Alcohol-Related Liver Disease: An Overview on Pathophysiology, Diagnosis and Therapeutic Perspectives

AI-enabled opportunistic measurement of liver steatosis in coronary artery calcium scans predicts cardiovascular events and all-cause mortality: an AI-CVD study within the Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

About one-third of adults in the USA have some grade of hepatic steatosis. Coronary artery calcium (CAC) scans contain more information than currently reported. We previously reported new artificial intelligence (AI) algorithms applied to CAC scans for opportunistic measurement of bone mineral density, cardiac chamber volumes, left ventricular mass, and other imaging biomarkers collectively referred to as AI-cardiovascular disease (CVD). In this study, we investigate a new AI-CVD algorithm for opportunistic measurement of liver steatosis.

METHODS

We applied AI-CVD to CAC scans from 5702 asymptomatic individuals (52% female, age 62±10 years) in the Multi-Ethnic Study of Atherosclerosis. Liver attenuation index (LAI) was measured using the percentage of voxels below 40 Hounsfield units. We used Cox proportional hazards regression to examine the association of LAI with incident CVD and mortality over 15 years, adjusted for CVD risk factors and the Agatston CAC score.

RESULTS

A total of 751 CVD and 1343 deaths accrued over 15 years. Mean±SD LAI in females and males was 38±15% and 43±13%, respectively. Participants in the highest versus lowest quartile of LAI had greater incidence of CVD over 15 years: 19% (95% CI 17% to 22%) vs 12% (10% to 14%), respectively, p<0.0001. Individuals in the highest quartile of LAI (Q4) had a higher risk of CVD (HR 1.43, 95% CI 1.08 to 1.89), stroke (HR 1.77, 95% CI 1.09 to 2.88), and all-cause mortality (HR 1.36, 95% CI 1.10 to 1.67) compared with those in the lowest quartile (Q1), independent of CVD risk factors.

CONCLUSION

AI-enabled liver steatosis measurement in CAC scans provides opportunistic and actionable information for early detection of individuals at elevated risk of CVD events and mortality, without additional radiation.

Therapeutic Role of Probiotics Against Environmental-Induced Hepatotoxicity: Mechanisms, Clinical Perspectives, Limitations, and Future

Hepatotoxicity is one of the biggest health challenges, particularly in the context of liver diseases, often aggravated by gut microbiota dysbiosis. The gut-liver axis has been regarded as a key idea in liver health. It indicates that changes in gut flora caused by various hepatotoxicants, including alcoholism, acetaminophen, carbon tetrachloride, and thioacetamide, can affect the balance of the gut's microflora, which may lead to increased dysbiosis and intestinal permeability. As a result, bacterial endotoxins would eventually enter the bloodstream and liver, causing hepatotoxicity and inducing inflammatory reactions. Many treatments, including liver transplantation and modern drugs, can be used to address these issues. However, because of the many side effects of these approaches, scientists and medical experts are still hoping for a therapeutic approach with fewer side effects and more positive results. Thus, probiotics have become well-known as an adjunctive strategy for managing, preventing, or reducing hepatotoxicity in treating liver injury. By altering the gut microbiota, probiotics offer a secure, non-invasive, and economical way to improve liver health in the treatment of hepatotoxicity. Through various mechanisms such as regulation of gut microbiota, reduction of pathogenic overgrowth, suppression of inflammatory mediators, modification of hepatic lipid metabolism, improvement in the performance of the epithelial barrier of the gut, antioxidative effects, and modulation of mucosal immunity, probiotics play their role in the treatment and prevention of hepatotoxicity. This review highlights the mechanistic effects of probiotics in environmental toxicants-induced hepatotoxicity and current findings on this therapeutic approach's experimental and clinical trials.

Gut-liver axis: Recent concepts in pathophysiology in alcohol-associated liver disease

The growing recognition of the role of the gut microbiome's impact on alcohol-associated diseases, especially in alcohol-associated liver disease, emphasizes the need to understand molecular mechanisms involved in governing organ-organ communication to identify novel avenues to combat alcohol-associated diseases. The gut-liver axis refers to the bidirectional communication and interaction between the gut and the liver. Intestinal microbiota plays a pivotal role in maintaining homeostasis within the gut-liver axis, and this axis plays a significant role in alcohol-associated liver disease. The intricate communication between intestine and liver involves communication between multiple cellular components in each organ that enable them to carry out their physiological functions. In this review, we focus on novel approaches to understanding how chronic alcohol exposure impacts the microbiome and individual cells within the liver and intestine, as well as the impact of ethanol on the molecular machinery required for intraorgan and interorgan communication.

Ethanol with thioacetamide murine model of alcoholic liver disease identifies hepatic pathways as targets for the human disease

INTRODUCTION AND OBJECTIVES

Hepatic proteome and gut microbiota alterations are known in alcohol-associated hepatitis (AAH). Current animal models sparsely mimic human AAH. We aimed to develop an murine model that closely resembled human AAH.

MATERIALS AND METHODS

Male C57BL/6N mice were pair-fed control/incremental ethanol Lieber-DeCarli diets and thioacetamide (TAA) for 12-weeks to induce AAH. Hepatic proteome was analyzed using LC-MS/MS. Gut-bacteria was determined using 16s-rRNA sequencing.

RESULTS

Mice exposed to EtOH+TAA displayed higher expression of liver triglycerides (1.5-fold, p = 0.001), pro-inflammatory (IL6, 1.5-fold, p = 0.002 and TNFα, 1.7-fold, p = 0.01), fibrotic (TGF-β, 2.7-fold, p = 0.01 and Col1α1, 2-fold, p = 0.01) and oxidative markers (GSH and SOD (-1.5 fold, p = 0.004 & 0.005 respectively)) as compared to EtOH alone. Histology of EtOH+TAA liver displayed pericellular liver fibrosis, increased steatosis, and neutrophil infiltration, which resembled human AAH. In the 12wk EtOH+TAA group, Desulfobacteria, Campylobacteria, and Patescibacteria increased by 2-fold (p = 0.02). Pathway combined score (CS, log10) in EtOH+TAA treatment showed upregulated hepatic ethanol oxidation (CS=1.93), fatty acid biosynthesis (CS=2.48), necrosis (CS=1.59), collagen formation (CS=1.28) and hypoxia (CS=0.68) and downregulated fatty acid beta-oxidation (CS=2.37), PPAR signaling (CS=1.35) fatty acid degradation (CS=2.35), bile acid metabolism (CS=1.87), and oxidative phosphorylation (CS=1.50), as observed in human disease.

CONCLUSIONS

Using an ethanol-thioacetamide combination in mice results in a faster establishment of AAH with fibrosis than previously known models. Differential protein expression strongly correlates with pathways found altered in human AAH, thus making the model mimic human disease better than other known models., respectively. Thioacetamide (TAA) was administered to enhance liver fibrosis and mimic human AAH.

Cyanidin-3-O-glucoside alleviates ethanol-induced liver injury by promoting mitophagy in a Gao-binge mouse model of alcohol-associated liver disease

BACKGROUND

Alcohol-associated liver disease (ALD) is a leading cause of liver disease-related deaths worldwide. Unfortunately, approved medications for the treatment of this condition are quite limited. One promising candidate is the anthocyanin, Cyanidin-3-O-glucoside (C3G), which has been reported to protect mice against hepatic lipid accumulation, as well as fibrosis in different animal models. However, the specific effects and mechanisms of C3G on ALD remain to be investigated.

EXPERIMENTAL APPROACH

In this report, a Gao-binge mouse model of ALD was used to investigate the effects of C3G on ethanol-induced liver injury. The mechanisms of these C3G effects were assessed using AML12 hepatocytes.

RESULTS

C3G administration ameliorated ethanol-induced liver injury by suppressing hepatic oxidative stress, as well as through reducing hepatic lipid accumulation and inflammation. Mechanistically, C3G activated the AMPK pathway and enhanced mitophagy to eliminate damaged mitochondria, thus reducing mitochondria-derived reactive oxidative species in ethanol-challenged hepatocytes.

CONCLUSIONS

The results of this study indicate that mitophagy plays a potentially important role underlying the hepatoprotective action of C3G, as demonstrated in a Gao-binge mouse model of ALD. Accordingly, C3G may serve as a promising, new therapeutic drug candidate for use in ALD.

Research progress and application of liver organoids for disease modeling and regenerative therapy

The liver is a major metabolic organ of the human body and has a high incidence of diseases. In recent years, the annual incidence of liver disease has increased, seriously endangering human life and health. The study of the occurrence and development mechanism of liver diseases, discovery of new therapeutic targets, and establishment of new methods of medical treatment are major issues related to the national economy and people's livelihood. The development of stable and effective research models is expected to provide new insights into the pathogenesis of liver diseases and the search for more effective treatment options. Organoid technology is a new in vitro culture system, and organoids constructed by human cells can simulate the morphological structure, gene expression, and glucose and lipid metabolism of organs in vivo, providing a new model for related research on liver diseases. This paper reviews the latest research progress on liver organoids from the establishment of cell sources and application of liver organoids and discusses their application potential in the field of liver disease research.

From Shadows to Spotlight: Exploring the Escalating Burden of Alcohol-Associated Liver Disease and Alcohol Use Disorder in Young Women

INTRODUCTION

The burden of alcohol-related complications is considerable, particularly alcohol-associated liver disease and alcohol use disorder (AUD). However, there are deficiencies in comprehensive epidemiological research focusing on these issues, especially among young women who display higher susceptibility to such complications compared with their male counterparts. We thus aimed to determine the global burden of these conditions in this vulnerable group.

METHODS

Leveraging data from the Global Burden of Disease Study 2019, we analyzed the prevalence, mortality, and disability-adjusted life years of alcohol-associated cirrhosis (AC), liver cancer from alcohol, and AUD in young women. The findings were categorized by region, nation, and sociodemographic index.

RESULTS

The highest age-standardized prevalence rates were observed in AUD (895.96 [95% uncertainty interval (UI) 722.6-1,103.58]), followed by AC (65.33 [95% UI 48.37-86.49]) and liver cancer from alcohol (0.13 [95% UI 0.09-0.19]) per 100,000 people. The highest age-standardized mortality rates were observed in AC (0.75 [95% UI 0.55-0.97]), followed by AUD (0.48 [95% UI 0.43-0.53]) and liver cancer from alcohol (0.06 [95% UI 0.04-0.09]). The highest burdens of AC and AUD were observed in Central Europe, whereas the high-income Asia Pacific had the highest burden of liver cancer from alcohol.

DISCUSSION

Throughout the past decade, the trend of AUD varied among regions while the impact of alcohol-associated liver disease has increased, requiring urgent public health strategy to mitigate these complications, particularly in female patients in Europe and the Asia-Pacific region.

Hovenia dulcis: a Chinese medicine that plays an essential role in alcohol-associated liver disease

Globally, alcohol-associated liver disease (ALD) has become an increased burden for society. Disulfirams, Benzodiazepines (BZDs), and corticosteroids are commonly used to treat ALD. However, the occurrence of side effects such as hepatotoxicity and dependence, impedes the achievement of desirable and optimal therapeutic efficacy. Therefore, there is an urgent need for more effective and safer treatments. Hovenia dulcis is an herbal medicine promoting alcohol removal clearance, lipid-lowering, anti-inflammatory, and hepatoprotective properties. Hovenia dulcis has a variety of chemical components such as dihydromyricetin, quercetin and beta-sitosterol, which can affect ALD through multiple pathways, including ethanol metabolism, immune response, hepatic fibrosis, oxidative stress, autophagy, lipid metabolism, and intestinal barrier, suggesting its promising role in the treatment of ALD. Thus, this work aims to comprehensively review the chemical composition of Hovenia dulcis and the molecular mechanisms involved in the process of ALD treatment.

Contributing roles of mitochondrial dysfunction and hepatocyte apoptosis in liver diseases through oxidative stress, post-translational modifications, inflammation, and intestinal barrier dysfunction

This review provides an update on recent findings from basic, translational, and clinical studies on the molecular mechanisms of mitochondrial dysfunction and apoptosis of hepatocytes in multiple liver diseases, including but not limited to alcohol-associated liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), and drug-induced liver injury (DILI). While the ethanol-inducible cytochrome P450-2E1 (CYP2E1) is mainly responsible for oxidizing binge alcohol via the microsomal ethanol oxidizing system, it is also responsible for metabolizing many xenobiotics, including pollutants, chemicals, drugs, and specific diets abundant in n-6 fatty acids, into toxic metabolites in many organs, including the liver, causing pathological insults through organelles such as mitochondria and endoplasmic reticula. Oxidative imbalances (oxidative stress) in mitochondria promote the covalent modifications of lipids, proteins, and nucleic acids through enzymatic and non-enzymatic mechanisms. Excessive changes stimulate various post-translational modifications (PTMs) of mitochondrial proteins, transcription factors, and histones. Increased PTMs of mitochondrial proteins inactivate many enzymes involved in the reduction of oxidative species, fatty acid metabolism, and mitophagy pathways, leading to mitochondrial dysfunction, energy depletion, and apoptosis. Unique from other organelles, mitochondria control many signaling cascades involved in bioenergetics (fat metabolism), inflammation, and apoptosis/necrosis of hepatocytes. When mitochondrial homeostasis is shifted, these pathways become altered or shut down, likely contributing to the death of hepatocytes with activation of inflammation and hepatic stellate cells, causing liver fibrosis and cirrhosis. This review will encapsulate how mitochondrial dysfunction contributes to hepatocyte apoptosis in several types of liver diseases in order to provide recommendations for targeted therapeutics.

Association between serum trace elements and sleep disturbance in patients with decompensated cirrhosis

BACKGROUND

Sleep disturbance and trace elements imbalance are common features in patients with decompensated cirrhosis, partially sharing similar mechanistic contributors and linking to adverse outcomes. However, there is a paucity of data concerning their relationship.

OBJECTIVES

To investigate the association between serum trace elements levels and sleep quality in the context of cirrhosis.

DESIGN

Cross-sectional study.

METHODS

We consecutively enrolled 160 patients with decompensated cirrhosis. The sleep disturbance was determined by the Pittsburgh Sleep Quality Index (PSQI > 5). Serum trace elements [magnesium, calcium, iron, copper (Cu), zinc (Zn), lead, and manganese] was measured by inductively coupled plasma mass spectrometry. Association of examined trace elements levels and sleep disturbance was analyzed by multiple linear (global PSQI scores) and multivariate logistic (dichotomized PSQI categories) regression models, respectively.

RESULTS

In total, 91 patients (56.88%) represented PSQI-defined sleep disturbance, characterized by female preponderance, lower body mass index levels, and higher serum Cu levels (all p < 0.05). Looking into its clinical relevance with debilitating conditions, we showed that Cu/Zn ratio (CZr) is significantly higher in cirrhosis with poor sleep quality (1.77 versus 1.48, p = 0.003). Diagnostic performance analysis indicated CZr > 1.62 to exhibit better discrimination relative to respective Cu. Both multiple linear (β = 0.355, p < 0.001) and multivariate logistic regression (odds ratio = 2.364, p = 0.019) identified higher CZr as an independent risk factor associated with sleep disturbance.

CONCLUSION

Our findings implied an association between higher CZr and the presence of sleep disturbance in patients with decompensated cirrhosis.

Estimated projection of incidence and mortality of alcohol-related liver disease in China from 2022 to 2040: a modeling study

BACKGROUND

China has one of the highest numbers of liver disease cases in the world, including 6.4 million cirrhosis associated with alcohol-related liver disease (ALD) cases. However, there is still a lack of urgent awareness about the growth of alcohol consumption and the increased burden of ALD in China. Therefore, we aimed to project the potential impact of changes in alcohol consumption on the burden of ALD in China up to 2040 under different scenarios.

METHODS

We developed a Markov model to simulate the natural history of ALD until 2040 in China. We estimated the incidence and mortality of alcohol-related cirrhosis and hepatocellular carcinoma between 2022 and 2040 under four projected scenarios: status quo scenario and scenarios with a 2%, 4%, and 8% annual decrease in excessive alcohol consumption, respectively.

RESULTS

Under the status quo scenario, the cumulative new cases of cirrhosis from 2022 to 2040 was projected to be 3.61 million (95% UI 3.03-4.44 million), resulting in a cumulative 1.96 million (1.66-2.32 million) deaths from alcohol-related cirrhosis and hepatocellular carcinoma. However, a 2% annual reduction in excessive alcohol consumption was expected to avert 0.3 million deaths associated with ALD, and a 4% annual reduction was projected to prevent about 1.36 million new cases of cirrhosis and prevent 0.5 million ALD-related deaths. Moreover, an 8% annual reduction would prevent about 2 million new cases of cirrhosis and 0.82 million deaths.

CONCLUSIONS

Without any substantial change in alcohol attitudes and policies to regulate excessive drinking, the disease burden of ALD in China will increase enormously. Strengthening the implementation of alcohol restriction interventions is critical and urgent to reduce the impact of ALD on the Chinese population.