1 2348 119 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 2 2505 72 EPIGENETICS AND MUSCLE DYSFUNCTION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMMON, PREVENTABLE, AND TREATABLE DISEASE AND A MAJOR LEADING CAUSE OF MORBIDITY AND MORTALITY WORLDWIDE. IN COPD, COMORBIDITIES, ACUTE EXACERBATIONS, AND SYSTEMIC MANIFESTATIONS NEGATIVELY INFLUENCE DISEASE SEVERITY AND PROGRESSION REGARDLESS OF THE RESPIRATORY CONDITION. SKELETAL MUSCLE DYSFUNCTION, WHICH IS ONE OF THE COMMONEST SYSTEMIC MANIFESTATIONS IN PATIENTS WITH COPD, HAS A TREMENDOUS IMPACT ON THEIR EXERCISE CAPACITY AND QUALITY OF LIFE. SEVERAL PATHOPHYSIOLOGICAL AND MOLECULAR UNDERLYING MECHANISMS INCLUDING EPIGENETICS (THE PROCESS WHEREBY GENE EXPRESSION IS REGULATED BY HERITABLE MECHANISMS THAT DO NOT AFFECT DNA SEQUENCE) HAVE BEEN SHOWN TO PARTICIPATE IN THE ETIOLOGY OF COPD MUSCLE DYSFUNCTION. THE EPIGENETIC MODIFICATIONS IDENTIFIED SO FAR IN CELLS INCLUDE DNA METHYLATION, HISTONE ACETYLATION AND METHYLATION, AND NONCODING RNAS SUCH AS MICRORNAS. HEREIN, WE FIRST REVIEW THE ROLE OF EPIGENETIC MECHANISMS IN MUSCLE DEVELOPMENT AND ADAPTATION TO ENVIRONMENTAL FACTORS IN SEVERAL MODELS. MOREOVER, THE EPIGENETIC EVENTS REPORTED SO FAR TO BE POTENTIALLY INVOLVED IN MUSCLE DYSFUNCTION AND MASS LOSS OF PATIENTS WITH COPD ARE ALSO DISCUSSED. FURTHERMORE, THE DIFFERENT EXPRESSION PROFILE OF SEVERAL MUSCLE-ENRICHED MICRORNAS IN THE DIAPHRAGM AND VASTUS LATERALIS MUSCLES OF PATIENTS WITH COPD ARE ALSO REVIEWED FROM RESULTS RECENTLY OBTAINED IN OUR GROUP. THE ROLE OF PROTEIN HYPERACETYLATION IN ENHANCED MUSCLE PROTEIN CATABOLISM OF LIMB MUSCLES IS ALSO DISCUSSED. FUTURE RESEARCH SHOULD FOCUS ON THE FULL ELUCIDATION OF THE TRIGGERS OF EPIGENETIC MECHANISMS AND THEIR SPECIFIC DOWNSTREAM BIOLOGICAL PATHWAYS IN COPD MUSCLE DYSFUNCTION AND WASTING. 2015 3 4410 46 MOLECULAR AND BIOLOGICAL PATHWAYS OF SKELETAL MUSCLE DYSFUNCTION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) WILL BE A MAJOR LEADING CAUSE OF DEATH WORLDWIDE IN THE NEAR FUTURE. WEAKNESS AND ATROPHY OF THE QUADRICEPS ARE ASSOCIATED WITH A SIGNIFICANTLY POORER PROGNOSIS AND INCREASED MORTALITY IN COPD. DESPITE THAT SKELETAL MUSCLE DYSFUNCTION MAY AFFECT BOTH RESPIRATORY AND LIMB MUSCLE GROUPS IN COPD, THE LATTER ARE FREQUENTLY MORE SEVERELY AFFECTED. THEREFORE, MUSCLE DYSFUNCTION IN COPD IS A COMMON SYSTEMIC MANIFESTATION THAT SHOULD BE EVALUATED ON ROUTINE BASIS IN CLINICAL SETTINGS. IN THE PRESENT REVIEW, SEVERAL ASPECTS OF COPD MUSCLE DYSFUNCTION ARE BEING REVIEWED, WITH SPECIAL EMPHASIS ON THE UNDERLYING BIOLOGICAL MECHANISMS. FIGURES ON THE PREVALENCE OF COPD MUSCLE DYSFUNCTION AND THE MOST RELEVANT ETIOLOGIC CONTRIBUTORS ARE ALSO PROVIDED. DESPITE THAT ONGOING RESEARCH WILL SHED LIGHT INTO THE CONTRIBUTION OF ADDITIONAL MECHANISMS TO COPD MUSCLE DYSFUNCTION, CURRENT KNOWLEDGE POINTS TOWARD THE INVOLVEMENT OF A WIDE SPECTRUM OF CELLULAR AND MOLECULAR EVENTS THAT ARE DIFFERENTIALLY EXPRESSED IN RESPIRATORY AND LIMB MUSCLES. SUCH MECHANISMS ARE THOROUGHLY DESCRIBED IN THE ARTICLE. THE CONTRIBUTION OF EPIGENETIC EVENTS ON COPD MUSCLE DYSFUNCTION IS ALSO REVIEWED. WE CONCLUDE THAT IN VIEW OF THE LATEST DISCOVERIES, FROM NOW, ON NEW AVENUES OF RESEARCH SHOULD BE DESIGNED TO SPECIFICALLY TARGET CELLULAR MECHANISMS AND PATHWAYS THAT IMPAIR MUSCLE MASS AND FUNCTION IN COPD USING PHARMACOLOGICAL STRATEGIES AND/OR EXERCISE TRAINING MODALITIES. 2016 4 6199 41 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 5 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 6 2360 30 EPIGENETIC REGULATION OF SKELETAL MUSCLE METABOLISM. NORMAL SKELETAL MUSCLE METABOLISM IS ESSENTIAL FOR WHOLE BODY METABOLIC HOMOEOSTASIS AND DISRUPTIONS IN MUSCLE METABOLISM ARE ASSOCIATED WITH A NUMBER OF CHRONIC DISEASES. TRANSCRIPTIONAL CONTROL OF METABOLIC ENZYME EXPRESSION IS A MAJOR REGULATORY MECHANISM FOR MUSCLE METABOLIC PROCESSES. SUBSTANTIAL EVIDENCE IS EMERGING THAT HIGHLIGHTS THE IMPORTANCE OF EPIGENETIC MECHANISMS IN THIS PROCESS. THIS REVIEW WILL EXAMINE THE IMPORTANCE OF EPIGENETICS IN THE REGULATION OF MUSCLE METABOLISM, WITH A PARTICULAR EMPHASIS ON DNA METHYLATION AND HISTONE ACETYLATION AS EPIGENETIC CONTROL POINTS. THE EMERGING CROSS-TALK BETWEEN METABOLISM AND EPIGENETICS IN THE CONTEXT OF HEALTH AND DISEASE WILL ALSO BE EXAMINED. THE CONCEPT OF INHERITANCE OF SKELETAL MUSCLE METABOLIC PHENOTYPES WILL BE DISCUSSED, IN ADDITION TO EMERGING EPIGENETIC THERAPIES THAT COULD BE USED TO ALTER MUSCLE METABOLISM IN CHRONIC DISEASE STATES. 2016 7 3581 38 IMPACT OF PHYSICAL ACTIVITY AND EXERCISE ON THE EPIGENOME IN SKELETAL MUSCLE AND EFFECTS ON SYSTEMIC METABOLISM. EXERCISE AND PHYSICAL ACTIVITY INDUCES PHYSIOLOGICAL RESPONSES IN ORGANISMS, AND ADAPTATIONS IN SKELETAL MUSCLE, WHICH IS BENEFICIAL FOR MAINTAINING HEALTH AND PREVENTING AND/OR TREATING MOST CHRONIC DISEASES. THESE ADAPTATIONS ARE MAINLY INSTIGATED BY TRANSCRIPTIONAL RESPONSES THAT ENSUE IN REACTION TO EACH INDIVIDUAL EXERCISE, EITHER RESISTANCE OR ENDURANCE. CONSEQUENTLY, CHANGES IN KEY METABOLIC, REGULATORY, AND MYOGENIC GENES IN SKELETAL MUSCLE OCCUR AS BOTH AN EARLY AND LATE RESPONSE TO EXERCISE, AND THESE EPIGENETIC MODIFICATIONS, WHICH ARE INFLUENCED BY ENVIRONMENTAL AND GENETIC FACTORS, TRIGGER THOSE ALTERATIONS IN THE TRANSCRIPTIONAL RESPONSES. DNA METHYLATION AND HISTONE MODIFICATIONS ARE THE MOST SIGNIFICANT EPIGENETIC CHANGES DESCRIBED IN GENE TRANSCRIPTION, LINKED TO THE SKELETAL MUSCLE TRANSCRIPTIONAL RESPONSE TO EXERCISE, AND MEDIATING THE EXERCISE ADAPTATIONS. NEVERTHELESS, OTHER ALTERATIONS IN THE EPIGENETICS MARKERS, SUCH AS EPITRANSCRIPTOMICS, MODIFICATIONS MEDIATED BY MIRNAS, AND LACTYLATION AS A NOVEL EPIGENETIC MODIFICATION, ARE EMERGING AS KEY EVENTS FOR GENE TRANSCRIPTION. HERE, WE PROVIDE AN OVERVIEW AND UPDATE OF THE IMPACT OF EXERCISE ON EPIGENETIC MODIFICATIONS, INCLUDING THE WELL-DESCRIBED DNA METHYLATIONS AND HISTONE MODIFICATIONS, AND THE EMERGING MODIFICATIONS IN THE SKELETAL MUSCLE. IN ADDITION, WE DESCRIBE THE EFFECTS OF EXERCISE ON EPIGENETIC MARKERS IN OTHER METABOLIC TISSUES; ALSO, WE PROVIDE INFORMATION ABOUT HOW SYSTEMIC METABOLISM OR ITS METABOLITES INFLUENCE EPIGENETIC MODIFICATIONS IN THE SKELETAL MUSCLE. 2022 8 2499 31 EPIGENETICS AND EXERCISE. EPIGENETICS CAN BE DEFINED AS 'THE STRUCTURAL ADAPTATION OF CHROMOSOMAL REGIONS SO AS TO REGISTER, SIGNAL, OR PERPETUATE ALTERED ACTIVITY STATES.' INCREASED TRANSCRIPTION OF KEY REGULATORY, METABOLIC, AND MYOGENIC GENES IS AN EARLY RESPONSE TO EXERCISE AND IS IMPORTANT IN MEDIATING SUBSEQUENT ADAPTATIONS IN SKELETAL MUSCLE. DNA HYPOMETHYLATION AND HISTONE HYPERACETYLATION ARE EMERGING AS IMPORTANT CRUCIAL EVENTS FOR INCREASED TRANSCRIPTION. THE COMPLEX INTERACTIONS BETWEEN MULTIPLE EPIGENETIC MODIFICATIONS AND THEIR REGULATION BY METABOLIC CHANGES AND SIGNALING EVENTS DURING EXERCISE, WITH IMPLICATIONS FOR ENHANCED UNDERSTANDING OF THE ACUTE AND CHRONIC ADAPTATIONS TO EXERCISE, ARE QUESTIONS FOR FURTHER INVESTIGATION. 2019 9 2357 44 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 10 4543 45 MUSCLE DYSFUNCTION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE: UPDATE ON CAUSES AND BIOLOGICAL FINDINGS. RESPIRATORY AND/OR LIMB MUSCLE DYSFUNCTION, WHICH ARE FREQUENTLY OBSERVED IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS, CONTRIBUTE TO THEIR DISEASE PROGNOSIS IRRESPECTIVE OF THE LUNG FUNCTION. MUSCLE DYSFUNCTION IS CAUSED BY THE INTERACTION OF LOCAL AND SYSTEMIC FACTORS. THE KEY DELETERIOUS ETIOLOGIC FACTORS ARE PULMONARY HYPERINFLATION FOR THE RESPIRATORY MUSCLES AND DECONDITIONING SECONDARY TO REDUCED PHYSICAL ACTIVITY FOR LIMB MUSCLES. NONETHELESS, CIGARETTE SMOKE, SYSTEMIC INFLAMMATION, NUTRITIONAL ABNORMALITIES, EXERCISE, EXACERBATIONS, ANABOLIC INSUFFICIENCY, DRUGS AND COMORBIDITIES ALSO SEEM TO PLAY A RELEVANT ROLE. ALL THESE FACTORS MODIFY THE PHENOTYPE OF THE MUSCLES, THROUGH THE INDUCTION OF SEVERAL BIOLOGICAL PHENOMENA IN PATIENTS WITH COPD. WHILE RESPIRATORY MUSCLES IMPROVE THEIR AEROBIC PHENOTYPE (PERCENTAGE OF OXIDATIVE FIBERS, CAPILLARIZATION, MITOCHONDRIAL DENSITY, ENZYME ACTIVITY IN THE AEROBIC PATHWAYS, ETC.), LIMB MUSCLES EXHIBIT THE OPPOSITE PHENOTYPE. IN ADDITION, BOTH MUSCLE GROUPS SHOW OXIDATIVE STRESS, SIGNS OF DAMAGE AND EPIGENETIC CHANGES. HOWEVER, FIBER ATROPHY, INCREASED NUMBER OF INFLAMMATORY CELLS, ALTERED REGENERATIVE CAPACITY; SIGNS OF APOPTOSIS AND AUTOPHAGY, AND AN IMBALANCE BETWEEN PROTEIN SYNTHESIS AND BREAKDOWN ARE RATHER CHARACTERISTIC FEATURES OF THE LIMB MUSCLES, MOSTLY IN PATIENTS WITH REDUCED BODY WEIGHT. DESPITE THAT SIGNIFICANT PROGRESS HAS BEEN ACHIEVED IN THE LAST DECADES, FULL ELUCIDATION OF THE SPECIFIC ROLES OF THE TARGET BIOLOGICAL MECHANISMS INVOLVED IN COPD MUSCLE DYSFUNCTION IS STILL REQUIRED. SUCH AN ACHIEVEMENT WILL BE CRUCIAL TO ADEQUATELY TACKLE WITH THIS RELEVANT CLINICAL PROBLEM OF COPD PATIENTS IN THE NEAR-FUTURE. 2015 11 2161 38 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 12 5471 36 RESPIRATORY MUSCLE SENESCENCE IN AGEING AND CHRONIC LUNG DISEASES. AGEING IS A PROGRESSIVE CONDITION THAT USUALLY LEADS TO THE LOSS OF PHYSIOLOGICAL PROPERTIES. THIS PROCESS IS ALSO PRESENT IN RESPIRATORY MUSCLES, WHICH ARE AFFECTED BY BOTH SENESCENT CHANGES OCCURRING IN THE WHOLE ORGANISM AND THOSE THAT ARE MORE SPECIFIC FOR MUSCLES. THE MECHANISMS OF THE LATTER CHANGES INCLUDE OXIDATIVE STRESS, DECREASE IN NEUROTROPHIC FACTORS AND DNA ABNORMALITIES. AGEING NORMALLY COEXISTS WITH COMORBIDITIES, INCLUDING RESPIRATORY DISEASES, WHICH FURTHER DETERIORATE THE STRUCTURE AND FUNCTION OF RESPIRATORY MUSCLES. IN THIS CONTEXT, CHANGES INTRINSIC TO AGEING BECOME ENHANCED BY MORE SPECIFIC FACTORS SUCH AS THE IMPAIRMENT IN LUNG MECHANICS AND GAS EXCHANGE, EXACERBATIONS AND HYPOXIA. HYPOXIA IN PARTICULAR HAS A DIRECT EFFECT ON MUSCLES, MAINLY THROUGH THE EXPRESSION OF INDUCIBLE FACTORS (HYPOXIC-INDUCIBLE FACTOR), AND CAN RESULT IN OXIDATIVE STRESS AND CHANGES IN DNA, DECREASE IN MITOCHONDRIAL BIOGENESIS AND DEFECTS IN THE TISSUE REPAIR MECHANISMS. INTENSE EXERCISE CAN ALSO CAUSE DAMAGE IN RESPIRATORY MUSCLES OF ELDERLY RESPIRATORY PATIENTS, BUT THIS CAN BE FOLLOWED BY TISSUE REPAIR AND REMODELLING. HOWEVER, AGEING INTERFERES WITH MUSCLE REPAIR BY TAMPERING WITH THE FUNCTION OF SATELLITE CELLS, MAINLY DUE TO OXIDATIVE STRESS, DNA DAMAGE AND EPIGENETIC MECHANISMS. IN ADDITION TO THE NORMAL PROCESS OF AGEING, STRESS-INDUCED PREMATURE SENESCENCE CAN ALSO OCCUR, INVOLVING CHANGES IN THE EXPRESSION OF MULTIPLE GENES BUT WITHOUT MODIFICATIONS IN TELOMERE LENGTH. 2020 13 6533 42 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 14 2457 36 EPIGENETIC TARGETS FOR THERAPEUTIC APPROACHES IN COPD AND ASTHMA. NUTRIGENOMICS - POSSIBLE OR ILLUSIVE. OXIDATIVE STRESS GENERATED BY CIGARETTE SMOKING, ENVIRONMENTAL POLLUTION, OR OTHER NOXIOUS PARTICLES LEADS TO EPIGENETIC CHANGES IN THE CELLS OF THE RESPIRATORY TRACT. THEY REFLECT CELL ADAPTATION IN RESPONSE TO CHRONIC EXPOSURE TO EXTERNAL FACTORS. ALTHOUGH THERE IS NO CHANGE IN THE GENETIC CODE, EPIGENETIC CHANGES MAY BE HERITABLE AND TRANSLATED FROM ONE GENERATION TO ANOTHER, ACCUMULATING ABNORMALITIES AND RENDERING CELLS INTO ENTIRELY DIFFERENT PHENOTYPE, CAUSING DISEASE. DNA METHYLATION, POST-TRANSLATION HISTONE MODIFICATION, UBIQUITINATION, SUMOYLATION AND MIRNA TRANSCRIPTIONAL REGULATION ARE THE MAJOR PROCESSES THAT ARE RESPONSIBLE FOR THE EPIGENETIC CONTROL OF GENE EXPRESSION. ALL OF THEM ARE REVERSIBLE. THEY CAN BE REGULATED BY TARGETING SPECIFIC ENZYMES/PROTEINS INVOLVED IN THE PROCESS IN ORDER TO MITIGATE INFLAMMATION. CHRONIC RESPIRATORY DISEASES HAVE EPIGENETIC SIGNATURES THAT AFFECT GENE EXPRESSION IN THE LUNG. TARGETING THEM PROVIDES THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND THERAPEUTIC APPROACHES IN RESPIRATORY MEDICINE. NUTRIGENOMICS REVEALS THE BENEFICIAL EFFECT OF NATURAL PHYTOCHEMICALS, AFFECTING KEY STEPS IN THE SIGNALING PATHWAYS OF CHRONIC RESPIRATORY DISEASES. 2019 15 3966 39 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 16 4901 27 OXIDATIVE, INFLAMMATORY, GENETIC, AND EPIGENETIC BIOMARKERS ASSOCIATED WITH CHRONIC OBSTRUCTIVE PULMONARY DISORDER. A LARGE BODY OF EVIDENCE INDICATES THAT CHRONIC OBSTRUCTIVE PULMONARY DISORDER (COPD) IS ACCOMPANIED BY OXIDATIVE STRESS AND INFLAMMATORY AND GENETIC PATHWAYS. EPIDEMIOLOGICAL STUDIES INDICATE THAT COPD IS A MAJOR CAUSE OF MORTALITY AND MORBIDITY IN THE WORLD. RECENT RESEARCH DEVELOPMENT IN COPD FOCUSES ON ACCELERATED AGING AND VARIOUS OXIDATIVE STRESS BIOMARKERS. IT INVOLVES THE CLINICAL MANIFESTATION OF THE DISEASE PROCESS AND MAY ALSO CONTAIN BIOCHEMICAL, IMMUNOLOGICAL, PHYSIOLOGICAL, MORPHOLOGICAL, AND GENETIC ASPECTS THAT ADD TO THE PROGRESSIVENESS OF THE DISEASE. HEREIN, WE SUMMARIZE FINDINGS THAT HIGHLIGHT THE ROLE OF DIMENSIONS OF COPD IN THE INVESTIGATION OF OXIDATIVE STRESS, INFLAMMATORY RESPONSES, GENETIC AND EPIGENETIC STUDIES, AND PHARMACOLOGICAL AND DIETARY ANTIOXIDANT INTERVENTION. 2019 17 2333 36 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 18 971 33 CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND THE HALLMARKS OF AGING. AGING IS CHARACTERIZED BY PROGRESSIVE DETERIORATION OF PHYSIOLOGICAL INTEGRITY, DECLINE IN HOMEOSTASIS, AND DEGENERATION OF THE TISSUES THAT OCCURS AFTER THE REPRODUCTIVE PHASE OF LIFE IS COMPLETE, LEADING TO IMPAIRED FUNCTION. THIS DETERIORATION IS AN IMPORTANT RISK FACTOR FOR CHRONIC LUNG PATHOLOGIES SUCH AS CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). COPD IS A DISEASE THAT DEVELOPS GRADUALLY. EMPHYSEMATOUS CHANGES IN THE LUNG TAKE YEARS TO DEVELOP AFTER EXPOSURE TO CIGARETTE SMOKE; HENCE, THE VAST MAJORITY OF PATIENTS ARE ELDERLY. THERE HAS BEEN A DRAMATIC INCREASE IN THE LIFE EXPECTANCY OF THE GENERAL POPULATION, RESULTING IN AN INCREASED BURDEN OF CHRONIC LUNG DISEASES. THERE IS GROWING EVIDENCE THAT MOLECULAR MECHANISMS INVOLVED IN AGING MAY ALSO PLAY A ROLE IN COPD PATHOGENESIS. RECENTLY, THE NINE HALLMARKS OF AGING WERE IDENTIFIED. IN THIS ARTICLE, WE WILL REVIEW THE NINE HALLMARKS OF AGING AND HOW EACH HALLMARK CONTRIBUTES TO THE PATHOGENESIS OF COPD. 2018 19 6340 38 THE ROLE OF EPIGENETIC FACTORS IN PSORIASIS. PSORIASIS IS A CHRONIC, SYSTEMIC, IMMUNE-MEDIATED DISEASE WITH AN INCIDENCE OF APPROXIMATELY 2%. THE PATHOGENESIS OF THE DISEASE IS COMPLEX AND NOT YET FULLY UNDERSTOOD. GENETIC FACTORS PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS OF THE DISEASE. IN PREDISPOSED INDIVIDUALS, MULTIPLE TRIGGER FACTORS MAY CONTRIBUTE TO DISEASE ONSET AND EXACERBATIONS OF SYMPTOMS. ENVIRONMENTAL FACTORS (STRESS, INFECTIONS, CERTAIN MEDICATIONS, NICOTINISM, ALCOHOL, OBESITY) PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS OF PSORIASIS. IN ADDITION, EPIGENETIC MECHANISMS ARE CONSIDERED RESULT IN MODULATION OF INDIVIDUAL GENE EXPRESSION AND AN INCREASED LIKELIHOOD OF THE DISEASE. STUDIES HIGHLIGHT THE SIGNIFICANT ROLE OF EPIGENETIC FACTORS IN THE ETIOLOGY AND PATHOGENESIS OF PSORIASIS. EPIGENETIC MECHANISMS IN PSORIASIS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS. EPIGENETIC MECHANISMS INDUCE GENE EXPRESSION CHANGES UNDER THE INFLUENCE OF CHEMICAL MODIFICATIONS OF DNA AND HISTONES, WHICH ALTER CHROMATIN STRUCTURE AND ACTIVATE TRANSCRIPTION FACTORS OF SELECTED GENES, THUS LEADING TO TRANSLATION OF NEW MRNA WITHOUT AFFECTING THE DNA SEQUENCE. EPIGENETIC FACTORS CAN REGULATE GENE EXPRESSION AT THE TRANSCRIPTIONAL (VIA HISTONE MODIFICATION, DNA METHYLATION) AND POSTTRANSCRIPTIONAL LEVELS (VIA MICRORNAS AND LONG NON-CODING RNAS). THIS STUDY AIMS TO PRESENT AND DISCUSS THE DIFFERENT EPIGENETIC MECHANISMS IN PSORIASIS BASED ON A REVIEW OF THE AVAILABLE LITERATURE. 2021 20 4026 37 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