1 5560 97 ROLE OF HISTONE DEACETYLASE 2 IN EPIGENETICS AND CELLULAR SENESCENCE: IMPLICATIONS IN LUNG INFLAMMAGING AND COPD. HISTONE DEACETYLASE 2 (HDAC2) IS A CLASS I HISTONE DEACETYLASE THAT REGULATES VARIOUS CELLULAR PROCESSES, SUCH AS CELL CYCLE, SENESCENCE, PROLIFERATION, DIFFERENTIATION, DEVELOPMENT, APOPTOSIS, AND GLUCOCORTICOID FUNCTION IN INHIBITING INFLAMMATORY RESPONSE. HDAC2 HAS BEEN SHOWN TO PROTECT AGAINST DNA DAMAGE RESPONSE AND CELLULAR SENESCENCE/PREMATURE AGING VIA AN EPIGENETIC MECHANISM IN RESPONSE TO OXIDATIVE STRESS. THESE PHENOMENA ARE OBSERVED IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). HDAC2 IS POSTTRANSLATIONALLY MODIFIED BY OXIDATIVE/CARBONYL STRESS IMPOSED BY CIGARETTE SMOKE AND OXIDANTS, LEADING TO ITS REDUCTION VIA AN UBIQUITINATION-PROTEASOME DEPENDENT DEGRADATION IN LUNGS OF PATIENTS WITH COPD. IN THIS PERSPECTIVE, WE HAVE DISCUSSED THE ROLE OF HDAC2 POSTTRANSLATIONAL MODIFICATIONS AND ITS ROLE IN REGULATION OF INFLAMMATION, HISTONE/DNA EPIGENETIC MODIFICATIONS, DNA DAMAGE RESPONSE, AND CELLULAR SENESCENCE, PARTICULARLY IN INFLAMMAGING, AND DURING THE DEVELOPMENT OF COPD. WE HAVE ALSO DISCUSSED THE POTENTIAL DIRECTIONS FOR FUTURE TRANSLATIONAL RESEARCH AVENUES IN MODULATING LUNG INFLAMMAGING AND CELLULAR SENESCENCE BASED ON EPIGENETIC CHROMATIN MODIFICATIONS IN DISEASES ASSOCIATED WITH INCREASED OXIDATIVE STRESS. 2012 2 2212 39 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 3 4898 40 OXIDATIVE STRESS INDUCED LUNG CANCER AND COPD: OPPORTUNITIES FOR EPIGENETIC THERAPY. REACTIVE OXYGEN SPECIES (ROS) FORM AS A NATURAL BY-PRODUCT OF THE NORMAL METABOLISM OF OXYGEN AND PLAY IMPORTANT ROLES WITHIN THE CELL. UNDER NORMAL CIRCUMSTANCES THE CELL IS ABLE TO MAINTAIN AN ADEQUATE HOMEOSTASIS BETWEEN THE FORMATION OF ROS AND ITS REMOVAL THROUGH PARTICULAR ENZYMATIC PATHWAYS OR VIA ANTIOXIDANTS. IF HOWEVER, THIS BALANCE IS DISTURBED A SITUATION CALLED OXIDATIVE STRESS OCCURS. CRITICALLY, OXIDATIVE STRESS PLAYS IMPORTANT ROLES IN THE PATHOGENESIS OF MANY DISEASES, INCLUDING CANCER. EPIGENETICS IS A PROCESS WHERE GENE EXPRESSION IS REGULATED BY HERITABLE MECHANISMS THAT DO NOT CAUSE ANY DIRECT CHANGES TO THE DNA SEQUENCE ITSELF, AND DISRUPTION OF EPIGENETIC MECHANISMS HAS IMPORTANT IMPLICATIONS IN DISEASE. EVIDENCE IS EMERGING THAT HISTONE DEACETYLASES (HDACS) PLAY DECISIVE ROLES IN REGULATING IMPORTANT CELLULAR OXIDATIVE STRESS PATHWAYS INCLUDING THOSE INVOLVED WITH SENSING OXIDATIVE STRESS AND THOSE INVOLVED WITH REGULATING THE CELLULAR RESPONSE TO OXIDATIVE STRESS. IN PARTICULAR ABERRANT REGULATION OF THESE PATHWAYS BY HDACS MAY PLAY CRITICAL ROLES IN CANCER PROGRESSION. IN THIS REVIEW WE DISCUSS THE CURRENT EVIDENCE LINKING EPIGENETICS AND OXIDATIVE STRESS AND CANCER, USING CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND NON-SMALL CELL LUNG CANCER TO ILLUSTRATE THE IMPORTANCE OF EPIGENETICS ON THESE PATHWAYS WITHIN THESE DISEASE SETTINGS. 2009 4 2161 31 EPIGENETIC MECHANISMS IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. EPIGENETIC MODIFICATION MAY AFFECT THE EXPRESSION OF MULTIPLE INFLAMMATORY GENES IN LUNGS OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). MAJOR EPIGENETIC EVENTS INCLUDE DNA METHYLATION AND VARIOUS POST-TRANSLATIONAL MODIFICATIONS OF HISTONES, SUCH AS HISTONE METHYLATION, ACETYLATION, PHOSPHORYLATION, UBIQUITINATION, AND SUMOYLATION. ENZYMES WHICH REGULATE THESE EPIGENETIC MODIFICATIONS CAN BE ACTIVATED BY SMOKING. BOTH ENVIRONMENTAL AND GENETIC FACTORS PLAY SIGNIFICANT EFFECT IN DEVELOPMENT OF COPD WHICH HAVE BEEN REPORTED BY MOST REFERENCES; HOWEVER, LITTLE IS KNOWN ABOUT THE EPIGENETIC PATHWAYS INVOLVED IN THE DISEASE. UNDERSTANDING THE EPIGENETIC MECHANISMS CAN HELP US CLARIFY THE PATHOGENESIS OF COPD AND IDENTIFY NOVEL TARGETS FOR DEVELOPING NEW THERAPIES FOR PATIENTS WITH COPD. 2015 5 2357 40 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 6 1244 43 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 7 5550 42 ROLE OF EPIGENETICS IN INFLAMMATION-ASSOCIATED DISEASES. THERE IS CONSIDERABLE EVIDENCE SUGGESTING THAT EPIGENETIC MECHANISMS MAY MEDIATE DEVELOPMENT OF CHRONIC INFLAMMATION BY MODULATING THE EXPRESSION OF PRO-INFLAMMATORY CYTOKINE TNF-ALPHA, INTERLEUKINS, TUMOR SUPPRESSOR GENES, ONCOGENES AND AUTOCRINE AND PARACRINE ACTIVATION OF THE TRANSCRIPTION FACTOR NF-KAPPAB. THESE MOLECULES ARE CONSTITUTIVELY PRODUCED BY A VARIETY OF CELLS UNDER CHRONIC INFLAMMATORY CONDITIONS, WHICH IN TURN LEADS TO THE DEVELOPMENT OF MAJOR DISEASES SUCH AS AUTOIMMUNE DISORDERS, CHRONIC OBSTRUCTIVE PULMONARY DISEASES, NEURODEGENERATIVE DISEASES AND CANCER. DISTINCT OR GLOBAL CHANGES IN THE EPIGENETIC LANDSCAPE ARE HALLMARKS OF CHRONIC INFLAMMATION DRIVEN DISEASES. EPIGENETICS INCLUDE CHANGES TO DISTINCT MARKERS ON THE GENOME AND ASSOCIATED CELLULAR TRANSCRIPTIONAL MACHINERY THAT ARE COPIED DURING CELL DIVISION (MITOSIS AND MEIOSIS). THESE CHANGES APPEAR FOR A SHORT SPAN OF TIME AND THEY NECESSARILY DO NOT MAKE PERMANENT CHANGES TO THE PRIMARY DNA SEQUENCE ITSELF. HOWEVER, THE MOST FREQUENTLY OBSERVED EPIGENETIC CHANGES INCLUDE ABERRANT DNA METHYLATION, AND HISTONE ACETYLATION AND DEACETYLATION. IN THIS CHAPTER, WE FOCUS ON PRO-INFLAMMATORY MOLECULES THAT ARE REGULATED BY ENZYMES INVOLVED IN EPIGENETIC MODIFICATIONS SUCH AS ARGININE AND LYSINE METHYL TRANSFERASES, DNA METHYLTRANSFERASE, HISTONE ACETYLTRANSFERASES AND HISTONE DEACETYLASES AND THEIR ROLE IN INFLAMMATION DRIVEN DISEASES. AGENTS THAT MODULATE OR INHIBIT THESE EPIGENETIC MODIFICATIONS, SUCH AS HAT OR HDAC INHIBITORS HAVE SHOWN GREAT POTENTIAL IN INHIBITING THE PROGRESSION OF THESE DISEASES. GIVEN THE PLASTICITY OF THESE EPIGENETIC CHANGES AND THEIR READINESS TO RESPOND TO INTERVENTION BY SMALL MOLECULE INHIBITORS, THERE IS A TREMENDOUS POTENTIAL FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS THAT WILL SERVE AS DIRECT OR ADJUVANT THERAPEUTIC COMPOUNDS IN THE TREATMENT OF THESE DISEASES. 2013 8 2493 45 EPIGENETICS AND CHROMATIN REMODELING PLAY A ROLE IN LUNG DISEASE. EPIGENETICS IS DEFINED AS HERITABLE CHANGES THAT AFFECT GENE EXPRESSION WITHOUT ALTERING THE DNA SEQUENCE. EPIGENETIC REGULATION OF GENE EXPRESSION IS FACILITATED THROUGH DIFFERENT MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND RNA-ASSOCIATED SILENCING BY SMALL NON-CODING RNAS. ALL THESE MECHANISMS ARE CRUCIAL FOR NORMAL DEVELOPMENT, DIFFERENTIATION AND TISSUE-SPECIFIC GENE EXPRESSION. THESE THREE SYSTEMS INTERACT AND STABILIZE ONE ANOTHER AND CAN INITIATE AND SUSTAIN EPIGENETIC SILENCING, THUS DETERMINING HERITABLE CHANGES IN GENE EXPRESSION. HISTONE ACETYLATION REGULATES DIVERSE CELLULAR FUNCTIONS INCLUDING INFLAMMATORY GENE EXPRESSION, DNA REPAIR AND CELL PROLIFERATION. TRANSCRIPTIONAL COACTIVATORS POSSESS INTRINSIC HISTONE ACETYLTRANSFERASE ACTIVITY AND THIS ACTIVITY DRIVES INFLAMMATORY GENE EXPRESSION. ELEVEN CLASSICAL HISTONE DEACETYLASES (HDACS) ACT TO REGULATE THE EXPRESSION OF DISTINCT SUBSETS OF INFLAMMATORY/IMMUNE GENES. THUS, LOSS OF HDAC ACTIVITY OR THE PRESENCE OF HDAC INHIBITORS CAN FURTHER ENHANCE INFLAMMATORY GENE EXPRESSION BY PRODUCING A GENE-SPECIFIC CHANGE IN HAT ACTIVITY. FOR EXAMPLE, HDAC2 EXPRESSION AND ACTIVITY ARE REDUCED IN LUNG MACROPHAGES, BIOPSY SPECIMENS, AND BLOOD CELLS FROM PATIENTS WITH SEVERE ASTHMA AND SMOKING ASTHMATICS, AS WELL AS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THIS MAY ACCOUNT, AT LEAST IN PART, FOR THE ENHANCED INFLAMMATION AND REDUCED STEROID RESPONSIVENESS SEEN IN THESE PATIENTS. OTHER PROTEINS, PARTICULARLY TRANSCRIPTION FACTORS, ARE ALSO ACETYLATED AND ARE TARGETS FOR DEACETYLATION BY HDACS AND SIRTUINS, A RELATED FAMILY OF 7 PREDOMINANTLY PROTEIN DEACETYLASES. THUS THE ACETYLATION/DEACETYLATION STATUS OF NF-KAPPAB AND THE GLUCOCORTICOID RECEPTOR CAN ALSO AFFECT THE OVERALL EXPRESSION PATTERN OF INFLAMMATORY GENES AND REGULATE THE INFLAMMATORY RESPONSE. UNDERSTANDING AND TARGETING SPECIFIC ENZYMES INVOLVED IN THIS PROCESS MIGHT LEAD TO NEW THERAPEUTIC AGENTS, PARTICULARLY IN SITUATIONS IN WHICH CURRENT ANTI-INFLAMMATORY THERAPIES ARE SUBOPTIMAL. 2011 9 3535 29 IMMUNE AND GENETIC MECHANISMS IN COPD: POSSIBLE TARGETS FOR THERAPEUTIC INTERVENTIONS. GENETIC, IMMUNE AND ENVIRONMENTAL INTERACTIONS ARE KEY ELEMENTS FOR THE DEVELOPMENT OF COPD. CIGARETTE SMOKING IS CONSIDERED THE PRIMARY RISK FACTOR INITIATING INFLAMMATORY CASCADES IN GENETICALLY SUSCEPTIBLE INDIVIDUALS. THE "DANGER SIGNALS" ELICITED BY THE INJURED CELLS OF NON-SPECIFIC IMMUNITY INDUCE THE DOWNSTREAM ACTIVATION OF PROINFLAMMATORY CASCADES AND ANTIGEN-SPECIFIC ADAPTIVE IMMUNE RESPONSES. THE PRODUCED OXIDATIVE STRESS FURTHER DAMAGES THE LUNG LEADING TO ACQUIRED GENETIC CHANGES (HISTONE DEACETYLATION, MICROSATELLITE DNA INSTABILITY, DNA METHYLATION, TELOMERE SHORTENING, MIRNA ALTERATIONS) DUE TO AN INEFFICIENT DNA REPAIR MACHINERY. ON THE OTHER HAND, AUGMENTED APOPTOSIS, IMPAIRED EFFEROCYTOSIS AND ABNORMAL TISSUE REMODELING CONTRIBUTE TO THE CHRONIC INFLAMMATORY RESPONSE AND TISSUE DESTRUCTION IN COPD. THIS REVIEW FOCUSES ON THE ROLE OF GENETIC, EPIGENETIC AND IMMUNE MECHANISMS IN THE DEVELOPMENT OF COPD IN ORDER TO PUT FORWARD POSSIBLE PROGNOSTIC AND THERAPEUTIC TARGETS. 2013 10 6839 34 [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 11 1251 44 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 12 5943 37 TARGETING OXIDATIVE STRESS IN CANCER. IMPORTANCE OF THE FIELD: REACTIVE OXYGEN SPECIES (ROS) OCCUR AS NATURAL BY-PRODUCTS OF OXYGEN METABOLISM AND HAVE IMPORTANT CELLULAR FUNCTIONS. NORMALLY, THE CELL IS ABLE TO MAINTAIN AN ADEQUATE BALANCE BETWEEN THE FORMATION AND REMOVAL OF ROS EITHER VIA ANTI-OXIDANTS OR THROUGH THE USE SPECIFIC ENZYMATIC PATHWAYS. HOWEVER, IF THIS BALANCE IS DISTURBED, OXIDATIVE STRESS MAY OCCUR IN THE CELL, A SITUATION LINKED TO THE PATHOGENESIS OF MANY DISEASES, INCLUDING CANCER. AREAS COVERED IN THIS REVIEW: HDACS ARE IMPORTANT REGULATORS OF MANY OXIDATIVE STRESS PATHWAYS INCLUDING THOSE INVOLVED WITH BOTH SENSING AND COORDINATING THE CELLULAR RESPONSE TO OXIDATIVE STRESS. IN PARTICULAR ABERRANT REGULATION OF THESE PATHWAYS BY HISTONE DEACETYLASES MAY PLAY CRITICAL ROLES IN CANCER PROGRESSION. WHAT THE READER WILL GAIN: IN THIS REVIEW WE DISCUSS THE NOTION THAT TARGETING HDACS MAY BE A USEFUL THERAPEUTIC AVENUE IN THE TREATMENT OF OXIDATIVE STRESS IN CANCER, USING CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), NSCLC AND HEPATOCELLULAR CARCINOMA (HCC) AS EXAMPLES TO ILLUSTRATE THIS POSSIBILITY. TAKE HOME MESSAGE: EPIGENETIC MECHANISMS MAY BE AN IMPORTANT NEW THERAPEUTIC AVENUE FOR TARGETING OXIDATIVE STRESS IN CANCER. 2010 13 4953 52 PATHOGENESIS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) INDUCED BY CIGARETTE SMOKE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMMON RESPIRATORY DISEASE THAT IS CHARACTERIZED BY FUNCTIONAL AND STRUCTURAL ALTERATIONS PRIMARILY CAUSED BY LONG-TERM INHALATION OF HARMFUL PARTICLES. CIGARETTE SMOKE (CS) INDUCES AIRWAY INFLAMMATION IN COPD, WHICH IS KNOWN TO PERSIST EVEN AFTER SMOKING CESSATION. THIS REVIEW DISCUSSES THE BASIC PATHOGENESIS OF COPD, WITH PARTICULAR FOCUS ON AN ENDOGENOUS PROTECTIVE MECHANISM AGAINST OXIDATIVE STRESS VIA NRF2, ALTERED IMMUNE RESPONSE OF THE AIRWAY INFLAMMATORY CELLS, EXAGGERATED CELLULAR SENESCENCE OF THE LUNG STRUCTURAL CELLS, AND CELL DEATH WITH EXPANDED INFLAMMATION. RECENTLY, CS-INDUCED MITOCHONDRIA AUTOPHAGY IS REPORTED TO INITIATE PROGRAMMED NECROSIS (NECROPTOSIS). NECROPTOSIS IS A NEW CONCEPT OF CELL DEATH WHICH IS DRIVEN BY A DEFINED MOLECULAR PATHWAY ALONG WITH EXAGGERATED INFLAMMATION. THIS NEW CELL DEATH MECHANISM IS OF IMPORTANCE DUE TO ITS ABILITY TO PRODUCE MORE INFLAMMATORY SUBSTANCES DURING THE PROCESS OF EPITHELIAL DEATH, CONTRIBUTING TO PERSISTENT AIRWAY INFLAMMATION THAT CANNOT BE EXPLAINED BY APOPTOSIS-DERIVED CELL DEATH. AUTOPHAGY IS AN AUTO-CELL COMPONENT DEGRADATION SYSTEM EXECUTED BY LYSOSOMES THAT CONTROLS PROTEIN AND ORGANELLE DEGRADATION FOR SUCCESSFUL HOMEOSTASIS. AS WELL AS IN THE PROCESS OF NECROPTOSIS, AUTOPHAGY IS ALSO OBSERVED DURING CELLULAR SENESCENCE. AGING OF THE LUNGS RESULTS IN THE ACQUISITION OF SENESCENCE-ASSOCIATED SECRETORY PHENOTYPES (SASP) THAT ARE KNOWN TO SECRETE INFLAMMATORY CYTOKINES, CHEMOKINES, GROWTH FACTORS, AND MATRIX METALLOPROTEINASES RESULTING IN CHRONIC LOW-GRADE INFLAMMATION. IN FUTURE RESEARCH, WE INTEND TO HIGHLIGHT THE GENETIC AND EPIGENETIC APPROACHES THAT CAN FACILITATE THE UNDERSTANDING OF DISEASE SUSCEPTIBILITY. THE GOAL OF PRECISION MEDICINE IS TO ESTABLISH MORE ACCURATE DIAGNOSIS AND TREATMENT METHODS BASED ON THE PATIENT-SPECIFIC PATHOGENIC CHARACTERISTICS. THIS REVIEW PROVIDES INSIGHTS INTO CS-INDUCED COPD PATHOGENESIS, WHICH CONTRIBUTES TO A VERY COMPLEX DISEASE. INVESTIGATING THE MECHANISM OF DEVELOPING COPD, ALONG WITH THE AVAILABILITY OF THE PARTICULAR INHIBITORS, WILL LEAD TO NEW THERAPEUTIC APPROACHES IN COPD TREATMENT. 2019 14 6533 41 TRANSCRIPTIONAL REGULATION OF INFLAMMATORY GENES ASSOCIATED WITH SEVERE ASTHMA. THE 10% OF PATIENTS WITH THE MOST SEVERE ASTHMA ARE RESPONSIBLE FOR A LARGE PART OF HEALTHCARE EXPENDITURE AND MORBIDITY. UNDERSTANDING THE PROCESSES INVOLVED IS KEY IF NEW THERAPEUTIC APPROACHES ARE TO BE DEVELOPED. EVIDENCE IS ACCUMULATING THAT CHRONIC DISEASES SUCH AS ASTHMA ARE ASSOCIATED WITH TEMPORAL AND SPATIAL ALTERATIONS IN THE PATTERN OF INFLAMMATORY GENE EXPRESSION WITHIN THE AIRWAYS. EXPRESSION OF THESE GENES CAN BE REGULATED BY TRANSCRIPTIONAL, POSTTRANSCRIPTIONAL, TRANSLATIONAL AND EPIGENETIC MECHANISMS. IT IS WELL ESTABLISHED THAT BINDING OF ACTIVATED TRANSCRIPTION FACTORS TO SPECIFIC INDUCIBLE GENE PROMOTER SITES IS TIGHTLY CONTROLLED BY CHROMATIN STATE AS A RESULT OF HISTONE MODIFICATIONS, PARTICULARLY THE BALANCE BETWEEN HISTONE ACETYLATION AND DEACETYLATION [1]. THE INTERACTION BETWEEN TRANSCRIPTION FACTORS AND THE PROMOTER IS KEY TO THE DIVERSIFICATION OF GENE EXPRESSION IN A TIME DEPENDENT MANNER LEADING TO ALTERED GENE EXPRESSION PROFILES. ALTERATIONS OF THE ACCESSIBILITY OF TRANSCRIPTION FACTORS TO THE DNA CAN HAVE RESIDING EFFECTS UPON GENE TRANSCRIPTION. THIS REVIEW WILL FOCUS ON THE REGULATION OF SEVERAL GROUPS OF KEY GENES WHICH ARE INVOLVED IN CHRONIC AIRWAY INFLAMMATION AND REMODELLING IN ASTHMA DRAWING MAINLY FROM OUR EXPERIENCE OF STUDYING THESE PROCESSES IN AIRWAY SMOOTH MUSCLE CELLS. AN OVERVIEW IS SHOWN IN FIGURE 1. 2011 15 2348 38 EPIGENETIC REGULATION OF MUSCLE PHENOTYPE AND ADAPTATION: A POTENTIAL ROLE IN COPD MUSCLE DYSFUNCTION. QUADRICEPS MUSCLE DYSFUNCTION OCCURS IN ONE-THIRD OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IN VERY EARLY STAGES OF THEIR CONDITION, EVEN PRIOR TO THE DEVELOPMENT OF AIRWAY OBSTRUCTION. AMONG SEVERAL FACTORS, DECONDITIONING AND MUSCLE MASS LOSS ARE THE MOST RELEVANT CONTRIBUTING FACTORS LEADING TO THIS DYSFUNCTION. MOREOVER, EPIGENETICS, DEFINED AS THE PROCESS WHEREBY GENE EXPRESSION IS REGULATED BY HERITABLE MECHANISMS THAT DO NOT AFFECT DNA SEQUENCE, COULD BE INVOLVED IN THE SUSCEPTIBILITY TO MUSCLE DYSFUNCTION, PATHOGENESIS, AND PROGRESSION. HEREIN, WE REVIEW THE ROLE OF EPIGENETIC MECHANISMS IN MUSCLE DEVELOPMENT AND ADAPTATION TO ENVIRONMENTAL FACTORS SUCH AS IMMOBILIZATION AND EXERCISE, AND THEIR IMPLICATIONS IN THE PATHOPHYSIOLOGY AND SUSCEPTIBILITY TO MUSCLE DYSFUNCTION IN COPD. THE EPIGENETIC MODIFICATIONS IDENTIFIED SO FAR INCLUDE DNA METHYLATION, HISTONE ACETYLATION AND METHYLATION, AND NON-CODING RNAS SUCH AS MICRORNAS (MIRNAS). IN THE PRESENT REVIEW, WE DESCRIBE THE SPECIFIC CONTRIBUTION OF EPIGENETIC MECHANISMS TO THE REGULATION OF EMBRYONIC MYOGENESIS, MUSCLE STRUCTURE AND METABOLISM, IMMOBILIZATION, AND EXERCISE, AND IN MUSCLES OF COPD PATIENTS. EVENTS RELATED TO MUSCLE DEVELOPMENT AND REGENERATION AND THE RESPONSE TO EXERCISE AND IMMOBILIZATION ARE TIGHTLY REGULATED BY EPIGENETIC MECHANISMS. THESE ENVIRONMENTAL FACTORS PLAY A KEY ROLE IN THE OUTCOME OF MUSCLE MASS AND FUNCTION AS WELL AS IN THE SUSCEPTIBILITY TO MUSCLE DYSFUNCTION IN COPD. FUTURE RESEARCH REMAINS TO BE DONE TO SHED LIGHT ON THE SPECIFIC TARGET PATHWAYS OF MIRNA FUNCTION AND OTHER EPIGENETIC MECHANISMS IN THE SUSCEPTIBILITY, PATHOGENESIS, AND PROGRESSION OF COPD MUSCLE DYSFUNCTION. 2013 16 6100 37 THE EMERGING ROLE OF EPIGENETIC MODIFIERS IN REPAIR OF DNA DAMAGE ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES. AT SITES OF CHRONIC INFLAMMATION EPITHELIAL CELLS ARE EXPOSED TO HIGH LEVELS OF REACTIVE OXYGEN SPECIES (ROS), WHICH CAN CONTRIBUTE TO THE INITIATION AND DEVELOPMENT OF MANY DIFFERENT HUMAN CANCERS. ABERRANT EPIGENETIC ALTERATIONS THAT CAUSE TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES ARE ALSO IMPLICATED IN MANY DISEASES ASSOCIATED WITH INFLAMMATION, INCLUDING CANCER. HOWEVER, IT IS NOT CLEAR HOW ALTERED EPIGENETIC GENE SILENCING IS INITIATED DURING CHRONIC INFLAMMATION. THE HIGH LEVEL OF ROS AT SITES OF INFLAMMATION IS KNOWN TO INDUCE OXIDATIVE DNA DAMAGE IN SURROUNDING EPITHELIAL CELLS. FURTHERMORE, DNA DAMAGE IS KNOWN TO TRIGGER SEVERAL RESPONSES, INCLUDING RECRUITMENT OF DNA REPAIR PROTEINS, TRANSCRIPTIONAL REPRESSION, CHROMATIN MODIFICATIONS AND OTHER CELL SIGNALING EVENTS. RECRUITMENT OF EPIGENETIC MODIFIERS TO CHROMATIN IN RESPONSE TO DNA DAMAGE RESULTS IN TRANSIENT COVALENT MODIFICATIONS TO CHROMATIN SUCH AS HISTONE UBIQUITINATION, ACETYLATION AND METHYLATION AND DNA METHYLATION. DNA DAMAGE ALSO ALTERS NON-CODING RNA EXPRESSION. ALL OF THESE ALTERATIONS HAVE THE POTENTIAL TO ALTER GENE EXPRESSION AT SITES OF DAMAGE. TYPICALLY, THESE MODIFICATIONS AND GENE TRANSCRIPTION ARE RESTORED BACK TO NORMAL ONCE THE REPAIR OF THE DNA DAMAGE IS COMPLETED. HOWEVER, CHRONIC INFLAMMATION MAY INDUCE SUSTAINED DNA DAMAGE AND DNA DAMAGE RESPONSES THAT RESULT IN THESE TRANSIENT COVALENT CHROMATIN MODIFICATIONS BECOMING MITOTICALLY STABLE EPIGENETIC ALTERATIONS. UNDERSTANDING HOW EPIGENETIC ALTERATIONS ARE INITIATED DURING CHRONIC INFLAMMATION WILL ALLOW US TO DEVELOP PHARMACEUTICAL STRATEGIES TO PREVENT OR TREAT CHRONIC INFLAMMATION-INDUCED CANCER. THIS REVIEW WILL FOCUS ON TYPES OF DNA DAMAGE AND EPIGENETIC ALTERATIONS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES, THE TYPES OF DNA DAMAGE AND TRANSIENT COVALENT CHROMATIN MODIFICATIONS INDUCED BY INFLAMMATION AND OXIDATIVE DNA DAMAGE AND HOW THESE MODIFICATIONS MAY RESULT IN EPIGENETIC ALTERATIONS. 2019 17 1245 44 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 18 3703 34 INFLAMMATORY SIGNALLING AS MEDIATOR OF EPIGENETIC MODULATION IN TISSUE-SPECIFIC CHRONIC INFLAMMATION. RECENT SUCCESSES OF THERAPEUTIC INTERVENTION IN CHRONIC INFLAMMATORY DISEASES USING EPIGENETIC MODIFIERS SUCH AS HISTONE DEACETYLASE INHIBITORS AND INHIBITORS OF DNA METHYLATION SUGGEST THAT EPIGENETIC REPROGRAMMING PLAYS A ROLE IN THE AETIOLOGY OF THESE DISEASES. THE EPIGENETIC SIGNATURE OF A GIVEN IMMUNE CELL IS REFLECTED IN THE HISTORY OF MODIFICATIONS FROM DIFFERENT SIGNALS THE CELL HAS BEEN SUBJECTED TO DURING DIFFERENTIATION. LIKE OTHER CELLS, DIFFERENTIATING IMMUNE CELLS ARE DEPENDENT ON A COMPLEX COMBINATION OF INTER- AND INTRACELL SIGNALLING AS WELL AS TRANSCRIPTION MACHINERIES TO MODULATE THEIR EPIGENOMES IN ORDER TO MEDIATE DIFFERENTIATION. DESPITE EXTENSIVE RESEARCH INTO THESE PROCESSES, THE LINK BETWEEN CELLULAR SIGNALLING AND EPIGENETIC MODULATION REMAINS POORLY UNDERSTOOD. HERE, WE REVIEW RECENT PROGRESS AND DISCUSS KEY FACTORS DRIVING EPIGENETIC MODULATION IN CHRONIC INFLAMMATION. 2009 19 5581 30 ROLE OF NF-KAPPAB IN AGEING AND AGE-RELATED DISEASES: LESSONS FROM GENETICALLY MODIFIED MOUSE MODELS. AGEING IS A COMPLEX PROCESS, INDUCED BY MULTIFACETED INTERACTION OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. IT IS MANIFESTED BY A DECLINE IN THE PHYSIOLOGICAL FUNCTIONS OF ORGANISMS AND ASSOCIATED TO THE DEVELOPMENT OF AGE-RELATED CHRONIC DISEASES AND CANCER DEVELOPMENT. IT IS CONSIDERED THAT AGEING FOLLOWS A STRICTLY-REGULATED PROGRAM, IN WHICH SOME SIGNALING PATHWAYS CRITICALLY CONTRIBUTE TO THE ESTABLISHMENT AND MAINTENANCE OF THE AGED STATE. CHRONIC INFLAMMATION IS A MAJOR MECHANISM THAT PROMOTES THE BIOLOGICAL AGEING PROCESS AND COMORBIDITY, WITH THE TRANSCRIPTION FACTOR NF-KAPPAB (NUCLEAR FACTOR KAPPA-LIGHT-CHAIN-ENHANCER OF ACTIVATED B CELLS) AS A CRUCIAL MEDIATOR OF INFLAMMATORY RESPONSES. THIS, TOGETHER WITH THE FINDING THAT THE ACTIVATION OR INHIBITION OF NF-KAPPAB CAN INDUCE OR REVERSE RESPECTIVELY THE MAIN FEATURES OF AGED ORGANISMS, HAS BROUGHT IT UNDER CONSIDERATION AS A KEY TRANSCRIPTION FACTOR THAT ACTS AS A DRIVER OF AGEING. IN THIS REVIEW, WE FOCUSED ON THE DATA OBTAINED ENTIRELY THROUGH THE GENERATION OF KNOCKOUT AND TRANSGENIC MOUSE MODELS OF EITHER PROTEIN INVOLVED IN THE NF-KAPPAB SIGNALING PATHWAY THAT HAVE PROVIDED RELEVANT INFORMATION ABOUT THE INTRICATE PROCESSES OR MOLECULAR MECHANISMS THAT CONTROL AGEING. WE HAVE REVIEWED THE RELATIONSHIP OF NF-KAPPAB AND PREMATURE AGEING; THE DEVELOPMENT OF CANCER ASSOCIATED WITH AGEING AND THE IMPLICATION OF NF-KAPPAB ACTIVATION IN THE DEVELOPMENT OF AGE-RELATED DISEASES, SOME OF WHICH GREATLY INCREASE THE RISK OF DEVELOPING CANCER. 2021 20 1597 30 DNA METHYLATION REGULATED GENE EXPRESSION IN ORGAN FIBROSIS. DNA METHYLATION IS A MAJOR EPIGENETIC MECHANISM TO REGULATE GENE EXPRESSION. EPIGENETIC REGULATION, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND RNA INTERFERENCE, RESULTS IN HERITABLE CHANGES IN GENE EXPRESSION INDEPENDENT OF ALTERATIONS IN DNA SEQUENCE. EPIGENETIC REGULATION OFTEN OCCURS IN RESPONSE TO AGING AND ENVIRONMENT STIMULI, INCLUDING EXPOSURES AND DIET. STUDIES HAVE SHOWN THAT DNA METHYLATION IS CRITICAL IN THE PATHOGENESIS OF FIBROSIS INVOLVING MULTIPLE ORGAN SYSTEMS, CONTRIBUTING TO SIGNIFICANT MORBIDITY AND MORTALITY. ABERRANT DNA METHYLATION CAN SILENCE OR ACTIVATE GENE EXPRESSION PATTERNS THAT DRIVE THE FIBROSIS PROCESS. FIBROSIS IS A PATHOLOGICAL WOUND HEALING PROCESS IN RESPONSE TO CHRONIC INJURY. IT IS CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX PRODUCTION AND ACCUMULATION, WHICH EVENTUALLY AFFECTS ORGAN ARCHITECTURE AND RESULTS IN ORGAN FAILURE. FIBROSIS CAN AFFECT A WIDE RANGE OF ORGANS, INCLUDING THE HEART AND LUNGS, AND HAVE LIMITED THERAPEUTIC OPTIONS. DNA METHYLATION, LIKE OTHER EPIGENETIC PROCESS, IS REVERSIBLE, THEREFORE REGARDED AS ATTRACTIVE THERAPEUTIC INTERVENTIONS. ALTHOUGH EPIGENETIC MECHANISMS ARE HIGHLY INTERACTIVE AND OFTEN REINFORCING, THIS REVIEW DISCUSSES DNA METHYLATION-DEPENDENT MECHANISMS IN THE PATHOGENESIS OF ORGAN FIBROSIS, WITH FOCUS ON CARDIAC AND PULMONARY FIBROSIS. WE DISCUSS SPECIFIC PRO- AND ANTI-FIBROTIC GENES AND PATHWAYS REGULATED BY DNA METHYLATION IN ORGAN FIBROSIS; WE FURTHER HIGHLIGHT THE POTENTIAL BENEFITS AND SIDE-EFFECTS OF EPIGENETIC THERAPIES IN FIBROTIC DISORDERS. 2017