Progression Of Non-alcoholic Fatty Liver Disease Research Articles

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.

SENP1 prevents high fat diet-induced non-alcoholic fatty liver diseases by regulating mitochondrial dynamics

Mitochondrial dynamics plays a crucial role in the occurrence and development of non-alcoholic fatty liver diseases (NAFLD). SENP1, a SUMO-specific protease, catalyzes protein de-SUMOylation and involves in various physiological and pathological processes. However, the exact role of SENP1 in NAFLD remains unclear. Therefore, we investigated the regulatory role of SENP1 in mitochondrial dynamics during the progression of NAFLD. In the study, the NAFLD in vivo model induced by high fat diet (HFD) and in vitro model induced by free fatty acids (FFA) were established to investigate the role and underlying mechanism of SENP1 through detecting mitochondrial morphology and dynamics. Our results showed that the down-regulation of SENP1 expression and the mitochondrial dynamics dysregulation occurred in the NAFLD, evidenced as mitochondrial fragmentation, up-regulation of p-Drp1 ser616 and down-regulation of MFN2, OPA1. However, over-expression of SENP1 significantly alleviated the NAFLD, rectified the mitochondrial dynamics disorder, reduced Cyt-c release and ROS levels induced by FFA or HFD; moreover, the over-expression of SENP1 also reduced the SUMOylation levels of Drp1 and prevented the Drp1 translocation to mitochondria. Our findings suggest that the possible mechanisms of SENP1 were through rectifying the mitochondrial dynamics disorder, reducing Cyt-c release and ROS-mediated oxidative stress. The findings would provide a novel target for the prevention and treatment of NALFD.

Mechanism of mesenchymal stem cells in liver regeneration: Insights and future directions.

Mesenchymal stem cells (MSCs) are a prevalent source for stem cell therapy and play a crucial role in modulating both innate and adaptive immune responses. Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of triglycerides in liver cells and involves immune system activation, leading to histological changes, tissue damage, and clinical symptoms. A recent publication by Jiang et al, highlighted the potential of MSCs to mitigate in NAFLD progression by targeting various molecular pathways, including glycolipid metabolism, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. In this editorial, we comment on their research and discuss the efficacy of MSC therapy in treating NAFLD.

Innovative mesenchymal stem cell treatments for fatty liver disease.

The incidence of non-alcoholic fatty liver disease (NAFLD) and alcohol-associated liver disease (ALD) is increasing year by year due to changes in the contemporary environment and dietary structure, and is an important public health problem worldwide. There is an urgent need to continuously improve the understanding of their disease mechanisms and develop novel therapeutic strategies. Mesenchymal stem cells (MSCs) have shown promise as a potential therapeutic strategy in therapeutic studies of NAFLD and ALD. NAFLD and ALD have different triggers and their specific mechanisms of disease progression are different, but both involve disease processes such as hepatocellular steatosis and potential fibrosis, cirrhosis, and even hepatocellular carcinoma. MSCs have metabolic regulatory, anti-apoptotic, antioxidant, and immunomodulatory effects that together promote liver injury repair and functional recovery, and have demonstrated positive results in preclinical studies. This editorial is a continuum of Jiang et al's review focusing on the advantages and limitations of MSCs and their derivatives as therapeutics for NAFLD and ALD. They detail how MSCs attenuate the progression of NAFLD by modulating molecular pathways involved in glucolipid metabolism, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. Based on recent advances, we discuss MSCs and their derivatives as therapeutic strategies for NAFLD and ALD, providing useful information for their clinical application.

Non-Invasive Serum Markers of Non-Alcoholic Fatty Liver Disease Fibrosis: Potential Tools for Detecting Patients with Cardiovascular Disease.

Non-alcoholic fatty liver disease (NAFLD), one of the most common chronic liver diseases with a prevalence of 23%-25% globally, is an independent risk factor for cardiovascular diseases (CVDs). Growing evidence indicates that the development of NAFLD, ranging from non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), advanced fibrosis to cirrhosis, and even hepatocellular carcinoma, is at substantial risk for CVDs, which clinically contribute to increased cardiovascular morbidity and mortality. Non-invasive serum markers assessing liver fibrosis, such as fibrosis-4 (FIB-4) score, aspartate transaminase-to-platelet ratio index (APRI), and NAFLD fibrosis score (NFS), are expected to be useful tools for clinical management of patients with CVDs. This review aims to provide an overview of the evidence for the relationship between the progression of NAFLD and CVDs and the clinical application of non-invasive markers of liver fibrosis in managing patients with CVDs.

Non-alcoholic fatty liver disease: Genetic susceptibility

The prevalence of Non-alcoholic Fatty Liver Disease (NAFLD) is increasing, particularly in individuals who consume minimal to no alcohol. Currently, NAFLD affects at least 32% of the global population. Although not all but approximately 5-10% cases of NAFLD progress to non-alcoholic steatohepatitis (NASH), a condition arising from lipotoxicity. Patients with NASH may further develop liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). However, it is important to note that progression from NAFLD to NASH and HCC is not inevitable for all patients. The pathogenesis of HCC in the context of NAFLD and NASH remains poorly understood, however, fat accumulation, often due to obesity or metabolic syndrome, leads to lipotoxicity. In individuals with type 2 diabetes (T2D), elevated insulin levels promote lipolysis in adipose tissue and activate lipid-synthesizing enzymes such as fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD1), which contribute to lipid accumulation in the liver. Additionally, high glucose levels in T2D can alter gene regulation by activating carbohydrate response-element binding protein (ChREBP) and insulin can increase the activity of sterol regulatory element binding protein (SREBP-1c). These lipogenic transcription factors are known to directly or indirectly activate patatin-like phospholipase domain-containing protein 3 (PNPLA3). Recent research has found elevated levels of angiotensinogen (AGT) and des-angiotensin in both experimental animals and patients with NAFLD. Emerging evidence highlights the significance of genetic factors in the risk of developing NAFLD. Here we explore the association between specific genes and hepatosteatosis, detailing the roles of T2D and obesity in the progression from NAFLD to NASH, and involvement of hepatic stellate cells in liver fibrosis. Additionally, we examine the impact of genes such as PNPLA3, MBOAT7, TM6SF2, GKRP, CCN3, and AGT as well as role of single nucleotide polymorphisms in gene regulation and their contribution to the risk of NAFLD.