1 5482 73 RETHINKING GENETIC MODELS OF ASTHMA: THE ROLE OF ENVIRONMENTAL MODIFIERS. ASTHMA IS A COMMON, CHRONIC DISEASE WITH A COMPLEX ETIOLOGY. TO DATE, MORE THAN 35 GENES HAVE BEEN ASSOCIATED WITH ASTHMA OR RELATED PHENOTYPES IN MULTIPLE POPULATIONS, BUT NONE OF THEM HAS BEEN SHOWN TO CONTRIBUTE TO RISK IN ALL POPULATIONS STUDIED. WE SUGGEST THAT GENETIC SUSCEPTIBILITY IS BOTH CONTEXT DEPENDENT AND DEVELOPMENTALLY REGULATED, AND THAT IGNORING THE ENVIRONMENTAL CONTEXT WILL MISS MANY IMPORTANT ASSOCIATIONS AND CLUES TO PATHOGENESIS. WE DEFINE 'ENVIRONMENT' BROADLY TO INCLUDE THE IN UTERO ENVIRONMENT, MATERNAL AFFECTION STATUS AND SEX, AND PROPOSE THAT EPIGENETIC MECHANISMS ARE THE LINK BETWEEN OUR GENES AND OUR ENVIRONMENT. 2005 2 2160 26 EPIGENETIC MECHANISMS IN ASTHMA. ASTHMA AND ALLERGIC DISEASES ARE AMONG THE MOST PREVALENT CHRONIC NONCOMMUNICABLE DISEASES OF CHILDHOOD, BUT THE UNDERLYING PATHOGENETIC MECHANISMS ARE POORLY UNDERSTOOD. BECAUSE EPIGENETIC MECHANISMS LINK GENE REGULATION TO ENVIRONMENTAL CUES AND DEVELOPMENTAL TRAJECTORIES, THEIR CONTRIBUTION TO ASTHMA AND ALLERGY PATHOGENESIS IS UNDER ACTIVE INVESTIGATION. DNA METHYLATION SIGNATURES ASSOCIATED WITH CONCURRENT DISEASE AND WITH THE DEVELOPMENT OF ASTHMA DURING CHILDHOOD ASTHMA HAVE BEEN IDENTIFIED, BUT THEIR SIGNIFICANCE IS NOT EASILY INTERPRETABLE. ON THE OTHER HAND, THE CHARACTERIZATION OF EARLY EPIGENETIC PREDICTORS OF ASTHMA POINTS TO A POTENTIAL ROLE OF EPIGENETIC MECHANISMS IN REGULATING THE INCEPTION OF, AND THE SUSCEPTIBILITY TO, THIS DISEASE. 2016 3 2492 24 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 4 396 29 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 6811 33 [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 6 2651 30 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 7 5552 30 ROLE OF EPIGENETICS IN THE PATHOGENESIS OF ASTHMA. ASTHMA IS A COMPLEX, HETEROGENEOUS AND CHRONIC AIRWAY INFLAMMATORY DISEASE WITH DIFFERENT CLINICAL PHENOTYPES CAUSED BY DIVERSE TRIGGERS AND PATHOPHYSIOLOGICAL MECHANISMS. ASTHMA HERITABILITY HAS BEEN ESTABLISHED IN MANY GENETIC STUDIES BUT IT IS EVIDENT THAT ONLY GENETIC ELEMENTS ARE NOT RESPONSIBLE FOR THE DEVELOPMENT OF ASTHMA. INCREASING RATE OF ASTHMA INCIDENCE DURING PAST DECADES HAS IMPLICATED THE ROLE OF EPIGENETICS IN DEVELOPMENT OF ASTHMA. ENVIRONMENTAL FACTORS PERFORM AS INITIATOR SIGNALS THROUGH EPIGENETIC MECHANISMS. THREE EPIGENETIC MECHANISMS HAVE BEEN IDENTIFIED, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, AND SMALL NONCODING RNAS. THESE MECHANISMS REGULATE THE IMMUNE RESPONSES AND INFLAMMATORY GENES EXPRESSION IN ASTHMA AND ALLERGY. THIS REVIEW EXPLAINS THE ROLE OF EPIGENETIC MODIFICATIONS IN CONTROLLING TH2 RESPONSE AND IGE PRODUCTION IN ASTHMA AND ALSO BRIEFLY OVERVIEWS THE ROLE OF ENVIRONMENTAL FACTORS SUCH AS POLLUTIONS, ALLERGENS, PRENATAL EXPOSURES AND DIET IN DEVELOPING ASTHMA. RECOGNIZING ENVIRONMENTAL RISK FACTORS AND THEIR EFFECTS ON EPIGENETIC MECHANISMS WOULD BE OF GREAT INTEREST FOR PROGNOSTIC AND PREVENTIVE ASPECT IN TREATMENT OF ASTHMA. 2017 8 6735 30 WHAT HAVE MECHANISTIC STUDIES TAUGHT US ABOUT CHILDHOOD ASTHMA? CHILDHOOD ASTHMA IS A CHRONIC HETEROGENEOUS SYNDROME CONSISTING OF DIFFERENT DISEASE ENTITIES OR PHENOTYPES. THE IMMUNOLOGIC AND CELLULAR PROCESSES THAT OCCUR DURING ASTHMA DEVELOPMENT ARE STILL NOT FULLY UNDERSTOOD BUT REPRESENT DISTINCT ENDOTYPES. MECHANISTIC STUDIES HAVE EXAMINED THE ROLE OF GENE EXPRESSION, PROTEIN LEVELS, AND CELL TYPES IN EARLY LIFE DEVELOPMENT AND THE MANIFESTATION OF ASTHMA, MANY UNDER THE INFLUENCE OF ENVIRONMENTAL STIMULI, WHICH CAN BE BOTH PROTECTIVE AND RISK FACTORS FOR ASTHMA. GENETIC VARIANTS CAN REGULATE GENE EXPRESSION, CONTROLLED PARTLY BY DIFFERENT EPIGENETIC MECHANISMS. IN ADDITION, ENVIRONMENTAL FACTORS, SUCH AS LIVING SPACE, NUTRITION, AND SMOKING, CAN CONTRIBUTE TO THESE MECHANISMS. ALL OF THESE FACTORS PRODUCE MODIFICATIONS IN GENE EXPRESSION THAT CAN ALTER THE DEVELOPMENT AND FUNCTION OF IMMUNE AND EPITHELIAL CELLS AND SUBSEQUENTLY DIFFERENT TRAJECTORIES OF CHILDHOOD ASTHMA. THESE EARLY CHANGES IN A PARTIALLY IMMATURE IMMUNE SYSTEM CAN HAVE DRAMATIC EFFECTS (E.G., CAUSING DYSREGULATION), WHICH IN TURN CONTRIBUTE TO DIFFERENT DISEASE ENDOTYPES AND MAY HELP TO EXPLAIN DIFFERENTIAL RESPONSIVENESS TO ASTHMA TREATMENT. IN THIS REVIEW, WE SUMMARIZE PUBLISHED STUDIES THAT HAVE AIMED TO UNCOVER DISTINCT MECHANISMS IN CHILDHOOD ASTHMA, CONSIDERING GENETICS, EPIGENETICS, AND ENVIRONMENT. MOREOVER, A DISCUSSION OF NEW, POWERFUL TOOLS FOR SINGLE-CELL IMMUNOLOGIC ASSAYS FOR PHENOTYPIC AND FUNCTIONAL ANALYSIS IS INCLUDED, WHICH PROMISE NEW MECHANISTIC INSIGHTS INTO CHILDHOOD ASTHMA DEVELOPMENT AND THERAPEUTIC AND PREVENTIVE STRATEGIES. 2023 9 527 35 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 10 2531 22 EPIGENETICS IN ASTHMA. PURPOSE OF REVIEW: ASTHMA IS ONE OF THE MOST COMMON CHRONIC RESPIRATORY DISEASES LINKED WITH INCREASED MORBIDITY AND HEALTHCARE UTILIZATION. THE UNDERLYING PATHOPHYSIOLOGICAL PROCESSES AND CAUSAL RELATIONSHIPS OF ASTHMA WITH EPIGENETIC MECHANISMS ARE PARTIALLY UNDERSTOOD. HERE WE REVIEW HUMAN STUDIES OF EPIGENETIC MECHANISMS IN ASTHMA, WITH A SPECIAL FOCUS ON DNA METHYLATION. RECENT FINDINGS: EPIGENETIC STUDIES OF CHILDHOOD ASTHMA HAVE IDENTIFIED SPECIFIC METHYLATION SIGNATURES ASSOCIATED WITH ALLERGIC INFLAMMATION IN THE AIRWAY AND IMMUNE CELLS, DEMONSTRATING A REGULATORY ROLE FOR METHYLATION IN ASTHMA PATHOGENESIS. DESPITE THESE NOVEL FINDINGS, ADDITIONAL RESEARCH IN THE ROLE OF EPIGENETIC MECHANISMS UNDERLYING ASTHMA ENDOTYPES IS NEEDED. SIMILARLY, STUDIES OF HISTONE MODIFICATIONS ARE ALSO LACKING IN ASTHMA. FUTURE STUDIES OF EPIGENETIC MECHANISMS IN ASTHMA WILL BENEFIT FROM DATA INTEGRATION IN WELL PHENOTYPED COHORTS. THIS REVIEW PROVIDES AN OVERVIEW OF THE CURRENT LITERATURE ON EPIGENETIC STUDIES IN HUMAN ASTHMA, WITH SPECIAL EMPHASIS ON METHYLATION AND CHILDHOOD ASTHMA. 2019 11 1546 21 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 12 2530 28 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 13 2330 27 EPIGENETIC REGULATION OF IMMUNE FUNCTION IN ASTHMA. ASTHMA IS A COMMON COMPLEX RESPIRATORY DISEASE CHARACTERIZED BY CHRONIC AIRWAY INFLAMMATION AND PARTIALLY REVERSIBLE AIRFLOW OBSTRUCTION RESULTING FROM GENETIC AND ENVIRONMENTAL DETERMINANTS. BECAUSE EPIGENETIC MARKS INFLUENCE GENE EXPRESSION AND CAN BE MODIFIED BY BOTH ENVIRONMENTAL EXPOSURES AND GENETIC VARIATION, THEY ARE INCREASINGLY RECOGNIZED AS RELEVANT TO THE PATHOGENESIS OF ASTHMA AND MAY BE A KEY LINK BETWEEN ENVIRONMENTAL EXPOSURES AND ASTHMA SUSCEPTIBILITY. UNLIKE CHANGES TO DNA SEQUENCE, EPIGENETIC SIGNATURES ARE DYNAMIC AND REVERSIBLE, CREATING AN OPPORTUNITY FOR NOT ONLY THERAPEUTIC TARGETS BUT MAY SERVE AS BIOMARKERS TO FOLLOW DISEASE COURSE AND IDENTIFY MOLECULAR SUBTYPES IN HETEROGENEOUS DISEASES SUCH AS ASTHMA. IN THIS REVIEW, WE WILL EXAMINE THE RELATIONSHIP BETWEEN ASTHMA AND 3 KEY EPIGENETIC PROCESSES THAT MODIFY GENE EXPRESSION: DNA METHYLATION, MODIFICATION OF HISTONE TAILS, AND NONCODING RNAS. IN ADDITION TO PRESENTING A COMPREHENSIVE ASSESSMENT OF THE EXISTING EPIGENETIC STUDIES FOCUSING ON IMMUNE REGULATION IN ASTHMA, WE WILL DISCUSS FUTURE DIRECTIONS FOR EPIGENETIC INVESTIGATION IN ALLERGIC AIRWAY DISEASE. 2022 14 6288 36 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 15 738 26 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 16 3028 22 GENETICS OF COMPLEX AIRWAY DISEASE. THE PAST 3 YEARS HAVE SEEN HIGHLY SIGNIFICANT GENETIC EFFECTS IDENTIFIED FOR A WIDE VARIETY OF COMMON COMPLEX DISEASES, INCLUDING THE AIRWAY DISORDERS OF ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. IT APPEARS THAT ONLY A PORTION OF THE GENETICALLY MEDIATED SUSCEPTIBILITY TO COMPLEX DISEASES HAS BEEN IDENTIFIED, AND THERE IS MUCH LEFT TO BE DISCOVERED. THIS REVIEW BRIEFLY DESCRIBES THE RESULTS OF THE GENOME-WIDE ASSOCIATION STUDIES OF ASTHMA AND GIVES AN OVERVIEW OF THE PARALLEL AND INCREASINGLY LARGE-SCALE STUDIES THAT ARE TAKING PLACE WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE FUTURE IMPACT IS DISCUSSED OF TECHNOLOGICAL ADVANCES THAT ALLOW INCREASINGLY LARGE-SCALE GENE EXPRESSION STUDIES, NEXT-GENERATION SEQUENCING, AND GENOME-WIDE TESTING FOR EPIGENETIC EFFECTS. THE USE OF GENETIC TECHNOLOGY TO EXAMINE THE AIRWAY MICROBIOTA THAT INTERACT WITH THE MUCOSA IN HEALTH AND DISEASE IS DESCRIBED. 2011 17 1938 30 EPIDEMIOLOGIC EVIDENCE FOR ASSOCIATION BETWEEN ADVERSE ENVIRONMENTAL EXPOSURES IN EARLY LIFE AND EPIGENETIC VARIATION: A POTENTIAL LINK TO DISEASE SUSCEPTIBILITY? A GROWING BODY OF EVIDENCE SUGGESTS THAT THE RISK OF DEVELOPMENT AND PROGRESSION OF A VARIETY OF HUMAN CHRONIC DISEASES DEPENDS ON EPIGENETIC MODIFICATIONS TRIGGERED BY ENVIRONMENTAL CUES DURING EARLY LIFE SENSITIVE STAGES. EXPOSURES TO ENVIRONMENTAL FACTORS SUCH AS ADVERSE NUTRITIONAL, PSYCHOLOGICAL, AND SOCIAL CONDITIONS, AS WELL AS POLLUTANTS AND SUBSTANCE ABUSE IN EARLY LIFE, HAVE BEEN SHOWN TO BE IMPORTANT DETERMINANTS OF EPIGENETIC PROGRAMMING OF CHRONIC PATHOLOGICAL CONDITIONS IN HUMAN POPULATIONS. OVER THE PAST YEARS, IT HAS BECOME INCREASINGLY CLEAR DUE TO THE EPIGENOME-WIDE ASSOCIATION STUDIES (EWASS) THAT EARLY LIFE ADVERSE ENVIRONMENTAL EVENTS MAY TRIGGER WIDESPREAD AND PERSISTENT ALTERATIONS IN TRANSCRIPTIONAL PROFILING. SEVERAL CANDIDATE GENES HAVE BEEN IDENTIFIED UNDERLYING THESE ASSOCIATIONS. IN THIS CONTEXT, DNA METHYLATION IS THE MOST INTENSIVELY STUDIED EPIGENETIC PHENOMENON. IN THIS REVIEW, THE CLINICAL AND EPIDEMIOLOGICAL EVIDENCE FOR THE ROLE OF EPIGENETIC FACTORS IN MEDIATING THE LINK BETWEEN EARLY LIFE EXPERIENCES AND LONG-TERM HEALTH OUTCOMES ARE SUMMARIZED. 2015 18 3706 30 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 19 6905 25 [THE ROLE OF EPIGENETIC REGULATIONS IN EARLY CHILDHOOD DISEASES]. WITH THE ACCEPTANCE OF "THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE" CONCEPT IN THE 1990S, IT BECAME CLEAR THAT EPIGENETIC INHERITANCE, WHICH DO NOT INVOLVE CHANGES IN THE DNA SEQUENCE HAS IMPORTANT ROLE IN THE PATHOGENESIS OF DISEASES. EPIGENETIC REGULATION SERVES THE ADAPTATION TO THE CHANGING ENVIRONMENT AND MAINTAINS THE REPRODUCTIVE FITNESS EVEN ON THE DRAWBACK OF INCREASED RISK OF DISEASES IN LATER LIFE. THE ROLE OF EPIGENETIC MECHANISMS IN CHRONIC NON-COMMUNICABLE DISEASES HAS BEEN WELL ESTABLISHED. RECENT STUDIES HAVE REVEALED THAT EPIGENETIC CHANGES HAVE ALSO CAUSAL ROLE IN CERTAIN PEDIATRIC DISEASES. THE REVIEW EVALUATES THE RECENT EPIGENETIC FINDINGS IN THE PATHOMECHANISM OF COMMON PEDIATRIC DISEASES. THE WIDE RANGE AND LONG-LASTING DURATION OF EPIGENETIC REGULATIONS GIVE IMPORTANCE TO THE SUBJECT. METHODS ARE ALREADY AVAILABLE TO EVALUATE A PART OF THE EPIGENETIC CHANGES IN THE CLINICAL PRACTICE, PRESENTLY AIMING PRIMARILY THE ESTIMATION OF THE DISEASE RISK OR DEFINITION OF DIAGNOSIS. FURTHERMORE, THERE ARE ALREADY AVAILABLE LIMITED MEANS TO INFLUENCE THE EPIGENETIC REGULATION. 2019 20 1757 23 EARLY ORIGINS OF ASTHMA (AND ALLERGY). ASTHMA IS THE MOST COMMON CHRONIC DISEASE STARTING IN CHILDHOOD AND PERSISTING INTO ADULTHOOD IN MANY CASES. DURING CHILDHOOD, DIFFERENT FORMS OF ASTHMA AND WHEEZING DISORDERS EXIST THAT CAN BE DISCRIMINATED BY THE MECHANISMS THEY ARE CAUSED BY. SPECIFIC GENETIC CONSTELLATIONS AND EXPOSURE AGAINST ENVIRONMENTAL FACTORS DURING EARLY CHILDHOOD AND IN UTERO PLAY A DECISIVE ROLE IN THE EARLY DEVELOPMENT OF THE DISEASE. EPIGENETIC MECHANISMS WHICH ARE MASTER REGULATORS OF GENE TRANSCRIPTION AND THUS GOVERN THE ACCESSIBILITY AND USE OF GENOME INFORMATION, HAVE RECENTLY BEEN IDENTIFIED AS A "THIRD POWER" DETERMINING MANY FEATURES IN THE EARLY DEVELOPMENT OF ASTHMA AND ALLERGY. 2016