Visceral Fat and Diabetes: Associations With Liver Fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease.

Background: The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, is increasing globally. Noninvasive methods, such as bioelectrical impedance analysis (BIA), which measures body composition, including visceral fat, are gaining interest in evaluating MASLD patients. Our study aimed to identify factors associated with significant liver fibrosis, compare noninvasive scores, and highlight the importance of visceral fat measurement using BIA. Methods: MASLD patients seen in our out-patient department underwent comprehensive evaluations, including liver stiffness using transient elastography, body composition analysis using BIA, and metabolic measurements. Significant fibrosis was defined as a liver stiffness measurement of ≥8.2 kPa. Using multivariate analysis, we identified factors associated with significant liver fibrosis and compared four noninvasive scores with a novel diabetes-visceral fat 15 (DVF15) score. Results: We analyzed data from 609 MASLD patients seen between February 2022 and March 2023. The median age was 43 years (81% male). Among these, 78 (13%) had significant fibrosis. Patients with significant fibrosis had higher rates of type 2 diabetes (41% vs 21%, P < 0.001) and elevated levels of aspartate aminotransferase, alanine aminotransferase, hemoglobin A1c, Fibosis-4, aspartate-aminotransferase-to platelet-ratio index, and NAFLD fibrosis scores. They also exhibited higher visceral and subcutaneous fat. Binary logistic regression revealed type 2 diabetes and a visceral fat level of >15% as associated with significant liver fibrosis. Additionally, the DVF15 score, combining these factors, showed a modest area under the receiver operating characteristic curve of 0.664 (P < 0.001). Conclusion: Our study identified diabetes and high visceral fat as factors associated with significant liver fibrosis in MASLD patients. We recommend that visceral fat measurement using BIA be an essential part of MASLD evaluation. The presence of either diabetes or a visceral fat level of >15% should prompt clinicians to check for significant fibrosis in MASLD patients. Further research is warranted to validate our findings and evaluate the utility of the DVF15 score in larger cohorts and diverse populations.

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.

Inhibition of ATGL alleviates MASH via impaired PPARα signalling that favours hydrophilic bile acid composition in mice.

BACKGROUND AND AIMS: Adipose triglyceride lipase (ATGL) is an attractive therapeutic target in insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD). This study investigated the effects of pharmacological ATGL inhibition on the development of metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis in mice. METHODS: Streptozotocin-injected male mice were fed an HFD to induce MASH. Mice receiving the ATGL inhibitor, Atglistatin (ATGLi), were compared to controls using liver histology, lipidomics, metabolomics, 16s rRNA, and RNA sequencing. Human ileal organoids, HepG2 cells, and Caco2 cells treated with the human ATGL inhibitor NG-497, HepG2 ATGL knockdown cells, gel-shift, and luciferase assays were analysed for mechanistic insights. We validated its benefits on steatohepatitis and fibrosis in a low-methionine choline-deficient mouse model. RESULTS: ATGLi improved serum liver enzymes, hepatic lipid content, and histological liver injury. Mechanistically, ATGLi attenuated PPARα signalling, favouring hydrophilic bile acid (BA) synthesis with increased Cyp7a1, Cyp27a1, Cyp2c70, and reduced Cyp8b1 expression. Additionally, reduced intestinal Cd36 and Abca1, along with increased Abcg5 expression, were consistent with reduced levels of hepatic TAG-species containing PUFAs like linoleic acids as well as reduced cholesterol levels in the liver and plasma. Similar changes in gene expression associated with PPARα signaling and intestinal lipid transport were observed in ileal organoids treated with NG-497. Furthermore, HepG2 ATGL knockdown cells revealed reduced expression of PPARα target genes and upregulation of genes involved in hydrophilic BA synthesis, consistent with reduced PPARα binding and luciferase activity in the presence of the ATGL inhibitors. CONCLUSIONS: Inhibition of ATGL attenuates PPARα signalling, translating into hydrophilic BAs, interfering with dietary lipid absorption, and improving metabolic disturbances. The validation with NG-497 opens a new therapeutic perspective for MASLD. IMPACT AND IMPLICATIONS: The global prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is a crucial public health concern. Since adherence to behavioural interventions is limited, pharmacological strategies are necessary, as highlighted by the recent FDA approval of resmetirom. However, since our current mechanistic understanding and pathophysiology-oriented therapeutic options for MASLD are still limited, novel mechanistic insights are urgently needed. Our present work uncovers that pharmacological inhibition of ATGL, the key enzyme in lipid hydrolysis using Atglistatin (ATGLi), improves metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, and associated key features of metabolic dysfunction in a mouse model of MASH and MCD-induced liver fibrosis. Mechanistically, we demonstrated that attenuation of PPARα signalling in the liver and gut favours hydrophilic bile acid composition, ultimately interfering with dietary lipid absorption. One of the drawbacks of ATGLi is its lack of efficacy against human ATGL, thus limiting its clinical applicability. Against this backdrop, we could show that ATGL inhibition using the human inhibitor NG-497 in human primary ileum-derived organoids, Caco2 cells, and HepG2 cells translated into therapeutic mechanisms similar to ATGLi. Collectively, these findings open a new avenue for MASLD treatment development by inhibiting human ATGL activity.

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

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.

Contribution of extracellular vesicles to steatosis-related liver disease and their therapeutic potential.

Extracellular vesicles (EVs) are small particles released by many cell types in different tissues, including the liver, and transfer specific cargo molecules from originating cells to receptor cells. This process generally culminates in activation of distant cells and inflammation and progression of certain diseases. The global chronic liver disease (CLD) epidemic is estimated at 1.5 billion patients worldwide. Cirrhosis and liver cancer are the most common risk factors for CLD. However, hepatitis C and B virus infection and obesity are also highly associated with CLD. Nonetheless, the etiology of many CLD pathophysiological, cellular, and molecular events are unclear. Changes in hepatic lipid metabolism can lead to lipotoxicity events that induce EV release. Here, we aimed to present an overview of EV features, from definition to types and biogenesis, with particular focus on the molecules related to steatosis-related liver disease, diagnosis, and therapy.

acFibroMASH index for the diagnosis of fibrotic MASH and prediction of liver-related events: An international multicenter study.

BACKGROUND & AIMS: Metabolic dysfunction-associated steatohepatitis (MASH) and fibrotic MASH are significant health challenges. This multi-national study aimed to validate the acMASH index (including serum creatinine and aspartate aminotransferase concentrations) for MASH diagnosis and develop a new index (acFibroMASH) for non-invasively identifying fibrotic MASH and exploring its predictive value for liver-related events (LREs). METHODS: We analyzed data from 3,004 individuals with biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD) across 29 Chinese and nine international cohorts to validate the acMASH index and develop the acFibroMASH index. Additionally, we utilized the independent external data from a multi-national cohort of 9,034 patients with MAFLD to examine associations between the acFibroMASH index and the risk of LREs. RESULTS: In the pooled global cohort, the acMASH index identified MASH with an AUROC of 0.802 (95%CI 0.786-0.818). The acFibroMASH index (including the acMASH index plus liver stiffness measurement) accurately identified fibrotic MASH with an AUROC of 0.808 in the derivation cohort and 0.800 in the validation cohort. Notably, the AUROC for the acFibroMASH index was 0.835 (95% CI 0.786-0.882), superior to that of the FAST score at 0.750 (95% CI 0.693-0.800, P<0.01) in predicting the 5-year risk of LREs. Patients with acFibroMASH >0.39 had a higher risk of LREs than those with acFibroMASH <0.15 (adjusted-hazard ratio: 11.23 95%CI 3.98-31.66). CONCLUSIONS: This multi-ethnic study validates the acMASH index as a reliable, non-invasive test for identifying MASH. The newly proposed acFibroMASH index is a reliable test for identifying fibrotic MASH and predicting the risk of LREs.

Evaluation of Gremlin-1 as a therapeutic target in metabolic dysfunction-associated steatohepatitis.

Gremlin-1 has been implicated in liver fibrosis in metabolic dysfunction-associated steatohepatitis (MASH) via inhibition of bone morphogenetic protein (BMP) signalling and has thereby been identified as a potential therapeutic target. Using rat in vivo and human in vitro and ex vivo model systems of MASH fibrosis, we show that neutralisation of Gremlin-1 activity with monoclonal therapeutic antibodies does not reduce liver inflammation or liver fibrosis. Still, Gremlin-1 was upregulated in human and rat MASH fibrosis, but expression was restricted to a small subpopulation of COL3A1/THY1+ myofibroblasts. Lentiviral overexpression of Gremlin-1 in LX-2 cells and primary hepatic stellate cells led to changes in BMP-related gene expression, which did not translate to increased fibrogenesis. Furthermore, we show that Gremlin-1 binds to heparin with high affinity, which prevents Gremlin-1 from entering systemic circulation, prohibiting Gremlin-1-mediated organ crosstalk. Overall, our findings suggest a redundant role for Gremlin-1 in the pathogenesis of liver fibrosis, which is unamenable to therapeutic targeting.

The multifaceted roles of B lymphocytes in metabolic dysfunction-associated steatotic liver disease.

Recent evidence suggests that adaptive immune cells are important contributors to metabolic dysfunction-associated steatotic liver disease (MASLD, formerly non-alcoholic fatty liver disease, NAFLD). In liver biopsies from MASLD patients, the accumulation of intrahepatic B cells is positively correlated with the MASLD activity score. Hepatic B-cell infiltration is observed in experimental models of metabolic dysfunction-associated steatohepatitis (MASH, formerly non-alcoholic steatohepatitis, NASH). Intrahepatic B2 cells have been shown to contribute to MASLD/MASH by activating T cells, macrophages and hepatic stellate cells, and by producing pathogenic IgG antibodies. In mice fed a MASH diet, selective depletion of B2 cells reduces steatohepatitis and fibrosis. Intestinal B cells are metabolically activated in MASH and promote T-cell activation independently of TCR signaling. In addition, B cells have been shown to contribute to liver fibrosis by activating monocyte-derived macrophages through the secretion of IgA immunoglobulins. Furthermore, our recent study indicates that certain B cell subsets, very likely regulatory B cells, may play a protective role in MASLD. This review summarizes the molecular mechanisms of B cell functions and discusses future research directions on the different roles of B cells in MASLD and MASH.

An insight into the updated pharmacotherapy of metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals: a review.

Metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals represents a distinctive subset of MASH. Current pharmacotherapies, for MASH as demonstrated in clinical trials, predominantly target obese patients with limited consideration for lean MASH. We aimed to systematically review the literature on the pharmacotherapy of lean MASH. We searched standard medical databases, such as PubMed, Embase, Scopus, Cochrane CENTRAL, and ClinicalTrials.gov to identify eligible studies published in English up to 31 December 2023 regarding the effect of pharmacological interventions in individuals with lean MASH. We have summarized the role of various drug classes including peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, vitamin E, farnesoid X receptor agonists, selective thyroid hormone receptor-ß agonists, and selective cholesterol absorption inhibitors. Consequently, lifestyle interventions, encompassing dietary modifications, exercise, and weight loss particularly directed at visceral obesity or achieving a reduction in body weight are recommended for all non-obese individuals with MASH. A highlight on the only available treatment recommendation for lean MASH is also presented. The available evidence regarding the efficacy of various drugs for the treatment of lean MASH is limited. Conclusive evidence is warranted from clinical trials exclusively involving lean individuals with MASH.

Impact of gut microbiota on metabolic dysfunction-associated steatohepatitis and hepatocellular carcinoma: pathways, diagnostic opportunities and therapeutic advances.

Metabolic dysfunction-associated steatohepatitis (MASH) and progression to hepatocellular carcinoma (HCC) exhibits distinct molecular and immune characteristics. These traits are influenced by multiple factors, including the gut microbiome, which interacts with the liver through the "gut-liver axis". This bidirectional relationship between the gut and its microbiota and the liver plays a key role in driving various liver diseases, with microbial metabolites and immune responses being central to these processes. Our review consolidates the latest research on how gut microbiota contributes to MASH development and its progression to HCC, emphasizing new diagnostic and therapeutic possibilities. We performed a comprehensive literature review across PubMed/MedLine, Scopus, and Web of Science from January 2000 to August 2024, focusing on both preclinical and clinical studies that investigate the gut microbiota's roles in MASH and HCC. This includes research on pathogenesis, as well as diagnostic and therapeutic advancements related to the gut microbiota. This evidence emphasizes the critical role of the gut microbiome in the pathogenesis of MASH and HCC, highlighting the need for further clinical studies and trials. This is to refine diagnostic techniques and develop targeted therapies that exploit the microbiome's capabilities, aiming to enhance patient care in liver diseases.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

[Steatosis]. / Stéatose.

Steatosis is defined by hepatocyte accumulation of lipids. Different types of steatosis are described (macro-, medio- and microvacuolar). Macrovacuolar steatosis is a common lesion, mainly observed during metabolic syndrome and excessive alcohol consumption. Steatohepatitis combines steatosis, the presence of ballooned hepatocytes and lobular inflammatory foci. Liver fibrosis is the main consequence of steatohepatitis. Liver biopsy is the gold standard diagnostic test.

Chitinase 1: a novel therapeutic target in metabolic dysfunction-associated steatohepatitis.

Background: Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by persistent inflammatory cascades, with macrophage activation playing a pivotal role. Chitinase 1 (CHIT1), produced by activated macrophages, is a key player in this cascade. In this study, we aimed to explore the role of CHIT1 in MASH with progressive liver fibrosis. Methods: Fibrotic liver tissue and serum from distinct patient groups were analyzed using nCounter MAX, flow cytometry, immunohistochemistry, and enzyme-linked immunosorbent assay. A MASH mouse model was constructed to evaluate the effectiveness of OATD-01, a chitinase inhibitor. Macrophage profiling was performed using single-nuclei RNA sequencing and flow cytometry. Results: CHIT1 expression in fibrotic liver tissues was significantly correlated with the extent of liver fibrosis, macrophages, and inflammation. Single-nuclei RNA sequencing demonstrated a notable increase in macrophages numbers, particularly of lipid-associated macrophages, in MASH mice. Treatment with OATD-01 reduced non-alcoholic fatty liver disease activity score and Sirius red-positive area. Additionally, OATD-01-treated mice had lower CHIT1, F4/80, and α-smooth muscle actin positivity, as well as significantly lower levels of inflammatory markers, pro-fibrotic genes, and matrix remodeling-related mRNAs than vehicle-treated mice. Although the population of F4/80+CD11b+ intrahepatic mononuclear phagocytes remained unchanged, their infiltration and activation (CHIT1+MerTK+) significantly decreased in OATD-01-treated mice, compared with that observed in vehicle-treated mice. Conclusions: Our study underscores the pivotal role of CHIT1 in MASH. The observed significant improvement in inflammation and hepatic fibrosis, particularly at higher doses of the CHIT1 inhibitor, strongly suggests the potential of CHIT1 as a therapeutic target in MASH accompanied by progressive liver fibrosis.

Rifaximin alleviates MCD diet-induced NASH in mice by restoring the gut microbiota and intestinal barrier.

AIMS: Due to the increasing global incidence rate of nonalcoholic steatohepatitis (NASH) combined with the lack of effective treatment methods for this disease, there is an urgent need to find new treatment strategies. The aim of this study was to investigate the efficacy of rifaximin in preventing and treating NASH and the related mechanism. MATERIALS AND METHODS: A NASH model was constructed by feeding male C57BL/6 mice a methionine-choline-deficient (MCD) diet for 4 weeks. Rifaximin was administered for 1 week before MCD diet feeding or during the last week of MCD diet feeding to investigate its preventive or therapeutic effects. Liver pathology, hepatic enzyme levels and metabolic indices were measured to evaluate the effects of rifaximin on NASH. Intestinal barrier integrity was measured via the Ussing chamber system and western blotting. 16S rDNA sequencing was conducted to investigate the fecal microbiota composition. Western blotting was performed to evaluate peroxisome proliferator activated receptor (PPAR)α and PPARγ protein levels. KEY FINDINGS: Rifaximin effectively alleviated MCD diet-induced NASH. The microbiota composition in MCD diet-fed mice was significantly altered, and intestinal barrier integrity was disrupted. Dysbiosis and intestinal barrier dysfunction were reversed by rifaximin. In addition, rifaximin modulated PPARα and PPARγ expression in the liver. SIGNIFICANCE: Rifaximin effectively alleviated MCD diet-induced NASH by restoring the gut microbiota and reversing intestinal barrier dysfunction, suggesting that rifaximin treatment is a new approach for preventing and treating NASH.

The effect of probiotic supplementation on non-alcoholic fatty liver disease (NAFLD) fibrosis score in patients attending a tertiary hospital clinic in Cairo, Egypt.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic fat accumulation (> 5% of liver tissue) in the absence of alcohol abuse or other chronic liver diseases. NAFLD can progress to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). This study aimed to assess the efficacy of probiotic (lactobacillus) supplementation on NAFLD fibrosis score. METHODOLOGY: A double-arm randomized controlled trial was conducted in the family medicine clinic of a tertiary hospital, enrolling patients with sonographic evidence of NAFLD. Fifty patients were divided into two groups: the Probiotic group received lifestyle modification instructions along with daily probiotic supplementation for twelve weeks, with regular monthly follow-up visits. The Standard Treatment group received low-fat diet and lifestyle modification instructions only. RESULTS: The mean age of participants was 46.10 years (SD 10.11), with 70% females and 30% males. The study found a statistically significant difference in liver enzymes (ALT and AST) and BMI in the probiotic group before and after intervention. However, there was no significant difference in NAFLD fibrosis score between the two groups. CONCLUSION: Short-term probiotic treatment resulted in improvements in ALT, AST, and BMI in the probiotic group, but did not significantly affect NAFLD fibrosis score. Further research with larger sample sizes and longer follow-up periods is warranted. TRIAL REGISTRATION: The clinical trial was registered at Protocol Registration and Results System with number NCT06074094 (12/09/2021).

Deletion of platelet-derived growth factor receptor ß suppresses tumorigenesis in metabolic dysfunction-associated steatohepatitis (MASH) mice with diabetes.

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

Role of PNPLA3 in Hepatic Stellate Cells and Hepatic Cellular Crosstalk.

AIMS: Since its discovery, the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409 C>G p.I148M) variant has been studied extensively to unravel its molecular function. Although several studies proved a causal relationship between the PNPLA3 I148M variant and MASLD development and particularly fibrosis, the pathological mechanisms promoting this phenotype have not yet been fully clarified. METHODS: We summarise the latest data regarding the PNPLA3 I148M variant in hepatic stellate cells (HSCs) activation and macrophage biology or the path to inflammation-induced fibrosis. RESULTS: Elegant but contradictory studies have ascribed PNPLA3 a hydrolase or an acyltransferase function. The PNPLA3 I148M results in hepatic lipid accumulation, which predisposes the hepatocyte to lipotoxicity and lipo-apoptosis, producing DAMPs, cytokines and chemokines leading to recruitment and activation of macrophages and HSCs, propagating fibrosis. Recent studies showed that the PNPLA3 I148M variant alters HSCs biology via attenuation of PPARγ, AP-1, LXRα and TGFß activity and signalling. CONCLUSIONS: The advent of refined techniques in isolating HSCs has made PNPLA3's direct role in HSCs for liver fibrosis development more apparent. However, many other mechanisms still need detailed investigations.

Frailty and risk of metabolic dysfunction-associated steatotic liver disease and other chronic liver diseases.

BACKGROUND & AIMS: Frailty is associated with multiple morbidities. However, its effect on chronic liver diseases remains largely unexplored. This study evaluated the association of frailty with the risk of incident metabolic dysfunction-associated steatotic liver disease (MASLD), cirrhosis, liver cancer, and liver-related mortality. METHODS: A total of 339,298 participants without prior liver diseases from the UK Biobank were included. Baseline frailty was assessed by using physical frailty and the frailty index, categorizing participants as nonfrail, prefrail, or frail. The primary outcome was MASLD, with secondary outcomes, including cirrhosis, liver cancer, and liver-related mortality, confirmed through hospital admission records and death registries. RESULTS: During a median follow-up of 11.6 years, 4,667 MASLD, 1,636 cirrhosis, 257 liver cancer, and 646 liver-related mortality cases were identified. After multivariable adjustment, the risk of MASLD was found to be higher in participants with prefrailty (physical frailty: HR = 1.66, 95% CI = 1.40-1.97; frailty index: HR = 2.01, 95% CI = 1.67-2.42) and frailty (physical frailty: HR = 3.32, 95% CI = 2.54-4.34; frailty index: HR = 4.54, 95% CI = 3.65-5.66) than in those with nonfrailty. Similar results were also observed for cirrhosis, liver cancer, and liver-related mortality. Additionally, the frail groups had a higher risk of MASLD, which was defined as magnetic resonance imaging-derived liver proton density fat fraction > 5%, than the nonfrail group (physical frailty: OR = 1.64, 95% CI = 1.32-2.04; frailty index: OR = 1.48, 95% CI = 1.30-1.68). CONCLUSIONS: Frailty was associated with an increased risk of chronic liver diseases. Public health strategies should target reducing chronic liver disease risk in frail individuals. IMPACT AND IMPLICATIONS: While frailty is common and associated with a poor prognosis in people with MASLD and advanced chronic liver diseases, its impact on the subsequent risk of these outcomes remains largely unexplored. Our study showed that frailty was associated with the increased risks of MASLD, cirrhosis, liver cancer, and liver-related mortality. This finding suggests that assessing frailty may help identify a high-risk population vulnerable to developing chronic liver diseases. Implementing strategies that target frailty could have major public health benefits for liver-related disease prevention.

Effect of Indo-Mediterranean diet versus calorie-restricted diet in children with non-alcoholic fatty liver disease: A pilot randomized control trial.

BACKGROUND: Dietary interventions and increased physical activity are the cornerstones for management of the paediatric non-alcoholic fatty liver disease (NAFLD). Though, no specific diet has been proven superior, Indo-Mediterranean diet (IMD) has shown promise in adult literature. Thus, we aimed to compare the effect of IMD and a standard calorie-restricted diet (CRD) in Indian overweight children and adolescents with biopsy-proven NAFLD. METHODS: Thirty-nine consecutive biopsy-proven NAFLD children between the ages of 8 and 18 years were randomized into either IMD or CRD for 180 days, and various parameters were evaluated at baseline and then after 180 days (NCT05073588). RESULTS: A total of 34 subjects (18 in IMD and 16 in CRD group) completed the study. There was a significantly higher decrease in controlled attenuation parameter (CAP) values (as a marker of hepatic steatosis; on transient elastography) (95% CI: 4.2-73.4, p = 0.042), weight (95% CI: 0.75-5.5, p = 0.046) and body mass index (BMI) (95% CI: 0.21-2.05, p = 0.014) (but not in Pediatric NAFLD Fibrosis Index or PNFI; as a marker of hepatic fibrosis) in IMD group compared to the CRD group. Liver stiffness measurement, serum cholesterol and low-density lipoprotein levels and HOMA-IR decreased only in the IMD group (p < 0.001). Our statistical model showed that delta-Weight was the only independent variable associated with delta-CAP. CONCLUSION: Both IMD and CRD can improve the various anthropometric, clinical, imaging and biochemical parameters but IMD was superior to CRD in terms of reducing CAP values and weight/BMI over 180 days in overweight/obese NAFLD children.