Toll-like receptors and metabolic (dysfunction)-associated fatty liver disease

Effect of the total flavonoids of Dracocephalum moldavica L. on metabolic associated fatty liver disease in rats

Introduction

Metabolic-associated fatty liver disease (MAFLD) is a liver disease syndrome. The total flavonoids of Dracocephalum moldavica L. (D. moldavica), the main active components of D. moldavica, have been demonstrated not only to have anti-inflammatory and antioxidant effects but also to regulate gut microbiota. However, the mechanism by which it improves MAFLD is unclear. So we want to investigate how the total flavonoids of D. moldavica alleviate high-fat diet (HFD)-induced MAFLD in rats.

Methods

Firstly, MAFLD rat models were established by feeding with HFD, while the total flavonoids of D. moldavica were administered via gavage. Then, the experiments analyzed the changes of gut microbiota by the 16S rRNA sequencing and detected intestinal barrier permeability and liver inflammation to explore the mechanism of the total flavonoids of D. moldavica in the prevention and treatment of MAFLD.

Results

We found that the total flavonoids of D. moldavica reduced systemic inflammation and could alleviate serum and liver lipid metabolism disorders in MAFLD rats. The results of the 16S rRNA sequencing demonstrated that the total flavonoids of D. moldavica increased the abundance and diversity of gut microbiota. Furthermore, the total flavonoids of D. moldavica have been demonstrated to enhance the intestinal mucosal barrier function, reduce LPS translocation, and inhibit the activation of hepatic TLR4/MyD88/NF-κB pathway. This could effectively ameliorate the hepatic lesions in MAFLD rats.

Conclusions

The aforementioned outcomes indicate that the total flavonoids ofD moldavica may potentially alleviate MAFLD by modulating gut microbiota, intestinal mucosal barrier and hepatic inflammation.

Pathophysiological underpinnings of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is emerging as the leading cause of chronic liver disease worldwide, reflecting the global epidemics of obesity, metabolic syndrome, and type 2 diabetes. Beyond its strong association with excess adiposity, MASLD encompasses a heterogeneous population that includes individuals with normal body weight ("lean MASLD") highlighting the complexity of its pathogenesis. This disease results from a complex interplay between genetic susceptibility, epigenetic modifications, and environmental factors, which converge to disrupt metabolic homeostasis. Adipose tissue dysfunction and insulin resistance trigger an overflow of lipids to the liver, leading to mitochondrial dysfunction, oxidative stress, and hepatocellular injury. These processes promote hepatic inflammation and fibrogenesis, driven by cross talk among hepatocytes, immune cells, and hepatic stellate cells, with key contributions from gut-liver axis perturbations. Recent advances have unraveled pivotal molecular pathways, such as transforming growth factor-β signaling, Notch-induced osteopontin, and sphingosine kinase 1-mediated responses, that orchestrate fibrogenic activation. Understanding these interconnected mechanisms is crucial for developing targeted therapies. This review integrates current knowledge on the pathophysiology of MASLD, emphasizing emerging concepts such as lean metabolic dysfunction-associated steatohepatitis (MASH), epigenetic alterations, hepatic extracellular vesicles, and the relevance of extrahepatic signals. It also discusses novel therapeutic strategies under investigation, aiming to provide a comprehensive and structured overview of the evolving MASLD landscape for both basic scientists and clinicians.

Histone methyltransferase SMYD2 regulates the activation of hepatic stellate cells by activating TLR4 signaling

Liver fibrosis represents a pathological outcome in the progression of chronic liver diseases, primarily driven by the activation of hepatic stellate cells (HSCs) induced by various chronic liver injury factors. Substantial evidence indicates that under inflammatory conditions, aberrant activation of HSCs leads to excessive deposition of extracellular matrix (ECM). Therefore, identifying novel molecular targets to inhibit HSCs activation and proliferation is of significant clinical importance for the prevention and treatment of liver fibrosis. SMYD2 (SET and MYND domain containing 2) is a histone methyltransferase primarily responsible for catalyzing the methylation of lysine 36 on histone H3 (H3K36). However, the specific role and mechanisms of SMYD2 in the progression of liver fibrosis remain poorly understood. Thus, this study aims to systematically investigate the molecular regulatory mechanisms of SMYD2 in the development of liver fibrosis. Our findings demonstrate that both SMYD2 and its catalytic product, H3K36me2, are significantly upregulated in carbon tetrachloride (CCl4)-induced liver fibrosis tissues in mice and during the spontaneous activation of primary mouse HSCs in vitro. Knockdown of SMYD2 expression significantly reduces H3K36me2 modification levels and effectively inhibits transforming growth factor-β1 (TGF-β1)-induced HSC activation. Further mechanistic studies reveal that the toll-like receptor 4 (TLR4) -nuclear factor kappa-B(NF-κB) signaling pathway is involved in this regulatory process, where Smyd2 positively regulates Tlr4 gene expression by modulating H3K36me2 modification levels. These findings suggest that SMYD2 may serve as a potential therapeutic target for liver fibrosis, warranting further exploration in subsequent clinical translational research.

Unraveling the link between metabolic dysfunction-associated steatotic liver disease and osteoporosis: a bridging function of gut microbiota

This review examines the strong association between metabolic dysfunction-associated steatotic liver disease (MASLD) and osteoporosis (OP), with a particular focus on the role of gut microbiota in linking these two disorders. Both MASLD and OP are closely linked to metabolic syndrome, and their pathogenesis involves multiple factors, such as inflammatory response, insulin resistance, altered intestinal permeability, and estrogen deficiency. Dysregulation of gut microbiota not only affects hepatic fat accumulation and bone metabolism disorders through metabolites, such as short-chain fatty acids, but also exacerbates systemic chronic inflammation by impairing the intestinal barrier function, thus accelerating the progression of both diseases. This article summarizes recent studies that highlight the central role of gut microbiota as a co-morbid factor in MASLD and OP, offering new perspectives for future diagnostic and therapeutic strategies.

Effectiveness of body roundness index for the prediction of nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Several anthropometric indices, such as body mass index and waist circumference, have been used as clinical screening tools for the prediction of nonalcoholic fatty liver disease (NAFLD). To further refine these clinical tools for NAFLD, the body roundness index (BRI) has recently been evaluated. In this systematic review and meta-analysis, the objective was to evaluate the relationship and predictive capability of the BRI in identifying NAFLD.

METHODS

A comprehensive search was conducted in PubMed, Embase, Web of Science, and Scopus up to December 31, 2024. Eligibility criteria included observational studies on adults (≥ 18 years old) with measured BRI and its association with NAFLD. The Joanna Briggs Institute tool was used for risk of bias assessment. Meta-analyses used random-effects models to pool data on mean difference, odds ratio, sensitivity, specificity, and the area under the curve (AUC), with heterogeneity and publication bias assessed.

RESULTS

Ten studies involving 59,466 participants were included. The pooled mean difference in BRI between the NAFLD and non-NAFLD groups was 1.73 (95% confidence interval [CI]: 1.31-2.15). The pooled sensitivity and specificity of BRI for diagnosing NAFLD were 0.806 and 0.692, respectively. The pooled AUC for BRI was 0.803 (95% CI: 0.775-0.830), indicating good diagnostic accuracy. Unlike subgroup analysis by country, subgroup analysis by sex showed no significant differences. Higher BRI values were associated with increased odds of NAFLD (pooled OR = 2.87, 95% CI: 1.39; 5.96). Studies provided mixed results on the predictive ability of BRI compared to other indices like body mass index, mostly favoring BRI over conventional indices.

CONCLUSION

BRI demonstrates a good diagnostic performance for NAFLD, suggesting it may be a valuable clinical tool for NAFLD assessment. Further research is necessary to validate these findings and strengthen the evidence base.

Effect of oral resveratrol-loaded nanoliposomes on hyperlipidemia via toll-like receptor 3 and TIR domain-containing adaptor inducing interferon-β protein expression in an animal model

Hyperlipidemia, a critical risk factor for various health conditions, necessitates innovative therapeutic strategies. Investigating the effectiveness of liposomal formulations in managing hyperlipidemia is essential. Resveratrol (RES)-loaded nanoliposomes present a promising new approach for hyperlipidemia treatment. In this study, we investigated the anti-hyperlipidemic potential of RES-loaded nanoliposomes in high-fat diet (HFD)-fed rats. The nanoliposomes were prepared using a thin-film hydration method. According to transmission electron microscopy (TEM) and dynamic light scattering (DLS) results, the mean size of prepared RES-loaded nanoliposomes were about 42 nm and 68 nm, respectively, with a zeta potential of -65.6 mV. The entrapment efficiency and loading content were 83.78% and 14.25%, respectively. Additionally, the RES-loaded nanoliposomes exhibited controlled release kinetics compared to the free RES form. Moreover, in a hyperlipidemic rat model induced by an HFD, orally administered RES-loaded nanoliposomes significantly reduced total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglycerides (TG), while concurrently increasing high-density lipoprotein cholesterol (HDL-C) levels. Additionally, liver damage induced by HFD was alleviated by RES-loaded nanoliposomes. The expression levels of Toll-like receptor 3 (TLR3) and TIR domain-containing adaptor-inducing interferon-β (TRIF) were assessed using fluorescence immunohistochemistry. Notably, RES-loaded nanoliposomes significantly reduced the expression of these protein. The effect of RES-loaded nanoliposomes was measured on body weight of HFD rats, demonstrting RES-loaded nanoliposomes hold promise for weight management. These findings underscore the potential of RES-loaded nanoliposomes as a safe and effective therapeutic option for hyperlipidemia.

Grape pomace extract attenuates high fat diet-induced endotoxemia and liver steatosis in mice

Obesity is a prominent global health concern associated with chronic inflammation and metabolic disorders, such as insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). Excessive consumption of saturated fats exacerbates these conditions by increasing intestinal barrier permeability and circulating endotoxins. This study aims to investigate, in a murine model of high-fat diet (HFD)-induced obesity, the potential beneficial effects of a grape pomace extract (GPE), rich in phenolic compounds, at mitigating endotoxemia, and liver steatosis. Underlying mechanisms were characterized in an in vitro model of intestinal inflammation and permeabilization, as induced by tumor necrosis factor alpha (TNFα) in Caco-2 cell monolayers. Consumption of a HFD (60% calories from fat) for 13 weeks induced obesity, insulin resistance, and liver damage, evidenced by higher levels of plasma alanine aminotransferase (ALT), hepatic triglycerides content, and steatosis. In addition, HFD caused metabolic endotoxemia, hepatic toll-like receptor 4 (TLR4) upregulation and inflammation. GPE supplementation significantly reduced body weight and subcutaneous and visceral adipose tissue weight, and attenuated metabolic dysregulation. Furthermore, GPE decreased circulating LPS levels and mitigated HFD-mediated hepatic TLR4 upregulation, nuclear factor kappa B (NF-κB) activation, and downstream expression of proteins involved in oxidative stress and inflammation (NOX4, TNFα, and F4/80). In Caco-2 cells, GPE mitigated TNFα-induced monolayer permeabilization, decreased tight junction (TJ) protein levels, enhanced cellular oxidant production, activated redox-sensitive signaling, i.e., NF-κB and ERK1/2, and increased NOX1 and MLCK mRNA levels, the latter being a key regulator of monolayer permeability. The above findings suggest that GPE may protect against HFD-induced obesity and associated metabolic dysfunction (insulin resistance and NAFLD) by modulating intestinal barrier integrity and related endotoxemia.

Zhuyu pill attenuates metabolic-associated fatty liver disease by regulating macrophage polarization through TLR4 signaling pathway

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is the leading chronic liver disease globally, impacting a large segment of the population. The Zhuyu Pill (ZYP), a traditional Chinese remedy, has been clinically used for treating MAFLD, with its effectiveness demonstrated in both human patients and animal models. However, the underlying mechanisms of how ZYP addresses MAFLD still require further investigation.

OBJECTIVE

This study investigated the molecular mechanism of ZYP in treating MAFLD through both in vivo and vitro methods.

METHODS

A murine MAFLD model was induced by a high-fat, high-fructose diet for 12 weeks. ZYP was administered for 4 weeks, with fenofibrate serving as a positive control. Indicators of lipid metabolism in serum and liver tissue were detected by automatic biochemical analyzer and ELISA, respectively. Histopathological evaluation of liver sections was performed using HE and oil red O staining. Transcriptomics was employed to further investigate the therapeutic mechanism of ZYP in MAFLD. Additionally, macrophages and their polarization in the liver were analyzed using ELISA, flow cytometry, immunohistochemistry, and immunofluorescence (IF). Candidate proteins and pathways were validated in vivo and in vitro by western blotting and IF. Validation of the pathway was performed in vitro using inhibitors and co-culture strategies.

RESULTS

ZYP significantly improved obesity and hepatic steatosis in MAFLD mice, reducing body/liver weight and regulating lipid metabolism indicators in serum and liver tissue. Bioinformatics analysis of transcriptomic data highlighted lipid metabolism regulation and inflammation control as key effects of ZYP in treating MAFLD. The in vivo experimental results showed that ZYP inhibited M1 polarization of macrophages (pro-inflammatory) and promoted M2 polarization of macrophages (anti-inflammatory) in MAFLD mice. Further in vivo and vitro experiments indicated that ZYP competes with LPS to bind to Toll-like receptor 4 (TLR4), suppressing M1 polarization in liver macrophages, and improving MAFLD. The in vitro co-culture system also confirmed that ZYP reduces liver lipid deposition by modulating M1 macrophage polarization.

CONCLUSIONS

ZYP alleviates MAFLD by inhibiting M1 polarization of liver macrophages, indicating that ZYP may be a promising treatment for MAFLD. Its mechanism of action is to inhibit the TLR4/MyD88/TRAF6 signaling pathway, modulate macrophage polarization, and improve inflammatory response.

Nephroprotective potential of robinin to counteract aldicarb induced renal dysfunction via modulating TLR4/MyD88, HMGB1/RAGE, NF-κB pathway: A biochemical and pharmacodynamic approach

The current investigation was conducted to evaluate the nephroprotective potential of robinin (RBN) to avert aldicarb (ALD) induced renal impairments. Thirty-two adult albino rats (Sprague Dawley) were divided into four groups including control, ALD (15 mgkg-1), ALD (15 mgkg-1) + RBN (6 mgkg-1) and RBN (6 mgkg-1) alone treated group. The results of the current study demonstrated that ALD intoxication increased the gene expression of receptor for advanced glycation end products (RAGE), tumor necrosis factor- α (TNF-α), toll-like receptor 4 (TLR4), high mobility group box1 (HMGB1), nuclear factor-kappa B (NF-κB), myeloid differentiation primary response protein 88 (MyD88), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), and interleukin-1β (IL-1β). Moreover, activities of HO-1, GSH, GPx, SOD, GSR, and CAT were suppressed while the levels of ROS and MDA were escalated following the ALD exposure. ALD intoxication upregulated the levels of cystatin C, KIM-1, creatinine, NAG, uric acid, urea, NGAL and BUN while reducing the levels of creatinine clearance in renal tissues. The levels of Bax, Caspase-9 and Caspase-3 were elevated while the levels of Bcl-2 were reduced after ALD administration. Histopathological analysis showed ALD disrupted the normal architecture of renal tissues. However, RBN therapy substantially protected the renal tissues owing to its antioxidative, anti-inflammatory and anti-apoptotic potential.

Macronutrient Modulation in Metabolic Dysfunction-Associated Steatotic Liver Disease-the Molecular Role of Fatty Acids compared with Sugars in Human Metabolism and Disease Progression

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a significant public health concern, with its progression to metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis leading to severe outcomes including cirrhosis, hepatocellular carcinoma, and liver failure. Whereas obesity and excess energy intake are well-established contributors to the development and progression of MASLD, the distinct role of specific macronutrients is less clear. This review examines the mechanistic pathways through which dietary fatty acids and sugars contribute to the development of hepatic inflammation and fibrosis, offering a nuanced understanding of their respective roles in MASLD progression. In terms of addressing potential therapeutic options, human intervention studies that investigate whether modifying the intake of dietary fats and carbohydrates affects MASLD progression are reviewed. By integrating this evidence, this review seeks to bridge the gap in the understanding between the mechanisms of macronutrient-driven MASLD progression and the effect of altering the intake of these nutrients in the clinical setting and presents a foundation for future research into targeted dietary strategies for the treatment of the disease.

Dietary inflammatory potential and metabolic (dysfunction)-associated steatotic liver disease and its complications: A comprehensive review

Metabolic (dysfunction)-associated steatotic liver disease (MASLD) represents a spectrum of liver pathologies linked to metabolic syndrome components. Inflammation emerges as a pivotal player in MASLD pathogenesis, initiating and perpetuating hepatic injury. Diet, a modifiable risk factor, influences inflammation levels and MASLD progression. This review synthesizes existing evidence on the association between pro-inflammatory diets, assessed via the Dietary Inflammatory Index (DII) and Empirical Dietary Inflammatory Potential (EDIP), and MASLD. Evidence suggests a significant association between higher DII/EDIP scores and MASLD risk, with studies revealing a positive correlation between inflammatory diet intake and MASLD occurrence, particularly in males. However, inconsistencies exist regarding the influence of body mass index (BMI) on this association and criticisms regarding adjustment for BMI and reliance on surrogate markers necessitate cautious interpretation. Limited data suggest a potential link between dietary inflammatory potential and advanced liver fibrosis and heightened risk of hepatocellular carcinoma (HCC) with increased DII/EDIP scores, albeit requiring further confirmation through gold-standard assessment methods. Dietary-induced inflammation exacerbates MASLD pathogenesis through multiple pathways, including insulin resistance, adipose tissue dysfunction, gut microbiota alterations, and oxidative stress, culminating in hepatic steatosis, inflammation, and fibrosis. Further research utilizing robust methodologies is imperative to confirm these findings and elucidate underlying mechanisms, thus informing targeted dietary interventions for MASLD management.

Polyphenols synergistic drugs to ameliorate non-alcoholic fatty liver disease via signal pathway and gut microbiota: A review

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with an increasing incidence worldwide. Single drug therapy may have toxic side effects and disrupt gut microbiota balance. Polyphenols are widely used in disease intervention due to their distinctive nutritional properties and medicinal value, which a potential gut microbiota modulator. However, there is a lack of comprehensive review to explore the efficacy and mechanism of combined therapy with drugs and polyphenols for NAFLD.

AIM OF REVIEW

Based on this, this review firstly discusses the link between NAFLD and gut microbiota, and outlines the effects of polyphenols and drugs on gut microbiota. Secondly, it examined recent advances in the treatment and intervention of NAFLD with drugs and polyphenols and the therapeutic effect of the combination of the two. Finally, we highlight the underlying mechanisms of polyphenol combined drug therapy in NAFLD. This is mainly in terms of signaling pathways (NF-κB, AMPK, Nrf2, JAK/STAT, PPAR, SREBP-1c, PI3K/Akt and TLR) and gut microbiota. Furthermore, some emerging mechanisms such as microRNA potential biomarker therapies may provide therapeutic avenues for NAFLD.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Drawing inspiration from combination drug strategies, the use of active substances in combination with drugs for NAFLD intervention holds transformative and prospective potential, both improve NAFLD and restore gut microbiota balance while reducing the required drug dosage. This review systematically discusses the bidirectional interactions between gut microbiota and NAFLD, and summarizes the potential mechanisms of polyphenol synergistic drugs in the treatment of NAFLD by modulating signaling pathways and gut microbiota. Future researches should develop multi-omics technology to identify patients who benefit from polyphenols combination drugs and devising individualized treatment plans to enhance its therapeutic effect.

The relationship between nonalcoholic fatty liver disease and frailty: A systematic review and meta-analysis

BACKGROUND AND AIM

Frailty is frequently observed in end-stage liver disease of various etiologies, but its role in nonalcoholic fatty liver disease (NAFLD) remains incompletely understood. We aimed to conduct a systematic review and meta-analysis to assess the association and prevalence of frailty in NAFLD.

METHODS

A systematic review of PubMed/MEDLINE, EMBASE, Web of Science, and Scopus was performed. The random-effects model was used to estimate the pooled prevalence of frailty. Meta-analyzed odds ratios (OR) were calculated to examine the association between frailty and NAFLD.

RESULTS

Among the initial 430 articles identified, 18 studies were included. Three studies involving 3673 participants had a pooled OR of 2.03 (95% CI: 1.51-2.72; Iˆ2 = 1.1%; p < 0.0001) for the association between frailty and NAFLD. The pooled prevalence of frailty in individuals with NAFLD was 23% (95% CI: 13%-38%; Iˆ2 = 93.5%) using the liver frailty index (LFI) and 8% (95% CI: 3%-21%; Iˆ2 = 98.1%) using the Fried frailty index (FFI). NAFLD patients' mean grip strength and balance time were 26.4 kg (95% CI: 23.0-29.8) and 23s (95% CI: 10-35), respectively. Among studies that also included individuals with liver cirrhosis, grip strength was lower in those with cirrhosis vs. the broader population of those with NAFLD.

CONCLUSIONS

Our study suggests that frailty is highly prevalent in individuals with NAFLD, with a significantly higher prevalence compared to those without NAFLD. Individuals with NAFLD have more than two-fold increased odds of frailty. Assessing frailty in NAFLD patients enables targeted management to improve outcomes.

Prevention of fenitrothion induced hepatic toxicity by saponarin via modulating TLR4/MYD88, JAK1/STAT3 and NF-κB signaling pathways

Fenitrothion (FEN) is an organophosphate insecticidal agent that is considered as major source of organs toxicity. Saponarin (SAP) is a naturally occurring novel flavone that exhibits a wide range of medicinal properties. The current trial was conducted to evaluate the ameliorative potential of SAP against FEN instigated liver toxicity in rats. Thirty-two male albino rats were apportioned into four groups including control, FEN (10 mg/kg), FEN (10 mg/kg) + SAP (80 mg/kg), and SAP (80 mg/kg) alone treated group. It was revealed that FEN administration upregulated the gene expression of TNF-α, TLR4, IL-1β, MYD88, IL-6, TRAF6, COX-2, NF-κB, JAK1 and STAT3 while reducing the gene expression of IκB. Moreover, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) were increased while the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme-oxygenase-1 (HO-1) and glutathione reductase (GSR) were decreased after FEN exposure. Furthermore, FEN administration notably escalated the levels of hepatic enzymes including alanine transaminase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) whereas reduced the levels of total proteins and albumin. Besides, FEN intake upregulated the levels of Caspase-9, Bax and Caspase-3 while reducing the levels of Bcl-2. Hepatic histology was impaired after FEN intoxication. Nonetheless, SAP treatment remarkably protected the normal state of liver via regulating abovementioned irregularities. Our in-silico analysis confirmed that SAP hold that potential to interact with binding pocket of these proteins, highlighting its ability as a therapeutic compound to alleviate FEN-induced liver damage.

Inter-organ metabolic interaction networks in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multisystem metabolic disorder, marked by abnormal lipid accumulation and intricate inter-organ interactions, which contribute to systemic metabolic imbalances. NAFLD may progress through several stages, including simple steatosis (NAFL), non-alcoholic steatohepatitis (NASH), cirrhosis, and potentially liver cancer. This disease is closely associated with metabolic disorders driven by overnutrition, with key pathological processes including lipid dysregulation, impaired lipid autophagy, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and local inflammation. While hepatic lipid metabolism in NAFLD is well-documented, further research into inter-organ communication mechanisms is crucial for a deeper understanding of NAFLD progression. This review delves into intrahepatic networks and tissue-specific signaling mediators involved in NAFLD pathogenesis, emphasizing their impact on distal organs.

New Insights into AMPK, as a Potential Therapeutic Target in Metabolic Dysfunction-Associated Steatotic Liver Disease and Hepatic Fibrosis

AMP-activated protein kinase (AMPK) activators have garnered significant attention for their potential to prevent the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) into liver fibrosis and to fundamentally improve liver function. The broad spectrum of pathways regulated by AMPK activators makes them promising alternatives to conventional liver replacement therapies and the limited pharmacological treatments currently available. In this study, we aim to illustrate the newly detailed multiple mechanisms of MASLD progression based on the multiple-hit hypothesis. This model posits that impaired lipid metabolism, combined with insulin resistance and metabolic imbalance, initiates inflammatory cascades, gut dysbiosis, and the accumulation of toxic metabolites, ultimately promoting fibrosis and accelerating MASLD progression to irreversible hepatocellular carcinoma (HCC). AMPK plays a multifaceted protective role against these pathological conditions by regulating several key downstream signaling pathways. It regulates biological effectors critical to metabolic and inflammatory responses, such as SIRT1, Nrf2, mTOR, and TGF-β, through complex and interrelated mechanisms. Due to these intricate connections, AMPK's role is pivotal in managing metabolic and inflammatory disorders. In this review, we demonstrate the specific roles of AMPK and its related pathways. Several agents directly activate AMPK by binding as agonists, while some others indirectly activate AMPK by modulating upstream molecules, including adiponectin, LKB1, and the AMP: ATP ratio. As AMPK activators can target each stage of MASLD progression, the development of AMPK activators offers immense potential to expand therapeutic strategies for liver diseases such as MASH, MASLD, and liver fibrosis.

From adiposity to steatosis: metabolic dysfunction-associated steatotic liver disease, a hepatic expression of metabolic syndrome - current insights and future directions

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing health concern and the risk of its development is connected with the increasing prevalence of metabolic syndrome (MetS) which occurs as a result of some complex obesity-induced metabolic changes. It is a common chronic liver disease characterized by excessive fat accumulation in the liver, the tendency to progress to more severe forms, and a corresponding increase in morbidity and mortality. Thus, effectively addressing the rising burden of the disease requires a thorough understanding of its complex interrelationship with obesity and MetS.

MAIN BODY

MASLD results from complex interactions involving obesity, insulin resistance, and dyslipidaemia, leading to hepatic lipid accumulation, and is influenced by several genetic and environmental factors such as diet and gut microbiota dysbiosis. It has extensive metabolic and non-metabolic implications, including links to MetS components like hyperglycaemia, hypertension, and dyslipidaemia, and progresses to significant liver damage and other extra-hepatic risks like cardiovascular disease and certain cancers. Diagnosis often relies on imaging and histology, with non-invasive methods preferred over liver biopsies. Emerging biomarkers and OMIC technologies offer improved diagnostic capabilities but face practical challenges. Advancements in artificial intelligence (AI), lifestyle interventions, and pharmacological treatments show promise, with future efforts focusing on precision medicine and novel diagnostic tools to improve patient outcome.

CONCLUSION

Understanding the pathogenic mechanisms underlying the development of MASLD within the context of metabolic syndrome (MetS) is essential for identifying potential therapeutic targets. Advancements in non-invasive diagnostic tools and novel pharmacological treatments, hold promise for improving the management of MASLD. Future research should focus on precision medicine and innovative therapies to effectively address the disease and its consequences.

Glucose-lowering drugs and liver-related outcomes among individuals with type 2 diabetes: A systematic review of longitudinal population-based studies

AIMS

While randomized controlled trials data on the long-term effect of glucose-lowering drugs (GLDs) on liver-related outcomes are lacking, population-based studies have evaluated the associations of GLDs with liver-related outcomes in individuals with type 2 diabetes (T2D). we aimed to conduct a systematic review of population-based studies evaluating the effects of GLDs on liver-related outcomes in people with T2D.

METHODS

PubMed, Web of Science, and Embase databases were systematically searched for population-based studies testing the associations of GLDs with liver-related outcomes in individuals with T2D and no liver disease other than non-alcoholic fatty liver disease (NAFLD) from inception to 23 February 2024. GLDs included SGLT2is, TZDs, insulin, GLP-1 RAs and dipeptidyl peptidase-4 inhibitors (DPP4Is).

RESULTS

Ten cohort studies, comprising 1,274,641 participants, met the inclusion criteria. The median follow-up period ranged from 8.9 to 76 months. Of all the GLDs under investigation, SGLT2is were associated with the strongest reduction in NAFLD incidence, cirrhosis, and composite liver-related events compared to other medications. TZDs were associated with a reduced risk of developing NAFLD and cirrhosis but were not significantly associated with a lower incidence of hepatocellular carcinoma. GLP-1 RAs demonstrated a significant association with reduced liver-related mortality.

CONCLUSIONS

Observational data from population-based studies suggest that GLDs such as SGLT2is are associated with beneficial long-term liver-related outcomes in T2D patients with NAFLD. Additional studies, including randomized controlled trials with long-term follow-up, are needed to confirm these findings.

REGISTRATION NUMBER

PROSPERO CRD442024536872.

Metabolic Dysfunction-Associated Steatotic Liver Disease: The Associations between Inflammatory Markers, TLR4, and Cytokines IL-17A/F, and Their Connections to the Degree of Steatosis and the Risk of Fibrosis

Background: The pathogenesis of MASLD (metabolic dysfunction-associated steatotic liver disease) is driven by environmental, genetic, metabolic, immune, and inflammatory factors. IL-17 and TLR4 determine hepatic steatosis, inflammation, and finally fibrosis. Objectives: To explore the associations between the plasma levels of inflammatory markers, TLR4, and the cytokines IL17A/F, as well as their connections with the degree of hepatic steatosis and the risk of hepatic fibrosis (defined by the FIB-4 score) in MASLD patients. Methods: The study cohort included 80 patients diagnosed with MASLD. The IL-17A/F and TLR4 serum concentrations were determined using the ELISA method. Results: We found a significant difference in the CAR levels (C-reactive protein to albumin ratio) when comparing MASLD patients with severe steatosis to those with mild/moderate steatosis (Student's t test, t (71) = 2.32, p = 0.023). The PIV (pan-immune inflammatory value) was positively correlated with the SII (systemic immune inflammation index), (r = 0.86, p < 0.0001) and the CAR (r = 0.41, p = 0.033) in MASLD patients with severe steatosis. In contrast, increased values of the LMR (lymphocyte to monocyte ratio) were significantly associated, with decreased levels of the SII (ρ = -0.38, p = 0.045). We also found a positive correlation between the CAR and the SII (r = 0.41, p = 0.028). In patients with mild/moderate steatosis, a significant positive correlation was observed between the SII and IL17A (r = 0.36, p = 0.010), the PIV and the CAR (r = 0.29, p = 0.011), the PIV and the SII (r = 0.87, p < 0.0001) and the PIV and IL17A (r = 0.3, p = 0.036). A negative correlation was observed between the LMR and the SII (r = -0.55, p < 0.0001) and the CAR and IL17F (r = -0.37, p = 0.011). Regarding the inflammatory markers, the PIV (336.4 vs. 228.63, p = 0.0107), and the SII (438.47 vs. 585.39, p = 0.0238) had significantly lower levels in patients with an intermediate-high risk of hepatic fibrosis as compared with the patients with a low risk of hepatic fibrosis. The PNI (prognostic nutritional index) (47.16 vs. 42.41, p = 0.0392) had significantly different levels in patients with the likelihood of hepatic fibrosis than those with a low risk of hepatic fibrosis. Conclusions: Regarding the inflammatory markers, the PIV and the SII hold promise as biomarkers for discriminating between MASLD patients with an intermediate-high risk and those with a low risk of hepatic fibrosis. Our findings underscore the role of IL-17A and its potential relationship with inflammatory markers in MASLD pathogenesis and the progression to hepatic fibrosis.

Protective effects of 17-β-estradiol on liver injury: The role of TLR4 signaling pathway and inflammatory response

Liver injury, a major global health issue, stems from various causes such as alcohol consumption, nonalcoholic steatohepatitis, obesity, diabetes, metabolic syndrome, hepatitis, and certain medications. The liver's unique susceptibility to ischemia and hypoxia, coupled with the critical role of the gut-liver axis in inflammation, underscores the need for effective therapeutic interventions. The study highlights E2's interaction with estrogen receptors (ERs) and its modulation of the Toll-like receptor 4 (TLR4) signaling pathway as key mechanisms in mitigating liver injury. Activation of TLR4 leads to the release of pro-inflammatory cytokines and chemokines, exacerbating liver inflammation and injury. E2 down-regulates TLR4 expression, reduces oxidative stress, and inhibits pro-inflammatory cytokines, thereby protecting the liver. Both classic (ERα and ERβ) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are influenced by E2. ERα is particularly crucial for liver regeneration, preventing liver failure by promoting hepatocyte proliferation. Furthermore, E2 exerts anti-inflammatory, antioxidant, and anti-apoptotic effects by inhibiting cytokines such as IL-6, IL-1β, TNF-α, and IL-17, and by reducing lipid peroxidation and free radical damage. The article calls for further clinical research to validate these findings and to develop estrogen-based treatments for liver injuries. Overall, the research emphasizes the significant potential of E2 as a therapeutic agent for liver injuries. It advocates for extensive clinical studies to validate E2 hepatoprotective properties and develop effective estrogen-based treatments.

Circulating Gut Microbe-Derived Metabolites Are Associated with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. The gut microbiome has been implicated in outcomes for HCC, and gut microbe-derived products may serve as potential non-invasive indices for early HCC detection. This study evaluated differences in plasma concentrations of gut microbiota-derived metabolites.

METHODS

Forty-one patients with HCC and 96 healthy controls were enrolled from surgical clinics at the Cleveland Clinic from 2016 to 2020. Gut microbiota-derived circulating metabolites detectable in plasma were compared between patients with HCC and healthy controls. Hierarchical clustering was performed for generating heatmaps based on circulating metabolite concentrations using ClustVis, with Euclidean and Ward settings and significant differences between metabolite concentrations were tested using a binary logistic regression model.

RESULTS

In patients with HCC, 25 (61%) had histologically confirmed cirrhosis. Trimethylamine (TMA)-related metabolites were found at higher concentrations in those with HCC, including choline (p < 0.001), betaine (p < 0.001), carnitine (p = 0.007), TMA (p < 0.001) and trimethylamine N-oxide (TMAO, p < 0.001). Notably, concentrations of P-cresol glucuronide (p < 0.001), indole-lactic acid (p = 0.038), 5-hydroxyindoleacetic acid (p < 0.0001) and 4-hydroxyphenyllactic acid (p < 0.001) were also increased in those with HCC compared to healthy controls. Hierarchical clustering of the metabolite panel separated patients based on the presence of HCC (p < 0.001), but was not able to distinguish between patients with HCC based on the presence of cirrhosis (p = 0.42).

CONCLUSIONS

Gut microbiota-derived metabolites were differentially abundant in patients with HCC versus healthy controls. The observed perturbations of the TMAO pathway in HCC seem particularly promising as a target of future research and may have both diagnostic and therapeutic implications.

Emerging mechanisms of non-alcoholic steatohepatitis and novel drug therapies

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of chronic liver disease globally. It initiates with simple steatosis (NAFL) and can progress to the more severe condition of non-alcoholic steatohepatitis (NASH). NASH often advances to end-stage liver diseases such as liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Notably, the transition from NASH to end-stage liver diseases is irreversible, and the precise mechanisms driving this progression are not yet fully understood. Consequently, there is a critical need for the development of effective therapies to arrest or reverse this progression. This review provides a comprehensive overview of the pathogenesis of NASH, examines the current therapeutic targets and pharmacological treatments, and offers insights for future drug discovery and development strategies for NASH therapy.

HDAC6 inhibitor ACY-1215 protects from nonalcoholic fatty liver disease via inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by hepatic steatosis, for which there is currently no effective treatment. ACY-1215 is a selective inhibitor of histone deacetylation 6, which has shown therapeutic potential in many tumors, as well as acute liver injury. However, no research about ACY-1215 on NAFLD has been published. Therefore, our study aims to explore the role and mechanism of ACY-1215 in the experimental model of NAFLD, to propose a new treatment strategy for NAFLD.

METHODS

We established cell and animal models of NAFLD and verified the effect of ACY-1215 on NAFLD. The mechanism of ACY-1215 on NAFLD was preliminarily explored through TMT relative quantitative proteomics, and then we verify the mechanism discovered in the experimental model of NAFLD.

RESULTS

ACY-1215 can reduce lipid aggregation, IL-1β, and TNF α mRNA levels in liver cells in vitro. ACY-1215 can reduce the weight gain and steatosis in the liver of the NAFLD mouse model, alleviate the deterioration of liver function, and reduce IL-1βs and TNF α mRNA levels in hepatocytes. TMT relative quantitative proteomics found that ACY-1215 decreased the expression of CD14 in hepatocytes. It was found that ACY-1215 can inhibit the activation level of CD14/TLR4/MyD88/MAPK/NFκB pathway in the NAFLD experimental model.

CONCLUSIONS

ACY-1215 has a protective effect on the cellular model of NAFLD induced by fatty acids and lipopolysaccharide, as well as the C57BL/6J mouse model induced by a high-fat diet. ACY-1215 may play a protective role by inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway.

The current landscape of antifibrotic therapy across different organs: A systematic approach

Fibrosis is a common pathological process that can affect virtually all the organs, but there are hardly any effective therapeutic options. This has led to an intense search for antifibrotic therapies over the last decades, with a great number of clinical assays currently underway. We have systematically reviewed all current and recently finished clinical trials involved in the development of new antifibrotic drugs, and the preclinical studies analyzing the relevance of each of these pharmacological strategies in fibrotic processes affecting tissues beyond those being clinically studied. We analyze and discuss this information with the aim of determining the most promising options and the feasibility of extending their therapeutic value as antifibrotic agents to other fibrotic conditions.

Effects of Metabolic Dysfunction-Associated Steatotic Liver Disease on Bone Density and Fragility Fractures: Associations and Mechanisms

Metabolic dysfunction-associated steatotic liver disease (MASLD) has profound adverse effects on bone health and homeostasis. MASLD appears to be associated with changes in bone mineral density (BMD) and fracture rate. However, the data are ambiguous and conflicting. Although several studies have shown that children and adolescents with MASLD have decreased BMD, the data on the prevalence of fragility fractures among children are scarce. In adults, increasing evidence suggests that MASLD decreases BMD and increases the risk of fragility fractures, which appears to be due to deterioration of bone architecture in addition to a decrease in BMD. Effects of MASLD on bone health may also be age- and race-specific. MASLD does not seem to increase fracture risk in children and adolescents but increases the risk of fractures in elderly men, especially those of Asian origin. From a mechanistic perspective, bone remodeling is a continuous process between osteoblasts (bone-forming) and osteoclasts (bone-resorbing), with any imbalance resulting in metabolic bone disease. In individuals with MASLD, loss of anabolic insulin receptor signaling (insulin resistance) in osteoblasts and increased receptor activator of nuclear factor κB (RANK)/RANK ligand signaling in osteoclasts (proinflammatory cytokines) swings the pendulum toward accelerated bone loss. These processes are further complicated by the concomitant presence of obesity, type 2 diabetes mellitus, or sarcopenia in individuals with MASLD. This study reviews the current literature associated with the effects of MASLD on BMD and fragility fractures in children/adolescents and adults. This review also discusses the pathomechanisms that link MASLD with changes in BMD and fragility fractures.

Role of pattern recognition receptors in the development of MASLD and potential therapeutic applications

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become one of the most prevalent liver diseases worldwide, and its occurrence is strongly associated with obesity, insulin resistance (IR), genetics, and metabolic stress. Ranging from simple fatty liver to metabolic dysfunction-associated steatohepatitis (MASH), even to severe complications such as liver fibrosis and advanced cirrhosis or hepatocellular carcinoma, the underlying mechanisms of MASLD progression are complex and involve multiple cellular mediators and related signaling pathways. Pattern recognition receptors (PRRs) from the innate immune system, including Toll-like receptors (TLRs), C-type lectin receptors (CLRs), NOD-like receptors (NLRs), RIG-like receptors (RLRs), and DNA receptors, have been demonstrated to potentially contribute to the pathogenesis for MASLD. Their signaling pathways can induce inflammation, mediate oxidative stress, and affect the gut microbiota balance, ultimately resulting in hepatic steatosis, inflammatory injury and fibrosis. Here we review the available literature regarding the involvement of PRR-associated signals in the pathogenic and clinical features of MASLD, in vitro and in animal models of MASLD. We also discuss the emerging targets from PRRs for drug developments that involved agent therapies intended to arrest or reverse disease progression, thus enabling the refinement of therapeutic targets that can accelerate drug development.

Dried tangerine peel polysaccharide (DTPP) alleviates hepatic steatosis by suppressing TLR4/MD-2-mediated inflammation and endoplasmic reticulum stress

Non-alcoholic fatty liver disease (NAFLD) is a complex pathogenic metabolic syndrome characterized by increased inflammation and endoplasmic reticulum stress. In recent years, natural polysaccharides derived from traditional Chinese medicine have shown significant anti-inflammatory effects, making them an attractive therapeutic option. However, little research has been conducted on the therapeutic potential of dried tangerine peel polysaccharide (DTPP) - one of the most important medicinal resources in China. The results of the present study showed that DTPP substantially reduced macrophage infiltration in vivo and suppressed the expression of pro-inflammatory factors and endoplasmic reticulum stress-related genes. Additionally, surface plasmon resonance analysis revealed that DTPP had a specific affinity to myeloid differentiation factor 2, which consequently suppressed lipopolysaccharide-induced inflammation via interaction with the toll-like receptor 4 signaling pathway. This study provides a potential molecular mechanism underlying the anti-inflammatory effects of DTPP on NAFLD and suggests DTPP as a promising therapeutic strategy for NAFLD treatment.

Effect and mechanism of quercetin or quercetin-containing formulas against COVID-19: From bench to bedside

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global coronavirus disease 2019 (COVID-19) pandemic since 2019. Immunopathogenesis and thromboembolic events are central to its pathogenesis. Quercetin exhibits several beneficial activities against COVID-19, including antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antithrombotic effects. Although several reviews have been published, these reviews are incomplete from the viewpoint of translational medicine. The authors comprehensively evaluated the evidence of quercetin against COVID-19, both basically and clinically, to apply quercetin and/or its derivatives in the future. The authors searched the PubMed, Embase, and the Cochrane Library databases without any restrictions. The search terms included COVID-19, SARS-CoV-2, quercetin, antiviral, anti-inflammatory, immunomodulatory, thrombosis, embolism, oxidative, and microbiota. The references of relevant articles were also reviewed. All authors independently screened and reviewed the quality of each included manuscript. The Cochrane Risk of Bias Tool, version 2 (RoB 2) was used to assess the quality of the included randomized controlled trials (RCTs). All selected studies were discussed monthly. The effectiveness of quercetin against COVID-19 is not solid due to methodological flaws in the clinical trials. High-quality studies are also required for quercetin-containing traditional Chinese medicines. The low bioavailability and highly variable pharmacokinetics of quercetin hinder its clinical applications. Its positive impact on immunomodulation through reverting dysbiosis of gut microbiota still lacks robust evidence. Quercetin against COVID-19 does not have tough clinical evidence. Strategies to improve its bioavailability and/or to develop its effective derivatives are needed. Well-designed RCTs are also crucial to confirm their effectiveness in the future.

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

Punicic acid ameliorates obesity-related hyperlipidemia and fatty liver in mice via regulation of intestinal flora and lipopolysaccharide-related signaling pathways

Punicic acid (PA), mainly found in pomegranate seed oil (PSO), has attracted increasing attention due to its potential to mitigate obesity. The regulation of intestinal microflora was identified as a crucial factor and an effective strategy to reverse obesity-related hyperlipidemia and non-alcoholic fatty liver disease (NAFLD). To assess the impact of PSO on hyperlipidemia related to obesity, we investigated the hepatic lipid status and gut microbiota regulation in mice over 13 weeks of feeding a high-fructose high-fat diet (HFHFD). Serum lipid markers, including TG, TC and LDL-C, were markedly reduced in hyperlipidemic mice. PSO supplementation reduced hepatic lipid accumulation and steatosis, inhibited the expression of pro-inflammatory mediators (including IL-6 and IL-1β), and restored the normal levels of the anti-inflammatory cytokine IL-10. In addition, PSO also alleviated oxidative stress and increased T-AOC and SOD activities, as well as GSH levels, while reducing the MDA content in the liver of HFHFD-fed mice. The activation of TLR4/MyD88/NF-κB and TLR4/IL-22/STAT3 signaling pathways in the liver due to the HFHFD was also evidently inhibited by PSO. Furthermore, supplementation of PSO ameliorated the HFHFD-induced dysbiosis of intestinal microflora, resulting in a markedly increased proportion of Muribaculaceae, a decreased ratio of Blautia, and elevated levels of microbiota-derived short-chain fatty acids (SCFAs). Moreover, the expression of tight junction proteins correlated with intestinal barrier function was notably restored in the colon. The collected results indicate that PSO may be an effective nutraceutical ingredient for attenuating lipid metabolic disorders.

Gut microbiota induced epigenetic modifications in the non-alcoholic fatty liver disease pathogenesis

Non-alcoholic fatty liver disease (NAFLD) represents a growing global health concern that can lead to liver disease and cancer. It is characterized by an excessive accumulation of fat in the liver, unrelated to excessive alcohol consumption. Studies indicate that the gut microbiota-host crosstalk may play a causal role in NAFLD pathogenesis, with epigenetic modification serving as a key mechanism for regulating this interaction. In this review, we explore how the interplay between gut microbiota and the host epigenome impacts the development of NAFLD. Specifically, we discuss how gut microbiota-derived factors, such as lipopolysaccharides (LPS) and short-chain fatty acids (SCFAs), can modulate the DNA methylation and histone acetylation of genes associated with NAFLD, subsequently affecting lipid metabolism and immune homeostasis. Although the current literature suggests a link between gut microbiota and NAFLD development, our understanding of the molecular mechanisms and signaling pathways underlying this crosstalk remains limited. Therefore, more comprehensive epigenomic and multi-omic studies, including broader clinical and animal experiments, are needed to further explore the mechanisms linking the gut microbiota to NAFLD-associated genes. These studies are anticipated to improve microbial markers based on epigenetic strategies and provide novel insights into the pathogenesis of NAFLD, ultimately addressing a significant unmet clinical need.

Effects of Berberine on Lipid Metabolism, Antioxidant Status, and Immune Response in Liver of Tilapia (Oreochromis niloticus) under a High-Fat Diet Feeding

Berberine, a natural alkaloid found abundantly in various medicinal plants, exhibits antioxidative, anti-inflammatory, and lipid metabolism-regulatory properties. Nonetheless, its protective effects and the molecular mechanisms underlying liver injury in fish have not been fully elucidated. The aims of this study were to investigate the antioxidative, anti-inflammatory, and lipid metabolism-regulating effects of berberine against high-fat diet (HFD)-induced liver damage and to clarify the underlying molecular mechanisms. Tilapia were fed diets containing two doses of berberine (50 and 100 mg/kg diet) alongside high fat for 60 days. The results showed that berberine treatments (50 and/or 100 mg/kg) significantly reduced elevated aminotransferases, triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) in the plasma. In the liver, berberine treatments significantly increased the expression of peroxisome proliferator-activated receptor α (pparα) and carnitine palmitoyltransferase 1 (cpt-1) genes, leading to a reduction in lipid accumulation. Meanwhile, berberine treatment suppressed lipid peroxidation formation and enhanced antioxidant capacity. Berberine upregulated the mRNA levels of erythroid 2-related factor 2 (nrf2) and its downstream genes including heme oxygenase 1 (ho-1) and glutathione-S-transferase (gstα). Additionally, berberine attenuated the inflammation by inhibiting the expression of toll-like receptor 2 (tlr2), myeloid differential protein-88 (myd88), relb, and inflammatory cytokines such as interleukin-1β (il-1β), tumor necrosis factor-α (tnf-α), and il-8. In summary, this study suggested that berberine offers protection against HFD-induced liver damage in tilapia via regulating lipid metabolism, antioxidant status, and immune response. This protective effect may be attributed to the modulation of the Nrf2, TLR2/MyD88/NF-κB, and PPARα signaling pathways.

Gut microbiota in MAFLD: therapeutic and diagnostic implications

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is becoming a significant contributor to chronic liver disease globally, surpassing other etiologies, such as viral hepatitis. Prevention and early treatment strategies to curb its growing prevalence are urgently required. Recent evidence suggests that targeting the gut microbiota may help treat and alleviate disease progression in patients with MAFLD. This review aims to explore the complex relationship between MAFLD and the gut microbiota in relation to disease pathogenesis. Additionally, it delves into the therapeutic strategies targeting the gut microbiota, such as diet, exercise, antibiotics, probiotics, synbiotics, glucagon-like peptide-1 receptor agonists, and fecal microbiota transplantation, and discusses novel biomarkers, such as microbiota-derived testing and liquid biopsy, for their diagnostic and staging potential. Overall, the review emphasizes the urgent need for preventive and therapeutic strategies to address the devastating consequences of MAFLD at both individual and societal levels and recognizes that further exploration of the gut microbiota may open avenues for managing MAFLD effectively in the future.

Metabolic-Associated Steatotic Liver Disease (MASLD): A New Term for a More Appropriate Therapy in Pediatrics?

The term "non-alcoholic fatty liver disease" (NAFLD) has been, for a long time, used to describe the spectrum of liver lesions encompassing steatosis, steatohepatitis (NASH), and steatotic cirrhosis [...].

Polyethylene microplastics induced gut microbiota dysbiosis leading to liver injury via the TLR2/NF-κB/NLRP3 pathway in mice

Microplastics (MPs) are ubiquitous environmental contaminants that have negative impacts on health and safety. The gut microbiota plays multiple roles as a newly discovered virtual metabolic organ. The objective of this study was to investigate the potential of MPs to cause liver injury by disrupting the balance of gut microbiota. The results indicated that exposure to MPs resulted in liver damage and disrupted the homeostasis of gut microbiota. MPs significantly reduced the liver organ coefficient, leading to liver cell injury and impaired function. Additionally, there was an increase in the expression of fibril-related proteins, which positively correlated with MPs concentration. Furthermore, MPs increased the relative abundances of Desulfovibrio, Clostridia, Enterorhabdus, Bacteroides, and Gemella while decreasing the abundance of Dubosoella. Different concentrations of MPs exhibited varying effects on specific bacterial groups, however, both concentrations resulted in an increase in pathogenic bacteria and a decrease in beneficial bacteria, as well as alterations in microbial structure. Moreover, MPs induced oxidative stress, inflammation, apoptosis and necrosis in liver cells. The study found that MPs disrupted gut microbiota homeostasis and activated TLR2/NF-κB/NLRP3 pathway in the liver, providing a new insight into the mechanism underlying MPs-induced liver injury. These findings serve as a warning regarding environmental pollution caused by MPs.

Network pharmacological analysis on the mechanism of Linggui Zhugan decoction for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), represents a chronic progressive disease that imposes a significant burden on patients and the healthcare system. Linggui Zhugan decoction (LGZGD) plays a substantial role in treating NAFLD, but its exact molecular mechanism is unknown. Using network pharmacology, this study aimed to investigate the mechanism of action of LGZGD in treating NAFLD. Active ingredients and targets were identified through the integration of data from the TCMSP, GEO, GeneCards, and OMIM databases. Cytoscape 3.9.1 software, in conjunction with the STRING platform, was employed to construct network diagrams and screen core targets. The enrichment analysis of gene ontology and the Kyoto Encyclopedia of Genes and Genomes pathways were conducted by using the R. Molecular docking of the active ingredients and core targets was performed with AutoDock Vina software. We obtained 93 and 112 active ingredients and potential targets using the bioinformatic analysis of LGZGD in treating NAFLD. The primary ingredients of LGZGD included quercetin, kaempferol, and naringenin. The core targets were identified AKT1, MYC, HSP90AA1, HIF1A, ESR1, TP53, and STAT3. Gene ontology function enrichment analysis revealed associations with responses to nutrient and oxygen levels, nuclear receptor activity, and ligand-activated transcription factor activity. Kyoto Encyclopedia of Genes and Genomes signaling pathway analysis implicated the involvement of the PI3K-Akt, IL-17, TNF, Th17 cell differentiation, HIF-1, and TLR signaling pathways. Molecular docking studies indicated strong binding affinities between active ingredients and targets. LGZGD intervenes in NAFLD through a multi-ingredient, multi-target, and multi-pathway approach. Treatment with LGZGD can improve insulin resistance, oxidative stress, inflammation, and lipid metabolism associated with NAFLD.

Fecal microbiota transplantation for treatment of non-alcoholic fatty liver disease: Mechanism, clinical evidence, and prospect

The population of non-alcoholic fatty liver disease (NAFLD) patients along with relevant advanced liver disease is projected to continue growing, because currently no medications are approved for treatment. Fecal microbiota transplantation (FMT) is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease. There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment, however, existing findings diverge on its effects. Herein, we briefly summarized the mechanism of FMT for NAFLD treatment, reviewed randomized controlled trials for evaluating its efficacy in NAFLD, and proposed the prospect of future trials on FMT.

Lipotoxicity and immunometabolism in ischemic acute kidney injury: current perspectives and future directions

Dysregulated lipid metabolism is implicated in the pathophysiology of a range of kidney diseases. The specific mechanisms through which lipotoxicity contributes to acute kidney injury (AKI) remain poorly understood. Herein we review the cardinal features of lipotoxic injury in ischemic kidney injury; lipid accumulation and mitochondrial lipotoxicity. We then explore a new mechanism of lipotoxicity, what we define as "immunometabolic" lipotoxicity, and discuss the potential therapeutic implications of targeting this lipotoxicity using lipid lowering medications.

Involvement of Bile Acid Metabolism and Gut Microbiota in the Amelioration of Experimental Metabolism-Associated Fatty Liver Disease by Nobiletin

Metabolism-associated fatty liver disease (MAFLD), a growing health problem worldwide, is one of the major risks for the development of cirrhosis and liver cancer. Oral administration of nobiletin (NOB), a natural citrus flavonoid, modulates the gut microbes and their metabolites in mice. In the present study, we established a mouse model of MAFLD by subjecting mice to a high-fat diet (HFD) for 12 weeks. Throughout this timeframe, NOB was administered to investigate its potential benefits on gut microbial balance and bile acid (BA) metabolism using various techniques, including 16S rRNA sequencing, targeted metabolomics of BA, and biological assays. NOB effectively slowed the progression of MAFLD by reducing serum lipid levels, blood glucose levels, LPS levels, and hepatic IL-1β and TNF-α levels. Furthermore, NOB reinstated diversity within the gut microbial community, increasing the population of bacteria that produce bile salt hydrolase (BSH) to enhance BA excretion. By exploring further, we found NOB downregulated hepatic expression of the farnesoid X receptor (FXR) and its associated small heterodimer partner (SHP), and it increased the expression of downstream enzymes, including cholesterol 7α-hydroxylase (CYP7A1) and cytochrome P450 27A1 (CYP27A1). This acceleration in cholesterol conversion within the liver contributes to mitigating MAFLD. The present findings underscore the significant role of NOB in regulating gut microbial balance and BA metabolism, revealing that long-term intake of NOB plays beneficial roles in the prevention or intervention of MAFLD.

Immunomodulation in non-alcoholic fatty liver disease: exploring mechanisms and applications

Non-alcoholic fatty liver disease (NAFLD) exhibits increased lipid enrichment in hepatocytes. The spectrum of this disease includes stages such as nonalcoholic simple fatty liver (NAFL), nonalcoholic steatohepatitis (NASH), and liver fibrosis. Changes in lifestyle behaviors have been a major factor contributing to the increased cases of NAFLD patients globally. Therefore, it is imperative to explore the pathogenesis of NAFLD, identify therapeutic targets, and develop new strategies to improve the clinical management of the disease. Immunoregulation is a strategy through which the organism recognizes and eliminates antigenic foreign bodies to maintain physiological homeostasis. In this process, multiple factors, including immune cells, signaling molecules, and cytokines, play a role in governing the evolution of NAFLD. This review seeks to encapsulate the advancements in research regarding immune regulation in NAFLD, spanning from underlying mechanisms to practical applications.

Hydrogen gas alleviates acute ethanol-induced hepatotoxicity in mice via modulating TLR4/9 innate immune signaling and pyroptosis

Alcoholic liver disease (ALD), which is induced by chronic heavy alcohol consumption, accompanies complicated pathological mechanisms, including oxidative stress, inflammation, cell death, epigenetic changes and acetaldehyde-mediated toxicity. Hydrogen (H2) is the lightest gas with multiple biological effects such as high selective anti-oxidation, anti-inflammation and anti-apoptosis. However, the dose effects and innate immune mechanisms of intraperitoneal injection of H2 on ALD are limited. Here, we used acute ethanol-induced hepatotoxicity mice models to estimate the actions of intraperitoneal injection of H2 on ALD. The effects of H2 on acute ethanol-induced liver damage were examined by hepatic oil red O staining, quantitative PCR (qPCR) for lipid metabolic genes, hepatic triglyceride (TG) and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Hepatic mitochondrial superoxide (MitoSOX), 3-nitrotyrosine (3-NT), malondialdehyde (MDA), and glutathione (GSH) levels were examined to evaluate oxidative stress. Immunoblot, and immunofluorescence staining were used to further confirm the innate immune molecular targets of H2. Our results showed that intraperitoneal injection of H2 improved acute ethanol-induced liver injury in mice in a dose dependent manner, as indicated by decreasing serum ALT and AST levels, hepatic TG levels, and increasing lipid export genes (Mttp and Apob) mRNA levels and reducing fatty acid uptake gene (CD36) mRNA levels. Mechanistically, H2 inhibited hepatic oxidative stress as indicated by reducing reactive oxygen species (ROS), 3-NT, and MDA levels in the liver, while increasing hepatic GSH levels; inhibited the overactived TLR4/9-NF-κB-TNF-α/IL-1β/IL-18 innate immune signaling; suppressed the canonical Caspase-1-GSDMD pyroptosis signaling, and the non-canonical pyroptosis signaling, such as Caspase-11-GSDMD, Caspase-8-GSDMD and Caspase-3-GSDME signaling. Therefore, our study highlights that intraperitoneal injection of H2 may represent a novel therapeutic and safe strategy for ALD via modulating oxidative stress, innate immunity and pyroptosis.

Correlation analysis of hepatic steatosis and hepatitis B virus: a cross-sectional study

BACKGROUND

The co-occurrence of chronic hepatitis B (CHB) and metabolic dysfunction-associated fatty liver disease (MAFLD) has drawn considerable attention due to its impact on disease outcomes. This study aimed to investigate the association between hepatic steatosis and hepatitis B virus (HBV) and analyzed the influence of hepatic steatosis on hepatitis B virology in patients with CHB.

METHODS

In this cross-sectional study, 272 patients infected with HBV who were treatment-naïve or had ceased antiviral treatment for > 6 months were categorized into the CHB group (n = 128) and CHB + MAFLD group (n = 144). Furthermore, based on whether HBV DNA was higher than 2000 IU/mL, patients were categorized into the high-level HBV DNA group (n = 129) and the low-level HBV DNA group (n = 143). The impact of hepatic steatosis on hepatitis B virology was analyzed within the CHB cohort. Multivariate logistic regression analysis was employed to identify independent factors influencing pre-genomic RNA (pgRNA) levels below the lower limit of detection (LLD) in patients with CHB.

RESULTS

Among the 272 patients, compared with CHB group, HBV DNA levels (4.11 vs. 3.62 log10 IU/mL, P = 0.045), hepatitis B surface antigen (HBsAg) levels (3.52 vs. 3.20 log10 IU/mL, P = 0.008) and the hepatitis B e antigen (HBeAg) positive rate (33.6% vs. 22.2%, P = 0.036) were significantly decreased in the CHB + MAFLD group; In 143 low-level HBV DNA patients, the CHB + MAFLD group exhibited decreased levels of pgRNA and HBsAg compared to the CHB group. However, in 129 high-level HBV DNA patients, a more significant decrease was observed in pgRNA (3.85 vs 3.35 log10 copies/mL, P = 0.044) and HBsAg (3.85 vs 3.59 log10 IU/mL, P = 0.033); Spearman correlation analysis revealed a negative correlation between hepatic steatosis and pgRNA (r =  - 0.529, P < 0.001), HBV DNA (r =  - 0.456, P < 0.001), HBsAg (r =  - 0.465, P < 0.001) and HBeAg (r =  - 0.339, P < 0.001) levels; Multivariate logistic regression analysis identified HBV DNA (odds ratio [OR] = 0.283, P < 0.001), HBsAg (OR = 0.300, P < 0.001), and controlled attenuation parameter (CAP) values (OR = 1.013, P = 0.038) as independent factors influencing pgRNA levels below the LLD in patients with CHB.

CONCLUSIONS

This study establishes a negative correlation between hepatic steatosis and hepatitis B virology, demonstrating decreased HBV expression in patients with CHB + MAFLD.

Immunology of gut microbiome and liver in non-alcoholic fatty liver disease (NAFLD): mechanisms, bacteria, and novel therapeutic targets

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Most important contributors to its development are diet and obesity. Gut microbiome's importance for immune system and inflammatory pathways more widely accepted as an important component in NAFLD and other liver diseases' pathogenesis. In this article we review potential mechanisms of microbiome alteration of local and systemic immune responses leading to NAFLD's development, and how can modulate them for the treatment. Our review mentions different immune system pathways and microorganisms regulating metabolism, liver inflammation and fibrosis. We specifically point out TLR-4 as a potential key immune pathway activated by bacterial lipopolysaccharides producing pro-inflammatory cytokines in NAFLD. Also, we discuss three endotoxin-producing strains (Enterobacter cloacae B29, Escherichia coli PY102, Klebsiella pneumoniae A7) that can promote NAFLD development via TLR4-dependent immune response activation in animal models and how they potentially contribute to disease progression in humans. Additionally, we discuss their other immune and non-immune mechanisms contributing to NAFLD pathogenesis. In the end we point out gut microbiome researches' future perspective in NAFLD as a potential new target for both diagnostic and treatment.

CARD9 deficiency aggravated nonalcoholic steatohepatitis in mice through increasing inflammatory response

Nonalcoholic steatohepatitis (NASH), a subtype of nonalcoholic fatty liver disease (NAFLD), is the leading cause of liver-related morbidity worldwide. Caspase recruitment domain family member 9 (CARD9), a myeloid cell-specific signaling protein, belongs to the CARD protein family. However, its role in NASH is unknown. Therefore, this study aimed to investigate the role of CARD9 in the development of NASH. NASH models were established using CARD9-knockout and wild-type mice. They were either fed a methionine/choline deficient (MCD) diet for 6 weeks or a high-fat high-cholesterol (HFHC) diet for 16 weeks. Liver fibrosis model was also developed using CCl4. CARD9 deficiency accelerated steatohepatitis development in MCD or HFHC diet-fed mice, accompanied by an upregulation of fibrosis, adipogenesis, and proinflammatory genes. CARD9 deficiency was found to exacerbate CCl4-induced liver fibrosis. In vitro studies demonstrated that CARD9 deficiency induced the expression of S100a8/a9 through Toll-like receptor in Kupffer cells treated with palmitate. This led to an increased expression of proinflammatory, fibrosis, and lipid metabolism-related genes in NASH progression. These results highlight the role of CARD9 in the development of NASH and provide new insights into the therapeutic strategies for NASH.

Rotundic acid improves nonalcoholic steatohepatitis in mice by regulating glycolysis and the TLR4/AP1 signaling pathway

BACKGROUND

Steatosis and inflammation are the hallmarks of nonalcoholic steatohepatitis (NASH). Rotundic acid (RA) is among the key triterpenes of Ilicis Rotundae Cortex and has exhibited multipronged effects in terms of lowering the lipid content and alleviating inflammation. The study objective is to systematically evaluate the potential mechanisms through which RA affects the development and progression of NASH.

METHODS

Transcriptomic and proteomic analyses of primary hepatocytes isolated from the control, high-fat diet-induced NASH, and RA treatment groups were performed through Gene Ontology analysis and pathway enrichment. Hub genes were identified through network analysis. Integrative analysis revealed key RA-regulated pathways, which were verified by gene and protein expression studies and cell assays.

RESULTS

Hub genes were identified and enriched in the Toll-like receptor 4 (TLR4)/activator protein-1 (AP1) signaling pathway and glycolysis pathway. RA reversed glycolysis and attenuated the TLR4/AP1 pathway, thereby reducing lipid accumulation and inflammation. Additionally, lactate release in L-02 cells increased with NaAsO2-treated and significantly decreased with RA treatment, thus revealing that RA had a major impact on glycolysis.

CONCLUSIONS

RA is effective in lowering the lipid content and reducing inflammation in mice with NASH by ameliorating glycolysis and TLR4/AP1 pathways, which contributes to the existing knowledge and potentially sheds light on the development of therapeutic interventions for patients with NASH.

Unveiling the role of gut dysbiosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial complicated condition, reflected by the accumulation of extra fat in the liver. A detailed study of literature throws light on the fascinating connection between gut dysbiosis and NAFLD. The term 'gut dysbiosis' describes an imbalance in the harmony and operation of the gut microflora, which can upshoot a number of metabolic disorders. To recognize the underlying mechanisms and determine treatment options, it is essential to comprehend the connection between gut dysbiosis and NAFLD. This in-depth review discusses the normal gut microflora composition and its role in health, alterations in the gut microflora composition that leads to disease state focusing on NAFLD. The potential mechanisms influencing the advent and aggravation of NAFLD suggested disturbance of microbial metabolites, changes in gut barrier integrity, and imbalances in the composition of the gut microflora. Furthermore, it was discovered that gut dysbiosis affected immune responses, liver inflammation, and metabolic pathways, aggravating NAFLD.

Pterostilbene exerts cytotoxicity on activated hepatic stellate cells by inhibiting excessive proliferation through the crosstalk of Sirt1 and STAT3 pathways

Pterostilbene (PTE), a natural analogue of resveratrol, abundantly exists in blueberries and grapes and has several beneficial potentials against oxidative stress, inflammation, and cancer. In current study, we investigated the effects of PTE on hepatic fibrosis in vitro and in vivo. Activation of hepatic stellate cells (HSCs) is an initiating event in the initiation of hepatic fibrosis. MTT assay revealed that PTE (3.125-12.5 μM) displayed cytotoxicity on activated HSCs, no cytotoxicity on AML-12 and quiescent HSCs. PTE significantly inhibited the expressions of α-SMA, collagen Ⅰ and TIMP-1/MMP13 ratio; suppressed inflammatory cascade activation to reduce inflammatory cytokines release, such as Caspase-1, IL-1β and IL-6. PTE activated Sirt1 and decreased STAT3 phosphorylation, functioning as SRT1720 and Niclosamide. Sirt1 deficiency significantly elevated p-STAT3 expression, while STAT3 deficiency resulted in Sirt1 increasing and inhibited fibrosis and inflammatory cytokines expressions. In mice with hepatic fibrosis induced by thioacetamide (TAA), PTE significantly decreased ALT and AST activities, reduced fibrosis markers, STAT3 phosphorylation and activated Sirt1 expression. PTE showed cytotoxicity on activated HSCs to ameliorate hepatic fibrosis via regulating fibrogenesis, energy metabolism and inflammation and targeting the crosstalk of Sirt1 and STAT3. In conclusion, PTE could be potentially beneficial as a natural plant metabolite in preventing and treating hepatic fibrosis.

Targeting gut-liver axis by dietary lignans ameliorate obesity: evidences and mechanisms

An imbalance between energy consumption and energy expenditure causes obesity. It is characterized by increased adipose accumulation and accompanied by chronic low-grade inflammation. Many studies have suggested that the gut microbiota of the host mediates the relationship between high-fat diet consumption and the development of obesity. Diet and nutrition of the body are heavily influenced by gut microbiota. The alterations in the microbiota in the gut may have effects on the homeostasis of the host's energy levels, systemic inflammation, lipid metabolism, and insulin sensitivity. The liver is an important organ for fat metabolism and gut-liver axis play important role in the fat metabolism. Gut-liver axis is a bidirectional relationship between the gut and its microbiota and the liver. As essential plant components, lignans have been shown to have different biological functions. Accumulating evidences have suggested that lignans may have lipid-lowering properties. Lignans can regulate the level of the gut microbiota and their metabolites in the host, thereby affecting signaling pathways related to fat synthesis and metabolism. These signaling pathways can make a difference in inhibiting fat accumulation, accelerating energy metabolism, affecting appetite, and inhibiting chronic inflammation. It will provide the groundwork for future studies on the lipid-lowering impact of lignans and the creation of functional meals based on those findings.

New Insights into the Pathogenesis of Metabolic-Associated Fatty Liver Disease (MAFLD): Gut-Liver-Heart Crosstalk

Metabolism-associated fatty liver disease (MAFLD) is a multifaceted disease that involves complex interactions between various organs, including the gut and heart. It is defined by hepatic lipid accumulation and is related to metabolic dysfunction, obesity, and diabetes. Understanding the intricate interplay of the gut-liver-heart crosstalk is crucial for unraveling the complexities of MAFLD and developing effective treatment and prevention strategies. The gut-liver crosstalk participates in the regulation of the metabolic and inflammatory processes through host-microbiome interactions. Gut microbiota have been associated with the development and progression of MAFLD, and its dysbiosis contributes to insulin resistance, inflammation, and oxidative stress. Metabolites derived from the gut microbiota enter the systemic circulation and influence both the liver and heart, resulting in the gut-liver-heart axis playing an important role in MAFLD. Furthermore, growing evidence suggests that insulin resistance, endothelial dysfunction, and systemic inflammation in MAFLD may contribute to an increased risk of cardiovascular disease (CVD). Additionally, the dysregulation of lipid metabolism in MAFLD may also lead to cardiac dysfunction and heart failure. Overall, the crosstalk between the liver and heart involves a complex interplay of molecular pathways that contribute to the development of CVD in patients with MAFLD. This review emphasizes the current understanding of the gut-liver-heart crosstalk as a foundation for optimizing patient outcomes with MAFLD.