1 3653 79 INDIVIDUAL EPIGENETIC VARIATION: WHEN, WHY, AND SO WHAT? EPIGENETICS PROVIDES A POTENTIAL EXPLANATION FOR HOW ENVIRONMENTAL FACTORS MODIFY THE RISK FOR COMMON DISEASES AMONG INDIVIDUALS. INTERINDIVIDUAL VARIATION IN DNA METHYLATION AND EPIGENETIC REGULATION HAS BEEN REPORTED AT SPECIFIC GENOMIC REGIONS INCLUDING TRANSPOSABLE ELEMENTS, GENOMICALLY IMPRINTED GENES AND THE 'INACTIVE' X CHROMOSOMES IN FEMALES. WE CURRENTLY HAVE A VERY POOR UNDERSTANDING OF THE FACTORS THAT CONTRIBUTE TO INTERINDIVIDUAL EPIGENETIC VARIATION. IN PARTICULAR, IT IS IMPORTANT TO UNDERSTAND WHEN DURING THE LIFE CYCLE EPIGENETIC VARIATION ARISES, WHY EPIGENETIC REGULATION VARIES AMONG INDIVIDUALS, AND WHETHER EPIGENETIC INTERINDIVIDUALITY AFFECTS SUSCEPTIBILITY TO DIET-RELATED CHRONIC DISEASE. IN THIS REVIEW WE WILL SUMMARIZE CURRENT PROGRESS TOWARD ANSWERING THESE QUESTIONS. 2008 2 2651 32 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 3 2136 29 EPIGENETIC INFLUENCES IN THE OBESITY/COLORECTAL CANCER AXIS: A NOVEL THERAGNOSTIC AVENUE. THE WORLD HEALTH ORGANIZATION (WHO) CONSIDERS THAT OBESITY HAS REACHED PROPORTIONS OF PANDEMIC. EXPERTS ALSO INSIST ON THE IMPORTANCE OF CONSIDERING OBESITY AS A CHRONIC DISEASE AND ONE OF THE MAIN CONTRIBUTORS TO THE WORLDWIDE BURDEN OF OTHER NONTRANSMISSIBLE CHRONIC DISEASES, WHICH HAVE A GREAT IMPACT ON HEALTH, LIFESTYLE, AND ECONOMIC COST. ONE OF THE MOST CURRENT CHALLENGES OF BIOMEDICAL SCIENCE FACES IS TO UNDERSTAND THE ORIGIN OF THE CHRONIC NONTRANSMISSIBLE DISEASES, SUCH AS OBESITY AND CANCER. THERE IS A LARGE EVIDENCE, BOTH IN EPIDEMIOLOGICAL STUDIES IN HUMANS AND IN ANIMAL MODELS, OF THE ASSOCIATION BETWEEN OBESITY AND AN INCREASED RISK OF CANCER INCIDENCE. IN THE LAST YEARS, THE INITIAL DISCOVERY OF EPIGENETIC MECHANISMS REPRESENTS THE MOST RELEVANT FINDING TO EXPLAIN HOW THE GENOME INTERACTS WITH ENVIRONMENTAL FACTORS AND THE RIPPLE EFFECTS ON DISEASE PATHOGENESES. SINCE THEN, ALL EPIGENETIC PROCESS HAS BEEN INVESTIGATED BY THE SCIENTIFIC COMMUNITIES FOR NEARLY TWO DECADES TO DETERMINE WHICH COMPONENTS ARE INVOLVED IN THIS PROCESS. DNA/RNA METHYLATION AND MIRNA ARE CLASSIFIED AS TWO OF THE MOST IMPORTANT REPRESENTATIVE CLASSES OF SUCH EPIGENETIC MECHANISMS AND DYSREGULATED ACTIVITY OF SUCH MECHANISM CAN CERTAINLY CONTRIBUTE TO DISEASE PATHOGENESIS AND/OR PROGRESSION ESPECIALLY IN TUMORS. THIS REVIEW ARTICLE SERVES TO HIGHLIGHT THE IMPACT OF DNA/RNA METHYLATION AND MIRNA-BASED EPIGENETIC MECHANISM ACTIVITIES IN THE INTERPLAY BETWEEN OBESITY AND THE DEVELOPMENT AND CLINICAL SIGNIFICANCE OF COLORECTAL CANCER. 2019 4 6459 18 TIME TO CHANGE FROM A SIMPLE LINEAR MODEL TO A COMPLEX SYSTEMS MODEL. A SIMPLE LINEAR MODEL TO TEST THE HYPOTHESIS BASED ON ONE-ON-ONE RELATIONSHIP HAS BEEN USED TO FIND THE CAUSATIVE FACTORS OF DISEASES. HOWEVER, WE NOW KNOW THAT NOT JUST ONE, BUT MANY FACTORS FROM DIFFERENT SYSTEMS SUCH AS CHEMICAL EXPOSURE, GENES, EPIGENETIC CHANGES, AND PROTEINS ARE INVOLVED IN THE PATHOGENESIS OF CHRONIC DISEASES SUCH AS DIABETES MELLITUS. SO, WITH AVAILABILITY OF MODERN TECHNOLOGIES TO UNDERSTAND THE INTRICATE NATURE OF RELATIONS AMONG COMPLEX SYSTEMS, WE NEED TO MOVE FORWARD TO THE FUTURE BY TAKING COMPLEX SYSTEMS MODEL. 2016 5 3020 36 GENETICS AND EPIGENETICS OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A COMMON AGE-RELATED DISEASE THAT AFFECTS THE TISSUES OF THE SYNOVIAL JOINT, LEADING TO LOSS OF FUNCTION AND PAIN. IT IMPACTS ON BOTH PATIENT MORBIDITY AND MORTALITY. IT IS A COMPLEX, POLYGENIC DISEASE THAT LACKS ANY LARGE-EFFECT SUSCEPTIBILITY LOCI. INSTEAD, OA SUSCEPTIBILITY ALLELES INDIVIDUALLY CONTRIBUTE ONLY MODESTLY TO THE OVERALL DISEASE RISK, MAKING THEIR IDENTIFICATION CHALLENGING. DESPITE THIS, BREAKTHROUGHS HAVE OCCURRED WITH COMPELLING ASSOCIATIONS SO FAR REPORTED TO POLYMORPHISMS WITHIN THE GENES GDF5 AND MCF2L AND TO THE GENOMIC REGION 7Q22. THE LATTER TWO HAVE EMERGED FROM GENOME-WIDE ASSOCIATION SCANS, WHICH ARE LIKELY TO YIELD MORE HITS IN THE NEAR FUTURE. AS FOR MANY COMPLEX DISEASES, IT IS NOW APPARENT THAT EPIGENETIC EFFECTS ARE ALSO IMPORTANT MEDIATORS OF DISEASE BIOLOGY, WITH DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS ALL HAVING A ROLE. AT PRESENT, MUCH OF THE EPIGENETIC FOCUS HAS BEEN ON CARTILAGE, THE TISSUE AT THE CENTER OF THE OA DISEASE PROCESS. IF WE ARE TO GET CLOSE TO A QUALITATIVE AND QUANTITATIVE UNDERSTANDING OF THE IMPACT OF EPIGENETICS ON OA, THEN IN FUTURE THE OTHER TISSUES OF THE JOINT WILL ALSO NEED TO BE INVESTIGATED. ONE OF THE MORE EXCITING INSIGHTS TO HAVE EMERGED RECENTLY IS THE FACT THAT EPIGENETIC EFFECTS CAN IMPACT ON OA GENETIC EFFECTS AND THIS MAY BE A PARTICULARLY FRUITFUL AVENUE FOR INTEGRATING BOTH AS WE MOVE TOWARD A CLEARER UNDERSTANDING OF THE PATHOPHYSIOLOGY OF THIS INTRIGUING DISEASE. 2012 6 3706 29 INFLUENCE OF GENETICS ON DISEASE SUSCEPTIBILITY AND PROGRESSION. FOR MANY CHRONIC DISEASES, THE INFLUENCE OF GENETICS IS COMPLEX AND PHENOTYPES DO NOT CONFORM TO SIMPLE MENDELIAN PATTERNS OF INHERITANCE. DISCUSSED HERE ARE TWO TYPES OF GENETIC INFLUENCES ON HEALTHY AGING. THE FIRST INVOLVES VARIATION IN THE GENE SEQUENCE ITSELF AND HOW THIS MAY INFLUENCE DISEASE SUSCEPTIBILITY, PROGRESSION, AND SEVERITY, INTERACTING WITH OTHER RECOGNIZED RISK FACTORS. THE SECOND INVOLVES EPIGENETIC REGULATORY MECHANISMS THAT MAY POTENTIALLY PROVIDE INSIGHT INTO HOW ENVIRONMENTAL INFLUENCES AFFECT THE EXPRESSED GENOME, THUS IMPROVING OUR UNDERSTANDING OF THE GENETIC MECHANISMS UNDERLYING MULTIFACTORIAL DISEASES. THE INTERLEUKIN-1 FAMILY OF CYTOKINES CAN BE USED TO ILLUSTRATE HOW GENETIC SEQUENCE VARIATION MAY AFFECT SUCH DISEASES. THIS CYTOKINE FAMILY PLAYS A KEY ROLE IN MEDIATING INFLAMMATION, WHICH IS NOW UNDERSTOOD TO BE A CENTRAL COMPONENT OF A GROWING NUMBER OF CHRONIC DISEASES. RECENT WORK HAS REVEALED MANY SEQUENCE VARIATIONS IN THE REGULATORY DNA OF GENES ENCODING IMPORTANT MEMBERS OF THE INTERLEUKIN-1 FAMILY, AND THESE VARIATIONS ARE ASSOCIATED WITH DIFFERENTIAL EFFECTS ON THE INFLAMMATORY RESPONSE. THE INTERACTIONS OF ENVIRONMENTAL FACTORS WITH BOTH DNA SEQUENCE VARIATIONS AND EPIGENETIC MODIFICATIONS ARE LIKELY TO DETERMINE THE PHENOTYPES OF MULTIFACTORIAL DISEASES OF AGING AS WELL AS THE PHENOTYPE OF HEALTHY AGING. 2007 7 5376 29 RECENT DEVELOPMENTS IN EPIGENETICS OF ACUTE AND CHRONIC KIDNEY DISEASES. THE GROWING EPIDEMIC OF OBESITY AND DIABETES, THE AGING POPULATION AS WELL AS PREVALENCE OF DRUG ABUSE HAS LED TO SIGNIFICANT INCREASES IN THE RATES OF THE CLOSELY ASSOCIATED ACUTE AND CHRONIC KIDNEY DISEASES, INCLUDING DIABETIC NEPHROPATHY. FURTHERMORE, EVIDENCE SHOWS THAT PARENTAL BEHAVIOR AND DIET CAN AFFECT THE PHENOTYPE OF SUBSEQUENT GENERATIONS VIA EPIGENETIC TRANSMISSION MECHANISMS. THESE DATA SUGGEST A STRONG INFLUENCE OF THE ENVIRONMENT ON DISEASE SUSCEPTIBILITY AND THAT, APART FROM GENETIC SUSCEPTIBILITY, EPIGENETIC MECHANISMS NEED TO BE EVALUATED TO GAIN CRITICAL NEW INFORMATION ABOUT KIDNEY DISEASES. EPIGENETICS IS THE STUDY OF PROCESSES THAT CONTROL GENE EXPRESSION AND PHENOTYPE WITHOUT ALTERATIONS IN THE UNDERLYING DNA SEQUENCE. EPIGENETIC MODIFICATIONS, INCLUDING CYTOSINE DNA METHYLATION AND COVALENT POST-TRANSLATIONAL MODIFICATIONS OF HISTONES IN CHROMATIN, ARE PART OF THE EPIGENOME, THE INTERFACE BETWEEN THE STABLE GENOME AND THE VARIABLE ENVIRONMENT. THIS DYNAMIC EPIGENETIC LAYER RESPONDS TO EXTERNAL ENVIRONMENTAL CUES TO INFLUENCE THE EXPRESSION OF GENES ASSOCIATED WITH DISEASE STATES. THE FIELD OF EPIGENETICS HAS SEEN REMARKABLE GROWTH IN THE PAST FEW YEARS WITH SIGNIFICANT ADVANCES IN BASIC BIOLOGY, CONTRIBUTIONS TO HUMAN DISEASE, AS WELL AS EPIGENOMICS TECHNOLOGIES. FURTHER UNDERSTANDING OF HOW THE RENAL CELL EPIGENOME IS ALTERED BY METABOLIC AND OTHER STIMULI CAN YIELD NOVEL NEW INSIGHTS INTO THE PATHOGENESIS OF KIDNEY DISEASES. IN THIS REVIEW, WE HAVE DISCUSSED THE CURRENT KNOWLEDGE ON THE ROLE OF EPIGENETIC MECHANISMS (PRIMARILY DNAME AND HISTONE MODIFICATIONS) IN ACUTE AND CHRONIC KIDNEY DISEASES, AND THEIR TRANSLATIONAL POTENTIAL TO IDENTIFY MUCH NEEDED NEW THERAPIES. 2015 8 2586 23 EPIGENETICS OF PAIN MEDIATORS. PURPOSE OF REVIEW: THE FIELD OF EPIGENETICS CONTINUES ITS INFLUENTIAL RISE AS A MEANS TO BETTER UNDERSTAND AN ORGANISM'S UNIQUE DEVELOPMENTAL IDENTITY OVER A LIFESPAN. WHEREAS A GENOME IS CONSTANT AND UNCHANGING, AN EPIGENOME IS DYNAMIC AND ALTERABLE. EPIGENETIC CHANGES ARE IN RESPONSE TO INNUMERABLE INTERNAL AND EXTERNAL INFLUENCES INCLUDING ENVIRONMENTAL CHANGES SUCH AS DIET, EXERCISE, DISEASE, TOXINS, AND STRESS. EPIGENETICS IS OF PARTICULAR INTEREST IN THE MEDICAL RESEARCH COMMUNITY BOTH FOR THE POTENTIAL TO CAUSE DISEASE AND AS A TARGET FOR THERAPEUTIC INTERVENTIONS. THIS ARTICLE PROVIDES A SUCCINCT EXPLANATION OF THE POTENTIAL FOR EPIGENETICS TO INFLUENCE THE UNDERSTANDING OF PAIN AS WELL AS A REVIEW OF RELEVANT RESEARCH ON THE TOPIC. RECENT FINDINGS: STUDIES ON EPIGENETICS AND PAIN REMAIN LARGELY PRECLINICAL AND INVESTIGATE THE THEORETICAL ABILITY OF EPIGENETICS TO ALTER THE NOCICEPTIVE PATHWAYS BOTH IN THE PERIPHERY AND CENTRALLY. SIGNIFICANT EVIDENCE NOW EXISTS FOR THE ABILITY OF EPIGENETICS TO MODIFY BROADLY CATEGORIZED PAIN TYPES, INCLUDING INFLAMMATORY, NEUROPATHIC, VISCERAL, AND CANCER RELATED. SUMMARY: BOTH PATIENTS AND PROVIDERS RECOGNIZE THAT NOVEL MEDICATIONS FOR THE TREATMENT OF BOTH ACUTE AND CHRONIC PAIN CONDITIONS ARE SORELY NEEDED. THE UNDERSTANDING OF EPIGENETICS AND ITS INFLUENCE ON NOCICEPTION REMAINS IN RELATIVE INFANCY BUT EARLY EVIDENCE IS STRONG FOR POTENTIAL THERAPEUTIC BENEFITS TO TREAT THESE CONDITIONS. 2018 9 2507 28 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 10 1453 20 DISCOVERING HOW ENVIRONMENTAL EXPOSURES ALTER GENES COULD LEAD TO NEW TREATMENTS FOR CHRONIC ILLNESSES. EMERGING RESEARCH DEMONSTRATES THAT DIET, POLLUTION, AND OTHER ENVIRONMENTAL TRIGGERS CAN ALTER BOTH THE FUNCTION AND EXPRESSION OF HUMAN GENES AND LEAD TO A HEIGHTENED DISEASE RISK. THESE ENVIRONMENT-GENE INTERACTIONS CAN CAUSE SO-CALLED EPIGENETIC CHANGES IN GENE EXPRESSION-PATTERNS OF WHICH GENES ARE SWITCHED "ON" OR "OFF"-THAT MAY ACCOUNT FOR THE RISING MORTALITY FROM CHRONIC DISEASES IN INDUSTRIALIZED NATIONS. IN THIS PAPER, WE CALL FOR A NEW TRANSDISCIPLINARY APPROACH TO PUBLIC HEALTH THAT WOULD EXAMINE HOW ENVIRONMENTAL EXPOSURES, BOTH PHYSICAL AND SOCIAL, INFLUENCE GENE EXPRESSION AND A PERSON'S SUSCEPTIBILITY TO CHRONIC DISEASE. THIS INITIATIVE COULD LEAD TO NEW WAYS TO PREVENT AND TREAT SUCH ILLNESSES. 2011 11 738 23 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 12 6811 30 [EPIGENETICS, ENVIRONMENT AND ASTHMA]. ASTHMA IS A CHRONIC INFLAMMATORY DISEASE OF THE RESPIRATORY TRACT WITH A COMPLEX GENETIC BACKGROUND INFLUENCED BY THE EXPOSITION TO A SERIES OF ENVIRONMENTAL FACTORS. GENETIC STUDIES CAN ONLY ELUCIDATE PART OF THE HERITABILITY AND SUSCEPTIBILITY OF ASTHMA AND EVEN THOUGH SEVERAL DISEASES HAVE AN EVIDENT GENETIC ETIOLOGY, ONLY A FRACTION OF THE GENES INVOLVED IN THEIR PATHOGENICITY HAVE BEEN IDENTIFIED. THE EPIGENETIC REGULATION OF THE LATTER IS A FACT ONE SHOULD BEAR IN MIND IN ORDER TO EXPLAIN THE MAJOR TRIGGERS OF DISEASES WHOSE UNDERSTANDING IS COMPLICATED, SUCH AS ALLERGIES AND ASTHMA. EXTERNAL STIMULUS SUCH AS NOURISHMENT, STRESS, PHYSICAL ACTIVITY, ATMOSPHERIC POLLUTION, TOBACCO SMOKING AND ALCOHOL DRINKING CAN INDUCE EITHER GENE SILENCING OR GENE EXPRESSION. IN THIS REGARD, EPIGENETICS CAN EXPLAIN HOW THESE ENVIRONMENTAL FACTORS INFLUENCE OUR GENETIC INHERITANCE. THERE IS GROWING EVIDENCE THAT BACKS-UP THE FACT THAT DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATION AND MICRORNA EXPRESSION ARE INFLUENCED BY THE ENVIRONMENT. THIS HELPS EXPLAINING HOW SEVERAL OF THE RISK FACTORS MENTIONED CONTRIBUTE TO THE DEVELOPMENT AND INHERITANCE OF ASTHMA. IN THIS REVIEW, DIFFERENT ENVIRONMENTAL FACTORS AND THEIR RELATION WITH THE MAIN EPIGENETIC REGULATORY MECHANISMS WILL BE ANALYZED, AS WELL AS THEIR POSSIBLE ROLE IN THE DEVELOPMENT OF ASTHMA. 2014 13 2049 19 EPIGENETIC CODE AND POTENTIAL EPIGENETIC-BASED THERAPIES AGAINST CHRONIC DISEASES IN DEVELOPMENTAL ORIGINS. ACCUMULATED FINDINGS HAVE DEMONSTRATED THAT THE EPIGENETIC CODE PROVIDES A POTENTIAL LINK BETWEEN PRENATAL STRESS AND CHANGES IN GENE EXPRESSION THAT COULD BE INVOLVED IN THE DEVELOPMENTAL PROGRAMMING OF VARIOUS CHRONIC DISEASES IN LATER LIFE. MEANWHILE, BASED ON THE FACT THAT EPIGENETIC MODIFICATIONS ARE REVERSIBLE AND CAN BE MANIPULATED, THIS PROVIDES A UNIQUE CHANCE TO DEVELOP MULTIPLE NOVEL EPIGENETIC-BASED THERAPEUTIC STRATEGIES AGAINST MANY CHRONIC DISEASES IN EARLY DEVELOPMENTAL PERIODS. THIS ARTICLE WILL GIVE A SHORT REVIEW OF RECENT FINDINGS OF PRENATAL INSULT-INDUCED EPIGENETIC CHANGES IN DEVELOPMENTAL ORIGINS OF SEVERAL CHRONIC DISEASES, AND WILL ATTEMPT TO PROVIDE AN OVERVIEW OF THE CURRENT EPIGENETIC-BASED STRATEGIES APPLIED IN THE EARLY PREVENTION, DIAGNOSIS AND POSSIBLE THERAPIES FOR HUMAN CHRONIC DISEASES. 2014 14 1865 30 EMERGING CONCEPTS ON THE ROLE OF EPIGENETICS IN THE RELATIONSHIPS BETWEEN NUTRITION AND HEALTH. UNDERSTANDING THE PHYSIOLOGICAL AND METABOLIC UNDERPINNINGS THAT CONFER INDIVIDUAL DIFFERENCES IN RESPONSES TO DIET AND DIET-RELATED CHRONIC DISEASE IS ESSENTIAL TO ADVANCE THE FIELD OF NUTRITION. THIS INCLUDES ELUCIDATING THE DIFFERENCES IN GENE EXPRESSION THAT ARE MEDIATED THROUGH PROGRAMMING OF THE GENOME THROUGH EPIGENETIC CHROMATIN MODIFICATIONS. EPIGENETIC LANDSCAPES ARE INFLUENCED BY AGE, GENETICS, TOXINS AND OTHER ENVIRONMENTAL FACTORS, INCLUDING DIETARY EXPOSURES AND NUTRITIONAL STATUS. EPIGENETIC MODIFICATIONS INFLUENCE TRANSCRIPTION AND GENOME STABILITY ARE ESTABLISHED DURING DEVELOPMENT WITH LIFE-LONG CONSEQUENCES. THEY CAN BE INHERITED FROM ONE GENERATION TO THE NEXT. THE COVALENT MODIFICATIONS OF CHROMATIN, WHICH INCLUDE METHYLATION AND ACETYLATION, ON DNA NUCLEOTIDE BASES, HISTONE PROTEINS AND RNA ARE DERIVED FROM INTERMEDIATES OF ONE-CARBON METABOLISM AND CENTRAL METABOLISM. THEY INFLUENCE KEY PHYSIOLOGICAL PROCESSES THROUGHOUT LIFE, AND TOGETHER WITH INHERITED DNA PRIMARY SEQUENCE, CONTRIBUTE TO RESPONSIVENESS TO ENVIRONMENTAL STRESSES, DIET AND RISK FOR AGE-RELATED CHRONIC DISEASE. REVEALING DIET-EPIGENETIC RELATIONSHIPS HAS THE POTENTIAL TO TRANSFORM NUTRITION SCIENCE BY INCREASING OUR FUNDAMENTAL UNDERSTANDING OF: (I) THE ROLE OF NUTRIENTS IN BIOLOGICAL SYSTEMS, (II) THE RESILIENCE OF LIVING ORGANISMS IN RESPONDING TO ENVIRONMENTAL PERTURBATIONS, AND (III) THE DEVELOPMENT OF DIETARY PATTERNS THAT PROGRAMME PHYSIOLOGY FOR LIFE-LONG HEALTH. EPIGENETICS MAY ALSO ENABLE THE CLASSIFICATION OF INDIVIDUALS WITH CHRONIC DISEASE FOR SPECIFIC DIETARY MANAGEMENT AND/OR FOR EFFICACIOUS DIET-PHARMACEUTICAL COMBINATION THERAPIES. THESE NEW EMERGING CONCEPTS AT THE INTERFACE OF NUTRITION AND EPIGENETICS WERE DISCUSSED, AND FUTURE RESEARCH NEEDS IDENTIFIED BY LEADING EXPERTS AT THE 26TH MARABOU SYMPOSIUM ENTITLED 'NUTRITION, EPIGENETICS, GENETICS: IMPACT ON HEALTH AND DISEASE'. FOR A COMPILATION OF THE GENERAL DISCUSSION AT THE MARABOU SYMPOSIUM, CLICK HERE HTTP://WWW.MARABOUSYMPOSIUM.ORG/. 2018 15 396 25 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 16 2492 28 EPIGENETICS AND CHILDHOOD ASTHMA: CURRENT EVIDENCE AND FUTURE RESEARCH DIRECTIONS. ASTHMA IS THE MOST COMMON CHRONIC DISEASE OF CHILDHOOD, AFFECTING ONE IN EIGHT CHILDREN IN THE USA AND WORLDWIDE. IT IS A COMPLEX DISEASE, INFLUENCED BY BOTH ENVIRONMENTAL EXPOSURES AND GENETIC FACTORS. ALTHOUGH EPIGENETIC MODIFICATIONS (DNA METHYLATION, HISTONE MODIFICATION AND MIRNA) CAN AFFECT TRANSCRIPTIONAL ACTIVITY IN MULTIPLE GENETIC PATHWAYS RELEVANT FOR ASTHMA DEVELOPMENT, VERY LIMITED WORK HAS BEEN CARRIED OUT SO FAR TO EXAMINE THE ROLE OF EPIGENETIC VARIATIONS ON ASTHMA DEVELOPMENT AND MANAGEMENT. THIS REVIEW PROVIDES A BRIEF OVERVIEW OF EPIGENETIC MODIFICATIONS, SUMMARIZES RECENT FINDINGS, AND DISCUSSES SOME OF THE MAJOR METHODOLOGICAL CONCERNS THAT ARE RELEVANT FOR ASTHMA EPIGENETICS. 2012 17 2184 27 EPIGENETIC MECHANISMS THAT UNDERPIN METABOLIC AND CARDIOVASCULAR DISEASES. CELLULAR COMMITMENT TO A SPECIFIC LINEAGE IS CONTROLLED BY DIFFERENTIAL SILENCING OF GENES, WHICH IN TURN DEPENDS ON EPIGENETIC PROCESSES SUCH AS DNA METHYLATION AND HISTONE MODIFICATION. DURING EARLY EMBRYOGENESIS, THE MAMMALIAN GENOME IS 'WIPED CLEAN' OF MOST EPIGENETIC MODIFICATIONS, WHICH ARE PROGRESSIVELY RE-ESTABLISHED DURING EMBRYONIC DEVELOPMENT. THUS, THE EPIGENOME OF EACH MATURE CELLULAR LINEAGE CARRIES THE RECORD OF ITS DEVELOPMENTAL HISTORY. THE SUBSEQUENT TRAJECTORY AND PATTERN OF DEVELOPMENT ARE ALSO RESPONSIVE TO ENVIRONMENTAL INFLUENCES, AND SUCH PLASTICITY IS LIKELY TO HAVE AN EPIGENETIC BASIS. EPIGENETIC MARKS MAY BE TRANSMITTED ACROSS GENERATIONS, EITHER DIRECTLY BY PERSISTING THROUGH MEIOSIS OR INDIRECTLY THROUGH REPLICATION IN THE NEXT GENERATION OF THE CONDITIONS IN WHICH THE EPIGENETIC CHANGE OCCURRED. DEVELOPMENTAL PLASTICITY EVOLVED TO MATCH AN ORGANISM TO ITS ENVIRONMENT, AND A MISMATCH BETWEEN THE PHENOTYPIC OUTCOME OF ADAPTIVE PLASTICITY AND THE CURRENT ENVIRONMENT INCREASES THE RISK OF METABOLIC AND CARDIOVASCULAR DISEASE. THESE CONSIDERATIONS POINT TO EPIGENETIC PROCESSES AS A KEY MECHANISM THAT UNDERPINS THE DEVELOPMENTAL ORIGINS OF CHRONIC NONCOMMUNICABLE DISEASE. HERE, WE REVIEW THE EVIDENCE THAT ENVIRONMENTAL INFLUENCES DURING MAMMALIAN DEVELOPMENT LEAD TO STABLE CHANGES IN THE EPIGENOME THAT ALTER THE INDIVIDUAL'S SUSCEPTIBILITY TO CHRONIC METABOLIC AND CARDIOVASCULAR DISEASE, AND DISCUSS THE CLINICAL IMPLICATIONS. 2009 18 2027 28 EPIGENETIC CHANGES IN CHRONIC INFLAMMATORY DISEASES. THE NUMBER OF PEOPLE DIAGNOSED WITH CHRONIC INFLAMMATORY DISEASES HAS INCREASED NOTEWORTHY IN THE LAST 40 YEARS. SPONDYLOARTHRITIS (SPA), INFLAMMATORY BOWEL DISEASES (IBD), AND PSORIASIS ARE THE MOST FREQUENT CHRONIC INFLAMMATORY DISEASES, RESULTING FROM A COMBINATION OF GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. EPIGENETIC MODIFICATIONS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND SMALL AND LONG NONCODING RNAS. THEY ARE INFLUENCED BY ENVIRONMENTAL EXPOSURE, LIFE-STYLE, AND AGING AND HAVE RECENTLY BEEN SHOWN TO BE ALTERED IN MANY COMPLEX DISEASES INCLUDING INFLAMMATORY DISEASES. WHILE EPIGENETIC MODIFICATIONS HAVE BEEN WELL CHARACTERIZED IN OTHER DISEASES SUCH AS CANCER AND AUTOIMMUNE DISEASES, KNOWLEDGE ON CHANGES IN INFLAMMATORY DISEASES IS LAGGING BEHIND WITH SOME DISEASE-SPECIFIC DIFFERENCES. WHILE THE DNA METHYLATION PROFILE OF DIFFERENT CELL TYPES IN PATIENTS WITH IBD HAS BEEN RELATIVELY WELL DESCRIBED, LESS IS KNOWN ON CHANGES IMPLICATED IN PSORIASIS, AND NO SYSTEMATIC GENOME-WIDE STUDIES HAVE SO FAR BEEN PERFORMED IN SPA. IN THIS CHAPTER, WE REVIEW IN DETAIL THE REPORTED CHANGES IN PATTERNS OF DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS IN CHRONIC INFLAMMATORY DISEASES HIGHLIGHTING POTENTIAL CONNECTIONS BETWEEN DISEASE-ASSOCIATED PATHOPHYSIOLOGICAL CHANGES SUCH AS THE DYSBIOSIS OF THE MICROBIOME OR GENETIC VARIATIONS ASSOCIATED WITH DISEASE SUSCEPTIBILITY AND THE EPIGENOME. WE ALSO DISCUSS IMPORTANT PARAMETERS OF MEANINGFUL EPIGENETIC STUDIES SUCH AS THE USE OF WELL DEFINED, DISEASE-RELEVANT CELL POPULATIONS, AND ELUDE ON THE POTENTIAL FUTURE OF ENGINEERING OF THE EPIGENOME IN INFLAMMATORY DISEASES. 2017 19 527 27 ASTHMA AND THE MISSING HERITABILITY PROBLEM: NECESSITY FOR MULTIOMICS APPROACHES IN DETERMINING ACCURATE RISK PROFILES. ASTHMA IS RANKED AMONG THE MOST COMMON CHRONIC CONDITIONS AND HAS BECOME A SIGNIFICANT PUBLIC HEALTH ISSUE DUE TO THE RECENT AND RAPID INCREASE IN ITS PREVALENCE. INVESTIGATIONS INTO THE UNDERLYING GENETIC FACTORS PREDICT A HERITABLE COMPONENT FOR ITS INCIDENCE, ESTIMATED BETWEEN 35% AND 90% OF CAUSATION. DESPITE THE APPLICATION OF LARGE-SCALE GENOME-WIDE ASSOCIATION STUDIES (GWAS) AND ADMIXTURE MAPPING APPROACHES, THE PROPORTION OF VARIANTS IDENTIFIED ACCOUNTS FOR LESS THAN 15% OF THE OBSERVED HERITABILITY OF THE DISEASE. THE DISCREPANCY BETWEEN THE PREDICTED HERITABLE COMPONENT OF DISEASE AND THE PROPORTION OF HERITABILITY MAPPED TO THE CURRENTLY IDENTIFIED SUSCEPTIBILITY LOCI HAS BEEN TERMED THE 'MISSING HERITABILITY PROBLEM.' HERE, WE EXAMINE RECENT STUDIES INVOLVING BOTH THE ANALYSIS OF GENETICALLY ENCODED FEATURES THAT CONTRIBUTE TO ASTHMA AND ALSO THE ROLE OF NON-ENCODED HERITABLE CHARACTERISTICS, INCLUDING EPIGENETIC, ENVIRONMENTAL, AND DEVELOPMENTAL ASPECTS OF DISEASE. THE IMPORTANCE OF VERTICAL MATERNAL MICROBIOME TRANSFER AND THE INFLUENCE OF MATERNAL IMMUNE FACTORS ON FETAL CONDITIONING IN THE INHERITANCE OF DISEASE ARE ALSO DISCUSSED. IN ORDER TO HIGHLIGHT THE BROAD ARRAY OF BIOLOGICAL INPUTS THAT CONTRIBUTE TO THE SUM OF HERITABLE RISK FACTORS ASSOCIATED WITH ALLERGIC DISEASE INCIDENCE THAT, TOGETHER, CONTRIBUTE TO THE INDUCTION OF A PRO-ATOPIC STATE. CURRENTLY, THERE IS A NEED TO DEVELOP IN-DEPTH MODELS OF ASTHMA RISK FACTORS TO OVERCOME THE LIMITATIONS ENCOUNTERED IN THE INTERPRETATION OF GWAS RESULTS IN ISOLATION, WHICH HAVE RESULTED IN THE MISSING HERITABILITY PROBLEM. HENCE, MULTIOMICS ANALYSES NEED TO BE ESTABLISHED CONSIDERING GENETIC, EPIGENETIC, AND FUNCTIONAL DATA TO CREATE A TRUE SYSTEMS BIOLOGY-BASED APPROACH FOR ANALYZING THE REGULATORY PATHWAYS THAT UNDERLIE THE INHERITANCE OF ASTHMA AND TO DEVELOP ACCURATE RISK PROFILES FOR DISEASE. 2022 20 6288 33 THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS ON DIFFERENT FACETS IN THE PERIODONTAL PATHOGENESIS. PERIODONTITIS IS A CHRONIC INFLAMMATORY DISEASE THAT AFFECTS THE SUPPORTING STRUCTURES OF TEETH. IN THE LITERATURE, THE ASSOCIATION BETWEEN THE PATHOGENICITY OF BACTERIA AND ENVIRONMENTAL FACTORS IN THIS REGARD HAVE BEEN EXTENSIVELY EXAMINED. IN THE PRESENT STUDY, WE WILL SHED LIGHT ON THE POTENTIAL ROLE THAT EPIGENETIC CHANGE CAN PLAY ON DIFFERENT FACETS OF ITS PROCESS, MORE PARTICULARLY THE MODIFICATIONS CONCERNING THE GENES INVOLVED IN INFLAMMATION, DEFENSE, AND IMMUNE SYSTEMS. SINCE THE 1960S, THE ROLE OF GENETIC VARIANTS IN THE ONSET AND SEVERITY OF PERIODONTAL DISEASE HAS BEEN WIDELY DEMONSTRATED. THESE MAKE SOME PEOPLE MORE SUSCEPTIBLE TO DEVELOPING IT THAN OTHERS. IT HAS BEEN DOCUMENTED THAT THE WIDE VARIATION IN ITS FREQUENCY FOR VARIOUS RACIAL AND ETHNIC POPULATIONS IS DUE PRIMARILY TO THE COMPLEX INTERPLAY AMONG GENETIC FACTORS WITH THOSE AFFECTING THE ENVIRONMENT AND THE DEMOGRAPHY. IN MOLECULAR BIOLOGY, EPIGENETIC MODIFICATIONS ARE DEFINED AS ANY CHANGE IN THE PROMOTER FOR THE CPG ISLANDS, IN THE STRUCTURE OF THE HISTONE PROTEIN, AS WELL AS POST-TRANSLATIONAL REGULATION BY MICRORNAS (MIRNAS), BEING KNOWN TO CONTRIBUTE TO THE ALTERATION IN GENE EXPRESSION FOR COMPLEX MULTIFACTORIAL DISEASES SUCH AS PERIODONTITIS. THE KEY ROLE OF EPIGENETIC MODIFICATION IS TO UNDERSTAND THE MECHANISM INVOLVED IN THE GENE-ENVIRONMENT INTERACTION, AND THE DEVELOPMENT OF PERIODONTITIS IS NOW THE SUBJECT OF MORE AND MORE STUDIES THAT ATTEMPT TO IDENTIFY WHICH FACTORS ARE STIMULATING IT, BUT ALSO AFFECT THE REDUCED RESPONSE TO THERAPY. 2023