1 6161 98 THE GENETICS OF ASTHMA: ADAM33 AS AN EXAMPLE OF A SUSCEPTIBILITY GENE. THE ABILITY TO IDENTIFY NOVEL DISEASE GENES BY POSITIONAL CLONING LED TO THE IDENTIFICATION OF A DISINTEGRIN AND METALLOPROTEASE (ADAM)33 GENE ON CHROMOSOME 20P13 AS A SUSCEPTIBILITY GENE FOR ASTHMA. CASE-CONTROL AND FAMILY-BASED ASSOCIATION STUDIES HAVE MOSTLY CONFIRMED A LINK BETWEEN ADAM33 AND ASTHMA. ITS RESTRICTED EXPRESSION TO MESENCHYMAL CELLS AS WELL AS ITS ASSOCIATION WITH BRONCHIAL HYPERRESPONSIVENESS AND ACCELERATED DECLINE IN LUNG FUNCTION OVER TIME POINT STRONGLY TO ITS INVOLVEMENT IN THE STRUCTURAL AIRWAY COMPONENTS OF ASTHMA, SUCH AS REMODELING. EXTENSIVE ALTERNATIVE SPLICING, EXPRESSION DURING BRANCHING MORPHOGENSIS IN THE DEVELOPING FETUS, IMPAIRED LUNG FUNCTION IN CHILDHOOD, THE PRODUCTION OF A SOLUBLE FORM LINKED TO CHRONIC ASTHMA, AND TIGHT EPIGENETIC REGULATION INDICATE A LEVEL OF COMPLEXITY IN THE WAY ADAM33 INFLUENCES DISEASE PHENOTYPE. ITS RECENT ASSOCIATION WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE AS WELL AS WITH ASTHMA AND LUNG DEVELOPMENT POINTS TO FUNCTIONS RELATING TO AIRWAY WALL MODELING AND REMODELING AS A GENERAL MORPHOGENETIC REPAIR GENE RATHER THAN BEING RESTRICTED TO ASTHMA. 2006 2 2059 25 EPIGENETIC CONTROL OF GENE EXPRESSION IN THE LUNG. EPIGENETICS IS TRADITIONALLY DEFINED AS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. THERE ARE THREE MAIN CLASSES OF EPIGENETIC MARKS--DNA METHYLATION, MODIFICATIONS OF HISTONE TAILS, AND NONCODING RNAS--EACH OF WHICH MAY BE INFLUENCED BY THE ENVIRONMENT, DIET, DISEASES, AND AGEING. IMPORTANTLY, EPIGENETIC MARKS HAVE BEEN SHOWN TO INFLUENCE IMMUNE CELL MATURATION AND ARE ASSOCIATED WITH THE RISK OF DEVELOPING VARIOUS FORMS OF CANCER, INCLUDING LUNG CANCER. MOREOVER, THERE IS EMERGING EVIDENCE THAT THESE EPIGENETIC MARKS AFFECT GENE EXPRESSION IN THE LUNG AND ARE ASSOCIATED WITH BENIGN LUNG DISEASES, SUCH AS ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND INTERSTITIAL LUNG DISEASE. TECHNOLOGICAL ADVANCES HAVE MADE IT FEASIBLE TO STUDY EPIGENETIC MARKS IN THE LUNG, AND IT IS ANTICIPATED THAT THIS KNOWLEDGE WILL ENHANCE OUR UNDERSTANDING OF THE DYNAMIC BIOLOGY IN THE LUNG AND LEAD TO THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND THERAPEUTIC APPROACHES FOR OUR PATIENTS WITH LUNG DISEASE. 2011 3 6199 33 THE IMPORTANCE OF EPIGENETICS IN THE DEVELOPMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. IT IS GENERALLY ACCEPTED THAT GENETIC PREDISPOSITION PLAYS A ROLE IN COPD DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS. THEREFORE, MANY CANDIDATE GENES THAT COULD BE LINKED TO THE DEVELOPMENT OF DISEASE HAVE BEEN EXAMINED IN COPD. HOWEVER, INCONSISTENT RESULTS IN DIFFERENT STUDY POPULATIONS OFTEN LIMIT THIS APPROACH, SUGGESTING THAT NOT ONLY GENETICS, BUT ALSO OTHER FACTORS, MAY BE CONTRIBUTED TO THE SUSCEPTIBILITY TO COPD. EPIGENETIC MECHANISMS CAN AFFECT THE TRANSCRIPTIONAL ACTIVITY OF SPECIFIC GENES, AT DIFFERENT POINTS IN TIME, AND IN DIFFERENT ORGANS. MOREOVER, THESE MECHANISMS CAN HAVE AN EFFECT ON PEOPLE'S HEALTH. RECENTLY, THERE IS EMERGING EVIDENCE SUPPORTING A ROLE OF EPIGENETICS FOR THE REGULATION OF INFLAMMATORY GENES IN DISEASES SUCH AS ASTHMA AND COPD. MOREOVER, RECENT STUDIES SUGGEST THAT THE CURRENTLY USED TREATMENTS INCLUDING CORTICOSTEROIDS MAY WORK THROUGH EPIGENETIC MECHANISMS. EPIGENETIC REGULATION CAN BE REPROGRAMMED, POTENTIALLY AFFECTING THE RISK, AETIOLOGY AND TREATMENT OF VARIOUS DISEASE STATES. THE EPIGENETICALLY INFLUENCED PHENOTYPE COULD BE REVERSED WITH DEMETHYLATING OR DEACETYLATING AGENTS, CONSISTENT WITH EPIGENETIC PLASTICITY. THE POSTNATAL REVERSIBILITY OF THESE METHYLATION OR ACETYLATION EVENTS MAY THEREFORE PROVIDE GOOD OPPORTUNITIES FOR INTERVENTION. THE RECOGNITION OF THE ROLE OF GENETIC AND EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF COPD MAY IDENTIFY NOVEL TARGETS THAT HATCH NEW THERAPIES FOR PATIENTS WITH COPD. 2011 4 3543 21 IMMUNOLOGY, GENETICS AND MICROBIOTA IN THE COPD PATHOPHYSIOLOGY: POTENTIAL SCOPE FOR PATIENT STRATIFICATION. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS CHARACTERIZED BY SUSTAINED INFLAMMATION OF THE AIRWAYS, LEADING TO DESTRUCTION OF LUNG TISSUE AND DECLINING PULMONARY FUNCTION. ALTHOUGH SMOKING IS THE MOST OBVIOUS RISK FACTOR FOR COPD, ONLY ABOUT 20% OF SMOKERS DEVELOP COPD AND SMOKING CESSATION DOES NOT REVERSE PROGRESSION OF COPD, INDICATING THAT WHILE SMOKING IS AN IMPORTANT CAUSE OR INITIATING FACTOR, IT IS NOT THE ONLY DRIVER OF ONGOING CHRONIC INFLAMMATION AND DISEASE PROGRESSION IN COPD PATIENTS. WE HYPOTHESIZE THAT SMOKING-INDUCED CHANGES IN LUNG MICROBIOTA, EPITHELIAL INTEGRITY AND EPIGENETIC CONTROL OF GENE EXPRESSION RESULT IN AUTOANTIGEN INDUCTION AND PERTURBED IMMUNE REGULATION IN GENETICALLY VUNERABLE INDIVIDUALS. IN OUR VIEW, COPD PATIENTS MAY BE STRATIFIED ACCORDING TO THEIR IMMUNOLOGICAL AND INFLAMMATORY STATUS RELATED TO SPECIFIC CHANGES IN THE LUNG MICROBIOTA (INNATE AND ADAPTIVE IMMUNITY), PRESENCE OF AUTOANTIGENS (ADAPTIVE IMMUNITY: TH1-B-CELL AXIS) AND EPIGENETIC MODIFICATIONS (INFLAMMATION AND STRUCTURAL CHANGES). 2015 5 2648 29 EPIGENOMIC TARGETS FOR THE TREATMENT OF RESPIRATORY DISEASE. BACKGROUND: A NUMBER OF PROCESSES LEAD TO EPIGENETIC AND EPIGENOMIC MODIFICATIONS. OBJECTIVE: TO ADDRESS THE IMPORTANCE OF EPIGENOMICS IN RESPIRATORY DISEASE. METHODS: STUDIES OF EPIGENOMICS WERE ANALYSED IN RELATION TO CHRONIC RESPIRATORY DISEASES. RESULTS/CONCLUSION: IN LUNG CANCER AND MESOTHELIOMA, A NUMBER OF GENES INVOLVED IN CARCINOGENESIS HAVE BEEN DEMONSTRATED TO BE HYPERMETHYLATED, IMPLICATING EPIGENOMIC CHANGES IN THE AETIOLOGY OF THESE CANCERS. HYPERMETHYLATED GENES HAVE ALSO BEEN ASSOCIATED WITH LUNG CANCER RECURRENCE, INDICATING EPIGENOMIC REGULATION OF METASTASIS. IN AIRWAY DISEASES, MODULATION OF HISTONE FUNCTION MAY ACTIVATE INFLAMMATORY MECHANISMS IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE PATIENTS AND LEAD TO RELATIVE STEROID RESISTANCE. THERE IS EMERGING EVIDENCE FOR THE ROLE OF EPIGENETIC CHANGES IN CHRONIC LUNG DISEASES SUCH AS ASTHMA, INCLUDING RESPONSES TO ENVIRONMENTAL EXPOSURES IN UTERO AND TO THE EFFECTS OF AIR POLLUTION. INSIGHT INTO EPIGENOMICS WILL LEAD TO THE DEVELOPMENT OF NOVEL BIOMARKERS AND TREATMENT TARGETS IN RESPIRATORY DISEASES. 2009 6 2022 31 EPIGENETIC CHANGES ASSOCIATED WITH DISEASE PROGRESSION IN A MOUSE MODEL OF CHILDHOOD ALLERGIC ASTHMA. DEVELOPMENT OF ASTHMA IN CHILDHOOD IS LINKED TO VIRAL INFECTIONS OF THE LOWER RESPIRATORY TRACT IN EARLY LIFE, WITH SUBSEQUENT CHRONIC EXPOSURE TO ALLERGENS. PROGRESSION TO PERSISTENT ASTHMA IS ASSOCIATED WITH A TH2-BIASED IMMUNOLOGICAL RESPONSE AND STRUCTURAL REMODELLING OF THE AIRWAYS. THE UNDERLYING MECHANISMS ARE UNCLEAR, BUT COULD INVOLVE EPIGENETIC CHANGES. TO INVESTIGATE THIS, WE EMPLOYED A RECENTLY DEVELOPED MOUSE MODEL IN WHICH SELF-LIMITED NEONATAL INFECTION WITH A PNEUMOVIRUS, FOLLOWED BY SENSITISATION TO OVALBUMIN VIA THE RESPIRATORY TRACT AND LOW-LEVEL CHRONIC CHALLENGE WITH AEROSOLISED ANTIGEN, LEADS TO DEVELOPMENT OF AN ASTHMATIC PHENOTYPE. WE ASSESSED EXPRESSION OF MICRORNA BY CELLS IN THE PROXIMAL AIRWAYS, COMPARING CHANGES OVER THE PERIOD OF DISEASE PROGRESSION, AND USED TARGET PREDICTION DATABASES TO IDENTIFY GENES LIKELY TO BE UP- OR DOWNREGULATED AS A CONSEQUENCE OF ALTERED REGULATION OF MICRORNA. IN PARALLEL, WE ASSESSED DNA METHYLATION IN PULMONARY CD4(+) T CELLS. WE FOUND THAT A LIMITED NUMBER OF MICRORNAS EXHIBITED MARKED UP- OR DOWNREGULATION FOLLOWING EARLY-LIFE INFECTION AND SENSITISATION, FOR MANY OF WHICH THE LEVELS OF EXPRESSION WERE FURTHER CHANGED FOLLOWING CHRONIC CHALLENGE WITH THE SENSITIZING ANTIGEN. TARGETS OF THESE MICRORNAS INCLUDED GENES INVOLVED IN IMMUNE OR INFLAMMATORY RESPONSES (E.G. GATA3, KITL) AND IN TISSUE REMODELLING (E.G. IGF1, TGFBR1), AS WELL AS GENES FOR VARIOUS TRANSCRIPTION FACTORS AND SIGNALLING PROTEINS. IN PULMONARY CD4(+) T CELLS, THERE WAS SIGNIFICANT DEMETHYLATION AT PROMOTER SITES FOR INTERLEUKIN-4 AND INTERFERON-GAMMA, THE LATTER INCREASING FOLLOWING CHRONIC CHALLENGE. WE CONCLUDE THAT, IN THIS MODEL, PROGRESSION TO AN ASTHMATIC PHENOTYPE IS LINKED TO EPIGENETIC REGULATION OF GENES ASSOCIATED WITH INFLAMMATION AND STRUCTURAL REMODELLING, AND WITH T-CELL COMMITMENT TO A TH2 IMMUNOLOGICAL RESPONSE. EPIGENETIC CHANGES ASSOCIATED WITH THIS PATTERN OF GENE ACTIVATION MIGHT PLAY A ROLE IN THE DEVELOPMENT OF CHILDHOOD ASTHMA. 2013 7 2330 28 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 8 305 29 AIRWAY WALL REMODELING IN CHILDHOOD ASTHMA-A PERSONALIZED PERSPECTIVE FROM CELL TYPE-SPECIFIC BIOLOGY. AIRWAY WALL REMODELING IS A PATHOLOGY OCCURRING IN CHRONIC INFLAMMATORY LUNG DISEASES INCLUDING ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND FIBROSIS. IN 2017, THE AMERICAN THORACIC SOCIETY RELEASED A RESEARCH STATEMENT HIGHLIGHTING THE GAPS IN KNOWLEDGE AND UNDERSTANDING OF AIRWAY WALL REMODELING. THE FOUR MAJOR CHALLENGES ADDRESSED IN THIS STATEMENT WERE: (I) THE LACK OF CONSENSUS TO DEFINE "AIRWAY WALL REMODELING" IN DIFFERENT DISEASES, (II) METHODOLOGIC LIMITATIONS AND INAPPROPRIATE MODELS, (III) THE LACK OF ANTI-REMODELING THERAPIES, AND (IV) THE DIFFICULTY TO DEFINE ENDPOINTS AND OUTCOMES IN RELEVANT STUDIES. THIS REVIEW FOCUSES ON THE IMPORTANCE OF CELL-CELL INTERACTION, ESPECIALLY THE BRONCHIAL EPITHELIUM, IN ASTHMA-ASSOCIATED AIRWAY WALL REMODELING. THE PATHOLOGY OF "AIRWAY WALL REMODELING" SUMMARIZES ALL STRUCTURAL CHANGES OF THE AIRWAY WALL WITHOUT DIFFERENTIATING BETWEEN DIFFERENT PHENO- OR ENDO-TYPES OF ASTHMA. INDICATORS OF AIRWAY WALL REMODELING HAVE BEEN REPORTED IN CHILDHOOD ASTHMA IN THE ABSENCE OF ANY SIGN OF INFLAMMATION; THUS, THE INITIATION EVENT REMAINS UNKNOWN. RECENT STUDIES HAVE IMPLIED THAT THE INTERACTION BETWEEN THE EPITHELIUM WITH IMMUNE CELLS AND SUB-EPITHELIAL MESENCHYMAL CELLS IS MODIFIED IN ASTHMA BY A YET UNKNOWN EPIGENETIC MECHANISM DURING EARLY CHILDHOOD. 2021 9 5534 25 ROLE OF AIRWAY EPITHELIAL CELLS IN THE DEVELOPMENT OF DIFFERENT ASTHMA PHENOTYPES. THE TERM (BRONCHIAL) ASTHMA DESCRIBES A DISORDER SYNDROME THAT COMPRISES SEVERAL DISEASE PHENOTYPES, ALL CHARACTERIZED BY CHRONIC INFLAMMATION IN THE BRONCHIAL EPITHELIUM, WITH A VARIETY OF SUBSEQUENT FUNCTIONAL CONSEQUENCES. THUS, THE EPITHELIUM IN THE CONDUCTING AIRWAYS IS THE MAIN LOCALIZATION OF THE COMPLEX PATHOLOGICAL CHANGES IN THE DISEASE. IN THIS REGARD, BRONCHIAL EPITHELIAL CELLS ARE NOT PASSIVELY AFFECTED BY INFLAMMATORY MECHANISMS INDUCED BY IMMUNOLOGICAL PROCESSES BUT RATHER ACTIVELY INVOLVED IN ALL STEPS OF DISEASE DEVELOPMENT FROM INITIATION AND PERPETUATION TO CHRONIFICATION. IN RECENT YEARS IT TURNED OUT THAT BRONCHIAL EPITHELIAL CELLS SHOW A HIGH LEVEL OF STRUCTURAL AND FUNCTIONAL DIVERSITY AND PLASTICITY WITH EPIGENETIC MECHANISMS PLAYING A CRUCIAL ROLE IN THE REGULATION OF THESE PROCESSES. THUS, IT IS QUITE REASONABLE THAT DIFFERENTIAL FUNCTIONAL ACTIVITIES OF THE BRONCHIAL EPITHELIUM ARE INVOLVED IN THE DEVELOPMENT OF DIFFERENT ASTHMA PHENOTYPES AND/OR STAGES OF DISEASE. THE CURRENT KNOWLEDGE ON THIS TOPIC WILL BE DISCUSSED IN THIS REVIEW ARTICLE. 2020 10 927 25 CHRONIC INFLAMMATION, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND LUNG CANCER. PURPOSE OF REVIEW: SMOKING IS A MAJOR RISK FACTOR FOR LUNG CANCER, WHICH IS THE LEADING CAUSE OF CANCER-RELATED DEATHS BOTH IN THE USA AND WORLDWIDE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND EMPHYSEMA ARE COMORBID CONDITIONS OFTEN FOUND IN LUNG CANCER PATIENTS. THE INFLAMMATORY PATHWAYS THAT LINK CHRONIC OBSTRUCTIVE PULMONARY DISEASE, EMPHYSEMA, AND LUNG CANCER LIKELY INVOLVE GENETIC AND EPIGENETIC MODULATIONS DUE TO CHRONIC TISSUE INJURY AND ABNORMAL TUMOR IMMUNITY IN SUSCEPTIBLE HOSTS. RECENT FINDINGS: CHRONIC AIRWAY INFLAMMATION CONTRIBUTES TO ALTERATIONS IN THE BRONCHIAL EPITHELIUM AND LUNG MICROENVIRONMENT, PROVOKING A MILIEU CONDUCIVE TO PULMONARY CARCINOGENESIS. FOR EXAMPLE, INFLAMMATION-INDUCIBLE CYCLOOXYGENASE-2 IS UPREGULATED IN NONSMALL CELL LUNG CANCER AND ALSO PLAYS AN IMPORTANT ROLE IN PROMOTING EPITHELIAL-TO-MESENCHYMAL TRANSITION. GENETIC CHANGES IN THE AIRWAY EPITHELIUM OF SMOKERS MAY HELP PREDICT OR IDENTIFY INDIVIDUALS AT RISK FOR LUNG CANCER. FINALLY, RADIOGRAPHIC FINDINGS OF EMPHYSEMA HAVE BEEN ESTABLISHED AS INDEPENDENT RISK FACTORS FOR LUNG CANCER. SUMMARY: THE RELATIONSHIPS BETWEEN INFLAMMATION, AIRFLOW OBSTRUCTION, AND LUNG CANCER ARE COMPLEX. DEREGULATED INFLAMMATION IS COMPLICIT IN THE PATHOGENESIS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND LUNG CANCER, BUT THE OVERLAP OF SIGNALING EVENTS IS NOT YET FULLY UNDERSTOOD. TOBACCO EXPOSURE IS AN IMPORTANT RISK FACTOR THAT CONFERS LONG-TERM RISK OF LUNG DISEASE. DIAGNOSTIC SENSITIVITY OF DETECTING LUNG CANCER MAY IMPROVE WITH THE UTILIZATION OF GENETIC PROFILING IN COMBINATION WITH PATHOLOGIC EVALUATION OF AIRWAY EPITHELIUM. ADDITIONAL RESEARCH IS REQUIRED TO UNDERSTAND THE ROLE OF EPITHELIAL-TO-MESENCHYMAL TRANSITION IN CHRONIC INFLAMMATORY LUNG DISEASES AND LUNG CARCINOGENESIS. 2009 11 6005 30 THE AIRWAY EPITHELIUM-A CENTRAL PLAYER IN ASTHMA PATHOGENESIS. ASTHMA IS A CHRONIC INFLAMMATORY AIRWAY DISEASE CHARACTERIZED BY VARIABLE AIRFLOW OBSTRUCTION IN RESPONSE TO A WIDE RANGE OF EXOGENOUS STIMULI. THE AIRWAY EPITHELIUM IS THE FIRST LINE OF DEFENSE AND PLAYS AN IMPORTANT ROLE IN INITIATING HOST DEFENSE AND CONTROLLING IMMUNE RESPONSES. INDEED, INCREASING EVIDENCE INDICATES A RANGE OF ABNORMALITIES IN VARIOUS ASPECTS OF EPITHELIAL BARRIER FUNCTION IN ASTHMA. A CENTRAL PART OF THIS IMPAIRMENT IS A DISRUPTION OF THE AIRWAY EPITHELIAL LAYER, ALLOWING INHALED SUBSTANCES TO PASS MORE EASILY INTO THE SUBMUCOSA WHERE THEY MAY INTERACT WITH IMMUNE CELLS. FURTHERMORE, MANY OF THE IDENTIFIED SUSCEPTIBILITY GENES FOR ASTHMA ARE EXPRESSED IN THE AIRWAY EPITHELIUM. THIS REVIEW FOCUSES ON THE BIOLOGY OF THE AIRWAY EPITHELIUM IN HEALTH AND ITS PATHOBIOLOGY IN ASTHMA. WE WILL SPECIFICALLY DISCUSS EXTERNAL TRIGGERS SUCH AS ALLERGENS, VIRUSES AND ALARMINS AND THE EFFECT OF TYPE 2 INFLAMMATORY RESPONSES ON AIRWAY EPITHELIAL FUNCTION IN ASTHMA. WE WILL ALSO DISCUSS EPIGENETIC MECHANISMS RESPONDING TO EXTERNAL STIMULI ON THE LEVEL OF TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL REGULATION OF GENE EXPRESSION, AS WELL THE AIRWAY EPITHELIUM AS A POTENTIAL TREATMENT TARGET IN ASTHMA. 2020 12 629 22 BIOLOGICAL AND GENETIC MECHANISMS OF COPD, ITS DIAGNOSIS, TREATMENT, AND RELATIONSHIP WITH LUNG CANCER. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS ONE OF THE MOST PREVALENT CHRONIC ADULT DISEASES, WITH SIGNIFICANT WORLDWIDE MORBIDITY AND MORTALITY. ALTHOUGH LONG-TERM TOBACCO SMOKING IS A CRITICAL RISK FACTOR FOR THIS GLOBAL HEALTH PROBLEM, ITS MOLECULAR MECHANISMS REMAIN UNCLEAR. SEVERAL PHENOMENA ARE THOUGHT TO BE INVOLVED IN THE EVOLUTION OF EMPHYSEMA, INCLUDING AIRWAY INFLAMMATION, PROTEINASE/ANTI-PROTEINASE IMBALANCE, OXIDATIVE STRESS, AND GENETIC/EPIGENETIC MODIFICATIONS. FURTHERMORE, COPD IS ONE MAIN RISK FOR LUNG CANCER (LC), THE DEADLIEST FORM OF HUMAN TUMOR; FORMATION AND CHRONIC INFLAMMATION ACCOMPANYING COPD CAN BE A POTENTIAL DRIVER OF MALIGNANCY MATURATION (0.8-1.7% OF COPD CASES DEVELOP CANCER/PER YEAR). RECENTLY, THE DEVELOPMENT OF MORE RESEARCH BASED ON COPD AND LUNG CANCER MOLECULAR ANALYSIS HAS PROVIDED NEW LIGHT FOR UNDERSTANDING THEIR PATHOGENESIS, IMPROVING THE DIAGNOSIS AND TREATMENTS, AND ELUCIDATING MANY CONNECTIONS BETWEEN THESE DISEASES. OUR REVIEW EMPHASIZES THE BIOLOGICAL FACTORS INVOLVED IN COPD AND LUNG CANCER, THE ADVANCES IN THEIR MOLECULAR MECHANISMS' RESEARCH, AND THE STATE OF THE ART OF DIAGNOSIS AND TREATMENTS. THIS WORK COMBINES MANY BIOLOGICAL AND GENETIC ELEMENTS INTO A SINGLE WHOLE AND STRONGLY LINKS COPD WITH LUNG TUMOR FEATURES. 2023 13 2279 30 EPIGENETIC REGULATION IN ALLERGIC DISEASES AND RELATED STUDIES. ASTHMA, A CHRONIC INFLAMMATORY DISORDER OF THE AIRWAY, HAS FEATURES OF BOTH HERITABILITY AS WELL AS ENVIRONMENTAL INFLUENCES WHICH CAN BE INTRODUCED IN UTERO EXPOSURES AND MODIFIED THROUGH AGING, AND THE FEATURES MAY ATTRIBUTE TO EPIGENETIC REGULATION. EPIGENETIC REGULATION EXPLAINS THE ASSOCIATION BETWEEN EARLY PRENATAL MATERNAL SMOKING AND LATER ASTHMA-RELATED OUTCOMES. EPIGENETIC MARKS (DNA METHYLATION, MODIFICATIONS OF HISTONE TAILS OR NONCODING RNAS) WORK WITH OTHER COMPONENTS OF THE CELLULAR REGULATORY MACHINERY TO CONTROL THE LEVELS OF EXPRESSED GENES, AND SEVERAL ALLERGY- AND ASTHMA-RELATED GENES HAVE BEEN FOUND TO BE SUSCEPTIBLE TO EPIGENETIC REGULATION, INCLUDING GENES IMPORTANT TO T-EFFECTOR PATHWAYS (IFN-GAMMA, INTERLEUKIN [IL] 4, IL-13, IL-17) AND T-REGULATORY PATHWAYS (FOXP3). THEREFORE, THE MECHANISM BY WHICH EPIGENETIC REGULATION CONTRIBUTES TO ALLERGIC DISEASES IS A CRITICAL ISSUE. IN THE PAST MOST PUBLISHED EXPERIMENTAL WORK, WITH FEW EXCEPTIONS, HAS ONLY COMPRISED SMALL OBSERVATIONAL STUDIES AND MODELS IN CELL SYSTEMS AND ANIMALS. HOWEVER, VERY RECENTLY EXCITING AND ELEGANT EXPERIMENTAL STUDIES AND NOVEL TRANSLATIONAL RESEARCH WORKS WERE PUBLISHED WITH NEW AND ADVANCED TECHNOLOGIES INVESTIGATING EPIGENETIC MARK ON A GENOMIC SCALE AND COMPREHENSIVE APPROACHES TO DATA ANALYSIS. INTERESTINGLY, A POTENTIAL LINK BETWEEN EXPOSURE TO ENVIRONMENTAL POLLUTANTS AND THE OCCURRENCE OF ALLERGIC DISEASES IS REVEALED RECENTLY, PARTICULAR IN DEVELOPED AND INDUSTRIALIZED COUNTRIES, AND ENDOCRINE DISRUPTING CHEMICALS (EDCS) AS ENVIRONMENTAL HORMONE MAY PLAY A KEY ROLE. THIS REVIEW ADDRESSES THE IMPORTANT QUESTION OF HOW EDCS (NONYLPHENOL, 4 OCTYLPHENOL, AND PHTHALATES) INFLUENCES ON ASTHMA-RELATED GENE EXPRESSION VIA EPIGENETIC REGULATION IN IMMUNE CELLS, AND HOW ANTI-ASTHMATIC AGENTS PROHIBIT EXPRESSION OF INFLAMMATORY GENES VIA EPIGENETIC MODIFICATION. THE DISCOVERY AND VALIDATION OF EPIGENETIC BIOMARKERS LINKING EXPOSURE TO ALLERGIC DISEASES MIGHT LEAD TO BETTER EPIGENOTYPING OF RISK, PROGNOSIS, TREATMENT PREDICTION, AND DEVELOPMENT OF NOVEL THERAPIES. 2014 14 2299 30 EPIGENETIC REGULATION OF AIRWAY EPITHELIUM IMMUNE FUNCTIONS IN ASTHMA. ASTHMA IS A CHRONIC INFLAMMATORY DISEASE OF THE RESPIRATORY TRACT CHARACTERIZED BY RECURRENT BREATHING PROBLEMS RESULTING FROM AIRWAY OBSTRUCTION AND HYPERRESPONSIVENESS. HUMAN AIRWAY EPITHELIUM PLAYS AN IMPORTANT ROLE IN THE INITIATION AND CONTROL OF THE IMMUNE RESPONSES TO DIFFERENT TYPES OF ENVIRONMENTAL FACTORS CONTRIBUTING TO ASTHMA PATHOGENESIS. USING PATTERN RECOGNITION RECEPTORS AIRWAY EPITHELIUM SENSES EXTERNAL STIMULI, SUCH AS ALLERGENS, MICROBES, OR POLLUTANTS, AND SUBSEQUENTLY SECRETES ENDOGENOUS DANGER SIGNALING MOLECULES ALARMING AND ACTIVATING DENDRITIC CELLS. HENCE, AIRWAY EPITHELIAL CELLS NOT ONLY MEDIATE INNATE IMMUNE RESPONSES BUT ALSO BRIDGE THEM WITH ADAPTIVE IMMUNE RESPONSES INVOLVING T AND B CELLS THAT PLAY A CRUCIAL ROLE IN THE PATHOGENESIS OF ASTHMA. THE EFFECTS OF ENVIRONMENTAL FACTORS ON THE DEVELOPMENT OF ASTHMA ARE MEDIATED, AT LEAST IN PART, BY EPIGENETIC MECHANISMS. THOSE COMPRISE CLASSICAL EPIGENETICS INCLUDING DNA METHYLATION AND HISTONE MODIFICATIONS AFFECTING TRANSCRIPTION, AS WELL AS MICRORNAS INFLUENCING TRANSLATION. THE COMMON FEATURE OF SUCH MECHANISMS IS THAT THEY REGULATE GENE EXPRESSION WITHOUT AFFECTING THE NUCLEOTIDE SEQUENCE OF THE GENOMIC DNA. EPIGENETIC MECHANISMS PLAY A PIVOTAL ROLE IN THE REGULATION OF DIFFERENT CELL POPULATIONS INVOLVED IN ASTHMA PATHOGENESIS, WITH THE REMARKABLE EXAMPLE OF T CELLS. RECENTLY, HOWEVER, THERE IS INCREASING EVIDENCE THAT EPIGENETIC MECHANISMS ARE ALSO CRUCIAL FOR THE REGULATION OF AIRWAY EPITHELIAL CELLS, ESPECIALLY IN THE CONTEXT OF EPIGENETIC TRANSFER OF ENVIRONMENTAL EFFECTS CONTRIBUTING TO ASTHMA PATHOGENESIS. IN THIS REVIEW, WE SUMMARIZE THE ACCUMULATING EVIDENCE FOR THIS VERY IMPORTANT ASPECT OF AIRWAY EPITHELIAL CELL PATHOBIOLOGY. 2020 15 3028 24 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 16 4028 22 LUNG TUMORS, COPD AND IMMUNE RESPONSE: IS EPIGENETICS THE BOTTOM LINE? NSCLC IS A HETEROGENEOUS DISORDER CONSISTING OF DISTINCT MOLECULAR SUBTYPES WHICH CAN BE TREATED BY USING SPECIFIC DRUGS TARGETED TO DISTINCT GENETIC LESIONS. IT IS WELL KNOWN THAT NSCLS INCIDENCE IS HIGHER IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS BECAUSE THEY SHARE A COMMON RISK FACTOR (CIGARETTE SMOKING) AND IT IS BELIEVED THAT THE TYPICAL INFLAMMATORY MICROENVIRONMENT OBSERVED IN COPD MAY INFLUENCE THE MOLECULAR MECHANISMS RESPONSIBLE OF CARCINOGENESIS. IN THE LAST YEARS, THE ROLE OF EPIGENETIC PROCESSES IN CELL BIOLOGY AND TISSUE PATHOLOGY HAS BEEN EXTENSIVELY STUDIED BOTH IN COPD AND NSCLC. THE RECENT PAPER BY WAUTERS ET AL. SHOWED A SPECIFIC PATTERN OF DRIVER MUTATIONS AND MOLECULAR FEATURES IN NSCLC RAISING IN THE CONTEXT OF COPD. ALL THESE FINDINGS HAVE SHOWN FOR THE FIRST TIME THAT LUNG TUMORS FOUND IN COPD PATIENTS DIFFER FROM THOSE OBSERVED IN PATIENT WITHOUT COPD DUE TO THE PRESENCE OF A SPECIFIC TUMOR MICROENVIRONMENT WHICH IS CHARACTERIZED BY REDUCED CD4+ TREG CELLS. ON THIS BASIS, THE PRESENT WORK AIMS AT DISCUSSING AND ANALYZING THE CONTEXT-SPECIFIC MECHANISMS OF CLONAL SELECTION AND EVOLUTION MAINLY FOCUSING ON THE EPIGENETIC ALTERATIONS AND AT POINTING OUT THE POTENTIAL THERAPEUTIC IMPLICATIONS. 2016 17 6628 24 UNDERSTANDING THE GENETICS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE, ALPHA1-ANTITRYPSIN DEFICIENCY, AND IMPLICATIONS FOR CLINICAL PRACTICE. CIGARETTE SMOKING AND POOR AIR QUALITY ARE THE GREATEST RISK FACTORS FOR DEVELOPING CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), BUT GROWING EVIDENCE INDICATES THAT GENETIC FACTORS ALSO AFFECT PREDISPOSITION TO AND CLINICAL EXPRESSION OF DISEASE. WITH THE EXCEPTION OF ALPHA1-ANTITRYPSIN DEFICIENCY (AATD), A RARE AUTOSOMAL RECESSIVE DISORDER THAT IS PRESENT IN 1-3% OF INDIVIDUALS WITH COPD, NO SINGLE GENE IS ASSOCIATED WITH THE DEVELOPMENT OF OBSTRUCTIVE LUNG DISEASE. INSTEAD, A COMPLEX INTERPLAY OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS IS THE BASIS FOR PERSISTENT INFLAMMATORY RESPONSES, ACCELERATED CELL AGING, CELL DEATH, AND FIBROSIS, LEADING TO THE CLINICAL SYMPTOMS OF COPD AND DIFFERENT PHENOTYPIC PRESENTATIONS. IN THIS BRIEF REVIEW, WE DISCUSS CURRENT UNDERSTANDING OF THE GENETICS OF COPD, PATHOGENETICS OF AATD, EPIGENETIC INFLUENCES ON THE DEVELOPMENT OF OBSTRUCTIVE LUNG DISEASE, AND HOW CLASSIFYING COPD BY PHENOTYPE CAN INFLUENCE CLINICAL TREATMENT AND PATIENT OUTCOMES. 2021 18 4112 25 MECHANISMS CONTRIBUTING TO THE COMORBIDITY OF COPD AND LUNG CANCER. LUNG CANCER AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) OFTEN CO-OCCUR, AND INDIVIDUALS WITH COPD ARE AT A HIGHER RISK OF DEVELOPING LUNG CANCER. WHILE THE UNDERLYING MECHANISM FOR THIS RISK IS NOT WELL UNDERSTOOD, ITS MAJOR CONTRIBUTING FACTORS HAVE BEEN PROPOSED TO INCLUDE GENOMIC, IMMUNE, AND MICROENVIRONMENT DYSREGULATION. HERE, WE REVIEW THE EVIDENCE AND SIGNIFICANT STUDIES THAT EXPLORE THE MECHANISMS UNDERLYING THE HEIGHTENED LUNG CANCER RISK IN PEOPLE WITH COPD. GENETIC AND EPIGENETIC CHANGES, AS WELL AS THE ABERRANT EXPRESSION OF NON-CODING RNAS, PREDISPOSE THE LUNG EPITHELIUM TO CARCINOGENESIS BY ALTERING THE EXPRESSION OF CANCER- AND IMMUNE-RELATED GENES. OXIDATIVE STRESS GENERATED BY TOBACCO SMOKING PLAYS A ROLE IN REDUCING GENOMIC INTEGRITY, PROMOTING EPITHELIAL-MESENCHYMAL-TRANSITION, AND GENERATING A CHRONIC INFLAMMATORY ENVIRONMENT. THIS LEADS TO ABNORMAL IMMUNE RESPONSES THAT PROMOTE CANCER DEVELOPMENT, THOUGH NOT ALL SMOKERS DEVELOP LUNG CANCER. SEX DIFFERENCES IN THE METABOLISM OF TOBACCO SMOKE PREDISPOSE FEMALES TO DEVELOPING COPD AND ACCUMULATING DAMAGE FROM OXIDATIVE STRESS THAT POSES A RISK FOR THE DEVELOPMENT OF LUNG CANCER. DYSREGULATION OF THE LUNG MICROENVIRONMENT AND MICROBIOME CONTRIBUTES TO CHRONIC INFLAMMATION, WHICH IS OBSERVED IN COPD AND KNOWN TO FACILITATE CANCER INITIATION IN VARIOUS TUMOR TYPES. FURTHER, THERE IS A NEED TO BETTER CHARACTERIZE AND IDENTIFY THE PROPORTION OF INDIVIDUALS WITH COPD WHO ARE AT A HIGH RISK FOR DEVELOPING LUNG CANCER. WE EVALUATE POSSIBLE NOVEL AND INDIVIDUALIZED SCREENING STRATEGIES, INCLUDING BIOMARKERS IDENTIFIED IN GENETIC STUDIES AND EXHALED BREATH CONDENSATE ANALYSIS. WE ALSO DISCUSS THE USE OF CORTICOSTEROIDS AND STATINS AS CHEMOPREVENTIVE AGENTS TO PREVENT LUNG CANCER. IT IS CRUCIAL THAT WE OPTIMIZE THE CURRENT METHODS FOR THE EARLY DETECTION AND MANAGEMENT OF LUNG CANCER AND COPD IN ORDER TO IMPROVE THE HEALTH OUTCOMES FOR A LARGE AFFECTED POPULATION. 2023 19 4826 30 OF PLEIOTROPY AND TRAJECTORIES: DOES THE TGF-BETA PATHWAY LINK CHILDHOOD ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE? THE STUDY OF DEVELOPMENTAL TRAJECTORIES IS WHERE EPIGENETICS TRULY SHINES. THE "EPI" IN EPIGENETICS CAPTURES THE FACT THAT ALTHOUGH EPIGENETIC PROCESSES ALSO PRESIDE OVER THE MAINTENANCE AND TERMINATION OF GENE EXPRESSION, THE UNFOLDING AND REMODELING OF CHROMATIN ARCHITECTURE ARE ESPECIALLY CRITICAL TO PREPARE GENES FOR REGULATED TRANSCRIPTION. THESE PROPERTIES IMPLY BEING ON A PATH, A TRAJECTORY TO EVENTS THAT WILL OCCUR LATER THANKS TO EPIGENETIC PROGRAMMING. THUS EPIGENETICS IS ABOUT TIMED AND TIMELY EVENTS. IN THIS ARTICLE WE DISCUSS EPIGENETIC AND GENETIC EVIDENCE FROM SEVERAL INDEPENDENT STUDIES OF ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND LUNG FUNCTION, WHICH CONVERGE TO HIGHLIGHT A POTENTIAL ROLE OF THE TGF-BETA GENE PATHWAY IN THESE PROCESSES. THESE RESULTS RAISE THE POSSIBILITY THAT AT LEAST IN A SUBSET OF SUBJECTS, THESE CONDITIONS MIGHT BE FUNCTIONALLY CONNECTED IN WAYS THAT NEED TO BE FURTHER DEFINED BUT THAT LIKELY REFLECT THE UNIQUELY PLEIOTROPIC NATURE OF TGF-BETA PATHWAY GENES, PARTICULARLY THEIR ABILITY TO CONTROL BOTH LUNG DEVELOPMENT AND IMMUNE RESPONSES ESSENTIAL FOR REGULATION AND INFLAMMATION. FURTHER CHARACTERIZATION OF THIS PATHWAY IN LONGITUDINALLY PHENOTYPED POPULATIONS MIGHT UNMASK NOVEL TRAJECTORIES TO LUNG DISEASE THAT BEGIN IN UTERO AND UNFOLD INTO OLD AGE. 2018 20 5552 26 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