1 2124 94 EPIGENETIC IMPLICATION OF GENE-ADJACENT RETROELEMENTS IN HELICOBACTER PYLORI-INFECTED ADULTS. A CHRONIC INFLAMMATORY CONDITION OF GASTRIC MUCOSA CAN FACILITATE THE INFLUX OF NEW STEM CELLS INTO THE STOMACH. EPIGENETIC CODES, SUCH AS DNA METHYLATION, MAY BE RESPONSIBLE FOR THE STABLE MAINTENANCE OF EPIGENETIC PHENOTYPES ESTABLISHED IN THE NEW STOMACH-ADAPTED STEM CELLS. A NUMBER OF HYPOTHESES HAVE BEEN MADE FOR THE ROLE OF CPG-ISLAND METHYLATION, WHICH IS COMMON IN THE HELICOBACTER PYLORI-INFECTED STOMACH. HOWEVER, THEY COULD NOT EXPLAIN THE PLAUSIBLE ROLE OF CPG-ISLAND METHYLATION IN THE RE-ESTABLISHMENT OF EPIGENETIC PHENOTYPES. THESE ISLANDS ARE HIGHLY REPETITIVE SEQUENCES DENSELY METHYLATED THROUGHOUT THE HUMAN GENOME, THE SO-CALLED PARASITIC RETROELEMENTS, WHICH EXPAND A NUMBER OF CDNA COPIES WITH REVERSE TRANSCRIPTASE. THE DENSELY METHYLATED RETROELEMENTS ADJACENT TO THE HOST GENES CAN FORM THE TRANSITIONAL-CPG SITES AROUND GENE-CONTROL REGIONS THAT ARE BARELY METHYLATED. THIS REVIEW FOCUSES ON THE PUTATIVE ROLE OF TRANSITIONAL CPG METHYLATION IN THE ADAPTIVE DIFFERENTIATION OF NEW STEM CELLS IN THE H. PYLORI-INFECTED STOMACH. 2012 2 1134 27 COMPREHENSIVE GENETIC AND EPIGENETIC ANALYSIS OF OCCULT HEPATITIS B FROM LIVER TISSUE SAMPLES. BACKGROUND: OCCULT INFECTION WITH HEPATITIS B VIRUS (HBV) IS A TYPE OF CHRONIC HBV INFECTION THAT IS CHARACTERIZED BY THE ABSENCE OF A DETECTABLE HEPATITIS B SURFACE ANTIGEN IN THE BLOOD AND BY VERY LOW LEVELS OF HBV DNA IN THE BLOOD AND LIVER. THE MECHANISMS LEADING TO OCCULT HBV INFECTION REMAIN POORLY UNDERSTOOD BUT INCLUDE POSSIBLE GENETIC MUTATIONS AND DELETIONS. RECENTLY, IT HAS BEEN SHOWN THAT HBV HAS CPG ISLANDS THAT ARE METHYLATED, RAISING THE POSSIBILITY THAT EPIGENETIC CHANGES MAY ALSO BE IMPORTANT. METHODS: THE FULL-LENGTH GENOMES OF ISOLATES FROM 5 CASES OF OCCULT HBV INFECTION WERE CLONED AND ANALYZED FOR MUTATIONS AND DELETIONS. ADDITIONAL STUDIES WERE PERFORMED TO EXAMINE FOR APOBEC3G (1 MEMBER OF A FAMILY OF DEAMINATING PROTEINS THAT ARE PART OF THE INNATE IMMUNE SYSTEM'S DEFENSE AGAINST VIRAL INFECTION) HYPEREDITING AND METHYLATION OF VIRAL DNA. RESULTS: NUMEROUS MUTATIONS AND DELETIONS WERE FOUND IN THE GENOMES OF OCCULT HBV. HOWEVER, SIMILAR TYPES AND LOCATIONS OF POLYMORPHISMS WERE ALSO NOTED IN THE GENOME SEQUENCES OF HBV ISOLATED FROM CONTROL LIVER TISSUE SAMPLES OBTAINED FROM INDIVIDUALS WITH NONOCCULT HBV INFECTION. EVIDENCE OF APOBEC3G HYPEREDITING WAS FOUND IN 1 CASE OF OCCULT HBV INFECTION, BUT HYPEREDITED SEQUENCES MADE UP ONLY A SMALL PROPORTION OF THE VIRAL SEQUENCES. METHYLATION OF HBV CPG ISLANDS 1 AND 2 WAS EVIDENT IN BOTH OCCULT AND NONOCCULT HBV SEQUENCES, WITH ISLAND 2 MORE DENSELY METHYLATED IN OCCULT HBV SEQUENCES AND ISLAND 1 MORE DENSELY METHYLATED IN NONOCCULT HBV SEQUENCES. CONCLUSION: DELETIONS AND MUTATIONS ARE COMMON IN OCCULT HBV BUT ARE ALSO FOUND IN CONTROL NONOCCULT HBV, AND NO UNIQUE GENETIC SIGNATURE FOR OCCULT HBV WAS FOUND. METHYLATION PATTERNS DIFFER BETWEEN CASES OF OCCULT AND NONOCCULT HBV INFECTION, SUGGESTING THAT EPIGENETIC CHANGES MAY BE RELEVANT TO OCCULT HBV. TOGETHER, THESE FINDINGS SUGGEST THAT MULTIPLE MECHANISMS CAN CONTRIBUTE TO OCCULT HBV INFECTION. 2008 3 1347 26 DETECTION OF TYPE 2 DIABETES RELATED MODULES AND GENES BASED ON EPIGENETIC NETWORKS. BACKGROUND: TYPE 2 DIABETES (T2D) IS ONE OF THE MOST COMMON CHRONIC METABOLIC DISEASES CHARACTERIZED BY INSULIN RESISTANCE AND THE DECREASE OF INSULIN SECRETION. GENETIC VARIATION CAN ONLY EXPLAIN PART OF THE HERITABILITY OF T2D, SO THERE NEED NEW METHODS TO DETECT THE SUSCEPTIBILITY GENES OF THE DISEASE. EPIGENETICS COULD ESTABLISH THE INTERFACE BETWEEN THE ENVIRONMENTAL FACTOR AND THE T2D PATHOLOGICAL MECHANISM. RESULTS: BASED ON THE NETWORK THEORY AND BY COMBINING EPIGENETIC CHARACTERISTICS WITH HUMAN INTERACTOME, THE WEIGHTED HUMAN DNA METHYLATION NETWORK (WMPN) WAS CONSTRUCTED, AND A T2D-RELATED SUBNETWORK (TMSN) WAS OBTAINED THROUGH T2D-RELATED DIFFERENTIALLY METHYLATED GENES. IT IS FOUND THAT TMSN HAD A T2D SPECIFIC NETWORK STRUCTURE THAT NON-FATAL METABOLIC DISEASE CAUSING GENES WERE OFTEN LOCATED IN THE TOPOLOGICAL AND FUNCTIONAL PERIPHERY OF NETWORK. COMBINED WITH CHROMATIN MODIFICATIONS, THE WEIGHTED CHROMATIN MODIFICATION NETWORK (WCPN) WAS BUILT, AND A T2D-RELATED CHROMATIN MODIFICATION PATTERN SUBNETWORK WAS OBTAINED BY THE TMSN GENE SET. TCSN HAD A DENSELY CONNECTED NETWORK COMMUNITY, INDICATING THAT TMSN AND TCSN COULD REPRESENT A COLLECTION OF T2D-RELATED EPIGENETIC DYSREGULATED SUB-PATHWAYS. USING THE CUMULATIVE HYPERGEOMETRIC TEST, 24 INTERPLAY MODULES OF DNA METHYLATION AND CHROMATIN MODIFICATIONS WERE IDENTIFIED. BY THE ANALYSIS OF GENE EXPRESSION IN HUMAN T2D ISLET TISSUE, IT IS FOUND THAT THERE EXISTED GENES WITH THE VARIANT EXPRESSION LEVEL CAUSED BY THE ABERRANT DNA METHYLATION AND (OR) CHROMATIN MODIFICATIONS, WHICH MIGHT AFFECT AND PROMOTE THE DEVELOPMENT OF T2D. CONCLUSIONS: HERE WE HAVE DETECTED THE POTENTIAL INTERPLAY MODULES OF DNA METHYLATION AND CHROMATIN MODIFICATIONS FOR T2D. THE STUDY OF T2D EPIGENETIC NETWORKS PROVIDES A NEW WAY FOR UNDERSTANDING THE PATHOGENIC MECHANISM OF T2D CAUSED BY EPIGENETIC DISORDERS. 2014 4 5767 34 SPECIES-SPECIFIC ROLE OF GENE-ADJACENT RETROELEMENTS IN HUMAN AND MOUSE GASTRIC CARCINOGENESIS. HELICOBACTER PYLORI (HP) INFECTION PROMOTES THE RECRUITMENT OF BONE MARROW STEM CELLS INTO CHRONIC GASTRITIS LESIONS. SOME OF THESE MARROW STEM CELLS CAN DIFFERENTIATE INTO GASTRIC EPITHELIAL CELLS AND NEOPLASTIC CELLS. WE PROPOSE THAT HP-ASSOCIATED METHYLATION COULD STABILIZE TRANS-DIFFERENTIATION OF MARROW-DERIVED STEM CELLS AND THAT AN UNSTABLE METHYLATION STATUS IS ASSOCIATED WITH A RISK OF GASTRIC CANCER. PATHOBIOLOGIC BEHAVIOR OF EXPERIMENTAL MOUSE GASTRIC CANCER IS MILD COMPARED TO INVASIVE AND METASTATIC HUMAN GASTRIC CANCER. DIFFERENCES IN EPIGENETIC STABILIZATION OF ADULT CELL PHENOTYPES BETWEEN HUMANS AND MICE COULD PROVIDE A FOUNDATION TO EXPLORE THE DEVELOPMENT OF INVASIVE AND METASTATIC GASTRIC CANCER. RETROELEMENTS ARE HIGHLY REPETITIVE SEQUENCES THAT PLAY AN ESSENTIAL ROLE IN THE GENERATION OF SPECIES DIVERSITY. IN THIS REVIEW, WE ANALYZED RETROELEMENTS ADJACENT TO HUMAN AND MOUSE HOUSEKEEPING GENES AND PROPOSED A POSSIBLE EPIGENETIC MECHANISM FOR HP-ASSOCIATED CARCINOGENESIS. 2018 5 3225 23 HELICOBACTER PYLORI INFECTION INTRODUCES DNA DOUBLE-STRAND BREAKS IN HOST CELLS. GASTRIC CANCER IS AN INFLAMMATION-RELATED MALIGNANCY RELATED TO LONG-STANDING ACUTE AND CHRONIC INFLAMMATION CAUSED BY INFECTION WITH THE HUMAN BACTERIAL PATHOGEN HELICOBACTER PYLORI. INFLAMMATION CAN RESULT IN GENOMIC INSTABILITY. HOWEVER, THERE ARE CONSIDERABLE DATA THAT H. PYLORI ITSELF CAN ALSO PRODUCE GENOMIC INSTABILITY BOTH DIRECTLY AND THROUGH EPIGENETIC PATHWAYS. OVERALL, THE MECHANISMS OF H. PYLORI-INDUCED HOST GENOMIC INSTABILITIES REMAIN POORLY UNDERSTOOD. WE USED MICROARRAY SCREENING OF H. PYLORI-INFECTED HUMAN GASTRIC BIOPSY SPECIMENS TO IDENTIFY CANDIDATE GENES INVOLVED IN H. PYLORI-INDUCED HOST GENOMIC INSTABILITIES. WE FOUND UPREGULATION OF ATM EXPRESSION IN VIVO IN GASTRIC MUCOSAL CELLS INFECTED WITH H. PYLORI. USING GASTRIC CANCER CELL LINES, WE CONFIRMED THAT THE H. PYLORI-RELATED ACTIVATION OF ATM WAS DUE TO THE ACCUMULATION OF DNA DOUBLE-STRAND BREAKS (DSBS). DSBS WERE OBSERVED FOLLOWING INFECTION WITH BOTH CAG PATHOGENICITY ISLAND (PAI)-POSITIVE AND -NEGATIVE STRAINS, BUT THE EFFECT WAS MORE ROBUST WITH CAG PAI-POSITIVE STRAINS. THESE RESULTS ARE CONSISTENT WITH THE FACT THAT INFECTIONS WITH BOTH CAG PAI-POSITIVE AND -NEGATIVE STRAINS ARE ASSOCIATED WITH GASTRIC CARCINOGENESIS, BUT THE RISK IS HIGHER IN INDIVIDUALS INFECTED WITH CAG PAI-POSITIVE STRAINS. 2014 6 3420 23 HUMAN LUNG DNA METHYLATION QUANTITATIVE TRAIT LOCI COLOCALIZE WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE GENOME-WIDE ASSOCIATION LOCI. RATIONALE: AS THE THIRD LEADING CAUSE OF DEATH IN THE UNITED STATES, THE IMPACT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) MAKES IDENTIFICATION OF ITS MOLECULAR MECHANISMS OF GREAT IMPORTANCE. GENOME-WIDE ASSOCIATION STUDIES (GWASS) HAVE IDENTIFIED MULTIPLE GENOMIC REGIONS ASSOCIATED WITH COPD. HOWEVER, GENETIC VARIATION ONLY EXPLAINS A SMALL FRACTION OF THE SUSCEPTIBILITY TO COPD, AND SUB-GENOME-WIDE SIGNIFICANT LOCI MAY PLAY A ROLE IN PATHOGENESIS. OBJECTIVES: REGULATORY ANNOTATION WITH EPIGENETIC EVIDENCE MAY GIVE PRIORITY FOR FURTHER INVESTIGATION, PARTICULARLY FOR GWAS ASSOCIATIONS IN NONCODING REGIONS. WE PERFORMED INTEGRATIVE GENOMICS ANALYSES USING DNA METHYLATION PROFILING AND GENOME-WIDE SNP GENOTYPING FROM LUNG TISSUE SAMPLES FROM 90 SUBJECTS WITH COPD AND 36 CONTROL SUBJECTS. METHODS: WE PERFORMED METHYLATION QUANTITATIVE TRAIT LOCI (MQTL) ANALYSES, TESTING FOR SNPS ASSOCIATED WITH PERCENT DNA METHYLATION AND ASSESSED THE COLOCALIZATION OF THESE RESULTS WITH PREVIOUS COPD GWAS FINDINGS USING BAYESIAN METHODS IN THE R PACKAGE COLOC TO HIGHLIGHT POTENTIAL REGULATORY FEATURES OF THE LOCI. MEASUREMENTS AND MAIN RESULTS: WE IDENTIFIED 942,068 UNIQUE SNPS AND 33,996 UNIQUE CPG SITES AMONG THE SIGNIFICANT (5% FALSE DISCOVERY RATE) CIS-MQTL RESULTS. THE GENOME-WIDE SIGNIFICANT AND SUBTHRESHOLD (P < 10(-4)) GWAS SNPS WERE ENRICHED IN THE SIGNIFICANT MQTL SNPS (HYPERGEOMETRIC TEST P < 0.00001). WE OBSERVED ENRICHMENT FOR SITES LOCATED IN CPG SHORES AND SHELVES, BUT NOT CPG ISLANDS. USING BAYESIAN COLOCALIZATION, WE IDENTIFIED LOCI IN REGIONS NEAR KCNK3, EEFSEC, PIK3CD, DCDC2C, TCERG1L, FRMD4B, AND IL27. CONCLUSIONS: COLOCALIZATION OF MQTL AND GWAS LOCI PROVIDES REGULATORY CHARACTERIZATION OF SIGNIFICANT AND SUBTHRESHOLD GWAS FINDINGS, SUPPORTING A ROLE FOR GENETIC CONTROL OF METHYLATION IN COPD PATHOGENESIS. 2018 7 1118 23 COMPARATIVE GENOTYPING AND PHENOTYPING OF ASPERGILLUS FUMIGATUS ISOLATES FROM HUMANS, DOGS AND THE ENVIRONMENT. BACKGROUND: ASPERGILLUS FUMIGATUS IS A UBIQUITOUS SAPROTROPHIC FUNGUS AND AN OPPORTUNISTIC PATHOGEN OF HUMANS AND ANIMALS. HUMANS AND ANIMALS CAN INHALE HUNDREDS OF A. FUMIGATUS SPORES DAILY. NORMALLY THIS IS HARMLESS FOR HUMANS, BUT IN CASE OF IMMUNODEFICIENCY, INVASIVE PULMONARY ASPERGILLOSIS (IPA) CAN DEVELOP WITH A HIGH MORTALITY RATE. A. FUMIGATUS ALSO CAUSES NON-INVASIVE MYCOSES LIKE SINO-NASAL ASPERGILLOSIS (SNA) IN DOGS. RESULTS: IN THIS STUDY WE COMPARED A. FUMIGATUS ISOLATES FROM HUMANS WITH SUSPECTED IPA, DOGS WITH SNA, AND A SET OF ENVIRONMENTAL ISOLATES. PHYLOGENETIC INFERENCE BASED ON CALMODULIN (CAM) AND BETA-TUBULIN (BENA) SEQUENCES DID NOT REVEAL A. FUMIGATUS SUB-GROUPS LINKED TO THE ORIGIN OF THE ISOLATES. GENOTYPING AND MICROSATELLITE ANALYSIS SHOWED THAT EACH DOG WAS INFECTED BY ONE A. FUMIGATUS GENOTYPE, WHEREAS HUMAN PATIENTS HAD MIXED INFECTIONS. AZOLE RESISTANCE WAS DETERMINED BY ANTIFUNGAL SUSCEPTIBILITY TESTING AND SEQUENCING OF THE CYP51A GENE. A TOTAL OF 12 OUT OF 29 HUMAN ISOLATES AND 1 OUT OF 27 ENVIRONMENTAL ISOLATES WERE AZOLE RESISTANT. OF THE AZOLE RESISTANT STRAINS, 11 HUMAN ISOLATES SHOWED TR(34)/L98H (N = 6) OR TR46/Y121F/T289A (N = 5). PHENOTYPICALLY, ISOLATES FROM DOGS WERE MORE VARIABLE IN GROWTH SPEED AND MORPHOLOGY WHEN COMPARED TO THOSE ISOLATED FROM HUMAN AND THE ENVIRONMENT. CONCLUSIONS: 1. A. FUMIGATUS FROM DOGS WITH SNA ARE PHENOTYPICALLY VERY DIVERSE IN CONTRAST TO THEIR ENVIRONMENTAL AND HUMAN COUNTERPARTS. 2. PHENOTYPIC VARIABILITY CAN BE INDUCED DURING THE CHRONIC INFECTION PROCESS IN THE SINUS OF THE DOGS. THE BASIS OF THIS HETEROGENEITY MIGHT BE DUE TO GENOMIC DIFFERENCES AND/OR EPIGENETIC VARIATIONS. 3. DIFFERENCES IN DOGS IS A COULD BE A RESULT OF WITHIN-HOST ADAPTION AND MIGHT BE TRIGGERED BY ENVIRONMENTAL FACTORS IN THE SINUS, HOWEVER THIS HYPOTHESIS STILL NEEDS TO BE TESTED. 2018 8 4227 20 METHYLATION OF FREE-FLOATING DEOXYRIBONUCLEIC ACID FRAGMENTS IN THE BRONCHOALVEOLAR LAVAGE FLUID OF DOGS WITH CHRONIC BRONCHITIS EXPOSED TO ENVIRONMENTAL TOBACCO SMOKE. BACKGROUND: THE ETIOLOGY OF CANINE CHRONIC BRONCHITIS (CB) IS NOT COMPLETELY UNDERSTOOD, ALTHOUGH EXPOSURE TO ENVIRONMENTAL TOBACCO SMOKE (ETS) AFFECTS THE AIRWAY INFLAMMATORY RESPONSES IN SOME DOGS WITH CB. THE MECHANISM BY WHICH THIS OCCURS IS UNKNOWN. FINDINGS: WE INVESTIGATED THE CONCENTRATIONS AND METHYLATION RATES OF FREE-FLOATING DNA FRAGMENTS IN BRONCHOALVEOLAR LAVAGE FLUID (BALF) FROM DOGS WITH CHRONIC BRONCHITIS. BASED ON SERUM COTININE LEVELS, DOGS WITH CB WERE DIVIDED INTO 2 GROUPS: DOGS THAT EITHER HAD OR HAD NOT BEEN EXPOSED TO ETS. OUR RESULTS DEMONSTRATED THAT THE TOTAL NUCLEATED CELL AND MACROPHAGE NUMBERS INCREASED IN BALF OF ETS-EXPOSED DOGS WITH CB. THERE WERE NO SIGNIFICANT DIFFERENCES IN DNA CONCENTRATIONS AND METHYLATION RATES IN BALF BETWEEN THE 2 GROUPS. HOWEVER, 3 OUT OF 8 DOGS EXPOSED TO ETS HAD HIGH DNA METHYLATION RATES IN THEIR BALF SAMPLES. CONCLUSION: OUR RESULTS SUGGEST THAT ETS EXPOSURE LEADS TO EPIGENETIC MODIFICATIONS OF CELLULAR COMPONENTS IN BALF IN DOGS DIAGNOSED WITH CB. 2015 9 1450 26 DISAGREEMENT BETWEEN TWO COMMON BIOMARKERS OF GLOBAL DNA METHYLATION. BACKGROUND: THE QUANTIFICATION OF GLOBAL DNA METHYLATION HAS BEEN ESTABLISHED IN EPIGENETIC SCREENING. AS MORE PRACTICABLE ALTERNATIVES TO THE HPLC-BASED GOLD STANDARD, THE METHYLATION ANALYSIS OF CPG ISLANDS IN REPEATABLE ELEMENTS (LINE-1) AND THE LUMINOMETRIC METHYLATION ASSAY (LUMA) OF OVERALL 5-METHYLCYTOSINE CONTENT IN "CCGG" RECOGNITION SITES ARE MOST WIDELY USED. BOTH METHODS ARE APPLIED AS VIRTUALLY EQUIVALENT, DESPITE THE HINTS THAT THEIR RESULTS ONLY PARTLY AGREE. THIS TRIGGERED THE PRESENT AGREEMENT ASSESSMENTS. RESULTS: THREE DIFFERENT HUMAN CELL TYPES (CULTURED MCF7 AND SHSY5Y CELL LINES TREATED WITH DIFFERENT CHEMICAL MODULATORS OF DNA METHYLATION AND WHOLE BLOOD DRAWN FROM PAIN PATIENTS AND HEALTHY VOLUNTEERS) WERE SUBMITTED TO THE GLOBAL DNA METHYLATION ASSAYS EMPLOYING LINE-1 OR LUMA-BASED PYROSEQUENCING MEASUREMENTS. THE AGREEMENT BETWEEN THE TWO BIOASSAYS WAS ASSESSED USING GENERALLY ACCEPTED APPROACHES TO THE STATISTICS FOR LABORATORY METHOD COMPARISON STUDIES. ALTHOUGH GLOBAL DNA METHYLATION LEVELS MEASURED BY THE TWO METHODS CORRELATED, FIVE DIFFERENT LINES OF STATISTICAL EVIDENCE CONSISTENTLY REJECTED THE ASSUMPTION OF COMPLETE AGREEMENT. SPECIFICALLY, A BIAS WAS OBSERVED BETWEEN THE TWO METHODS. IN ADDITION, BOTH THE MAGNITUDE AND DIRECTION OF BIAS WERE TISSUE-DEPENDENT. INTERASSAY DIFFERENCES COULD BE GROUPED BASED ON BAYESIAN STATISTICS, AND THESE GROUPS ALLOWED IN TURN TO RE-IDENTIFY THE ORIGINATING TISSUE. CONCLUSIONS: ALTHOUGH PROVIDING PARTLY CORRELATED MEASUREMENTS OF DNA METHYLATION, INTERCHANGEABILITY OF THE QUANTITATIVE RESULTS OBTAINED WITH LINE-1 AND LUMA WAS JEOPARDIZED BY A CONSISTENT BIAS BETWEEN THE RESULTS. MOREOVER, THE PRESENT ANALYSES STRONGLY INDICATE A TISSUE SPECIFICITY OF THE DIFFERENCES BETWEEN THE TWO METHODS. 2016 10 3487 27 IDENTIFICATION OF DIFFERENTIALLY METHYLATED SITES WITH WEAK METHYLATION EFFECTS. DEOXYRIBONUCLEIC ACID (DNA) METHYLATION IS AN EPIGENETIC ALTERATION CRUCIAL FOR REGULATING STRESS RESPONSES. IDENTIFYING LARGE-SCALE DNA METHYLATION AT SINGLE NUCLEOTIDE RESOLUTION IS MADE POSSIBLE BY WHOLE GENOME BISULFITE SEQUENCING. AN ESSENTIAL TASK FOLLOWING THE GENERATION OF BISULFITE SEQUENCING DATA IS TO DETECT DIFFERENTIALLY METHYLATED CYTOSINES (DMCS) AMONG TREATMENTS. MOST STATISTICAL METHODS FOR DMC DETECTION DO NOT CONSIDER THE DEPENDENCY OF METHYLATION PATTERNS ACROSS THE GENOME, THUS POSSIBLY INFLATING TYPE I ERROR. FURTHERMORE, SMALL SAMPLE SIZES AND WEAK METHYLATION EFFECTS AMONG DIFFERENT PHENOTYPE CATEGORIES MAKE IT DIFFICULT FOR THESE STATISTICAL METHODS TO ACCURATELY DETECT DMCS. TO ADDRESS THESE ISSUES, THE WAVELET-BASED FUNCTIONAL MIXED MODEL (WFMM) WAS INTRODUCED TO DETECT DMCS. TO FURTHER EXAMINE THE PERFORMANCE OF WFMM IN DETECTING WEAK DIFFERENTIAL METHYLATION EVENTS, WE USED BOTH SIMULATED AND EMPIRICAL DATA AND COMPARE WFMM PERFORMANCE TO A POPULAR DMC DETECTION TOOL METHYLKIT. ANALYSES OF SIMULATED DATA THAT REPLICATED THE EFFECTS OF THE HERBICIDE GLYPHOSATE ON DNA METHYLATION IN ARABIDOPSIS THALIANA SHOW THAT WFMM RESULTS IN HIGHER SENSITIVITY AND SPECIFICITY IN DETECTING DMCS COMPARED TO METHYLKIT, ESPECIALLY WHEN THE METHYLATION DIFFERENCES AMONG PHENOTYPE GROUPS ARE SMALL. MOREOVER, THE PERFORMANCE OF WFMM IS ROBUST WITH RESPECT TO SMALL SAMPLE SIZES, MAKING IT PARTICULARLY ATTRACTIVE CONSIDERING THE CURRENT HIGH COSTS OF BISULFITE SEQUENCING. ANALYSIS OF EMPIRICAL ARABIDOPSIS THALIANA DATA UNDER VARYING GLYPHOSATE DOSAGES, AND THE ANALYSIS OF MONOZYGOTIC (MZ) TWINS WHO HAVE DIFFERENT PAIN SENSITIVITIES-BOTH DATASETS HAVE WEAK METHYLATION EFFECTS OF <1%-SHOW THAT WFMM CAN IDENTIFY MORE RELEVANT DMCS RELATED TO THE PHENOTYPE OF INTEREST THAN METHYLKIT. DIFFERENTIALLY METHYLATED REGIONS (DMRS) ARE GENOMIC REGIONS WITH DIFFERENT DNA METHYLATION STATUS ACROSS BIOLOGICAL SAMPLES. DMRS AND DMCS ARE ESSENTIALLY THE SAME CONCEPTS, WITH THE ONLY DIFFERENCE BEING HOW METHYLATION INFORMATION ACROSS THE GENOME IS SUMMARIZED. IF METHYLATION LEVELS ARE DETERMINED BY GROUPING NEIGHBORING CYTOSINE SITES, THEN THEY ARE DMRS; IF METHYLATION LEVELS ARE CALCULATED BASED ON SINGLE CYTOSINES, THEY ARE DMCS. 2018 11 785 28 CELL-TYPE SPECIFIC EWAS IDENTIFIES GENES INVOLVED IN HIV PATHOGENESIS AND ONCOGENESIS AMONG PEOPLE WITH HIV INFECTION. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) OF HETEROGENOUS BLOOD CELLS HAVE IDENTIFIED CPG SITES ASSOCIATED WITH CHRONIC HIV INFECTION, WHICH OFFER LIMITED KNOWLEDGE OF CELL-TYPE SPECIFIC METHYLATION PATTERNS ASSOCIATED WITH HIV INFECTION. APPLYING A COMPUTATIONAL DECONVOLUTION METHOD VALIDATED BY CAPTURE BISULFITE DNA METHYLATION SEQUENCING, WE CONDUCTED A CELL TYPE-BASED EWAS AND IDENTIFIED DIFFERENTIALLY METHYLATED CPG SITES SPECIFIC FOR CHRONIC HIV INFECTION AMONG FIVE IMMUNE CELL TYPES IN BLOOD: CD4+ T-CELLS, CD8+ T-CELLS, B CELLS, NATURAL KILLER (NK) CELLS, AND MONOCYTES IN TWO INDEPENDENT COHORTS (N (TOTAL) =1,134). DIFFERENTIALLY METHYLATED CPG SITES FOR HIV-INFECTION WERE HIGHLY CONCORDANT BETWEEN THE TWO COHORTS. CELL-TYPE LEVEL META-EWAS REVEALED DISTINCT PATTERNS OF HIV-ASSOCIATED DIFFERENTIAL CPG METHYLATION, WHERE 67% OF CPG SITES WERE UNIQUE TO INDIVIDUAL CELL TYPES (FALSE DISCOVERY RATE, FDR <0.05). CD4+ T-CELLS HAD THE LARGEST NUMBER OF HIV-ASSOCIATED CPG SITES (N=1,472) COMPARED TO ANY OTHER CELL TYPE. GENES HARBORING STATISTICALLY SIGNIFICANT CPG SITES ARE INVOLVED IN IMMUNITY AND HIV PATHOGENESIS (E.G. CX3CR1 IN CD4+ T-CELLS, CCR7 IN B CELLS, IL12R IN NK CELLS, LCK IN MONOCYTES). MORE IMPORTANTLY, HIV-ASSOCIATED CPG SITES WERE OVERREPRESENTED FOR HALLMARK GENES INVOLVED IN CANCER PATHOLOGY ( FDR <0.05) (E.G. BCL FAMILY, PRDM16, PDCD1LGD, ESR1, DNMT3A, NOTCH2 ). HIV-ASSOCIATED CPG SITES WERE ENRICHED AMONG GENES INVOLVED IN HIV PATHOGENESIS AND ONCOGENESIS SUCH AS KRAS-SIGNALING, INTERFERON-ALPHA AND -GAMMA, TNF-ALPHA, INFLAMMATORY, AND APOPTOTIC PATHWAYS. OUR FINDINGS ARE NOVEL, UNCOVERING CELL-TYPE SPECIFIC MODIFICATIONS IN THE HOST EPIGENOME FOR PEOPLE WITH HIV THAT CONTRIBUTE TO THE GROWING BODY OF EVIDENCE REGARDING PATHOGEN-INDUCED EPIGENETIC ONCOGENICITY, SPECIFICALLY ON HIV AND ITS COMORBIDITY WITH CANCERS. 2023 12 1169 26 CONTRIBUTION OF GENETIC, EPIGENETIC AND TRANSCRIPTOMIC DIFFERENCES TO TWIN DISCORDANCE IN MULTIPLE SCLEROSIS. EVALUATION OF: BARANZINI SE, MUDGE J, VAN VELKINBURGH JC ET AL. GENOME, EPIGENOME AND RNA SEQUENCES OF MONOZYGOTIC TWINS DISCORDANT FOR MULTIPLE SCLEROSIS. NATURE 464, 1351-1356 (2010). MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY DISEASE OF THE CNS. GENETICALLY IDENTICAL (MONOZYGOTIC) TWINS HAVE A CONCORDANCE RATE FOR MS OF APPROXIMATELY 30%, LENDING SUPPORT TO THE NOTION THAT THE DISEASE HAS A COMPLEX ETIOLOGY, DEVELOPING AS A RESULT OF GENETIC AND ENVIRONMENTAL FACTORS AND THEIR INTERACTIONS. HOWEVER, RECENT STUDIES HAVE HIGHLIGHTED THE FACT THAT MONOZYGOTIC TWINS MIGHT NOT ACTUALLY BE GENETICALLY IDENTICAL. IN AN EFFORT TO SEE IF THIS CAN EXPLAIN MS TWIN DISCORDANCE, BARANZINI AND COLLEAGUES SEQUENCED THE GENOME FROM A PAIR OF MONOZYGOTIC TWINS DISCORDANT FOR MS, AND ALSO EXAMINED DNA METHYLATION AND GENE EXPRESSION ACROSS THE GENOME IN THIS TWIN PAIR AND AN ADDITIONAL TWO MORE TWIN PAIRS. NO CONSISTENT DIFFERENCES IN DNA SEQUENCE, DNA METHYLATION OR GENE EXPRESSION WERE FOUND. HERE WE PUT THESE FINDINGS INTO CONTEXT AND DISCUSS THEIR SIGNIFICANCE. 2010 13 1555 26 DNA METHYLATION MAPPING IDENTIFIES GENE REGULATORY EFFECTS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS. OBJECTIVES: SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE CONDITION WITH HETEROGENEOUS PRESENTATION AND COMPLEX AETIOLOGY WHERE DNA METHYLATION CHANGES ARE EMERGING AS A CONTRIBUTING FACTOR. IN ORDER TO DISCOVER NOVEL EPIGENETIC ASSOCIATIONS AND INVESTIGATE THEIR RELATIONSHIP TO GENETIC RISK FOR SLE, WE ANALYSED DNA METHYLATION PROFILES IN A LARGE COLLECTION OF PATIENTS WITH SLE AND HEALTHY INDIVIDUALS. METHODS: DNA EXTRACTED FROM BLOOD FROM 548 PATIENTS WITH SLE AND 587 HEALTHY CONTROLS WERE ANALYSED ON THE ILLUMINA HUMANMETHYLATION 450 K BEADCHIP, WHICH TARGETS 485 000 CPG SITES ACROSS THE GENOME. SINGLE NUCLEOTIDE POLYMORPHISM (SNP) GENOTYPE DATA FOR 196 524 SNPS ON THE ILLUMINA IMMUNOCHIP FROM THE SAME INDIVIDUALS WERE UTILISED FOR METHYLATION QUANTITATIVE TRAIT LOCI (CIS-MEQTLS) ANALYSES. RESULTS: WE IDENTIFIED AND REPLICATED DIFFERENTIALLY METHYLATED CPGS (DMCS) IN SLE AT 7245 CPG SITES IN THE GENOME. THE LARGEST METHYLATION DIFFERENCES WERE OBSERVED AT TYPE I INTERFERON-REGULATED GENES WHICH EXHIBITED DECREASED METHYLATION IN SLE. WE MAPPED CIS-MEQTLS AND IDENTIFIED GENETIC REGULATION OF METHYLATION LEVELS AT 466 OF THE DMCS IN SLE. THE MEQTLS FOR DMCS IN SLE WERE ENRICHED FOR GENETIC ASSOCIATION TO SLE, AND INCLUDED SEVEN SLE GENOME-WIDE ASSOCIATION STUDY (GWAS) LOCI: PTPRC (CD45), MHC-CLASS III, UHRF1BP1, IRF5, IRF7, IKZF3 AND UBE2L3. IN ADDITION, WE OBSERVED ASSOCIATION BETWEEN GENOTYPE AND VARIANCE OF METHYLATION AT 20 DMCS IN SLE, INCLUDING AT THE HLA-DQB2 LOCUS. CONCLUSIONS: OUR RESULTS SUGGEST THAT SEVERAL OF THE GENETIC RISK VARIANTS FOR SLE MAY EXERT THEIR INFLUENCE ON THE PHENOTYPE THROUGH ALTERATION OF DNA METHYLATION LEVELS AT REGULATORY REGIONS OF TARGET GENES. 2018 14 53 25 A DNA METHYLATION NETWORK INTERACTION MEASURE, AND DETECTION OF NETWORK ONCOMARKERS. EPIGENETIC PROCESSES--INCLUDING DNA METHYLATION--ARE INCREASINGLY SEEN AS HAVING A FUNDAMENTAL ROLE IN CHRONIC DISEASES LIKE CANCER. DNA METHYLATION PATTERNS OFFER A ROUTE TO DEVELOP PROGNOSTIC MEASURES BASED DIRECTLY ON DNA MEASUREMENTS, RATHER THAN LESS-STABLE RNA MEASUREMENTS. A NOVEL DNA METHYLATION-BASED MEASURE OF THE CO-ORDINATED INTERACTIVE BEHAVIOUR OF GENES IS DEVELOPED, IN A NETWORK CONTEXT. IT IS SHOWN THAT THIS MEASURE REFLECTS WELL THE CO-REGULATORY BEHAVIOUR LINKED TO GENE EXPRESSION (AT THE MRNA LEVEL) OVER THE SAME NETWORK INTERACTIONS. THIS MEASURE, DEFINED FOR PAIRS OF GENES IN A SINGLE PATIENT/SAMPLE, ASSOCIATES WITH OVERALL SURVIVAL OUTCOME INDEPENDENT OF KNOWN PROGNOSTIC CLINICAL FEATURES, IN SEVERAL INDEPENDENT DATA SETS RELATING TO DIFFERENT CANCER TYPES. IN TOTAL, MORE THAN HALF A BILLION CPGS IN OVER 1600 SAMPLES, TAKEN FROM NINE DIFFERENT CANCER ENTITIES, ARE ANALYSED. IT IS FOUND THAT GROUPS OF GENE-PAIR INTERACTIONS WHICH ASSOCIATE SIGNIFICANTLY WITH SURVIVAL IDENTIFY STATISTICALLY SIGNIFICANT SUBNETWORK MODULES. MANY OF THESE SUBNETWORK MODULES ARE SHOWN TO BE BIOLOGICALLY RELEVANT BY STRONG CORRELATION WITH PRE-DEFINED GENE SETS, SUCH AS IMMUNE FUNCTION, WOUND HEALING, MITOCHONDRIAL FUNCTION AND MAP-KINASE SIGNALLING. IN PARTICULAR, THE WOUND HEALING MODULE CORRESPONDS TO AN INCREASE IN CO-ORDINATED INTERACTIVE BEHAVIOUR BETWEEN GENES FOR WORSE PROGNOSIS, AND THE IMMUNE MODULE CORRESPONDS TO A DECREASE IN CO-ORDINATED INTERACTIVE BEHAVIOUR BETWEEN GENES FOR WORSE PROGNOSIS. THIS MEASURE HAS GREAT POTENTIAL FOR DEFINING DNA-BASED CANCER BIOMARKERS. SUCH BIOMARKERS COULD NATURALLY BE DEVELOPED FURTHER, BY DRAWING ON THE RAPIDLY EXPANDING KNOWLEDGE BASE OF NETWORK SCIENCE. 2014 15 758 27 CAS9-TARGETED NANOPORE SEQUENCING REVEALS EPIGENETIC HETEROGENEITY AFTER DE NOVO ASSEMBLY OF NATIVE FULL-LENGTH HEPATITIS B VIRUS GENOMES. HEPATITIS B VIRUS (HBV) CONTAINS A 3.2 KB DNA GENOME AND CAUSES ACUTE AND CHRONIC HEPATITIS. HBV INFECTION IS A GLOBAL HEALTH PROBLEM, WITH 350 MILLION CHRONICALLY INFECTED PEOPLE AT INCREASED RISK OF DEVELOPING LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). METHYLATION OF HBV DNA IN A CPG CONTEXT (5MCPG) CAN ALTER THE EXPRESSION PATTERNS OF VIRAL GENES RELATED TO INFECTION AND CELLULAR TRANSFORMATION. MOREOVER, IT MAY ALSO PROVIDE CLUES AS TO WHY CERTAIN INFECTIONS ARE CLEARED OR PERSIST WITH OR WITHOUT PROGRESSION TO CANCER. THE DETECTION OF 5MCPG OFTEN REQUIRES TECHNIQUES THAT DAMAGE DNA OR INTRODUCE BIAS THROUGH A MYRIAD OF LIMITATIONS. THEREFORE, WE DEVELOPED A METHOD FOR THE DETECTION OF 5MCPG ON THE HBV GENOME THAT DOES NOT RELY ON BISULFITE CONVERSION OR PCR. WITH CAS9-GUIDED RNPS TO SPECIFICALLY TARGET THE HBV GENOME, WE ENRICHED IN HBV DNA FROM PRIMARY HUMAN HEPATOCYTES (PHHS) INFECTED WITH DIFFERENT HBV GENOTYPES, AS WELL AS ENRICHING IN HBV FROM INFECTED PATIENT LIVER TISSUE, FOLLOWED BY SEQUENCING WITH OXFORD NANOPORE TECHNOLOGIES MINION. DETECTION OF 5MCPG BY NANOPORE SEQUENCING WAS BENCHMARKED WITH BISULFITE-QUANTITATIVE METHYL-SPECIFIC QPCR (BS-QMSP). THE 5MCPG LEVELS IN HBV DETERMINED BY BS-QMSP AND NANOPORE SEQUENCING WERE HIGHLY CORRELATED. OUR NANOPORE SEQUENCING APPROACH ACHIEVED A COVERAGE OF ~2000X OF HBV DEPENDING ON INFECTION EFFICIENCY, SUFFICIENT COVERAGE TO PERFORM A DE NOVO ASSEMBLY AND DETECT SMALL FLUCTUATIONS IN HBV METHYLATION, PROVIDING THE FIRST DE NOVO ASSEMBLY OF NATIVE HBV DNA, AS WELL AS THE FIRST LANDSCAPE OF 5MCPG FROM NATIVE HBV SEQUENCES. MOREOVER, BY CAPTURING ENTIRE HBV GENOMES, WE EXPLORED THE EPIGENETIC HETEROGENEITY OF HBV IN INFECTED PATIENTS AND IDENTIFIED FOUR EPIGENETICALLY DISTINCT CLUSTERS BASED ON METHYLATION PROFILES. THIS METHOD IS A NOVEL APPROACH THAT ENABLES THE ENRICHMENT OF VIRAL DNA IN A MIXTURE OF NUCLEIC ACID MATERIAL FROM DIFFERENT SPECIES AND WILL SERVE AS A VALUABLE TOOL FOR INFECTIOUS DISEASE MONITORING. 2021 16 1837 27 EFFECTS OF PALMITATE ON GENOME-WIDE MRNA EXPRESSION AND DNA METHYLATION PATTERNS IN HUMAN PANCREATIC ISLETS. BACKGROUND: CIRCULATING FREE FATTY ACIDS ARE OFTEN ELEVATED IN PATIENTS WITH TYPE 2 DIABETES (T2D) AND OBESE INDIVIDUALS. CHRONIC EXPOSURE TO HIGH LEVELS OF SATURATED FATTY ACIDS HAS DETRIMENTAL EFFECTS ON ISLET FUNCTION AND INSULIN SECRETION. ALTERED GENE EXPRESSION AND EPIGENETICS MAY CONTRIBUTE TO T2D AND OBESITY. HOWEVER, THERE IS LIMITED INFORMATION ON WHETHER FATTY ACIDS ALTER THE GENOME-WIDE TRANSCRIPTOME PROFILE IN CONJUNCTION WITH DNA METHYLATION PATTERNS IN HUMAN PANCREATIC ISLETS. TO DISSECT THE MOLECULAR MECHANISMS LINKING LIPOTOXICITY TO IMPAIRED INSULIN SECRETION, WE INVESTIGATED THE EFFECTS OF A 48 H PALMITATE TREATMENT IN VITRO ON GENOME-WIDE MRNA EXPRESSION AND DNA METHYLATION PATTERNS IN HUMAN PANCREATIC ISLETS. METHODS: GENOME-WIDE MRNA EXPRESSION WAS ANALYZED USING AFFYMETRIX GENECHIP((R)) HUMAN GENE 1.0 ST WHOLE TRANSCRIPT-BASED ARRAY (N = 13) AND GENOME-WIDE DNA METHYLATION WAS ANALYZED USING INFINIUM HUMANMETHYLATION450K BEADCHIP (N = 13) IN HUMAN PANCREATIC ISLETS EXPOSED TO PALMITATE OR CONTROL MEDIA FOR 48 H. A NON-PARAMETRIC PAIRED WILCOXON STATISTICAL TEST WAS USED TO ANALYZE MRNA EXPRESSION. APOPTOSIS WAS MEASURED USING APO-ONE((R)) HOMOGENEOUS CASPASE-3/7 ASSAY (N = 4). RESULTS: WHILE GLUCOSE-STIMULATED INSULIN SECRETION WAS DECREASED, THERE WAS NO SIGNIFICANT EFFECT ON APOPTOSIS IN HUMAN ISLETS EXPOSED TO PALMITATE. WE IDENTIFIED 1,860 DIFFERENTIALLY EXPRESSED GENES IN PALMITATE-TREATED HUMAN ISLETS. THESE INCLUDE CANDIDATE GENES FOR T2D, SUCH AS TCF7L2, GLIS3, HNF1B AND SLC30A8. ADDITIONALLY, GENES IN GLYCOLYSIS/GLUCONEOGENESIS, PYRUVATE METABOLISM, FATTY ACID METABOLISM, GLUTATHIONE METABOLISM AND ONE CARBON POOL BY FOLATE WERE DIFFERENTIALLY EXPRESSED IN PALMITATE-TREATED HUMAN ISLETS. PALMITATE TREATMENT ALTERED THE GLOBAL DNA METHYLATION LEVEL AND DNA METHYLATION LEVELS OF CPG ISLAND SHELVES AND SHORES, 5'UTR, 3'UTR AND GENE BODY REGIONS IN HUMAN ISLETS. MOREOVER, 290 GENES WITH DIFFERENTIAL EXPRESSION HAD A CORRESPONDING CHANGE IN DNA METHYLATION, FOR EXAMPLE, TCF7L2 AND GLIS3. IMPORTANTLY, OUT OF THE GENES DIFFERENTIALLY EXPRESSED DUE TO PALMITATE TREATMENT IN HUMAN ISLETS, 67 WERE ALSO ASSOCIATED WITH BMI AND 37 WERE DIFFERENTIALLY EXPRESSED IN ISLETS FROM T2D PATIENTS. CONCLUSION: OUR STUDY DEMONSTRATES THAT PALMITATE TREATMENT OF HUMAN PANCREATIC ISLETS GIVES RISE TO EPIGENETIC MODIFICATIONS THAT TOGETHER WITH ALTERED GENE EXPRESSION MAY CONTRIBUTE TO IMPAIRED INSULIN SECRETION AND T2D. 2014 17 3065 21 GENOME-WIDE DNA METHYLATION PATTERNS IN CD4+ T CELLS FROM CHINESE HAN PATIENTS WITH RHEUMATOID ARTHRITIS. INTRODUCTION: RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE DISEASE THAT CAUSES CHRONIC INFLAMMATION OF THE JOINTS. RECENT EVIDENCE INDICATED THE EPIGENETIC CHANGES MAY CONTRIBUTE TO THE PATHOGENESIS OF RA. METHOD: TO UNDERSTAND THE EXTENT AND NATURE OF DYSREGULATED DNA METHYLATION IN RA CD4T CELLS, WE PERFORMED A GENOME-WIDE DNA METHYLATION STUDY IN CD4 + T CELLS IN 12 RA PATIENTS COMPARED TO 12 MATCHED NORMAL HEALTHY CONTROLS. CYTOSINE METHYLATION STATUS WAS QUANTIFIED WITH ILLUMINA METHYLATION 450K MICROARRAY. RESULT: THE DNA METHYLATION PROFILING SHOWED 383 HYPER- AND 785 HYPO-METHYLATED GENES IN THE CD4 + T CELLS OF THE RA PATIENTS (P < 3.4 X 10(-7)). GENE ONTOLOGY ANALYSIS INDICATED TRANSCRIPT ALTERNATIVE SPLICING AND PROTEIN MODIFICATION MEDIATED BY DNA METHYLATION MIGHT PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF RA. IN ADDITION, THE RESULT SHOWED THAT HUMAN LEUKOCYTE ANTIGEN (HLA) REGION INCLUDING HLA-DRB6, HLA-DQA1 AND HLA-E WAS FREQUENTLY HYPOMETHYLATED, BUT HLA-DQB1 HYPERMETHYLATED IN CPG ISLAND REGION AND HYPOMETHYLATED IN CPG SHELF REGION IN RA PATIENTS. OUTSIDE THE MHC REGION, HDAC4, NXN, TBCD AND TMEM61 WERE THE MOST HYPERMETHYLATED GENES, WHILE ITIH3, TCN2, PRDM16, SLC1A5 AND GALNT9 ARE THE MOST HYPOMETHYLATED GENES. CONCLUSION: GENOME-WIDE DNA METHYLATION PROFILE REVEALED SIGNIFICANT DNA METHYLATION CHANGE IN CD4 + T CELLS FROM PATIENTS WITH RA. 2017 18 3284 25 HIDRADENITIS SUPPURATIVA PRESENTS A METHYLOME DYSREGULATION CAPABLE TO EXPLAIN THE PRO-INFLAMMATORY MICROENVIRONMENT: ARE THESE DNA METHYLATIONS POTENTIAL THERAPEUTIC TARGETS? BACKGROUND: HIDRADENITIS SUPPURATIVA (HS) IS A CHRONIC, SYSTEMIC, INFLAMMATORY SKIN CONDITION WITH ELUSIVE PATHOGENESIS THAT AFFECTS THERAPEUTIC INTERVENTION DIRECTLY. OBJECTIVE: TO CHARACTERIZE EPIGENETIC VARIATIONS IN CYTOKINES GENES CONTRIBUTING TO HS. METHODS: EPIGENOME-WIDE DNA METHYLATION PROFILING WITH THE ILLUMINA EPIC ARRAY WAS PERFORMED ON BLOOD DNA SAMPLES FROM 24 HS PATIENTS AND 24 AGE- AND SEX-MATCHED CONTROLS TO EXPLORE DNA METHYLATION CHANGES IN CYTOKINE GENES. RESULTS: WE IDENTIFIED 170 CYTOKINE GENES INCLUDING 27 HYPERMETHYLATED CPG SITES AND 143 GENES WITH HYPOMETHYLATED SITES RESPECTIVELY. HYPERMETHYLATED GENES, INCLUDING LIF, HLA-DRB1, HLA-G, MTOR, FADD, TGFB3, MALAT1 AND CCL28; HYPOMETHYLATED GENES, INCLUDING NCSTN, SMAD3, IGF1R, IL1F9, NOD2, NOD1, YY1, DLL1 AND BCL2 MAY CONTRIBUTE TO THE PATHOGENESIS OF HS. THESE GENES WERE ENRICHED IN THE 117 DIFFERENT PATHWAYS (FDR P-VALUES 2, WHICH WOULD BE EXPECTED BY A NORMAL GENE-DOSAGE EFFECT. THIS FINDING POINTS TO AN EPIGENETIC PATHOMECHANISM. WE FIND THAT THE TWO COPIES OF THE CRITICAL REGION REPLICATE ASYNCHRONOUSLY, SUGGESTING DIFFERENTIAL CHROMATIN PACKAGING OF THE TWO COPIES OF 13Q14.3. ALTHOUGH WE ALSO DETECT MONOALLELIC SILENCING OF GENES LOCALIZED IN THE CRITICAL REGION, MONOALLELIC EXPRESSION ORIGINATES FROM EITHER THE MATERNAL OR PATERNAL COPY, EXCLUDING AN IMPRINTING MECHANISM. DNA METHYLATION ANALYSES REVEALED ONE CPG ISLAND OF THE REGION TO BE METHYLATED. DNA DEMETHYLATION OF THIS CPG ISLAND AND GLOBAL HISTONE HYPERACETYLATION INDUCED BIALLELIC EXPRESSION, WHEREAS REPLICATION TIMING WAS NOT AFFECTED. WE PROPOSE THAT DIFFERENTIAL REPLICATION TIMING REPRESENTS AN EARLY EPIGENETIC MARK THAT DISTINGUISHES THE TWO COPIES OF 13Q14.3, RESULTING IN DIFFERENTIAL CHROMATIN PACKAGING AND MONOALLELIC EXPRESSION. ACCORDINGLY, DELETION OF THE SINGLE ACTIVE COPY OF 13Q14.3 RESULTS IN SIGNIFICANT DOWN-REGULATION OF THE CANDIDATE GENES AND LOSS OF FUNCTION, PROVIDING A MODEL FOR THE INTERACTION OF GENETIC LESIONS AND EPIGENETIC SILENCING AT 13Q14.3 IN B CELL CHRONIC LYMPHOCYTIC LEUKEMIA. 2006 20 2142 28 EPIGENETIC INVESTIGATION OF VARIABLY X CHROMOSOME INACTIVATED GENES IN MONOZYGOTIC FEMALE TWINS DISCORDANT FOR PRIMARY BILIARY CIRRHOSIS. PRIMARY BILIARY CIRRHOSIS (PBC) IS AN AUTOIMMUNE CHRONIC CHOLESTATIC LIVER DISEASE WITH A STRONG GENETIC SUSCEPTIBILITY DUE TO THE HIGH CONCORDANCE IN MONOZYGOTIC (MZ) TWINS AND A STRIKING FEMALE PREDOMINANCE. WOMEN WITH PBC MANIFEST AN ENHANCED X MONOSOMY RATE IN PERIPHERAL LYMPHOCYTES AND WE THUS HYPOTHESIZED AN X CHROMOSOME EPIGENETIC COMPONENT TO EXPLAIN PBC FEMALE PREVALENCE. WHILE MOST GENES ON THE FEMALE INACTIVE X CHROMOSOME ARE SILENCED BY PROMOTER METHYLATION FOLLOWING X CHROMOSOME INACTIVATION (XCI), APPROXIMATELY 10% OF X- LINKED GENES EXHIBIT VARIABLE ESCAPE FROM XCI IN HEALTHY FEMALES. THIS STUDY WAS DESIGNED TO TEST THE HYPOTHESIS THAT SUSCEPTIBILITY TO PBC IS MODIFIED BY ONE OR MORE X-LINKED GENE WITH VARIABLE XCI STATUS. PERIPHERAL BLOOD MRNA AND DNA SAMPLES WERE OBTAINED FROM A UNIQUE COHORT OF MZ TWIN SETS DISCORDANT AND CONCORDANT FOR PBC. TRANSCRIPT LEVELS OF THE 125 VARIABLE XCI STATUS GENES WAS DETERMINED BY QUANTITATIVE RT-PCR ANALYSIS AND TWO GENES (CLIC2 AND PIN4) WERE IDENTIFIED AS CONSISTENTLY DOWNREGULATED IN THE AFFECTED TWIN OF DISCORDANT PAIRS. BOTH CLIC2 AND PIN4 DEMONSTRATED PARTIAL AND VARIABLE METHYLATION OF CPG SITES WITHIN 300 BP OF THE TRANSCRIPTION START SITE THAT DID NOT PREDICT THE XCI STATUS. PROMOTER METHYLATION OF CLIC2 MANIFESTED NO SIGNIFICANT DIFFERENCE BETWEEN SAMPLES AND NO SIGNIFICANT CORRELATION WITH TRANSCRIPT LEVELS. PIN4 METHYLATION SHOWED A POSITIVE TREND WITH TRANSCRIPTION IN ALL SAMPLES BUT NO DIFFERENTIAL METHYLATION WAS OBSERVED BETWEEN DISCORDANT TWINS. A GENETIC POLYMORPHISM AFFECTING THE NUMBER OF CPG SITES IN THE PIN4 PROMOTER DID NOT IMPACT METHYLATION OR TRANSCRIPT LEVELS IN A HETEROZYGOUS TWIN PAIR AND SHOWED A SIMILAR FREQUENCY IN INDEPENDENT SERIES OF UNRELATED PBC CASES AND CONTROLS. OUR RESULTS SUGGEST THAT EPIGENETIC FACTORS INFLUENCING PBC ONSET ARE MORE COMPLEX THAN METHYLATION DIFFERENCES AT X-LINKED PROMOTERS AND VARIABLY 3 INACTIVATED X-LINKED GENES MAY BE CHARACTERIZED BY PARTIAL PROMOTER METHYLATION AND BIALLELIC TRANSCRIPTION. 2011