1 5532 183 RODENT MODELS OF GROUP 1 PULMONARY HYPERTENSION. WORLD HEALTH ORGANIZATION CATEGORY 1 PULMONARY HYPERTENSION (PH) IS A HETEROGENEOUS SYNDROME IN WHICH PH ORIGINATES IN THE SMALL PULMONARY ARTERIES AND IS THEREFORE ALSO REFERRED TO AS PULMONARY ARTERIAL HYPERTENSION (PAH). COMMON PATHOPHYSIOLOGIC FEATURES INCLUDE ENDOTHELIAL DYSFUNCTION, EXCESSIVE PROLIFERATION AND IMPAIRED APOPTOSIS OF VASCULAR CELLS, AND MITOCHONDRIAL FRAGMENTATION. THE PROLIFERATION/APOPTOSIS IMBALANCE RELATES IN PART TO ACTIVATION OF THE TRANSCRIPTION FACTORS HYPOXIA-INDUCIBLE FACTOR-1ALPHA (HIF-1ALPHA) AND NUCLEAR FACTOR OF ACTIVATED T-CELLS (NFAT) AND APOPTOSIS REPRESSORS, SUCH AS SURVIVIN. PERIVASCULAR INFLAMMATION, DISRUPTION OF ADVENTITIAL CONNECTIVE TISSUE, AND A GLYCOLYTIC METABOLIC SHIFT IN VASCULAR CELLS AND RIGHT VENTRICULAR MYOCYTES ALSO OCCUR IN PAH. THERE ARE IMPORTANT GENETIC AND EPIGENETIC PREDISPOSITIONS TO PAH. THIS REVIEW ASSESSES THE FIDELITY OF EXISTING ANIMAL MODELS TO HUMAN PAH. NO SINGLE MODEL CAN PERFECTLY RECAPITULATE THE MANY DIVERSE FORMS OF PH IN CATEGORY 1; HOWEVER, ACCEPTABLE MODELS EXIST. PAH INDUCED BY MONOCROTALINE AND CHRONIC HYPOXIA PLUS SU-5416 (CH+SU) IN RATS DISPLAY ENDOTHELIAL DYSFUNCTION, PROLIFERATION/APOPTOSIS IMBALANCE, AND DEVELOP THE GLYCOLYTIC METABOLIC PROFILE OF HUMAN PAH. HISTOLOGICALLY, CH+SU BEST CONFORMS TO PAH IN THAT IT DEVELOPS COMPLEX VASCULAR LESIONS, INCLUDING PLEXIFORM LESIONS. HOWEVER, THE MONOCROTALINE MODEL CAN BE INDUCED TO MANIFEST COMPLEX VASCULAR LESIONS AND DOES MANIFEST THE TENDENCY OF PAH PATIENTS TO DIE OF RIGHT VENTRICULAR (RV) FAILURE. MURINE MODELS OFFER GREATER MOLECULAR CERTAINTY THAN RAT MODELS BUT RARELY DEVELOP SIGNIFICANT PH, HAVE LESS RIGHT VENTRICULAR HYPERTROPHY (RVH) AND PULMONARY ARTERY (PA) REMODELING, AND ARE HARDER TO IMAGE AND CATHETERIZE. THE USE OF HIGH FIDELITY CATHETERIZATION AND ADVANCED IMAGING (MICROPET-CT, HIGH FREQUENCY ECHOCARDIOGRAPHY, HIGH FIELD STRENGTH MRI) AND FUNCTIONAL TESTING (TREADMILL) PERMIT ACCURATE PHENOTYPING OF EXPERIMENTAL MODELS OF PAH. PRECLINICAL TRIAL DESIGN IS AN IMPORTANT ASPECT OF TESTING EXPERIMENTAL PAH THERAPIES. THE USE OF MULTIPLE COMPLEMENTARY MODELS WITH ADEQUATE SAMPLE SIZE AND TRIAL DURATION AND APPROPRIATE ENDPOINTS ARE REQUIRED FOR PRECLINICAL ASSESSMENT OF EXPERIMENTAL PAH THERAPIES. 2013 2 2356 48 EPIGENETIC REGULATION OF PULMONARY ARTERIAL HYPERTENSION-INDUCED VASCULAR AND RIGHT VENTRICULAR REMODELING: NEW OPPORTUNITIES? PULMONARY ARTERY HYPERTENSION (PAH) IS A RARE CHRONIC DISEASE WITH HIGH IMPACT ON PATIENTS' QUALITY OF LIFE AND CURRENTLY NO AVAILABLE CURE. PAH IS CHARACTERIZED BY CONSTANT REMODELING OF THE PULMONARY ARTERY BY INCREASED PROLIFERATION AND MIGRATION OF PULMONARY ARTERIAL SMOOTH MUSCLE CELLS (PASMCS), FIBROBLASTS (FBS) AND ENDOTHELIAL CELLS (ECS). THIS REMODELING EVENTUALLY LEADS TO INCREASED PRESSURE IN THE RIGHT VENTRICLE (RV) AND SUBSEQUENT RIGHT VENTRICLE HYPERTROPHY (RVH) WHICH, WHEN LEFT UNTREATED, PROGRESSES INTO RIGHT VENTRICLE FAILURE (RVF). PAH CAN NOT ONLY ORIGINATE FROM HERITABLE MUTATIONS, BUT ALSO DEVELOP AS A CONSEQUENCE OF CONGENITAL HEART DISEASE, EXPOSURE TO DRUGS OR TOXINS, HIV, CONNECTIVE TISSUE DISEASE OR BE IDIOPATHIC. WHILE MUCH ATTENTION WAS DRAWN INTO INVESTIGATING AND DEVELOPING THERAPIES RELATED TO THE MOST WELL UNDERSTOOD SIGNALING PATHWAYS IN PAH, IN THE LAST DECADE, A SHIFT TOWARDS UNDERSTANDING THE EPIGENETIC MECHANISMS DRIVING THE DISEASE OCCURRED. IN THIS REVIEW, WE REFLECT ON THE DIFFERENT EPIGENETIC REGULATORY FACTORS THAT ARE ASSOCIATED WITH THE PATHOLOGY OF RV REMODELING, AND ON THEIR RELEVANCE TOWARDS A BETTER UNDERSTANDING OF THE DISEASE AND SUBSEQUENTLY, THE DEVELOPMENT OF NEW AND MORE EFFICIENT THERAPEUTIC STRATEGIES. 2020 3 4978 37 PATHOPHYSIOLOGY AND NEW ADVANCES IN PULMONARY HYPERTENSION. PULMONARY HYPERTENSION IS A PROGRESSIVE AND OFTEN FATAL CARDIOPULMONARY CONDITION CHARACTERISED BY INCREASED PULMONARY ARTERIAL PRESSURE, STRUCTURAL CHANGES IN THE PULMONARY CIRCULATION, AND THE FORMATION OF VASO-OCCLUSIVE LESIONS. THESE CHANGES LEAD TO INCREASED RIGHT VENTRICULAR AFTERLOAD, WHICH OFTEN PROGRESSES TO MALADAPTIVE RIGHT VENTRICULAR REMODELLING AND EVENTUALLY DEATH. PULMONARY ARTERIAL HYPERTENSION REPRESENTS ONE OF THE MOST SEVERE AND BEST STUDIED TYPES OF PULMONARY HYPERTENSION AND IS CONSISTENTLY TARGETED BY DRUG TREATMENTS. THE UNDERLYING MOLECULAR PATHOGENESIS OF PULMONARY HYPERTENSION IS A COMPLEX AND MULTIFACTORIAL PROCESS, BUT CAN BE CHARACTERISED BY SEVERAL HALLMARKS: INFLAMMATION, IMPAIRED ANGIOGENESIS, METABOLIC ALTERATIONS, GENETIC OR EPIGENETIC ABNORMALITIES, INFLUENCE OF SEX AND SEX HORMONES, AND ABNORMALITIES IN THE RIGHT VENTRICLE. CURRENT TREATMENTS FOR PULMONARY ARTERIAL HYPERTENSION AND SOME OTHER TYPES OF PULMONARY HYPERTENSION TARGET PATHWAYS INVOLVED IN THE CONTROL OF PULMONARY VASCULAR TONE AND PROLIFERATION; HOWEVER, THESE TREATMENTS HAVE LIMITED EFFICACY ON PATIENT OUTCOMES. THIS REVIEW DESCRIBES KEY FEATURES OF PULMONARY HYPERTENSION, DISCUSSES CURRENT AND EMERGING THERAPEUTIC INTERVENTIONS, AND POINTS TO FUTURE DIRECTIONS FOR RESEARCH AND PATIENT CARE. BECAUSE MOST PROGRESS IN THE SPECIALTY HAS BEEN MADE IN PULMONARY ARTERIAL HYPERTENSION, THIS REVIEW FOCUSES ON THIS TYPE OF PULMONARY HYPERTENSION. THE REVIEW HIGHLIGHTS KEY PATHOPHYSIOLOGICAL CONCEPTS AND EMERGING THERAPEUTIC DIRECTIONS, TARGETING INFLAMMATION, CELLULAR METABOLISM, GENETICS AND EPIGENETICS, SEX HORMONE SIGNALLING, BONE MORPHOGENETIC PROTEIN SIGNALLING, AND INHIBITION OF TYROSINE KINASE RECEPTORS. 2023 4 3299 29 HIGH-FAT DIET RELATED LUNG FIBROSIS-EPIGENETIC REGULATION MATTERS. PULMONARY FIBROSIS (PF) IS AN INTERSTITIAL LUNG DISEASE CHARACTERIZED BY THE DESTRUCTION OF THE PULMONARY PARENCHYMA CAUSED BY EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION. DESPITE THE WELL-KNOWN ETIOLOGICAL FACTORS SUCH AS SENESCENCE, ABERRANT EPITHELIAL CELL AND FIBROBLAST ACTIVATION, AND CHRONIC INFLAMMATION, PF HAS RECENTLY BEEN RECOGNIZED AS A METABOLIC DISEASE AND ABNORMAL LIPID SIGNATURE WAS OBSERVED BOTH IN SERUM AND BRONCHOALVEOLAR LAVAGE FLUID (BALF) OF PF PATIENTS AND MICE PF MODEL. CLINICALLY, OBSERVATIONAL STUDIES SUGGEST A SIGNIFICANT LINK BETWEEN HIGH-FAT DIET (HFD) AND PF AS MANIFESTED BY HIGH INTAKE OF SATURATED FATTY ACIDS (SFAS) AND MEAT INCREASES THE RISK OF PF AND MICE LUNG FIBROSIS. HOWEVER, THE POSSIBLE MECHANISMS BETWEEN HFD AND PF REMAIN UNCLEAR. IN THE CURRENT REVIEW WE EMPHASIZE THE DIVERSITY EFFECTS OF THE EPIGENETIC DYSREGULATION INDUCED BY HFD ON THE FIBROTIC FACTORS SUCH AS EPITHELIAL CELL INJURY, ABNORMAL FIBROBLAST ACTIVATION AND CHRONIC INFLAMMATION. FINALLY, WE DISCUSS THE POTENTIAL WAYS FOR PATIENTS TO IMPROVE THEIR CONDITIONS AND EMPHASIZE THE PROSPECT OF TARGETED THERAPY BASED ON EPIGENETIC REGULATION FOR SCIENTIFIC RESEARCHERS OR DRUG DEVELOPERS. 2023 5 3846 36 IS ATHEROSCLEROSIS A NEUROGENIC PHENOMENON? IDENTIFIED RISK FACTORS FOR ATHEROSCLEROSIS INCLUDE DIET, AGE, GENDER, FAMILY HISTORY, STRESS, LIFESTYLE, SMOKING, DIABETES, DYSLIPIDEMIAS, HYPERTENSION, AND HIV. THE MECHANISTIC RATIONALE TO EXPLAIN THESE ASSOCIATIONS REMAINS POORLY UNDERSTOOD. WE BELIEVE THAT THESE SEEMINGLY UNRELATED ENTITIES MAY PROMOTE ATHEROSCLEROSIS THROUGH A COMMON PATHWAY BY INDUCING ADVENTITIAL AUTONOMIC DYSFUNCTION, SPECIFICALLY AS AN ADVENTITIAL STRESS DYSFUNCTION OF NEUROGENIC ORIGIN. ATHEROSCLEROSIS MAY REPRESENT A LOCAL VASCULAR MANIFESTATION OF THE GLOBAL AUTONOMIC DYSFUNCTION INDUCED BY AGE, SMOKING, HYPERTENSION, HIV, AND DIABETES. ATHEROSCLEROSIS MAY ALSO PARTICIPATE IN A FEED-FORWARD CYCLE AS AGING, DIABETES, DYSLIPIDEMIA, AND HYPERTENSION MAY ALSO REPRESENT INDEPENDENT DOWNSTREAM CONSEQUENCES OF GLOBAL SYMPATHETIC BIAS. CHRONIC PHYSIOLOGIC STRESS AND BEHAVIORAL STRESS CAN SHIFT THE AUTONOMIC BALANCE TOWARDS A STATE OF SYMPATHETIC PREDOMINANCE. THE HIGHLY COMMUNICABLE NATURE OF BEHAVIORAL STRESS MAY PARTIALLY IMPLICATE THE FAMILIAL ASSOCIATION OF ATHEROSCLEROSIS AS AN EPIGENETIC PHENOMENON, INDEPENDENT OF PUTATIVE GENETIC MECHANISMS. HOST STRESS, GLOBAL AUTONOMIC DYSFUNCTION, AND SYMPATHETIC BIAS MAY ALSO ARISE FROM CHRONIC MALADAPTIVE CONSUMPTION OF STRESSED FOODS, AS ORGANISMS DETECT AND ASSIMILATE THE STRESS PHENOTYPES OF THEIR DIETARY CONSTITUENTS THROUGH A PROCESS CALLED XENOHORMESIS. THE BENEFITS OF EXERCISE MAY OPERATE THROUGH REDUCTION OF CHRONIC PHYSIOLOGIC STRESS ASSOCIATED WITH GLOBAL SYMPATHETIC BIAS. THE NEUROGENIC ADVENTITIAL STRESS RESPONSE MAY EXPLAIN THE LOCAL TISSUE REMODELING SEEN IN ATHEROSCLEROSIS, INCLUDING ADVENTITIAL ADIPOSE DYSFUNCTION, INFLAMMATION, ADVENTITIAL ANGIOGENESIS, THROMBOSIS, AND ENDOTHELIAL DYSFUNCTION. WE BELIEVE THAT THE LOCATIONS OF ATHEROSCLEROTIC LESIONS CORRESPOND TO REGIONS OF NEUROGENIC ADVENTITIAL AUTONOMIC DYSFUNCTION, IN SIMILAR FASHION TO THE SEGMENTAL PATTERNS OF INVOLVEMENT FOUND IN INFLAMMATORY BOWEL DISEASE. THE DIFFUSE ATHEROSCLEROSIS EXHIBITED IN TRANSPLANTED HEARTS MAY REFLECT A DIFFUSE SYMPATHETIC BIAS OF THE DONOR HEART, SINCE TISSUES AND ORGANS EXHIBIT AN INTRINSIC SYMPATHETIC BIAS IN THE ABSENCE OF AN EXTRINSIC SOURCE OF AUTONOMIC HEGEMONY. ONCE WE REGARD ATHEROSCLEROSIS AS A NEUROGENIC PHENOMENON MANIFESTED IN ADVENTITIAL AUTONOMIC DYSFUNCTION, NOVEL DIAGNOSTIC AND THERAPEUTIC PARADIGMS BECOME EVIDENT. 2007 6 4111 42 MECHANISMS CONTRIBUTING TO PERSISTENTLY ACTIVATED CELL PHENOTYPES IN PULMONARY HYPERTENSION. CHRONIC PULMONARY HYPERTENSION (PH) IS CHARACTERIZED BY THE ACCUMULATION OF PERSISTENTLY ACTIVATED CELL TYPES IN THE PULMONARY VESSEL EXHIBITING ABERRANT EXPRESSION OF GENES INVOLVED IN APOPTOSIS RESISTANCE, PROLIFERATION, INFLAMMATION AND EXTRACELLULAR MATRIX (ECM) REMODELLING. CURRENT THERAPIES FOR PH, FOCUSING ON VASODILATATION, DO NOT NORMALIZE THESE ACTIVATED PHENOTYPES. FURTHERMORE, CURRENT APPROACHES TO DEFINE ADDITIONAL THERAPEUTIC TARGETS HAVE FOCUSED ON DETERMINING THE INITIATING SIGNALS AND THEIR DOWNSTREAM EFFECTORS THAT ARE IMPORTANT IN PH ONSET AND DEVELOPMENT. ALTHOUGH THESE APPROACHES HAVE PRODUCED A LARGE NUMBER OF COMPELLING PH TREATMENT TARGETS, MANY PROMISING HUMAN DRUGS HAVE FAILED IN PH CLINICAL TRIALS. HEREIN, WE PROPOSE THAT ONE CONTRIBUTING FACTOR TO THESE FAILURES IS THAT PROCESSES IMPORTANT IN PH DEVELOPMENT MAY NOT BE GOOD TREATMENT TARGETS IN THE ESTABLISHED PHASE OF CHRONIC PH. WE HYPOTHESIZE THAT THIS IS DUE TO ALTERATIONS OF CHROMATIN STRUCTURE IN PH CELLS, RESULTING IN FUNCTIONAL DIFFERENCES BETWEEN THE SAME FACTOR OR PATHWAY IN NORMAL OR EARLY PH CELLS VERSUS CELLS IN CHRONIC PH. WE PROPOSE THAT THE HIGH EXPRESSION OF GENES INVOLVED IN THE PERSISTENTLY ACTIVATED PHENOTYPE OF PH VASCULAR CELLS IS PERPETUATED BY AN OPEN CHROMATIN STRUCTURE AND MULTIPLE TRANSCRIPTION FACTORS (TFS) VIA THE RECRUITMENT OF HIGH LEVELS OF EPIGENETIC REGULATORS INCLUDING THE HISTONE ACETYLASES P300/CBP, HISTONE ACETYLATION READERS INCLUDING BRDS, THE MEDIATOR COMPLEX AND THE POSITIVE TRANSCRIPTION ELONGATION FACTOR (ABSTRACT FIGURE). THUS, DETERMINING HOW GENE EXPRESSION IS CONTROLLED BY EXAMINING CHROMATIN STRUCTURE, TFS AND EPIGENETIC REGULATORS ASSOCIATED WITH ABERRANTLY EXPRESSED GENES IN PULMONARY VASCULAR CELLS IN CHRONIC PH, MAY UNCOVER NEW PH THERAPEUTIC TARGETS. 2019 7 6449 44 THERAPEUTIC TARGETING OF TELOMERASE. TELOMERE LENGTH AND CELL FUNCTION CAN BE PRESERVED BY THE HUMAN REVERSE TRANSCRIPTASE TELOMERASE (HTERT), WHICH SYNTHESIZES THE NEW TELOMERIC DNA FROM A RNA TEMPLATE, BUT IS NORMALLY RESTRICTED TO CELLS NEEDING A HIGH PROLIFERATIVE CAPACITY, SUCH AS STEM CELLS. CONSEQUENTLY, TELOMERASE-BASED THERAPIES TO ELONGATE SHORT TELOMERES ARE DEVELOPED, SOME OF WHICH HAVE SUCCESSFULLY REACHED THE STAGE I IN CLINICAL TRIALS. TELOMERASE IS ALSO PERMISSIVE FOR TUMORIGENESIS AND 90% OF ALL MALIGNANT TUMORS USE TELOMERASE TO OBTAIN IMMORTALITY. THUS, REVERSAL OF TELOMERASE UPREGULATION IN TUMOR CELLS IS A POTENTIAL STRATEGY TO TREAT CANCER. NATURAL AND SMALL-MOLECULE TELOMERASE INHIBITORS, IMMUNOTHERAPEUTIC APPROACHES, OLIGONUCLEOTIDE INHIBITORS, AND TELOMERASE-DIRECTED GENE THERAPY ARE USEFUL TREATMENT STRATEGIES. TELOMERASE IS MORE WIDELY EXPRESSED THAN ANY OTHER TUMOR MARKER. THE LOW EXPRESSION IN NORMAL TISSUES, TOGETHER WITH THE LONGER TELOMERES IN NORMAL STEM CELLS VERSUS CANCER CELLS, PROVIDES SOME DEGREE OF SPECIFICITY WITH LOW RISK OF TOXICITY. HOWEVER, LONG TERM TELOMERASE INHIBITION MAY ELICIT NEGATIVE EFFECTS IN HIGHLY-PROLIFERATIVE CELLS WHICH NEED TELOMERASE FOR SURVIVAL, AND IT MAY INTERFERE WITH TELOMERE-INDEPENDENT PHYSIOLOGICAL FUNCTIONS. MOREOVER, ONLY A FEW HTERT MOLECULES ARE REQUIRED TO OVERCOME SENESCENCE IN CANCER CELLS, AND TELOMERASE INHIBITION REQUIRES PROLIFERATING CELLS OVER A SUFFICIENT NUMBER OF POPULATION DOUBLINGS TO INDUCE TUMOR SUPPRESSIVE SENESCENCE. THESE LIMITATIONS MAY EXPLAIN THE MODERATE SUCCESS RATES IN MANY CLINICAL STUDIES. DESPITE EXTENSIVE STUDIES, ONLY ONE VACCINE AND ONE TELOMERASE ANTAGONIST ARE ROUTINELY USED IN CLINICAL WORK. FOR COMPLETE ERADICATION OF ALL SUBPOPULATIONS OF CANCER CELLS A SIMULTANEOUS TARGETING OF SEVERAL MECHANISMS WILL LIKELY BE NEEDED. POSSIBLE TECHNICAL IMPROVEMENTS HAVE BEEN PROPOSED INCLUDING THE DEVELOPMENT OF MORE SPECIFIC INHIBITORS, METHODS TO INCREASE THE EFFICACY OF VACCINATION METHODS, AND PERSONALIZED APPROACHES. TELOMERASE ACTIVATION AND CELL REJUVENATION IS SUCCESSFULLY USED IN REGENERATIVE MEDICINE FOR TISSUE ENGINEERING AND RECONSTRUCTIVE SURGERY. HOWEVER, THERE ARE ALSO A NUMBER OF PITFALLS IN THE TREATMENT WITH TELOMERASE ACTIVATING PROCEDURES FOR THE WHOLE ORGANISM AND FOR LONGER PERIODS OF TIME. EXTENDED CELL LIFESPAN MAY ACCUMULATE RARE GENETIC AND EPIGENETIC ABERRATIONS THAT CAN CONTRIBUTE TO MALIGNANT TRANSFORMATION. THEREFORE, NOVEL VECTOR SYSTEMS HAVE BEEN DEVELOPED FOR A 'MILD' INTEGRATION OF TELOMERASE INTO THE HOST GENOME AND LOSS OF THE VECTOR IN RAPIDLY-PROLIFERATING CELLS. IT IS CURRENTLY UNCLEAR IF THIS TECHNIQUE CAN ALSO BE USED IN HUMAN BEINGS TO TREAT CHRONIC DISEASES, SUCH AS ATHEROSCLEROSIS. 2016 8 5618 26 SARS-COV-2 INTERACTION WITH HUMAN DNA METHYL TRANSFERASE 1: A POTENTIAL RISK FOR INCREASING THE INCIDENCE OF LATER CHRONIC DISEASES IN THE SURVIVED PATIENTS. CURRENTLY, THE COVID-19 PANDEMIC IS THE MOST DISCUSSED SUBJECT IN MEDICAL RESEARCHES WORLDWIDE. AS THE KNOWLEDGE IS EXPANDED ABOUT THE DISEASE, MORE HYPOTHESES BECOME CREATED. A RECENT STUDY ON THE VIRAL PROTEIN INTERACTION MAP REVEALED THAT SARS-COV-2 OPEN READING FRAME 8 (ORF8) INTERACTS WITH HUMAN DNA METHYL TRANSFERASE1 (DNMT1), AN ACTIVE EPIGENETIC AGENT IN DNA METHYLATION. MOREOVER, DNMT1 IS A CONTRIBUTOR TO A VARIETY OF CHRONIC DISEASES WHICH COULD CAUSE SOME EPIGENETIC DYSREGULATION IN INFECTED CELLS, ESPECIALLY LEUKOCYTES, PANCREATIC BETA, AND ENDOTHELIAL CELLS. REGARDING THE FACT THAT EPIGENETIC ALTERATIONS HAVE A PARTIAL, BUT NOT COMPLETELY REVERSIBLE PHENOMENA, IT RAISES THE QUESTION THAT IF THIS INTERACTION MAY CAUSE LONG-TERM COMPLICATIONS SUCH AS DIABETES, ATHEROSCLEROSIS, CANCER, AND AUTOIMMUNE DISEASES. ACCORDINGLY, LONG FOLLOW-UP STUDIES ON THE RECOVERED PATIENTS FROM COVID-19 ARE RECOMMENDED. 2022 9 2687 38 EVIDENCE OF EPIGENETIC ALTERATIONS IN THROMBOSIS AND COAGULATION: A SYSTEMATIC REVIEW. THROMBOSIS IN THE CONTEXT OF CARDIOVASCULAR DISEASE (CVD) AFFECTS MAINLY THE BLOOD VESSELS SUPPLYING THE HEART, BRAIN AND PERIPHERIES AND IT IS THE LEADING CAUSE OF DEATH WORLDWIDE. THE PATHOPHYSIOLOGICAL THROMBOTIC MECHANISMS ARE LARGELY UNKNOWN. HERITABILITY CONTRIBUTES TO A 30% OF THE INCIDENCE OF CVD. THE REMAINING VARIATION CAN BE EXPLAINED BY LIFE STYLE FACTORS SUCH AS SMOKING, DIETARY AND EXERCISE HABITS, ENVIRONMENTAL EXPOSURE TO TOXINS, AND DRUG USAGE AND OTHER COMORBIDITIES. EPIGENETIC VARIATION CAN BE ACQUIRED OR INHERITED AND CONSTITUTES AN INTERACTION BETWEEN GENES AND THE ENVIRONMENT. EPIGENETICS HAVE BEEN IMPLICATED IN ATHEROSCLEROSIS, ISCHEMIA/REPERFUSION DAMAGE AND THE CARDIOVASCULAR RESPONSE TO HYPOXIA. EPIGENETIC REGULATORS OF GENE EXPRESSION ARE MAINLY THE METHYLATION OF CPG ISLANDS, HISTONE POST TRANSLATIONAL MODIFICATIONS (PTMS) AND MICRORNAS (MIRNAS). THESE EPIGENETIC REGULATORS CONTROL GENE EXPRESSION EITHER THROUGH ACTIVATION OR SILENCING. EPIGENETIC CONTROL IS MOSTLY DYNAMIC AND CAN POTENTIALLY BE MANIPULATED TO PREVENT OR REVERSE THE UNCONTROLLED EXPRESSION OF GENES, A TRAIT THAT RENDERS THEM PUTATIVE THERAPEUTIC TARGETS. IN THE CURRENT REVIEW, WE SYSTEMATICALLY STUDIED AND PRESENT AVAILABLE DATA ON EPIGENETIC ALTERATIONS IMPLICATED IN THROMBOSIS DERIVED FROM HUMAN STUDIES. EVIDENCE OF EPIGENETIC ALTERATIONS IS OBSERVED IN SEVERAL THROMBOTIC DISEASES SUCH AS CORONARY ARTERY DISEASE AND CEREBROVASCULAR DISEASE, PREECLAMPSIA AND ANTIPHOSPHOLIPID SYNDROME. DIFFERENTIAL CPG METHYLATION AND SPECIFIC HISTONE PTMS THAT CONTROL TRANSCRIPTION OF PROTHROMBOTIC AND PROINFLAMMATORY GENES HAVE ALSO BEEN ASSOCIATED WITH PREDISPOSING FACTORS OF THROMBOSIS AND CVD, SUCH US SMOKING, AIR POLLUTION, HYPERTRIGLYCERIDEMIA, OCCUPATIONAL EXPOSURE TO PARTICULATE MATTER AND COMORBIDITIES INCLUDING CANCER, CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND CHRONIC KIDNEY DISEASE. THESE CLINICAL OBSERVATIONS ARE FURTHER SUPPORTED BY IN VITRO EXPERIMENTS AND INDICATE THAT EPIGENETIC REGULATION AFFECTS THE PATHOPHYSIOLOGY OF THROMBOTIC DISORDERS WITH POTENTIAL DIAGNOSTIC OR THERAPEUTIC UTILITY. 2019 10 540 32 ATMOSPHERIC FINE PARTICULATE MATTER AND EPITHELIAL MESENCHYMAL TRANSITION IN PULMONARY CELLS: STATE OF THE ART AND CRITICAL REVIEW OF THE IN VITRO STUDIES. EXPOSURE TO FINE PARTICULATE MATTER (PM(2.5)) HAS BEEN ASSOCIATED WITH SEVERAL DISEASES INCLUDING ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER. MECHANISMS SUCH AS OXIDATIVE STRESS AND INFLAMMATION ARE WELL-DOCUMENTED AND ARE CONSIDERED AS THE STARTING POINT OF SOME OF THE PATHOLOGICAL RESPONSES. HOWEVER, A NUMBER OF STUDIES ALSO FOCUSED ON EPITHELIAL-MESENCHYMAL TRANSITION (EMT), WHICH IS A BIOLOGICAL PROCESS INVOLVED IN FIBROTIC DISEASES AND CANCER PROGRESSION NOTABLY VIA METASTASIS INDUCTION. UP UNTIL NOW, EMT WAS WIDELY REPORTED IN VIVO AND IN VITRO IN VARIOUS CELL TYPES BUT INVESTIGATIONS DEALING WITH IN VITRO STUDIES OF PM(2.5) INDUCED EMT IN PULMONARY CELLS ARE LIMITED. FURTHER, FEW INVESTIGATIONS COMBINED THE NECESSARY ENDPOINTS FOR VALIDATION OF THE EMT STATE IN CELLS: SUCH AS EXPRESSION OF SEVERAL SURFACE, CYTOSKELETON OR EXTRACELLULAR MATRIX BIOMARKERS AND ACTIVATION OF TRANSCRIPTION MARKERS AND EPIGENETIC FACTORS. STUDIES EXPLORED VARIOUS CELL TYPES, CULTURED UNDER DIFFERING CONDITIONS AND EXPOSED FOR VARIOUS DURATIONS TO DIFFERENT DOSES. SUCH UNHARMONIZED PROTOCOLS (1) MIGHT INTRODUCE BIAS, (2) MAKE DIFFICULT COMPARISON OF RESULTS AND (3) PRECLUDE REACHING A DEFINITIVE CONCLUSION REGARDING THE ABILITY OF AIRBORNE PM(2.5) TO INDUCE EMT IN PULMONARY CELLS. SOME QUESTIONS REMAIN, IN PARTICULAR THE SPECIFIC PM(2.5) COMPONENTS RESPONSIBLE FOR EMT TRIGGERING. THE AIM OF THIS REVIEW IS TO EXAMINE THE AVAILABLE PM(2.5) INDUCED EMT IN VITRO STUDIES ON PULMONARY CELLS WITH SPECIAL EMPHASIS ON THE CRITICAL PARAMETERS CONSIDERED TO CARRY OUT FUTURE RESEARCH IN THIS FIELD. THIS CLARIFICATION APPEARS NECESSARY FOR PRODUCTION OF RELIABLE AND COMPARABLE RESULTS. 2020 11 5318 31 PSYCHONEUROENDOCRINE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE: A REVIEW. THERE IS EVIDENCE SUGGESTING THAT IMMUNOSENESCENCE CAN BE ACCELERATED BY EXTERNAL FACTORS SUCH AS CHRONIC STRESS. HERE WE REVIEW POTENTIAL PSYCHONEUROENDOCRINE DETERMINANTS OF PREMATURE AGING OF THE IMMUNE SYSTEM AND DISCUSS AVAILABLE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE. CHRONIC STRESS MAY ACCELERATE VARIOUS FEATURES OF IMMUNOSENESCENCE BY ACTIVATING KEY ALLOSTATIC SYSTEMS, NOTABLY THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. THE IMMUNOLOGICAL IMPACT OF SUCH NEUROENDOCRINE DYSREGULATION MAY BE FURTHER AMPLIFIED BY A DRAMATIC DECLINE IN DEHYDROEPIANDROSTERONE (DHEA) LEVELS, ACTING IN PART AS AN ENDOGENOUS GLUCOCORTICOID ANTAGONIST. STRESS-BUFFERING STRATEGIES SHOW BENEFICIAL EFFECTS ON VARIOUS BIOMARKERS IN ELDERLY POPULATIONS. LIKEWISE, SUPPLEMENTATION OF DHEA, MELATONIN OR GROWTH HORMONE HAS YIELDED SIGNIFICANT BENEFICIAL EFFECTS IN A NUMBER OF STUDIES, INCLUDING: INCREASED WELL-BEING, MEMORY PERFORMANCE, BONE MINERAL DENSITY AND IMPROVED IMMUNOCOMPETENCE AS EVIDENCED BY RESULTS OF IN VITRO (T CELL PROLIFERATION, CYTOTOXICITY, CYTOKINE PRODUCTION), AND IN VIVO IMMUNE CHALLENGES. HOWEVER, THE SIDE-EFFECTS OF HORMONAL SUPPLEMENTATION ARE ALSO DISCUSSED. FINALLY, MODERATE EXERCISE VIA THE PROMOTION OF CORTISOL/DHEA BALANCE OR EPIGENETIC MODIFICATIONS, IS ASSOCIATED WITH LOWER SERUM PRO-INFLAMMATORY CYTOKINES, GREATER LYMPHOPROLIFERATIVE RESPONSES AND LOWER COUNTS OF SENESCENT T CELLS. TAKEN TOGETHER, THESE DATA SUGGEST THAT IMMUNE SYSTEM IS PLASTIC AND IMMUNOSENESCENCE CAN BE ATTENUATED PSYCHONEUROENDOCRINE INTERVENTIONS. 2013 12 6199 39 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 13 4029 39 LUNGS, BONE MARROW, AND ADIPOSE TISSUE. A NETWORK APPROACH TO THE PATHOBIOLOGY OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) OFTEN SUFFER OTHER CONCOMITANT DISORDERS, SUCH AS CARDIOVASCULAR DISEASES AND METABOLIC DISORDERS, THAT INFLUENCE SIGNIFICANTLY (AND INDEPENDENTLY OF LUNG FUNCTION) THEIR HEALTH STATUS AND PROGNOSIS. THUS, COPD IS NOT A SINGLE ORGAN CONDITION, AND DISTURBANCES OF A COMPLEX NETWORK OF INTERORGAN CONNECTED RESPONSES OCCUR AND MODULATE THE NATURAL HISTORY OF THE DISEASE. HERE, WE PROPOSE A NOVEL HYPOTHESIS THAT CONSIDERS A VASCULARLY CONNECTED NETWORK WITH (1) THE LUNGS AS THE MAIN EXTERNAL SENSOR OF THE SYSTEM AND A MAJOR SOURCE OF "DANGER SIGNALS"; (2) THE ENDOTHELIUM AS AN INTERNAL SENSOR OF THE SYSTEM (ALSO A POTENTIAL TARGET TISSUE); AND (3) TWO KEY RESPONDING ELEMENTS, BONE MARROW AND ADIPOSE TISSUE, WHICH PRODUCE BOTH INFLAMMATORY AND REPAIR SIGNALS. ACCORDING TO THE MODEL, THE DEVELOPMENT OF COPD, AND ASSOCIATED MULTIMORBIDITIES (HERE WE FOCUS ON CARDIOVASCULAR DISEASE AS AN IMPORTANT EXAMPLE), DEPEND ON THE MANNER IN WHICH THE VASCULAR CONNECTED NETWORK RESPONDS, ADAPTS, OR FAILS TO ADAPT (DICTATED BY THE GENETIC AND EPIGENETIC BACKGROUND OF THE INDIVIDUAL) TO THE INHALATION OF PARTICLES AND GASES, MAINLY IN CIGARETTE SMOKE. THE CAVEATS AND LIMITATIONS OF THE HYPOTHESIS, AS WELL AS THE EXPERIMENTAL AND CLINICAL RESEARCH NEEDED TO TEST AND EXPLORE THE PROPOSED MODEL, ARE ALSO BRIEFLY DISCUSSED. 2013 14 5471 35 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 15 288 39 AGING AND INDUCED SENESCENCE AS FACTORS IN THE PATHOGENESIS OF LUNG EMPHYSEMA. CLASSICALLY, THE DEVELOPMENT OF EMPHYSEMA IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE IS BELIEVED TO INVOLVE INFLAMMATION INDUCED BY CIGARETTE SMOKE AND LEUKOCYTE ACTIVATION, INCLUDING OXIDANT-ANTIOXIDANT AND PROTEASE-ANTIPROTEASE IMBALANCES. WHILE THERE IS SUBSTANTIAL EVIDENCE FOR THIS, ADDITIONAL ASPECTS HAVE BEEN SUGGESTED BY A NUMBER OF CLINICAL AND EXPERIMENTAL OBSERVATIONS. SMOKERS EXHIBIT SIGNS OF PREMATURE AGING, PARTICULARLY OBVIOUS IN THE SKIN. THE LINK BETWEEN AGING AND CHRONIC DISEASE IS WELL-KNOWN, E.G., FOR THE BRAIN AND MUSCULOSKELETAL OR CARDIOVASCULAR SYSTEM, AS WELL AS THE CLINICAL LINK BETWEEN MALNUTRITION AND EMPHYSEMA, AND THE EXPERIMENTAL LINK TO CALORIC RESTRICTION. INTERESTINGLY, THIS INTERVENTION ALSO INCREASES LIFESPAN, IN PARALLEL WITH ALTERATIONS IN METABOLISM, OXIDANT BURDEN AND ENDOCRINE SIGNALING. OF SPECIAL INTEREST IS THE OBSERVATION THAT, EVEN IN THE ABSENCE OF AN INFLAMMATORY ENVIRONMENT, LUNG FIBROBLASTS FROM PATIENTS WITH EMPHYSEMA SHOW PERSISTENT ALTERATIONS, POSSIBLY BASED ON EPIGENETIC MECHANISMS. THE IMPORTANCE OF THESE MECHANISMS FOR CELLULAR REPROGRAMMING AND RESPONSE PATTERNS, INDIVIDUAL RISK PROFILE AND THERAPEUTIC OPTIONS IS BECOMING INCREASINGLY RECOGNIZED. THE SAME APPLIES TO CELLULAR SENESCENCE. RECENT FINDINGS FROM PATIENTS AND EXPERIMENTAL MODELS OPEN NOVEL VIEWS INTO THE ARENA OF GENE-ENVIRONMENT INTERACTIONS, INCLUDING THE ROLE OF SYSTEMIC ALTERATIONS, CELLULAR STRESS, TELOMERES, CDK INHIBITORS SUCH AS P16, P21, PRB, PI3K, MTOR, FOXO TRANSCRIPTION FACTORS, HISTONE MODIFICATIONS, AND SIRTUINS. THIS ARTICLE AIMS TO OUTLINE THIS EMERGING PICTURE AND TO STIMULATE THE IDENTIFICATION OF CHALLENGING QUESTIONS. SUCH INSIGHTS ALSO BEAR IMPLICATIONS FOR THE LONG-TERM COURSE OF THE DISEASE IN RELATION TO EXISTING OR FUTURE THERAPIES AND THE EXPLORATION OF POTENTIAL LUNG REGENERATION. 2008 16 3676 38 INFLAMMATION AND NEUTROPHIL IMMUNOSENESCENCE IN HEALTH AND DISEASE: TARGETED TREATMENTS TO IMPROVE CLINICAL OUTCOMES IN THE ELDERLY. DESPITE INCREASING LONGEVITY, MANY OLD PEOPLE ARE NOT IN GOOD HEALTH. THERE HAS BEEN AN INCREASE IN THE PREVALENCE OF AGE-ASSOCIATED MULTI-MORBIDITY (TWO OR MORE CHRONIC CONDITIONS IN THE SAME PERSON). ALSO, SEVERE INFECTIONS, SUCH AS PNEUMONIA, REMAIN SIGNIFICANT CAUSES OF MORTALITY AND MORBIDITY IN THIS AGING GROUP. MANY CHRONIC HEALTH CONDITIONS SHARE RISK FACTORS SUCH AS INCREASING AGE, SMOKING, A SEDENTARY LIFE STYLE AND BEING PART OF A LOWER SOCIOECONOMIC GROUP. HOWEVER, DESPITE THIS, MULTI-MORBIDITIES OFTEN CO-OCCUR MORE COMMONLY THAN WOULD BE PREDICTED. THIS HAS LED TO THE HYPOTHESIS THAT THEY SHARE COMMON UNDERLYING MECHANISMS. THIS IS AN IMPORTANT CONCEPT, FOR IF IT WERE TRUE, TREATMENTS COULD BE DEVISED WHICH TARGET THESE COMMON PATHWAYS AND IMPROVE A NUMBER OF AGE-ASSOCIATED HEALTH CONDITIONS. MANY CHRONIC ILLNESSES ASSOCIATED WITH MULTI-MORBIDITY AND SEVERE INFECTIONS ARE CHARACTERIZED BY AN ABNORMAL AND SUSTAINED INFLAMMATORY RESPONSE, WITH NEUTROPHILS BEING KEY EFFECTOR CELLS IN THE PATHOLOGICAL PROCESS. STUDIES HAVE DESCRIBED ABERRANT NEUTROPHIL FUNCTIONS ACROSS THESE CONDITIONS, AND SOME HAVE HIGHLIGHTED POTENTIAL MECHANISMS FOR ALTERED CELL BEHAVIOURS WHICH APPEAR SHARED ACROSS DISEASE STATES. IT HAS BEEN SUGGESTED THAT ALTERED FUNCTIONS MAY REPRESENT NEUTROPHIL "SENESCENCE". THIS REVIEW CONSIDERS HOW AND WHY NEUTROPHIL FUNCTIONS CHANGE AS THE CELL AGES, AND HOW AND WHY NEUTROPHIL FUNCTIONS CHANGE AS THE HOST AGES IN HEALTH AND DISEASE AND DISCUSSES WHETHER NEUTROPHIL FUNCTIONS COULD BE TARGETED TO IMPROVE HEALTH OUTCOMES IN OLDER ADULTS. 2018 17 4028 32 LUNG TUMORS, COPD AND IMMUNE RESPONSE: IS EPIGENETICS THE BOTTOM LINE? NSCLC IS A HETEROGENEOUS DISORDER CONSISTING OF DISTINCT MOLECULAR SUBTYPES WHICH CAN BE TREATED BY USING SPECIFIC DRUGS TARGETED TO DISTINCT GENETIC LESIONS. IT IS WELL KNOWN THAT NSCLS INCIDENCE IS HIGHER IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS BECAUSE THEY SHARE A COMMON RISK FACTOR (CIGARETTE SMOKING) AND IT IS BELIEVED THAT THE TYPICAL INFLAMMATORY MICROENVIRONMENT OBSERVED IN COPD MAY INFLUENCE THE MOLECULAR MECHANISMS RESPONSIBLE OF CARCINOGENESIS. IN THE LAST YEARS, THE ROLE OF EPIGENETIC PROCESSES IN CELL BIOLOGY AND TISSUE PATHOLOGY HAS BEEN EXTENSIVELY STUDIED BOTH IN COPD AND NSCLC. THE RECENT PAPER BY WAUTERS ET AL. SHOWED A SPECIFIC PATTERN OF DRIVER MUTATIONS AND MOLECULAR FEATURES IN NSCLC RAISING IN THE CONTEXT OF COPD. ALL THESE FINDINGS HAVE SHOWN FOR THE FIRST TIME THAT LUNG TUMORS FOUND IN COPD PATIENTS DIFFER FROM THOSE OBSERVED IN PATIENT WITHOUT COPD DUE TO THE PRESENCE OF A SPECIFIC TUMOR MICROENVIRONMENT WHICH IS CHARACTERIZED BY REDUCED CD4+ TREG CELLS. ON THIS BASIS, THE PRESENT WORK AIMS AT DISCUSSING AND ANALYZING THE CONTEXT-SPECIFIC MECHANISMS OF CLONAL SELECTION AND EVOLUTION MAINLY FOCUSING ON THE EPIGENETIC ALTERATIONS AND AT POINTING OUT THE POTENTIAL THERAPEUTIC IMPLICATIONS. 2016 18 551 35 AUTOIMMUNITY AS AN ETIOLOGICAL FACTOR OF CANCER: THE TRANSFORMATIVE POTENTIAL OF CHRONIC TYPE 2 INFLAMMATION. RECENT EPIDEMIOLOGICAL STUDIES HAVE FOUND AN ALARMING TREND OF INCREASED CANCER INCIDENCE IN ADULTS YOUNGER THAN 50 YEARS OF AGE AND PROJECTED A SUBSTANTIAL RISE IN CANCER INCIDENCE OVER THE NEXT 10 YEARS IN THIS AGE GROUP. THIS TREND WAS EXEMPLIFIED IN THE INCIDENCE OF NON-CARDIA GASTRIC CANCER AND ITS DISPROPORTIONATE IMPACT ON NON-HISPANIC WHITE FEMALES UNDER THE AGE OF 50. THE TREND IS CONCURRENT WITH THE INCREASING INCIDENCE OF AUTOIMMUNE DISEASES IN INDUSTRIALIZED COUNTRIES, SUGGESTING A CAUSAL LINK BETWEEN THE TWO. WHILE AUTOIMMUNITY HAS BEEN SUSPECTED TO BE A RISK FACTOR FOR SOME CANCERS, THE EXACT MECHANISMS UNDERLYING THE CONNECTION BETWEEN AUTOIMMUNITY AND CANCER REMAIN UNCLEAR AND ARE OFTEN CONTROVERSIAL. THE LINK HAS BEEN ATTRIBUTED TO SEVERAL MEDIATORS SUCH AS IMMUNE SUPPRESSION, INFECTION, DIET, ENVIRONMENT, OR, PERHAPS MOST PLAUSIBLY, CHRONIC INFLAMMATION BECAUSE OF ITS WELL-RECOGNIZED ROLE IN TUMORIGENESIS. IN THAT REGARD, AUTOIMMUNE CONDITIONS ARE COMMON CAUSES OF CHRONIC INFLAMMATION AND MAY TRIGGER REPETITIVE CYCLES OF ANTIGEN-SPECIFIC CELL DAMAGE, TISSUE REGENERATION, AND WOUND HEALING. ILLUSTRATING THE CONNECTION BETWEEN AUTOIMMUNE DISEASES AND CANCER ARE PATIENTS WHO HAVE AN INCREASED RISK OF CANCER DEVELOPMENT ASSOCIATED WITH GENETICALLY PREDISPOSED INSUFFICIENCY OF CYTOTOXIC T LYMPHOCYTE-ASSOCIATED PROTEIN 4 (CTLA4), A PROTOTYPICAL IMMUNE CHECKPOINT AGAINST AUTOIMMUNITY AND ONE OF THE MAIN TARGETS OF CANCER IMMUNE THERAPY. THE TUMORIGENIC PROCESS TRIGGERED BY CTLA4 INSUFFICIENCY HAS BEEN SHOWN IN A MOUSE MODEL TO BE DEPENDENT ON THE TYPE 2 CYTOKINES INTERLEUKIN-4 (IL4) AND INTERLEUKIN-13 (IL13). IN THIS TYPE 2 INFLAMMATORY MILIEU, CROSSTALK WITH TYPE 2 IMMUNE CELLS MAY INITIATE EPIGENETIC REPROGRAMMING OF EPITHELIAL CELLS, LEADING TO A METAPLASTIC DIFFERENTIATION AND EVENTUALLY MALIGNANT TRANSFORMATION EVEN IN THE ABSENCE OF CLASSICAL ONCOGENIC MUTATIONS. THOSE FINDINGS COMPLEMENT A LARGE BODY OF EVIDENCE FOR TYPE 1, TYPE 3, OR OTHER INFLAMMATORY MEDIATORS IN INFLAMMATORY TUMORIGENESIS. THIS REVIEW ADDRESSES THE POTENTIAL OF AUTOIMMUNITY AS A CAUSAL FACTOR FOR TUMORIGENESIS, THE UNDERLYING INFLAMMATORY MECHANISMS THAT MAY VARY DEPENDING ON HOST-ENVIRONMENT VARIATIONS, AND IMPLICATIONS TO CANCER PREVENTION AND IMMUNOTHERAPY. 2021 19 3710 42 INFLUENCES OF POLYCYCLIC AROMATIC HYDROCARBON ON THE EPIGENOME TOXICITY AND ITS APPLICABILITY IN HUMAN HEALTH RISK ASSESSMENT. THE EXISTENCE OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMBIENT AIR IS AN ESCALATING CONCERN WORLDWIDE BECAUSE OF THEIR ABILITY TO CAUSE CANCER AND INDUCE PERMANENT CHANGES IN THE GENETIC MATERIAL. GROWING EVIDENCE IMPLIES THAT DURING EARLY LIFE-SENSITIVE STAGES, THE RISK OF PROGRESSION OF ACUTE AND CHRONIC DISEASES DEPENDS ON EPIGENETIC CHANGES INITIATED BY THE INFLUENCE OF ENVIRONMENTAL CUES. SEVERAL REPORTS DECIPHERED THE RELATIONSHIP BETWEEN EXPOSURE TO ENVIRONMENTAL CHEMICALS AND EPIGENETICS, AND HAVE KNOWN TOXICANTS THAT ALTER THE EPIGENETIC STATES. AMONGST PAHS, BENZO[A]PYRENE (B[A]P) IS ACCEPTED AS A GROUP 1 CANCER-CAUSING AGENT BY THE INTERNATIONAL AGENCY FOR THE RESEARCH ON CANCER (IARC). B[A]P IS A WELL-STUDIED PRO-CARCINOGEN THAT IS METABOLICALLY ACTIVATED BY THE ARYL HYDROCARBON RECEPTOR (AHR)/CYTOCHROME P450 PATHWAY. CYTOCHROME P450 PLAYS A PIVOTAL ROLE IN THE STIMULATION STEP, WHICH IS ESSENTIAL FOR DNA ADDUCT FORMATION. ACCRUING EVIDENCE SUGGESTS THAT EPIGENETIC ALTERATIONS ASSUME A FUNDAMENTAL PART IN PAH-PROMOTED CARCINOGENESIS. THIS INTERACTION BETWEEN PAHS AND EPIGENETIC FACTORS RESULTS IN AN ALTERED PROFILE OF THESE MARKS, GLOBALLY AND LOCUS-SPECIFIC. SOME OF THE EPIGENETIC CHANGES DUE TO EXPOSURE TO PAHS LEAD TO INCREASED DISEASE SUSCEPTIBILITY AND PROGRESSION. IT IS WELL UNDERSTOOD THAT EXPOSURE TO ENVIRONMENTAL CARCINOGENS, SUCH AS PAH TRIGGERS DISEASE PATHWAYS THROUGH CHANGES IN THE GENOME. SEVERAL EVIDENCE REPORTED DUE TO THE EPIGENOME-WIDE ASSOCIATION STUDIES, THAT EARLY LIFE ADVERSE ENVIRONMENTAL EVENTS MAY TRIGGER WIDESPREAD AND PERSISTENT VARIATIONS IN TRANSCRIPTIONAL PROFILING. MOREOVER, THESE VARIATIONS RESPOND TO DNA DAMAGE AND/OR A CONSEQUENCE OF EPIGENETIC MODIFICATIONS THAT NEED FURTHER INVESTIGATION. GROWING EVIDENCE HAS ASSOCIATED PAHS WITH EPIGENETIC VARIATIONS INVOLVING ALTERATIONS IN DNA METHYLATION, HISTONE MODIFICATION, AND MICRO RNA (MIRNA) REGULATION. EPIGENETIC ALTERATIONS TO PAH EXPOSURE WERE RELATED TO CHRONIC DISEASES, SUCH AS PULMONARY DISEASE, CARDIOVASCULAR DISEASE, ENDOCRINE DISRUPTOR, NERVOUS SYSTEM DISORDER, AND CANCER. THIS HORMETIC RESPONSE GIVES A NOVEL PERCEPTION CONCERNING THE TOXICITY OF PAHS AND THE BIOLOGICAL REACTION THAT MAY BE A DISTINCT RELIANCE ON EXPOSURE. THIS REVIEW SHEDS LIGHT ON UNDERSTANDING THE LATEST EVIDENCE ABOUT HOW PAHS CAN ALTER EPIGENETIC PATTERNS AND HUMAN HEALTH. IN CONCLUSION, AS SEVERAL EPIGENETIC CHANGE MECHANISMS REMAIN UNCLEAR YET, FURTHER ANALYSES DERIVED FROM PAHS EXPOSURE MUST BE PERFORMED TO FIND NEW TARGETS AND DISEASE BIOMARKERS. IN SPITE OF THE CURRENT LIMITATIONS, NUMEROUS EVIDENCE SUPPORTS THE PERCEPTION THAT EPIGENETICS GRIPS SUBSTANTIAL POTENTIAL FOR ADVANCING OUR KNOWLEDGE ABOUT THE MOLECULAR MECHANISMS OF ENVIRONMENTAL TOXICANTS, ALSO FOR PREDICTING HEALTH-ASSOCIATED RISKS DUE TO ENVIRONMENTAL CIRCUMSTANCES EXPOSURE AND INDIVIDUAL SUSCEPTIBILITY. 2022 20 4543 37 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