NUAK1 promotes metabolic dysfunction-associated steatohepatitis progression by activating Caspase 6-driven pyroptosis and inflammation.

BACKGROUND: lNUAK1 is strongly associated with organ fibrosis, but its causal mechanism for modulating lipid metabolism and hepatic inflammation underlying MASH has not been fully clarified. METHOD: In our study, human liver tissues from patients with MASH and control subjects were obtained to evaluate NUAK1 expression. MASH models were established using C57BL/6 mice. Liver damage and molecular mechanisms of the NUAK1-Caspase 6 signaling were tested in vivo and in vitro. RESULTS: In the clinical arm, NUAK1 expression was upregulated in liver samples from patients with MASH. Moreover, increased NUAK1 was detected in mouse MASH models. NUAK1 inhibition ameliorated steatohepatitis development in MASH mice accompanied by the downregulation of hepatic steatosis and fibrosis. Intriguingly, NUAK1 was found to facilitate Caspase 6 activation and trigger pyroptosis in MASH-stressed livers. Disruption of hepatocytes Caspase 6 decreased MASH-induced liver inflammation with upregulated TAK1 but diminished RIPK1. Moreover, we found that NUAK1/Caspase 6 axis inhibition could accelerate the interaction between TAK1 and RIPK1, which in turn led to the degradation of RIPK1. CONCLUSIONS: In summary, our study elucidates that NUAK1-Caspase 6 signaling controls inflammation activation in MASH through the interaction between TAK1 and RIPK1, which is crucial for controlling pyroptosis and promoting the progression of MASH.

Alanine aminotransferase predicts incident steatotic liver disease of metabolic etiology: Long life to the old biomarker!

Alanine aminotransferase (ALT) serum levels increase because of hepatocellular damage. Metabolic dysfunction-associated fatty liver disease (MAFLD), which identifies steatotic liver disease (SLD) associated with ≥ 2 metabolic abnormalities, has prominent sexual differences. The Metabolic Syndrome defines a cluster comprising abdominal obesity, altered glucose metabolism, dyslipidemia, and hypertension. Male sex, body mass index, glucose, lipids, ferritin, hypertension, and age independently predict ALT levels among blood donors. Over the last few decades, the reference range of ALT levels has been animatedly debated owing to attempts to update sex-specific reference ranges. With this backset, Chen et al have recently published a study which has two main findings. First, > 80% of individuals with MAFLD had normal ALT levels. Second, there was a linear increasing trend in the association between cumulative excess high-normal ALT levels and the rate of incident MAFLD. This study has biologically credible findings. However, it inaccurately considered sex differences in the MAFLD arena. Therefore, future studies on SLD owing to metabolic dysfunction should adopt locally determined and prospectively validated reference ranges of ALT and carefully consider sex differences in liver enzymes and MAFLD pathobiology.

Clinical and genetic risk factors for progressive fibrosis in metabolic dysfunction-associated steatotic liver disease.

BACKGROUND: Fibrosis-4 (FIB4) is a recommended noninvasive test to assess hepatic fibrosis among patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we used FIB4 trajectory over time (ie, "slope" of FIB4) as a surrogate marker of liver fibrosis progression and examined if FIB4 slope is associated with clinical and genetic factors among individuals with clinically defined MASLD within the Million Veteran Program Cohort. METHODS: In this retrospective cohort study, FIB4 slopes were estimated through linear regression for participants with clinically defined MASLD and FIB4 <2.67 at baseline. FIB4 slope was correlated with demographic parameters and clinical outcomes using logistic regression and Cox proportional hazard models. FIB4 slope as a quantitative phenotype was used in a genome-wide association analysis in ancestry-specific analysis and multiancestry meta-analysis using METAL. RESULTS: FIB4 slopes, generated from 98,361 subjects with MASLD (16,045 African, 74,320 European, and 7996 Hispanic), showed significant associations with sex, ancestry, and cardiometabolic risk factors (p < 0.05). FIB4 slopes also correlated strongly with hepatic outcomes and were independently associated with time to cirrhosis. Five genetic loci showed genome-wide significant associations (p < 5 × 10-8) with FIB4 slope among European ancestry subjects, including 2 known (PNPLA3 and TM6SF2) and 3 novel loci (TERT 5.1 × 10-11; LINC01088, 3.9 × 10-8; and MRC1, 2.9 × 10-9). CONCLUSIONS: Linear trajectories of FIB4 correlated significantly with time to progression to cirrhosis, with liver-related outcomes among individuals with MASLD and with known and novel genetic loci. FIB4 slope may be useful as a surrogate measure of fibrosis progression.

Gut microbial metabolites in MASLD: Implications of mitochondrial dysfunction in the pathogenesis and treatment.

With an increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major global health problem. MASLD is well-known as a multifactorial disease. Mitochondrial dysfunction and alterations in the gut bacteria are 2 vital events in MASLD. Recent studies have highlighted the cross-talk between microbiota and mitochondria, and mitochondria are recognized as pivotal targets of the gut microbiota to modulate the host's physiological state. Mitochondrial dysfunction plays a vital role in MASLD and is associated with multiple pathological changes, including hepatocyte steatosis, oxidative stress, inflammation, and fibrosis. Metabolites are crucial mediators of the gut microbiota that influence extraintestinal organs. Additionally, regulation of the composition of gut bacteria may serve as a promising therapeutic strategy for MASLD. This study reviewed the potential roles of several common metabolites in MASLD, emphasizing their impact on mitochondrial function. Finally, we discuss the current treatments for MASLD, including probiotics, prebiotics, antibiotics, and fecal microbiota transplantation. These methods concentrate on restoring the gut microbiota to promote host health.

Serum macroelements and microelements levels in periparturient dairy cows in relation to fatty liver diseases.

BACKGROUND: Fatty liver in dairy cows is a common metabolic disease defined by triglyceride (TG) buildup in the hepatocyte. Clinical diagnosis of fatty liver is usually done by liver biopsy, causing considerable economic losses in the dairy industry owing to the lack of more effective diagnostic methods. Therefore, this study aimed to investigate the potential utility of blood biomarkers for the diagnosis and early warning of fatty liver in dairy cows. RESULTS: A total of twenty-four lactating cows within 28 days after parturition were randomly selected as experimental animals and divided into healthy cows (liver biopsy tested, n = 12) and cows with fatty liver (liver biopsy tested, n = 12). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the macroelements and microelements in the serum of two groups of cows. Compared to healthy cows (C), concentrations of calcium (Ca), potassium (K), magnesium (Mg), strontium (Sr), selenium (Se), manganese (Mn), boron (B) and molybdenum (Mo) were lower and copper (Cu) was higher in fatty liver cows (F). Meanwhile, the observed differences in macroelements and microelements were related to delivery time, with the greatest major disparity between C and F occurring 7 days after delivery. Multivariable analysis was used to test the correlation between nine serum macroelements, microelements and fatty liver. Based on variable importance projection and receiver operating characteristic (ROC) curve analysis, minerals Ca, Se, K, B and Mo were screened as the best diagnostic indicators of fatty liver in postpartum cows. CONCLUSIONS: Our data suggested that serum levels of Ca, K, Mg, Se, B, Mo, Mn, and Sr were lower in F than in C. The most suitable period for an early-warning identification of fatty liver in cows was 7 days after delivery, and Ca, Se, K, B and Mo were the best diagnostic indicators of fatty liver in postpartum cows.

Biochemical and Anthropometric Indices of Insulin Resistance in Obese and Overweight Children with Metabolic Dysfunction-Associated Fatty Liver Disease.

BACKGROUND The prevalence of metabolic (dysfunction)-associated fatty liver disease (MAFLD) increases together with the epidemic of childhood obesity. An important mechanism in the phenomenon appears to be insulin resistance (IR), the assessment of which in children is problematic. The homeostatic model assessment of IR (HOMA-IR), commonly used for this, is not standardized and appears not to correlate with IR in the pediatric population. Therefore, our study aimed to evaluate potential substitute indices of IR, including the triglyceride-glucose index (TyG), triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), modified TyG indices: TyG-waist circumference (TyG-WC) and TyG-body mass index (TyG-BMI) as surrogate markers of MAFLD in obese children suspected to have liver disease. MATERIAL AND METHODS The retrospective study included 264 obese children admitted to the Department to diagnose suspected liver disease. MAFLD was diagnosed according to the International Expert Consensus Statement. Anthropometric measurements and laboratory tests were made and the indices were calculated. Receiver operating characteristics analysis was performed to calculate the power of the indices. RESULTS MAFLD was diagnosed in 184 patients (70%). Obese children with MAFLD showed significantly higher activity of liver enzymes and concentration of total cholesterol, TG, WC, and waist-to-hip ratio compared to non-hepatopathic obese controls (n=80). The most important indices in identifying MAFLD were: TyG (AUC=0.641, p<0.001, cut-off =8.41, sensitivity=57.4%, specificity=68.8%), and TG/HDL-C (AUC=0.638, p<0.001, cut-off=2.5, sensitivity=48.6%, specificity=76.3%). TyG-BMI and HOMA-IR were not useful predictors. CONCLUSIONS TyG and TG/HDL-C can be considered as potential surrogate biomarkers in predicting MAFLD in obese children.

[Hypothetical Alcohol Consumption Interventions and Hepatic Steatosis: A Longitudinal Study in a Large Cohort]. / æ¨¡æ‹Ÿé¥®é ’å¹²é¢„ä¸Žè‚è„‚è‚ªå˜æ€§ï¼šä¸€é¡¹å¤§åž‹é˜Ÿåˆ—çš„çºµå‘ç ”ç©¶.

Objective: Non-alcoholic fatty liver disease (NAFLD) and alcohol-associated fatty liver disease (ALD) are the most common chronic liver diseases. Hepatic steatosis is an early histological subtype of both NAFLD and ALD. Excessive alcohol consumption is widely known to lead to hepatic steatosis and subsequent liver damage. However, reported findings concerning the association between moderate alcohol consumption and hepatic steatosis remain inconsistent. Notably, alcohol consumption as a modifiable lifestyle behavior is likely to change over time, but most previous studies covered alcohol intake only once at baseline. These inconsistent findings from existing studies do not inform decision-making concerning policies and clinical guidelines, which are of greater interest to health policymakers and clinician-scientists. Additionally, recommendations on the types of alcoholic beverages are not available. Usually, assessing the effects of two or more hypothetical alcohol consumption interventions on hepatic steatosis provides answers to questions concerning the population risk of hepatic steatosis if everyone changes from heavy drinking to abstinence, or if everyone keeps on drinking moderately, or if everyone of the drinking population switches from red wine to beer? Thus, we simulated a target trial to estimate the effects of several hypothetical interventions, including changes in the amount of alcohol consumption or the types of alcoholic beverages consumed, on hepatic steatosis using longitudinal data, to inform decisions about alcohol-related policymaking and clinical care. Methods: This longitudinal study included 12687 participants from the UK Biobank (UKB), all of whom participated in both baseline and repeat surveys. We excluded participants with missing data related to components of alcohol consumption and fatty liver index (FLI) in the baseline and the repeat surveys, as well as those who had reported liver diseases or cancer at the baseline survey. We used FLI as an outcome indicator and divided the participants into non-, moderate, and heavy drinkers. The surrogate marker FLI has been endorsed by many international organizations' guidelines, such as the European Association for the Study of the Liver. The calculation of FLI was based on laboratory and anthropometric data, including triglyceride, gamma-glutamyl transferase, body mass index, and waist circumference. Participants responded to questions about the types of alcoholic beverages, which were defined in 5 categories, including red wine, white wine/fortified wine/champagne, beer or cider, spirits, and mixed liqueurs, along with the average weekly or monthly amounts of alcohol consumed. Alcohol consumption was defined as pure alcohol consumed per week and was calculated according to the amount of alcoholic beverages consumed per week and the average ethanol content by volume in each alcoholic beverage. Participants were categorized as non-drinkers, moderate drinkers, and heavy drinkers according to the amount of their alcohol consumption. Moderate drinking was defined as consuming no more than 210 g of alcohol per week for men and 140 g of alcohol per week for women. We defined the following hypothetical interventions for the amount of alcohol consumed: sustaining a certain level of alcohol consumption from baseline to the repeat survey (e.g., none to none, moderate to moderate, heavy to heavy) and changing from one alcohol consumption level to another (e.g., none to moderate, moderate to heavy). The hypothetical interventions for the types of alcoholic beverages were defined in a similar way to those for the amount of alcohol consumed (e.g., red wine to red wine, red wine to beer/cider). We applied the parametric g-formula to estimate the effect of each hypothetical alcohol consumption intervention on the FLI. To implement the parametric g-formula, we first modeled the probability of time-varying confounders and FLI conditional on covariates. We then used these conditional probabilities to estimate the FLI value if the alcohol consumption level of each participant was under a specific hypothetical intervention. The confidence interval was obtained by 200 bootstrap samples. Results: For the alcohol consumption from baseline to the repeat surveys, 6.65% of the participants were sustained non-drinkers, 63.68% were sustained moderate drinkers, and 14.74% were sustained heavy drinkers, while 8.39% changed from heavy drinking to moderate drinking. Regarding the types of alcoholic beverages from baseline to the repeat surveys, 27.06% of the drinkers sustained their intake of red wine. Whatever the baseline alcohol consumption level, the hypothetical interventions for increasing alcohol consumption from the baseline alcohol consumption were associated with a higher FLI than that of the sustained baseline alcohol consumption level. When comparing sustained non-drinking with the hypothetical intervention of changing from non-drinking to moderate drinking, the mean ratio of FLI was 1.027 (95% confidence interval [CI]: 0.997-1.057). When comparing sustained non-drinking with the hypothetical intervention of changing from non-drinking to heavy drinking, the mean ratio of FLI was 1.075 (95% CI: 1.042-1.108). When comparing sustained heavy drinking with the hypothetical intervention of changing from heavy drinking to moderate drinking, the mean ratio of FLI was 0.953 (95% CI: 0.938-0.968). The hypothetical intervention of changing to red wine in the UKB was associated with lower FLI levels, compared with sustained consumption of other types of alcoholic beverages. For example, when comparing sustaining spirits with the hypothetical intervention of changing from spirits to red wine, the mean ratio of FLI was 0.981 (95% CI: 0.948-1.014). Conclusions: Regardless of the current level of alcohol consumption, interventions that increase alcohol consumption could raise the risk of hepatic steatosis in Western populations. The findings of this study could inform the formulation of future practice guidelines and health policies. If quitting drinking is challenging, red wine may be a better option than other types of alcoholic beverages in Western populations.

Impaired GK-GKRP interaction rather than direct GK activation worsens lipid profiles and contributes to long-term complications: a Mendelian randomization study.

BACKGROUND: Glucokinase (GK) plays a key role in glucose metabolism. In the liver, GK is regulated by GK regulatory protein (GKRP) with nuclear sequestration at low plasma glucose level. Some GK activators (GKAs) disrupt GK-GKRP interaction which increases hepatic cytoplasmic GK level. Excess hepatic GK activity may exceed the capacity of glycogen synthesis with excess triglyceride formation. It remains uncertain whether hypertriglyceridemia associated with some GKAs in previous clinical trials was due to direct GK activation or impaired GK-GKRP interaction. METHODS: Using publicly available genome-wide association study summary statistics, we selected independent genetic variants of GCKR and GCK associated with fasting plasma glucose (FPG) as instrumental variables, to mimic the effects of impaired GK-GKRP interaction and direct GK activation, respectively. We applied two-sample Mendelian Randomization (MR) framework to assess their causal associations with lipid-related traits, risks of metabolic dysfunction-associated steatotic liver disease (MASLD) and cardiovascular diseases. We verified these findings in one-sample MR analysis using individual-level statistics from the Hong Kong Diabetes Register (HKDR). RESULTS: Genetically-proxied impaired GK-GKRP interaction increased plasma triglycerides, low-density lipoprotein cholesterol and apolipoprotein B levels with increased odds ratio (OR) of 14.6 (95% CI 4.57-46.4) per 1 mmol/L lower FPG for MASLD and OR of 2.92 (95% CI 1.78-4.81) for coronary artery disease (CAD). Genetically-proxied GK activation was associated with decreased risk of CAD (OR 0.69, 95% CI 0.54-0.88) and not with dyslipidemia. One-sample MR validation in HKDR showed consistent results. CONCLUSIONS: Impaired GK-GKRP interaction, rather than direct GK activation, may worsen lipid profiles and increase risks of MASLD and CAD. Development of future GKAs should avoid interfering with GK-GKRP interaction.

[Analysis of the correlation between fatty liver index and myocardial remodeling].

Objective: To analyze the correlation between fatty liver index (FLI) and myocardial remodeling. Methods: For cross-sectional study, cluster sampling was used to conduct a follow-up study of "Risk evaluation of cancers in Chinese diabetic individuals: A longitudinal (REACTION) study" among communities of Gucheng and Pingguoyuan of Beijing from April 2015 to September 2015. According to the inclusion and exclusion criteria, 8 848 participants were selected. Biochemical indicators such as body mass index, waist circumference, triglycerides, and γ-glutamyl transpeptidase were detected to calculate the FLI. The correlation between FLI and myocardial remodeling was analyzed. Interventricular septal thickness (IVS), left atrial diameter (LAD), left ventricular end diastolic diameter (LVEDD), and the presence of diastolic dysfunction were measured by color doppler ultrasound. The participants were divided into Q1 group (FLI<30, 4 529 cases), Q2 group (30≤FLI<60, 2 762 cases), and Q3 group (FLI≥60, 1 557 cases) based on FLI levels. Single factor analysis of variance was used for inter-group comparison, logistic regression analysis was used to analyze the correlation between FLI and myocardial remodeling. Results: A total of 8 848 subjects were selected for the study (3 110 male and 5 738 female, mean age: 59.96 years). The IVS of Q1, Q2, and Q3 groups were (9.35±1.08), (9.73±1.22), and (10.07±1.31) mm, respectively. The LAD were (30.94±3.90), (33.37±4.12), and (34.98±4.47) mm, respectively. The LVEDD were (42.51±5.05), (44.43±5.10), and (46.06±5.52) mm, respectively. All increased with the increase of FLI (all P<0.001). FLI was an independent risk factor for IVS thickening, LAD increase, LVEDD increase, and diastolic function decrease. The respective risks for IVS thickening, LAD increase, LVEDD increase, and diastolic function decrease in a population with intermediate and higher FLI levels was 1.62 times (95%CI 1.39-1.89) and 2.53 times (95%CI 2.13-3.00); 2.71 times (95%CI 2.39-3.06) and 5.00 times (95%CI 4.12-6.08); 2.36 times (95%CI 1.85-3.00) and 4.33 times (95%CI 3.33-5.62); and 1.90 times (95%CI 1.63-2.19) and 1.95 times (95%CI 1.60-2.37) than those with lower FLI levels. Conclusion: There is a certain relevance between FLI and myocardial remodeling.

[MRI-Based Assessment of Hepatic Iron Overload and Steatosis in Patients Undergoing Hemodialysis:Current Status,Challenges,and Perspectives].

Long-term treatment of anemia involving frequent blood transfusions and intravenous iron administration increases the risks of hepatic iron overload and steatosis in the patients undergoing hemodialysis.Pathological accumulation of iron damages hepatocytes,not only elevating the risks of progressive hepatic fibrosis and cirrhosis but also potentially accelerating the process of hepatic steatosis.Iron overload and steatosis may interact with each other,exacerbating liver damage and ultimately leading to further deterioration of hepatic fibrosis and cirrhosis.MRI characterized by non-invasiveness and high repeatability,enables the simultaneous quantitative assessment of hepatic iron and fat content,providing crucial information for early diagnosis and intervention of liver diseases.In recent years,researchers have achieved significant advances in the application of MRI in the diagnosis and treatment of liver diseases.MRI can accurately reflect the extent of hepatic iron overload and steatosis in patients and predict the risk of liver diseases.This article reviews the latest advances,challenges,and perspectives in the application of MRI in assessing hepatic iron overload and steatosis in the patients undergoing hemodialysis,aiming to offer valuable references for clinical practice.

Therapeutic implications for sphingolipid metabolism in metabolic dysfunction-associated steatohepatitis.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), a leading cause of chronic liver disease, has increased worldwide along with the epidemics of obesity and related dysmetabolic conditions characterized by impaired glucose metabolism and insulin signaling, such as type 2 diabetes mellitus (T2D). MASLD can be defined as an excessive accumulation of lipid droplets in hepatocytes that occurs when the hepatic lipid metabolism is totally surpassed. This metabolic lipid inflexibility constitutes a central node in the pathogenesis of MASLD and is frequently linked to the overproduction of lipotoxic species, increased cellular stress, and mitochondrial dysfunction. A compelling body of evidence suggests that the accumulation of lipid species derived from sphingolipid metabolism, such as ceramides, contributes significantly to the structural and functional tissue damage observed in more severe grades of MASLD by triggering inflammatory and fibrogenic mechanisms. In this context, MASLD can further progress to metabolic dysfunction-associated steatohepatitis (MASH), which represents the advanced form of MASLD, and hepatic fibrosis. In this review, we discuss the role of sphingolipid species as drivers of MASH and the mechanisms involved in the disease. In addition, given the absence of approved therapies and the limited options for treating MASH, we discuss the feasibility of therapeutic strategies to protect against MASH and other severe manifestations by modulating sphingolipid metabolism.

Intermittent hypoxia exacerbates metabolic dysfunction-associated fatty liver disease by aggravating hepatic copper deficiency-induced ferroptosis.

Intermittent hypoxia (IH) is an independent risk factor for metabolic dysfunction-associated fatty liver disease (MAFLD). Copper deficiency can disrupt redox homeostasis, iron, and lipid metabolism. Here, we investigated whether hepatic copper deficiency plays a role in IH-associated MAFLD and explored the underlying mechanism(s). Male C57BL/6 mice were fed a western-type diet with adequate copper (CuA) or marginally deficient copper (CuD) and were exposed separately to room air (RA) or IH. Hepatic histology, plasma biomarkers, copper-iron status, and oxidative stress were assessed. An in vitro HepG2 cell lipotoxicity model and proteomic analysis were used to elucidate the specific targets involved. We observed that there were no differences in hepatic phenotypes between CuA-fed and CuD-fed mice under RA. However, in IH exposure, CuD-fed mice showed more pronounced hepatic steatosis, liver injury, and oxidative stress than CuA-fed mice. IH induced copper accumulation in the brain and heart and exacerbated hepatic copper deficiency and secondary iron deposition. In vitro, CuD-treated cells with IH exposure showed elevated levels of lipid accumulation, oxidative stress, and ferroptosis susceptibility. Proteomic analysis identified 360 upregulated and 359 downregulated differentially expressed proteins between CuA and CuD groups under IH; these proteins were mainly enriched in citrate cycle, oxidative phosphorylation, fatty acid metabolism, the peroxisome proliferator-activated receptor (PPAR)α pathway, and ferroptosis. In IH exposure, CuD significantly upregulated the ferroptosis-promoting factor arachidonyl-CoA synthetase long chain family member (ACSL)4. ACSL4 knockdown markedly eliminated CuD-induced ferroptosis and lipid accumulation in IH exposure. In conculsion, IH can lead to reduced hepatic copper reserves and secondary iron deposition, thereby inducing ferroptosis and subsequent MAFLD progression. Insufficient dietary copper may worsen IH-associated MAFLD.

Association between triglyceride-glucose related indices and mortality among individuals with non-alcoholic fatty liver disease or metabolic dysfunction-associated steatotic liver disease.

BACKGROUND: The prognostic value of triglyceride-glucose (TyG) related indices in non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD) is still unclear. This study aimed to determine the associations between TyG-related indices and long-term mortality in this population. METHODS: The data came from the National Health and Nutrition Examination Survey (NHANES III) and National Death Index (NDI). Baseline TyG, TyG combining with body mass index (TyG-BMI), and TyG combining with waist circumference (TyG-WC) indices were calculated, and mortality status was determined through 31 December 2019. Multivariate Cox and restricted cubic spline (RCS) regression models were performed to evaluate the relationship between TyG-related indices and long-term mortality among participants with NAFLD/MASLD. In addition, we examined the association between TyG-related indices and all-cause mortality within subgroups defined by age, sex, race/ethnicity, and fibrosis-4 index (FIB-4). RESULTS: There were 10,390 participants with completed ultrasonography and laboratory data included in this study. NAFLD was diagnosed in 3672/10,390 (35.3%) participants, while MASLD in 3556/10,390 (34.2%) amongst the overall population. The multivariate Cox regression analyses showed high levels of TyG-related indices, particularly in TyG-BMI and TyG-WC indices were significantly associated with the all-cause mortality, cardiovascular mortality, and diabetes mortality in either NAFLD or MASLD. The RCS curves showed a nonlinear trend between three TyG-related indices with all-cause mortality in either NAFLD or MASLD. Subgroup analyses showed that TyG-BMI and TyG-WC indices were more suitable for predicting all-cause mortality in patients without advanced fibrosis. CONCLUSION: Our study highlights the clinical value of TyG-related indices in predicting the survival of the NAFLD/MASLD population. TyG-BMI and TyG-WC indices would be the surrogate biomarkers for the follow-up of the population without advanced fibrosis.

Dynamic changes of gut microbiota in mouse models of metabolic dysfunction-associated steatohepatitis and its transition to hepatocellular carcinoma.

Dysbiosis of gut microbiota may account for pathobiology in simple fatty liver (SFL), metabolic dysfunction-associated steatohepatitis (MASH), fibrotic progression, and transformation to MASH-associated hepatocellular carcinoma (MASH-HCC). The aim of the present study is to investigate gut dysbiosis in this progression. Fecal microbial rRNA-16S sequencing, absolute quantification, histopathologic, and biochemical tests were performed in mice fed high fat/calorie diet plus high fructose and glucose in drinking water (HFCD-HF/G) or control diet (CD) for 2, 16 weeks, or 14 months. Histopathologic examination verified an early stage of SFL, MASH, fibrotic, or MASH-HCC progression with disturbance of lipid metabolism, liver injury, and impaired gut mucosal barrier as indicated by loss of occludin in ileum mucosa. Gut dysbiosis occurred as early as 2 weeks with reduced α diversity, expansion of Kineothrix, Lactococcus, Akkermansia; and shrinkage in Bifidobacterium, Lactobacillus, etc., at a genus level. Dysbiosis was found as early as MAHS initiation, and was much more profound through the MASH-fibrotic and oncogenic progression. Moreover, the expansion of specific species, such as Lactobacillus johnsonii and Kineothrix alysoides, was confirmed by an optimized method for absolute quantification. Dynamic alterations of gut microbiota were characterized in three stages of early SFL, MASH, and its HCC transformation. The findings suggest that the extent of dysbiosis was accompanied with MASH progression and its transformation to HCC, and the shrinking or emerging of specific microbial species may account at least in part for pathologic, metabolic, and immunologic alterations in fibrogenic progression and malignant transition in the liver.

IFNγ-IL12 axis regulates intercellular crosstalk in metabolic dysfunction-associated steatotic liver disease.

Obesity is a major cause of metabolic dysfunction-associated steatohepatitis (MASH) and is characterized by inflammation and insulin resistance. Interferon-γ (IFNγ) is a pro-inflammatory cytokine elevated in obesity and modulating macrophage functions. Here, we show that male mice with loss of IFNγ signaling in myeloid cells (Lyz-IFNγR2-/-) are protected from diet-induced insulin resistance despite fatty liver. Obesity-mediated liver inflammation is also attenuated with reduced interleukin (IL)-12, a cytokine primarily released by macrophages, and IL-12 treatment in vivo causes insulin resistance by impairing hepatic insulin signaling. Following MASH diets, Lyz-IFNγR2-/- mice are rescued from developing liver fibrosis, which is associated with reduced fibroblast growth factor (FGF) 21 levels. These results indicate critical roles for IFNγ signaling in macrophages and their release of IL-12 in modulating obesity-mediated insulin resistance and fatty liver progression to MASH. In this work, we identify the IFNγ-IL12 axis in regulating intercellular crosstalk in the liver and as potential therapeutic targets to treat MASH.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD)-related advanced fibrosis and cirrhosis in the United States population utilizing AGILE 3 + and AGILE 4 scores: analysis of the NHANES 2017-2018 cycle.

BACKGROUND: Studies attempted to estimate MASLD-related advanced fibrosis (AF) and cirrhosis (MC) prevalence utilized tests with low positive predictive value (PPV) which overestimates prevalence. AGILE3 + and 4 scores were developed to increase the PPV of both; respectively. In this study, we used these scores to assess the prevalence of AF and MC. METHODS: Participants aged ≥ 18 years with VCTE exam in the NHANES 2017-2018 cycle were included. We excluded pregnant women, patients with excessive alcohol intake, hepatitis B/C, and ALT or AST > 500 IU/L. MASLD was defined with CAP score > 248 dB/m. MASLD subjects with AGILE 3 + score of ≥ 0.68 and AGILE 4 score of ≥ 0.57 were considered to have advanced fibrosis and cirrhosis; respectively. AGILE 3 + of 0.45-0.67 and AGILE 4 of 0.25-0.57 were grey zone, whereas AGILE 3 + < 0.45 and AGILE 4 < 0.25 were considered a rule-out. RESULTS: 1244 subjects were included in the final analysis. The Median age was 53 (51.4-54.6) years, 55.6% were male, median BMI was 33.8 kg/m2 and 41.1% had T2DM. Based on AGILE 3+, 80.3% of the MASLD population were at low risk for AF and 11.5% were in grey zone. The prevalence of AF due to MASLD was 8.1% corresponding to 4.5 million Americans. Based on AGILE 4 score, 96.5% of the MASLD population were at low risk for cirrhosis and 2.4% were in the grey zone. The prevalence of MASLD-cirrhosis was 1.1% corresponding to 610,000 Americans. CONCLUSION: Our results suggest that approximately 4.5 million people in the U.S. have AF and 0.6 million have cirrhosis due to MASLD.

Targeting BRD4 mitigates hepatocellular lipotoxicity by suppressing the NLRP3 inflammasome activation and GSDMD-mediated hepatocyte pyroptosis.

Nod-like receptor family pyrin-containing protein 3 (NLRP3) inflammasome plays a pathologic role in metabolic dysfunction-associated steatohepatitis (MASH), but the molecular mechanism regulating the NLRP3 inflammasome activation in hepatocellular lipotoxicity remains largely unknown. Bromodomain-containing protein 4 (BRD4) has emerged as a key epigenetic reader of acetylated lysine residues in enhancer regions that control the transcription of key genes. The aim of this study is to investigate if and how BRD4 regulated the NLRP3 inflammasome activation and pyroptosis in MASH. Using the AML12 and primary mouse hepatocytes stimulated by palmitic acid (PA) as an in vitro model of hepatocellular lipotoxicity, we found that targeting BRD4 by genetic knockdown or a selective BRD4 inhibitor MS417 protected against hepatosteatosis; and this protective effect was attributed to inhibiting the activation of NLRP3 inflammasome and reducing the expression of Caspase-1, gasdermin D (GSDMD), interleukin (IL)-1ß and IL-6. Moreover, BRD4 inhibition limited the voltage-dependent anion channel-1 (VDAC1) expression and oligomerization in PA-treated AML12 hepatocytes, thereby suppressing the NLRP3 inflammasome activation. Additionally, the expression of BRD4 enhanced in MASH livers of humans. Mechanistically, BRD4 was upregulated during hepatocellular lipotoxicity that in turn modulated the active epigenetic mark H3K27ac at the promoter regions of the Vdac and Gsdmd genes, thereby enhancing the expression of VDAC and GSDMD. Altogether, our data provide novel insights into epigenetic mechanisms underlying BRD4 activating the NLRP3 inflammasome and promoting GSDMD-mediated pyroptosis in hepatocellular lipotoxicity. Thus, BRD4 might serve as a novel therapeutic target for the treatment of MASH.

Bioelectrical impedance parameters add incremental value to waist-to-hip ratio for prediction of metabolic dysfunction associated steatotic liver disease in youth with overweight and obesity.

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) presents a growing health concern in pediatric populations due to its association with obesity and metabolic syndrome. Bioelectrical impedance analysis (BIA) offers a non-invasive and potentially effective alternative for identifying MASLD risk in youth with overweight or obesity. Therefore, this study aimed to assess the utility of BIA for screening for MASLD in the youth. Method: This retrospective, cross-sectional study included 206 children and adolescents aged <20 years who were overweight and obese. The correlations between anthropometric measurements and BIA parameters and alanine aminotransferase (ALT) levels were assessed using Pearson's correlation analysis. Logistic regression analysis was performed to examine the associations between these parameters and ALT level elevation and MASLD score. Receiver operating characteristic (ROC) curves were generated to assess the predictive ability of the parameters for MASLD. Results: Pearson's correlation analysis revealed that waist-to-hip ratio (WHR), percentage body fat (PBF), and BIA parameters combined with anthropometric measurements were correlated with ALT level. Logistic regression revealed that WHR, skeletal muscle mass/WHR, PBF-WHR, fat-free mass/WHR, and appendicular skeletal muscle mass/WHR were correlated with ALT level elevation after adjusting for age, sex, and puberty. WHR, PBF-WHR, and visceral fat area (VFA)-WHR were positively correlated with the MASLD score in the total population after adjusting for age, sex, and puberty. PBF-WHR and VFA-WHR were correlated with the MASLD score even in youth with a normal ALT level. The cutoff points and area under the ROC curves were 34.6 and 0.69 for PBF-WHR, respectively, and 86.6 and 0.79 for VFA-WHR, respectively. Discussion: This study highlights the utility of combining BIA parameters and WHR in identifying the risk of MASLD in overweight and obese youth, even in those with a normal ALT level. BIA-based screening offers a less burdensome and more efficient alternative to conventional MASLD screening methods, facilitating early detection and intervention in youth at risk of MASLD.