1 6348 109 THE ROLE OF EPIGENETICS IN RESPIRATORY HEALTH IN URBAN POPULATIONS IN LOW AND MIDDLE-INCOME COUNTRIES. AS URBANIZATION INCREASES IN LOW- AND MIDDLE-INCOME COUNTRIES (LMICS), URBAN POPULATIONS WILL BE INCREASINGLY EXPOSED TO A RANGE OF ENVIRONMENTAL RISK FACTORS FOR NON-COMMUNICABLE DISEASES. INADEQUATE LIVING CONDITIONS IN URBAN SETTINGS MAY INFLUENCE MECHANISMS THAT REGULATE GENE EXPRESSION, LEADING TO THE DEVELOPMENT OF NON-COMMUNICABLE RESPIRATORY DISEASES. WE CONDUCTED A SYSTEMATIC REVIEW OF THE LITERATURE TO ASSESS THE RELATIONSHIP BETWEEN RESPIRATORY HEALTH AND EPIGENETIC FACTORS TO URBAN ENVIRONMENTAL EXPOSURES OBSERVED IN LMICS USING MEDLINE, PUBMED, EMBASE, AND GOOGLE SCHOLAR SEARCHING A COMBINATION OF THE TERMS: EPIGENETICS, CHRONIC RESPIRATORY DISEASES (CRDS), LUNG DEVELOPMENT, CHRONIC OBSTRUCTIVE AIRWAY DISEASE, AND ASTHMA. A TOTAL OF 2835 ARTICLES WERE OBTAINED, AND 48 ARTICLES WERE INCLUDED IN THIS REVIEW. WE FOUND THAT ENVIRONMENTAL FACTORS DURING EARLY DEVELOPMENT ARE RELATED TO EPIGENETIC EFFECTS THAT MAY BE ASSOCIATED WITH A HIGHER RISK OF CRDS. EPIGENETIC DYSREGULATION OF GENE EXPRESSION OF THE HISTONE DEACETYLASE (HDAC) AND HISTONE ACETYLTRANSFERASE GENE FAMILIES WAS LIKELY INVOLVED IN LUNG HEALTH OF SLUM DWELLERS. RESPIRATORY-RELATED ENVIRONMENTAL EXPOSURES INFLUENCE HDAC FUNCTION AND DEOXYRIBONUCLEIC ACID METHYLATION AND ARE IMPORTANT RISK FACTORS IN THE DEVELOPMENT OF CRD. ADDITIONAL EPIGENETIC RESEARCH IS NEEDED TO IMPROVE OUR UNDERSTANDING OF ASSOCIATIONS BETWEEN ENVIRONMENTAL EXPOSURES AND NON-COMMUNICABLE RESPIRATORY DISEASES. 2019 2 247 42 ADULTHOOD ASTHMA AS A CONSEQUENCE OF CHILDHOOD ADVERSITY: A SYSTEMATIC REVIEW OF EPIGENETICALLY AFFECTED GENES. THERE IS AN ACCUMULATING DATA THAT SHOWS RELATION BETWEEN CHILDHOOD ADVERSITY AND VULNERABILITY TO CHRONIC DISEASES AS WELL AS EPIGENETIC INFLUENCES THAT IN TURN GIVE RISE TO THESE DISEASES. ASTHMA IS ONE OF THE CHRONIC DISEASES THAT IS INFLUENCED FROM GENETIC REGULATION OF THE INFLAMMATORY BIOMOLECULES AND THEREFORE THE HYPOTHESIS IN THIS RESEARCH WAS CHILDHOOD ADVERSITY MIGHT HAVE CAUSED EPIGENETIC DIFFERENTIATION IN THE ASTHMA-RELATED GENES IN THE POPULATION WHO HAD CHILDHOOD TRAUMA. TO TEST THIS HYPOTHESIS, THE LITERATURE WAS SYSTEMATICALLY REVIEWED TO EXTRACT EPIGENETICALLY MODIFIED GENE DATA OF THE ADULTS WHO HAD CHILDHOOD ADVERSITY, AND AFFECTED GENES WERE FURTHER EVALUATED FOR THEIR ASSOCIATION WITH ASTHMA. PRISMA GUIDELINES WERE ADOPTED AND PUBMED AND GOOGLE SCHOLAR WERE INCLUDED IN THE SEARCHED DATABASES, TO EVALUATE EPIGENETIC MODIFICATIONS IN ASTHMA-RELATED GENES OF PHYSICALLY, EMOTIONALLY OR SEXUALLY ABUSED CHILDREN. AFTER RETRIEVING A TOTAL OF 5245 ARTICLES, 36 OF THEM WERE INCLUDED IN THE STUDY. SEVERAL GENES AND PATHWAYS THAT MAY CONTRIBUTE TO PATHOGENESIS OF ASTHMA DEVELOPMENT, INCREASED INFLAMMATION, OR RESPONSE TO ASTHMA TREATMENT WERE FOUND EPIGENETICALLY AFFECTED BY CHILDHOOD TRAUMAS. CHILDHOOD ADVERSITY, CAUSING EPIGENETIC CHANGES IN DNA, MAY LEAD TO ASTHMA DEVELOPMENT OR INFLUENCE THE COURSE OF THE DISEASE AND THEREFORE SHOULD BE TAKEN INTO ACCOUNT FOR THE PROLONGED HEALTH CONSEQUENCES. 2022 3 1324 43 DEOXYRIBONUCLEIC ACID (DNA) METHYLATION IN CHILDREN EXPOSED TO AIR POLLUTION: A POSSIBLE MECHANISM UNDERLYING RESPIRATORY HEALTH EFFECTS DEVELOPMENT. AIR POLLUTION IS A SUBSTANTIAL ENVIRONMENTAL THREAT TO CHILDREN AND ACTS AS ACUTE AND CHRONIC DISEASE RISK FACTORS ALIKE. SEVERAL STUDIES HAVE PREVIOUSLY EVALUATED EPIGENETIC MODIFICATIONS CONCERNING ITS EXPOSURE ACROSS VARIOUS LIFE STAGES. HOWEVER, FINDINGS ON EPIGENETIC MODIFICATIONS AS THE CONSEQUENCES OF AIR POLLUTION DURING CHILDHOOD ARE RATHER MINIMAL. THIS REVIEW EVALUATED HIGHLY RELEVANT STUDIES IN THE FIELD TO ANALYZE THE EXISTING LITERATURE REGARDING EXPOSURE TO AIR POLLUTION, WITH A FOCUS ON EPIGENETIC ALTERATIONS DURING CHILDHOOD AND THEIR CONNECTIONS WITH RESPIRATORY HEALTH EFFECTS. THE SEARCH WAS CONDUCTED USING READILY AVAILABLE ELECTRONIC DATABASES (PUBMED AND SCIENCEDIRECT) TO SCREEN FOR CHILDREN'S STUDIES ON EPIGENETIC MECHANISMS FOLLOWING EITHER PRE- OR POST-NATAL EXPOSURE TO AIR POLLUTANTS. STUDIES RELEVANT ENOUGH AND MATCHED THE PREDETERMINED CRITERIA WERE CHOSEN TO BE REVIEWED. NON-ENGLISH ARTICLES AND STUDIES THAT DID NOT REPORT BOTH AIR MONITORING AND EPIGENETIC OUTCOMES IN THE SAME ARTICLE WERE EXCLUDED. THE REVIEW FOUND THAT EPIGENETIC CHANGES HAVE BEEN LINKED WITH EXPOSURE TO AIR POLLUTANTS DURING EARLY LIFE WITH EVIDENCE AND REPORTS OF HOW THEY MAY DEREGULATE THE EPIGENOME BALANCE, THUS INDUCING DISEASE PROGRESSION IN THE FUTURE. EPIGENETIC STUDIES EVOLVE AS A PROMISING NEW APPROACH IN DECIPHERING THE UNDERLYING IMPACTS OF AIR POLLUTION ON DEOXYRIBONUCLEIC ACID (DNA) DUE TO LINKS ESTABLISHED BETWEEN SOME OF THESE EPIGENETIC MECHANISMS AND ILLNESSES. 2021 4 396 35 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 1546 32 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 6 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 7 4807 32 OBESITY IN LOW- AND MIDDLE-INCOME COUNTRIES: BURDEN, DRIVERS, AND EMERGING CHALLENGES. WE HAVE REVIEWED THE DISTINCTIVE FEATURES OF EXCESS WEIGHT, ITS CAUSES, AND RELATED PREVENTION AND MANAGEMENT EFFORTS, AS WELL AS DATA GAPS AND RECOMMENDATIONS FOR FUTURE RESEARCH IN LOW- AND MIDDLE-INCOME COUNTRIES (LMICS). OBESITY IS RISING IN EVERY REGION OF THE WORLD, AND NO COUNTRY HAS BEEN SUCCESSFUL AT REVERSING THE EPIDEMIC ONCE IT HAS BEGUN. IN LMICS, OVERWEIGHT IS HIGHER IN WOMEN COMPARED WITH MEN, IN URBAN COMPARED WITH RURAL SETTINGS, AND IN OLDER COMPARED WITH YOUNGER INDIVIDUALS; HOWEVER, THE URBAN-RURAL OVERWEIGHT DIFFERENTIAL IS SHRINKING IN MANY COUNTRIES. OVERWEIGHT OCCURS ALONGSIDE PERSISTENT BURDENS OF UNDERWEIGHT IN LMICS, ESPECIALLY IN YOUNG WOMEN. CHANGES IN THE GLOBAL DIET AND PHYSICAL ACTIVITY ARE AMONG THE HYPOTHESIZED LEADING CONTRIBUTORS TO OBESITY. EMERGING RISK FACTORS INCLUDE ENVIRONMENTAL CONTAMINANTS, CHRONIC PSYCHOSOCIAL STRESS, NEUROENDOCRINE DYSREGULATION, AND GENETIC/EPIGENETIC MECHANISMS. DATA ON EFFECTIVE STRATEGIES TO PREVENT THE ONSET OF OBESITY IN LMICS OR ELSEWHERE ARE LIMITED. EXPANDING THE RESEARCH IN THIS AREA IS A KEY PRIORITY AND HAS IMPORTANT POSSIBILITIES FOR REVERSE INNOVATION THAT MAY ALSO INFORM INTERVENTIONS IN HIGH-INCOME COUNTRIES. 2017 8 2651 33 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 9 2492 25 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 10 5434 29 RELATIONSHIP BETWEEN ENVIRONMENTAL EXPOSURES IN CHILDREN AND ADULT LUNG DISEASE: THE CASE FOR OUTDOOR EXPOSURES. THERE IS A GROWING UNDERSTANDING THAT CHRONIC RESPIRATORY DISEASES IN ADULTS HAVE THEIR ORIGINS IN EARLY LIFE. ADVERSE ENVIRONMENTAL EXPOSURES OCCURRING IN VULNERABLE PERIODS DURING LUNG GROWTH AND DEVELOPMENT IN THE FETAL PERIOD AND IN EARLY CHILDHOOD THAT ALTER LUNG STRUCTURE AND LIMIT THE GROWTH IN LUNG FUNCTION MAY HAVE LIFELONG CONSEQUENCES. EVIDENCE IS INCREASING THAT EXPOSURE TO THE AMBIENT ENVIRONMENT, INCLUDING AIR POLLUTANTS, PERSISTENT TOXIC SUBSTANCES, WATER POLLUTANTS AND RESPIRATORY VIRAL INFECTIONS, CAN INHIBIT LUNG FUNCTION GROWTH AND PREDISPOSE TO CHRONIC NON-MALIGNANT LUNG DISEASES. THESE EXPOSURES GENERALLY INTERACT WITH A GENETIC PREDISPOSITION, AND GENE-ENVIRONMENT INTERACTIONS AND EPIGENETIC PHENOMENA ARE ATTRACTING CONSIDERABLE STUDY. AN UNDERSTANDING OF HOW AMBIENT EXPOSURES IMPACT ON NORMAL LUNG GROWTH AND DEVELOPMENT WILL AID IN UNDERSTANDING OF HOW CHRONIC RESPIRATORY DISEASES OF ADULTS DEVELOP AND MAY LEAD TO NEW PREVENTATIVE STRATEGIES. 2010 11 2531 32 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 12 2330 38 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 13 6811 37 [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 14 625 32 BIOLOGICAL AGE AND ENVIRONMENTAL RISK FACTORS FOR DEMENTIA AND STROKE: MOLECULAR MECHANISMS. SINCE THE DEVELOPMENT OF ANTIBIOTICS AND VACCINATION, AS WELL AS MAJOR IMPROVEMENTS IN PUBLIC HYGIENE, THE MAIN RISK FACTORS FOR MORBIDITY AND MORTALITY ARE AGE AND CHRONIC EXPOSURE TO ENVIRONMENTAL FACTORS, BOTH OF WHICH CAN INTERACT WITH GENETIC PREDISPOSITIONS. AS THE AVERAGE AGE OF THE POPULATION INCREASES, THE PREVALENCE AND COSTS OF CHRONIC DISEASES, ESPECIALLY NEUROLOGICAL CONDITIONS, ARE RAPIDLY INCREASING. THE DELETERIOUS EFFECTS OF AGE AND ENVIRONMENTAL RISK FACTORS, DEVELOP CHRONICALLY OVER RELATIVELY LONG PERIODS OF TIME, IN CONTRAST TO THE RELATIVELY RAPID DELETERIOUS EFFECTS OF INFECTIOUS DISEASES OR ACCIDENTS. OF PARTICULAR INTEREST IS THE HYPOTHESIS THAT THE DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS MAY BE MEDIATED BY ACCELERATION OF BIOLOGICAL AGE. THIS HYPOTHESIS IS SUPPORTED BY EVIDENCE THAT DIETARY RESTRICTION, WHICH UNIVERSALLY DELAYS AGE-RELATED DISEASES, ALSO AMELIORATES DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS. CONVERSELY, BOTH AGE AND ENVIRONMENTAL RISK FACTORS ARE ASSOCIATED WITH THE ACCUMULATION OF SOMATIC MUTATIONS IN MITOTIC CELLS AND EPIGENETIC MODIFICATIONS THAT ARE A MEASURE OF "BIOLOGICAL AGE", A BETTER PREDICTOR OF AGE-RELATED MORBIDITY AND MORTALITY THAN CHRONOLOGICAL AGE. HERE WE REVIEW EVIDENCE THAT ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING AND AIR POLLUTION MAY ALSO DRIVE NEUROLOGICAL CONDITIONS, INCLUDING ALZHEIMER'S DISEASE, BY THE ACCELERATION OF BIOLOGICAL AGE, MEDIATED BY CUMULATIVE AND PERSISTENT EPIGENETIC EFFECTS AS WELL AS SOMATIC MUTATIONS. ELUCIDATION OF SUCH MECHANISMS COULD PLAUSIBLY ALLOW THE DEVELOPMENT OF INTERVENTIONS WHICH DELAY DELETERIOUS EFFECTS OF BOTH AGING AND ENVIRONMENTAL RISK FACTORS. 2022 15 5194 36 PRENATAL EXPOSURE TO POTENTIALLY TOXIC METALS AND THEIR EFFECTS ON GENETIC MATERIAL IN OFFSPRING: A SYSTEMATIC REVIEW. IN RECENT YEARS, THE BACKGROUND LEVEL OF ENVIRONMENTAL POLLUTANTS, INCLUDING METALS, HAS INCREASED. POLLUTANT EXPOSURE DURING THE EARLIEST STAGES OF LIFE MAY DETERMINE CHRONIC DISEASE SUSCEPTIBILITY IN ADULTHOOD BECAUSE OF GENETIC OR EPIGENETIC CHANGES. THE OBJECTIVE OF THIS REVIEW WAS TO IDENTIFY THE ASSOCIATION BETWEEN PRENATAL AND EARLY POSTNATAL EXPOSURE TO POTENTIALLY TOXIC METALS (PTMS) AND THEIR ADVERSE EFFECTS ON THE GENETIC MATERIAL OF OFFSPRING. A SYSTEMATIC REVIEW WAS CARRIED OUT FOLLOWING THE COCHRANE METHODOLOGY IN FOUR DATABASES: PUBMED, SCOPUS, WEB OF SCIENCE, AND THE COCHRANE LIBRARY. ELIGIBLE PAPERS WERE THOSE CONDUCTED IN HUMANS AND PUBLISHED IN ENGLISH BETWEEN 2010/01/01 AND 2021/04/30. A TOTAL OF 57 ARTICLES WERE INCLUDED, MOST OF WHICH EVALUATED PRENATAL EXPOSURE. MOST COMMONLY EVALUATED PTMS WERE AS, CD, AND PB. MAIN ADVERSE EFFECTS ON THE GENETIC MATERIAL OF NEWBORNS ASSOCIATED WITH PTM PRENATAL EXPOSURE WERE ALTERATIONS IN TELOMERE LENGTH, GENE OR PROTEIN EXPRESSION, MITOCHONDRIAL DNA CONTENT, METABOLOMICS, DNA DAMAGE, AND EPIGENETIC MODIFICATIONS. MANY OF THESE EFFECTS WERE SEX-SPECIFIC, BEING PREDOMINANT IN BOYS. ONE ARTICLE REPORTED A SYNERGISTIC INTERACTION BETWEEN AS AND HG, AND TWO ARTICLES OBSERVED ANTAGONISTIC INTERACTIONS BETWEEN PTMS AND ESSENTIAL METALS, SUCH AS CU, SE, AND ZN. THE FINDINGS IN THIS REVIEW HIGHLIGHT THAT THE PROBLEM OF PTM EXPOSURE PERSISTS, AFFECTING THE MOST SUSCEPTIBLE POPULATIONS, SUCH AS NEWBORNS. SOME OF THESE ASSOCIATIONS WERE OBSERVED AT LOW CONCENTRATIONS OF PTMS. MOST OF THE STUDIES HAVE FOCUSED ON SINGLE EXPOSURES; HOWEVER, THREE INTERACTIONS BETWEEN ESSENTIAL AND NONESSENTIAL METALS WERE OBSERVED, HIGHLIGHTING THAT METAL MIXTURES NEED MORE ATTENTION. 2023 16 2530 29 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 17 2638 23 EPIGENOME: BIOSENSOR OF CUMULATIVE EXPOSURE TO CHEMICAL AND NONCHEMICAL STRESSORS RELATED TO ENVIRONMENTAL JUSTICE. UNDERSTANDING DIFFERENTIAL DISEASE SUSCEPTIBILITY REQUIRES NEW TOOLS TO QUANTIFY THE CUMULATIVE EFFECTS OF ENVIRONMENTAL STRESS. EVIDENCE SUGGESTS THAT SOCIAL, PHYSICAL, AND CHEMICAL STRESSORS CAN INFLUENCE DISEASE THROUGH THE ACCUMULATION OF EPIGENETIC MODIFICATIONS. GEOGRAPHICALLY STABLE EPIGENETIC ALTERATIONS COULD IDENTIFY PLAUSIBLE MECHANISMS FOR HEALTH DISPARITIES AMONG THE DISADVANTAGED AND POOR. RELATIONS BETWEEN NEIGHBORHOOD-SPECIFIC EPIGENETIC MARKERS AND DISEASE WOULD IDENTIFY THE MOST APPROPRIATE TARGETS FOR MEDICAL AND ENVIRONMENTAL INTERVENTION. COMPLEX INTERACTIONS AMONG GENES, THE ENVIRONMENT, AND DISEASE REQUIRE THE EXAMINATION OF HOW EPIGENETIC CHANGES REGULATE SUSCEPTIBILITY TO ENVIRONMENTAL STRESSORS. PROGRESS IN UNDERSTANDING DISPARITIES IN DISEASE SUSCEPTIBILITY MAY DEPEND ON ASSESSING THE CUMULATIVE EFFECT OF ENVIRONMENTAL STRESSORS ON GENETIC SUBSTRATES. WE HIGHLIGHT KEY CONCEPTS REGARDING THE INTERFACE BETWEEN ENVIRONMENTAL STRESS, EPIGENETICS, AND CHRONIC DISEASE. 2014 18 1014 30 CIGARETTE SMOKING AND DNA METHYLATION. DNA METHYLATION IS THE MOST STUDIED EPIGENETIC MODIFICATION, CAPABLE OF CONTROLLING GENE EXPRESSION IN THE CONTEXTS OF NORMAL TRAITS OR DISEASES. IT IS HIGHLY DYNAMIC DURING EARLY EMBRYOGENESIS AND REMAINS RELATIVELY STABLE THROUGHOUT LIFE, AND SUCH PATTERNS ARE INTRICATELY RELATED TO HUMAN DEVELOPMENT. DNA METHYLATION IS A QUANTITATIVE TRAIT DETERMINED BY A COMPLEX INTERPLAY OF GENETIC AND ENVIRONMENTAL FACTORS. GENETIC VARIANTS AT A SPECIFIC LOCUS CAN INFLUENCE BOTH REGIONAL AND DISTANT DNA METHYLATION. THE ENVIRONMENT CAN HAVE VARYING EFFECTS ON DNA METHYLATION DEPENDING ON WHEN THE EXPOSURE OCCURS, SUCH AS DURING PRENATAL LIFE OR DURING ADULTHOOD. IN PARTICULAR, CIGARETTE SMOKING IN THE CONTEXT OF BOTH CURRENT SMOKING AND PRENATAL EXPOSURE IS A STRONG MODIFIER OF DNA METHYLATION. EPIGENOME-WIDE ASSOCIATION STUDIES HAVE UNCOVERED CANDIDATE GENES ASSOCIATED WITH CIGARETTE SMOKING THAT HAVE BIOLOGICALLY RELEVANT FUNCTIONS IN THE ETIOLOGY OF SMOKING-RELATED DISEASES. AS SUCH, DNA METHYLATION IS A POTENTIAL MECHANISTIC LINK BETWEEN CURRENT SMOKING AND CANCER, AS WELL AS PRENATAL CIGARETTE-SMOKE EXPOSURE AND THE DEVELOPMENT OF ADULT CHRONIC DISEASES. 2013 19 2495 39 EPIGENETICS AND DOHAD: FROM BASICS TO BIRTH AND BEYOND. DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE (DOHAD) IS THE STUDY OF HOW THE EARLY LIFE ENVIRONMENT CAN IMPACT THE RISK OF CHRONIC DISEASES FROM CHILDHOOD TO ADULTHOOD AND THE MECHANISMS INVOLVED. EPIGENETIC MODIFICATIONS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS ARE INVOLVED IN MEDIATING HOW EARLY LIFE ENVIRONMENT IMPACTS LATER HEALTH. THIS REVIEW IS A SUMMARY OF THE EPIGENETICS AND DOHAD WORKSHOP HELD AT THE 2016 DOHAD SOCIETY OF AUSTRALIA AND NEW ZEALAND CONFERENCE. OUR EXTENSIVE KNOWLEDGE OF HOW THE EARLY LIFE ENVIRONMENT IMPACTS LATER RISK FOR CHRONIC DISEASE WOULD NOT HAVE BEEN POSSIBLE WITHOUT ANIMAL MODELS. IN THIS REVIEW WE HIGHLIGHT SOME ANIMAL MODEL EXAMPLES THAT DEMONSTRATE HOW AN ADVERSE EARLY LIFE EXPOSURE RESULTS IN EPIGENETIC AND GENE EXPRESSION CHANGES THAT MAY CONTRIBUTE TO INCREASED RISK OF CHRONIC DISEASE LATER IN LIFE. TYPE 2 DIABETES AND CARDIOVASCULAR DISEASE ARE CHRONIC DISEASES WITH AN INCREASING INCIDENCE DUE TO THE INCREASED NUMBER OF CHILDREN AND ADULTS THAT ARE OBESE. EPIGENETIC CHANGES SUCH AS DNA METHYLATION HAVE BEEN SHOWN TO BE ASSOCIATED WITH METABOLIC HEALTH MEASURES AND POTENTIALLY PREDICT FUTURE METABOLIC HEALTH STATUS. ALTHOUGH MORE DIFFICULT TO ELUCIDATE IN HUMANS, RECENT STUDIES SUGGEST THAT DNA METHYLATION MAY BE ONE OF THE EPIGENETIC MECHANISMS THAT MEDIATES THE EFFECTS OF EARLY LIFE EXPOSURES ON LATER LIFE RISK OF OBESITY AND OBESITY RELATED DISEASES. FINALLY, WE DISCUSS THE ROLE OF THE MICROBIOME AND HOW IT IS A NEW PLAYER IN DEVELOPMENTAL PROGRAMMING AND MEDIATING EARLY LIFE EXPOSURES ON LATER RISK OF CHRONIC DISEASE. 2017 20 2507 30 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