1 243 135 ADOLESCENT CHRONIC INTERMITTENT TOLUENE INHALATION DYNAMICALLY REGULATES THE TRANSCRIPTOME AND NEURONAL METHYLOME WITHIN THE RAT MEDIAL PREFRONTAL CORTEX. INHALANTS CONTAINING THE VOLATILE SOLVENT TOLUENE ARE MISUSED TO INDUCE EUPHORIA OR INTOXICATION. INHALANT ABUSE IS MOST COMMON DURING ADOLESCENCE AND CAN RESULT IN COGNITIVE IMPAIRMENTS DURING AN IMPORTANT MATURATIONAL PERIOD. DESPITE EVIDENCE SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY UNDERPIN THE COGNITIVE EFFECTS OF INHALANTS, NO STUDIES TO DATE HAVE THOROUGHLY INVESTIGATED TOLUENE-INDUCED REGULATION OF THE TRANSCRIPTOME OR DISCRETE EPIGENETIC MODIFICATIONS WITHIN THE BRAIN. TO ADDRESS THIS, WE INVESTIGATED EFFECTS OF ADOLESCENT CHRONIC INTERMITTENT TOLUENE (CIT) INHALATION ON GENE EXPRESSION AND DNA METHYLATION PROFILES WITHIN THE RAT MEDIAL PREFRONTAL CORTEX (MPFC), WHICH UNDERGOES MATURATION THROUGHOUT ADOLESCENCE AND HAS BEEN IMPLICATED IN TOLUENE-INDUCED COGNITIVE DEFICITS. EMPLOYING BOTH RNA-SEQ AND GENOME-WIDE METHYL CPG BINDING DOMAIN (MBD) ULTRA-SEQ ANALYSIS, WE DEMONSTRATE THAT ADOLESCENT CIT INHALATION (10 000 PPM FOR 1 H/DAY, 3 DAYS/WEEK FOR 4 WEEKS) INDUCES BOTH TRANSIENT AND PERSISTENT CHANGES TO THE TRANSCRIPTOME AND DNA METHYLOME WITHIN THE RAT MPFC FOR AT LEAST 2 WEEKS FOLLOWING TOLUENE EXPOSURE. WE DEMONSTRATE FOR THE FIRST TIME THAT ADOLESCENT CIT EXPOSURE RESULTS IN DYNAMIC REGULATION OF THE MPFC TRANSCRIPTOME LIKELY RELATING TO ACUTE INFLAMMATORY RESPONSES AND PERSISTENT DEFICITS IN SYNAPTIC PLASTICITY. THESE ADAPTATIONS MAY CONTRIBUTE TO THE COGNITIVE DEFICITS ASSOCIATED WITH CHRONIC TOLUENE EXPOSURE AND PROVIDE NOVEL MOLECULAR TARGETS FOR PREVENTING LONG-TERM NEUROPHYSIOLOGICAL ABNORMALITIES FOLLOWING CHRONIC TOLUENE INHALATION. 2021 2 813 32 CHANGES IN POLY(ADP-RIBOSYL)ATION PATTERNS IN WORKERS EXPOSED TO BTX. OCCUPATIONAL EXPOSURE TO (BENZENE, TOLUENE AND XYLENE, BTX IS COMMON IN THE CHINESE WORKPLACE. CHRONIC OCCUPATIONAL EXPOSURE TO BENZENE IS ASSOCIATED WITH AN INCREASED RISK OF HEMATOLOGICAL MALIGNANCIES SUCH AS ACUTE MYELOID LEUKEMIA (AML), BUT THE UNDERLYING MECHANISMS ARE STILL UNCLEAR. THIS STUDY INVESTIGATES CHANGES IN POLY(ADP-RIBOSYL)ATION AND DNA METHYLATION IN SUBJECTS OCCUPATIONALLY EXPOSED TO A BTX. BLOOD DNA SAMPLES AND EXPOSURE DATA WERE OBTAINED FROM SUBJECTS WITH DIFFERENT LEVELS OF EXPOSURE, INCLUDING 132 DECORATORS, 129 PAINTERS, AND 130 UNEXPOSED REFERENTS IN A CONTAINER-MANUFACTURING FACTORY IN SHENZHEN, CHINA. OCCUPATIONAL EXPOSURE ASSESSMENT INCLUDED PERSONAL MONITORING OF AIRBORNE BENZENE, TOLUENE AND XYLENE. HEMATOLOGICAL PARAMETERS WERE MEASURED AND THE CYTOKINESIS-BLOCK MICRONUCLEUS (CBMN) ASSAY WAS USED TO DETECT DNA DAMAGE IN PERIPHERAL LYMPHOCYTES. QUANTITATIVE REAL-TIME PCR WAS USED TO DETECT THE MRNA EXPRESSION OF POLY(ADP-RIBOSE) POLYMERASE 1 (PARP1) AND POLY(ADP-RIBOSE) GLYCOHYDROLASE (PARG), DNA METHYLTRANSFERASES (DNMTS) INCLUDING DNMT1, DNMT3A AND DNMT3B, METHYL-CPG-BINDING DOMAIN PROTEIN 2(MBD2). PARP1 ASSAY WAS USED TO MEASURE PARP ACTIVITY. AIRBORNE LEVELS OF BENZENE, TOLUENE AND XYLENE IN THE TWO EXPOSED GROUPS WERE SIGNIFICANTLY HIGHER THAN THOSE OF CONTROLS (P<0.001). THE TWO EXPOSED GROUPS (DECORATORS, PAINTERS) SHOWED DECREASED PARP1, DNMTS AND MBD2 EXPRESSION RELATIVE TO CONTROLS (P<0.05), AND PARP ACTIVITY WAS ALSO DECREASED (P<0.05). DECREASED PARP1, DNMT1, DNMT3A, DNMT3B AND MBD2 MRNA EXPRESSION WAS CORRELATED WITH INCREASED AIRBORNE BTX (PEARSON'S R: -0.587, -0.314, -0.636, -0.567 AND -0.592 RESPECTIVELY, P<0.001). NO SIGNIFICANT DIFFERENCES IN HEMATOLOGICAL PARAMETERS AND CBMN WERE FOUND AMONG THE THREE GROUPS. TOGETHER, THESE RESULTS SUGGEST THAT DECREASED DNMTS, MBD2 AND PARP1 MIGHT BE INVOLVED IN THE GLOBAL HYPOMETHYLATION ASSOCIATED WITH BTX EXPOSURE, AND THE IMBALANCE OF PARP/PARG MIGHT PARTICIPATE IN THE DOWN-REGULATION OF DNMTS. THIS IS THE FIRST HUMAN STUDY TO LINK ALTERED POLY(ADP-RIBOSYL)ATION PATTERNS, WHICH REPRODUCE THE ABERRANT EPIGENETIC PATTERNS FOUND IN BENZENE-TREATED CELLS, TO CHRONIC OCCUPATIONAL EXPOSURE TO BTX. 2014 3 6477 36 TOLUENE IMPAIRS LEARNING AND MEMORY, HAS ANTINOCICEPTIVE EFFECTS, AND MODIFIES HISTONE ACETYLATION IN THE DENTATE GYRUS OF ADOLESCENT AND ADULT RATS. TOLUENE MISUSE USUALLY INITIATES AT AN EARLY AGE WHEN THE CENTRAL NERVOUS SYSTEM IS STILL IMMATURE, CAUSING DELETERIOUS EFFECTS SUCH AS COGNITIVE IMPAIRMENT. EPIGENETIC REGULATORY MECHANISMS HAVE BEEN PROPOSED TO EXPLAIN LONG-TERM CHANGES INVOLVED NOT ONLY IN MEMORY, BUT ALSO IN TOLUENE'S ACTIONS. THE AIM OF THIS STUDY WAS TO EVALUATE THE EFFECTS OF ACUTE AND CHRONIC TOLUENE EXPOSURE ON LEARNING, MEMORY AND HISTONE ACETYLATION IN THE RAT HIPPOCAMPUS DURING TWO STAGES OF LIFE: ADOLESCENCE AND YOUNG ADULTHOOD. BECAUSE THE MEMORY TESTS USED IN THIS WORK INVOLVED OBJECT EXPLORATION AND THE PERCEPTION OF A NOXIOUS STIMULUS, GENERAL ACTIVITY AND NOCICEPTION TESTS WERE ALSO CONDUCTED. ACUTE AND CHRONIC TOLUENE INHALATION IMPAIRED LEARNING, SHORT-TERM AND LONG-TERM MEMORY IN AN OBJECT-RECOGNITION TEST AND IN AN INHIBITORY AVOIDANCE TASK IN BOTH GROUPS OF AGE. THIS EFFECT WAS CONCENTRATION-DEPENDENT AND OCCURRED EVEN AT LOW TOLUENE CONCENTRATIONS (1000, 2000 PPM) THAT WERE OTHERWISE NON-EFFECTIVE. ACUTE TOLUENE INHALATION PRODUCED ANTINOCICEPTION, AND TOLERANCE TO THIS EFFECT DEVELOPED AFTER CHRONIC EXPOSURE. HISTONE ACETYLATION IN THE DENTATE GYRUS SHOWED DIFFERENCES DEPENDING ON THE HISTONE, TREATMENT AND AGE: A SINGLE TOLUENE EXPOSURE INCREASED H4 ACETYLATION IN ADOLESCENTS AND YOUNG ADULT RATS, WHEREAS CHRONIC EXPOSURE DECREASED H3 ACETYLATION, BUT ONLY IN ADULTS. IN CONCLUSION, THIS WORK PROVIDES EVIDENCE OF TOLUENE-INDUCED IMPAIRMENT ON LEARNING, SHORT- AND LONG-TERM MEMORY IN ADOLESCENT AND YOUNG ADULT RATS, AND SHOWS THAT EVEN A SINGLE TOLUENE EXPOSURE CAN INDUCE EPIGENETIC MODIFICATIONS IN THE RAT HIPPOCAMPUS. 2012 4 1264 33 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 5 5444 44 REPEATED TOLUENE EXPOSURE MODIFIES THE ACETYLATION PATTERN OF HISTONES H3 AND H4 IN THE RAT BRAIN. TOLUENE IS A VOLATILE ORGANIC SOLVENT WITH ADDICTIVE POTENTIAL THAT EXHIBITS SIMILARITIES IN ITS PHYSIOLOGICAL EFFECTS AND MODES OF ACTION TO OTHER ADDICTIVE DRUGS. DESPITE ITS WIDESPREAD ABUSE, THE MOLECULAR MECHANISMS DRIVING THE RESPONSE AND ADAPTATION OF THE ORGANISM TO THIS DRUG ARE NOT FULLY UNDERSTOOD. IN RECENT YEARS, DIFFERENT EPIGENETIC MECHANISMS THAT MODULATE GENE EXPRESSION HAVE BEEN SHOWN TO BE ASSOCIATED TO COCAINE, AMPHETAMINE AND ALCOHOL MISUSE-INDUCED ALTERATIONS IN NEURONAL FUNCTION. FOR EXAMPLE, IT HAS BEEN DEMONSTRATED THAT DRUG CONSUMPTION INDUCES VARIATIONS IN HISTONE ACETYLATION LEVELS IN BRAIN REWARD REGIONS AND THESE PLAY A RELEVANT ROLE ON THE ABUSE-ASSOCIATED BEHAVIORAL PLASTICITY. IN ORDER TO DECIPHER WHETHER REPEATED TOLUENE EXPOSURE COULD MEDIATE EPIGENETIC CHANGES IN THE RAT BRAIN, WE HERE ANALYZED THE ACETYLATION PATTERN OF HISTONES H3 AND H4 IN THREE BRAIN AREAS THAT HAVE BEEN PREVIOUSLY ASSOCIATED TO SUBSTANCE ABUSE REWARD PATHWAYS: THE NUCLEUS ACCUMBENS (NAC), THE VENTRAL TEGMENTAL AREA (VTA) AND THE CENTRAL AMYGDALA (CEA). USING IMMUNOFLUORESCENCE ANALYSIS OF BRAIN SECTIONS WITH SPECIFIC ANTIBODIES THAT RECOGNIZE THE ACETYLATED FORMS OF HISTONES H3 AND H4, WE DEMONSTRATE THAT CHRONIC TOLUENE INHALATION DIFFERENTIALLY MODIFIES HISTONE H3 AND H4 ACETYLATION IN THE NAC AND THE VTA WHILE NO EFFECT IS OBSERVED IN THE CEA. OUR RESULTS SUGGEST THAT THE ACTIVITY OF CHROMATIN-MODIFYING ENZYMES SUCH AS HISTONE DE-ACETYLASES (HDACS) IN CERTAIN BRAIN AREAS ARE RESPONSIVE TO TOLUENE INHALATION AND MIGHT BE CRUCIAL MEDIATORS IN THE ADDICTIVE RESPONSE TO TOLUENE. 2011 6 3441 32 HYPERMETHYLATION IN GENE PROMOTERS ARE INDUCED BY CHRONIC EXPOSURE TO BENZENE, TOLUENE, ETHYLBENZENE AND XYLENES. BACKGROUND AND OBJECTIVE: GAS STATION ATTENDANTS ARE OCCUPATIONALLY EXPOSED TO BENZENE, TOLUENE, ETHYLBENZENE AND XYLENE (BTEX) COMPOUNDS AND THUS MORE SUSCEPTIBLE TO THE BIOLOGICAL EFFECTS OF THIS MIXTURE PRESENT IN GASOLINE, ESPECIALLY DUE TO THE CARCINOGENICITY OF BENZENE. FURTHERMORE, THE HARMFUL EFFECTS OF BTEX EXPOSURE MAY BE POTENTIATED BY GENETIC AND EPIGENETIC INACTIVATION OF CRITICAL GENES. THE OBJECTIVE WAS TO EVALUATE SUCH GENE-BTEX INTERACTIONS ACCESSING THE PROMOTER METHYLATION STATUS OF P14ARF, P16INK4A AND GSTP1 IN PERIPHERAL BLOOD LEUKOCYTE SAMPLES. MATERIALS AND METHODS: THE 59 EXPOSED AND 68 UNEXPOSED PARTICIPANTS FROM RIO DE JANEIRO, BRAZIL, WERE INCLUDED. THE PROMOTER METHYLATION STATUS WAS ACCESSED BY METHYLATION-SPECIFIC PCR (MSP) AND GSTP1 ILE105VAL POLYMORPHISM WAS INVESTIGATED BY PCR-RESTRICTION FRAGMENT LENGTH POLYMORPHISM (PCR-RFLP) TECHNIQUE. RESULTS: BOTH P14ARF AND P16INK4A WERE SIGNIFICANTLY HYPERMETHYLATED IN EXPOSED SUBJECTS COMPARED TO UNEXPOSED (P = 0.004 AND P<0.001, RESPECTIVELY). ADDITIONALLY, P16INK4A HYPERMETHYLATION IN THE EXPOSED GROUP WAS CORRELATED WITH CHROMOSOMAL ABNORMALITIES (CAS) (P = 0.018), THUS HIGHLIGHTING THE INFLUENCE OF THE GENE-ENVIRONMENT INTERACTIONS ON GENOME INSTABILITY. NOTEWORTHY, P16INK4A METHYLATION WAS SIGNIFICANTLY ASSOCIATED WITH MISCARRIAGE AMONG FEMALE ATTENDANTS (P = 0.047), IN WHICH THOSE WHO REPORTED MISCARRIAGE EXHIBITED HYPERMETHYLATION IN AT LEAST 2 OF THE 3 GENES ANALYZED. THE GSTP1 HETEROZYGOTE GENOTYPE, WHICH COULD AFFECT THE METABOLISM OF BENZENE DETOXIFICATION, WAS FOUND IN BOTH GROUPS BUT WAS MORE FREQUENT IN THOSE OCCUPATIONALLY EXPOSED. NO SIGNIFICANT ASSOCIATION WAS OBSERVED BETWEEN GSTP1 GENOTYPES AND METHYLATION STATUS. CONCLUSION: TOGETHER, THESE FINDINGS INDICATE THAT GAS STATION ATTENDANTS WITH THE AFOREMENTIONED EPIGENETIC AND GENETIC PROFILES MAY BE AT GREATER RISK OF OCCUPATIONAL BTEX EXPOSURE-INDUCED GENOME INSTABILITY, WHICH COULD REQUIRE CONCERTED EFFORTS TO ESTABLISH MORE PREVENTIVE ACTIONS AND CONSTANT BIOMONITORING IN GAS STATION ATTENDANTS. 2020 7 143 22 ABERRANT DNA METHYLATION OF TWO TUMOR SUPPRESSOR GENES, P14(ARF) AND P15(INK4B), AFTER CHRONIC OCCUPATIONAL EXPOSURE TO LOW LEVEL OF BENZENE. BACKGROUND: EXPOSURE TO BENZENE WOULD BE ASSOCIATED WITH MANY DISEASES INCLUDING LEUKEMIA. EPIGENETIC ALTERATIONS SEEM TO BE AMONG THE MAIN MECHANISMS INVOLVED. OBJECTIVE: TO DETERMINE IF CHRONIC OCCUPATIONAL EXPOSURE TO LOW LEVEL OF BENZENE WOULD BE ASSOCIATED WITH DNA METHYLATION. METHODS: GLOBAL DNA METHYLATION AND PROMOTER-SPECIFIC METHYLATION OF THE TWO TUMOR SUPPRESSOR GENES, P14(ARF) AND P15(INK4B), WERE ASSESSED EMPLOYING METHYLATION-SPECIFIC PCR USING THE DNA EXTRACTED FROM 40 PETROCHEMICAL WORKERS EXPOSED TO AMBIENT BENZENE LEVELS OF <1 PPM, AND 31 OFFICE WORKERS NOT EXPOSED TO BENZENE OR ITS DERIVATIVES. RESULTS: WHILE AN INCREASE IN GLOBAL DNA METHYLATION OF 5% IN P14(ARF) (P=0.501) AND 28% IN P15(INK4B) (P=0.02) GENES WAS OBSERVED IN THE EXPOSED GROUP, NO HYPERMETHYLATION IN EITHER OF THE STUDIED GENES WAS OBSERVED IN THE UNEXPOSED GROUP. NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN THE FREQUENCY OF ABERRANT METHYLATION AND EITHER OF AGE, WORK EXPERIENCE, AND SMOKING HABIT IN THE EXPOSED GROUP. CONCLUSION: CHRONIC OCCUPATIONAL EXPOSURE TO LOWER THAN THE PERMISSIBLE EXPOSURE LIMIT OF BENZENE MAY STILL RESULT IN DNA METHYLATION OF TUMOR SUPPRESSOR GENES THAT MAY ULTIMATELY LEAD TO DEVELOPMENT OF CANCER. 2018 8 1916 31 ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO CHEMICALS AND TELOMERE LENGTH IN HUMAN STUDIES. TELOMERES ARE COMPLEXES OF TANDEM REPEATS OF DNA (5'-TTAGGG-3') AND PROTEIN THAT CAP EUKARYOTIC CHROMOSOMES AND PLAY A CRITICAL ROLE IN CHROMOSOME STABILITY. TELOMERES SHORTEN WITH AGING AND THIS PROCESS CAN BE ACCELERATED BY INCREASED OXIDATIVE STRESS AND EPISODES OF INFLAMMATION. EVIDENCE IS RAPIDLY GROWING THAT TELOMERE LENGTH (TL) MAY BE AFFECTED BY ENVIRONMENTAL CHEMICALS THAT HAVE FREQUENTLY BEEN ASSOCIATED WITH CHRONIC DISEASES. IN THIS ARTICLE, WE REVIEW THE PUBLISHED DATA ON TL IN RELATION TO ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO SEVERAL CHEMICALS BASED ON OUR OWN AND OTHERS' STUDIES. THE ENVIRONMENTAL AND OCCUPATIONAL EXPOSURES ASSOCIATED WITH SHORTER TL INCLUDE TRAFFIC-RELATED AIR POLLUTION (IE, PARTICULATE MATTER (PM), BLACK CARBON (BC), AND BENZENE AND TOLUENE), POLYCYCLIC AROMATIC HYDROCARBONS (PAHS), N-NITROSAMINES, PESTICIDES, LEAD, EXPOSURE IN CAR MECHANICAL WORKSHOPS, AND HAZARDOUS WASTE EXPOSURE. ARSENIC, PERSISTENT ORGANIC POLLUTANTS (POPS) AND SHORT-TERM EXPOSURE TO PM ARE ASSOCIATED WITH LONGER TL. WE DISCUSS THE POSSIBLE REASONS FOR THE DIFFERENCES IN RESULTS, INCLUDING TIME- AND DOSE-RELATED ISSUES, STUDY DESIGN, AND POSSIBLE MECHANISMS INVOLVED IN TELOMERE REGULATION. WE ALSO DISCUSS THE FUTURE DIRECTIONS AND CHALLENGES FOR TL-RELATED ENVIRONMENTAL AND OCCUPATIONAL HEALTH RESEARCH, SUCH AS INVESTIGATION OF TL IN SUBPOPULATIONS OF BLOOD LEUKOCYTES, AND THE STUDY OF GENETIC AND EPIGENETIC FACTORS THAT MAY REGULATE TELOMERE INTEGRITY USING LONGITUDINAL DESIGNS. 2013 9 4930 39 PATERNAL ALCOHOL EXPOSURE REDUCES ACQUISITION OF OPERANT ALCOHOL SELF-ADMINISTRATION AND AFFECTS BDNF DNA METHYLATION IN MALE AND FEMALE OFFSPRING. FAMILIAL TRANSMISSION OF ALCOHOL USE DISORDER REFLECTS GENETIC AND ENVIRONMENTAL FACTORS. PATERNAL ALCOHOL EXPOSURE MAY AFFECT RODENT OFFSPRING VIA EPIGENETIC MODIFICATIONS TRANSMITTED THROUGH THE MALE GERM LINE. WHILE SUCH EXPOSURE ALTERS ALCOHOL SENSITIVITY IN MOUSE OFFSPRING, NO STUDIES EXAMINED IF IT IMPACTS THE DEVELOPMENT OF OPERANT ALCOHOL SELF-ADMINISTRATION IN RATS. WE EXPOSED MALE (SIRES) WISTAR RATS TO CHRONIC INTERMITTENT ETHANOL IN VAPOUR CHAMBERS (16 H/DAY; 5 DAYS/WEEK) OR TO AIR FOR 6 WEEKS. EIGHT WEEKS LATER, RATS WERE MATED WITH ALCOHOL-NAIVE FEMALES. ADULT ALCOHOL- AND CONTROL-SIRED F1 OFFSPRING WERE ASSESSED IN ACQUISITION OF ALCOHOL SELF-ADMINISTRATION IN WHICH INCREASING ALCOHOL CONCENTRATIONS (2.5%, 5% AND 10%, V/V) WERE DELIVERED AFTER ONE LEVER PRESS (FIXED RATIO 1 OR FR1). PRIOR TO ALCOHOL SESSIONS, RATS WERE TRAINED TO LEVER PRESS FOR FOOD DELIVERY UNDER AN FR1 SCHEDULE OF REINFORCEMENT. DNA METHYLATION LEVELS OF THE BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) GENE WERE MEASURED IN SPERM, NUCLEUS ACCUMBENS (NAC) AND MEDIAL PREFRONTAL CORTEX (MPFC) IN SIRES AND IN OFFSPRING. ALCOHOL-EXPOSED SIRES HAD LOWER BDNF DNA METHYLATION LEVELS IN NAC AND GREATER METHYLATION LEVELS IN MPFC. ALTHOUGH THIS PATTERN WAS NOT RECAPITULATED IN OFFSPRING, ALCOHOL-SIRED OFFSPRING OF BOTH SEXES DID SHOW ABERRANT BDNF DNA METHYLATION PATTERNS COMPARED TO CONTROL-SIRED OFFSPRING. ALCOHOL-SIRED OFFSPRING SELF-ADMINISTERED LESS ALCOHOL (5% AND 10%) WITH NO GROUP DIFFERENCES IN FOOD RESPONDING. RESULTS INDICATE THAT PATERNAL ALCOHOL EXPOSURE PRIOR TO CONCEPTION PROTECTS AGAINST ALCOHOL'S INITIAL REINFORCING EFFECTS BUT THE PATTERN OF DYSREGULATED BDNF METHYLATION IN REWARD-RELATED CIRCUITRY DID NOT MIMIC CHANGES SEEN IN SIRES. 2022 10 3331 28 HISTONE DEACETYLASE INHIBITOR SUBERANILOHYDROXAMIC ACID TREATMENT REVERSES HYPOSENSITIVITY TO GAMMA-AMINOBUTYRIC ACID IN THE VENTRAL TEGMENTAL AREA DURING ETHANOL WITHDRAWAL. BACKGROUND: THE VENTRAL TEGMENTAL AREA (VTA) IS IMPORTANT FOR ALCOHOL-RELATED REWARD AND REINFORCEMENT. MOUSE VTA NEURONS ARE HYPOSENSITIVE TO GAMMA-AMINOBUTYRIC ACID (GABA) DURING ETHANOL (ETOH) WITHDRAWAL, AND GABA RESPONSIVENESS IS NORMALIZED BY IN VITRO TREATMENT WITH HISTONE DEACETYLASE INHIBITORS (HDACI). THE PRESENT STUDY EXAMINED THE EFFECT OF A SYSTEMICALLY ADMINISTERED HDACI, SUBERANILOHYDROXAMIC ACID (SAHA) ON GABA SENSITIVITY, AND RELATED MOLECULAR CHANGES IN VTA NEURONS DURING WITHDRAWAL AFTER CHRONIC ETOH INTAKE IN RATS. METHODS: SPRAGUE DAWLEY MALE ADULT RATS WERE FED WITH LIEBER-DECARLI DIET (9% ETOH OR CONTROL DIET) FOR 16 DAYS. EXPERIMENTAL GROUPS INCLUDED CONTROL DIET-FED AND ETOH DIET-FED (0- OR 24-HOUR WITHDRAWAL) RATS TREATED WITH EITHER SAHA OR VEHICLE INJECTION. SINGLE-UNIT RECORDINGS WERE USED TO MEASURE THE RESPONSE OF VTA NEURONS TO GABA. IMMUNOHISTOCHEMISTRY WAS PERFORMED TO EXAMINE LEVELS OF HDAC2, ACETYLATED HISTONE H3 LYSINE 9 (ACH3K9), AND GABA(A) RECEPTOR ALPHA1 AND ALPHA5 SUBUNITS IN THE VTA; QUANTITATIVE POLYMERASE CHAIN REACTION WAS PERFORMED TO EXAMINE THE MRNA LEVELS OF HDAC2 AND GABA(A) RECEPTOR SUBUNITS. RESULTS: VTA NEURONS FROM THE WITHDRAWAL GROUP EXHIBITED GABA HYPOSENSITIVITY. IN VIVO SAHA TREATMENT 2 HOURS BEFORE SACRIFICE NORMALIZED THE SENSITIVITY OF VTA NEURONS TO GABA. ETOH WITHDRAWAL WAS ASSOCIATED WITH INCREASED HDAC2 AND DECREASED ACH3K9 PROTEIN LEVELS; SAHA TREATMENT NORMALIZED ACH3K9 LEVELS. INTERESTINGLY, NO SIGNIFICANT CHANGE WAS OBSERVED IN THE MRNA LEVELS OF HDAC2. THE MRNA LEVELS, BUT NOT PROTEIN LEVELS, OF GABA(A) RECEPTOR ALPHA1 AND ALPHA5 SUBUNITS WERE INCREASED DURING WITHDRAWAL. CONCLUSIONS: WITHDRAWAL FROM CHRONIC ETOH EXPOSURE RESULTS IN A DECREASE IN GABA-MEDIATED INHIBITION, AND THIS GABA HYPOSENSITIVITY IS NORMALIZED BY IN VIVO SAHA TREATMENT. DISRUPTION OF SIGNALING IN THE VTA PRODUCED BY ALTERATION OF GABA NEUROTRANSMISSION COULD BE 1 NEUROADAPTIVE PHYSIOLOGICAL PROCESS LEADING TO CRAVING AND RELAPSE. THESE RESULTS SUGGEST THAT HDACI PHARMACOTHERAPY WITH AGENTS LIKE SAHA MIGHT BE AN EFFECTIVE TREATMENT FOR ALCOHOLISM. 2018 11 5683 26 SHORTER TELOMERE LENGTH IN PERIPHERAL BLOOD LYMPHOCYTES OF WORKERS EXPOSED TO POLYCYCLIC AROMATIC HYDROCARBONS. SHORTER TELOMERE LENGTH (TL) IN PERIPHERAL BLOOD LYMPHOCYTES (PBLS) IS PREDICTIVE OF LUNG CANCER RISK. POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) ARE ESTABLISHED LUNG CARCINOGENS THAT CAUSE CHROMOSOME INSTABILITY. WHETHER PAH EXPOSURE AND ITS MOLECULAR EFFECTS ARE LINKED WITH SHORTER TL HAS NEVER BEEN EVALUATED. IN THE PRESENT STUDY, WE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO PAHS ON TL MEASURED IN PBLS OF POLISH MALE NON-CURRENT SMOKING COKEOVEN WORKERS AND MATCHED CONTROLS. PAH EXPOSURE AND MOLECULAR EFFECTS WERE CHARACTERIZED USING MEASURES OF INTERNAL DOSE (URINARY 1-PYRENOL), EFFECTIVE DOSE [ANTI-BENZO[A]PYRENE DIOLEPOXIDE (ANTI-BPDE)-DNA ADDUCT], GENETIC INSTABILITY (MICRONUCLEI, MN) AND DNA METHYLATION [P53 PROMOTER AND ALU AND LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) REPETITIVE ELEMENTS, AS SURROGATE MEASURES OF GLOBAL METHYLATION] IN PBLS. TL WAS MEASURED BY REAL-TIME POLYMERASE CHAIN REACTION. COKEOVEN WORKERS WERE HEAVILY EXPOSED TO PAHS (79% EXCEEDED THE URINARY 1-PYRENOL BIOLOGICAL EXPOSURE INDEX) AND EXHIBITED LOWER TL (P = 0.038) THAN CONTROLS, AS WELL AS HIGHER LEVELS OF GENETIC AND CHROMOSOMAL ALTERATIONS [I.E. ANTI-BPDE-DNA ADDUCT AND MN (P < 0.0001)] AND EPIGENETIC CHANGES [I.E. P53 GENE-SPECIFIC PROMOTER AND GLOBAL METHYLATION (P