Progression Of Non-alcoholic Fatty Liver Disease Research Articles

Short-term exposure to low doses of aflatoxin B1 aggravates nonalcoholic steatohepatitis by TLR4-mediated necroptosis.

Aflatoxin B1 (AFB1), a worldwide mycotoxin found in food and foodstuffs, is a potent hepatotoxin in humans and animals. Non-alcoholic fatty liver disease (NAFLD), a widespread disease, could progress from simple steatosis to non-alcoholic steatohepatitis (NASH), hepatic cirrhosis, and even hepatocellular carcinoma (HCC). To date, little is known concerning the relationship between AFB1 and the progression of NAFLD. The effects of low doses of AFB1 on the development of NASH and their mechanism were investigated in vivo and in vitro. The results in vivo showed that AFB1 at 20 and 40 μg/kg.bw aggravated CDAHFD-induced NASH in mice as demonstrated by increasing the serum and liver lipid accumulation, liver inflammation and injury. The results in vitro showed that AFB1 at 1.0 μM aggravated FFA-induced lipid accumulation, inflammation and cell damage in HepG2 cells. In addition, RNA-seq indicated that necroptosis, Toll like receptor signaling and TNF-α signaling showed a significant change in KEGG pathway enrichment in AFB1 at 40 μg/kg.bw. AFB1 significantly upregulated the mRNA and protein levels of TLR4, RIPK3, p-RIPK3, MLKL and p-MLKL, and increased TUNEL positive cells. Also, immunofluorescence results showed that TUNEL, TLR4, TNF-α had co-localized with RIPK3, respectively. Necroptosis inhibitor (GSK-872) attenuated the aggravating effects of AFB1 on NASH. Knockout of TLR4 inhibited necroptosis and rescued the aggravating effects of AFB1 on NASH. These data indicate that low dose of AFB1 aggravated NASH via TLR4-mediated necroptosis. This suggests that low dose of AFB1 is potentially harmful to animals and humans, as they exacerbate NASH.

The Impact of Aerobic and Anaerobic Exercise Interventions on the Management and Outcomes of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder that includes non-alcoholic hepatic steatosis without or with moderate inflammation and non-alcoholic steatohepatitis (NASH), characterized by necroinflammation and a more rapid progression of fibrosis. It is the primary pathological basis for hepatocellular carcinoma. With its prevalence escalating annually, NAFLD has emerged as a global health epidemic, presenting a significant hazard to public health worldwide. Existing studies have shown that physical activity and exercise training have a positive effect on NAFLD. However, the extent to which exercise improves NAFLD depends on the type, intensity, and duration. Therefore, the type of exercise that has the best effect on improving NAFLD remains to be explored. To date, the most valuable discussions involve aerobic and anaerobic exercise. Exercise intervenes in the pathological process of NAFLD by regulating physiological changes in cells through multiple signaling pathways. The review aims to summarize the signaling pathways affected by two different exercise types associated with the onset and progression of NAFLD. It provides a new basis for improving and managing NAFLD in clinical practice.

Integrative multiomic analysis identifies distinct molecular subtypes of NAFLD in a Chinese population.

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.

Multiple Machine Learning Identifies Key Gene PHLDA1 Suppressing NAFLD Progression.

Non-alcoholic fatty liver disease (NAFLD) poses a serious global health threat, with its progression mechanisms not yet fully understood. While several molecular markers for NAFLD have been developed in recent years, a lack of robust evidence hampers their clinical application. Therefore, identifying novel and potent biomarkers would directly aid in the prediction, prevention, and personalized treatment of NAFLD. We downloaded NAFLD-related datasets from the Gene Expression Omnibus (GEO). Differential expression analysis and functional analysis were initially conducted. Subsequently, Weighted Gene Co-expression Network Analysis (WGCNA) and multiple machine learning strategies were employed to screen and identify key genes, and the diagnostic value was assessed using Receiver Operating Characteristic (ROC) analysis. We then explored the relationship between genes and immune cells using transcriptome data and single-cell RNA sequencing (scRNA-seq) data. Finally, we validated our findings in cell and mouse NAFLD models. We obtained 23 overlapping differentially expressed genes (DEGs) across three NAFLD datasets. Enrichment analysis revealed that DEGs were associated with Apoptosis, Parathyroid hormone synthesis, secretion and action, Colorectal cancer, p53 signaling pathway, and Biosynthesis of unsaturated fatty acids. After employing machine learning strategies, we identified one gene, pleckstrin homology like domain family A member 1 (PHLDA1), downregulated in NAFLD and showing high diagnostic accuracy. CIBERSORT analysis revealed significant associations of PHLDA1 with various immune cells. Single-cell data analysis demonstrated downregulation of PHLDA1 in NAFLD, with PHLDA1 exhibiting a significant negative correlation with macrophages. Furthermore, we found PHLDA1 to be downregulated in an in vitro hepatic steatosis cell model, and overexpression of PHLDA1 significantly reduced lipid accumulation, as well as the expression of key molecules involved in hepatic lipogenesis and fatty acid uptake, such as FASN, SCD-1, and CD36. Additionally, gene set enrichment analysis (GSEA) pathway enrichment analysis suggested that PHLDA1 may influence NAFLD progression through pathways such as Cytokine Cytokine Receptor Interaction, Ecm Receptor Interaction, Parkinson's Disease, and Ribosome pathways. Our conclusions were further validated in a mouse model of NAFLD. Our study reveals that PHLDA1 inhibits the progression of NAFLD, as overexpression of PHLDA1 significantly reduces lipid accumulation in cells and markedly decreases the expression of key molecules involved in liver lipogenesis and fatty acid uptake. Therefore, PHLDA1 may emerge as a novel potential target for future prediction, diagnosis, and targeted prevention of NAFLD.

Exosomes Derived from Diabetic Microenvironment-Preconditioned Mesenchymal Stem Cells Ameliorate Nonalcoholic Fatty Liver Disease and Inhibit Pyroptosis of Hepatocytes

AimPyroptosis, a type of programmed cell death, is a key mechanism underlying non-alcoholic fatty liver disease (NAFLD). Mesenchymal stem cell (MSC)-derived exosomes (MSC-Exos) have the potential to ameliorate NAFLD, an effect that is enhanced by curcumin preconditioning. We previously reported that diabetic microenvironment preconditioning enhances the secretion capacity and anti-inflammatory activity of MSCs. Therefore, we hypothesized that MSC-Exos would inhibit hepatocyte pyroptosis and thereby ameliorate NAFLD, and that diabetic microenvironment preconditioning would enhance these effects. MethodsMSCs were preconditioned in a diabetic microenvironment (pMSCs). MSC-Exos and pMSC-Exos collected from MSCs or pMSCs were applied to methionine- and choline-deficient (MCD)-induced NAFLD mice and in vitro models involving induction with lipopolysaccharide or palmitic acid to mimic hepatic steatosis and injury. MCC950 treatment was used as a positive control. We analyzed the characteristics of NAFLD and pyroptosis markers. Protein profiles of MSC-Exos and pMSC-Exos were evaluated by label-free quantitative proteomics. ResultsIn vivo, MSC-Exos partially attenuated inflammation and fibrosis, but not lipid deposition and NAFLD progression in the livers of NAFLD mice. pMSC-Exos significantly improved lipid metabolism, hepatic steatosis, inflammation, and fibrosis but also retarded the progression of NAFLD. Pyroptosis was upregulated in the liver of NAFLD mice. MSC-Exos and pMSC-Exos inhibited pyroptosis, and the effect of the latter was greater than that of the former. In vitro, MSC-Exos and pMSC-Exos ameliorated hepatocyte steatosis, lipid metabolism disorder, and inflammation, and pMSC-Exos exerted a greater inhibitory effect on hepatocyte pyroptosis than MSC-Exos did, which were remitted after inhibition of peroxiredoxin-1 (PRDX-1). ConclusionMSC-Exos ameliorated NAFLD and inhibited hepatocyte pyroptosis by downregulating the NLRP3/Caspase-1/GSDMD pathway, effects enhanced by pMSC-Exos, partly due to PRDX-1 upregulation.

Identification of diagnostic markers pyrodeath-related genes in non-alcoholic fatty liver disease based on machine learning and experiment validation

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.

Evolving epidemiology of NAFLD in South Korea: incidence, prevalence, progression, and healthcare implications from 2010 to 2022.

Non-alcoholic fatty liver disease (NAFLD), now the most common chronic liver worldwide, has become a significant public health concern. This study aims to analyze the evolving epidemiology of NAFLD in South Korea. We utilized claim data from the Korean National Health Insurance Service from 2010 to 2022 to analyze NAFLD's incidence, prevalence, and progression. From 2010 to 2022, the incidence and prevalence rates of NAFLD each increased from 1.87% to 4.47% and from 10.49% to 17.13%, respectively. The differences in prevalence rates between urban and rural areas were minimal in 2012 and 2022, yet both areas showed significant increases in the prevalence of NAFLD over the decade. The NAFLD group had a higher prevalence of comorbidities compared to the control group, and the most common comorbid condition was hypertension. Moreover, the ten-year incidence rates of malignancy, heart disease, and stroke in the NAFLD group were 13.42%, 15.72%, and 8.36%, respectively, which were significantly higher than those in the control group. The incidence rates of cirrhosis and hepatocellular carcinoma in NAFLD over 10 years were 2.22% and 0.77%, respectively. The total medical costs of NAFLD patients more than doubled over ten years and were all significantly higher than those of the control group. A significant increase in NAFLD prevalence and its impact on healthcare utilization was observed in South Korea. With NAFLD leading to serious liver diseases and increased healthcare costs, integrated care strategies that include both medical treatment and lifestyle modifications are essential.

Adipokine/hepatokines profiling of fatty liver in adolescents and young adults: cross-sectional and prospective analyses of the BCAMS study.

The underlying connections between obesity and non-alcoholic fatty liver disease (NAFLD) are not fully understood. One potential link might be the imbalanced adipokines and hepatokines. We aimed to explore the associations between specific adipokines/hepatokines and NAFLD in Chinese youth and to determine how these biomarkers mediate the obesity-NAFLD relationship. We analyzed data from the 10-year follow-up visit of the Beijing Children and Adolescents Metabolic Syndrome (BCAMS) study (n = 509; mean age = 20.2years) for a comprehensive metabolic risk assessment, including liver ultrasound and plasma measurements of adiponectin, leptin, fibroblast growth factor 21 (FGF21), retinol-binding protein 4 (RBP4), and angiopoietin-like protein 8 (ANGPTL8). Longitudinal analysis was performed on a subgroup (n = 307), with complete baseline (mean age = 12.2years) and follow-up data. Mediation models assessed how obesity at baseline and follow-up influence NAFLD through these biomarkers. Participants with NAFLD exhibited a high prevalence of central obesity (90.9%). Both cross-sectional and prospective analyses identified increased RBP4, FGF21, leptin, and decreased adiponectin levels as significant predictors of NAFLD. More adipokine/hepatokine abnormalities were linked to higher NAFLD risk. Furthermore, ratios reflecting adipokine/hepatokine imbalances, including leptin/adiponectin, FGF21/adiponectin, and RBP4/adiponectin, demonstrated stepwise changes correlating with NAFLD severity (all p < 0.05). Mediation analysis indicated that these four adipokines/hepatokines accounted for approximately 72.4% of the central obesity-NAFLD relationship and 80.1% in the subgroup analysis using baseline childhood data. Dysregulated adipokines/hepatokines may explain the onset or progression of obesity-related NAFLD in youths. Higher RBP4, FGF21 and leptin, alongside lower adiponectin, could serve as early biomarkers for NAFLD.

Body Composition and Progression of Biopsy-Proven Non-Alcoholic Fatty Liver Disease in Patients With Obesity.

Obesity is a significant risk factor for the progression of non-alcoholic fatty liver disease (NAFLD). However, a convenient and efficacious non-invasive test for monitoring NAFLD progression in patients with obesity is currently lacking. This study aims to investigate the associations between CT-based body composition and the progression of biopsy-proven NAFLD in patients with obesity. Liver biopsy was conducted in patients with obesity, and the progression of NAFLD was evaluated by the NAFLD activity score (NAS). Body composition was assessed through abdominal computed tomography (CT) scans. A total of 602 patients with an average age of 31.65 (±9.33) years old were included, comprising 217 male patients and 385 female patients. The wall skeletal muscle index (SMI), total SMI, and visceral fat index (VFI) were positively correlated with NAS in both male and female patients. Multivariate regression analysis demonstrated significant associations between high liver steatosis and wall SMI (HR: 1.60, 95% CI: 1.12 to 2.30), total SMI (HR: 1.50, 95% CI: 1.02 to 2.08), VSI (HR: 2.16, 95% CI: 1.48 to 3.14), visceral fat to muscle ratio (HR: 1.51, 95% CI: 1.05 to 2.18), and visceral to subcutaneous fat ratio (HR: 1.51, 95% CI: 1.07 to 2.12). Non-alcoholic steatohepatitis (NASH) was significantly associated with wall SMI (HR: 1.52, 95% CI: 1.06 to 2.19) and VSI (HR: 1.50, 95% CI: 1.03 to 2.17). Liver fibrosis ≥ F2 was significantly associated with psoas muscle index (HR: 0.64, 95% CI: 0.44 to 0.93) and psoas skeletal muscle density (HR: 0.61, 95% CI: 0.41 to 0.89). Our study suggested that certain CT-based body composition indicators, notably high VFI, were significantly associated with the progression of NAFLD in patients with obesity. Great attentions and timely managements should be given to these patients with body composition characteristics associated with the risk of NAFLD progression.

Exploring serum bile acids as potential noninvasive biomarkers for nonalcoholic fatty liver disease

BackgroundBile acids are vital regulators of liver metabolism, and their dysregulation is closely linked with the progression of nonalcoholic fatty liver disease (NAFLD). Profiling these bile acids may provide valuable diagnostic and prognostic markers for these conditions. This study aimed to evaluate bile acid profiles in NAFLD patients and assess their potential as biomarkers for diagnosing and predicting disease progression. Serum levels of 14 bile acids were measured in 25 normal healthy controls (NHC), 35patients with metabolic dysfunction–associated steatotic liver disease (MASLD), and 40 patients with NASH, categorized by the NAFLD Activity Score (NAS). Quantification was performed using high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS).ResultsPrimary unconjugated bile acids, CA and CDCA, along with conjugated acids GCA, GCDCA, TCA, and TCDCA, were significantly elevated in both MASLD and NASH compared to NHC (all p < 0.05). While levels increased progressively from NHC to MASLD to NASH, no significant differences were observed between MASLD and NASH except for GCA and TCA (P < 0.05). Similarly, secondary bile acids LCA, TLCA, GUDCA, and TUDCA were higher in MASLD and NASH compared to NHC (all p < 0.05).Logistic regression identified CA (odds ratio = 2.05, p = 0.02), CDCA (odds ratio = 1.58, p = 0.04), GCA (odds ratio = 1.92, p = 0.03) and DCA (odds ratio = 2.06, p = 0.04) as significant predictors of fibrosis. For active inflammation, GCA (odds ratio = 2.04, p = 0.04), and TCA (odds ratio = 1.94, p = 0.04) were significant predictors. In steatosis, CA, CDCA, GCA, DCA, TDCA, TLCA, and UDCA were notable predictors, with high odds ratios.ConclusionThe study highlights significant alterations in bile acid profiles associated with NAFLD progression. Specific bile acids, such as CA, GCA, TCA, and TCDCA are strong predictors of disease severity, indicating their potential as biomarkers for NAFLD treatment and prognosis.

Advancing non-alcoholic fatty liver disease prediction: a comprehensive machine learning approach integrating SHAP interpretability and multi-cohort validation.

Non-alcoholic fatty liver disease (NAFLD) represents a major global health challenge, often undiagnosed because of suboptimal screening tools. Advances in machine learning (ML) offer potential improvements in predictive diagnostics, leveraging complex clinical datasets. We utilized a comprehensive dataset from the Dryad database for model development and training and performed external validation using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 cycles. Seven distinct ML models were developed and rigorously evaluated. Additionally, we employed the SHapley Additive exPlanations (SHAP) method to enhance the interpretability of the models, allowing for a detailed understanding of how each variable contributes to predictive outcomes. A total of 14,913 participants were eligible for this study. Among the seven constructed models, the light gradient boosting machine achieved the highest performance, with an area under the receiver operating characteristic curve of 0.90 in the internal validation set and 0.81 in the external NHANES validation cohort. In detailed performance metrics, it maintained an accuracy of 87%, a sensitivity of 92.9%, and an F1 score of 0.92. Key predictive variables identified included alanine aminotransferase, gammaglutamyl transpeptidase, triglyceride glucose-waist circumference, metabolic score for insulin resistance, and HbA1c, which are strongly associated with metabolic dysfunctions integral to NAFLD progression. The integration of ML with SHAP interpretability provides a robust predictive tool for NAFLD, enhancing the early identification and potential management of the disease. The model's high accuracy and generalizability across diverse populations highlight its clinical utility, though future enhancements should include longitudinal data and lifestyle factors to refine risk assessments further.

6428 Update on Genetic F6428 actors of Nonalcoholic Fatty Liver Disease

Abstract Disclosure: H.M. Heshmati: None. Background: Nonalcoholic fatty liver disease (NAFLD) is a pandemic with a prevalence of 25% among the adult population worldwide. NAFLD is a spectrum of liver disorders ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). NASH can progress to cirrhosis and hepatocellular cancer. The pathogenesis of NAFLD is complex and multifactorial, involving metabolic, epigenetic, and genetic factors. Several medical conditions (e.g., obesity, type 2 diabetes, inflammation, insulin resistance, disrupted gut microbiome, and impaired intestinal barrier function) are important risk factors associated with and/or contributing to NAFLD. This review presents an update on the genetic factors of NAFLD identified by the genome-wide association studies (GWAS). Methods: A systematic search of literature was conducted using the search terms nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, cirrhosis, hepatocellular cancer, obesity, type 2 diabetes, epigenetics, and genetics. Results: Evidence for the contribution of genetic factors to NAFLD is further emphasized by the ethnic differences in the prevalence of NAFLD (e.g., higher prevalence among Hispanic American compared to African American adults). Based on the results of the GWAS, several genetic modifiers are relevant to NAFLD development and progression. They include variations in patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily 2 (TM6SF2), membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7), glucokinase regulatory protein (GCKR), programmed cell death protein 1 (PDCD1), and hydroxysteroid 17β-dehydrogenase 13 (HSD17B13) genes (non-exhaustive list). These genetic modifiers interact with the metabolic and epigenetic factors for the development and progression of NAFLD and are responsible for the variability in the severity of NAFLD. The PNPLA3 gene variant (rs738409), which is the first and the best validated genetic modifier, is associated with a high risk of development and progression of NAFLD. The PDCD1 gene variant (rs7421861) is independently associated with hepatocellular cancer development. In contrast, the HSD17B13 gene variant (rs72613567) may have a protective effect for NAFLD risk. Conclusion: NAFLD is a multifactorial condition with a complex pathogenesis involving the interactions between metabolic, epigenetic, and genetic factors. The prevalence and risk of NAFLD differ across populations mainly due to genetic polymorphisms. Genetic factors relevant to NAFLD include variations in PNPLA3, TM6SF2, MBOAT7, GCKR, PDCD1, and HSD17B13 genes. A better understanding of these genetic modifiers and their mechanisms of action should allow a better risk prediction of the development of NAFLD and its progression to cirrhosis and hepatocellular cancer and help the development of new and selected therapies for NAFLD. Presentation: 6/3/2024

8599 Development of an androgen receptor transgenic mouse that displays the complete attributes of Metabolic Syndrome

Abstract Disclosure: C. Alvarado: None. L.K. Beitel: None. M. Paliouras: None. M.A. Trifiro: None. The mouse androgen receptor (AR) shares over 90% homology with the human ortholog, but it lacks the CAG encoded poly-Q tract; instead, it contains a mixed glutamine/histidine tract. To study AR functionality in a more structured fashion, we created a knock-in mouse model that has only the equivalent of human poly-Q tract while maintaining the remaining mouse receptor sequence intact. Our humanized androgen receptor mouse (AR-19Q) displays a phenotype that is best described as Metabolic Syndrome (MetS). The mice gain excess weight, have hypertension, hyperglycemia, pancreatic islet cell abnormalities, and progressive non-alcoholic fatty liver disease (NAFLD). Features of MetS begin at approximately 4 months and progress till 12-14 months. Obesity: AR-19Q mice are significantly heavier, with a 35% gain of weight vs C57BL/6 mice. However, these mice are not hyperphagic at any time and eat identical quantities of chow. To assess obesity status, and found AR-19Q mice to have a significantly higher depositions of total white adipose visceral, lingual and subcutaneous vs age-matched controls. NAFLD: The progression of NAFLD is observed in AR-19Q mice. AR-19Q Histological analysis and immunohistochemistry reveal microvesicular steatosis, superseded by macrovesicular steatosis with hepatocyte balloon degeneration, scattered lobular inflammation (macrophages and lymphocytes) (6-9 months) and further superseded by perisinusoidal fibrosis (12 months). Biochemical blood analysis confirms. that there is a significant increase in alanine aminotransferase (ALT) levels, indicative of liver damage. With time classical NASH hepatitis and subsequent NASH fibrosis ensues; with several mice developing hepatocellular carcinoma (overall 20% of mice). Gene expression profiling AR-19Q mice for fatty liver genes, we observe an upregulation of inflammation genes Il-6, Il-10 and Tnf. In addition, increased Lpl (lipoprotein lipase) is indicative of increased blood triglyceride levels. On the other hand, down-regulation of G6pc (glucose-6-phosphatase) could be linked to glycogen storage disease. Down-regulation of Slc2a2 and Slc2a4, that encode GLUT2 and GLUT4, should have an influence on glucose levels, glucose homeostasis and insulin sensitivity, as insulin promotes glucose uptake through GLUT4. Type 2 Diabetes: Glucose intolerance is observed by 3-4 months followed by fasting hyperglycemia. Pancreases show advanced islet hyperplasia, concurrent with insulin resistance and type 2 diabetes. Pancreases of middle-age AR-19Q mice present with a significant islet hyperplasia, suggesting peripheral insulin resistance. We propose the use of the AR-19Q mice as a model to study the metabolic dysfunction/ deficiency leading to the MetS. The model will allow us to a better understanding into the mechanisms responsible for T2D and NAFLD-related disorders. Presentation: 6/2/2024

9285 Development of an androgen receptor transgenic mouse that displays the complete attributes of Metabolic Syndrome

Abstract Disclosure: C. Alvarado: None. L.K. Beitel: None. M. Paliouras: None. M.A. Trifiro: None. The mouse androgen receptor (AR) shares over 90% homology with the human ortholog, but it lacks the CAG encoded poly-Q tract; instead, it contains a mixed glutamine/histidine tract. To study AR functionality in a more structured fashion, we created a knock-in mouse model that has only the equivalent of human poly-Q tract while maintaining the remaining mouse receptor sequence intact. Our humanized androgen receptor mouse (AR-19Q) displays a phenotype that is best described as Metabolic Syndrome (MetS). The mice gain excess weight, have hypertension, hyperglycemia, pancreatic islet cell abnormalities, and progressive non-alcoholic fatty liver disease (NAFLD). Features of MetS begin at approximately 4 months and progress till 12-14 months. Obesity: AR-19Q mice are significantly heavier, with a 35% gain of weight vs C57BL/6 mice. However, these mice are not hyperphagic at any time and eat identical quantities of chow. To assess obesity status, and found AR-19Q mice to have a significantly higher depositions of total white adipose visceral, lingual and subcutaneous vs age-matched controls. NAFLD: The progression of NAFLD is observed in AR-19Q mice. AR-19Q Histological analysis and immunohistochemistry reveal microvesicular steatosis, superseded by macrovesicular steatosis with hepatocyte balloon degeneration, scattered lobular inflammation (macrophages and lymphocytes) (6-9 months) and further superseded by perisinusoidal fibrosis (12 months). Biochemical blood analysis confirms. that there is a significant increase in alanine aminotransferase (ALT) levels, indicative of liver damage. With time classical NASH hepatitis and subsequent NASH fibrosis ensues; with several mice developing hepatocellular carcinoma (overall 20% of mice). Gene expression profiling AR-19Q mice for fatty liver genes, we observe an upregulation of inflammation genes Il-6, Il-10 and Tnf. In addition, increased Lpl (lipoprotein lipase) is indicative of increased blood triglyceride levels. On the other hand, down-regulation of G6pc (glucose-6-phosphatase) could be linked to glycogen storage disease. Down-regulation of Slc2a2 and Slc2a4, that encode GLUT2 and GLUT4, should have an influence on glucose levels, glucose homeostasis and insulin sensitivity, as insulin promotes glucose uptake through GLUT4. Type 2 Diabetes: Glucose intolerance is observed by 3-4 months followed by fasting hyperglycemia. Pancreases show advanced islet hyperplasia, concurrent with insulin resistance and type 2 diabetes. Pancreases of middle-age AR-19Q mice present with a significant islet hyperplasia, suggesting peripheral insulin resistance. We propose the use of the AR-19Q mice as a model to study the metabolic dysfunction/ deficiency leading to the MetS. The model will allow us to a better understanding into the mechanisms responsible for T2D and NAFLD-related disorders. Presentation: 6/2/2024

CDT1 is a Potential Therapeutic Target for the Progression of NAFLD to HCC and the Exacerbation of Cancer

Aims: This study aimed to identify potential therapeutic targets in the progression from non-alcoholic fatty liver disease (NAFLD) to hepatocellular carcinoma (HCC), with a focus on genes that could influence disease development and progression. Background: Hepatocellular carcinoma, significantly driven by non-alcoholic fatty liver disease, represents a major global health challenge due to late-stage diagnosis and limited treatment options. This study utilizes bioinformatics to analyze data from GEO and TCGA, aiming to uncover molecular biomarkers that bridge NAFLD to HCC. Through identifying critical genes and pathways, our research seeks to advance early detection and develop targeted therapies, potentially improving prognosis and personalizing treatment for NAFLD-HCC patients. Objective: Identify key genes that differ between NAFLD and HCC; Analyze these genes to understand their roles in disease progression; Validate the functions of these genes in NAFLD to HCC transition. Methods: Initially, we identified a set of genes differentially expressed in both NAFLD and HCC using second-generation sequencing data from the GEO and TCGA databases. We then employed a Cox proportional hazards model and a Lasso regression model, applying machine learning techniques to the large sample data from TCGA. This approach was used to screen for key disease-related genes, and an external dataset was utilized for model validation. Additionally, pseudo-temporal sequencing analysis of single-cell sequencing data was performed to further examine the variations in these genes in NAFLD and HCC. Results: The machine learning analysis identified IGSF3, CENPW, CDT1, and CDC6 as key genes. Furthermore, constructing a machine learning model for CDT1 revealed it to be the most critical gene, with model validation yielding an ROC value greater than 0.80. The single-cell sequencing data analysis confirmed significant variations in the four predicted key genes between the NAFLD and HCC groups. Conclusion: Our study underscores the pivotal role of CDT1 in the progression from NAFLD to HCC. This finding opens new avenues for early diagnosis and targeted therapy of HCC, highlighting CDT1 as a potential therapeutic target.

CHIP ameliorates nonalcoholic fatty liver disease via promoting K63- and K27-linked STX17 ubiquitination to facilitate autophagosome-lysosome fusion

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.

Ubiquitin-specific peptidase 25 ameliorates hepatic steatosis by stabilizing peroxisome proliferator-activated receptor alpha

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. USP25 in adipocytes has been proven to be involved in insulin resistance, a noteworthy characteristic of NAFLD. However, the roles of USP25 in NAFLD remain unclear. In this study, we aimed to elucidate the role of USP25 in NAFLD. Hepatic USP25 protein levels were measured in NAFLD patients and models. USP25 expression was manipulated in both mice and cells to evaluate its role in NAFLD. A downstream target of USP25 in NAFLD progression was identified through proteomic profiling analyses and confirmed. Additionally, a USP25 inhibitor was used to determine whether USP25 could be a viable treatment target for NAFLD. We found that USP25 protein levels were significantly decreased in the livers of NAFLD patients and NAFLD model mice. USP25 protein levels were also decreased in both mouse primary hepatocytes and Huh7 cells treated with free fatty acids (FFAs). We also found that Usp25 knockout mice presented much more severe hepatic steatosis when they were fed a high-fat diet. Similarly, knocking down USP25 in Huh7 cell lines aggravated FFA-induced steatosis, whereas USP25 overexpression ameliorated FFA-induced steatosis in Huh7 cell lines. Further proteomic profiling revealed that the PPARα signaling pathway was a downstream target of USP25, which was confirmed in both mice and cell lines. Moreover, USP25 could stabilize PPARα by promoting its deubiquitination. Finally, a USP25 inhibitor exacerbated diet-induced steatosis in mice. In conclusion, USP25 may play a role in NAFLD through the PPARα signaling pathway and could be a potential therapeutic target for NAFLD.

Caveolin-1 ameliorates hepatic injury in non-alcoholic fatty liver disease by inhibiting ferroptosis via the NOX4/ROS/GPX4 pathway

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally, with a complex and contentious pathogenesis. Caveolin-1 (CAV1) is an important regulator of liver function and can mitigate liver injury by scavenging reactive oxygen species (ROS). Evidence suggests that NOX4 is a source of ROS production, that oxidative stress and ferroptosis are closely related, and that both are involved in the onset and progression of NAFLD. However, whether CAV1 attenuates liver injury in NAFLD caused by high-fat diet via the NOX4/ROS/GPX4 pathway remains unclear. An in vivo fatty liver model was established by feeding mice with a high-fat diet for 16 weeks. In addition, an in vitro fatty liver model was established by incubating AML-12 cells with free fatty acids for 24 h using an in vitro culture method. In our study, it was observed that a high-fat diet induces mitochondrial damage and worsens oxidative stress in NAFLD. This diet also hinders GPX4 expression, leading to an escalation of ferroptosis and lipid accumulation. To counteract these effects, intraperitoneal administration of CSD peptide in mice attenuated the high-fat diet-induced liver mitochondrial damage and ferroptosis. Likewise, overexpression of CAV1 resulted in an increase in GPX4 expression and a reduction in levels of ROS-mediated iron metamorphosis, thus mitigating the progression of the disease. However, the effects of CAV1 on GPX4-mediated ferroptosis and lipid deposition could be reversed by CAV1 small interfering RNA (SiRNA). Finally, NOX4 inhibitor (GLX351322) treatment increased CAV1 siRNA-mediated GPX4 expression and decreased the level of ROS-mediated ferroptosis. These findings suggest a potential mechanism underlying the protective role of CAV1 against high-fat diet-induced hepatotoxicity in NAFLD, shedding new light on the interplay between CAV1, GPX4, and ferroptosis in liver pathology

Identification of necroptosis genes and characterization of immune infiltration in non-alcoholic steatohepatitis

BackgroundThe 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.MethodsThe 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.ResultsWe 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.ConclusionsWe 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.

Altered gut microbial profile accompanied by abnormal short chain fatty acid metabolism exacerbates nonalcoholic fatty liver disease progression

Dysregulation of the gut microbiome has associated with the occurrence and progression of non-alcoholic fatty liver disease (NAFLD). To determine the diagnostic capacity of this association, we compared fecal microbiomes across 104 participants including non-NAFLD controls and NAFLD subtypes patients that were distinguished by magnetic resonance imaging. We measured their blood biochemical parameters, 16 S rRNA-based gut microbiota and fecal short-chain fatty acids (SCFAs). Multi-omic analyses revealed that NAFLD patients exhibited specific changes in gut microbiota and fecal SCFAs as compared to non-NAFLD subjects. Four bacterial genera (Faecalibacterium, Subdoligranulum, Haemophilus, and Roseburia) and two fecal SCFAs profiles (acetic acid, and butyric acid) were closely related to NAFLD phenotypes and could accurately distinguish NAFLD patients from healthy non-NAFLD subjects. Twelve genera belonging to Faecalibacterium, Subdoligranulum, Haemophilus, Intestinibacter, Agathobacter, Lachnospiraceae_UCG-004, Roseburia, Butyricicoccus, Actinomycetales_unclassified, [Eubacterium]_ventriosum_group, Rothia, and Rhodococcus were effective to distinguish NAFLD subtypes. Of them, combination of five genera can distinguish effectively mild NAFLD from non-NAFLD with an area under curve (AUC) of 0.84. Seven genera distinguish moderate NAFLD with an AUC of 0.83. Eight genera distinguish severe NAFLD with an AUC of 0.90. In our study, butyric acid distinguished mild-NAFLD from non-NAFLD with AUC value of 0.83. And acetic acid distinguished moderate-NAFLD and severe-NAFLD from non-NAFLD with AUC value of 0.84 and 0.70. In summary, our study and further analysis showed that gut microbiota and fecal SCFAs maybe a method with convenient detection advantages and invasive manner that are not only a good prediction model for early warning of NAFLD occurrence, but also have a strong ability to distinguish NAFLD subtypes.