Hepatic steatosis, characterized by fat accumulation in hepatocytes, can result from metabolic dysfunction-associated steatotic liver disease (MASLD), infections, alcoholism, chemotherapy, and toxins. MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction-associated steatohepatitis, potentially leading to fibrosis, cirrhosis, or cancer. The coexistence of hepatic steatosis with chronic hepatitis B (CHB) is mainly related to metabolic factors and increases mortality and cancer risks. As a noninvasive method, attenuation imaging (ATI) shows promise in quantifying liver fat, demonstrating strong correlation with liver biopsy.

To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.

The study enrolled 249 patients who underwent both ATI and liver biopsy, including 78 with CHB and 171 with MASLD. Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present. Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system. The diagnostic performance of attenuation coefficient (AC) values across different groups was compared for each grade of steatosis. Factors associated with the AC values were determined through linear regression analysis. A multivariate logistic regression model was established to predict ≥ S2 within the MASLD group.

In both the CHB and the MASLD groups, AC values increased significantly with higher steatosis grade (P < 0.001). In the CHB group, the areas under the curve (AUCs) of AC for predicting steatosis grades ≥ S1, ≥ S2 and S3 were 0.918, 0.960 and 0.987, respectively. In contrast, the MASLD group showed AUCs of 0.836, 0.774, and 0.688 for the same steatosis grades. The diagnostic performance of AC for detecting ≥ S2 and S3 indicated significant differences between the two groups (both P < 0.001). Multivariate linear regression analysis identified body mass index, triglycerides, and steatosis grade as significant factors for AC. When the steatosis grade is ≥ S2, it can progress to more serious liver conditions. A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of ≥ S2, achieving an AUC of 0.848.

The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups. In the MASLD group, when combined with blood biochemical parameters, AC exhibited better predictive ability for moderate to severe steatosis.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is one of the leading causes of chronic liver disease globally. Based on the 2023 definition, MASLD is characterized by the presence of metabolic dysfunction and limited alcohol consumption (<140 grams/week for women, <210 grams/week for men). Given the significant burden of MASLD in Latin America, this guidance was developed by the Latin American Association for the Study of the Liver (ALEH) Working Group to address key aspects of its clinical assessment and therapeutic strategies. In Latin America, ultrasonography is recommended as the initial screening tool for hepatic steatosis due to its accessibility, while Fibrosis-4 (FIB-4) is preferred for fibrosis risk stratification, with further evaluation using more specific techniques (i.e., vibration-controlled transient elastography or Enhanced Liver Fibrosis [ELF] test). A Mediterranean diet is advised for all MASLD patients, with a target of 7-10% weight loss for those with excess weight. Complete alcohol abstinence is recommended for patients with significant fibrosis, and smoking cessation is encouraged regardless of fibrosis stage. Pharmacological options should be tailored based on the presence of steatohepatitis, liver fibrosis, excess weight, and diabetes, including resmetirom, incretin-based therapies, pioglitazone, and sodium-glucose cotransporter-2 inhibitors. Bariatric surgery may be considered for MASLD patients with obesity unresponsive to lifestyle and medical interventions. Hepatocellular carcinoma screening is advised for all cirrhotic patients, with consideration given to those with advanced fibrosis based on individual risk. Finally, routine cardiovascular risk assessment and proper diabetes prevention and management remain crucial for all patients with MASLD.

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by injury to steatotic hepatocytes that triggers the release of endogenous danger-associated molecular patterns. Recent work demonstrated that exposed lipid droplets (LDs) serve as a pathogenic signal that promotes monocyte infiltration and its maturation into triggering receptor expressed in myeloid cells 2 (TREM2+) macrophages in MASH liver. Here we explore the role of LD exposure in modulating inflammatory signaling in macrophages. We found that LD efferocytosis triggers a global transcriptional response and dampens pro-inflammatory signaling in macrophages. LD treatment attenuated NLRP3 inflammasome activation via mechanisms independent of lysosomal LD hydrolysis. While TREM2 was dispensable for LD efferocytosis by macrophages, it was required for the attenuation of proinflammatory signaling upon LD exposure. Additionally, MS4A7 downregulation contributes to LD efferocytosis-mediated dampening of inflammatory response. These results underscore the dual role of LD exposure in MASH liver by promoting monocyte infiltration and TREM2+ macrophage induction, while restraining proinflammatory response in macrophages.

Metabolic dysfunction-associated steatohepatitis (MASH) is a leading cause of liver failure globally and is characterized by hepatic steatosis and inflammation, which may progress to fibrosis, the severity of which is highly predictive of patient demise and death. In view of the lack of treatment options for MASH, we investigated the therapeutic properties of extracellular vesicles (EVs) from normal human hepatocytes, which we have previously been shown to alleviate toxin-mediated hepatic fibrosis in mice.

C57BI/6J mice were fed a choline-deficient amino acid-defined high (60%) fat (CDAA-HF) diet for up to 12 weeks while receiving i.p. administration of EVs purified from cultured human HepG2 hepatocytes.

CDAA-HF diet consumption resulted in severe hepatic steatosis, increased frequency of CD45+ lymphocytes and F4/80+ macrophages, robust production of aortic smooth muscle actin (ACTA2), and deposition of interstitial collagen, as well as altered serum levels of ALT, AST, cholesterol, triglycerides, alkaline phosphatase, unconjugated bilirubin, and total protein, thus recapitulating typical MASH phenotypes. EVs administered preventively or therapeutically resulted in the restoration of serum marker levels, reduced hepatic inflammation and attenuation of collagen deposition, ACTA2 production, and expression of fibrosis-associated genes. HepG2 EVs contained 205 miRs and, among the 30 most abundant miRs, seven (miRs-423-5p, -483-5p, -191-5p, -148a-3p, -423-3p, -92a-3p, -122-5p) are predicted to directly target fibrosis-related genes (collagens, ACTA2, MMPs, and TIMPs).

Hepatocyte EVs are therapeutic in a mouse model of diet-induced steatohepatitis with fibrosis. Further studies of hepatocyte EVs or their cargo components as novel therapeutics for MASH in humans are warranted, including treatment of fibrotic stages, which are associated with clinical demise and are predictive of patient death.

Prognostication of compensated advanced chronic liver disease (cACLD) is of paramount importance for the physician-and-patient communication and for rational clinical decisions. The paper published by Dallio et al reports on red cell distribution width (RDW)/platelet ratio (RPR) as a non-invasive biomarker in predicting decompensation of metabolic dysfunction-associated steatotic liver disease (MASLD)-related cACLD. Differently from other biomarkers and algorithms, RPR is inexpensive and widely available, based on parameters which are included in a complete blood count. RPR is computed on the grounds of two different items, one of which, RDW, mirrors the host's response to a variety of disease stimuli and is non-specific. The second parameter involved in RPR, platelet count, is more specific and has been used in the hepatological clinic to discriminate cirrhotic from non-cirrhotic chronic liver disease for decades. Cardiovascular disease is the primary cause of mortality among MASLD subjects, followed by extra-hepatic cancers and liver-related mortality. Therefore, MASLD biomarkers should be validated not only in terms of liver-related events but also in the prediction of major adverse cardiovascular events and cardiovascular mortality and extra-hepatic cancers. Adequately sized multi-ethnic confirmatory investigation is required to define the role and significance of RPR in the stratification of MASLD-cACLD.

This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD).

Patients with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus. The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment.

Ninety-four patients were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of patients had type 2 diabetes mellitus. At week 12, relative reductions in LFC from baseline were 46.6% (95% CI -63.7 to -29.6), 68.5% (95% CI -84.4 to -52.5), and 57.1% (95% CI -76.1 to -38.1) for the pemvidutide 1.2 mg, 1.8 mg, and 2.4 mg groups, respectively, vs. 4.4% (95% CI -20.2 to 11.3) for the placebo group (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of patients achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events.

In patients with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo.

Metabolic dysfunction-associated steatotic liver disease, and its progressive form steatohepatitis, are strongly associated with overweight/obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/glucagon receptor agonist, to significantly reduce liver fat content, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both metabolic dysfunction-associated steatohepatitis and obesity.

NCT05006885.

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

A two-way relationship exists between type 2 diabetes (T2DM) and human nonalcoholic steatohepatitis (NASH). Several diabetic NASH models have the disadvantages of long cycles or inconsistent with the actual incidence of human disease, which would be costly and time-consuming to investigate disease pathogenesis and develop drugs. Therefore, there is an urgent need to establish a diabetic NASH mouse model.

The combination between Fructose-palmitate-cholesterol diet (FPC) and Streptozotocin (STZ) (FPC+STZ) was used to construct diabetic NASH mouse model. The in vivo effects of silencing acid-sensitive Ion Channel 1a (ASIC1a) were examined with an adeno-associated virus 9 (AAV9) carrying ASIC1a short hairpin RNA (shRNA) in FPC+STZ model.

The mice fed with FPC for 12 weeks had insulin resistance, hyperinsulinemia, lipid accumulation, and increased hepatic levels of inflammatory factors. However, it still did not develop remarkable liver fibrosis. Most interestingly, noticeable fibrotic scars were observed in the liver of mice from FPC+STZ group. Furthermore, insulin therapy significantly ameliorated FPC+STZ-induced NASH-related liver fibrosis, indicating that hyperglycemia is of great significance in NASH development and progression. Importantly, ASIC1a was found to be involved in the pathogenesis of diabetic NASH as demonstrated that silencing ASIC1a in HSCs significantly ameliorated FPC+STZ-induced NASH fibrosis. Mechanistically, ASIC1a interacted with Poly Adp-adenosine ribose polymerase (PARP1) to promote HSC activation by inducing autophagy.

A FPC diet combined with an injection of STZ induces a diabetic NASH mouse model in a shorter period. Targeting ASIC1a may provide a novel therapeutic target for the treatment of diabetic NASH.

Non-alcoholic fatty liver disease (NAFLD), spanning from non-alcoholic steatohepatitis (NASH) to liver fibrosis, poses a global health challenge amid rising obesity and metabolic syndrome rates. Effective pharmacological treatments for NASH and liver fibrosis are limited.

This study systematically reviews and meta-analyzes the safety and efficacy of resmetirom, a selective thyroid hormone receptor-β agonist, in NASH and liver fibrosis treatment. By analyzing data from clinical trials, we aim to offer evidence-based recommendations for resmetirom's use in managing these conditions and identify avenues for future research.

Electronic databases (PubMed, Scopus, Science Direct, Google Scholar, ClinicalTrials.gov, and Cochrane CENTRAL) were systematically searched, supplemented by manual screening of relevant sources. Only English-language randomized controlled trials were included. Data extraction, risk of bias assessment, pooled analyses, and meta-regression were performed.

Three randomized controlled trials involving 2231 participants were analyzed. Resmetirom demonstrated significant reductions in hepatic fat fraction [standardized mean difference (SMD) -4.61, 95% CI -6.77 to -2.44, P < 0.0001], NASH resolution without worsening fibrosis [risk ratio (RR) 2.51, 95% CI 1.74-3.64, P = 0.00001), and liver fibrosis improvement (RR 2.31, 95% CI 1.20-4.44, P = 0.01). Secondary outcomes showed significant improvements in lipid profiles, liver enzymes, and NASH biomarkers with resmetirom treatment. Meta-regression revealed associations between covariates and primary outcomes.

Resmetirom exhibits promising efficacy in reducing hepatic fat, improving NASH resolution, and ameliorating liver fibrosis with a favorable safety profile. Further research is warranted to validate findings and optimize therapeutic strategies for NASH and liver fibrosis management.

The formation of fibrotic tissue, characterized by the excessive accumulation of extracellular matrix (ECM) components such as collagen and fibronectin, is a normal and crucial stage of tissue repair in all organs. The over-synthesis, deposition, and remodeling of ECM components lead to organ dysfunction, posing a significant medical burden. Berberine, an isoquinoline alkaloid, is commonly used in the treatment of gastrointestinal diseases. With the deepening of scientific research, it has been gradually discovered that berberine also plays an important role in fibrotic diseases. In this review, we systematically introduce the effective role of berberine in fibrosis-related diseases. Specifically, this paper aims to provide a comprehensive review of the therapeutic role of berberine in treating fibrosis in organs such as the heart, liver, lungs, and kidneys. By summarizing its various pathways and mechanisms of action, including the inhibition of the transforming growth factor-[Formula: see text]/Smad signaling pathway, PI3K/Akt signaling pathway, MAPK signaling pathway, RhoA/ROCK signaling, and mTOR/p70S6K signaling pathway, as well as its activation of the Nrf2-ARE signaling pathway, AMPK signaling pathway, phosphorylated Smad 2/3 and Smad 7, and other signaling pathways, this review offers additional evidence to support the treatment of fibrotic diseases.

Intramuscular fat (IMF) refers to the lipid stored in skeletal muscle tissue. The number and size of intramuscular adipocytes are the primary factors that regulate IMF content. Intramuscular adipocytes can be derived from either in situ or ectopic migration. In this study, it was discovered that the regulation of IMF levels is achieved through the chemokine (C-C motif) ligand 5 (CCL5)/chemokine (C-C motif) receptor 5 (CCR5) pathway by modulating adipocyte migration. In coculture experiments, C2C12 myotubes were more effective in promoting the migration of 3T3-L1 preadipocytes than C2C12 myoblasts, along with increasing CCL5. Correspondingly, overexpressing the CCR5, one of the receptors of CCL5, in 3T3-L1 preadipocytes facilitated their migration. Conversely, the application of the CCL5/CCR5 inhibitor, MARAVIROC (MVC), reduced this migration. In vivo, transplanted experiments of subcutaneous adipose tissue (SCAT) from transgenic mice expressing green fluorescent protein (GFP) provided evidence that injecting recombinant CCL5 (rCCL5) into skeletal muscle promotes the migration of subcutaneous adipocytes to the skeletal muscle. The level of CCL5 in skeletal muscle increased with obesity. Blocking the CCL5/CCR5 axis by MVC inhibited IMF deposition, whereas elevated skeletal muscle CCL5 promoted IMF deposition in obese mice. These results establish a link between the IMF and the CCL5/CCR5 pathway, which could have a potential application for modulating IMF through adipocyte migration.NEW & NOTEWORTHY C2C12 myotubes attract 3T3-L1 preadipocyte migration regulated by the chemokine (C-C motif) ligand 5 (CCL5)/ chemokine (C-C motif) receptor 5 (CCR5) axis. High levels of skeletal muscle-specific CCL5 promote the migration of subcutaneous adipocytes to skeletal muscle and induce the intramuscular fat (IMF) content.

Cancer and diabetes are significant diseases that pose a threat to human health. Their interconnection is complex, particularly when they coexist, often necessitating multiple therapeutic approaches to attain remission. Sodium-glucose cotransporter protein two inhibitors (SGLT-2i) emerged as a treatment for hyperglycemia, but subsequently exhibited noteworthy extra-glycemic properties, such as being registered for the treatment of heart failure and chronic kidney disease, especially with co-existing albuminuria, prompting its assessment as a potential treatment for various non-metabolic diseases. Considering its overall tolerability and established use in diabetes management, SGLT-2i may be a promising candidate for cancer therapy and as a supplementary component to conventional treatments. This narrative review aimed to examine the potential roles and mechanisms of SGLT-2i in the management of diverse types of cancer. Future investigations should focus on elucidating the antitumor efficacy of individual SGLT-2i in different cancer types and exploring the underlying mechanisms. Additionally, clinical trials to evaluate the safety and feasibility of incorporating SGLT-2i into the treatment regimen of specific cancer patients and determining appropriate dosage combinations with established antitumor agents would be of significant interest.

Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis (NASH), is an advanced stage of metabolic fatty liver disease. The pathogenic mechanisms of MASH center on hepatocyte injury and the ensuing immune response within the liver microenvironment. Recent work has implicated TREM2+ macrophages in various disease conditions, and substantial induction of TREM2+ NASH-associated macrophages (NAMs) serves as a hallmark of metabolic liver disease. Despite this, the mechanisms through which NAMs contribute to MASH pathogenesis remain poorly understood. Here, we identify membrane-spanning 4-domains a7 (MS4A7) as a NAM-specific pathogenic factor that exacerbates MASH progression in mice. Hepatic MS4A7 expression was strongly induced in mouse and human MASH and associated with the severity of liver injury. Whole-body and myeloid-specific ablation of Ms4a7 alleviated diet-induced MASH pathologies in male mice. We demonstrate that exposure to lipid droplets (LDs), released upon injury of steatotic hepatocytes, triggered NAM induction and exacerbated MASH-associated liver injury in an MS4A7-dependent manner. Mechanistically, MS4A7 drove NLRP3 inflammasome activation via direct physical interaction and shaped disease-associated cell states within the liver microenvironment. This work reveals the LD-MS4A7-NLRP3 inflammasome axis as a pathogenic driver of MASH progression and provides insights into the role of TREM2+ macrophages in disease pathogenesis.

Liver disease is among the leading causes of global mortality and morbidity. Given their substantial impact on public health, raising awareness about liver diseases is paramount for their prevention and effective management. This study aimed to evaluate the knowledge, awareness, attitudes, and behaviors of Syrians regarding liver health, chronic liver disorders, and their associated serious and irreversible complications.

We conducted a cross-sectional study encompassing the adult Syrian population between August 25 and September 29, 2023, excluding non-Syrians and individuals below the age of 18 years. A validated questionnaire, adapted from a previous study, was employed, consisting of 31 questions that covered topics related to knowledge and awareness of liver health and diseases (3-point Likert scale), attitudes towards liver screening, diagnosis, and treatment, and awareness of treatment options and vaccination. Statistical analysis including logistic regression was conducted using Statistical Product and Service Solutions (SPSS, version 28; IBM SPSS Statistics for Windows, Armonk, NY), with statistical significance set established at pp-values below 0.05.

This study included 941 participants, with an average age of 26.5 years. While two-thirds of respondents demonstrated awareness of hepatitis B and C as viral diseases (663 (70.4%) and 612 (65.4%), respectively), approximately 66 (7%) were unaware of the potential for hepatitis to induce chronic liver inflammation or lead to liver failure. Over half of the participants were knowledgeable about the non-genetic nature of hepatitis B and C, and 579 (61.7%) were informed about the transmission risks associated with these infections. The most common reason cited for not participating in health screening tests was the perception of being in good health (219, 77.4%), and prescription medication was the most frequently sought treatment for hepatitis (543, 83.9%). Bivariate analysis revealed correlations between participant knowledge and sex, socioeconomic status, educational level, and occupation (P < 0.05). Similarly, the study identified significant associations between participant attitudes and age, gender, economic status, job, and educational level (P < 0.05). Moreover, the multivariate analysis demonstrated that gender, occupation, and educational level significantly influenced both participants' knowledge and attitudes. Specifically, males exhibited lower knowledge and less favorable attitudes than females (P = 0.041 and P < 0.001, respectively).

The Syrian population possessed moderate knowledge of liver health and liver disorders. To bridge this knowledge gap and enhance preventive measures, it is recommended that additional health programs and awareness initiatives be implemented, involving healthcare providers and leveraging their expertise.

This narrative review aims to illustrate the notion that nonalcoholic steatohepatitis (NASH), recently renamed metabolic dysfunction-associated steatohepatitis (MASH), is a systemic metabolic disorder featuring both adverse hepatic and extrahepatic outcomes. In recent years, several NASH trials have failed to identify effective pharmacological treatments and, therefore, lifestyle changes are the cornerstone of therapy for NASH. with this context, we analyze the epidemiological burden of NASH and the possible pathogenetic factors involved. These include genetic factors, insulin resistance, lipotoxicity, immuno-thrombosis, oxidative stress, reprogramming of hepatic metabolism, and hypoxia, all of which eventually culminate in low-grade chronic inflammation and increased risk of fibrosis progression. The possible explanations underlying the failure of NASH trials are also accurately examined. We conclude that the high heterogeneity of NASH, resulting from variable genetic backgrounds, exposure, and responses to different metabolic stresses, susceptibility to hepatocyte lipotoxicity, and differences in repair-response, calls for personalized medicine approaches involving research on noninvasive biomarkers. Future NASH trials should aim at achieving a complete assessment of systemic determinants, modifiers, and correlates of NASH, thus adopting a more holistic and unbiased approach, notably including cardiovascular-kidney-metabolic outcomes, without restricting therapeutic perspectives to histological surrogates of liver-related outcomes alone.

Nonalcoholic fatty liver disease (NAFLD), which affects approximately 25% of the global population, is an urgent health issue leading to various metabolic comorbidities. Circular RNAs (circRNAs), covalently closed RNA molecules, are characterized by ubiquity, diversity, stability, and conservatism. Indeed, they participate in various biological processes via distinct mechanisms that could modify the natural history of NAFLD. In this review, we briefly introduce the biogenesis, characteristics, and biological functions of circRNAs. Furthermore, we summarize circRNAs expression profiles in NAFLD by intersecting seven sequencing data sets and describe the cellular roles of circRNAs and their potential advantages as biomarkers of NAFLD. In addition, we emphatically discuss the exosomal non-coding RNA sorting mechanisms and possible functions in recipient cells. Finally, we extensively discuss the potential application of targeting disease-related circRNAs and competing endogenous RNA networks through gain-of-function and loss-of-function approaches in targeted therapy of NAFLD.

Vertical transmission of obesity is a critical contributor to the unabated obesity pandemic and the associated surge in metabolic diseases. Existing experimental models insufficiently recapitulate "human-like" obesity phenotypes, limiting the discovery of how severe obesity in pregnancy instructs vertical transmission of obesity. Here, via utility of thermoneutral housing and obesogenic diet feeding coupled to syngeneic mating of WT obese female and lean male mice on a C57BL/6 background, we present a tractable, more "human-like" approach to specifically investigate how maternal obesity contributes to offspring health. Using this model, we found that maternal obesity decreased neonatal survival, increased offspring adiposity, and accelerated offspring predisposition to obesity and metabolic disease. We also show that severe maternal obesity was sufficient to skew offspring microbiome and create a proinflammatory gestational environment that correlated with inflammatory changes in the offspring in utero and adulthood. Analysis of a human birth cohort study of mothers with and without obesity and their infants was consistent with mouse study findings of maternal inflammation and offspring weight gain propensity. Together, our results show that dietary induction of obesity in female mice coupled to thermoneutral housing can be used for future mechanistic interrogations of obesity and metabolic disease in pregnancy and vertical transmission of pathogenic traits.

Despite the rising prevalence and costs for the society, obesity etiology, and its precise cellular and molecular mechanisms are still insufficiently understood. The excessive accumulation of fat by adipocytes plays a key role in obesity progression and has many repercussions on total body physiology. In recent years the immune system as a gatekeeper of adipose tissue homeostasis has been evidenced and has become a focal point of research. Herein we focus on eosinophils, an important component of type 2 immunity, assuming fundamental, yet ill-defined, roles in the genesis, and progression of obesity and related metabolic disorders. We summarize eosinophilopoiesis and eosinophils recruitment into adipose tissue and discuss how the adipose tissue environments shape their function and vice versa. Finally, we also detail how obesity transforms the local eosinophil niche. Understanding eosinophil crosstalk with the diverse cell types within the adipose tissue environment will allow us to framework the therapeutic potential of eosinophils in obesity.

Nonalcoholic steatohepatitis (NASH) is a leading cause for chronic liver diseases. Current therapeutic options are limited due to an incomplete mechanistic understanding of how steatosis transitions to NASH. Here we show that the TRIM21 E3 ubiquitin ligase is induced by the synergistic actions of proinflammatory TNF-α and fatty acids in livers of humans and mice with NASH. TRIM21 ubiquitinates and degrades ChREBP, SREBP1, ACC1, and FASN, key regulators of de novo lipogenesis, and A1CF, an alternative splicing regulator of the high-activity ketohexokinase-C (KHK-C) isoform and rate-limiting enzyme of fructose metabolism. TRIM21-mediated degradation of these lipogenic activators improved steatosis and hyperglycemia as well as fructose and glucose tolerance. Our study identifies TRIM21 as a negative regulator of liver steatosis in NASH and provides mechanistic insights into an immunometabolic crosstalk that limits fatty acid synthesis and fructose metabolism during metabolic stress. Thus, enhancing this natural counteracting force of steatosis through inhibition of key lipogenic activators via TRIM21-mediated ubiquitination may provide a therapeutic opportunity to treat NASH.

The mammalian liver harbors heterogeneous cell types that communicate via local paracrine signaling. Recent studies have delineated the transcriptomic landscape of the liver in NASH that provides insights into liver cell heterogeneity, intercellular crosstalk, and disease-associated reprogramming. However, the nature of intrahepatic signaling and its role in NASH progression remain obscure.

Here, we performed transcriptomic analyses and identified cardiotrophin-like cytokine factor 1 (CLCF1), a member of the IL-6 family cytokines, as a cholangiocyte-derived paracrine factor that was elevated in the liver from diet-induced NASH mice and patients with NASH. Adenovirus-associated virus-mediated overexpression of CLCF1 in the liver ameliorated NASH pathologies in two diet-induced NASH models in mice, illustrating that CLCF1 induction may serve an adaptive and protective role during NASH pathogenesis. Unexpectedly, messenger RNA and protein levels of leukemia inhibitory factor receptor (LIFR), a subunit of the receptor complex for CLCF1, were markedly downregulated in NASH liver. Hepatocyte-specific inactivation of LIFR accelerated NASH progression in mice, supporting an important role of intrahepatic cytokine signaling in maintaining tissue homeostasis under metabolic stress conditions.

Together, this study sheds light on the molecular nature of intrahepatic paracrine signaling during NASH pathogenesis and uncovers potential targets for therapeutic intervention.

Non-alcoholic fatty liver disease (NAFLD) has recently emerged as a major public health concern worldwide due to its rapidly rising prevalence and its potential to progress into end-stage liver disease. While the precise pathophysiology underlying NAFLD remains incompletely understood, it is strongly associated with various environmental triggers and other metabolic disorders. Epigenetics examines changes in gene expression that are not caused by alterations in the DNA sequence itself. There is accumulating evidence that epigenetics plays a key role in linking environmental cues to the onset and progression of NAFLD. Our understanding of how epigenetic mechanisms contribute to NAFLD pathophysiology has expanded considerably in recent years as research on the epigenetics of NAFLD has developed. This review summarizes recent insights into major epigenetic processes that have been implicated in NAFLD pathogenesis including DNA methylation, histone acetylation, and microRNAs that have emerged as promising targets for further investigation. Elucidating epigenetic mechanisms in NAFLD may uncover novel diagnostic biomarkers and therapeutic targets for this disease. However, many questions have remained unanswered regarding how epigenetics promotes NAFLD onset and progression. Additional studies are needed to further characterize the epigenetic landscape of NAFLD and validate the potential of epigenetic markers as clinical tools. Nevertheless, an enhanced understanding of the epigenetic underpinnings of NAFLD promises to provide key insights into disease mechanisms and pave the way for novel prognostic and therapeutic approaches.

Obeticholic acid (OCA) is a first-in-class farnesoid X receptor agonist and antifibrotic agent in development for the treatment of pre-cirrhotic liver fibrosis due to non-alcoholic steatohepatitis (NASH). We aimed to validate the original 18-month liver biopsy analysis from the phase III REGENERATE trial of OCA for the treatment of NASH with a consensus panel analysis, provide additional histology data in a larger population, and evaluate safety from >8,000 total patient-years' exposure with nearly 1,000 participants receiving study drug for >4 years.

Digitized whole-slide images were evaluated independently by panels of three pathologists using the NASH Clinical Research Network scoring system. Primary endpoints were (1) ≥1 stage improvement in fibrosis with no worsening of NASH or (2) NASH resolution with no worsening of fibrosis. Safety was assessed by laboratory values and adverse events.

Prespecified efficacy analyses included 931 participants. The proportion of participants achieving a ≥1 stage improvement in fibrosis with no worsening of NASH was 22.4% for OCA 25 mg vs. 9.6% for placebo (p <0.0001). More participants receiving OCA 25 mg vs. placebo achieved NASH resolution with no worsening of fibrosis (6.5% vs. 3.5%, respectively; p = 0.093). Histology data in a larger population of 1,607 participants supported these results. Safety data included 2,477 participants. The incidence of treatment-emergent adverse events (TEAEs), serious TEAEs, and deaths was not substantively different across treatment groups. Pruritus was the most common TEAE. Rates of adjudicated hepatic, renal, and cardiovascular events were low and similar across treatment groups.

These results confirm the antifibrotic effect of OCA 25 mg. OCA was generally well tolerated over long-term dosing. These data support a positive benefit:risk profile in patients with pre-cirrhotic liver fibrosis due to NASH.

Patients with non-alcoholic steatohepatitis (NASH) often have liver scarring (fibrosis), which causes an increased risk of liver-related illness and death. Preventing progression of fibrosis to cirrhosis or reversing fibrosis are the main goals of drug development for NASH. In this clinical trial of obeticholic acid (OCA) in patients with NASH (REGENERATE), we reaffirmed our previous results demonstrating that OCA was superior to placebo in improving fibrosis using a more rigorous consensus panel analysis of liver biopsies taken at month 18. We also showed that OCA treatment resulted in dose-dependent reductions of serum liver biochemistries and liver stiffness measurements compared with placebo, even in participants in whom histologic fibrosis did not change at 18 months, providing evidence that the benefit of OCA extends beyond what is captured by the ordinal NASH CRN scoring system. OCA was well tolerated with a favorable safety profile supporting a positive benefit: risk profile in patients with pre-cirrhotic liver fibrosis due to NASH.

Elafibranor is a dual peroxisome proliferator-activated receptor (PPAR)α and β/δ agonist that has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we examined the effects of elafibranor in mice fed a choline-deficient high-fat diet (CD-HFD), a model of metabolic dysfunction-associated steatohepatitis (MASH) that presents obesity and insulin resistance. Our findings revealed that elafibranor treatment ameliorated steatosis, inflammation, and fibrogenesis in the livers of CD-HFD-fed mice. Unexpectedly, elafibranor also increased the levels of the epithelial-mesenchymal transition (EMT)-promoting protein S100A4 via PPARβ/δ activation. The increase in S100A4 protein levels caused by elafibranor was accompanied by changes in the levels of markers associated with the EMT program. The S100A4 induction caused by elafibranor was confirmed in the BRL-3A rat liver cells and a mouse primary hepatocyte culture. Furthermore, elafibranor reduced the levels of ASB2, a protein that promotes S100A4 degradation, while ASB2 overexpression prevented the stimulating effect of elafibranor on S100A4. Collectively, these findings reveal an unexpected hepatic effect of elafibranor on increasing S100A4 and promoting the EMT program.

PM2.5 can cause adverse health effects via several pathways, such as inducing pulmonary and systemic inflammation, penetration into circulation, and activation of the autonomic nervous system. In particular, the impact of PM2.5 exposure on the liver, which plays an important role in metabolism and detoxification to maintain internal environment homeostasis, is getting more attention in recent years. In the present study, C57BL/6J mice were randomly assigned and treated with PM2.5 suspension and PBS solution for 8 weeks. Then, hepatic tissue was prepared and identified by metabolomics analysis and transcriptomics analysis. PM2.5 exposure can cause extensive metabolic disturbances, particularly in lipid and amino acids metabolic dysregulation.128 differential expression metabolites (DEMs) and 502 differently expressed genes (DEGs) between the PM2.5 exposure group and control group were detected. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that DEGs were significantly enriched in two disease pathways, non-alcoholic fatty liver disease (NAFLD) and type II diabetes mellitus (T2DM), and three signaling pathways, which are TGF-beta signaling, AMPK signaling, and mTOR signaling. Besides, further detection of acylcarnitine levels revealed accumulation in liver tissue, which caused restricted lipid consumption. Furthermore, lipid droplet accumulation in the liver was confirmed by Oil Red O staining, suggesting hepatic steatosis. Moreover, the aberrant expression of three key transcription factors revealed the potential regulatory effects in lipid metabolic disorders, the peroxisomal proliferative agent-activated receptors (PPARs) including PPARα and PPARγ is inhibited, and the activated sterol regulator-binding protein 1 (SREBP1) is overexpressed. Our results provide a novel molecular and genetic basis for a better understanding of the mechanisms of PM2.5 exposure-induced hepatic metabolic diseases, especially in lipid metabolism.

Inhibition of immunocyte infiltration and activation has been suggested to effectively ameliorate nonalcoholic steatohepatitis (NASH). Paired immunoglobulin-like receptor B (PirB) and its human ortholog receptor, leukocyte immunoglobulin-like receptor B (LILRB2), are immune-inhibitory receptors. However, their role in NASH pathogenesis is still unclear. Here, we demonstrate that PirB/LILRB2 regulates the migration of macrophages during NASH by binding with its ligand angiopoietin-like protein 8 (ANGPTL8). Hepatocyte-specific ANGPTL8 knockout reduces MDM infiltration and resolves lipid accumulation and fibrosis progression in the livers of NASH mice. In addition, PirB^-/- bone marrow (BM) chimeras abrogate ANGPTL8-induced MDM migration to the liver. And yet, PirB ectodomain protein could ameliorate NASH by sequestering ANGPTL8. Furthermore, LILRB2-ANGPTL8 binding-promoted MDM migration and inflammatory activation are also observed in human peripheral blood monocytes. Taken together, our findings reveal the role of PirB/LILRB2 in NASH pathogenesis and identify PirB/LILRB2-ANGPTL8 signaling as a potential target for the management or treatment of NASH.

Tylophora yunnanensis Schltr (TYS) is widely distributed in Yunnan, Guizhou, and other places in China. It is commonly used by folks to treat hepatitis and other liver-related diseases; however, its mechanism of action is still unclear.

This study aimed to determine the effects of TYS on regulating gut microbiota and its metabolites in non-alcoholic steatohepatitis (NASH) rats by inhibiting the activation of NOD-like receptor protein3 (NLRP3).

An HFD-induced rat model was established to investigate if the intragastric administration of TYS could mediate gut microbiota and their metabolites to ultimately improve the symptoms of NASH. The improving effects of TYS on NASH rats were assessed by measuring their body weight, lipid levels, histopathology, and inflammatory factor levels in the rat models. The regulatory effects of TYS on NLRP3 in the NASH rats were analyzed using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), which determined the levels of NLRP3-related factors. The changes in the composition of the gut microbiota of NASH rats were analyzed using 16S rRNA gene sequencing technology. Meanwhile, the Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for the non-targeted analysis of metabolites in the cecum contents.

The results showed that TYS could improve NASH by decreasing the body weight and levels of lipid, AST, ALT, LPS, FFA, VLDL, IL-1β, IL-6, TNF-α, TGF-β, NLRP3, ASC, and Caspase-1 in the NASH rats. The analysis of gut microbiota showed that TYS could improve the diversity and abundance of gut microbiota and alter their composition by decreasing the Firmicutes/Bacteroidetes (F/B) ratio and relative abundances of Lachnospiraceae, Christensenellaceae, Blautia, etc. while increasing those of Muribaculaceae, Rumiaococcus, Ruminococcaceae, etc. The analysis of metabolites in the cecum contents suggested that the arachidonic acid metabolism, bile secretion, serotonergic synapse, Fc epsilon RI signaling pathway, etc. were regulated by TYS. The metabolites enriched in these pathways mainly included chenodeoxycholic acid, prostaglandin D2, TXB2, 9-OxoODE, and 13(S)-HOTrE.

These findings suggested that TYS could alleviate the NASH symptoms by decreasing the body weight, regulating the lipid levels, reducing the inflammatory response, and inhibiting the expression levels of NLRP3, ASC, and Caspase-1 in the NASH rats. The changes in the composition of gut microbiota and their metabolic disorder were closely related to the activation of NLRP3. TYS could significantly inhibit the activation of NLRP3 and regulate the composition of gut microbiota and the disorder of metabolites during NASH modeling.

The NASHmap model is a non-invasive tool using 14 variables (features) collected in standard clinical practice to classify patients as probable nonalcoholic steatohepatitis (NASH) or non-NASH, and here we have explored its performance and prediction accuracy. The National Institute of Diabetes and Digestive Kidney Diseases (NIDDK) NAFLD Adult Database and the Optum Electronic Health Record (EHR) were used for patient data. Model performance metrics were calculated from correct and incorrect classifications for 281 NIDDK (biopsy-confirmed NASH and non-NASH, with and without stratification by type 2 diabetes status) and 1,016 Optum (biopsy-confirmed NASH) patients. NASHmap sensitivity in NIDDK is 81%, with a slightly higher sensitivity in T2DM patients (86%) than non-T2DM patients (77%). NIDDK patients misclassified by NASHmap had mean feature values distinct from correctly predicted patients, particularly for aspartate transaminase (AST; 75.88 U/L true positive vs 34.94 U/L false negative), and alanine transaminase (ALT; 104.09 U/L vs 47.99 U/L). Sensitivity was slightly lower in Optum at 72%. In an undiagnosed Optum cohort at risk for NASH (n = 2.9 M), NASHmap predicted 31% of patients as NASH. This predicted NASH group had AST and ALT mean levels above normal range of 0-35 U/L, and 87% had HbA1C levels > 5.7%. Overall, NASHmap demonstrates good sensitivity in predicting NASH status in both datasets, and NASH patients misclassified as non-NASH by NASHmap have clinical profiles closer to non-NASH patients.

Dysregulated bile acid (BA) metabolism has been linked to steatosis, inflammation, and fibrosis in nonalcoholic fatty liver disease (NAFLD).

To determine whether circulating BA levels accurately stage liver fibrosis in NAFLD.

We recruited 550 Chinese adults with biopsy-proven NAFLD and varying levels of fibrosis. Ultra-performance liquid chromatography coupled with tandem mass spectrometry was performed to quantify 38 serum BAs.

Compared to those without fibrosis, patients with mild fibrosis (stage F1) had significantly higher levels of secondary BAs, and increased diastolic blood pressure (DBP), alanine aminotransferase (ALT), body mass index, and waist circumstance (WC). The combination of serum BAs with WC, DBP, ALT, or Homeostatic Model Assessment for Insulin Resistance performed well in identifying mild fibrosis, in men and women, and in those with/without obesity, with AUROCs 0.80, 0.88, 0.75 and 0.78 in the training set (n = 385), and 0.69, 0.80, 0.61 and 0.69 in the testing set (n = 165), respectively. In comparison, the combination of BAs and clinical/biochemical biomarkers performed less well in identifying significant fibrosis (F2-4). In women and in non-obese subjects, AUROCs were 0.75 and 0.71 in the training set, 0.65 and 0.66 in the validation set, respectively. However, these AUROCs were higher than those observed for the fibrosis-4 index, NAFLD fibrosis score, and Hepamet fibrosis score.

Secondary BA levels were significantly increased in NAFLD, especially in those with mild fibrosis. The combination of serum BAs and clinical/biochemical biomarkers for identifying mild fibrosis merits further assessment.

Nonalcoholic fatty liver disease (NAFLD) is a strong stimulant of cardiovascular diseases, affecting one-quarter of the world's population. TBC1 domain family member 25 (TBC1D25) regulates the development of myocardial hypertrophy and cerebral ischemia-reperfusion injury; however, its effect on NAFLD/nonalcoholic steatohepatitis (NASH) has not been reported. In this study, we demonstrated that TBC1D25 expression is upregulated in NASH. TBC1D25 deficiency aggravated hepatic steatosis, inflammation, and fibrosis in NASH. In vitro tests revealed that TBC1D25 overexpression restrained NASH responses. Subsequent mechanistic validation experiments demonstrated that TBC1D25 interfered with NASH progression by inhibiting abnormal lipid accumulation and inflammation. TBC1D25 deficiency significantly promoted NASH occurrence and development. Therefore, TBC1D25 may potentially be used as a clinical therapeutic target for NASH treatment.

Qushi Huayu decoction (QHD) has been clinically used for treating non-alcoholic steatohepatits (NASH). However, little is known about the effect of QHD on fatty acid β-oxidation (FAO)-dependent lipid consumption.

To investigate the mechanism of QHD on FAO-related hepatic lipid accumulation.

Male C57BL/6J mice were randomly divided into 5 groups (n = 8): normal diet and drinking water (CON), high-fat and high-carbohydrate diet (HFHC), QHD-L (2.875 g/kg), QHD-H (11.5 g/kg) and obeticholic acid (OCA) (10 mg/kg/day) groups. All mice freely consumed an appropriate diet for 18 weeks, and QHD was orally administered in the last 6 weeks. Measurements of general condition, hepatic histopathology, and JAK2/STAT3 signalling pathway were taken.

QHD significantly improved NASH in mice, as reflected by improving serum glucolipid metabolism, decreasing enzymes activities, reducing hepatic triglyceride (HFHC: 70.07 ± 2.81 mg/g; QHD-H: 34.06 ± 5.74 mg/g) and ameliorating hepatic steatosis, inflammation in pathology. Further, both the mRNA and protein level of hepatic CPT-1A (p < 0.05), a rate-limiting enzyme of FAO, increased drastically following QHD treatment. Meanwhile, the content of hepatic ATP (p < 0.05) increased significantly after treatment with QHD. Further mechanistic results revealed that both the total protein and nuclear p-STAT3 in the liver were significantly down-regulated after QHD treatment. The protein level of hepatic p-JAK2 was significantly inhibited by QHD (p < 0.05 or p < 0.01).

QHD could attenuate lipid accumulation by increasing JAK2/STAT3/CPT-1A-related FAO, which provides a scientific basis for the clinical application of QHD in treating NASH.

Non-alcoholic fatty liver disease (NAFLD) is increasingly affecting human health and the economy worldwide due to various factors. Here, we found that the expression of TGF-β1 and TLR2 was significantly up-regulated in liver samples from both rats and mice nonalcoholic steatohepatitis (NASH) models. By constructing corresponding cell model, we found that TGF-β1 challenge can positively regulate the expression of TLR2 and p-Smad2/3, and the dual luciferase reporter gene system and EMSA assay confirmed the existence of Smad3 binding site (-916 ∼ -906) in the promoter region of TLR2. The overexpression and interference changes of Smad2/3 further verified the above experimental results. Taken together, these findings suggest that TGF-β1 promotes TLR2 transcription and its target gene expression via Smad3, leading to malignant exacerbation of liver inflammation in NASH, which provides new insights into the treatment of NASH.