1 1619 240 DNA METHYLTRANSFERASE REGULATES NITRIC OXIDE HOMEOSTASIS AND VIRULENCE IN A CHRONICALLY ADAPTED PSEUDOMONAS AERUGINOSA STRAIN. OPPORTUNISTIC PATHOGENS SUCH AS PSEUDOMONAS AERUGINOSA ADAPT THEIR GENOMES RAPIDLY DURING CHRONIC INFECTIONS. UNDERSTANDING THEIR EPIGENETIC REGULATION MAY PROVIDE BIOMARKERS FOR DIAGNOSIS AND REVEAL NOVEL REGULATORY MECHANISMS. WE PERFORMED SINGLE-MOLECULE REAL-TIME SEQUENCING (SMRT-SEQ) TO CHARACTERIZE THE METHYLOME OF A CHRONICALLY ADAPTED P. AERUGINOSA CLINICAL STRAIN, TBCF10839. TWO N(6)-METHYLADENINE (6MA) METHYLATION RECOGNITION MOTIFS (RCCANNNNNNNTGAR AND TRGANNNNNNTGC [MODIFICATION SITES ARE IN BOLD]) WERE IDENTIFIED AND PREDICTED AS NEW TYPE I METHYLATION SITES USING REBASE ANALYSIS. WE CONFIRMED THAT THE MOTIF TRGANNNNNNTGC WAS METHYLATED BY THE METHYLTRANSFERASE (MTASE) M.PAETBCFII, ACCORDING TO METHYLATION SENSITIVITY ASSAYS IN VIVO AND VITRO. TRANSCRIPTOMIC ANALYSIS SHOWED THAT A DELTAPAETBCFIIM KNOCKOUT MUTANT SIGNIFICANTLY DOWNREGULATED NITRIC OXIDE REDUCTASE (NOR) REGULATION AND EXPRESSION OF CODING GENES SUCH AS NOSR AND NORB, WHICH CONTAIN METHYLATED MOTIFS IN THEIR PROMOTERS OR CODING REGIONS. THE DELTAPAETBCFIIM STRAIN EXHIBITED REDUCED INTERCELLULAR SURVIVAL CAPACITY IN NO-PRODUCING RAW264.7 MACROPHAGES AND ATTENUATED VIRULENCE IN A GALLERIA MELLONELLA INFECTION MODEL; THE COMPLEMENTED STRAIN RECOVERED THESE DEFECTIVE PHENOTYPES. FURTHER PHYLOGENETIC ANALYSIS DEMONSTRATED THAT HOMOLOGS OF M.PAETBCFII OCCUR FREQUENTLY IN P. AERUGINOSA AS WELL AS OTHER BACTERIAL SPECIES. OUR WORK THEREFORE PROVIDED NEW INSIGHTS INTO THE RELATIONSHIP BETWEEN DNA METHYLATION, NO DETOXIFICATION, AND BACTERIAL VIRULENCE, LAYING A FOUNDATION FOR FURTHER EXPLORING THE MOLECULAR MECHANISM OF DNA METHYLTRANSFERASE IN REGULATING THE PATHOGENICITY OF P. AERUGINOSA. IMPORTANCE PSEUDOMONAS AERUGINOSA IS AN OPPORTUNISTIC PATHOGEN WHICH CAUSES ACUTE AND CHRONIC INFECTIONS THAT ARE DIFFICULT TO TREAT. COMPARATIVE GENOMIC ANALYSIS HAS SHOWED BROAD GENOME DIVERSITY AMONG P. AERUGINOSA CLINICAL STRAINS AND REVEALED THEIR DIFFERENT REGULATORY TRAITS COMPARED TO THE LABORATORY STRAINS. WHILE CURRENT INVESTIGATION OF THE EPIGENETICS OF P. AERUGINOSA IS STILL LACKING, UNDERSTANDING EPIGENETIC REGULATION MAY PROVIDE BIOMARKERS FOR DIAGNOSIS AND FACILITATE DEVELOPMENT OF NOVEL THERAPIES. DENITRIFICATION CAPABILITY IS CRITICAL FOR MICROBIAL VERSATILITY IN RESPONSE TO DIFFERENT ENVIRONMENTAL STRESS CONDITIONS, INCLUDING THE BACTERIAL INFECTION PROCESS, WHERE NITRIC OXIDE (NO) CAN BE GENERATED BY PHAGOCYTIC CELLS. THE DENITRIFICATION REGULATION MECHANISMS HAVE BEEN STUDIED INTENSIVELY AT GENETIC AND BIOCHEMICAL LEVELS. HOWEVER, THERE IS VERY LITTLE EVIDENCE ABOUT THE EPIGENETIC REGULATION OF BACTERIAL DENITRIFICATION MECHANISM. P. AERUGINOSA TBCF10839 IS A CHRONICALLY HOST-ADAPTED STRAIN ISOLATED FROM A CYSTIC FIBROSIS (CF) PATIENT WITH SPECIAL ANTIPHAGOCYTOSIS CHARACTERISTICS. HERE, WE INVESTIGATED THE REGULATORY EFFECT OF AN ORPHAN DNA MTASE, M.PAETBCFII, IN P. AERUGINOSA TBCF10839. WE DEMONSTRATED THAT THE DNA MTASE REGULATES THE TRANSCRIPTION OF DENITRIFICATION GENES REPRESENTED BY NOR AND AFFECTS ANTIPHAGOCYTIC ABILITY IN BACTERIA. IN SILICO ANALYSIS SUGGESTED THAT DNA METHYLATION MODIFICATION MAY ENHANCE GENE EXPRESSION BY AFFECTING THE BINDING OF TRANSACTING FACTORS SUCH AS DNR AND RPON. OUR FINDINGS NOT ONLY DEEPEN THE UNDERSTANDING OF THE ROLE OF DNA MTASE IN TRANSCRIPTIONAL REGULATION IN P. AERUGINOSA BUT ALSO PROVIDE A THEORETICAL FOUNDATION FOR THE IN-DEPTH STUDY OF THE MOLECULAR MECHANISM OF THE EPIGENETIC REGULATION ON DENITRIFICATION, VIRULENCE, AND HOST-PATHOGEN INTERACTION. 2022 2 5464 40 RESILIENCE IN LONG-TERM VIRAL INFECTION: GENETIC DETERMINANTS AND INTERACTIONS. VIRUS-INDUCED NEUROLOGICAL SEQUELAE RESULTING FROM INFECTION BY THEILER'S MURINE ENCEPHALOMYELITIS VIRUS (TMEV) ARE USED FOR STUDYING HUMAN CONDITIONS RANGING FROM EPILEPTIC SEIZURES TO DEMYELINATING DISEASE. MOUSE STRAINS ARE TYPICALLY CONSIDERED SUSCEPTIBLE OR RESISTANT TO TMEV INFECTION BASED ON VIRAL PERSISTENCE AND EXTREME PHENOTYPES, SUCH AS DEMYELINATION. WE HAVE IDENTIFIED A BROADER SPECTRUM OF PHENOTYPIC OUTCOMES BY INFECTING STRAINS OF THE GENETICALLY DIVERSE COLLABORATIVE CROSS (CC) MOUSE RESOURCE. WE EVALUATED THE CHRONIC-INFECTION GENE EXPRESSION PROFILES OF HIPPOCAMPI AND THORACIC SPINAL CORDS FOR 19 CC STRAINS IN RELATION TO PHENOTYPIC SEVERITY AND TMEV PERSISTENCE. STRAINS WERE CLUSTERED BASED ON SIMILAR PHENOTYPIC PROFILES AND TMEV LEVELS AT 90 DAYS POST-INFECTION, AND WE CATEGORIZED DISTINCT TMEV RESPONSE PROFILES. THE THREE MOST COMMON PROFILES INCLUDED "RESISTANT" AND "SUSCEPTIBLE," AS BEFORE, AS WELL AS A "RESILIENT" TMEV RESPONSE GROUP WHICH EXPERIENCED BOTH TMEV PERSISTENCE AND MILD NEUROLOGICAL PHENOTYPES EVEN AT 90 DAYS POST-INFECTION. EACH PROFILE HAD A DISTINCT GENE EXPRESSION SIGNATURE, ALLOWING THE IDENTIFICATION OF PATHWAYS AND NETWORKS SPECIFIC TO EACH TMEV RESPONSE GROUP. CC FOUNDER HAPLOTYPES FOR GENES INVOLVED IN THESE PATHWAYS/NETWORKS REVEALED CANDIDATE RESPONSE-SPECIFIC ALLELES. THESE ALLELES DEMONSTRATED PLEIOTROPY AND EPIGENETIC (MIRNA) REGULATION IN LONG-TERM TMEV INFECTION, WITH PARTICULAR RELEVANCE FOR RESILIENT MOUSE STRAINS. 2021 3 3764 53 INTEGRATIVE ANALYSIS OF DNA METHYLATION AND GENE EXPRESSION DATA IDENTIFIES EPAS1 AS A KEY REGULATOR OF COPD. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMPLEX DISEASE. GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS ARE KNOWN TO CONTRIBUTE TO COPD RISK AND DISEASE PROGRESSION. THEREFORE WE DEVELOPED A SYSTEMATIC APPROACH TO IDENTIFY KEY REGULATORS OF COPD THAT INTEGRATES GENOME-WIDE DNA METHYLATION, GENE EXPRESSION, AND PHENOTYPE DATA IN LUNG TISSUE FROM COPD AND CONTROL SAMPLES. OUR INTEGRATIVE ANALYSIS IDENTIFIED 126 KEY REGULATORS OF COPD. WE IDENTIFIED EPAS1 AS THE ONLY KEY REGULATOR WHOSE DOWNSTREAM GENES SIGNIFICANTLY OVERLAPPED WITH MULTIPLE GENES SETS ASSOCIATED WITH COPD DISEASE SEVERITY. EPAS1 IS DISTINCT IN COMPARISON WITH OTHER KEY REGULATORS IN TERMS OF METHYLATION PROFILE AND DOWNSTREAM TARGET GENES. GENES PREDICTED TO BE REGULATED BY EPAS1 WERE ENRICHED FOR BIOLOGICAL PROCESSES INCLUDING SIGNALING, CELL COMMUNICATIONS, AND SYSTEM DEVELOPMENT. WE CONFIRMED THAT EPAS1 PROTEIN LEVELS ARE LOWER IN HUMAN COPD LUNG TISSUE COMPARED TO NON-DISEASE CONTROLS AND THAT EPAS1 GENE EXPRESSION IS REDUCED IN MICE CHRONICALLY EXPOSED TO CIGARETTE SMOKE. AS EPAS1 DOWNSTREAM GENES WERE SIGNIFICANTLY ENRICHED FOR HYPOXIA RESPONSIVE GENES IN ENDOTHELIAL CELLS, WE TESTED EPAS1 FUNCTION IN HUMAN ENDOTHELIAL CELLS. EPAS1 KNOCKDOWN BY SIRNA IN ENDOTHELIAL CELLS IMPACTED GENES THAT SIGNIFICANTLY OVERLAPPED WITH EPAS1 DOWNSTREAM GENES IN LUNG TISSUE INCLUDING HYPOXIA RESPONSIVE GENES, AND GENES ASSOCIATED WITH EMPHYSEMA SEVERITY. OUR FIRST INTEGRATIVE ANALYSIS OF GENOME-WIDE DNA METHYLATION AND GENE EXPRESSION PROFILES ILLUSTRATES THAT NOT ONLY DOES DNA METHYLATION PLAY A 'CAUSAL' ROLE IN THE MOLECULAR PATHOPHYSIOLOGY OF COPD, BUT IT CAN BE LEVERAGED TO DIRECTLY IDENTIFY NOVEL KEY MEDIATORS OF THIS PATHOPHYSIOLOGY. 2015 4 1584 36 DNA METHYLATION PROFILES OF SELECTED PRO-INFLAMMATORY CYTOKINES IN ALZHEIMER DISEASE. BY MEANS OF FUNCTIONAL GENOMICS ANALYSIS, WE RECENTLY DESCRIBED THE MRNA EXPRESSION PROFILES OF VARIOUS GENES INVOLVED IN THE NEUROINFLAMMATORY RESPONSE IN THE BRAINS OF SUBJECTS WITH LATE-ONSET ALZHEIMER DISEASE (LOAD). SOME OF THESE GENES, NAMELY INTERLEUKIN (IL)-1BETA AND IL-6, SHOWED DISTINCT EXPRESSION PROFILES WITH PEAK EXPRESSION DURING THE FIRST STAGES OF THE DISEASE AND CONTROL-LIKE LEVELS AT LATER STAGES. IL-1BETA AND IL-6 GENES ARE MODULATED BY DNA METHYLATION IN DIFFERENT CHRONIC AND DEGENERATIVE DISEASES; IT IS ALSO WELL KNOWN THAT LOAD MAY HAVE AN EPIGENETIC BASIS. INDEED, WE AND OTHERS HAVE PREVIOUSLY REPORTED GENE-SPECIFIC DNA METHYLATION ALTERATIONS IN LOAD AND IN RELATED ANIMAL MODELS. BASED ON THESE DATA, WE STUDIED THE DNA METHYLATION PROFILES, AT SINGLE CYTOSINE RESOLUTION, OF IL-1BETA AND IL-6 5'-FLANKING REGION BY BISULPHITE MODIFICATION IN THE CORTEX OF HEALTHY CONTROLS AND LOAD PATIENTS AT 2 DIFFERENT DISEASE STAGES: BRAAK I-II/A AND BRAAK V-VI/C. OUR ANALYSIS PROVIDES EVIDENCE THAT NEUROINFLAMMATION IN LOAD IS ASSOCIATED WITH (AND POSSIBLY MEDIATED BY) EPIGENETIC MODIFICATIONS. 2017 5 3468 56 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 6 1948 66 EPIGENETIC ACQUISITION OF INDUCIBILITY OF TYPE III CYTOTOXICITY IN P. AERUGINOSA. BACKGROUND: PSEUDOMONAS AERUGINOSA, AN OPPORTUNISTIC PATHOGEN, IS OFTEN ENCOUNTERED IN CHRONIC LUNG DISEASES SUCH AS CYSTIC FIBROSIS OR CHRONIC OBSTRUCTIVE PNEUMONIA, AS WELL AS ACUTE SETTINGS LIKE MECHANICAL VENTILATION ACQUIRED PNEUMONIA OR NEUTROPENIC PATIENTS. IT IS A MAJOR CAUSE OF MORTALITY AND MORBIDITY IN THESE DISEASES. IN LUNGS, P. AERUGINOSA SETTLES IN A BIOFILM MODE OF GROWTH WITH THE SECRETION OF EXOPOLYSACCHARIDES IN WHICH IT IS ENCAPSULATED, ENHANCING ITS ANTIBIOTIC RESISTANCE AND CONTRIBUTING TO THE RESPIRATORY DEFICIENCY OF PATIENTS. HOWEVER, BACTERIA MUST FIRST MULTIPLY TO A HIGH DENSITY AND DISPLAY A CYTOTOXIC PHENOTYPE TO AVOID THE HOST'S DEFENCES. A VIRULENCE DETERMINANT IMPLICATED IN THIS STEP OF INFECTION IS THE TYPE III SECRETION SYSTEM (TTSS), ALLOWING TOXIN INJECTION DIRECTLY INTO HOST CELLS. AT THE BEGINNING OF THE INFECTION, MOST STRAINS ISOLATED FROM PATIENTS' LUNGS POSSESS AN INDUCIBLE TTSS ALLOWING TOXINS INJECTION OR SECRETION UPON IN VIVO OR IN VITRO ACTIVATION SIGNALS. AS THE INFECTION PERSISTS MOST OF THE BACTERIA PERMANENTLY LOOSE THIS CAPACITY, ALTHOUGH NO MUTATIONS HAVE BEEN EVIDENCED. WE NAME "NON INDUCIBLE" THIS PHENOTYPE. AS SUGGESTED BY THE PRESENCE OF A POSITIVE FEEDBACK CIRCUIT IN THE REGULATORY NETWORK CONTROLLING TTSS EXPRESSION, IT MAY BE DUE TO AN EPIGENETIC SWITCH ALLOWING HERITABLE PHENOTYPIC MODIFICATIONS WITHOUT GENOTYPE'S MUTATIONS. RESULTS: USING THE GENERALISED LOGICAL METHOD, WE DESIGNED A MINIMAL MODEL OF THE TTSS REGULATORY NETWORK THAT COULD SUPPORT THE EPIGENETIC HYPOTHESIS, AND STUDIED ITS DYNAMICS WHICH HELPED TO DEFINE A DISCRIMINATING EXPERIMENTAL SCENARIO SUFFICIENT TO VALIDATE THE EPIGENETIC HYPOTHESIS. A MATHEMATICAL FRAMEWORK BASED ON FORMAL METHODS FROM COMPUTER SCIENCE ALLOWED A RIGOROUS VALIDATION AND CERTIFICATION OF PARAMETERS OF THIS MODEL LEADING TO EPIGENETIC BEHAVIOUR. THEN, WE DEMONSTRATED THAT A NON INDUCIBLE STRAIN OF P. AERUGINOSA CAN STABLY ACQUIRE THE CAPACITY TO BE INDUCED BY CALCIUM DEPLETION FOR THE TTSS AFTER A SHORT PULSE OF A REGULATORY PROTEIN. FINALLY, THE INCREASED CYTOTOXICITY OF A STRAIN AFTER THIS EPIGENETIC SWITCH WAS DEMONSTRATED IN VIVO IN AN ACUTE PULMONARY INFECTION MODEL. CONCLUSION: THESE RESULTS MAY OFFER NEW PERSPECTIVES FOR THERAPEUTIC STRATEGIES TO PREVENT LETHAL INFECTIONS BY P. AERUGINOSA BY REVERTING THE EPIGENETIC INDUCIBILITY OF TYPE III CYTOTOXICITY. 2006 7 2340 49 EPIGENETIC REGULATION OF LEUKOCYTE INFLAMMATORY MEDIATOR PRODUCTION DICTATES STAPHYLOCOCCUS AUREUS CRANIOTOMY INFECTION OUTCOME. STAPHYLOCOCCUS AUREUS IS A COMMON CAUSE OF SURGICAL-SITE INFECTIONS, INCLUDING THOSE ARISING AFTER CRANIOTOMY, WHICH IS PERFORMED TO ACCESS THE BRAIN FOR THE TREATMENT OF TUMORS, EPILEPSY, OR HEMORRHAGE. CRANIOTOMY INFECTION IS CHARACTERIZED BY COMPLEX SPATIAL AND TEMPORAL DYNAMICS OF LEUKOCYTE RECRUITMENT AND MICROGLIAL ACTIVATION. WE RECENTLY IDENTIFIED UNIQUE TRANSCRIPTIONAL PROFILES OF THESE IMMUNE POPULATIONS DURING S. AUREUS CRANIOTOMY INFECTION. EPIGENETIC PROCESSES ALLOW RAPID AND REVERSIBLE CONTROL OVER GENE TRANSCRIPTION; HOWEVER, LITTLE IS KNOWN ABOUT HOW EPIGENETIC PATHWAYS INFLUENCE IMMUNITY TO LIVE S. AUREUS. AN EPIGENETIC COMPOUND LIBRARY SCREEN IDENTIFIED BROMODOMAIN AND EXTRATERMINAL DOMAIN-CONTAINING (BET) PROTEINS AND HISTONE DEACETYLASES (HDACS) AS CRITICAL FOR REGULATING TNF, IL-6, IL-10, AND CCL2 PRODUCTION BY PRIMARY MOUSE MICROGLIA, MACROPHAGES, NEUTROPHILS, AND GRANULOCYTIC MYELOID-DERIVED SUPPRESSOR CELLS IN RESPONSE TO LIVE S. AUREUS. CLASS I HDACS (C1HDACS) WERE INCREASED IN THESE CELL TYPES IN VITRO AND IN VIVO DURING ACUTE DISEASE IN A MOUSE MODEL OF S. AUREUS CRANIOTOMY INFECTION. HOWEVER, SUBSTANTIAL REDUCTIONS IN C1HDACS WERE OBSERVED DURING CHRONIC INFECTION, HIGHLIGHTING TEMPORAL REGULATION AND THE IMPORTANCE OF THE TISSUE MICROENVIRONMENT FOR DICTATING C1HDAC EXPRESSION. MICROPARTICLE DELIVERY OF HDAC AND BET INHIBITORS IN VIVO CAUSED WIDESPREAD DECREASES IN INFLAMMATORY MEDIATOR PRODUCTION, WHICH SIGNIFICANTLY INCREASED BACTERIAL BURDEN IN THE BRAIN, GALEA, AND BONE FLAP. THESE FINDINGS IDENTIFY HISTONE ACETYLATION AS AN IMPORTANT MECHANISM FOR REGULATING CYTOKINE AND CHEMOKINE PRODUCTION ACROSS DIVERSE IMMUNE CELL LINEAGES THAT IS CRITICAL FOR BACTERIAL CONTAINMENT. ACCORDINGLY, ABERRANT EPIGENETIC REGULATION MAY BE IMPORTANT FOR PROMOTING S. AUREUS PERSISTENCE DURING CRANIOTOMY INFECTION. 2023 8 546 44 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 9 2395 49 EPIGENETIC REPROGRAMMING IN MIST1(-/-) MICE PREDICTS THE MOLECULAR RESPONSE TO CERULEIN-INDUCED PANCREATITIS. GENE EXPRESSION IS AFFECTED BY MODIFICATIONS TO HISTONE CORE PROTEINS WITHIN CHROMATIN. CHANGES IN THESE MODIFICATIONS, OR EPIGENETIC REPROGRAMMING, CAN DICTATE CELL FATE AND PROMOTE SUSCEPTIBILITY TO DISEASE. THE GOAL OF THIS STUDY WAS TO DETERMINE THE EXTENT OF EPIGENETIC REPROGRAMMING IN RESPONSE TO CHRONIC STRESS THAT OCCURS FOLLOWING ABLATION OF MIST1 (MIST1(-/-) ), WHICH IS REPRESSED IN PANCREATIC DISEASE. CHROMATIN IMMUNOPRECIPITATION FOR TRIMETHYLATION OF LYSINE RESIDUE 4 ON HISTONE 3 (H3K4ME3) IN PURIFIED ACINAR CELLS FROM WILD TYPE AND MIST1(-/-) MICE WAS FOLLOWED BY NEXT GENERATION SEQUENCING (CHIP-SEQ) OR CHIP-QPCR. H3K4ME3-ENRICHED GENES WERE ASSESSED FOR EXPRESSION BY QRT-PCR IN PANCREATIC TISSUE BEFORE AND AFTER INDUCTION OF CERULEIN-INDUCED PANCREATITIS. WHILE MOST OF H3K4ME3-ENRICHMENT IS RESTRICTED TO TRANSCRIPTIONAL START SITES, >25% OF ENRICHMENT SITES ARE FOUND WITHIN, DOWNSTREAM OR BETWEEN ANNOTATED GENES. LESS THAN 10% OF THESE SITES WERE ALTERED IN MIST1(-/-) ACINI, WITH MOST CHANGES IN H3K4ME3 ENRICHMENT NOT REFLECTING ALTERED GENE EXPRESSION. INGENUITY PATHWAY ANALYSIS OF GENES DIFFERENTIALLY-ENRICHED FOR H3K4ME3 REVEALED AN ASSOCIATION WITH PANCREATITIS AND PANCREATIC DUCTAL ADENOCARCINOMA IN MIST1(-/-) TISSUE. MOST OF THESE GENES WERE NOT DIFFERENTIALLY EXPRESSED BUT SEVERAL WERE READILY INDUCED BY ACUTE EXPERIMENTAL PANCREATITIS, WITH SIGNIFICANTLY INCREASED EXPRESSION IN MIST1(-/-) TISSUE RELATIVE TO WILD TYPE MICE. WE SUGGEST THAT THE CHRONIC CELL STRESS OBSERVED IN THE ABSENCE OF MIST1 RESULTS IN EPIGENETIC REPROGRAMMING OF GENES INVOLVED IN PROMOTING PANCREATITIS TO A POISED STATE, THEREBY INCREASING THE SENSITIVITY TO EVENTS THAT PROMOTE DISEASE. 2014 10 2776 54 EXTRAUTERINE GROWTH RESTRICTION ON PULMONARY VASCULAR ENDOTHELIAL DYSFUNCTION IN ADULT MALE RATS: THE ROLE OF EPIGENETIC MECHANISMS. OBJECTIVE: EARLY POSTNATAL LIFE IS CONSIDERED AS A CRITICAL TIME WINDOW FOR THE DETERMINATION OF LONG-TERM METABOLIC STATES AND ORGAN FUNCTIONS. EXTRAUTERINE GROWTH RESTRICTION (EUGR) CAUSES THE DEVELOPMENT OF ADULT-ONSET CHRONIC DISEASES, INCLUDING PULMONARY HYPERTENSION. HOWEVER, THE EFFECTS OF NUTRITIONAL DISADVANTAGES DURING THE EARLY POSTNATAL PERIOD ON PULMONARY VASCULAR CONSEQUENCES IN LATER LIFE ARE NOT FULLY UNDERSTOOD. OUR STUDY WAS DESIGNED TO TEST WHETHER EPIGENETICS DYSREGULATION MEDIATES THE CELLULAR MEMORY OF THIS EARLY POSTNATAL EVENT. METHODS AND RESULTS: TO TEST THIS HYPOTHESIS, WE ISOLATED PULMONARY VASCULAR ENDOTHELIAL CELLS BY MAGNETIC-ACTIVATED CELL SORTING FROM EUGR AND CONTROL RATS. A POSTNATAL INSULT, NUTRITIONAL RESTRICTION-INDUCED EUGR CAUSED DEVELOPMENT OF AN INCREASED PULMONARY ARTERY PRESSURE AT 9 WEEKS OF AGE IN MALE SPRAGUE-DAWLEY RATS. METHYL-DNA IMMUNE PRECIPITATION CHIP, GENOME-SCALE MAPPING STUDIES TO SEARCH FOR DIFFERENTIALLY METHYLATED LOCI BETWEEN CONTROL AND EUGR RATS, REVEALED SIGNIFICANT DIFFERENCE IN CYTOSINE METHYLATION BETWEEN EUGR AND CONTROL RATS. EUGR CHANGES THE CYTOSINE METHYLATION AT APPROXIMATELY 500 LOCI IN MALE RATS AT 9 WEEKS OF AGE, PRECEDING THE DEVELOPMENT OF PULMONARY HYPERTENSION AND THESE REPRESENT THE CANDIDATE LOCI FOR MEDIATING THE PATHOGENESIS OF PULMONARY VASCULAR DISEASE THAT OCCURS LATER IN LIFE. GENE ONTOLOGY ANALYSIS ON DIFFERENTIALLY METHYLATED GENES SHOWED THAT HYPERMETHYLATED GENES IN EUGR ARE VASCULAR DEVELOPMENT-ASSOCIATED GENES AND HYPOMETHYLATED GENES IN EUGR ARE LATE-DIFFERENTIATION-ASSOCIATED AND SIGNAL TRANSDUCTION GENES. WE VALIDATED CANDIDATE DYSREGULATED LOCI WITH THE QUANTITATIVE ASSAYS OF CYTOSINE METHYLATION AND GENE EXPRESSIONS. CONCLUSION: THESE RESULTS DEMONSTRATE THAT EPIGENETICS DYSREGULATION IS A STRONG MECHANISM FOR PROPAGATING THE CELLULAR MEMORY OF EARLY POSTNATAL EVENTS, CAUSING CHANGES IN THE EXPRESSION OF GENES AND LONG-TERM SUSCEPTIBILITY TO PULMONARY HYPERTENSION, AND FURTHER PROVIDING A NEW INSIGHT INTO THE PREVENTION AND TREATMENT OF EUGR-RELATED PULMONARY HYPERTENSION. 2014 11 1162 47 CONTRASTING EFFECTS OF ACUTE AND CHRONIC STRESS ON THE TRANSCRIPTOME, EPIGENOME, AND IMMUNE RESPONSE OF ATLANTIC SALMON. STRESS EXPERIENCED DURING EARLY LIFE MAY HAVE LASTING EFFECTS ON THE IMMUNE SYSTEM, WITH IMPACTS ON HEALTH AND DISEASE DEPENDENT ON THE NATURE AND DURATION OF THE STRESSOR. THE EPIGENOME IS ESPECIALLY SENSITIVE TO ENVIRONMENTAL STIMULI DURING EARLY LIFE AND REPRESENTS A POTENTIAL MECHANISM THROUGH WHICH STRESS MAY CAUSE LONG-LASTING HEALTH EFFECTS. HOWEVER, THE EXTENT TO WHICH THE EPIGENOME RESPONDS DIFFERENTLY TO CHRONIC VS ACUTE STRESSORS IS UNCLEAR, ESPECIALLY FOR NON-MAMMALIAN SPECIES. WE EXAMINED THE EFFECTS OF ACUTE STRESS (COLD-SHOCK DURING EMBRYOGENESIS) AND CHRONIC STRESS (ABSENCE OF TANK ENRICHMENT DURING LARVAL-STAGE) ON GLOBAL GENE EXPRESSION (USING RNA-SEQ) AND DNA METHYLATION (USING RRBS) IN THE GILLS OF ATLANTIC SALMON (SALMO SALAR) FOUR MONTHS AFTER HATCHING. CHRONIC STRESS INDUCED PRONOUNCED TRANSCRIPTIONAL DIFFERENCES, WHILE ACUTE STRESS CAUSED FEW LASTING TRANSCRIPTIONAL EFFECTS. HOWEVER, BOTH ACUTE AND CHRONIC STRESS CAUSED LASTING AND CONTRASTING CHANGES IN THE METHYLOME. CRUCIALLY, WE FOUND THAT ACUTE STRESS ENHANCED TRANSCRIPTIONAL IMMUNE RESPONSE TO A PATHOGENIC CHALLENGE (BACTERIAL LIPOPOLYSACCHARIDE, LPS), WHILE CHRONIC STRESS SUPPRESSED IT. WE IDENTIFIED STRESS-INDUCED CHANGES IN PROMOTER AND GENE-BODY METHYLATION THAT WERE ASSOCIATED WITH ALTERED EXPRESSION FOR A SMALL PROPORTION OF IMMUNE-RELATED GENES, AND EVIDENCE OF WIDER EPIGENETIC REGULATION WITHIN SIGNALLING PATHWAYS INVOLVED IN IMMUNE RESPONSE. OUR RESULTS SUGGEST THAT STRESS CAN AFFECT IMMUNO-COMPETENCE THROUGH EPIGENETIC MECHANISMS, AND HIGHLIGHT THE MARKEDLY DIFFERENT EFFECTS OF CHRONIC LARVAL AND ACUTE EMBRYONIC STRESS. THIS KNOWLEDGE COULD BE USED TO HARNESS THE STIMULATORY EFFECTS OF ACUTE STRESS ON IMMUNITY, PAVING THE WAY FOR IMPROVED STRESS AND DISEASE MANAGEMENT THROUGH EPIGENETIC CONDITIONING. 2018 12 1545 56 DNA METHYLATION IN LIVER TUMORIGENESIS IN FISH FROM THE ENVIRONMENT. THE LINK BETWEEN ENVIRONMENT, ALTERATION IN DNA METHYLATION AND CANCER HAS BEEN WELL ESTABLISHED IN HUMANS; YET, IT IS UNDER-STUDIED IN UNSEQUENCED NON-MODEL ORGANISMS. THE OCCURRENCE OF LIVER TUMORS IN THE FLATFISH DAB COLLECTED AT CERTAIN UK SAMPLING SITES EXCEEDS 20%, YET THE CAUSATIVE AGENTS AND THE MOLECULAR MECHANISMS OF TUMOR FORMATION ARE NOT KNOWN, ESPECIALLY REGARDING THE BALANCE BETWEEN EPIGENETIC AND GENETIC FACTORS. METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) COMBINED WITH DE NOVO HIGH-THROUGHPUT DNA SEQUENCING WERE USED TO INVESTIGATE DNA METHYLATION CHANGES IN DAB HEPATOCELLULAR ADENOMA TUMORS FOR THE FIRST TIME IN AN UNSEQUENCED SPECIES. NOVEL CUSTOM-MADE DAB GENE EXPRESSION ARRAYS WERE DESIGNED AND USED TO DETERMINE THE RELATIONSHIP BETWEEN DNA METHYLATION AND GENE EXPRESSION. IN ADDITION, THE CONFIRMATORY TECHNIQUES OF BISULFITE SEQUENCING PCR (BSP) AND RT-PCR WERE APPLIED. GENES INVOLVED IN PATHWAYS RELATED TO CANCER, INCLUDING APOPTOSIS, WNT/BETA-CATENIN SIGNALING AND GENOMIC AND NON-GENOMIC ESTROGEN RESPONSES, WERE ALTERED BOTH IN METHYLATION AND TRANSCRIPTION. GLOBAL METHYLATION WAS STATISTICALLY SIGNIFICANTLY 1.8-FOLD REDUCED IN HEPATOCELLULAR ADENOMA AND NON-CANCEROUS SURROUNDING TISSUES COMPARED WITH LIVER FROM NON-CANCER BEARING DAB. BASED ON THE IDENTIFIED CHANGES AND CHEMICAL EXPOSURE DATA, OUR STUDY SUPPORTS THE EPIGENETIC MODEL OF CANCER. WE HYPOTHESIZE THAT CHRONIC EXPOSURE TO A MIXTURE OF ENVIRONMENTAL CONTAMINANTS CONTRIBUTES TO A GLOBAL HYPOMETHYLATION FOLLOWED BY FURTHER EPIGENETIC AND GENOMIC CHANGES. THE FINDINGS SUGGEST A LINK BETWEEN ENVIRONMENT, EPIGENETICS AND CANCER IN FISH TUMORS IN THE WILD AND SHOW THE UTILITY OF THIS METHODOLOGY FOR STUDIES IN NON-MODEL ORGANISMS. 2011 13 6230 40 THE LONG NONCODING RNA LANDSCAPE IN HYPOXIC AND INFLAMMATORY RENAL EPITHELIAL INJURY. LONG NONCODING RNAS (LNCRNAS) ARE EMERGING AS KEY SPECIES-SPECIFIC REGULATORS OF CELLULAR AND DISEASE PROCESSES. TO IDENTIFY POTENTIAL LNCRNAS RELEVANT TO ACUTE AND CHRONIC RENAL EPITHELIAL INJURY, WE PERFORMED UNBIASED WHOLE TRANSCRIPTOME PROFILING OF HUMAN PROXIMAL TUBULAR EPITHELIAL CELLS (PTECS) IN HYPOXIC AND INFLAMMATORY CONDITIONS. RNA SEQUENCING REVEALED THAT THE PROTEIN-CODING AND NONCODING TRANSCRIPTOMIC LANDSCAPE DIFFERED BETWEEN HYPOXIA-STIMULATED AND CYTOKINE-STIMULATED HUMAN PTECS. HYPOXIA- AND INFLAMMATION-MODULATED LNCRNAS WERE PRIORITIZED FOR FOCUSED FOLLOWUP ACCORDING TO THEIR DEGREE OF INDUCTION BY THESE STRESS STIMULI, THEIR EXPRESSION IN HUMAN KIDNEY TISSUE, AND WHETHER EXPOSURE OF HUMAN PTECS TO PLASMA OF CRITICALLY ILL SEPSIS PATIENTS WITH ACUTE KIDNEY INJURY MODULATED THEIR EXPRESSION. FOR THREE LNCRNAS (MIR210HG, LINC-ATP13A4-8, AND LINC-KIAA1737-2) THAT FULFILLED OUR CRITERIA, WE VALIDATED THEIR EXPRESSION PATTERNS, EXAMINED THEIR LOCI FOR CONSERVATION AND SYNTENY, AND DEFINED THEIR ASSOCIATED EPIGENETIC MARKS. THE LNCRNA LANDSCAPE CHARACTERIZED HERE PROVIDES INSIGHTS INTO NOVEL TRANSCRIPTOMIC VARIATIONS IN THE RENAL EPITHELIAL CELL RESPONSE TO HYPOXIC AND INFLAMMATORY STRESS. 2015 14 4736 49 NOVEL EPIGENETIC BIOMARKERS MEDIATING BISPHENOL A EXPOSURE AND METABOLIC PHENOTYPES IN FEMALE MICE. THERE IS COMPELLING EVIDENCE THAT EPIGENETIC MODIFICATIONS LINK DEVELOPMENTAL ENVIRONMENTAL INSULTS TO ADULT DISEASE SUSCEPTIBILITY. ANIMAL STUDIES HAVE ASSOCIATED PERINATAL BISPHENOL A (BPA) EXPOSURE TO ALTERED DNA METHYLATION, BUT THESE STUDIES ARE OFTEN LIMITED TO CANDIDATE GENE AND GLOBAL NON-LOCI-SPECIFIC APPROACHES. BY USING AN EPIGENOME-WIDE DISCOVERY PLATFORM, WE ELUCIDATED EPIGENETIC ALTERATIONS IN LIVER TISSUE FROM ADULT MICE OFFSPRING (10 MONTHS) FOLLOWING PERINATAL BPA EXPOSURE AT HUMAN PHYSIOLOGICALLY RELEVANT DOSES (50-NG, 50-MUG, AND 50-MG BPA/KG DIET). BIOLOGICAL PATHWAY ANALYSIS IDENTIFIED AN ENRICHMENT OF SIGNIFICANT DIFFERENTIALLY METHYLATED REGIONS IN METABOLIC PATHWAYS AMONG FEMALES. FURTHERMORE, THROUGH THE USE OF TOP ENRICHED BIOLOGICAL PATHWAYS, 4 CANDIDATE GENES WERE CHOSEN TO ASSESS DNA METHYLATION AS A MEDIATING FACTOR LINKING THE ASSOCIATION OF PERINATAL BPA EXPOSURE TO METABOLIC PHENOTYPES PREVIOUSLY OBSERVED IN FEMALE OFFSPRING. DNA METHYLATION STATUS AT JANUS KINASE-2 (JAK-2), RETINOID X RECEPTOR (RXR), REGULATORY FACTOR X-ASSOCIATED PROTEIN (RFXAP), AND TRANSMEMBRANE PROTEIN 238 (TMEM238) WAS USED WITHIN A MEDIATIONAL REGRESSION ANALYSIS. DNA METHYLATION IN ALL FOUR OF THE CANDIDATE GENES WAS IDENTIFIED AS A MEDIATOR IN THE MECHANISTIC PATHWAY OF DEVELOPMENTAL BPA EXPOSURE AND FEMALE-SPECIFIC ENERGY EXPENDITURE, BODY WEIGHT, AND BODY FAT PHENOTYPES. DATA GENERATED FROM THIS STUDY ARE CRUCIAL FOR DECIPHERING THE MECHANISTIC ROLE OF EPIGENETICS IN THE PATHOGENESIS OF CHRONIC DISEASE AND THE DEVELOPMENT OF EPIGENETIC-BASED PREVENTION AND THERAPEUTIC STRATEGIES FOR COMPLEX HUMAN DISEASE. 2017 15 984 49 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 16 2637 53 EPIGENOME-WIDE STUDY IDENTIFIES EPIGENETIC OUTLIERS IN NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. NONGENETIC PREDISPOSITION TO COLORECTAL CANCER CONTINUES TO BE DIFFICULT TO MEASURE PRECISELY, HAMPERING EFFORTS IN TARGETED PREVENTION AND SCREENING. EPIGENETIC CHANGES IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER CAN SERVE AS A TOOL IN PREDICTING COLORECTAL CANCER OUTCOMES. WE IDENTIFIED EPIGENETIC CHANGES AFFECTING THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. DNA METHYLATION PROFILING ON NORMAL COLON MUCOSA FROM 77 PATIENTS WITH COLORECTAL CANCER AND 68 CONTROLS IDENTIFIED A DISTINCT SUBGROUP OF NORMALLY-APPEARING MUCOSA WITH MARKEDLY DISRUPTED DNA METHYLATION AT A LARGE NUMBER OF CPGS, TERMED AS "OUTLIER METHYLATION PHENOTYPE" (OMP) AND ARE PRESENT IN 15 OF 77 PATIENTS WITH CANCER VERSUS 0 OF 68 CONTROLS (P < 0.001). SIMILAR FINDINGS WERE ALSO SEEN IN PUBLICLY AVAILABLE DATASETS. COMPARISON OF NORMAL COLON MUCOSA TRANSCRIPTION PROFILES OF PATIENTS WITH OMP CANCER WITH THOSE OF PATIENTS WITH NON-OMP CANCER INDICATES GENES WHOSE PROMOTERS ARE HYPERMETHYLATED IN THE OMP PATIENTS ARE ALSO TRANSCRIPTIONALLY DOWNREGULATED, AND THAT MANY OF THE GENES MOST AFFECTED ARE INVOLVED IN INTERACTIONS BETWEEN EPITHELIAL CELLS, THE MUCUS LAYER, AND THE MICROBIOME. ANALYSIS OF 16S RRNA PROFILES SUGGESTS THAT NORMAL COLON MUCOSA OF OMPS ARE ENRICHED IN BACTERIAL GENERA ASSOCIATED WITH COLORECTAL CANCER RISK, ADVANCED TUMOR STAGE, CHRONIC INTESTINAL INFLAMMATION, MALIGNANT TRANSFORMATION, NOSOCOMIAL INFECTIONS, AND KRAS MUTATIONS. IN CONCLUSION, OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. PROSPECTIVE STUDIES ARE NEEDED TO DETERMINE WHETHER OMP COULD SERVE AS A BIOMARKER FOR AN ELEVATED EPIGENETIC RISK FOR COLORECTAL CANCER DEVELOPMENT. PREVENTION RELEVANCE: OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. IDENTIFICATION OF OMPS IN HEALTHY CONTROLS AND PATIENTS WITH COLORECTAL CANCER WILL LEAD TO PREVENTION AND BETTER PROGNOSIS, RESPECTIVELY. 2022 17 6137 43 THE EPIGENETICS OF PSYCHOSIS: A STRUCTURED REVIEW WITH REPRESENTATIVE LOCI. THE EVIDENCE FOR AN ENVIRONMENTAL COMPONENT IN CHRONIC PSYCHOTIC DISORDERS IS STRONG AND RESEARCH ON THE EPIGENETIC MANIFESTATIONS OF THESE ENVIRONMENTAL IMPACTS HAS COMMENCED IN EARNEST. IN REVIEWING THIS RESEARCH, THE FOCUS IS ON THREE GENES AS MODELS FOR DIFFERENTIAL METHYLATION, MCHR1, AKT1 AND TDO2, EACH OF WHICH HAVE BEEN INVESTIGATED FOR GENETIC ASSOCIATION WITH PSYCHOTIC DISORDERS. ENVIRONMENTAL FACTORS ASSOCIATED WITH PSYCHOTIC DISORDERS, AND WHICH INTERACT WITH THESE MODEL GENES, ARE EXPLORED IN DEPTH. THE LOCATION OF TRANSCRIPTION FACTOR MOTIFS RELATIVE TO KEY METHYLATION SITES IS EVALUATED FOR PREDICTED GENE EXPRESSION RESULTS, AND FOR OTHER SITES, EVIDENCE IS PRESENTED FOR METHYLATION DIRECTING ALTERNATIVE SPLICING. EXPERIMENTAL RESULTS FROM KEY STUDIES SHOW DIFFERENTIAL METHYLATION: FOR MCHR1, IN PSYCHOSIS CASES VERSUS CONTROLS; FOR AKT1, AS A PRE-EXISTING METHYLATION PATTERN INFLUENCING BRAIN ACTIVATION FOLLOWING ACUTE ADMINISTRATION OF A PSYCHOSIS-ELICITING ENVIRONMENTAL STIMULUS; AND FOR TDO2, IN A PATTERN ASSOCIATED WITH A DEVELOPMENTAL FACTOR OF RISK FOR PSYCHOSIS, IN ALL CASES THE PREDICTED EXPRESSION IMPACT BEING HIGHLY DEPENDENT ON LOCATION. METHYLATION INDUCED BY SMOKING, A CONFOUNDING VARIABLE, EXHIBITS AN INTRIGUING PATTERN FOR ALL THREE GENES. FINALLY, HOW DIFFERENTIAL METHYLATION MESHES WITH DARWINIAN PRINCIPLES IS EXAMINED, IN PARTICULAR AS IT RELATES TO THE "FLEXIBLE STEM" THEORY OF EVOLUTION. 2022 18 5785 41 SPONTANEOUS NEOPLASTIC TRANSFORMATION OF WB-F344 RAT LIVER EPITHELIAL CELLS. SEVERAL STUDIES HAVE SHOWN THAT CULTURED RAT LIVER EPITHELIAL CELLS TRANSFORM SPONTANEOUSLY AFTER CHRONIC MAINTENANCE IN A CONFLUENT STATE IN VITRO. IN THE PRESENT STUDY, MULTIPLE INDEPENDENT LINEAGES OF LOW-PASSAGE WB-F344 RAT LIVER EPITHELIAL STEM-LIKE CELLS WERE INITIATED AND SUBJECTED IN PARALLEL TO SELECTION FOR SPONTANEOUS TRANSFORMATION TO DETERMINE WHETHER SPONTANEOUS ACQUISITION OF TUMORIGENICITY WAS THE RESULT OF EVENTS (GENETIC OR EPIGENETIC) THAT OCCURRED INDEPENDENTLY AND STOCHASTICALLY, OR REFLECTED THE EXPRESSION OF A PRE-EXISTING ALTERATION WITHIN THE PARENTAL WB-F344 CELL LINE. TEMPORAL ANALYSIS OF THE SPONTANEOUS ACQUISITION OF TUMORIGENICITY BY WB-F344 CELLS DEMONSTRATED LINEAGE-SPECIFIC DIFFERENCES IN THE TIME OF FIRST EXPRESSION OF THE TUMORIGENIC PHENOTYPE, FREQUENCIES AND LATENCIES OF TUMOR FORMATION, AND TUMOR DIFFERENTIATIONS. ALTHOUGH SPONTANEOUSLY TRANSFORMED WB-F344 CELLS PRODUCED DIVERSE TUMOR TYPES (INCLUDING HEPATOCELLULAR CARCINOMAS, CHOLANGIOCARCINOMAS, HEPATOBLASTOMAS, AND OSTEOGENIC SARCOMAS), INDIVIDUAL LINEAGES YIELDED TUMORS WITH CONSISTENT AND SPECIFIC PATTERNS OF DIFFERENTIATION. THESE RESULTS PROVIDE SUBSTANTIAL EVIDENCE THAT THE STOCHASTIC ACCUMULATION OF INDEPENDENT TRANSFORMING EVENTS DURING THE SELECTION REGIMEN IN VITRO WERE RESPONSIBLE FOR SPONTANEOUS NEOPLASTIC TRANSFORMATION OF WB-F344 CELLS. FURTHERMORE, CELL LINEAGE COMMITMENT TO A SPECIFIC DIFFERENTIATION PROGRAM WAS STABLE WITH TIME IN CULTURE AND WITH SITE OF TRANSPLANTATION. THIS IS THE FIRST REPORT OF A COHORT OF RELATED, BUT INDEPENDENT, RAT LIVER EPITHELIAL CELL LINES THAT COLLECTIVELY PRODUCE A SPECTRUM OF TUMOR TYPES BUT INDIVIDUALLY REPRODUCE A SPECIFIC TUMOR TYPE. THESE CELL LINES WILL PROVIDE VALUABLE REAGENTS FOR INVESTIGATION OF THE MOLECULAR MECHANISMS INVOLVED IN THE DIFFERENTIATION OF HEPATIC STEM-LIKE CELLS AND FOR EXAMINATION OF POTENTIAL CAUSAL RELATIONSHIPS IN SPONTANEOUSLY TRANSFORMED RAT LIVER EPITHELIAL CELL LINES BETWEEN MOLECULAR/CELLULAR ALTERATIONS AND THE ABILITY TO PRODUCE TUMORS IN SYNGENEIC ANIMALS. 1998 19 6642 41 UNRAVELING THE PATHOGENESIS OF ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE OVERLAP: FOCUSING ON EPIGENETIC MECHANISMS. ASTHMA AND COPD OVERLAP (ACO) IS CHARACTERIZED BY PATIENTS PRESENTING WITH PERSISTENT AIRFLOW LIMITATION AND FEATURES OF BOTH ASTHMA AND COPD. IT IS ASSOCIATED WITH A HIGHER FREQUENCY AND SEVERITY OF EXACERBATIONS, A FASTER LUNG FUNCTION DECLINE, AND A HIGHER HEALTHCARE COST. SYSTEMIC INFLAMMATION IN COPD AND ASTHMA IS DRIVEN BY TYPE 1 T HELPER (TH1) AND TH2 IMMUNE RESPONSES, RESPECTIVELY, BOTH OF WHICH MAY CONTRIBUTE TO AIRWAY REMODELING IN ACO. ACO-RELATED BIOMARKERS CAN BE CLASSIFIED INTO FOUR CATEGORIES: NEUTROPHIL-MEDIATED INFLAMMATION, TH2 CELL RESPONSES, ARACHIDONIC ACID-EICOSANOIDS PATHWAY, AND METABOLITES. GENE-ENVIRONMENT INTERACTIONS ARE KEY CONTRIBUTORS TO THE COMPLEXITY OF ACO AND ARE REGULATED BY EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, AND NON-CODING RNAS. THUS, THIS REVIEW FOCUSES ON THE LINK BETWEEN EPIGENETICS AND ACO, AND OUTLINES THE FOLLOWING: (I) INHERITING EPIGENOTYPES WITHOUT CHANGE WITH ENVIRONMENTAL STIMULI, OR EPIGENETIC CHANGES IN RESPONSE TO LONG-TERM EXPOSURE TO INHALED PARTICLES PLUS INTERMITTENT EXPOSURE TO SPECIFIC ALLERGENS; (II) EPIGENETIC MARKERS DISTINGUISHING ACO FROM COPD AND ASTHMA; (III) POTENTIAL EPIGENETIC DRUGS THAT CAN REVERSE OXIDATIVE STRESS, GLUCOCORTICOID INSENSITIVITY, AND CELL INJURY. IMPROVED UNDERSTANDING OF THE EPIGENETIC REGULATIONS HOLDS GREAT VALUE TO GIVE DEEPER INSIGHT INTO THE MECHANISMS, AND CLARIFY THEIR IMPLICATIONS FOR BIOMEDICAL RESEARCH IN ACO. 2022 20 323 53 ALKBH4 STABILIZATION IS REQUIRED FOR ARSENIC-INDUCED 6MA DNA METHYLATION INHIBITION, KERATINOCYTE MALIGNANT TRANSFORMATION, AND TUMORIGENICITY. INORGANIC ARSENIC IS ONE OF THE WELL-KNOWN HUMAN SKIN CARCINOGENS. HOWEVER, THE MOLECULAR MECHANISM BY WHICH ARSENIC PROMOTES CARCINOGENESIS REMAINS UNCLEAR. PREVIOUS STUDIES HAVE ESTABLISHED THAT EPIGENETIC CHANGES, INCLUDING CHANGES IN DNA METHYLATION, ARE AMONG THE CRITICAL MECHANISMS THAT DRIVE CARCINOGENESIS. N(6)-METHYLADENINE (6MA) METHYLATION ON DNA IS A WIDESPREAD EPIGENETIC MODIFICATION THAT WAS INITIALLY FOUND ON BACTERIAL AND PHAGE DNA. ONLY RECENTLY HAS 6MA BEEN IDENTIFIED IN MAMMALIAN GENOMES. HOWEVER, THE FUNCTION OF 6MA IN GENE EXPRESSION AND CANCER DEVELOPMENT IS NOT WELL UNDERSTOOD. HERE, WE SHOW THAT CHRONIC LOW DOSES OF ARSENIC INDUCE MALIGNANT TRANSFORMATION AND TUMORIGENESIS IN KERATINOCYTES AND LEAD TO THE UPREGULATION OF ALKBH4 AND DOWNREGULATION OF 6MA ON DNA. WE FOUND THAT REDUCED 6MA LEVELS IN RESPONSE TO LOW LEVELS OF ARSENIC WERE MEDIATED BY THE UPREGULATION OF THE 6MA DNA DEMETHYLASE ALKBH4. MOREOVER, WE FOUND THAT ARSENIC INCREASED ALKBH4 PROTEIN LEVELS AND THAT ALKBH4 DELETION IMPAIRED ARSENIC-INDUCED TUMORIGENICITY IN VITRO AND IN MICE. MECHANISTICALLY, WE FOUND THAT ARSENIC PROMOTED ALKBH4 PROTEIN STABILITY THROUGH REDUCED AUTOPHAGY. TOGETHER, OUR FINDINGS REVEAL THAT THE DNA 6MA DEMETHYLASEALKBH4 PROMOTES ARSENIC TUMORIGENICITY AND ESTABLISHES ALKBH4 AS A PROMISING TARGET FOR ARSENIC-INDUCED TUMORIGENESIS. 2022