RESUMEN
It is well known that vulnerability to stress is a risk factor for alcohol use disorder (AUD). Chronic alcohol use can result in neuroadaptations in cortico-striatal pathways and hypothalamic pituitary adrenal (HPA) axis function that are manifested in altered behavioral and cognitive control functions contributing to alcohol craving, compulsive motivation, consumption, and consequences. This symposium brings together studies utilizing novel approaches to help improve our understanding of stress - past, acute, and chronic - on alcohol seeking and consumption and related outcomes using a combination of human laboratory models, neuroimaging, and clinical measures. Examining factors that determine vulnerability as well as resilience to stress are of particular interest in the study of AUD because, in addition to increasing our understanding of the risk factors for AUD, such knowledge can be used to develop more effective treatments. Dr. Stangl presented a novel human experimental model that demonstrates, for the first time, stress-induced increases in alcohol self-administration in binge drinkers using a guided imagery paradigm combined with intravenous alcohol self-administration (IV-ASA). Dr. Blaine presented data demonstrating that glucocorticoid response to stress drives compulsive alcohol motivation and intake in binge/heavy drinkers. Dr. Plawecki presented data examining sex differences in the effect of two distinct stress paradigms - mood induction and abstinence - on IV-ASA in moderate drinkers. Dr. Schwandt presented clinical data providing a new perspective on the relationship between childhood trauma and AUD by suggesting possible underlying mechanisms that confer resilience, rather than vulnerability, to severe early life stress exposure.
Asunto(s)
Adultos Sobrevivientes del Maltrato a los Niños/psicología , Alcoholismo/psicología , Consumo Excesivo de Bebidas Alcohólicas/psicología , Depresores del Sistema Nervioso Central/administración & dosificación , Etanol/administración & dosificación , Estrés Psicológico/psicología , Administración Intravenosa , Experiencias Adversas de la Infancia , Humanos , Sistema Hipotálamo-Hipofisario , Personalidad , Sistema Hipófiso-Suprarrenal , Resiliencia Psicológica , Autoadministración , Factores SexualesRESUMEN
Epidemiological studies have been used to show associations between modifiable lifestyle habits and the incidence of breast cancer. Among such factors, a history of alcohol use has been reported in multiple studies and meta-analyses over the past decades. However, associative epidemiological studies that were interpreted as evidence that even moderate alcohol consumption increases breast cancer incidence have been controversial. In this review, we consider the literature on the relationship between moderate or heavy alcohol use, both in possible biological mechanisms and in variations in susceptibility due to genetic or epigenetic factors. We argue that there is a need to incorporate additional approaches to move beyond the associations that are reported in traditional epidemiological analyses and incorporate information on molecular pathologic signatures as a requirement to posit causal inferences. In particular, we point to the efforts of the transdisciplinary field of molecular pathological epidemiology (MPE) to evaluate possible causal relationships, if any, of alcohol consumption and breast cancer. A wider application of the principles of MPE to this field would constitute a giant step that could enhance our understanding of breast cancer and multiple modifiable risk factors, a step that would be particularly suited to the era of "personalized medicine".
RESUMEN
The symposium, "Role of Nutrition in Alcoholic Liver Disease", was held at the European Society for Biomedical Research on Alcoholism Congress on 9 October 2017 in Crete, Greece. The goal of the symposium was to highlight recent advances and developments in the field of alcohol and nutrition. The symposium was focused on experimental and clinical aspects in relation to the role of different types of dietary nutrients and malnutrition in the pathogenesis of alcoholic liver disease (ALD). The following is a summary of key research presented at this session. The speakers discussed the role of dietary fats and carbohydrates in the development and progression of alcohol-induced multi-organ pathology in animal models of ALD, analyzed novel nutrition-related therapeutics (specifically, betaine and zinc) in the treatment of ALD, and addressed clinical relevance of malnutrition and nutrition support in ALD. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows.
Asunto(s)
Alcoholismo , Hepatopatías Alcohólicas , Desnutrición , Grasas de la Dieta/metabolismo , Etanol/metabolismo , Humanos , Hepatopatías Alcohólicas/dietoterapia , Hepatopatías Alcohólicas/tratamiento farmacológico , Hepatopatías Alcohólicas/metabolismoRESUMEN
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
Cancer is a multifactorial disease that results from complex interactions of numerous risk factors - genetic and environmental - over time, eventually leading to the diseased phenotypes. Thus, while epidemiological studies can point to risk factors, they cannot determine cause and effect relationships, and are unable to give biological and clinical insights into carcinogenesis. The link between any risk factor and carcinogenesis needs to be validated in experimental models. This is particularly true in epidemiological studies on alcohol consumption and its consequences. While there is no doubt that heavy alcohol consumption has devastating health effects, the inconsistencies in alcohol-related epidemiological studies and cancer suffer from possible sources of the variability in outcomes, ranging from inaccuracy of self-report of consumption to the problem of correlating cancer that started decades earlier to current or recent alcohol consumption. To further study the interactions between alcohol and cancer, the use of "Molecular Pathological Epidemiology" (MPE) advocated by Ogino et al. for dissecting the interplay between etiological factors, cellular and molecular characteristics, and disease progression in cancer is appropriate. MPE does not consider cancer as a single entity, rather it integrates analyses of epidemiological studies with the macroenvironment and molecular and microenvironment. This approach allows investigating the relationships between potential etiological agents and cancer based on molecular signatures. More research is needed to fully elucidate the link between heavy alcohol consumption and pancreatic cancer, and to further investigate the roles of acetaldehyde and FAEEs in pancreatic carcinogenesis.
Asunto(s)
Alcoholismo/complicaciones , Carcinoma Hepatocelular/etiología , Neoplasias Hepáticas/etiología , Neoplasias Pancreáticas/etiología , Acetaldehído/metabolismo , Inmunidad Adaptativa/efectos de los fármacos , Carcinoma Hepatocelular/epidemiología , Depresores del Sistema Nervioso Central/farmacocinética , Etanol/farmacocinética , Humanos , Inmunidad Innata/efectos de los fármacos , Hepatopatías Alcohólicas/complicaciones , Neoplasias Hepáticas/epidemiología , Neovascularización Patológica , Estrés Oxidativo/fisiología , Neoplasias Pancreáticas/epidemiología , Pancreatitis Alcohólica/complicaciones , Especies Reactivas de Oxígeno/metabolismo , Factores de RiesgoRESUMEN
This review summarizes the proceedings of a symposium presented at the "Alcoholism and Stress: A Framework for Future Treatment Strategies" conference held in Volterra, Italy on May 6-9, 2014. The overall goal of the symposium titled "Applying the New Genomics to Alcohol Dependence", chaired by Dr. Adron Harris, was to highlight recent genomic discoveries and applications for profiling alcohol use disorder (AUD). Dr. Sean Farris discussed the gene expression networks related to lifetime consumption of alcohol within human prefrontal cortex. Dr. Andrzej Pietrzykowski presented the effects of alcohol on microRNAs in humans and animal models. Alcohol-induced alterations in the synaptic transcriptome were discussed by Dr. Michael Miles. Dr. Pietro Sanna examined methods to probe the gene regulatory networks that drive excessive alcohol drinking, and Dr. Samir Zakhari served as a panel discussant and summarized the proceedings. Collectively, the presentations emphasized the power of integrating multiple levels of genetics and transcriptomics with convergent biological processes and phenotypic behaviors to determine causal factors of AUD. The combined use of diverse data types demonstrates how unique approaches and applications can help categorize genetic complexities into relevant biological networks using a systems-level model of disease.
Asunto(s)
Alcoholismo/genética , Epigénesis Genética/genética , Regulación de la Expresión Génica , MicroARNs/genética , Transcriptoma/genética , Animales , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Genómica , Humanos , Análisis de Secuencia de ARNRESUMEN
CONTEXT: We focused on certain plant active constituents considered to be the most promising/studied for liver disease and that were critically investigated from the basic science point of view and, to some extent, the clinical one. Due to insufficient pharmacological data, most of the herbal formulations containing these molecules cannot be recommended for the treatment of liver disease. OBJECTIVE: To present the most promising compounds tested experimentally and/or clinically and describe in brief popular models in experimental testing of potential hepatoprotective compounds. METHODS: A literature search using Web of Science (WOS), PubMed, and Google search was performed. RESULTS: Focusing on a few herbal hepatoprotective active constituents is useful to health professionals working in the field of therapeutics to develop evidence-based hepatoprotective agents by conducting research on pure chemical structures or on molecular modifications using computational chemistry. This review demonstrates that multi-pathways in the liver pathobiology can be interrupted at one or more levels by natural hepatoprotective studied, such as interference with the oxidative stress at multiple levels to reduce reactive oxygen/nitrogen species, resulting in ameliorating hepatotoxicity. CONCLUSION: Hepatoprotective constituents of herbal medications are poorly absorbed after oral administration; methods that can improve their bioavailability are being developed. It is recommended that controlled prospective double-blind multicenter studies on isolated active plant constituents, or on related newly designed molecules after structural modifications, should be performed. This effort will lead to expanding the existing, limited drugs for the vast majority of liver diseases.
Asunto(s)
Hepatopatías/prevención & control , Plantas Medicinales/química , Sustancias Protectoras/farmacología , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Humanos , Extractos Vegetales/farmacologíaRESUMEN
Breast cancer is the most diagnosed cancer in women worldwide. Epidemiological studies have suggested a possible causative role of alcohol consumption as a risk factor for breast cancer. However, such conclusions should be interpreted with considerable caution for several reasons. While epidemiological studies can help identify the roots of health problems and disease incidence in a community, they are by necessity associative and cannot determine cause and effect relationships. In addition, all these studies rely on self-reporting to determine the amount and type of alcoholic beverage consumed, which introduces recall bias. This is documented in a recent study which stated that the apparent increased risk of cancer among light-moderate drinkers may be "substantially due to underreporting of intake." Another meta-analysis about alcohol and breast cancer declared "the modest size of the association and variation in results across studies leave the causal role of alcohol in question." Furthermore, breast cancer develops over decades; thus, correlations between alcohol consumption and breast cancer cannot be determined in epidemiological studies with windows of alcohol exposure that captures current or recent alcohol intake, after clinical diagnosis. Numerous risk factors are involved in breast carcinogenesis; some are genetic and beyond the control of a woman; others are influenced by lifestyle factors. Breast cancer is a heterogeneous and polygenic disease which is further influenced by epigenetic mechanisms that affect the transciptomes, proteomes and metabolomes, and ultimately breast cancer evolution. Environmental factors add another layer of complexity by their interactions with the susceptibility genes for breast cancer and metabolic diseases. The current state-of-knowledge about alcohol and breast cancer association is ambiguous and confusing to both a woman and her physician. Confronting the huge global breast cancer issue should be addressed by sound science. It is advised that women with or without a high risk for breast cancer should avoid overconsumption of alcohol and should consult with their physician about risk factors involved in breast cancer. Since studies associating moderate alcohol consumption and breast cancer are contradictory, a woman and her physician should weigh the risks and benefits of moderate alcohol consumption.
Asunto(s)
Neoplasias de la Mama/inducido químicamente , Etanol/toxicidad , Estudios Epidemiológicos , Estrógenos/metabolismo , Etanol/metabolismo , Femenino , Ácido Fólico/metabolismo , Humanos , Factores de RiesgoRESUMEN
This paper is based upon the 'Charles Lieber Satellite Symposia' organized by Manuela G. Neuman at each of the 2009-2012 Research Society on Alcoholism (RSA) Annual Meetings. The presentations represent a broad spectrum dealing with alcoholic liver disease (ALD). In addition, a literature search (2008-2013) in the discussed area was performed in order to obtain updated data. The presentations are focused on genetic polymorphisms of ethanol metabolizing enzymes and the role of cytochrome P4502E1 (CYP2E1) in ALD. In addition, alcohol-mediated hepatocarcinogenesis, immune response to alcohol and fibrogenesis in alcoholic hepatitis as well as its co-morbidities with chronic viral hepatitis infections in the presence or absence of human deficiency virus are discussed. Finally, emphasis was led on alcohol and drug interactions as well as liver transplantation for end-stage ALD.
Asunto(s)
Etanol/farmacocinética , Hepatopatías Alcohólicas/enzimología , Terapia Antirretroviral Altamente Activa/efectos adversos , Inductores del Citocromo P-450 CYP2E1/farmacocinética , Inductores del Citocromo P-450 CYP2E1/farmacología , Interacciones Farmacológicas , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/metabolismo , Antagonistas de los Receptores H2 de la Histamina/efectos adversos , Humanos , Hepatopatías Alcohólicas/complicaciones , Hepatopatías Alcohólicas/genética , Trasplante de Hígado/mortalidadRESUMEN
The designation of acetaldehyde associated with the consumption of alcoholic beverages as "carcinogenic to humans" (Group 1) by the International Agency for Research on Cancer (IARC) has brought renewed attention to the biological effects of acetaldehyde, as the primary oxidative metabolite of alcohol. Therefore, the overall focus of this review is on acetaldehyde and its direct and indirect effects on the nuclear and mitochondrial genome. We first consider different acetaldehyde-DNA adducts, including a critical assessment of the evidence supporting a role for acetaldehyde-DNA adducts in alcohol related carcinogenesis, and consideration of additional data needed to make a conclusion. We also review recent data on the role of the Fanconi anemia DNA repair pathway in protecting against acetaldehyde genotoxicity and carcinogenicity, as well as teratogenicity. We also review evidence from the older literature that acetaldehyde may impact the genome indirectly, via the formation of adducts with proteins that are themselves critically involved in the maintenance of genetic and epigenetic stability. Finally, we note the lack of information regarding acetaldehyde effects on the mitochondrial genome, which is notable since aldehyde dehydrogenase 2 (ALDH2), the primary acetaldehyde metabolic enzyme, is located in the mitochondrion, and roughly 30% of East Asian individuals are deficient in ALDH2 activity due to a genetic variant in the ALDH2 gene. In summary, a comprehensive understanding of all of the mechanisms by which acetaldehyde impacts the function of the genome has implications not only for alcohol and cancer, but types of alcohol related pathologies as well.
Asunto(s)
Acetaldehído/toxicidad , Carcinogénesis/genética , Carcinógenos/toxicidad , Aductos de ADN , Neoplasias/genética , Acetaldehído/metabolismo , Consumo de Bebidas Alcohólicas/efectos adversos , Animales , Carcinogénesis/metabolismo , Carcinógenos/metabolismo , Daño del ADN , Reparación del ADN , Genoma Humano , Humanos , Metiltransferasas/metabolismo , Neoplasias/metabolismoRESUMEN
Metabolites, including those generated during ethanol metabolism, can impact disease states by binding to transcription factors and/or modifying chromatin structure, thereby altering gene expression patterns. For example, the activities of enzymes involved in epigenetic modifications such as DNA and histone methylation and histone acetylation, are influenced by the levels of metabolites such as nicotinamide adenine dinucleotide (NAD), adenosine triphosphate (ATP), and S-adenosylmethionine (SAM). Chronic alcohol consumption leads to significant reductions in SAM levels, thereby contributing to DNA hypomethylation. Similarly, ethanol metabolism alters the ratio of NAD+ to reduced NAD (NADH) and promotes the formation of reactive oxygen species and acetate, all of which impact epigenetic regulatory mechanisms. In addition to altered carbohydrate metabolism, induction of cell death, and changes in mitochondrial permeability transition, these metabolism-related changes can lead to modulation of epigenetic regulation of gene expression. Understanding the nature of these epigenetic changes will help researchers design novel medications to treat or at least ameliorate alcohol-induced organ damage.
Asunto(s)
Depresores del Sistema Nervioso Central/metabolismo , Epigénesis Genética/efectos de los fármacos , Etanol/metabolismo , Acetilación/efectos de los fármacos , Depresores del Sistema Nervioso Central/farmacología , Metilación de ADN/efectos de los fármacos , Etanol/farmacología , Histonas/efectos de los fármacos , Histonas/metabolismo , Humanos , Inactivación Metabólica , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , S-Adenosilmetionina/efectos de los fármacos , S-Adenosilmetionina/metabolismo , Sirtuina 1/efectos de los fármacos , Sirtuina 1/metabolismoRESUMEN
Despite major progress in understanding and managing liver disease in the past 30 years, it is now among the top 10 most common causes of death globally. Several risk factors, such as genetics, diabetes, obesity, excessive alcohol consumption, viral infection, gender, immune dysfunction, and medications, acting individually or in concert, are known to precipitate liver damage. Viral hepatitis, excessive alcohol consumption, and obesity are the major factors causing liver injury. Estimated numbers of hepatitis B virus (HBV) and hepatitis C virus (HCV)-infected subjects worldwide are staggering (370 and 175 million, respectively), and of the 40 million known human immunodeficiency virus positive subjects, 4 and 5 million are coinfected with HBV and HCV, respectively. Alcohol and HCV are the leading causes of end-stage liver disease worldwide and the most common indication for liver transplantation in the United States and Europe. In addition, the global obesity epidemic that affects up to 40 million Americans, and 396 million worldwide, is accompanied by an alarming incidence of end-stage liver disease, a condition exacerbated by alcohol. This article focuses on the interactions between alcohol, viral hepatitis, and obesity (euphemistically described here as the Bermuda Triangle of liver disease), and discusses common mechanisms and synergy.
Asunto(s)
Enfermedad Hepática en Estado Terminal/epidemiología , Enfermedad Hepática en Estado Terminal/etiología , Consumo de Bebidas Alcohólicas/epidemiología , Costo de Enfermedad , Citocromo P-450 CYP2E1/metabolismo , Enfermedad Hepática en Estado Terminal/metabolismo , Enfermedad Hepática en Estado Terminal/patología , Etanol/metabolismo , Femenino , Fibrosis , Salud Global , Hepatitis B/complicaciones , Hepatitis B/epidemiología , Hepatitis C/complicaciones , Hepatitis C/epidemiología , Humanos , Incidencia , Hígado/metabolismo , Hígado/patología , Hepatopatías Alcohólicas/epidemiología , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/patología , Masculino , Obesidad/complicaciones , Obesidad/epidemiología , Estrés Oxidativo , Factores de RiesgoRESUMEN
Epidemiologic studies indicate that moderate alcohol consumption increases breast cancer risk in women. Understanding the mechanistic basis of this relationship has important implications for women's health and breast cancer prevention. In this commentary, we focus on some recent epidemiologic studies linking moderate alcohol consumption to breast cancer risk and place the results of those studies within the framework of our current understanding of the temporal and mechanistic basis of human carcinogenesis. This analysis supports the hypothesis that alcohol acts as a weak cumulative breast carcinogen and may also be a tumor promoter. We discuss the implications of these mechanisms for the prevention and treatment of alcohol-related breast cancer and present some considerations for future studies. Moderate alcohol consumption has been shown to benefit cardiovascular health and recently been associated with healthy aging. Therefore, a better understanding of how moderate alcohol consumption impacts breast cancer risk will allow women to make better informed decisions about the risks and benefits of alcohol consumption in the context of their overall health and at different stages of their life. Such mechanistic information is also important for the development of rational clinical interventions to reduce ethanol-related breast cancer mortality.
Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Neoplasias de la Mama/etiología , Carcinógenos/farmacología , Etanol/efectos adversos , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/prevención & control , Depresores del Sistema Nervioso Central/efectos adversos , Femenino , HumanosRESUMEN
Frank Burr Mallory's landmark observation in 1911 on the histopathology of alcoholic liver disease (ALD) was the first identification of a link between inflammation and ALD. In this review, we summarize recent advances regarding the origins and roles of various inflammatory components in ALD. Metabolism of ethanol generates a number of metabolites, including acetate, reactive oxygen species, acetaldehyde, and epigenetic changes, that can induce inflammatory responses. Alcohol and its metabolites can also initiate and aggravate inflammatory conditions by promoting gut leakiness of microbial products, by sensitizing immune cells to stimulation, and by activating innate immune pathways, such as complement. Chronic alcohol consumption also sensitizes nonimmune cells, e.g., hepatocytes, to inflammatory signals and impairs their ability to respond to protective signals. Based on these advances, a number of inflammatory targets have been identified with potential for therapeutic intervention in ALD, presenting new opportunities and challenges for translational research.
Asunto(s)
Sistema Inmunológico/inmunología , Hepatopatías Alcohólicas/inmunología , Animales , Antioxidantes/uso terapéutico , Humanos , Sistema Inmunológico/efectos de los fármacos , Sistema Inmunológico/metabolismo , Sistema Inmunológico/patología , Factores Inmunológicos/uso terapéutico , Mediadores de Inflamación/sangre , Mediadores de Inflamación/metabolismo , Mediadores de Inflamación/uso terapéutico , Hepatopatías Alcohólicas/tratamiento farmacológico , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/patologíaRESUMEN
Clinical observations have demonstrated that excessive chronic alcohol use negatively affects human immunodeficiency virus (HIV) infection and contributes to the liver manifestations of the disease, even in HIV mono-infection. HIV/hepatitis C virus (HCV) co-infection is associated with increased progression of HVC liver disease compared to HCV infection alone, and both of these are negatively affected by alcohol use. Recent data suggest that alcohol use and HIV infection have common targets that contribute to progression of liver disease. Both HIV infection and chronic alcohol use are associated with increased gut permeability and elevated plasma levels of lipopolysaccharide; a central activator of inflammatory responses. Both alcoholic liver disease and HIV infection result in non-specific activation of innate immunity, proinflammatory cytokine cascade upregulation, as well as impaired antigen presenting cell and dendritic cell functions. Finally, alcohol, HIV and antiretroviral therapy affect hepatocyte functions, which contributes to liver damage. The common targets of alcohol and HIV infection in liver disease are discussed in this mini-review.
Asunto(s)
Infecciones por VIH/epidemiología , Infecciones por VIH/fisiopatología , Hepatopatías Alcohólicas/epidemiología , Hepatopatías Alcohólicas/fisiopatología , Terapia Antirretroviral Altamente Activa , Comorbilidad , Progresión de la Enfermedad , Infecciones por VIH/tratamiento farmacológico , Hepatitis B/epidemiología , Hepatitis B/fisiopatología , Hepatitis C/epidemiología , Hepatitis C/fisiopatología , Humanos , Hígado/efectos de los fármacos , Hígado/fisiopatologíaRESUMEN
Excessive alcohol consumption is a leading cause of chronic liver disease in the Western world. Alcohol-induced hepatotoxicity and oxidative stress are important mechanisms contributing to the pathogenesis of alcoholic liver disease. However, emerging evidence suggests that activation of innate immunity involving TLR4 and complement also plays an important role in initiating alcoholic steatohepatitis and fibrosis, but the role of adaptive immunity in the pathogenesis of alcoholic liver disease remains obscure. Activation of a TLR4-mediated MyD88-independent (TRIF/IRF-3) signaling pathway in Kupffer cells contributes to alcoholic steatohepatitis, whereas activation of TLR4 signaling in hepatic stellate cells promotes liver fibrosis. Alcohol consumption activates the complement system in the liver by yet unidentified mechanisms, leading to alcoholic steatohepatitis. In contrast to activation of TLR4 and complement, alcohol consumption can inhibit natural killer cells, another important innate immunity component, contributing to alcohol-mediated acceleration of viral infection and liver fibrosis in patients with chronic viral hepatitis. Understanding of the role of innate immunity in the pathogenesis of alcoholic liver disease may help us identify novel therapeutic targets to treat this disease.
Asunto(s)
Inmunidad Innata/inmunología , Hepatopatías Alcohólicas/inmunología , Hígado/inmunología , Humanos , Células Asesinas Naturales/inmunología , Macrófagos del Hígado/inmunología , Transducción de Señal/inmunología , Receptor Toll-Like 4/inmunologíaRESUMEN
Chronic inflammation is often associated with alcohol-related medical conditions. The key inducer of such inflammation, and also the best understood, is gut microflora-derived lipopolysaccharide (LPS). Alcohol can significantly increase the translocation of LPS from the gut. In healthy individuals, the adverse effects of LPS are kept in check by the actions and interactions of multiple organs. The liver plays a central role in detoxifying LPS and producing a balanced cytokine milieu. The central nervous system contributes to anti-inflammatory regulation through neuroimmunoendocrine actions. Chronic alcohol use impairs not only gut and liver functions, but also multi-organ interactions, leading to persistent systemic inflammation and ultimately, to organ damage. The study of these interactions may provide potential new targets for therapeutic intervention.
Asunto(s)
Encéfalo , Etanol/farmacología , Tracto Gastrointestinal , Inflamación , Hígado , Consumo de Bebidas Alcohólicas , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Depresores del Sistema Nervioso Central/farmacología , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/patología , Humanos , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/patología , Lipopolisacáridos/farmacología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Neuroinmunomodulación/efectos de los fármacosRESUMEN
While the effects of chronic ethanol consumption on liver have been well studied and documented, its effect on the cardiovascular system is bimodal. Thus, moderate drinking in many population studies is related to lower prevalence of coronary artery disease (CAD). In contrast, heavy drinking correlates with higher prevalence of CAD. In several other studies of cardiovascular mortalities, abstainers and heavy drinkers are at higher risk than light or moderate drinkers. The composite of this disparate relation in several population studies of cardiovascular mortality has been a "U-" or "J-"shaped curve. Apart from its ability to eliminate cholesterol from the intima of the arteries by reverse cholesterol transport, another major mechanism by which HDL may have this cardioprotective property is by virtue of the ability of its component enzyme paraoxonase1 (PON1) to inhibit LDL oxidation and/or inactivate OxLDL. Therefore, PON1 plays a central role in the disposal of OxLDL and thus is antiatherogenic. Furthermore, PON1 is a multifunctional antioxidant enzyme that can also detoxify the homocysteine metabolite, homocysteine thiolactone (HTL), which can pathologically cause protein damage by homocysteinylation of the lysine residues, thereby leading to atherosclerosis. We demonstrated that moderate alcohol up regulates liver PON1 gene expression and serum activity, whereas heavy alcohol consumption had the opposite effects in both animal models and in humans. The increase in PON1 activity in light drinkers was not due to preferential distribution of high PON1 genotype in this group. It is well known that wine consumption in several countries shows a remarkable inverse correlation to local rates of CAD mortality. Significantly, apart from its alcohol content, red wine also has polyphenols such as quercetin and resveratrol that are also known to have cardioprotective effects. We have shown that quercetin also up regulates PON1 gene in rats and in human liver cells. The action of quercetin seems to be mediated via the active form of the nuclear lipogenic transcription factor, sterol-regulatory element-binding protein 2 (SREBP2) that is translocated from endoplasmic reticulum to the nucleus. However, the mechanism of action of ethanol-mediated up-regulation of PON1 gene remains to be elucidated. We conclude that both moderate ethanol and quercetin, the two major components of red wine, exhibit cardioprotective properties via the up-regulation of the antiatherogenic gene PON1.
RESUMEN
Although heavy alcohol consumption has deleterious effects on heart health, moderate drinking is thought to have cardioprotective effects, reducing the risk of coronary artery disease and improving prognosis after a myocardial infarction. It still is unclear, however, if this effect can be achieved with all types of alcoholic beverages and results from the alcohol itself, from other compounds found in alcoholic beverages, or both. For example, the polyphenolic compound resveratrol, which is found particularly in red wine, can reduce the risk of atherosclerosis; however, it is not clear if the resveratrol levels present in wine are sufficient to achieve this result. Alcohol itself contributes to cardioprotection through several mechanisms. For example, it can improve the cholesterol profile, increasing the levels of "good" cholesterol and reducing the levels of "bad" cholesterol. Alcohol also may contribute to blood clot dissolution and may induce a phenomenon called pre-conditioning, whereby exposure to moderate alcohol levels (like short bouts of blood supply disruption [i.e., ischemia]), and result in reduced damage to the heart tissue after subsequent prolonged ischemia. Finally, the enzyme aldehyde dehydrogenase (ALDH) 2, which is involved in alcohol metabolism, also may contribute to alcohol-related cardioprotection by metabolizing other harmful aldehydes that could damage the heart muscle.