1 4873 149 OVER-EXPRESSION OF PROTHYMOSIN-ALPHA ANTAGONIZES TGFBETA SIGNALLING TO PROMOTE THE DEVELOPMENT OF EMPHYSEMA. EMPHYSEMA, A MAJOR CONSEQUENCE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IS CHARACTERIZED BY THE PERMANENT AIRFLOW RESTRICTION RESULTING FROM ENLARGEMENT OF ALVEOLAR AIRSPACE AND LOSS OF LUNG ELASTICITY. TRANSFORMING GROWTH FACTOR-BETA (TGFBETA) SIGNALLING REGULATES THE BALANCE OF MATRIX METALLOPROTEINASE (MMP)/TISSUE INHIBITOR OF MATRIX METALLOPROTEINASE (TIMP) TO CONTROL MATRIX HOMEOSTASIS. PATIENTS WITH COPD HAVE DYSREGULATED TGFBETA SIGNALLING AND REDUCED HISTONE DEACETYLASE (HDAC) ACTIVITY THROUGH EPIGENETIC UP-REGULATION OF HISTONE ACETYLATION IN THE PROMOTERS OF PRO-INFLAMMATORY GENES. HOWEVER, THE POTENTIAL LINK BETWEEN DECREASED HDAC ACTIVITY AND DYSREGULATED TGFBETA SIGNALLING IN EMPHYSEMA PATHOGENESIS REMAINS TO BE DETERMINED. PROTHYMOSIN ALPHA (PROT), A HIGHLY CONSERVED ACIDIC NUCLEAR PROTEIN, PLAYS A ROLE IN THE ACETYLATION OF HISTONE AND NON-HISTONE PROTEINS. THE AIM OF THIS STUDY WAS TO TEST THE HYPOTHESIS THAT PROT INHIBITS TGFBETA-SMAD SIGNALLING THROUGH SMAD7, THEREBY CONTRIBUTING TO EMPHYSEMA PATHOGENESIS. WE SHOW THAT PROT ENHANCES SMAD7 ACETYLATION BY DECREASING ITS ASSOCIATION WITH HDAC AND THEREBY DOWN-REGULATES TGFBETA-SMAD SIGNALLING. PROT CAUSED AN IMBALANCE BETWEEN MMP AND TIMP THROUGH ACETYLATED SMAD7 IN FAVOUR OF MMP EXPRESSION. IN ADDITION TO INTERFERING WITH R-SMAD ACTIVATION AND TARGETING RECEPTORS FOR DEGRADATION IN THE CYTOPLASM, ACETYLATED SMAD7 POTENTIATED BY PROT COMPETITIVELY ANTAGONIZED BINDING OF THE PSMAD2/3-SMAD4 COMPLEX TO THE TIMP-3 PROMOTER, RESULTING IN REDUCED TIMP-3 EXPRESSION. THESE EFFECTS WERE DETECTED IN PROT-OVER-EXPRESSING CELLS, LUNGS OF PROT TRANSGENIC MICE DISPLAYING AN EMPHYSEMA PHENOTYPE AND IN EMPHYSEMA PATIENTS. IMPORTANTLY, INCREASED SMAD7 AND REDUCED TIMP-3 WERE FOUND IN THE LUNGS OF EMPHYSEMA PATIENTS AND MICE WITH CIGARETTE SMOKE EXTRACT (CSE)-INDUCED EMPHYSEMA. SUCH EFFECTS COULD BE ABROGATED BY SILENCING ENDOGENOUS PROT EXPRESSION. COLLECTIVELY, OUR RESULTS UNCOVER ACETYLATED SMAD7 REGULATED BY PROT AS AN IMPORTANT DETERMINANT IN DYSREGULATED TGFBETA SIGNALLING THAT CONTRIBUTES TO EMPHYSEMA PATHOGENESIS. 2016 2 3301 18 HIGH-FAT OR ETHINYL-OESTRADIOL INTAKE DURING PREGNANCY INCREASES MAMMARY CANCER RISK IN SEVERAL GENERATIONS OF OFFSPRING. MATERNAL EXPOSURES TO ENVIRONMENTAL FACTORS DURING PREGNANCY INFLUENCE THE RISK OF MANY CHRONIC ADULT-ONSET DISEASES IN THE OFFSPRING. HERE WE INVESTIGATE WHETHER FEEDING PREGNANT RATS A HIGH-FAT (HF)- OR ETHINYL-OESTRADIOL (EE2)-SUPPLEMENTED DIET AFFECTS CARCINOGEN-INDUCED MAMMARY CANCER RISK IN DAUGHTERS, GRANDDAUGHTERS AND GREAT-GRANDDAUGHTERS. WE SHOW THAT MAMMARY TUMOURIGENESIS IS HIGHER IN DAUGHTERS AND GRANDDAUGHTERS OF HF RAT DAMS AND IN DAUGHTERS AND GREAT-GRANDDAUGHTERS OF EE2 RAT DAMS. OUTCROSS EXPERIMENTS SUGGEST THAT THE INCREASE IN MAMMARY CANCER RISK IS TRANSMITTED TO HF GRANDDAUGHTERS EQUALLY THROUGH THE FEMALE OR MALE GERM LINES, BUT IT IS ONLY TRANSMITTED TO EE2 GRANDDAUGHTERS THROUGH THE FEMALE GERM LINE. THE EFFECTS OF MATERNAL EE2 EXPOSURE ON OFFSPRING'S MAMMARY CANCER RISK ARE ASSOCIATED WITH CHANGES IN THE DNA METHYLATION MACHINERY AND METHYLATION PATTERNS IN MAMMARY TISSUE OF ALL THREE EE2 GENERATIONS. WE CONCLUDE THAT DIETARY AND OESTROGENIC EXPOSURES IN PREGNANCY INCREASE BREAST CANCER RISK IN MULTIPLE GENERATIONS OF OFFSPRING, POSSIBLY THROUGH EPIGENETIC MEANS. 2012 3 4023 47 LSD1-S112A EXACERBATES THE PATHOGENESIS OF CSE/LPS-INDUCED CHRONIC OBSTRUCTIVE PULMONARY DISEASE IN MICE. LYSINE-SPECIFIC DEMETHYLASE 1 (LSD1) IS AN EPIGENETIC REGULATOR THAT MODULATES THE CHROMATIN STATUS, CONTRIBUTING TO GENE ACTIVATION OR REPRESSION. THE POST-TRANSLATIONAL MODIFICATION OF LSD1 IS CRITICAL FOR THE REGULATION OF MANY OF ITS BIOLOGICAL PROCESSES. PHOSPHORYLATION OF SERINE 112 OF LSD1 BY PROTEIN KINASE C ALPHA (PKCALPHA) IS CRUCIAL FOR REGULATING INFLAMMATION, BUT ITS PHYSIOLOGICAL SIGNIFICANCE IS NOT FULLY UNDERSTOOD. THIS STUDY AIMED TO INVESTIGATE THE ROLE OF LSD1-S112A, A PHOSPHORYLATION DEFECTIVE MUTANT, IN THE CIGARETTE SMOKE EXTRACT/LPS-INDUCED CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) MODEL USING LSD1SA/SA MICE AND TO EXPLORE THE POTENTIAL MECHANISM UNDERPINNING THE DEVELOPMENT OF COPD. WE FOUND THAT LSD1SA/SA MICE EXHIBITED INCREASED SUSCEPTIBILITY TO CSE/LPS-INDUCED COPD, INCLUDING HIGH INFLAMMATORY CELL INFLUX INTO THE BRONCHOALVEOLAR LAVAGE FLUID AND AIRSPACE ENLARGEMENT. ADDITIONALLY, THE HIGH GENE EXPRESSION ASSOCIATED WITH THE INFLAMMATORY RESPONSE AND OXIDATIVE STRESS WAS OBSERVED IN CELLS AND MICE CONTAINING LSD1-S112A. SIMILAR RESULTS WERE OBTAINED FROM THE MOUSE EMBRYONIC FIBROBLASTS EXPOSED TO A PKCALPHA INHIBITOR, GO6976. THUS, THE LACK OF LSD1 PHOSPHORYLATION EXACERBATES CSE/LPS-INDUCED COPD BY ELEVATING INFLAMMATION AND OXIDATIVE STRESS. [BMB REPORTS 2021; 54(10): 522-527]. 2021 4 5227 45 PRMT6 MEDIATES INFLAMMATION VIA ACTIVATION OF THE NF-KAPPAB/P65 PATHWAY ON A CIGARETTE SMOKE EXTRACT-INDUCED MURINE EMPHYSEMA MODEL. INTRODUCTION: SMOKE-DRIVEN LUNG INFLAMMATION IS CONSIDERED TO BE THE MAJOR PATHOPHYSIOLOGY MECHANISM OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)/EMPHYSEMA. PROTEIN ARGININE METHYLTRANSFERASE 6 (PRMT6) IS A KEY EPIGENETIC ENZYME, WHICH IS RELATED TO PROTECTING THE TRI-METHYLATION OF H3K4 (H3K4ME3). WE HYPOTHESIZED THAT PTMT6 PROTECTS LUNG INFLAMMATION THROUGH THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY. METHODS: MICE WERE INJECTED WITH CIGARETTE SMOKE EXTRACT (CSE) OR PBS TO ESTABLISH A MICE MODEL, INTRATRACHEALLY INSTILLED WITH OVEREXPRESSED PRMT6 OR NEGATIVE CONTROL VECTOR. MORPHOMETRY OF LUNG SLIDES AND LUNG FUNCTION WERE MEASURED. WE DETERMINED THE PROTEIN EXPRESSION OF PRMT6 AND ITS RELATED HISTONE TARGETS, THE ACTIVATION OF NF-KAPPAB PATHWAY, THE LEVEL OF TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) AND INTERLEUKIN-1BETA (IL-1BETA). RESULTS: AFTER PRMT6 OVEREXPRESSION, THE MORPHOMETRY INDEXES AND LUNG FUNCTION WERE IMPROVED. ALSO, THE EXPRESSION OF H3K4ME3 WAS DECREASED. OVEREXPRESSED PRMT6 COULD SUPPRESS CSE-INDUCED NF-KAPPAB ACTIVATION AND PRO-INFLAMMATION GENES EXPRESSION. CONCLUSIONS: THE OVEREXPRESSED PRMT6 COULD SERVE AS AN INFLAMMATION INHIBITOR, POTENTIALLY THROUGH BLOCKING THE NF-KAPPAB/P65 PATHWAY IN THE MURINE EMPHYSEMA MODEL. 2020 5 6719 44 VITAMIN D AND SUSCEPTIBILITY OF CHRONIC LUNG DISEASES: ROLE OF EPIGENETICS. VITAMIN D DEFICIENCY IS LINKED TO ACCELERATED DECLINE IN LUNG FUNCTION, INCREASED INFLAMMATION, AND REDUCED IMMUNITY IN CHRONIC LUNG DISEASES. EPIDEMIOLOGICAL STUDIES HAVE SUGGESTED THAT VITAMIN D INSUFFICIENCY IS ASSOCIATED WITH LOW LUNG FUNCTION IN SUSCEPTIBLE SUBJECTS WHO ARE EXPOSED TO HIGHER LEVELS OF ENVIRONMENTAL AGENTS (AIRBORNE PARTICULATES). RECENT STUDIES HAVE HIGHLIGHTED THE ROLE OF VITAMIN D AND VITAMIN D RECEPTOR (VDR) IN REGULATION OF SEVERAL GENES THAT ARE INVOLVED IN INFLAMMATION, IMMUNITY, CELLULAR PROLIFERATION, DIFFERENTIATION, AND APOPTOSIS. VITAMIN D HAS ALSO BEEN IMPLICATED IN REVERSAL OF STEROID RESISTANCE AND AIRWAY REMODELING, WHICH ARE THE HALLMARKS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND SEVERE ASTHMA. VDR PROTEIN LEVEL IS DECREASED IN LUNGS OF PATIENTS WITH COPD. VDR DEFICIENT MICE DEVELOP AN ABNORMAL LUNG PHENOTYPE WITH CHARACTERISTICS OF COPD, SUCH AS AIRSPACE ENLARGEMENT AND DECLINE IN LUNG FUNCTION ASSOCIATED WITH INCREASED LUNG INFLAMMATORY CELLULAR INFLUX, AND IMMUNE-LYMPHOID AGGREGATES FORMATION. DIETARY VITAMIN D MAY REGULATE EPIGENETIC EVENTS, IN PARTICULAR ON GENES WHICH ARE RESPONSIBLE FOR COPD SUSCEPTIBILITY. ACTIVE METABOLITE OF VITAMIN D, 1,25-DIHYDROXYVITAMIN D(3) PLAYS AN ESSENTIAL ROLE IN CELLULAR METABOLISM AND DIFFERENTIATION VIA ITS NUCLEAR RECEPTOR (VDR) THAT COOPERATES WITH SEVERAL OTHER CHROMATIN MODIFICATION ENZYMES (HISTONE ACETYLTRANSFERASES AND HISTONE DEACETYLASES), THEREBY MEDIATING COMPLEX EPIGENETIC EVENTS IN VITAMIN D SIGNALING AND METABOLISM. THIS REVIEW PROVIDES AN UPDATE ON THE CURRENT KNOWLEDGE AND UNDERSTANDING ON VITAMIN D, AND SUSCEPTIBILITY OF CHRONIC LUNG DISEASES IN RELATION TO THE POSSIBLE ROLE OF EPIGENETICS IN ITS MOLECULAR ACTION. UNDERSTANDING THE MOLECULAR EPIGENETIC MECHANISM OF VITAMIN D/VDR WOULD PROVIDE RATIONALE FOR DIETARY VITAMIN D-MEDIATED INTERVENTION IN PREVENTION AND MANAGEMENT OF CHRONIC LUNG DISEASES LINKED WITH VITAMIN D DEFICIENCY. 2011 6 6015 39 THE ARGININE METHYLTRANSFERASE PRMT7 PROMOTES EXTRAVASATION OF MONOCYTES RESULTING IN TISSUE INJURY IN COPD. EXTRAVASATION OF MONOCYTES INTO TISSUE AND TO THE SITE OF INJURY IS A FUNDAMENTAL IMMUNOLOGICAL PROCESS, WHICH REQUIRES RAPID RESPONSES VIA POST TRANSLATIONAL MODIFICATIONS (PTM) OF PROTEINS. PROTEIN ARGININE METHYLTRANSFERASE 7 (PRMT7) IS AN EPIGENETIC FACTOR THAT HAS THE CAPACITY TO MONO-METHYLATE HISTONES ON ARGININE RESIDUES. HERE WE SHOW THAT IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS, PRMT7 EXPRESSION IS ELEVATED IN THE LUNG TISSUE AND LOCALIZED TO THE MACROPHAGES. IN MOUSE MODELS OF COPD, LUNG FIBROSIS AND SKIN INJURY, REDUCED EXPRESSION OF PRMT7 ASSOCIATES WITH DECREASED RECRUITMENT OF MONOCYTES TO THE SITE OF INJURY AND HENCE LESS SEVERE SYMPTOMS. MECHANISTICALLY, ACTIVATION OF NF-KAPPAB/RELA IN MONOCYTES INDUCES PRMT7 TRANSCRIPTION AND CONSEQUENTIAL MONO-METHYLATION OF HISTONES AT THE REGULATORY ELEMENTS OF RAP1A, WHICH LEADS TO INCREASED TRANSCRIPTION OF THIS GENE THAT IS RESPONSIBLE FOR ADHESION AND MIGRATION OF MONOCYTES. PERSISTENT MONOCYTE-DERIVED MACROPHAGE ACCUMULATION LEADS TO ALOX5 OVER-EXPRESSION AND ACCUMULATION OF ITS METABOLITE LTB4, WHICH TRIGGERS EXPRESSION OF ACSL4 A FERROPTOSIS PROMOTING GENE IN LUNG EPITHELIAL CELLS. CONCLUSIVELY, INHIBITION OF ARGININE MONO-METHYLATION MIGHT OFFER TARGETED INTERVENTION IN MONOCYTE-DRIVEN INFLAMMATORY CONDITIONS THAT LEAD TO EXTENSIVE TISSUE DAMAGE IF LEFT UNTREATED. 2022 7 4889 35 OXIDATIVE STRESS AND CHROMATIN REMODELING IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND SMOKING-RELATED DISEASES. SIGNIFICANCE: CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS PREDOMINANTLY A TOBACCO SMOKE-TRIGGERED DISEASE WITH FEATURES OF CHRONIC LOW-GRADE SYSTEMIC INFLAMMATION AND AGING (INFLAMMAGING) OF THE LUNG ASSOCIATED WITH STEROID RESISTANCE INDUCED BY CIGARETTE SMOKE (CS)-MEDIATED OXIDATIVE STRESS. OXIDATIVE STRESS INDUCES VARIOUS KINASE SIGNALING PATHWAYS LEADING TO CHROMATIN MODIFICATIONS (HISTONE ACETYLATION/DEACETYLATION AND HISTONE METHYLATION/DEMETHYLATION) IN INFLAMMATION, SENESCENCE, AND STEROID RESISTANCE. RECENT ADVANCES: HISTONE MONO-, DI-, OR TRI-METHYLATION AT LYSINE RESIDUES RESULT IN EITHER GENE ACTIVATION (H3K4, H3K36, AND H3K79) OR REPRESSION (H3K9, H3K27, AND H3K20). CROSS-TALK OCCURS BETWEEN VARIOUS EPIGENETIC MARKS ON HISTONES AND DNA METHYLATION. BOTH CS AND OXIDANTS ALTER HISTONE ACETYLATION/DEACETYLATION AND METHYLATION/DEMETHYLATION LEADING TO ENHANCED PROINFLAMMATORY GENE EXPRESSION. CHROMATIN MODIFICATIONS OCCUR IN LUNGS OF PATIENTS WITH COPD. HISTONE DEACETYLASE 2 (HDAC2) REDUCTION (LEVELS AND ACTIVITY) IS ASSOCIATED WITH STEROID RESISTANCE IN RESPONSE TO OXIDATIVE STRESS. CRITICAL ISSUES: HISTONE MODIFICATIONS ARE ASSOCIATED WITH DNA DAMAGE/REPAIR AND EPIGENOMIC INSTABILITY AS WELL AS PREMATURE LUNG AGING, WHICH HAVE IMPLICATIONS IN THE PATHOGENESIS OF COPD. HDAC2/SIRTUIN1 (SIRT1)-DEPENDENT CHROMATIN MODIFICATIONS ARE ASSOCIATED WITH DNA DAMAGE-INDUCED INFLAMMATION AND SENESCENCE IN RESPONSE TO CS-MEDIATED OXIDATIVE STRESS. FUTURE DIRECTIONS: UNDERSTANDING CS/OXIDATIVE STRESS-MEDIATED CHROMATIN MODIFICATIONS AND THE CROSS-TALK BETWEEN HISTONE ACETYLATION AND METHYLATION WILL DEMONSTRATE THE INVOLVEMENT OF EPIGENETIC REGULATION OF CHROMATIN REMODELING IN INFLAMMAGING. THIS WILL LEAD TO IDENTIFICATION OF NOVEL EPIGENETIC-BASED THERAPIES AGAINST COPD AND OTHER SMOKING-RELATED LUNG DISEASES. PHARMACOLOGICAL ACTIVATION OF HDAC2/SIRT1 OR REVERSAL OF THEIR OXIDATIVE POST-TRANSLATIONAL MODIFICATIONS MAY OFFER THERAPIES FOR TREATMENT OF COPD AND CS-RELATED DISEASES BASED ON EPIGENETIC HISTONE MODIFICATIONS. 2013 8 1251 35 CURRENT PERSPECTIVES ON ROLE OF CHROMATIN MODIFICATIONS AND DEACETYLASES IN LUNG INFLAMMATION IN COPD. CHROMATIN MODIFICATIONS AND EPIGENETIC REGULATION ARE CRITICAL FOR SUSTAINED AND ABNORMAL INFLAMMATORY RESPONSE SEEN IN LUNGS OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) BECAUSE THE ACTIVITIES OF ENZYMES THAT REGULATE THESE EPIGENETIC MODIFICATIONS ARE ALTERED IN RESPONSE TO CIGARETTE SMOKE. CIGARETTE SMOKE INDUCES CHROMATIN MODIFICATIONS AND EPIGENETIC CHANGES BY CAUSING POST-TRANSLATIONAL MODIFICATIONS OF HISTONE ACETYLTRANSFERASES, AND HISTONE/NON-HISTONE DEACETYLASES (HDACS), SUCH AS HDAC2 AND SIRTUIN 1 (SIRT1), WHICH LEADS TO CHROMATIN REMODELING. IN THIS REVIEW, WE DISCUSSED THE CURRENT KNOWLEDGE ON CIGARETTE SMOKE/OXIDANTS-INDUCED POST-TRANSLATIONAL MODIFICATIONS OF DEACETYLASES (HDAC2 AND SIRT1), DISRUPTION OF HDAC2/SIRT1-RELA/P65 COREPRESSOR COMPLEX ASSOCIATED WITH ACETYLATION OF RELA/P65, AND CHROMATIN MODIFICATIONS (HISTONE H3 PHOSPHO-ACETYLATION) LEADING TO SUSTAINED PRO-INFLAMMATORY GENE TRANSCRIPTION. KNOWLEDGE ON MOLECULAR MECHANISMS OF EPIGENETIC CHANGES IN ABNORMAL LUNG INFLAMMATION WILL HELP IN UNDERSTANDING THE PATHOPHYSIOLOGY OF COPD WHICH MAY LEAD TO THE DEVELOPMENT OF NOVEL EPIGENETIC THERAPIES IN THE NEAR FUTURE. 2009 9 1012 39 CIGARETTE SMOKE INDUCES DISTINCT HISTONE MODIFICATIONS IN LUNG CELLS: IMPLICATIONS FOR THE PATHOGENESIS OF COPD AND LUNG CANCER. CIGARETTE SMOKE (CS)-MEDIATED OXIDATIVE STRESS INDUCES SEVERAL SIGNALING CASCADES, INCLUDING KINASES, WHICH RESULTS IN CHROMATIN MODIFICATIONS (HISTONE ACETYLATION/DEACETYLATION AND HISTONE METHYLATION/DEMETHYLATION). WE HAVE PREVIOUSLY REPORTED THAT CS INDUCES CHROMATIN REMODELING IN PRO-INFLAMMATORY GENE PROMOTERS; HOWEVER, THE UNDERLYING SITE-SPECIFIC HISTONE MARKS FORMED IN HISTONES H3 AND H4 DURING CS EXPOSURE IN LUNGS IN VIVO AND IN LUNG CELLS IN VITRO, WHICH CAN EITHER DRIVE GENE EXPRESSION OR REPRESSION, ARE NOT KNOWN. WE HYPOTHESIZE THAT CS EXPOSURE IN MOUSE AND HUMAN BRONCHIAL EPITHELIAL CELLS (H292) CAN CAUSE SITE-SPECIFIC POSTTRANSLATIONAL HISTONE MODIFICATIONS (PTMS) THAT MAY PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF CS-INDUCED CHRONIC LUNG DISEASES. WE USED A BOTTOM-UP MASS SPECTROMETRY APPROACH TO IDENTIFY SOME POTENTIALLY NOVEL HISTONE MARKS, INCLUDING ACETYLATION, MONOMETHYLATION, AND DIMETHYLATION, IN SPECIFIC LYSINE AND ARGININE RESIDUES OF HISTONES H3 AND H4 IN MOUSE LUNGS AND H292 CELLS. WE FOUND THAT CS-INDUCED DISTINCT POSTTRANSLATIONAL HISTONE MODIFICATION PATTERNS IN HISTONE H3 AND HISTONE H4 IN LUNG CELLS, WHICH MAY BE CONSIDERED AS USABLE BIOMARKERS FOR CS-INDUCED CHRONIC LUNG DISEASES. THESE IDENTIFIED HISTONE MARKS (HISTONE H3 AND HISTONE H4) MAY PLAY AN IMPORTANT ROLE IN THE EPIGENETIC STATE DURING THE PATHOGENESIS OF SMOKING-INDUCED CHRONIC LUNG DISEASES, SUCH AS CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND LUNG CANCER. 2014 10 5585 41 ROLE OF OXIDATIVE STRESS AND GENETIC POLYMORPHISM OF MATRIX METALLOPROTEINASE-2 AND TISSUE INHIBITOR OF METALLOPROTEINASE-2 IN COPD. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), A COMPLAINT DESCRIBED BY PROGRESSIVE AND INADEQUATELY REVERSIBLE LIMITATION IN LUNGS WITH SYSTEMIC INFLAMMATION, IS LARGELY CURRENT IN INDIA. THERE'S NO REMEDY AVAILABLE SO FAR IT IS, THUS, IMPERATIVE TO UNDERSTAND THE UNDERPINNING PATHOGENESIS OF THE COMPLAINANT. A SET OF PROTEASES KNOWN AS MATRIX METALLOPROTEINASE (MMPS) ARE ESPECIALLY INVOLVED IN THE PROCESS OF ALVEOLAR DESTRUCTION AND MUCUS HYPERSECRETION. THERE ARE RESPONSIBLE FACTORS IN AN INHERITABLE POSITION TO CONTROL COPD LIKE MMPS AND TIMPS (TISSUE INHIBITOR OF METALLOPROTEINASES). MMPS DEGRADE EXTRACELLULAR MATRIX AND LEAD TO THE PATHOGENESIS OF COPD [1]. TIMPS PROTEINS THAT HELP TO INHIBIT THE MATRIX METALLOPROTEINASES. [2]. THIS REVIEW SUMMARIZES THE IMPLICIT PART OF CRUCIAL MMP-2 AND TIMP-2 IN COPD DISEASE. THOUGH THE CONCEPT SEEMS PROMISING, LIMITED KNOWLEDGE ABOUT THE EXACT FUNCTIONS OF A PARTICULAR MMP IN COPD AND THE COMPLICATIONS OF MMP IN SUBSTRATE AFFINITY MAKES THIS A GRUELING TASK. MMP2 AND TIMP2 BOTH ARE DIRECTLY OR INDIRECTLY REGULATED BY OXIDATIVE STRESS AND EPIGENETIC MECHANISM WHICH REGULATES THEIR EXPRESSIONS. COPD IS A SEDITIOUS RESPONSE TO FACTORS LIKE DUST, SMOKE, ETC., AND TRIGGERS EXTRA-PULMONARY GOODS WHICH CAUSE INFLAMMATION. [3]. THIS REVIEW EXPLAINS THE RELATIONSHIP BETWEEN MMP2 AND TIMP2 IN COPD PATIENTS WITH OXIDATIVE STRESS, ITS IMPACT ON COPD PATHOGENESIS, AND GENE EXPRESSION OF TIMP2 AND MMP2 WITH THEIR DOWNSTREAM EFFECTS. THIS ALSO GIVES SOME INSIGHTS INTO THERAPEUTIC INTERVENTIONS FOR TARGETING THESE ENZYMES. MMP2 AND TIMP2 BOTH PLAY A ROLE IN THE DEVELOPMENT OF COPD AND THEY NEED TO BE STUDIED WITH THE UTMOST FOCUS. 2023 11 4954 26 PATHOGENESIS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE PATHOGENESIS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) ENCOMPASSES A NUMBER OF INJURIOUS PROCESSES, INCLUDING AN ABNORMAL INFLAMMATORY RESPONSE IN THE LUNGS TO INHALED PARTICLES AND GASES. OTHER PROCESSES, SUCH AS FAILURE TO RESOLVE INFLAMMATION, ABNORMAL CELL REPAIR, APOPTOSIS, ABNORMAL CELLULAR MAINTENANCE PROGRAMS, EXTRACELLULAR MATRIX DESTRUCTION (PROTEASE/ANTIPROTEASE IMBALANCE), AND OXIDATIVE STRESS (OXIDANT/ANTIOXIDANT IMBALANCE) ALSO HAVE A ROLE. THE INFLAMMATORY RESPONSES TO THE INHALATION OF ACTIVE AND PASSIVE TOBACCO SMOKE AND URBAN AND RURAL AIR POLLUTION ARE MODIFIED BY GENETIC AND EPIGENETIC FACTORS. THE SUBSEQUENT CHRONIC INFLAMMATORY RESPONSES LEAD TO MUCUS HYPERSECRETION, AIRWAY REMODELING, AND ALVEOLAR DESTRUCTION. THIS ARTICLE PROVIDES AN UPDATE ON THE CELLULAR AND MOLECULAR MECHANISMS OF THESE PROCESSES IN THE PATHOGENESIS OF COPD. 2007 12 4358 35 MIR-338-3P BLOCKS TGFBETA-INDUCED MYOFIBROBLAST DIFFERENTIATION THROUGH THE INDUCTION OF PTEN. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC INTERSTITIAL LUNG DISEASE. THE PATHOGENESIS OF IPF IS NOT COMPLETELY UNDERSTOOD. HOWEVER, NUMEROUS GENES ARE ASSOCIATED WITH THE DEVELOPMENT AND PROGRESSION OF PULMONARY FIBROSIS, INDICATING THERE IS A SIGNIFICANT GENETIC COMPONENT TO THE PATHOGENESIS OF IPF. EPIGENETIC INFLUENCES ON THE DEVELOPMENT OF HUMAN DISEASE, INCLUDING PULMONARY FIBROSIS, REMAIN TO BE FULLY ELUCIDATED. IN THIS PAPER, WE IDENTIFY MIR-338-3P AS A MICRORNA SEVERELY DOWNREGULATED IN THE LUNGS OF PATIENTS WITH PULMONARY FIBROSIS AND IN EXPERIMENTAL MODELS OF PULMONARY FIBROSIS. TREATMENT OF PRIMARY HUMAN LUNG FIBROBLASTS WITH MIR-338-3P INHIBITS MYOFIBROBLAST DIFFERENTIATION AND MATRIX PROTEIN PRODUCTION. PUBLISHED AND PROPOSED TARGETS OF MIR-338-3P SUCH AS TGFBETA RECEPTOR 1, MEK/ERK 1/2, CDK4, AND CYCLIN D ARE ALSO NOT RESPONSIBLE FOR THE REGULATION OF PULMONARY FIBROBLAST BEHAVIOR BY MIR-338-3P. MIR-338-3P INHIBITS MYOFIBROBLAST DIFFERENTIATION BY PREVENTING TGFBETA-MEDIATED DOWNREGULATION OF PHOSPHATASE AND TENSIN HOMOLOG (PTEN), A KNOWN ANTIFIBROTIC MEDIATOR. 2022 13 1244 38 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 14 3767 34 INTEGRATIVE EPIGENOMIC ANALYSIS IN DIFFERENTIATED HUMAN PRIMARY BRONCHIAL EPITHELIAL CELLS EXPOSED TO CIGARETTE SMOKE. CIGARETTE SMOKE (CS) IS ONE OF THE MAJOR RISK FACTORS FOR MANY PULMONARY DISEASES, INCLUDING CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER. THE FIRST LINE OF DEFENSE FOR CS EXPOSURE IS THE BRONCHIAL EPITHELIAL CELLS. ELUCIDATION OF THE EPIGENETIC CHANGES DURING CS EXPOSURE IS KEY TO GAINING A MECHANISTIC UNDERSTANDING INTO HOW MATURE AND DIFFERENTIATED BRONCHIAL EPITHELIAL CELLS RESPOND TO CS. THEREFORE, WE PERFORMED EPIGENOMIC PROFILING IN CONJUNCTION WITH TRANSCRIPTIONAL PROFILING IN WELL-DIFFERENTIATED HUMAN BRONCHIAL EPITHELIAL (HBE) CELLS CULTURED IN AIR-LIQUID INTERFACE (ALI) EXPOSED TO THE VAPOR PHASE OF CS. THE GENOME-WIDE ENRICHMENT OF HISTONE 3 LYSINE 27 ACETYLATION WAS DETECTED BY CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY NEXT GENERATION SEQUENCING (CHIP-SEQ) IN HBE CELLS AND SUGGESTED THE PLAUSIBLE BINDING OF SPECIFIC TRANSCRIPTION FACTORS RELATED TO CS EXPOSURE. ADDITIONALLY, INTERROGATION OF CHIP-SEQ DATA WITH GENE EXPRESSION PROFILING OF HBE CELLS AFTER CS EXPOSURE FOR DIFFERENT DURATIONS (3 HOURS, 2 DAYS, 4 DAYS) SUGGESTED THAT EARLIER EPIGENETIC CHANGES (3 HOURS AFTER CS EXPOSURE) MAY BE ASSOCIATED WITH LATER GENE EXPRESSION CHANGES INDUCED BY CS EXPOSURE (4 DAYS). THE INTEGRATION OF EPIGENETICS AND GENE EXPRESSION DATA REVEALED SIGNALING PATHWAYS RELATED TO CS-INDUCED EPIGENETIC CHANGES IN HBE CELLS THAT MAY IDENTIFY NOVEL REGULATORY PATHWAYS RELATED TO CS-INDUCED COPD. 2018 15 2737 39 EXPOSING A DEADLY ALLIANCE: NOVEL INSIGHTS INTO THE BIOLOGICAL LINKS BETWEEN COPD AND LUNG CANCER. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AFFECTS MORE THAN 200 MILLION PEOPLE WORLDWIDE AND IS EXPECTED TO BECOME THE THIRD LEADING CAUSE OF DEATH IN 2020. COPD IS CHARACTERIZED BY PROGRESSIVE AIRFLOW LIMITATION, DUE TO A COMBINATION OF CHRONIC INFLAMMATION AND REMODELING OF THE SMALL AIRWAYS (BRONCHIOLITIS) AND LOSS OF ELASTIC RECOIL CAUSED BY DESTRUCTION OF THE ALVEOLAR WALLS (EMPHYSEMA). LUNG CANCER IS THE MOST IMPORTANT CAUSE OF CANCER-RELATED DEATH IN THE WORLD. (CIGARETTE) SMOKING IS THE PRINCIPAL CULPRIT CAUSING BOTH COPD AND LUNG CANCER; IN ADDITION, EXPOSURE TO ENVIRONMENTAL TOBACCO SMOKE, BIOMASS FUEL SMOKE, COAL SMOKE AND OUTDOOR AIR POLLUTION HAVE ALSO BEEN ASSOCIATED WITH AN INCREASED INCIDENCE OF BOTH DISEASES. IMPORTANTLY, SMOKERS WITH COPD--DEFINED AS EITHER NOT FULLY REVERSIBLE AIRFLOW LIMITATION OR EMPHYSEMA--HAVE A TWO- TO FOUR-FOLD INCREASED RISK TO DEVELOP LUNG CANCER. IN THIS REVIEW, WE HIGHLIGHT SEVERAL OF THE GENETIC, EPIGENETIC AND INFLAMMATORY MECHANISMS, WHICH LINK COPD AND CARCINOGENESIS IN THE LUNGS. ELUCIDATING THE BIOLOGICAL PATHWAYS AND NETWORKS, WHICH UNDERLIE THE INCREASED SUSCEPTIBILITY OF LUNG CANCER IN PATIENTS WITH COPD, HAS IMPORTANT IMPLICATIONS FOR SCREENING, PREVENTION, DIAGNOSIS AND TREATMENT OF THESE TWO DEVASTATING PULMONARY DISEASES. 2013 16 4116 32 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 17 756 39 CARM1 REGULATES SENESCENCE DURING AIRWAY EPITHELIAL CELL INJURY IN COPD PATHOGENESIS. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A LIFE-THREATENING LUNG DISEASE. ALTHOUGH CIGARETTE SMOKE WAS CONSIDERED THE MAIN CAUSE OF DEVELOPMENT, THE HETEROGENEOUS NATURE OF THE DISEASE LEAVES IT UNCLEAR WHETHER OTHER FACTORS CONTRIBUTE TO THE PREDISPOSITION OR IMPAIRED REGENERATION RESPONSE OBSERVED. RECENTLY, EPIGENETIC MODIFICATION HAS EMERGED TO BE A KEY PLAYER IN THE PATHOGENESIS OF COPD. THE ADDITION OF METHYL GROUPS TO ARGININE RESIDUES IN BOTH HISTONE AND NONHISTONE PROTEINS BY PROTEIN ARGININE METHYLTRANSFERASES (PRMTS) IS AN IMPORTANT POSTTRANSLATIONAL EPIGENETIC MODIFICATION EVENT REGULATING CELLULAR PROLIFERATION, DIFFERENTIATION, APOPTOSIS, AND SENESCENCE. HERE, WE HYPOTHESIZE THAT COACTIVATOR-ASSOCIATED ARGININE METHYLTRANSFERASE-1 (CARM1) REGULATES AIRWAY EPITHELIAL CELL INJURY IN COPD PATHOGENESIS BY CONTROLLING CELLULAR SENESCENCE. USING THE NAPHTHALENE (NA)-INDUCED MOUSE MODEL OF AIRWAY EPITHELIAL DAMAGE, WE DEMONSTRATE THAT LOSS OF CC10-POSITIVE CLUB CELLS IS ACCOMPANIED BY A REDUCTION IN CARM1-EXPRESSING CELLS OF THE AIRWAY EPITHELIUM. FURTHERMORE, CARM1 HAPLOINSUFFFICENT MICE SHOWED PERTURBED CLUB CELL REGENERATION FOLLOWING NA TREATMENT. IN ADDITION, CARM1 REDUCTION LED TO DECREASED NUMBERS OF ANTISENESCENT SIRTUIN 1-EXPRESSING CELLS ACCOMPANIED BY HIGHER P21, P16, AND BETA-GALACTOSIDASE-POSITIVE SENESCENT CELLS IN THE MOUSE AIRWAY FOLLOWING NA TREATMENT. IMPORTANTLY, CARM1-SILENCED HUMAN BRONCHIAL EPITHELIAL CELLS SHOWED IMPAIRED WOUND HEALING AND HIGHER BETA-GALACTOSIDASE ACTIVITY. THESE RESULTS DEMONSTRATE THAT CARM1 CONTRIBUTES TO AIRWAY REPAIR AND REGENERATION BY REGULATING AIRWAY EPITHELIAL CELL SENESCENCE. 2019 18 1245 36 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 19 5422 44 REGULATION OF LUNG EPITHELIAL CELL SENESCENCE IN SMOKING-INDUCED COPD/EMPHYSEMA BY MICROR-125A-5P VIA SP1 MEDIATION OF SIRT1/HIF-1A. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AFFECTS THE HEALTH OF MORE THAN 300 MILLION PEOPLE WORLDWIDE; AT PRESENT, THERE IS NO EFFECTIVE DRUG TO TREAT COPD. SMOKING IS THE MOST IMPORTANT RISK FACTOR, BUT THE MOLECULAR MECHANISM BY WHICH SMOKING CAUSES THE DISEASE IS UNCLEAR. THE SENESCENCE OF LUNG EPITHELIAL CELLS IS RELATED TO DEVELOPMENT OF COPD. REGULATION OF MIRNAS IS THE MAIN EPIGENETIC MECHANISM RELATED TO AGING. BETA-GALACTOSE STAINING SHOWED THAT THE LUNG TISSUES OF SMOKERS HAVE A HIGHER DEGREE OF CELLULAR SENESCENCE, AND THE EXPRESSION OF MIR-125A-5P IS HIGH. THIS EFFECT IS OBVIOUS FOR SMOKERS WITH COPD/EMPHYSEMA, AND THERE IS A NEGATIVE CORRELATION BETWEEN MIR-125A-5P LEVELS AND VALUES FOR FORCED EXPIRATORY VOLUME IN ONE SECOND (FEV1)/FORCED VITAL CAPACITY (FVC). AFTER BALB/C MICE WERE CHRONICALLY EXPOSED TO VARIOUS CONCENTRATIONS OF CIGARETTE SMOKE (CS), PLETHYSMOGRAPHY SHOWED THAT LUNG FUNCTION WAS IMPAIRED, LUNG TISSUE SENESCENCE WAS INCREASED, AND THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP) IN BRONCHOALVEOLAR LAVAGE FLUID WAS INCREASED. FOR MOUSE LUNG EPITHELIAL (MLE)-12 CELLS TREATED WITH CIGARETTE SMOKE EXTRACT (CSE), SP1 AND SIRT1 LEVELS WERE LOW, HIF-1ALPHA ACETYLATION LEVELS WERE HIGH, AND CELL SENESCENCE AND SECRETION OF SASP FACTORS WERE ELEVATED. DOWN-REGULATION OF MIR-125A-5P OR UP-REGULATION OF SP1 REVERSED THESE EFFECTS. IN ADDITION, COMPARED WITH MICE EXPOSED TO CS, KNOCKDOWN OF MIR-125A-5P REDUCED LUNG EPITHELIAL CELL SENESCENCE AND COPD/EMPHYSEMA. THEREFORE, IN SMOKING-INDUCED COPD, ELEVATED MIR-125A-5P PARTICIPATES IN THE SENESCENCE OF LUNG EPITHELIAL CELLS THROUGH SP1/SIRT1/HIF-1ALPHA. THESE FINDINGS PROVIDE EVIDENCE RELATED TO THE PATHOGENESIS OF COPD/EMPHYSEMA CAUSED BY CHRONIC SMOKING. 2022 20 5301 31 PROTEIN PHOSPHATASE 2A CATALYTIC SUBUNIT ALPHA PLAYS A MYD88-DEPENDENT, CENTRAL ROLE IN THE GENE-SPECIFIC REGULATION OF ENDOTOXIN TOLERANCE. MYD88, THE INTRACELLULAR ADAPTOR OF MOST TLRS, MEDIATES EITHER PROINFLAMMATORY OR IMMUNOSUPPRESSIVE SIGNALING THAT CONTRIBUTES TO CHRONIC INFLAMMATION-ASSOCIATED DISEASES. ALTHOUGH GENE-SPECIFIC CHROMATIN MODIFICATIONS REGULATE INFLAMMATION, THE ROLE OF MYD88 SIGNALING IN ESTABLISHING SUCH EPIGENETIC LANDSCAPES UNDER DIFFERENT INFLAMMATORY STATES REMAINS ELUSIVE. USING QUANTITATIVE PROTEOMICS TO ENUMERATE THE INFLAMMATION-PHENOTYPIC CONSTITUENTS OF THE MYD88 INTERACTOME, WE FOUND THAT IN ENDOTOXIN-TOLERANT MACROPHAGES, PROTEIN PHOSPHATASE 2A CATALYTIC SUBUNIT ALPHA (PP2AC) ENHANCES ITS ASSOCIATION WITH MYD88 AND IS CONSTITUTIVELY ACTIVATED. KNOCKDOWN OF PP2AC PREVENTS SUPPRESSION OF PROINFLAMMATORY GENES AND RESISTANCE TO APOPTOSIS. THROUGH SITE-SPECIFIC DEPHOSPHORYLATION, CONSTITUTIVELY ACTIVE PP2AC DISRUPTS THE SIGNAL-PROMOTING TLR4-MYD88 COMPLEX AND BROADLY SUPPRESSES THE ACTIVITIES OF MULTIPLE PROINFLAMMATORY/PROAPOPTOTIC PATHWAYS AS WELL, SHIFTING PROINFLAMMATORY MYD88 SIGNALING TO A PROSURVIVAL MODE. CONSTITUTIVELY ACTIVE PP2AC TRANSLOCATED WITH MYD88 INTO THE NUCLEI OF TOLERANT MACROPHAGES ESTABLISHES THE IMMUNOSUPPRESSIVE PATTERN OF CHROMATIN MODIFICATIONS AND REPRESSES CHROMATIN REMODELING TO SELECTIVELY SILENCE PROINFLAMMATORY GENES, COORDINATING THE MYD88-DEPENDENT INFLAMMATION CONTROL AT BOTH SIGNALING AND EPIGENETIC LEVELS UNDER ENDOTOXIN-TOLERANT CONDITIONS. 2013