MAVS) pathway response. In vitro, the research using HepG2 cells confirmed that miR-29a reduces MAVS expression and decreases the release of mt-dsRNA and superoxide initiated by palmitic acid (PA). Analysis of luciferase activity further established that the specific binding of miR-29a to the 3'UTR of MAVS led to a repression of its expression. In conclusion, these groundbreaking findings underscore the potential of miR-29a in improving the treatment of NAFLD and liver steatofibrosis by inhibiting the MAVS signaling pathway., Competing Interests: Declaration of competing interest All authors hereby declare that they have no financial conflicts of interest to disclose regarding this article., (Copyright © 2024 The Authors. Published by Elsevier B.V. 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.)

The tumor protein D52 (TPD52) gene encodes a proto-oncogene protein associated with various medical conditions, including breast and prostate cancers. It plays a role in multiple biological pathways such as cell growth, differentiation, and apoptosis. The function of TPD52 in lipid droplet biosynthesis has been investigated in vitro. However, its precise role in lipid metabolism in animal models is not fully understood. To investigate the functions of TPD52 in vivo, we performed a conditional TPD52 protein expression analysis using a Tet-off transgenic system to establish conditionally expressed Tpd52 transgenic zebrafish. The effect of Tpd52 on lipogenesis was assessed using various methods, including whole-mount Oil Red O staining, histological examination, and measurement of inflammatory markers and potential targets using real-time quantitative polymerase chain reaction and immunoblotting in Tpd52 fish. Zebrafish with increased Tpd52 levels exhibited notable weight gain and the enlargement of fat deposits, which were mainly attributed to an increase in the volume of adipocytes. Moreover, Tpd52 overexpression was correlated with the triggering of the adipocyte differentiation signaling pathway. During adipocytic differentiation in response to nutrient status, our observations revealed adipogenesis, nonalcoholic fatty liver disease, and metabolic cardiomyopathy (MCM) in Tpd52 transgenic zebrafish. To gain a deeper understanding of the contribution of these proteins to the regulation of cellular growth, we investigated the expression of their corresponding genes and proteins in zebrafish. In the present study, the activated protein kinase pathway was identified as the primary target of TPD52. Adult Tpd52 zebrafish showed increased lipid accumulation, resulting in the development of visceral obesity, nonalcoholic fatty liver disease, and MCM. These findings strongly suggest that TPD52 actively contributes to adipose tissue expansion and its subsequent effects. This investigation provides compelling evidence that Tpd52 facilitates adipocyte development and related metabolic comorbidities in zebrafish., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Non-alcoholic fatty liver disease (NAFLD) is deemed as an emerging global epidemic, whereas the underlying pathogenic mechanism remains to be clarified. We aimed to systemically analyze all the NAFLD-related gene expression datasets from published human-based studies, by which exploring potential key factors and mechanisms accounting for the pathogenesis of NAFLD., Methods: Robust rank aggregation (RRA) method was used to integrate NAFLD-related gene expression datasets. For fatty liver study, adeno-associated virus (AAV) delivery and genetic knockout mice were used to create IGFBP2 (Insulin-like growth factor binding protein 2) gain- or loss-of function models. Western blot, Co-immunoprecipitation (Co-IP), immunofluorescent (IF) staining, luciferase assay, molecular docking simulation were performed to reveal the IGFBP2-EGFR-STAT3 axis involved. Key axis protein levels in livers from healthy donors and patients with NAFLD were assessed via immunohistochemical staining., Results: By using RRA method, the present study identified IGFBP2 being the most significantly down-regulated gene in all NAFLD subjects. The decreased IGFBP2 expression was further confirmed in the liver tissues from patients and animal models of NAFLD. IGFBP2 deficiency aggravated hepatic steatosis and NASH phenotypes and promoted lipogenic gene expression both in vivo and in vitro. Mechanistically, IGFBP2 directly binds to and regulates EGFR, whereas blockage of the IGFBP2-EGFR complex by knockdown of IGFBP2 resulted in the EGFR-STAT3 pathway activation, which in turn promoted the promoter activity of Srebf1. By using molecular docking simulation and protein-protein interaction analysis, the sequence of 233-257 amino acids in IGFBP2 was characterized as a key motif responding for its specific binding to EGFR and the protective effect against hepatic steatosis., Conclusions: The current study has, for the first time, identified IGFBP2 as a novel protector against hepatosteatosis. The protective effect is mediated by its specific interaction with EGFR and thereby suppressing the EGFR-STAT3 pathway. Therefore, pharmaceutically targeting the IGFBP2-EGFR-STAT3 axis may provide a theoretical basis for for the treatment of NAFLD/NASH and the associated diseases., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest that pertain to this work., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Objective: Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA. N-acetyltransferase 10 (NAT10) has not been fully explored in MASLD and MASH., Methods: The clinical relevance of NAT10 was evaluated based on its expression in various mouse and human models of MASLD and MASH. Acetylated RNA immunoprecipitation sequencing and mRNA stability assays were used to explore the role of NAT10 in regulating ac4C modification and expression of target genes. Genetically engineered mice were employed to investigate the role of NAT10 in MASLD and MASH progression., Results: Hepatic NAT10 expression was significantly increased in multiple mice and humans of MASLD and MASH. Genetic knockout of NAT10 protected mice from diet-induced hepatic steatosis and steatohepatitis, whereas overexpression of NAT10 exacerbated high-fat-diet-induced liver steatosis. Mechanistically, NAT10 binds to Srebp-1c mRNA, promoting its stability and expression, thereby upregulating lipogenic enzymes. Treatment with Remodelin, a NAT10-specific inhibitor, effectively ameliorates liver steatosis and dyslipidemia in a preclinical mouse model., Conclusions: Our findings indicate that NAT10 could regulate lipid metabolism in MASLD and MASH by stabilizing Srebp-1c mRNA and upregulating lipogenic enzymes. This study highlights the role of NAT10 and RNA acetylation in the pathogenesis of MASLD and MASH. Thus, our findings suggest a promising new therapeutic approach, such as the use of NAT10 inhibitor, for treating metabolic liver disease., Competing Interests: Declaration of competing interest No potential conflicts of interest relevant to this article were reported., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Numerous studies have suggested a strong association between paternal adverse environmental exposure and increased disease susceptibility in offspring. However, the impact of paternal pre-pregnant caffeine exposure (PPCE) on offspring health remains unexplored. This study elucidates the sperm reprogramming mechanism and potential intervention targets for PPCE-induced non-alcoholic steatohepatitis (NASH) in offspring. Here, male rats are administrated caffeine (15-60 mg kg -1 /d) by gavage for 8 weeks and then mated with females to produce offspring. This study finds that NASH with transgenerational inheritance occurred in PPCE adult offspring. Mechanistically, a reduction of miR-142-3p is implicated in the occurrence of NASH, characterized by hepatic lipid metabolism dysfunction and chronic inflammation through an increase in ACSL4. Conversely, overexpression of miR-142-3p mitigated these manifestations. The origin of reduced miR-142-3p levels is traced to hypermethylation in the miR-142-3p promoter region of parental sperm, induced by elevated corticosterone levels rather than by caffeine per se. Similar outcomes are confirmed in offspring conceived via in vitro fertilization using miR-142-3p KO sperm. Overall, this study provides the first evidence of transgenerational inheritance of NASH in PPCE offspring and identifies miR-142-3p as a potential therapeutic target for NASH induced by paternal environmental adversities., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

In the present study, we investigated the consequences of deleting the glutaredoxin-2 gene (Glrx2 -/- ) on the development of non-alcoholic fatty liver disease (NAFLD) in male and female C57BL6N mice fed a control (CD) or high-fat diet (HFD). We report that the HFD induced a significant increase in body mass in the wild-type (Wt) and Glrx2 -/- male, but not female, mice, which was associated with the hypertrophying of the abdominal fat. Interestingly, while the Wt male mice fed the HFD developed NAFLD, the deletion of the Glrx2 gene mitigated vesicle formation, intrahepatic lipid accumulation, and fibrosis in the males. The protective effect associated with ablating the Glrx2 gene in male mice was due to enhancement of mitochondrial redox buffering capacity. Specifically, liver mitochondria from male Glrx2 -/- fed a CD or HFD produced significantly less hydrogen peroxide (mtH 2 O 2 ), had lower malondialdehyde levels, greater activities for glutathione peroxidase and thioredoxin reductase, and less protein glutathione mixed disulfides (PSSG) when compared to the Wt male mice fed the HFD. These effects correlated with the S-glutathionylation of α-ketoglutarate dehydrogenase (KGDH), a potent mtH 2 O 2 source and key redox sensor in hepatic mitochondria. In comparison to the male mice, both Wt and Glrx2 -/- female mice displayed almost complete resistance to HFD-induced body mass increases and the development of NAFLD, which was attributed to the superior redox buffering capacity of the liver mitochondria. Together, our findings show that modulation of mitochondrial S-glutathionylation signaling through Glrx2 augments resistance of male mice towards the development of NAFLD through preservation of mitochondrial redox buffering capacity. Additionally, our findings demonstrate the sex dimorphisms associated with the manifestation of NAFLD is related to the superior redox buffering capacity and modulation of the S-glutathionylome in hepatic mitochondria from female mice., 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. No COI., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Non-alcoholic fatty liver disease (NAFLD), a metabolic-associated fatty liver disease, has become the most common chronic liver disease worldwide. Recently, the discovery of cuproptosis, a newly identified mode of cell death, further highlighted the importance of copper in maintaining metabolic homeostasis. An increasing number of studies have confirmed that liver copper metabolism is closely related to the pathogenesis of NAFLD. However, the relationship between NAFLD and copper metabolism, especially cuproptosis, remains unclear. In this review, we aim to summarize the current understanding of copper metabolism and its dysregulation, particularly the role of copper metabolism dysregulation in the pathogenesis of NAFLD. More importantly, this review emphasizes potential gene-targeted therapeutic strategies, challenges and the future of cuproptosis-related genes in the treatment of NAFLD. This review aims to provide innovative therapeutic strategies for NAFLD., (© 2024 The Author(s). Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by intermittent hypoxia (IH) and is associated with the occurrence and development of nonalcoholic fatty liver disease (NAFLD). However, the specific mechanism by which OSA induces NAFLD remains unclear. Therefore, effective interventions are lacking. This study aims to investigate the role and mechanism of ferroptosis in OSA-related NAFLD using clinical data analyses, cell-based molecular experiments, and animal experiments. Indicators of liver function, lipid accumulation, and ferroptosis are also examined. RNA-seq, qPCR, western blotting, gene intervention, and E3 ligase prediction using UbiBrowser and co-IP are used to explore the potential underlying mechanisms. The results show that ferroptosis increases in the liver tissues of patients with OSA. Chronic IH promotes NAFLD progression in mice and is alleviated by a ferroptosis inhibitor Fer-1. The increased secretion of IL6 by macrophages can promote the expression of MARCH3 in hepatocytes under intermittent conditions, and subsequently promote the ubiquitination and degradation of GPX4 to regulate ferroptosis and lipid accumulation in hepatocytes. Hence, targeted inhibition of MARCH3 may alleviate IH-induced ferroptosis and lipid accumulation in liver tissues and inhibit the progression of NAFLD., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Aim: Low birthweight is an issue during pregnancy associated with an increased risk of developing liver disease later in life. Previous Mendelian randomisation (MR) studies which explored this issue have not isolated the direct impact of the foetus on birthweight. In the present study, MR was used to assess whether direct foetal effects on birthweight were causally associated with liver structure, function and disease risk independent of intrauterine effects., Materials and Methods: We extracted single nucleotide polymorphisms (SNPs) from genome-wide association studies (GWAS) about direct foetal-affected birthweight (321 223 cases) to conduct univariable and multivariable MR analyses to explore the relationships between birthweight and 4 liver structure measures, 9 liver function measures and 18 liver diseases. A two-step MR analysis was used to further assess and quantify the mediating effects of the mediators., Results: When isolating direct foetal effects, genetically predicted lower birthweight was associated with a higher risk of non-alcoholic fatty liver disease (NAFLD) (odds ratios [OR], 95% confidence interval [CI]: 1.61, 1.29-2.02, p < 0.001), higher magnetic resonance imaging [MRI] proton density fat fraction (PDFF) and higher serum gamma glutamyltransferase (GGT). Two-step MR identified two candidate mediators that partially mediate the direct foetal effect of lower birthweight on NAFLD, including fasting insulin (proportion mediated: 22.29%) and triglycerides (6.50%)., Conclusions: Our MR analysis reveals a direct causal association between lower birthweight and liver MRI PDFF, as well as the development of NAFLD, which persisted even after accounting for the potential influence of maternal factors. In addition, we identified fasting insulin and triglycerides as mediators linking birthweight and hepatic outcomes, providing insights for early clinical interventions., (© 2024 John Wiley & Sons Ltd.)

Background: The identification of biomarkers for the early diagnosis of nonalcoholic fatty liver disease (NAFLD) is urgently needed. Here, we aimed to identify NAFLD biomarkers in the early stages of steatosis (SS) and nonalcoholic steatohepatitis (NASH) based on differential gene expression from bioinformatics data., Methods: A meta-analysis was performed from transcriptomic databases retrieved from public repositories containing data from biopsies of patients at various stages of NAFLD development. The status of the selected molecules was validated in the serum of patients with NAFLD by ELISA., Results: We identified 121 differentially expressed genes (DEGs) associated with SS and 402 associated with NASH. Gene Ontology (GO) enrichment revealed that the altered genes were primarily associated with dysfunction of primary cellular processes, and pathway analyses were mainly related to cholesterol metabolism. We identified ACSS2, PCSK9, and CYP7A1 as candidate biomarkers for SS and ANGPTL3, CD36, CYP51A1, FASN, FAS, FDFT1, and LSS as candidate biomarkers for NASH., Conclusions: By experimental validation of bioinformatics data from patients with NAFLD, we identified promising biomarkers for detecting SS and NASH that might be useful for screening and diagnosing early NAFLD stages in humans., 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 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Background and Aims: The patatin-like phospholipase domain-containing protein 3 ( PNPLA3 ) rs738409 variant is associated with steatotic liver disease and its progression. We examined the association between PNPLA3 and the development of major adverse liver outcomes (MALOs) and how nonmodifiable and modifiable conditions modify this relationship., Approach and Results: A total of 2075 adults with biopsy-confirmed metabolic dysfunction-associated steatotic liver disease (MASLD) were enrolled in the metabolic dysfunction-associated steatohepatitis Clinical Research Network (MASH CRN) studies and followed prospectively until death, transplant, or withdrawal of consent. One hundred four MALOs were recorded during an average of 4.3 years. PNPLA3 G-allele (Adj. sub-hazard ratio (sHR): 1.4, 95% CI: 1.07-1.8), advanced fibrosis (AF) (Adj. sHR: 7.8, 95% CI: 4.4-13.8), age >60 years (Adj. sHR: 2.9, 95% CI: 1.3-6.8), and type 2 diabetes mellitus (Adj. sHR: 2.8, 95% CI: 1.8-4.2) were associated with MALO. Among participants with AF, those carrying the G-allele displayed the highest cumulative incidence of MALO (85%) versus noncarriers (53%), p =0.03, and p -value for interaction <0.01. The strength of the association between PNPLA3 and MALO was statistically significantly greater among older than 60 years (sHR: 2.1, 95% CI: 1.5-2.8), women (sHR: 1.4, 95% CI: 1.1-1.9), and those with AF (sHR: 1.9, 95% CI: 1.5-2.4) or type 2 diabetes mellitus (sHR: 2.1, 95% CI: 1.5-2.8) as compared with their counterparts, p -value for interaction between PNPLA3 and each factor<0.01., Conclusions: The deleterious effects of PNPLA3 rs738409 on the risk of MALO are significantly worsened by AF, age, type 2 diabetes mellitus, and sex., (Copyright © 2024 American Association for the Study of Liver Diseases.)

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.)

Non-alcoholic fatty liver disease (NAFLD) is a major global health concern, with its prevalence increasing steadily. While plasma proteins have been implicated in NAFLD, establishing causal relationships has been challenging due to confounding factors in observational studies. This study aims to explore the causal relationships between plasma proteins and NAFLD using Mendelian randomization (MR) analysis. We utilized genome-wide association study (GWAS) data from multiple sources to conduct MR analyses. Plasma protein data were obtained from the deCODE open database, and NAFLD data were sourced from the Finnish genetic sample collection (FinnGen). We performed MR analysis to identify plasma proteins causally related to NAFLD and explored the potential mediation effect of antibody-immune responses. Our MR analysis identified three plasma proteins-KNG1, MICB, and PKD2-with significant causal relationships to NAFLD. Mediation analysis further revealed that KNG1 negatively mediated the risk of NAFLD through Epstein-Barr virus EA-D antibody levels, while MICB and PKD2 positively mediated NAFLD risk through the same antibody levels. This study provides novel genetic evidence of causal relationships between specific plasma proteins and NAFLD risk. Measuring the levels of KNG1, MICB, PKD2, and Epstein-Barr virus EA-D antibody levels in patients may help clinicians assess NAFLD risk more accurately. Further clinical research is warranted to validate these findings and explore their potential therapeutic implications., (© 2024. The Author(s).)

This study investigates the effects of bariatric surgery on non-alcoholic fatty liver disease (NAFLD) by examining the interplay between gut microbiota, epigenetics, and metabolic health. A cohort of 22 patients undergoing sleeve gastrectomy (SG) was analyzed for changes in gut microbial composition and DNA methylation profiles before and six months after surgery. Correlations between gut microbial abundance and clinical markers at baseline revealed that certain genera were associated with worse metabolic health and liver markers. Following SG, significant improvements were observed in the clinical, anthropometric, and biochemical parameters of the NAFLD patients. Although alpha-diversity indices (i.e., Chao1, Simpson, Shannon) did not show significant changes, beta-diversity analysis revealed a slight shift in microbial composition (PERMANOVA, p = 0.036). Differential abundance analysis identified significant changes in specific bacterial taxa, including an increase in beneficial Lactobacillus species such as Lactobacillus crispatus and Lactobacillus iners and a decrease in harmful taxa like Erysipelotrichia. Additionally, DNA methylation analysis revealed 609 significant differentially methylated CpG sites between the baseline values and six months post-surgery, with notable enrichment in genes related to the autophagy pathway, such as IRS4 and ATG4B . The results highlight the individualized responses to bariatric surgery and underscore the potential for personalized treatment strategies. In conclusion, integrating gut microbiota and epigenetic factors into NAFLD management could enhance treatment outcomes, suggesting that future research should explore microbiome-targeted therapies and long-term follow-ups on liver health post-surgery.

Non-alcoholic fatty liver disease (NAFLD) poses a global health challenge. While pyroptosis is implicated in various diseases, its specific involvement in NAFLD remains unclear. Thus, our study aims to elucidate the role and mechanisms of pyroptosis in NAFLD. Utilizing data from the Gene Expression Omnibus (GEO) database, we analyzed the expression levels of pyroptosis-related genes (PRGs) in NAFLD and normal tissues using the R data package. We investigated protein interactions, correlations, and functional enrichment of these genes. Key genes were identified employing multiple machine learning techniques. Immunoinfiltration analyses were conducted to discern differences in immune cell populations between NAFLD patients and controls. Key gene expression was validated using a cell model. Analysis of GEO datasets, comprising 206 NAFLD samples and 10 controls, revealed two key PRGs (TIRAP, and GSDMD). Combining these genes yielded an area under the curve (AUC) of 0.996 for diagnosing NAFLD. In an external dataset, the AUC for the two key genes was 0.825. Nomogram, decision curve, and calibration curve analyses further validated their diagnostic efficacy. These genes were implicated in multiple pathways associated with NAFLD progression. Immunoinfiltration analysis showed significantly lower numbers of various immune cell types in NAFLD patient samples compared to controls. Single sample gene set enrichment analysis (ssGSEA) was employed to assess the immune microenvironment. Finally, the expression of the two key genes was validated in cell NAFLD model using qRT-PCR. We developed a prognostic model for NAFLD based on two PRGs, demonstrating robust predictive efficacy. Our findings enhance the understanding of pyroptosis in NAFLD and suggest potential avenues for therapeutic exploration., (© 2024. The Author(s).)

It is known that telomere length (TL) (evaluated with T/S ratio) is shortened in the presence of obesity. In this study, we aimed to investigate how obesity in adolescents and non-alcoholic liver disease (NAFLD) within the obese group affect TL and the clinical significance of the human telomerase reverse transcriptase (hTERT) gene MNS16A VNTR variant in terms of NAFLD. Adolescents with exogenous obesity and healthy controls (aged 10-19 years) who applied to our adolescent outpatient clinic between May-October 2023 were included in this study. We performed upper abdominal ultrasonography to investigate the presence of NAFLD in adolescents with obesity and divided into two groups: those without hepatosteatosis (obese NAFLD (-)) and those with hepatosteatosis (obese NAFLD (+)). We recorded body weight, height, waist circumference, and blood pressure measurements and measured the T/S ratio (telomere sequence copy number/gene single copy number) by the Quantitative Polymerase Chain Reaction method. The groups were compared using frequentist and Bayesian methods. Eighty-three obese adolescents [63 NAFLD(+) 20 NAFLD(-)] and 69 lean controls were included in the study. Pairwise comparisons revealed that T/S ratio was significantly lower in the obese NAFLD (-) group than the obese NAFLD (+) and the control group (p = 0.025, p = 0.007, respectively). T/S ratio was lower in the LL allele group than in the other alleles (p = 0.022) and slightly higher in the obese group with metabolic syndrome compared to the obese group without metabolic syndrome (p = 0.072). hTERT-MNS16A-VNTR gene variant LL allele had a negative correlation with T/S ratio among the obese adolescent group. Patients with LL alleles had higher ALT, GGT, HOMA-IR, and ALT/AST. Diastolic blood pressure had a significant correlation with the T/S ratio. The T/S ratio was shorter in the obese adolescent group compared to healthy ones but was higher in the NAFLD (+) obese compared to the NAFLD (-) obese. ALT level and ALT/AST ratio were higher, T/S ratio was lower in the hTERT MNS16A VNTR variant LL allele group among obese adolescents. In addition, there was a significant correlation between the T/S ratio and diastolic blood pressure in obese adolescents., (© 2024. The Author(s).)

Nonalcoholic steatohepatitis (NASH) is a prevalent chronic disease, yet its exact mechanisms and effective treatments remain elusive. Nuclear receptor subfamily 5 group A member 2 (NR5A2), a transcription factor closely associated with cholesterol metabolism in the liver, has been hindered from comprehensive investigation due to the lethality of NR5A2 loss in cell lines and animal models. To elucidate the role of NR5A2 in NASH, we generated hepatocyte-specific knockout mice for Nr5a2 (Nr5a2 HKO ) and examined their liver morphology across different age groups under a regular diet. Furthermore, we established cell lines expressing haploid levels of NR5A2 and subsequently reintroduced various isoforms of NR5A2. In the liver of Nr5a2 HKO mice, inflammation and fibrosis spontaneously emerged from an early age, independent of lipid accumulation. Pyroptosis occurred in NR5A2-deficient cell lines, and different isoforms of NR5A2 reversed this form of cell death. Our findings unveiled that inhibition of NR5A2 triggers pyroptosis, a proinflammatory mode of cell death primarily mediated by the activation of the NF-κB pathway induced by reactive oxygen species (ROS). As a transcriptionally regulated molecule of NR5A2, aldehyde dehydrogenase 1 family member B1 (ALDH1B1) participates in pyroptosis through modulation of ROS level. In conclusion, the diverse isoforms of NR5A2 exert hepatoprotective effects against NASH by maintaining a finely tuned balance of ROS, which is contingent upon the activity of ALDH1B1., (© 2024. The Author(s).)

Metabolic dysfunction-associated steatohepatitis (MASH) represents a global health threat. MASH pathophysiology involves hepatic lipid accumulation and progression to severe conditions like cirrhosis and, eventually, hepatocellular carcinoma. Fibroblast growth factor (FGF)-19 has emerged as a key regulator of metabolism, offering potential therapeutic avenues for MASH and associated disorders. We evaluated the therapeutic potential of non-mitogenic (NM)-FGF19 mRNA formulated in liver-targeted lipid nanoparticles (NM-FGF19-mRNAs-LNPs) in C57BL/6NTac male mice with diet-induced obesity and MASH (DIO-MASH: 40% kcal fat, 20% kcal fructose, 2% cholesterol). After feeding this diet for 21 weeks, NM-FGF19-mRNAs-LNPs or control (C-mRNA-LNPs) were administered (0.5 mg/kg, i.v.) weekly for another six weeks, in which diet feeding continued. NM-FGF19-mRNAs-LNPs treatment in DIO-MASH mice resulted in reduced body weight, adipose tissue depots, and serum transaminases, along with improved insulin sensitivity. Histological analyses confirmed the reversal of MASH features, including steatosis reduction without worsening fibrosis. NM-FGF19-mRNAs-LNPs reduced total hepatic bile acids (BAs) and changed liver BA composition, markedly influencing cholesterol homeostasis and metabolic pathways as observed in transcriptomic analyses. Extrahepatic effects included the down-regulation of metabolic dysfunction-associated genes in adipose tissue. This study highlights the potential of NM-FGF19-mRNA-LNPs therapy for MASH, addressing both hepatic and systemic metabolic dysregulation. NM-FGF19-mRNA demonstrates efficacy in reducing liver steatosis, improving metabolic parameters, and modulating BA levels and composition. Given the central role played by BA in dietary fat absorption, this effect of NM-FGF19-mRNA may be mechanistically relevant. Our study underscores the high translational potential of mRNA-based therapies in addressing the multifaceted landscape of MASH and associated metabolic perturbations., (© 2024 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

The disease burden of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. Emerging evidence has revealed that silica nanoparticles (SiNPs) could disorder the liver lipid metabolism and cause hepatotoxicity, but the underlying mechanism remains unknown. The purpose of this study is to elucidate the molecular mechanism of hepatic lipid metabolism disorder caused by SiNPs, and to reveal the role of ferroptosis in SiNPs-induced hepatotoxicity. To explore the phenotypic changes in liver, the wild-type C57BL/6J mice were exposed to different doses of SiNPs (5, 10, 20 mg/kg·bw) with or without melatonin (20 mg/kg·bw). SiNPs accelerated hepatic oxidative stress and promoted pathological injury and lipid accumulation, resulting in NAFLD development. Melatonin significantly inhibited the oxidative damage caused by SiNPs. Then, the hepatocytes were treated with SiNPs, the ferroptosis inducer and inhibitor, respectively. In vitro, SiNPs (25 μg/mL) generated mitochondrial and intracellular Fe 2+ accumulation and lipid peroxidation repair ability impairment, decreased the activity of GPX4 through ACSL4/p38 MAPK signaling pathway, resulting in ferroptosis of hepatocytes. Notably, Erastin (the ferroptosis activator, 5 μM) increased the sensitivity of hepatocytes to ferroptosis. Ferrostatin-1 (Fer-1, the ferroptosis inhibitor, 5 μM) restored GPX4 activity and protected against deterioration of lipid hydroperoxides (LOOHs) to salvage SiNPs-induced cytotoxicity. Finally, the liver tissue conditional ACSL4 knockout (cKO) mice and ACSL4-KO hepatocytes were adopted to further identify the role of the ACSL4-mediated ferroptosis on SiNPs-induced NAFLD development. The results displayed ACSL4 knockout could down-regulate the lipid peroxidation and ferroptosis, ultimately rescuing the progression of NAFLD. In summary, our data indicated that ACSL4/p38 MAPK/GPX4-mediated ferroptosis was a novel and critical mechanism of SiNPs-induced NAFLD., 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 Ltd. All rights reserved.)

Non-alcoholic fatty liver disease (NAFLD) is the fastest-growing cause of liver-associated death globally. Whole-body knockout (KO) of Na+/H+ exchanger 1 (NHE1, SLC9A1) was previously proposed to protect against high-fat diet-induced liver damage; however, mechanistic insight was lacking. The aim of the present work was to address this question in vitro to determine how NHE1, specifically in hepatocytes, impacts lipid overload-induced inflammation, fibrosis, and hepatocyte-hepatic stellate cell (HSC) crosstalk. We induced palmitate (PA)-based steatosis in AML12 and HepG2 hepatocytes; manipulated NHE1 activity pharmacologically and by CRISPR/Cas9-mediated KO and overexpression; and measured intracellular pH (pHi), steatosis-associated inflammatory and fibrotic mediators, and cell death. PA treatment increased NHE1 mRNA levels but modestly reduced NHE1 protein expression and hepatocyte pHi. NHE1 KO in hepatocytes did not alter lipid droplet accumulation but reduced inflammatory signaling (p38 MAPK activity), lipotoxicity (4-HNE accumulation), and apoptosis (poly-ADP-ribose-polymerase-1 (PARP) cleavage). Conditioned medium from PA-treated hepatocytes increased the expression of NHE1 and of the fibrosis regulator tissue inhibitor of matrix metalloproteinases-2 in LX-2 HSCs, in a manner abolished by NHE1 KO in hepatocytes. We conclude that NHE1 is regulated in NAFLD in vitro and contributes to the ensuing damage by aggravating hepatocyte injury and stimulating hepatocyte-HSC crosstalk.

The fusion of autophagosomes and lysosomes is essential for the prevention of nonalcoholic fatty liver disease (NAFLD). Here, we generate a hepatocyte-specific CHIP knockout (H-KO) mouse model that develops NAFLD more rapidly in response to a high-fat diet (HFD) or high-fat, high-fructose diet (HFHFD). The accumulation of P62 and LC3 in the livers of H-KO mice and CHIP-depleted cells indicates the inhibition of autophagosome-lysosome fusion. AAV8-mediated overexpression of CHIP in the murine liver slows the progression of NAFLD induced by HFD or HFHFD feeding. Mechanistically, CHIP induced K63- and K27-linked polyubiquitination at the lysine 198 residue of STX17, resulting in increased STX17-SNAP29-VAMP8 complex formation. The STX17 K198R mutant was not ubiquitinated by CHIP; it interfered with its interaction with VAMP8, rendering STX17 incapable of inhibiting steatosis development in mice. These results indicate that a signaling regulatory mechanism involving CHIP-mediated non-degradative ubiquitination of STX17 is necessary for autophagosome-lysosome fusion., (© 2024. The Author(s).)

Background: Patients with non-alcoholic fatty liver disease (NAFLD) often exhibit hepatic steatosis and dyslipidemia. Studies have shown that intestinal microorganisms are closely related to the occurrence of NAFLD and atherosclerosis. Our previous study has underscored the protective role of microRNA-30a-5p (miR-30a-5p) against atherosclerosis., Methods and Results: In the present study, we aimed to elucidate the effect and underlying mechanism of the intestinal microorganisms of miR-30a-5p knockout (KO) mice on NAFLD. Our findings demonstrated that KO exacerbated high-fat diet (HFD)-induced hepatic steatosis and disrupted liver function, as evidenced by elevated levels of total cholesterol, low-density lipoprotein, alanine aminotransferase, aspartate transaminase, and total bile acids in serum. Fecal microbiota from HFD-fed KO mice induced hepatic steatosis, dyslipidemia, and higher levels of enzymes indicative of liver damage in wild-type mice. Remarkably, KO mice significantly intensified the above effects. 16s rDNA sequencing and metabolomics of the intestinal microbiota in the HFD-treated KO and WT mice showed that the loss of miR-30a-5p resulted in intestinal microbiota imbalance and was highly related to the arachidonic acid metabolic pathway. Targeted metabolomic in the liver tissues unveiled upregulation of COX-related (PGF2a, 8-iso-PGF2a and PGF2) and LOX-related (LTB4, LTD4, 12S-HETE and 15S-HETE) factors in HFD-treated KO mice. Immunohistochemistry and transcriptional analyses showed that miR-30a-5p affected arachidonic acid metabolism through the LOX/COX pathways. Besides, COX/LOX pathways and hepatic steatosis were reversed after reintroducing miR-30a-5p in HFD-treated KO mice., Conclusions: This study reveals the pivotal mechanism by which miR-30a-5p and intestinal microbes regulate hepatic steatosis and abnormal lipid metabolism, offering promising avenues for NAFLD and atherosclerosis therapeutics., Highlights: MiR-30a-5p deletion aggravated hepatic steatosis and lipid disorder induced by an HFD in mice. Gut microbiota participated in the regulation of hepatic steatosis in the context of miR-30a-5p. Gut microbiota metabolism-related arachidonic acid metabolic pathway contributed to miR-30a-5p-regulated hepatic steatosis and lipid disorder. Reintroducing miR-30a-5p reversed hepatic steatosis and arachidonic acid metabolism disorder caused by HFD and miR-30a-5p deletion., (© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

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.)

Background: The most common progressive form of non-alcoholic fatty liver disease (NAFLD) is non-alcoholic steatohepatitis (NASH), which is characterized by the development of cirrhosis, and requires liver transplantation. We screened for the differentially expressed necroptosis-related genes in NASH in this study, and analyzed immune infiltration through microarray and bioinformatics analysis to identify potential biomarkers, and explore the molecular mechanisms involved in NASH., Methods: The GSE24807 microarray dataset of NASH patients and healthy controls was downloaded, and we identified the differentially expressed genes (DEGs). Necroptosis-related differential genes (NRDEGs) were extracted from these DEGs, and functionally annotated by enrichment analyses. The core genes were obtained by constructing gene co-expression networks using weighted gene co-expression network analysis (WGCNA). Finally, the transcription factor (TF) regulatory network and the mRNA-miRNA network were constructed, and the infiltrating immune cell populations were analyzed with CIBERSORT., Results: We identified six necroptosis-related genes (CASP1, GLUL, PYCARD, IL33, SHARPIN, and IRF9), and they are potential diagnostic biomarkers for NASH. In particular, PYCARD is a potential biomarker for NAFLD progression. Analyses of immune infiltration showed that M2 macrophages, γδ T cells, and T follicular helper cells were associated with the immune microenvironment of NASH, which is possibly regulated by CASP1, IL33, and IRF9., Conclusions: We identified six necroptosis-related genes in NASH, which are also potential diagnostic biomarkers. Our study provides new insights into the molecular mechanisms and immune microenvironment of NASH., (© 2024. The Author(s).)

Exercise training is a cornerstone treatment for non-alcoholic fatty liver disease (NAFLD). This study aims to investigate the effects of exercises on lipid accumulation in non-alcoholic steatohepatitis (NASH) and to explore the molecular mechanism. Established NASH mice were remained sedentary or subjected to moderate-intensity continuous training or high-intensity interval training (HIIT). The two training regimens, especially the latter one, reduced liver weight, steatosis, inflammation, lipid accumulation, collagen deposition, and cholesterol content in the mouse liver. Similarly, the HIIT regimen improved clinical presentation of NAFLD patients. RNA sequencing analysis revealed lysine methyltransferase 2D (Kmt2d) and isopentenyl-diphosphate delta isomerase 1 (Idi1) as two important genes downregulated in mice underwent HIIT. By using mouse hepatocytes AML12, we found that KMT2D promoted Idi1 expression by catalyzing H3K4me1 modification near its promoter. Upregulation of either KMT2D or IDI1 blocked the ameliorating effects of HIIT on mice. Meanwhile, in AML12 cells modeled by palmitic acid and oleic acid treatment, KMT2D and IDI1 were found to be correlated with lipid accumulation, cholesterol content, inflammation, and cell death and senescence. In conclusion, this study demonstrates that the ameliorating effects of exercise training on NASH might involve the downregulation of the KMT2D/IDI1 axis., 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.)

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.

Overnutrition has gradually become the primary causative factor in nonalcoholic fatty liver disease (NAFLD). However, how nutritional signals are integrated to orchestrate the transcriptional programs important for NAFLD progression remains poorly understood. We identified hepatic BAF60b as a lipid-sensitive subunit of the switch/sucrose nonfermentable chromatin-remodeling complex that is negatively associated with liver steatosis in mice and humans. Hepatic BAF60b deficiency promotes high-fat diet (HFD)-induced liver steatosis in mice, whereas transgenic expression of BAF60b in the liver attenuates HFD-induced obesity and NAFLD, both accompanied by a marked regulation of peroxisome proliferator-activated receptor γ (PPARγ) expression. Mechanistically, through motif analysis of liver assay for transposase-accessible chromatin sequencing and multiple validation experiments, we identified C/EBPβ as the transcription factor that interacts with BAF60b to suppress Pparγ gene expression, thereby controlling hepatic lipid accumulation and NAFLD progression. This work identifies hepatic BAF60b as a negative regulator of liver steatosis through C/EBPβ-dependent chromatin remodeling., (© 2024 by the American Diabetes Association.)

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 and Aim: Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common chronic liver diseases worldwide, characterized by the presence of lipid droplets. Rab18 is an important lipid droplet protein; however, its effects and mechanisms of action on NAFLD remain unclear., Methods: Free fatty acid-stimulated AML-12 cells and high-fat diet (HFD)-fed mice were used as NAFLD models. Lentiviruses overexpressing Rab18 (Rab18-OE) or knockdown (Rab18-KD) were used to generate stable cell lines for genetic analysis. Blood serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, and leptin were measured using a biochemical autoanalyzer. Hematoxylin and eosin staining was performed to detect pathological damage to the liver. Lipid accumulation in the cells was assessed by Oil Red O staining. Target expression was measured using qPCR, western blotting, and immunocytochemistry., Results: Rab18 mRNA and protein expression levels increased in free fatty acid-stimulated AML-12 cells and the livers of HFD-fed mice. Rab18-OE increased lipid accumulation in vitro, which was attenuated by Rab18-KD. In vivo, Rab18-OE augmented liver pathological damage, serum alanine aminotransferase/aspartate aminotransferase activity, and triglyceride, total cholesterol, and low-density lipoprotein levels, whereas Rab18-KD decreased these indicators. Rab18-KD also downregulated blood glucose levels in HFD-fed mice. Mechanistically, Rab18-OE and Rab18-KD regulated the mRNA and protein expression levels of perilipin 2 (PLIN2) and peroxisome proliferator-activated receptor gamma (PPARγ) in vitro and in vivo, respectively. Immunocytochemistry revealed that Rab18 colocalized with PLIN2 and PPARγ in AML-12 cells., Conclusion: Rab18 expression was elevated in vitro and in vivo in the NAFLD mouse model. Rab18 regulates PLIN2 and PPARγ expression to exaggerate liver injury and lipid accumulation in patients with NAFLD. Thus, Rab18 may be a crucial protein in this disease and a potential therapeutic target., (© 2024 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

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.)

Objective: Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease worldwide while still lacks drugs for treatment or prevention. We aimed to investigate the causal role of glucose-dependent insulinotropic polypeptide receptor agonists (GIPRAs) on NAFLD and identify the mediated risk factors by which GIPRAs exert their therapeutic effects., Methods: Genetic proxies of GIPRAs were identified as cis-SNPs of GIPR associated with both the gene expression level and HbA1c and analyses including colocalization and linkage disequilibrium (LD) were performed for validation. We then performed two-sample two-step mendelian randomization to determine the causal effect of GIPRAs on NAFLD., Results: The MR analysis suggested genetic proxies of GIPRAs were causally associated with reduced risk of NAFLD (Odds ratio (OR): 0.46, 95 % confidence interval (95 % CI): 0.24-0.88, P = 0.02) and T2DM (OR: 0.10, 95 % CI: 0.07-0.13, P < 0.01). In addition, Mediation analysis showed evidence of indirect effect of GIPRAs on NAFLD via TRIG (0.88, [0.85-0.92], P < 0.01) and HDL-C (0.85, [0.80-0.90], P < 0.01)., Conclusions: Our study provided strong evidence to support the causal role of GIPRAs on reducing the risk of NAFLD probably through improving lipid metabolism, especially TG and HDL-C, providing guidance for future clinical trials., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background and Aims: NAFLD is a major disease burden and a foremost cause of chronic liver disease. Presently, nearly 300 trials evaluate the therapeutic efficacy of > 20 drugs. Remarkably, the majority of drugs fail. To better comprehend drug failures, we investigated the reproducibility of fatty liver genomic data across 418 liver biopsies and evaluated the interpatient variability of 18 drug targets., Approach and Results: Apart from our own data, we retrieved NAFLD biopsy genomic data sets from public repositories and considered patient demographics. We divided the data into test and validation sets, assessed the reproducibility of differentially expressed genes and performed gene enrichment analysis. Patients were stratified by disease activity score, fibrosis grades and sex, and we investigated the regulation of 18 drug targets across 418 NAFLD biopsies of which 278 are NASH cases. We observed poor reproducibility of differentially expressed genes across 9 independent studies. On average, only 4% of differentially expressed genes are commonly regulated based on identical sex and 2% based on identical NAS disease score and fibrosis grade. Furthermore, we observed sex-specific gene regulations, and for females, we noticed induced expression of genes coding for inflammatory response, Ag presentation, and processing. Conversely, extracellular matrix receptor interactions are upregulated in males, and the data agree with clinical findings. Strikingly, and with the exception of stearoyl-CoA desaturase, most drug targets are not regulated in > 80% of patients., Conclusions: Lack of data reproducibility, high interpatient variability, and the absence of disease-dependent drug target regulations are likely causes of NASH drug failures in clinical trials., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

In up to one-third of nonalcoholic fatty liver disease (NAFLD) patients, simple steatosis progresses to its more severe form, nonalcoholic steatohepatitis (NASH), but the precise mechanisms underlying this transition are not fully understood. Toll/interleukin-1 receptor 8 (TIR8), a conventional innate immune regulator highly expressed in hepatic tissue, has shown potential for ameliorating various inflammation-related disorders. However, its role in NASH pathogenesis, especially its regulatory effects on lipid metabolism and inflammatory responses, is still unclear. Here, using a TIR8 knockout (TIR8KO) mouse model and mass spectrometry analyses, we found that TIR8KO mice displayed aggravated hepatic steatosis and inflammation, whereas TIR8 overexpression attenuated these adverse effects. Ectopic TIR8 expression counteracts free fatty acid (FFA)-induced PPARα inhibition and downstream signaling. A decrease in TIR8 levels in hepatocytes heightened lipopolysaccharide (LPS) sensitivity. Notably, FFA stimulation led to a direct interaction between TIR8 and proteasome subunit alpha type 4 (PSMA4), facilitating TIR8 degradation. These results revealed that TIR8 safeguards PPARα-regulated lipid metabolism and mitigates inflammation induced by external factors during NASH progression. Our study highlights TIR8 as a promising target for NASH therapy, indicating the potential of TIR8 agonists in treatment strategies., Competing Interests: Declaration of competing interest None of the authors has any conflict of interest related to this manuscript., (Copyright © 2024. Published by Elsevier Inc.)

Background and Aim: Lipid metabolism disorder is the primary feature of numerous refractory chronic diseases. Fatty acid oxidation, an essential aerobic biological process, is closely related to the progression of NAFLD. The forkhead transcription factor FOXO1 has been reported to play an important role in lipid metabolism. However, the molecular mechanism through which FOXO1 regulates fatty acid oxidation remains unclear., Methods: Transcriptomic analysis was performed to examine the cellular expression profile to determine the functional role of FOXO1 in HepG2 cells with palmitic acid (PA)-induced lipid accumulation. FOXO1-binding motifs at the promoter region of aldehyde dehydrogenase 1 family member L2 (ALDH1L2) were predicted via bioinformatic analysis and confirmed via luciferase reporter assay. Overexpression of ALDH1L2 was induced to recover the impaired fatty acid oxidation in FOXO1-knockout cells., Results: Knockout of FOXO1 aggravated lipid deposition in hepatic cells. Transcriptomic profiling revealed that knockout of FOXO1 increased the expression of genes associated with fatty acid synthesis but decreased the expression of carnitine palmitoyltransferase1a (CPT1α) and adipose triglyceride lipase (ATGL), which contribute to fatty acid oxidation. Mechanistically, FOXO1 was identified as a transcription factor of ALDH1L2. Knockout of FOXO1 significantly decreased the protein expression of ALDH1L2 and CPT1α in vitro and in vivo. Furthermore, overexpression of ALDH1L2 restored fatty acid oxidation in FOXO1-knockout cells., Conclusion: The findings of this study indicate that FOXO1 modulates fatty acid oxidation by targeting ALDH1L2., (© 2024 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common liver disease worldwide. The risk of developing MAFLD varies among individuals, due to a combination of environmental inherited and acquired genetic factors. Genome-wide association and next-generation sequencing studies are leading to the discovery of the common and rare genetic determinants of MAFLD. Thanks to the great advances in genomic technologies and bioinformatics analysis, genetic and epigenetic factors involved in the disease can be used to develop genetic risk scores specific for liver-related complications, which can improve risk stratification. Genetic and epigenetic factors lead to the identification of specific sub-phenotypes of MAFLD, and predict the individual response to a pharmacological therapy. Moreover, the variant transcripts and protein themselves represent new therapeutic targets. This review will discuss the current status of research into genetic as well as epigenetic modifiers of MAFLD development and progression., (© 2024. The Author(s).)

Background: Metabolic-associated fatty liver disease (MAFLD) is a leading cause of chronic liver disease worldwide. Autophagy plays a pivotal role in lipid metabolism; however, the mechanism underlying the reduced autophagic activity in MAFLD remains elusive., Methods: Autophagy was monitored by TUNEL assay and immunofluorescence staining of LC3. The expression of autophagy-related proteins, PPARα, HDAC2, and HRD1 was detected by Western blot. The association between HDAC2 and PPARα promoter was assessed by chromatin immunoprecipitation (ChIP) and dual-luciferase assays, and the HRD1-mediated ubiquitin-proteasomal degradation of HDAC2 was detected by co-immunoprecipitation (co-IP). The in vitro findings were validated in a hypoxia-induced MAFLD mouse model. Histological changes, fibrosis, and apoptosis in liver tissues were detected by hematoxylin and eosin staining, Masson's trichrome staining, and TUNEL assay. The immunoreactivities of key molecules were examined by IHC analysis., Results: Hypoxia-suppressed autophagy in hepatocytes. Hypoxic exposure downregulated HRD1 and PPARα, while upregulating HDAC2 in hepatocytes. Overexpression of PPARα promoted hepatic autophagy, while knocking down HDAC2 or overexpressing HRD1 reduced hypoxia-suppressed autophagy in hepatocytes. Mechanistically, HDAC2 acted as a transcriptional repressor of PPARα, and HRD1 mediated the degradation of HDAC2 through the ubiquitin-proteasome pathway. Functional studies further showed that hypoxia-suppressed hepatic autophagy via the HRD1/HDAC2/PPARα axis in vitro and in vivo., Conclusion: HRD1-mediated ubiquitination of HDAC2 regulates PPARα-mediated autophagy and ameliorates hypoxia-induced MAFLD., 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.)

Fibroblast growth factor 21 (FGF21) is pivotal in regulating energy metabolism, highlighting substantial therapeutic potential for non-alcoholic steatohepatitis (NASH). Previously, we reported a long-acting FGF21 fusion protein, PsTag-FGF21, which was prepared by genetically fusing human FGF21 with a 648-residue polypeptide (PsTag). While this fusion protein demonstrated therapeutic efficacy against NASH, our final product analysis revealed the presence of fixed impurities resistant to effective removal, indicating potential degradation of PsTag-FGF21. Here, we enriched and analyzed the impurities, confirming our hypothesis regarding the C-terminal degradation of PsTag-FGF21. We now describe a new variant developed to eliminate the C-terminal degradation. By introducing one mutation located at the C-terminal of PsTag-FGF21(V169L), we demonstrated that the new molecule, PsTag-FGF21(V169L), exhibits many improved attributes. Compared with PsTag-FGF21, PsTag-FGF21(V169L) displayed elevated bioactivity and stability, along with a twofold enhanced binding affinity to the coreceptor β-Klotho. In vivo, the circulating half-life of PsTag-FGF21(V169L) was further enhanced compared with that of PsTag-FGF21. In NASH mice, PsTag-FGF21(V169L) demonstrated efficacy with sustained improvements in multiple metabolic parameters. Besides, PsTag-FGF21(V169L) demonstrated the ability to alleviate NASH by decreasing hepatocyte apoptosis. The superior biophysical, pharmacokinetic, and pharmacodynamic properties, along with the positive metabolic effects, imply that further clinical development of PsTag-FGF21(V169L) as a metabolic therapy for NASH patients may be warranted., 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. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

Purpose: Nonalcoholic steatohepatitis (NASH) has been an increasingly significant contributor to hepatocellular carcinoma (HCC). Understanding the progression from NASH to HCC is critical to early diagnosis and elucidating the underlying mechanisms., Results: 5 significant prognostic genes related to NASH-HCC transformation were identified through algorithm selection, which were ME1, TP53I3, SOCS2, GADD45G and CYP7A1. A diagnostic model for NASH prediction was established (AUC=0.988). TP53I3 and SOCS2 were selected as potential critical genes in the progression of NASH-HCC by external dataset validation and in vitro experiments on NASH and HCC cell lines. Immune infiltration analysis illustrated the correlation between 5 significant prognostic genes and immune cells. Single-cell analysis identified hepatocytes related to NASH-HCC transformation markers, revealing their promoting role in the transformation from NASH to HCC., Conclusion: With bulk-seq analysis and single-cell analysis, 5 significant prognostic genes related to NASH-HCC transformation were identified and validated at both dataset and in vitro experiment level. Among them, TP53I3 and SOCS2 might be potential critical genes in NASH-HCC progression. Single-cell analysis identified and revealed the critical role that NASH-HCC related hepatocytes play in NASH-HCC tansformation. Our research may introduce a new perspective to the diagnosis, treatment of NASH-related HCC., Competing Interests: Declaration of Competing Interest 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 Elsevier Ltd. All rights reserved.)