Stages Of Alcoholic Liver Disease Research Articles

Molecular insights on intracellular Wnt/β-catenin signaling in alcoholic liver disease.

Alcoholic liver disease (ALD) is one of the most common health problems worldwide, especially in developing countries caused by chronic consumption of alcohol on a daily basis. The ALD spectrum is initiated with the early stages of alcoholic fatty liver (steatosis), progressing to alcoholic steatohepatitis, followed by the later stages of fibrosis and in some cases, cirrhosis and hepatocellular carcinoma (HCC). The Wnt/β-catenin signaling required for healthy liver development, function, and regeneration is found to be aberrated in ALD, attributed to its progression. This review is to elucidate the association of Wnt/β-catenin signaling with various stages of ALD progression. Alcohol causes downregulation of Wnt/β-catenin signaling components and thereby suppressing the pathway. Reports have been published that aberrated Wnt/β-catenin signaling, especially the absence of β-catenin, results in decreased alcohol metabolism, causing steatosis followed by steatohepatitis via lipid accumulation, lipid peroxidation, liver injury, increased oxidative stress and apoptosis of hepatocytes, contributing to the advancement of ALD. Contrastingly, the progression of later stages of ALD like fibrosis and HCC depends on the increased activation of Wnt/β-catenin signaling and its components. Existing studies reveal the varied expression of Wnt/β-catenin signaling in ALD. However, the dual role of the Wnt/β-catenin pathway in earlier and later stages of ALD is not clear. Therefore, studies on the Wnt/β-catenin pathway and its components in various manifestations of ALD might provide insight in targeting the Wnt/β-catenin pathway in ALD treatment.

Intestinal Microbiotas and Alcoholic Hepatitis: Pathogenesis and Therapeutic Value.

Alcoholic hepatitis (AH) is a rapidly progressing and severe stage of alcoholic liver disease, presenting a grim prognosis. Extensive research has elucidated several underlying mechanisms that contribute to the development of AH, including metabolic alterations, immune stimulation, and intestinal dysbiosis. These pathological changes intricately intertwine during the progression of AH. Notably, recent studies have increasingly highlighted the pivotal role of alterations in the intestinal microbiota in the pathogenesis of AH. Consequently, future investigations should place significant emphasis on exploring the dynamics of intestinal microbiota. In this comprehensive review, we consolidate the primary causes of AH while underscoring the influence of gut microbes. Furthermore, by examining AH treatment strategies, we delineate the potential therapeutic value of interventions targeting the gut microbiota. Given the existing limitations in AH treatment options, we anticipate that this review will contribute to forthcoming research endeavors aimed at advancing AH treatment modalities.

Stress mechanism involved in the progression of alcoholic liver disease and the therapeutic efficacy of nanoparticles.

Alcoholic liver disease (ALD) poses a significant threat to human health, with excessive alcohol intake disrupting the immunotolerant environment of the liver and initiating a cascade of pathological events. This progressive disease unfolds through fat deposition, proinflammatory cytokine upregulation, activation of hepatic stellate cells, and eventual development of end-stage liver disease, known as hepatocellular carcinoma (HCC). ALD is intricately intertwined with stress mechanisms such as oxidative stress mediated by reactive oxygen species, endoplasmic reticulum stress, and alcohol-induced gut dysbiosis, culminating in increased inflammation. While the initial stages of ALD can be reversible with diligent care and abstinence, further progression necessitates alternative treatment approaches. Herbal medicines have shown promise, albeit limited by their poor water solubility and subsequent lack of extensive exploration. Consequently, researchers have embarked on a quest to overcome these challenges by delving into the potential of nanoparticle-mediated therapy. Nanoparticle-based treatments are being explored for liver diseases that share similar mechanisms with alcoholic liver disease. It underscores the potential of these innovative approaches to counteract the complex pathogenesis of ALD, providing new avenues for therapeutic intervention. Nevertheless, further investigations are imperative to fully unravel the therapeutic potential and unlock the promise of nanoparticle-mediated therapy specifically tailored for ALD treatment.

Knockdown of GBP5 alleviates lipid accumulation and inflammation in alcoholic fatty liver through inhibition of NF-κB pathway in mice

Alcoholic liver disease (ALD) is a global liver disease that manifests in a variety of forms, including alcoholic hepatitis, liver inflammation, fatty liver, and liver cirrhosis. One of the early stages of ALD is alcoholic fatty liver (AFL) disease, which is primarily characterized by the accumulation of lipids and inflammation in hepatocytes. Guanylate binding protein 5 (GBP5) has been investigated for its involvement in disease progression. The regulatory effects of GBP5 on the progression of AFL disease are still not well understood. This study aims to investigate the impact of GBP5 on AFL progression and its underlying mechanism of action. To achieve this, gene expression was evaluated using western blot and reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods. Lipid accumulation was confirmed using the Oil Red O staining assay, while the levels of Triglyceride (TG), aspartate aminotransferases (AST), and alanine aminotransferases (ALT) were measured using commercial kits. The levels of inflammatory cytokines were assessed using enzyme-linked immuno sorbent assay (ELISA) assay. Finally, cell apoptosis was evaluated using flow cytometry. Cell apoptosis was evaluated through flow cytometry. Our work demonstrated that GBP5 expression was up-regulated in the Ethyl Alcohol (EtOH) group. Additionally, lipid accumulation was increased after EtOH inducement, but this change was attenuated by silencing GBP5. Silencing of GBP5 reduced EtOH-mediated inflammation and cell apoptosis. Finally, it was discovered that knockdown of GBP5 retarded the EtOH-stimulated nuclear factor kappa-B (NF-κB) pathway. Knockdown of GBP5 alleviated lipid accumulation and inflammation in AFL through inhibition of NF-κB pathway. This finding suggested that GBP5 may be a useful bio-target for AFL treatment.

Lipid and renal profile in assessing the severity of alcoholic liver disease.

Lipid and Renal dysfunction in Alcoholic liver disease (ALD) patients occurs either due to multi-organ involvement or secondary to alcoholism. This study was conducted to evaluate the role of lipid and renal parameters in assessing the severity of progression of ALD. Sixty cases of ALD (two groups based on compensated and decompensated features) and thirty healthy controls for comparison were included. Lipid profile (Total Cholesterol, LDL, HDL and Triglycerides) and renal parameters (serum urea, creatinine and uric acid), total and direct bilirubin, total protein and albumin were measured using automated chemistry analyzer. There was a significant decrease in Total cholesterol ,LDL and HDL levels and increased triglycerides when compared to controls (mean of 128.4 ± 59 vs 155 ± 27.2, 77 ± 44.3 vs 97.4 ± 27.2, 28.3 ± 18 vs 39.5 ± 14.1 and 115.8 ± 70.4 vs 91 ± 38 mg/dL respectively). Lipid profile showed a linear decrease while progressing from compensated to decompensated ALD. Renal parameters revealed a statistically significant decrease in serum urea ,increased creatinine and uric acid levels when compared to controls (17.57±2.96 vs23.73±4.94, 1.12±0.55 vs0.88±0.16,6.60±1.32 vs 4.68±1.40 mg/dL respectively).Total cholesterol and HDL showed a linear decrease when ALD progresses. Serum uric acid showed an early increase in compensated stage of ALD. This study inferred that Total cholesterol, TGL, HDL and uric acid can be used for assessing the severity of progression of ALD.

Deconvolution of Bulk RNAseq Data from Human Liver Samples Reveals a Metabolic Switch in Periportal Hepatocytes in Alcoholic Hepatitis

The prevalence of alcoholic liver disease (ALD) is rapidly increasing, however, few if any therapies are successful in the treatment of this disease as the development of such therapies is hampered by the lack of animal models. In this work, we aim to identify points of metabolic divergence driving the progression of ALD, which may provide therapeutic potential in the treatment of the disease. To determine the differences in metabolic landscapes across these progressing stages of ALD, bulk RNA‐seq was performed on alcoholic hepatitis (AH), progressing ALD, non‐alcoholic liver disease (NALD), and healthy control human liver samples. Hierarchical clustering of metabolic genes revealed N‐glycan metabolism, nucleotide metabolism and protein modification associated with AH samples, while oxidative phosphorylation, drug metabolism and retinol metabolism associated with healthy control and NALD samples. To further investigate which hepatic cell types may be involved in this shift in metabolic activity, we performed deconvolution of the bulk RNA‐seq data using a previously published single‐cell RNA‐seq dataset from healthy human liver tissue. Two imputed populations of hepatocytes, the periportal Hep 4 population and the mid‐lobular Hep 6 population, showed a decrease in cell proportions with increasing disease severity from healthy control to AH. Oppositely, there was an increase in cholangiocyte and hepatic stellate cell (HSCs) proportions with AH progression. Hierarchical clustering of metabolic genes from each cell type showed similar clustering to the bulk data, with groups of genes partitioned into (1) those upregulated with AH and (2) those upregulated in healthy control and NALD. Clusters of upregulated metabolic genes within the AH states from the Hep 4, cholangiocyte, and HSC populations all showed overrepresentation of metabolic pathways common to those upregulated in the bulk data, which differed from the Hep 6 population, whose enriched processes were downregulated in the bulk data. However, both hepatocyte populations displayed overrepresented metabolic pathways similar to the bulk data when analyzing the cluster of upregulated metabolic genes in the NALD and healthy states. These results indicate that the Hep 4, HSC and cholangiocyte populations act synergistically to upregulate specific metabolic genes in the AH state, while only the hepatocyte populations are responsible for the upregulation of metabolic genes in the healthy control and NALD states. It is crucial to further analyze the Hep 4 cluster of cells as they seem to be driving the metabolic switch activity separating the AH states from the NALD and healthy control disease states.

Liver metabolomics identifies bile acid profile changes at early stages of alcoholic liver disease in mice

Alcohol consumption is a global healthcare problem with enormous social, economic, and clinical consequences. The liver sustains the earliest and the greatest degree of tissue injury due to chronic alcohol consumption and it has been estimated that alcoholic liver disease (ALD) accounts for almost 50% of all deaths from cirrhosis in the world. In this study, we used a modified Lieber-DeCarli (LD) diet to treat mice with alcohol and simulate chronic alcohol drinking. Using an untargeted metabolomics approach, our aim was to identify the various metabolites and pathways that are altered in the early stages of ALD. Histopathology showed minimal changes in the liver after 6 weeks of alcohol consumption. However, untargeted metabolomics analyses identified 304 metabolic features that were either up- or down-regulated in the livers of ethanol-consuming mice. Pathway analysis revealed significant alcohol-induced alterations, the most significant of which was in the FXR/RXR activation pathway. Targeted metabolomics focusing on bile acid biosynthesis showed elevated taurine-conjugated cholic acid compounds in ethanol-consuming mice. In summary, we showed that the changes in the liver metabolome manifest very early in the development of ALD, and when minimal changes in liver histopathology have occurred. Although alterations in biochemical pathways indicate a complex pathology in the very early stages of alcohol consumption, bile acid changes may serve as biomarkers of the early onset of ALD.

Real-time imaging of acute alcoholic liver injury in vivo via a robust viscosity probe with aggregation-induced emission nature

As the early stage of alcoholic liver disease, acute alcoholic liver injury (AALI) is usually ignored or misdiagnosed due to the lack of typical clinic symptoms, however, it will probably progress to severe liver lesions without proper intervention. Therefore, it is of great significance to develop a sensitive probe to timely diagnose AALI and monitor its progression. In this paper, AALI was found to be accompanied with the elevated intracellular viscosity originating from the malfunction of mitochondria, which enables the mitochondrial viscosity a promising biomarker for AALI. Through delicate structure engineering, a robust fluorescent probe HOTPy with aggregation-induced emission (AIE) nature was developed with sufficient aqueous solubility and prominent chemical stability, which imparted distinctive interference-resisting ability to the probe. HOTPy specifically responded to the mitochondrial viscosity in LO2 cell imaging. It further successfully diagnosed the mouse with AALI through differentiating the viscosity alternations by in vivo imaging. More importantly, when medication was applied to alleviate the liver injury of the AALI mouse, HOTPy could also dynamically track the liver improvement process in situ. In summary, HOTPy is a promising tool for diagnosis and management of AALI through real-time fluorescence imaging.

English

BACKGROUND Alcoholism remains to be the major cause of morbidity and mortality throughout the world. Consuming alcohol is the potent etiological factor for the development of alcoholic liver diseases (ALD), ranging from fatty liver to hepatocellular carcinoma with varying rates of development in both genders depending on the quality, quantity, and duration of the drink. Zinc deficiency has been documented with the progression of alcoholic liver disease. It is also a well-known fact that zinc is a co-factor for enzyme alkaline phosphatase. This study aims to assess the zinc status and alkaline phosphatase activity in patients with various stages of alcoholic liver disease, correlate zinc with alkaline phosphatase activity, albumin, gamma glutamyl transferase activity, MELD score and duration of alcohol intake and analysing the need for evaluating zinc in these patients. METHODS This comparative observational study involves group I healthy controls and group II patients diagnosed to have ethanol related decompensated liver disease with or without portal hypertension for more than three years from the Department of Medical Gastroenterology, Government Medical College Hospital. 5 ml of venous blood in fasting state was collected from both groups and assayed for serum zinc, and serum alkaline phosphatase activity. The data was statistically analysed. RESULTS The study results demonstrate that higher percentage of patients with alcoholic liver disease have low serum zinc levels than healthy controls. Zinc when compared with variables like serum albumin, duration of alcohol intake, MELD score, serum gamma glutamyl transferase and alkaline phosphatase in the case and control groups were found to be statistically significant. CONCLUSIONS There is decrease in serum zinc level and increased alkaline phosphatase activity in patients with alcoholic liver disease. The statistically significant data is a strong rationale for evaluating the zinc status and thereby supplementing zinc to patients with alcoholic liver disease. KEYWORDS Alcoholic Liver Disease, Zinc, Alkaline Phosphatase, MELD Score

Mechano-structural alteration in proximal femora of individuals with alcoholic liver disease: Implications for increased bone fragility.

Although increased hip fracture risk is noted in patients with alcoholic liver disease (ALD), their femoral microstructural and mechanical properties were not investigated previously. The present study aimed to analyze the associations between subregional deteriorations in femoral mechano-structural properties and clinical imaging findings to explain increased femoral fracture risk among ALD patients. This study analyzed proximal femora of 33 male cadaveric donors, divided into ALD (n=13, 57±13years) and age-matched control group (n=20, 54±13years). After pathohistological verification of ALD stage, DXA and HSA measurements of the proximal femora were performed, followed by micro-CT and Vickers microindentation of the superolateral neck, inferomedial neck, and intertrochanteric region. Bone mineral density and cross sectional area of the femoral neck were deteriorated in ALD donors, compared with healthy controls (p<0.05). Significant ALD-induced degradation of trabecular and cortical microstructure and Vickers microhardness reduction were noted in the analyzed femoral regions (p<0.05). Still, the most prominent ALD-induced mechano-structural deterioration was noted in intertrochanteric region. Additionally, more severe bone alterations were observed in individuals with an irreversible stage of ALD, alcoholic liver cirrhosis (ALC), than in those with an initial ALD stage, fatty liver disease. Observed osteodensitometric and mechano-structural changes illuminate the basis for increased femoral fracture risk in ALD patients. Additionally, our data suggest bone strength reduction that may result in increased susceptibility to intertrochanteric femoral fracture in men with ALD. Thus, femoral fracture risk assessment should be advised for all ALD patients, especially in those with ALC.

Metformin and Probiotics Interplay in Amelioration of Ethanol-Induced Oxidative Stress and Inflammatory Response in an In Vitro and In Vivo Model of Hepatic Injury.

Alcohol-induced liver injury implicates inflammation and oxidative stress as important mediators. Despite rigorous research, there is still no Food and Drug Administration (FDA) approved therapies for any stage of alcoholic liver disease (ALD). Interestingly, metformin (Met) and several probiotic strains possess the potential of inhibiting alcoholic liver injury. Therefore, we investigated the effectiveness of combination therapy using a mixture of eight strains of lactic acid-producing bacteria, commercialized as Visbiome® (V) and Met in preventing the ethanol-induced hepatic injury using in vitro and in vivo models. Human HepG2 cells and male Wistar rats were exposed to ethanol and simultaneously treated with probiotic V or Met alone as well as in combination. Endoplasmic reticulum (ER) stress markers, inflammatory markers, lipid metabolism, reactive oxygen species (ROS) production, and oxidative stress were evaluated, using qRT-PCR, Oil red O staining, fluorimetry, and HPLC. In vitro, probiotic V and Met in combination prevented ethanol-induced cellular injury, ER stress, oxidative stress, and regulated lipid metabolism as well as inflammatory response in HepG2 cells. Probiotic V and Met also promoted macrophage polarization towards the M2 phenotype in ethanol-exposed RAW 264.7 macrophage cells. In vivo, combined administration of probiotic V and Met ameliorated the histopathological changes, inflammatory response, hepatic markers (liver enzymes), and lipid metabolism induced by ethanol. It also improved the antioxidant markers (HO-1 and Nrf-2), as seen by their protein levels in both HepG2 cells as well as liver tissue using ELISA. Hence, probiotic V may act, in addition to the Met, as an effective preventive treatment against ethanol-induced hepatic injury.

Streptococcus, the Predominant Bacterium to Predict the Severity of Liver Injury in Alcoholic Liver Disease.

BackgroundNew evidence implies that the imbalance of gut microbiota is associated with the progression of alcoholic liver disease (ALD) and that the composition of gut microbiota is altered in ALD patients. However, the predominant bacterium in patients involved in the progress of ALD has not been identified. The purpose of this study is to investigate the predominant bacterium in the early and end-stages of ALD as well as the relationship between the bacterium and the degree of liver injury.MethodsWe enrolled 21 alcoholic fatty liver (AFL) patients, 17 alcoholic liver cirrhosis (ALC) patients and 27 healthy controls, and sequenced the 16S rRNA gene of their fecal microbiota. The gut microbiota composition and its relationship with the indicators of clinical hepatic function were assessed using canonical correspondence analysis (CCA), spearman correlation heatmap and multivariate association with linear (MaAsLin) Models.ResultsThe composition and structure of gut microbiota changed greatly in different stages of ALD, and the degree of disorder was aggravated with the progression of ALD, even in the early stage. Moreover, the relative abundance of Streptococcus was highly enriched only in patients with ALC (P <0.001), and positively correlated with AST level (P = 0.029). The abundance of Streptococcus distinguished the liver injury of ALC patients from the controls with an area under the receiver-operating characteristic curve (AUC) of 0.877 (P < 0.001).ConclusionsThese findings indicate that the imbalance of gut microbiota exists at the early and end-stages of ALD, and the degree of disorder is aggravated with the progression of ALD. Streptococcus, as the predominant bacterium, may be a microbiological marker to evaluate the severity of liver injury in ALD patients.

Sulforaphane ameliorates ethanol plus carbon tetrachloride-induced liver fibrosis in mice through the Nrf2-mediated antioxidant response and acetaldehyde metabolization with inhibition of the LPS/TLR4 signaling pathway

Alcoholic liver disease (ALD)-related fibrosis results from a variety of mechanisms including the accumulation of acetaldehyde, reactive oxygen species, and hepatic overload of endogenous lipopolysaccharide (LPS). Alcohol cessation is the therapeutic mainstay for patients with all stages of ALD, whereas pharmacological strategies for liver fibrosis have not been established. Sulforaphane, a phytochemical found in cruciferous vegetables, activates nuclear factor erythroid 2-related factor 2 (Nrf2) and exerts anticancer, antidiabetic, and antimicrobial effects; however, few studies investigated its efficacy in the development of ALD-related fibrosis. Herein, we investigated the effect of sulforaphane on acetaldehyde metabolism and liver fibrosis in HepaRG and LX-2 cells, human hepatoma and hepatic stellate cell lines, respectively, as well as in a mouse model of alcoholic liver fibrosis induced by ethanol plus carbon tetrachloride (EtOH/CCl4). Sulforaphane treatment induced the activity of acetaldehyde-metabolizing mitochondrial aldehyde dehydrogenase in HepaRG cells and suppressed the acetaldehyde-induced proliferation and profibrogenic activity in LX-2 cells with upregulation of Nrf2-regulated antioxidant genes, including HMOX1, NQO1, and GSTM3. Moreover, sulforaphane attenuated the LPS/toll-like receptor 4-mediated sensitization to transforming growth factor-β with downregulation of NADPH oxidase 1 (NOX1) and NOX4. In EtOH/CCl4-treated mice, oral sulforaphane administration augmented hepatic acetaldehyde metabolism. Additionally, sulforaphane significantly inhibited Kupffer cell infiltration and fibrosis, decreased fat accumulation and lipid peroxidation, and induced Nrf2-regulated antioxidant response genes in EtOH/CCl4-treated mice. Furthermore, sulforaphane treatment blunted hepatic exposure of gut-derived LPS and suppressed hepatic toll-like receptor 4 signaling pathway. Taken together, these results suggest sulforaphane as a novel therapeutic strategy in ALD-related liver fibrosis.

Progress in inflammasome activation and pyrolysis in alcoholic liver disease.

Alcoholic liver disease (ALD) is a chronic liver disease characterized by large accumulation of lipids in the liver, accompanied by inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma. In the different stages of ALD, mediators of the immune system, such as cytokines or inflammasomes, are crucially involved. In the ALD disease spectrum, the upregulation of the inflammatory cascade is the main factor in the development of steatohepatitis into severe alcoholic hepatitis. Activation of the inflammatory cascade requires multiple stimuli. Pyroptosis is a new type of programmed cell death that relies on caspase. Inflammasomes play a crucial role in the process of cell death. Cellular infection or cellular stress can activate inflammatory corpuscles, leading to assembly of inflammasome polyprotein complexes, activation of caspase-1 and its downstream substrates pro-IL-1β, pro-IL-18 and gasdermin D activation and maturation, thus participating in the body's immune inflammatory response and induced cell death. In recent years, there is increasing evidence that activation of inflammatory bodies and pyroptosis play a key role in the development of alcoholic liver disease.

Liver-specific ceramide reduction alleviates steatosis and insulin resistance in alcohol-fed mice

Alcohol’s impairment of both hepatic lipid metabolism and insulin resistance (IR) are key drivers of alcoholic steatosis, the initial stage of alcoholic liver disease (ALD). Pharmacologic reduction of lipotoxic ceramide prevents alcoholic steatosis and glucose intolerance in mice, but potential off-target effects limit its strategic utility. Here, we employed a hepatic-specific acid ceramidase (ASAH) overexpression model to reduce hepatic ceramides in a Lieber-DeCarli model of experimental alcoholic steatosis. We examined effects of alcohol on hepatic lipid metabolism, body composition, energy homeostasis, and insulin sensitivity as measured by hyperinsulinemic-euglycemic clamp. Our results demonstrate that hepatic ceramide reduction ameliorates the effects of alcohol on hepatic lipid droplet (LD) accumulation by promoting VLDL secretion and lipophagy, the latter of which involves ceramide cross-talk between the lysosomal and LD compartments. We additionally demonstrate that hepatic ceramide reduction prevents alcohol’s inhibition of hepatic insulin signaling. These effects on the liver are associated with a reduction in oxidative stress markers and are relevant to humans, as we observe peri- LD ASAH expression in human ALD. Together, our results suggest a potential role for hepatic ceramide inhibition in preventing ALD.

Gentiopicroside Ameliorates the Progression from Hepatic Steatosis to Fibrosis Induced by Chronic Alcohol Intake.

In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol-containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.

Research progress in relationship between microRNAs and alcoholic liver disease

Alcoholic liver disease (ALD) is a major health problem globally. Long-term drinking can lead to fatty liver and inflammation, which in turn may cause liver fibrosis, cirrhosis or liver cancer. At present, the potential mechanism is not fully understood, and growing evidence shows that microRNAs (miRNAs, miR) play an important role in different stages of ALD. In this paper, the research progress in the role of various miRNAs in different stages of ALD is reviewed, and their application in ALD is prospected. Key words: Alcoholic liver disease; MicroRNA; Alcoholic fatty liver; Alcoholic hepatitis; Alcohol hepatic fibrosis

Investigating RNA expression profiles altered by nicotinamide mononucleotide therapy in a chronic model of alcoholic liver disease

BackgroundChronic alcohol consumption is a significant cause of liver disease worldwide. Several biochemical mechanisms have been linked to the initiation and progression of alcoholic liver disease (ALD) such as oxidative stress, inflammation, and metabolic dysregulation, including the disruption of NAD+/NADH. Indeed, an ethanol-mediated reduction in hepatic NAD+ levels is thought to be one factor underlying ethanol-induced steatosis, oxidative stress, steatohepatitis, insulin resistance, and inhibition of gluconeogenesis. Therefore, we applied a NAD+ boosting supplement to investigate alterations in the pathogenesis of early-stage ALD.MethodsTo examine the impact of NAD+ therapy on the early stages of ALD, we utilized nicotinamide mononucleotide (NMN) at 500 mg/kg intraperitoneal injection every other day, for the duration of a Lieber-DeCarli 6-week chronic ethanol model in mice. Numerous strategies were employed to characterize the effect of NMN therapy, including the integration of RNA-seq, immunoblotting, and metabolomics analysis.ResultsOur findings reveal that NMN therapy increased hepatic NAD+ levels, prevented an ethanol-induced increase in plasma ALT and AST, and changed the expression of 25% of the genes that were modulated by ethanol metabolism. These genes were associated with a number of pathways including the MAPK pathway. Interestingly, our analysis revealed that NMN treatment normalized Erk1/2 signaling and prevented an induction of Atf3 overexpression.ConclusionsThese findings reveal previously unreported mechanisms by which NMN supplementation alters hepatic gene expression and protein pathways to impact ethanol hepatotoxicity in an early-stage murine model of ALD. Overall, our data suggest further research is needed to fully characterize treatment paradigms and biochemical implications of NAD+-based interventions.

Study of Fecal and Urinary Metabolite Perturbations Induced by Chronic Ethanol Treatment in Mice by UHPLC-MS/MS Targeted Profiling.

Alcoholic liver disease (ALD) as a consequence of ethanol chronic consumption could lead to hepatic cirrhosis that is linked to high morbidity and mortality. Disease diagnosis is still very challenging and usually clear findings are obtained in the later stage of ALD. The profound effect of ethanol on metabolism can be depicted using metabolomics; thus, the discovery of novel biomarkers could shed light on the initiation and the progression of the ALD, serving diagnostic purposes. In the present study, Hydrophilic Interaction Liquid Chromatography tandem Mass Spectrometry HILIC-MS/MS based metabolomics analyisis of urine and fecal samples of C57BL/6 mice of both sexes at two sampling time points was performed, monitoring the effect of eight-week ethanol consumption. The altered hepatic metabolism caused by ethanol consumption induces extensive biochemical perturbations and changes in gut microbiota population on a great scale. Fecal samples were proven to be a suitable specimen for studying ALD since it was more vulnerable to the metabolic changes in comparison to urine samples. The metabolome of male mice was affected on a greater scale than the female metabolome due to ethanol exposure. Precursor small molecules of essential pathways of energy production responded to ethanol exposure. A meaningful correlation between the two studied specimens demonstrated the impact of ethanol in endogenous and symbiome metabolism.

Alcohol-induced microtubule acetylation leads to the accumulation of large, immobile lipid droplets.

Although steatosis (fatty liver) is a clinically well-described early stage of alcoholic liver disease, surprisingly little is known about how it promotes hepatotoxicity. We have shown that ethanol consumption leads to microtubule hyperacetylation that can explain ethanol-induced defects in protein trafficking. Because almost all steps of the lipid droplet life cycle are microtubule dependent and because microtubule acetylation promotes adipogenesis, we examined droplet dynamics in ethanol-treated cells. In WIF-B cells treated with ethanol and/or oleic acid (a fatty acid associated with the "Western" diet), we found that ethanol dramatically increased lipid droplet numbers and led to the formation of large, peripherally located droplets. Enhanced droplet formation required alcohol dehydrogenase-mediated ethanol metabolism, and peripheral droplet distributions required intact microtubules. We also determined that ethanol-induced microtubule acetylation led to impaired droplet degradation. Live-cell imaging revealed that droplet motility was microtubule dependent and that droplets were virtually stationary in ethanol-treated cells. To determine more directly whether microtubule hyperacetylation could explain impaired droplet motility, we overexpressed the tubulin-specific acetyltransferase αTAT1 to promote microtubule acetylation in the absence of alcohol. Droplet motility was impaired in αTAT1-expressing cells but to a lesser extent than in ethanol-treated cells. However, in both cases, the large immotile droplets (but not small motile ones) colocalized with dynein and dynactin (but not kinesin), implying that altered droplet-motor microtubule interactions may explain altered dynamics. These studies further suggest that modulating cellular acetylation is a potential strategy for treating alcoholic liver disease.NEW & NOTEWORTHY Chronic alcohol consumption with the "Western diet" enhances the development of fatty liver and leads to impaired droplet motility, which may have serious deletrious effects on hepatocyte function.