1 469 126 ARID1A LOSS DRIVES NONALCOHOLIC STEATOHEPATITIS IN MICE THROUGH EPIGENETIC DYSREGULATION OF HEPATIC LIPOGENESIS AND FATTY ACID OXIDATION. NONALCOHOLIC STEATOHEPATITIS (NASH) IS A RAPIDLY GROWING CAUSE OF CHRONIC LIVER DAMAGE, CIRRHOSIS, AND HEPATOCELLULAR CARCINOMA. HOW FATTY LIVER PATHOGENESIS IS SUBJECT TO EPIGENETIC REGULATION IS UNKNOWN. WE HYPOTHESIZED THAT CHROMATIN REMODELING IS IMPORTANT FOR THE PATHOGENESIS OF FATTY LIVER DISEASE. AT-RICH INTERACTIVE DOMAIN-CONTAINING PROTEIN 1A (ARID1A), A DNA-BINDING COMPONENT OF THE SWITCH/SUCROSE NONFERMENTABLE ADENOSINE TRIPHOSPHATE-DEPENDENT CHROMATIN-REMODELING COMPLEX, CONTRIBUTES TO NUCLEOSOME REPOSITIONING AND ACCESS BY TRANSCRIPTIONAL REGULATORS. LIVER-SPECIFIC DELETION OF ARID1A (ARID1A LIVER KNOCKOUT [LKO]) CAUSED THE DEVELOPMENT OF AGE-DEPENDENT FATTY LIVER DISEASE IN MICE. TRANSCRIPTOME ANALYSIS REVEALED UP-REGULATION OF LIPOGENESIS AND DOWN-REGULATION OF FATTY ACID OXIDATION GENES. AS EVIDENCE OF DIRECT REGULATION, ARID1A DEMONSTRATED DIRECT BINDING TO THE PROMOTERS OF MANY OF THESE DIFFERENTIALLY REGULATED GENES. ADDITIONALLY, ARID1A LKO MICE WERE MORE SUSCEPTIBLE TO HIGH-FAT DIET-INDUCED LIVER STEATOSIS AND FIBROSIS. WE DELETED PTEN IN COMBINATION WITH ARID1A TO SYNERGISTICALLY DRIVE FATTY LIVER PROGRESSION. INHIBITION OF LIPOGENESIS USING CAT-2003, A POTENT STEROL REGULATORY ELEMENT-BINDING PROTEIN INHIBITOR, MEDIATED IMPROVEMENTS IN MARKERS OF FATTY LIVER DISEASE PROGRESSION IN THIS ARID1A/PTEN DOUBLE KNOCKOUT MODEL. CONCLUSION: ARID1A PLAYS A ROLE IN THE EPIGENETIC REGULATION OF HEPATIC LIPID HOMEOSTASIS, AND ITS SUPPRESSION CONTRIBUTES TO FATTY LIVER PATHOGENESIS. COMBINED ARID1A AND PTEN DELETION SHOWS ACCELERATED FATTY LIVER DISEASE PROGRESSION AND IS A USEFUL MOUSE MODEL FOR STUDYING THERAPEUTIC STRATEGIES FOR NASH. 2019 2 6393 33 THE ROLE OF THE HISTONE METHYLTRANSFERASE EZH2 IN LIVER INFLAMMATION AND FIBROSIS IN STAM NASH MICE. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A LEADING FORM OF CHRONIC LIVER DISEASE, WITH FEW BIOMARKERS AND TREATMENT OPTIONS CURRENTLY AVAILABLE. NON-ALCOHOLIC STEATOHEPATITIS (NASH), A PROGRESSIVE DISEASE OF NAFLD, MAY LEAD TO FIBROSIS, CIRRHOSIS, AND HEPATOCELLULAR CARCINOMA. EPIGENETIC MODIFICATION CAN CONTRIBUTE TO THE PROGRESSION OF NAFLD CAUSING NON-ALCOHOLIC STEATOHEPATITIS (NASH), IN WHICH THE EXACT ROLE OF EPIGENETICS REMAINS POORLY UNDERSTOOD. TO IDENTIFY POTENTIAL THERAPEUTICS FOR NASH, WE TESTED SMALL-MOLECULE INHIBITORS OF THE EPIGENETIC TARGET HISTONE METHYLTRANSFERASE EZH2, TAZEMETOSTAT (EPZ-6438), AND UNC1999 IN STAM NASH MICE. THE RESULTS DEMONSTRATE THAT TREATMENT WITH EZH2 INHIBITORS DECREASED SERUM TNF-ALPHA IN NASH. IN THIS STUDY, WE INVESTIGATED THAT INHIBITION OF EZH2 REDUCED MRNA EXPRESSION OF INFLAMMATORY CYTOKINES AND FIBROSIS MARKERS IN NASH MICE. IN CONCLUSION, THESE RESULTS SUGGEST THAT EZH2 MAY PRESENT A PROMISING THERAPEUTIC TARGET IN THE TREATMENT OF NASH. 2020 3 3243 34 HEPATIC STEATOSIS IN HEPATITIS C IS A STORAGE DISEASE DUE TO HCV INTERACTION WITH MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN (MTP). LIVER STEATOSIS IS A FREQUENT HISTOLOGICAL FEATURE IN PATIENTS CHRONICALLY INFECTED WITH HEPATITIS C VIRUS (HCV). THE RELATIONSHIP BETWEEN HCV AND HEPATIC STEATOSIS SEEMS TO BE THE RESULT OF BOTH EPIGENETIC AND GENETIC FACTORS. IN VIVO AND IN VITRO STUDIES HAVE SHOWN THAT HCV CAN ALTER INTRAHEPATIC LIPID METABOLISM BY AFFECTING LIPID SYNTHESIS, OXIDATIVE STRESS, LIPID PEROXIDATION, INSULIN RESISTANCE AND THE ASSEMBLY AND SECRETION OF VLDL. MANY STUDIES SUGGEST THAT HCV-RELATED STEATOSIS MIGHT BE THE RESULT OF A DIRECT INTERACTION BETWEEN THE VIRUS AND MTP. IT HAS BEEN DEMONSTRATED THAT MTP IS CRITICAL FOR THE SECRETION OF HCV PARTICLES AND THAT INHIBITION OF ITS LIPID TRANSFER ACTIVITY REDUCES HCV PRODUCTION. HOWEVER, HIGHER DEGREES OF HEPATIC STEATOSIS WERE FOUND IN CHRONIC HEPATITIS C PATIENTS CARRYING THE T ALLELE OF MTP -493G/T POLYMORPHISM THAT SEEMS TO BE ASSOCIATED WITH INCREASED MTP TRANSCRIPTION. WE PROPOSE HERE THAT LIVER STEATOSIS IN HEPATITIS C COULD BE A STORAGE DISEASE INDUCED BY THE EFFECTS OF THE VIRUS AND OF ITS PROTEINS ON THE INTRACELLULAR LIPID MACHINERY AND ON MTP. AVAILABLE DATA SUPPORT THE HYPOTHESIS THAT HCV MAY MODULATE MTP EXPRESSION AND ACTIVITY THROUGH A NUMBER OF MECHANISMS SUCH AS INHIBITION OF ITS ACTIVITY AND TRANSCRIPTIONAL CONTROL. INITIAL UP REGULATION COULD FAVOUR PROPAGATION OF HCV WHILE DOWN REGULATION IN CHRONIC PHASE COULD CAUSE IMPAIRMENT OF TRIGLYCERIDE SECRETION AND EXCESSIVE LIPID ACCUMULATION, WITH ABNORMAL LIPID DROPLETS FACILITATING THE "STORAGE" OF VIRUS PARTICLES FOR PERSISTENT INFECTION. 2010 4 1615 38 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 5 4105 20 MECHANISM AND THERAPEUTIC TARGETS OF C-JUN-N-TERMINAL KINASES ACTIVATION IN NONALCOHOLIC FATTY LIVER DISEASE. NON-ALCOHOLIC FATTY LIVER (NAFL) IS THE MOST COMMON CHRONIC LIVER DISEASE. ACTIVATION OF MITOGEN-ACTIVATED KINASES (MAPK) CASCADE, WHICH LEADS TO C-JUN N-TERMINAL KINASE (JNK) ACTIVATION OCCURS IN THE LIVER IN RESPONSE TO THE NUTRITIONAL AND METABOLIC STRESS. THE ABERRANT ACTIVATION OF MAPKS, ESPECIALLY C-JUN-N-TERMINAL KINASES (JNKS), LEADS TO UNWANTED GENETIC AND EPI-GENETIC MODIFICATIONS IN ADDITION TO THE METABOLIC STRESS ADAPTATION IN HEPATOCYTES. A MECHANISM OF SUSTAINED P-JNK ACTIVATION WAS IDENTIFIED IN ACUTE AND CHRONIC LIVER DISEASES, SUGGESTING AN IMPORTANT ROLE OF ABERRANT JNK ACTIVATION IN NASH. THEREFORE, MODULATION OF JNK ACTIVATION, RATHER THAN TARGETING JNK PROTEIN LEVELS, IS A PLAUSIBLE THERAPEUTIC APPLICATION FOR THE TREATMENT OF CHRONIC LIVER DISEASE. 2022 6 6092 31 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 7 222 31 ACUTE LIVER STEATOSIS TRANSLATIONALLY CONTROLS THE EPIGENETIC REGULATOR MIER1 TO PROMOTE LIVER REGENERATION IN A STUDY WITH MALE MICE. THE EARLY PHASE LIPID ACCUMULATION IS ESSENTIAL FOR LIVER REGENERATION. HOWEVER, WHETHER THIS ACUTE LIPID ACCUMULATION CAN SERVE AS SIGNALS TO DIRECT LIVER REGENERATION RATHER THAN SIMPLY PROVIDING BUILDING BLOCKS FOR CELL PROLIFERATION REMAINS UNCLEAR. THROUGH IN VIVO CRISPR SCREENING, WE IDENTIFY MIER1 (MESODERM INDUCTION EARLY RESPONSE 1) AS A KEY EPIGENETIC REGULATOR THAT BRIDGES THE ACUTE LIPID ACCUMULATION AND CELL CYCLE GENE EXPRESSION DURING LIVER REGENERATION IN MALE ANIMALS. PHYSIOLOGICALLY, LIVER ACUTE LIPID ACCUMULATION INDUCES THE PHOSPHORYLATION OF EIF2S1(EUKARYOTIC TRANSLATION INITIATION FACTOR 2), WHICH CONSEQUENTLY ATTENUATED MIER1 TRANSLATION. MIER1 DOWNREGULATION IN TURN PROMOTES CELL CYCLE GENE EXPRESSION AND REGENERATION THROUGH CHROMATIN REMODELING. IMPORTANTLY, THE LIPIDS-EIF2S1-MIER1 PATHWAY IS IMPAIRED IN ANIMALS WITH CHRONIC LIVER STEATOSIS; WHEREAS MIER1 DEPLETION SIGNIFICANTLY IMPROVES REGENERATION IN THESE ANIMALS. TAKEN TOGETHER, OUR STUDIES IDENTIFY AN EPIGENETIC MECHANISM BY WHICH THE EARLY PHASE LIPID REDISTRIBUTION FROM ADIPOSE TISSUE TO LIVER DURING REGENERATION IMPACTS HEPATOCYTE PROLIFERATION, AND SUGGEST A POTENTIAL STRATEGY TO BOOST LIVER REGENERATION. 2023 8 3277 26 HEPATOCYTE PLOIDY AND PATHOLOGICAL MUTATIONS IN HEPATOCELLULAR CARCINOMA: IMPACT ON ONCOGENESIS AND THERAPEUTICS. HEPATOCELLULAR CARCINOMA (HCC) OCCURS IN THE CHRONIC LIVER INFLAMMATION SUCH AS VIRAL HEPATITIS, ALCOHOLIC AND NON-ALCOHOLIC STEATOHEPATITIS. WHILE ANTI-VIRAL TREATMENT HAS BEEN SIGNIFICANTLY IMPROVED, THE PREVALENCE OF HCC REMAINS HIGH AND TREATMENT IS STILL CHALLENGING. THE CONTINUATION OF HEPATOCYTE DEATH, INFLAMMATION, AND FIBROSIS LEADS TO THE ACCUMULATION OF GENE ALTERATIONS, WHICH MAY TRIGGER CARCINOGENESIS. HEPATOCYTES ARE A UNIQUE CELL TYPE HAVING MORE THAN ONE COMPLETE SET OF 23 CHROMOSOMES, TERMED POLYPLOIDY. DUE TO GENE REDUNDANCY, HEPATOCYTES MAY TOLERATE LETHAL MUTATIONS. NEXT GENERATION SEQUENCING TECHNOLOGY HAS REVEALED GENE ALTERATIONS IN HCC RELATED TO TELOMERE MAINTENANCE, WNT/BETA-CATENIN PATHWAY, P53 CELL-CYCLE PATHWAY, EPIGENETIC MODIFIERS, OXIDATIVE STRESS PATHWAY, PI3K/AKT/MTOR, AND RAS/RAF/MAPK PATHWAY WITH OR WITHOUT A CHROMOSOMAL INSTABILITY. SOME TYPE OF DRIVER GENE MUTATIONS ACCUMULATES IN HEPATOCYTES AND BREAKS THE ORCHESTRATION OF EXCESSIVE COPIES OF CHROMOSOMES, WHICH MAY LEAD TO UNFAVORABLE GENE EXPRESSIONS AND FUEL TUMORIGENESIS. RECENTLY, MOLECULAR TARGETED DRUGS, DEVELOPED WITH THE AIM OF INTERFERING WITH THESE SIGNALING PATHWAYS, ARE BEING USED FOR HCC PATIENTS IN THE CLINICS. THEREFORE, A DEEPER UNDERSTANDING OF HEPATOCYTE PLOIDY AND GENETIC OR EPIGENETIC ALTERATIONS IS INDISPENSABLE FOR THE ESTABLISHMENT OF NOVEL THERAPEUTIC STRATEGIES AGAINST HCC. 2020 9 413 33 ANALYSIS OF MIRNAS PROFILES IN SERUM OF PATIENTS WITH STEATOSIS AND STEATOHEPATITIS. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS EMERGING AS ONE OF THE MOST COMMON CHRONIC LIVER DISEASES WORLDWIDE, AFFECTING 25% OF THE WORLD POPULATION. IN RECENT YEARS, THERE HAS BEEN INCREASING EVIDENCE FOR THE INVOLVEMENT OF MICRORNAS IN THE EPIGENETIC REGULATION OF GENES TAKING PART IN THE DEVELOPMENT OF STEATOSIS AND STEATOHEPATITIS-TWO MAIN STAGES OF NAFLD PATHOGENESIS. IN THE PRESENT STUDY, MIRNA PROFILES WERE STUDIED IN GROUPS OF PATIENTS WITH STEATOSIS AND STEATOHEPATITIS TO COMPARE THE CHARACTERISTICS OF RNA-DEPENDENT EPIGENETIC REGULATION OF THE STAGES OF NAFLD DEVELOPMENT. ACCORDING TO THE RESULTS OF MIRNA SCREENING, 23 MIRNAS WERE DIFFERENTIALLY EXPRESSED SERUM IN A GROUP OF PATIENTS WITH STEATOHEPATITIS AND 2 IN A GROUP OF PATIENTS WITH STEATOSIS. MIR-195-5P AND MIR-16-5P ARE COMMON DIFFERENTIALLY EXPRESSED MIRNAS FOR BOTH STEATOSIS AND STEATOHEPATITIS. WE ANALYZED THE OBTAINED RESULTS: THE SEARCH FOR TARGET GENES FOR THE DIFFERENTIALLY EXPRESSED MIRNAS IN OUR STUDY AND THE SUBSEQUENT GENE SET ENRICHMENT ANALYSIS PERFORMED ON KEGG AND REACTOME DATABASES REVEALED WHICH METABOLIC PATHWAYS UNDERGO CHANGES IN RNA-DEPENDENT EPIGENETIC REGULATION IN STEATOSIS AND STEATOHEPATITIS. NEW FINDINGS WITHIN THE FRAMEWORK OF THIS STUDY ARE THE DYSREGULATION OF NEUROHUMORAL PATHWAYS IN THE PATHOGENESIS OF NAFLD AS AN OBJECT OF CHANGES IN RNA-DEPENDENT EPIGENETIC REGULATION. THE MIRNAS DIFFERENTIALLY EXPRESSED IN OUR STUDY WERE FOUND TO TARGET 7% OF GENES IN THE CLASSIC PATHOGENESIS OF NAFLD IN THE GROUP OF PATIENTS WITH STEATOSIS AND 50% IN THE GROUP OF PATIENTS WITH STEATOHEPATITIS. THE EFFECTS OF THESE MICRORNAS ON GENES FOR THE PATHOGENESIS OF NAFLD WERE ANALYZED IN DETAIL. MIR-374A-5P, MIR-1-3P AND MIR-23A-3P DO NOT TARGET GENES DIRECTLY INVOLVED IN THE PATHOGENESIS OF NAFLD. THE DIFFERENTIALLY EXPRESSED MIRNAS FOUND IN THIS STUDY TARGET GENES LARGELY RESPONSIBLE FOR MITOCHONDRIAL FUNCTION. THE ROLE OF MIR-423-5P, MIR-143-5P AND MIR-200C-3 IN REGULATING APOPTOTIC PROCESSES IN THE LIVER AND HEPATOCARCINOGENESIS IS OF INTEREST FOR FUTURE EXPERIMENTAL STUDIES. THESE MIR-374A, MIR-143, MIR-1, MIR-23A, AND MIR-423 HAVE POTENTIAL FOR STEATOHEPATITIS DIAGNOSIS AND ARE POORLY STUDIED IN THE CONTEXT OF NAFLD. THUS, THIS WORK OPENS UP PROSPECTS FOR FURTHER STUDIES OF MICRORNAS AS DIAGNOSTIC AND THERAPEUTIC BIOMARKERS FOR NAFLD. 2021 10 4108 28 MECHANISMS AND DISEASE CONSEQUENCES OF NONALCOHOLIC FATTY LIVER DISEASE. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE LEADING CHRONIC LIVER DISEASE WORLDWIDE. ITS MORE ADVANCED SUBTYPE, NONALCOHOLIC STEATOHEPATITIS (NASH), CONNOTES PROGRESSIVE LIVER INJURY THAT CAN LEAD TO CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. HERE WE PROVIDE AN IN-DEPTH DISCUSSION OF THE UNDERLYING PATHOGENETIC MECHANISMS THAT LEAD TO PROGRESSIVE LIVER INJURY, INCLUDING THE METABOLIC ORIGINS OF NAFLD, THE EFFECT OF NAFLD ON HEPATIC GLUCOSE AND LIPID METABOLISM, BILE ACID TOXICITY, MACROPHAGE DYSFUNCTION, AND HEPATIC STELLATE CELL ACTIVATION, AND CONSIDER THE ROLE OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS THAT PROMOTE FIBROSIS PROGRESSION AND RISK OF HEPATOCELLULAR CARCINOMA IN NASH. 2021 11 5890 31 SYSTEMS BIOLOGY ELUCIDATES COMMON PATHOGENIC MECHANISMS BETWEEN NONALCOHOLIC AND ALCOHOLIC-FATTY LIVER DISEASE. THE ABNORMAL ACCUMULATION OF FAT IN THE LIVER IS OFTEN RELATED EITHER TO METABOLIC RISK FACTORS ASSOCIATED WITH METABOLIC SYNDROME IN THE ABSENCE OF ALCOHOL CONSUMPTION (NONALCOHOLIC FATTY LIVER DISEASE, NAFLD) OR TO CHRONIC ALCOHOL CONSUMPTION (ALCOHOLIC FATTY LIVER DISEASE, AFLD). CLINICAL AND HISTOLOGICAL STUDIES SUGGEST THAT NAFLD AND AFLD SHARE PATHOGENIC MECHANISMS. NEVERTHELESS, CURRENT DATA ARE STILL INCONCLUSIVE AS TO WHETHER THE UNDERLYING BIOLOGICAL PROCESS AND DISEASE PATHWAYS OF NAFLD AND AFLD ARE ALIKE. OUR PRIMARY AIM WAS TO INTEGRATE OMICS AND PHYSIOLOGICAL DATA TO ANSWER THE QUESTION OF WHETHER NAFLD AND AFLD SHARE MOLECULAR PROCESSES THAT LEAD TO DISEASE DEVELOPMENT. WE ALSO EXPLORED THE EXTENT TO WHICH INSULIN RESISTANCE (IR) IS A DISTINCTIVE FEATURE OF NAFLD. TO ANSWER THESE QUESTIONS, WE USED SYSTEMS BIOLOGY APPROACHES, SUCH AS GENE ENRICHMENT ANALYSIS, PROTEIN-PROTEIN INTERACTION NETWORKS, AND GENE PRIORITIZATION, BASED ON MULTI-LEVEL DATA EXTRACTED BY COMPUTATIONAL DATA MINING. WE OBSERVED THAT THE LEADING DISEASE PATHWAYS ASSOCIATED WITH NAFLD DID NOT SIGNIFICANTLY DIFFER FROM THOSE OF AFLD. HOWEVER, SYSTEMS BIOLOGY REVEALED THE IMPORTANCE OF EACH MOLECULAR PROCESS BEHIND EACH OF THE TWO DISEASES, AND DISSECTED DISTINCTIVE MOLECULAR NAFLD AND AFLD-SIGNATURES. COMPARATIVE CO-ANALYSIS OF NAFLD AND AFLD CLARIFIED THE PARTICIPATION OF NAFLD, BUT NOT AFLD, IN CARDIOVASCULAR DISEASE, AND SHOWED THAT INSULIN SIGNALING IS IMPAIRED IN FATTY LIVER REGARDLESS OF THE NOXA, BUT THE PUTATIVE REGULATORY MECHANISMS ASSOCIATED WITH NAFLD SEEM TO ENCOMPASS A COMPLEX NETWORK OF GENES AND PROTEINS, PLAUSIBLE OF EPIGENETIC MODIFICATIONS. GENE PRIORITIZATION SHOWED A CANCER-RELATED FUNCTIONAL MAP THAT SUGGESTS THAT THE FATTY TRANSFORMATION OF THE LIVER TISSUE IS REGARDLESS OF THE CAUSE, AN EMERGING MECHANISM OF UBIQUITOUS ONCOGENIC ACTIVATION. IN CONCLUSION, SIMILAR UNDERLYING DISEASE MECHANISMS LEAD TO NAFLD AND AFLD, BUT SPECIFIC ONES DEPICT A PARTICULAR DISEASE SIGNATURE THAT HAS A DIFFERENT IMPACT ON THE SYSTEMIC CONTEXT. 2013 12 5234 43 PROFILE ANALYSIS AND FUNCTIONAL MODELING IDENTIFY CIRCULAR RNAS IN NONALCOHOLIC FATTY LIVER DISEASE AS REGULATORS OF HEPATIC LIPID METABOLISM. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE LEADING CAUSE OF CHRONIC LIVER DISEASE, ASSOCIATED WITH AN OUTCOME OF HEPATIC FIBROSIS/CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. HOWEVER, LIMITED EXPLORATION OF THE UNDERLYING MECHANISMS HINDERS ITS PREVENTION AND TREATMENT. TO INVESTIGATE THE MECHANISMS OF EPIGENETIC REGULATION IN NAFLD, THE EXPRESSION PROFILE OF CIRCULAR RNA (CIRCRNA) OF RODENTS IN WHICH NAFLD WAS INDUCED BY A HIGH-FAT, HIGH-CHOLESTEROL (HFHC) DIET WAS STUDIED. MODELING OF THE CIRCRNA-MICRORNA (MIRNA) -MRNA REGULATORY NETWORK REVEALED THE FUNCTIONAL CHARACTERISTICS OF NAFLD-SPECIFIC CIRCRNAS. THE TARGETS AND EFFECTS IN THE LIVER OF SUCH NAFLD-SPECIFIC CIRCRNAS WERE FURTHER ASSESSED. OUR RESULTS UNCOVERED THAT THE DOWNREGULATION OF 28 ANNOTATED CIRCRNAS CHARACTERIZES HFHC DIET-INDUCED NAFLD. AMONG THE DOWNREGULATED CIRCRNAS, LONG INTERGENIC NON-PROTEIN CODING RNA, P53 INDUCED TRANSCRIPT (LNCPINT) -DERIVED CIRCRNAS (CIRC_0001452, CIRC_0001453, AND CIRC_0001454) TARGETED BOTH MIR-466I-3P AND MIR-669C-3P. THEIR DEFICIENCY IN NAFLD ABROGATED THE CIRCRNA-BASED INHIBITORY EFFECT ON BOTH MIRNAS, WHICH FURTHER INACTIVATED THE AMPK SIGNALING PATHWAY VIA AMPK-ALPHA1 SUPPRESSION. INHIBITION OF THE AMPK SIGNALING PATHWAY PROMOTES HEPATIC STEATOSIS, DEPENDING ON THE TRANSCRIPTIONAL AND TRANSLATIONAL UPREGULATION OF LIPOGENIC GENES, SUCH AS THOSE ENCODING STEROL REGULATORY ELEMENT-BINDING PROTEIN 1 (SREBP1) AND FATTY ACID SYNTHASE (FASN) IN HEPATOCYTES. THE LEVELS OF LNCPINT-DERIVED CIRCRNAS DISPLAYED A NEGATIVE ASSOCIATION WITH HEPATIC TRIGLYCERIDE (TG) CONCENTRATION. THESE FINDINGS SUGGEST THAT LOSS OF LNCPINT-DERIVED CIRCRNAS MAY UNDERLIE NAFLD VIA MIR-466I-3P- AND MIR-669C-3P-DEPENDENT INACTIVATION OF THE AMPK SIGNALING PATHWAY. 2022 13 2322 25 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 14 1348 29 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 15 6339 29 THE ROLE OF EPIGENETIC CHANGES IN THE PROGRESSION OF ALCOHOLIC STEATOHEPATITIS. ALCOHOLIC STEATOHEPATITIS (ASH) IS A PROGRESSION HEPATITIS WITH SEVERE FATTY LIVER AND ITS MORTALITY RATE FOR 30-DAYS IN PATIENTS ARE OVER 30%. ADDITIONALLY, ASH IS WELL KNOWN FOR ONE-FIFTH ALL ALCOHOLIC RELATED LIVER DISEASES IN THE WORLD. EXCESSIVE CHRONIC ALCOHOL CONSUMPTION IS ONE OF THE MOST COMMON CAUSES OF THE PROGRESSION OF ASH AND IS ASSOCIATED WITH POOR PROGNOSIS AND LIVER FAILURE. ALCOHOL ABUSE DYSREGULATES THE LIPID HOMEOSTASIS AND CAUSES OXIDATIVE STRESS AND INFLAMMATION IN THE LIVER. CONSEQUENTLY, METABOLIC PATHWAYS STIMULATING HEPATIC ACCUMULATION OF EXCESSIVE LIPID DROPLETS ARE INDUCED. RECENTLY, MANY STUDIES HAVE INDICATED A LINK BETWEEN ASH AND EPIGENETIC CHANGES, SHOWING DIFFERENTIAL EXPRESSION OF ALCOHOL-INDUCED EPIGENETIC GENES IN THE LIVER. HOWEVER, THE SPECIFIC MECHANISMS UNDERLYING THE PATHOGENESIS OF ASH REMAIN ELUSIVE. THUS, WE HERE SUMMARIZE THE CURRENT KNOWLEDGE ABOUT THE ROLES OF EPIGENETICS IN LIPOGENESIS, INFLAMMATION, AND APOPTOSIS IN THE CONTEXT OF ASH PATHOPHYSIOLOGY. ESPECIALLY, WE HIGHLIGHT THE LATEST FINDINGS ON THE ROLES OF SIRTUINS, A CONSERVED FAMILY OF CLASS-III HISTONE DEACETYLASES, IN ASH. ADDITIONALLY, WE DISCUSS THE INVOLVEMENT OF DNA METHYLATION, HISTONE MODIFICATIONS, AND MIRNAS IN ASH AS WELL AS THE ONGOING EFFORTS FOR THE CLINICAL TRANSLATION OF THE FINDINGS IN ASH-RELATED EPIGENETIC CHANGES. 2021 16 2002 24 EPIGENETIC AND POST-TRANSCRIPTIONAL REPRESSION SUPPORT METABOLIC SUPPRESSION IN CHRONICALLY HYPOXIC GOLDFISH. GOLDFISH ENTER A HYPOMETABOLIC STATE TO SURVIVE CHRONIC HYPOXIA. WE RECENTLY DESCRIBED TISSUE-SPECIFIC CONTRIBUTIONS OF MEMBRANE LIPID COMPOSITION REMODELING AND MITOCHONDRIAL FUNCTION TO METABOLIC SUPPRESSION ACROSS DIFFERENT GOLDFISH TISSUES. HOWEVER, THE MOLECULAR AND ESPECIALLY EPIGENETIC FOUNDATIONS OF HYPOXIA TOLERANCE IN GOLDFISH UNDER METABOLIC SUPPRESSION ARE NOT WELL UNDERSTOOD. HERE WE SHOW THAT COMPONENTS OF THE MOLECULAR OXYGEN-SENSING MACHINERY ARE ROBUSTLY ACTIVATED ACROSS TISSUES IRRESPECTIVE OF HYPOXIA DURATION. INDUCTION OF GENE EXPRESSION OF ENZYMES INVOLVED IN DNA METHYLATION TURNOVER AND MICRORNA BIOGENESIS SUGGEST A ROLE FOR EPIGENETIC TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL SUPPRESSION OF GENE EXPRESSION IN THE HYPOXIA-ACCLIMATED BRAIN. CONVERSELY, MECHANISTIC TARGET OF RAPAMYCIN-DEPENDENT TRANSLATIONAL MACHINERY ACTIVITY IS NOT REDUCED IN LIVER AND WHITE MUSCLE, SUGGESTING THIS PATHWAY DOES NOT CONTRIBUTE TO LOWERING CELLULAR ENERGY EXPENDITURE. FINALLY, MOLECULAR EVIDENCE SUPPORTS PREVIOUSLY REPORTED CHRONIC HYPOXIA-DEPENDENT CHANGES IN MEMBRANE CHOLESTEROL, LIPID METABOLISM AND MITOCHONDRIAL FUNCTION VIA CHANGES IN TRANSCRIPTS INVOLVED IN CHOLESTEROL BIOSYNTHESIS, BETA-OXIDATION, AND MITOCHONDRIAL FUSION IN MULTIPLE TISSUES. OVERALL, THIS STUDY SHOWS THAT CHRONIC HYPOXIA ROBUSTLY INDUCES EXPRESSION OF OXYGEN-SENSING MACHINERY ACROSS TISSUES, INDUCES REPRESSIVE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL EPIGENETIC MARKS ESPECIALLY IN THE CHRONIC HYPOXIA-ACCLIMATED BRAIN AND SUPPORTS A ROLE FOR MEMBRANE REMODELING AND MITOCHONDRIAL FUNCTION AND DYNAMICS IN PROMOTING METABOLIC SUPPRESSION. 2022 17 5533 26 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 18 6421 31 THE THERAPEUTIC PROPERTIES OF RESMINOSTAT FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON FORM OF PRIMARY LIVER CANCER WITH INCREASES IN NEW CASES BEING REPORTED ANNUALLY. HISTOPATHOLOGISTS HAVE IDENTIFIED HEPATIC STEATOSIS AS A CHARACTERISTIC OF A BROAD RANGE OF CHRONIC LIVER DISEASES THAT ARE ASSOCIATED WITH THE ONSET AND DEVELOPMENT OF HCC. IN THIS CONTEXT, EPIGENETIC MODIFICATIONS MAY SERVE AS PRECANCEROUS FACTORS PREDISPOSING NORMAL CELLS TO THE INITIATION OF CARCINOGENESIS. THIS STUDY DEMONSTRATED THAT HEPATIC TUMORIGENESIS AND DIFFERENTIATED ADIPOCYTES MAY MODULATE BOTH GLOBAL HISTONE DEACETYLASE (HDAC) EXPRESSION AND SPECIFIC CLASS I HDAC GENES IN THE TUMOUR MICROENVIRONMENT. THE NOVEL CLASS I HDAC INHIBITOR RESMINOSTAT WAS SHOWN TO REDUCE THE PROLIFERATION OF HCC CELLS ALONG WITH ITS SPECIFICITY IN TARGETING CLASS I HDACS AND ONCOGENES. THE COMBINED EFFECT OF RESMINOSTAT WITH SEVERAL PHARMACEUTICAL AGENTS SUCH AS SORAFENIB, CISPLATIN AND DOXORUBICIN WAS ALSO DEMONSTRATED. THE INHIBITION OF HEAT SHOCK PROTEIN 90 (HSP90) HAS BEEN DEMONSTRATED AS A POTENTIAL THERAPEUTIC OPTION FOR HCC. IN LINE WITH THIS, THE SPECIFIC HSP90 INHIBITOR 17-(ALLYLAMINO)-17-DEMETHOXYGELDANAMYCIN (17-AAG) WAS SELECTED AND IT WAS FOUND THAT THE COMBINATION OF RESMINOSTAT AND 17-AAG MAY PROVIDE A "SMART" CLINICAL STRATEGY FOR HCC PATIENTS BY TARGETING CELLULAR COMMUNICATION WITHIN THE TUMOUR MICROENVIRONMENT. THIS STUDY PROVIDES AN INSIGHT INTO THE USE OF RESMINOSTAT AS AN EPIGENETIC BASED THERAPEUTIC FOR HCC ALONG WITH OTHER PHARMACEUTICAL OPTIONS, IN PARTICULAR BY TARGETING THE CELL-TO-CELL COMMUNICATION THAT OCCURS BETWEEN HEPATOMA AND ADIPOCYTES. 2018 19 6106 33 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 20 2323 21 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