1 666 166 BLOOD-BASED DNA METHYLATION BIOMARKERS FOR TYPE 2 DIABETES: POTENTIAL FOR CLINICAL APPLICATIONS. TYPE 2 DIABETES (T2D) IS A LEADING CAUSE OF DEATH AND DISABILITY WORLDWIDE. IT IS A CHRONIC METABOLIC DISORDER THAT DEVELOPS DUE TO AN INTERPLAY OF GENETIC, LIFESTYLE, AND ENVIRONMENTAL FACTORS. THE BIOLOGICAL ONSET OF THE DISEASE OCCURS LONG BEFORE CLINICAL SYMPTOMS DEVELOP, THUS THE SEARCH FOR EARLY DIAGNOSTIC AND PROGNOSTIC BIOMARKERS, WHICH COULD FACILITATE INTERVENTION STRATEGIES TO PREVENT OR DELAY DISEASE PROGRESSION, HAS INCREASED CONSIDERABLY IN RECENT YEARS. EPIGENETIC MODIFICATIONS REPRESENT IMPORTANT LINKS BETWEEN GENETIC, ENVIRONMENTAL AND LIFESTYLE CUES AND INCREASING EVIDENCE IMPLICATE ALTERED EPIGENETIC MARKS SUCH AS DNA METHYLATION, THE MOST CHARACTERIZED AND WIDELY STUDIED EPIGENETIC MECHANISM, IN THE PATHOGENESIS OF T2D. THIS REVIEW PROVIDES AN UPDATE OF THE CURRENT STATUS OF DNA METHYLATION AS A BIOMARKER FOR T2D. FOUR DATABASES, SCOPUS, PUBMED, COCHRANE CENTRAL, AND GOOGLE SCHOLAR WERE SEARCHED FOR STUDIES INVESTIGATING DNA METHYLATION IN BLOOD. THIRTY-SEVEN STUDIES WERE IDENTIFIED, AND ARE SUMMARIZED WITH RESPECT TO POPULATION CHARACTERISTICS, BIOLOGICAL SOURCE, AND METHOD OF DNA METHYLATION QUANTIFICATION (GLOBAL, CANDIDATE GENE OR GENOME-WIDE). WE HIGHLIGHT THAT DIFFERENTIAL METHYLATION OF THE TCF7L2, KCNQ1, ABCG1, TXNIP, PHOSPHO1, SREBF1, SLC30A8, AND FTO GENES IN BLOOD ARE REPRODUCIBLY ASSOCIATED WITH T2D IN DIFFERENT POPULATION GROUPS. THESE GENES SHOULD BE PRIORITIZED AND REPLICATED IN LONGITUDINAL STUDIES ACROSS MORE POPULATIONS IN FUTURE STUDIES. FINALLY, WE DISCUSS THE LIMITATIONS FACED BY DNA METHYLATION STUDIES, WHICH INCLUDE INCLUDING INTERPATIENT VARIABILITY, CELLULAR HETEROGENEITY, AND LACK OF ACCOUNTING FOR STUDY CONFOUNDERS. THESE LIMITATIONS AND CHALLENGES MUST BE OVERCOME BEFORE THE IMPLEMENTATION OF BLOOD-BASED DNA METHYLATION BIOMARKERS INTO A CLINICAL SETTING. WE EMPHASIZE THE NEED FOR LONGITUDINAL PROSPECTIVE STUDIES TO SUPPORT THE ROBUSTNESS OF THE CURRENT FINDINGS OF THIS REVIEW. 2018 2 6458 50 TIME COURSE OF DNA METHYLATION IN PAIN CONDITIONS: FROM EXPERIMENTAL MODELS TO HUMANS. BACKGROUND AND OBJECTIVE: THROUGHOUT THE LAST DECADE, RESEARCH HAS UNCOVERED ASSOCIATIONS BETWEEN PAIN AND EPIGENETIC ALTERATIONS CAUSED BY ENVIRONMENTAL FACTORS. SPECIFICALLY, STUDIES HAVE DEMONSTRATED CORRELATIONS BETWEEN PAIN CONDITIONS AND ALTERED DNA METHYLATION PATTERNS. THUS, DNA METHYLATION HAS BEEN REVEALED AS A POSSIBLE MODULATOR OR CONTRIBUTOR TO PAIN CONDITIONS, PROVIDING A POTENTIAL THERAPEUTIC TARGET FOR TREATMENT BY DNA METHYLATION MODIFICATION. TO DEVELOP SUCH TREATMENTS, IT IS NECESSARY TO CLARIFY A WIDE NUMBER OF ASPECTS ON HOW DNA METHYLATION AFFECTS PAIN PERCEPTION; FIRST AND FOREMOST, THE TEMPORAL DYNAMICS. THE OBJECTIVE OF THE PRESENT REVIEW IS TO PROVIDE AN OVERVIEW OF CURRENT KNOWLEDGE ON TEMPORAL DYNAMICS OF DNA METHYLATION IN RESPONSE TO PAIN, AND TO INVESTIGATE IF A TIMEFRAME CAN BE ESTABLISHED BASED ON THE DATA OF CURRENTLY PUBLISHED STUDIES. DATABASES AND DATA TREATMENT: PUBMED, MEDLINE, GOOGLE SCHOLAR AND EMBASE WERE SEARCHED COMPREHENSIVELY FOR STUDIES OF DNA METHYLATION IN NEUROPATHIC, INFLAMMATORY AND ALTERNATIVE ANIMAL PAIN MODELS, AND IN CHRONIC PAIN PATIENTS INCLUDING COMPLEX REGIONAL PAIN SYNDROME, CHRONIC POSTSURGICAL PAIN, CHRONIC WIDESPREAD PAIN, FIBROMYALGIA AND CROHN'S DISEASE. RESULTS: WE IDENTIFIED 34 ARTICLES HIGHLIGHTING VARIATIONS IN TEMPORAL DYNAMICS OF DNA METHYLATION ACROSS SPECIES AND BETWEEN DIFFERENT TYPES OF PAIN. THESE STUDIES REPRESENT A STARTING POINT TO UNCOVER NEW INSIGHTS IN THE DNA METHYLATION TIME COURSE IN PAIN. CONCLUSIONS: NO TIMEFRAME CAN CURRENTLY BE MADE FOR THE DNA METHYLATION RESPONSE TO PAIN IN ANY OF THE REVIEWED CONDITIONS, HIGHLIGHTING AN IMPORTANT FOCUS AREA FOR FUTURE RESEARCH. 2021 3 1546 37 DNA METHYLATION IN NASAL EPITHELIUM: STRENGTHS AND LIMITATIONS OF AN EMERGENT BIOMARKER FOR CHILDHOOD ASTHMA. ASTHMA IS ONE OF THE MOST WIDESPREAD CHRONIC RESPIRATORY CONDITIONS. THIS DISEASE PRIMARILY DEVELOPS IN CHILDHOOD AND IS INFLUENCED BY DIFFERENT FACTORS, MAINLY GENETICS AND ENVIRONMENTAL FACTORS. DNA METHYLATION IS AN EPIGENETIC MECHANISM WHICH MAY REPRESENT A BRIDGE BETWEEN THESE TWO FACTORS, PROVIDING A TOOL TO COMPREHEND THE INTERACTION BETWEEN GENETICS AND ENVIRONMENT. MOST EPIDEMIOLOGICAL STUDIES IN THIS FIELD HAVE BEEN CONDUCTED USING BLOOD SAMPLES, ALTHOUGH DNA METHYLATION MARKS IN BLOOD MAY NOT BE RELIABLE FOR DRAWING EXHAUSTIVE CONCLUSIONS ABOUT DNA METHYLATION IN THE AIRWAYS. BECAUSE OF THE ROLE OF NASAL EPITHELIUM IN ASTHMA AND THE TISSUE SPECIFICITY OF DNA METHYLATION, STUDYING THE RELATIONSHIP BETWEEN DNA METHYLATION AND CHILDHOOD ASTHMA MIGHT REVEAL CRUCIAL INFORMATION ABOUT THIS WIDESPREAD RESPIRATORY DISEASE. THE PURPOSE OF THIS REVIEW IS TO DESCRIBE CURRENT FINDINGS IN THIS FIELD OF RESEARCH. WE WILL PRESENT A VIEWPOINT OF SELECTED STUDIES, CONSIDER STRENGTHS AND LIMITATIONS, AND PROPOSE FUTURE RESEARCH IN THIS AREA. 2020 4 396 43 AN UPDATE ON EPIGENETICS AND CHILDHOOD RESPIRATORY DISEASES. EPIGENETIC MECHANISMS, DEFINED AS CHANGES IN PHENOTYPE OR GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE, HAVE BEEN PROPOSED TO CONSTITUTE A LINK BETWEEN GENETIC AND ENVIRONMENTAL FACTORS THAT AFFECT COMPLEX DISEASES. RECENT STUDIES SHOW THAT DNA METHYLATION, ONE OF THE KEY EPIGENETIC MECHANISMS, IS ALTERED IN CHILDREN EXPOSED TO AIR POLLUTANTS AND ENVIRONMENTAL TOBACCO SMOKE EARLY IN LIFE. SEVERAL CANDIDATE GENE STUDIES ON EPIGENETICS HAVE BEEN PUBLISHED TO DATE, BUT IT IS ONLY RECENTLY THAT GLOBAL METHYLATION ANALYSES HAVE BEEN PERFORMED FOR RESPIRATORY DISORDERS SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HOWEVER, LARGE-SCALE STUDIES WITH ADEQUATE POWER ARE YET TO BE PRESENTED IN CHILDREN, AND IMPLICATIONS FOR CLINICAL USE REMAIN TO BE EVALUATED. IN THIS REVIEW, WE SUMMARIZE THE RECENT ADVANCES IN EPIGENETICS AND RESPIRATORY DISORDERS IN CHILDREN, WITH A MAIN FOCUS ON METHODOLOGICAL CHALLENGES AND ANALYSES RELATED TO PHENOTYPE AND EXPOSURE USING GLOBAL METHYLATION APPROACHES. 2014 5 1240 25 CURRENT ADVANCES OF EPIGENETICS IN PERIODONTOLOGY FROM ENCODE PROJECT: A REVIEW AND FUTURE PERSPECTIVES. BACKGROUND: THE ENCYCLOPEDIA OF DNA ELEMENTS (ENCODE) PROJECT HAS ADVANCED OUR KNOWLEDGE OF THE FUNCTIONAL ELEMENTS IN THE GENOME AND EPIGENOME. THE AIM OF THIS ARTICLE WAS TO PROVIDE THE COMPREHENSION ABOUT CURRENT RESEARCH TRENDS FROM ENCODE PROJECT AND ESTABLISH THE LINK BETWEEN EPIGENETICS AND PERIODONTAL DISEASES BASED ON EPIGENOME STUDIES AND SEEK THE FUTURE DIRECTION. MAIN BODY: GLOBAL EPIGENOME RESEARCH PROJECTS HAVE EMPHASIZED THE IMPORTANCE OF EPIGENETIC RESEARCH FOR UNDERSTANDING HUMAN HEALTH AND DISEASE, AND CURRENT INTERNATIONAL CONSORTIA SHOW AN IMPROVED INTEREST IN THE IMPORTANCE OF ORAL HEALTH WITH SYSTEMIC HEALTH. THE EPIGENETIC STUDIES IN DENTAL FIELD HAVE BEEN MAINLY CONDUCTED IN PERIODONTOLOGY AND HAVE FOCUSED ON DNA METHYLATION ANALYSIS. ADVANCES IN SEQUENCING TECHNOLOGY HAVE BROADENED THE TARGET FOR EPIGENETIC STUDIES FROM SPECIFIC GENES TO GENOME-WIDE ANALYSES. CONCLUSIONS: IN LINE WITH GLOBAL RESEARCH TRENDS, FURTHER EXTENDED AND ADVANCED EPIGENETIC STUDIES WOULD PROVIDE CRUCIAL INFORMATION FOR THE REALIZATION OF COMPREHENSIVE DENTAL MEDICINE AND EXPAND THE SCOPE OF ONGOING LARGE-SCALE RESEARCH PROJECTS. 2021 6 2213 48 EPIGENETIC MODIFICATIONS AS OUTCOMES OF EXERCISE INTERVENTIONS RELATED TO SPECIFIC METABOLIC ALTERATIONS: A SYSTEMATIC REVIEW. BACKGROUND: CHRONIC DISEASES ARISE AS A CONSEQUENCE OF AN UNHEALTHY LIFESTYLE PRIMARILY CHARACTERIZED BY PHYSICAL INACTIVITY AND UNBALANCED DIETS. REGULAR PHYSICAL ACTIVITY CAN IMPROVE HEALTH, AND THERE IS CONSISTENT EVIDENCE THAT THESE IMPROVEMENTS MAY BE THE RESULT OF EPIGENETIC MODIFICATIONS. OBJECTIVE: TO IDENTIFY EPIGENETIC MODIFICATIONSAS OUTCOMES OF EXERCISE INTERVENTIONS RELATED TO SPECIFIC METABOLIC ALTERATIONS. METHODS: THE PREFERRED REPORTING ITEMS FOR SYSTEMATIC REVIEWS AND META-ANALYSES PROTOCOLS (PRISMA-P) METHODOLOGY FOR MANUSCRIPT RESEARCH AND PREPARATION WAS FOLLOWED USING PUBMED AND EBSCO DATABASES FOR LITERATURE REVIEW. OUT OF 2,638 ARTICLES IDENTIFIED, ONLY 34 ARTICLES MET THE INCLUSION CRITERIA. RESULTS: THE SECTIONS OF THE REVIEW WERE ORGANIZED BY METABOLIC ALTERATIONS IN WHICH STUDIES WERE GROUPED ACCORDING TO HEALTHY, DISEASED, AND TRAINED INDIVIDUALS. RESISTANCE EXERCISE IN HUMANS INDUCED EPIGENETIC CHANGES IN PATHWAYS ASSOCIATED WITH ENERGY METABOLISM AND INSULIN SENSITIVITY, CONTRIBUTING TO HEALTHY SKELETAL MUSCLE. ENDURANCE EXERCISE ALSO CAUSED MODIFICATIONS IN BIOMARKERS ASSOCIATED TO METABOLIC ALTERATIONS THROUGH CHANGES IN DNA METHYLATION AND THE EXPRESSION OF SPECIFIC MIRNAS. HOWEVER, BOTH RESISTANCE AND ENDURANCE EXERCISE ARE NECESSARY TO OBTAIN A BETTER PHYSIOLOGICAL ADAPTATION AND A COMBINATION OF BOTH SEEMS TO BE NEEDED TO PROPERLY TACKLE THE INCREASING PREVALENCE OF NON-COMMUNICABLE PATHOLOGIES. CONCLUSION: GIVEN THE HETEROGENEITY AND COMPLEXITY OF THE EXISTING LITERATURE, IT IS CURRENTLY NOT POSSIBLE TO PROPOSE A SPECIFIC RECOMMENDATION ABOUT THE TYPE, INTENSITY, OR DURATION OF EXERCISE THAT COULD BE BENEFICIAL FOR DIFFERENT SUBSETS OF THE POPULATION (HEALTHY, DISEASED, AND/OR TRAINED). NEVERTHELESS, THIS REVIEW HIGHLIGHTS THE IMPORTANCE OF EXERCISE FOR HEALTH AND SHOWS THE NEED TO PERFORM MORE RESEARCH IN THIS EMERGING AREA TO IDENTIFY EPIGENETIC BIOMARKERS THAT COULD SERVE AS INDICATORS OF EXERCISE ADAPTATIONS. 2019 7 2651 42 EPIGENOMICS AND TRANSCRIPTOMICS IN THE PREDICTION AND DIAGNOSIS OF CHILDHOOD ASTHMA: ARE WE THERE YET? ASTHMA IS THE MOST COMMON NON-COMMUNICABLE CHRONIC DISEASE OF CHILDHOOD. DESPITE ITS HIGH PREVALENCE, TO DATE WE LACK METHODS THAT ARE BOTH EFFICIENT AND ACCURATE IN DIAGNOSING ASTHMA. MOST TRADITIONAL APPROACHES HAVE BEEN BASED ON GARNERING CLINICAL EVIDENCE, SUCH AS RISK FACTORS AND EXPOSURES. GIVEN THE HIGH HERITABILITY OF ASTHMA, MORE RECENT APPROACHES HAVE LOOKED AT GENETIC POLYMORPHISMS AS POTENTIAL "RISK FACTORS." HOWEVER, GENETIC VARIANTS EXPLAIN ONLY A SMALL PROPORTION OF ASTHMA RISK, AND HAVE BEEN LESS THAN OPTIMAL AT PREDICTING RISK FOR INDIVIDUAL SUBJECTS. EPIGENOMIC STUDIES OFFER SIGNIFICANT ADVANTAGES OVER PREVIOUS APPROACHES. EPIGENETIC REGULATION IS HIGHLY TISSUE-SPECIFIC, AND CAN INDUCE BOTH SHORT- AND LONG-TERM CHANGES IN GENE EXPRESSION. SUCH CHANGES CAN START IN UTERO, CAN VARY THROUGHOUT THE LIFE SPAN, AND IN SOME INSTANCES CAN BE PASSED ON FROM ONE GENERATION TO ANOTHER. MOST IMPORTANTLY, THE EPIGENOME CAN BE MODIFIED BY ENVIRONMENTAL FACTORS AND EXPOSURES, AND THUS EPIGENETIC AND TRANSCRIPTOMIC PROFILING MAY YIELD THE MOST ACCURATE RISK ESTIMATES FOR A GIVEN PATIENT BY INCORPORATING ENVIRONMENTAL (AND TREATMENT) EFFECTS THROUGHOUT THE LIFESPAN. HERE WE WILL REVIEW THE MOST RECENT ADVANCES IN THE USE OF EPIGENETIC AND TRANSCRIPTOMIC ANALYSIS FOR THE EARLY DIAGNOSIS OF ASTHMA AND ATOPY, AS WELL AS CHALLENGES AND FUTURE DIRECTIONS IN THE FIELD AS IT MOVES FORWARD. WE WILL PARTICULARLY FOCUS ON DNA METHYLATION, THE MOST STUDIED MECHANISM OF EPIGENETIC REGULATION. 2019 8 6462 41 TISSUE AND CIRCULATING MICRORNAS AS BIOMARKERS OF RESPONSE TO OBESITY TREATMENT STRATEGIES. BACKGROUND: OBESITY, CHARACTERIZED BY AN INCREASED AMOUNT OF ADIPOSE TISSUE, IS A METABOLIC CHRONIC ALTERATION WHICH HAS REACHED PANDEMIC PROPORTION. LIFESTYLE CHANGES ARE THE FIRST LINE THERAPY FOR OBESITY AND A LARGE VARIETY OF DIETARY APPROACHES HAVE DEMONSTRATED EFFICACY IN PROMOTING WEIGHT LOSS AND IMPROVING OBESITY-RELATED METABOLIC ALTERATIONS. BESIDES DIET AND PHYSICAL ACTIVITY, BARIATRIC SURGERY MIGHT BE AN EFFECTIVE THERAPEUTIC STRATEGY FOR MORBID OBESE PATIENTS. RESPONSE TO WEIGHT-LOSS INTERVENTIONS IS CHARACTERISED BY HIGH INTER-INDIVIDUAL VARIABILITY, WHICH MIGHT INVOLVE EPIGENETIC FACTORS. MICRORNAS HAVE CRITICAL ROLES IN METABOLIC PROCESSES AND THEIR DYSREGULATED EXPRESSION HAS BEEN REPORTED IN OBESITY. AIM: THE AIM OF THIS REVIEW IS TO PROVIDE A COMPREHENSIVE OVERVIEW OF CURRENT STUDIES EVALUATING CHANGES IN MICRORNA EXPRESSION IN OBESE PATIENTS UNDERGOING LIFESTYLE INTERVENTIONS OR BARIATRIC SURGERY. RESULTS: A CONSIDERABLE NUMBER OF STUDIES HAVE REPORTED A DIFFERENTIAL EXPRESSION OF CIRCULATING MICRORNAS BEFORE AND AFTER VARIOUS DIETARY AND BARIATRIC SURGERY APPROACHES, IDENTIFYING SEVERAL CANDIDATE BIOMARKERS OF RESPONSE TO WEIGHT LOSS. SIGNIFICANT CHANGES IN MICRORNA EXPRESSION HAVE BEEN OBSERVED AT A TISSUE LEVEL AS WELL, WITH ENTIRELY DIFFERENT PATTERNS BETWEEN VISCERAL AND SUBCUTANEOUS ADIPOSE TISSUE. INTERESTINGLY, RELEVANT DIFFERENCES IN MICRORNA EXPRESSION HAVE EMERGED BETWEEN RESPONDERS AND NON-RESPONDERS TO DIETARY OR SURGICAL INTERVENTIONS. A WIDE VARIETY OF DYSREGULATED MICRORNA TARGET PATHWAYS HAVE ALSO BEEN IDENTIFIED, HELPING TO UNDERSTAND THE PATHOPHYSIOLOGICAL MECHANISMS UNDERLYING OBESITY AND OBESITY-RELATED METABOLIC DISEASES. CONCLUSIONS: ALTHOUGH FURTHER RESEARCH IS NEEDED TO DRAW FIRM CONCLUSIONS, THERE IS INCREASING EVIDENCE ABOUT MICRORNAS AS POTENTIAL BIOMARKERS FOR WEIGHT LOSS AND RESPONSE TO INTERVENTION STRATEGIES IN OBESITY. 2021 9 2530 44 EPIGENETICS IN ALLERGIC DISEASES. PURPOSE OF REVIEW: ALLERGIC DISEASES ARE AMONG THE MOST PREVALENT CHRONIC DISEASES OF CHILDHOOD, AFFECTING MORE THAN 7 MILLION CHILDREN IN THE UNITED STATES. EPIDEMIOLOGICAL EVIDENCE SUPPORTS THE IDEA THAT THE INCEPTION OF ALLERGIC DISEASES IS TYPICALLY BEFORE THE PRESCHOOL YEARS, EVEN WHEN CHRONIC SYMPTOMS DO NOT EMERGE UNTIL ADULTHOOD. THE ROLE OF EPIGENETIC MECHANISMS (PARTICULARLY DNA METHYLATION) IN ALLERGIC DISEASE IS UNDER ACTIVE INVESTIGATION BECAUSE THESE MECHANISMS ARE KNOWN TO BE AT THE INTERFACE OF GENE REGULATION, ENVIRONMENTAL STIMULI, AND DEVELOPMENTAL PROCESSES, ALL OF WHICH ARE ESSENTIAL FOR THE PATHOGENESIS FOR ASTHMA AND ALLERGY. THIS ARTICLE SPECIFICALLY REVIEWS GENOME-WIDE DNA METHYLATION STUDIES IN ALLERGIC DISEASE. RECENT FINDINGS: DIFFERENTIAL DNA METHYLATION AT SPECIFIC REGIONS APPEARS TO BE ASSOCIATED WITH CONCURRENT ALLERGIC DISEASE. A FEW STUDIES HAVE IDENTIFIED METHYLATION SIGNATURES PREDICTIVE OF DISEASE. SUMMARY: DNA METHYLATION SIGNATURES HAVE BEEN SHOWN TO BE ASSOCIATED WITH SEVERAL ALLERGIC DISEASE PHENOTYPES, TYPICALLY CONCURRENTLY WITH DISEASE. THE FEW THAT HAVE BEEN FOUND TO PRECEDE DIAGNOSIS ARE ESPECIALLY INTERESTING BECAUSE THEY HIGHLIGHT AN EARLY TRAJECTORY TO DISEASE. 2015 10 1958 38 EPIGENETIC AGING AND COLORECTAL CANCER: STATE OF THE ART AND PERSPECTIVES FOR FUTURE RESEARCH. ALTHOUGH TRANSLATIONAL RESEARCH HAS IDENTIFIED A LARGE NUMBER OF POTENTIAL BIOMARKERS INVOLVED IN COLORECTAL CANCER (CRC) CARCINOGENESIS, A BETTER UNDERSTANDING OF THE MOLECULAR PATHWAYS ASSOCIATED WITH BIOLOGICAL AGING IN COLORECTAL CELLS AND TISSUES IS NEEDED. HERE, WE AIM TO SUMMARIZE THE STATE OF THE ART ABOUT THE ROLE OF AGE ACCELERATION, DEFINED AS THE DIFFERENCE BETWEEN EPIGENETIC AGE AND CHRONOLOGICAL AGE, IN THE DEVELOPMENT AND PROGRESSION OF CRC. SOME STUDIES HAVE SHOWN THAT ACCELERATED BIOLOGICAL AGING IS POSITIVELY ASSOCIATED WITH THE RISK OF CANCER AND DEATH IN GENERAL. IN LINE WITH THESE FINDINGS, OTHER STUDIES HAVE SHOWN HOW THE ASSESSMENT OF EPIGENETIC AGE IN PEOPLE AT RISK FOR CRC COULD BE HELPFUL FOR MONITORING THE MOLECULAR RESPONSE TO PREVENTIVE INTERVENTIONS. MOREOVER, IT WOULD BE INTERESTING TO INVESTIGATE WHETHER ABERRANT EPIGENETIC AGING COULD HELP IDENTIFY CRC PATIENTS WITH A HIGH RISK OF RECURRENCE AND A WORST PROGNOSIS, AS WELL AS THOSE WHO RESPOND POORLY TO TREATMENT. YET, THE APPLICATION OF THIS NOVEL CONCEPT IS STILL IN ITS INFANCY, AND FURTHER RESEARCH SHOULD BE ENCOURAGED IN ANTICIPATION OF FUTURE APPLICATIONS IN CLINICAL PRACTICE. 2020 11 4793 35 NUTRITIONAL FACTORS, DNA METHYLATION, AND RISK OF TYPE 2 DIABETES AND OBESITY: PERSPECTIVES AND CHALLENGES. A HEALTHY DIET IMPROVES LIFE EXPECTANCY AND HELPS TO PREVENT COMMON CHRONIC DISEASES SUCH AS TYPE 2 DIABETES (T2D) AND OBESITY. THE MECHANISMS DRIVING THESE EFFECTS ARE NOT FULLY UNDERSTOOD, BUT ARE LIKELY TO INVOLVE EPIGENETICS. EPIGENETIC MECHANISMS CONTROL GENE EXPRESSION, MAINTAINING THE DNA SEQUENCE, AND THEREFORE THE FULL GENOMIC INFORMATION INHERITED FROM OUR PARENTS, UNCHANGED. AN INTERESTING FEATURE OF EPIGENETIC CHANGES LIES IN THEIR DYNAMIC NATURE AND REVERSIBILITY. ACCORDINGLY, THEY ARE SUSCEPTIBLE TO CORRECTION THROUGH TARGETED INTERVENTIONS. HERE WE WILL REVIEW THE EVIDENCE SUPPORTING A ROLE FOR NUTRITIONAL FACTORS IN MEDIATING METABOLIC DISEASE RISK THROUGH DNA METHYLATION CHANGES. SPECIAL EMPHASIS WILL BE PLACED ON THE POTENTIAL OF USING DNA METHYLATION TRAITS AS BIOMARKERS TO PREDICT RISK OF OBESITY AND T2D AS WELL AS ON THEIR RESPONSE TO DIETARY AND PHARMACOLOGICAL (EPI-DRUG) INTERVENTIONS. 2019 12 1516 44 DNA METHYLATION AS A BIOMARKER OF AGING IN EPIDEMIOLOGIC STUDIES. CANCER IS LARGELY AN AGING DISEASE. ACCELERATED BIOLOGICAL AGING MAY BE THE STRONGEST PREDICTOR OF CANCER AND OTHER CHRONIC DISEASE RISKS. IN THE ABSENCE OF RELIABLE AND QUANTIFIABLE BIOMARKERS OF AGING TO DATE, IT HAS LONG BEEN OBSERVED THAT TUMORIGENESIS SHARES DISTINCT EPIGENETIC ALTERATIONS WITH THE AGING PROCESS. RECENTLY, EPIGENETIC AGE ESTIMATES HAVE BEEN DEVELOPED BASED ON THE AVAILABILITY OF GENOME-WIDE DNA METHYLATION PROFILES, BY APPLYING IN THE PREDICTION FORMULA THE METHYLATION LEVEL AT A SUBSET OF HIGHLY PREDICTIVE METHYLATION SITES, CALLED EPIGENETIC CLOCK. THESE DNA METHYLATION AGE ESTIMATES HAVE PRODUCED REMARKABLY STRONG CORRELATIONS WITH CHRONOLOGICAL AGE, WITH A SMALL DEVIATION AND HIGH REPRODUCIBILITY ACROSS DIFFERENT AGE GROUPS AND STUDY POPULATIONS. MOREOVER, AN INCREASING NUMBER OF EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED AN INDEPENDENT ASSOCIATION OF DNA METHYLATION AGE OR THE EXTENT OF ACCELERATION WITH MORTALITY AND VARIOUS AGING-RELATED CONDITIONS, EVEN AFTER ACCOUNTING FOR DIFFERENCES IN CHRONOLOGICAL AGE AND OTHER RISK FACTORS. ALTHOUGH EPIGENETIC PROFILES ARE KNOWN TO BE TISSUE-SPECIFIC, BOTH TARGET TISSUE- AND MULTIPLE TISSUE-DERIVED ESTIMATES APPEAR TO PERFORM WELL TO CAPTURE WHAT IS THOUGHT TO BE THE CUMULATIVE EPIGENETIC DRIFT THAT REPRESENTS A MULTIFACTORIAL DEGENERATIVE PROCESS ACROSS TISSUES AND ORGANISMS. FURTHER REFINEMENT OF THE EPIGENETIC AGE ESTIMATES IS ANTICIPATED OVER TIME TO ACCOMMODATE A BETTER TECHNOLOGICAL COVERAGE OF THE METHYLOME AND A BETTER UNDERSTANDING OF THE BIOLOGY UNDERLYING PREDICTIVE REGIONS. EPIDEMIOLOGIC PRINCIPLES WILL REMAIN CRITICAL FOR THE EVALUATION OF RESEARCH FINDINGS INVOLVING, FOR EXAMPLE, DIFFERENT STUDY POPULATIONS, DESIGN, FOLLOW-UP TIME, AND QUALITY OF COVARIATE DATA. OVERALL, THE EPIGENETIC AGE ESTIMATES ARE AN EXCITING DEVELOPMENT WITH USEFUL IMPLICATIONS FOR BIOMEDICAL RESEARCH OF HEALTHY AGING AND DISEASE PREVENTION AND CONTROL. 2018 13 2955 44 GENETIC AND EPIGENETIC FACTORS INFLUENCING CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) HAS BECOME A SERIOUS PUBLIC HEALTH PROBLEM BECAUSE OF ITS ASSOCIATED MORBIDITY, PREMATURE MORTALITY, AND ATTENDANT HEALTHCARE COSTS. THE RISING NUMBER OF PERSONS WITH CKD IS LINKED WITH THE AGING POPULATION STRUCTURE AND AN INCREASED PREVALENCE OF DIABETES, HYPERTENSION, AND OBESITY. THERE IS AN INHERITED RISK ASSOCIATED WITH DEVELOPING CKD, AS EVIDENCED BY FAMILIAL CLUSTERING AND DIFFERING PREVALENCE RATES ACROSS ETHNIC GROUPS. PREVIOUS STUDIES TO DETERMINE THE INHERITED RISK FACTORS FOR CKD RARELY IDENTIFIED GENETIC VARIANTS THAT WERE ROBUSTLY REPLICATED. HOWEVER, IMPROVEMENTS IN GENOTYPING TECHNOLOGIES AND ANALYTIC METHODS ARE NOW HELPING TO IDENTIFY PROMISING GENETIC LOCI AIDED BY INTERNATIONAL COLLABORATION AND MULTICONSORTIA EFFORTS. MORE RECENTLY, EPIGENETIC MODIFICATIONS HAVE BEEN PROPOSED TO PLAY A ROLE IN BOTH THE INHERITED SUSCEPTIBILITY TO CKD AND, IMPORTANTLY, TO EXPLAIN HOW THE ENVIRONMENT DYNAMICALLY INTERACTS WITH THE GENOME TO ALTER AN INDIVIDUAL'S DISEASE RISK. GENOME-WIDE, EPIGENOME-WIDE, AND WHOLE TRANSCRIPTOME STUDIES HAVE BEEN PERFORMED, AND OPTIMAL APPROACHES FOR INTEGRATIVE ANALYSIS ARE BEING DEVELOPED. THIS REVIEW SUMMARIZES RECENT RESEARCH AND THE CURRENT STATUS OF GENETIC AND EPIGENETIC RISK FACTORS INFLUENCING CKD USING POPULATION-BASED INFORMATION. 2014 14 6469 57 TISSUE-SPECIFIC METHYLATION PROFILE IN OBESE PATIENTS WITH TYPE 2 DIABETES BEFORE AND AFTER ROUX-EN-Y GASTRIC BYPASS. EATING HABITS, LIFESTYLES, AND EXPOSURE TO SPECIFIC ENVIRONMENTAL FACTORS CAN GREATLY IMPACT THE RISK OF DEVELOPING TYPE 2 DIABETES (T2D), INFLUENCE THE GENOME EPIGENETICALLY, AND AFFECT THE EXPRESSION OF GENES, INCLUDING GENES RELATED TO GLYCEMIC CONTROL, AT ANY STAGE OF LIFE. THE EPIGENETIC MECHANISM UNDERLYING OBESITY AND T2D PATHOGENESIS REMAINS POORLY UNDERSTOOD. CONVENTIONAL STRATEGIES FOR THE TREATMENT OF OBESITY AND ITS COMORBIDITIES OFTEN HAVE POOR LONG-TERM ADHERENCE, AND PHARMACOLOGICAL INTERVENTIONS ARE LIMITED. BARIATRIC SURGERY IS THE MOST EFFECTIVE CURRENT OPTION TO TREAT SEVERE OBESITY, AND ROUX-EN-Y GASTRIC BYPASS (RYGB) IS THE MOST APPLIED TECHNIQUE WORLDWIDE. EPIGENETIC CHANGES DIFFER DEPENDING ON THE APPROACH USED TO TREAT OBESITY AND ITS ASSOCIATED COMORBIDITIES (CLINICAL OR SURGICAL). COMPARED TO PRIMARY CLINICAL CARE, BARIATRIC SURGERY LEADS TO MUCH GREATER LOSS OF BODY WEIGHT AND HIGHER REMISSION RATES OF T2D AND METABOLIC SYNDROME, WITH METHYLATION PROFILES IN PROMOTER REGIONS OF GENES IN OBESE INDIVIDUALS BECOMING SIMILAR TO THOSE OF NORMAL-WEIGHT INDIVIDUALS. BARIATRIC SURGERY CAN INFLUENCE DNA METHYLATION IN PARALLEL WITH CHANGES IN GENE EXPRESSION PATTERN. CHANGES IN CLINICAL BIOMARKERS THAT REFLECT IMPROVEMENTS IN GLUCOSE AND LIPID METABOLISM AFTER RYGB OFTEN OCCUR BEFORE MAJOR WEIGHT LOSS AND ARE COORDINATED BY SURGERY-INDUCED CHANGES IN INTESTINAL HORMONES. THEREFORE, THE INTESTINE METHYLATION PROFILE WOULD ASSIST IN UNDERSTANDING THE MECHANISMS INVOLVED IN IMPROVED GLYCEMIC CONTROL AFTER BARIATRIC SURGERY. THE MAIN OBJECTIVES IN THIS AREA FOR THE FUTURE ARE TO IDENTIFY EPIGENETIC MARKS THAT COULD BE USED AS EARLY INDICATORS OF METABOLIC RISK, AND TO DEVELOP TREATMENTS ABLE TO DELAY OR EVEN REVERSE THESE EPIGENETIC CHANGES. STUDIES THAT PROVIDE THE "HUMAN EPIGENETIC PROFILE" WILL BE OF CONSIDERABLE VALUE TO IDENTIFY TISSUE-SPECIFIC EPIGENETIC SIGNATURES AND THEIR ROLE IN THE DEVELOPMENT OF CHRONIC DISEASES. FURTHER STUDIES SHOULD APPLY METHODS BASED ON GLOBAL ANALYSIS OF THE GENOME TO IDENTIFY METHYLATED SITES ASSOCIATED WITH DISEASE AND EPIGENETIC MARKS ASSOCIATED WITH THE REMODELING RESPONSE TO BARIATRIC SURGERY. THIS REVIEW DESCRIBES THE MAIN EPIGENETIC ALTERATIONS ASSOCIATED WITH OBESITY AND T2D AND THE POTENTIAL ROLE OF RYGB IN REMODELING THESE CHANGES. 2017 15 2526 46 EPIGENETICS APPLIED TO PSYCHIATRY: CLINICAL OPPORTUNITIES AND FUTURE CHALLENGES. PSYCHIATRIC DISORDERS ARE CLINICALLY HETEROGENEOUS AND DEBILITATING CHRONIC DISEASES RESULTING FROM A COMPLEX INTERPLAY BETWEEN GENE VARIANTS AND ENVIRONMENTAL FACTORS. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INSTRUCT THE CELL/TISSUE TO CORRECTLY INTERPRET EXTERNAL SIGNALS AND ADJUST ITS FUNCTIONS ACCORDINGLY. GIVEN THAT EPIGENETIC MODIFICATIONS ARE SENSITIVE TO ENVIRONMENT, STABLE, AND REVERSIBLE, EPIGENETIC STUDIES IN PSYCHIATRY COULD REPRESENT A PROMISING APPROACH TO BETTER UNDERSTANDING AND TREATING DISEASE. IN THE PRESENT REVIEW, WE AIM TO DISCUSS THE CLINICAL OPPORTUNITIES AND CHALLENGES ARISING FROM THE EPIGENETIC RESEARCH IN PSYCHIATRY. USING SELECTED EXAMPLES, WE FIRST RECAPITULATE KEY FINDINGS SUPPORTING THE ROLE OF ADVERSE LIFE EVENTS, ALONE OR IN COMBINATION WITH GENETIC RISK, IN EPIGENETIC PROGRAMMING OF NEUROPSYCHIATRIC SYSTEMS. EPIGENETIC STUDIES FURTHER REPORT ENCOURAGING FINDINGS ABOUT THE USE OF METHYLATION CHANGES AS DIAGNOSTIC MARKERS OF DISEASE PHENOTYPE AND PREDICTIVE TOOLS OF PROGRESSION AND RESPONSE TO TREATMENT. THEN WE DISCUSS THE POTENTIAL OF USING TARGETED EPIGENETIC PHARMACOTHERAPY, COMBINED WITH PSYCHOSOCIAL INTERVENTIONS, FOR FUTURE PERSONALIZED MEDICINE FOR PATIENTS. FINALLY, WE REVIEW THE METHODOLOGICAL LIMITATIONS THAT COULD HINDER INTERPRETATION OF EPIGENETIC DATA IN PSYCHIATRY. THEY MAINLY ARISE FROM HETEROGENEITY AT THE INDIVIDUAL AND TISSUE LEVEL AND REQUIRE FUTURE STRATEGIES IN ORDER TO REINFORCE THE BIOLOGICAL RELEVANCE OF EPIGENETIC DATA AND ITS TRANSLATIONAL USE IN PSYCHIATRY. OVERALL, WE SUGGEST THAT EPIGENETICS COULD PROVIDE NEW INSIGHTS INTO A MORE COMPREHENSIVE INTERPRETATION OF MENTAL ILLNESS AND MIGHT EVENTUALLY IMPROVE THE NOSOLOGY, TREATMENT, AND PREVENTION OF PSYCHIATRIC DISORDERS. 2018 16 6159 45 THE GENETICS AND EPIGENETICS OF FATIGUE. FATIGUE IS A COMMON SYMPTOM AND INCLUDES BOTH PHYSICAL AND MENTAL COMPONENTS. IT CAN BE ASSOCIATED WITH A VARIETY OF DIFFERENT SYNDROMES AND DISEASES, BUT IN MANY CASES IS NOT ASSOCIATED WITH OTHER COMORBID CONDITIONS. MOST HUMANS HAVE EXPERIENCED ACUTE FATIGUE IN RELATION TO DIFFERENT STRESSORS. ACUTE FATIGUE TYPICALLY DECREASES AS THE EFFECT OF THE TRIGGERING FACTOR IS REDUCED AND A NORMAL HOMEOSTATIC BALANCE IS RESTORED. FATIGUE THAT PERSISTS FOR 6 MONTHS OR MORE IS TERMED CHRONIC FATIGUE. CHRONIC FATIGUE (CF) IN COMBINATION WITH A MINIMUM OF 4 OF 8 SYMPTOMS AND THE ABSENCE OF DISEASES THAT COULD EXPLAIN THESE SYMPTOMS, CONSTITUTE THE CASE DEFINITION FOR CHRONIC FATIGUE SYNDROME. IN SPITE OF ITS PREVALENCE, THE BIOLOGY OF FATIGUE IS RELATIVELY POORLY UNDERSTOOD AND BIOLOGICAL MARKERS HAVE NOT YET BEEN IDENTIFIED. THIS LITERATURE SEARCH WAS PERFORMED IN PUBMED TO IDENTIFY RESEARCH ON THE GENETICS AND EPIGENETICS OF FATIGUE. PUBLICATIONS WERE INCLUDED IF FATIGUE WAS A MAJOR TOPIC AND THE TOPIC WAS COMBINED WITH GENETIC AND/OR EPIGENETIC MEASUREMENTS IN ADULT HUMANS. A TOTAL OF 40 PUBLICATIONS WERE IDENTIFIED. ALTHOUGH ALTERED FUNCTIONING IN THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS, THE SEROTONERGIC SYSTEM, AND ASSOCIATIONS WITH INFECTIOUS AGENTS HAVE BEEN IDENTIFIED, THE SEARCH FOR GENETIC OR EPIGENETIC MARKERS OF FATIGUE, EITHER IN THE CONTEXT OF CF OR CHRONIC FATIGUE SYNDROME (CFS) HAS BEEN RELATIVELY UNPRODUCTIVE OR, IN THE CASE OF EPIGENETICS, NONEXISTENT. ALTHOUGH SEVERAL STUDIES, BOTH HYPOTHESIS-TESTING AND HYPOTHESIS-GENERATING, HAVE BEEN PERFORMED TO SEARCH FOR BIOMARKERS, THEY HAVE MOSTLY BEEN UNDERPOWERED, RESTRICTED BY THE HETEROGENEITY OF THE PHENOTYPE, OR LIMITED BY AN UNSYSTEMATIC STUDY DESIGN. TO BE ABLE TO CONFIRM THE HYPOTHESIS THAT RISK FOR, OR LEVELS OF, FATIGUE ARE INFLUENCED BY THE GENETIC OR EPIGENETIC BACKGROUND OF AN INDIVIDUAL, STUDIES NEED TO BE BASED ON LARGER SAMPLE SIZES WITH A MORE CLEARLY DEFINED PHENOTYPE. STUDIES NEED TO FOCUS NOT ONLY ON THE INFLUENCE OF A SINGLE ASPECT SUCH AS SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) OR DIFFERENTIAL GENE EXPRESSION ON DISEASE RISK OR STATE, BUT ALSO ON THE SYSTEMS BIOLOGY BEHIND THE DISEASE IN COMBINATION WITH INFORMATION ON ENVIRONMENTAL INFLUENCES AND VALIDATION OF FINDINGS IN FUNCTIONAL STUDIES. 2010 17 1385 46 DIABETES IN CHILDHOOD CANCER SURVIVORS: EMERGING CONCEPTS IN PATHOPHYSIOLOGY AND FUTURE DIRECTIONS. WITH ADVANCEMENTS IN CANCER TREATMENT AND SUPPORTIVE CARE, THERE IS A GROWING POPULATION OF CHILDHOOD CANCER SURVIVORS WHO EXPERIENCE A SUBSTANTIAL BURDEN OF COMORBIDITIES RELATED TO HAVING RECEIVED CANCER TREATMENT AT A YOUNG AGE. DESPITE AN OVERALL REDUCTION IN THE INCIDENCE OF MOST CHRONIC HEALTH CONDITIONS IN CHILDHOOD CANCER SURVIVORS OVER THE PAST SEVERAL DECADES, THE CUMULATIVE INCIDENCE OF CERTAIN LATE EFFECTS, IN PARTICULAR DIABETES MELLITUS (DM), HAS INCREASED. THE IMPLICATIONS ARE SIGNIFICANT, BECAUSE DM IS A KEY RISK FACTOR FOR CARDIOVASCULAR DISEASE, A LEADING CAUSE OF PREMATURE DEATH IN CHILDHOOD CANCER SURVIVORS. THE UNDERLYING PATHOPHYSIOLOGY OF DM IN CANCER SURVIVORS IS MULTIFACTORIAL. DM DEVELOPS AT YOUNGER AGES IN SURVIVORS COMPARED TO CONTROLS, WHICH MAY REFLECT AN "ACCELERATED AGING" PHENOTYPE IN THESE INDIVIDUALS. THE TREATMENT-RELATED EXPOSURES (I.E., CHEMOTHERAPY, RADIATION) THAT INCREASE RISK FOR DM IN CHILDHOOD CANCER SURVIVORS MAY BE MORE THAN ADDITIVE WITH ESTABLISHED DM RISK FACTORS (E.G., OLDER AGE, OBESITY, RACE, AND ETHNICITY). EMERGING RESEARCH ALSO POINTS TO PARALLELS IN CELLULAR PROCESSES IMPLICATED IN AGING- AND CANCER TREATMENT-RELATED DM. STILL, THERE REMAINS MARKED INTER-INDIVIDUAL VARIABILITY REGARDING RISK OF DM THAT IS NOT EXPLAINED BY DEMOGRAPHIC AND THERAPEUTIC RISK FACTORS ALONE. RECENT STUDIES HAVE HIGHLIGHTED THE ROLE OF GERMLINE GENETIC RISK FACTORS AND EPIGENETIC MODIFICATIONS THAT ARE ASSOCIATED WITH RISK OF DM IN BOTH THE GENERAL AND ONCOLOGY POPULATIONS. THIS REVIEW SUMMARIZES OUR CURRENT UNDERSTANDING OF RECOGNIZED RISK FACTORS FOR DM IN CHILDHOOD CANCER SURVIVORS TO HELP INFORM TARGETED APPROACHES FOR DISEASE SCREENING, PREVENTION, AND TREATMENT. FURTHERMORE, IT HIGHLIGHTS THE EXISTING SCIENTIFIC GAPS IN UNDERSTANDING THE RELATIVE CONTRIBUTIONS OF INDIVIDUAL THERAPEUTIC EXPOSURES AND THE MECHANISMS BY WHICH THEY EXERT THEIR EFFECTS THAT UNIQUELY PREDISPOSE THIS POPULATION TO DM FOLLOWING CANCER TREATMENT. 2023 18 738 31 CANCER SUSCEPTIBILITY: EPIGENETIC MANIFESTATION OF ENVIRONMENTAL EXPOSURES. CANCER IS A DISEASE THAT RESULTS FROM BOTH GENETIC AND EPIGENETIC CHANGES. DISCORDANT PHENOTYPES AND VARYING INCIDENCES OF COMPLEX DISEASES SUCH AS CANCER IN MONOZYGOTIC TWINS AS WELL AS GENETICALLY IDENTICAL LABORATORY ANIMALS HAVE LONG BEEN ATTRIBUTED TO DIFFERENCES IN ENVIRONMENTAL EXPOSURES. ACCUMULATING EVIDENCE INDICATES, HOWEVER, THAT DISPARITIES IN GENE EXPRESSION RESULTING FROM VARIABLE MODIFICATIONS IN DNA METHYLATION AND CHROMATIN STRUCTURE IN RESPONSE TO THE ENVIRONMENT ALSO PLAY A ROLE IN DIFFERENTIAL SUSCEPTIBILITY TO DISEASE. DESPITE A GROWING CONSENSUS ON THE IMPORTANCE OF EPIGENETICS IN THE ETIOLOGY OF CHRONIC HUMAN DISEASES, THE GENES MOST PRONE TO EPIGENETIC DYSREGULATION ARE INCOMPLETELY DEFINED. MOREOVER, NEITHER THE ENVIRONMENTAL AGENTS MOST STRONGLY AFFECTING THE EPIGENOME NOR THE CRITICAL WINDOWS OF VULNERABILITY TO ENVIRONMENTALLY INDUCED EPIGENETIC ALTERATIONS ARE ADEQUATELY CHARACTERIZED. THESE MAJOR DEFICITS IN KNOWLEDGE MARKEDLY IMPAIR OUR ABILITY TO UNDERSTAND FULLY THE ETIOLOGY OF CANCER AND THE IMPORTANCE OF THE EPIGENOME IN DIAGNOSING AND PREVENTING THIS DEVASTATING DISEASE. 2007 19 3848 35 IS EPIGENETICS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE? BACKGROUND: EPIGENETIC MECHANISMS PROVIDE ONE POTENTIAL EXPLANATION FOR HOW ENVIRONMENTAL INFLUENCES IN EARLY LIFE CAUSE LONG-TERM CHANGES IN CHRONIC DISEASE SUSCEPTIBILITY. WHEREAS EPIGENETIC DYSREGULATION IS INCREASINGLY IMPLICATED IN VARIOUS RARE DEVELOPMENTAL SYNDROMES AND CANCER, THE ROLE OF EPIGENETICS IN COMPLEX CHRONIC DISEASES, SUCH AS CARDIOVASCULAR DISEASE, TYPE 2 DIABETES AND OBESITY, REMAINS LARGELY UNCHARACTERIZED. EXTENSIVE WORK IN ANIMAL MODELS IS REQUIRED TO DEVELOP SPECIFIC HYPOTHESES THAT CAN BE PRACTICABLY TESTED IN HUMANS. ANIMAL MODELS: WE HAVE DEVELOPED A MOUSE MODEL SHOWING THAT METHYL DONOR SUPPLEMENTATION PREVENTS TRANSGENERATIONAL AMPLIFICATION OF OBESITY, SUGGESTING A ROLE FOR DNA METHYLATION IN THE DEVELOPMENTAL ESTABLISHMENT OF BODY WEIGHT REGULATION. CONCLUSIONS: COUPLING SUCH MODELS WITH RECENTLY DEVELOPED EPIGENOMIC TECHNOLOGIES SHOULD ULTIMATELY ENABLE US TO DETERMINE IF EPIGENETICS IS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE. 2009 20 2507 41 EPIGENETICS AND OBESITY: THE DEVIL IS IN THE DETAILS. OBESITY IS A COMPLEX DISEASE WITH MULTIPLE WELL-DEFINED RISK FACTORS. NEVERTHELESS, SUSCEPTIBILITY TO OBESITY AND ITS SEQUELAE WITHIN OBESOGENIC ENVIRONMENTS VARIES GREATLY FROM ONE PERSON TO THE NEXT, SUGGESTING A ROLE FOR GENE X ENVIRONMENT INTERACTIONS IN THE ETIOLOGY OF THE DISORDER. EPIGENETIC REGULATION OF THE HUMAN GENOME PROVIDES A PUTATIVE MECHANISM BY WHICH SPECIFIC ENVIRONMENTAL EXPOSURES CONVEY RISK FOR OBESITY AND OTHER HUMAN DISEASES AND IS ONE POSSIBLE MECHANISM THAT UNDERLIES THE GENE X ENVIRONMENT/TREATMENT INTERACTIONS OBSERVED IN EPIDEMIOLOGICAL STUDIES AND CLINICAL TRIALS. A STUDY PUBLISHED IN BMC MEDICINE THIS MONTH BY WANG ET AL. REPORTS ON AN EXAMINATION OF DNA METHYLATION IN PERIPHERAL BLOOD LEUKOCYTES OF LEAN AND OBESE ADOLESCENTS, COMPARING METHYLATION PATTERNS BETWEEN THE TWO GROUPS. THE AUTHORS IDENTIFIED TWO GENES THAT WERE DIFFERENTIALLY METHYLATED, BOTH OF WHICH HAVE ROLES IN IMMUNE FUNCTION. HERE WE OVERVIEW THE FINDINGS FROM THIS STUDY IN THE CONTEXT OF THOSE EMERGING FROM OTHER RECENT GENETIC AND EPIGENETIC STUDIES, DISCUSS THE STRENGTHS AND WEAKNESSES OF THE STUDY AND SPECULATE ON THE FUTURE OF EPIGENETICS IN CHRONIC DISEASE RESEARCH. 2010