1 4659 133 NEW APPROACHES FOR STUDYING ALCOHOLIC LIVER DISEASE. ALCOHOLIC LIVER DISEASE (ALD) IS MAJOR CAUSE OF CHRONIC LIVER INJURY WHICH RESULTS IN LIVER FIBROSIS AND CIRRHOSIS. ACCORDING TO THE SURVEILLANCE REPORT PUBLISHED BY THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM, LIVER CIRRHOSIS IS THE 12TH LEADING CAUSE OF DEATH IN THE UNITED STATES WITH 48 % OF THESE DEATHS BEING ATTRIBUTED TO EXCESSIVE ALCOHOL CONSUMPTION. ALD INCLUDES A SPECTRUM OF DISORDERS FROM SIMPLE STEATOSIS TO STEATOHEPATITIS, FIBROSIS, AND HEPATOCELLULAR CARCINOMA. SEVERAL MECHANISMS PLAY A CRITICAL ROLE IN THE PATHOGENESIS OF ALD. THESE INCLUDE ETHANOL-INDUCED OXIDATIVE STRESS AND DEPLETION OF GLUTATHIONE, PATHOLOGICAL METHIONINE METABOLISM, INCREASED GUT PERMEABILITY AND RELEASE OF ENDOTOXINS INTO THE PORTAL BLOOD, RECRUITMENT AND ACTIVATION OF INFLAMMATORY CELLS INCLUDING BONE MARROW-DERIVED AND LIVER RESIDENT MACROPHAGES (KUPFFER CELLS). CHRONIC ALCOHOL CONSUMPTION RESULTS IN LIVER DAMAGE AND ACTIVATION OF HEPATIC STELLATE CELLS (HSCS) AND MYOFIBROBLASTS, LEADING TO LIVER FIBROSIS. HERE WE DISCUSS THE CURRENT VIEW ON FACTORS THAT ARE SPECIFIC FOR DIFFERENT STAGES OF ALD AND THOSE THAT REGULATE ITS PROGRESSION, INCLUDING CYTOKINES AND CHEMOKINES, ALCOHOL-RESPONSIVE INTRACELLULAR SIGNALING PATHWAYS, AND TRANSCRIPTIONAL FACTORS. WE ALSO REVIEW RECENT STUDIES DEMONSTRATING THAT ALCOHOL-MEDIATED CHANGES CAN BE REGULATED ON AN EPIGENETIC LEVEL, INCLUDING MICRORNAS. FINALLY, WE DISCUSS THE REVERSIBILITY OF LIVER FIBROSIS AND INACTIVATION OF HSCS AS A POTENTIAL STRATEGY FOR TREATING ALCOHOL-INDUCED LIVER DAMAGE. 2014 2 320 75 ALCOHOLIC LIVER DISEASE: PATHOGENESIS AND NEW THERAPEUTIC TARGETS. ALCOHOLIC LIVER DISEASE (ALD) IS A MAJOR CAUSE OF CHRONIC LIVER DISEASE WORLDWIDE AND CAN LEAD TO FIBROSIS AND CIRRHOSIS. THE LATEST SURVEILLANCE REPORT PUBLISHED BY THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM SHOWED THAT LIVER CIRRHOSIS WAS THE 12TH LEADING CAUSE OF DEATH IN THE UNITED STATES, WITH A TOTAL OF 29,925 DEATHS IN 2007, 48% OF WHICH WERE ALCOHOL RELATED. THE SPECTRUM OF ALD INCLUDES SIMPLE STEATOSIS, ALCOHOLIC HEPATITIS, FIBROSIS, CIRRHOSIS, AND SUPERIMPOSED HEPATOCELLULAR CARCINOMA. EARLY WORK ON THE PATHOGENESIS OF THE DISEASE FOCUSED ON ETHANOL METABOLISM-ASSOCIATED OXIDATIVE STRESS AND GLUTATHIONE DEPLETION, ABNORMAL METHIONINE METABOLISM, MALNUTRITION, AND PRODUCTION OF ENDOTOXINS THAT ACTIVATE KUPFFER CELLS. WE REVIEW FINDINGS FROM RECENT STUDIES THAT HAVE CHARACTERIZED SPECIFIC INTRACELLULAR SIGNALING PATHWAYS, TRANSCRIPTIONAL FACTORS, ASPECTS OF INNATE IMMUNITY, CHEMOKINES, EPIGENETIC FEATURES, MICRORNAS, AND STEM CELLS THAT ARE ASSOCIATED WITH ALD, IMPROVING OUR UNDERSTANDING OF ITS PATHOGENESIS. DESPITE THIS PROGRESS, NO TARGETED THERAPIES ARE AVAILABLE. THE CORNERSTONE OF TREATMENT FOR ALCOHOLIC HEPATITIS REMAINS AS IT WAS 40 YEARS AGO: ABSTINENCE, NUTRITIONAL SUPPORT, AND CORTICOSTEROIDS. THERE IS AN URGENT NEED TO DEVELOP NEW PATHOPHYSIOLOGY-ORIENTED THERAPIES. RECENT TRANSLATIONAL STUDIES OF HUMAN SAMPLES AND ANIMAL MODELS HAVE IDENTIFIED PROMISING THERAPEUTIC TARGETS. 2011 3 2323 34 EPIGENETIC REGULATION OF HEPATIC STELLATE CELL ACTIVATION AND MACROPHAGE IN CHRONIC LIVER INFLAMMATION. CHRONIC LIVER INFLAMMATION IS A COMPLEX PATHOLOGICAL PROCESS UNDER DIFFERENT STRESS CONDITIONS, AND THE ROLES OF STELLATE CELLS AND MACROPHAGES IN CHRONIC LIVER INFLAMMATION HAVE BEEN WIDELY REPORTED. MODERATE LIVER INFLAMMATION CAN PROTECT THE LIVER FROM DAMAGE AND FACILITATE THE RECOVERY OF LIVER INJURY. HOWEVER, AN INFLAMMATORY RESPONSE THAT IS TOO INTENSE CAN RESULT IN MASSIVE DEATH OF HEPATOCYTES, WHICH LEADS TO IRREVERSIBLE DAMAGE TO THE LIVER PARENCHYMA. EPIGENETIC REGULATION PLAYS A KEY PART IN LIVER INFLAMMATION. THIS STUDY REVIEWS THE REGULATION OF EPIGENETICS ON STELLATE CELLS AND MACROPHAGES TO EXPLORE THE NEW MECHANISMS OF EPIGENETICS ON LIVER INFLAMMATION AND PROVIDE NEW IDEAS FOR THE TREATMENT OF LIVER DISEASE. 2021 4 321 44 ALCOHOLIC-RELATED LIVER DISEASE: PATHOGENESIS, MANAGEMENT AND FUTURE THERAPEUTIC DEVELOPMENTS. ALCOHOL-RELATED LIVER DISEASE (ALD) IS THE MOST FREQUENT CAUSE OF ADVANCED CHRONIC LIVER DISEASE WORLDWIDE. EXCESSIVE AND PROLONGED ALCOHOL USE LEADS TO ALD, WHICH RANGES FROM EARLY FORMS SUCH AS ALCOHOLIC FATTY LIVER (AFL) AND ALCOHOLIC STEATOHEPATITIS (ASH), THROUGH PROGRESSIVE FIBROSIS TO CIRRHOSIS AND THE DEVELOPMENT OF HEPATOCELLULAR CANCER (HCC). IN ADDITION, PATIENTS WITH UNDERLYING ALD AND CONTINUOUS ALCOHOL USE CAN DEVELOP ALCOHOLIC HEPATITIS (AH), WHICH PRESENTS A RAPID PROGRESSION OF LIVER FAILURE AND HAS A HIGH SHORT-TERM MORTALITY. GENETIC, ENVIRONMENTAL AND EPIGENETIC FACTORS INFLUENCE THE PROGRESSION OF ALD TO MORE SEVERE FORMS. THE PATHOGENESIS OF ALD IS COMPLEX AND INVOLVES MULTIPLE PATHWAYS. RECENT TRANSLATIONAL STUDIES HAVE DEMONSTRATED A KEY ROLE OF THE GUT-LIVER AXIS AND INNATE IMMUNITY IN HEPATOCELLULAR DAMAGE AND FIBROSIS. IN SEVERE FORMS, HEPATOCELLULAR DE-DIFFERENTIATION AND SYSTEMIC INFLAMMATION CONTRIBUTE TO LIVER FAILURE AND MULTIORGAN FAILURE. ALCOHOL ABSTINENCE IS THE CORNERSTONE OF THERAPY FOR ALD AND THE PREVENTION OF ITS COMPLICATIONS, BUT THE EFFICACY AND ACCESSIBILITY OF PSYCHO-FAMILIAL-SOCIAL INTERVENTIONS IS STILL POOR AND EFFECTIVE PUBLIC HEALTH POLICIES TO LIMIT PROBLEMATIC ALCOHOL USE NEED TO BE IMPLEMENTED. PREDNISOLONE IS THE ONLY CURRENT OPTION FOR AH, WITH A TRANSIENT BENEFICIAL EFFECT OVER PLACEBO. FOR PATIENTS WITH DECOMPENSATED ALD-CIRRHOSIS AND/OR DEVELOPMENT OF HCC, LIVER TRANSPLANTATION (LT) MAY BE REQUIRED. IN RECENT YEARS, EARLY LT IS BEING INCREASINGLY OFFERED TO CAREFULLY SELECTED AH PATIENTS, WITH EXCELLENT LONG-TERM SURVIVAL. NEW TRIALS OF AH TREATMENTS ARE CURRENTLY ONGOING, AND TRANSLATIONAL STUDIES IN HUMAN SAMPLES ARE PAVING THE WAY TO NEW PROMISING TARGETED THERAPIES. 2020 5 2502 30 EPIGENETICS AND LIVER FIBROSIS. LIVER FIBROSIS ARISES BECAUSE PROLONGED INJURY COMBINED WITH EXCESSIVE SCAR DEPOSITION WITHIN HEPATIC PARENCHYMA ARISING FROM OVERACTIVE WOUND HEALING RESPONSE MEDIATED BY ACTIVATED MYOFIBROBLASTS. FIBROSIS IS THE COMMON END POINT FOR ANY TYPE OF CHRONIC LIVER INJURY INCLUDING ALCOHOLIC LIVER DISEASE, NONALCOHOLIC FATTY LIVER DISEASE, VIRAL HEPATITIS, AND CHOLESTATIC LIVER DISEASES. ALTHOUGH GENETIC INFLUENCES ARE IMPORTANT, IT IS EPIGENETIC MECHANISMS THAT HAVE BEEN SHOWN TO ORCHESTRATE MANY ASPECTS OF FIBROGENESIS IN THE LIVER. NEW DISCOVERIES IN THE FIELD ARE LEADING TOWARD THE DEVELOPMENT OF EPIGENETIC BIOMARKERS AND TARGETED THERAPIES. THIS REVIEW CONSIDERS EPIGENETIC MECHANISMS AS WELL AS RECENT ADVANCES IN EPIGENETIC PROGRAMMING IN THE CONTEXT OF HEPATIC FIBROSIS. 2017 6 4705 45 NLRP3: A NEW THERAPEUTIC TARGET IN ALCOHOLIC LIVER DISEASE. THE LIVER IS IN CHARGE OF A WIDE RANGE OF CRITICAL PHYSIOLOGICAL PROCESSES AND IT PLAYS AN IMPORTANT ROLE IN ACTIVATING THE INNATE IMMUNE SYSTEM WHICH ELICITS THE INFLAMMATORY EVENTS. CHRONIC ETHANOL EXPOSURE DISRUPTS HEPATIC INFLAMMATORY MECHANISM AND LEADS TO THE RELEASE OF PROINFLAMMATORY MEDIATORS SUCH AS CHEMOKINES, CYTOKINES AND ACTIVATION OF INFLAMMASOMES. THE MECHANISM OF LIVER FIBROSIS/CIRRHOSIS INVOLVE ACTIVATION OF NLRP3 INFLAMMASOME, LEADING TO THE DESTRUCTION OF HEPATOCYTES AND SUBSEQUENT METABOLIC DYSREGULATION IN HUMANS. IN ADDITION, INCREASING EVIDENCE SUGGESTS THAT ALCOHOL INTAKE SIGNIFICANTLY MODIFIES LIVER EPIGENETICS, PROMOTING THE DEVELOPMENT OF ALCOHOLIC LIVER DISEASE (ALD). EPIGENETIC CHANGES INCLUDING HISTONE MODIFICATION, MICRORNA-INDUCED GENETIC MODULATION, AND DNA METHYLATION ARE CRUCIAL IN ALCOHOL-EVOKED CELL SIGNALING THAT AFFECTS GENE EXPRESSION IN THE HEPATIC SYSTEM. THOUGH WE ARE AT THE BEGINNING STAGE WITHOUT HAVING THE ENTIRE PRINT OF EPIGENETIC SIGNATURE, IT IS TIME TO FOCUS MORE ON NLRP3 INFLAMMASOME AND EPIGENETIC MODIFICATIONS. HERE WE REVIEW THE NOVEL ASPECT OF ALD PATHOLOGY LINKING TO INFLAMMATION AND HIGHLIGHTING THE ROLE OF EPIGENETIC MODIFICATION ASSOCIATED WITH NLRP3 INFLAMMASOME AND HOW IT COULD BE A THERAPEUTIC TARGET IN ALD. 2023 7 6106 45 THE EMERGING ROLE OF MICRORNAS IN NAFLD: HIGHLIGHT OF MICRORNA-29A IN MODULATING OXIDATIVE STRESS, INFLAMMATION, AND BEYOND. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A COMMON CAUSE OF CHRONIC LIVER DISEASE AND RANGES FROM STEATOSIS TO STEATOHEPATITIS AND TO LIVER FIBROSIS. LIPOTOXICITY IN HEPATOCYTES, ELEVATED OXIDATIVE STRESS AND THE ACTIVATION OF PROINFLAMMATORY MEDIATORS OF KUPFFER CELLS, AND FIBROGENIC PATHWAYS OF ACTIVATED HEPATIC STELLATE CELLS CAN CONTRIBUTE TO THE DEVELOPMENT OF NAFLD. MICRORNAS (MIRS) PLAY A CRUCIAL ROLE IN THE DYSREGULATED METABOLISM AND INFLAMMATORY SIGNALING CONNECTED WITH NAFLD AND ITS PROGRESSION TOWARDS MORE SEVERE STAGES. OF NOTE, THE PROTECTIVE EFFECT OF NON-CODING MIR-29A ON LIVER DAMAGE AND ITS VERSATILE ACTION ON EPIGENETIC ACTIVITY, MITOCHONDRIAL HOMEOSTASIS AND IMMUNOMODULATION MAY IMPROVE OUR PERCEPTION OF THE PATHOGENESIS OF NAFLD. HEREIN, WE REVIEW THE BIOLOGICAL FUNCTIONS OF CRITICAL MIRS IN NAFLD, AS WELL AS HIGHLIGHT THE EMERGING ROLE OF MIR-29A IN THERAPEUTIC APPLICATION AND THE RECENT ADVANCES IN MOLECULAR MECHANISMS UNDERLYING ITS LIVER PROTECTIVE EFFECT. 2020 8 4976 44 PATHOPHYSIOLOGICAL MECHANISMS OF HEPATIC STELLATE CELLS ACTIVATION IN LIVER FIBROSIS. LIVER FIBROSIS IS A COMPLEX PATHOLOGICAL PROCESS CONTROLLED BY A VARIETY OF CELLS, MEDIATORS AND SIGNALING PATHWAYS. HEPATIC STELLATE CELLS PLAY A CENTRAL ROLE IN THE DEVELOPMENT OF LIVER FIBROSIS. IN CHRONIC LIVER DISEASE, HEPATIC STELLATE CELLS UNDERGO DRAMATIC PHENOTYPIC ACTIVATION AND ACQUIRE FIBROGENIC PROPERTIES. THIS REVIEW FOCUSES ON THE PATHOPHYSIOLOGICAL MECHANISMS OF HEPATIC STELLATE CELLS ACTIVATION IN LIVER FIBROSIS. THEY ENTER THE CELL CYCLE UNDER THE INFLUENCE OF VARIOUS TRIGGERS. THE "INITIATION" PHASE OF HEPATIC STELLATE CELLS ACTIVATION OVERLAPS AND CONTINUES WITH THE "PERPETUATION" PHASE, WHICH IS CHARACTERIZED BY A PRONOUNCED INFLAMMATORY AND FIBROGENIC REACTION. THIS IS FOLLOWED BY A RESOLUTION PHASE IF THE INJURY SUBSIDES. KNOWLEDGE OF THESE PATHOPHYSIOLOGICAL MECHANISMS PAVED THE WAY FOR DRUGS AIMED AT PREVENTING THE DEVELOPMENT AND PROGRESSION OF LIVER FIBROSIS. IN THIS RESPECT, IMPAIRMENTS IN INTRACELLULAR SIGNALING, EPIGENETIC CHANGES AND CELLULAR STRESS RESPONSE CAN BE THE TARGETS OF THERAPY WHERE THE GOAL IS TO DEACTIVATE HEPATIC STELLATE CELLS. POTENTIAL ANTIFIBROTIC THERAPY MAY FOCUS ON INDUCING HEPATIC STELLATE CELLS TO RETURN TO AN INACTIVE STATE THROUGH CELLULAR AGING, APOPTOSIS, AND/OR CLEARANCE BY IMMUNE CELLS, AND SERVE AS POTENTIAL ANTIFIBROTIC THERAPY. IT IS ESPECIALLY IMPORTANT TO PREVENT THE FORMATION OF LIVER CIRRHOSIS SINCE THE ONLY RADICAL APPROACH TO ITS TREATMENT IS LIVER TRANSPLANTATION WHICH CAN BE PERFORMED IN ONLY A LIMITED NUMBER OF COUNTRIES. 2022 9 5533 41 ROLE AND MECHANISM OF DNA METHYLATION AND ITS INHIBITORS IN HEPATIC FIBROSIS. LIVER FIBROSIS IS A REPAIR RESPONSE TO INJURY CAUSED BY VARIOUS CHRONIC STIMULI THAT CONTINUALLY ACT ON THE LIVER. AMONG THEM, THE ACTIVATION OF HEPATIC STELLATE CELLS (HSCS) AND THEIR TRANSFORMATION INTO A MYOFIBROBLAST PHENOTYPE IS A KEY EVENT LEADING TO LIVER FIBROSIS, HOWEVER THE MECHANISM HAS NOT YET BEEN ELUCIDATED. THE MOLECULAR BASIS OF HSC ACTIVATION INVOLVES CHANGES IN THE REGULATION OF GENE EXPRESSION WITHOUT CHANGES IN THE GENOME SEQUENCE, NAMELY, VIA EPIGENETIC REGULATION. DNA METHYLATION IS A KEY FOCUS OF EPIGENETIC RESEARCH, AS IT AFFECTS THE EXPRESSION OF FIBROSIS-RELATED, METABOLISM-RELATED, AND TUMOR SUPPRESSOR GENES. INCREASING STUDIES HAVE SHOWN THAT DNA METHYLATION IS CLOSELY RELATED TO SEVERAL PHYSIOLOGICAL AND PATHOLOGICAL PROCESSES INCLUDING HSC ACTIVATION AND LIVER FIBROSIS. THIS REVIEW AIMED TO DISCUSS THE MECHANISM OF DNA METHYLATION IN THE PATHOGENESIS OF LIVER FIBROSIS, EXPLORE DNA METHYLATION INHIBITORS AS POTENTIAL THERAPIES FOR LIVER FIBROSIS, AND PROVIDE NEW INSIGHTS ON THE PREVENTION AND CLINICAL TREATMENT OF LIVER FIBROSIS. 2023 10 2164 38 EPIGENETIC MECHANISMS IN HEPATIC STELLATE CELL ACTIVATION DURING LIVER FIBROSIS AND CARCINOGENESIS. LIVER FIBROSIS IS AN ESSENTIAL COMPONENT OF CHRONIC LIVER DISEASE (CLD) AND HEPATOCARCINOGENESIS. THE FIBROTIC STROMA IS A CONSEQUENCE OF SUSTAINED LIVER DAMAGE COMBINED WITH EXACERBATED EXTRACELLULAR MATRIX (ECM) ACCUMULATION. IN THIS CONTEXT, ACTIVATION OF HEPATIC STELLATE CELLS (HSCS) PLAYS A KEY ROLE IN BOTH INITIATION AND PERPETUATION OF FIBROGENESIS. THESE CELLS SUFFER PROFOUND REMODELING OF GENE EXPRESSION IN THIS PROCESS. THIS REVIEW IS FOCUSED ON THE EPIGENETIC ALTERATIONS PARTICIPATING IN THE TRANSDIFFERENTIATION OF HSCS FROM THE QUIESCENT TO ACTIVATED STATE. RECENT ADVANCES IN THE FIELD OF DNA METHYLATION AND POST-TRANSLATIONAL MODIFICATIONS (PTM) OF HISTONES (ACETYLATION AND METHYLATION) PATTERNS ARE DISCUSSED HERE, TOGETHER WITH ALTERED EXPRESSION AND ACTIVITY OF EPIGENETIC REMODELERS. WE ALSO CONSIDER RECENT ADVANCES IN TRANSLATIONAL APPROACHES, INCLUDING THE USE OF EPIGENETIC MARKS AS BIOMARKERS AND THE PROMISING ANTIFIBROTIC PROPERTIES OF EPIGENETIC DRUGS THAT ARE CURRENTLY BEING USED IN PATIENTS. 2019 11 2104 41 EPIGENETIC EVENTS IN LIVER CANCER RESULTING FROM ALCOHOLIC LIVER DISEASE. EPIGENETIC MECHANISMS PLAY AN EXTENSIVE ROLE IN THE DEVELOPMENT OF LIVER CANCER (I.E., HEPATOCELLULAR CARCINOMA [HCC]) ASSOCIATED WITH ALCOHOLIC LIVER DISEASE (ALD) AS WELL AS IN LIVER DISEASE ASSOCIATED WITH OTHER CONDITIONS. FOR EXAMPLE, EPIGENETIC MECHANISMS, SUCH AS CHANGES IN THE METHYLATION AND/OR ACETYLATION PATTERN OF CERTAIN DNA REGIONS OR OF THE HISTONE PROTEINS AROUND WHICH THE DNA IS WRAPPED, CONTRIBUTE TO THE REVERSION OF NORMAL LIVER CELLS INTO PROGENITOR AND STEM CELLS THAT CAN DEVELOP INTO HCC. CHRONIC EXPOSURE TO BEVERAGE ALCOHOL (I.E., ETHANOL) CAN INDUCE ALL OF THESE EPIGENETIC CHANGES. THUS, ETHANOL METABOLISM RESULTS IN THE FORMATION OF COMPOUNDS THAT CAN CAUSE CHANGES IN DNA METHYLATION AND INTERFERE WITH OTHER COMPONENTS OF THE NORMAL PROCESSES REGULATING DNA METHYLATION. ALCOHOL EXPOSURE ALSO CAN ALTER HISTONE ACETYLATION/DEACETYLATION AND METHYLATION PATTERNS THROUGH A VARIETY OF MECHANISMS AND SIGNALING PATHWAYS. ALCOHOL ALSO ACTS INDIRECTLY ON ANOTHER MOLECULE CALLED TOLL-LIKE RECEPTOR 4 (TLR4) THAT IS A KEY COMPONENT IN A CRUCIAL REGULATORY PATHWAY IN THE CELLS AND WHOSE DYSREGULATION IS INVOLVED IN THE DEVELOPMENT OF HCC. FINALLY, ALCOHOL USE REGULATES AN EPIGENETIC MECHANISM INVOLVING SMALL MOLECULES CALLED MIRNAS THAT CONTROL TRANSCRIPTIONAL EVENTS AND THE EXPRESSION OF GENES IMPORTANT TO ALD. 2013 12 2219 45 EPIGENETIC MODIFICATIONS IN HEPATIC STELLATE CELLS CONTRIBUTE TO LIVER FIBROSIS. LIVER FIBROSIS REPRESENTS THE FINAL COMMON PATHWAY OF VIRTUALLY ALL TYPES OF CHRONIC LIVER DISEASES, AND IT HAS BEEN A MAJOR PUBLIC HEALTH CONCERN. MANY GENES HAVE BEEN DEMONSTRATED TO BE INVOLVED IN THE PATHOGENESIS OF LIVER FIBROSIS, WHILE THE MECHANISMS UNDERLYING GENE REGULATION STILL NEEDS FURTHER RESEARCH. ON THE OTHER HAND, HEPATIC STELLATE CELLS (HSCS) ARE QUIESCENT CELLS IN THE PERISINUSOIDAL SPACE IN LIVER. HSCS FACILITATE HEPATOCYTES INTERACTIONS VIA RELEASING SOLUBLE INFLAMMATORY FACTORS AND PRODUCING EXTRACELLULAR MATRIX. HSCS CAN BE ACTIVATED IN RESPONSE TO LIVER INJURY, AND THEY DIFFERENTIATE TO MYOFIBROBLASTS, WHICH GREATLY CONTRIBUTE TO THE FIBROGENESIS PROCESS. VARIOUS EPIGENETIC PROCEDURES, INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND FORMATION OF PARTICULAR CHROMATIN STRUCTURE, PLAY CRUCIAL ROLES IN THE GENE TRANSCRIPTIONAL EXPRESSION IN HSCS, REGULATING VARIOUS VITAL PROCESSES. FOR INSTANCE, EPIGENETIC MODULATION ON THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPAR-GAMMA) GENE PROMOTER ACCOUNTS FOR HSC DIFFERENTIATION THROUGH INTERACTING PATHWAYS. ABERRANT EXPRESSION OF A SERIES OF HISTONES AND CHEMOKINES IN ACTIVATED HSCS CAN AGGRAVATE INFLAMMATION AND OXIDATIVE STRESS, WHICH IN TURN PROMOTES DIFFERENTIATION OF HSCS TO MYOFIBROBLASTS AND ENHANCES THE WHOLE FIBROGENESIS PROCESS. DEGRADATION OF EXTRACELLULAR MATRIX IS ALSO REGULATED THROUGH EPIGENETIC MODULATION ON MATRIX ASSOCIATED ENZYMES. MOREOVER, FIBROSIS-RELATED EPIGENETIC MODIFICATIONS IN THE PARENTAL GENERATION MAY BE INHERITED TO THEIR OFFSPRING. IN THIS REVIEW, WE FIRSTLY SUMMARIZE THE VITAL EPIGENETIC MODIFICATIONS OF FIBROSIS-RELATED GENES IN HSCS, AND HIGHLIGHT SPECIFIC NUCLEIC ACID SEQUENCES AND STRUCTURES IN GENE PROMOTERS AS IMPORTANT ACTION SITES, WHICH MAY PROVIDE INDICATORS FOR LIVER FIBROSIS DIAGNOSIS IN THE FUTURE. 2013 13 5805 52 STRATEGIES TO PREVENT AND REVERSE LIVER FIBROSIS IN HUMANS AND LABORATORY ANIMALS. LIVER FIBROSIS RESULTS FROM CHRONIC DAMAGE TO THE LIVER IN CONJUNCTION WITH VARIOUS PATHWAYS AND IS MEDIATED BY A COMPLEX MICROENVIRONMENT. BASED ON CLINICAL OBSERVATIONS, IT IS NOW EVIDENT THAT FIBROSIS IS A DYNAMIC, BIDIRECTIONAL PROCESS WITH AN INHERENT CAPACITY FOR RECOVERY AND REMODELING. THE MAJOR MECHANISMS INVOLVED IN LIVER FIBROSIS INCLUDE THE REPETITIVE INJURY OF HEPATOCYTES, THE ACTIVATION OF THE INFLAMMATORY RESPONSE AFTER INJURY STIMULATION, AND THE ACTIVATION AND PROLIFERATION OF HEPATIC STELLATE CELLS (HSCS), WHICH REPRESENTS THE MAJOR EXTRACELLULAR MATRIX (ECM)-PRODUCING CELLS, STIMULATED BY HEPATOCYTE INJURY AND INFLAMMATION. THE MICROENVIRONMENT IN THE LIVER IS SYNERGISTICALLY REGULATED ABNORMAL ECM DEPOSITION, SCAR FORMATION, ANGIOGENESIS, AND FIBROGENESIS. MOREOVER, RECENT STUDIES HAVE CLARIFIED NOVEL MECHANISM IN FIBROSIS SUCH AS EPIGENETIC REGULATION OF HSCS, THE LEPTIN AND PPARGAMMA PATHWAYS, THE COAGULATION SYSTEM, AND EVEN AUTOPHAGY. UNCOVERING THE MECHANISMS OF LIVER FIBROGENESIS PROVIDES A BASIS TO DEVELOP POTENTIAL THERAPIES TO REVERSE AND TREAT THE FIBROTIC RESPONSE, THEREBY IMPROVING THE OUTCOMES OF PATIENTS WITH CHRONIC LIVER DISEASE. ALTHOUGH BOTH SCIENTIFIC AND CLINICAL CHALLENGES REMAIN, EMERGING STUDIES ATTEMPT TO REVEAL THE IDEAL ANTI-FIBROTIC DRUG THAT COULD BE EASILY DELIVERED TO THE LIVER WITH HIGH SPECIFICITY AND LOW TOXICITY. THIS REVIEW HIGHLIGHTS THE MECHANISMS, INCLUDING NOVEL PATHWAYS UNDERLYING FIBROGENESIS THAT MAY BE TRANSLATED INTO PREVENTIVE AND TREATMENT STRATEGIES, REVIEWS BOTH CURRENT AND NOVEL AGENTS THAT TARGET SPECIFIC PATHWAYS OR MULTIPLE TARGETS, AND DISCUSSES NOVEL DRUG DELIVERY SYSTEMS SUCH AS NANOTECHNOLOGY THAT CAN BE APPLIED IN THE TREATMENT OF LIVER FIBROSIS. IN ADDITION, WE ALSO DISCUSS SOME CURRENT TREATMENT STRATEGIES THAT ARE BEING APPLIED IN ANIMAL MODELS AND IN CLINICAL TRIALS. 2015 14 5772 52 SPECTRUM, SCREENING, AND DIAGNOSIS OF ALCOHOL-RELATED LIVER DISEASE. ALCOHOL-RELATED LIVER DISEASE (ALD) REPRESENTS ONE OF THE LEADING CAUSES OF CHRONIC LIVER DISEASE AND IS A MAJOR CAUSE OF LIVER-RELATED DEATHS WORLDWIDE. ALD ENCOMPASSES A RANGE OF DISORDERS INCLUDING SIMPLE STEATOSIS, ALCOHOLIC STEATOHEPATITIS, FIBROSIS, CIRRHOSIS, AND HEPATOCELLULAR CARCINOMA. PATIENTS WITH UNDERLYING ALD AND CONTINUED HEAVY ALCOHOL CONSUMPTION CAN ALSO DEVELOP AN EPISODE OF ACUTE-ON-CHRONIC LIVER INJURY CALLED ALCOHOL-ASSOCIATED HEPATITIS, THE MOST SEVERE FORM OF THE DISEASE, WHICH PORTENDS A POOR PROGNOSIS. THE MOST IMPORTANT RISK FACTOR FOR THE DEVELOPMENT OF ALD IS THE AMOUNT OF ALCOHOL CONSUMED. INDIVIDUAL SUSCEPTIBILITY TO PROGRESSION TO ADVANCED FIBROSIS AMONG HEAVY DRINKERS IS LIKELY DETERMINED BY A COMBINATION OF BEHAVIORAL, ENVIRONMENTAL, GENETIC, AND EPIGENETIC FACTORS, BUT THE MECHANISMS ARE LARGELY UNKNOWN. THE ONLY EFFECTIVE THERAPY FOR ALD IS PROLONGED ALCOHOL ABSTINENCE. DIAGNOSIS OF ALD INVOLVES ASSESSING PATIENTS FOR ALCOHOL USE DISORDER AND SIGNS OF ADVANCED LIVER DISEASE. IN CLINICAL PRACTICE, THE HISTOLOGICAL ASSESSMENT FOR ALD DIAGNOSIS IS UNCOMMON, AND IT IS USUALLY BASED ON THE MEDICAL HISTORY, CLINICAL MANIFESTATIONS, AND LABORATORY AND IMAGING TESTS. SEVERAL PROMISING BIOMARKERS THAT CAN HAVE BOTH DIAGNOSTIC AND PROGNOSTIC VALUE IN PATIENTS WITH ALD HAVE BEEN IDENTIFIED IN RECENT YEARS. THIS REVIEW PROVIDES AN OVERVIEW OF THE CLINICAL SPECTRUM OF ALD, THE DIAGNOSTIC APPROACH OF THE DISEASE FROM DIFFERENT PERSPECTIVES AS WELL AS CURRENT DIAGNOSTIC AND PROGNOSTIC BIOMARKERS. 2023 15 4897 42 OXIDATIVE STRESS IN ALCOHOL-RELATED LIVER DISEASE. ALCOHOL CONSUMPTION IS ONE OF THE LEADING CAUSES OF THE GLOBAL BURDEN OF DISEASE AND RESULTS IN HIGH HEALTHCARE AND ECONOMIC COSTS. HEAVY ALCOHOL MISUSE LEADS TO ALCOHOL-RELATED LIVER DISEASE, WHICH IS RESPONSIBLE FOR A SIGNIFICANT PROPORTION OF ALCOHOL-ATTRIBUTABLE DEATHS GLOBALLY. OTHER THAN REDUCING ALCOHOL CONSUMPTION, THERE ARE CURRENTLY NO EFFECTIVE TREATMENTS FOR ALCOHOL-RELATED LIVER DISEASE. OXIDATIVE STRESS REFERS TO AN IMBALANCE IN THE PRODUCTION AND ELIMINATION OF REACTIVE OXYGEN SPECIES AND ANTIOXIDANTS. IT PLAYS IMPORTANT ROLES IN SEVERAL ASPECTS OF ALCOHOL-RELATED LIVER DISEASE PATHOGENESIS. HERE, WE REVIEW HOW CHRONIC ALCOHOL USE RESULTS IN OXIDATIVE STRESS THROUGH INCREASED METABOLISM VIA THE CYTOCHROME P450 2E1 SYSTEM PRODUCING REACTIVE OXYGEN SPECIES, ACETALDEHYDE AND PROTEIN AND DNA ADDUCTS. THESE TRIGGER INFLAMMATORY SIGNALING PATHWAYS WITHIN THE LIVER LEADING TO EXPRESSION OF PRO-INFLAMMATORY MEDIATORS CAUSING HEPATOCYTE APOPTOSIS AND NECROSIS. REACTIVE OXYGEN SPECIES EXPOSURE ALSO RESULTS IN MITOCHONDRIAL STRESS WITHIN HEPATOCYTES CAUSING STRUCTURAL AND FUNCTIONAL DYSREGULATION OF MITOCHONDRIA AND UPREGULATING APOPTOTIC SIGNALING. THERE IS ALSO EVIDENCE THAT OXIDATIVE STRESS AS WELL AS THE DIRECT EFFECT OF ALCOHOL INFLUENCES EPIGENETIC REGULATION. INCREASED GLOBAL HISTONE METHYLATION AND ACETYLATION AND SPECIFIC HISTONE ACETYLATION INHIBITS ANTIOXIDANT RESPONSES AND PROMOTES EXPRESSION OF KEY PRO-INFLAMMATORY GENES. THIS REVIEW HIGHLIGHTS ASPECTS OF THE ROLE OF OXIDATIVE STRESS IN DISEASE PATHOGENESIS THAT WARRANT FURTHER STUDY INCLUDING MITOCHONDRIAL STRESS AND EPIGENETIC REGULATION. IMPROVED UNDERSTANDING OF THESE PROCESSES MAY IDENTIFY NOVEL TARGETS FOR THERAPY. 2020 16 6372 35 THE ROLE OF MIR-29A IN THE REGULATION, FUNCTION, AND SIGNALING OF LIVER FIBROSIS. BOTH FIBROSIS AND CIRRHOSIS OF THE LIVER ARE THE END RESULTS OF MOST KINDS OF CHRONIC LIVER DAMAGE AND REPRESENT A COMMON BUT DIFFICULT CLINICAL CHALLENGE THROUGHOUT THE WORLD. THE INHIBITION OF THE FIBROGENIC, PROLIFERATIVE, AND MIGRATORY EFFECTS OF HEPATIC STELLATE CELLS (HSCS) HAS BECOME AN EXPERIMENTAL THERAPY FOR PREVENTING AND EVEN REVERSING HEPATIC FIBROSIS. FURTHERMORE, A COMPLETE UNDERSTANDING OF THE FUNCTION OF NON-CODING RNA-MEDIATED EPIGENETIC MECHANISMS IN HSC ACTIVATION MAY IMPROVE OUR PERCEPTION OF LIVER FIBROSIS PATHOGENESIS. THIS REVIEW FOCUSES ON THE EVOLVING VIEW OF THE MOLECULAR MECHANISMS BY WHICH HSC ACTIVATION BY MIR-29A SIGNALING MAY MODERATE THE PROFIBROGENIC PHENOTYPE OF THESE CELLS, THUS SUPPORTING THE USE OF MIR-29A AGONISTS AS A POTENTIAL THERAPY FOR TREATING LIVER FIBROSIS IN THE FUTURE. 2018 17 4104 40 MECHANISM AND THERAPEUTIC OPPORTUNITIES OF HISTONE MODIFICATIONS IN CHRONIC LIVER DISEASE. CHRONIC LIVER DISEASE (CLD) REPRESENTS A GLOBAL HEALTH PROBLEM, ACCOUNTING FOR THE HEAVY BURDEN OF DISABILITY AND INCREASED HEALTH CARE UTILIZATION. EPIGENOME ALTERATIONS PLAY AN IMPORTANT ROLE IN THE OCCURRENCE AND PROGRESSION OF CLD. HISTONE MODIFICATIONS, WHICH INCLUDE ACETYLATION, METHYLATION, AND PHOSPHORYLATION, REPRESENT AN ESSENTIAL PART OF EPIGENETIC MODIFICATIONS THAT AFFECT THE TRANSCRIPTIONAL ACTIVITY OF GENES. DIFFERENT FROM GENETIC MUTATIONS, HISTONE MODIFICATIONS ARE PLASTIC AND REVERSIBLE. THEY CAN BE MODULATED PHARMACOLOGICALLY WITHOUT CHANGING THE DNA SEQUENCE. THUS, THERE MIGHT BE CHANCES TO ESTABLISH INTERVENTIONAL SOLUTIONS BY TARGETING HISTONE MODIFICATIONS TO REVERSE CLD. HERE WE SUMMARIZED THE ROLES OF HISTONE MODIFICATIONS IN THE CONTEXT OF ALCOHOLIC LIVER DISEASE (ALD), METABOLIC ASSOCIATED FATTY LIVER DISEASE (MAFLD), VIRAL HEPATITIS, AUTOIMMUNE LIVER DISEASE, DRUG-INDUCED LIVER INJURY (DILI), AND LIVER FIBROSIS OR CIRRHOSIS. THE POTENTIAL TARGETS OF HISTONE MODIFICATIONS FOR TRANSLATION INTO THERAPEUTICS WERE ALSO INVESTIGATED. IN PROSPECT, HIGH EFFICACY AND LOW TOXICITY DRUGS THAT ARE SELECTIVELY TARGETING HISTONE MODIFICATIONS ARE REQUIRED TO COMPLETELY REVERSE CLD AND PREVENT THE DEVELOPMENT OF LIVER CIRRHOSIS AND MALIGNANCY. 2021 18 4045 43 MACROPHAGES IN THE AGING LIVER AND AGE-RELATED LIVER DISEASE. THE NUMBER OF INDIVIDUALS AGED 65 OR OLDER IS PROJECTED TO INCREASE GLOBALLY FROM 524 MILLION IN 2010 TO NEARLY 1. 5 BILLION IN 2050. AGED INDIVIDUALS ARE PARTICULARLY AT RISK FOR DEVELOPING CHRONIC ILLNESS, WHILE BEING LESS ABLE TO REGENERATE HEALTHY TISSUE AND TOLERATE WHOLE ORGAN TRANSPLANTATION PROCEDURES. IN THE LIVER, THESE AGE-RELATED DISEASES INCLUDE NON-ALCOHOLIC FATTY LIVER DISEASE, ALCOHOLIC LIVER DISEASE, HEPATITIS, FIBROSIS, AND CIRRHOSIS. HEPATIC MACROPHAGES, A POPULATION COMPRISED OF BOTH KUPFFER CELLS AND INFILTRATING MONOCYTE DERIVED MACROPHAGES, ARE IMPLICATED IN SEVERAL CHRONIC LIVER DISEASES AND ALSO PLAY IMPORTANT ROLES IN THE HOMEOSTATIC FUNCTIONS OF THE LIVER. THE EFFECTS OF AGING ON HEPATIC MACROPHAGE POPULATION DYNAMICS, POLARIZATION, AND FUNCTION ARE NOT WELL UNDERSTOOD. STUDIES PERFORMED ON MACROPHAGES DERIVED FROM OTHER AGED SOURCES, SUCH AS THE BONE MARROW, PERITONEAL CAVITY, LUNGS, AND BRAIN, DEMONSTRATE GENERAL REDUCTIONS IN AUTOPHAGY AND PHAGOCYTOSIS, DYSFUNCTION IN CYTOKINE SIGNALING, AND ALTERED MORPHOLOGY AND DISTRIBUTION, LIKELY MEDIATED BY EPIGENETIC CHANGES AND MITOCHONDRIAL DEFECTS, THAT MAY BE APPLICABLE TO HEPATIC MACROPHAGES. THIS REVIEW HIGHLIGHTS RECENT FINDINGS IN MACROPHAGE DEVELOPMENTAL BIOLOGY AND FUNCTION, PARTICULARLY IN THE LIVER, AND DISCUSSES THE ROLE OF MACROPHAGES IN VARIOUS AGE-RELATED LIVER DISEASES. A BETTER UNDERSTANDING OF THE BIOLOGY OF AGING THAT INFLUENCES HEPATIC MACROPHAGES AND THUS THE PROGRESSION OF CHRONIC LIVER DISEASE WILL BE CRUCIAL IN ORDER TO DEVELOP NEW INTERVENTIONS AND TREATMENTS FOR LIVER DISEASE IN AGING POPULATIONS. 2018 19 2545 38 EPIGENETICS IN LIVER FIBROSIS: COULD HDACS BE A THERAPEUTIC TARGET? CHRONIC LIVER DISEASES (CLD) REPRESENT A WORLDWIDE HEALTH PROBLEM. WHILE CLDS MAY HAVE DIVERSE ETIOLOGIES, A COMMON PATHOGENIC DENOMINATOR IS THE PRESENCE OF LIVER FIBROSIS. CIRRHOSIS, THE END-STAGE OF CLD, IS CHARACTERIZED BY EXTENSIVE FIBROSIS AND IS MARKEDLY ASSOCIATED WITH THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA. THE MOST IMPORTANT EVENT IN HEPATIC FIBROGENESIS IS THE ACTIVATION OF HEPATIC STELLATE CELLS (HSC) FOLLOWING LIVER INJURY. ACTIVATED HSCS ACQUIRE A MYOFIBROBLAST-LIKE PHENOTYPE BECOMING PROLIFERATIVE, FIBROGENIC, AND CONTRACTILE CELLS. WHILE TRANSIENT ACTIVATION OF HSCS IS PART OF THE PHYSIOLOGICAL MECHANISMS OF TISSUE REPAIR, PROTRACTED ACTIVATION OF A WOUND HEALING REACTION LEADS TO ORGAN FIBROSIS. THE PHENOTYPIC CHANGES OF ACTIVATED HSCS INVOLVE EPIGENETIC MECHANISMS MEDIATED BY NON-CODING RNAS (NCRNA) AS WELL AS BY CHANGES IN DNA METHYLATION AND HISTONE MODIFICATIONS. DURING CLD THESE EPIGENETIC MECHANISMS BECOME DEREGULATED, WITH ALTERATIONS IN THE EXPRESSION AND ACTIVITY OF EPIGENETIC MODULATORS. HERE WE PROVIDE AN OVERVIEW OF THE EPIGENETIC ALTERATIONS INVOLVED IN FIBROGENIC HSCS TRANSDIFFERENTIATION WITH PARTICULAR FOCUS ON HISTONES ACETYLATION CHANGES. WE ALSO DISCUSS RECENT STUDIES SUPPORTING THE PROMISING THERAPEUTIC POTENTIAL OF HISTONE DEACETYLASE INHIBITORS IN LIVER FIBROSIS. 2020 20 319 42 ALCOHOLIC LIVER DISEASE. ALCOHOLIC LIVER DISEASE (ALD) IS THE MOST PREVALENT TYPE OF CHRONIC LIVER DISEASE WORLDWIDE. ALD CAN PROGRESS FROM ALCOHOLIC FATTY LIVER (AFL) TO ALCOHOLIC STEATOHEPATITIS (ASH), WHICH IS CHARACTERIZED BY HEPATIC INFLAMMATION. CHRONIC ASH CAN EVENTUALLY LEAD TO FIBROSIS AND CIRRHOSIS AND IN SOME CASES HEPATOCELLULAR CANCER (HCC). IN ADDITION, SEVERE ASH (WITH OR WITHOUT CIRRHOSIS) CAN LEAD TO ALCOHOLIC HEPATITIS, WHICH IS AN ACUTE CLINICAL PRESENTATION OF ALD THAT IS ASSOCIATED WITH LIVER FAILURE AND HIGH MORTALITY. MOST INDIVIDUALS CONSUMING >40 G OF ALCOHOL PER DAY DEVELOP AFL; HOWEVER, ONLY A SUBSET OF INDIVIDUALS WILL DEVELOP MORE ADVANCED DISEASE. GENETIC, EPIGENETIC AND NON-GENETIC FACTORS MIGHT EXPLAIN THE CONSIDERABLE INTERINDIVIDUAL VARIATION IN ALD PHENOTYPE. THE PATHOGENESIS OF ALD INCLUDES HEPATIC STEATOSIS, OXIDATIVE STRESS, ACETALDEHYDE-MEDIATED TOXICITY AND CYTOKINE AND CHEMOKINE-INDUCED INFLAMMATION. DIAGNOSIS OF ALD INVOLVES ASSESSING PATIENTS FOR ALCOHOL USE DISORDER AND SIGNS OF ADVANCED LIVER DISEASE. THE DEGREE OF AFL AND LIVER FIBROSIS CAN BE DETERMINED BY ULTRASONOGRAPHY, TRANSIENT ELASTOGRAPHY, MRI, MEASUREMENT OF SERUM BIOMARKERS AND LIVER BIOPSY HISTOLOGY. ALCOHOL ABSTINENCE ACHIEVED BY PSYCHOSOMATIC INTERVENTION IS THE BEST TREATMENT FOR ALL STAGES OF ALD. IN THE CASE OF ADVANCED DISEASE SUCH AS CIRRHOSIS OR HCC, LIVER TRANSPLANTATION MAY BE REQUIRED. THUS, NEW THERAPIES ARE URGENTLY NEEDED. 2018