1   89 241 A PILOT INVESTIGATION OF DIFFERENTIAL HYDROXYMETHYLATION LEVELS IN PATIENT-DERIVED NEURAL STEM CELLS IMPLICATES ALTERED CORTICAL DEVELOPMENT IN BIPOLAR DISORDER. INTRODUCTION: BIPOLAR DISORDER (BD) IS A CHRONIC MENTAL ILLNESS CHARACTERIZED BY RECURRENT EPISODES OF MANIA AND DEPRESSION AND ASSOCIATED WITH SOCIAL AND COGNITIVE DISTURBANCES. ENVIRONMENTAL FACTORS, SUCH AS MATERNAL SMOKING AND CHILDHOOD TRAUMA, ARE BELIEVED TO MODULATE RISK GENOTYPES AND CONTRIBUTE TO THE PATHOGENESIS OF BD, SUGGESTING A KEY ROLE IN EPIGENETIC REGULATION DURING NEURODEVELOPMENT. 5-HYDROXYMETHYLCYTOSINE (5HMC) IS AN EPIGENETIC VARIANT OF PARTICULAR INTEREST, AS IT IS HIGHLY EXPRESSED IN THE BRAIN AND IS IMPLICATED IN NEURODEVELOPMENT, AND PSYCHIATRIC AND NEUROLOGICAL DISORDERS. METHODS: INDUCED PLURIPOTENT STEM CELLS (IPSCS) WERE GENERATED FROM THE WHITE BLOOD CELLS OF TWO ADOLESCENT PATIENTS WITH BIPOLAR DISORDER AND THEIR SAME-SEX AGE-MATCHED UNAFFECTED SIBLINGS (N = 4). FURTHER, IPSCS WERE DIFFERENTIATED INTO NEURONAL STEM CELLS (NSCS) AND CHARACTERIZED FOR PURITY USING IMMUNO-FLUORESCENCE. WE USED REDUCED REPRESENTATION HYDROXYMETHYLATION PROFILING (RRHP) TO PERFORM GENOME-WIDE 5HMC PROFILING OF IPSCS AND NSCS, TO MODEL 5HMC CHANGES DURING NEURONAL DIFFERENTIATION AND ASSESS THEIR IMPACT ON BD RISK. FUNCTIONAL ANNOTATION AND ENRICHMENT TESTING OF GENES HARBORING DIFFERENTIATED 5HMC LOCI WERE PERFORMED WITH THE ONLINE TOOL DAVID. RESULTS: APPROXIMATELY 2 MILLION SITES WERE MAPPED AND QUANTIFIED, WITH THE MAJORITY (68.8%) LOCATED IN GENIC REGIONS, WITH ELEVATED 5HMC LEVELS PER SITE OBSERVED FOR 3' UTRS, EXONS, AND 2-KB SHORELINES OF CPG ISLANDS. PAIRED T-TESTS OF NORMALIZED 5HMC COUNTS BETWEEN IPSC AND NSC CELL LINES REVEALED GLOBAL HYPO-HYDROXYMETHYLATION IN NSCS AND ENRICHMENT OF DIFFERENTIALLY HYDROXYMETHYLATED SITES WITHIN GENES ASSOCIATED WITH PLASMA MEMBRANE (FDR = 9.1 X 10(-12)) AND AXON GUIDANCE (FDR = 2.1 X 10(-6)), AMONG OTHER NEURONAL PROCESSES. THE MOST SIGNIFICANT DIFFERENCE WAS OBSERVED FOR A TRANSCRIPTION FACTOR BINDING SITE FOR THE KCNK9 GENE (P = 8.8 X 10(-6)), ENCODING A POTASSIUM CHANNEL PROTEIN INVOLVED IN NEURONAL ACTIVITY AND MIGRATION. PROTEIN-PROTEIN-INTERACTION (PPI) NETWORKING SHOWED SIGNIFICANT CONNECTIVITY (P = 3.2 X 10(-10)) BETWEEN PROTEINS ENCODED BY GENES HARBORING HIGHLY DIFFERENTIATED 5HMC SITES, WITH GENES INVOLVED IN AXON GUIDANCE AND ION TRANSMEMBRANE TRANSPORT FORMING DISTINCT SUB-CLUSTERS. COMPARISON OF NSCS OF BD CASES AND UNAFFECTED SIBLINGS REVEALED ADDITIONAL PATTERNS OF DIFFERENTIATION IN HYDROXYMETHYLATION LEVELS, INCLUDING SITES IN GENES WITH FUNCTIONS RELATED TO SYNAPSE FORMATION AND REGULATION, SUCH AS CUX2 (P = 2.4 X 10(-5)) AND DOK-7 (P = 3.6 X 10(-3)), AS WELL AS AN ENRICHMENT OF GENES INVOLVED IN THE EXTRACELLULAR MATRIX (FDR = 1.0 X 10(-8)). DISCUSSION: TOGETHER, THESE PRELIMINARY RESULTS LEND EVIDENCE TOWARD A POTENTIAL ROLE FOR 5HMC IN BOTH EARLY NEURONAL DIFFERENTIATION AND BD RISK, WITH VALIDATION AND MORE COMPREHENSIVE CHARACTERIZATION TO BE ACHIEVED THROUGH FOLLOW-UP STUDY.	2023	

2 3077  46 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
3  344  49 ALTERED BDNF METHYLATION IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN AND HIGH BIOPSYCHOSOCIAL COMPLEXITY. PURPOSE: THE INTERMED INSTRUMENT, WHICH WAS DEVELOPED TO MEASURE PATIENT'S BIOPSYCHOSOCIAL (BPS) COMPLEXITY, REPRESENTS A POWERFUL DIAGNOSTIC AND THERAPEUTIC TOOL. EPIGENETIC CHANGES ARE THE INTERFACE BETWEEN SIGNALS FROM THE ENVIRONMENT AND GENETIC MODIFICATIONS, AFFECTING GENE EXPRESSION, IN PARTICULAR, BY DNA METHYLATION OF CPG DINUCLEOTIDES IN PROMOTOR REGIONS OF THE CORRESPONDING GENES. THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) GENE PLAYS A CRUCIAL ROLE IN THE CENTRAL SENSITIZATION (CS) OF PAIN. IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC PAIN MODIFIES THE METHYLATION LEVELS OF THE BDNF GENE IN A MANNER THAT IS INTERCONNECTED WITH THE BPS STATUS. PATIENTS AND METHODS: FIFTY-EIGHT CHRONIC MUSCULOSKELETAL PAIN PATIENTS (CMSP) WERE ENROLLED IN THE STUDY. DNA WAS EXTRACTED FROM BLOOD SAMPLES, THE METHYLATION LEVELS OF 13 CPG SITES IN THE BDNF PROMOTER WERE MEASURED BY PYROSEQUENCING, AND ASSOCIATION STUDIES WITH VARIOUS PATIENT PARAMETERS AND THE INTERMED SCORES WERE PERFORMED. RESULTS: INTERESTINGLY, A NEGATIVE CORRELATION (-0.40) WAS FOUND BETWEEN THE TOTAL INTERMED SCORES AND THE AVERAGE CPG METHYLATION VALUES OF THE BDNF GENE, BUT NO CORRELATION WAS OBSERVED WITH THE SEVERITY OF PAIN, DEGREE OF ANXIETY, DEPRESSION, OR KINESIOPHOBIA AND CATASTROPHISM. MOREOVER, THE ASSOCIATION WAS INDEPENDENT OF AGE, SEX AND LEVEL OF COMORBIDITIES. CONCLUSION: THIS RESULT SHOWS THAT CMSP, IN ASSOCIATION WITH ITS BIOPSYCHOSOCIAL CONTEXT, EPIGENETICALLY DECREASES THE DEGREE OF METHYLATION OF THE BDNF PROMOTER AND SHOULD THEREFORE INCREASE THE LEVEL OF BDNF TRANSCRIPTION. IT ALSO SUGGESTS A ROLE OF THE INTERMED TOOL TO DETECT A RELATIONSHIP BETWEEN THE BPS COMPLEXITY AND THE EPIGENETIC CONTROL OF A TARGET GENE. THE POSSIBLE UPREGULATION OF BDNF EXPRESSION MIGHT BE, AT LEAST IN PART, THE SIGNAL FOR CHRONIC PAIN-INDUCED CENTRAL SENSITIZATION (CS). THIS COULD PARTLY EXPLAIN WHY PATIENTS WITH A HIGHER LEVEL OF COMPLEXITY FEEL MORE PAIN THAN THOSE WITH LOWER COMPLEXITY.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
4  839  33 CHEMO-ENZYMATIC FLUORESCENCE LABELING OF GENOMIC DNA FOR SIMULTANEOUS DETECTION OF GLOBAL 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE. 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE ARE EPIGENETIC MODIFICATIONS INVOLVED IN GENE REGULATION AND CANCER. WE PRESENT A NEW, SIMPLE, AND HIGH-THROUGHPUT PLATFORM FOR MULTI-COLOR EPIGENETIC ANALYSIS. THE NOVELTY OF OUR APPROACH IS THE ABILITY TO MULTIPLEX METHYLATION AND DE-METHYLATION SIGNALS IN THE SAME ASSAY. WE UTILIZE AN ENGINEERED METHYLTRANSFERASE ENZYME THAT RECOGNIZES AND LABELS ALL UNMODIFIED CPG SITES WITH A FLUORESCENT COFACTOR. IN COMBINATION WITH THE ALREADY ESTABLISHED LABELING OF THE DE-METHYLATION MARK 5-HYDROXYMETHYLCYTOSINE VIA ENZYMATIC GLYCOSYLATION, WE OBTAINED A ROBUST PLATFORM FOR SIMULTANEOUS EPIGENETIC ANALYSIS OF THESE MARKS. WE ASSESSED THE GLOBAL EPIGENETIC LEVELS IN MULTIPLE SAMPLES OF COLORECTAL CANCER AND OBSERVED A 3.5-FOLD REDUCTION IN 5HMC LEVELS BUT NO CHANGE IN DNA METHYLATION LEVELS BETWEEN SICK AND HEALTHY INDIVIDUALS. WE ALSO MEASURED EPIGENETIC MODIFICATIONS IN CHRONIC LYMPHOCYTIC LEUKEMIA AND OBSERVED A DECREASE IN BOTH MODIFICATION LEVELS (5-HYDROXYMETHYLCYTOSINE: WHOLE BLOOD 30 %; PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) 40 %. 5-METHYLCYTOSINE: WHOLE BLOOD 53 %; PBMCS 48 %). OUR FINDINGS PROPOSE USING A SIMPLE BLOOD TEST AS A VIABLE METHOD FOR ANALYSIS, SIMPLIFYING SAMPLE HANDLING IN DIAGNOSTICS. IMPORTANTLY, OUR RESULTS HIGHLIGHT THE ASSAY'S POTENTIAL FOR EPIGENETIC EVALUATION OF CLINICAL SAMPLES, BENEFITING RESEARCH AND PATIENT MANAGEMENT.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
5  990  46 CHRONIC SOCIAL STRESS INDUCES DNA METHYLATION CHANGES AT AN EVOLUTIONARY CONSERVED INTERGENIC REGION IN CHROMOSOME X. CHRONIC STRESS RESULTING FROM PROLONGED EXPOSURE TO NEGATIVE LIFE EVENTS INCREASES THE RISK OF MOOD AND ANXIETY DISORDERS. ALTHOUGH CHRONIC STRESS CAN CHANGE GENE EXPRESSION RELEVANT FOR BEHAVIOR, MOLECULAR REGULATORS OF THIS CHANGE HAVE NOT BEEN FULLY DETERMINED. ONE PROCESS THAT COULD PLAY A ROLE IS DNA METHYLATION, AN EPIGENETIC PROCESS WHEREBY A METHYL GROUP IS ADDED ONTO NUCLEOTIDES, PREDOMINANTLY CYTOSINE IN THE CPG CONTEXT, AND WHICH CAN BE INDUCED BY CHRONIC STRESS. IT IS UNKNOWN TO WHAT EXTENT CHRONIC SOCIAL DEFEAT, A MODEL OF HUMAN SOCIAL STRESS, INFLUENCES DNA METHYLATION PATTERNS ACROSS THE GENOME. OUR STUDY ADDRESSED THIS QUESTION BY USING A TARGETED-CAPTURE APPROACH CALLED METHYL-SEQ TO INVESTIGATE DNA METHYLATION PATTERNS OF THE DENTATE GYRUS AT PUTATIVE REGULATORY REGIONS ACROSS THE MOUSE GENOME FROM MICE EXPOSED TO 14 DAYS OF SOCIAL DEFEAT. FINDINGS WERE REPLICATED IN INDEPENDENT COHORTS BY BISULFITE-PYROSEQUENCING. TWO DIFFERENTIALLY METHYLATED REGIONS (DMRS) WERE IDENTIFIED. ONE DMR WAS LOCATED AT INTRON 9 OF DROSHA, AND IT SHOWED REDUCED METHYLATION IN STRESSED MICE. THIS OBSERVATION REPLICATED IN ONE OF TWO INDEPENDENT COHORTS. A SECOND DMR WAS IDENTIFIED AT AN INTERGENIC REGION OF CHROMOSOME X, AND METHYLATION IN THIS REGION WAS INCREASED IN STRESSED MICE. THIS METHYLATION DIFFERENCE REPLICATED IN TWO INDEPENDENT COHORTS AND IN MAJOR DEPRESSIVE DISORDER (MDD) POSTMORTEM BRAINS. THESE RESULTS HIGHLIGHT A REGION NOT PREVIOUSLY KNOWN TO BE DIFFERENTIALLY METHYLATED BY CHRONIC SOCIAL DEFEAT STRESS AND WHICH MAY BE INVOLVED IN MDD.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
6 2079  47 EPIGENETIC DNA METHYLATION CHANGES ASSOCIATED WITH HEADACHE CHRONIFICATION: A RETROSPECTIVE CASE-CONTROL STUDY. BACKGROUND THE BIOLOGICAL MECHANISMS OF HEADACHE CHRONIFICATION ARE POORLY UNDERSTOOD. WE AIMED TO IDENTIFY CHANGES IN DNA METHYLATION ASSOCIATED WITH THE TRANSFORMATION FROM EPISODIC TO CHRONIC HEADACHE. METHODS PARTICIPANTS WERE RECRUITED FROM THE POPULATION-BASED NORWEGIAN HUNT STUDY. THIRTY-SIX FEMALE HEADACHE PATIENTS WHO TRANSFORMED FROM EPISODIC TO CHRONIC HEADACHE BETWEEN BASELINE AND FOLLOW-UP 11 YEARS LATER WERE MATCHED AGAINST 35 CONTROLS WITH EPISODIC HEADACHE. DNA METHYLATION WAS QUANTIFIED AT 485,000 CPG SITES, AND CHANGES IN METHYLATION LEVEL AT THESE SITES WERE COMPARED BETWEEN CASES AND CONTROLS BY LINEAR REGRESSION ANALYSIS. DATA WERE ANALYZED IN TWO STAGES (STAGES 1 AND 2) AND IN A COMBINED META-ANALYSIS. RESULTS NONE OF THE TOP 20 CPG SITES IDENTIFIED IN STAGE 1 REPLICATED IN STAGE 2 AFTER MULTIPLE TESTING CORRECTION. IN THE COMBINED META-ANALYSIS THE STRONGEST ASSOCIATED CPG SITES WERE RELATED TO SH2D5 AND NPTX2, TWO BRAIN-EXPRESSED GENES INVOLVED IN THE REGULATION OF SYNAPTIC PLASTICITY. FUNCTIONAL ENRICHMENT ANALYSIS POINTED TO PROCESSES INCLUDING CALCIUM ION BINDING AND ESTROGEN RECEPTOR PATHWAYS. CONCLUSION IN THIS FIRST GENOME-WIDE STUDY OF DNA METHYLATION IN HEADACHE CHRONIFICATION SEVERAL POTENTIALLY IMPLICATED LOCI AND PROCESSES WERE IDENTIFIED. THE STUDY EXEMPLIFIES THE USE OF PROSPECTIVELY COLLECTED POPULATION COHORTS TO SEARCH FOR EPIGENETIC MECHANISMS OF DISEASE.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
7 1537  35 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
8 1436  37 DIFFERENTIAL METHYLATION OF THE TRPA1 PROMOTER IN PAIN SENSITIVITY. CHRONIC PAIN IS A GLOBAL PUBLIC HEALTH PROBLEM, BUT THE UNDERLYING MOLECULAR MECHANISMS ARE NOT FULLY UNDERSTOOD. HERE WE EXAMINE GENOME-WIDE DNA METHYLATION, FIRST IN 50 IDENTICAL TWINS DISCORDANT FOR HEAT PAIN SENSITIVITY AND THEN IN 50 FURTHER UNRELATED INDIVIDUALS. WHOLE-BLOOD DNA METHYLATION WAS CHARACTERIZED AT 5.2 MILLION LOCI BY MEDIP SEQUENCING AND ASSESSED LONGITUDINALLY TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH HIGH OR LOW PAIN SENSITIVITY (PAIN DMRS). NINE META-ANALYSIS PAIN DMRS SHOW ROBUST EVIDENCE FOR ASSOCIATION (FALSE DISCOVERY RATE 5%) WITH THE STRONGEST SIGNAL IN THE PAIN GENE TRPA1 (P=1.2 X 10(-13)). SEVERAL PAIN DMRS SHOW LONGITUDINAL STABILITY CONSISTENT WITH SUSCEPTIBILITY EFFECTS, HAVE SIMILAR METHYLATION LEVELS IN THE BRAIN AND ALTERED EXPRESSION IN THE SKIN. OUR APPROACH IDENTIFIES EPIGENETIC CHANGES IN BOTH NOVEL AND ESTABLISHED CANDIDATE GENES THAT PROVIDE MOLECULAR INSIGHTS INTO PAIN AND MAY GENERALIZE TO OTHER COMPLEX TRAITS.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
9 5706  40 SINGLE-MOLECULE QUANTIFICATION OF 5-HYDROXYMETHYLCYTOSINE FOR DIAGNOSIS OF BLOOD AND COLON CANCERS. BACKGROUND: THE DNA MODIFICATION 5-HYDROXYMETHYLCYTOSINE (5HMC) IS NOW REFERRED TO AS THE SIXTH BASE OF DNA WITH EVIDENCE OF TISSUE-SPECIFIC PATTERNS AND CORRELATION WITH GENE REGULATION AND EXPRESSION. THIS EPIGENETIC MARK WAS RECENTLY REPORTED AS A POTENTIAL BIOMARKER FOR MULTIPLE TYPES OF CANCER, BUT ITS APPLICATION IN THE CLINIC IS LIMITED BY THE UTILITY OF RECENT 5HMC QUANTIFICATION ASSAYS. WE USE A RECENTLY DEVELOPED, ULTRA-SENSITIVE, FLUORESCENCE-BASED SINGLE-MOLECULE METHOD FOR GLOBAL QUANTIFICATION OF 5HMC IN GENOMIC DNA. THE HIGH SENSITIVITY OF THE METHOD GIVES ACCESS TO PRECISE QUANTIFICATION OF EXTREMELY LOW 5HMC LEVELS COMMON IN MANY CANCERS. METHODS: WE ASSESSED 5HMC LEVELS IN DNA EXTRACTED FROM A SET OF COLON AND BLOOD CANCER SAMPLES AND COMPARED 5HMC LEVELS WITH HEALTHY CONTROLS, IN A SINGLE-MOLECULE APPROACH. RESULTS: USING OUR METHOD, WE OBSERVED A SIGNIFICANTLY REDUCED LEVEL OF 5HMC IN BLOOD AND COLON CANCERS AND COULD DISTINGUISH BETWEEN COLON TUMOR AND COLON TISSUE ADJACENT TO THE TUMOR BASED ON THE GLOBAL LEVELS OF THIS MOLECULAR BIOMARKER. CONCLUSIONS: SINGLE-MOLECULE DETECTION OF 5HMC ALLOWS DISTINGUISHING BETWEEN MALIGNANT AND HEALTHY TISSUE IN CLINICALLY RELEVANT AND ACCESSIBLE TISSUE SUCH AS BLOOD AND COLON. THE PRESENTED METHOD OUTPERFORMS CURRENT COMMERCIALLY AVAILABLE QUANTIFICATION KITS AND MAY POTENTIALLY BE DEVELOPED INTO A WIDELY USED, 5HMC QUANTIFICATION ASSAY FOR RESEARCH AND CLINICAL DIAGNOSTICS. FURTHERMORE, USING THIS METHOD, WE CONFIRM THAT 5HMC IS A GOOD MOLECULAR BIOMARKER FOR DIAGNOSING COLON AND VARIOUS TYPES OF BLOOD CANCER.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
10 6311  41 THE RELATION BETWEEN DNA METHYLATION PATTERNS AND SERUM CYTOKINE LEVELS IN COMMUNITY-DWELLING ADULTS: A PRELIMINARY STUDY. BACKGROUND: THE LEVELS OF CIRCULATING CYTOKINES FLUCTUATE WITH AGE, ACUTE ILLNESS, AND CHRONIC DISEASE, AND ARE PREDICTIVE OF MORTALITY; THIS IS ALSO TRUE FOR PATTERNS OF DNA (CPG) METHYLATION. GIVEN THAT IMMUNE CELLS ARE PARTICULARLY SENSITIVE TO CHANGES IN THE CONCENTRATION OF CYTOKINES IN THEIR MICROENVIRONMENT, WE HYPOTHESIZED THAT SERUM LEVELS OF TNF, IL-6, IL-8 AND IL-10 WOULD CORRELATE WITH GENOME-WIDE ALTERATIONS IN THE DNA METHYLATION LEVELS OF BLOOD LEUKOCYTES. TO TEST THIS, WE EVALUATED COMMUNITY-DWELLING ADULTS (N = 14; 48-78 YEARS OLD) RECRUITED TO A PILOT STUDY FOR THE CANADIAN LONGITUDINAL STUDY ON AGING (CLSA), EXAMINING DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD MONONUCLEAR CELLS USING THE ILLUMINA HUMANMETHYLATION 450 K BEADCHIP. RESULTS: WE SHOW THAT, APART FROM AGE, SERUM IL-10 LEVELS EXHIBITED THE MOST SUBSTANTIAL ASSOCIATION TO DNA METHYLATION PATTERNS, FOLLOWED BY TNF, IL-6 AND IL-8. FURTHERMORE, WHILE THE LEVELS OF THESE CYTOKINES WERE HIGHER IN ELDERLY ADULTS, NO ASSOCIATIONS WITH EPIGENETIC ACCELERATED AGING, DERIVED USING THE EPIGENETIC CLOCK, WERE OBSERVED. CONCLUSIONS: AS A PRELIMINARY STUDY WITH A SMALL SAMPLE SIZE, THE CONCLUSIONS DRAWN FROM THIS WORK MUST BE VIEWED WITH CAUTION; HOWEVER, OUR OBSERVATIONS ARE ENCOURAGING AND CERTAINLY WARRANT MORE SUITABLY POWERED STUDIES OF THIS RELATIONSHIP.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
11  665  56 BLOOD TRANSCRIPTOMICS OF DRUG-NAIVE SPORADIC PARKINSON'S DISEASE PATIENTS. BACKGROUND: PARKINSON'S DISEASE (PD) IS A CHRONIC PROGRESSIVE NEURODEGENERATIVE DISORDER THAT IS CLINICALLY DEFINED IN TERMS OF MOTOR SYMPTOMS. THESE ARE PRECEDED BY PRODROMAL NON-MOTOR MANIFESTATIONS THAT PROVE THE SYSTEMIC NATURE OF THE DISEASE. IDENTIFYING GENES AND PATHWAYS ALTERED IN LIVING PATIENTS PROVIDE NEW INFORMATION ON THE DIAGNOSIS AND PATHOGENESIS OF SPORADIC PD. METHODS: CHANGES IN GENE EXPRESSION IN THE BLOOD OF 40 SPORADIC PD PATIENTS AND 20 HEALTHY CONTROLS ("DISCOVERY SET") WERE ANALYZED BY TAKING ADVANTAGE OF THE AFFYMETRIX PLATFORM. PATIENTS WERE AT THE ONSET OF MOTOR SYMPTOMS AND BEFORE INITIATING ANY PHARMACOLOGICAL TREATMENT. DATA ANALYSIS WAS PERFORMED BY APPLYING RANKING-PRINCIPAL COMPONENT ANALYSIS, PUMA AND SIGNIFICANCE ANALYSIS OF MICROARRAYS. FUNCTIONAL ANNOTATIONS WERE ASSIGNED USING GO, DAVID, GSEA TO UNVEIL SIGNIFICANT ENRICHED BIOLOGICAL PROCESSES IN THE DIFFERENTIALLY EXPRESSED GENES. THE EXPRESSIONS OF SELECTED GENES WERE VALIDATED USING RT-QPCR AND SAMPLES FROM AN INDEPENDENT COHORT OF 12 PATIENTS AND CONTROLS ("VALIDATION SET"). RESULTS: GENE EXPRESSION PROFILING OF BLOOD SAMPLES DISCRIMINATES PD PATIENTS FROM HEALTHY CONTROLS AND IDENTIFIES DIFFERENTIALLY EXPRESSED GENES IN BLOOD. THE MAJORITY OF THESE ARE ALSO PRESENT IN DOPAMINERGIC NEURONS OF THE SUBSTANTIA NIGRA, THE KEY SITE OF NEURODEGENERATION. TOGETHER WITH NEURONAL APOPTOSIS, LYMPHOCYTE ACTIVATION AND MITOCHONDRIAL DYSFUNCTION, ALREADY FOUND IN PREVIOUS ANALYSIS OF PD BLOOD AND POST-MORTEM BRAINS, WE UNVEILED TRANSCRIPTOME CHANGES ENRICHED IN BIOLOGICAL TERMS RELATED TO EPIGENETIC MODIFICATIONS INCLUDING CHROMATIN REMODELING AND METHYLATION. CANDIDATE TRANSCRIPTS AS CBX5, TCF3, MAN1C1 AND DOCK10 WERE VALIDATED BY RT-QPCR. CONCLUSIONS: OUR DATA SUPPORT THE USE OF BLOOD TRANSCRIPTOMICS TO STUDY NEURODEGENERATIVE DISEASES. IT IDENTIFIES CHANGES IN CRUCIAL COMPONENTS OF CHROMATIN REMODELING AND METHYLATION MACHINERIES AS EARLY EVENTS IN SPORADIC PD SUGGESTING EPIGENETICS AS TARGET FOR THERAPEUTIC INTERVENTION.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
12 4879  27 OVERLAPPING SIGNATURES OF CHRONIC PAIN IN THE DNA METHYLATION LANDSCAPE OF PREFRONTAL CORTEX AND PERIPHERAL T CELLS. WE TESTED THE HYPOTHESIS THAT EPIGENETIC MECHANISMS IN THE BRAIN AND THE IMMUNE SYSTEM ARE ASSOCIATED WITH CHRONIC PAIN. GENOME-WIDE DNA METHYLATION ASSESSED IN 9 MONTHS POST NERVE-INJURY (SNI) AND SHAM RATS, IN THE PREFRONTAL CORTEX (PFC) AS WELL AS IN T CELLS REVEALED A VAST DIFFERENCE IN THE DNA METHYLATION LANDSCAPE IN THE BRAIN BETWEEN THE GROUPS AND A REMARKABLE OVERLAP (72%) BETWEEN DIFFERENTIALLY METHYLATED PROBES IN T CELLS AND PREFRONTAL CORTEX. DNA METHYLATION STATES IN THE PFC SHOWED ROBUST CORRELATION WITH PAIN SCORE OF ANIMALS IN SEVERAL GENES INVOLVED IN PAIN. FINALLY, ONLY 11 DIFFERENTIALLY METHYLATED PROBES IN T CELLS WERE SUFFICIENT TO DISTINGUISH SNI OR SHAM INDIVIDUAL RATS. THIS STUDY SUPPORTS THE PLAUSIBILITY OF DNA METHYLATION INVOLVEMENT IN CHRONIC PAIN AND DEMONSTRATES THE POTENTIAL FEASIBILITY OF DNA METHYLATION MARKERS IN T CELLS AS NONINVASIVE BIOMARKERS OF CHRONIC PAIN SUSCEPTIBILITY.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
13 1345  50 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
14 6547  49 TRANSCRIPTOMICS OF LONG-TERM MEDITATION PRACTICE: EVIDENCE FOR PREVENTION OR REVERSAL OF STRESS EFFECTS HARMFUL TO HEALTH. BACKGROUND AND OBJECTIVES: STRESS CAN OVERLOAD ADAPTIVE MECHANISMS, LEADING TO EPIGENETIC EFFECTS HARMFUL TO HEALTH. RESEARCH ON THE REVERSAL OF THESE EFFECTS IS IN ITS INFANCY. EARLY RESULTS SUGGEST SOME MEDITATION TECHNIQUES HAVE HEALTH BENEFITS THAT GROW WITH REPEATED PRACTICE. THIS STUDY FOCUSED ON POSSIBLE TRANSCRIPTOMIC EFFECTS OF 38 YEARS OF TWICE-DAILY TRANSCENDENTAL MEDITATION((R)) (TM((R))) PRACTICE. MATERIALS AND METHODS: FIRST, USING ILLUMINA((R)) BEADCHIP MICROARRAY TECHNOLOGY, DIFFERENCES IN GLOBAL GENE EXPRESSION IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) WERE SOUGHT BETWEEN HEALTHY PRACTITIONERS AND TIGHTLY MATCHED CONTROLS (N = 12, AGE 65). SECOND, THESE MICROARRAY RESULTS WERE VERIFIED ON A SUBSET OF GENES USING QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) AND WERE VALIDATED USING QPCR IN LARGER TM AND CONTROL GROUPS (N = 45, AGE 63). BIOINFORMATICS INVESTIGATION EMPLOYED INGENUITY((R)) PATHWAY ANALYSIS (IPA((R))), DAVID, GENOMATIX, AND R PACKAGES. RESULTS: THE 200 GENES AND LOCI FOUND TO MEET STRICT CRITERIA FOR DIFFERENTIAL EXPRESSION IN THE MICROARRAY EXPERIMENT SHOWED CONTRASTING PATTERNS OF EXPRESSION THAT DISTINGUISHED THE TWO GROUPS. DIFFERENTIAL EXPRESSION RELATING TO IMMUNE FUNCTION AND ENERGY EFFICIENCY WERE MOST APPARENT. IN THE TM GROUP, RELATIVE TO THE CONTROL, ALL 49 GENES ASSOCIATED WITH INFLAMMATION WERE DOWNREGULATED, WHILE GENES ASSOCIATED WITH ANTIVIRAL AND ANTIBODY COMPONENTS OF THE DEFENSE RESPONSE WERE UPREGULATED. THE LARGEST EXPRESSION DIFFERENCES WERE SHOWN BY SIX GENES RELATED TO ERYTHROCYTE FUNCTION THAT APPEARED TO REFLECT A CONDITION OF LOWER ENERGY EFFICIENCY IN THE CONTROL GROUP. RESULTS SUPPORTING THESE GENE EXPRESSION DIFFERENCES WERE OBTAINED WITH QPCR-MEASURED EXPRESSION BOTH IN THE WELL-MATCHED MICROARRAY GROUPS AND IN THE LARGER, LESS WELL-MATCHED GROUPS. CONCLUSIONS: THESE FINDINGS ARE CONSISTENT WITH PREDICTIONS BASED ON RESULTS FROM EARLIER RANDOMIZED TRIALS OF MEDITATION AND MAY PROVIDE EVIDENCE FOR STRESS-RELATED MOLECULAR MECHANISMS UNDERLYING REDUCTIONS IN ANXIETY, POST-TRAUMATIC STRESS DISORDER (PTSD), CARDIOVASCULAR DISEASE (CVD), AND OTHER CHRONIC DISORDERS AND DISEASES.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
15  277  57 AGE-RELATED EPIGENOME-WIDE DNA METHYLATION AND HYDROXYMETHYLATION IN LONGITUDINAL MOUSE BLOOD. DNA METHYLATION AT CYTOSINE-PHOSPHATE-GUANINE (CPG) DINUCLEOTIDES CHANGES AS A FUNCTION OF AGE IN HUMANS AND ANIMAL MODELS, A PROCESS THAT MAY CONTRIBUTE TO CHRONIC DISEASE DEVELOPMENT. RECENT STUDIES HAVE INVESTIGATED THE ROLE OF AN OXIDIZED FORM OF DNA METHYLATION - 5-HYDROXYMETHYLCYTOSINE (5HMC) - IN THE EPIGENOME, BUT ITS CONTRIBUTION TO AGE-RELATED DNA METHYLATION REMAINS UNCLEAR. WE TESTED THE HYPOTHESIS THAT 5HMC CHANGES WITH AGE, BUT IN A DIRECTION OPPOSITE TO 5-METHYLCYTOSINE (5MC), POTENTIALLY PLAYING A DISTINCT ROLE IN AGING. TO CHARACTERIZE EPIGENETIC AGING, GENOME-WIDE 5MC AND 5HMC WERE MEASURED IN LONGITUDINAL BLOOD SAMPLES (2, 4, AND 10 MONTHS OF AGE) FROM ISOGENIC MICE USING TWO SEQUENCING METHODS - ENHANCED REDUCED REPRESENTATION BISULFITE SEQUENCING AND HYDROXYMETHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. EXAMINING THE EPIGENOME BY AGE, WE IDENTIFIED 28,196 UNIQUE DIFFERENTIALLY METHYLATED CPGS (DMCS) AND 8,613 DIFFERENTIALLY HYDROXYMETHYLATED REGIONS (DHMRS). MOUSE BLOOD SHOWED A GENERAL PATTERN OF EPIGENOME-WIDE HYPERMETHYLATION AND HYPO-HYDROXYMETHYLATION WITH AGE. COMPARING AGE-RELATED DMCS AND DHMRS, 1,854 ANNOTATED GENES SHOWED BOTH DIFFERENTIAL 5MC AND 5HMC, INCLUDING ONE GENE - NFIC - AT FIVE CPGS IN THE SAME 250 BP CHROMOSOMAL REGION. AT THIS REGION, 5MC AND 5HMC LEVELS BOTH DECREASED WITH AGE. REFLECTING THESE AGE-RELATED EPIGENETIC CHANGES, NFIC RNA EXPRESSION IN BLOOD DECREASED WITH AGE, SUGGESTING THAT AGE-RELATED REGULATION OF THIS GENE MAY BE DRIVEN BY 5HMC, NOT CANONICAL DNA METHYLATION. COMBINED, OUR GENOME-WIDE RESULTS SHOW AGE-RELATED DIFFERENTIAL 5MC AND 5HMC, AS WELL AS SOME EVIDENCE THAT CHANGES IN 5HMC MAY DRIVE AGE-RELATED DNA METHYLATION AND GENE EXPRESSION.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
16 2920  48 GENE-SET ANALYSIS IS SEVERELY BIASED WHEN APPLIED TO GENOME-WIDE METHYLATION DATA. MOTIVATION: DNA METHYLATION IS AN EPIGENETIC MARK THAT CAN STABLY REPRESS GENE EXPRESSION. BECAUSE OF ITS BIOLOGICAL AND CLINICAL SIGNIFICANCE, SEVERAL METHODS HAVE BEEN DEVELOPED TO COMPARE GENOME-WIDE PATTERNS OF METHYLATION BETWEEN GROUPS OF SAMPLES. THE APPLICATION OF GENE SET ANALYSIS TO IDENTIFY RELEVANT GROUPS OF GENES THAT ARE ENRICHED FOR DIFFERENTIALLY METHYLATED GENES IS OFTEN A MAJOR COMPONENT OF THE ANALYSIS OF THESE DATA. THIS CAN BE USED, FOR EXAMPLE, TO IDENTIFY PROCESSES OR PATHWAYS THAT ARE PERTURBED IN DISEASE DEVELOPMENT. WE SHOW THAT GENE-SET ANALYSIS, AS IT IS TYPICALLY APPLIED TO GENOME-WIDE METHYLATION ASSAYS, IS SEVERELY BIASED AS A RESULT OF DIFFERENCES IN THE NUMBERS OF CPG SITES ASSOCIATED WITH DIFFERENT CLASSES OF GENES AND GENE PROMOTERS. RESULTS: WE DEMONSTRATE THIS BIAS USING PUBLISHED DATA FROM A STUDY OF DIFFERENTIAL CPG ISLAND METHYLATION IN LUNG CANCER AND A DATASET WE GENERATED TO STUDY METHYLATION CHANGES IN PATIENTS WITH LONG-STANDING ULCERATIVE COLITIS. WE SHOW THAT SEVERAL OF THE GENE SETS THAT SEEM ENRICHED WOULD ALSO BE IDENTIFIED WITH RANDOMIZED DATA. WE SUGGEST TWO EXISTING APPROACHES THAT CAN BE ADAPTED TO CORRECT THE BIAS. ACCOUNTING FOR THE BIAS IN THE LUNG CANCER AND ULCERATIVE COLITIS DATASETS PROVIDES NOVEL BIOLOGICAL INSIGHTS INTO THE ROLE OF METHYLATION IN CANCER DEVELOPMENT AND CHRONIC INFLAMMATION, RESPECTIVELY. OUR RESULTS HAVE SIGNIFICANT IMPLICATIONS FOR MANY PREVIOUS GENOME-WIDE METHYLATION STUDIES THAT HAVE DRAWN CONCLUSIONS ON THE BASIS OF SUCH STRONGLY BIASED ANALYSIS. CONTACT: CATHAL.SEOIGHE@NUIGALWAY.IE SUPPLEMENTARY INFORMATION: SUPPLEMENTARY DATA ARE AVAILABLE AT BIOINFORMATICS ONLINE.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
17 3652  45 INDIVIDUAL DNA METHYLATION PATTERN SHIFTS IN NANOPARTICLES-EXPOSED WORKERS ANALYZED IN FOUR CONSECUTIVE YEARS. A DNA METHYLATION PATTERN REPRESENTS AN ORIGINAL PLAN OF THE FUNCTION SETTINGS OF INDIVIDUAL CELLS AND TISSUES. THE BASIC STRATEGIES OF ITS DEVELOPMENT AND CHANGES DURING THE HUMAN LIFETIME ARE KNOWN, BUT THE DETAILS RELATED TO ITS MODIFICATION OVER THE YEARS ON AN INDIVIDUAL BASIS HAVE NOT YET BEEN STUDIED. MOREOVER, CURRENT EVIDENCE SHOWS THAT ENVIRONMENTAL EXPOSURE COULD GENERATE CHANGES IN DNA METHYLATION SETTINGS AND, SUBSEQUENTLY, THE FUNCTION OF GENES. IN THIS STUDY, WE ANALYZED THE EFFECT OF CHRONIC EXPOSURE TO NANOPARTICLES (NP) IN OCCUPATIONALLY EXPOSED WORKERS REPEATEDLY SAMPLED IN FOUR CONSECUTIVE YEARS (2016-2019). A DETAILED METHYLATION PATTERN ANALYSIS OF 14 PERSONS (10 EXPOSED AND 4 CONTROLS) WAS PERFORMED ON AN INDIVIDUAL BASIS. A MICROARRAY-BASED APPROACH USING CHIPS, ALLOWING THE ASSESSMENT OF MORE THAN 850 K CPG LOCI, WAS USED. INDIVIDUAL DNA METHYLATION PATTERNS WERE COMPARED BY PRINCIPAL COMPONENT ANALYSIS (PCA). THE RESULTS SHOW THE SHIFT IN DNA METHYLATION PATTERNS IN INDIVIDUAL YEARS IN ALL THE EXPOSED AND CONTROL SUBJECTS. THE OVERALL RANGE OF DIFFERENCES VARIED BETWEEN THE YEARS IN INDIVIDUAL PERSONS. THE DIFFERENCES BETWEEN THE FIRST AND LAST YEAR OF EXAMINATION (A THREE-YEAR TIME PERIOD) SEEM TO BE CONSISTENTLY GREATER IN THE NP-EXPOSED SUBJECTS IN COMPARISON WITH THE CONTROLS. THE SELECTED 14 MOST DIFFERENTLY METHYLATED CG LOCI WERE RELATIVELY STABLE IN THE CHRONICALLY EXPOSED SUBJECTS. IN SUMMARY, THE SPECIFIC TYPE OF LONG-TERM EXPOSURE CAN CONTRIBUTE TO THE FIXING OF RELEVANT EPIGENETIC CHANGES RELATED TO A SPECIFIC ENVIRONMENT AS, E.G., NP INHALATION.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
18 2625  41 EPIGENOME-WIDE ASSOCIATION STUDY AND MULTI-TISSUE REPLICATION OF INDIVIDUALS WITH ALCOHOL USE DISORDER: EVIDENCE FOR ABNORMAL GLUCOCORTICOID SIGNALING PATHWAY GENE REGULATION. ALCOHOL USE DISORDER (AUD) IS A CHRONIC DEBILITATING DISORDER WITH LIMITED TREATMENT OPTIONS AND POORLY DEFINED PATHOPHYSIOLOGY. THERE ARE SUBSTANTIAL GENETIC AND EPIGENETIC COMPONENTS; HOWEVER, THE UNDERLYING MECHANISMS CONTRIBUTING TO AUD REMAIN LARGELY UNKNOWN. WE CONDUCTED THE LARGEST DNA METHYLATION EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) ANALYSES CURRENTLY AVAILABLE FOR AUD (TOTAL N = 625) AND EMPLOYED A TOP HIT REPLICATION (N = 4798) USING A CROSS-TISSUE/CROSS-PHENOTYPIC APPROACH WITH THE GOAL OF IDENTIFYING NOVEL EPIGENETIC TARGETS RELEVANT TO AUD. RESULTS SHOW THAT A NETWORK OF DIFFERENTIALLY METHYLATED REGIONS IN GLUCOCORTICOID SIGNALING AND INFLAMMATION-RELATED GENES WERE ASSOCIATED WITH ALCOHOL USE BEHAVIORS. A TOP PROBE CONSISTENTLY ASSOCIATED ACROSS ALL COHORTS WAS LOCATED IN THE LONG NON-CODING RNA GROWTH ARREST SPECIFIC FIVE GENE (GAS5) (P < 10(-24)). GAS5 HAS BEEN IMPLICATED IN REGULATING TRANSCRIPTIONAL ACTIVITY OF THE GLUCOCORTICOID RECEPTOR AND HAS MULTIPLE FUNCTIONS RELATED TO APOPTOSIS, IMMUNE FUNCTION AND VARIOUS CANCERS. ENDOPHENOTYPIC ANALYSES USING PERIPHERAL CORTISOL LEVELS AND NEUROIMAGING PARADIGMS SHOWED THAT METHYLOMIC VARIATION IN GAS5 NETWORK-RELATED PROBES WERE ASSOCIATED WITH STRESS PHENOTYPES. POSTMORTEM BRAIN ANALYSES DOCUMENTED INCREASED GAS5 EXPRESSION IN THE AMYGDALA OF INDIVIDUALS WITH AUD. OUR DATA SUGGEST THAT ALCOHOL USE IS ASSOCIATED WITH DIFFERENTIAL METHYLATION IN THE GLUCOCORTICOID SYSTEM THAT MIGHT INFLUENCE STRESS AND INFLAMMATORY REACTIVITY AND SUBSEQUENTLY RISK FOR AUD.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
19 6083  51 THE EFFECT OF SMOKING ON DNA METHYLATION OF PERIPHERAL BLOOD MONONUCLEAR CELLS FROM AFRICAN AMERICAN WOMEN. BACKGROUND: REGULAR SMOKING IS ASSOCIATED WITH A WIDE VARIETY OF SYNDROMES WITH PROMINENT INFLAMMATORY COMPONENTS SUCH AS CANCER, OBESITY AND TYPE 2 DIABETES. HEAVY REGULAR SMOKING IS ALSO ASSOCIATED WITH CHANGES IN THE DNA METHYLATION OF PERIPHERAL MONONUCLEAR CELLS. HOWEVER, IN YOUNGER SMOKERS, INFLAMMATORY EPIGENETIC FINDINGS ARE LARGELY ABSENT WHICH SUGGESTS THE INFLAMMATORY RESPONSE(S) TO SMOKING MAY BE DOSE DEPENDENT. TO HELP UNDERSTAND WHETHER PERIPHERAL MONONUCLEAR CELLS HAVE A ROLE IN MEDIATING THESE RESPONSES IN OLDER SMOKERS WITH HIGHER CUMULATIVE SMOKE EXPOSURE, WE EXAMINED GENOME-WIDE DNA METHYLATION IN A GROUP OF WELL CHARACTERIZED ADULT AFRICAN AMERICAN SUBJECTS INFORMATIVE FOR SMOKING, AS WELL AS SERUM C-REACTIVE PROTEIN (CRP) AND INTERLEUKIN-6 RECEPTOR (IL6R) LEVELS. IN ADDITION, COMPLEMENTARY BIOINFORMATIC ANALYSES WERE CONDUCTED TO DELINEATE POSSIBLE PATHWAYS AFFECTED BY LONG-TERM SMOKING. RESULTS: GENOME-WIDE DNA METHYLATION ANALYSIS WITH RESPECT TO SMOKING STATUS YIELDED 910 SIGNIFICANT LOCI AFTER BENJAMINI-HOCHBERG CORRECTION. IN PARTICULAR, TWO LOCI FROM THE AHRR GENE (CG05575921 AND CG23576855) AND ONE LOCUS FROM THE GPR15 GENE (CG19859270) WERE IDENTIFIED AS HIGHLY SIGNIFICANTLY DIFFERENTIALLY METHYLATED BETWEEN SMOKERS AND NON-SMOKERS. THE BIOINFORMATIC ANALYSES SHOWED THAT LONG-TERM CHRONIC SMOKING IS ASSOCIATED WITH ALTERED PROMOTER DNA METHYLATION OF GENES CODING FOR PROTEINS MAPPING TO CRITICAL SUB-NETWORKS MODERATING INFLAMMATION, IMMUNE FUNCTION, AND COAGULATION. CONCLUSIONS: WE CONCLUDE THAT CHRONIC REGULAR SMOKING IS ASSOCIATED WITH CHANGES IN PERIPHERAL MONONUCLEAR CELL METHYLATION SIGNATURE WHICH PERTURB INFLAMMATORY AND IMMUNE FUNCTION PATHWAYS AND MAY CONTRIBUTE TO INCREASED VULNERABILITY FOR COMPLEX ILLNESSES WITH INFLAMMATORY COMPONENTS.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
20 1589  58 DNA METHYLATION PROFILING IN A CIGARETTE SMOKE-EXPOSED MOUSE MODEL OF AIRWAY INFLAMMATION. PURPOSE: DNA METHYLATION, A MAJOR EPIGENETIC MODIFICATION, HAS BEEN DOCUMENTED TO PLAY AN IMPORTANT ROLE IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN THIS STUDY, WE AIMED TO PROFILE THE DNA METHYLATION PATTERNS IN A MOUSE MODEL OF AIRWAY INFLAMMATION INDUCED BY CIGARETTE SMOKE (CS), A FOREMOST RISK FACTOR OF COPD. MATERIAL AND METHODS: TO ESTABLISH A MODEL OF AIRWAY INFLAMMATION, WILD-TYPE MICE WERE EXPOSED TO MAINSTREAM CS OR ROOM AIR FOR 2 HOURS TWICE DAILY, 6 DAYS PER WEEK FOR CONSECUTIVE 4 WEEKS. LUNG TISSUES OF THE MICE WERE COLLECTED FOR GENOME-WIDE DNA METHYLATION ANALYSIS BY LIQUID HYBRIDIZATION CAPTURE-BASED BISULFITE SEQUENCING, WHICH WERE USED FOR INTERSECTION ANALYSIS WITH GENE EXPRESSION BY CDNA MICROARRAY TO IDENTIFY CANDIDATE METHYLATED GENES. THEN, FUNCTIONAL ENRICHMENT ANALYSES WITH PROTEIN-PROTEIN INTERACTION (PPI) NETWORK REGARDING THESE GENES WERE CONDUCTED TO EXPLORE THE POTENTIAL MECHANISMS. RESULTS: AFTER 4-WEEK CS EXPOSURE, THE LEVEL OF DNA METHYLATION ACCOMPANIED BY A SUBACUTE AIRWAY INFLAMMATION WAS MARKEDLY ENHANCED, AND 2002 DIFFERENTIALLY METHYLATED GENES (DMGS) WERE ANNOTATED, INCLUDING 565 DMGS CONTAINED METHYLATIONS IN GENE PROMOTERS, WHICH WERE USED FOR INTERSECTION WITH THE DIFFERENTIALLY EXPRESSED GENES. THEN, 135 CANDIDATE METHYLATED GENES WERE FURTHER SELECTED BY THE INTERSECTION, AMONG WHICH 58 GENES WITH FUNCTIONAL METHYLATED MODIFICATION WERE FINALLY IDENTIFIED. FURTHER ANALYSES REVEALED CANDIDATE METHYLATED GENES WERE SIGNIFICANTLY ENRICHED IN A COMPLICATED NETWORK OF SIGNALS AND PROCESSES, INCLUDING INTERLEUKINS, TOLL-LIKE RECEPTORS, T-CELLS DIFFERENTIATION, OXIDATIVE STRESS, MAST CELLS ACTIVATION, STEM CELLS PROLIFERATION, ETC., AS WELL AS THE 58 FUNCTIONAL METHYLATED GENES WERE PARTIALLY LOCATED AT KEY POSITIONS IN PPI NETWORK, ESPECIALLY CXCL1, DDX58 AND JAK3. CONCLUSION: THIS STUDY SUGGESTS CS EXPOSURE SIGNIFICANTLY ENHANCES DNA METHYLATED LEVEL, AND THE POTENTIAL FUNCTIONAL METHYLATED GENES ARE CLOSELY RELATED TO COMPLICATED INFLAMMATORY-IMMUNE RESPONSES, WHICH MAY PROVIDE SOME NEW EXPERIMENTAL EVIDENCE IN UNDERSTANDING THE EPIGENETIC MECHANISMS OF CS-INDUCED AIRWAY INFLAMMATION IN COPD.	2022