Genetic Factors That Affect Risk of Alcoholic and Nonalcoholic Fatty Liver Disease

Alcohol and Metabolic Syndrome Interaction

Alcohol-related liver disease and metabolic-dysfunction-associated steatotic liver disease are the most common causes of chronic liver disease. Globally, alcohol intake, and metabolic syndrome driven by excessive caloric intake and sedentary lifestyle have steadily increased over the past decades. Given the high prevalence rates of both excessive alcohol consumption and components of metabolic syndrome, both can frequently coexist in the same individuals and impact their lives. In this article, we review the impact of alcohol and metabolic syndrome on liver-related outcomes.

miR-21: A therapeutic target for delaying severe liver disease and hepatocellular carcinoma in high-fat-diet-fed mice

Liver disease, including hepatocellular carcinoma (HCC), is a major global health concern, claiming approximately 2 million lives worldwide annually, yet curative treatments remain elusive. In this study, we aimed to investigate the role of microRNA-21-5p (miR-21) in metabolic dysfunction-associated steatotic liver disease (previously NAFLD), metabolic-associated steatohepatitis (previously NASH), and HCC within the context of a Western high-fat diet, without additional choline (HFD) and offering potential therapeutic insights. We found that reduced miR-21 levels correlated with liver disease progression in WT mice fed on HFD, while miR-21 knockout mice showed exacerbated metabolic dysfunction, including obesity, hepatomegaly, hyperglycemia, insulin resistance, steatosis, fibrosis, and HCC. Our study reveals that miR-21 plays a protective role in metabolic syndrome and in the progression of liver disease to cancer. MiR-21 directly targets Transforming growth factor beta-induced (Tgfbi), a gene also known to be significantly upregulated and a potential oncogene in HCC. Further, our study showed that intervention with the administration of a miR-21 mimic in WT livers effectively improves insulin sensitivity, steatosis, fibrosis, Tgfbi expression and tumor burden in HFD conditions. These findings indicate that miR-21 could serve as an effective strategy to delay or prevent liver disease in high-fat-diet environments.

A Comprehensive Investigation of Dietary Micronutrient Intakes and Risk of Alcoholic Liver Disease

BACKGROUND

The investigation of dietary micronutrient intakes and risk of alcoholic liver disease (ALD) based on observational studies was limited.

OBJECTIVES

Our study aimed to explore the associations of 30 dietary micronutrients intakes with risk of ALD, interactions between dietary micronutrients and genetic variation, and mediation effects of blood and urinary biomarkers on the associations between dietary micronutrients and risk of ALD.

METHODS

A case-control study was conducted within the UK Biobank cohort, with 231 incident ALD cases and 1386 controls. Dietary data were collected using a dietary questionnaire that relied on a 24-h dietary recall of the previous day. Logistic regression models were employed to assess the associations of dietary micronutrient intakes with risk of ALD. We conducted stratified analyses on the associations between dietary micronutrient intakes and risk of ALD by PNPLA3 rs738409 and tested the interactions between dietary micronutrients and genetic variation. In addition, we conducted mediation analyses to investigate the mediating effects of biomarkers on the associations between dietary micronutrients and risk of ALD.

RESULTS

Our findings indicated significant inverse associations of thiamin, riboflavin, niacin equivalent, pantothenic acid, vitamin B-6, folate, vitamin E, calcium, magnesium, phosphorus, potassium, copper, iodine, and manganese with risk of ALD (all false discovery rate-Ptrend < 0.050). We also found a significant interaction between PNPLA3 rs738409 and magnesium (Pinteraction = 0.028). Creatinine (enzymatic) in urine, aspartate aminotransferase, and insulin-like growth factor 1 were the top 3 biomarkers with the highest number of significant mediation effects on the associations between the dietary micronutrients and risk of ALD.

CONCLUSIONS

Dietary intakes of thiamin, riboflavin, niacin equivalent, pantothenic acid, vitamin B-6, folate, vitamin E, calcium, magnesium, phosphorus, potassium, copper, iodine, and manganese were inversely associated with risk of ALD.

Team players in the pathogenesis of metabolic dysfunctions-associated steatotic liver disease: The basis of development of pharmacotherapy

Nutrient metabolism is regulated by several factors. Social determinants of health with or without genetics are the primary regulator of metabolism, and an unhealthy lifestyle affects all modulators and mediators, leading to the adaptation and finally to the exhaustion of cellular functions. Hepatic steatosis is defined by presence of fat in more than 5% of hepatocytes. In hepatocytes, fat is stored as triglycerides in lipid droplet. Hepatic steatosis results from a combination of multiple intracellular processes. In a healthy individual nutrient metabolism is regulated at several steps. It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component. Several hormones, peptides, and genes have been described that participate in nutrient metabolism. Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP. As of now several publications have revealed very intricate regulation of nutrient metabolism, where most of the regulatory factors are tied to each other bidirectionally, making it difficult to comprehend chronological sequence of events. Insulin hormone is the primary regulator of all nutrients' metabolism both in prandial and fasting states. Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes; metabolic, inflammation and repair, and cell growth and regeneration. Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands, adiponectin, leptin, and adiponutrin. Insulin hormone has direct effect on these final modulators. Whereas blood glucose level, serum lipids, incretin hormones, bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle. The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) that help us understand the disease natural course, risk stratification, role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine. PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states; MASLD, cardiovascular disease and cancer. More than 1000 publications including original research and review papers were reviewed.

NAFLD (MASLD)/NASH (MASH): Does It Bother to Label at All? A Comprehensive Narrative Review

Nonalcoholic fatty liver disease (NAFLD), or metabolic dysfunction-associated steatotic liver disease (MASLD), is a liver condition that is linked to overweight, obesity, diabetes mellitus, and metabolic syndrome. Nonalcoholic steatohepatitis (NASH), or metabolic dysfunction-associated steatohepatitis (MASH), is a form of NAFLD/MASLD that progresses over time. While steatosis is a prominent histological characteristic and recognizable grossly and microscopically, liver biopsies of individuals with NASH/MASH may exhibit several other abnormalities, such as mononuclear inflammation in the portal and lobular regions, hepatocellular damage characterized by ballooning and programmed cell death (apoptosis), misfolded hepatocytic protein inclusions (Mallory-Denk bodies, MDBs), megamitochondria as hyaline inclusions, and fibrosis. Ballooning hepatocellular damage remains the defining feature of NASH/MASH. The fibrosis pattern is characterized by the initial expression of perisinusoidal fibrosis ("chicken wire") and fibrosis surrounding the central veins. Children may have an alternative form of progressive NAFLD/MASLD characterized by steatosis, inflammation, and fibrosis, mainly in Rappaport zone 1 of the liver acinus. To identify, synthesize, and analyze the scientific knowledge produced regarding the implications of using a score for evaluating NAFLD/MASLD in a comprehensive narrative review. The search for articles was conducted between 1 January 2000 and 31 December 2023, on the PubMed/MEDLINE, Scopus, Web of Science, and Cochrane databases. This search was complemented by a gray search, including internet browsers (e.g., Google) and textbooks. The following research question guided the study: "What are the basic data on using a score for evaluating NAFLD/MASLD?" All stages of the selection process were carried out by the single author. Of the 1783 articles found, 75 were included in the sample for analysis, which was implemented with an additional 25 articles from references and gray literature. The studies analyzed indicated the beneficial effects of scoring liver biopsies. Although similarity between alcoholic steatohepatitis (ASH) and NASH/MASH occurs, some patterns of hepatocellular damage seen in alcoholic disease of the liver do not happen in NASH/MASH, including cholestatic featuring steatohepatitis, alcoholic foamy degeneration, and sclerosing predominant hyaline necrosis. Generally, neutrophilic-rich cellular infiltrates, prominent hyaline inclusions and MDBs, cholestasis, and obvious pericellular sinusoidal fibrosis should favor the diagnosis of alcohol-induced hepatocellular injury over NASH/MASH. Multiple grading and staging methods are available for implementation in investigations and clinical trials, each possessing merits and drawbacks. The systems primarily used are the Brunt, the NASH CRN (NASH Clinical Research Network), and the SAF (steatosis, activity, and fibrosis) systems. Clinical investigations have utilized several approaches to link laboratory and demographic observations with histology findings with optimal platforms for clinical trials of rapidly commercialized drugs. It is promising that machine learning procedures (artificial intelligence) may be critical for developing new platforms to evaluate the benefits of current and future drug formulations.

Genotypic variation in CYP2E1, GCKR, and PNPLA3 among nonalcoholic steatohepatitis patients of Turkish origin

BACKGROUND

This study examines genetic variations in CYP2E1 (rs6413432, rs3813867), GCKR (rs780094, rs1260326), and PNPLA3 (rs738409) among Turkish patients to assess their influence on nonalcoholic steatohepatitis.

METHODS

Allele and genotype frequencies were compared between 245 NASH patients and 120 healthy controls using SNP genotyping via polymerase chain reaction-restriction fragment length polymorphism. Additionally, the deviation of the observed genotype frequencies from Hardy-Weinberg proportion was examined.

RESULTS

No significant differences were found in the allelic and genotypic distributions of rs6413432, rs3813867, and rs780094 between NASH patients and healthy controls. However, significant disparities were noted for rs1260326 and rs738409. Gender and age-specific distributions showed no notable differences. The only observed deviation from Hardy-Weinberg proportion was in the genotype frequency of rs738409.

CONCLUSIONS

Variants in GCKR (rs1260326) and PNPLA3 (rs738409) are significantly associated with increased NASH risk in the Turkish population, with the rs738409 variant potentially playing a more prominent role in NASH development.

Clinical features of individuals with laboratory values suggestive of advanced liver fibrosis when first treated for alcohol use disorder

BACKGROUND

Effective screening for alcohol-associated liver disease is relevant in the context of chronic, excessive alcohol consumption. Patients with alcohol-associated liver disease are often not diagnosed until their liver disease is decompensated. We analyzed the prevalence and associations of Fibrosis-4 index (FIB-4) values suggestive of advanced liver fibrosis in patients referred for their first treatment of alcohol use disorder (AUD).

METHODS

We conducted a cross-sectional, multicenter study of noncirrhotic individuals referred for their first AUD treatment between March 2013 and April 2021. We obtained sociodemographic data, substance use characteristics, and blood samples at admission. We considered a FIB-4 value ≥2.67 suggestive of advanced liver fibrosis and used logistic regression analyses to identify features associated with this value.

RESULTS

We included 604 patients (67% male), with a median age at admission of 48 years [IQR: 41-56 years]. The median duration of regular alcohol consumption was 21 years [IQR: 18-30 years] and the median alcohol consumption was 105 standard drink units (SDU)/week [IQR: 63-160 SDU/week]. A FIB-4 value ≥ 2.67 was present in 19.3% of cases. These patients reported more frequent binge drinking (75.4% vs. 66%, p = 0.05) than those with FIB-4 values below 2.67. In multivariate analysis, a history of binge drinking (OR 1.9, 95% CI, 1.05-3.47), anemia (OR 2.95, 95% CI, 1.42-6.11), leukopenia (OR 7.46, 95% CI, 2.07-26.8), and total serum bilirubin >1 mg/dL (OR 6.46, 95% CI, 3.57-11.7) were independently associated with FIB-4 values ≥2.67.

CONCLUSIONS

One in five patients admitted to treatment for AUD without evidence of decompensated liver disease have FIB-4 values suggestive of advanced liver fibrosis. The presence of a binge drinking history, anemia, leukopenia, and elevated bilirubin levels is associated with high FIB-4 values.

Metabolic Dysfunction-Associated Steatotic Liver Disease: From Pathogenesis to Current Therapeutic Options

The epidemiological burden of liver steatosis associated with metabolic diseases is continuously growing worldwide and in all age classes. This condition generates possible progression of liver damage (i.e., inflammation, fibrosis, cirrhosis, hepatocellular carcinoma) but also independently increases the risk of cardio-metabolic diseases and cancer. In recent years, the terminological evolution from "nonalcoholic fatty liver disease" (NAFLD) to "metabolic dysfunction-associated fatty liver disease" (MAFLD) and, finally, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been paralleled by increased knowledge of mechanisms linking local (i.e., hepatic) and systemic pathogenic pathways. As a consequence, the need for an appropriate classification of individual phenotypes has been oriented to the investigation of innovative therapeutic tools. Besides the well-known role for lifestyle change, a number of pharmacological approaches have been explored, ranging from antidiabetic drugs to agonists acting on the gut-liver axis and at a systemic level (mainly farnesoid X receptor (FXR) agonists, PPAR agonists, thyroid hormone receptor agonists), anti-fibrotic and anti-inflammatory agents. The intrinsically complex pathophysiological history of MASLD makes the selection of a single effective treatment a major challenge, so far. In this evolving scenario, the cooperation between different stakeholders (including subjects at risk, health professionals, and pharmaceutical industries) could significantly improve the management of disease and the implementation of primary and secondary prevention measures. The high healthcare burden associated with MASLD makes the search for new, effective, and safe drugs a major pressing need, together with an accurate characterization of individual phenotypes. Recent and promising advances indicate that we may soon enter the era of precise and personalized therapy for MASLD/MASH.

Alcohol-associated liver disease-Global epidemiology

Alcohol-associated liver disease (ALD), as highlighted in this narrative review, is a major public health concern, increasingly impacting global disease burden and premature mortality. In 2019, ALD accounted for the loss of 11 million life-years worldwide. The rising number of deaths and disability-adjusted life-years attributed to ALD, particularly pronounced in the United States, are alarming. Projections suggest that the economic impact of ALD, as seen in the United States, could potentially double by 2040. ALD is increasingly prevalent among younger adults (20-45 y) and has become the leading cause of liver transplantation in both United States and Europe. During the COVID-19 pandemic, the existing trend was further amplified as high-risk drinking patterns coincided with a rise in hospital admissions for alcohol-associated hepatitis and increased ALD-related mortality. The prevalence of ALD is estimated at 3.5% in the general population, 26.0% among hazardous drinkers, and 55.1% among those with alcohol use disorders. Alarmingly, 5-year mortality rates for patients with ALD exceed 50%, with even higher rates in more advanced disease stages. Methodological challenges, such as underreporting, diagnostic difficulties, and variability in registry data quality, complicate the accurate assessment of the impact of ALD. Additionally, the contribution of alcohol to the progression of other liver diseases is often under acknowledged in health care registries, leading to a significant underestimation of its broader implications for liver health. Addressing the growing ALD concern requires robust public health initiatives, heightened awareness, refined diagnostic techniques, and comprehensive epidemiological studies. These measures are vital to tackle the increasing prevalence of ALD and mitigate its extensive impact on individuals and health care systems.

Bidirectional two-sample mendelian randomization analysis identifies causal associations of MRI-based cortical thickness and surface area relation to NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) patients have exhibited extra-hepatic neurological changes, but the causes and mechanisms remain unclear. This study investigates the causal effect of NAFLD on cortical structure through bidirectional two-sample Mendelian randomization analysis.

METHODS

Genetic data from 778,614 European individuals across four NAFLD studies were used to determine genetically predicted NAFLD. Abdominal MRI scans from 32,860 UK Biobank participants were utilized to evaluate genetically predicted liver fat and volume. Data from the ENIGMA Consortium, comprising 51,665 patients, were used to evaluate the associations between genetic susceptibility, NAFLD risk, liver fat, liver volume, and alterations in cortical thickness (TH) and surface area (SA). Inverse-variance weighted (IVW) estimation, Cochran Q, and MR-Egger were employed to assess heterogeneity and pleiotropy.

RESULTS

Overall, NAFLD did not significantly affect cortical SA or TH. However, potential associations were noted under global weighting, relating heightened NAFLD risk to reduced parahippocampal SA and decreased cortical TH in the caudal middle frontal, cuneus, lingual, and parstriangularis regions. Liver fat and volume also influenced the cortical structure of certain regions, although no Bonferroni-adjusted p-values reached significance. Two-step MR analysis revealed that liver fat, AST, and LDL levels mediated the impact of NAFLD on cortical structure. Multivariable MR analysis suggested that the impact of NAFLD on the cortical TH of lingual and parstriangularis was independent of BMI, obesity, hyperlipidemia, and diabetes.

CONCLUSION

This study provides evidence that NAFLD causally influences the cortical structure of the brain, suggesting the existence of a liver-brain axis in the development 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.

Binge-pattern alcohol consumption and genetic risk as determinants of alcohol-related liver disease

Alcohol-related liver disease (ARLD) represents a major public health burden. Identification of high-risk individuals would allow efficient targeting of public health interventions. Here, we show significant interactions between pattern of drinking, genetic predisposition (polygenic risk score, PRS) and diabetes mellitus, and risk of incident ARLD, in 312,599 actively drinking adults in UK Biobank. Binge and heavy binge drinking significantly increase the risk of alcohol-related cirrhosis (ARC), with higher genetic predisposition further amplifying the risk. Further, we demonstrate a pronounced interaction between heavy binge drinking and high PRS, resulting in a relative excess risk due to interaction (RERI) of 6.07. Diabetes consistently elevates ARC risk across all drinking and PRS categories, and showed significant interaction with both binge patterns and genetic risk. Overall, we demonstrate synergistic effects of binge drinking, genetics, and diabetes on ARC, with potential to identify high-risk individuals for targeted interventions.

Alcohol use disorder identification test renamed Glu-Glu Test in an area of north-west of Italy: preliminary descriptive results

BACKGROUND

The first two causes of liver cirrhosis and hepatocellular carcinoma are alcoholic and dysmetabolic. In the early stages alcohol related liver disease (ALD) is silent. For this reason, more efforts should be made to identify early individuals with hazardous/harmful alcohol consumption (AC). Alcohol use disorder identification test (AUDIT) is a validated test.

METHODS

ASL3 (Ligurian Local Health Company 3) has included the AUDIT renamed Glu-Glu Test on its institutional website dedicated to citizens. The renaming was carried out to bring citizens closer to the test with greater ease, especially younger citizens. At the end of the compilation of the test, the calculator provides the citizen with his score: in relation to his possible risk band, provides him with the appropriate advice. In case of a score higher than 7, ultrasonography and elastography (2D-SWE) are proposed.

RESULTS

From December 15, 2021, to July 15, 2022, 270 asymptomatic subjects requested a medical examination autonomously, without the indication of a health worker. In 167 patients the score found hazardous AC, in 65 harmful AC and in 38 alcohol addiction. In case of hazardous AC, fibrosis grade 1-2 was evidenced in 16.7%, fibrosis grade 3 in 4.8% and fibrosis grade 4 in 3.6% of subjects. In case of harmful AC fibrosis grade 1-2 was evidenced in 37%, grade 3 in 9%, grade 4 in 6%. In this group an HCC nodule was diagnosed. In case of alcohol addiction, fibrosis grade 1-2 was evidenced in 73.6%, grade 3 in 10.5% and grade 4 in 10.5%.

CONCLUSIONS

This preliminary experience clearly tells us that it is possible to make an early diagnosis of fibrosis and HCC starting from the AC reported autonomously by citizens.

From Non-Alcoholic Steatohepatitis (NASH) to Hepatocellular Carcinoma (HCC): Epidemiology, Incidence, Predictions, Risk Factors, and Prevention

Non-alcoholic fatty liver disease (NAFLD) affects up to a quarter of the adult population in many developed and developing countries. This spectrum of liver disease ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) and cirrhosis. The incidence of NASH is projected to increase by up to 56% over the next 10 years. There is growing epidemiological evidence that NAFLD has become the fastest-growing cause of hepatocellular carcinoma (HCC) in industrialized countries. The annual incidence of HCC varies between patients with NASH cirrhosis and patients with noncirrhotic NAFLD. In this review, NAFLD/NASH-associated HCC will be described, including its epidemiology, risk factors promoting hepatocarcinogenesis, and management of HCC in patients with obesity and associated metabolic comorbidities, including preventive strategies and therapeutic approaches to address this growing problem.

Molecular Aspects of MAFLD-New Insights on Pathogenesis and Treatment

Metabolic-associated liver disease (MAFLD) affects up to 70% of overweight and more than 90% of morbidly obese people, and its pathogenesis is rather complex and multifactorial. The criteria for MAFLD include the presence of hepatic steatosis in addition to one of the following three criteria: overweight or obesity, presence of type 2 diabetes mellitus (T2DM), or evidence of metabolic dysregulation. If the specific criteria are present, the diagnosis of MAFLD can be made regardless of alcohol consumption and previous liver disease. The pathophysiological mechanisms of MAFLD, including inflammation, lipotoxicity, mitochondrial disfunction, and oxidative stress, as well as the impact of intestinal gut microbiota, are constantly being elucidated. Treatment strategies that are continually emerging are based on different key points in MAFLD pathogenesis. Yet, the ideal therapeutic option has still not been found and future research is of great importance, as MAFLD represents a multisystemic disease with numerous complications.

Inflammation-induced TRIM21 represses hepatic steatosis by promoting the ubiquitination of lipogenic regulators

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

Metabolic dysfunction-associated fatty liver disease (MAFLD): an update of the recent advances in pharmacological treatment

Metabolic dysfunction-associated fatty liver disease (MAFLD) is nowadays considered the liver manifestation of metabolic syndrome. Its prevalence is increasing worldwide in parallel to the epidemic of diabetes and obesity. MAFLD includes a wide spectrum of liver injury including simple steatosis and non-alcoholic steatohepatitis (NASH) that may lead to serious complications such as liver cirrhosis and liver cancer. The complexity of its pathophysiology and the intricate mechanisms underlying disease progression explains the huge variety of molecules targeting diverse biological mechanisms that have been tested in preclinical and clinical settings in the last two decades. Thanks to the large number of clinical trials of the last few years, most of them still ongoing, the pharmacotherapy scenario of MAFLD is rapidly evolving. The three major components of MAFLD, steatosis, inflammation, and fibrosis seem to be safely targeted with different agents at least in a large proportion of patients. Likely, in the next few years more than one drug will be approved for the treatment of MAFLD at different disease stages. The aim of this review is to synthesize the characteristics and the results of the most advanced clinical trials for the treatment of NASH to evaluate the recent advances of pharmacotherapy in this disease.

The gut-liver axis and gut microbiota in health and liver disease

The trillions of microorganisms in the human intestine are important regulators of health, and disruptions in the gut microbial communities can cause disease. The gut, liver and immune system have a symbiotic relationship with these microorganisms. Environmental factors, such as high-fat diets and alcohol consumption, can disrupt and alter microbial communities. This dysbiosis can lead to dysfunction of the intestinal barrier, translocation of microbial components to the liver and development or progression of liver disease. Changes in metabolites produced by gut microorganisms can also contribute to liver disease. In this Review, we discuss the importance of the gut microbiota in maintenance of health and the alterations in microbial mediators that contribute to liver disease. We present strategies for modulation of the intestinal microbiota and/or their metabolites as potential treatments for liver disease.

A common variant that alters SUN1 degradation associates with hepatic steatosis and metabolic traits in multiple cohorts

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD), and its progressive form steatohepatitis (NASH), represent a genetically and phenotypically diverse entity for which there is no approved therapy, making it imperative to define the spectrum of pathways contributing to its pathogenesis. Rare variants in genes encoding nuclear envelope proteins cause lipodystrophy with early-onset NAFLD/NASH; we hypothesized that common variants in nuclear envelope-related genes might also contribute to hepatic steatosis and NAFLD.

METHODS

Using hepatic steatosis as the outcome of interest, we performed an association meta-analysis of nuclear envelope-related coding variants in three large discovery cohorts (N >120,000 participants), followed by phenotype association studies in large validation cohorts (N >600,000) and functional testing of the top steatosis-associated variant in cell culture.

RESULTS

A common protein-coding variant, rs6461378 (SUN1 H118Y), was the top steatosis-associated variant in our association meta-analysis (p <0.001). In ancestrally distinct validation cohorts, rs6461378 associated with histologic NAFLD and with NAFLD-related metabolic traits including increased serum fatty acids, type 2 diabetes, hypertension, cardiovascular disease, and decreased HDL. SUN1 H118Y was subject to increased proteasomal degradation relative to wild-type SUN1 in cells, and SUN1 H118Y-expressing cells exhibited insulin resistance and increased lipid accumulation.

CONCLUSIONS

Collectively, these data support a potential causal role for the common SUN1 variant rs6461378 in NAFLD and metabolic disease.

IMPACT AND IMPLICATIONS

Non-alcoholic fatty liver disease (NAFLD), with an estimated global prevalence of nearly 30%, is a growing cause of morbidity and mortality for which there is no approved pharmacologic therapy. Our data provide a rationale for broadening current concepts of NAFLD genetics and pathophysiology to include the nuclear envelope, and particularly Sad1 and UNC84 domain containing 1 (SUN1), as novel contributors to this common liver disease. Furthermore, if future studies confirm causality of the common SUN1 H118Y variant, it has the potential to become a broadly relevant therapeutic target in NAFLD and metabolic disease.

Genomic approaches to explore susceptibility and pathogenesis of alcohol use disorder and alcohol-associated liver disease

Excessive alcohol use is a major risk factor for the development of an alcohol use disorder (AUD) and contributes to a wide variety of other medical illnesses, including alcohol-associated liver disease (ALD). Both AUD and ALD are complex and causally interrelated diseases, and multiple factors other than alcohol consumption are implicated in the disease pathogenesis. While the underlying pathophysiology of AUD and ALD is complex, there is substantial evidence for a genetic susceptibility of both diseases. Current genome-wide association studies indicate that the genes associated with clinical AUD only poorly overlap with the genes identified for heavy drinking and, in turn, neither overlap with the genes identified for ALD. Uncovering the main genetic factors will enable us to identify molecular drivers underlying the pathogenesis, discover potential targets for therapy, and implement patient care early in disease progression. In this review, we described multiple genomic approaches and their implications to investigate the susceptibility and pathogenesis of both AUD and ALD. We concluded our review with a discussion of the knowledge gaps and future research on genomic studies in these 2 diseases.

Plant-based diets, genetic predisposition and risk of non-alcoholic fatty liver disease

BACKGROUND

Diets rich in plant-based foods are associated with lower risks of non-alcoholic fatty liver disease (NAFLD), while the prospective evidence is limited. We aimed to examine longitudinal associations of plant-based diets and genetic susceptibility with NAFLD risk.

METHODS

This longitudinal cohort study included 159,222 participants (58.0 ± 8.0 years old, 55.7% female) free of NAFLD in the UK Biobank. We calculated the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI). New-onset NAFLD was the primary outcome. The weighted polygenic risk score was calculated based on risk variants associated with NAFLD. Hazard ratios (HR) and 95% confidential intervals (CI) were estimated by Cox proportional hazards model. Magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) measured liver fat content in a subsample of 20,692 participants (57.5 ± 7.4 years old, 52.6% female) was the secondary outcome. The associations between plant-based diet indices and MRI-PDFF were evaluated using generalized linear models.

RESULTS

During a median follow-up of 9.5 years, 1541 new-onset NAFLD cases were documented. Compared to the lowest quintile, multivariable-adjusted hazard ratios (HRs) of NAFLD in the highest quintile were 0.78 (95% confidential intervals [CI], 0.66-0.93, p-trend =0.02), 0.74 (95% CI, 0.62-0.87, p-trend <0.0001), and 1.24 (95% CI, 1.05-1.46, p-trend = 0.02) for overall PDI, hPDI, and uPDI, respectively. For liver fat content, higher overall PDI and hPDI were associated with lower MRI-PDFF, while higher uPDI was associated with higher liver fat content. We observed a significant interaction between hPDI and PRS (p-interaction =0.03), and the NAFLD risk was lowest among participants with the highest hPDI and low genetic risk.

CONCLUSIONS

Higher intake of plant-based diets especially healthful plant-based diets was associated with lower NAFLD risk and liver fat content regardless of genetic susceptibility, whereas an unhealthful plant-based diet was associated with higher NAFLD risk and intrahepatic steatosis. These results suggest that the quality of plant-based foods should be highlighted when adopting a plant-based diet.

Corrected and republished from: Metabolic associated liver disease

Alcohol consumption (AC) and metabolic syndrome (MS) represent the first cause of liver disease, hepatocellular carcinoma and liver transplantation. The habit of consuming alcoholic beverages and the presence of MS and non-alcoholic fatty liver disease (NAFLD) often coexist in the same patient. The histoclinical boundaries between alcohol related liver disease (ALD) and NAFLD are often not well defined. The co-presence of AC and MS increases the risk of hepatic and extra-hepatic disease. The terminological evolution from NAFLD to metabolic associated fatty liver disease (MAFLD) is certainly a useful advance. However, it is known that the appearance of liver fibrosis increases oncologic and cardiovascular disease risk, which in the case of cirrhosis can be present even in the absence of steatosis and that the mechanisms of fibrogenesis can act independently of the presence of steatosis/steatohepatitis. For this reason, as already stated recently, a further terminological evolution can be hypothesized. This article was originally published with mistakes in the text. The new corrected citable version appears below.

Dietary strategies in non-alcoholic fatty liver disease patients: From evidence to daily clinical practice, a systematic review

Lifestyle modification comprising calorie restriction (CR) and increased physical activity enabling weight loss is the first-line of treatment for non-alcoholic fatty liver disease (NAFLD). However, CR alone is not optimal and evidence suggests that dietary pattern and composition are also critical in NAFLD management. Accordingly, high consumption of red and processed meat, saturated fat, added sugar, and sweetened beverages are associated with an increased risk of developing NAFLD and hepatocellular carcinoma, while other foods and compounds such as fish, olive oil, and polyphenols are, in contrast, beneficial for metabolic disorders. Therefore, several dietary interventions have been studied in order to determine which strategy would be the most beneficial for NAFLD. The evidence regarding the effectiveness of different dietary interventions such as low carbohydrate/low-fat diet, time-restricted eating diet, CR, and the well-studied Mediterranean diet is summarized.

Is the Development of Ascites in Alcoholic Liver Patients Influenced by Specific KIR/HLA Gene Profiles?

Decompensated cirrhosis is the most common cause of ascites due to hemodynamic and renal alteration by continuous fluid leakage from the hepatic sinusoids and splanchnic capillaries into the interstitial space. Then, fluid leakage exceeds lymphatic return, leading to progressive fluid accumulation directly into the peritoneal cavity. Alcohol consumption is one of the main risks of developing alcoholic cirrhosis (AC), but not all AC patients develop ascites. Avoiding the development of ascites is crucial, given that it deteriorates prognosis and increases the patient mortality patient. The innate immune system plays a crucial role in cirrhosis through natural killer cells, which are abundant in the liver. The aim of this study was to analyze the KIR/HLA-C genetic profile in AC patients with and without ascites to understand this pathology and find predictive clinical susceptibility biomarkers that can help to establish risks and prevent the development of ascites in AC patients. A total of 281 AC patients with and without ascites were analyzed and compared with 319 healthy controls. Genomic DNA was extracted from peripheral blood in all groups. A PCR-SSO assay was performed for KIR/HLA genotyping analysis. A total of 16 activating and inhibitor KIR genes and their corresponding known ligands, epitopes of HLA-C, and their genotypes were analyzed. According to our analysis, C1 epitopes were statistically significantly decreased in AC patients with and without ascites. When comparing AC patients with ascites and healthy controls, a significant decrease in C1 epitope frequency was also observed. A statistically significant decrease was also found when comparing the C1C2 genotype in AC patients without ascites with controls. In conclusion, the absence of KIR2DL2 and KIR3DL1 genes may be a predisposing factor for the development of ascites in AC patients. The KIR2DS2/KIR2DL2 may could be involved in grade I ascites development, and the presence of the C1+ epitope and the homozygous C2C2 genotype may be protective genetic factors against ascites development in AC patients.

Chronic-binge ethanol feeding aggravates systemic dyslipidemia in Ldlr-/- mice, thereby accelerating hepatic fibrosis

Objective

Chronic ethanol consumption is known to cause alcohol-associated liver disease, which poses a global health concern as almost a quarter of heavy drinkers develop severe liver damage. Alcohol-induced liver disease ranges from a mild, reversible steatotic liver to alcoholic steatohepatitis and irreversible liver fibrosis and cirrhosis, ultimately requiring liver transplantation. While ethanol consumption is associated with dysregulated lipid metabolism and altered cholesterol homeostasis, the impact of dyslipidemia and pre-existing hypercholesterolemia on the development of alcohol-associated liver disease remains to be elucidated.

Design

To address the influence of systemic dyslipidemia on ethanol-induced liver disease, chronic-binge ethanol feeding was applied to female C57BL/6J (wild type) mice and mice deficient for the low-density lipoprotein receptor (Ldlr-/-), which display a human-like lipoprotein profile with elevated cholesterol and triglyceride levels in circulation. Respective control groups were pair-fed an isocaloric diet.

Results

Chronic-binge ethanol feeding did not alter systemic lipid levels in wild type mice. While increased systemic cholesterol levels in Ldlr-/- mice were not affected by ethanol feeding, chronic-binge ethanol diet aggravated elevated plasma triglyceride levels in Ldlr-/- mice. Despite higher circulatory triglyceride levels in Ldlr-/- mice, hepatic lipid levels and the development of hepatic steatosis were not different from wild type mice after ethanol diet, while hepatic expression of genes related to lipid metabolism (Lpl) and transport (Cd36) showed minor changes. Immunohistochemical assessment indicated a lower induction of infiltrating neutrophils in the livers of ethanol-fed Ldlr-/- mice compared to wild type mice. In line, hepatic mRNA levels of the pro-inflammatory genes Ly6g, Cd11b, Ccr2, Cxcl1 and F4/80 were reduced, indicating less inflammation in the livers of Ldlr-/- mice which was associated with reduced Tlr9 induction. While systemic ALT and hepatic MDA levels were not different, Ldlr-deficient mice showed accelerated liver fibrosis development after chronic-binge ethanol diet than wild type mice, as indicated by increased levels of Sirius Red staining and higher expression of pro-fibrotic genes Tgfb, Col1a1 and Col3a1. Ldlr-/- and wild type mice had similar plasma ethanol levels and did not show differences in the hepatic mRNA levels of Adh1 and Cyp2e1, important for ethanol metabolism.

Conclusion

Our results highlight that chronic-binge ethanol feeding enhances systemic dyslipidemia in Ldlr-/- mice which might accelerate the development of hepatic fibrosis, independent of hepatic lipid levels.

NAFLD and AATD Are Two Diseases with Unbalanced Lipid Metabolism: Similarities and Differences

Non-alcoholic fatty liver disease (NAFLD) is a type of steatosis commonly associated with obesity, dyslipidemia, hypertension, and diabetes. Other diseases such as inherited alpha-1 antitrypsin deficiency (AATD) have also been related to the development of liver steatosis. The primary reasons leading to hepatic lipid deposits can be genetic and epigenetic, and the outcomes range from benign steatosis to liver failure, as well as to extrahepatic diseases. Progressive hepatocellular damage and dysregulated systemic immune responses can affect extrahepatic organs, specifically the heart and lungs. In this review, we discuss the similarities and differences between the molecular pathways of NAFLD and AATD, and the putative value of hepatic organoids as novel models to investigate the physio pathological mechanisms of liver steatosis.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease Cross Talk

Nonalcoholic fatty liver disease is a multisystem condition with effects beyond the liver. The identification of chronic kidney disease as an independent mediator of nonalcoholic fatty liver disease or associated entity with shared cardiometabolic risk factors remains controversial and continues to draw scientific interest. With increasing prevalence of nonalcoholic fatty liver disease and lack of Food and Drug Administration approved therapies, these shared cardiometabolic risk factors have drawn significant attention. In this article, we review shared pathophysiological mechanisms between nonalcoholic fatty liver disease and chronic kidney disease along with current treatment strategies that might be useful for both disease processes.

High fat in blood and body and increased risk of clinically diagnosed non-alcoholic fatty liver disease in 105,981 individuals

BACKGROUND AND AIMS

High caloric diets rich in fat and carbohydrates lead to increased fat accumulation in adipose tissue and blood. This may lead to increased risk of non-alcoholic fatty liver disease. We hypothesized that baseline high nonfasting plasma triglycerides, body mass index (BMI), and waist circumference, individually and combined, associate with increased risk of clinically diagnosed non-alcoholic fatty liver disease during follow-up.

METHODS

Cohort of 105,981 white Danish individuals recruited in 2003-2015 with end of follow-up on December 13th, 2018. Mean follow-up was 9.2 years during which time 418 were clinically diagnosed at hospitals with non-alcoholic fatty liver disease.

RESULTS

Risk of clinically diagnosed non-alcoholic fatty liver disease increased with higher plasma triglycerides, higher BMI, and with higher waist circumference, continuously and stepwise using multivariable adjusted hazard ratios and cumulative incidences. Combining clinical categories of plasma triglycerides with BMI or waist circumference categories, illustrated an almost additive risk with increasing categories. Compared with plasma triglycerides of <1 mmol/L and BMI <25 kg/m2, the multivariable adjusted hazard ratio was 5.2(95% confidence interval: 1.3-21.6) for individuals with both plasma triglycerides of ≥5 mmol/L and BMI ≥35 kg/m2. The corresponding hazard ratio for individuals with plasma triglycerides ≥5 mmol/L and waist circumference was >88 cm for women and >102 cm for men was 4.8(2.3-9.7). Triglyceride results were more pronounced in women versus men.

CONCLUSIONS

High fat in blood and body measured by plasma triglycerides, BMI, and waist circumference, individually and especially combined, are associated with up to a 5-fold increased risk of clinically diagnosed non-alcoholic fatty liver disease.

Geographic Density of Gastroenterologists Is Associated With Decreased Mortality From Alcohol-Associated Liver Disease

BACKGROUND & AIMS

Alcohol-associated liver disease (ALD) is the leading cause of liver-related mortality and has been increasing. To inform public health efforts to address the growing incidence of ALD, we assessed the association of geographic density of gastroenterologists with ALD-related mortality.

METHODS

National data were obtained for adults aged ≥25 years with state-level demographics and 2010-2019 mortality estimates by linking federally maintained registries (WONDER, NSSATS, BRFSS, HRSA, US Census Bureau). Multivariable linear regression was used to assess the association of state-level geographic density of gastroenterologists with ALD-related mortality, adjusting for age, sex, race/ethnicity, and other potential confounders.

RESULTS

Among 50 states and the District of Columbia, the national mean geographic density of gastroenterologists was 4.6 per 100,000 population, and annual ALD-related mortality rate was 85.6 per 1,000,000 population. There was greater than 5-fold differences in geographic density of gastroenterologists and ALD-related mortality across states. In multivariable analysis, the geographic density of gastroenterologists was significantly associated with lower ALD-related mortality (9.0 [95% confidence interval, 1.3-16.7] fewer ALD-related deaths per 1,000,000 population for each additional gastroenterologist per 100,000 population). The association appeared to peak at a threshold of ≥7.5 gastroenterologists per 100,000 population. We estimated that differences in geographic density of gastroenterologists across states may potentially represent 40% of national ALD-related mortality. Exploratory analyses to assess for confounding by generalized subspecialty care, transplant access, alcohol taxation, and substance use or mental health services, including negative control analyses, did not affect primary results.

CONCLUSIONS

State-level geographic density of gastroenterologists is associated with lower ALD-related mortality. These results may inform medical societies and health policymakers to address anticipated workforce gaps to address the growing epidemic of ALD.

Causal effect of adiposity on the risk of 19 gastrointestinal diseases: a Mendelian randomization study

OBJECTIVE

Although the association between adiposity and gastrointestinal (GI) diseases has been explored, the causal effects of adiposity on GI diseases are largely unknown.

METHODS

Mendelian randomization was conducted using single-nucleotide polymorphisms associated with BMI and waist circumference (WC) as instrumental variables, and the causal associations of BMI or WC with GI conditions were estimated among >400,000 UK Biobank participants, >170,000 Finnish-descent participants, and numerous consortia participants of predominantly European ancestry.

RESULTS

Genetically predicted BMI was robustly associated with increased risk of nonalcoholic fatty liver disease (NAFLD), cholecystitis, cholelithiasis, and primary biliary cholangitis. For the diseases, the odds ratio per 1-SD increase in genetically predicted BMI (4.77 kg/m2 ) ranged from 1.22 (95% CI: 1.12-1.34; p < 0.0001) for NAFLD to 1.65 (95% CI: 1.31-2.06; p < 0.0001) for cholecystitis. Genetically predicted WC was robustly associated with increased risk of NAFLD, alcoholic liver disease, cholecystitis, cholelithiasis, colon cancer, and gastric cancer. Alcoholic liver disease was consistently associated with WC even after adjusting for alcohol consumption in a multivariable Mendelian randomization analysis. The odds ratio per 1-SD increase in genetically predicted WC (12.52 cm) for such associations ranged from 1.41 (95% CI: 1.17-1.70; p = 0.0015) for gastric cancer to 1.74 (95% CI: 1.21-1.78; p < 0.0001) for cholelithiasis.

CONCLUSIONS

High genetically predicted adiposity was causally associated with an increased risk of GI abnormalities, particularly of hepatobiliary organs (liver, biliary tract, and gallbladder) that are functionally related to fat metabolism.

Different Dietary Approaches, Non-Alcoholic Fatty Liver Disease and Cardiovascular Disease: A Literature Review

Non-alcoholic fatty liver disease (NAFLD) is the first cause of chronic liver disease and is also associated with other harmful entities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. NAFLD is a significant public health concern worldwide, impacting individuals of all ages, and its prevalence is projected to increase in the near future due to its connection with obesity. Intrinsic (genetics) and external (lifestyle) factors may also modulate NAFLD, and, in turn, may partly explain the observed relationship between NAFLD and cardiovascular disease (CVD). Although many drugs are been tested to treat NAFLD, to date, no drug has indication to specifically treat this disorder. Thus, the current management of NAFLD relies on lifestyle modifications and specifically on weight loss, physical activity, and the intake of a healthy diet. In the present narrative review, we will discuss the effects of certain dietary patterns on NAFLD incidence and progression.

Fibroblast Growth Factors for Nonalcoholic Fatty Liver Disease: Opportunities and Challenges

Nonalcoholic fatty liver disease (NAFLD), a chronic condition associated with metabolic dysfunction and obesity, has reached epidemic proportions worldwide. Although early NAFLD can be treated with lifestyle changes, the treatment of advanced liver pathology, such as nonalcoholic steatohepatitis (NASH), remains a challenge. There are currently no FDA-approved drugs for NAFLD. Fibroblast growth factors (FGFs) play essential roles in lipid and carbohydrate metabolism and have recently emerged as promising therapeutic agents for metabolic diseases. Among them, endocrine members (FGF19 and FGF21) and classical members (FGF1 and FGF4) are key regulators of energy metabolism. FGF-based therapies have shown therapeutic benefits in patients with NAFLD, and substantial progress has recently been made in clinical trials. These FGF analogs are effective in alleviating steatosis, liver inflammation, and fibrosis. In this review, we describe the biology of four metabolism-related FGFs (FGF19, FGF21, FGF1, and FGF4) and their basic action mechanisms, and then summarize recent advances in the biopharmaceutical development of FGF-based therapies for patients with NAFLD.

Abdominal obesity and alcohol use modify the impact of genetic risk for incident advanced liver disease in the general population

BACKGROUND & AIMS

Genetic variants, abdominal obesity and alcohol use are risk factors for incident liver disease (ILD). We aimed to study whether variants either alone or when aggregated into genetic risk scores (GRSs) associate with ILD, and whether waist-hip ratio (WHR) or alcohol use interacts with this risk.

METHODS

Our study included 33 770 persons (mean age 50 years, 47% men) who participated in health-examination surveys (FINRISK 1992-2012 or Health 2000) with data on alcohol use, WHR and 63 genotypes associated with liver disease. Data were linked with national health registers for liver-related outcomes (hospitalizations, malignancies and death). Exclusions were baseline clinical liver disease. Mean follow-up time was 12.2 years. Cox regression analyses between variants and ILD were adjusted for age, sex and BMI.

RESULTS

Variants in PNPLA3, IFNL4, TM6SF2, FDFT1, PPP1R3B, SERPINA1 and HSD17B13 were associated with ILD. GRSs calculated from these variants were not associated with WHR or alcohol use, but were exponentially associated with ILD (up to 25-fold higher risk in high versus low score). The risk of ILD in individuals with high GRS and high WHR or alcohol use compared with those with none of these risk factors was increased by up to 90-fold. GRSs provided new prognostic information particularly in individuals with high WHR.

CONCLUSIONS

The effect of multiple genetic variants on the risk of ILD is potentiated by abdominal obesity and alcohol use. Simple GRSs may help to identify individuals with adverse lifestyle who are at a particularly high risk of ILD.

Metabolic associated liver disease

In real practice the patient with liver disease is often the carrier of multiple etiological factors such as metabolic syndrome (MS) and alcohol consumption (AC). Their copresence is often underestimated and AC is not adequately studied. Traditionally to diagnose non-alcoholic fatty liver disease (NAFLD), AC must not exceed 30 gr for men and 20 gr for women per day. This limit should still be reduced, especially in relation to the AC and fibrogenesis ratio and also frequent misestimation of AC or unrecognized MS may underestimate multi caused liver injury. AC is a contributing cause of MS and alcoholic and non-alcoholic liver disease have a substantially overlapping histopathological picture. Moreover, AC and MS are cause and contributing cause of extra-hepatic morbidity and mortality. It can be concluded that the possible simplification of terminology at metabolic associated liver disease (MALD) makes clinical activity more usable and immediate, facilitates better communication and cooperation between scientific societies and specialists who apparently deal with different medical sectors, facilitates early identification of related hepatic and extra-hepatic pathology, allows to "see the person in a unitary way," to create more streamlined care pathways, to reduce the hospitalization rate with relative cost-benefit advantage and to create unitary prevention and health promotion policies.

Advancements in MAFLD Modeling with Human Cell and Organoid Models

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is one of the most prevalent liver diseases and has no approved therapeutics. The high failure rates witnessed in late-phase MAFLD drug trials reflect the complexity of the disease, and how the disease develops and progresses remains to be fully understood. In vitro, human disease models play a pivotal role in mechanistic studies to unravel novel disease drivers and in drug testing studies to evaluate human-specific responses. This review focuses on MAFLD disease modeling using human cell and organoid models. The spectrum of patient-derived primary cells and immortalized cell lines employed to model various liver parenchymal and non-parenchymal cell types essential for MAFLD development and progression is discussed. Diverse forms of cell culture platforms utilized to recapitulate tissue-level pathophysiology in different stages of the disease are also reviewed.

A machine-learning approach for nonalcoholic steatohepatitis susceptibility estimation

BACKGROUND

Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease, can lead to advanced liver damage and has become an increasingly prominent health problem worldwide. Predictive models for early identification of high-risk individuals could help identify preventive and interventional measures. Traditional epidemiological models with limited predictive power are based on statistical analysis. In the current study, a novel machine-learning approach was developed for individual NASH susceptibility prediction using candidate single nucleotide polymorphisms (SNPs).

METHODS

A total of 245 NASH patients and 120 healthy individuals were included in the study. Single nucleotide polymorphism genotypes of candidate genes including two SNPs in the cytochrome P450 family 2 subfamily E member 1 (CYP2E1) gene (rs6413432, rs3813867), two SNPs in the glucokinase regulator (GCKR) gene (rs780094, rs1260326), rs738409 SNP in patatin-like phospholipase domain-containing 3 (PNPLA3), and gender parameters were used to develop models for identifying at-risk individuals. To predict the individual's susceptibility to NASH, nine different machine-learning models were constructed. These models involved two different feature selections including Chi-square, and support vector machine recursive feature elimination (SVM-RFE) and three classification algorithms including k-nearest neighbor (KNN), multi-layer perceptron (MLP), and random forest (RF). All nine machine-learning models were trained using 80% of both the NASH patients and the healthy controls data. The nine machine-learning models were then tested on 20% of both groups. The model's performance was compared for model accuracy, precision, sensitivity, and F measure.

RESULTS

Among all nine machine-learning models, the KNN classifier with all features as input showed the highest performance with 86% F measure and 79% accuracy.

CONCLUSIONS

Machine learning based on genomic variety may be applicable for estimating an individual's susceptibility for developing NASH among high-risk groups with a high degree of accuracy, precision, and sensitivity.

The impact of polymorphism in PNPLA3 and TM6SF2 genes on the susceptibility and survival of hepatitis C-related hepatocellular carcinoma

Background

Genetic variants of Patatin-like phospholipase domain-containing protein 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes have been reported with the development of hepatocellular carcinoma (HCC). This study aims to explore the role of The PNPLA3 rs738409 and TM6SF2 rs58542926 single-nucleotide polymorphisms (SNPs) on the incidence and survival of HCV-induced HCC in Egyptians.

Methods and results

This case-control study included (120) HCC and (144) hepatitis C virus (HCV) patients. Baseline clinical, laboratory, tumor characteristics data, HCC recurrence, and overall survival were collected. PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphism were detected by TaqMan allelic discrimination assay. We found that HCC patients were significantly older with male predominance. A significant difference between the TT genotypes of TM6SF2 frequency was observed in HCC compared with HCV patients. Moreover, the T allele of TM6SF2 distributions revealed a significant contribution to the different stages of HCC (p=0.03). Both PNPLA3 rs738409 and TM6SF2 rs58542926 variants showed a significant relation with treatment response according to the modified RECIST criteria. Age and diabetes mellitus were the independent factors associated with the development of HCC by multivariate regression analysis.

Conclusions

TM6SF2 rs58542926 polymorphism, not PNPLA3 rs738409, could be implicated in the development of HCV-induced HCC and its progression.

HSPA8 Single-Nucleotide Polymorphism Is Associated with Serum HSC70 Concentration and Carotid Artery Atherosclerosis in Nonalcoholic Fatty Liver Disease

There is an association between nonalcoholic fatty liver disease (NAFLD) and atherosclerosis, but the genetic risk of atherosclerosis in NAFLD remains unclear. Here, a single-nucleotide polymorphism (SNP) of the heat shock 70 kDa protein 8 (HSPA8) gene was analyzed in 123 NAFLD patients who had been diagnosed using a liver biopsy, and the NAFLD phenotype including the maximum intima–media thickness (Max-IMT) of the carotid artery was investigated. Patients with the minor allele (A/G or G/G) of rs2236659 showed a lower serum heat shock cognate 71 kDa protein concentration than those with the major A/A allele. Compared with the patients with the major allele, those with the minor allele showed a higher prevalence of hypertension and higher Max-IMT in men. No significant associations between the HSPA8 genotype and hepatic pathological findings were identified. In decision-tree analysis, age, sex, liver fibrosis, and HSPA8 genotype were individually associated with severe carotid artery atherosclerosis (Max-IMT ≥ 1.5 mm). Noncirrhotic men aged ≥ 65 years were most significantly affected by the minor allele of HSPA8. To predict the risk of atherosclerosis and cardiovascular disease, HSPA8 SNP genotyping might be useful, particularly for older male NAFLD patients.

Hepatic Myofibroblasts: A Heterogeneous and Redox-Modulated Cell Population in Liver Fibrogenesis

During chronic liver disease (CLD) progression, hepatic myofibroblasts (MFs) represent a unique cellular phenotype that plays a critical role in driving liver fibrogenesis and then fibrosis. Although they could originate from different cell types, MFs exhibit a rather common pattern of pro-fibrogenic phenotypic responses, which are mostly elicited or sustained both by oxidative stress and reactive oxygen species (ROS) and several mediators (including growth factors, cytokines, chemokines, and others) that often operate through the up-regulation of the intracellular generation of ROS. In the present review, we will offer an overview of the role of MFs in the fibrogenic progression of CLD from different etiologies by focusing our attention on the direct or indirect role of ROS and, more generally, oxidative stress in regulating MF-related phenotypic responses. Moreover, this review has the purpose of illustrating the real complexity of the ROS modulation during CLD progression. The reader will have to keep in mind that a number of issues are able to affect the behavior of the cells involved: a) the different concentrations of reactive species, b) the intrinsic state of the target cells, as well as c) the presence of different growth factors, cytokines, and other mediators in the extracellular microenvironment or of other cellular sources of ROS.

Regulatory Roles of Caspase-11 Non-Canonical Inflammasome in Inflammatory Liver Diseases

An inflammatory response consists of two consecutive steps: priming and triggering, to prepare and activate inflammatory responses, respectively. The cardinal feature of the triggering step is the activation of intracellular protein complexes called inflammasomes, which provide a platform for the activation of inflammatory signaling pathways. Despite many studies demonstrating the regulatory roles of canonical inflammasomes in inflammatory liver diseases, the roles of newly discovered non-canonical inflammasomes in inflammatory liver diseases are still largely unknown. Recent studies have reported the regulatory roles of the caspase-11 non-canonical inflammasome in inflammatory liver diseases, providing strong evidence that the caspase-11 non-canonical inflammasome may play key roles in the pathogenesis of inflammatory liver diseases. This review comprehensively discusses the emerging roles of the caspase-11 non-canonical inflammasome in the pathogenesis of inflammatory liver diseases, focusing on non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and inflammatory liver injuries and its underlying mechanisms. This review highlights the current knowledge on the regulatory roles of the caspase-11 non-canonical inflammasome in inflammatory liver diseases, providing new insights into the development of potential therapeutics to prevent and treat inflammatory liver diseases by targeting the caspase-11 non-canonical inflammasome.

Sociodemographic and genetic determinants of nonalcoholic fatty liver disease in type 2 diabetes mellitus patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) showed significant association with PNPLA3 rs738409 polymorphism in unrelated individuals. However, it is still unknown whether the relationship of NAFLD with PNPLA3 variant exists or not among subjects with type 2 diabetes mellitus (T2DM). Therefore, the study aimed to evaluate sociodemographic and genetic determinants of NAFLD in type 2 diabetics.

METHODS

The cross-sectional analytical study was conducted at the Department of Molecular Biology, Virtual University of Pakistan, Lahore, Pakistan, during 2019-2020. A total of 153 known cases of T2DM were enrolled using convenience sampling. After excluding patients (n = 24) with HCV, alcoholism, or missing information, data from 129 eligible diabetics with and without NAFLD were analyzed using SPSS. Odds ratios using crosstabs and adjusted odds ratios using binary and multinomial logistic regression were calculated to measure the risk of NAFLD.

RESULTS

Adults 18-35 years were 7.0%, 36-55 years were 64.3%, ≥ 56 years were 28.7%, and females were 66.7%. A total of 41.1% of patients had obesity, 52.7% had NAFLD, and 29.05% carried mutant G allele of rs738409 polymorphism. Among overall diabetics, NAFLD showed association with female (OR = 2.998, p = 0.007), illiterate (OR = 3.067, p = 0.005), and obese (OR = 2.211, p = 0.046) but not with PNPLA3 genotype under any model (all p = > 0.05). Among obese diabetics, NAFLD showed association with female (AOR = 4.010, p = 0.029), illiterate (AOR = 3.506, p = 0.037), GG + CG/CC (AOR = 3.303, p = 0.033), and GG/CG + CC (AOR = 4.547, p = 0.034) using binary regression and with female (AOR = 3.411, p = 0.051), illiterate (AOR = 3.323, p = 0.048), GG + CG/CC (AOR = 3.270, p = 0.029), and GG/CG + CC (AOR = 4.534, p = 0.024) using multinomial regression.

CONCLUSIONS

NAFLD and obesity were the most common comorbid diseases of T2DM. Gender female, being illiterate, and PNPLA3 rs738409 polymorphism were significant risk factors of NAFLD among obese diabetic patients.

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.

The role of genetic mutation in alcoholic liver disease

Background

Alcoholic liver disease (ALD) is the world’s most common type of liver disease caused due to overconsumption of alcohol. The liver supports the best level of tissue damage by hefty drinking since it is the binding site of ethanol digestion. This disease can progress to alcoholic steatohepatitis from alcoholic fatty liver, which implies steatosis has become the most punctual reaction to hefty drinking and is portrayed by the deposition of fat hepatocytes. In addition, steatosis can advance to steatohepatitis, a more extreme, provocative sort of liver damage described by hepatic inflammation. Constant and unnecessary liquor utilization delivers a wide range of hepatic sores, fibrosis and cirrhosis, and sometimes hepatocellular carcinoma. Most people consuming > 40 g of liquor each day create alcoholic fatty liver (AFL); notwithstanding, just a subset of people will grow further developed infection. Hereditary, epigenetic, and non-hereditary components may clarify the impressive interindividual variety in the ALD phenotype.

Main body

This systematic review is to classify new candidate genes associated with alcoholic liver disorders, such as RASGRF2, ALDH2, NFE2L2, ADH1B, PNPLA3, DRD2, MTHFR, TM6SF2, IL1B, and CYP2E1, MBOAT7 as well as to revise the functions of each gene in its polymorphic sequence. The information obtained from the previously published articles revealed the crucial relationship between the genes and ALD and discussed each selected gene’s mechanism.

Conclusion

The aim of this review is to highlight the candidate genes associated with the ALD, and the evidence of this study is to deliberate the part of genetic alterations and modifications that can serve as an excellent biological maker, risk predictors, and therapeutic targets for this disease.

Effects of Moderate Alcohol Consumption in Non-Alcoholic Fatty Liver Disease

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) have emerged as leading causes of chronic liver diseases worldwide. ALD and NAFLD share several pathophysiological patterns as well as histological features, while clinically, they are distinguished by the amount of alcohol consumed daily. However, NAFLD coexists with moderate alcohol consumption in a growing proportion of the population. Here, we investigated the effects of moderate alcohol consumption on liver injury, lipid metabolism, and gut microbiota in 30 NAFLD-patients. We anonymously assessed drinking habits, applying the AUDIT- and CAGE-questionnaires and compared subgroups of abstainers vs. low to harmful alcohol consumers (AUDIT) and Cage 0-1 vs. Cage 2-4. Patients who did not drink any alcohol had lower levels of γGT, ALT, triglycerides, and total cholesterol. While the abundance of Bacteroidaceae, Bifidobacteriaceae, Streptococcaceae, and Ruminococcaceae was higher in the low to harmful alcohol drinking cohort, the abundance of Rikenellaceae was higher in the abstainers. Our study suggests that even moderate alcohol consumption has an impact on the liver and lipid metabolism, as well as on the composition of gut microbiota.

Increased serum miR-193a-5p during non-alcoholic fatty liver disease progression: Diagnostic and mechanistic relevance

BACKGROUND & AIMS

Serum microRNA (miRNA) levels are known to change in non-alcoholic fatty liver disease (NAFLD) and may serve as useful biomarkers. This study aimed to profile miRNAs comprehensively at all NAFLD stages.

METHODS

We profiled 2,083 serum miRNAs in a discovery cohort (183 cases with NAFLD representing the complete NAFLD spectrum and 10 population controls). miRNA libraries generated by HTG EdgeSeq were sequenced by Illumina NextSeq. Selected serum miRNAs were profiled in 372 additional cases with NAFLD and 15 population controls by quantitative reverse transcriptase PCR.

RESULTS

Levels of 275 miRNAs differed between cases and population controls. Fewer differences were seen within individual NAFLD stages, but miR-193a-5p consistently showed increased levels in all comparisons. Relative to NAFL/non-alcoholic steatohepatitis (NASH) with mild fibrosis (stage 0/1), 3 miRNAs (miR-193a-5p, miR-378d, and miR378d) were increased in cases with NASH and clinically significant fibrosis (stages 2-4), 7 (miR193a-5p, miR-378d, miR-378e, miR-320b, miR-320c, miR-320d, and miR-320e) increased in cases with NAFLD activity score (NAS) 5-8 compared with lower NAS, and 3 (miR-193a-5p, miR-378d, and miR-378e) increased but 1 (miR-19b-3p) decreased in steatosis, activity, and fibrosis (SAF) activity score 2-4 compared with lower SAF activity. The significant findings for miR-193a-5p were replicated in the additional cohort with NAFLD. Studies in Hep G2 cells showed that following palmitic acid treatment, miR-193a-5p expression decreased significantly. Gene targets for miR-193a-5p were investigated in liver RNAseq data for a case subgroup (n = 80); liver GPX8 levels correlated positively with serum miR-193a-5p.

CONCLUSIONS

Serum miR-193a-5p levels correlate strongly with NAFLD activity grade and fibrosis stage. MiR-193a-5p may have a role in the hepatic response to oxidative stress and is a potential clinically tractable circulating biomarker for progressive NAFLD.

LAY SUMMARY

MicroRNAs (miRNAs) are small pieces of nucleic acid that may turn expression of genes on or off. These molecules can be detected in the blood circulation, and their levels in blood may change in liver disease including non-alcoholic fatty liver disease (NAFLD). To see if we could detect specific miRNA associated with advanced stages of NAFLD, we carried out miRNA sequencing in a group of 183 patients with NAFLD of varying severity together with 10 population controls. We found that a number of miRNAs showed changes, mainly increases, in serum levels but that 1 particular miRNA miR-193a-5p consistently increased. We confirmed this increase in a second group of cases with NAFLD. Measuring this miRNA in a blood sample may be a useful way to determine whether a patient has advanced NAFLD without an invasive liver biopsy.

MDG, an Ophiopogon japonicus polysaccharide, inhibits non-alcoholic fatty liver disease by regulating the abundance of Akkermansia muciniphila

MDG, a polysaccharide derived from Ophiopogon japonicus, displays a protective effect against obesity and non-alcoholic fatty liver disease (NAFLD). However, there is no definitive evidence proving the specific mechanism of MDG against NAFLD. The results showed MDG supplementation ameliorated lipid accumulation, liver steatosis, and chronic inflammation in high-fat diet-induced NAFLD mice. Besides, MDG increased the abundance and diversity of microbial communities in the gut. These effects were mediated by the colonization of fecal microbiota. Further investigation revealed that Akkermansia muciniphila levels correlated negatively with NAFLD development, and lipid metabolism-related signaling might be the key regulator. Our study suggested that MDG treatment could inhibit obesity and the NAFLD process by modulating lipid-related pathways via altering the structure and diversity of gut microbiota. In addition, Akkermansia miniciphila might be a promising candidate in future research into NAFLD.

Clinical and sociodemographic determinants of disease progression in patients with nonalcoholic steatohepatitis in the United States

One fifth of patients with nonalcoholic fatty liver disease (NAFLD) may progress to nonalcoholic steatohepatitis (NASH), which can increase the risk of cirrhosis, cancer, and death. To date, reported predictors of NASH progression have been heterogeneous.We identified determinants of fibrosis progression in patients with NASH in the United States using physician-reported data from the real-world Global Assessment of the Impact of NASH (GAIN) study, including demographics and clinical characteristics, NASH diagnostic information, fibrosis stage, comorbidities, and treatment. We developed a logistic regression model to assess the likelihood of fibrosis progression since diagnosis, controlling for sociodemographic and clinical variables. An iterative nested model selection approach using likelihood ratio test determined the final model.A total of 989 patients from the GAIN US cohort were included; 46% were women, 58% had biopsy-proven NAFLD, and 74% had fibrosis stage F0-F2 at diagnosis. The final multivariable model included age, years since diagnosis, sex, employment status, smoking status, obesity, fibrosis stage, diagnostic biopsy, Vitamin E, and liver transplant proposed at diagnosis. Odds of progression were 17% higher (odds ratio, 1.17 [95% CI: 1.11-1.23]; P < .001) with each year since NASH diagnosis, 41% lower (0.59 [0.38-0.90]; P = .016) for women than men, 131% higher (2.31 [1.30-4.03]; P = .004) for smokers versus non-smokers, and 89% higher (1.89 [1.26-2.86]; P = .002) with obesity. Odds of progression were also higher with part-time, retired, unemployed, and unable to work due to NASH status versus full-time employment, and when a liver transplant was proposed at diagnosis.Disease duration and severity, obesity, smoking, and lack of full-time employment were significant determinants of fibrosis progression. These findings can support clinical and health-policy decisions to improve NASH management in the US.

Statins in Non-alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the primary cause of chronic liver disease. The range is extensive, including hepatocellular carcinoma, cirrhosis, fibrosis, fatty liver, and non-alcoholic steatohepatitis (NASH). NASH is a condition related to obesity, overweight, metabolic syndrome, diabetes, and dyslipidemia. It is a dynamic condition that can regress to isolated steatosis or progress to fibrosis and cirrhosis. Statins exert anti-inflammatory, proapoptotic, and antifibrotic effects. It has been proposed that these drugs could have a relevant role in NASH. In this review, we provide an overview of current evidence, from mechanisms of statins involved in the modulation of NASH to human trials about the use of statins to treat or attenuate NASH.