1 5234 137 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 2 469 43 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 3 6393 30 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 4 413 39 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 5 3243 38 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 6 2427 42 EPIGENETIC SILENCING OF MICRORNA-125B-5P PROMOTES LIVER FIBROSIS IN NONALCOHOLIC FATTY LIVER DISEASE VIA INTEGRIN ALPHA8-MEDIATED ACTIVATION OF RHOA SIGNALING PATHWAY. BACKGROUND: NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS ONE OF THE MOST COMMON CHRONIC LIVER DISEASES THAT MAY PROGRESS TO LIVER FIBROSIS OR CANCER. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLE OF MICRORNA-125B-5P (MIR-125B-5P) IN NAFLD AND TO FURTHER EXPLORE UNDERLYING MOLECULAR MECHANISMS. METHODS: A MOUSE MODEL OF NAFLD WAS CONSTRUCTED BY HIGH CHOLESTEROL DIET FEEDING AND A CELL-MODEL WAS DEVELOPED BY TREATING THE MOUSE LIVER CELL LINE NCTC1469 WITH PALMITIC ACID. GAIN- AND LOSS-OF-FUNCTION EXPERIMENTS WERE PERFORMED TO DETERMINE THE EFFECTS OF MIR-125B-5P, INTEGRIN ALPHA8 (ITGA8), AND THE RHOA SIGNALING PATHWAY ON LIVER FIBROSIS IN NAFLD. AFTER THE EXPRESSION LEVELS OF MIR-125B-5P, ITGA8, AND RHOA WERE DETERMINED, LIVER FIBROSIS WAS EVALUATED IN VIVO AND IN VITRO. THE BINDING RELATIONSHIP OF MIR-125B-5P AND ITGA8 WAS THEN VALIDATED. FINALLY, MIR-125B-5P PROMOTER METHYLATION IN NAFLD LIVER TISSUES AND CELLS WAS DETERMINED. RESULTS: IN NAFLD CLINICAL SAMPLES, MOUSE MODEL, AND CELL-MODEL, MIR-125B-5P EXPRESSION WAS REDUCED, WHILE ITGA8 EXPRESSION WAS INCREASED. MOREOVER, MIR-125B-5P TARGETED AND DOWNREGULATED ITGA8, LEADING TO INHIBITION OF THE RHOA SIGNALING PATHWAY. IN NAFLD LIVER TISSUES AND CELLS, THE CPG ISLAND IN THE MIR-125B-5P PROMOTER WAS METHYLATED, CAUSING EPIGENETIC SILENCING OF MIR-125B-5P. BOTH MIR-125B-5P SILENCING AND ITGA8 OVEREXPRESSION PROMOTED IN VITRO AND IN VIVO LIVER FIBROSIS IN NAFLD VIA ACTIVATION OF THE RHOA SIGNALING PATHWAY. CONCLUSIONS: COLLECTIVELY, EPIGENETIC SILENCING OF MIR-125B-5P UPREGULATES ITGA8 EXPRESSION TO ACTIVATE THE RHOA SIGNALING PATHWAY, LEADING TO LIVER FIBROSIS IN NAFLD. 2020 7 1666 51 DOWNREGULATION OF MICRORNA-145A-5P PROMOTES STEATOSIS-TO-NASH PROGRESSION THROUGH UPREGULATION OF NR4A2. BACKGROUND & AIMS: THE MOLECULAR MECHANISMS UNDERLYING THE PROGRESSION OF SIMPLE STEATOSIS TO NON-ALCOHOLIC STEATOHEPATITIS (NASH) REMAIN INCOMPLETELY UNDERSTOOD, THOUGH THE POTENTIAL ROLE OF EPIGENETIC REGULATION BY MICRORNA (MIRNAS) IS AN AREA OF INCREASING INTEREST. IN THE PRESENT STUDY, WE AIMED TO INVESTIGATE THE ROLE AND MECHANISM OF MIRNAS DURING STEATOSIS-TO-NASH PROGRESSION. METHODS: MIR-145A-5P WAS IDENTIFIED AS AN IMPORTANT CHECKPOINT IN STEATOSIS-TO-NASH PROGRESSION. IN VIVO LOSS-OF-FUNCTION AND GAIN-OF-FUNCTION STUDIES WERE PERFORMED TO EXPLORE THE ROLE OF MIR-145A-5P AND NR4A2 IN NASH PROGRESSION. RNA-SEQUENCING AND BIOINFORMATIC ANALYSIS WERE USED TO INVESTIGATE THE TARGETS OF MIR-145A-5P. RESULTS: SUPPRESSION OF MIR-145A-5P IN THE LIVER AGGRAVATED LIPID ACCUMULATION AND ACTIVATED HEPATIC INFLAMMATION, LIVER INJURY AND FIBROSIS IN STEATOTIC MICE, WHEREAS ITS RESTORATION MARKEDLY ATTENUATED DIET-INDUCED NASH PATHOGENESIS. MECHANISTICALLY, MIR-145A-5P WAS ABLE TO DOWNREGULATE THE NUCLEAR RECEPTOR NR4A2 AND THUS INHIBIT THE EXPRESSION OF NASH-ASSOCIATED GENES. SIMILARLY, NR4A2 OVEREXPRESSION PROMOTED STEATOSIS-TO-NASH PROGRESSION WHILE LIVER-SPECIFIC NR4A2 KNOCKOUT MICE WERE PROTECTED FROM DIET-INDUCED NASH. THIS ROLE OF THE MIR-145A-5P/NR4A2 REGULATORY AXIS WAS ALSO CONFIRMED IN PRIMARY HUMAN HEPATOCYTES. FURTHERMORE, THE EXPRESSION OF MIR-145A-5P WAS REDUCED AND THE EXPRESSION OF NR4A2 WAS INCREASED IN THE LIVERS OF PATIENTS WITH NASH, WHILE THEIR EXPRESSION LEVELS SIGNIFICANTLY NEGATIVELY AND POSITIVELY CORRELATED WITH FEATURES OF LIVER PATHOLOGY, RESPECTIVELY. CONCLUSIONS: OUR FINDINGS HIGHLIGHT THE ROLE OF THE MIR-145A-5P/NR4A2 REGULATORY AXIS IN STEATOSIS-TO-NASH PROGRESSION, SUGGESTING THAT EITHER SUPPLEMENTATION OF MIR-145A-5P OR PHARMACOLOGICAL INHIBITION OF NR4A2 IN HEPATOCYTES MAY PROVIDE A PROMISING THERAPEUTIC APPROACH FOR THE TREATMENT OF NASH. IMPACT AND IMPLICATIONS: NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A DYNAMIC SPECTRUM OF CHRONIC LIVER DISEASES RANGING FROM SIMPLE STEATOSIS TO NON-ALCOHOLIC STEATOHEPATITIS (NASH). UNFORTUNATELY, THERE ARE CURRENTLY NO APPROVED DRUGS FOR NASH. OUR CURRENT STUDY IDENTIFIED MIR-145A-5P AS A NOVEL REGULATOR THAT INHIBITS STEATOSIS-TO-NASH PROGRESSION. WE FOUND THAT MIR-145A-5P WAS ABLE TO DOWNREGULATE THE NUCLEAR RECEPTOR NR4A2 TO SUPPRESS THE EXPRESSION OF NASH-ASSOCIATED GENES. THE DIFFERENTIAL EXPRESSION OF MIR-145A-5P AND NR4A2 WAS FURTHER CONFIRMED IN PATIENTS WITH NASH, RAISING THE POSSIBILITY THAT SUPPLEMENTATION OF MIR-145A-5P OR SUPPRESSION OF NR4A2 IN HEPATOCYTES MIGHT PROVIDE NOVEL STRATEGIES FOR TREATING NASH. 2023 8 1615 33 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 9 4286 44 MICRORNA EXPRESSION ANALYSIS IN HIGH FAT DIET-INDUCED NAFLD-NASH-HCC PROGRESSION: STUDY ON C57BL/6J MICE. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON MALIGNANT TUMOR OF THE LIVER. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A FREQUENT CHRONIC LIVER DISORDER IN DEVELOPED COUNTRIES. NAFLD CAN PROGRESS THROUGH THE MORE SEVERE NON ALCOHOLIC STEATOHEPATITIS (NASH), CIRRHOSIS AND, LASTLY, HCC. GENETIC AND EPIGENETIC ALTERATIONS OF CODING GENES AS WELL AS DEREGULATION OF MICRORNAS (MIRNAS) ACTIVITY PLAY A ROLE IN HCC DEVELOPMENT. IN THIS STUDY, THE C57BL/6J MOUSE MODEL WAS LONG TERM HIGH-FAT (HF) OR LOW-FAT (LF) DIET FED, IN ORDER TO ANALYZE MOLECULAR MECHANISMS RESPONSIBLE FOR THE HEPATIC DAMAGE PROGRESSION. METHODS: MICE WERE HF OR LF DIET FED FOR DIFFERENT TIME POINTS, THEN PLASMA AND HEPATIC TISSUES WERE COLLECTED. HISTOLOGICAL AND CLINICAL CHEMISTRY ASSAYS WERE PERFORMED TO ASSESS THE PROGRESSION OF LIVER DISEASE. MICRORNAS' DIFFERENTIAL EXPRESSION WAS EVALUATED ON POOLED RNAS FROM TISSUES, AND SOME MIRNAS SHOWING DYSREGULATION WERE FURTHER ANALYZED AT THE INDIVIDUAL LEVEL. RESULTS: CHOLESTEROL, LOW AND HIGH DENSITY LIPOPROTEINS, TRIGLYCERIDES AND ALANINE AMINOTRANSFERASE INCREASE WAS DETECTED IN HF MICE. GROSS ANATOMICAL EXAMINATION REVEALED HEPATOMEGALY IN HF LIVERS, AND HISTOLOGICAL ANALYSIS HIGHLIGHTED DIFFERENT DEGREES AND LEVELS OF STEATOSIS, INFLAMMATORY INFILTRATE AND FIBROSIS IN HF AND LF ANIMALS, DEMONSTRATING THE PROGRESSION FROM NAFLD THROUGH NASH. MACROSCOPIC NODULES, SHOWING TYPICAL NEOPLASTIC FEATURES, WERE OBSERVED IN 20% OF HF DIET FED MICE. FIFTEEN MIRNAS DIFFERENTIALLY EXPRESSED IN HF WITH RESPECT TO LF HEPATIC TISSUES DURING THE PROGRESSION OF LIVER DAMAGE, AND IN TUMORS WITH RESPECT TO HF NON TUMOR LIVER SPECIMENS WERE IDENTIFIED. AMONG THEM, MIR-340-5P, MIR-484, MIR-574-3P, MIR-720, WHOSE EXPRESSION WAS NEVER DESCRIBED IN NAFLD, NASH AND HCC TISSUES, AND MIR-125A-5P AND MIR-182, WHICH SHOWED EARLY AND SIGNIFICANT DYSREGULATION IN THE SEQUENTIAL HEPATIC DAMAGE PROCESS. CONCLUSIONS: IN THIS STUDY, FIFTEEN MICRORNAS WHICH WERE MODULATED IN HEPATIC TISSUES AND IN TUMORS DURING THE TRANSITION NAFLD-NASH-HCC ARE REPORTED. BESIDES SOME ALREADY DESCRIBED, NEW AND EARLY DYSREGULATED MIRNAS WERE IDENTIFIED. FUNCTIONAL ANALYSES ARE NEEDED TO VALIDATE THE RESULTS HERE OBTAINED, AND TO BETTER DEFINE THE ROLE OF THESE MOLECULES IN THE PROGRESSION OF THE HEPATIC DISEASE. 2016 10 6092 37 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 11 5890 42 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 1022 41 CIRCULAR RNA HSA_CIRC_0098181 INHIBITS METASTASIS IN HEPATOCELLULAR CARCINOMA BY ACTIVATING THE HIPPO SIGNALING PATHWAY VIA INTERACTION WITH EEF2. INTRODUCTION AND OBJECTIVES: THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IS A MULTI-STEP PROCESS THAT ACCUMULATES GENETIC AND EPIGENETIC ALTERATIONS, INCLUDING CHANGES IN CIRCULAR RNA (CIRCRNA). THIS STUDY AIMED TO UNDERSTAND THE ALTERATIONS IN CIRCRNA EXPRESSION IN HCC DEVELOPMENT AND METASTASIS AND TO EXPLORE THE BIOLOGICAL FUNCTIONS OF CIRCRNA. MATERIALS AND METHODS: TEN PAIRS OF ADJACENT CHRONIC HEPATITIS TISSUES AND HCC TISSUES FROM PATIENTS WITHOUT VENOUS METASTASES, AND TEN HCC TISSUES FROM PATIENTS WITH VENOUS METASTASES WERE ANALYZED USING HUMAN CIRCRNA MICROARRAYS. DIFFERENTIALLY EXPRESSED CIRCRNAS WERE THEN VALIDATED BY QUANTITATIVE REAL-TIME PCR. IN VITRO AND IN VIVO ASSAYS WERE PERFORMED TO ASSESS THE ROLES OF THE CIRCRNA IN HCC PROGRESSION. RNA PULL-DOWN ASSAY, MASS SPECTROMETRY ANALYSIS, AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION WERE CONDUCTED TO EXPLORE THE PROTEIN PARTNERS OF THE CIRCRNA. RESULTS: CIRCRNA MICROARRAYS REVEALED THAT THE EXPRESSION PATTERNS OF CIRCRNAS ACROSS THE THREE GROUPS WERE SIGNIFICANTLY DIFFERENT. AMONG THESE, HSA_CIRC_0098181 WAS VALIDATED TO BE LOWLY EXPRESSED AND ASSOCIATED WITH POOR PROGNOSIS IN HCC PATIENTS. ECTOPIC EXPRESSION OF HSA_CIRC_0098181 DELAYED HCC METASTASIS IN VITRO AND IN VIVO. MECHANISTICALLY, HSA_CIRC_0098181 SEQUESTERED EUKARYOTIC TRANSLATION ELONGATION FACTOR 2 (EEF2) AND DISSOCIATED EEF2 FROM FILAMENTOUS ACTIN (F-ACTIN) TO PREVENT F-ACTIN FORMATION, WHICH BLOCKED ACTIVATION OF THE HIPPO SIGNALING PATHWAY. IN ADDITION, THE RNA BINDING PROTEIN QUAKING-5 BOUND DIRECTLY TO HSA_CIRC_0098181 AND INDUCED ITS BIOGENESIS. CONCLUSIONS: OUR STUDY REVEALS CHANGES IN CIRCRNA EXPRESSION FROM CHRONIC HEPATITIS, PRIMARY HCC, TO METASTATIC HCC. FURTHER, THE QKI5-HSA_CIRC_0098181-EEF2-HIPPO SIGNALING PATHWAY EXERTS A REGULATORY ROLE IN HCC. 2023 13 3354 42 HISTONE DEMETHYLATION PROFILES IN NONALCOHOLIC FATTY LIVER DISEASE AND PROGNOSTIC VALUES IN HEPATOCELLULAR CARCINOMA: A BIOINFORMATIC ANALYSIS. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE MOST COMMON CHRONIC LIVER DISEASE WITH MULTIFACTORIAL PATHOGENESIS; HISTONE DEMETHYLASES (HDMS) ARE EMERGING AS ATTRACTIVE TARGETS. WE IDENTIFIED HDM GENES (INCLUDING KDM5C, KDM6B, KDM8, KDM4A, AND JMJD7) THAT WERE DIFFERENTIALLY EXPRESSED IN NAFLD AND NORMAL SAMPLES BY EXPLORING GENE EXPRESSION PROFILING DATASETS. THERE WAS NO SIGNIFICANT DIFFERENCE IN THE EXPRESSION OF GENES RELATED TO HISTONE DEMETHYLATION BETWEEN MILD AND ADVANCED NAFLD. IN VITRO AND IN VIVO STUDIES INDICATED THAT KDM6B AND JMJD7 WERE UPREGULATED AT THE MRNA LEVEL IN NAFLD. WE EXPLORED THE EXPRESSION LEVELS AND PROGNOSTIC VALUES OF THE IDENTIFIED HDM GENES IN HEPATOCELLULAR CARCINOMA (HCC). KDM5C AND KDM4A WERE UPREGULATED IN HCC COMPARED TO NORMAL TISSUE, WHILE KDM8 SHOWED DOWNREGULATION. THE ABNORMAL EXPRESSION LEVELS OF THESE HDMS COULD PROVIDE PROGNOSTIC VALUES. FURTHERMORE, KDM5C AND KDM4A WERE ASSOCIATED WITH IMMUNE CELL INFILTRATION IN HCC. HDMS WERE ASSOCIATED WITH CELLULAR AND METABOLIC PROCESSES AND MAY BE INVOLVED IN THE REGULATION OF GENE EXPRESSION. DIFFERENTIALLY EXPRESSED HDM GENES IDENTIFIED IN NAFLD MAY PROVIDE VALUE TO UNDERSTANDING PATHOGENESIS AND IN THE DEVELOPMENT OF EPIGENETIC THERAPEUTIC TARGETS. HOWEVER, ON THE BASIS OF THE INCONSISTENT RESULTS OF IN VITRO STUDIES, FUTURE IN VIVO EXPERIMENTS COMBINED WITH TRANSCRIPTOMIC ANALYSIS ARE NEEDED FOR FURTHER VALIDATION. 2023 14 222 32 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 15 1021 31 CIRCULAR RNA AS AN EPIGENETIC REGULATOR IN CHRONIC LIVER DISEASES. CIRCULAR RNA (CIRCRNA) IS A TYPE OF NON-CODING RNA CHARACTERIZED BY A COVALENTLY CLOSED CONTINUOUS LOOP. CIRCRNA IS GENERATED BY PRE-MRNA THROUGH BACK-SPLICING AND IS PROBABLY CLEARED UP BY EXTRACELLULAR VESICLES. CIRCRNAS PLAY A PIVOTAL ROLE IN THE EPIGENETIC REGULATION OF GENE EXPRESSION AT TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL LEVELS. RECENTLY, CIRCRNAS HAVE BEEN DEMONSTRATED TO BE INVOLVED IN THE REGULATION OF LIVER HOMEOSTASIS AND DISEASES. HOWEVER, THE EPIGENETIC ROLE AND UNDERLYING MECHANISMS OF CIRCRNAS IN CHRONIC LIVER DISEASES REMAIN UNCLEAR. THIS REVIEW DISCUSSED THE ROLE OF CIRCRNAS IN NON-NEOPLASTIC CHRONIC LIVER DISEASES, INCLUDING ALCOHOLIC LIVER DISEASE (ALD), METABOLIC-ASSOCIATED FATTY LIVER DISEASE (MAFLD), VIRAL HEPATITIS, LIVER INJURY AND REGENERATION, LIVER CIRRHOSIS, AND AUTOIMMUNE LIVER DISEASE. THE REVIEW ALSO HIGHLIGHTED THAT FURTHER EFFORTS ARE URGENTLY NEEDED TO DEVELOP CIRCRNAS AS NOVEL DIAGNOSTICS AND THERAPEUTICS FOR CHRONIC LIVER DISEASES. 2021 16 1131 44 COMPREHENSIVE CIRCULAR RNA EXPRESSION PROFILING WITH ASSOCIATED CERNA NETWORK REVEALS THEIR THERAPEUTIC POTENTIAL IN CHOLESTEATOMA. CHOLESTEATOMA IS A CHRONIC DISEASE THAT PATHOLOGICALLY DISPLAYS A BENIGN TUMOR WITH EXCESSIVE SQUAMOUS EPITHELIAL CELL PROLIFERATION IN THE MIDDLE EAR. CLINICALLY, HOWEVER, IT CAN MANIFEST MALIGNANT BEHAVIOR BY DESTROYING ADJACENT TISSUES AND ORGANS. ALTHOUGH PREVIOUS STUDIES HAVE DEMONSTRATED THAT THE PATHOGENESIS OF CHOLESTEATOMA IS CORRELATED WITH EPIGENETIC DYSREGULATION, THE EXACT MECHANISM REMAINS UNCLEAR. CIRCULAR RNAS (CIRCRNAS) HAVE BEEN REVEALED AS BEING ABUNDANTLY EXPRESSED IN VARIOUS ORGANISMS AND HAVE BEEN FOUND TO CONTRIBUTE TO THE REGULATION OF MANY DISEASES. TO DATE, NO REPORTS HAVE ELUCIDATED THEIR EXPRESSION PROFILES AND FUNCTIONS IN CHOLESTEATOMA. IN THE PRESENT STUDY, THE CIRCRNA EXPRESSION PROFILE IN CHOLESTEATOMA WAS EXPLORED FOR THE FIRST TIME BY USING MICROARRAY ANALYSIS. WE OBTAINED A TOTAL OF 355 SIGNIFICANTLY DIFFERENTIALLY EXPRESSED CIRCRNAS IN CHOLESTEATOMA, AMONG WHICH 101 WERE IDENTIFIED TO BE UPREGULATED AND 254 DOWNREGULATED. BY CONSTRUCTING CIRCRNA?LNCRNA?MIRNA?MRNA COMPETING ENDOGENOUS RNA (CERNA) NETWORK, IT WAS DISCOVERED THAT CIRCRNAS MAY FUNCTION AS CERNAS AND CONTRIBUTE TO THE FORMATION OF CHOLESTEATOMA. THESE RESULTS PROVIDE NOVEL INSIGHT INTO THE PATHOGENESIS OF CHOLESTEATOMA AND SUGGEST CIRCRNAS AS POTENTIAL PROMISING THERAPEUTIC TARGETS FOR CHOLESTEATOMA. 2020 17 4105 23 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 18 5571 32 ROLE OF MICRORNA 1207-5P AND ITS HOST GENE, THE LONG NON-CODING RNA PVT1, AS MEDIATORS OF EXTRACELLULAR MATRIX ACCUMULATION IN THE KIDNEY: IMPLICATIONS FOR DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY IS THE MOST COMMON CAUSE OF CHRONIC KIDNEY FAILURE AND END-STAGE RENAL DISEASE IN THE WESTERN WORLD. ONE OF THE MAJOR CHARACTERISTICS OF THIS DISEASE IS THE EXCESSIVE ACCUMULATION OF EXTRACELLULAR MATRIX (ECM) IN THE KIDNEY GLOMERULI. WHILE BOTH ENVIRONMENTAL AND GENETIC DETERMINANTS ARE RECOGNIZED FOR THEIR ROLE IN THE DEVELOPMENT OF DIABETIC NEPHROPATHY, EPIGENETIC FACTORS, SUCH AS DNA METHYLATION, LONG NON-CODING RNAS, AND MICRORNAS, HAVE ALSO RECENTLY BEEN FOUND TO UNDERLIE SOME OF THE BIOLOGICAL MECHANISMS, INCLUDING ECM ACCUMULATION, LEADING TO THE DISEASE. WE PREVIOUSLY FOUND THAT A LONG NON-CODING RNA, THE PLASMACYTOMA VARIANT TRANSLOCATION 1 (PVT1), INCREASES PLASMINOGEN ACTIVATOR INHIBITOR 1 (PAI-1) AND TRANSFORMING GROWTH FACTOR BETA 1 (TGF-BETA1) IN MESANGIAL CELLS, THE TWO MAIN CONTRIBUTORS TO ECM ACCUMULATION IN THE GLOMERULI UNDER HYPERGLYCEMIC CONDITIONS, AS WELL AS FIBRONECTIN 1 (FN1), A MAJOR ECM COMPONENT. HERE, WE REPORT THAT MIR-1207-5P, A PVT1-DERIVED MICRORNA, IS ABUNDANTLY EXPRESSED IN KIDNEY CELLS, AND IS UPREGULATED BY GLUCOSE AND TGF-BETA1. WE ALSO FOUND THAT LIKE PVT1, MIR-1207-5P INCREASES EXPRESSION OF TGF-BETA1, PAI-1, AND FN1 BUT IN A MANNER THAT IS INDEPENDENT OF ITS HOST GENE. IN ADDITION, REGULATION OF MIR-1207-5P EXPRESSION BY GLUCOSE AND TGFBETA1 IS INDEPENDENT OF PVT1. THESE RESULTS PROVIDE EVIDENCE SUPPORTING IMPORTANT ROLES FOR MIR-1207-5P AND ITS HOST GENE IN THE COMPLEX PATHOGENESIS OF DIABETIC NEPHROPATHY. 2013 19 3752 33 INTEGRATED ANALYSIS OF CIRCRNAS AND MRNAS EXPRESSION PROFILE REVEALED THE INVOLVEMENT OF HSA_CIRC_0007919 IN THE PATHOGENESIS OF ULCERATIVE COLITIS. BACKGROUND: ULCERATIVE COLITIS (UC) IS CHARACTERIZED BY CHRONIC INFLAMMATION IN THE COLON AND EPIGENETIC FACTORS UNDERLYING THE OCCURRENCE. CIRCULAR RNAS (CIRCRNAS) HAVE BEEN UNDER INTENSIVE FOCUS DUE TO THE CIRCULAR CONSTRUCT AND GENE-REGULATING FUNCTIONS. HOWEVER, THE CHANGES AND ROLES OF CIRCRNAS IN UC REMAIN UNKNOWN. METHODS: MICROARRAYS WERE USED TO DETECT THE DIFFERENTIALLY EXPRESSED GENES, AND QUANTITATIVE REAL-TIME PCR WAS USED TO IDENTIFY THE CHANGES IN UC. IN SILICO ANALYSES WERE PERFORMED TO PREDICT THE FUNCTIONS OF CIRCRNAS AND MRNAS. IN VITRO, EPITHELIAL CELL LINES WERE STIMULATED BY PRO-INFLAMMATION EFFECTORS TO TEST THE ALTERATIONS IN CIRCRNAS. CIRCRNAS-MICRORNAS-MRNAS NETWORK CLARIFIED THE POTENTIAL MECHANISMS UNDERLYING CIRCRNAS IN UC. THE BINDING SITE BETWEEN HSA_CIRC_0007919 AND MIR-138 OR LET-7A WAS VERIFIED USING DUAL-LUCIFERASE ASSAY. RESULTS: A TOTAL OF 264 SIGNIFICANTLY DYSREGULATED CIRCRNAS AND 1869 DIFFERENTIALLY EXPRESSED MRNAS IN INFLAMED MUCOSA WERE COMPARED WITH THE NON-INFLAMED MUCOSA IN UC. HSA_CIRC_0004662 AND HSA_CIRC_0007919 WERE ALTERED LARGELY IN UC TISSUES. HSA_CIRC_0007919 WAS REDUCED PERSISTENTLY AFTER INFLAMMATORY TREATMENTS, AND IT WAS RELEVANT TO MAYO ENDOSCOPIC SUBSCORES AND THE EXPRESSION OF TIGHT JUNCTION MOLECULES. FINALLY, HSA_CIRC_0007919 COULD HARBOR MIR-138, AND LET-7A TO REGULATE THE TARGETED MRNAS EPC1 AND VIPR1. CONCLUSIONS: SEVERAL CIRCRNAS WERE DIFFERENTIALLY EXPRESSED IN UC. HSA_CIRC_0007919 IS RELATED TO CLINICAL CHARACTERISTICS AND EPITHELIAL INTEGRITY BY BINDING TO HSA-LET-7A, HSA-MIR-138 TO REGULATE THE TARGET GENES. CIRCRNAS, ESPECIALLY HSA_CIRC_0007919, ARE ASSOCIATED WITH THE PATHOGENESIS AND DEVELOPMENT OF UC, WITH POTENTIAL DIAGNOSTIC AND THERAPEUTIC IMPLICATIONS. 2019 20 2780 29 EZH2 DOWN-REGULATION EXACERBATES LIPID ACCUMULATION AND INFLAMMATION IN IN VITRO AND IN VIVO NAFLD. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS ONE OF THE MOST PREVALENT, CHRONIC LIVER DISEASES, WORLDWIDE. IT IS A MULTIFACTORIAL DISEASE CAUSED BY COMPLEX INTERACTIONS BETWEEN GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. RECENTLY, SEVERAL MICRORNAS, SOME OF WHICH EPIGENETICALLY REGULATED, HAVE BEEN FOUND TO BE UP- AND/OR DOWN-REGULATED DURING NAFLD DEVELOPMENT. HOWEVER, IN NAFLD, THE ESSENTIAL ROLE OF THE POLYCOMB GROUP PROTEIN ENHANCER OF ZESTE HOMOLOG 2 (EZH2), WHICH CONTROLS THE EPIGENETIC SILENCING OF SPECIFIC GENES AND/OR MICRORNAS BY TRIMETHYLATING LYS27 ON HISTONE H3, STILL REMAINS UNKNOWN. IN THIS STUDY, WE DEMONSTRATE THAT THE NUCLEAR EXPRESSION/ACTIVITY OF THE EZH2 PROTEIN IS DOWN-REGULATED BOTH IN LIVERS FROM NAFLD RATS AND IN THE FREE FATTY ACID-TREATED HEPG2. THE DROP IN EZH2 IS INVERSELY CORRELATED WITH: (I) LIPID ACCUMULATION; (II) THE EXPRESSION OF PRO-INFLAMMATORY MARKERS INCLUDING TNF-ALPHA AND TGF-BETA; AND (III) THE EXPRESSION OF MIR-200B AND MIR-155. CONSISTENTLY, THE PHARMACOLOGICAL INHIBITION OF EZH2 BY 3-DEAZANEPLANOCIN A (DZNEP) SIGNIFICANTLY REDUCES EZH2 EXPRESSION/ACTIVITY, WHILE IT INCREASES LIPID ACCUMULATION, INFLAMMATORY MOLECULES AND MICRORNAS. IN CONCLUSION, THE RESULTS OF THIS STUDY SUGGEST THAT THE DEFECTIVE ACTIVITY OF EZH2 CAN ENHANCE THE NAFLD DEVELOPMENT BY FAVOURING STEATOSIS AND THE DE-REPRESSION OF THE INFLAMMATORY GENES AND THAT OF SPECIFIC MICRORNAS. 2013