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.

A polygenic risk score for alcohol-associated cirrhosis among heavy drinkers with European ancestry.

BACKGROUND: Polygenic Risk Scores (PRS) based on results from genome-wide association studies offer the prospect of risk stratification for many common and complex diseases. We developed a PRS for alcohol-associated cirrhosis by comparing single-nucleotide polymorphisms among patients with alcohol-associated cirrhosis (ALC) versus drinkers who did not have evidence of liver fibrosis/cirrhosis. METHODS: Using a data-driven approach, a PRS for ALC was generated using a meta-genome-wide association study of ALC (N=4305) and an independent cohort of heavy drinkers with ALC and without significant liver disease (N=3037). It was validated in 2 additional independent cohorts from the UK Biobank with diagnosed ALC (N=467) and high-risk drinking controls (N=8981) and participants in the Indiana Biobank Liver cohort with alcohol-associated liver disease (N=121) and controls without liver disease (N=3239). RESULTS: A 20-single-nucleotide polymorphisms PRS for ALC (PRSALC) was generated that stratified risk for ALC comparing the top and bottom deciles of PRS in the 2 validation cohorts (ORs: 2.83 [95% CI: 1.82 -4.39] in UK Biobank; 4.40 [1.56 -12.44] in Indiana Biobank Liver cohort). Furthermore, PRSALC improved the prediction of ALC risk when added to the models of clinically known predictors of ALC risk. It also stratified the risk for metabolic dysfunction -associated steatotic liver disease -cirrhosis (3.94 [2.23 -6.95]) in the Indiana Biobank Liver cohort -based exploratory analysis. CONCLUSIONS: PRSALC incorporates 20 single-nucleotide polymorphisms, predicts increased risk for ALC, and improves risk stratification for ALC compared with the models that only include clinical risk factors. This new score has the potential for early detection of heavy drinking patients who are at high risk for ALC.

Non-invasive tests for alcohol-associated liver disease.

Alcohol consumption is a global phenomenon and a major contributor to alcohol-associated liver disease (ALD). Detecting individuals at risk of ALD has been challenging, with only a small fraction of patients being identified at early stages compared to other chronic liver diseases. In response to this challenge, non-invasive tests (NITs) have become essential tools for the detection of ALD, offering opportunities for early identification and intervention to mitigate the disease burden. Non-invasive alcohol consumption biomarkers are crucial in estimating individuals' recent alcohol intake, providing valuable insights into their drinking patterns. Various NITs have been investigated for the initial screening of asymptomatic individuals at risk of ALD, as well as for identifying specific stages of the disease. These NITs are applied in two main clinical scenarios: population-based stratification for identifying and predicting liver-related symptoms, and diagnosing and prognosticating compensated cirrhosis or advanced chronic liver disease in secondary or tertiary care settings. Moreover, NITs play a significant role in the prognostic assessment of patients with various manifestations of ALD, including alcohol-associated hepatitis, decompensated cirrhosis, and metabolic and alcohol-associated liver disease. These tests guide appropriate treatment decisions and predict outcomes. In this review, various NITs for the early detection and monitoring of alcohol consumption were discussed. Additionally, the evaluation of NITs for screening and predicting ALD and liver complications was addressed comprehensively. Future perspectives of NITs for ALD were explored, alongside a thorough discussion of the opportunities and challenges associated with NITs for ALD screening.

Incidence of liver cancer in young adults according to the global burden of disease database 2019.

OBJECTIVE: The worldwide burden of cancer is increasing in younger populations. However, the epidemiology of primary liver cancer remains understudied in young adults compared to other cancer forms. METHODS: This study analyzed data from the Global Burden of Disease (GBD) study between 2010 and 2019 to assess the age-standardized incidence, mortality, and disability-adjusted life years (DALYs) associated with primary liver cancer in the young (15-49 y), stratified by region, nation, sociodemographic index, and sex. RESULTS: The study found a global estimate of 78,299 primary liver cancer cases, 60,602 deaths, and 2.90 million DALYs in the young population. The Western Pacific region exhibited the highest burden in 2019, showing the most significant increase compared to other regions between 2010-2019. More than half of countries worldwide have undergone an increase in primary liver cancer incidence rates in young adults. Around 12.51% of deaths due to primary liver cancer occur in young individuals. Throughout the study period, there was a significant decline in primary liver cancer mortality due to most etiologies, except for metabolic dysfunction-associated steatotic liver disease (MASLD)-attributable primary liver cancer (annual percentage change [APC] +0.87%, 95% confidence interval 0.70-1.05%) and alcohol-attributable primary liver cancer (APC +0.21%, 95% confidence interval 0.01-0.42%). Limitations of the GBD database include reliance on the quality of primary data and possible underestimation of alcohol consumption. CONCLUSION: Over the past decade, there has been a marked increase in the burden of primary liver cancer, especially that originating from steatotic liver disease. This trend calls for the development of urgent and comprehensive strategies to mitigate this rising burden globally.

Platelets in Alcohol-Associated Liver Disease: Interaction With Neutrophils.

Alcohol-associated liver disease (ALD) is a major contributor to liver-related mortality globally. An increasing body of evidence underscores the pivotal role of platelets throughout the spectrum of liver injury and recovery, offering unique insights into liver homeostasis and pathobiology. Alcoholic-associated steatohepatitis is characterized by the infiltration of hepatic neutrophils. Recent studies have highlighted the extensive distance neutrophils travel through sinusoids to reach the liver injury site, relying on a platelet-paved endothelium for efficient crawling. The adherence of platelets to neutrophils is crucial for accurate migration from circulation to the inflammatory site. A gradual decline in platelet levels leads to diminished neutrophil recruitment. Platelets exhibit the ability to activate neutrophils. Platelet activation is heightened upon the release of platelet granule contents, which synergistically activate neutrophils through their respective receptors. The sequence culminates in the formation of platelet-neutrophil complexes and the release of neutrophil extracellular traps intensifies liver damage, fosters inflammatory immune responses, and triggers hepatotoxic processes. Neutrophil infiltration is a hallmark of alcohol-associated steatohepatitis, and the roles of neutrophils in ALD pathogenesis have been studied extensively, however, the involvement of platelets in ALD has received little attention. The current review consolidates recent findings on the intricate and diverse roles of platelets and neutrophils in liver pathophysiology and in ALD. Potential therapeutic strategies are highlighted, focusing on targeting platelet-neutrophil interactions and activation in ALD. The anticipation is that innovative methods for manipulating platelet and neutrophil functions will open promising avenues for future ALD therapy.

S-Adenosylmethionine Negatively Regulates the Mitochondrial Respiratory Chain Repressor MCJ in the Liver.

MCJ (Methylation-Controlled J protein), an endogenous repressor of the mitochondrial respiratory chain, is upregulated in multiple liver diseases but little is known about how it is regulated. S-adenosylmethionine (SAMe), the biological methyl donor, is frequently depleted in chronic liver diseases. Here, we show that SAMe negatively regulates MCJ in the liver. While deficiency in methionine adenosyltransferase alpha 1 (MATα1), enzyme that catalyzes SAMe biosynthesis, leads to hepatic MCJ upregulation, MAT1A overexpression and SAMe treatment reduced MCJ expression. We found that MCJ is methylated at lysine residues and that it interacts with MATα1 in liver mitochondria, likely to facilitate its methylation. Lastly, we observed that MCJ is upregulated in alcohol-associated liver disease, a condition characterized by reduced MAT1A expression and SAMe levels along with mitochondrial injury. MCJ silencing protected against alcohol-induced mitochondrial dysfunction and lipid accumulation. Our study demonstrates a new role of MATα1 and SAMe in reducing hepatic MCJ expression.

Development and evaluation of objective trial performance metrics for multisite clinical studies: Experience from the AlcHep Network.

BACKGROUND: Recruitment and retention are critical in clinical studies but there are limited objective metrics of trial performance. We tested if development of trial performance metrics will allow for objective evaluation of study quality. Performance metrics were developed using data from the observational cohort (OBS) and randomized clinical trial (RCT) arms of the prospective Alcoholic Hepatitis Network. METHODS: Yield-rate (%YR; eligible/screened), recruitment index (RI; mean recruitment time/patient), completion index (CI; average number of days to complete the follow-up/patient), and protocol adherence index (AI; average number of deviations/subject recruited) were determined. RESULTS: 2250 patients (1168 for OBS; 1082 for RCT) were screened across 8 sites. Recruitment in the RCT (57% target) was similar to that in the OBS (59% target). Of those screened, 743 (63.6%) subjects in the OBS and 147 (13.6%) subjects in the RCT were enrolled in the study. In OBS study, 253 (34.1%) subjects, and in the RCT, 68 (46.3%) subjects, completed the study or reached a censoring event. Across all sites (range), YR for OBS was 63.6% (41.3-98.3%) and for RCT was 13.6% (5.5-92.6%); RI for OBS was 1.66 (8.79-19.85) and for RCT was 4.05 (19.76-36.43); CI for OBS was 4.87 (22.6-118.3) and for RCT was 8.75 (27.27-161.5); and AR for OBS was 0.56 (0.08-1.04) and for RCT was 1.55 (0.39-3.21. Factors related to participants, research design, study team, and research sponsors contributed to lower performance metrics. CONCLUSIONS: Objective measures of clinical trial performance allow for strategies to enhance study quality and development of site-specific improvement plans. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT4072822 NCT03850899.

Thirty-Day Readmissions Are Largely Not Preventable in Patients With Cirrhosis.

INTRODUCTION: Hospital readmissions are common in patients with cirrhosis, but there are few studies describing readmission preventability. We aimed to describe the incidence, causes, and risk factors for preventable readmission in this population. METHODS: We performed a prospective cohort study of patients with cirrhosis hospitalized at a single center between June 2014 and March 2020 and followed up for 30 days postdischarge. Demographic, clinical, and socioeconomic data, functional status, and quality of life were collected. Readmission preventability was independently and systematically adjudicated by 3 reviewers. Multinomial logistic regression was used to compare those with (i) preventable readmission, (ii) nonpreventable readmission/death, and (iii) no readmission. RESULTS: Of 654 patients, 246 (38%) were readmitted, and 29 (12%) were preventable readmissions. Reviewers agreed on preventability for 70% of readmissions. Twenty-two (including 2 with preventable readmission) died. The most common reasons for readmission were hepatic encephalopathy (22%), gastrointestinal bleeding (13%), acute kidney injury (13%), and ascites (6%), and these reasons were similar between preventable and nonpreventable readmissions. Preventable readmission was often related to paracentesis timeliness, diuretic adjustment monitoring, and hepatic encephalopathy treatment. Compared with nonreadmitted patients, preventable readmission was independently associated with racial and ethnic minoritized individuals (odds ratio [OR] 5.80; 95% CI, 1.96-17.13), nonmarried marital status (OR 2.88; 95% CI, 1.18-7.05), and admission in the prior 30 days (OR 3.45; 95% CI, 1.48-8.04). DISCUSSION: For patients with cirrhosis, readmission is common, but most are not preventable. Preventable readmissions are often related to ascites and hepatic encephalopathy and are associated with racial and ethnic minorities, nonmarried status, and prior admissions.

FK-binding protein 5: Possible relevance to the pathogenesis of metabolic dysfunction and alcohol-associated liver disease.

The FK506-binding protein (FKBP5) plays significant roles in mediating stress responses by interacting with glucocorticoids, participating in adipogenesis, and influencing various cellular pathways throughout the body. In this review, we described the potential role of FKBP5 in the pathogenesis of two common chronic liver diseases, metabolic dysfunction-associated steatotic liver disease (MASLD), and alcohol-associated liver disease (ALD). We provided an overview of the FK-binding protein family and elucidated their roles in cellular stress responses, metabolic diseases, and adipogenesis. We explored how FKBP5 may mechanistically influence the pathogenesis of MASLD and ALD and provided insights for further investigation into the role of FKBP5 in these two diseases.

HMGB2 is a potential diagnostic marker and therapeutic target for liver fibrosis and cirrhosis.

BACKGROUND: High mobility group proteins 1 and 2 (HMGB1 and HMGB2) are 80% conserved in amino acid sequence. The function of HMGB1 in inflammation and fibrosis has been extensively characterized. However, an unaddressed central question is the role of HMGB2 on liver fibrosis. In this study, we provided convincing evidence that the HMGB2 expression was significantly upregulated in human liver fibrosis and cirrhosis, as well as in several mouse liver fibrosis models. METHODS: The carbon tetrachloride (CCl4) induced liver fibrosis mouse model was used. AAV8-Hmgb2 was utilized to overexpress Hmgb2 in the liver, while Hmgb2-/- mice were used for loss of function experiments. The HMGB2 inhibitor inflachromene and liposome-shHMGB2 (lipo-shHMGB2) were employed for therapeutic intervention. RESULTS: The serum HMGB2 levels were also markedly elevated in patients with liver fibrosis and cirrhosis. Deletion of Hmgb2 in Hmgb2-/- mice or inhibition of HMGB2 in mice using a small molecule ICM slowed the progression of CCl4-induced liver fibrosis despite constant HMGB1 expression. In contrast, AAV8-mediated overexpression of Hmgb2 enchanced CCl4-incuded liver fibrosis. Primary hepatic stellate cells (HSCs) isolated from Hmgb2-/- mice showed significantly impaired transdifferentiation and diminished activation of α-SMA, despite a modest induction of HMGB1 protein. RNA-seq analysis revealed the induction of top 45 CCl4-activated genes in multiple signaling pathways including integrin signaling and inflammation. The activation of these genes by CCl4 were abolished in Hmgb2-/- mice or in ICM-treated mice. These included C-X3-C motif chemokine receptor 1 (Cx3cr1) associated with inflammation, cyclin B (Ccnb) associated with cell cycle, DNA topoisomerase 2-alpha (Top2a) associated with intracellular component, and fibrillin (Fbn) and fibromodulin (Fmod) associated with extracellular matrix. CONCLUSION: We conclude that HMGB2 is indispensable for stellate cell activation. Therefore, HMGB2 may serve as a potential therapeutic target to prevent HSC activation during chronic liver injury. The blood HMGB2 level may also serve as a potential diagnostic marker to detect early stage of liver fibrosis and cirrhosis in humans.

Epidemiology and trends of alcohol use disorder and alcohol-associated liver disease.

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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.

Epidemic within a pandemic: Alcohol-associated hepatitis and COVID-19.

BACKGROUND: There was an increase in alcoholic beverage sales during the peak of the COVID pandemic in the United States. However, little is known about the impact of SARS-CoV-2 infection among hospitalized alcohol-associated hepatitis (AH) patients. METHODS: We analyzed the available National Inpatient Data (NIS) data from 2020 to determine mortality and healthcare utilization among hospitalized AH patients with and without COVID-19 in the United States. RESULTS: We observed a ~15.6% increase in cases of hospitalized AH patients from 136,620 in 2019 to 157,885 in 2020, a significant increase from an average of 5.5% per annum despite an 8.7% decline in US hospital admissions over the same time span. Men younger than 40 were the fastest growing AH group, with a 23% increase in 2020. Approximately 1.8% of hospitalized AH patients had a SARS-CoV-2 infection, which significantly worsened the mortality among patients with AH (11.4% vs. 4.1%, p < 0.0001). This was especially true among older AH patients with concomitant conditions such as clinically apparent cirrhosis, acute renal failure, upper gastrointestinal bleeding, and sepsis. AH patients with COVID-19 also had a longer length of stay (8.6 vs. 6.1 days, p < 0.0001) and higher hospital charges during the stay ($93,670 vs. $66,283, p < 0.0001) than those without COVID-19. CONCLUSION: Our study highlights the rise in AH cases during the COVID-19 pandemic. Screening and appropriate management of excessive alcohol use and preventive measures such as COVID-19 vaccination should be considered to reduce morbidity and mortality among patients with AH.

SPRR1A is a key downstream effector of MiR-150 during both maladaptive cardiac remodeling in mice and human cardiac fibroblast activation.

MicroRNA-150 (miR-150) is conserved between rodents and humans, is significantly downregulated during heart failure (HF), and correlates with patient outcomes. We previously reported that miR-150 is protective during myocardial infarction (MI) in part by decreasing cardiomyocyte (CM) apoptosis and that proapoptotic small proline-rich protein 1a (Sprr1a) is a direct CM target of miR-150. We also showed that Sprr1a knockdown in mice improves cardiac dysfunction and fibrosis post-MI and that Sprr1a is upregulated in pathological mouse cardiac fibroblasts (CFs) from ischemic myocardium. However, the direct functional relationship between miR-150 and SPRR1A during both post-MI remodeling in mice and human CF (HCF) activation was not established. Here, using a novel miR-150 knockout;Sprr1a-hypomorphic (Sprr1ahypo/hypo) mouse model, we demonstrate that Sprr1a knockdown blunts adverse post-MI effects caused by miR-150 loss. Moreover, HCF studies reveal that SPRR1A is upregulated in hypoxia/reoxygenation-treated HCFs and is downregulated in HCFs exposed to the cardioprotective ß-blocker carvedilol, which is inversely associated with miR-150 expression. Significantly, we show that the protective roles of miR-150 in HCFs are directly mediated by functional repression of profibrotic SPRR1A. These findings delineate a pivotal functional interaction between miR-150 and SPRR1A as a novel regulatory mechanism pertinent to CF activation and ischemic HF.

Upregulation of the ERRγ-VDAC1 axis underlies the molecular pathogenesis of pancreatitis.

Emerging evidence suggest that transcription factors play multiple roles in the development of pancreatitis, a necroinflammatory condition lacking specific therapy. Estrogen-related receptor γ (ERRγ), a pleiotropic transcription factor, has been reported to play a vital role in pancreatic acinar cell (PAC) homeostasis. However, the role of ERRγ in PAC dysfunction remains hitherto unknown. Here, we demonstrated in both mice models and human cohorts that pancreatitis is associated with an increase in ERRγ gene expression via activation of STAT3. Acinar-specific ERRγ haploinsufficiency or pharmacological inhibition of ERRγ significantly impaired the progression of pancreatitis both in vitro and in vivo. Using systematic transcriptomic analysis, we identified that voltage-dependent anion channel 1 (VDAC1) acts as a molecular mediator of ERRγ. Mechanistically, we showed that induction of ERRγ in cultured acinar cells and mouse pancreata enhanced VDAC1 expression by directly binding to specific site of the Vdac1 gene promoter and resulted in VDAC1 oligomerization. Notably, VDAC1, whose expression and oligomerization were dependent on ERRγ, modulates mitochondrial Ca2+ and ROS levels. Inhibition of the ERRγ-VDAC1 axis could alleviate mitochondrial Ca2+ accumulation, ROS formation and inhibit progression of pancreatitis. Using two different mouse models of pancreatitis, we showed that pharmacological blockade of ERRγ-VDAC1 pathway has therapeutic benefits in mitigating progression of pancreatitis. Likewise, using PRSS1R122H-Tg mice to mimic human hereditary pancreatitis, we demonstrated that ERRγ inhibitor also alleviated pancreatitis. Our findings highlight the importance of ERRγ in pancreatitis progression and suggests its therapeutic intervention for prevention and treatment of pancreatitis.

Enhanced Ca2+-channeling complex formation at the ER-mitochondria interface underlies the pathogenesis of alcohol-associated liver disease.

Ca2+ overload-induced mitochondrial dysfunction is considered as a major contributing factor in the pathogenesis of alcohol-associated liver disease (ALD). However, the initiating factors that drive mitochondrial Ca2+ accumulation in ALD remain elusive. Here, we demonstrate that an aberrant increase in hepatic GRP75-mediated mitochondria-associated ER membrane (MAM) Ca2+-channeling (MCC) complex formation promotes mitochondrial dysfunction in vitro and in male mouse model of ALD. Unbiased transcriptomic analysis reveals PDK4 as a prominently inducible MAM kinase in ALD. Analysis of human ALD cohorts further corroborate these findings. Additional mass spectrometry analysis unveils GRP75 as a downstream phosphorylation target of PDK4. Conversely, non-phosphorylatable GRP75 mutation or genetic ablation of PDK4 prevents alcohol-induced MCC complex formation and subsequent mitochondrial Ca2+ accumulation and dysfunction. Finally, ectopic induction of MAM formation reverses the protective effect of PDK4 deficiency in alcohol-induced liver injury. Together, our study defines a mediatory role of PDK4 in promoting mitochondrial dysfunction in ALD.

Reporting the cases of alcohol-associated hepatitis using the National Inpatient Sample data.

The letter is to respond to the recent publication "Trends in hospitalization for alcoholic hepatitis from 2011 to 2017: A USA nationwide study" (World J Gastroenterol 2022; 28: 5036-5046). We noticed a significant difference in the total numbers of reported hospitalized alcohol-associated hepatitis (AH) patients between this publication and our publication on Alcohol Clin Exp Res (2022; 46: 1472-1481). We believe the number of "AH-related hospitalizations" inflated by the inclusion of patients with non-AH forms of alcohol-associated liver disease.

Ethanol and its Nonoxidative Metabolites Promote Acute Liver Injury by Inducing ER Stress, Adipocyte Death, and Lipolysis.

BACKGROUND & AIMS: Binge drinking in patients with metabolic syndrome accelerates the development of alcohol-associated liver disease. However, the underlying mechanisms remain elusive. We investigated if oxidative and nonoxidative alcohol metabolism pathways, diet-induced obesity, and adipose tissues influenced the development of acute liver injury in a single ethanol binge model. METHODS: A single ethanol binge was administered to chow-fed or high-fat diet (HFD)-fed wild-type and genetically modified mice. RESULTS: Oral administration of a single dose of ethanol induced acute liver injury and hepatic endoplasmic reticulum (ER) stress in chow- or HFD-fed mice. Disruption of the Adh1 gene increased blood ethanol concentration and exacerbated acute ethanol-induced ER stress and liver injury in both chow-fed and HFD-fed mice, while disruption of the Aldh2 gene did not affect such hepatic injury despite high blood acetaldehyde levels. Mechanistic studies showed that alcohol, not acetaldehyde, promoted hepatic ER stress, fatty acid synthesis, and increased adipocyte death and lipolysis, contributing to acute liver injury. Increased serum fatty acid ethyl esters (FAEEs), which are formed by an enzyme-mediated esterification of ethanol with fatty acids, were detected in mice after ethanol gavage, with higher levels in Adh1 knockout mice than in wild-type mice. Deletion of the Ces1d gene in mice markedly reduced the acute ethanol-induced increase of blood FAEE levels with a slight but significant reduction of serum aminotransferase levels. CONCLUSIONS: Ethanol and its nonoxidative metabolites, FAEEs, not acetaldehyde, promoted acute alcohol-induced liver injury by inducing ER stress, adipocyte death, and lipolysis.