1 947 135 CHRONIC MEHG EXPOSURE MODIFIES THE HISTONE H3K4ME3 EPIGENETIC LANDSCAPE IN CAENORHABDITIS ELEGANS. METHYLMERCURY (MEHG) IS A PERSISTENT ENVIRONMENTAL POLLUTANT THAT OCCURS IN THE FOOD CHAIN, AT OCCUPATIONAL SITES, AND VIA MEDICAL PROCEDURES. EXPOSURE IN HUMANS AND ANIMAL MODELS RESULTS IN RENAL, NEURO, AND REPRODUCTIVE TOXICITIES. IN THIS STUDY, WE DEMONSTRATE THAT CHRONIC EXPOSURE TO MEHG (10MUM) CAUSES EPIGENETIC LANDSCAPE MODIFICATIONS OF HISTONE H3K4 TRIMETHYLATION (H3K4ME3) MARKS IN CAENORHABDITIS ELEGANS USING CHROMATIN IMMUNO-PRECIPITATION SEQUENCING (CHIP-SEQ). THE MODIFICATIONS CORRESPOND TO THE LOCATIONS OF 1467 GENES WITH ENHANCED AND 508 GENES WITH REDUCED SIGNALS. AMONG ENHANCED GENES ARE THOSE ENCODING GLUTATHIONE-S-TRANSFERASES, LIPOCALIN-RELATED PROTEIN AND A CUTICULAR COLLAGEN. CHIP-SEQ ENHANCEMENT OF THESE GENES WAS CONFIRMED WITH INCREASED MRNA EXPRESSION LEVELS REVEALED BY QRT-PCR. FURTHERMORE, WE OBSERVED ENHANCEMENT OF H3K4ME3 MARKS IN THESE GENES IN ANIMALS EXPOSED TO MEHG IN UTERO AND ASSAYED AT L4 STAGE. IN UTERO EXPOSURE ENHANCED MARKS WITHOUT ALTERATIONS IN MRNA EXPRESSION EXCEPT FOR THE LPR-5 GENE. FINALLY, KNOCKDOWN OF LIPOCALIN-RELATED PROTEIN GENE LPR-5, WHICH IS INVOLVED IN INTERCELLULAR SIGNALING, AND CUTICULAR COLLAGEN GENE DPY-7, STRUCTURAL COMPONENT OF THE CUTICLE, BY RNA INTERFERENCE (RNAI) RESULTED IN INCREASED LETHALITY OF ANIMALS AFTER MEHG EXPOSURE. OUR RESULTS PROVIDE NEW DATA ON THE EPIGENETIC LANDSCAPE CHANGES ELICITED BY MEHG EXPOSURE, AS WELL AS DESCRIBE A UNIQUE MODEL FOR STUDYING IN UTERO EFFECTS OF HEAVY METALS. TOGETHER, THESE FINDINGS MAY HELP TO UNDERSTAND THE TOXICOLOGICAL EFFECTS OF MEHG AT THE MOLECULAR LEVEL. 2017 2 3570 39 IMPACT OF JUVENILE HORMONE ANALOGUE INSECTICIDES ON THE WATER FLEA MOINA MACROCOPA: GROWTH, REPRODUCTION AND TRANSGENERATIONAL EFFECT. THE INCREASING QUANTITIES OF INSECTICIDES THAT LEACH INTO WATER BODIES SEVERELY AFFECT THE HEALTH OF THE AQUATIC ENVIRONMENT. JUVENILE HORMONE ANALOGUE (JHA) INSECTICIDES ARE ENDOCRINE DISRUPTERS THAT INTERFERE WITH HORMONAL ACTIVITY IN INSECTS BY MIMICKING JUVENILE HORMONES (JHS). BECAUSE THE STRUCTURE AND FUNCTIONS OF METHYL FARNESOATE IN CRUSTACEANS ARE SIMILAR TO THE INSECT JHS, EXOGENOUS JHA INSECTICIDES MAY CAUSE ADVERSE EFFECTS ON THE GROWTH AND REPRODUCTION IN CRUSTACEANS SIMILAR TO THOSE OBSERVED IN INSECTS. THIS STUDY EXAMINED THE TOXIC EFFECTS OF TWO JHA INSECTICIDES, METHOPRENE AND FENOXYCARB, ON THE WATER FLEA MOINA MACROCOPA. THE 24-H AND 48-H LC(50) VALUES FOR FENOXYCARB AND METHOPRENE WERE 0.53 AND 0.32 MG/L AND 0.70 AND 0.54 MG/L, RESPECTIVELY. CHRONIC EXPOSURE TO THE TWO JHAS CAUSED A SERIES OF TOXIC EFFECTS IN M. MACROCOPA, INCLUDING SHORTENING OF LIFE EXPECTANCY, REPRESSION OF BODY GROWTH, REDUCTION IN FECUNDITY, AND DISTURBED THE EXPRESSION OF GENES INVOLVED IN THE JH SIGNALING PATHWAY, IN CUTICLE DEVELOPMENT, AND IN THE CARBOHYDRATE, AMINO ACID, AND ATP METABOLIC PROCESSES. MOREOVER, JHA EXPOSURE IMPAIRED THE GROWTH AND REPRODUCTION OF THE OFFSPRING OF M. MACROCOPA EXPOSED TO JHAS, EVEN WHEN THE NEONATES WERE NOT EXPOSED TO THE CHEMICALS. IN ADDITION, CHANGES IN THE EXPRESSION OF GENES RELATED TO HISTONE METHYLATION INDICATE THAT EPIGENETIC CHANGES MAY PROMOTE TRANSGENERATIONAL IMPAIRMENT IN M. MACROCOPA. THESE RESULTS DEMONSTRATE THE TOXIC EFFECTS OF FENOXYCARB AND METHOPRENE ON NON-TARGET AQUATIC ORGANISMS. THE DAMAGES DONE BY THESE JHA INSECTICIDES TO THE AQUATIC ENVIRONMENT IS WORTHY OF OUR ATTENTION AND FURTHER STUDIES. 2020 3 4180 41 MERCURY EXPOSURE INDUCES CYTOSKELETON DISRUPTION AND LOSS OF RENAL FUNCTION THROUGH EPIGENETIC MODULATION OF MMP9 EXPRESSION. MERCURY IS ONE OF THE MAJOR HEAVY METAL POLLUTANTS OCCURRING IN ELEMENTAL, INORGANIC AND ORGANIC FORMS. DUE TO BAN ON MOST INORGANIC MERCURY CONTAINING PRODUCTS, HUMAN EXPOSURE TO MERCURY GENERALLY OCCURS AS METHYLMERCURY (MEHG) BY CONSUMPTION OF CONTAMINATED FISH AND OTHER SEA FOOD. ANIMAL AND EPIDEMIOLOGICAL STUDIES INDICATE THAT MEHG AFFECTS NEURAL AND RENAL FUNCTION. OUR STUDY IS FOCUSED ON NEPHROTOXIC POTENTIAL OF MEHG. IN THIS STUDY, WE HAVE SHOWN FOR THE FIRST TIME HOW MEHG COULD EPIGENETICALLY MODULATE MATRIX METALLOPROTEINASE 9(MMP9) TO PROMOTE NEPHROTOXICITY USING AN ANIMAL MODEL OF SUB CHRONIC MEHG EXPOSURE. MEHG CAUSED RENAL TOXICITY AS WAS SEEN BY INCREASED LEVELS OF SERUM CREATININE AND EXPRESSION OF EARLY NEPHROTOXICITY MARKERS (KIM-1, CLUSTERIN, IP-10, AND TIMP). MEHG EXPOSURE ALSO CORRELATED STRONGLY WITH INDUCTION OF MMP9 MRNA AND PROTEIN IN A DOSE DEPENDENT MANNER. FURTHER, WHILE INDUCTION OF MMP9 PROMOTED CYTOSKELETON DISRUPTION AND LOSS OF CELL-CELL ADHESION (LOSS OF F-ACTIN, VIMENTIN AND FIBRONECTIN), INHIBITION OF MMP9 WAS FOUND TO REDUCE THESE DISRUPTIONS. MECHANISTIC STUDIES BY CHIP ANALYSIS SHOWED THAT MEHG MODULATED MMP9 BY PROMOTING DEMETHYLATION OF ITS REGULATORY REGION TO INCREASE ITS EXPRESSION. BISULFITE SEQUENCING IDENTIFIED CRITICAL CPGS IN THE FIRST EXON OF MMP9 WHICH WERE DEMETHYLATED FOLLOWING MEHG EXPOSURE. CHIP STUDIES ALSO SHOWED LOSS OF METHYL BINDING PROTEIN, MECP2 AND TRANSCRIPTION FACTOR PEA3 AT THE DEMETHYLATED SITE CONFIRMING DECREASED CPG METHYLATION. OUR STUDIES THUS SHOW HOW MEHG COULD EPIGENETICALLY MODULATE MMP9 TO PROMOTE CYTOSKELETON DISRUPTION LEADING TO LOSS OF RENAL FUNCTION. 2017 4 871 35 CHRONIC ALCOHOL EXPOSURE AFFECTS PANCREATIC ACINAR MITOCHONDRIAL THIAMIN PYROPHOSPHATE UPTAKE: STUDIES WITH MOUSE 266-6 CELL LINE AND PRIMARY CELLS. THIAMIN IS ESSENTIAL FOR NORMAL METABOLIC ACTIVITY OF ALL MAMMALIAN CELLS, INCLUDING THOSE OF THE PANCREAS. CELLS OBTAIN THIAMIN FROM THEIR SURROUNDINGS AND ENZYMATICALLY CONVERT IT INTO THIAMIN PYROPHOSPHATE (TPP) IN THE CYTOPLASM; TPP IS THEN TAKEN UP BY MITOCHONDRIA VIA A SPECIFIC CARRIER THE MITOCHONDRIAL TPP TRANSPORTER (MTPPT; PRODUCT OF THE SLC25A19 GENE). CHRONIC ALCOHOL EXPOSURE NEGATIVELY IMPACTS THE HEALTH OF PANCREATIC ACINAR CELLS (PAC), BUT ITS EFFECT ON PHYSIOLOGICAL/MOLECULAR PARAMETERS OF MTPPT IS NOT KNOWN. WE ADDRESSED THIS ISSUE USING MOUSE PANCREATIC ACINAR TUMOR CELL LINE 266-6 AND PRIMARY PAC OF WILD-TYPE AND TRANSGENIC MICE CARRYING THE SLC25A19 PROMOTER THAT WERE FED ALCOHOL CHRONICALLY. CHRONIC ALCOHOL EXPOSURE OF 266-6 CELLS (BUT NOT TO ITS NONOXIDATIVE METABOLITES ETHYL PALMITATE AND ETHYL OLEATE) LED TO A SIGNIFICANT INHIBITION IN MITOCHONDRIAL TPP UPTAKE, WHICH WAS ASSOCIATED WITH A DECREASED EXPRESSION OF MTPPT PROTEIN, MRNA, AND ACTIVITY OF THE SLC25A19 PROMOTER. SIMILARLY, CHRONIC ALCOHOL FEEDING OF MICE LED TO A SIGNIFICANT INHIBITION IN EXPRESSION OF MTPPT PROTEIN, MRNA, HETEROGENEOUS NUCLEAR RNA, AS WELL AS IN ACTIVITY OF SLC25A19 PROMOTER IN PAC. WHILE CHRONIC ALCOHOL EXPOSURE DID NOT AFFECT DNA METHYLATION OF THE SLC25A19 PROMOTER, A SIGNIFICANT DECREASE IN HISTONE H3 EUCHROMATIN MARKERS AND AN INCREASE IN H3 HETEROCHROMATIN MARKER WERE OBSERVED. THESE FINDINGS SHOW, FOR THE FIRST TIME, THAT CHRONIC ALCOHOL EXPOSURE NEGATIVELY IMPACTS PANCREATIC MTPPT, AND THAT THIS EFFECT IS EXERTED, AT LEAST IN PART, AT THE LEVEL OF SLC25A19 TRANSCRIPTION AND APPEARS TO INVOLVE EPIGENETIC MECHANISM(S). 2015 5 3715 36 INHERITED EFFECTS OF LOW-DOSE EXPOSURE TO METHYLMERCURY IN NEURAL STEM CELLS. METHYLMERCURY (MEHG) IS AN ENVIRONMENTAL CONTAMINANT WITH RECOGNIZED NEUROTOXIC EFFECTS, PARTICULARLY TO THE DEVELOPING NERVOUS SYSTEM. IN THE PRESENT STUDY, WE SHOW THAT NANOMOLAR CONCENTRATIONS OF MEHG CAN INDUCE LONG-LASTING EFFECTS IN NEURAL STEM CELLS (NSCS). WE INVESTIGATED SHORT-TERM DIRECT AND LONG-TERM INHERITED EFFECTS OF EXPOSURE TO MEHG (2.5 OR 5.0 NM) USING PRIMARY CULTURES OF RAT EMBRYONIC CORTICAL NSCS. WE FOUND THAT MEHG HAD NO ADVERSE EFFECT ON CELL VIABILITY BUT REDUCED NSC PROLIFERATION AND ALTERED THE EXPRESSION OF CELL CYCLE REGULATORS (P16 AND P21) AND SENESCENCE-ASSOCIATED MARKERS. IN ADDITION, WE DEMONSTRATED A DECREASE IN GLOBAL DNA METHYLATION IN THE EXPOSED CELLS, INDICATING THAT EPIGENETIC CHANGES MAY BE INVOLVED IN THE MECHANISMS UNDERLYING THE MEHG-INDUCED EFFECTS. THESE CHANGES WERE OBSERVED IN CELLS DIRECTLY EXPOSED TO MEHG (PARENT CELLS) AND IN THEIR DAUGHTER CELLS CULTURED UNDER MEHG-FREE CONDITIONS. IN AGREEMENT WITH OUR IN VITRO DATA, A TREND WAS FOUND FOR DECREASED CELL PROLIFERATION IN THE SUBGRANULAR ZONE IN THE HIPPOCAMPI OF ADULT MICE EXPOSED TO LOW DOSES OF MEHG DURING THE PERINATAL PERIOD. INTERESTINGLY, THIS IMPAIRED PROLIFERATION HAD A MEASURABLE IMPACT ON THE TOTAL NUMBER OF NEURONS IN THE HIPPOCAMPAL DENTATE GYRUS. IMPORTANTLY, THIS EFFECT COULD BE REVERSED BY CHRONIC ANTIDEPRESSANT TREATMENT. OUR STUDY PROVIDES NOVEL EVIDENCE FOR PROGRAMMING EFFECTS INDUCED BY MEHG IN NSCS AND SUPPORTS THE IDEA THAT DEVELOPMENTAL EXPOSURE TO LOW LEVELS OF MEHG MAY RESULT IN LONG-TERM CONSEQUENCES PREDISPOSING TO NEURODEVELOPMENTAL DISORDERS AND/OR NEURODEGENERATION. 2012 6 3971 37 LONG-LASTING NEUROTOXIC EFFECTS OF EXPOSURE TO METHYLMERCURY DURING DEVELOPMENT. AMONGST ENVIRONMENTAL CHEMICAL CONTAMINANTS, METHYLMERCURY (MEHG) REMAINS A MAJOR CONCERN BECAUSE OF ITS DETRIMENTAL EFFECTS ON DEVELOPING ORGANISMS, WHICH APPEAR TO BE PARTICULARLY SUSCEPTIBLE TO ITS TOXICITY. HERE, WE INVESTIGATED THE EFFECTS OF LOW MEHG LEVELS ON THE DEVELOPMENT OF THE NERVOUS SYSTEM USING BOTH IN VITRO AND IN VIVO EXPERIMENTAL MODELS. IN NEURAL STEM CELLS (NSCS), MEHG DECREASED PROLIFERATION AND NEURONAL DIFFERENTIATION AND INDUCED CELLULAR SENESCENCE ASSOCIATED WITH IMPAIRMENT IN MITOCHONDRIAL FUNCTION AND A CONCOMITANT DECREASE IN GLOBAL DNA METHYLATION. INTERESTINGLY, THE EFFECTS WERE HERITABLE AND COULD BE OBSERVED IN DAUGHTER NSCS NEVER DIRECTLY EXPOSED TO MEHG. BY CHRONICALLY EXPOSING PREGNANT/LACTATING MICE TO MEHG, WE FOUND PERSISTENT BEHAVIOURAL CHANGES IN THE MALE OFFSPRING, WHICH EXHIBITED DEPRESSION-LIKE BEHAVIOUR THAT COULD BE REVERSED BY CHRONIC TREATMENT WITH THE ANTIDEPRESSANT FLUOXETINE. THE BEHAVIOURAL ALTERATIONS WERE ASSOCIATED WITH A DECREASED NUMBER OF PROLIFERATING CELLS AND LOWER EXPRESSION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) MRNA IN THE HIPPOCAMPAL DENTATE GYRUS. MEHG EXPOSURE ALSO INDUCED LONG-LASTING DNA HYPERMETHYLATION, INCREASED HISTONE H3-K27 TRI-METHYLATION AND DECREASED H3 ACETYLATION AT THE BDNF PROMOTER IV, INDICATING THAT EPIGENETIC MECHANISMS PLAY A CRITICAL ROLE IN MEDIATING THE LONG-LASTING EFFECTS OF PERINATAL EXPOSURE TO MEHG. FLUOXETINE TREATMENT RESTORED THE BDNF MRNA EXPRESSION LEVELS, AS WELL AS THE NUMBER OF PROLIFERATING CELLS IN THE GRANULE CELL LAYER OF THE DENTATE GYRUS, WHICH FURTHER SUPPORTS THE HYPOTHESIS THAT LINKS DEPRESSION TO IMPAIRED NEUROGENESIS. ALTOGETHER, OUR FINDINGS HAVE SHOWN THAT LOW CONCENTRATIONS OF MEHG INDUCE LONG-LASTING EFFECTS IN NSCS THAT CAN POTENTIALLY PREDISPOSE INDIVIDUALS TO DEPRESSION, WHICH WE HAVE REPORTED EARLIER TO OCCUR IN EXPERIMENTAL ANIMALS EXPOSED TO MEHG DURING PRENATAL AND EARLY POSTNATAL DEVELOPMENT. 2013 7 2484 37 EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES IN TWO GENERATIONS OF DAPHNIA MAGNA EXPOSED TO THE DNA METHYLATION INHIBITOR 5-AZACYTIDINE. THE WATER FLEA DAPHNIA MAGNA IS A KEYSTONE SPECIES IN FRESHWATER ECOSYSTEMS AND HAS BEEN WIDELY USED AS A MODEL ORGANISM IN ENVIRONMENTAL ECOTOXICOLOGY. THIS AQUATIC CRUSTACEAN IS SENSITIVE TO ENVIRONMENTAL STRESSORS AND DISPLAYS CONSIDERABLE PLASTICITY IN ADAPTING TO CHANGING ENVIRONMENTAL CONDITIONS. PART OF THIS PLASTICITY MAY BE DUE TO EPIGENETIC REGULATION OF GENE EXPRESSION, INCLUDING CHANGES TO DNA METHYLATION AND HISTONE MODIFICATIONS. BECAUSE OF THE GENERALLY HYPOMETHYLATED GENOME OF THIS SPECIES, WE HYPOTHESIZED THAT THE HISTONE CODE MAY HAVE AN ESSENTIAL ROLE IN THE EPIGENETIC CONTROL AND THAT HISTONE MODIFICATIONS MIGHT BE AN EARLY MARKER FOR STRESS. THIS STUDY AIMS TO CHARACTERIZE THE EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES AND THEIR CAUSAL LINKAGES IN DIRECTLY EXPOSED ADULT (F0) DAPHNIA AND PERITONEAL EXPOSED NEONATES (F1) AFTER A CHRONIC (7-DAY) EXPOSURE TO A SUBLETHAL CONCENTRATION (10 MG/L) OF 5-AZACYTIDINE, A WELL-STUDIED VERTEBRATE DNA METHYLATION INHIBITOR. EXPOSURE OF THE F0 GENERATION SIGNIFICANTLY REDUCED THE CUMULATIVE FECUNDITY, ACCOMPANIED WITH DIFFERENTIAL EXPRESSION OF GENES IN THE ONE-CARBON-CYCLE METABOLIC PATHWAY. IN THE EPIGENOME OF THE F0 GENERATION, A DECREASE IN GLOBAL DNA METHYLATION, BUT NO SIGNIFICANT CHANGES ON H3K4ME3 OR H3K27ME3, WERE OBSERVED. IN THE F1 OFFSPRING GENERATION, CHANGES IN GENE EXPRESSION, A SIGNIFICANT REDUCTION IN GLOBAL DNA METHYLATION AND CHANGES IN HISTONE MODIFICATIONS WERE IDENTIFIED. THE RESULTS INDICATE THAT EXPOSURE DURING ADULTHOOD MAY RESULT IN MORE PRONOUNCED EFFECTS ON EARLY DEVELOPMENT IN THE OFFSPRING GENERATION, THOUGH INTERPRETATION OF THE DATA SHOULD BE CAREFULLY DONE SINCE BOTH THE EXPOSURE REGIME AND DEVELOPMENTAL PERIOD IS DIFFERENT IN THE TWO GENERATIONS EXAMINED. THE OBTAINED RESULTS IMPROVE OUR UNDERSTANDING OF CRUSTACEAN EPIGENETICS AND THE TOOLS DEVELOPED MAY PROMOTE USE OF EPIGENETIC MARKERS IN HAZARD ASSESSMENT OF ENVIRONMENTAL STRESSORS. 2019 8 3727 36 INHIBITION OF PANCREATIC ACINAR MITOCHONDRIAL THIAMIN PYROPHOSPHATE UPTAKE BY THE CIGARETTE SMOKE COMPONENT 4-(METHYLNITROSAMINO)-1-(3-PYRIDYL)-1-BUTANONE. THIAMIN IS ESSENTIAL FOR NORMAL METABOLISM IN PANCREATIC ACINAR CELLS (PAC) AND IS OBTAINED FROM THEIR MICROENVIRONMENT THROUGH SPECIFIC PLASMA-MEMBRANE TRANSPORTERS, CONVERTED TO THIAMIN PYROPHOSPHATE (TPP) IN THE CYTOPLASM, FOLLOWED BY UPTAKE OF TPP BY MITOCHONDRIA THROUGH THE MITOCHONDRIAL TPP (MTPP) TRANSPORTER (MTPPT; PRODUCT OF SLC25A19 GENE). TPP IS ESSENTIAL FOR NORMAL MITOCHONDRIAL FUNCTION. WE EXAMINED THE EFFECT OF LONG-TERM/CHRONIC EXPOSURE OF PAC IN VITRO (PANCREATIC ACINAR 266-6 CELLS) AND IN VIVO (WILD-TYPE OR TRANSGENIC MICE CARRYING THE SLC25A19 PROMOTER) OF THE CIGARETTE SMOKE TOXIN, 4-(METHYLNITROSAMINO)-1-(3-PYRIDYL)-1-BUTANONE (NNK), ON THE MTPP UPTAKE PROCESS. OUR IN VITRO AND IN VIVO FINDINGS DEMONSTRATE THAT NNK NEGATIVELY AFFECTS MTPP UPTAKE AND REDUCED EXPRESSION OF MTPPT PROTEIN, MTPPT MRNA, AND HETEROGENOUS NUCLEAR RNA, AS WELL AS SLC25A19 PROMOTER ACTIVITY. THE EFFECT OF NNK ON SLC25A19 TRANSCRIPTION WAS NEITHER MEDIATED BY CHANGES IN EXPRESSION OF TRANSCRIPTIONAL FACTOR NFY-1 (KNOWN TO DRIVE SLC25A19 TRANSCRIPTION), NOR DUE TO CHANGES IN METHYLATION PROFILE OF THE SLC25A19 PROMOTER. RATHER, IT APPEARS TO BE DUE TO CHANGES IN HISTONE MODIFICATIONS THAT INVOLVE SIGNIFICANT DECREASES IN HISTONE H3K4-TRIMETHYLATION AND H3K9-ACETYLATION (ACTIVATION MARKERS). THE EFFECT OF NNK ON MTPPT FUNCTION IS MEDIATED THROUGH THE NONNEURONAL ALPHA7-NICOTINIC ACETYLCHOLINE RECEPTOR (ALPHA7-NACHR), AS INDICATED BY BOTH IN VITRO (USING THE NACHR ANTAGONIST MECAMYLAMINE) AND IN VIVO (USING AN ALPHA7-NACHR(-/-) MOUSE MODEL) STUDIES. THESE FINDINGS DEMONSTRATE THAT CHRONIC EXPOSURE OF PAC TO NNK NEGATIVELY IMPACTS PAC MTPP UPTAKE. THIS EFFECT APPEARS TO BE EXERTED AT THE LEVEL OF SLC25A19 TRANSCRIPTION, INVOLVE EPIGENETIC MECHANISM(S), AND IS MEDIATED THROUGH THE ALPHA7-NACHR. 2016 9 3619 34 IN VIVO ACUTE ON CHRONIC ETHANOL EFFECTS IN LIVER: A MOUSE MODEL EXHIBITING EXACERBATED INJURY, ALTERED METABOLIC AND EPIGENETIC RESPONSES. CHRONIC ALCOHOLICS WHO ALSO BINGE DRINK (I.E., ACUTE ON CHRONIC) ARE PRONE TO AN EXACERBATED LIVER INJURY BUT ITS MECHANISM IS NOT UNDERSTOOD. WE THEREFORE INVESTIGATED THE IN VIVO EFFECTS OF CHRONIC AND BINGE ETHANOL INGESTION AND COMPARED TO CHRONIC ETHANOL FOLLOWED BY THREE REPEAT BINGE ETHANOL ON THE LIVER OF MALE C57/BL6 MICE FED ETHANOL IN LIQUID DIET (4%) FOR FOUR WEEKS FOLLOWED BY BINGE ETHANOL (INTRAGASTRIC ADMINISTRATION, 3.5 G/KG BODY WEIGHT, THREE DOSES, 12H APART). CHRONIC FOLLOWED BY BINGE ETHANOL EXACERBATED FAT ACCUMULATION, NECROSIS, DECREASE IN HEPATIC SAM AND SAM:SAH RATIO, INCREASE IN ADENOSINE LEVELS, AND ELEVATED CYP2E1 LEVELS. HISTONE H3 LYSINE ACETYLATION (H3ACK9), DUALLY MODIFIED PHOSPHOACETYLATED HISTONE H3 (H3ACK9/PS10), AND PHOSPHORYLATED H2AX INCREASED AFTER BINGE WHEREAS PHOSPHORYLATION OF HISTONE H3 SER 10 (H3S10) AND H3 SER 28 (H3S28) INCREASED AFTER CHRONIC ETHANOL-BINGE. HISTONE H3 LYSINE 4 AND 9 DIMETHYLATION INCREASED WITH A MARKED DIMETHYLATION IN H3K9 IN CHRONIC ETHANOL BINGE GROUP. TRIMETHYLATED HISTONE H3 LEVELS DID NOT CHANGE. NUCLEAR LEVELS OF HISTONE ACETYL TRANSFERASE GCN5 AND HISTONE DEACETYLASE HDAC3 WERE ELEVATED WHEREAS PHOSPHO-CREB DECREASED IN A DISTINCTIVE MANNER. TAKEN TOGETHER, ACUTE ON CHRONIC ETHANOL INGESTION CAUSED AMPLIFICATION OF LIVER INJURY AND ELICITED CHARACTERISTIC PROFILES OF HISTONE MODIFICATIONS, METABOLIC ALTERATIONS, AND CHANGES IN NUCLEAR PROTEIN LEVELS. THESE FINDINGS DEMONSTRATE THAT CHRONIC ETHANOL EXPOSURE RENDERS LIVER MORE SUSCEPTIBLE TO REPEAT ACUTE/BINGE ETHANOL INDUCED ACCELERATION OF ALCOHOLIC LIVER DISEASE. 2015 10 166 33 ABNORMAL OVARIAN DNA METHYLATION PROGRAMMING DURING GONAD MATURATION IN WILD CONTAMINATED FISH. THERE IS INCREASING EVIDENCE THAT POLLUTANTS MAY CAUSE DISEASES VIA EPIGENETIC MODIFICATIONS. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION PARTICIPATE IN THE REGULATION OF GENE TRANSCRIPTION. SURPRISINGLY, EPIGENETICS RESEARCH IS STILL LIMITED IN ECOTOXICOLOGY. IN THIS STUDY, WE INVESTIGATED WHETHER CHRONIC EXPOSURE TO CONTAMINANTS EXPERIENCED BY WILD FEMALE FISH (ANGUILLA ANGUILLA) THROUGHOUT THEIR JUVENILE PHASE CAN AFFECT THE DNA METHYLATION STATUS OF THEIR OOCYTES DURING GONAD MATURATION. THUS, FISH WERE SAMPLED IN TWO LOCATIONS PRESENTING A LOW OR A HIGH CONTAMINATION LEVEL. THEN, FISH WERE TRANSFERRED TO THE LABORATORY AND ARTIFICIALLY MATURED. BEFORE HORMONAL TREATMENT, THE DNA METHYLATION LEVELS OF THE GENES ENCODING FOR THE AROMATASE AND THE RECEPTOR OF THE FOLLICLE STIMULATING HORMONE WERE HIGHER IN CONTAMINATED FISH THAN IN FISH FROM THE CLEAN SITE. FOR THE HORMONE RECEPTOR, THIS HYPERMETHYLATION WAS POSITIVELY CORRELATED WITH THE CONTAMINATION LEVEL OF FISH AND WAS ASSOCIATED WITH A DECREASE IN ITS TRANSCRIPTION LEVEL. IN ADDITION, WHEREAS GONAD GROWTH WAS ASSOCIATED WITH AN INCREASE IN DNA METHYLATION IN FISH FROM THE CLEAN SITE, NO CHANGES WERE OBSERVED IN CONTAMINATED FISH IN RESPONSE TO HORMONAL TREATMENT. FINALLY, A HIGHER GONAD GROWTH WAS OBSERVED IN FISH FROM THE REFERENCE SITE IN COMPARISON TO CONTAMINATED FISH. 2014 11 5531 22 RNAI THERAPEUTICS: AN ANTIVIRAL STRATEGY FOR HUMAN INFECTIONS. GENE SILENCING INDUCED BY RNAI REPRESENTS A PROMISING ANTIVIRAL DEVELOPMENT STRATEGY. THIS REVIEW WILL SUMMARISE THE CURRENT STATE OF RNAI THERAPEUTICS FOR TREATING ACUTE AND CHRONIC HUMAN VIRUS INFECTIONS. THE GENE SILENCING PATHWAYS EXPLOITED BY RNAI THERAPEUTICS WILL BE DESCRIBED AND INCLUDE BOTH CLASSIC RNAI, INDUCING CYTOPLASMIC MRNA DEGRADATION POST-TRANSCRIPTION AND NOVEL RNAI, MEDIATING EPIGENETIC MODIFICATIONS AT THE TRANSCRIPTION LEVEL IN THE NUCLEUS. FINALLY, THE CHALLENGE OF DELIVERING GENE MODIFICATIONS VIA RNAI WILL BE DISCUSSED, ALONG WITH THE UNIQUE CHARACTERISTICS OF RESPIRATORY VERSUS SYSTEMIC ADMINISTRATION ROUTES TO HIGHLIGHT RECENT ADVANCES AND FUTURE POTENTIAL OF RNAI ANTIVIRAL TREATMENT STRATEGIES. 2020 12 4076 40 MATERNAL HIGH-FAT DIET MODIFIES EPIGENETIC MARKS H3K27ME3 AND H3K27AC IN BONE TO REGULATE OFFSPRING OSTEOBLASTOGENESIS IN MICE. STUDIES FROM BOTH HUMANS AND ANIMAL MODELS INDICATED THAT MATERNAL CHRONIC POOR-QUALITY DIET, ESPECIALLY A HIGH FAT DIET (HFD), IS SIGNIFICANTLY ASSOCIATED WITH REDUCED BONE DENSITY AND CHILDHOOD FRACTURES IN OFFSPRING. WHEN PREVIOUSLY STUDIED IN A RAT MODEL, OUR DATA SUGGESTED THAT MATERNAL HFD CHANGES EPIGENETIC MARKS SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS TO CONTROL OSTEOBLAST METABOLISM. IN MOUSE EMBRYONIC AND POSTNATAL OFFSPRING BONE SAMPLES, A CHIP-SEQUENCING (CHIP-SEQ)-BASED GENOME-WIDE METHOD WAS USED TO LOCATE THE REPRESSIVE HISTONE MARK H3K27ME3 (MEDIATED VIA THE POLYCOMB HISTONE METHYLTRANSFERASE, EZH2) AND EXPRESSIVE HISTONE MARK H3K27AC (P300/CBP MEDIATED) THROUGHOUT THE GENOME. USING ISOLATED MOUSE EMBRYONIC CELLS FROM FOETAL CALVARIA (OSTEOBLAST-LIKE CELLS), H3K27ME3 CHIP-SEQ SHOWED THAT 147 GENE BODIES AND 26 GENE PROMOTERS IN HFD EMBRYOTIC SAMPLES HAD A GREATER THAN TWOFOLD INCREASE IN H3K27ME PEAKS COMPARED TO CONTROLS. AMONG THE HFD SAMPLES, PTHLH AND COL2A1 THAT ARE IMPORTANT GENES PLAYING ROLES DURING CHONDRO- AND OSTEOGENESIS HAD SIGNIFICANTLY ENRICHED LEVELS OF H3K27ME3. THEIR DECREASED MRNA EXPRESSION WAS CONFIRMED BY REAL-TIME PCR AND STANDARD CHIP ANALYSIS, INDICATING A STRONG ASSOCIATION WITH EZH2 MEDIATED H3K27ME3 EPIGENETIC CHANGES. USING EMBRYONIC CALVARIA OSTEOBLASTIC CELLS AND OFFSPRING BONE SAMPLES, H3K27AC CHIP-SEQ ANALYSIS SHOWED THAT OSTEOBLAST INHIBITOR GENES TNFAIP3 AND TWIST1 HAD SIGNIFICANTLY ENRICHED PEAKS OF H3K27AC IN HFD SAMPLES COMPARED TO CONTROLS. THEIR INCREASED GENE EXPRESSION AND ASSOCIATION WITH H3K27AC WERE ALSO CONFIRMED BY REAL-TIME PCR AND STANDARD CHIP ANALYSIS. THESE FINDINGS INDICATE THAT CHRONIC MATERNAL HFD CHANGES HISTONE TRIMETHYLATION AND ACETYLATION EPIGENETIC MARKS TO REGULATE EXPRESSION OF GENES CONTROLLING OSTEOBLASTOGENESIS. 2022 13 3475 30 IDENTIFICATION OF A STAT5 TARGET GENE, DPF3, PROVIDES NOVEL INSIGHTS IN CHRONIC LYMPHOCYTIC LEUKEMIA. STAT5 CONTROLS ESSENTIAL CELLULAR FUNCTIONS AND IS ENCODED BY TWO GENES, STAT5A AND STAT5B. TO PROVIDE INSIGHT TO THE MECHANISMS LINKING HEMATOLOGIC MALIGNANCY TO STAT5 ACTIVATION/REGULATION OF TARGET GENES, WE IDENTIFIED STAT5 TARGET GENES AND FOCUSED ON DPF3 GENE, WHICH ENCODES FOR AN EPIGENETIC FACTOR. DPF3 EXPRESSION WAS INDUCED UPON IL-3 STIMULATION IN BA/F3 CELLS, WHILE STRONG BINDING OF BOTH STAT5A AND STAT5B WAS DETECTED IN ITS PROMOTER. REDUCED EXPRESSION OF DPF3 WAS DETECTED IN BA/F3 CELLS WITH STAT5A AND STAT5B KNOCK-DOWN, SUGGESTING THAT THIS GENE IS POSITIVELY REGULATED BY STAT5, UPON IL-3 STIMULATION. FURTHERMORE, THIS GENE WAS SIGNIFICANTLY UP-REGULATED IN CLL PATIENTS, WHERE DPF3 GENE/PROTEIN UP-REGULATION AND STRONG STAT5 BINDING TO THE DPF3 PROMOTER, CORRELATED WITH INCREASED STAT5 ACTIVATION, MAINLY IN NON-MALIGNANT MYELOID CELLS (GRANULOCYTES). OUR FINDINGS PROVIDE INSIGHTS IN THE STAT5 DEPENDENT TRANSCRIPTIONAL REGULATION OF DPF3, AND DEMONSTRATE FOR THE FIRST TIME INCREASED STAT5 ACTIVATION IN GRANULOCYTES OF CLL PATIENTS. NOVEL ROUTES OF INVESTIGATION ARE OPENED TO FACILITATE THE UNDERSTANDING OF THE ROLE OF STAT5 ACTIVATION IN THE COMMUNICATION BETWEEN NON-MALIGNANT MYELOID AND MALIGNANT B-CELLS, AND THE FUNCTIONS OF STAT5 TARGET GENES NETWORKS IN CLL BIOLOGY. 2013 14 5675 28 SHIFTS IN PODOCYTE HISTONE H3K27ME3 REGULATE MOUSE AND HUMAN GLOMERULAR DISEASE. HISTONE PROTEIN MODIFICATIONS CONTROL FATE DETERMINATION DURING NORMAL DEVELOPMENT AND DEDIFFERENTIATION DURING DISEASE. HERE, WE SET OUT TO DETERMINE THE EXTENT TO WHICH DYNAMIC CHANGES TO HISTONES AFFECT THE DIFFERENTIATED PHENOTYPE OF ORDINARILY QUIESCENT ADULT GLOMERULAR PODOCYTES. TO DO THIS, WE EXAMINED THE CONSEQUENCES OF SHIFTING THE BALANCE OF THE REPRESSIVE HISTONE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3) MARK IN PODOCYTES. ADRIAMYCIN NEPHROTOXICITY AND SUBTOTAL NEPHRECTOMY (SNX) STUDIES INDICATED THAT DELETION OF THE HISTONE METHYLATING ENZYME EZH2 FROM PODOCYTES DECREASED H3K27ME3 LEVELS AND SENSITIZED MICE TO GLOMERULAR DISEASE. H3K27ME3 WAS ENRICHED AT THE PROMOTER REGION OF THE NOTCH LIGAND JAG1 IN PODOCYTES, AND DEREPRESSION OF JAG1 BY EZH2 INHIBITION OR KNOCKDOWN FACILITATED PODOCYTE DEDIFFERENTIATION. CONVERSELY, INHIBITION OF THE JUMONJI C DOMAIN-CONTAINING DEMETHYLASES JMJD3 AND UTX INCREASED THE H3K27ME3 CONTENT OF PODOCYTES AND ATTENUATED GLOMERULAR DISEASE IN ADRIAMYCIN NEPHROTOXICITY, SNX, AND DIABETES. PODOCYTES IN GLOMERULI FROM HUMANS WITH FOCAL SEGMENTAL GLOMERULOSCLEROSIS OR DIABETIC NEPHROPATHY EXHIBITED DIMINISHED H3K27ME3 AND HEIGHTENED UTX CONTENT. ANALOGOUS TO HUMAN DISEASE, INHIBITION OF JMJD3 AND UTX ABATED NEPHROPATHY PROGRESSION IN MICE WITH ESTABLISHED GLOMERULAR INJURY AND REDUCED H3K27ME3 LEVELS. TOGETHER, THESE FINDINGS INDICATE THAT OSTENSIBLY STABLE CHROMATIN MODIFICATIONS CAN BE DYNAMICALLY REGULATED IN QUIESCENT CELLS AND THAT EPIGENETIC REPROGRAMMING CAN IMPROVE OUTCOMES IN GLOMERULAR DISEASE BY REPRESSING THE REACTIVATION OF DEVELOPMENTAL PATHWAYS. 2018 15 1381 39 DI-(2-ETHYLHEXYL) PHTHALATE TRIGGERS DNA METHYLTRANSFERASE 1 EXPRESSION RESULTING IN ELEVATED CPG-METHYLATION AND ENRICHMENT OF MECP2 IN THE P21 PROMOTER IN VITRO. LEACHING OF THE PLASTIC CONSTITUENTS LEADING TO THEIR CHRONIC EXPOSURE TO HUMANS IS A MAJOR CONCERN FOR OUR ENVIRONMENTAL AND OCCUPATIONAL HEALTH. OUR PREVIOUS AND OTHER NUMEROUS STUDIES HAVE DEMONSTRATED THAT ENVIRONMENTAL CHEMICALS LIKE DI (2-ETHYLHEXYL)-PHTHALATE (DEHP) COULD POSE A RISK TOWARDS THE EPIGENETIC MECHANISMS. YET, THE MECHANISMS UNDERLYING ITS POSSIBLE EPIGENOTOXICITY ARE POORLY UNDERSTOOD. WE AIMED TO ASSESS THE IMPACT OF DEHP EXPOSURE TO THE HUMAN BREAST CANCER CELLS (MCF-7) AND RESULTANT CHANGES IN DNA METHYLATION REGULATORS ULTIMATELY ALTERING THE EXPRESSION OF THE CELL CYCLE REGULATOR P21 AS A MODEL GENE. THE MCF-7 CELLS WERE EXPOSED TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS (50-500 NM) FOR 24 H. THE RESULTS SHOWED THAT DEHP WAS PROLIFERATIVE TOWARDS THE MCF-7 CELLS WHILE IT INDUCED GLOBAL DNA HYPERMETHYLATION WITH SELECTIVE UPREGULATION OF DNMT1 AND MECP2. IN ADDITION, DEHP SIGNIFICANTLY REDUCED P53 PROTEIN AND ITS ENRICHMENT TO THE DNMT1 PROMOTER BINDING SITE, WHILE ELEVATING SP1 AND E2F1 TRANSCRIPTION FACTOR LEVELS, STIMULATING THEIR BINDING TO THE PROMOTER DNA. COINCIDENTLY, INCREASED DNMT1 LEVEL WAS HIGHLY ASSOCIATED WITH LOSS OF P21 EXPRESSION AND INCREASED CYCLIN D1 LEVELS. IMPORTANTLY, THE P21, BUT NOT CYCLIN D1 PROMOTER CPG-DINUCLEOTIDES WERE HYPERMETHYLATED AFTER EXPOSURE TO 500 NM DEHP FOR 24 H. FURTHERMORE, IT WAS OBSERVED THAT DEHP SIGNIFICANTLY ENRICHED DNMT1 AND MECP2 TO THE P21 PROMOTER TO INDUCE DNA METHYLATION-BASED EPIGENETIC SILENCING OF P21, RESULTING IN INCREASED CELL PROLIFERATION. OUR RESULTS SUGGEST DEHP COULD POTENTIALLY INDUCE THE EPIGENETIC ALTERATIONS THAT MIGHT INCREASE THE RISK OF BREAST CANCER, GIVEN THAT THE UNDERLYING MECHANISMS SHOULD BE FULLY ELUCIDATED. 2022 16 1839 25 EFFECTS OF PRENATAL NICOTINE EXPOSURE ON HEPATIC GLUCOSE AND LIPID METABOLISM IN OFFSPRING RATS AND ITS HEREDITABILITY. PRENATAL NICOTINE EXPOSURE (PNE) COULD INDUCE AN INCREASED SUSCEPTIBILITY TO MULTIPLE CHRONIC DISEASES IN ADULT OFFSPRING, THAT MAINLY CAUSED BY INTRAUTERINE MATERNAL GLUCOCORTICOID (GC) OVER-EXPOSURE. WE INVESTIGATED THE CHANGES AND INHERITABILITY OF HEPATIC GLUCOSE AND LIPID METABOLISM CAUSED BY PNE, TO DECIPHER THE POSSIBLE INTRAUTERINE PROGRAMMING MECHANISM. PREGNANT WISTAR RATS WERE ADMINISTERED SUBCUTANEOUSLY WITH 2 MG/KG.D NICOTINE FROM GESTATIONAL DAY (GD) 9 APPROXIMATELY 20, AND SECOND-GENERATION (F2) WERE SET ACCORDING TO THE MATING BETWEEN CONTROL FEMALES AND PNE MALES. THE RESULTS SHOWED THAT SERUM PHENOTYPES AND HEPATIC ENZYMES OF GLUCOSE AND LIPID METABOLISM WERE LOWER IN F1 FETAL RATS OF PNE BUT HIGHER IN THE F1 ADULT RATS. MEANWHILE, THE ACTIVATED STATES OF HEPATIC GLUCOCORTICOID-ACTIVATION SYSTEM, INCLUDING TYPE 1 AND TYPE 2 11BETA-HYDROXYSTEROID DEHYDROGENASES (HSD11B1/2), NUCLEAR RECEPTOR SUBFAMILY 3, GROUP C, MEMBER 1 (NR3C1) AND CCAAT ENHANCER BINDING PROTEIN ALPHA (CEBPA), WERE POSITIVELY CORRELATED WITH SERUM CORTICOSTERONE LEVELS BUT NEGATIVELY CORRELATED WITH THE HISTONE ACETYLATION (H3K27AC) AND EXPRESSION LEVELS OF INSULIN-LIKE GROWTH FACTOR 1 (IGF1) BEFORE AND AFTER BIRTH. FURTHERMORE, SERUM PHENOTYPES AND HEPATIC ENZYMES OF GLUCOSE AND LIPID METABOLISM WERE LOWER IN BOTH F2 FETAL AND ADULT RATS OF PNE, WHICH WERE CONSISTENT WITH THE HEPATIC CHANGES OF GC-IGF1 AXIS AND THE GLUCOCORTICOID-ACTIVATION SYSTEM. IN CONCLUSION, PNE COULD LEAD TO INHERITABLE CHANGES OF HEPATIC GLUCOSE AND LIPID METABOLISM, WHICH ARE RELATED TO THE INTRAUTERINE PROGRAMMING OF GC-IGF1 AXIS INDUCED BY THE GLUCOCORTICOID-ACTIVATION SYSTEM. 2020 17 1264 30 CYP2E1 EPIGENETIC REGULATION IN CHRONIC, LOW-LEVEL TOLUENE EXPOSURE: RELATIONSHIP WITH OXIDATIVE STRESS AND SMOKING HABIT. BACKGROUND: CYP2E1 IS A VERSATILE PHASE I DRUG-METABOLIZING ENZYME RESPONSIBLE FOR THE BIOTRANSFORMATION OF MOST VOLATILE ORGANIC COMPOUNDS, INCLUDING TOLUENE. HUMAN TOLUENE EXPOSURE INCREASES CYP2E1 MRNA AND MODIFIES ITS ACTIVITY IN LEUCOCYTES; HOWEVER, EPIGENETIC IMPLICATIONS OF THIS INTERACTION HAVE NOT BEEN INVESTIGATED. GOAL: TO DETERMINE PROMOTER METHYLATION OF CYP2E1 AND OTHER GENES KNOWN TO BE AFFECTED BY TOLUENE EXPOSURE. METHODS: WE OBTAINED VENOUS BLOOD FROM 24 TANNERY WORKERS EXPOSED TO TOLUENE (MEAN LEVELS: 10.86+/-7MG/M(3)) AND 24 ADMINISTRATIVE WORKERS (REFERENCE GROUP, MEAN LEVELS 0.21+/-0.02MG/M(3)) ALL OF THEM FROM THE CITY OF LEON, GUANAJUATO, MEXICO. AFTER DNA EXTRACTION AND BISULFITE TREATMENT, WE PERFORMED PCR-PYROSEQUENCING IN ORDER TO MEASURE METHYLATION LEVELS AT PROMOTER REGION OF 13 GENES. RESULTS: IN EXPOSED GROUP WE FOUND SIGNIFICANT CORRELATIONS BETWEEN TOLUENE AIRBORNE LEVELS AND CYP2E1 PROMOTER METHYLATION (R=-.36, P<0.05), AS WELL AS FOR IL6 PROMOTER METHYLATION LEVELS (R=.44, P<0.05). MOREOVER, CYP2E1 PROMOTER METHYLATION LEVELS WHERE HIGHER IN TOLUENE-EXPOSED SMOKERS COMPARED TO NONSMOKERS (P=0.009). WE ALSO OBSERVED SIGNIFICANT CORRELATIONS FOR CYP2E1 PROMOTER METHYLATION WITH GSTP1 AND SOD1 PROMOTER METHYLATION LEVELS (R=-.37, P<0.05 AND R=-.34, P<0.05 RESPECTIVELY). CONCLUSION: THESE RESULTS HIGHLIGHT THE IMPORTANCE OF CONSIDERING CYP2E1 EPIGENETIC MODIFICATIONS, AS WELL AS ITS INTERACTIONS WITH OTHER GENES, AS KEY FACTORS FOR UNRAVELING THE SUB CELLULAR MECHANISMS OF TOXICITY EXERTED BY OXIDATIVE STRESS, WHICH CAN INITIATE DISEASE PROCESS IN CHRONIC, LOW-LEVEL TOLUENE EXPOSURE. PEOPLE CO-EXPOSED TO TOLUENE AND TOBACCO SMOKE ARE IN HIGHER RISK DUE TO A POSSIBLE CYP2E1 REPRESSION. 2015 18 5791 45 STABLE HISTONE METHYLATION CHANGES AT PROTEOGLYCAN NETWORK GENES FOLLOWING ETHANOL EXPOSURE. ALCOHOL USE DISORDER (AUD) IS A CHRONIC MENTAL ILLNESS IN WHICH PATIENTS OFTEN ACHIEVE PROTRACTED PERIODS OF ABSTINENCE PRIOR TO RELAPSE. EPIGENETIC MECHANISMS MAY PROVIDE AN EXPLANATION FOR THE PERSISTING GENE EXPRESSION CHANGES THAT CAN BE OBSERVED EVEN AFTER LONG PERIODS OF ABSTINENCE AND MAY CONTRIBUTE TO RELAPSE. IN THIS STUDY, WE EXAMINED TWO HISTONE MODIFICATIONS, HISTONE 3 LYSINE 4 TRI-METHYLATION (H3K4ME3) AND HISTONE 3 LYSINE 27 TRI-METHYLATION (H3K27ME3), IN THE PREFRONTAL CORTEX OF WITHDRAWAL SEIZURE RESISTANT (WSR) MICE 21 DAYS AFTER 72 H OF ETHANOL VAPOR EXPOSURE. THESE HISTONE MODIFICATIONS WERE SELECTED BECAUSE THEY ARE ASSOCIATED WITH ACTIVE PROMOTERS (H3K4ME3) AND REPRESSED GENE EXPRESSION IN A EUCHROMATIC ENVIRONMENT (H3K27ME3). WE PERFORMED A GENOME-WIDE ANALYSIS TO IDENTIFY DIFFERENCES IN H3K4ME3 AND H3K27ME3 LEVELS IN POST-ETHANOL EXPOSURE VS. CONTROL MICE BY CHIP-SEQ. WE DETECTED A GLOBAL REDUCTION IN H3K4ME3 PEAKS AND INCREASE IN H3K27ME3 PEAKS IN POST-ETHANOL EXPOSURE MICE COMPARED TO CONTROLS, THESE CHANGES ARE CONSISTENT WITH PERSISTENT REDUCTIONS IN GENE EXPRESSION. PATHWAY ANALYSIS OF GENES DISPLAYING CHANGES IN H3K4ME3 AND H3K27ME3 REVEALED ENRICHMENT FOR GENES INVOLVED IN PROTEOGLYCAN AND CALCIUM SIGNALING PATHWAYS, RESPECTIVELY. MICROARRAY ANALYSIS OF 7,683 GENES AND QPCR ANALYSIS IDENTIFIED EIGHT GENES DISPLAYING CONCORDANT REGULATION OF GENE EXPRESSION AND H3K4ME3/H3K27ME3. WE ALSO COMPARED CHANGES IN H3K4ME3 AND/OR H3K27ME3 FROM OUR STUDY WITH CHANGES IN GENE EXPRESSION IN RESPONSE TO ETHANOL FROM PUBLISHED LITERATURE AND WE FOUND THAT THE EXPRESSION OF 52% OF THE GENES WITH ALTERED H3K4ME3 BINDING AND 40% OF GENES WITH H3K27ME3 DIFFERENCES ARE ALTERED BY ETHANOL EXPOSURE. THE CHROMATIN CHANGES ASSOCIATED WITH THE 21-DAY POST-EXPOSURE PERIOD SUGGEST THAT THIS PERIOD IS A UNIQUE STATE IN THE ADDICTION CYCLE THAT DIFFERS FROM ETHANOL INTOXICATION AND ACUTE WITHDRAWAL. THESE RESULTS PROVIDE INSIGHTS INTO THE ENDURING EFFECTS OF ETHANOL ON PROTEOGLYCAN AND CALCIUM SIGNALING GENES IN THE BRAIN. 2018 19 2792 26 FAT10 IS AN EPIGENETIC MARKER FOR LIVER PRENEOPLASIA IN A DRUG-PRIMED MOUSE MODEL OF TUMORIGENESIS. THERE IS CLINICAL EVIDENCE THAT CHRONIC LIVER DISEASES IN WHICH MDBS (MALLORY DENK BODIES) FORM PROGRESS TO HEPATOCELLULAR CARCINOMA. THE PRESENT STUDY PROVIDES EVIDENCE THAT LINKS MDB FORMATION INDUCED BY CHRONIC DRUG INJURY, WITH PRENEOPLASIA AND LATER TO THE FORMATION OF TUMORS, WHICH DEVELOP LONG AFTER DRUG WITHDRAWAL. EVIDENCE INDICATED THAT THIS LINK WAS DUE TO AN EPIGENETIC CELLULAR MEMORY INDUCED BY CHRONIC DRUG INGESTION. MICROARRAY ANALYSIS SHOWED THAT THE EXPRESSIONS OF MANY MARKERS OF PRENEOPLASIA (UBD, ALPHA FETOPROTEIN, KLF6 AND GLUTATHIONE-S-TRANSFERASE MU2) WERE INCREASED TOGETHER WHEN THE DRUG DDC WAS REFED. THESE CHANGES WERE SUPPRESSED BY S-ADENOSYLMETHIONINE FEEDING, INDICATING THAT THE DRUG WAS AFFECTING DNA AND HISTONES METHYLATION IN AN EPIGENETIC MANNER. THE LINK BETWEEN MDB FORMATION AND NEOPLASIA FORMATION WAS LIKELY DUE TO THE OVER EXPRESSION OF UBD (ALSO CALLED FAT10), WHICH IS UP REGULATED IN 90% OF HUMAN HEPATOCELLULAR CARCINOMAS. IMMUNOHISTOCHEMICAL STAINING OF DRUG-PRIMED MOUSE LIVERS SHOWED THAT FAT10 POSITIVE LIVER CELLS PERSISTED UP TO 4 MONTHS AFTER DRUG WITHDRAWAL AND THEY WERE STILL FOUND IN THE LIVERS OF MICE, 14 MONTHS AFTER DRUG WITHDRAWAL. THE REFEEDING OF DDC INCREASED THE PERCENT OF FAT10 HEPATOCYTES. 2008 20 5556 35 ROLE OF FLUORIDE INDUCED HISTONE TRIMETHYLATION IN DEVELOPMENT OF SKELETAL FLUOROSIS. CHRONIC EXPOSURE TO FLUORIDE HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. LIMITED REPORTS ARE AVAILABLE ON FLUORIDE INDUCED HISTONE MODIFICATION. HOWEVER, THE ROLE OF HISTONE MODIFICATION IN THE PATHOGENESIS OF SKELETAL FLUOROSIS IS NOT INVESTIGATED. IN THE PRESENT STUDY, WE HAVE INVESTIGATED THE ROLE OF FLUORIDE INDUCED HISTONE MODIFICATION ON FLUOROSIS DEVELOPMENT USING HUMAN OSTEOSARCOMA (HOS) CELL LINE. THE EXPRESSION OF HISTONE METHYLTRANSFERASES (EHMT1 AND EHZ2) AND LEVEL OF GLOBAL HISTONE TRIMETHYLATION (H3K9 AND H3K27) HAVE BEEN ASSESSED AND OBSERVED TO BE INCREASED SIGNIFICANTLY AFTER FLUORIDE EXPOSURE (8 MG/L). EPITECT CHROMATIN IMMUNOPRECIPITATION (CHIP) QPCR ARRAY (HUMAN TGFBETA/BMP SIGNALING PATHWAY) WAS PERFORMED TO ASSESS THE H3K9 TRIMETHYLATION AT PROMOTER REGIONS OF PATHWAY-SPECIFIC GENES. H3K9 CHIP PCR ARRAY ANALYSIS IDENTIFIED HYPER H3K9 TRIMETHYLATION IN PROMOTER REGIONS OF TGFBR2 AND SMAD3. QPCR AND STRING ANALYSIS WAS CARRIED OUT TO DETERMINE THE REPRESSIVE EPIGENETIC EFFECT OF H3K9 TRIMETHYLATION ON EXPRESSION PATTERN AND FUNCTIONAL ASSOCIATION OF IDENTIFIED GENES. IDENTIFIED GENES (TGFBR2 AND SMAD3) SHOWED DOWN-REGULATION WHICH CONFIRMS THE REPRESSIVE EPIGENETIC EFFECT OF PROMOTER H3K9 HYPER TRIMETHYLATION. EXPRESSION OF TWO OTHER VITAL GENES COL1A1 AND MMP13 INVOLVED IN TGFBR2-SMAD SIGNALING PATHWAY WAS ALSO FOUND TO BE DOWN-REGULATED WITH A DECREASE IN EXPRESSION OF TGFBR2 AND SMAD3. STRING ANALYSIS REVEALED FUNCTIONAL ASSOCIATION AND INVOLVEMENT OF IDENTIFIED GENES TGFBR2, SMAD3, COL1A1 AND MMP13 IN THE COLLAGEN AND CARTILAGE DEVELOPMENT/MORPHOGENESIS, CONNECTIVE TISSUE FORMATION, BIO-MINERAL TISSUE DEVELOPMENT, ENDOCHONDRAL BONE FORMATION, BONE AND SKELETAL MORPHOGENESIS. IN CONCLUSION, PRESENT INVESTIGATION IS A FIRST ATTEMPT TO LINK FLUORIDE INDUCED HYPER H3K9 TRI-METHYLATION MEDIATED REPRESSION OF TGFBR2 AND SMAD3 WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. 2018