1 1560 157 DNA METHYLATION OF ALZHEIMER DISEASE AND TAUOPATHY-RELATED GENES IN POSTMORTEM BRAIN. DNA METHYLATION OCCURS PREDOMINANTLY AT CYTOSINES THAT PRECEDE GUANINES IN DINUCLEOTIDE CPG SITES; IT IS ONE OF THE MOST IMPORTANT MECHANISMS FOR EPIGENETIC DNA REGULATION DURING NORMAL DEVELOPMENT AND FOR ABERRANT DNA IN CANCER. TO DETERMINE THE FEASIBILITY OF DNA METHYLATION STUDIES IN THE POSTMORTEM HUMAN BRAIN, WE EVALUATED BRAIN SAMPLES WITH VARIABLE POSTMORTEM ARTIFICIALLY INCREASED DELAYS UP TO 48 HOURS. DNA METHYLATION WAS ANALYZED IN SELECTED REGIONS OF MAPT, APP, AND PSEN1 IN THE FRONTAL CORTEX AND HIPPOCAMPUS OF CONTROLS (N=26) AND THOSE WITH ALZHEIMER DISEASE AT STAGES I TO II (N=17); ALZHEIMER DISEASE AT STAGES III TO IV (N=15); ALZHEIMER DISEASE AT STAGES V TO VI (N=12); ARGYROPHILIC GRAIN DISEASE (N=10); FRONTOTEMPORAL LOBAR DEGENERATION LINKED TO TAU MUTATIONS (N=6); FRONTOTEMPORAL LOBAR DEGENERATION WITH UBIQUITIN-IMMUNOREACTIVE INCLUSIONS (N=4); FRONTOTEMPORAL LOBAR DEGENERATION WITH MOTOR NEURON DISEASE (N=3); PICK DISEASE (N=3); PARKINSON DISEASE (N=8); DEMENTIA WITH LEWY BODIES, PURE FORM (N=5); AND DEMENTIA WITH LEWY BODIES, COMMON FORM (N=15). UCHL1 (UBIQUITIN CARBOXYL-TERMINAL HYDROLASE 1 GENE) WAS ANALYZED IN THE FRONTAL CORTEX OF CONTROLS AND THOSE WITH PARKINSON DISEASE AND RELATED SYNUCLEINOPATHIES. DNA METHYLATION SITES WERE VERY REPRODUCIBLE IN EVERY CASE. NO DIFFERENCES IN THE PERCENTAGE OF CPG METHYLATION WERE FOUND BETWEEN CONTROL AND DISEASE SAMPLES OR AMONG THE DIFFERENT PATHOLOGICAL ENTITIES IN ANY REGION ANALYZED. BECAUSE SMALL CHANGES IN METHYLATION OF DNA PROMOTERS IN VULNERABLE CELLS MIGHT HAVE NOT BEEN DETECTED IN TOTAL HOMOGENATES, HOWEVER, THESE RESULTS SHOULD BE INTERPRETED WITH CAUTION, PARTICULARLY AS THEY RELATE TO CHRONIC DEGENERATIVE DISEASES IN WHICH SMALL MODIFICATIONS MAY BE SUFFICIENT TO MODULATE DISEASE PROGRESSION. 2009 2 1600 32 DNA METHYLATION SIGNATURES OF ALZHEIMER'S DISEASE NEUROPATHOLOGY IN THE CORTEX ARE PRIMARILY DRIVEN BY VARIATION IN NON-NEURONAL CELL-TYPES. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISEASE CHARACTERIZED BY THE PROGRESSIVE ACCUMULATION OF AMYLOID-BETA AND NEUROFIBRILLARY TANGLES OF TAU IN THE NEOCORTEX. WE PROFILED DNA METHYLATION IN TWO REGIONS OF THE CORTEX FROM 631 DONORS, PERFORMING AN EPIGENOME-WIDE ASSOCIATION STUDY OF MULTIPLE MEASURES OF AD NEUROPATHOLOGY. WE META-ANALYZED OUR RESULTS WITH THOSE FROM PREVIOUS STUDIES OF DNA METHYLATION IN AD CORTEX (TOTAL N = 2013 DONORS), IDENTIFYING 334 CORTICAL DIFFERENTIALLY METHYLATED POSITIONS (DMPS) ASSOCIATED WITH AD PATHOLOGY INCLUDING METHYLOMIC VARIATION AT LOCI NOT PREVIOUSLY IMPLICATED IN DEMENTIA. WE SUBSEQUENTLY PROFILED DNA METHYLATION IN NEUN+ (NEURONAL-ENRICHED), SOX10+ (OLIGODENDROCYTE-ENRICHED) AND NEUN-/SOX10- (MICROGLIA- AND ASTROCYTE-ENRICHED) NUCLEI, FINDING THAT THE MAJORITY OF DMPS IDENTIFIED IN 'BULK' CORTEX TISSUE REFLECT DNA METHYLATION DIFFERENCES OCCURRING IN NON-NEURONAL CELLS. OUR STUDY HIGHLIGHTS THE POWER OF UTILIZING MULTIPLE MEASURES OF NEUROPATHOLOGY TO IDENTIFY EPIGENETIC SIGNATURES OF AD AND THE IMPORTANCE OF CHARACTERIZING DISEASE-ASSOCIATED VARIATION IN PURIFIED CELL-TYPES. 2022 3 1584 32 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 4 20 36 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 5 1537 30 DNA METHYLATION IN ADOLESCENTS WITH ANXIETY DISORDER: A LONGITUDINAL STUDY. ANXIETY DISORDERS (AD) TYPICALLY MANIFEST IN CHILDREN AND ADOLESCENTS AND MIGHT PERSIST INTO ADULTHOOD. HOWEVER, THERE ARE STILL FEW DATA CONCERNING EPIGENETIC MECHANISMS ASSOCIATED WITH ONSET, PERSISTENCE OR REMISSION OF AD OVER TIME. WE INVESTIGATED A COHORT OF ADOLESCENTS AND YOUNG ADULTS AT BASELINE (AGE; 13.19 +/- 2.38) AND AFTER 5 YEARS AND CLASSIFIED THEM ACCORDING TO THE AD DIAGNOSIS AND THEIR LONGITUDINAL TRAJECTORIES INTO 4 GROUPS: (1) TYPICALLY DEVELOPING COMPARISONS (TDC; CONTROL GROUP, N = 14); (2) INCIDENT (AD IN THE SECOND EVALUATION ONLY, N = 11); (3) PERSISTENT (AD IN BOTH EVALUATIONS, N = 14) AND (4) REMITTENT (AD IN THE FIRST EVALUATION ONLY, N = 8). DNA METHYLATION WAS EVALUATED WITH THE INFINIUM HUMANMETHYLATION450 BEADCHIP FROM SALIVA SAMPLES COLLECTED AT BOTH EVALUATIONS. GENE SET ENRICHMENT ANALYSIS WAS APPLIED TO CONSIDER BIOLOGICAL PATHWAYS. WE FOUND DECREASED DNA METHYLATION IN TDC GROUP WHILE THE CHRONIC CASES OF AD PRESENTED HYPERMETHYLATION IN CENTRAL NERVOUS SYSTEM DEVELOPMENT PATHWAYS. MOREOVER, WE SHOWED THAT THIS PERSISTENT GROUP ALSO PRESENTED HYPERMETHYLATION WHILE THE OTHER THREE GROUPS WERE ASSOCIATED WITH HYPOMETHYLATION IN NERVOUS SYSTEM DEVELOPMENT PATHWAY. INCIDENCE AND REMISSION GROUPS WERE ASSOCIATED WITH INCREASED AND DECREASED METHYLATION IN NEURON DEVELOPMENT PATHWAYS, RESPECTIVELY. LARGER STUDIES ARE LIKELY TO DETECT SPECIFIC GENES RELEVANT TO AD. 2018 6 2654 33 EPILEPSY PROGRESSION IS ASSOCIATED WITH CUMULATIVE DNA METHYLATION CHANGES IN INFLAMMATORY GENES. MESIAL TEMPORAL LOBE EPILEPSY WITH HIPPOCAMPAL SCLEROSIS (MTLE-HS) IS THE MOST COMMON FOCAL EPILEPSY IN ADULTS. IT IS CHARACTERIZED BY ALARMING RATES OF PHARMACORESISTANCE. EPILEPTOGENESIS IS ASSOCIATED WITH THE OCCURRENCE OF EPIGENETIC ALTERATIONS, AND THE FEW EPIGENETIC STUDIES CARRIED OUT IN MTLE-HS HAVE MAINLY FOCUSED ON THE HIPPOCAMPUS. IN THIS STUDY, WE OBTAINED THE DNA METHYLATION PROFILES FROM BOTH THE HIPPOCAMPUS AND ANTERIOR TEMPORAL NEOCORTEX OF MTLE-HS PATIENTS SUBJECTED TO RESECTIVE EPILEPSY SURGERY AND AUTOPSIED NON-EPILEPTIC CONTROLS. WE ASSESSED THE PROGRESSIVE NATURE OF DNA METHYLATION CHANGES IN RELATION TO EPILEPSY DURATION. WE IDENTIFIED SIGNIFICANTLY ALTERED HIPPOCAMPAL DNA METHYLATION PATTERNS ENCOMPASSING MULTIPLE PATHWAYS KNOWN TO BE INVOLVED IN EPILEPTOGENESIS. DNA METHYLATION CHANGES WERE EVEN MORE STRIKING IN THE NEOCORTEX, WHEREIN PATHOGENIC PATHWAYS AND GENES WERE COMMON TO BOTH TISSUES. MOST IMPORTANTLY, DNA METHYLATION CHANGES AT MANY GENOMIC SITES VARIED SIGNIFICANTLY WITH EPILEPSY DURATION. SUCH PROGRESSIVE CHANGES WERE ASSOCIATED WITH INFLAMMATION-RELATED GENES IN THE HIPPOCAMPUS. OUR RESULTS SUGGEST THAT THE NEOCORTEX, RELATIVELY SPARED OF EXTENSIVE HISTOPATHOLOGICAL DAMAGE, MAY ALSO BE INVOLVED IN EPILEPSY DEVELOPMENT. THESE RESULTS ALSO OPEN THE POSSIBILITY THAT THE OBSERVED NEOCORTICAL IMPAIRMENT COULD REPRESENT A PRELIMINARY STAGE OF EPILEPTOGENESIS BEFORE THE ESTABLISHMENT OF CHRONIC LESIONS OR A CONSEQUENCE OF PROLONGED SEIZURE EXPOSURE. OUR TWO-TISSUE MULTI-LEVEL CHARACTERIZATION OF THE MTLE-HS DNA METHYLOME SUGGESTS THE OCCURRENCE OF A SELF-PROPAGATING INFLAMMATORY WAVE OF EPIGENETIC DYSREGULATION. 2022 7 381 36 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 8 3076 34 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 9 2653 38 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 10 3077 30 GENOME-WIDE METHYL-SEQ ANALYSIS OF BLOOD-BRAIN TARGETS OF GLUCOCORTICOID EXPOSURE. CHRONIC EXPOSURE TO GLUCOCORTICOIDS (GCS) CAN LEAD TO PSYCHIATRIC COMPLICATIONS THROUGH EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION (DNAM). WE SOUGHT TO DETERMINE WHETHER EPIGENETIC CHANGES IN A PERIPHERAL TISSUE CAN SERVE AS A SURROGATE FOR THOSE IN A RELATIVELY INACCESSIBLE TISSUE SUCH AS THE BRAIN. DNA EXTRACTED FROM THE HIPPOCAMPUS AND BLOOD OF MICE TREATED WITH GCS OR VEHICLE SOLUTION WAS ASSAYED USING A GENOME-WIDE DNAM PLATFORM (METHYL-SEQ) TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS (DMRS) INDUCED BY GC TREATMENT. WE OBSERVED THAT APPROXIMATELY 70% OF THE DMRS IN BOTH TISSUES LOST METHYLATION FOLLOWING GC TREATMENT. OF THE 3,095 DMRS THAT MAPPED TO THE SAME GENES IN BOTH TISSUES, 1,853 DMRS UNDERWENT DNAM CHANGES IN THE SAME DIRECTION. INTERESTINGLY, ONLY 209 DMRS (<7%) OVERLAPPED IN GENOMIC COORDINATES BETWEEN THE 2 TISSUES, SUGGESTING TISSUE-SPECIFIC DIFFERENCES IN GC-TARGETED LOCI. PATHWAY ANALYSIS SHOWED THAT THE DMR-ASSOCIATED GENES WERE MEMBERS OF PATHWAYS INVOLVED IN METABOLISM, IMMUNE FUNCTION, AND NEURODEVELOPMENT. ALSO, CHANGES IN CELL TYPE COMPOSITION OF BLOOD AND BRAIN WERE EXAMINED BY FLUORESCENCE-ACTIVATED CELL SORTING. SEPARATION OF THE CORTEX INTO NEURONAL AND NON-NEURONAL FRACTIONS AND THE LEUKOCYTES INTO T-CELLS, B-CELLS, AND NEUTROPHILS SHOWED THAT GC-INDUCED METHYLATION CHANGES PRIMARILY OCCURRED IN NEURONS AND T-CELLS, WITH THE BLOOD TISSUE ALSO UNDERGOING A SHIFT IN THE PROPORTION OF CONSTITUENT CELL TYPES WHILE THE PROPORTION OF NEURONS AND GLIA IN THE BRAIN REMAINED STABLE. FROM THE CURRENT PILOT STUDY, WE FOUND THAT DESPITE TISSUE-SPECIFIC EPIGENETIC CHANGES AND CELLULAR HETEROGENEITY, BLOOD CAN SERVE AS A SURROGATE FOR GC-INDUCED CHANGES IN THE BRAIN. 2017 11 1345 42 DETECTION OF DIFFERENTIALLY METHYLATED REGIONS USING BAYES FACTOR FOR ORDINAL GROUP RESPONSES. RESEARCHERS IN GENOMICS ARE INCREASINGLY INTERESTED IN EPIGENETIC FACTORS SUCH AS DNA METHYLATION, BECAUSE THEY PLAY AN IMPORTANT ROLE IN REGULATING GENE EXPRESSION WITHOUT CHANGES IN THE DNA SEQUENCE. THERE HAVE BEEN SIGNIFICANT ADVANCES IN DEVELOPING STATISTICAL METHODS TO DETECT DIFFERENTIALLY METHYLATED REGIONS (DMRS) ASSOCIATED WITH BINARY DISEASE STATUS. MOST OF THESE METHODS ARE BEING DEVELOPED FOR DETECTING DIFFERENTIAL METHYLATION RATES BETWEEN CASES AND CONTROLS. WE CONSIDER MULTIPLE SEVERITY LEVELS OF DISEASE, AND DEVELOP A BAYESIAN STATISTICAL METHOD TO DETECT THE REGION WITH INCREASING (OR DECREASING) METHYLATION RATES AS THE DISEASE SEVERITY INCREASES. PATIENTS ARE CLASSIFIED INTO MORE THAN TWO GROUPS, BASED ON THE DISEASE SEVERITY (E.G., STAGES OF CANCER), AND DMRS ARE DETECTED BY USING MOVING WINDOWS ALONG THE GENOME. WITHIN EACH WINDOW, THE BAYES FACTOR IS CALCULATED TO TEST THE HYPOTHESIS OF MONOTONIC INCREASE IN METHYLATION RATES CORRESPONDING TO SEVERITY OF THE DISEASE VERSUS NO DIFFERENCE. A MIXED-EFFECT MODEL IS USED TO INCORPORATE THE CORRELATION OF METHYLATION RATES OF NEARBY CPG SITES IN THE REGION. RESULTS FROM EXTENSIVE SIMULATION INDICATE THAT OUR PROPOSED METHOD IS STATISTICALLY VALID AND REASONABLY POWERFUL. WE DEMONSTRATE OUR APPROACH ON A BISULFITE SEQUENCING DATASET FROM A CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) STUDY. 2019 12 810 30 CHANGES IN DNA METHYLATION IN APOE AND ACKR3 GENES IN MULTIPLE SCLEROSIS PATIENTS AND THE RELATIONSHIP WITH THEIR HEAVY METAL BLOOD LEVELS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY DISEASE WITH DEMYELINATED LESIONS IN THE CENTRAL NERVOUS SYSTEM CAUSED BY GENETIC AND ENVIRONMENTAL FACTORS. DNA METHYLATION AS AN EPIGENETIC CHANGE INFLUENCED BY ENVIRONMENTAL FACTORS, INCLUDING HEAVY METALS HAS BEEN IMPLEMENTED IN MS DISEASE. WE INVESTIGATED THE CORRELATION OF DNA METHYLATION CHANGES IN APOE AND ACKR3 GENES IN MS PATIENTS AND THE POSSIBLE ASSOCIATION WITH BLOOD CONCENTRATION OF ARSENIC (AS), CADMIUM (CD) AND LEAD (PB) AS MAJOR HEAVY METAL POLLUTANTS. THIS STUDY INCLUDED 69 RELAPSING-REMITTING MULTIPLE SCLEROSIS (RR-MS) PATIENTS AND 69 AGE/GENDER-MATCHED HEALTHY SUBJECTS. THE HRM REAL-TIME PCR METHOD WAS USED TO INVESTIGATE THE CHANGES IN DNA METHYLATION AND HEAVY METAL CONCENTRATIONS WERE MEASURED BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY. OUR RESULTS SHOWED THAT THE METHYLATION PATTERN IN THE ACKR3 GENE OF THE PATIENT GROUP WAS MORE HYPOMETHYLATED, WHILE IN THE CASE OF THE APOE GENE, THIS PATTERN WAS MORE TOWARDS HYPERMETHYLATION COMPARED TO HEALTHY SUBJECTS. MOREOVER, THE BLOOD LEVELS OF AS AND CD METALS, BUT NOT PB, WERE SIGNIFICANTLY HIGHER IN THE PATIENT GROUP COMPARE TO THE CONTROL GROUP (P