Systematic review of risk factors for fibrosis progression in non-alcoholic steatohepatitis

Development and validation of a nomogram for nonalcoholic fatty liver disease in Western Xinjiang, China

OBJECTIVE

The aim of this study was to establish a simple, nonalcoholic fatty liver disease (NAFLD) screening model using readily available variables to identify high-risk individuals in Western Xinjiang, China.

METHODS

A total of 40 033 patients from the National Health Examination were divided into a training group (70%) and a validation group (30%). Univariate regression and least absolute shrinkage and selection operator models optimized feature selection, while a multivariate logistic regression analysis constructed the prediction model. The model's performance was evaluated using the area under the receiver operating characteristic curve, and its clinical utility was assessed through decision curve analysis.

RESULTS

The nomogram assessed NAFLD risk based on factors such as sex, age, diastolic blood pressure, waist circumference, BMI, fasting plasma glucose, alanine aminotransferase, platelet count, total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol. The area under the receiver operating characteristic curves were 0.829 for men and 0.859 for women in the development group, and 0.817 for men and 0.865 for women in the validation group. The decision curve analysis confirmed the nomogram's clinical usefulness, with consistent findings in the validation set.

CONCLUSION

A user-friendly nomogram prediction model for NAFLD risk was successfully developed and validated for Western Xinjiang, China.

Incidence of metabolic dysfunction-associated steatotic liver disease and advanced fibrosis and impact of overweight/obesity in elderly population: a nationwide cohort study

BACKGROUND AND AIM

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing worldwide, coinciding with aging population. However, limited studies have evaluated its incidence and progression to advanced fibrosis in the elderly population. Therefore, our study aimed to investigate the incidence of MASLD and advanced fibrosis in this age group.

METHODS

We included 878 686 individuals aged ≥60 years from the Korea National Health Insurance Service-Senior cohort. After excluding participants with preexisting MASLD, 329 388 individuals were finally analyzed. Participants were categorized into four groups based on the presence of overweight/obesity and additional risk factors (aRF) included in the cardiometabolic diagnostic criteria of MASLD.

RESULTS

The overall incidence of MASLD was 1.94 per 100 person-years, and the incidence of advanced fibrosis in MASLD patients was 1.78 per 100 person-years. MASLD development was significantly higher in overweight/obese patients (2.65 per 100 person-years) compared to lean patients (1.09 per 100 person-years), and this trend persisted after stratification by the presence of aRF. Similarly, the incidence of advanced fibrosis among MASLD patients was higher in overweight/obese individuals (2.06 per 100 person-years) compared to lean counterparts (0.87 per 100 person-years), irrespective of aRF.

CONCLUSIONS

The lower incidence of MASLD in the elderly population compared to the general population underscores the importance of identifying age-specific risk factors. Overweight/obesity emerged as a robust predictor of MASLD development and advanced fibrosis. Additionally, the presence of additional cardiometabolic risk factors further increased the risk of incident MASLD and advanced fibrosis among the elderly.

Reference values and associated factors of controlled attenuation parameter and liver stiffness in adults: A cross-sectional study

BACKGROUND & AIMS

The utilization of non-invasive techniques for liver fibrosis and steatosis assessment has gained acceptance as a viable substitute for liver biopsy in clinical practice. This study aimed to establish normative data for the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) by age and gender, as well as to explore the relationship between anthropometric measures, clinical status, and biochemical profile according to the 90th percentile cut-off values for CAP/LSM in a U.S. adult population.

METHODS AND RESULTS

In this cross-sectional analysis, 7.522 US adults aged 20-80 years from the National Health and Nutrition Examination Survey (NHANES 2017-2020) were included. CAP and LSM were quantified using the FibroScan® 502-v2 device. A comprehensive range of data was collected, including sociodemographic, anthropometric, biochemical, lifestyle, and clinical conditions. Participants were segmented by sex and age. The median ± standard deviation (SD) for CAP was significantly lower in women (258.27 ± 61.02 dB/m) than in men (273.43 ± 63.56 dB/m), as was the median ± SD for LSM (women: 5.50 ± 4.12 kPa, men: 6.36 ± 5.63 kPa). Although median CAP and LSM values displayed an upward trend with age, statistical significance was not achieved. Notably, higher liver CAP values (above the 90th percentile) correlated with more pronounced clinical and biochemical profile differences compared to lower CAP values (below the 90th percentile) (p < 0.001).

CONCLUSIONS

Our study provides age- and sex-stratified standard values for CAP and LSM in a sizeable, nationally representative cohort of adults. The evidence of sex-specific variations in TE test results from our study sets the stage for future research to further corroborate these findings.

Probiotic Mixture Ameliorates a Diet-Induced MASLD/MASH Murine Model through the Regulation of Hepatic Lipid Metabolism and the Gut Microbiome

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent metabolic disease that has no effective treatment. Our proprietary probiotic mixture, Prohep, has been proven in a previous study to be helpful in reducing hepatocellular carcinoma (HCC) in vivo. However, its prospective benefits on the treatment of other liver diseases such as MASLD, which is one of the major risk factors in the development of HCC, are unclear. To investigate the potential of Prohep in modulating the development and progression of MASLD, we first explored the effect of Prohep supplementation via voluntary intake in a high-fat diet (HFD)-induced MASLD/metabolic dysfunction-associated steatohepatitis (MASH) murine model. Our results indicated that Prohep alleviated HFD-induced liver steatosis and reduced excessive hepatic lipid accumulation and improved the plasma lipid profile when compared with HFD-fed control mice through suppressing hepatic de novo lipogenesis and cholesterol biosynthesis gene expressions. In addition, Prohep was able to modulate the gut microbiome, modify the bile acid (BA) profile, and elevate fecal short-chain fatty acid (SCFA) levels. Next, in a prolonged HFD-feeding MASLD/MASH model, we observed the effectiveness of Prohep in preventing the transition from MASLD to MASH via amelioration in hepatic steatosis, inflammation, and fibrosis. Taken together, Prohep could ameliorate HFD-induced MASLD and control the MASLD-to-MASH progression in mice. Our findings provide distinctive insights into the development of novel microbial therapy for the management of MASLD and MASH.

Different aspects of immunological profile in patients with Non-Alcoholic Fatty liver disease

Background

NAFLD is thought to affect approximately one-fourth of the world's population. Therefore, we evaluated the role of serum complement and immunoglobulins in the NAFLD pathogenesis.

Patients and methods

200 participants were used in this study, divided into two groups; Group I: 100 NAFLD patients and Group II: 100 healthy volunteers. The diagnosis of NAFLD is based on non-invasive methods, following the EASL guideline 2022. IgG, IgM, IgA, C3, and C4 assays were performed on all participants.

Results

When the immunological profiles of patients with NAFLD and healthy controls were compared, it was found that the mean IgA in NAFLD patients was (4.20±5.07), whereas the mean IgA in healthy controls was (2.22±1.05) (P=0.000). Additionally, a significant increase in IgG was found in NAFLD patients (17.08±3.87) compared with healthy controls (11.59±3.34), with a P value of (p<0.001). complement C3 and complement C4 levels significantly increased in nonalcoholic fatty liver disease patients (1.28± 0.61 and 0.40 ± 0.19, respectively), compared to healthy controls (0.90 ±0.27 and 0.30 ±0.12, respectively), with a significant P value (p<0.001 for each).

Conclusions

Elevated IgA, IgG, C3 and C4 exist in patients with NAFLD and could be associated with fatty liver development and progression of hepatic fibrosis in patients with NAFLD.

Systemic immune-inflammatory biomarkers (SII, NLR, PLR and LMR) linked to non-alcoholic fatty liver disease risk

Background

Systemic immune-inflammatory biomarkers including systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have been demonstrated to be associated with the risk and severity of various liver diseases. However, studies on their role and clinical significance in metabolic diseases, especially in nonalcoholic fatty liver disease (NAFLD), are limited and results are inconsistent.

Methods

10821 adults aged 20 years or older were enrolled in this cross-sectional study, sourced from six cycles of the National Health and Nutrition Examination Survey (NHANES). Survey-weighted logistic regression was employed to investigate the correlation between systemic immune-inflammatory biomarkers (SII, NLR, PLR, and LMR) and NAFLD risk. Restricted cubic spline regression models and segmented regression models were used to describe nonlinear relationships and threshold effects. Subgroup and sensitivity analyses were also conducted.

Results

After adjusting for all confounding variables, there was a significant positive association observed between ln-transformed SII (OR= 1.46, 95% CI: 1.27-1.69, P <0.001), NLR (OR= 1.25, 95% CI: 1.05-1.49, P =0.015), LMR (OR= 1.39, 95% CI: 1.14-1.69, P = 0.002) with NAFLD. A nonlinear dose-response relationship with an inverted "U"-shaped threshold of 4.64 was observed between ln(PLR) and NAFLD risk. When ln(PLR) was below 4.64, each unit increase in ln(PLR) was associated with a 0.55-fold increase in the risk of NAFLD (OR= 1.55, 95% CI: 1.05-2.31, P <0.05). Conversely, when ln(PLR) exceeded 4.64, each unit increase in ln(PLR) was associated with a 0.40-fold decrease in the risk of NAFLD (OR= 0.60, 95% CI. 0.44-0.81, P <0.05).

Conclusion

ln-transformed SII, NLR, and LMR were linearly associated with NAFLD risk. ln(PLR) showed an inverted "U"-shaped nonlinear dose-response relationship with the risk of NAFLD.

Liver fibrosis in NAFLD/NASH: from pathophysiology towards diagnostic and therapeutic strategies

Liver fibrosis, as an excess deposition of extracellular matrix (ECM) components, results from chronic liver injury as well as persistent activation of inflammatory response and of fibrogenesis. Liver fibrosis is a major determinant for chronic liver disease (CLD) progression and in the last two decades our understanding on the major molecular and cellular mechanisms underlying the fibrogenic progression of CLD has dramatically improved, boosting pre-clinical studies and clinical trials designed to find novel therapeutic approaches. From these studies several critical concepts have emerged, starting to reveal the complexity of the pro-fibrotic microenvironment which involves very complex, dynamic and interrelated interactions between different hepatic and extrahepatic cell populations. This review will offer first a recapitulation of established and novel pathophysiological basic principles and concepts by intentionally focus the attention on NAFLD/NASH, a metabolic-related form of CLD with a high impact on the general population and emerging as a leading cause of CLD worldwide. NAFLD/NASH-related pro-inflammatory and profibrogenic mechanisms will be analysed as well as novel information on cells, mediators and signalling pathways which have taken advantage from novel methodological approaches and techniques (single cell genomics, imaging mass cytometry, novel in vitro two- and three-dimensional models, etc.). We will next offer an overview on recent advancement in diagnostic and prognostic tools, including serum biomarkers and polygenic scores, to support the analysis of liver biopsies. Finally, this review will provide an analysis of current and emerging therapies for the treatment of NAFLD/NASH patients.

Neutrophil extracellular traps promote MASH fibrosis by metabolic reprogramming of HSC

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) fibrosis is a reversible stage of liver disease accompanied by inflammatory cell infiltration. Neutrophils extrude a meshwork of chromatin fibers to establish neutrophil extracellular traps (NETs), which play important roles in inflammatory response regulation. Our previous work demonstrated that NETs promote HCC in MASH. However, it is still unknown if NETs play a role in the molecular mechanisms of liver fibrosis.

APPROACH AND RESULTS

Following 12 weeks of Western diet/carbon tetrachloride, MASH fibrosis was identified in C57BL/6 mice with increased NET formation. However, NET depletion using DNase I treatment or mice knocked out for peptidyl arginine deaminase type IV significantly attenuated the development of MASH fibrosis. NETs were demonstrated to induce HSCs activation, proliferation, and migration through augmented mitochondrial and aerobic glycolysis to provide additional bioenergetic and biosynthetic supplies. Metabolomic analysis revealed markedly an altered metabolic profile upon NET stimulation of HSCs that were dependent on arachidonic acid metabolism. Mechanistically, NET stimulation of toll-like receptor 3 induced cyclooxygenase-2 activation and prostaglandin E2 production with subsequent HSC activation and liver fibrosis. Inhibiting cyclooxygenase-2 with celecoxib reduced fibrosis in our MASH model.

CONCLUSIONS

Our findings implicate NETs playing a critical role in the development of MASH hepatic fibrosis by inducing metabolic reprogramming of HSCs through the toll-like receptor 3/cyclooxygenase-2/cyclooxygenase-2 pathway. Therefore, NET inhibition may represent an attractive treatment target for MASH liver fibrosis.

Endpoints in NASH Clinical Trials: Are We Blind in One Eye?

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.

Emerging role of lipophagy in liver disorders

Lipophagy is a selective degradation of lipids by a lysosomal-mediated pathway, and dysregulation of lipophagy is linked with the pathological hallmark of many liver diseases. Downregulation of lipophagy in liver cells results in abnormal accumulation of LDs (Lipid droplets) in hepatocytes which is a characteristic feature of several liver pathologies such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Contrarily, upregulation of lipophagy in activated hepatic stellate cells (HSCs) is associated with hepatic fibrosis and cirrhosis. Lipid metabolism reprogramming in violent cancer cells contributes to the progression of liver cancer. In this review, we have summarized the recent studies focusing on various components of the lipophagic machinery that can be modulated for their potential role as therapeutic agents against a wide range of liver diseases.

Hepatokine-based identification of fibrotic NASH and improved risk stratification in a multicentre cohort of NAFLD patients

BACKGROUND AND AIMS

The presence of significant liver fibrosis associated with non-alcoholic steatohepatitis (NASH) is regarded as the major prognostic factor in non-alcoholic fatty liver disease (NAFLD). Identification of patients at risk for NASH with significant fibrosis is therefore important. Although the established fibrosis score FIB-4 is suitable to exclude advanced fibrosis, it does not allow the prediction of significant fibrosis in NAFLD patients. We therefore evaluated whether the hepatokine fibroblast growth factor 21 (FGF21), a regulator of glucose and lipid metabolism, might identify 'at-risk NASH' in NAFLD.

METHODS

FGF21 levels were assessed by enzyme-linked immunosorbent assay in sera from an exploration (n = 137) and a validation (n = 88) cohort of biopsy-proven NAFLD patients with different disease activity and fibrosis stages. In addition, we evaluated whether the use of FGF21 could improve risk stratification in NAFLD patients with low (<1.3) or intermediate (1.3-2.67) FIB-4.

RESULTS

FGF21 levels could significantly discriminate between NASH and non-alcoholic fatty liver (NAFL) patients, even in the absence of diabetes. Moreover, patients with NASH and fibrosis ≥F2 showed significantly higher FGF21 levels compared to NAFLD patients without significant fibrosis. Significantly elevated FGF21 levels could even be detected in NAFLD patients with NASH and significant fibrosis despite low or intermediate FIB-4.

CONCLUSION

Serological FGF21 detection might allow the identification of NAFLD patients at risk and improves patient stratification in combination with FIB-4.

A Markov model of fibrosis development in nonalcoholic fatty liver disease predicts fibrosis progression in clinical cohorts

Disease progression in nonalcoholic steatohepatitis (NASH) is highly heterogenous and remains poorly understood. Fibrosis stage is currently the best predictor for development of end-stage liver disease and mortality. Better understanding and quantifying the impact of factors affecting NASH and fibrosis is essential to inform a clinical study design. We developed a population Markov model to describe the transition probability between fibrosis stages and mortality using a unique clinical nonalcoholic fatty liver disease cohort with serial biopsies over 3 decades. We evaluated covariate effects on all model parameters and performed clinical trial simulations to predict the fibrosis progression rate for external clinical cohorts. All parameters were estimated with good precision. Age and diagnosis of type 2 diabetes (T2D) were found to be significant predictors in the model. Increase in hepatic steatosis between visits was the most important predictor for progression of fibrosis. Fibrosis progression rate (FPR) was twofold higher for fibrosis stages 0 and 1 (F0-1) compared to fibrosis stage 2 and 3 (F2-3). A twofold increase in FPR was observed for T2D. A two-point steatosis worsening increased the FPR 11-fold. Predicted fibrosis progression was in good agreement with data from external clinical cohorts. Our fibrosis progression model shows that patient selection, particularly initial fibrosis stage distribution, can significantly impact fibrosis progression and as such the window for assessing drug efficacy in clinical trials. Our work highlights the increase in hepatic steatosis as the most important factor in increasing FPR, emphasizing the importance of well-defined lifestyle advise for reducing variability in NASH progression during clinical trials.

The Combination of Remnant Cholesterol and Waist Circumference Offers Predictive Value for Nonalcoholic Fatty Liver Disease: A Cross-Sectional Study from a Medical Examination Center

Objective

To explore the association between levels of remnant cholesterol (RC) and the incidence of non-alcoholic fatty liver disease (NAFLD) in the general population, ultimately leading to the assessment of a novel proposed model combining RC and waist circumference (R-W) as a predictor of NAFLD incidence.

Methods

A cross-sectional analysis was conducted of 4913 subjects undergoing physical examinations at Hebei General Hospital, with ultrasound findings being used to classify patients into individuals with and without NAFLD. Median RC values were used to separate subjects into those with low and high levels of RC, after which the predictive performance of RC and the novel R-W model when used to assess NAFLD risk was assessed through multifactorial logistic regression analyses and receiver operating characteristic curves.

Results

Subjects exhibiting higher RC levels were found to exhibit an elevated risk of NAFLD incidence with or without adjusting for confounding factors. The binary logistic regression analysis-based R-W model may thus offer utility as a tool to gauge the risk of NAFLD in the general population, as it outperformed RC or WC alone, particularly when assessing women or individuals < 45 years of age. The area under the ROC curve for this combined R-W model was 0.813 (0.802, 0.824), with respective sensitivity and specificity values of 83.86% and 63.91%, all of which were significantly higher than corresponding values for RC and WC (P < 0.001).

Conclusion

The present supports a strong association between RC levels and NAFLD in the general populace, and the combined R-W model exhibits greater utility as a tool to predict NAFLD incidence relative to RC or WC in isolation, particularly for individuals who are female or <45 years old.

Molecular magnetic resonance imaging of liver inflammation using an oxidatively activated probe

Background & Aims

Many liver diseases are driven by inflammation, but imaging to non-invasively diagnose and quantify liver inflammation has been underdeveloped. The inflammatory liver microenvironment is aberrantly oxidising owing in part to reactive oxygen species generated by myeloid leucocytes. We hypothesised that magnetic resonance imaging using the oxidatively activated probe Fe-PyC3A will provide a non-invasive biomarker of liver inflammation.

Methods

A mouse model of drug-induced liver injury was generated through intraperitoneal injection of a hepatoxic dose of acetaminophen. A mouse model of steatohepatitis was generated via a choline-deficient, l-amino acid defined high-fat diet (CDAHFD). Images were acquired dynamically before and after intravenous injection of Fe-PyC3A. The contrast agent gadoterate meglumine was used as a non-oxidatively activated negative control probe in mice fed CDAHFD. The (post-pre) Fe-PyC3A injection change in liver vs. muscle contrast-to-noise ratio (ΔCNR) recorded 2 min post-injection was correlated with liver function test values, histologic scoring assigned using the NASH Clinical Research Network criteria, and intrahepatic myeloid leucocyte composition determined by flow cytometry.

Results

For mice receiving i.p. injections of acetaminophen, intrahepatic neutrophil composition correlated poorly with liver test values but positively and significantly with ΔCNR (r = 0.64, p <0.0001). For mice fed CDAHFD, ΔCNR generated by Fe-PyC3A in the left lobe was significantly greater in mice meeting histologic criteria strongly associated with a diagnosis NASH compared to mice where histology was consistent with likely non-NASH (p = 0.0001), whereas no differential effect was observed using gadoterate meglumine. In mice fed CDAHFD, ΔCNR did not correlate strongly with fractional composition of any specific myeloid cell subpopulation as determined by flow cytometry.

Conclusions

Magnetic resonance imaging using Fe-PyC3A merits further evaluation as a non-invasive biomarker for liver inflammation.

Impact and implications

Non-invasive tests to diagnose and measure liver inflammation are underdeveloped. Inflammatory cells such as neutrophils release reactive oxygen species which creates an inflammatory liver microenvironment that can drive chemical oxidation. We recently invented a new class of magnetic resonance imaging probe that is made visible to the scanner only after chemical oxidation. Here, we demonstrate how this imaging technology could be applied as a non-invasive biomarker for liver inflammation.

Nanoparticle-Mediated RNA Therapy Attenuates Nonalcoholic Steatohepatitis and Related Fibrosis by Targeting Activated Hepatic Stellate Cells

Chronic liver injury and inflammation triggered by metabolic abnormalities initiate the activation of hepatic stellate cells (HSCs), driving fibrosis and parenchymal dysfunction, culminating in disorders such as nonalcoholic steatohepatitis (NASH). Unfortunately, there are currently no approved drugs capable of effectively treating NASH due to the challenges in addressing fibrosis and restoring extracellular matrix (ECM) homeostasis. We discovered a significant up-regulation of interleukin-11 (IL-11) in fibrotic livers using two well-established murine models of NASH. To leverage this signaling pathway, we developed a nanoparticle (NP)-assisted RNA interfering approach that specifically targets activated HSCs (aHSCs), blocking IL-11/ERK signaling to regulate HSC transdifferentiation along with fibrotic remodeling. The most potent NP, designated NP-AEAA, showed enhanced accumulation in fibrotic livers with NASH and was primarily enriched in aHSCs. We further investigated the therapeutic efficacy of aHSC-targeting NP-AEAA encapsulating small interfering RNA (siRNA) against IL11 or its cognate receptor IL11ra1 (termed siIL11@NP-AEAA or siIL11ra1@NP-AEAA, respectively) for resolving fibrosis and NASH. Our results demonstrate that both siIL11@NP-AEAA and siIL11ra1@NP-AEAA effectively inhibit HSC activation and resolve fibrosis and inflammation in two well-established murine models of NASH. Notably, siIL11ra1@NP-AEAA exhibits a superior therapeutic effect over siIL11@NP-AEAA, in terms of reducing liver steatosis and fibrosis as well as recovering liver function. These results constitute a targeted nanoparticulate siRNA therapeutic approach against the IL-11 signaling pathway of aHSCs in the fibrotic liver, offering a promising therapeutic intervention for NASH and other diseases.

Plantamajoside modulates immune dysregulation and hepatic lipid metabolism in rats with nonalcoholic fatty liver disease via AMPK/Nrf2 elevation

Nonalcoholic fatty liver disease (NAFLD) is a hepatic metabolic syndrome with a rapidly increasing prevalence globally. Plantamajoside (PMS), a phenylethanoid glycoside component extracted from Plantago asiatica, has various biological properties. However, its effect on NAFLD remains unknown. The study aimed to explore the effect and mechanism of PMS on NAFLD in the high-fat diet (HFD)-feeding rats. PMS induced a decrease in body and liver weight, and the amelioration in the blood lipid parameters and pathological symptoms in HFD-feeding rats. The increase in the serum concentrations and the relative protein expressions of proinflammatory factors was decreased by the PMS treatment in HFD-induced NAFLD rats. Additionally, PMS reduced the excessive lipid vacuoles, and modified the relative expressions of proteins involved in the fatty acid synthesis and uptake in HFD-feeding rats. Mechanically, the downregulation of AMPK/Nrf2 pathway in HFD-feeding rats was restored by the PMS treatment. Inhibition of AMPK pathway reversed the PMS-induced the increase in the level of inflammatory factors, pathological symptoms, excessive lipid vacuoles, and the relative expression of proteins involved in the fatty acid synthesis and uptake. Collectively, PMS ameliorated immune dysregulation and abnormal hepatic lipid metabolism by activating AMPK/Nrf2 pathway in rats with NAFLD.

Wnt/beta-catenin signaling and its modulators in nonalcoholic fatty liver diseases

Nonalcoholic fatty liver disease (NAFLD) is a global health concern associated with significant morbidity and mortality. NAFLD is a spectrum of diseases originating from simple steatosis, progressing through nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis that may lead to hepatocellular carcinoma (HCC). The pathogenesis of NAFLD is mediated by the triglyceride accumulation followed by proinflammatory cytokines expression leading to inflammation, oxidative stress, and mitochondrial dysfunction denoted as "two-hit hypothesis", advancing with a "third hit" of insufficient hepatocyte proliferation, leading to the increase in hepatic progenitor cells contributing to fibrosis and HCC. Wnt/β-catenin signaling is responsible for normal liver development, regeneration, hepatic metabolic zonation, ammonia and drug detoxification, hepatobiliary development, etc., maintaining the overall liver homeostasis. The key regulators of canonical Wnt signaling such as LRP6, Wnt1, Wnt3a, β-catenin, GSK-3β, and APC are abnormally regulated in NAFLD. Many experimental studies have shown the aberrated Wnt/β-catenin signaling during the NAFLD progression and NASH to hepatic fibrosis and HCC. Therefore, in this review, we have emphasized the role of Wnt/β-catenin signaling and its modulators that can potentially aid in the inhibition of NAFLD.

Identifying a distinct fibrosis subset of NAFLD via molecular profiling and the involvement of profibrotic macrophages

BACKGROUND

There are emerging studies suggesting that non-alcoholic fatty liver disease (NAFLD) is a heterogeneous disease with multiple etiologies and molecular phenotypes. Fibrosis is the key process in NAFLD progression. In this study, we aimed to explore molecular phenotypes of NAFLD with a particular focus on the fibrosis phenotype and also aimed to explore the changes of macrophage subsets in the fibrosis subset of NAFLD.

METHODS

To assess the transcriptomic alterations of key factors in NAFLD and fibrosis progression, we included 14 different transcriptomic datasets of liver tissues. In addition, two single-cell RNA sequencing (scRNA-seq) datasets were included to construct transcriptomic signatures that could represent specific cells. To explore the molecular subsets of fibrosis in NAFLD based on the transcriptomic features, we used a high-quality RNA-sequencing (RNA-seq) dataset of liver tissues from patients with NAFLD. Non-negative matrix factorization (NMF) was used to analyze the molecular subsets of NAFLD based on the gene set variation analysis (GSVA) enrichment scores of key molecule features in liver tissues.

RESULTS

The key transcriptomic signatures on NAFLD including non-alcoholic steatohepatitis (NASH) signature, fibrosis signature, non-alcoholic fatty liver (NAFL) signature, liver aging signature and TGF-β signature were constructed by liver transcriptome datasets. We analyzed two liver scRNA-seq datasets and constructed cell type-specific transcriptomic signatures based on the genes that were highly expressed in each cell subset. We analyzed the molecular subsets of NAFLD by NMF and categorized four main subsets of NAFLD. Cluster 4 subset is mainly characterized by liver fibrosis. Patients with Cluster 4 subset have more advanced liver fibrosis than patients with other subsets, or may have a high risk of liver fibrosis progression. Furthermore, we identified two key monocyte-macrophage subsets which were both significantly correlated with the progression of liver fibrosis in NAFLD patients.

CONCLUSION

Our study revealed the molecular subtypes of NAFLD by integrating key information from transcriptomic expression profiling and liver microenvironment, and identified a novel and distinct fibrosis subset of NAFLD. The fibrosis subset is significantly correlated with the profibrotic macrophages and M2 macrophage subset. These two liver macrophage subsets may be important players in the progression of liver fibrosis of NAFLD patients.

Disease State Transition Probabilities Across the Spectrum of NAFLD: A Systematic Review and Meta-Analysis of Paired Biopsy or Imaging Studies

BACKGROUND & AIMS

We conducted a meta-analysis to summarize the rates of progression to and regression of nonalcoholic fatty liver (NAFL), nonalcoholic steatohepatitis (NASH), and fibrosis in adults with nonalcoholic fatty liver disease (NAFLD).

METHODS

We searched PubMed/Medline and 4 other databases from 1985 through 2020. We included observational studies and randomized controlled trials in any language that used liver biopsy or imaging to diagnose NAFLD in adults with a follow-up period ≥48 weeks. Rates were calculated as incident cases per 100 person-years and pooled using the random-effects Poisson distribution model. Heterogeneity was assessed using the I2 statistic.

RESULTS

We screened 9744 articles and included 54 studies involving 26,738 patients. Among observational studies, 20% of healthy adults developed NAFL (incidence rate, 4.8/100 person-years) while 21% of people with fatty liver had resolution of NAFL (incidence rate, 2.4/100 person-years) after a median of approximately 4.5 years. In addition, 31% of patients developed NASH after 4.7 years (incidence rate, 7.4/100 person-years), whereas in 29% of those with NASH, resolution occurred after a median of 3.5 years (incidence rate, 5.1/100 person-years). Time to progress by 1 fibrosis stage was 9.9, 10.3, 13.3, and 22.2 years for F0, F1, F2, and F3, respectively. Time to regress by 1 stage was 21.3, 12.5, 20.4, and 40.0 years for F4, F3, F2, and F1, respectively. Rates estimated from randomized controlled trials were higher than those from observational studies.

CONCLUSIONS

In our meta-analysis, progression to NASH was more common than regression from NASH. Rates of fibrosis progression were similar across baseline stage, but patients with advanced fibrosis were more likely to regress than those with mild fibrosis.

Comparison between metabolic-associated fatty liver disease and nonalcoholic fatty liver disease: From nomenclature to clinical outcomes

As a result of the obesity epidemic, Nonalcoholic fatty liver disease (NAFLD) and its complications have increased among millions of people. Consequently, a group of experts recommended changing the term NAFLD to an inclusive terminology more reflective of the underlying pathogenesis; metabolic-associated fatty liver disease (MAFLD). This new term of MAFLD has its own disease epidemiology and clinical outcomes prompting efforts in studying its differences from NAFLD. This article discusses the rationale behind the nomenclature change, the main differences, and its clinical implications.

Polyunsaturated fatty acids drive neutrophil extracellular trap formation in nonalcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome. Non-resolving inflammation, triggered by sustained accumulation of lipids, is an important driving force of NASH. Thus, unveiling metabolic immune regulation could help better understand the pathology and intervention of NASH. In this study, we found the recruitment of neutrophils is an early inflammatory event in NASH mice, following the formation of neutrophil extracellular traps (NETs). NET is an initiating factor which exacerbates inflammatory responses in macrophages. Inhibition of NETs using DNase I significantly alleviated inflammation in NASH mice. We further carried out a metabolomic study to identify possible metabolic triggers of NETs, and linoleic acid (LA) metabolic pathway was the most altered pathway. We re-analyzed published clinical data and validated that LA metabolism was highly correlated with NASH. Consistently, both LA and γ-linolenic acid (GLA) were active in triggering NETs formation by oxidative burst. Furthermore, we identified silybin, a hepatoprotective agent, as a potent NETosis inhibitor, which effectively blocked NETs formation both in vitro and in vivo. Together, this study not only provide new insights into metabolism-immune causal link in NASH progression, but also demonstrate silybin as an important inhibitor of NETs and its therapeutical potential in treating NETosis-related diseases.

Effect of pemafibrate on liver enzymes and shear wave velocity in non-alcoholic fatty liver disease patients

Background/Aims

Pemafibrate is a selective peroxisome proliferator-activated receptor α modulator that improves serum alanine aminotransferase (ALT) in dyslipidemia patients. Pemafibrate was reported to reduce ALT in non-alcoholic fatty liver disease (NAFLD) patients, but efficacy was not clearly elucidated due to the small size of previous study populations. Therefore, we explored pemafibrate efficacy in NAFLD patients.

Methods

We retrospectively evaluated pemafibrate efficacy on liver enzymes (n = 132) and liver shear wave velocity (SWV, n = 51) in NAFLD patients who had taken pemafibrate for at least 24 weeks.

Results

Patient ALT levels were decreased from 81.0 IU/L at baseline to 48.0 IU/L at week 24 (P < 0.0001). Serum levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP) and triglyceride (TG) were significantly decreased, and high-density lipoprotein cholesterol and platelet count were significantly increased, with no change in body weight being observed. Study participant SWV values decreased from 1.45 m/s at baseline to 1.32 m/s at week 48 (P < 0.001). Older age (P = 0.035) and serum TG levels (P = 0.048) were significantly associated with normalized ALT. Changes in AST, ALT, γ-GTP and body weight were significantly correlated with change in SWV.

Conclusion

Pemafibrate significantly improves liver function, serum TG and liver stiffness in NAFLD patients. Pemafibrate is a promising therapeutic agent for NAFLD and may be a candidate for NAFLD patients with elevated TG.

Advances in the Diagnosis and Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease that affects approximately one-quarter of the global adult population, posing a significant threat to human health with wide-ranging social and economic implications. The main characteristic of NAFLD is considered that the excessive fat is accumulated and deposited in hepatocytes without excess alcohol intake or some other pathological causes. NAFLD is a progressive disease, ranging from steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis, hepatocellular carcinoma, liver transplantation, and death. Therefore, NAFLD will probably emerge as the leading cause of end-stage liver disease in the coming decades. Unlike other highly prevalent diseases, NAFLD has received little attention from the global public health community. Liver biopsy is currently considered the gold standard for the diagnosis and staging of NAFLD because of the absence of noninvasive and specific biomarkers. Due to the complex pathophysiological mechanisms of NAFLD and the heterogeneity of the disease phenotype, no specific pharmacological therapies have been approved for NAFLD at present, although several drugs are in advanced stages of development. This review summarizes the current evidence on the pathogenesis, diagnosis and treatment of NAFLD.

Non-alcoholic fatty liver disease: Definition and subtypes

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide, with a global prevalence of approximately 30%. However, the prevalence of NAFLD has been variously reported depending on the comorbidities. The rising prevalence of obesity in both the adult and pediatric populations is projected to consequently continue increasing NAFLD prevalence. It is a major cause of chronic liver disease worldwide, including cirrhosis and hepatocellular carcinoma (HCC). NAFLD has a variety of clinical phenotypes and heterogeneity due to the complexity of pathogenesis and clinical conditions of its occurrence, resulting in various clinical prognoses. In this article, we briefly described the basic definition of NAFLD and classified the subtypes based on current knowledge in this field.

Pathogenesis and treatment of non-alcoholic steatohepatitis and its fibrosis

The initial presentation of non-alcoholic steatohepatitis (NASH) is hepatic steatosis. The dysfunction of lipid metabolism within hepatocytes caused by genetic factors, diet, and insulin resistance causes lipid accumulation. Lipotoxicity, oxidative stress, mitochondrial dysfunction, and endoplasmic reticulum stress would further contribute to hepatocyte injury and death, leading to inflammation and immune dysfunction in the liver. During the healing process, the accumulation of an excessive amount of fibrosis might occur while healing. During the development of NASH and liver fibrosis, the gut-liver axis, adipose-liver axis, and renin-angiotensin system (RAS) may be dysregulated and impaired. Translocation of bacteria or its end-products entering the liver could activate hepatocytes, Kupffer cells, and hepatic stellate cells, exacerbating hepatic steatosis, inflammation, and fibrosis. Bile acids regulate glucose and lipid metabolism through Farnesoid X receptors in the liver and intestine. Increased adipose tissue-derived non-esterified fatty acids would aggravate hepatic steatosis. Increased leptin also plays a role in hepatic fibrogenesis, and decreased adiponectin may contribute to hepatic insulin resistance. Moreover, dysregulation of peroxisome proliferator-activated receptors in the liver, adipose, and muscle tissues may impair lipid metabolism. In addition, the RAS may contribute to hepatic fatty acid metabolism, inflammation, and fibrosis. The treatment includes lifestyle modification, pharmacological therapy, and non-pharmacological therapy. Currently, weight reduction by lifestyle modification or surgery is the most effective therapy. However, vitamin E, pioglitazone, and obeticholic acid have also been suggested. In this review, we will introduce some new clinical trials and experimental therapies for the treatment of NASH and related fibrosis.

Epidemiologic, Genetic, Pathogenic, Metabolic, Epigenetic Aspects Involved in NASH-HCC: Current Therapeutic Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is the sixth most frequent cancer in the world, being the third cause of cancer-related deaths. Nonalcoholic steatohepatitis (NASH) is characterized by fatty infiltration, oxidative stress and necroinflammation of the liver, with or without fibrosis, which can progress to advanced liver fibrosis, cirrhosis and HCC. Obesity, metabolic syndrome, insulin resistance, and diabetes exacerbates the course of NASH, which elevate the risk of HCC. The growing prevalence of obesity are related with increasing incidence of NASH, which may play a growing role in HCC epidemiology worldwide. In addition, HCC initiation and progression is driven by reprogramming of metabolism, which indicates growing appreciation of metabolism in the pathogenesis of this disease. Although no specific preventive pharmacological treatments have recommended for NASH, dietary restriction and exercise are recommended. This review focuses on the molecular connections between HCC and NASH, including genetic and risk factors, highlighting the metabolic reprogramming and aberrant epigenetic alterations in the development of HCC in NASH. Current therapeutic aspects of NASH/HCC are also reviewed.

Evaluation of ABCA1 gene polymorphism as a prognostic index of fibrosis progression in NAFLD patients

INTRODUCTION

It had been evident that non-alcoholic fatty liver disease (NAFLD) is the new era epidemic. Despite emergence of many drugs on the pipeline that considered candidates to cure NAFLD/NASH, the critical need for defining the cohort liable to fibrosis progression is yet unmet.

AIM

Evaluate ABCA1 (rs1800977) genotyping as a noninvasive predictor of liver fibrosis severity.

MATERIALS AND METHODS

This study included 118 liver biopsy-proven NAFLD-patients. According to Metavir-fibrosis-staging, cases were divided to early fibrosis (74 cases), and 44 cases with significant fibrosis (>F2), added to 49 healthy control subjects. All patients were subjected to liver function tests, lipids profile, triglyceride TG index, and hepatic steatosis index (HSI) and real-time PCR ABCA1 SNP (rs1800977).

RESULTS

Significant differences in transaminases (p > .05), albumin (p < .009), cholesterol (p0.03), low density lipoproteins (LDL) (0.006), triglycerides (p < .001), HSI (p < .001), FIB4 (p < .001) and APRI (p < .001) were reported in those with significant than early fibrosis and control groups. CC was the most prevalent in significant (36.4%) than early fibrosis (13.5%) and control groups (8.2%), with prevalence of C allele in significant fibrosis (p ≤ .003). Univariate analysis revealed that DM (p ≤ .001), TG index (p ≤ .022), cholesterol (p ≤ .03), HSI (p ≤ .006), LDL (p ≤ .02), HDL (p ≤ .01), APRI (p ≤ .02) and CC genotype (p ≤ .005) were the main factors affecting fibrosis progression in NAFLD. However multivariate analysis proved only the role of HSI (p ≤ .005), LDL (p ≤ .02), HDL (p ≤ .003) and CC genotype (p ≤ .03) in predicting fibrosis severity.

CONCLUSION

Dyslipidemias, hepatic steatosis index and ABCA1 (rs1800977) gene polymorphism CC genotype; were the only independent predictors of advanced fibrosis in NAFLD-patients.

Mac-2 binding protein glycosylation isomer, the FIB-4 index, and a combination of the two as predictors of non-alcoholic steatohepatitis

Approximately 10% non-alcoholic fatty liver disease (NAFLD) cases progress to non-alcoholic steatohepatitis (NASH). Liver biopsy, the gold standard for diagnosing NASH and associated liver fibrosis, is invasive with a risk of life-threatening complications. Therefore, reliable non-invasive biomarkers for predicting NASH are required to prevent unnecessary liver biopsies. We evaluated the performance of two non-invasive fibrosis markers, Mac-2 binding protein glycosylation isomer (M2BPGi) and the FIB-4 index for predicting the fibrosis staging, NAFLD activity scoring (NAS) index, and NASH. We also analyzed the correlation between the two markers. The sensitivities, specificities, positive predictive values (PPV), and negative predictive values of the FIB-4 index, M2BPGi, and a combination of both markers for NASH diagnosis were evaluated. The M2BPGi and FIB-4 index showed a good performance in diagnosing NASH, the fibrosis stage, and the NAS index in NAFLD patients. While both markers were well-correlated with each other in most cases, no correlation was found in some patients. Compared with the FIB-4 index or the M2BPGi alone, a combination of the two showed a higher specificity, PPV, and accuracy for NASH diagnosis. The M2BPGi and the FIB-4 index are easily accessible and reliable liver fibrosis markers. Diseases other than liver disease may cause dissociation between the two markers, causing failure to predict NASH. However, the combination of both markers can compensate for their disadvantages. Because the PPV of the combination was relatively high, patients who test positive for both markers should undergo liver biopsy for NASH diagnosis.

Water Specific MRI T1 Mapping for Evaluating Liver Inflammation Activity Grades in Rats With Methionine-Choline-Deficient Diet-Induced Nonalcoholic Fatty Liver Disease

BACKGROUND

Early detection and grading of liver inflammation are important for the management of nonalcoholic fatty liver disease (NAFLD) patients. There is still lack of a noninvasive way for the inflammation characterization in NAFLD.

PURPOSE

To assess liver inflammation grades by water specific T1 (wT1) in a rat model.

STUDY TYPE

Prospective.

ANIMAL MODEL

A total of 65 male rats with methionine-choline-deficient diet-induced NAFLD and 15 male normal rats as control.

FIELD STRENGTH/SEQUENCE

A 3 T; multiecho variable flip angle gradient echo sequence.

ASSESSMENT

The wT1 and proton density fat fraction were quantified. Inflammation and fibrosis were assessed histologically with H&E and Sirius red stained slices according to the nonalcoholic steatohepatitis scoring system. Inflammation grade was scored with G0/G1/G2/G3 as none/mild/moderate/severe inflammation in NALFD rats. G0 + G1 and G2 + G3 were combined as none-to-mild grade (GL) and moderate-to-severe grade (GH) inflammation groups.

STATISTICAL TESTS

Analysis of variance (ANOVA), Mann-Whitney U test, Spearman's correlation, and receiver operating characteristic (ROC) analysis were performed. The areas under ROC (AUROC) was used for the diagnostic performance of wT1 in discriminating GH and GL. A P value < 0.01 was considered statistically significant.

RESULTS

Seventy-six rats were included in the analysis. The numbers in G0-G3 groups were 5, 16, 13, and 27. wT1 of G0-G3 was 568.55 ± 63.93 msec, 582.53 ± 62.98 msec, 521.21 ± 67.31 msec, and 508.79 ± 60.53 msec. A moderate but significant negative correlation between wT1 and histopathological inflammation grades was observed (r_s  = -0.42). The wT1 of GH (512.80 ± 62.22 msec) was significantly lower than GL (579.20 ± 61.89 msec). The AUROC of wT1 was 0.79, and the optimal cut-off of wT1 was 562.64 msec (sensitivity: 90%, specificity: 76%), for the discrimination of GL and GH.

DATA CONCLUSIONS

wT1 could differentiate none-to-mild inflammation from moderate-to-severe inflammation in the early stage of the NAFLD rat model.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Food and Gut Microbiota-Derived Metabolites in Nonalcoholic Fatty Liver Disease

Diet and lifestyle are crucial factors that influence the susceptibility of humans to nonalcoholic fatty liver disease (NAFLD). Personalized diet patterns chronically affect the composition and activity of microbiota in the human gut; consequently, nutrition-related dysbiosis exacerbates NAFLD via the gut–liver axis. Recent advances in diagnostic technology for gut microbes and microbiota-derived metabolites have led to advances in the diagnosis, treatment, and prognosis of NAFLD. Microbiota-derived metabolites, including tryptophan, short-chain fatty acid, fat, fructose, or bile acid, regulate the pathophysiology of NAFLD. The microbiota metabolize nutrients, and metabolites are closely related to the development of NAFLD. In this review, we discuss the influence of nutrients, gut microbes, their corresponding metabolites, and metabolism in the pathogenesis of NAFLD.

Colonic inflammation accelerates the progression of liver disease: A protective role of dipotassium glycyrrhizate

BACKGROUND

The incidence of non-alcoholic fatty liver disease (NAFLD) and its more severe and progressive form, non-alcoholic steatohepatitis (NASH) is increasing worldwide. Gut inflammation seems to concur to the pathogenesis of NASH. No drugs are currently approved for NASH treatment.

AIMS

To investigate if inflamed gut directly contributes to the progression of NASH through gut epithelial and vascular barrier impairment and to evaluate the efficacy of dipotassium glycyrrhizate (DPG) to improve the liver disease.

METHODS

A NASH model was set up by feeding mice, for 8 and 13 weeks, with high fat diet with high fructose and glucose (HFD-FG) supplemented periodically with dextran sulfate sodium (DSS) in drinking water. A group was also treated with DPG by gavage. Histological, immunohistochemical and molecular analysis were performed.

RESULTS

DSS-induced colitis increased steatosis, inflammatory (IL-6, TNFα, NLRP3, MCP-1) as well as fibrotic (TGF-β, α-SMA) mediator expression in HFD-FG mice. Beneficial effect of DPG was associated with restoration of intestinal epithelial and vascular barriers, evaluated respectively by ZO-1 and PV-1 expression, that are known to limit bacterial translocation.

CONCLUSION

Colonic inflammation strongly contributes to the progression of NASH, likely by favouring bacterial translocation. DPG treatment could represent a novel strategy to reduce liver injury.

Gut microbiota contribution to hepatocellular carcinoma manifestation in non-alcoholic steatohepatitis

Recently, the gut microbiota has been recognized as an obvious active player in addition to liver steatosis/steatohepatitis in the pathophysiological mechanisms of the development of hepatocellular carcinoma (HCC), even in the absence of cirrhosis. Evidence from clinical and experimental studies shows the association of specific changes in the gut microbiome and the direct contribution to maintaining liver inflammation and/or cancerogenesis in nonalcoholic fatty liver disease-induced HCC. The composition of the gut microbiota differs significantly in obese and lean individuals, especially in the abundance of pro-inflammatory lipopolysaccharide-producing phyla, and, after establishing steatohepatitis, it undergoes minor changes during the progression of the disease toward advanced fibrosis. Experimental studies proved that the microbiota of obese subjects can induce steatohepatitis in normally fed mice. On the contrary, the transplantation of healthy microbiota to obese mice relieves steatosis. However, further studies are needed to confirm these findings and the mechanisms involved. In this review, we have evaluated well-documented clinical and experimental research on the role of the gut microbiota in the manifestation and promotion of HCC in nonalcoholic steatohepatitis (NASH). Furthermore, a literature review of microbiota alterations and consequences of dysbiosis for the promotion of NASH-induced HCC was performed, and the advantages and limitations of the microbiota as an early marker of the diagnosis of HCC were discussed.

Nonalcoholic fatty liver disease: opinions, population served, and management from a sample of French hepato(gastroentero)logists (PERSEPT study)

OBJECTIVE

The three-fold objective of this study was to describe the opinions, the population served, and tools used for the management of nonalcoholic fatty liver disease (NAFLD) by French hepato(gastro)enterologists (HGEs).

METHODS

Seventy-five French HGEs working in hospitals or in private practice, who regularly managed patients with NAFLD, completed three questionnaires: one about their opinions about disease management, one on the 10 first patients with NAFLD they saw in February 2020, and the third about the first five patients meeting the 2016 European Association for the Study of the Liver criteria for specialist referral.

RESULTS

Management of NAFLD was seen as challenging, complex, time-consuming, and frustrating. Available treatments were considered to be unsatisfactory by most participants. In the whole population studied (671 patients), 41% were obese, 50% overweight, 49% had type 2 diabetes, 61% dyslipidemia, 51% arterial hypertension, 57% nonalcoholic steato-hepatitis (NASH), 37% advanced fibrosis, and 19% cirrhosis. In the subgroup of 313 patients needing specialist referral, the use of liver biopsy was low (30%) and decreasing, whereas vibration-controlled transient elastometry was high (66%) and increasing; blood fibrosis tests were rarely used. NASH was usually diagnosed without liver biopsy. Nutritional counseling was provided to 3/4 patients, physical activity counseling in 1/5. A personalized therapeutic project was defined in less than one-third of patients. Ursodeoxycholic acid and vitamin E were used in a minority of patients.

CONCLUSION

The management of NAFLD is not considered satisfactory by French HGE who care for a relatively severe population. Noninvasive assessment of fibrosis and multidisciplinary management should be improved.

Recent Epidemiology and Risk Factors of Nonalcoholic Fatty Liver Disease

Because of the global obesity epidemic, the incidence and prevalence of nonalcoholic fatty liver disease (NAFLD) have increased worldwide, including among Koreans. Recently, the incidence rate of NAFLD in Korea was reported to be 45.1 per 1,000 person-years, and the prevalence as approximately 30% depending on the diagnostic methods used. The incidence of advanced fibrosis and hepatocellular carcinoma, as well as all-cause and liver-related mortality in NAFLD patients has increased substantially, imposing considerable public health costs in Korea. Genetic, demographic, environmental, and clinical factors are involved in the pathogenesis of NAFLD. Some genetic variants, such as patatin-like phospholipase domain-containing 3 (PNPLA-3) and sorting and assembly machinery component 50 (SAMM-50), play a major role in the occurrence of NAFLD. The risk of NAFLD and fibrosis increases with advancing age and in men. Nutritional factors, inadequate exercise, and sleep duration are also associated with increased risk of NAFLD. Obesity is a major risk factor for NAFLD; however, NAFLD in lean individuals has been noted in recent studies. Insulin resistance, type 2 diabetes, and metabolic syndrome and its components are closely associated with NAFLD development and liver fibrosis with various underlying mechanisms. Sarcopenia likely shares a common pathophysiology with NAFLD. The rapidly increasing incidence and prevalence of NAFLD and its complications, as well as the associated healthcare burden, warrant early assessment of NAFLD and its risk factors to prevent NAFLD-related complications in high risk groups.

Synergistic and Detrimental Effects of Alcohol Intake on Progression of Liver Steatosis

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the most common liver disorders worldwide and the major causes of non-viral liver cirrhosis in the general population. In NAFLD, metabolic abnormalities, obesity, and metabolic syndrome are the driving factors for liver damage with no or minimal alcohol consumption. ALD refers to liver damage caused by excess alcohol intake in individuals drinking more than 5 to 10 daily units for years. Although NAFLD and ALD are nosologically considered two distinct entities, they show a continuum and exert synergistic effects on the progression toward liver cirrhosis. The current view is that low alcohol use might also increase the risk of advanced clinical liver disease in NAFLD, whereas metabolic factors increase the risk of cirrhosis among alcohol risk drinkers. Therefore, special interest is now addressed to individuals with metabolic abnormalities who consume small amounts of alcohol or who binge drink, for the role of light-to-moderate alcohol use in fibrosis progression and clinical severity of the liver disease. Evidence shows that in the presence of NAFLD, there is no liver-safe limit of alcohol intake. We discuss the epidemiological and clinical features of NAFLD/ALD, aspects of alcohol metabolism, and mechanisms of damage concerning steatosis, fibrosis, cumulative effects, and deleterious consequences which include hepatocellular carcinoma.

Hepatic CDP-diacylglycerol synthase 2 deficiency causes mitochondrial dysfunction and promotes rapid progression of NASH and fibrosis

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of pathologies, ranging from steatosis to nonalcoholic steatohepatitis (NASH). The factors promoting the progression of steatosis to NASH are still unclear. Recent studies suggest that mitochondrial lipid composition is critical in NASH development. Here, we showed that CDP-DAG synthase 2 (Cds2) was downregulated in genetic or diet-induced NAFLD mouse models. Liver-specific deficiency of Cds2 provoked hepatic steatosis, inflammation and fibrosis in five-week-old mice. CDS2 is enriched in mitochondria-associated membranes (MAMs), and hepatic Cds2 deficiency impaired mitochondrial function and decreased mitochondrial PE levels. Overexpression of phosphatidylserine decarboxylase (PISD) alleviated the NASH-like phenotype in Cds2^f/f;AlbCre mice and abnormal mitochondrial morphology and function caused by CDS2 deficiency in hepatocytes. Additionally, dietary supplementation with an agonist of peroxisome proliferator-activated receptor alpha (PPARα) attenuated mitochondrial defects and ameliorated the NASH-like phenotype in Cds2^f/f;AlbCre mice. Finally, Cds2 overexpression protected against high-fat diet-induced hepatic steatosis and obesity. Thus, Cds2 modulates mitochondrial function and NASH development.

Genetics of murine type 2 diabetes and comorbidities

ABSTRAC

Type 2 diabetes (T2D) is a polygenic and multifactorial complex disease, defined as chronic metabolic disorder. It's a major global health concern with an estimated 463 million adults aged 20-79 years with diabetes and projected to increase up to 700 million by 2045. T2D was reported to be one of the four leading causes of non-communicable disease (NCD) deaths in 2012. Environmental factors play a part in the development of polygenic forms of diabetes. Polygenic forms of diabetes often run-in families. Fortunately, T2D, which accounts for 90-95% of the entire four types of diabetes including, Type 1 diabetes (T1D), T2D, monogenic diabetes syndromes (MGDS), and Gestational diabetes mellitus, can be prevented or delayed through nutrition and lifestyle changes as well as through pharmacologic interventions. Typical symptom of the T2D is high blood glucose levels and comprehensive insulin resistance of the body, producing an impaired glucose tolerance. Impaired glucose tolerance of T2D is accompanied by extensive health complications, including cardiovascular diseases (CVD) that vary in morbidity and mortality among populations. The pathogenesis of T2D varies between populations and/or ethnic groupings and is known to be attributed extremely by genetic components and environmental factors. It is evident that genetic background plays a critical role in determining the host response toward certain environmental conditions, whether or not of developing T2D (susceptibility versus resistant). T2D is considered as a silent disease that can progress for years before its diagnosis. Once T2D is diagnosed, many metabolic malfunctions are observed whether as side effects or as independent comorbidity. Mouse models have been proven to be a powerful tool for mapping genetic factors that underline the susceptibility to T2D development as well its comorbidities. Here, we have conducted a comprehensive search throughout the published data covering the time span from early 1990s till the time of writing this review, for already reported quantitative trait locus (QTL) associated with murine T2D and comorbidities in different mouse models, which contain different genetic backgrounds. Our search has resulted in finding 54 QTLs associated with T2D in addition to 72 QTLs associated with comorbidities associated with the disease. We summarized the genomic locations of these mapped QTLs in graphical formats, so as to show the overlapping positions between of these mapped QTLs, which may suggest that some of these QTLs could be underlined by sharing gene/s. Finally, we reviewed and addressed published reports that show the success of translation of the identified mouse QTLs/genes associated with the disease in humans.

A prospective cohort study of the use of the fatty liver index and Fibroscan to determine the prevalence of fatty liver disease in an Irish population

OBJECTIVES

Rates of nonalcoholic fatty liver disease (NAFLD) are increasing worldwide. The fatty liver index (FLI) is a noninvasive predictor of NAFLD. This prospective cohort study used the FLI to estimate the prevalence of NAFLD in patients attending an Irish Acute Medical Unit (AMU), and assessed the degree of fibrosis in this group using Fibroscan.

METHODS

Patients attending the AMU over a 3-month period were invited to participate. Patients with excess alcohol consumption or pre-existing liver disease were excluded. Using established FLI cut-offs, 414 participants were grouped into low (FLI ≤ 30), medium (30 < FLI ≤ 60) and high (FLI > 60) risk of NAFLD. High-risk patients were offered review including liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) score.

RESULTS

A total of 134 patients were at low-risk, 96 at medium-risk and 184 at high-risk of NAFLD. Male sex (P < 0.0001) and increasing age (P < 0.0001) were associated with higher risk. Of the 120 high-risk patients who attended follow up, 13 participants had LSM > 7 kPa. Higher FLI scores were associated with higher CAP scores (P < 0.0001) but did not predict higher LSMs. Fasting glucose and HbA1c were found to be associated with higher LSM.

CONCLUSION

About 44.4% of patients presenting to the AMU were at high risk of NAFLD according to the FLI. Only 10.8% of the high-risk group, and 3% of all those recruited had a LSM > 7 kPa suggesting development of fibrosis.

Platelet-Activating Factor Promotes the Development of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a multifaceted clinicopathological syndrome characterised by excessive hepatic lipid accumulation that causes steatosis, excluding alcoholic factors. Platelet-activating factor (PAF), a biologically active lipid transmitter, induces platelet activation upon binding to the PAF receptor. Recent studies have found that PAF is associated with gamma-glutamyl transferase, which is an indicator of liver disease. Moreover, PAF can stimulate hepatic lipid synthesis and cause hypertriglyceridaemia. Furthermore, the knockdown of the PAF receptor gene in the animal models of NAFLD helped reduce the inflammatory response, improve glucose homeostasis and delay the development of NAFLD. These findings suggest that PAF is associated with NAFLD development. According to reports, patients with NAFLD or animal models have marked platelet activation abnormalities, mainly manifested as enhanced platelet adhesion and aggregation and altered blood rheology. Pharmacological interventions were accompanied by remission of abnormal platelet activation and significant improvement in liver function and lipids in the animal model of NAFLD. These confirm that platelet activation may accompany a critical importance in NAFLD development and progression. However, how PAFs are involved in the NAFLD signalling pathway needs further investigation. In this paper, we review the relevant literature in recent years and discuss the role played by PAF in NAFLD development. It is important to elucidate the pathogenesis of NAFLD and to find effective interventions for treatment.

Associations of Uric Acid With Liver Steatosis and Fibrosis Applying Vibration Controlled Transient Elastography in the United States: A Nationwide Cross-Section Study

BACKGROUND AND OBJECTIVE

Serum uric acid (UA) is related to many metabolic diseases. However, the association of UA with liver diseases was not very clear. The objective of this study is to clarify the relationship of UA with liver steatosis and fibrosis.

METHODS

This is a cross-sectional study of 4364 people of National Health and Nutrition Examination Survey (NHANES) 2017-2018. Liver steatosis and fibrosis were assessed by controlled attenuation parameter (CAP) and liver stiffness measurements (LSM) using Vibration-controlled transient elastography (VCTE). Linear and logistic regressions were performed.

RESULTS

After adjusting for potential confounders, UA levels were associated with the prevalence of liver steatosis [OR=2.097 (95%CI: 1.245, 3.534)] and liver fibrosis [OR=2.983 (95%CI: 1.797, 4.952)]. Furthermore, the results were consistent in the subgroup analyses of males and females.

CONCLUSIONS

UA levels were positively associated with the prevalence of liver steatosis and fibrosis.

Immunoglobulin G in non-alcoholic steatohepatitis predicts clinical outcome: A prospective multi-centre cohort study

BACKGROUND

Autoimmune markers including plasma cells (PC), anti-smooth-muscle antibody (ASMA), anti-nuclear antibody (ANA), and raised immunoglobulin G (IgG) are commonly observed in non-alcoholic steatohepatitis (NASH), however their clinical significance is unknown.

AIM

To determine if autoimmune markers in NASH patients are independently associated with poorer clinical outcomes.

METHODS

Consecutive patients with biopsy proven NASH from Christchurch Hospital, New Zealand and Singapore General Hospital (SGH) were included between 2005 to 2016 in a prospective multi-centre cohort study. Patients with other causes of chronic liver disease were excluded. IgG > 14 g/L or globulin fraction > 50%, ANA ≥ 1:40, SMA ≥ 1:40 were considered positive. Multivariate analysis was performed to assess which markers were independently associated with mortality and hepatic decompensation.

RESULTS

Total 261 patients were included of which 201 were from SGH. The median age was 53 and 51.9% were male. Advanced fibrosis was present in 31.4% at diagnosis. PC, ASMA, ANA and raised IgG were observed in 13.1%, 4.9%, 27.8% and 30.1% of patients respectively. After multivariate analysis, elevated IgG [Hazard Ratio (HR) 6.79, 95%CI: 2.93-17.15] and fibrosis stage (HR 1.37, 95%CI: 1.03-1.87) were found to be independently associated with increased risk of liver decompensation. Age (HR 1.06, 95%CI: 1.02-1.10) and elevated IgG (HR 3.79, 95%CI: 1.90-7.68) were independent factors associated with higher mortality risk.

CONCLUSION

Elevated IgG, rather than ANA, ASMA or plasma cells, is independently associated with increased risk of hepatic decompensation and mortality in NASH. It could hence be important for prognostication.

Insights into Nonalcoholic Fatty-Liver Disease Heterogeneity

The acronym nonalcoholic fatty-liver disease (NAFLD) groups a heterogeneous patient population. Although in many patients the primary driver is metabolic dysfunction, a complex and dynamic interaction of different factors (i.e., sex, presence of one or more genetic variants, coexistence of different comorbidities, diverse microbiota composition, and various degrees of alcohol consumption among others) takes place to determine disease subphenotypes with distinct natural history and prognosis and, eventually, different response to therapy. This review aims to address this topic through the analysis of existing data on the differential contribution of known factors to the pathogenesis and clinical expression of NAFLD, thus determining the different clinical subphenotypes observed in practice. To improve our understanding of NAFLD heterogeneity and the dominant drivers of disease in patient subgroups would predictably impact on the development of more precision-targeted therapies for NAFLD.

New targets for NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease worldwide. It is characterised by steatosis, liver inflammation, hepatocellular injury and progressive fibrosis. Several preclinical models (dietary and genetic animal models) of NAFLD have deepened our understanding of its aetiology and pathophysiology. Despite the progress made, there are currently no effective treatments for NAFLD. In this review, we will provide an update on the known molecular pathways involved in the pathophysiology of NAFLD and on ongoing studies of new therapeutic targets.

Supplementation with a Specific Combination of Metabolic Cofactors Ameliorates Non-Alcoholic Fatty Liver Disease, Hepatic Fibrosis, and Insulin Resistance in Mice

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) have emerged as the leading causes of chronic liver disease in the world. Obesity, insulin resistance, and dyslipidemia are multifactorial risk factors strongly associated with NAFLD/NASH. Here, a specific combination of metabolic cofactors (a multi-ingredient; MI) containing precursors of glutathione (GSH) and nicotinamide adenine dinucleotide (NAD+) (betaine, N-acetyl-cysteine, L-carnitine and nicotinamide riboside) was evaluated as effective treatment for the NAFLD/NASH pathophysiology. Six-week-old male mice were randomly divided into control diet animals and animals exposed to a high fat and high fructose/sucrose diet to induce NAFLD. After 16 weeks, diet-induced NAFLD mice were distributed into two groups, treated with the vehicle (HFHFr group) or with a combination of metabolic cofactors (MI group) for 4 additional weeks, and blood and liver were obtained from all animals for biochemical, histological, and molecular analysis. The MI treatment reduced liver steatosis, decreasing liver weight and hepatic lipid content, and liver injury, as evidenced by a pronounced decrease in serum levels of liver transaminases. Moreover, animals supplemented with the MI cocktail showed a reduction in the gene expression of some proinflammatory cytokines when compared with their HFHFr counterparts. In addition, MI supplementation was effective in decreasing hepatic fibrosis and improving insulin sensitivity, as observed by histological analysis, as well as a reduction in fibrotic gene expression (Col1α1) and improved Akt activation, respectively. Taken together, supplementation with this specific combination of metabolic cofactors ameliorates several features of NAFLD, highlighting this treatment as a potential efficient therapy against this disease in humans.

Addition of hyaluronic acid to the FIB-4 liver fibrosis score improves prediction of incident cirrhosis and hepatocellular carcinoma in type 2 diabetes: The Edinburgh Type 2 Diabetes Study

BACKGROUND

Type 2 diabetes (T2D) is associated with increased risk of progression to cirrhosis and hepatocellular carcinoma (HCC) in people with chronic liver diseases, particularly non-alcoholic fatty liver disease (NAFLD). However, the absolute risk of progression is low. So, it is crucial to accurately identify patients who would benefit most from hepatology referral and intensified management. Current risk-stratification tools are suboptimal and perform worse in people with diabetes.

AIMS

To determine whether the addition of complementary biomarker(s) to current NAFLD risk-stratification tools in people with T2D could improve the identification of people who are at increased risk of developing incident cirrhosis or HCC.

METHODS

The Edinburgh Type 2 diabetes Study (ET2DS) is a cohort study of men and women with T2D (n = 1066, age 60-75 at baseline). Cases of cirrhosis and HCC were identified over 11 years of follow-up. Biomarkers were measured at baseline and year 1 and association with incident disease was assessed using logistic regression.

RESULTS

Of existing risk-stratification scores tested, the Fibrosis-4 (FIB-4) index and the AST:platelet ratio index (APRI) performed best in this cohort. Addition of hyaluronic acid (cut-point ≥ 50  μ  g/L) to FIB-4 (cut-point ≥ 1.3) maintained a false negative rate of ≤25% and reduced the number of people incorrectly identified as "high risk" for incident disease by ∼50%.

CONCLUSIONS

The addition of hyaluronic acid to FIB-4 reduced the proportion of people inappropriately identified as "high risk" for development of cirrhosis/HCC in a community population of otherwise asymptomatic people with T2D. These findings require a validation in independent cohorts.

Xanthohumol alleviates T2DM-induced liver steatosis and fibrosis by mediating the NRF2/RAGE/NF-κB signaling pathway

Hyperglycemia-associated advanced glycation end products (AGEs) and the receptor for AGE (RAGE) contribute to nonalcoholic fatty liver disease (NAFLD). Xanthohumol (XH) exhibits protective activities against liver diseases. Aim: To investigate the effects of XH on Type II diabetes mellitus (T2DM)-induced liver steatosis and fibrosis. Methods: NAFLD rat models were duplicated. Biomolecular markers were detected. Quantitative real-time PCR (RT-PCR) and western blot were used to detect mRNA and protein expression. Immunofluorescence assays were employed to identify the subcellular locations. Results: XH significantly ameliorated hyperglycemia and hyperlipidemia in rats. XH attenuated the expression of RAGE and NF-κB signaling. XH significantly alleviated inflammation and oxidation by upregulating NRF2 expression. Knockdown of NRF2 blocked XH protection in hepatocytes. Conclusion: XH protected against T2DM-induced liver steatosis and fibrosis by mediating NRF2/AGE/RAGE/NF-κB signaling.