RESUMEN
Alcohol-associated liver disease (ALD) is a serious public health problem with limited pharmacologic options. The goal of the current study was to investigate the efficacy of pharmacologic inhibition of soluble epoxide hydrolase (sEH), an enzyme involved in lipid metabolism, in experimental ALD, and to examine the underlying mechanisms. C57BL/6J male mice were subjected to acute-on-chronic ethanol (EtOH) feeding with or without the sEH inhibitor 4-[[trans-4-[[[[4-trifluoromethoxy phenyl]amino]carbonyl]-amino]cyclohexyl]oxy]-benzoic acid (TUCB). Liver injury was assessed by multiple end points. Liver epoxy fatty acids and dihydroxy fatty acids were measured by targeted metabolomics. Whole-liver RNA sequencing was performed, and free modified RNA bases were measured by mass spectrometry. EtOH-induced liver injury was ameliorated by TUCB treatment as evidenced by reduced plasma alanine aminotransferase levels and was associated with attenuated alcohol-induced endoplasmic reticulum stress, reduced neutrophil infiltration, and increased numbers of hepatic M2 macrophages. TUCB altered liver epoxy and dihydroxy fatty acids and led to a unique hepatic transcriptional profile characterized by decreased expression of genes involved in apoptosis, inflammation, fibrosis, and carcinogenesis. Several modified RNA bases were robustly changed by TUCB, including N6-methyladenosine and 2-methylthio-N6-threonylcarbamoyladenosine. These findings show the beneficial effects of sEH inhibition by TUCB in experimental EtOH-induced liver injury, warranting further mechanistic studies to explore the underlying mechanisms, and highlighting the translational potential of sEH as a drug target for this disease.
Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Hepatopatías Alcohólicas , Ratones , Animales , Masculino , Epóxido Hidrolasas/genética , Epóxido Hidrolasas/metabolismo , Transcriptoma , Ratones Endogámicos C57BL , Hepatopatías Alcohólicas/genética , Ácidos Grasos , Etanol , ARNRESUMEN
Lipids play a significant role in life activities and participate in the biological system through different pathways. Although comprehensive two-dimensional liquid chromatography-mass spectrometry (2DLC-MS) has been developed to profile lipid abundance changes, lipid identification and quantification from 2DLC-MS data remain a challenge. We created Lipid Wizard, open-source software for lipid assignment and isotopic peak stripping of the 2DLC-MS data. Lipid Wizard takes the peak list deconvoluted from the 2DLC-MS data as input and assigns each isotopic peak to the lipids recorded in the LIPID MAPS database by precursor ion m/z matching. The matched lipids are then filtered by the first-dimension retention time (1D RT), followed by the second-dimension retention time (2D RT), where the 2D RT of each lipid is predicted using an equivalent carbon number (ECN) model. The remaining assigned lipids are used for isotopic peak stripping via an iterative linear regression. The performance of Lipid Wizard was tested using a set of lipid standards and then applied to study the lipid changes in the livers of mice (fat-1) fed with alcohol.
Asunto(s)
Lípidos , Cromatografía Líquida con Espectrometría de Masas , Ratones , Animales , Lípidos/análisis , Programas Informáticos , Hígado/química , Bases de Datos FactualesRESUMEN
Alcohol-associated liver disease (ALD) is a major health problem with limited effective treatment options. Alcohol-associated hepatitis (AH) is a subset of severe ALD with a high rate of mortality due to infection, severe inflammation, and ultimately multi-organ failure. There is an urgent need for novel therapeutic approaches to alleviate the human suffering associated with this condition. Resolvin D1 (RvD1) promotes the resolution of inflammation and regulates immune responses. The current study aimed to test the therapeutic efficacy and mechanisms of RvD1-mediated effects on liver injury and inflammation in an experimental animal model that mimics severe AH in humans. Our data demonstrated that mice treated with RvD1 had attenuated liver injury and inflammation caused by EtOH and LPS exposure by limiting hepatic neutrophil accumulation and decreasing hepatic levels of pro-inflammatory cytokines. In addition, RvD1 treatment attenuated hepatic pyroptosis, an inflammatory form of cell death, via downregulation of pyroptosis-related genes such as GTPase family member b10 and guanylate binding protein 2, and reducing cleavage of caspase 11 and gasdermin-D. In vitro experiments with primary mouse hepatocytes and bone marrow-derived macrophages confirmed the effectiveness of RvD1 in the attenuation of pyroptosis. In summary, our data demonstrated that RvD1 treatment provided beneficial effects against liver injury and inflammation in an experimental animal model recapitulating features of severe AH in humans. Our results suggest that RvD1 may be a novel adjunct strategy to traditional therapeutic options for AH patients.
Asunto(s)
Etanol , Lipopolisacáridos , Humanos , Ratones , Animales , Lipopolisacáridos/toxicidad , Etanol/toxicidad , Ácidos Docosahexaenoicos/farmacología , Ácidos Docosahexaenoicos/uso terapéutico , Ácidos Docosahexaenoicos/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Hígado/metabolismoRESUMEN
Alcohol-associated liver disease is a global health care burden, with alcohol-associated cirrhosis (AC) and alcohol-associated hepatitis (AH) being two clinical manifestations with poor prognosis. The limited efficacy of standard of care for AC and AH highlights a need for therapeutic targets and strategies. The current study aimed to address this need through the identification of hepatic proteome and phosphoproteome signatures of AC and AH. Proteomic and phosphoproteomic analyses were conducted on explant liver tissue (test cohort) and liver biopsies (validation cohort) from patients with AH. Changes in protein expression across AH severity and similarities and differences in AH and AC hepatic proteome were analyzed. Significant alterations in multiple proteins involved in various biological processes were observed in both AC and AH, including elevated expression of transcription factors involved in fibrogenesis (eg, Yes1-associated transcriptional regulator). Another finding was elevated levels of hepatic albumin (ALBU) concomitant with diminished ALBU phosphorylation, which may prevent ALBU release, leading to hypoalbuminemia. Furthermore, altered expression of proteins related to neutrophil function and chemotaxis, including elevated myeloperoxidase, cathelicidin antimicrobial peptide, complement C3, and complement C5 were observed in early AH, which declined at later stages. Finally, a loss in expression of mitochondria proteins, including enzymes responsible for the synthesis of cardiolipin was observed. The current study identified hepatic protein signatures of AC and AH as well as AH severity, which may facilitate the development of therapeutic strategies.
Asunto(s)
Hepatitis Alcohólica , Hepatopatías Alcohólicas , Hepatitis Alcohólica/patología , Humanos , Cirrosis Hepática Alcohólica/complicaciones , Hepatopatías Alcohólicas/patología , Fosfoproteínas , Proteoma , ProteómicaRESUMEN
Alcohol-associated liver disease (ALD) is a major human health issue for which there are limited treatment options. Experimental evidence suggests that nutrition plays an important role in ALD pathogenesis, and specific dietary fatty acids, for example, n6 or n3-PUFAs, may exacerbate or attenuate ALD, respectively. The purpose of the current study was to determine whether the beneficial effects of n3-PUFA enrichment in ALD were mediated, in part, by improvement in Wnt signaling. Wild-type (WT) and fat-1 transgenic mice (that endogenously convert n6-PUFAs to n3) were fed ethanol (EtOH) for 6 weeks followed by a single LPS challenge. fat-1 mice had less severe liver damage than WT littermates as evidenced by reduced plasma alanine aminotransferase, hepatic steatosis, liver tissue neutrophil infiltration, and pro-inflammatory cytokine expression. WT mice had a greater downregulation of Axin2, a key gene in the Wnt pathway, than fat-1 mice in response to EtOH and LPS. Further, there were significant differences between WT and fat-1 EtOH+LPS-challenged mice in the expression of five additional genes linked to the Wnt signaling pathway, including Apc, Fosl1/Fra-1, Mapk8/Jnk-1, Porcn, and Nkd1. Compared to WT, primary hepatocytes isolated from fat-1 mice exhibited more effective Wnt signaling and were more resistant to EtOH-, palmitic acid-, or TNFα-induced cell death. Further, we demonstrated that the n3-PUFA-derived lipid mediators, resolvins D1 and E1, can regulate hepatocyte expression of several Wnt-related genes that were differentially expressed between WT and fat-1 mice. These data demonstrate a novel mechanism by which n3-PUFAs can ameliorate ALD.
Asunto(s)
Ácidos Grasos Omega-3/metabolismo , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/prevención & control , Sustancias Protectoras/metabolismo , Vía de Señalización Wnt , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Etanol/efectos adversos , Ácido Graso Desaturasas/deficiencia , Ácido Graso Desaturasas/genética , Femenino , Hepatocitos/citología , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Inflamación/genética , Lipopolisacáridos/efectos adversos , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Vía de Señalización Wnt/efectos de los fármacos , Vía de Señalización Wnt/genéticaRESUMEN
BACKGROUND: Alcohol use is a major global healthcare burden that contributes to numerous adverse health outcomes, including liver disease. Many factors influence individual susceptibility to alcohol-associated diseases, including nutritional factors. The objective of the current study was to examine inter-relations among alcohol, dietary micronutrients and macronutrient consumption, and liver health by analyzing data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES). METHODS: Based on self-reported alcohol consumption, NHANES respondents were assigned to one of four categories: never drinkers (lifetime abstainers), non-drinkers (past-year abstainers), moderate drinkers (1/2 drinks per day for females/males, respectively), and heavy drinkers (>1/>2 drinks per day for females/males, respectively, and/or frequent binge drinking). Survey-weighted regression analyses (adjusted for gender, age, race, education, and body mass index) were performed to examine associations between alcohol intake, dietary, and liver health characteristics. RESULTS: Individuals categorized as heavy drinkers were significantly younger, most often well-educated males with low incidences of diabetes and other comorbidities. They consumed the most overall calories and various micronutrients, indicating a diet that was not necessarily nutrient poor. Neither moderate nor heavy drinkers had liver steatosis or fibrosis as measured by liver elastography, although heavy drinkers had modestly elevated plasma biomarkers of liver injury, including ALT, AST, and GGT, compared with the other groups. CONCLUSIONS: Our findings suggest that the category of heavy drinkers in the 2017-2018 NHANES consisted of generally healthy individuals with high-energy intake and no evidence of liver steatosis or fibrosis. However, slightly increased plasma liver markers may indicate a risk of future progression to more advanced stages of liver disease over time in some individuals. Several limitations should be considered when interpreting these data, including the potential misclassification of drinking categories and the lack of standardized cutoff scores for fatty liver as assessed by elastography, among others.
Asunto(s)
Hígado Graso , Micronutrientes , Masculino , Femenino , Humanos , Encuestas Nutricionales , Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/epidemiología , Biomarcadores , FibrosisRESUMEN
Chronic alcohol consumption leads to disturbances in intestinal function which can be exacerbated by inflammation and modulated by different factors, e.g., polyunsaturated fatty acids (PUFAs). The mechanisms underlying these alterations are not well understood. In this study, RNA-seq analysis was performed on ileum tissue from WT and fat-1 transgenic mice (which have elevated endogenous n-3 PUFAs). Mice were chronically fed ethanol (EtOH) and challenged with a single lipopolysaccharide (LPS) dose to induce acute systemic inflammation. Both WT and fat-1 mice exhibited significant ileum transcriptome changes following EtOH + LPS treatment. Compared to WT, fat-1 mice had upregulated expression of genes associated with cell cycle and xenobiotic metabolism, while the expression of pro-inflammatory cytokines and pro-fibrotic genes was decreased. In response to EtOH + LPS, fat-1 mice had an increased expression of genes related to antibacterial B cells (APRIL and IgA), as well as an elevation in markers of pro-restorative macrophages and γδ T cells that was not observed in WT mice. Our study significantly expands the knowledge of regulatory mechanisms underlying intestinal alterations due to EtOH consumption and inflammation and identifies the beneficial transcriptional effects of n-3 PUFAs, which may serve as a viable nutritional intervention for intestinal damage resulting from excessive alcohol consumption.
Asunto(s)
Etanol/toxicidad , Ácido Graso Desaturasas/fisiología , Ácidos Grasos Omega-3/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Íleon/metabolismo , Inflamación/metabolismo , Animales , Depresores del Sistema Nervioso Central/toxicidad , Perfilación de la Expresión Génica , Humanos , Íleon/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Inflamación/genética , Masculino , Ratones , Ratones TransgénicosRESUMEN
Ethanol (EtOH)-induced alterations in intestinal homeostasis lead to multi-system pathologies, including liver injury. ω-6 PUFAs exert pro-inflammatory activity, while ω-3 PUFAs promote anti-inflammatory activity that is mediated, in part, through specialized pro-resolving mediators [e.g., resolvin D1 (RvD1)]. We tested the hypothesis that a decrease in the ω-6:ω-3 PUFA ratio would attenuate EtOH-mediated alterations in the gut-liver axis. ω-3 FA desaturase-1 (fat-1) mice, which endogenously increase ω-3 PUFA levels, were protected against EtOH-mediated downregulation of intestinal tight junction proteins in organoid cultures and in vivo. EtOH- and lipopolysaccharide-induced expression of INF-γ, Il-6, and Cxcl1 was attenuated in fat-1 and WT RvD1-treated mice. RNA-seq of ileum tissue revealed upregulation of several genes involved in cell proliferation, stem cell renewal, and antimicrobial defense (including Alpi and Leap2) in fat-1 versus WT mice fed EtOH. fat-1 mice were also resistant to EtOH-mediated downregulation of genes important for xenobiotic/bile acid detoxification. Further, gut microbiome and plasma metabolomics revealed several changes in fat-1 versus WT mice that may contribute to a reduced inflammatory response. Finally, these data correlated with a significant reduction in liver injury. Our study suggests that ω-3 PUFA enrichment or treatment with resolvins can attenuate the disruption in intestinal homeostasis caused by EtOH consumption and systemic inflammation with a concomitant reduction in liver injury.
Asunto(s)
Etanol/efectos adversos , Ácidos Grasos Omega-3/metabolismo , Ácidos Grasos Omega-6/metabolismo , Microbioma Gastrointestinal/efectos de los fármacos , Homeostasis/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/microbiología , Animales , Ácidos y Sales Biliares/metabolismo , Heces/química , Femenino , Mucosa Intestinal/metabolismo , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos C57BLRESUMEN
Circulating oxidized linoleic acid (LA) metabolites (OXLAMs) are increased in patients with nonalcoholic steatohepatitis (NASH) and their levels correlate with disease severity. However, the mechanisms by which OXLAMs contribute to NASH development are incompletely understood. We tested the hypothesis that LA or OXLAMs provided directly through the diet are involved in the development of hepatic injury. C57BL/6 mice were fed an isocaloric high-fat diet containing low LA, high LA, or OXLAMs for 8 weeks. The livers of OXLAM-fed mice showed lower triglyceride concentrations, but higher FA oxidation and lipid peroxidation in association with increased oxidative stress. OXLAM-induced mitochondrial dysfunction was associated with reduced Complex I protein and hepatic ATP levels, as well as increased mitochondrial biogenesis and cytoplasmic mitochondrial DNA. Oxidative stress increased thioredoxin-interacting protein (TXNIP) in the liver and stimulated the activation of mitochondrial apoptosis signal-regulating kinase 1 (ASK1) leading to apoptosis. We also found increased levels of NOD-like receptor protein 3 (NLRP3) inflammasome components and Caspase-1 activation in the livers of OXLAM-fed mice. In vitro, OXLAMs induced hepatocyte cell death, which was partly dependent on Caspase-1 activation. This study identified key mechanisms by which dietary OXLAMs contribute to NASH development, including mitochondrial dysfunction, hepatocyte cell death, and NLRP3 inflammasome activation.
Asunto(s)
Apoptosis/efectos de los fármacos , Ácido Linoleico/metabolismo , Ácido Linoleico/farmacología , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Proteínas Portadoras/metabolismo , Dieta Alta en Grasa/efectos adversos , Regulación de la Expresión Génica/efectos de los fármacos , Inflamasomas/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Tiorredoxinas/metabolismoRESUMEN
Alcoholic liver disease is a major human health problem leading to significant morbidity and mortality in the United States and worldwide. Dietary fat plays an important role in alcoholic liver disease pathogenesis. Herein, we tested the hypothesis that a combination of ethanol and a diet rich in linoleic acid (LA) leads to the increased production of oxidized LA metabolites (OXLAMs), specifically 9- and 13-hydroxyoctadecadienoic acids (HODEs), which contribute to a hepatic proinflammatory response exacerbating liver injury. Mice were fed unsaturated (with a high LA content) or saturated fat diets (USF and SF, respectively) with or without ethanol for 10 days, followed by a single binge of ethanol. Compared to SF+ethanol, mice fed USF+ethanol had elevated plasma alanine transaminase levels, enhanced hepatic steatosis, oxidative stress, and inflammation. Plasma and liver levels of 9- and 13-HODEs were increased in response to USF+ethanol feeding. We demonstrated that primarily 9-HODE, but not 13-HODE, induced the expression of several proinflammatory cytokines in vitro in RAW264.7 macrophages. Finally, deficiency of arachidonate 15-lipoxygenase, a major enzyme involved in LA oxidation and OXLAM production, attenuated liver injury and inflammation caused by USF+ethanol feeding but had no effect on hepatic steatosis. This study demonstrates that OXLAM-mediated induction of a proinflammatory response in macrophages is one of the potential mechanisms underlying the progression from alcohol-induced steatosis to alcoholic steatohepatitis.
Asunto(s)
Grasas de la Dieta/efectos adversos , Inflamación/patología , Ácido Linoleico/efectos adversos , Hígado/metabolismo , Hígado/patología , Animales , Araquidonato 15-Lipooxigenasa/metabolismo , Consumo Excesivo de Bebidas Alcohólicas , Composición Corporal , Citocinas/metabolismo , Modelos Animales de Enfermedad , Etanol , Ácidos Linoleicos/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Macrófagos/metabolismo , Metaboloma , Ratones , Ratones Endogámicos C57BL , Oxidación-Reducción , Estrés Oxidativo , Células RAW 264.7RESUMEN
Alcoholic liver disease (ALD) ranks among major causes of morbidity and mortality. Diet and crosstalk between the gut and liver are important determinants of ALD. We evaluated the effects of different types of dietary fat and ethanol on the gut microbiota composition and metabolic activity and the effect of these changes on liver injury in ALD. Compared with ethanol and a saturated fat diet (medium chain triglycerides enriched), an unsaturated fat diet (corn oil enriched) exacerbated ethanol-induced endotoxemia, liver steatosis, and injury. Major alterations in gut microbiota, including a reduction in Bacteroidetes and an increase in Proteobacteria and Actinobacteria, were seen in animals fed an unsaturated fat diet and ethanol but not a saturated fat diet and ethanol. Compared with a saturated fat diet and ethanol, an unsaturated fat diet and ethanol caused major fecal metabolomic changes. Moreover, a decrease in certain fecal amino acids was noted in both alcohol-fed groups. These data support an important role of dietary lipids in ALD pathogenesis and provide insight into mechanisms of ALD development. A diet enriched in unsaturated fats enhanced alcohol-induced liver injury and caused major fecal metagenomic and metabolomic changes that may play an etiologic role in observed liver injury. Dietary lipids can potentially serve as inexpensive interventions for the prevention and treatment of ALD.
Asunto(s)
Grasas Insaturadas en la Dieta/metabolismo , Grasas de la Dieta/metabolismo , Etanol/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Hepatopatías Alcohólicas/metabolismo , Animales , Modelos Animales de Enfermedad , Hígado/metabolismo , Masculino , Ratones Endogámicos C57BL , Triglicéridos/metabolismoRESUMEN
BACKGROUND: Interactions between the liver, the gut, and the immune system are critical components of alcoholic liver disease (ALD). The aim of this study was to explore the associations between alcohol-induced liver injury, endotoxemia, and inflammation at admission and over time during abstinence, as well as to examine the sex-related differences in these parameters in alcohol-dependent individuals admitted to an alcohol treatment program. METHODS: A cohort of 48 otherwise healthy participants with alcohol use disorder, but no clinical signs of alcoholic liver injury (34 males [M]/14 females [F]) admitted to an alcohol detoxification program, was stratified into 2 groups based on baseline plasma alanine aminotransferase (ALT) levels (as a marker of liver injury). Group 1 (ALT < 40 U/l, 7M/8F) and Group 2 (ALT ≥ 40 U/l, 27M/6F) were identified. Plasma biomarkers of liver damage, endotoxemia, and inflammation were examined at baseline, day 8, and day 15 of the admission. The drinking history was also evaluated. RESULTS: Sixty-nine percent of patients had elevated ALT and other markers of liver damage, including aspartate aminotransferase and cytokeratin 18 (CK18 M65 and CK M30) at baseline, indicating the presence of mild ALD. Elevated CK18 M65:M30 ratio suggested a greater contribution of necrotic rather than apoptotic hepatocyte cell death in the liver injury observed in these individuals. Females showed greater elevations of liver injury markers compared to males, although they had fewer drinks per day and shorter lifetime duration of heavy drinking. Liver injury was associated with systemic inflammation, specifically, elevated plasma tumor necrosis factor-alpha levels. Compared to patients without liver injury, patients with mild ALD had greater endotoxemia (increased serum lipopolysaccharide levels), which decreased with abstinence and this decrease preceded the drop in CK18 M65 levels. CONCLUSIONS: The study documented the association of mild alcohol-induced liver injury and endotoxemia, which improved with 2 weeks of abstinence, in a subset of individuals admitted to an alcohol detoxification program.
Asunto(s)
Alcoholismo/sangre , Endotoxemia/sangre , Mediadores de Inflamación/sangre , Hepatopatías Alcohólicas/sangre , Admisión del Paciente , Centros de Tratamiento de Abuso de Sustancias , Adulto , Alcoholismo/diagnóstico , Alcoholismo/terapia , Biomarcadores/sangre , Estudios de Cohortes , Endotoxemia/diagnóstico , Endotoxemia/terapia , Femenino , Humanos , Hepatopatías Alcohólicas/diagnóstico , Hepatopatías Alcohólicas/terapia , Masculino , Persona de Mediana Edad , National Institute on Alcohol Abuse and Alcoholism (U.S.)/tendencias , Admisión del Paciente/tendencias , Centros de Tratamiento de Abuso de Sustancias/tendencias , Estados UnidosRESUMEN
This paper is based upon the "8th Charles Lieber's Satellite Symposium" organized by Manuela G. Neuman at the Research Society on Alcoholism Annual Meeting, on June 25, 2016 at New Orleans, Louisiana, USA. The integrative symposium investigated different aspects of alcohol-induced liver disease (ALD) as well as non-alcohol-induced liver disease (NAFLD) and possible repair. We revealed the basic aspects of alcohol metabolism that may be responsible for the development of liver disease as well as the factors that determine the amount, frequency and which type of alcohol misuse leads to liver and gastrointestinal diseases. We aimed to (1) describe the immuno-pathology of ALD, (2) examine the role of genetics in the development of alcoholic hepatitis (ASH) and NAFLD, (3) propose diagnostic markers of ASH and non-alcoholic steatohepatitis (NASH), (4) examine age and ethnic differences as well as analyze the validity of some models, (5) develop common research tools and biomarkers to study alcohol-induced effects, 6) examine the role of alcohol in oral health and colon and gastrointestinal cancer and (7) focus on factors that aggravate the severity of organ-damage. The present review includes pre-clinical, translational and clinical research that characterizes ALD and NAFLD. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD with simple fatty infiltrations and chronic alcoholic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes and cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human deficiency virus were discussed. Dysregulation of metabolism, as a result of ethanol exposure, in the intestine leads to colon carcinogenesis. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota have been suggested. The clinical aspects of NASH, as part of the metabolic syndrome in the aging population, have been presented. The symposium addressed mechanisms and biomarkers of alcohol induced damage to different organs, as well as the role of the microbiome in this dialog. The microbiota regulates and acts as a key element in harmonizing immune responses at intestinal mucosal surfaces. It is known that microbiota is an inducer of proinflammatory T helper 17 cells and regulatory T cells in the intestine. The signals at the sites of inflammation mediate recruitment and differentiation in order to remove inflammatory inducers and promote tissue homeostasis restoration. The change in the intestinal microbiota also influences the change in obesity and regresses the liver steatosis. Evidence on the positive role of moderate alcohol consumption on heart and metabolic diseases as well on reducing steatosis have been looked up. Moreover nutrition as a therapeutic intervention in alcoholic liver disease has been discussed. In addition to the original data, we searched the literature (2008-2016) for the latest publication on the described subjects. In order to obtain the updated data we used the usual engines (Pub Med and Google Scholar). The intention of the eighth symposia was to advance the international profile of the biological research on alcoholism. We also wish to further our mission of leading the forum to progress the science and practice of translational research in alcoholism.
Asunto(s)
Alcoholismo/complicaciones , Estilo de Vida , Hepatopatías Alcohólicas/complicaciones , Microbiota , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Congresos como Asunto , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Hepatitis Alcohólica/complicaciones , Hepatitis Alcohólica/enzimología , Hepatitis Alcohólica/genética , Humanos , Hepatopatías Alcohólicas/enzimología , Hepatopatías Alcohólicas/genética , Enfermedad del Hígado Graso no Alcohólico/enzimología , Enfermedad del Hígado Graso no Alcohólico/genética , Polimorfismo GenéticoRESUMEN
An animal model of alcoholic liver disease (ALD) that recapitulates human disease is an unmet need. An alcohol-preferring strain and WT mice were fed alcohol by different techniques and with different diet compositions. Interestingly, the greatest alcohol consumers did not develop the worst ALD. This editorial highlights how diet and the gut microbiome/metabolome may influence the development/severity of ALD.
Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/fisiopatología , Modelos Animales de Enfermedad , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/fisiopatología , Consumo de Bebidas Alcohólicas/genética , Animales , Microbioma Gastrointestinal/fisiología , Humanos , Hepatopatías Alcohólicas/genética , Ratones , Factores de RiesgoRESUMEN
Experimental alcohol-induced liver injury is exacerbated by a high polyunsaturated fat diet rich in linoleic acid. We postulated that bioactive oxidized linoleic acid metabolites (OXLAMs) play a critical role in the development/progression of alcohol-mediated hepatic inflammation and injury. OXLAMs are endogenous ligands for transient receptor potential vanilloid 1 (TRPV1). Herein, we evaluated the role of signaling through TRPV1 in an experimental animal model of alcoholic liver disease (ALD). Chronic binge alcohol administration increased plasma OXLAM levels, specifically 9- and 13-hydroxy-octadecadienoic acids. This effect was associated with up-regulation of hepatic TRPV1. Exposure of hepatocytes to these OXLAMs in vitro resulted in activation of TRPV1 signal transduction with increased intracellular Ca(2+) levels. Genetic depletion of TRPV1 did not blunt hepatic steatosis caused by ethanol, but prevented hepatic injury. TRPV1 deficiency protected from hepatocyte death and prevented the increase in proinflammatory cytokine and chemokine expression, including tumor necrosis factor-α, IL-6, macrophage inflammatory protein-2, and monocyte chemotactic protein 1. TRPV1 depletion markedly blunted ethanol-mediated induction of plasminogen activator inhibitor-1, an important alcohol-induced hepatic inflammation mediator, via fibrin accumulation. This study indicates, for the first time, that TRPV1 receptor pathway may be involved in hepatic inflammatory response in an experimental animal model of ALD. TRPV1-OXLAM interactions appear to play a significant role in hepatic inflammation/injury, further supporting an important role for dietary lipids in ALD.
Asunto(s)
Hepatopatías Alcohólicas/genética , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/fisiología , Animales , Consumo Excesivo de Bebidas Alcohólicas/patología , Caspasa 3/metabolismo , Quimiocina CCL2/sangre , Quimiocina CXCL2/sangre , Modelos Animales de Enfermedad , Etanol/química , Células Hep G2 , Humanos , Inflamación/patología , Interleucina-6/sangre , Ligandos , Ácido Linoleico/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Factor de Necrosis Tumoral alfa/sangreAsunto(s)
Trastornos Relacionados con Alcohol/complicaciones , Etanol/efectos adversos , Hepatopatías/complicaciones , Consumo de Bebidas Alcohólicas/psicología , Trastornos Relacionados con Alcohol/diagnóstico , Diagnóstico Precoz , Tracto Gastrointestinal/efectos de los fármacos , Humanos , Hepatopatías/diagnóstico , Receptores de Trasplantes/psicologíaRESUMEN
This paper is based upon the "Charles Lieber Satellite Symposia" organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human immunodeficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible repair. We aim to (1) determine the immuno-pathology of alcohol-induced liver damage, (2) examine the role of genetics in the development of ASH, (3) propose diagnostic markers of ASH and NASH, (4) examine age differences, (5) develop common research tools to study alcohol-induced effects in clinical and pre-clinical studies, and (6) focus on factors that aggravate severity of organ-damage. The intention of these symposia is to advance the international profile of the biological research on alcoholism. We also wish to further our mission of leading the forum to progress the science and practice of translational research in alcoholism.
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Hígado Graso , Enfermedad del Hígado Graso no Alcohólico , Animales , HumanosRESUMEN
BACKGROUND: Alcohol-associated hepatitis (AH) is one of the clinical presentations of alcohol-associated liver disease. AH has poor prognosis, and corticosteroids remain the mainstay of drug therapy. However, ~40% of patients do not respond to this treatment, and the mechanisms underlying the altered response to corticosteroids are not understood. The current study aimed to identify changes in hepatic protein expression associated with responsiveness to corticosteroids and prognosis in patients with AH. METHODS: Patients with AH were enrolled based on the National Institute on Alcohol Abuse and Alcoholism inclusion criteria for acute AH and further confirmed by a diagnostic liver biopsy. Proteomic analysis was conducted on liver samples acquired from patients with AH grouped as nonresponders (AH-NR, n = 7) and responders (AH-R, n = 14) to corticosteroids, and nonalcohol-associated liver disease controls (n = 10). The definition of responders was based on the clinical prognostic model, the Lille Score, where a score < 0.45 classified patients as AH-R and a score > 0.45 as AH-NR. Primary outcomes used to assess steroid response were Lille Score (eg, improved liver function) and survival at 24 weeks. RESULTS: Reduced levels of the glucocorticoid receptor and its transcriptional co-activator, glucocorticoid modulatory element-binding protein 2, were observed in the hepatic proteome of AH-NR versus AH-R. The corticosteroid metabolizing enzyme, 11-beta-hydroxysteroid dehydrogenase 1, was increased in AH-NR versus AH-R along with elevated mitochondrial DNA repair enzymes, while several proteins of the heat shock pathway were reduced. Analysis of differentially expressed proteins in AH-NR who survived 24 weeks relative to AH-NR nonsurvivors revealed several protein expression changes, including increased levels of acute phase proteins, elevated coagulation factors, and reduced mast cell markers. CONCLUSIONS: This study identified hepatic proteomic changes that may predict responsiveness to corticosteroids and mortality in patients with AH.
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Hepatitis Alcohólica , Hepatopatías Alcohólicas , Humanos , Proteínas de Choque Térmico , Glucocorticoides/uso terapéutico , Proteómica , Esteroides , Hepatitis Alcohólica/diagnóstico , Hepatitis Alcohólica/tratamiento farmacológicoRESUMEN
BACKGROUND: Recently, we have demonstrated that acute alcohol exposure due to binge drinking leads to hepatic steatosis with the deregulation of hepatic histone deacetylase (HDAC) expression. Various class I, II, and IV HDACs were down-regulated, whereas expression of HDAC3 was solely up-regulated. Hence, in the present work, we specifically examined the mechanistic role of HDAC3 in the development of hepatic steatosis occurring in response to binge alcohol administration. METHODS: C57BL/6 mice were gavaged 3 times with ethanol (EtOH) at a dose of 4.5 g/kg. HDAC inhibitor, Trichostatin A (TSA) was simultaneously injected intraperitoneally at a dose of 1 mg/kg. Hepatic steatosis, injury, expression of HDAC3 and carnitine palmitoyltransferase 1α (CPT1α) were evaluated. HDAC3 and histone H3 acetylation levels at the Cpt1α promoter were analyzed by chromatin immunoprecipitation (ChIP). RESULTS: The binge EtOH-mediated increase in HDAC3 was prevented by simultaneous administration of HDAC inhibitor, TSA, which markedly attenuated hepatic steatosis and injury. Importantly, HDAC3 inhibition was able to normalize the down-regulation of Cpt1α expression. Causal role of HDAC3 in the transcriptional repression of Cpt1α was demonstrated by increased HDAC3 binding at the thyroid receptor element site in the Cpt1α distal promoter region. Further, a resultant decrease in the transcriptionally permissive histone H3 lysine 9 acetylation in the proximal promoter region near the transcriptional start site was observed. Notably, TSA treatment reduced HDAC3 binding and increased H3K9 acetylation at Cpt1α promoter leading to increased Cpt1α expression. These molecular events resulted in attenuation of binge alcohol-induced hepatic steatosis. CONCLUSIONS: These findings provide insights into potential epigenetic mechanisms underlying transcriptional regulation of Cpt1α in the hepatic steatosis occurring in response to binge EtOH administration.
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Consumo Excesivo de Bebidas Alcohólicas/metabolismo , Carnitina O-Palmitoiltransferasa/antagonistas & inhibidores , Carnitina O-Palmitoiltransferasa/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Hígado Graso/etiología , Histona Desacetilasas/metabolismo , Animales , Consumo Excesivo de Bebidas Alcohólicas/genética , Carnitina O-Palmitoiltransferasa/genética , Depresores del Sistema Nervioso Central/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Regulación hacia Abajo/genética , Etanol/efectos adversos , Hígado Graso/metabolismo , Regulación Enzimológica de la Expresión Génica , Histona Desacetilasas/genética , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: The prevalence of alcohol-associated liver disease (ALD), a subtype of fatty liver disease (FLD), continues to rise. ALD is a major cause of preventable death. Polychlorinated biphenyl (PCB) 126 is an environmentally relevant, dioxin-like pollutant whose negative metabolic effects have been well documented. In human and animal studies, PCB has been associated with the severity of nonalcoholic fatty liver disease (NAFLD). However, few studies have investigated whether exposures to environmental toxicants can worsen ALD. Thus, the objective of the current study was to develop an alcohol-plus-toxicant model to study how an environmental pollutant, PCB 126, impacts rodent ALD pathology. METHODS: Briefly, male C57BL/6J mice were exposed to 0.2 mg/kg PCB 126 or corn oil vehicle four days prior to ethanol feeding using the chronic-binge (10-plus-one) model. RESULTS: Concentrations of macromolecules, including hepatic lipids, carbohydrates, and protein (albumin) were impacted. Exposure to PCB 126 exacerbated hepatic steatosis and hepatomegaly in mice exposed to the chemical and fed an ethanol diet. Gene expression and the analysis of blood chemistry showed a potential net increase and retention of hepatic lipids and reductions in lipid oxidation and clearance capabilities. Depletion of glycogen and glucose was evident, which contributes to disease progression by generating systemic malnutrition. Granulocytic immune infiltrates were present but driven solely by ethanol feeding. Hepatic albumin gene expression and plasma levels were decreased by ~50% indicating a potential compromise of liver function. Finally, gene expression analyses indicated that the aryl hydrocarbon receptor and constitutive androstane receptor were activated by PCB 126 and ethanol, respectively. CONCLUSIONS: Various environmental toxicants are known to modify or enhance FLD in high-fat diet models. Findings from the present study suggest that they interact with other lifestyle factors such as alcohol consumption to reprogram intermediary metabolism resulting in exacerbated ethanol-associated systemic malnutrition in ALD.