1 1348 132 DETERMINANTS OF FIBROSIS PROGRESSION AND REGRESSION IN NASH. CIRRHOSIS HAS BECOME THE MAJOR LIVER-RELATED CLINICAL ENDPOINT IN NON-ALCOHOLIC STEATOHEPATITIS (NASH). HOWEVER, PROGRESSION TO CIRRHOSIS IS LESS PREDICTABLE IN NASH THAN IN OTHER CHRONIC LIVER DISEASES. THIS IS DUE TO THE COMPLEX AND MULTIFACTORIAL AETIOLOGY OF NASH, WHICH IS DETERMINED BY LIFESTYLE AND NUTRITION, MULTIPLE GENETIC AND EPIGENETIC FACTORS, AND A PROMINENT ROLE OF HEPATIC AND EXTRAHEPATIC COMORBIDITIES. THUS, MODEST CHANGES IN THESE COFACTORS CAN ALSO INDUCE FIBROSIS REGRESSION, AT LEAST IN PATIENTS WITH PRECIRRHOTIC LIVER DISEASE. FIBROGENESIS IN NASH CORRELATES WITH, BUT IS INDIRECTLY COUPLED TO, CLASSICAL INFLAMMATION, SINCE FIBROSIS PROGRESSION IS DRIVEN BY REPETITIVE PERIODS OF REPAIR. WHILE HEPATOCYTE LIPOAPOPTOSIS IS A KEY DRIVING FORCE OF FIBROSIS PROGRESSION, ACTIVATED HEPATIC STELLATE CELLS, MYOFIBROBLASTS, CHOLANGIOCYTES, MACROPHAGES AND COMPONENTS OF THE PATHOLOGICAL EXTRACELLULAR MATRIX ARE MAJOR FIBROGENIC EFFECTORS AND THUS PHARMACOLOGICAL TARGETS FOR THERAPIES AIMED AT INHIBITION OF FIBROSIS PROGRESSION OR INDUCTION OF FIBROSIS REVERSAL. THE ADVENT OF NOVEL, HIGHLY SENSITIVE AND SPECIFIC SERUM BIOMARKERS AND IMAGING METHODS TO ASSESS THE DYNAMICS OF LIVER FIBROSIS IN NASH WILL IMPROVE DETECTION, STRATIFICATION AND FOLLOW-UP OF PATIENTS WITH PROGRESSIVE NASH . THESE NON-INVASIVE TOOLS WILL ALSO PROMOTE THE CLINICAL DEVELOPMENT OF ANTIFIBROTIC DRUGS, BY PERMITTING THE DESIGN OF LEAN PROOF-OF-CONCEPT STUDIES, AND ENABLING DEVELOPMENT OF A PERSONALISED ANTIFIBROTIC THERAPY FOR PATIENTS WITH RAPID FIBROSIS PROGRESSION OR ADVANCED DISEASE. 2018 2 2691 30 EVOLUTION OF HEPATIC FIBROSIS RESEARCH. MOLECULAR ANALYSIS OF HEPATIC FIBROGENESIS HAS PROGRESSED WITH RESPECT TO BOTH FIBROSIS PROGRESSION AND REGRESSION BY USING CELL BIOLOGICAL, MOLECULAR BIOLOGICAL AND (EPI)GENETIC APPROACHES. RECENT RESEARCHES HAVE REVEALED SOURCES OF COLLAGEN-PRODUCING CELLS OTHER THAN HEPATIC STELLATE CELLS IN THE LIVER, AND THE INVOLVEMENT OF THE INNATE IMMUNE SYSTEM AND OXIDATIVE STRESS IN THE FIBROTIC PROCESS HAS ATTRACTED NEW ATTENTION. TOGETHER WITH THESE ADVANCEMENTS IN BASIC KNOWLEDGE ON THE CELLULAR AND MOLECULAR BIOLOGY OF HEPATIC FIBROSIS, CLINICAL RESEARCHES HAVE LINKED THE CLARIFICATION OF THE RELATIONSHIP BETWEEN PROGRESSION OF THE FIBROSIS STAGE AND THERAPEUTIC EFFICACY FOR CHRONIC VIRAL HEPATITIS AND NON-ALCOHOLIC STEATOHEPATITIS AND VALIDATION OF THE REGRESSION OF ADVANCED FIBROSIS, EVEN CIRRHOSIS, OF APPROPRIATE THERAPIES USING MODERN MEDICINES. FURTHERMORE, NON-INVASIVE ASSESSMENT OF LIVER FIBROSIS USING AN ULTRASOUND-BASED MODALITY HAS BECOME A FOCUS IN THE CLINICAL DIAGNOSIS OF LIVER FIBROSIS INSTEAD OF LIVER BIOPSY. TAKEN TOGETHER, LIVER FIBROSIS RESEARCH HAS BEEN EVOLVING BOTH BASICALLY AND CLINICALLY IN THE PAST THREE DECADES. 2011 3 2502 26 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 4 4980 39 PATHOPHYSIOLOGY OF LIVER FIBROSIS. PROGRESSIVE ACCUMULATION OF FIBRILLAR EXTRACELLULAR MATRIX (ECM) IN THE LIVER IS THE CONSEQUENCE OF REITERATED LIVER TISSUE DAMAGE DUE TO INFECTIVE (MOSTLY HEPATITIS B AND C VIRUSES), TOXIC/DRUG-INDUCED, METABOLIC AND AUTOIMMUNE CAUSES, AND THE RELATIVE CHRONIC ACTIVATION OF THE WOUND-HEALING REACTION. THE PROCESS MAY RESULT IN CLINICALLY EVIDENT LIVER CIRRHOSIS AND HEPATIC FAILURE. ALTHOUGH CIRRHOSIS IS THE COMMON RESULT OF PROGRESSIVE FIBROGENESIS, THERE ARE DISTINCT PATTERNS OF FIBROTIC DEVELOPMENT RELATED TO THE UNDERLYING DISORDERS CAUSING THE FIBROSIS. THESE DIFFERENT PATTERNS OF FIBROGENIC EVOLUTION ARE RELATED TO DIFFERENT FACTORS AND PARTICULARLY: (1) THE TOPOGRAPHIC LOCALIZATION OF TISSUE DAMAGE, (2) THE RELATIVE CONCENTRATION OF PROFIBROGENIC FACTORS AND (3) THE PREVALENT PROFIBROGENIC MECHANISM(S). THE MECHANISMS RESPONSIBLE FOR THE FIBROGENIC EVOLUTION OF CHRONIC LIVER DISEASES CAN BE SUMMARIZED IN THREE MAIN GROUPS: CHRONIC ACTIVATION OF THE WOUND-HEALING REACTION, OXIDATIVE STRESS-RELATED MOLECULAR MECHANISMS, AND THE DERANGEMENT OF THE SO-CALLED 'EPITHELIAL-MESENCHYMAL' INTERACTION LEADING TO THE GENERATION OF REACTIVE CHOLANGIOCYTES AND PERIBILIARY FIBROSIS. MOST OF THE KNOWLEDGE ON THE CELL AND MOLECULAR BIOLOGY OF HEPATIC FIBROSIS DERIVES FROM IN VITRO STUDIES EMPLOYING CULTURE OF ACTIVATED HEPATIC STELLATE CELLS ISOLATED FROM RAT, MOUSE OR HUMAN LIVER. IT IS NOW EVIDENT THAT OTHER ECM-PRODUCING CELLS, I.E. FIBROBLASTS AND MYOFIBROBLASTS OF THE PORTAL TRACT AND CIRCULATING 'FIBROCYTES', ARE LIKELY TO CONTRIBUTE TO LIVER FIBROSIS. MORE RECENTLY, THE ATTENTION IS PROGRESSIVELY SHIFTING TO THE PROFIBROTIC MICROENVIRONMENT OF THE LIVER WITH INCREASING INTEREST FOR THE ROLE OF IMMUNE CELLS AND SPECIFIC SUBSETS OF MACROPHAGES REGULATING THE PROGRESSION OR THE REGRESSION OF FIBROSIS, THE ROLE OF INTESTINAL MICROBIOTA AND THE INFLUENCE OF TISSUE STIFFNESS. OTHER MAJOR AREAS OF DEVELOPMENT INCLUDE THE ROLE OF TISSUE HYPOXIA AND THE ESTABLISHMENT OF AN ANAEROBIC PROINFLAMMATORY ENVIRONMENT AND THE INFLUENCE OF EPIGENETIC MODIFICATION IN CONDITIONING THE PROGRESSION OF FIBROSIS. 2015 5 4884 35 OVERVIEW OF THE PATHOGENESIS, GENETIC, AND NON-INVASIVE CLINICAL, BIOCHEMICAL, AND SCORING METHODS IN THE ASSESSMENT OF NAFLD. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE MOST PREVALENT CHRONIC LIVER DISEASE WORLDWIDE. IT REPRESENTS A RANGE OF DISORDERS, INCLUDING SIMPLE STEATOSIS, NONALCOHOLIC STEATOHEPATITIS (NASH), AND LIVER CIRRHOSIS, AND ITS PREVALENCE CONTINUES TO RISE. IN SOME CASES, HEPATOCELLULAR CARCINOMA (HCC) MAY DEVELOP. THE DEVELOP;MENT OF NON-INVASIVE DIAGNOSTIC AND SCREENING TOOLS IS NEEDED, IN ORDER TO REDUCE THE FREQUENCY OF LIVER BIOPSIES. THE MOST PROMISING METHODS ARE THOSE ABLE TO EXCLUDE ADVANCED FIBROSIS AND QUANTIFY STEATOSIS. IN THIS STUDY, NEW PERSPECTIVE MARKERS FOR INFLAMMATION, OXIDATIVE STRESS, APOPTOSIS, AND FIBROGENESIS; EMERGING SCORING MODELS FOR DETECTING HEPATIC STEATOSIS AND FIBROSIS; AND NEW GENETIC, EPIGENETIC, AND MULTIOMIC STUDIES ARE DISCUSSED. AS ISOLATED BIOCHEMICAL PARAMETERS ARE NOT SPECIFIC OR SENSITIVE ENOUGH TO PREDICT THE PRESENCE OF NASH AND FIBROSIS, THERE IS A TENDENCY TO USE VARIOUS MARKERS AND COMBINE THEM INTO MATHEMATICAL ALGORITHMS. SEVERAL PREDICTIVE MODELS AND SCORING SYSTEMS HAVE BEEN DEVELOPED. CURRENT DATA SUGGESTS THAT PANELS OF MARKERS (NAFLD FIBROSIS SCORE, FIB-4 SCORE, BARD SCORE, AND OTHERS) ARE USEFUL DIAGNOSTIC MODALITIES TO MINIMIZE THE NUMBER OF LIVER BIOPSIES. THE REVIEW UNVEILS PATHOPHYSIOLOGICAL ASPECTS RELATED TO NEW TRENDS IN CURRENT NON-INVASIVE BIOCHEMICAL, GENETIC, AND SCORING METHODS, AND PROVIDES INSIGHT INTO THEIR DIAGNOSTIC ACCURACIES AND SUITABILITY IN CLINICAL PRACTICE. 2019 6 1285 36 DECIPHERING THE ROLE OF ABERRANT DNA METHYLATION IN NAFLD AND NASH. THE GLOBAL INCIDENCE OF NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS MOUNTING INCESSANTLY, AND IT IS EMERGING AS THE MOST FREQUENT CAUSE OF CHRONIC AND END STAGE LIVER DISORDERS. IT IS THE STARTING POINT FOR A RANGE OF CONDITIONS FROM SIMPLE STEATOSIS TO MORE PROGRESSIVE NONALCOHOLIC STEATOHEPATITIS (NASH) AND ASSOCIATED HEPATOCELLULAR CARCINOMA (HCC). DYSREGULATION OF INSULIN SECRETION AND DYSLIPIDEMIA DUE TO OBESITY AND OTHER LIFESTYLE VARIABLES ARE THE PRIMARY CONTRIBUTORS TO ESTABLISHMENT OF NAFLD. ONSET AND PROGRESSION OF NAFLD IS ORCHESTRATED BY AN INTERPLAY OF METABOLIC ENVIRONMENT WITH GENETIC AND EPIGENETIC FACTORS. AN INCOMPLETELY UNDERSTOOD MECHANISM OF NAFLD PROGRESSION HAS GREATLY HAMPERED THE PROGRESS IN IDENTIFICATION OF NOVEL PROGNOSTIC AND THERAPEUTIC STRATEGIES. EMERGING EVIDENCE SUGGESTS ALTERED DNA METHYLATION PATTERN AS A KEY DETERMINANT OF NAFLD PATHOGENESIS. ENVIRONMENTAL AND LIFESTYLE FACTORS CAN MANIPULATE DNA METHYLATION PATTERNS IN A REVERSIBLE MANNER, WHICH MANIFESTS AS CHANGES IN GENE EXPRESSION. IN THIS REVIEW WE ATTEMPT TO HIGHLIGHT THE IMPORTANCE OF DNA METHYLATION IN ESTABLISHMENT AND PROGRESSION OF NAFLD. DEVELOPMENT OF NOVEL DIAGNOSTIC, PROGNOSTIC AND THERAPEUTIC STRATEGIES CENTERED AROUND DNA METHYLATION SIGNATURES AND MODIFIERS HAS ALSO BEEN EXPLORED. 2022 7 2322 33 EPIGENETIC REGULATION OF HEPATIC STELLATE CELL ACTIVATION AND LIVER FIBROSIS. CHRONIC LIVER INJURY TO HEPATOCYTES OR CHOLANGIOCYTES, WHEN LEFT UNMANAGED, LEADS TO THE DEVELOPMENT OF LIVER FIBROSIS, A CONDITION CHARACTERIZED BY THE EXCESSIVE INTRAHEPATIC DEPOSITION OF EXTRACELLULAR MATRIX PROTEINS. ACTIVATED HEPATIC STELLATE CELLS CONSTITUTE THE PREDOMINANT SOURCE OF EXTRACELLULAR MATRIX IN FIBROTIC LIVERS AND THEIR TRANSITION FROM A QUIESCENT STATE DURING FIBROGENESIS IS ASSOCIATED WITH IMPORTANT ALTERATIONS IN THEIR TRANSCRIPTIONAL AND EPIGENETIC LANDSCAPE. AREAS COVERED: WE BRIEFLY DESCRIBE THE PROCESSES INVOLVED IN HEPATIC STELLATE CELL ACTIVATION AND DISCUSS OUR CURRENT UNDERSTANDING OF ALTERATIONS IN THE EPIGENETIC LANDSCAPE, I.E DNA METHYLATION, HISTONE MODIFICATIONS AND THE FUNCTIONAL ROLE OF NON-CODING RNAS THAT ACCOMPANY THIS KEY EVENT IN THE DEVELOPMENT OF CHRONIC LIVER DISEASE. EXPERT COMMENTARY: ALTHOUGH GREAT PROGRESS HAS BEEN MADE, OUR UNDERSTANDING OF THE EPIGENETIC REGULATION OF HEPATIC STELLATE CELL ACTIVATION IS LIMITED AND, THUS FAR, INSUFFICIENT TO ALLOW THE DEVELOPMENT OF EPIGENETIC DRUGS THAT CAN SELECTIVELY INTERRUPT LIVER FIBROSIS. 2016 8 5805 41 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 9 6092 33 THE EFFECTS OF EPIGENETIC MODIFICATION ON THE OCCURRENCE AND PROGRESSION OF LIVER DISEASES AND THE INVOLVED MECHANISM. INTRODUCTION: EPIGENETIC MODIFICATION IS A TYPE OF GENE EXPRESSION AND REGULATION THAT DOES NOT INVOLVE CHANGES IN DNA SEQUENCES. AN INCREASING NUMBER OF STUDIES HAVE PROVEN THAT EPIGENETIC MODIFICATIONS PLAY AN IMPORTANT ROLE IN THE OCCURRENCE AND PROGRESSION OF LIVER DISEASES THROUGH THE GENE REGULATION AND PROTEIN EXPRESSIONS OF HEPATOCELLULAR LIPID METABOLISM, INFLAMMATORY REACTION, CELL PROLIFERATION, AND ACTIVATION, ETC.AREAS COVERED: IN THIS STUDY, WE ELABORATED AND ANALYZED THE UNDERLYING FUNCTIONAL MECHANISM OF EPIGENETIC MODIFICATION IN ALCOHOLIC LIVER DISEASE (ALD), NONALCOHOLIC FATTY LIVER DISEASE (NAFLD), LIVER FIBROSIS (LF), VIRAL HEPATITIS, HEPATOCELLULAR CARCINOMA (HCC), AND RESEARCH PROGRESS OF RECENT YEARS.EXPERT OPINION: THE FURTHER UNDERSTANDING OF EPIGENETIC MECHANISMS THAT CAN REGULATE GENE EXPRESSION AND CELL PHENOTYPE LEADS TO NEW INSIGHTS IN EPIGENETIC CONTROL OF CHRONIC LIVER DISEASE. CURRENTLY, HEPATOLOGISTS ARE EXPLORING THE ROLE OF DNA METHYLATION, HISTONE/CHROMATIN MODIFICATION, AND NON-CODING RNA IN SPECIFIC LIVER PATHOLOGY. THESE FINDINGS HAVE LED TO ADVANCES IN DIRECT EPIGENETIC BIOMARKER TESTING OF PATIENT TISSUE OR BODY FLUID SPECIMENS, AS WELL AS QUANTITATIVE ANALYSIS. BASED ON THESE FINDINGS, DRUG VALIDATION OF SOME TARGETS INVOLVED IN THE EPIGENETIC MECHANISM OF LIVER DISEASE IS GRADUALLY BEING CARRIED OUT CLINICALLY. 2020 10 4976 39 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 11 3270 28 HEPATOCELLULAR CARCINOMA IN THE CONTEXT OF NON-ALCOHOLIC STEATOHEPATITIS (NASH): RECENT ADVANCES IN THE PATHOGENIC MECHANISMS. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON TYPE OF LIVER CANCER. HCC IS PARTICULARLY AGGRESSIVE AND IS ONE OF THE LEADING CAUSES OF CANCER MORTALITY. IN RECENT DECADES, THE EPIDEMIOLOGICAL LANDSCAPE OF HCC HAS UNDERGONE SIGNIFICANT CHANGES. WHILE CHRONIC VIRAL HEPATITIS AND EXCESSIVE ALCOHOL CONSUMPTION HAVE LONG BEEN IDENTIFIED AS THE MAIN RISK FACTORS FOR HCC, NON-ALCOHOLIC STEATOHEPATITIS (NASH), PARALLELING THE WORLDWIDE EPIDEMIC OF OBESITY AND TYPE 2 DIABETES, HAS BECOME A GROWING CAUSE OF HCC IN THE US AND EUROPE. HERE, WE REVIEW THE RECENT ADVANCES IN EPIDEMIOLOGICAL, GENETIC, EPIGENETIC AND PATHOGENIC MECHANISMS AS WELL AS EXPERIMENTAL MOUSE MODELS THAT HAVE IMPROVED THE UNDERSTANDING OF NASH PROGRESSION TOWARD HCC. WE ALSO DISCUSS THE CLINICAL MANAGEMENT OF PATIENTS WITH NASH-RELATED HCC AND POSSIBLE THERAPEUTIC APPROACHES. 2020 12 6372 30 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 13 2323 26 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 14 1354 42 DEVELOPMENT AND REGRESSION OF CIRRHOSIS. LIVER CIRRHOSIS IS THE ULTIMATE CONSEQUENCE OF THE WOUND HEALING REACTION SUBSEQUENT TO A CHRONIC INJURY, WHICH LEADS TO A COMPLETE DERANGEMENT OF THE NORMAL HEPATIC LOBULAR AND VASCULAR ARCHITECTURE. CIRRHOSIS IS CHARACTERIZED BY PATTERNS OF EVOLUTION DEPENDING ON THE CAUSATIVE AGENT AND A SERIES OF COMPLEX UNDERLINING MECHANISMS IN WHICH NEO-ANGIOGENESIS AND NECRO-INFLAMMATION PLAY A KEY ROLE. THE IMPORTANCE OF THE DIFFERENT CELL TYPES INVOLVED AND OF THE EXTRACELLULAR MATRIX COMPOSITION AS WELL AS THE ROLE OF INNATE IMMUNITY, BACTERIAL TRANSLOCATION AND OXIDATIVE STRESS ARE ALSO EMERGING. A VARIABLE DEGREE OF REGRESSION OF FIBROSIS AND EVEN CIRRHOSIS HAS BEEN DESCRIBED, IN EXPERIMENTAL MODELS, AFTER SUSPENSION OF THE LIVER DISEASE CAUSATIVE AGENT. AS SOME INDIVIDUAL FEATURES INFLUENCE THE RATE OF FIBROSIS PROGRESSION, GENETIC AND EPIGENETIC FACTORS ARE LIKELY TO INFLUENCE FIBROSIS REGRESSION. KEY MESSAGES: THERE IS INCREASING AWARENESS THAT CIRRHOSIS IS NOT A STATIC CONDITION BUT A DYNAMIC PROCESS. CURRENT SEMI-QUANTITATIVE SCORES AND CLINICAL CLASSIFICATIONS ARE INACCURATE AND UNABLE TO IDENTIFY THE DIFFERENT PHASES OF EVOLUTION OF THE ADVANCED STAGES OF CHRONIC LIVER DISEASES (CLDS). THE INCREASING AVAILABILITY OF EFFECTIVE ETIOLOGY-DRIVEN THERAPEUTIC OPTIONS FOR CLDS MAKES REVERSION OF CIRRHOSIS A MORE POSSIBLE PROSPECTIVE. HOWEVER, THE REMOVAL OF THE CAUSING AGENT, DEPENDING ON THE STAGE OF THE DISEASE, DOES NOT NECESSARILY ELIMINATE THE RISK OF DISEASE PROGRESSION, DECOMPENSATION AND DEVELOPMENT OF HEPATOCELLULAR CARCINOMA. ALSO, THE NON-INVASIVE MARKERS CURRENTLY VALIDATED FOR THE ASSESSMENT OF FIBROSIS ARE NOT SUITABLE FOR AN EFFECTIVE EVALUATION OF FIBROSIS REGRESSION. CONCLUSIONS: THERE IS A CRITICAL NEED OF A SYSTEM THAT WOULD BE ABLE TO MORE ACCURATELY DESCRIBE THE DYNAMIC DEVELOPMENT OF CIRRHOSIS AND THE IMPACT OF TISSUE FIBROSIS, NEO-ANGIOGENESIS, NECRO-INFLAMMATION AND ATTEMPTED REGENERATION ON ITS EVOLUTION. EFFECTIVE TREATMENT OF CLD CAN LEAD TO A VARIABLE DEGREE OF FIBROSIS REGRESSION. NEW MARKERS ABLE TO EVALUATE THIS PROCESS WILL NEED TO BE DETECTED AND VALIDATED. 2016 15 5386 28 REDOX HOMEOSTASIS AND EPIGENETICS IN NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD). NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD), AN ACCUMULATION OF INTRA-HEPATIC TRIGLYCERIDES THAT IS OFTEN CONSIDERED THE HEPATIC MANIFESTATION OF INSULIN RESISTANCE, IS THE MOST COMMON CAUSE OF CHRONIC LIVER DISEASE IN THE WESTERN COUNTRIES WITH UP TO ONE THIRD OF THE POPULATION AFFECTED. NAFLD IS A SPECTRUM OF DISTURBANCES THAT ENCOMPASSES VARIOUS DEGREES OF LIVER DAMAGE RANGING FROM SIMPLE STEATOSIS TO NON-ALCOHOLIC STEATOHEPATITIS (NASH). NASH IS CHARACTERIZED BY HEPATOCELLULAR INJURY/INFLAMMATION WITH OR WITHOUT FIBROSIS. THE INDIVIDUALS WITH NAFLD DEVELOP NASH IN 10% OF THE CASES, AND ARE ALSO AT RISK OF DEVELOPING HEPATOCELLULAR CARCINOMA (HCC). EPIGENETIC MECHANISMS OF NUCLEAR CHROMATIN REMODELING, SUCH AS DNA METHYLATION, POST-TRANSLATIONAL MODIFICATIONS OF HISTONES, AND INCORPORATION OF HISTONE VARIANTS INTO THE CHROMATIN ARE INCREASINGLY RECOGNIZED AS CRUCIAL FACTORS IN THE PATHOPHYSIOLOGY OF NAFLD. NAFLD IS OFTEN ACCOMPANIED BY OXIDATIVE STRESS: REACTIVE OXYGEN SPECIES (ROS) ARE IMPLICATED IN ALTERED REDUCTION/OXIDATION (REDOX) REACTIONS THAT ATTACK CELLULAR MACROMOLECULES AND ARE DETECTED IN THE LIVER OF PATIENTS AND ANIMAL MODELS OF NAFLD. IN THIS REVIEW, WE SUMMARIZE RECENT KNOWLEDGE ADVANCEMENTS IN THE HEPATIC EPIGENETIC AND REDOX MECHANISMS, AND THEIR POSSIBLE LINKS, INVOLVED IN THE PATHOGENESIS AND TREATMENT OF NAFLD. 2013 16 5533 31 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 17 1858 32 ELUCIDATING POTENTIAL PROFIBROTIC MECHANISMS OF EMERGING BIOMARKERS FOR EARLY PROGNOSIS OF HEPATIC FIBROSIS. HEPATIC FIBROSIS HAS BEEN ASSOCIATED WITH A SERIES OF PATHOPHYSIOLOGICAL PROCESSES CAUSING EXCESSIVE ACCUMULATION OF EXTRACELLULAR MATRIX PROTEINS. SEVERAL CELLULAR PROCESSES AND MOLECULAR MECHANISMS HAVE BEEN IMPLICATED IN THE DISEASED LIVER THAT AUGMENTS FIBROGENESIS, FIBROGENIC CYTOKINES AND ASSOCIATED LIVER COMPLICATIONS. LIVER BIOPSY REMAINS AN ESSENTIAL DIAGNOSTIC TOOL FOR HISTOLOGICAL EVALUATION OF HEPATIC FIBROSIS TO ESTABLISH A PROGNOSIS. IN ADDITION TO BEING INVASIVE, THIS METHODOLOGY PRESENTS WITH SEVERAL LIMITATIONS INCLUDING POOR COST-EFFECTIVENESS, PROLONGED HOSPITALIZATIONS, AND RISKS OF PERITONEAL BLEEDING, WHILE THE CLINICAL USE OF THIS METHOD DOES NOT REVEAL UNDERLYING PATHOGENIC MECHANISMS. SEVERAL ALTERNATE NONINVASIVE DIAGNOSTIC STRATEGIES HAVE BEEN DEVELOPED, TO DETERMINE THE EXTENT OF HEPATIC FIBROSIS, INCLUDING THE USE OF DIRECT AND INDIRECT BIOMARKERS. IMMEDIATE DIAGNOSIS OF HEPATIC FIBROSIS BY NONINVASIVE MEANS WOULD BE MORE PALATABLE THAN A BIOPSY AND COULD ASSIST CLINICIANS IN TAKING EARLY INTERVENTIONS TIMELY, AVOIDING FATAL COMPLICATIONS, AND IMPROVING PROGNOSIS. THEREFORE, WE SOUGHT TO REVIEW SOME COMMON BIOMARKERS OF LIVER FIBROSIS ALONG WITH SOME EMERGING CANDIDATES, INCLUDING THE OXIDATIVE STRESS-MEDIATED BIOMARKERS, EPIGENETIC AND GENETIC MARKERS, EXOSOMES, AND MIRNAS THAT NEEDS FURTHER EVALUATION AND WOULD HAVE BETTER SENSITIVITY AND SPECIFICITY. WE ALSO AIM TO ELUCIDATE THE POTENTIAL ROLE OF CARDIOTONIC STEROIDS (CTS) AND EVALUATE THE PRO-INFLAMMATORY AND PROFIBROTIC EFFECTS OF CTS IN EXACERBATING HEPATIC FIBROSIS. BY UNDERSTANDING THE UNDERLYING PATHOGENIC PROCESSES, THE EFFICACY OF THESE BIOMARKERS COULD ALLOW FOR EARLY DIAGNOSIS AND TREATMENT OF HEPATIC FIBROSIS IN CHRONIC LIVER DISEASES, ONCE VALIDATED. 2020 18 2164 33 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 19 321 39 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 20 2544 28 EPIGENETICS IN LIVER DISEASE: FROM BIOLOGY TO THERAPEUTICS. KNOWLEDGE OF THE FUNDAMENTAL EPIGENETIC MECHANISMS GOVERNING GENE EXPRESSION AND CELLULAR PHENOTYPE ARE SUFFICIENTLY ADVANCED THAT NOVEL INSIGHTS INTO THE EPIGENETIC CONTROL OF CHRONIC LIVER DISEASE ARE NOW EMERGING. HEPATOLOGISTS ARE IN THE PROCESS OF SHEDDING LIGHT ON THE ROLES PLAYED BY DNA METHYLATION, HISTONE/CHROMATIN MODIFICATIONS AND NON-CODING RNAS IN SPECIFIC LIVER PATHOLOGIES. ALONGSIDE THESE DISCOVERIES ARE ADVANCES IN THE TECHNOLOGIES FOR THE DETECTION AND QUANTIFICATION OF EPIGENETIC BIOMARKERS, EITHER DIRECTLY FROM PATIENT TISSUE OR FROM BODY FLUIDS. THE PREMISE FOR THIS REVIEW IS TO SURVEY THE RECENT ADVANCES IN THE FIELD OF LIVER EPIGENETICS AND TO EXPLORE THEIR POTENTIAL FOR TRANSLATION BY INDUSTRY AND CLINICAL HEPATOLOGISTS FOR THE DESIGN OF NOVEL THERAPEUTICS AND DIAGNOSTIC/PROGNOSTIC BIOMARKERS. IN PARTICULAR, WE PRESENT FINDINGS IN THE CONTEXT OF HEPATOCELLULAR CARCINOMA, FIBROSIS AND NON-ALCOHOLIC FATTY LIVER DISEASE, WHERE THERE IS URGENT UNMET NEED FOR NEW CLINICAL INTERVENTIONS AND BIOMARKERS. 2016