1 1279 108 DE NOVO MUTATIONS IDENTIFIED BY WHOLE-GENOME SEQUENCING IMPLICATE CHROMATIN MODIFICATIONS IN OBSESSIVE-COMPULSIVE DISORDER. OBSESSIVE-COMPULSIVE DISORDER (OCD) IS A CHRONIC ANXIETY DISORDER WITH A SUBSTANTIAL GENETIC BASIS AND A BROADLY UNDISCOVERED ETIOLOGY. RECENT STUDIES OF DE NOVO MUTATION (DNM) EXOME-SEQUENCING STUDIES FOR OCD HAVE REINFORCED THE HYPOTHESIS THAT RARE VARIATION CONTRIBUTES TO THE RISK. WE PERFORMED, TO OUR KNOWLEDGE, THE FIRST WHOLE-GENOME SEQUENCING ON 53 PARENT-OFFSPRING FAMILIES WITH OFFSPRING AFFECTED WITH OCD TO INVESTIGATE ALL RARE DE NOVO VARIANTS AND INSERTIONS/DELETIONS. WE OBSERVED HIGHER MUTATION RATES IN PROMOTER-ANCHORED CHROMATIN LOOPS (EMPIRICAL P = 0.0015) AND REGIONS WITH HIGH FREQUENCIES OF HISTONE MARKS (EMPIRICAL P = 0.0001). MUTATIONS AFFECTING CODING REGIONS WERE SIGNIFICANTLY ENRICHED WITHIN COEXPRESSION MODULES OF GENES INVOLVED IN CHROMATIN MODIFICATION DURING HUMAN BRAIN DEVELOPMENT. FOUR GENES-SETD5, KDM3B, ASXL3, AND FBL-HAD STRONG AGGREGATED EVIDENCE AND FUNCTIONALLY CONVERGED ON TRANSCRIPTION'S EPIGENETIC REGULATION, SUGGESTING AN IMPORTANT OCD RISK MECHANISM. OUR DATA CHARACTERIZED DIFFERENT GENOME-WIDE DNMS AND HIGHLIGHTED THE CONTRIBUTION OF CHROMATIN MODIFICATION IN THE ETIOLOGY OF OCD. 2022 2 1545 34 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 3 6468 27 TISSUE-SPECIFIC ENRICHMENT OF LYMPHOMA RISK LOCI IN REGULATORY ELEMENTS. THOUGH NUMEROUS POLYMORPHISMS HAVE BEEN ASSOCIATED WITH RISK OF DEVELOPING LYMPHOMA, HOW THESE VARIANTS FUNCTION TO PROMOTE TUMORIGENESIS IS POORLY UNDERSTOOD. HERE, WE REPORT THAT LYMPHOMA RISK SNPS, ESPECIALLY IN THE NON-HODGKIN'S LYMPHOMA SUBTYPE CHRONIC LYMPHOCYTIC LEUKEMIA, ARE SIGNIFICANTLY ENRICHED FOR CO-LOCALIZATION WITH EPIGENETIC MARKS OF ACTIVE GENE REGULATION. THESE ENRICHMENTS WERE SEEN IN A LYMPHOID-SPECIFIC MANNER FOR NUMEROUS ENCODE DATASETS, INCLUDING DNASE-HYPERSENSITIVITY AS WELL AS MULTIPLE SEGMENTATION-DEFINED ENHANCER REGIONS. FURTHERMORE, WE IDENTIFY PUTATIVELY FUNCTIONAL SNPS THAT ARE BOTH IN REGULATORY ELEMENTS IN LYMPHOCYTES AND ARE ASSOCIATED WITH GENE EXPRESSION CHANGES IN BLOOD. WE DEVELOPED AN ALGORITHM, UES, THAT USES A MONTE CARLO SIMULATION APPROACH TO CALCULATE THE ENRICHMENT OF PREVIOUSLY IDENTIFIED RISK SNPS IN VARIOUS FUNCTIONAL ELEMENTS. THIS MULTISCALE APPROACH INTEGRATING MULTIPLE DATASETS HELPS DISENTANGLE THE UNDERLYING BIOLOGY OF LYMPHOMA, AND MORE BROADLY, IS GENERALLY APPLICABLE TO GWAS RESULTS FROM OTHER DISEASES AS WELL. 2015 4 6137 27 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 5 1584 25 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 6 2653 24 EPIGENOTYPING IN PERIPHERAL BLOOD CELL DNA AND BREAST CANCER RISK: A PROOF OF PRINCIPLE STUDY. BACKGROUND: EPIGENETIC CHANGES ARE EMERGING AS ONE OF THE MOST IMPORTANT EVENTS IN CARCINOGENESIS. TWO ALTERATIONS IN THE PATTERN OF DNA METHYLATION IN BREAST CANCER (BC) HAVE BEEN PREVIOUSLY REPORTED; ACTIVE ESTROGEN RECEPTOR-ALPHA (ER-ALPHA) IS ASSOCIATED WITH DECREASED METHYLATION OF ER-ALPHA TARGET (ERT) GENES, AND POLYCOMB GROUP TARGET (PCGT) GENES ARE MORE LIKELY THAN OTHER GENES TO HAVE PROMOTER DNA HYPERMETHYLATION IN CANCER. HOWEVER, WHETHER DNA METHYLATION IN NORMAL UNRELATED CELLS IS ASSOCIATED WITH BC RISK AND WHETHER THESE IMPRINTS CAN BE RELATED TO FACTORS WHICH CAN BE MODIFIED BY THE ENVIRONMENT, IS UNCLEAR. METHODOLOGY/PRINCIPAL FINDINGS: USING QUANTITATIVE METHYLATION ANALYSIS IN A CASE-CONTROL STUDY (N = 1,083) WE FOUND THAT DNA METHYLATION OF PERIPHERAL BLOOD CELL DNA PROVIDES GOOD PREDICTION OF BC RISK. WE ALSO REPORT THAT INVASIVE DUCTAL AND INVASIVE LOBULAR BC IS CHARACTERIZED BY TWO DIFFERENT SETS OF GENES, THE LATTER PARTICULAR BY GENES INVOLVED IN THE DIFFERENTIATION OF THE MESENCHYME (PITX2, TITF1, GDNF AND MYOD1). FINALLY WE DEMONSTRATE THAT ONLY ERT GENES PREDICT ER POSITIVE BC; LACK OF PERIPHERAL BLOOD CELL DNA METHYLATION OF ZNF217 PREDICTED BC INDEPENDENT OF AGE AND FAMILY HISTORY (ODDS RATIO 1.49; 95% CONFIDENCE INTERVAL 1.12-1.97; P = 0.006) AND WAS ASSOCIATED WITH ER-ALPHA BIOACTIVITY IN THE CORRESPONDING SERUM. CONCLUSION/SIGNIFICANCE: THIS FIRST LARGE-SCALE EPIGENOTYPING STUDY DEMONSTRATES THAT DNA METHYLATION MAY SERVE AS A LINK BETWEEN THE ENVIRONMENT AND THE GENOME. FACTORS THAT CAN BE MODULATED BY THE ENVIRONMENT (LIKE ESTROGENS) LEAVE AN IMPRINT IN THE DNA OF CELLS THAT ARE UNRELATED TO THE TARGET ORGAN AND INDICATE THE PREDISPOSITION TO DEVELOP A CANCER. FURTHER RESEARCH WILL NEED TO DEMONSTRATE WHETHER DNA METHYLATION PROFILES WILL BE ABLE TO SERVE AS A NEW TOOL TO PREDICT THE RISK OF DEVELOPING CHRONIC DISEASES WITH SUFFICIENT ACCURACY TO GUIDE PREVENTIVE MEASURES. 2008 7 20 37 5-HYDROXYMETHYLATION-ASSOCIATED EPIGENETIC MODIFIERS OF ALZHEIMER'S DISEASE MODULATE TAU-INDUCED NEUROTOXICITY. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISORDER CHARACTERIZED BY PROGRESSIVE DETERIORATION OF COGNITIVE FUNCTION. PATHOGENESIS OF AD IS INCOMPLETELY UNDERSTOOD; EVIDENCE SUGGESTS A ROLE FOR EPIGENETIC REGULATION, IN PARTICULAR THE CYTOSINE MODIFICATIONS 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE (5HMC). 5HMC IS ENRICHED IN THE NERVOUS SYSTEM AND DISPLAYS NEURODEVELOPMENT AND AGE-RELATED CHANGES. TO DETERMINE THE ROLE OF 5HMC IN AD, WE PERFORMED GENOME-WIDE ANALYSES OF 5HMC IN DNA FROM PREFRONTAL CORTEX OF POST-MORTEM AD PATIENTS, AND RNA-SEQ TO CORRELATE CHANGES IN 5HMC WITH TRANSCRIPTIONAL CHANGES. WE IDENTIFIED 325 GENES CONTAINING DIFFERENTIALLY HYDROXYMETHYLATED LOCI (DHMLS) IN BOTH DISCOVERY AND REPLICATION DATASETS. THESE ARE ENRICHED FOR PATHWAYS INVOLVED IN NEURON PROJECTION DEVELOPMENT AND NEUROGENESIS. OF THESE, 140 SHOWED CHANGES IN GENE EXPRESSION. PROTEINS ENCODED BY THESE GENES FORM DIRECT PROTEIN-PROTEIN INTERACTIONS WITH AD-ASSOCIATED GENES, EXPANDING THE NETWORK OF GENES IMPLICATED IN AD. WE IDENTIFIED AD-ASSOCIATED SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) LOCATED WITHIN OR NEAR DHMLS, SUGGESTING THESE SNPS MAY IDENTIFY REGIONS OF EPIGENETIC GENE REGULATION THAT PLAY A ROLE IN AD PATHOGENESIS. FINALLY, USING AN EXISTING AD FLY MODEL, WE SHOWED SOME OF THESE GENES MODULATE AD-ASSOCIATED TOXICITY. OUR DATA IMPLICATE NEURONAL PROJECTION DEVELOPMENT AND NEUROGENESIS PATHWAYS AS POTENTIAL TARGETS IN AD. BY INCORPORATING EPIGENOMIC AND TRANSCRIPTOMIC DATA WITH GENOME-WIDE ASSOCIATION STUDIES DATA, WITH VERIFICATION IN THE DROSOPHILA MODEL, WE CAN EXPAND THE KNOWN NETWORK OF GENES INVOLVED IN DISEASE PATHOGENESIS AND IDENTIFY EPIGENETIC MODIFIERS OF ALZHEIMER'S DISEASE. 2016 8 3740 33 INSIGHT INTO GENETIC PREDISPOSITION TO CHRONIC LYMPHOCYTIC LEUKEMIA FROM INTEGRATIVE EPIGENOMICS. GENOME-WIDE ASSOCIATION STUDIES HAVE PROVIDED EVIDENCE FOR INHERITED GENETIC PREDISPOSITION TO CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). TO GAIN INSIGHT INTO THE MECHANISMS UNDERLYING CLL RISK WE ANALYZE CHROMATIN ACCESSIBILITY, ACTIVE REGULATORY ELEMENTS MARKED BY H3K27AC, AND DNA METHYLATION AT 42 RISK LOCI IN UP TO 486 PRIMARY CLLS. WE IDENTIFY THAT RISK LOCI ARE SIGNIFICANTLY ENRICHED FOR ACTIVE CHROMATIN IN CLL WITH EVIDENCE OF BEING CLL-SPECIFIC OR DIFFERENTIALLY REGULATED IN NORMAL B-CELL DEVELOPMENT. WE THEN USE IN SITU PROMOTER CAPTURE HI-C, IN CONJUNCTION WITH GENE EXPRESSION DATA TO REVEAL LIKELY TARGET GENES OF THE RISK LOCI. CANDIDATE TARGET GENES ARE ENRICHED FOR PATHWAYS RELATED TO B-CELL DEVELOPMENT SUCH AS MYC AND BCL2 SIGNALLING. AT 14 LOCI THE ANALYSIS HIGHLIGHTS 63 VARIANTS AS THE PROBABLE FUNCTIONAL BASIS OF CLL RISK. BY INTEGRATING GENETIC AND EPIGENETIC INFORMATION OUR ANALYSIS REVEALS NOVEL INSIGHTS INTO THE RELATIONSHIP BETWEEN INHERITED PREDISPOSITION AND THE REGULATORY CHROMATIN LANDSCAPE OF CLL. 2019 9 2820 24 FINE-MAPPING INFLAMMATORY BOWEL DISEASE LOCI TO SINGLE-VARIANT RESOLUTION. INFLAMMATORY BOWEL DISEASES ARE CHRONIC GASTROINTESTINAL INFLAMMATORY DISORDERS THAT AFFECT MILLIONS OF PEOPLE WORLDWIDE. GENOME-WIDE ASSOCIATION STUDIES HAVE IDENTIFIED 200 INFLAMMATORY BOWEL DISEASE-ASSOCIATED LOCI, BUT FEW HAVE BEEN CONCLUSIVELY RESOLVED TO SPECIFIC FUNCTIONAL VARIANTS. HERE WE REPORT FINE-MAPPING OF 94 INFLAMMATORY BOWEL DISEASE LOCI USING HIGH-DENSITY GENOTYPING IN 67,852 INDIVIDUALS. WE PINPOINT 18 ASSOCIATIONS TO A SINGLE CAUSAL VARIANT WITH GREATER THAN 95% CERTAINTY, AND AN ADDITIONAL 27 ASSOCIATIONS TO A SINGLE VARIANT WITH GREATER THAN 50% CERTAINTY. THESE 45 VARIANTS ARE SIGNIFICANTLY ENRICHED FOR PROTEIN-CODING CHANGES (N = 13), DIRECT DISRUPTION OF TRANSCRIPTION-FACTOR BINDING SITES (N = 3), AND TISSUE-SPECIFIC EPIGENETIC MARKS (N = 10), WITH THE LAST CATEGORY SHOWING ENRICHMENT IN SPECIFIC IMMUNE CELLS AMONG ASSOCIATIONS STRONGER IN CROHN'S DISEASE AND IN GUT MUCOSA AMONG ASSOCIATIONS STRONGER IN ULCERATIVE COLITIS. THE RESULTS OF THIS STUDY SUGGEST THAT HIGH-RESOLUTION FINE-MAPPING IN LARGE SAMPLES CAN CONVERT MANY DISCOVERIES FROM GENOME-WIDE ASSOCIATION STUDIES INTO STATISTICALLY CONVINCING CAUSAL VARIANTS, PROVIDING A POWERFUL SUBSTRATE FOR EXPERIMENTAL ELUCIDATION OF DISEASE MECHANISMS. 2017 10 2105 30 EPIGENETIC EVIDENCE FOR INVOLVEMENT OF THE OXYTOCIN RECEPTOR GENE IN OBSESSIVE-COMPULSIVE DISORDER. BACKGROUND: OBSESSIVE-COMPULSIVE DISORDER (OCD) IS A CHRONIC NEURODEVELOPMENTAL DISORDER THAT AFFECTS UP TO 3% OF THE GENERAL POPULATION. ALTHOUGH EPIGENETIC MECHANISMS PLAY A ROLE IN NEURODEVELOPMENT DISORDERS, EPIGENETIC PATHWAYS ASSOCIATED WITH OCD HAVE RARELY BEEN INVESTIGATED. OXYTOCIN IS A NEUROPEPTIDE INVOLVED IN NEUROBEHAVIORAL FUNCTIONS. OXYTOCIN HAS BEEN SHOWN TO BE ASSOCIATED WITH THE REGULATION OF COMPLEX SOCIO-COGNITIVE PROCESSES SUCH AS ATTACHMENT, SOCIAL EXPLORATION, AND SOCIAL RECOGNITION, AS WELL AS ANXIETY AND OTHER STRESS-RELATED BEHAVIORS. OXYTOCIN HAS ALSO BEEN LINKED TO THE PATHOPHYSIOLOGY OF OCD, ALBEIT INCONSISTENTLY. THE AIM OF THIS STUDY WAS TO INVESTIGATE METHYLATION IN TWO TARGETS SEQUENCES LOCATED IN THE EXON III OF THE OXYTOCIN RECEPTOR GENE (OXTR), IN OCD PATIENTS AND HEALTHY CONTROLS. WE USED BISULFITE SEQUENCING TO QUANTIFY DNA METHYLATION IN PERIPHERAL BLOOD SAMPLES COLLECTED FROM 42 OCD PATIENTS AND 31 HEALTHY CONTROLS. RESULTS: WE FOUND THAT THE LEVEL OF METHYLATION OF THE CYTOSINE-PHOSPHATE-GUANINE SITES IN TWO TARGETS SEQUENCES ANALYZED WAS GREATER IN THE OCD PATIENTS THAN IN THE CONTROLS. THE HIGHER METHYLATION IN THE OCD PATIENTS CORRELATED WITH OCD SEVERITY. WE MEASURED DNA METHYLATION IN THE PERIPHERAL BLOOD, WHICH PREVENTED US FROM DRAWING ANY CONCLUSIONS ABOUT PROCESSES IN THE CENTRAL NERVOUS SYSTEM. CONCLUSION: TO OUR KNOWLEDGE, THIS IS THE FIRST STUDY INVESTIGATING DNA METHYLATION OF THE OXTR IN OCD. FURTHER STUDIES ARE NEEDED TO EVALUATE THE ROLES THAT DNA METHYLATION AND OXYTOCIN PLAY IN OCD. 2016 11 1050 26 CLINICAL FEATURES ASSOCIATED TO REFRACTORY OBSESSIVE-COMPULSIVE DISORDER. SOME PATIENTS WITH OBSESSIVE-COMPULSIVE DISORDER (OCD) EXHIBIT AN UNSATISFACTORY REDUCTION IN SYMPTOM SEVERITY DESPITE BEING TREATED WITH ALL THE AVAILABLE THERAPEUTIC ALTERNATIVES. THE CLINICAL VARIABLES ASSOCIATED WITH TREATMENT-REFRACTORINESS IN OCD ARE INCONSISTENTLY DESCRIBED IN THE LITERATURE. METHODS: TO INVESTIGATE FACTORS ASSOCIATED WITH TREATMENT-REFRACTORINESS OF PATIENTS WITH OCD, WE CONDUCTED A CASE-CONTROL STUDY, COMPARING 23 PATIENTS WITH TREATMENT-REFRACTORY OCD TO 26 PATIENTS WITH TREATMENT-RESPONDING OCD. RESULTS: THE FACTORS ASSOCIATED WITH REFRACTORINESS OF OCD WERE HIGHER SEVERITY OF SYMPTOMS SINCE THE ONSET OF OCD (P<0.001), CHRONIC COURSE (P=0.003), LACK OF A PARTNER (P=0.037), UNEMPLOYMENT (P=0.025), LOW ECONOMIC STATUS (P=0.015), PRESENCE OF OBSESSIVE-COMPULSIVE SYMPTOMS OF SEXUAL/RELIGIOUS CONTENT (P=0.043), AND HIGHER SCORES ON FAMILY ACCOMMODATION (P<0.001). ONLY THE THREE LATTER VARIABLES REMAINED SIGNIFICANTLY ASSOCIATED WITH TREATMENT-REFRACTORINESS AFTER REGRESSION ANALYSES. LIMITATIONS: SMALL SAMPLE SIZE, THE BIASES AND DRAWBACKS INHERENT TO A CASE-CONTROL STUDY, AND THE INCLUSION CRITERIA USED TO DEFINE THE STUDY GROUPS MAY HAVE LIMITED THE GENERALISATION OF THE RESULTS. CONCLUSION: A MAJOR STRENGTH OF THIS STUDY IS THE SYSTEMATIC AND STRUCTURED EVALUATION OF A VAST ARRAY OF VARIABLES RELATED TO THE CLINICAL EXPRESSION OF OCD, INCLUDING EPIGENETIC FACTORS AND RATINGS DERIVED FROM INSTRUMENTS EVALUATING FAMILY ACCOMMODATION. THE PRESENCE OF SEXUAL/RELIGIOUS SYMPTOMS, LOW ECONOMIC STATUS AND HIGH MODIFICATION ON FAMILY FUNCTION DUE TO OCD WERE INDEPENDENTLY ASSOCIATED WITH TREATMENT-REFRACTORINESS. FUTURE LONGITUDINAL STUDIES ARE WARRANTED TO VERIFY IF THESE VARIABLES REPRESENT PREDICTIVE FACTORS OF TREATMENT NON-RESPONSE. 2006 12 2209 25 EPIGENETIC MODIFICATIONS AND OBSESSIVE-COMPULSIVE DISORDER: WHAT DO WE KNOW? OBSESSIVE-COMPULSIVE DISORDER (OCD) IS A CHRONIC, SEVERE DISABLING NEUROPSYCHIATRIC DISORDER WHOSE PATHOPHYSIOLOGY IS NOT YET WELL DEFINED. GENERALLY, THE SYMPTOM ONSET OCCURS DURING PRE-ADULT LIFE AND AFFECTS SUBJECTS IN DIFFERENT LIFE ASPECTS, INCLUDING PROFESSIONAL AND SOCIAL RELATIONSHIPS. ALTHOUGH ROBUST EVIDENCE INDICATES THE PRESENCE OF GENETIC FACTORS IN THE ETIOPATHOLOGY OF OCD, THE ENTIRELY MECHANISMS ARE NOT TOTALLY CLARIFIED. THUS, THE POSSIBLE INTERACTIONS BETWEEN GENES AND ENVIRONMENTAL RISK FACTORS MEDIATED BY EPIGENETIC MECHANISMS SHOULD BE SOUGHT. THEREFORE, WE PROVIDE A REVIEW OF GENETIC AND EPIGENETIC MECHANISMS RELATED TO OCD WITH A DEEP FOCUS ON THE REGULATION OF CRITICAL GENES OF THE CENTRAL NERVOUS SYSTEM SEEKING POSSIBLE POTENTIAL BIOMARKERS. 2023 13 3455 33 HYPOMETHYLATION COORDINATES ANTAGONISTICALLY WITH HYPERMETHYLATION IN CANCER DEVELOPMENT: A CASE STUDY OF LEUKEMIA. BACKGROUND: METHYLATION CHANGES ARE FREQUENT IN CANCERS, BUT UNDERSTANDING HOW HYPER- AND HYPOMETHYLATED REGION CHANGES COORDINATE, ASSOCIATE WITH GENOMIC FEATURES, AND AFFECT GENE EXPRESSION IS NEEDED TO BETTER UNDERSTAND THEIR BIOLOGICAL SIGNIFICANCE. THE FUNCTIONAL SIGNIFICANCE OF HYPERMETHYLATION IS WELL STUDIED, BUT THAT OF HYPOMETHYLATION REMAINS LIMITED. HERE, WITH PAIRED EXPRESSION AND METHYLATION SAMPLES GATHERED FROM A PATIENT/CONTROL COHORT, WE ATTEMPT TO BETTER CHARACTERIZE THE GENE EXPRESSION AND METHYLATION CHANGES THAT TAKE PLACE IN CANCER FROM B CELL CHRONIC LYMPHOCYTE LEUKEMIA (B-CLL) SAMPLES. RESULTS: ACROSS THE DATASET, WE FOUND THAT CONSISTENT DIFFERENTIALLY HYPOMETHYLATED REGIONS (C-DMRS) ACROSS SAMPLES WERE RELATIVELY FEW COMPARED TO THE MANY POORLY CONSISTENT HYPO- AND HIGHLY CONSERVED HYPER-DMRS. HOWEVER, GENES IN THE HYPO-C-DMRS TENDED TO BE ASSOCIATED WITH FUNCTIONS ANTAGONISTIC TO THOSE IN THE HYPER-C-DMRS, LIKE DIFFERENTIATION, CELL-CYCLE REGULATION AND PROLIFERATION, SUGGESTING COORDINATED REGULATION OF METHYLATION CHANGES. HYPO-C-DMRS IN B-CLL WERE FOUND ENRICHED IN KEY SIGNALING PATHWAYS LIKE B CELL RECEPTOR AND P53 PATHWAYS AND GENES/MOTIFS ESSENTIAL FOR B LYMPHOPOIESIS. HYPO-C-DMRS TENDED TO BE PROXIMAL TO GENES WITH ELEVATED EXPRESSION IN CONTRAST TO THE TRANSCRIPTION SILENCING-MECHANISM IMPOSED BY HYPERMETHYLATION. HYPO-C-DMRS TENDED TO BE ENRICHED IN THE REGIONS OF ACTIVATING H4K4ME1/2/3, H3K79ME2, AND H3K27AC HISTONE MODIFICATIONS. IN COMPARISON, THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) SIGNATURE, MARKED BY EZH2, SUZ12, CTCF BINDING-SITES, REPRESSIVE H3K27ME3 MARKS, AND "REPRESSED/POISED PROMOTER" STATES WERE ASSOCIATED WITH HYPER-C-DMRS. MOST HYPO-C-DMRS WERE FOUND IN INTRONS (36 %), 3' UNTRANSLATED REGIONS (29 %), AND INTERGENIC REGIONS (24 %). MANY OF THESE GENIC REGIONS ALSO OVERLAPPED WITH ENHANCERS. THE METHYLATION OF CPGS FROM 3'UTR EXONS WAS FOUND TO HAVE WEAK BUT POSITIVE CORRELATION WITH GENE EXPRESSION. IN CONTRAST, METHYLATION IN THE 5'UTR WAS NEGATIVELY CORRELATED WITH EXPRESSION. TO BETTER CHARACTERIZE THE OVERLAP BETWEEN METHYLATION AND EXPRESSION CHANGES, WE IDENTIFIED CORRELATION MODULES THAT ASSOCIATE WITH "APOPTOSIS" AND "LEUKOCYTE ACTIVATION". CONCLUSIONS: DESPITE CLINICAL HETEROGENEITY IN DISEASE PRESENTATION, A NUMBER OF METHYLATION CHANGES, BOTH HYPO AND HYPER, APPEAR TO BE COMMON IN B-CLL. HYPOMETHYLATION APPEARS TO PLAY AN ACTIVE, TARGETED, AND COMPLEMENTARY ROLE IN CANCER PROGRESSION, AND IT INTERPLAYS WITH HYPERMETHYLATION IN A COORDINATED FASHION IN THE CANCER PROCESS. 2016 14 1587 32 DNA METHYLATION PROFILING IDENTIFIES NOVEL MARKERS OF PROGRESSION IN HEPATITIS B-RELATED CHRONIC LIVER DISEASE. BACKGROUND: CHRONIC HEPATITIS B INFECTION IS CHARACTERIZED BY HEPATIC IMMUNE AND INFLAMMATORY RESPONSE WITH CONSIDERABLE VARIATION IN THE RATES OF PROGRESSION TO CIRRHOSIS. GENETIC VARIANTS AND ENVIRONMENTAL CUES INFLUENCE PREDISPOSITION TO THE DEVELOPMENT OF CHRONIC LIVER DISEASE; HOWEVER, IT REMAINS UNKNOWN IF ABERRANT DNA METHYLATION IS ASSOCIATED WITH FIBROSIS PROGRESSION IN CHRONIC HEPATITIS B. RESULTS: TO IDENTIFY EPIGENETIC MARKS ASSOCIATED WITH INFLAMMATORY AND FIBROTIC PROCESSES OF THE HEPATITIS B-INDUCED CHRONIC LIVER DISEASE, WE CARRIED OUT HEPATIC GENOME-WIDE METHYLATION PROFILING USING ILLUMINA INFINIUM BEADARRAYS COMPARING MILD AND SEVERE FIBROTIC DISEASE IN A DISCOVERY COHORT OF 29 PATIENTS. WE OBTAINED 310 DIFFERENTIALLY METHYLATED REGIONS AND SELECTED FOUR LOCI COMPRISING THREE GENES FROM THE TOP DIFFERENTIALLY METHYLATED REGIONS: HYPERMETHYLATION OF HOXA2 AND HDAC4 ALONG WITH HYPOMETHYLATION OF PPP1R18 WERE SIGNIFICANTLY LINKED TO SEVERE FIBROSIS. WE REPLICATED THE PROMINENT METHYLATION MARKS IN AN INDEPENDENT COHORT OF 102 PATIENTS BY BISULFITE MODIFICATION AND PYROSEQUENCING. THE TIMING AND CAUSAL RELATIONSHIP OF EPIGENETIC MODIFICATIONS WITH DISEASE SEVERITY WAS FURTHER INVESTIGATED USING A COHORT OF PATIENTS WITH SERIAL BIOPSIES. CONCLUSIONS: OUR FINDINGS SUGGEST A LINKAGE OF WIDESPREAD EPIGENETIC DYSREGULATION WITH DISEASE PROGRESSION IN CHRONIC HEPATITIS B INFECTION. CPG METHYLATION AT NOVEL GENES SHEDS LIGHT ON NEW MOLECULAR PATHWAYS, WHICH CAN BE POTENTIALLY EXPLOITED AS A BIOMARKER OR TARGETED TO ATTENUATE INFLAMMATION AND FIBROSIS. 2016 15 1567 28 DNA METHYLATION OF THE KLF14 GENE REGION IN WHOLE BLOOD CELLS PROVIDES PREDICTION FOR THE CHRONIC INFLAMMATION IN THE ADIPOSE TISSUE. KRUPPEL-LIKE FACTOR 14 (KLF14) GENE, WHICH APPEARS TO BE A MASTER REGULATOR OF GENE EXPRESSION IN THE ADIPOSE TISSUE AND HAVE PREVIOUSLY BEEN ASSOCIATED WITH BMI AND TYPE 2 DIABETES (T2D) BY LARGE GENOME-WIDE ASSOCIATION STUDIES. IN ORDER TO FIND PREDICTIVE BIOMARKERS FOR THE DEVELOPMENT OF T2D, IT IS NECESSARY TO TAKE EPIGENOMIC CHANGES AFFECTED BY ENVIRONMENTAL FACTORS INTO ACCOUNT. THIS STUDY FOCUSES ON AGEING AND OBESITY, WHICH ARE T2D RISK FACTORS, AND EXAMINES EPIGENETIC CHANGES AND INFLAMMATORY CHANGES. WE INVESTIGATED DNA METHYLATION CHANGES IN THE KLF14 PROMOTER REGION IN DIFFERENT ORGANS OF MICE FOR COMPARING AGING AND WEIGHT. WE FOUND THAT METHYLATION LEVELS OF THESE SITES WERE INCREASED WITH AGING AND WEIGHT IN THE SPLEEN, THE ADIPOSE TISSUE, THE KIDNEY, THE LUNG, THE COLON AND THE WHOLE BLOOD CELLS. IN ADDITION, IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD, THESE EPIGENETIC CHANGES WERE ALSO SIGNIFICANTLY ASSOCIATED WITH INFLAMMATORY LEVELS. MOREOVER, NOT ONLY KLF14, BUT ALSO EXPRESSION LEVELS OF SOME DOWNSTREAM GENES WERE DECREASED WITH METHYLATION IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT METHYLATION CHANGES OF KLF14 IN THOSE TISSUES MAY BE ASSOCIATED WITH CHANGES IN GENE EXPRESSION AND INFLAMMATION ON THE ADIPOSE TISSUE OF OBESITY AND T2D. IN ADDITION, THE METHYLATION CHANGES IN THE WHOLE BLOOD CELLS MAY SERVE AS A PREDICTIVE EPIGENETIC BIOMARKER FOR THE DEVELOPMENT OF T2D. 2018 16 6195 19 THE IMPACT OF RECENT ALCOHOL USE ON GENOME WIDE DNA METHYLATION SIGNATURES. CHRONIC ALCOHOL INTAKE IS ASSOCIATED WITH A WIDE VARIETY OF ADVERSE HEALTH OUTCOMES INCLUDING DEPRESSION, DIABETES, AND HEART DISEASE. UNFORTUNATELY, THE MOLECULAR MECHANISMS THROUGH WHICH THESE EFFECTS ARE CONVEYED ARE NOT CLEARLY UNDERSTOOD. TO EXAMINE THE POTENTIAL ROLE OF EPIGENETIC FACTORS IN THIS PROCESS, WE EXAMINED THE RELATIONSHIP OF RECENT ALCOHOL INTAKE TO GENOME WIDE METHYLATION PATTERNS USING THE ILLUMINA 450 METHYLATION BEAD CHIP AND LYMPHOBLAST DNA DERIVED FROM 165 FEMALE SUBJECTS PARTICIPATING IN THE IOWA ADOPTION STUDIES. WE FOUND THAT THE PATTERN OF ALCOHOL USE OVER THE 6-MONTHS IMMEDIATELY PRIOR TO PHLEBOTOMY WAS ASSOCIATED WITH, SEVERITY-DEPENDENT CHANGES IN THE DEGREE OF GENOME WIDE METHYLATION THAT PREFERENTIALLY HYPERMETHYLATE THE CENTRAL PORTION OF CPG ISLANDS WITH METHYLATION AT CG05600126, A PROBE IN ABR, AND THE 5' UNTRANSLATED REGION OF BLCAP ATTAINING GENOME WIDE SIGNIFICANCE IN TWO POINT AND SLIDING WINDOW ANALYSES OF PROBE METHYLATION DATA, RESPECTIVELY. WE CONCLUDE THAT RECENT ALCOHOL USE IS ASSOCIATED WITH WIDESPREAD CHANGES IN DNA METHYLATION IN WOMEN AND THAT FURTHER STUDY TO CONFIRM THESE FINDINGS AND DETERMINE THEIR RELATIONSHIP TO SOMATIC FUNCTION ARE IN ORDER. 2012 17 3473 31 IDENTIFICATION OF A NOVEL, METHYLATION-DEPENDENT, RUNX2 REGULATORY REGION ASSOCIATED WITH OSTEOARTHRITIS RISK. OSTEOARTHRITIS (OA) IS A COMMON, MULTIFACTORIAL AND POLYGENIC SKELETAL DISEASE THAT, IN ITS SEVEREST FORM, REQUIRES JOINT REPLACEMENT SURGERY TO RESTORE MOBILITY AND TO RELIEVE CHRONIC PAIN. USING TISSUES FROM THE ARTICULATING JOINTS OF 260 PATIENTS WITH OA AND A RANGE OF IN VITRO EXPERIMENTS, INCLUDING CRISPR-CAS9, WE HAVE CHARACTERIZED AN INTERGENIC REGULATORY ELEMENT. HERE, GENOTYPE AT AN OA RISK LOCUS CORRELATES WITH DIFFERENTIAL DNA METHYLATION, WITH ALTERED GENE EXPRESSION OF BOTH A TRANSCRIPTIONAL REGULATOR (RUNX2), AND A CHROMATIN REMODELLING PROTEIN (SUPT3H). RUNX2 IS A STRONG CANDIDATE FOR OA SUSCEPTIBILITY, WITH ITS ENCODED PROTEIN BEING ESSENTIAL FOR SKELETOGENESIS AND HEALTHY JOINT FUNCTION. THE OA RISK LOCUS INCLUDES SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) LOCATED WITHIN AND FLANKING THE DIFFERENTIALLY METHYLATED REGION (DMR). THE OA ASSOCIATION SNP, RS10948172, DEMONSTRATES PARTICULARLY STRONG CORRELATION WITH METHYLATION, AND TWO INTERGENIC SNPS FALLING WITHIN THE DMR (RS62435998 AND RS62435999) DEMONSTRATE GENETIC AND EPIGENETIC EFFECTS ON THE REGULATORY ACTIVITY OF THIS REGION. WE THEREFORE POSIT THAT THE OA SIGNAL MEDIATES ITS EFFECT BY MODULATING THE METHYLATION OF THE REGULATORY ELEMENT, WHICH THEN IMPACTS ON GENE EXPRESSION, WITH RUNX2 BEING THE PRINCIPAL TARGET. OUR STUDY HIGHLIGHTS THE INTERPLAY BETWEEN DNA METHYLATION, OA GENETIC RISK AND THE DOWNSTREAM REGULATION OF GENES CRITICAL TO NORMAL JOINT FUNCTION. 2018 18 1607 26 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 19 3076 27 GENOME-WIDE EPIGENOMIC ANALYSES IN PATIENTS WITH NOCICEPTIVE AND NEUROPATHIC CHRONIC PAIN SUBTYPES REVEALS ALTERATIONS IN METHYLATION OF GENES INVOLVED IN THE NEURO-MUSCULOSKELETAL SYSTEM. NOCICEPTIVE PAIN INVOLVES THE ACTIVATION OF NOCICEPTORS WITHOUT DAMAGE TO THE NERVOUS SYSTEM, WHEREAS NEUROPATHIC PAIN IS RELATED TO AN ALTERATION IN THE CENTRAL OR PERIPHERAL NERVOUS SYSTEM. CHRONIC PAIN ITSELF AND THE TRANSITION FROM ACUTE TO CHRONIC PAIN MAY BE EPIGENETICALLY CONTROLLED. IN THIS CROSS-SECTIONAL STUDY, A GENOME-WIDE DNA METHYLATION ANALYSIS WAS PERFORMED USING THE BLOOD DNA REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS) TECHNIQUE. THREE PROSPECTIVE COHORTS INCLUDING 20 HEALTHY CONTROLS (CTL), 18 PATIENTS WITH CHRONIC NOCICEPTIVE PAIN (NOCI), AND 19 PATIENTS WITH CHRONIC NEUROPATHIC PAIN (NEURO) WERE COMPARED AT BOTH THE SINGLE CPG AND DIFFERENTIALLY METHYLATED REGION (DMR) LEVELS. GENES WITH DMRS WERE SEEN IN THE NOCI AND NEURO GROUPS BELONGED TO THE NEURO-MUSCULOSKELETAL SYSTEM AND DIFFERED BETWEEN NOCI AND NEURO PATIENTS. OUR RESULTS DEMONSTRATE THAT THE EPIGENETIC DISTURBANCES ACCOMPANYING NOCICEPTIVE PAIN ARE VERY DIFFERENT FROM THOSE ACCOMPANYING NEUROPATHIC PAIN. IN THE FORMER, AMONG OTHERS, THE EPIGENETIC DISTURBANCE OBSERVED WOULD AFFECT THE FUNCTION OF THE OPIOID ANALGESIC SYSTEM, WHEREAS IN THE LATTER IT WOULD AFFECT THAT OF THE GABAERGIC REWARD SYSTEM. THIS STUDY PRESENTS BIOLOGICAL FINDINGS THAT HELP TO CHARACTERIZE NOCI- AND NEURO-AFFECTED PATHWAYS AND OPENS THE POSSIBILITY OF DEVELOPING EPIGENETIC DIAGNOSTIC ASSAYS. PERSPECTIVE: OUR RESULTS HELP TO EXPLAIN THE VARIOUS BIOLOGICAL PATHWAYS MODIFICATIONS UNDERLYING THE DIFFERENT CLINICAL MANIFESTATIONS OF NOCICEPTIVE AND NEUROPATHIC PAINS. FURTHERMORE, THE NEW TARGETS IDENTIFIED IN OUR STUDY MIGHT HELP TO DISCOVER MORE SPECIFIC TREATMENTS FOR NOCICEPTIVE OR NEUROPATHIC PAINS. 2022 20 381 30 AN EPIGENOME-WIDE ASSOCIATION STUDY OF EARLY-ONSET MAJOR DEPRESSION IN MONOZYGOTIC TWINS. MAJOR DEPRESSION (MD) IS A DEBILITATING MENTAL HEALTH CONDITION WITH PEAK PREVALENCE OCCURRING EARLY IN LIFE. GENOME-WIDE EXAMINATION OF DNA METHYLATION (DNAM) OFFERS AN ATTRACTIVE COMPLEMENT TO STUDIES OF ALLELIC RISK GIVEN IT CAN REFLECT THE COMBINED INFLUENCE OF GENES AND ENVIRONMENT. THE CURRENT STUDY USED MONOZYGOTIC TWINS TO IDENTIFY DIFFERENTIALLY AND VARIABLY METHYLATED REGIONS OF THE GENOME THAT DISTINGUISH TWINS WITH AND WITHOUT A LIFETIME HISTORY OF EARLY-ONSET MD. THE SAMPLE INCLUDED 150 CAUCASIAN MONOZYGOTIC TWINS BETWEEN THE AGES OF 15 AND 20 (73% FEMALE; MAGE = 17.52 SD = 1.28) WHO WERE ASSESSED DURING A DEVELOPMENTAL STAGE CHARACTERIZED BY RELATIVELY DISTINCT NEUROPHYSIOLOGICAL CHANGES. ALL TWINS WERE GENERALLY HEALTHY AND CURRENTLY FREE OF MEDICATIONS WITH PSYCHOTROPIC EFFECTS. DNAM WAS MEASURED IN PERIPHERAL BLOOD CELLS USING THE INFINIUM HUMAN BEADCHIP 450 K ARRAY. MD ASSOCIATIONS WITH EARLY-ONSET MD WERE DETECTED AT 760 DIFFERENTIALLY AND VARIABLY METHYLATED PROBES/REGIONS THAT MAPPED TO 428 GENES. GENES AND GENOMIC REGIONS INVOLVED NEURAL CIRCUITRY FORMATION, PROJECTION, FUNCTIONING, AND PLASTICITY. GENE ENRICHMENT ANALYSES IMPLICATED GENES RELATED TO NEURON STRUCTURES AND NEURODEVELOPMENTAL PROCESSES INCLUDING CELL-CELL ADHESION GENES (E.G., PCDHA GENES). GENES PREVIOUSLY IMPLICATED IN MOOD AND PSYCHIATRIC DISORDERS AS WELL AS CHRONIC STRESS (E.G., NRG3) ALSO WERE IDENTIFIED. DNAM REGIONS ASSOCIATED WITH EARLY-ONSET MD WERE FOUND TO OVERLAP GENETIC LOCI IDENTIFIED IN THE LATEST PSYCHIATRIC GENOMICS CONSORTIUM META-ANALYSIS OF DEPRESSION. UNDERSTANDING THE TIME COURSE OF EPIGENETIC INFLUENCES DURING EMERGING ADULTHOOD MAY CLARIFY DEVELOPMENTAL PHASES WHERE CHANGES IN THE DNA METHYLOME MAY MODULATE INDIVIDUAL DIFFERENCES IN MD RISK. 2020