1 5411 112 REGULATION OF AIRWAY MUCIN GENE EXPRESSION. MUCINS ARE IMPORTANT COMPONENTS THAT EXERT A VARIETY OF FUNCTIONS IN CELL-CELL INTERACTION, EPIDERMAL GROWTH FACTOR RECEPTOR SIGNALING, AND AIRWAYS PROTECTION. IN THE CONDUCTING AIRWAYS OF THE LUNGS, MUCINS ARE THE MAJOR CONTRIBUTOR TO THE VISCOELASTIC PROPERTY OF MUCOUS SECRETION, WHICH IS THE MAJOR BARRIER TO TRAPPING INHALED MICROBIAL ORGANISM, PARTICULATES, AND OXIDATIVE POLLUTANTS. THE HOMEOSTASIS OF MUCIN PRODUCTION IS AN IMPORTANT FEATURE IN CONDUCTING AIRWAYS FOR THE MAINTENANCE OF MUCOCILIARY FUNCTION. ABERRANT MUCIN SECRETION AND ACCUMULATION IN AIRWAY LUMEN ARE CLINICAL HALLMARKS ASSOCIATED WITH VARIOUS LUNG DISEASES, SUCH AS ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, CYSTIC FIBROSIS, EMPHYSEMA, AND LUNG CANCER. AMONG 20 KNOWN MUCIN GENES IDENTIFIED, 11 OF THEM HAVE BEEN VERIFIED AT EITHER THE MRNA AND/OR PROTEIN LEVEL IN AIRWAYS. THE REGULATION OF MUCIN GENES IS COMPLICATED, AS ARE THE MEDIATORS AND SIGNALING PATHWAYS. THIS REVIEW SUMMARIZES THE CURRENT VIEW ON THE MEDIATORS, THE SIGNALING PATHWAYS, AND THE TRANSCRIPTIONAL UNITS THAT ARE INVOLVED IN THE REGULATION OF AIRWAY MUCIN GENE EXPRESSION. IN ADDITION, WE ALSO POINT OUT ESSENTIAL FEATURES OF EPIGENETIC MECHANISMS FOR THE REGULATION OF THESE GENES. 2008 2 927 38 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 3 1245 31 CURRENT CONCEPTS ON THE ROLE OF INFLAMMATION IN COPD AND LUNG CANCER. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER ARE LEADING CAUSE OF DEATH, AND BOTH ARE ASSOCIATED WITH CIGARETTE SMOKE EXPOSURE. IT HAS BEEN SHOWN THAT 50-70% OF PATIENTS DIAGNOSED WITH LUNG CANCER SUFFER FROM COPD, AND REDUCED LUNG FUNCTION IS AN IMPORTANT EVENT IN LUNG CANCER SUGGESTING AN ASSOCIATION BETWEEN COPD AND LUNG CANCER. HOWEVER, A CAUSAL RELATIONSHIP BETWEEN COPD AND LUNG TUMORIGENESIS IS NOT YET FULLY UNDERSTOOD. RECENT STUDIES HAVE SUGGESTED A CENTRAL ROLE OF CHRONIC INFLAMMATION IN THE PATHOGENESIS OF BOTH THE DISEASES. FOR EXAMPLE, IMMUNE DYSFUNCTION, ABNORMAL ACTIVATION OF NF-KAPPAB, EPITHELIAL-TO-MESENCHYMAL TRANSITION, ALTERED ADHESION SIGNALING PATHWAYS, AND EXTRACELLULAR MATRIX DEGRADATION/ALTERED SIGNALING ARE THE KEY UNDERLYING MECHANISMS IN BOTH COPD AND LUNG CANCER. THESE PARAMETERS ALONG WITH OTHER PROCESSES, SUCH AS CHROMATIN MODIFICATIONS/EPIGENETIC CHANGES, ANGIOGENESIS, AND AUTOPHAGY/APOPTOSIS ARE ALTERED BY CIGARETTE SMOKE, ARE CRUCIAL IN THE DEVELOPMENT OF COPD AND LUNG CANCER. UNDERSTANDING THE CELLULAR AND MOLECULAR MECHANISMS UNDERLYING THESE PROCESSES WILL PROVIDE NOVEL AVENUES FOR HALTING THE CHRONIC INFLAMMATION IN COPD AND DEVISING THERAPEUTIC STRATEGIES AGAINST LUNG CANCER. 2009 4 6005 38 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 5 2299 43 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 6 3966 38 LONG NONCODING TRANSCRIPTOME IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC AIRWAY INFLAMMATION FROM RECURRING EXPOSURES TO NOXIOUS ENVIRONMENTAL STIMULI RESULTS IN A PROGRESSIVE AND IRREVERSIBLE AIRFLOW LIMITATION AND THE LUNG PARENCHYMAL DAMAGE THAT CHARACTERIZES CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THE LARGE VARIABILITY OBSERVED IN THE ONSET AND PROGRESSION OF COPD IS PRIMARILY DRIVEN BY COMPLEX GENE-ENVIRONMENT INTERACTIONS. THE TRANSCRIPTOMIC AND EPIGENETIC MEMORY POTENTIAL OF LUNG EPITHELIAL AND INNATE IMMUNE CELLS DRIVE RESPONSES, SUCH AS MUCUS HYPERREACTIVITY AND AIRWAY REMODELING, THAT ARE TIGHTLY REGULATED BY VARIOUS MOLECULAR MECHANISMS, FOR WHICH SEVERAL CANDIDATE SUSCEPTIBILITY GENES HAVE BEEN DESCRIBED. HOWEVER, THE RECENTLY DESCRIBED NONCODING RNA SPECIES, IN PARTICULAR THE LONG NONCODING RNAS, MAY ALSO HAVE AN IMPORTANT ROLE IN MODULATING PULMONARY RESPONSES TO CHRONIC INHALATION OF TOXIC SUBSTANCES AND THE DEVELOPMENT OF COPD. THIS REVIEW OUTLINES THE FEATURES OF LONG NONCODING RNAS THAT HAVE BEEN IMPLICATED IN REGULATING THE AIRWAY INFLAMMATORY RESPONSES TO CIGARETTE SMOKE EXPOSURE AND THEIR POSSIBLE ASSOCIATION WITH COPD PATHOGENESIS. AS COPD CONTINUES TO DEBILITATE THE INCREASINGLY AGING POPULATION AND CONTRIBUTE TO HIGHER MORBIDITY AND MORTALITY RATES WORLDWIDE, THE SEARCH FOR BETTER BIOMARKERS AND ALTERNATIVE THERAPEUTIC OPTIONS IS PIVOTAL. 2019 7 1244 37 CURRENT CONCEPTS ON OXIDATIVE/CARBONYL STRESS, INFLAMMATION AND EPIGENETICS IN PATHOGENESIS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A GLOBAL HEALTH PROBLEM. THE CURRENT THERAPIES FOR COPD ARE POORLY EFFECTIVE AND THE MAINSTAYS OF PHARMACOTHERAPY ARE BRONCHODILATORS. A BETTER UNDERSTANDING OF THE PATHOBIOLOGY OF COPD IS CRITICAL FOR THE DEVELOPMENT OF NOVEL THERAPIES. IN THE PRESENT REVIEW, WE HAVE DISCUSSED THE ROLES OF OXIDATIVE/ALDEHYDE STRESS, INFLAMMATION/IMMUNITY, AND CHROMATIN REMODELING IN THE PATHOGENESIS OF COPD. AN IMBALANCE OF OXIDANTS/ANTIOXIDANTS CAUSED BY CIGARETTE SMOKE AND OTHER POLLUTANTS/BIOMASS FUELS PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF COPD BY REGULATING REDOX-SENSITIVE TRANSCRIPTION FACTORS (E.G., NF-KAPPAB), AUTOPHAGY AND UNFOLDED PROTEIN RESPONSE LEADING TO CHRONIC LUNG INFLAMMATORY RESPONSE. CIGARETTE SMOKE ALSO ACTIVATES CANONICAL/ALTERNATIVE NF-KAPPAB PATHWAYS AND THEIR UPSTREAM KINASES LEADING TO SUSTAINED INFLAMMATORY RESPONSE IN LUNGS. RECENTLY, EPIGENETIC REGULATION HAS BEEN SHOWN TO BE CRITICAL FOR THE DEVELOPMENT OF COPD BECAUSE THE EXPRESSION/ACTIVITY OF ENZYMES THAT REGULATE THESE EPIGENETIC MODIFICATIONS HAVE BEEN REPORTED TO BE ABNORMAL IN AIRWAYS OF COPD PATIENTS. HENCE, THE SIGNIFICANT ADVANCES MADE IN UNDERSTANDING THE PATHOPHYSIOLOGY OF COPD AS DESCRIBED HEREIN WILL IDENTIFY NOVEL THERAPEUTIC TARGETS FOR INTERVENTION IN COPD. 2011 8 4445 31 MOLECULAR LINKS BETWEEN COPD AND LUNG CANCER: NEW TARGETS FOR DRUG DISCOVERY? COPD AND LUNG CANCER ARE LEADING CAUSES OF MORBIDITY AND MORTALITY WORLDWIDE, AND THEY SHARE A COMMON ENVIRONMENTAL RISK FACTOR IN CIGARETTE SMOKE EXPOSURE AND A GENETIC PREDISPOSITION REPRESENTED BY THEIR INCIDENCE IN ONLY A FRACTION OF SMOKERS. THIS REFLECTS THE ABILITY OF CIGARETTE SMOKE TO INDUCE AN INFLAMMATORY RESPONSE IN THE AIRWAYS OF SUSCEPTIBLE SMOKERS. MOREOVER, COPD COULD BE A DRIVING FACTOR IN LUNG CANCER, BY INCREASING OXIDATIVE STRESS AND THE RESULTING DNA DAMAGE AND REPRESSION OF THE DNA REPAIR MECHANISMS, CHRONIC EXPOSURE TO PRO-INFLAMMATORY CYTOKINES, REPRESSION OF INNATE IMMUNITY AND INCREASED CELLULAR PROLIFERATION. AREAS COVERED: WE HAVE FOCUSED OUR REVIEW ON THE POTENTIAL PATHOGENIC MOLECULAR LINKS BETWEEN TOBACCO SMOKING-RELATED COPD AND LUNG CANCER AND THE POTENTIAL MOLECULAR TARGETS FOR NEW DRUG DEVELOPMENT BY UNDERSTANDING THE COMMON SIGNALING PATHWAYS INVOLVED IN COPD AND LUNG CANCER. EXPERT COMMENTARY: RESEARCH IN THIS FIELD IS MOSTLY LIMITED TO ANIMAL MODELS OR SMALL CLINICAL TRIALS. LARGE CLINICAL TRIALS ARE NEEDED BUT MOSTLY COMBINED MODELS OF COPD AND LUNG CANCER ARE NECESSARY TO INVESTIGATE THE PROCESSES CAUSED BY CHRONIC INFLAMMATION, INCLUDING GENETIC AND EPIGENETIC ALTERATION, AND THE EXPRESSION OF INFLAMMATORY MEDIATORS THAT LINK COPD AND LUNG CANCER, TO IDENTIFY NEW MOLECULAR THERAPEUTIC TARGETS. 2019 9 4026 27 LUNG CANCER AND ITS ASSOCIATION WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE: UPDATE ON NEXUS OF EPIGENETICS. PURPOSE OF REVIEW: CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER ARE THE LEADING CAUSES OF MORBIDITY AND MORTALITY WORLDWIDE. THE CURRENT RESEARCH IS FOCUSED ON IDENTIFYING THE COMMON AND DISPARATE EVENTS INVOLVED IN EPIGENETIC MODIFICATIONS THAT CONCURRENTLY OCCUR DURING THE PATHOGENESIS OF COPD AND LUNG CANCER. THE PURPOSE OF THIS REVIEW IS TO DESCRIBE THE CURRENT KNOWLEDGE AND UNDERSTANDING OF EPIGENETIC MODIFICATIONS IN PATHOGENESIS OF COPD AND LUNG CANCER. RECENT FINDINGS: THIS REVIEW PROVIDES AN UPDATE ON ADVANCES OF HOW EPIGENETIC MODIFICATIONS ARE LINKED TO COPD AND LUNG CANCER, AND THEIR COMMONALITIES AND DISPARITIES. THE KEY EPIGENETIC MODIFICATION ENZYMES (E.G. DNA METHYLTRANSFERASES -- CPG METHYLATION, HISTONE ACETYLASES/DEACETYLASES AND HISTONE METHYLTRANSFERASES/DEMETHYLASES) THAT ARE IDENTIFIED TO PLAY AN IMPORTANT ROLE IN COPD AND LUNG TUMORIGENESIS AND PROGRESSION ARE DESCRIBED IN THIS REVIEW. SUMMARY: DISTINCT DNA METHYLTRANSFERASES AND HISTONE MODIFICATION ENZYMES ARE DIFFERENTIALLY INVOLVED IN PATHOGENESIS OF LUNG CANCER AND COPD, ALTHOUGH SOME OF THE MODIFICATIONS ARE COMMON. UNDERSTANDING THE EPIGENETIC MODIFICATIONS INVOLVED IN PATHOGENESIS OF LUNG CANCER OR COPD WITH RESPECT TO COMMON AND DISPARATE MECHANISMS WILL LEAD TO TARGETING OF EPIGENETIC THERAPIES AGAINST THESE DISORDERS. 2011 10 4658 30 NEW ANTI-INFLAMMATORY TARGETS FOR CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS ASSOCIATED WITH CHRONIC INFLAMMATION OF THE PERIPHERAL AIRWAYS AND LUNG PARENCHYMA, WHICH LEADS TO PROGRESSIVE OBSTRUCTION OF THE AIRWAYS. CURRENT MANAGEMENT WITH LONG-ACTING BRONCHODILATORS DOES NOT REDUCE DISEASE PROGRESSION, AND THERE ARE NO TREATMENTS THAT EFFECTIVELY SUPPRESS CHRONIC INFLAMMATION IN COPD. AN INCREASED UNDERSTANDING OF THE INFLAMMATORY PROCESSES THAT ARE INVOLVED IN THE PATHOPHYSIOLOGY OF COPD HAS IDENTIFIED SEVERAL NEW THERAPEUTIC TARGETS. THIS REVIEW DISCUSSES SOME OF THE MOST PROMISING OF THESE TARGETS, INCLUDING NEW ANTIOXIDANTS, KINASE INHIBITORS AND DRUGS THAT TARGET CELLULAR SENESCENCE, MICROBIAL COLONIZATION, EPIGENETIC REGULATION OF INFLAMMATORY GENE EXPRESSION AND CORTICOSTEROID RESISTANCE. 2013 11 3543 26 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 12 4116 37 MECHANISMS OF AIRWAY EPITHELIAL INJURY AND ABNORMAL REPAIR IN ASTHMA AND COPD. THE AIRWAY EPITHELIUM COMPRISES OF DIFFERENT CELL TYPES AND ACTS AS A PHYSICAL BARRIER PREVENTING PATHOGENS, INCLUDING INHALED PARTICLES AND MICROBES, FROM ENTERING THE LUNGS. GOBLET CELLS AND SUBMUCOSAL GLANDS PRODUCE MUCUS THAT TRAPS PATHOGENS, WHICH ARE EXPELLED FROM THE RESPIRATORY TRACT BY CILIATED CELLS. BASAL CELLS ACT AS PROGENITOR CELLS, DIFFERENTIATING INTO DIFFERENT EPITHELIAL CELL TYPES, TO MAINTAIN HOMEOSTASIS FOLLOWING INJURY. ADHERENS AND TIGHT JUNCTIONS BETWEEN CELLS MAINTAIN THE EPITHELIAL BARRIER FUNCTION AND REGULATE THE MOVEMENT OF MOLECULES ACROSS IT. IN THIS REVIEW WE DISCUSS HOW ABNORMAL EPITHELIAL STRUCTURE AND FUNCTION, CAUSED BY CHRONIC INJURY AND ABNORMAL REPAIR, DRIVES AIRWAY DISEASE AND SPECIFICALLY ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN BOTH DISEASES, INHALED ALLERGENS, POLLUTANTS AND MICROBES DISRUPT JUNCTIONAL COMPLEXES AND PROMOTE CELL DEATH, IMPAIRING THE BARRIER FUNCTION AND LEADING TO INCREASED PENETRATION OF PATHOGENS AND A CONSTANT AIRWAY IMMUNE RESPONSE. IN ASTHMA, THE INFLAMMATORY RESPONSE PRECIPITATES THE EPITHELIAL INJURY AND DRIVES ABNORMAL BASAL CELL DIFFERENTIATION. THIS LEADS TO REDUCED CILIATED CELLS, GOBLET CELL HYPERPLASIA AND INCREASED EPITHELIAL MESENCHYMAL TRANSITION, WHICH CONTRIBUTE TO IMPAIRED MUCOCILIARY CLEARANCE AND AIRWAY REMODELLING. IN COPD, CHRONIC OXIDATIVE STRESS AND INFLAMMATION TRIGGER PREMATURE EPITHELIAL CELL SENESCENCE, WHICH CONTRIBUTES TO LOSS OF EPITHELIAL INTEGRITY AND AIRWAY INFLAMMATION AND REMODELLING. INCREASED NUMBERS OF BASAL CELLS SHOWING DEREGULATED DIFFERENTIATION, CONTRIBUTES TO CILIARY DYSFUNCTION AND MUCOUS HYPERPRODUCTION IN COPD AIRWAYS. DEFECTIVE ANTIOXIDANT, ANTIVIRAL AND DAMAGE REPAIR MECHANISMS, POSSIBLY DUE TO GENETIC OR EPIGENETIC FACTORS, MAY CONFER SUSCEPTIBILITY TO AIRWAY EPITHELIAL DYSFUNCTION IN THESE DISEASES. THE CURRENT EVIDENCE SUGGESTS THAT A CONSTANT CYCLE OF INJURY AND ABNORMAL REPAIR OF THE EPITHELIUM DRIVES CHRONIC AIRWAY INFLAMMATION AND REMODELLING IN ASTHMA AND COPD. MECHANISTIC UNDERSTANDING OF INJURY SUSCEPTIBILITY AND DAMAGE RESPONSE MAY LEAD TO IMPROVED THERAPIES FOR THESE DISEASES. 2023 13 629 28 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 14 5456 25 RESEARCH ADVANCES ON DNA METHYLATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC COMPLEX LUNG DISEASE WITH NO SPECIFIC TREATMENT AND POOR PROGNOSIS, CHARACTERIZED BY THE PULMONARY PROGRESSIVE FIBROSIS AND DYSFUNCTIONS THAT LEAD TO RESPIRATORY FAILURE. SEVERAL FACTORS MAY IMPACT THE PROGRESS OF IPF, INCLUDING AGE, CIGARETTE SMOKING, AND DUSTS, OF WHICH GENETIC AND EPIGENETIC FACTORS MAINLY CONTRIBUTE TO LUNG TISSUE FIBROSIS. DNA METHYLATION IS ONE OF EPIGENETIC PROCESSES THAT OCCUR IN MANY DISEASES AND REGULATE CHROMOSOMAL AND EXTRACHROMOSOMAL DNA FUNCTIONS IN RESPONSE TO ENVIRONMENTAL EXPOSURES. THE METHYLATION PLAYS PIVOTAL ROLES IN REGULATION OF GENE EXPRESSION TO FACILITATE THE FORMATION OF FIBROBLASTIC FOCI AND LUNG FIBROSIS. THIS CHAPTER WILL DESCRIBE ALTERATIONS AND EFFECTS OF THE DNA METHYLATION ON GENE EXPRESSION, THE POTENTIAL APPLICATION OF DNA METHYLATION AS A BIOMARKER, AND SIGNIFICANCE AS THERAPEUTIC TARGETS. THOSE UNDERSTANDING WILL PROVIDE US NEW INSIGHT INTO THE TREATMENT AND PROGNOSIS OF IPF. 2020 15 6839 29 [LUNG CANCER AND ITS EPIGENETICS ASSOCIATION WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE]. LUNG CANCER AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) ARE THE LEADING CAUSES OF MORBIDITY AND MORTALITY WORLDWIDE. DEVELOPMENT OF LUNG CANCER INVOLVES BOTH GENETIC AND ENVIRONMENT FACTORS. IN ADDITION TO GENETIC ALTERATIONS, EPIGENETIC MECHANISM IS CLOSELY INVOLVED IN PATHOGENESIS OF LUNG CANCER. CHARACTERIZED BY AN ABNORMAL PERSISTENT INFLAMMATORY RESPONSE TO NOXIOUS ENVIRONMENTAL STIMULATION, COPD HAS SHOWN TO INCREASE THE SUSCEPTIBILITY FOR LUNG TUMORIGENESIS IN PREVIOUS RESEARCH. CURRENT RESEARCH ON EPIGENETICS OF LUNG CANCER AND COPD HAS FOCUSED ON ABERRANT DNA METHYLATION, HISTONE ACETYLATION AND NON-CODING RNAS REGULATION. THE ABERRANT DNA METHYLATION ASSOCIATED WITH LUNG CANCER AND COPD HAS INCLUDED OVEREXPRESSION OF DNA METHYLTRANSFERASE, GLOBAL DNA HYPOMETHYLATION AND DNA HYPERMETHYLATION IN PROMOTER REGIONS, WHILE HISTONE ACETYLATION AND HISTONE METHYLATION ARE THE MAJOR CHANGES FOR HISTONE MODIFICATION, IN WHICH HISTONE ACETYLTRANSFERASES, HISTONE DEACETYLASES, HISTONE METHYLTRANSFERASES AND HISTONE DEMETHYLASES PLAY THE MOST IMPORTANT ROLES. RNA INTERFERENCE AND MICRORNAS ARE BOTH HOT TOPICS OF RESEARCH ON NON-CODING RNAS REGULATION. UNDERSTANDING OF CONCURRENT EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF LUNG CANCER AND COPD MAY FACILITATE IDENTIFICATION OF SPECIFIC THERAPEUTIC TARGETS AND DEVELOPMENT OF EFFECTIVE TREATMENT. 2013 16 2357 37 EPIGENETIC REGULATION OF PULMONARY INFLAMMATION. PULMONARY DISEASE SUCH AS CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), ASTHMA, PULMONARY FIBROSIS AND PULMONARY HYPERTENSION ARE THE LEADING CAUSE OF DEATHS. MORE IMPORTANTLY, LUNG DISEASES ARE ON THE RISE AND ENVIRONMENTAL FACTORS INDUCED EPIGENETIC MODIFICATIONS ARE MAJOR PLAYERS ON THIS INCREASED PREVALENCE. IT HAS BEEN REPORTED THAT DYSREGULATION OF GENES INVOLVED IN EPIGENETIC REGULATION SUCH AS THE HISTONE DEACETYLASE (HDACS) AND HISTONE ACETYLTRANSFERASE (HATS) PLAY IMPORTANT ROLE IN LUNG HEALTH AND PULMONARY DISEASE PATHOGENESIS. INFLAMMATION IS AN ESSENTIAL COMPONENT OF RESPIRATORY DISEASES. INJURY AND INFLAMMATION TRIGGER RELEASE OF EXTRACELLULAR VESICLES THAT CAN ACT AS EPIGENETIC MODIFIERS THROUGH TRANSFER OF EPIGENETIC REGULATORS SUCH AS MICRORNAS (MIRNAS), LONG NON-CODING RNAS (LNCRNAS), PROTEINS AND LIPIDS, FROM ONE CELL TO ANOTHER. THE IMMUNE DYSREGULATIONS CAUSED BY THE CARGO CONTENTS ARE IMPORTANT CONTRIBUTORS OF RESPIRATORY DISEASE PATHOGENESIS. N6 METHYLATION OF RNA IS ALSO EMERGING TO BE A CRITICAL MECHANISM OF EPIGENETIC ALTERATION AND UPREGULATION OF IMMUNE RESPONSES TO ENVIRONMENTAL STRESSORS. EPIGENETIC CHANGES SUCH AS DNA METHYLATION ARE STABLE AND OFTEN LONG TERM AND CAUSE ONSET OF CHRONIC LUNG CONDITIONS. THESE EPIGENETIC PATHWAYS ARE ALSO BEING UTILIZED FOR THERAPEUTIC INTERVENTION IN SEVERAL LUNG CONDITIONS. 2023 17 2212 31 EPIGENETIC MODIFICATIONS AND THERAPY IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD): AN UPDATE REVIEW. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) THAT IS ONE OF THE MOST PREVALENT CHRONIC ADULT DISEASES AND THE THIRD LEADING CAUSE OF FATALITY UNTIL 2020. ELASTASE/ANTI-ELASTASE HYPOTHESIS, CHRONIC INFLAMMATION, APOPTOSIS, OXIDANT-ANTIOXIDANT BALANCE AND INFECTIVE REPAIR CAUSE PATHOGENESIS OF COPD ARE AMONG THE FACTORS AT PLAY. EPIGENETIC CHANGES ARE POST-TRANSLATIONAL MODIFICATIONS IN HISTONE PROTEINS AND DNA SUCH AS METHYLATION AND ACETYLATION AS WELL AS DYSREGULATION OF MIRNAS EXPRESSION. IN THIS UPDATE REVIEW, WE HAVE EXAMINED RECENT STUDIES ON THE UPREGULATION OR DOWNREGULATION OF METHYLATION IN DIFFERENT GENES ASSOCIATED WITH COPD. DYSREGULATION OF HDAC ACTIVITY WHICH IS CAUSED BY SOME FACTORS AND MIRNAS PLAYS A KEY ROLE IN THE SUPPRESSION AND REDUCTION OF COPD DEVELOPMENT. ALSO, SOME THERAPEUTIC APPROACHES ARE PROPOSED AGAINST COPD BY TARGETING HDAC2 AND MIRNAS, WHICH HAVE THERAPEUTIC EFFECTS. 2020 18 970 26 CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER: COMMON PATHWAYS FOR PATHOGENESIS. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER COMPRISE THE LEADING CAUSES OF LUNG DISEASE-RELATED MORTALITY WORLDWIDE. EXPOSURE TO TOBACCO SMOKE IS A MUTUAL AETIOLOGY UNDERLYING THE TWO DISEASES, ACCOUNTING FOR ALMOST 90% OF CASES. THERE IS ACCUMULATING EVIDENCE SUPPORTING THE ROLE OF IMMUNE DYSFUNCTION, THE LUNG MICROBIOME, EXTRACELLULAR VESICLES AND UNDERLYING GENETIC SUSCEPTIBILITY IN THE DEVELOPMENT OF COPD AND LUNG CANCER. FURTHER, EPIGENETIC FACTORS, INVOLVING DNA METHYLATION AND MICRORNA EXPRESSION, HAVE BEEN IMPLICATED IN BOTH DISEASES. CHRONIC INFLAMMATION IS A KEY FEATURE OF COPD AND COULD BE A POTENTIAL DRIVER OF LUNG CANCER DEVELOPMENT. USING NEXT GENERATION TECHNOLOGIES, FURTHER STUDIES INVESTIGATING THE GENOMICS, EPIGENETICS AND GENE-ENVIRONMENT INTERACTION IN KEY MOLECULAR PATHWAYS WILL CONTINUE TO ELUCIDATE THE PATHOGENIC MECHANISMS UNDERLYING THE DEVELOPMENT OF COPD AND LUNG CANCER, AND CONTRIBUTE TO THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND PROGNOSTIC TOOLS FOR EARLY INTERVENTION AND PERSONALISED THERAPEUTIC STRATEGIES. 2019 19 2169 28 EPIGENETIC MECHANISMS IN PARENCHYMAL LUNG DISEASES: BYSTANDERS OR THERAPEUTIC TARGETS? EPIGENETIC RESPONSES DUE TO ENVIRONMENTAL CHANGES ALTER CHROMATIN STRUCTURE, WHICH IN TURN MODIFIES THE PHENOTYPE, GENE EXPRESSION PROFILE, AND ACTIVITY OF EACH CELL TYPE THAT HAS A ROLE IN THE PATHOPHYSIOLOGY OF A DISEASE. PULMONARY DISEASES ARE ONE OF THE MAJOR CAUSES OF DEATH IN THE WORLD, INCLUDING LUNG CANCER, IDIOPATHIC PULMONARY FIBROSIS (IPF), CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), PULMONARY HYPERTENSION (PH), LUNG TUBERCULOSIS, PULMONARY EMBOLISM, AND ASTHMA. SEVERAL LINES OF EVIDENCE INDICATE THAT EPIGENETIC MODIFICATIONS MAY BE ONE OF THE MAIN FACTORS TO EXPLAIN THE INCREASING INCIDENCE AND PREVALENCE OF LUNG DISEASES INCLUDING IPF AND COPD. INTERESTINGLY, ISOLATED FIBROBLASTS AND SMOOTH MUSCLE CELLS FROM PATIENTS WITH PULMONARY DISEASES SUCH AS IPF AND PH THAT WERE CULTURED EX VIVO MAINTAINED THE DISEASE PHENOTYPE. THE CELLS OFTEN SHOW A HYPER-PROLIFERATIVE, APOPTOSIS-RESISTANT PHENOTYPE WITH INCREASED EXPRESSION OF EXTRACELLULAR MATRIX (ECM) AND ACTIVATED FOCAL ADHESIONS SUGGESTING THE PRESENCE OF AN EPIGENETICALLY IMPRINTED PHENOTYPE. MOREOVER, MANY ABNORMALITIES OBSERVED IN MOLECULAR PROCESSES IN IPF PATIENTS ARE SHOWN TO BE EPIGENETICALLY REGULATED, SUCH AS INNATE IMMUNITY, CELLULAR SENESCENCE, AND APOPTOTIC CELL DEATH. DNA METHYLATION, HISTONE MODIFICATION, AND MICRORNA REGULATION CONSTITUTE THE MOST COMMON EPIGENETIC MODIFICATION MECHANISMS. 2022 20 4738 40 NOVEL FIBROBLAST PHENOTYPES IN HOMEOSTASIS AND CHRONIC INFLAMMATION: FROM FUNCTIONS TO POTENTIAL REGULATORS. FIBROBLASTS ARE ESSENTIAL COMPONENTS OF THE STROMA, SUSTAINING A VARIETY OF TISSUES AND BEING KEY TO THE PROCESS OF TISSUE REPAIR AFTER INJURY. THEIR ROLE IN TISSUE REPAIR HAS BEEN ATTRIBUTED TO THEIR ABILITY TO ACQUIRE A CONTRACTILE, EXTRACELLULAR MATRIX-PRODUCING PHENOTYPE KNOWN AS MYOFIBROBLASTS. THIS PROPERTY IS PRIMARILY DEPENDENT ON THEIR RESPONSE TO THE PLEIOTROPIC CYTOKINE TRANSFORMING GROWTH FACTOR-BETA1. UNTIL RECENTLY, THE POTENTIAL ROLE OF FIBROBLASTS IN OTHER HOMEOSTATIC AND DISEASE-RELATED PROCESSES WAS LESS WELL UNDERSTOOD. ALTHOUGH IN VITRO STUDIES INDICATED THAT FIBROBLASTS ARE ABLE TO RESPOND TO AND SECRETE INFLAMMATORY MEDIATORS, DEFINITIVE EVIDENCE OF THEIR CONTRIBUTION TO CHRONIC INFLAMMATION WAS LIMITED. HOWEVER, THE EMERGENCE OF TECHNIQUES THAT ALLOW EXPLORATION OF TISSUES AT THE SINGLE CELL LEVEL HAS CHALLENGED THE PREVIOUS PARADIGMS ON FIBROBLAST IDENTITY AND FUNCTIONS, AND HAS LED TO THE DISCOVERY OF SIGNIFICANT DIVERSITY, SHOWING THE PRESENCE OF FIBROBLASTS WITH ALTERNATE TRANSCRIPTIONAL PROFILES IN A VARIETY OF TISSUES. THESE STUDIES HAVE ALSO SUGGESTED POTENTIAL ROLES OF NOVEL FIBROBLAST SUBTYPES AS REGULATORS OF EPITHELIAL HOMEOSTASIS AND RENEWAL, INFLAMMATORY CELL INFILTRATION AND ACTIVATION, AND ANTIGEN PRESENTATION. HERE, WE PROVIDE A COMPREHENSIVE REVIEW OF THE RECENT LITERATURE ON FIBROBLAST DIVERSITY IN THE DIGESTIVE TRACT, SKIN, LUNGS AND JOINTS. WE ALSO REVIEW EVIDENCE OF THEIR CONTRIBUTION TO THE REGULATION OF HOMEOSTASIS AND CHRONIC INFLAMMATION, AS WELL AS THEIR INTERACTIONS WITH OTHER CELLS IN VARIOUS TISSUE COMPARTMENTS. WE DISCUSS EVIDENCE OF DIFFERENT FACTORS INVOLVED IN THE CONTROL OF FIBROBLAST FUNCTION, ADDRESSING THE ROLE OF VARIOUS CYTOKINES, TRANSCRIPTION FACTORS AND EPIGENETIC CHANGES, AS WELL AS MICROENVIRONMENTAL FACTORS, INCLUDING EXTRACELLULAR MATRIX STIFFNESS, HYPOXIA, AND METABOLIC SHIFTS. 2023