1 1640 68 DOES EPIGENETICS PLAY A ROLE IN HUMAN ASTHMA? ASTHMA AND OTHER ALLERGIC DISEASES ARE AMONG THE MOST PREVALENT CHRONIC NON-COMMUNICABLE DISEASES OF CHILDHOOD. ACCORDING TO THE WORLD HEALTH ORGANIZATION, ASTHMA AFFECTS >7.0 MILLION CHILDREN UNDER 18 IN THE UNITED STATES, WITH AN ECONOMIC BURDEN THAT IS ESTIMATED TO EXCEED THAT OF TUBERCULOSIS AND HIV/AIDS COMBINED. DESPITE MUCH RESEARCH, THE NATURAL HISTORY OF ASTHMA AND ITS PATHOGENESIS ARE STILL IN MANY WAYS ELUSIVE. THIS REVIEW DISCUSSES OUR CURRENT UNDERSTANDING OF THE ROLE EPIGENETIC PROCESSES PLAY IN ASTHMA PATHOGENESIS, FOCUSING ON GENOME-WIDE, POPULATION-BASED STUDIES. 2016 2 2492 22 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 3 2531 28 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 4 2651 22 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 5 2160 25 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 6 3580 24 IMPACT OF PERINATAL ENVIRONMENTAL TOBACCO SMOKE ON THE DEVELOPMENT OF CHILDHOOD ALLERGIC DISEASES. ALLERGIC DISEASES SUCH AS ASTHMA, ALLERGIC RHINITIS, ATOPIC DERMATITIS, AND FOOD ALLERGY, ARE MOST COMMON CHRONIC, NONCOMMUNICABLE DISEASES IN CHILDHOOD. IN THE PAST FEW DECADES, THE PREVALENCE HAS INCREASED ABRUPTLY WORLDWIDE. THERE ARE 2 POSSIBLE EXPLANATIONS FOR THE RISING PREVALENCE OF ALLERGIC DISEASES WORLDWIDE, THAT AN INCREASED DISEASE-AWARENESS OF PHYSICIAN, PATIENT, OR CAREGIVERS, AND AN ABRUPT EXPOSURE TO UNKNOWN HAZARDS. UNFORTUNATELY, THE UNDERLYING MECHANISMS REMAIN LARGELY UNKNOWN. DESPITE THE CONTINUING EFFORTS WORLDWIDE, THE ETIOLOGIES AND RISING PREVALENCE REMAIN UNCLEAR. THUS, IT IS IMPORTANT TO IDENTIFY AND CONTROL RISK FACTORS IN THE SUSCEPTIBLE INDIVIDUAL FOR THE BEST PREVENTION AND MANAGEMENT. GENETIC SUSCEPTIBILITY OR ENVIRONMENTS MAY BE A POTENTIAL BACKGROUND FOR THE DEVELOPMENT OF ALLERGIC DISEASE, HOWEVER THEY ALONE CANNOT EXPLAIN THE RISING PREVALENCE WORLDWIDE. THERE IS GROWING EVIDENCE THAT EPIGENETIC CHANGE DEPENDS ON THE GENE, ENVIRONMENT, AND THEIR INTERACTIONS, MAY INDUCE A LONG-LASTING ALTERED GENE EXPRESSION AND THE CONSEQUENT DEVELOPMENT OF ALLERGIC DISEASES. IN EPIGENETIC MECHANISMS, ENVIRONMENTAL TOBACCO SMOKE (ETS) EXPOSURE DURING CRITICAL PERIOD (I.E., DURING PREGNANCY AND EARLY LIFE) ARE CONSIDERED AS A POTENTIAL CAUSE OF THE DEVELOPMENT OF CHILDHOOD ALLERGIC DISEASES. HOWEVER, THE CAUSAL RELATIONSHIP IS STILL UNCLEAR. THIS REVIEW AIMED TO HIGHLIGHT THE IMPACT OF ETS EXPOSURE DURING THE PERINATAL PERIOD ON THE DEVELOPMENT OF CHILDHOOD ALLERGIC DISEASES AND TO PROPOSE A FUTURE RESEARCH DIRECTION. 2016 7 3421 24 HUMAN MATTERS IN ASTHMA: CONSIDERING THE MICROBIOME IN PULMONARY HEALTH. MICROBIAL COMMUNITIES FORM AN IMPORTANT SYMBIOTIC ECOSYSTEM WITHIN HUMANS AND HAVE DIRECT EFFECTS ON HEALTH AND WELL-BEING. NUMEROUS EXOGENOUS FACTORS INCLUDING AIRBORNE TRIGGERS, DIET, AND DRUGS IMPACT THESE ESTABLISHED, BUT FRAGILE COMMUNITIES ACROSS THE HUMAN LIFESPAN. CROSSTALK BETWEEN THE MUCOSAL MICROBIOTA AND THE IMMUNE SYSTEM AS WELL AS THE GUT-LUNG AXIS HAVE DIRECT CORRELATIONS TO IMMUNE BIAS THAT MAY PROMOTE CHRONIC DISEASES LIKE ASTHMA. ASTHMA INITIATION AND PATHOGENESIS ARE MULTIFACETED AND COMPLEX WITH INPUT FROM GENETIC, EPIGENETIC, AND ENVIRONMENTAL COMPONENTS. IN THIS REVIEW, WE SUMMARIZE AND DISCUSS THE ROLE OF THE AIRWAY MICROBIOME IN ASTHMA, AND HOW THE ENVIRONMENT, DIET AND THERAPEUTICS IMPACT THIS LOW BIOMASS COMMUNITY OF MICROORGANISMS. WE ALSO FOCUS THIS REVIEW ON THE PEDIATRIC AND BLACK POPULATIONS AS HIGH-RISK GROUPS REQUIRING SPECIAL ATTENTION, EMPHASIZING THAT THE WHOLE PATIENT MUST BE CONSIDERED DURING TREATMENT. ALTHOUGH NEW CULTURE-INDEPENDENT TECHNIQUES HAVE BEEN DEVELOPED AND ARE MORE ACCESSIBLE TO RESEARCHERS, THE EXACT CONTRIBUTION THE AIRWAY MICROBIOME MAKES IN ASTHMA PATHOGENESIS IS NOT WELL UNDERSTOOD. UNDERSTANDING HOW THE AIRWAY MICROBIOME, AS A LIVING ENTITY IN THE RESPIRATORY TRACT, PARTICIPATES IN LUNG IMMUNITY DURING THE DEVELOPMENT AND PROGRESSION OF ASTHMA MAY LEAD TO CRITICAL NEW TREATMENTS FOR ASTHMA, INCLUDING POPULATION-TARGETED INTERVENTIONS, OR EVEN MORE EFFECTIVE ADMINISTRATION OF CURRENTLY AVAILABLE THERAPEUTICS. 2022 8 396 22 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 9 2530 32 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 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 11 5552 20 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 12 6735 23 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 13 602 23 BETTER UNDERSTANDING OF CHILDHOOD ASTHMA, TOWARDS PRIMARY PREVENTION - ARE WE THERE YET? CONSIDERATION OF PERTINENT LITERATURE. ASTHMA IS A CHRONIC DISEASE, CHARACTERIZED BY REVERSIBLE AIRWAY OBSTRUCTION, AIRWAY INFLAMMATION AND HYPER-REACTIVITY. THE PREVALENCE OF ASTHMA HAS RISEN DRAMATICALLY OVER THE PAST DECADE, AFFECTING AROUND 300,000,000 PEOPLE. THE ETIOLOGY IS MULTIFACTORIAL, WITH GENETIC, EPIGENETIC, DEVELOPMENTAL AND ENVIRONMENTAL FACTORS PLAYING A ROLE. A COMPLEX INTERACTION BETWEEN THE INTRAUTERINE ENVIRONMENT, THE DEVELOPING IMMUNE SYSTEM, THE INFANT'S MICROBIOME AND INFECTIOUS ORGANISMS MAY LEAD TO THE DEVELOPMENT OF ALLERGIC SENSITIZATION AND ASTHMA. THUS, A LARGE NUMBER OF STUDIES HAVE INVESTIGATED THE RISK FACTORS FOR CHILDHOOD ASTHMA, WITH A METICULOUS SEARCH OF MODIFIABLE FACTORS THAT COULD AID IN PRIMARY PREVENTION. WE PRESENT A CURRENT LITERATURE REVIEW FROM 2014-2017, AS WELL AS OLDER CLASSIC PUBLICATIONS, ON THE PATHOGENESIS AND THE POTENTIAL MODIFIABLE FACTORS FOR PRIMARY PREVENTION OF ASTHMA. NO IDEAL PREVENTIVE MEASURE HAS YET BEEN FOUND. RATHER, CREATING FAVORABLE PRENATAL AND POSTNATAL ENVIRONMENTS, MINIMAL EXPOSURE TO HOSTILE ENVIRONMENTAL FACTORS, PREVENTION OF INFECTIONS IN EARLY LIFE, ALLERGIC DESENSITIZATION AND NUTRITIONAL MODIFICATIONS COULD POSSIBLY REDUCE ASTHMA INCEPTION. IN THE ERA OF PERSONALIZED MEDICINE, IDENTIFYING INDIVIDUAL RISK FACTORS AND TAILORING SPECIFIC PREVENTIVE MEASURES IS WARRANTED. 2017 14 527 26 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 15 2570 25 EPIGENETICS OF CHRONIC INFLAMMATORY DISEASES. CHRONIC, NONCOMMUNICABLE, AND INFLAMMATION-ASSOCIATED DISEASES REMAIN THE LARGEST CAUSE OF MORBIDITY AND MORTALITY GLOBALLY AND WITHIN THE UNITED STATES. THIS IS MAINLY DUE TO OUR LIMITED UNDERSTANDING OF THE MOLECULAR MECHANISMS THAT UNDERLIE THESE COMPLEX PATHOLOGIES. THE AVAILABLE EVIDENCE INDICATES THAT STUDIES OF EPIGENETICS (TRADITIONALLY DEFINED AS THE HERITABLE CHANGES TO GENE EXPRESSION THAT ARE INDEPENDENT OF CHANGES TO DNA) ARE SIGNIFICANTLY ADVANCING OUR KNOWLEDGE OF THESE INFLAMMATORY CONDITIONS. THIS REVIEW WILL FOCUS ON EPIGENETIC STUDIES OF THREE DISEASES, THAT ARE AMONG THE MOST BURDENSOME GLOBALLY: CARDIOVASCULAR DISEASE, THE NUMBER ONE CAUSE OF DEATHS WORLDWIDE, TYPE 2 DIABETES AND, ALZHEIMER'S DISEASE. THE CURRENT STATUS OF EPIGENETIC RESEARCH, INCLUDING THE ABILITY TO PREDICT DISEASE RISK, AND KEY PATHOPHYSIOLOGICAL DEFECTS ARE DISCUSSED. THE SIGNIFICANCE OF DEFINING THE CONTRIBUTION OF EPIGENETIC DEFECTS TO NONRESOLVING INFLAMMATION AND AGING, EACH ASSOCIATED WITH THESE DISEASES, IS HIGHLIGHTED, AS THESE ARE LIKELY TO PROVIDE NEW INSIGHTS INTO INFLAMMATORY DISEASE PATHOGENESIS. 2019 16 1409 21 DIETARY INTERVENTIONS AND NUTRITIONAL FACTORS IN THE PREVENTION OF PEDIATRIC ASTHMA. ASTHMA IS THE MOST FREQUENT CHRONIC DISEASE IN CHILDREN, AND ITS PATHOGENESIS INVOLVES GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. THE RAPID RISE IN THE PREVALENCE OF ASTHMA REGISTERED OVER THE LAST FEW DECADES HAS STRESSED THE NEED TO IDENTIFY THE ENVIRONMENTAL AND MODIFIABLE FACTORS ASSOCIATED WITH THE DEVELOPMENT OF THE DISEASE. IN PARTICULAR, THERE IS INCREASING INTEREST IN THE ROLE OF MODIFIABLE NUTRITIONAL FACTORS SPECIFIC TO BOTH THE PRENATAL AND POST-NATAL EARLY LIFE AS, DURING THIS TIME, THE IMMUNE SYSTEM IS PARTICULARLY VULNERABLE TO EXOGENOUS INTERFERENCES. SEVERAL DIETARY FACTORS, INCLUDING MATERNAL DIET DURING PREGNANCY, THE DURATION OF BREASTFEEDING, THE USE OF SPECIAL MILK FORMULAS, THE TIMING OF THE INTRODUCTION OF COMPLEMENTARY FOODS, AND PRENATAL AND EARLY LIFE SUPPLEMENTATION WITH VITAMINS AND PROBIOTICS/PREBIOTICS, HAVE BEEN ADDRESSED AS POTENTIAL TARGETS FOR THE PREVENTION OF ASTHMA. IN THIS REVIEW, WE OUTLINE RECENT FINDINGS ON THE POTENTIAL ROLE OF PRENATAL AND PERINATAL DIETARY AND NUTRITIONAL INTERVENTIONS FOR THE PRIMARY PREVENTION OF PEDIATRIC ASTHMA. MOREOVER, WE ADDRESSED UNMET NEEDS AND AREAS FOR FUTURE RESEARCH IN THE PREVENTION OF CHILDHOOD-ONSET ASTHMA. 2020 17 2330 22 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 18 1546 19 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 19 6808 18 [EPIGENETICS IN ALLERGIC DISEASES AND ASTHMA]. ALLERGIC DISEASES AND ASTHMA ARE THE RESULT OF COMPLEX INTERACTIONS BETWEEN GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. ASTHMA IS ONE OF THE MOST PREVALENT CHRONIC DISEASE AMONG CHILDREN. IN THIS ARTICLE WE REVIEW SOME ENVIRONMENTAL FACTORS LIKE: ALLERGEN EXPOSITION, TOBACCO, BACTERIA, MICROBIAL COMPONENTS, DIET, OBESITY AND STRESS, WHICH INFLUENCES DURING INTRAUTERINE AND INFANCY LIFE IN THE EPIGENETIC REGULATION OF ASTHMA AND ALLERGIC DISEASES. THE REVIEW HAS BEEN DONE IN THREE MODELS: IN-VITRO, ANIMAL AND HUMAN. 2016 20 6811 23 [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