1 276 115 AGE-RELATED DIFFERENCES IN MONOCYTE DNA METHYLATION AND IMMUNE FUNCTION IN HEALTHY KENYAN ADULTS AND CHILDREN. BACKGROUND: AGE-RELATED CHANGES IN ADAPTIVE AND INNATE IMMUNE CELLS HAVE BEEN ASSOCIATED WITH A DECLINE IN EFFECTIVE IMMUNITY AND CHRONIC, LOW-GRADE INFLAMMATION. EPIGENETIC, TRANSCRIPTIONAL, AND FUNCTIONAL CHANGES IN MONOCYTES OCCUR WITH AGING, THOUGH MOST STUDIES TO DATE HAVE FOCUSED ON DIFFERENCES BETWEEN YOUNG ADULTS AND THE ELDERLY IN POPULATIONS WITH EUROPEAN ANCESTRY; FEW DATA EXIST REGARDING CHANGES THAT OCCUR IN CIRCULATING MONOCYTES DURING THE FIRST FEW DECADES OF LIFE OR IN AFRICAN POPULATIONS. WE ANALYZED DNA METHYLATION PROFILES, CYTOKINE PRODUCTION, AND INFLAMMATORY GENE EXPRESSION PROFILES IN MONOCYTES FROM YOUNG ADULTS AND CHILDREN FROM WESTERN KENYA. RESULTS: WE IDENTIFIED SEVERAL HYPO- AND HYPER-METHYLATED CPG SITES IN MONOCYTES FROM KENYAN YOUNG ADULTS VS. CHILDREN THAT REPLICATED FINDINGS IN THE CURRENT LITERATURE OF DIFFERENTIAL DNA METHYLATION IN MONOCYTES FROM ELDERLY PERSONS VS. YOUNG ADULTS ACROSS DIVERSE POPULATIONS. DIFFERENTIALLY METHYLATED CPG SITES WERE ALSO NOTED IN GENE REGIONS IMPORTANT TO INFLAMMATION AND INNATE IMMUNE RESPONSES. MONOCYTES FROM KENYAN YOUNG ADULTS VS. CHILDREN DISPLAYED INCREASED PRODUCTION OF IL-8, IL-10, AND IL-12P70 IN RESPONSE TO TLR4 AND TLR2/1 STIMULATION AS WELL AS DISTINCT INFLAMMATORY GENE EXPRESSION PROFILES. CONCLUSIONS: THESE FINDINGS COMPLEMENT PREVIOUS REPORTS OF AGE-RELATED METHYLATION CHANGES IN ISOLATED MONOCYTES AND PROVIDE NOVEL INSIGHTS INTO THE ROLE OF AGE-ASSOCIATED CHANGES IN INNATE IMMUNE FUNCTIONS. 2021 2 1567 34 DNA METHYLATION OF THE KLF14 GENE REGION IN WHOLE BLOOD CELLS PROVIDES PREDICTION FOR THE CHRONIC INFLAMMATION IN THE ADIPOSE TISSUE. KRUPPEL-LIKE FACTOR 14 (KLF14) GENE, WHICH APPEARS TO BE A MASTER REGULATOR OF GENE EXPRESSION IN THE ADIPOSE TISSUE AND HAVE PREVIOUSLY BEEN ASSOCIATED WITH BMI AND TYPE 2 DIABETES (T2D) BY LARGE GENOME-WIDE ASSOCIATION STUDIES. IN ORDER TO FIND PREDICTIVE BIOMARKERS FOR THE DEVELOPMENT OF T2D, IT IS NECESSARY TO TAKE EPIGENOMIC CHANGES AFFECTED BY ENVIRONMENTAL FACTORS INTO ACCOUNT. THIS STUDY FOCUSES ON AGEING AND OBESITY, WHICH ARE T2D RISK FACTORS, AND EXAMINES EPIGENETIC CHANGES AND INFLAMMATORY CHANGES. WE INVESTIGATED DNA METHYLATION CHANGES IN THE KLF14 PROMOTER REGION IN DIFFERENT ORGANS OF MICE FOR COMPARING AGING AND WEIGHT. WE FOUND THAT METHYLATION LEVELS OF THESE SITES WERE INCREASED WITH AGING AND WEIGHT IN THE SPLEEN, THE ADIPOSE TISSUE, THE KIDNEY, THE LUNG, THE COLON AND THE WHOLE BLOOD CELLS. IN ADDITION, IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD, THESE EPIGENETIC CHANGES WERE ALSO SIGNIFICANTLY ASSOCIATED WITH INFLAMMATORY LEVELS. MOREOVER, NOT ONLY KLF14, BUT ALSO EXPRESSION LEVELS OF SOME DOWNSTREAM GENES WERE DECREASED WITH METHYLATION IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT METHYLATION CHANGES OF KLF14 IN THOSE TISSUES MAY BE ASSOCIATED WITH CHANGES IN GENE EXPRESSION AND INFLAMMATION ON THE ADIPOSE TISSUE OF OBESITY AND T2D. IN ADDITION, THE METHYLATION CHANGES IN THE WHOLE BLOOD CELLS MAY SERVE AS A PREDICTIVE EPIGENETIC BIOMARKER FOR THE DEVELOPMENT OF T2D. 2018 3 1584 29 DNA METHYLATION PROFILES OF SELECTED PRO-INFLAMMATORY CYTOKINES IN ALZHEIMER DISEASE. BY MEANS OF FUNCTIONAL GENOMICS ANALYSIS, WE RECENTLY DESCRIBED THE MRNA EXPRESSION PROFILES OF VARIOUS GENES INVOLVED IN THE NEUROINFLAMMATORY RESPONSE IN THE BRAINS OF SUBJECTS WITH LATE-ONSET ALZHEIMER DISEASE (LOAD). SOME OF THESE GENES, NAMELY INTERLEUKIN (IL)-1BETA AND IL-6, SHOWED DISTINCT EXPRESSION PROFILES WITH PEAK EXPRESSION DURING THE FIRST STAGES OF THE DISEASE AND CONTROL-LIKE LEVELS AT LATER STAGES. IL-1BETA AND IL-6 GENES ARE MODULATED BY DNA METHYLATION IN DIFFERENT CHRONIC AND DEGENERATIVE DISEASES; IT IS ALSO WELL KNOWN THAT LOAD MAY HAVE AN EPIGENETIC BASIS. INDEED, WE AND OTHERS HAVE PREVIOUSLY REPORTED GENE-SPECIFIC DNA METHYLATION ALTERATIONS IN LOAD AND IN RELATED ANIMAL MODELS. BASED ON THESE DATA, WE STUDIED THE DNA METHYLATION PROFILES, AT SINGLE CYTOSINE RESOLUTION, OF IL-1BETA AND IL-6 5'-FLANKING REGION BY BISULPHITE MODIFICATION IN THE CORTEX OF HEALTHY CONTROLS AND LOAD PATIENTS AT 2 DIFFERENT DISEASE STAGES: BRAAK I-II/A AND BRAAK V-VI/C. OUR ANALYSIS PROVIDES EVIDENCE THAT NEUROINFLAMMATION IN LOAD IS ASSOCIATED WITH (AND POSSIBLY MEDIATED BY) EPIGENETIC MODIFICATIONS. 2017 4 5894 36 T CELL EPIGENETIC REMODELING AND ACCELERATED EPIGENETIC AGING ARE LINKED TO LONG-TERM IMMUNE ALTERATIONS IN CHILDHOOD CANCER SURVIVORS. BACKGROUND: CANCER TREATMENTS HAVE SUBSTANTIALLY IMPROVED CHILDHOOD CANCER SURVIVAL BUT ARE ACCOMPANIED BY LONG-TERM COMPLICATIONS, NOTABLY CHRONIC INFLAMMATORY DISEASES. WE HYPOTHESIZE THAT CANCER TREATMENTS COULD LEAD TO LONG-TERM EPIGENETIC CHANGES IN IMMUNE CELLS, RESULTING IN INCREASED PREVALENCE OF INFLAMMATORY DISEASES IN CANCER SURVIVORS. RESULTS: TO TEST THIS HYPOTHESIS, WE ESTABLISHED THE EPIGENETIC AND TRANSCRIPTOMIC PROFILES OF IMMUNE CELLS FROM 44 CHILDHOOD CANCER SURVIVORS (CCS, > 16 YEARS OLD) ON FULL REMISSION (> 5 YEARS) WHO HAD RECEIVED CHEMOTHERAPY ALONE OR IN COMBINATION WITH TOTAL BODY IRRADIATION (TBI) AND HEMATOPOIETIC STEM CELL TRANSPLANT (HSCT). WE FOUND THAT MORE THAN 10 YEARS POST-TREATMENT, CCS TREATED WITH TBI/HSCT SHOWED AN ALTERED DNA METHYLATION SIGNATURE IN T CELL, PARTICULARLY AT GENES CONTROLLING IMMUNE AND INFLAMMATORY PROCESSES AND OXIDATIVE STRESS. DNA METHYLATION REMODELING IN T CELL WAS PARTIALLY ASSOCIATED WITH CHRONIC EXPRESSION CHANGES OF NEARBY GENES, INCREASED FREQUENCY OF TYPE 1 CYTOKINE-PRODUCING T CELL, ELEVATED SYSTEMIC LEVELS OF THESE CYTOKINES, AND OVER-ACTIVATION OF RELATED SIGNALING PATHWAYS. SURVIVORS EXPOSED TO TBI/HSCT WERE FURTHER CHARACTERIZED BY AN EPIGENETIC-AGING-SIGNATURE OF T CELL CONSISTENT WITH ACCELERATED EPIGENETIC AGING. TO INVESTIGATE THE POTENTIAL CONTRIBUTION OF IRRADIATION TO THESE CHANGES, WE ESTABLISHED TWO CELL CULTURE MODELS. WE IDENTIFIED THAT RADIATION PARTIALLY RECAPITULATED THE IMMUNE CHANGES OBSERVED IN SURVIVORS THROUGH A BYSTANDER EFFECT THAT COULD BE MEDIATED BY CIRCULATING FACTORS. CONCLUSION: CANCER TREATMENTS, IN PARTICULAR TBI/HSCT, ARE ASSOCIATED WITH LONG-TERM IMMUNE DISTURBANCES. WE PROPOSE THAT EPIGENETIC REMODELING OF IMMUNE CELLS FOLLOWING CANCER THERAPY AUGMENTS INFLAMMATORY- AND AGE-RELATED DISEASES, INCLUDING METABOLIC COMPLICATIONS, IN CHILDHOOD CANCER SURVIVORS. 2018 5 2820 29 FINE-MAPPING INFLAMMATORY BOWEL DISEASE LOCI TO SINGLE-VARIANT RESOLUTION. INFLAMMATORY BOWEL DISEASES ARE CHRONIC GASTROINTESTINAL INFLAMMATORY DISORDERS THAT AFFECT MILLIONS OF PEOPLE WORLDWIDE. GENOME-WIDE ASSOCIATION STUDIES HAVE IDENTIFIED 200 INFLAMMATORY BOWEL DISEASE-ASSOCIATED LOCI, BUT FEW HAVE BEEN CONCLUSIVELY RESOLVED TO SPECIFIC FUNCTIONAL VARIANTS. HERE WE REPORT FINE-MAPPING OF 94 INFLAMMATORY BOWEL DISEASE LOCI USING HIGH-DENSITY GENOTYPING IN 67,852 INDIVIDUALS. WE PINPOINT 18 ASSOCIATIONS TO A SINGLE CAUSAL VARIANT WITH GREATER THAN 95% CERTAINTY, AND AN ADDITIONAL 27 ASSOCIATIONS TO A SINGLE VARIANT WITH GREATER THAN 50% CERTAINTY. THESE 45 VARIANTS ARE SIGNIFICANTLY ENRICHED FOR PROTEIN-CODING CHANGES (N = 13), DIRECT DISRUPTION OF TRANSCRIPTION-FACTOR BINDING SITES (N = 3), AND TISSUE-SPECIFIC EPIGENETIC MARKS (N = 10), WITH THE LAST CATEGORY SHOWING ENRICHMENT IN SPECIFIC IMMUNE CELLS AMONG ASSOCIATIONS STRONGER IN CROHN'S DISEASE AND IN GUT MUCOSA AMONG ASSOCIATIONS STRONGER IN ULCERATIVE COLITIS. THE RESULTS OF THIS STUDY SUGGEST THAT HIGH-RESOLUTION FINE-MAPPING IN LARGE SAMPLES CAN CONVERT MANY DISCOVERIES FROM GENOME-WIDE ASSOCIATION STUDIES INTO STATISTICALLY CONVINCING CAUSAL VARIANTS, PROVIDING A POWERFUL SUBSTRATE FOR EXPERIMENTAL ELUCIDATION OF DISEASE MECHANISMS. 2017 6 6137 24 THE EPIGENETICS OF PSYCHOSIS: A STRUCTURED REVIEW WITH REPRESENTATIVE LOCI. THE EVIDENCE FOR AN ENVIRONMENTAL COMPONENT IN CHRONIC PSYCHOTIC DISORDERS IS STRONG AND RESEARCH ON THE EPIGENETIC MANIFESTATIONS OF THESE ENVIRONMENTAL IMPACTS HAS COMMENCED IN EARNEST. IN REVIEWING THIS RESEARCH, THE FOCUS IS ON THREE GENES AS MODELS FOR DIFFERENTIAL METHYLATION, MCHR1, AKT1 AND TDO2, EACH OF WHICH HAVE BEEN INVESTIGATED FOR GENETIC ASSOCIATION WITH PSYCHOTIC DISORDERS. ENVIRONMENTAL FACTORS ASSOCIATED WITH PSYCHOTIC DISORDERS, AND WHICH INTERACT WITH THESE MODEL GENES, ARE EXPLORED IN DEPTH. THE LOCATION OF TRANSCRIPTION FACTOR MOTIFS RELATIVE TO KEY METHYLATION SITES IS EVALUATED FOR PREDICTED GENE EXPRESSION RESULTS, AND FOR OTHER SITES, EVIDENCE IS PRESENTED FOR METHYLATION DIRECTING ALTERNATIVE SPLICING. EXPERIMENTAL RESULTS FROM KEY STUDIES SHOW DIFFERENTIAL METHYLATION: FOR MCHR1, IN PSYCHOSIS CASES VERSUS CONTROLS; FOR AKT1, AS A PRE-EXISTING METHYLATION PATTERN INFLUENCING BRAIN ACTIVATION FOLLOWING ACUTE ADMINISTRATION OF A PSYCHOSIS-ELICITING ENVIRONMENTAL STIMULUS; AND FOR TDO2, IN A PATTERN ASSOCIATED WITH A DEVELOPMENTAL FACTOR OF RISK FOR PSYCHOSIS, IN ALL CASES THE PREDICTED EXPRESSION IMPACT BEING HIGHLY DEPENDENT ON LOCATION. METHYLATION INDUCED BY SMOKING, A CONFOUNDING VARIABLE, EXHIBITS AN INTRIGUING PATTERN FOR ALL THREE GENES. FINALLY, HOW DIFFERENTIAL METHYLATION MESHES WITH DARWINIAN PRINCIPLES IS EXAMINED, IN PARTICULAR AS IT RELATES TO THE "FLEXIBLE STEM" THEORY OF EVOLUTION. 2022 7 2653 31 EPIGENOTYPING IN PERIPHERAL BLOOD CELL DNA AND BREAST CANCER RISK: A PROOF OF PRINCIPLE STUDY. BACKGROUND: EPIGENETIC CHANGES ARE EMERGING AS ONE OF THE MOST IMPORTANT EVENTS IN CARCINOGENESIS. TWO ALTERATIONS IN THE PATTERN OF DNA METHYLATION IN BREAST CANCER (BC) HAVE BEEN PREVIOUSLY REPORTED; ACTIVE ESTROGEN RECEPTOR-ALPHA (ER-ALPHA) IS ASSOCIATED WITH DECREASED METHYLATION OF ER-ALPHA TARGET (ERT) GENES, AND POLYCOMB GROUP TARGET (PCGT) GENES ARE MORE LIKELY THAN OTHER GENES TO HAVE PROMOTER DNA HYPERMETHYLATION IN CANCER. HOWEVER, WHETHER DNA METHYLATION IN NORMAL UNRELATED CELLS IS ASSOCIATED WITH BC RISK AND WHETHER THESE IMPRINTS CAN BE RELATED TO FACTORS WHICH CAN BE MODIFIED BY THE ENVIRONMENT, IS UNCLEAR. METHODOLOGY/PRINCIPAL FINDINGS: USING QUANTITATIVE METHYLATION ANALYSIS IN A CASE-CONTROL STUDY (N = 1,083) WE FOUND THAT DNA METHYLATION OF PERIPHERAL BLOOD CELL DNA PROVIDES GOOD PREDICTION OF BC RISK. WE ALSO REPORT THAT INVASIVE DUCTAL AND INVASIVE LOBULAR BC IS CHARACTERIZED BY TWO DIFFERENT SETS OF GENES, THE LATTER PARTICULAR BY GENES INVOLVED IN THE DIFFERENTIATION OF THE MESENCHYME (PITX2, TITF1, GDNF AND MYOD1). FINALLY WE DEMONSTRATE THAT ONLY ERT GENES PREDICT ER POSITIVE BC; LACK OF PERIPHERAL BLOOD CELL DNA METHYLATION OF ZNF217 PREDICTED BC INDEPENDENT OF AGE AND FAMILY HISTORY (ODDS RATIO 1.49; 95% CONFIDENCE INTERVAL 1.12-1.97; P = 0.006) AND WAS ASSOCIATED WITH ER-ALPHA BIOACTIVITY IN THE CORRESPONDING SERUM. CONCLUSION/SIGNIFICANCE: THIS FIRST LARGE-SCALE EPIGENOTYPING STUDY DEMONSTRATES THAT DNA METHYLATION MAY SERVE AS A LINK BETWEEN THE ENVIRONMENT AND THE GENOME. FACTORS THAT CAN BE MODULATED BY THE ENVIRONMENT (LIKE ESTROGENS) LEAVE AN IMPRINT IN THE DNA OF CELLS THAT ARE UNRELATED TO THE TARGET ORGAN AND INDICATE THE PREDISPOSITION TO DEVELOP A CANCER. FURTHER RESEARCH WILL NEED TO DEMONSTRATE WHETHER DNA METHYLATION PROFILES WILL BE ABLE TO SERVE AS A NEW TOOL TO PREDICT THE RISK OF DEVELOPING CHRONIC DISEASES WITH SUFFICIENT ACCURACY TO GUIDE PREVENTIVE MEASURES. 2008 8 1524 21 DNA METHYLATION CHANGES IN CYSTIC FIBROSIS: CAUSE OR CONSEQUENCE? TWIN AND SIBLING STUDIES HAVE SHOWN THAT LUNG DISEASE SEVERITY IS VARIABLE AMONG CYSTIC FIBROSIS (CF) PATIENTS AND AFFECTED TO THE SAME EXTENT BY GENETIC AND NONHERITABLE FACTORS. GENETIC FACTORS HAVE BEEN THOROUGHLY ASSESSED, WHEREAS THE MOLECULAR MECHANISMS WHEREBY NONHERITABLE FACTORS CONTRIBUTE TO THE PHENOTYPIC VARIABILITY OF CF PATIENTS ARE STILL UNKNOWN. EPIGENETIC MODIFICATIONS MAY REPRESENT THE MISSING LINK BETWEEN NONHERITABLE FACTORS AND PHENOTYPIC VARIATION IN CF. HEREIN, WE REVIEW RECENT STUDIES SHOWING THAT DNA METHYLATION IS ALTERED IN CF AND WE ADDRESS THREE POSSIBLE FACTORS RESPONSIBLE FOR THESE VARIATIONS: (I) OVERPRODUCTION OF REACTIVE OXYGEN SPECIES, (II) DEPLETION OF DNA METHYLATION COFACTORS AND (III) SUSCEPTIBILITY TO ACUTE AND CHRONIC BACTERIAL INFECTIONS. ALSO, WE HYPOTHESIZE THAT THE UNIQUE DNA METHYLATION PROFILE OF EACH PATIENT CAN MODULATE THE PHENOTYPE AND DISCUSS THE INTEREST OF IMPLEMENTING INTEGRATED GENOMIC, EPIGENOMIC AND TRANSCRIPTOMIC STUDIES TO FURTHER UNDERSTAND THE CLINICAL DIVERSITY OF CF PATIENTS (GRAPHICAL ABSTRACT). 2020 9 6720 34 VITAMIN D METABOLISM GENES ARE DIFFERENTIALLY METHYLATED IN INDIVIDUALS WITH CHRONIC KNEE PAIN. CONTEXT: RECENT EVIDENCE SUGGESTS THAT VITAMIN D MAY INTERACT WITH THE EPIGENOME AND PLAY A ROLE IN THE PAIN EXPERIENCE. IN ORDER FOR PROPER FUNCTIONING TO OCCUR, THERE MUST BE AN ADEQUATE LEVEL OF VITAMIN D PRESENT, MADE POSSIBLE BY ENZYMATIC REACTIONS THAT ALLOW VITAMIN D TO BE BIOLOGICALLY ACTIVE. THE PURPOSE OF THIS STUDY WAS TO EXPLORE THE EPIGENETIC LANDSCAPE OF GENES INVOLVED IN VITAMIN D METABOLISM IN INDIVIDUALS WITH AND WITHOUT CHRONIC KNEE PAIN. PROCEDURES: COMMUNITY-DWELLING INDIVIDUALS RECRUITED AS PART OF A LARGER STUDY FOCUSED ON KNEE PAIN PROVIDED DEMOGRAPHIC, CLINICAL AND PAIN-RELATED INFORMATION, AS WELL AS AN INTRAVENOUS BLOOD SAMPLE TO DETERMINE DNA METHYLATION LEVELS AT CPG SITES. MAIN FINDINGS: THERE WERE DIFFERENCES IN DNA METHYLATION BETWEEN THOSE WITH AND WITHOUT PAIN IN GENES THAT CODE FOR ENZYMES RELATED TO VITAMIN D METABOLISM: CYP24A1 (24-HYDROXYLASE) AND CYP27B1 (1-?-HYDROXYLASE). THERE WAS ALSO HYPERMETHYLATION ON THE GENE THAT CODES FOR THE VITAMIN D RECEPTOR (VDR). PRINCIPAL CONCLUSIONS: THE PRESENCE OF CHRONIC PAIN IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS IN GENES RESPONSIBLE FOR THE EXPRESSION OF ENZYMES INVOLVED IN VITAMIN D METABOLISM AND CELLULAR FUNCTION. THESE RESULTS LAY GROUNDWORK IN UNDERSTANDING THE MECHANISM UNDERLYING THE ASSOCIATION BETWEEN VITAMIN D AND CHRONIC PAIN. 2023 10 1594 37 DNA METHYLATION PROFILING REVEALS DIFFERENCES IN THE 3 HUMAN MONOCYTE SUBSETS AND IDENTIFIES UREMIA TO INDUCE DNA METHYLATION CHANGES DURING DIFFERENTIATION. HUMAN MONOCYTES ARE A HETEROGENEOUS CELL POPULATION CONSISTING OF 3 SUBSETS: CLASSICAL CD14++CD16-, INTERMEDIATE CD14++CD16+ AND NONCLASSICAL CD14+CD16++ MONOCYTES. VIA POORLY CHARACTERIZED MECHANISMS, INTERMEDIATE MONOCYTE COUNTS RISE IN CHRONIC INFLAMMATORY DISEASES, AMONG WHICH CHRONIC KIDNEY DISEASE IS OF PARTICULAR EPIDEMIOLOGIC IMPORTANCE. DNA METHYLATION IS A CENTRAL EPIGENETIC FEATURE THAT CONTROLS HEMATOPOIESIS. BY APPLYING NEXT-GENERATION METHYL-SEQUENCING WE NOW TESTED HOW FAR THE 3 MONOCYTE SUBSETS DIFFER IN THEIR DNA METHYLOME AND WHETHER UREMIA INDUCES DNA METHYLATION CHANGES IN DIFFERENTIATING MONOCYTES. WE FOUND THAT EACH MONOCYTE SUBSET DISPLAYS A UNIQUE PHENOTYPE WITH REGARDS TO DNA METHYLATION. GENES WITH DIFFERENTIALLY METHYLATED PROMOTER REGIONS IN INTERMEDIATE MONOCYTES WERE LINKED TO DISTINCT IMMUNOLOGICAL PROCESSES, WHICH IS IN LINE WITH RESULTS FROM RECENT GENE EXPRESSION ANALYSES. IN VITRO, UREMIA INDUCED DYSREGULATION OF DNA METHYLATION IN DIFFERENTIATING MONOCYTES, WHICH AFFECTED SEVERAL TRANSCRIPTION REGULATORS IMPORTANT FOR MONOCYTE DIFFERENTIATION (E.G., FLT3, HDAC1, MNT) AND LED TO ENHANCED GENERATION OF INTERMEDIATE MONOCYTES. AS POTENTIAL MEDIATOR, THE UREMIC TOXIN AND METHYLATION INHIBITOR S-ADENOSYLHOMOCYSTEINE INDUCED SHIFTS IN MONOCYTE SUBSETS IN VITRO, AND ASSOCIATED WITH MONOCYTE SUBSET COUNTS IN VIVO. OUR DATA SUPPORT THE CONCEPT OF MONOCYTE TRICHOTOMY AND THE DISTINCT ROLE OF INTERMEDIATE MONOCYTES IN HUMAN IMMUNITY. THE SHIFT IN MONOCYTE SUBSETS THAT OCCURS IN CHRONIC KIDNEY DISEASE, A PROINFLAMMATORY CONDITION OF SUBSTANTIAL EPIDEMIOLOGICAL IMPACT, MAY BE INDUCED BY ACCUMULATION OF UREMIC TOXINS THAT MEDIATE EPIGENETIC DYSREGULATION. 2016 11 6334 26 THE ROLE OF DNA METHYLATION AND HYDROXYMETHYLATION IN IMMUNOSENESCENCE. A HEALTHY FUNCTIONING IMMUNE SYSTEM IS CRITICAL TO STAVE OFF INFECTIOUS DISEASES, BUT AS HUMANS AND OTHER ORGANISMS AGE, THEIR IMMUNE SYSTEMS DECLINE. AS A RESULT, DISEASES THAT WERE READILY THWARTED IN EARLY LIFE POSE NONTRIVIAL HARM AND CAN EVEN BE DEADLY IN LATE LIFE. IMMUNOSENESCENCE IS DEFINED AS THE GENERAL DETERIORATION OF THE IMMUNE SYSTEM WITH AGE, AND IT IS CHARACTERIZED BY FUNCTIONAL CHANGES IN HEMATOPOIETIC STEM CELLS (HSCS) AND SPECIFIC BLOOD CELL TYPES AS WELL AS CHANGES IN LEVELS OF NUMEROUS FACTORS, PARTICULARLY THOSE INVOLVED IN INFLAMMATION. POTENTIAL MECHANISMS UNDERLYING IMMUNOSENESCENCE INCLUDE EPIGENETIC CHANGES SUCH AS CHANGES IN DNA METHYLATION (DNAM) AND DNA HYDROXYMETHYLATION (DNAHM) THAT OCCUR WITH AGE. THE PURPOSE OF THIS REVIEW IS TO DESCRIBE WHAT IS CURRENTLY KNOWN ABOUT THE RELATIONSHIP BETWEEN IMMUNOSENESCENCE AND THE AGE-RELATED CHANGES TO DNAM AND DNAHM, AND TO DISCUSS EXPERIMENTAL APPROACHES BEST SUITED TO FILL GAPS IN OUR UNDERSTANDING. 2019 12 177 25 ACCELERATED EPIGENETIC AGING AND INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) IN PATIENTS WITH CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS DEFINED BY A REDUCED ESTIMATED GLOMERULAR FILTRATION RATE (EGFR). THIS FAILURE CAN BE RELATED TO A PHENOTYPE OF ACCELERATED AGING. IN THIS WORK, WE CONSIDERED 76 PATIENTS WITH END-STAGE RENAL DISEASE (ESRD) AND 83 HEALTHY CONTROLS. WE CONCOMITANTLY EVALUATED FOR THE FIRST TIME TWO MEASURES THAT CAN BE INFORMATIVE OF THE RATE OF AGING, I.E., WHOLE BLOOD DNA METHYLATION USING THE ILLUMINA INFINIUM EPIC ARRAY AND PLASMA LEVELS OF A SELECTION OF INFLAMMATORY/IMMUNOLOGICAL PROTEINS USING MULTIPLEX IMMUNOASSAYS. FIRST OF ALL, WE DEMONSTRATED ACCELERATED AGING IN TERMS OF THE MOST COMMON EPIGENETIC AGE ESTIMATORS IN CKD PATIENTS. MOREOVER, WE DEVELOPED A NEW CLOCK/PREDICTOR OF AGE BASED ON THE INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) AND IDENTIFIED THE INFLAMMATORY/IMMUNOLOGICAL BIOMARKERS DIFFERENTIALLY EXPRESSED BETWEEN CASES AND CONTROLS. IPAGE APPEARED TO BE MORE SENSITIVE THAN EPIGENETIC CLOCKS IN QUANTIFYING THE ACCELERATED AGING PHENOTYPE OF ESRD PATIENTS. INTERESTINGLY, WE DID NOT FIND ANY CORRELATION BETWEEN THE AGE ACCELERATION EVALUATED ACCORDING TO THE EPIGENETIC CLOCKS AND IPAGE IN EITHER THE ESRD GROUP OR THE CONTROL GROUP. ON THE WHOLE, OUR DATA SHOW A CONSISTENT ACCELERATED AGING PHENOTYPE IN ESRD PATIENTS, WHICH IS BETTER APPRECIATED BY QUANTIFYING THE UNDERLYING INFLAMMATORY PROCESSES (INFLAMMAGING) BY IPAGE THAN BY USING EPIGENETIC CLOCKS. 2022 13 6195 24 THE IMPACT OF RECENT ALCOHOL USE ON GENOME WIDE DNA METHYLATION SIGNATURES. CHRONIC ALCOHOL INTAKE IS ASSOCIATED WITH A WIDE VARIETY OF ADVERSE HEALTH OUTCOMES INCLUDING DEPRESSION, DIABETES, AND HEART DISEASE. UNFORTUNATELY, THE MOLECULAR MECHANISMS THROUGH WHICH THESE EFFECTS ARE CONVEYED ARE NOT CLEARLY UNDERSTOOD. TO EXAMINE THE POTENTIAL ROLE OF EPIGENETIC FACTORS IN THIS PROCESS, WE EXAMINED THE RELATIONSHIP OF RECENT ALCOHOL INTAKE TO GENOME WIDE METHYLATION PATTERNS USING THE ILLUMINA 450 METHYLATION BEAD CHIP AND LYMPHOBLAST DNA DERIVED FROM 165 FEMALE SUBJECTS PARTICIPATING IN THE IOWA ADOPTION STUDIES. WE FOUND THAT THE PATTERN OF ALCOHOL USE OVER THE 6-MONTHS IMMEDIATELY PRIOR TO PHLEBOTOMY WAS ASSOCIATED WITH, SEVERITY-DEPENDENT CHANGES IN THE DEGREE OF GENOME WIDE METHYLATION THAT PREFERENTIALLY HYPERMETHYLATE THE CENTRAL PORTION OF CPG ISLANDS WITH METHYLATION AT CG05600126, A PROBE IN ABR, AND THE 5' UNTRANSLATED REGION OF BLCAP ATTAINING GENOME WIDE SIGNIFICANCE IN TWO POINT AND SLIDING WINDOW ANALYSES OF PROBE METHYLATION DATA, RESPECTIVELY. WE CONCLUDE THAT RECENT ALCOHOL USE IS ASSOCIATED WITH WIDESPREAD CHANGES IN DNA METHYLATION IN WOMEN AND THAT FURTHER STUDY TO CONFIRM THESE FINDINGS AND DETERMINE THEIR RELATIONSHIP TO SOMATIC FUNCTION ARE IN ORDER. 2012 14 6468 28 TISSUE-SPECIFIC ENRICHMENT OF LYMPHOMA RISK LOCI IN REGULATORY ELEMENTS. THOUGH NUMEROUS POLYMORPHISMS HAVE BEEN ASSOCIATED WITH RISK OF DEVELOPING LYMPHOMA, HOW THESE VARIANTS FUNCTION TO PROMOTE TUMORIGENESIS IS POORLY UNDERSTOOD. HERE, WE REPORT THAT LYMPHOMA RISK SNPS, ESPECIALLY IN THE NON-HODGKIN'S LYMPHOMA SUBTYPE CHRONIC LYMPHOCYTIC LEUKEMIA, ARE SIGNIFICANTLY ENRICHED FOR CO-LOCALIZATION WITH EPIGENETIC MARKS OF ACTIVE GENE REGULATION. THESE ENRICHMENTS WERE SEEN IN A LYMPHOID-SPECIFIC MANNER FOR NUMEROUS ENCODE DATASETS, INCLUDING DNASE-HYPERSENSITIVITY AS WELL AS MULTIPLE SEGMENTATION-DEFINED ENHANCER REGIONS. FURTHERMORE, WE IDENTIFY PUTATIVELY FUNCTIONAL SNPS THAT ARE BOTH IN REGULATORY ELEMENTS IN LYMPHOCYTES AND ARE ASSOCIATED WITH GENE EXPRESSION CHANGES IN BLOOD. WE DEVELOPED AN ALGORITHM, UES, THAT USES A MONTE CARLO SIMULATION APPROACH TO CALCULATE THE ENRICHMENT OF PREVIOUSLY IDENTIFIED RISK SNPS IN VARIOUS FUNCTIONAL ELEMENTS. THIS MULTISCALE APPROACH INTEGRATING MULTIPLE DATASETS HELPS DISENTANGLE THE UNDERLYING BIOLOGY OF LYMPHOMA, AND MORE BROADLY, IS GENERALLY APPLICABLE TO GWAS RESULTS FROM OTHER DISEASES AS WELL. 2015 15 1607 27 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 16 1739 43 EARLY DNA METHYLATION CHANGES IN CHILDREN DEVELOPING BETA CELL AUTOIMMUNITY AT A YOUNG AGE. AIMS/HYPOTHESIS: TYPE 1 DIABETES IS A CHRONIC AUTOIMMUNE DISEASE OF COMPLEX AETIOLOGY, INCLUDING A POTENTIAL ROLE FOR EPIGENETIC REGULATION. PREVIOUS EPIGENOMIC STUDIES FOCUSED MAINLY ON CLINICALLY DIAGNOSED INDIVIDUALS. THE AIM OF THE STUDY WAS TO ASSESS EARLY DNA METHYLATION CHANGES ASSOCIATED WITH TYPE 1 DIABETES ALREADY BEFORE THE DIAGNOSIS OR EVEN BEFORE THE APPEARANCE OF AUTOANTIBODIES. METHODS: REDUCED REPRESENTATION BISULPHITE SEQUENCING (RRBS) WAS APPLIED TO STUDY DNA METHYLATION IN PURIFIED CD4(+) T CELL, CD8(+) T CELL AND CD4(-)CD8(-) CELL FRACTIONS OF 226 PERIPHERAL BLOOD MONONUCLEAR CELL SAMPLES LONGITUDINALLY COLLECTED FROM SEVEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL INDIVIDUALS MATCHED FOR AGE, SEX, HLA RISK AND PLACE OF BIRTH. WE ALSO EXPLORED CORRELATIONS BETWEEN DNA METHYLATION AND GENE EXPRESSION USING RNA SEQUENCING DATA FROM THE SAME SAMPLES. TECHNICAL VALIDATION OF RRBS RESULTS WAS PERFORMED USING PYROSEQUENCING. RESULTS: WE IDENTIFIED 79, 56 AND 45 DIFFERENTIALLY METHYLATED REGIONS IN CD4(+) T CELLS, CD8(+) T CELLS AND CD4(-)CD8(-) CELL FRACTIONS, RESPECTIVELY, BETWEEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL PARTICIPANTS. THE ANALYSIS OF PRE-SEROCONVERSION SAMPLES IDENTIFIED DNA METHYLATION SIGNATURES AT THE VERY EARLY STAGE OF DISEASE, INCLUDING DIFFERENTIAL METHYLATION AT THE PROMOTER OF IRF5 IN CD4(+) T CELLS. FURTHER, WE VALIDATED RRBS RESULTS USING PYROSEQUENCING AT THE FOLLOWING CPG SITES: CHR19:18118304 IN THE PROMOTER OF ARRDC2; CHR21:47307815 IN THE INTRON OF PCBP3; AND CHR14:81128398 IN THE INTERGENIC REGION NEAR TRAF3 IN CD4(+) T CELLS. CONCLUSIONS/INTERPRETATION: THESE PRELIMINARY RESULTS PROVIDE NOVEL INSIGHTS INTO CELL TYPE-SPECIFIC DIFFERENTIAL EPIGENETIC REGULATION OF GENES, WHICH MAY CONTRIBUTE TO TYPE 1 DIABETES PATHOGENESIS AT THE VERY EARLY STAGE OF DISEASE DEVELOPMENT. SHOULD THESE FINDINGS BE VALIDATED, THEY MAY SERVE AS A POTENTIAL SIGNATURE USEFUL FOR DISEASE PREDICTION AND MANAGEMENT. 2022 17 3290 34 HIGH CORTISOL IN 5-YEAR-OLD CHILDREN CAUSES LOSS OF DNA METHYLATION IN SINE RETROTRANSPOSONS: A POSSIBLE ROLE FOR ZNF263 IN STRESS-RELATED DISEASES. BACKGROUND: CHILDHOOD STRESS LEADS TO INCREASED RISK OF MANY ADULT DISEASES, SUCH AS MAJOR DEPRESSION AND CARDIOVASCULAR DISEASE. STUDIES SHOW THAT ADULTS WITH EXPERIENCED CHILDHOOD STRESS HAVE SPECIFIC EPIGENETIC CHANGES, BUT TO UNDERSTAND THE PATHWAYS THAT LEAD TO DISEASE, WE ALSO NEED TO STUDY THE EPIGENETIC LINK PROSPECTIVELY IN CHILDREN. RESULTS: HERE, WE STUDIED A HOMOGENOUS GROUP OF 48 5-YEAR-OLD CHILDREN. BY COMBINING HAIR CORTISOL MEASUREMENTS (A WELL-DOCUMENTED BIOMARKER FOR CHRONIC STRESS), WITH WHOLE-GENOME DNA-METHYLATION SEQUENCING, WE SHOW THAT HIGH CORTISOL ASSOCIATES WITH A GENOME-WIDE DECREASE IN DNA METHYLATION AND TARGETS SHORT INTERSPERSED NUCLEAR ELEMENTS (SINES; A TYPE OF RETROTRANSPOSON) AND GENES IMPORTANT FOR CALCIUM TRANSPORT: PHENOMENA COMMONLY AFFECTED IN STRESS-RELATED DISEASES AND IN BIOLOGICAL AGING. MORE IMPORTANTLY, WE IDENTIFY A ZINC-FINGER TRANSCRIPTION FACTOR, ZNF263, WHOSE BINDING SITES WHERE HIGHLY OVERREPRESENTED IN REGIONS EXPERIENCING METHYLATION LOSS. THIS TYPE OF ZINC-FINGER PROTEIN HAS PREVIOUSLY SHOWN TO BE INVOLVED IN THE DEFENSE AGAINST RETROTRANSPOSONS. CONCLUSIONS: OUR RESULTS SHOW THAT STRESS IN PRESCHOOL CHILDREN LEADS TO CHANGES IN DNA METHYLATION SIMILAR TO THOSE SEEN IN BIOLOGICAL AGING. WE SUGGEST THAT THIS MAY AFFECT FUTURE DISEASE SUSCEPTIBILITY BY ALTERATIONS IN THE EPIGENETIC MECHANISMS THAT KEEP RETROTRANSPOSONS DORMANT. FUTURE TREATMENTS FOR STRESS- AND AGE-RELATED DISEASES MAY THEREFORE SEEK TO TARGET ZINC-FINGER PROTEINS THAT EPIGENETICALLY CONTROL RETROTRANSPOSON REACTIVATION, SUCH AS ZNF263. 2015 18 2776 34 EXTRAUTERINE GROWTH RESTRICTION ON PULMONARY VASCULAR ENDOTHELIAL DYSFUNCTION IN ADULT MALE RATS: THE ROLE OF EPIGENETIC MECHANISMS. OBJECTIVE: EARLY POSTNATAL LIFE IS CONSIDERED AS A CRITICAL TIME WINDOW FOR THE DETERMINATION OF LONG-TERM METABOLIC STATES AND ORGAN FUNCTIONS. EXTRAUTERINE GROWTH RESTRICTION (EUGR) CAUSES THE DEVELOPMENT OF ADULT-ONSET CHRONIC DISEASES, INCLUDING PULMONARY HYPERTENSION. HOWEVER, THE EFFECTS OF NUTRITIONAL DISADVANTAGES DURING THE EARLY POSTNATAL PERIOD ON PULMONARY VASCULAR CONSEQUENCES IN LATER LIFE ARE NOT FULLY UNDERSTOOD. OUR STUDY WAS DESIGNED TO TEST WHETHER EPIGENETICS DYSREGULATION MEDIATES THE CELLULAR MEMORY OF THIS EARLY POSTNATAL EVENT. METHODS AND RESULTS: TO TEST THIS HYPOTHESIS, WE ISOLATED PULMONARY VASCULAR ENDOTHELIAL CELLS BY MAGNETIC-ACTIVATED CELL SORTING FROM EUGR AND CONTROL RATS. A POSTNATAL INSULT, NUTRITIONAL RESTRICTION-INDUCED EUGR CAUSED DEVELOPMENT OF AN INCREASED PULMONARY ARTERY PRESSURE AT 9 WEEKS OF AGE IN MALE SPRAGUE-DAWLEY RATS. METHYL-DNA IMMUNE PRECIPITATION CHIP, GENOME-SCALE MAPPING STUDIES TO SEARCH FOR DIFFERENTIALLY METHYLATED LOCI BETWEEN CONTROL AND EUGR RATS, REVEALED SIGNIFICANT DIFFERENCE IN CYTOSINE METHYLATION BETWEEN EUGR AND CONTROL RATS. EUGR CHANGES THE CYTOSINE METHYLATION AT APPROXIMATELY 500 LOCI IN MALE RATS AT 9 WEEKS OF AGE, PRECEDING THE DEVELOPMENT OF PULMONARY HYPERTENSION AND THESE REPRESENT THE CANDIDATE LOCI FOR MEDIATING THE PATHOGENESIS OF PULMONARY VASCULAR DISEASE THAT OCCURS LATER IN LIFE. GENE ONTOLOGY ANALYSIS ON DIFFERENTIALLY METHYLATED GENES SHOWED THAT HYPERMETHYLATED GENES IN EUGR ARE VASCULAR DEVELOPMENT-ASSOCIATED GENES AND HYPOMETHYLATED GENES IN EUGR ARE LATE-DIFFERENTIATION-ASSOCIATED AND SIGNAL TRANSDUCTION GENES. WE VALIDATED CANDIDATE DYSREGULATED LOCI WITH THE QUANTITATIVE ASSAYS OF CYTOSINE METHYLATION AND GENE EXPRESSIONS. CONCLUSION: THESE RESULTS DEMONSTRATE THAT EPIGENETICS DYSREGULATION IS A STRONG MECHANISM FOR PROPAGATING THE CELLULAR MEMORY OF EARLY POSTNATAL EVENTS, CAUSING CHANGES IN THE EXPRESSION OF GENES AND LONG-TERM SUSCEPTIBILITY TO PULMONARY HYPERTENSION, AND FURTHER PROVIDING A NEW INSIGHT INTO THE PREVENTION AND TREATMENT OF EUGR-RELATED PULMONARY HYPERTENSION. 2014 19 1545 32 DNA METHYLATION IN LIVER TUMORIGENESIS IN FISH FROM THE ENVIRONMENT. THE LINK BETWEEN ENVIRONMENT, ALTERATION IN DNA METHYLATION AND CANCER HAS BEEN WELL ESTABLISHED IN HUMANS; YET, IT IS UNDER-STUDIED IN UNSEQUENCED NON-MODEL ORGANISMS. THE OCCURRENCE OF LIVER TUMORS IN THE FLATFISH DAB COLLECTED AT CERTAIN UK SAMPLING SITES EXCEEDS 20%, YET THE CAUSATIVE AGENTS AND THE MOLECULAR MECHANISMS OF TUMOR FORMATION ARE NOT KNOWN, ESPECIALLY REGARDING THE BALANCE BETWEEN EPIGENETIC AND GENETIC FACTORS. METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) COMBINED WITH DE NOVO HIGH-THROUGHPUT DNA SEQUENCING WERE USED TO INVESTIGATE DNA METHYLATION CHANGES IN DAB HEPATOCELLULAR ADENOMA TUMORS FOR THE FIRST TIME IN AN UNSEQUENCED SPECIES. NOVEL CUSTOM-MADE DAB GENE EXPRESSION ARRAYS WERE DESIGNED AND USED TO DETERMINE THE RELATIONSHIP BETWEEN DNA METHYLATION AND GENE EXPRESSION. IN ADDITION, THE CONFIRMATORY TECHNIQUES OF BISULFITE SEQUENCING PCR (BSP) AND RT-PCR WERE APPLIED. GENES INVOLVED IN PATHWAYS RELATED TO CANCER, INCLUDING APOPTOSIS, WNT/BETA-CATENIN SIGNALING AND GENOMIC AND NON-GENOMIC ESTROGEN RESPONSES, WERE ALTERED BOTH IN METHYLATION AND TRANSCRIPTION. GLOBAL METHYLATION WAS STATISTICALLY SIGNIFICANTLY 1.8-FOLD REDUCED IN HEPATOCELLULAR ADENOMA AND NON-CANCEROUS SURROUNDING TISSUES COMPARED WITH LIVER FROM NON-CANCER BEARING DAB. BASED ON THE IDENTIFIED CHANGES AND CHEMICAL EXPOSURE DATA, OUR STUDY SUPPORTS THE EPIGENETIC MODEL OF CANCER. WE HYPOTHESIZE THAT CHRONIC EXPOSURE TO A MIXTURE OF ENVIRONMENTAL CONTAMINANTS CONTRIBUTES TO A GLOBAL HYPOMETHYLATION FOLLOWED BY FURTHER EPIGENETIC AND GENOMIC CHANGES. THE FINDINGS SUGGEST A LINK BETWEEN ENVIRONMENT, EPIGENETICS AND CANCER IN FISH TUMORS IN THE WILD AND SHOW THE UTILITY OF THIS METHODOLOGY FOR STUDIES IN NON-MODEL ORGANISMS. 2011 20 5737 33 SMOKING AND HEALTH: ASSOCIATION BETWEEN TELOMERE LENGTH AND FACTORS IMPACTING ON HUMAN DISEASE, QUALITY OF LIFE AND LIFE SPAN IN A LARGE POPULATION-BASED COHORT UNDER THE EFFECT OF SMOKING DURATION. REACTIVE OXYGEN SPECIES (ROS) ARE OF PRIMARY IMPORTANCE AS THEY CAUSE DAMAGE TO LIPIDS, PROTEINS, AND DNA EITHER ENDOGENOUSLY BY CELLULAR MECHANISM, OR THROUGH EXOGENOUS EXPOSURE TO ENVIRONMENTAL INJURY FACTORS, INCLUDING OXIDATION INSULT FACTORS, SUCH AS TOBACCO SMOKE. CURRENTLY 46.3 MILLION ADULTS (25.7 PERCENT OF THE POPULATION) ARE SMOKERS. THIS INCLUDES 24 MILLION MEN (28.1 PERCENT OF THE TOTAL) AND MORE THAN 22 MILLION WOMEN (23.5 PERCENT). THE PREVALENCE IS HIGHEST AMONG PERSONS 25-44 YEARS OF AGE. CIGARETTE SMOKERS HAVE A HIGHER RISK OF DEVELOPING SEVERAL CHRONIC DISORDERS. THESE INCLUDE FATTY BUILDUPS IN ARTERIES, SEVERAL TYPES OF CANCER AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (LUNG PROBLEMS). AS PERIPHERAL LEUKOCYTES HAVE BEEN THE MAIN TARGET OF HUMAN TELOMERE RESEARCH, MOST OF WHAT IS KNOWN ABOUT HUMAN TELOMERE DYNAMICS IN VIVO IS BASED ON THESE CELLS. LEUKOCYTE TELOMERE LENGTH (TL) IS A COMPLEX TRAIT THAT IS SHAPED BY GENETIC, EPIGENETIC, AND ENVIRONMENTAL DETERMINANTS. IN THIS ARTICLE, WE CONSIDER THAT SMOKING MODIFIES LEUKOCYTE TL IN HUMANS AND CONTRIBUTES TO ITS VARIABILITY AMONG INDIVIDUALS, ALTHOUGH THE SMOKING EFFECT ON TL AND ITS RELATION WITH OTHER METABOLIC INDICES MAY ACCELERATE BIOLOGICAL AGING AND DEVELOPMENT OF SMOKING-INDUCED CHRONIC DISEASES IN A LARGE HUMAN POPULATION-BASED COHORTS WITH SMOKING BEHAVIOR. RECENT STUDIES CONFIRMED THAT INDIVIDUALS WITH SHORTER TELOMERES PRESENT A HIGHER PREVALENCE OF ARTERIAL LESIONS AND HIGHER RISK OF CARDIOVASCULAR DISEASE MORTALITY. THIS STUDY ORIGINALLY SUGGESTS THAT EFFICIENT THERAPEUTIC PROTECTION OF TL AND STRUCTURE IN RESPONSE TO STRESSES THAT ARE KNOWN TO REDUCE TL, SUCH AS OXIDATIVE DAMAGE OR INFLAMMATION ASSOCIATED WITH TOBACCO SMOKING, WOULD LEAD TO BETTER TELOMERE MAINTENANCE. RECENTLY, WE HAVE DISCOVERED THE POTENTIAL USE OF TELOMERE-RESTORATIVE IMIDAZOLE-CONTAINING DIPEPTIDE (NON-HYDROLIZED CARNOSINE, CARCININE) BASED THERAPY FOR BETTER SURVIVAL OF SMOKERS. WE CONCLUDE THAT A BETTER THERAPEUTIC OR NUTRITIONAL MAINTENANCE OF TL MAY CONFER HEALTHY AGING IN SMOKERS AND EXCEPTIONAL LONGEVITY IN REGULARLY ROS-EXPOSED HUMAN SURVIVORS. 2011