1 1476 99 DIVERSE EPIGENETIC REGULATIONS OF MACROPHAGES IN ATHEROSCLEROSIS. EMERGING RESEARCH ON EPIGENETICS HAS RESULTED IN MANY NOVEL DISCOVERIES IN ATHEROSCLEROSIS (AS), AN INFLAMMAGING-ASSOCIATED DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION PRIMARILY DRIVEN BY MACROPHAGES. THE BULK OF EVIDENCE HAS DEMONSTRATED THE CENTRAL ROLE OF EPIGENETIC MACHINERY IN MACROPHAGE POLARIZATION TO PRO- (M1-LIKE) OR ANTI-INFLAMMATORY (M2-LIKE) PHENOTYPE. AN INCREASING NUMBER OF EPIGENETIC ALTERATIONS AND THEIR MODIFIERS INVOLVED IN REPROGRAMMING MACROPHAGES BY REGULATING DNA METHYLATION OR HISTONE MODIFICATIONS (E.G., METHYLATION, ACETYLATION, AND RECENTLY LACTYLATION) HAVE BEEN IDENTIFIED. THEY MAY ACT TO DETERMINE OR SKEW THE DIRECTION OF MACROPHAGE POLARIZATION IN AS LESIONS, THEREBY REPRESENTING A PROMISING TARGET. HERE WE DESCRIBE THE CURRENT UNDERSTANDING OF THE EPIGENETIC MACHINERY INVOLVING MACROPHAGE POLARIZATION, TO SHED LIGHT ON CHRONIC INFLAMMATION-DRIVING ONSET AND PROGRESSION OF INFLAMMAGING-ASSOCIATED DISEASES, USING AS AS A PROTOTYPIC EXAMPLE, AND DISCUSS THE CHALLENGE FOR DEVELOPING EFFECTIVE THERAPIES TARGETING THE EPIGENETIC MODIFIERS AGAINST THESE DISEASES, PARTICULARLY HIGHLIGHTING A POTENTIAL STRATEGY BASED ON EPIGENETICALLY-GOVERNED REPOLARIZATION FROM M1-LIKE TO M2-LIKE PHENOTYPE. 2022 2 5632 26 SENESCENT CELLS: SASPECTED DRIVERS OF AGE-RELATED PATHOLOGIES. THE PROGRESSION OF PHYSIOLOGICAL AGEING IS DRIVEN BY INTRACELLULAR ABERRATIONS INCLUDING TELOMERE ATTRITION, GENOMIC INSTABILITY, EPIGENETIC ALTERATIONS AND LOSS OF PROTEOSTASIS. THESE IN TURN DAMAGE CELLS AND COMPROMISE THEIR FUNCTIONALITY. CELLULAR SENESCENCE, A STABLE IRREVERSIBLE CELL-CYCLE ARREST, IS ELICITED IN DAMAGED CELLS AND PREVENTS THEIR PROPAGATION IN THE ORGANISM. UNDER NORMAL CONDITIONS, SENESCENT CELLS RECRUIT THE IMMUNE SYSTEM WHICH FACILITATES THEIR REMOVAL FROM TISSUES. NEVERTHELESS, DURING AGEING, TISSUE-RESIDING SENESCENT CELLS TEND TO ACCUMULATE, AND MIGHT NEGATIVELY IMPACT THEIR MICROENVIRONMENT VIA PROFOUND SECRETORY PHENOTYPE WITH PRO-INFLAMMATORY CHARACTERISTICS, TERMED SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). INDEED, SENESCENT CELLS ARE MOSTLY ABUNDANT AT SITES OF AGE-RELATED PATHOLOGIES, INCLUDING DEGENERATIVE DISORDERS AND MALIGNANCIES. INTERESTINGLY, STUDIES ON PROGEROID MICE INDICATE THAT SELECTIVE ELIMINATION OF SENESCENT CELLS CAN DELAY AGE-RELATED DETERIORATION. THIS SUGGESTS THAT CHRONIC INFLAMMATION INDUCED BY SENESCENT CELLS MIGHT BE A MAIN DRIVER OF THESE PATHOLOGIES. IMPORTANTLY, SENESCENT CELLS ACCUMULATE AS A RESULT OF DEFICIENT IMMUNE SURVEILLANCE, AND THEIR REMOVAL IS INCREASED UPON THE USE OF IMMUNE STIMULATORY AGENTS. INSIGHTS INTO MECHANISMS OF SENESCENCE SURVEILLANCE COULD BE COMBINED WITH CURRENT APPROACHES FOR CANCER IMMUNOTHERAPY TO PROPOSE NEW PREVENTIVE AND THERAPEUTIC STRATEGIES FOR AGE-RELATED DISEASES. 2014 3 5322 23 PULMONARY DISEASES AND AGEING. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND IDIOPATHIC PULMONARY FIBROSIS ARE REGARDED AS A DISEASES OF ACCELERATED LUNG AGEING AND SHOW ALL OF THE HALLMARKS OF AGEING, INCLUDING TELOMERE SHORTENING, CELLULAR SENESCENCE, ACTIVATION OF PI3 KINASE-MTOR SIGNALING, IMPAIRED AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, STEM CELL EXHAUSTION, EPIGENETIC CHANGES, ABNORMAL MICRORNA PROFILES, IMMUNOSENESCENCE AND A LOW GRADE CHRONIC INFLAMMATION DUE TO SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). MANY OF THESE AGEING MECHANISMS ARE DRIVEN BY EXOGENOUS AND ENDOGENOUS OXIDATIVE STRESS. THERE IS ALSO A REDUCTION IN ANTI-AGEING MOLECULES, SUCH AS SIRTUINS AND KLOTHO, WHICH FURTHER ACCELERATE THE AGEING PROCESS. UNDERSTANDING THESE MOLECULAR MECHANISMS HAS IDENTIFIED SEVERAL NOVEL THERAPEUTIC TARGETS AND SEVERAL DRUGS AND DIETARY INTERVENTIONS ARE NOW IN DEVELOPMENT TO TREAT CHRONIC LUNG DISEASE. 2019 4 5931 75 TARGETING EPIGENETIC MODIFIERS TO REPROGRAMME MACROPHAGES IN NON-RESOLVING INFLAMMATION-DRIVEN ATHEROSCLEROSIS. EPIGENOMIC AND EPIGENETIC RESEARCH HAS BEEN PROVIDING SEVERAL NEW INSIGHTS INTO A VARIETY OF DISEASES CAUSED BY NON-RESOLVING INFLAMMATION, INCLUDING CARDIOVASCULAR DISEASES. ATHEROSCLEROSIS (AS) HAS LONG BEEN RECOGNIZED AS A CHRONIC INFLAMMATORY DISEASE OF THE ARTERIAL WALLS, CHARACTERIZED BY LOCAL PERSISTENT AND STEPWISE ACCELERATING INFLAMMATION WITHOUT RESOLUTION, ALSO KNOWN AS UNCONTROLLED INFLAMMATION. THE PATHOGENESIS OF AS IS DRIVEN PRIMARILY BY HIGHLY PLASTIC MACROPHAGES VIA THEIR POLARIZATION TO PRO- OR ANTI-INFLAMMATORY PHENOTYPES AS WELL AS OTHER NOVEL SUBTYPES RECENTLY IDENTIFIED BY SINGLE-CELL SEQUENCING. ALTHOUGH EMERGING EVIDENCE HAS INDICATED THE KEY ROLE OF THE EPIGENETIC MACHINERY IN THE REGULATION OF MACROPHAGE PLASTICITY, THE INVESTIGATION OF EPIGENETIC ALTERATIONS AND MODIFIERS IN AS AND RELATED INFLAMMATION IS STILL IN ITS INFANCY. AN INCREASING NUMBER OF THE EPIGENETIC MODIFIERS (E.G. TET2, DNMT3A, HDAC3, HDAC9, JMJD3, KDM4A) HAVE BEEN IDENTIFIED IN EPIGENETIC REMODELLING OF MACROPHAGES THROUGH DNA METHYLATION OR HISTONE MODIFICATIONS (E.G. METHYLATION, ACETYLATION, AND RECENTLY LACTYLATION) IN INFLAMMATION. THESE OR MANY UNEXPLORED MODIFIERS FUNCTION TO DETERMINE OR SWITCH THE DIRECTION OF MACROPHAGE POLARIZATION VIA TRANSCRIPTIONAL REPROGRAMMING OF GENE EXPRESSION AND INTRACELLULAR METABOLIC REWIRING UPON MICROENVIRONMENTAL CUES, THEREBY REPRESENTING A PROMISING TARGET FOR ANTI-INFLAMMATORY THERAPY IN AS. HERE, WE REVIEW UP-TO-DATE FINDINGS INVOLVING THE EPIGENETIC REGULATION OF MACROPHAGES TO SHED LIGHT ON THE MECHANISM OF UNCONTROLLED INFLAMMATION DURING AS ONSET AND PROGRESSION. WE ALSO DISCUSS CURRENT CHALLENGES FOR DEVELOPING AN EFFECTIVE AND SAFE ANTI-AS THERAPY THAT TARGETS THE EPIGENETIC MODIFIERS AND PROPOSE A POTENTIAL ANTI-INFLAMMATORY STRATEGY THAT REPOLARIZES MACROPHAGES FROM PRO- TO ANTI-INFLAMMATORY PHENOTYPES. 2021 5 3674 25 INFLAMMATION AND DYSREGULATED FIBROBLAST PROLIFERATION--NEW MECHANISMS? IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE MAY PRIMARILY BE DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS AND THE UNDERLYING MESENCHYME. THE MEDIATORS PRODUCED AND PRESENT IN THIS MICROENVIRONMENT INDUCE THE FORMATION OF FIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE DETAILED MECHANISMS THAT LINK IPF WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN, BUT SOME EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES MAY PLAY A ROLE. THIS REVIEW PROVIDES A BRIEF SYNOPSIS OF HIGHLIGHTS IN THE CURRENT UNDERSTANDING OF THE PATHOPHYSIOLOGY OF IPF, AS WELL AS NOVEL THERAPEUTICS BEING EXPLORED IN CLINICAL TRIALS FOR THE TREATMENT OF THIS DEVASTATING DISEASE. 2013 6 4037 19 MACROPHAGE IMMUNOMETABOLISM AND INFLAMMAGING: ROLES OF MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, CD38, AND NAD. AGING IS A COMPLEX PROCESS THAT INVOLVES DYSFUNCTION ON MULTIPLE LEVELS, ALL OF WHICH SEEM TO CONVERGE ON INFLAMMATION. MACROPHAGES ARE INTIMATELY INVOLVED IN INITIATING AND RESOLVING INFLAMMATION, AND THEIR DYSREGULATION WITH AGE IS A PRIMARY CONTRIBUTOR TO INFLAMMAGING-A STATE OF CHRONIC, LOW-GRADE INFLAMMATION THAT DEVELOPS DURING AGING. AMONG THE AGE-RELATED CHANGES THAT OCCUR TO MACROPHAGES ARE A HEIGHTENED STATE OF BASAL INFLAMMATION AND DIMINISHED OR HYPERACTIVE INFLAMMATORY RESPONSES, WHICH SEEM TO BE DRIVEN BY METABOLIC-DEPENDENT EPIGENETIC CHANGES. IN THIS REVIEW ARTICLE WE PROVIDE A BRIEF OVERVIEW OF MITOCHONDRIAL FUNCTIONS AND AGE-RELATED CHANGES THAT OCCUR TO MACROPHAGES, WITH AN EMPHASIS ON HOW THE INFLAMMAGING ENVIRONMENT, SENESCENCE, AND NAD DECLINE CAN AFFECT THEIR METABOLISM, PROMOTE DYSREGULATION, AND CONTRIBUTE TO INFLAMMAGING AND AGE-RELATED PATHOLOGIES. 2020 7 5407 24 REGULATION AND IMMUNOTHERAPEUTIC TARGETING OF THE EPIGENOME IN EXHAUSTED CD8 T CELL RESPONSES. EXHAUSTION IS A STATE OF CD8 T CELL DIFFERENTIATION THAT OCCURS IN SETTINGS OF CHRONIC AG SUCH AS TUMORS, CHRONIC VIRAL INFECTION, AND AUTOIMMUNITY. CELLULAR DIFFERENTIATION IS DRIVEN BY A SERIES OF ENVIRONMENTAL SIGNALS THAT PROMOTE EPIGENETIC LANDSCAPES THAT SET TRANSCRIPTOMES NEEDED FOR FUNCTION. FOR CD8 T CELLS, THE EPIGENOME THAT UNDERLIES EXHAUSTION IS DISTINCT FROM EFFECTOR AND MEMORY CELL DIFFERENTIATION, SUGGESTING THAT SIGNALS EARLY ON SET IN MOTION A PROCESS WHERE THE EPIGENOME IS MODIFIED TO PROMOTE A TRAJECTORY TOWARD A DYSFUNCTIONAL STATE. ALTHOUGH WE KNOW MANY SIGNALS THAT PROMOTE EXHAUSTION, PUTTING THIS IN THE CONTEXT OF THE EPIGENETIC CHANGES THAT OCCUR DURING DIFFERENTIATION HAS BEEN LESS CLEAR. IN THIS REVIEW, WE AIM TO SUMMARIZE THE EPIGENETIC CHANGES ASSOCIATED WITH EXHAUSTION IN THE CONTEXT OF SIGNALS THAT PROMOTE IT, HIGHLIGHTING IMMUNOTHERAPEUTIC STUDIES THAT SUPPORT THESE OBSERVATIONS OR AREAS FOR FUTURE THERAPEUTIC OPPORTUNITIES. 2023 8 3512 23 IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. THIS DISEASE WAS ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, BUT CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE IS DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS (AECS). THESE CELLS PRODUCE MEDIATORS THAT INDUCE THE FORMATION OF FIBROBLAST AND MYOFIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF THE EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE MECHANISMS THAT LINK IDIOPATHIC PULMONARY FIBROSIS WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN; EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES HAVE A ROLE. IN THIS SEMINAR, WE REVIEW RECENT DATA ON THE CLINICAL COURSE, THERAPEUTIC OPTIONS, AND UNDERLYING MECHANISMS THOUGHT TO BE INVOLVED IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. 2011 9 5140 22 POTENTIAL REGULATORS OF THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE DURING SENESCENCE AND AGING. SENESCENT CELLS EXPRESS AND SECRETE A VARIETY OF EXTRACELLULAR MODULATORS THAT INCLUDE CYTOKINES, CHEMOKINES, PROTEASES, GROWTH FACTORS, AND SOME ENZYMES ASSOCIATED WITH EXTRACELLULAR MATRIX REMODELING, DEFINED AS THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). SASP REINFORCES SENESCENT CELL CYCLE ARREST, STIMULATES AND RECRUITS IMMUNE CELLS FOR IMMUNE-MEDIATED CLEARANCE OF POTENTIALLY TUMORIGENIC CELLS, LIMITS OR INDUCES FIBROSIS, AND PROMOTES WOUND HEALING AND TISSUE REGENERATION. ON THE OTHER HAND, SASP MEDIATES CHRONIC INFLAMMATION LEADING TO THE DESTRUCTION OF TISSUE STRUCTURE AND FUNCTION AND STIMULATING THE GROWTH AND SURVIVAL OF TUMOR CELLS. SASP IS HIGHLY HETEROGENEOUS AND THE ROLE OF SASP DEPENDS ON THE CONTEXT. THE REGULATION OF SASP OCCURS AT MULTIPLE LEVELS INCLUDING CHROMATIN REMODELING, TRANSCRIPTION, MRNA TRANSLATION, INTRACELLULAR TRAFFICKING, AND SECRETION. SEVERAL SASP MODULATORS HAVE ALREADY BEEN IDENTIFIED SETTING THE STAGE FOR FUTURE RESEARCH ON THEIR CLINICAL APPLICATIONS. IN THIS REVIEW, WE SUMMARIZE IN DETAIL THE POTENTIAL SIGNALING PATHWAYS THAT TRIGGER AND REGULATE SASP PRODUCTION DURING AGING AND SENESCENCE. 2022 10 6212 19 THE INTERPLAY OF THE GENETIC ARCHITECTURE, AGING, AND ENVIRONMENTAL FACTORS IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC FIBROSING LUNG DISEASE OF INDETERMINATE ETIOLOGY AND LIMITED THERAPEUTIC OPTIONS. THE INITIATION, DEVELOPMENT, AND PROGRESSION OF IPF ARE INFLUENCED BY GENETIC PREDISPOSITION, AGING, AND HOST AND ENVIRONMENTAL FACTORS, BUT THE MAGNITUDE OF THE CONTRIBUTION OF EACH OF THEM AND THE SEQUENCE OF THE PATHOGENIC EVENTS ARE UNCERTAIN. CURRENT EVIDENCE INDICATES THAT ACCUMULATED ENVIRONMENTAL EXPOSURES IN A GENETICALLY PREDISPOSED INDIVIDUAL, USUALLY OVER 60 YEARS OF AGE, LEADS TO PHENOTYPIC AND FUNCTIONAL ALTERATIONS OF THE LUNG EPITHELIUM. ABERRANT ACTIVATION OF EPITHELIAL CELLS RESULTS, THROUGH A COMPLEX RELEASE OF NUMEROUS MEDIATORS, IN THE LOCAL EXPANSION OF PECULIAR SUBSETS OF AGGRESSIVE FIBROBLASTS AND MYOFIBROBLASTS, WHICH ARE CRUCIAL EFFECTOR CELLS OF FIBROTIC REMODELING AND LOSS OF THE NORMAL LUNG ARCHITECTURE AND FUNCTION. PROGRESSIVE INCREASE OF THE MECHANICAL STIFFNESS ACTIVATES CELL-AUTONOMOUS AND MATRIX-DEPENDENT PROCESSES CONTRIBUTING TO THE PERPETUATION OF THE FIBROTIC RESPONSE. THIS PERSPECTIVE PROVIDES AN INTEGRAL OVERVIEW OF THE MAJOR RISK FACTORS UNDERPINNING THE PATHOGENESIS OF IPF, INCLUDING GENE VARIANTS, AGING ALTERATIONS, ENVIRONMENTAL FACTORS, HOST RISK FACTORS, AND EPIGENETIC REPROGRAMMING. 2021 11 862 26 CHROMATIN REMODELING IN MONOCYTE AND MACROPHAGE ACTIVATION. INCREASING EVIDENCE COLLECTED DURING THE LAST YEARS SUPPORTS THE IDEA THAT MONOCYTE AND MACROPHAGE ACTIVATION IS NOT ONLY ASSOCIATED WITH TRANSCRIPTIONAL CHANGES BUT ALSO CHANGES IN THE CHROMATIN LANDSCAPE. MOREOVER, THE INTRODUCTION OF A MULTIDIMENSIONAL MODEL OF MACROPHAGE ACTIVATION ALLOWS A MORE PRECISE DESCRIPTION OF MONOCYTES AND MACROPHAGES UNDER HOMEOSTATIC AND PATHOPHYSIOLOGICAL CONDITIONS. MONOCYTES AND MACROPHAGES ARE MASTERS OF INTEGRATING MICROENVIRONMENTAL SIGNALS, THEREBY RESHAPING THEIR CHROMATIN LANDSCAPE AND AS A CONSEQUENCE THEIR TRANSCRIPTIONAL AND FUNCTIONAL PROGRAMS. ALBEIT THESE CELLS SHARE A LARGE NUMBER OF EPIGENETIC LANDMARKS, THEIR CHROMATIN IS SIGNIFICANTLY SHAPED BY ENVIRONMENTAL SIGNALS. THE CHROMATIN LANDSCAPE OF ANY GIVEN TISSUE MACROPHAGE IS A RATHER SPECIFIC FINGERPRINT OF THESE CELLS, WHICH IS DIRECTLY LINKED TO TISSUE-SPECIFIC FUNCTIONS OF THESE CELLS. MOREOVER, CHROMATIN REMODELING IN RESPONSE TO STRESS SIGNALS ALSO SEEMS TO BE AN IMPORTANT MECHANISM OF THESE CELLS TO INCREASE THEIR READINESS FOR FUTURE STRESSORS. UNDERSTANDING THIS SOPHISTICATED EPIGENETIC REGULATORY NETWORK IN MONOCYTES AND MACROPHAGES WILL OPEN UP NEW AVENUES TOWARD TISSUE- AND DISEASE-SPECIFIC THERAPEUTIC STRATEGIES IN MANY OF THE CHRONIC INFLAMMATORY DISEASES OUR SOCIETIES ARE CURRENTLY FACING. 2017 12 2342 31 EPIGENETIC REGULATION OF MACROPHAGE POLARIZATION AND FUNCTION. MACROPHAGE POLARIZATION REFERS TO DEVELOPMENT OF A SPECIFIC PHENOTYPE IMPORTANT FOR TISSUE HOMEOSTASIS OR HOST DEFENSE IN RESPONSE TO ENVIRONMENTAL CUES. ENVIRONMENTAL FACTORS THAT INDUCE MACROPHAGE POLARIZATION INCLUDE CYTOKINES AND MICROBIAL FACTORS PRODUCED BY PATHOGENS OR COMMENSAL MICROBIOTA. SIGNALING PATHWAYS UTILIZED BY THESE POLARIZING FACTORS HAVE BEEN WELL CHARACTERIZED, BUT IT IS LESS CLEAR HOW SIGNALS ARE CONVERTED INTO COMPLEX AND SUSTAINED PATTERNS OF GENE EXPRESSION, AND HOW MACROPHAGES ARE REPROGRAMMED DURING POLARIZATION TO ALTER THEIR RESPONSES TO SUBSEQUENT ENVIRONMENTAL CHALLENGES. EMERGING EVIDENCE, REVIEWED HERE, SUGGESTS AN IMPORTANT ROLE FOR EPIGENETIC MECHANISMS IN MODULATING AND TRANSMITTING SIGNALS DURING MACROPHAGE POLARIZATION AND REPROGRAMMING. DEEPER UNDERSTANDING OF EPIGENETIC REGULATION OF MACROPHAGE PHENOTYPE WILL ENABLE DEVELOPMENT OF GENE-SPECIFIC THERAPEUTIC APPROACHES TO ENHANCE HOST DEFENSE WHILE PRESERVING TISSUE INTEGRITY AND PREVENTING CHRONIC INFLAMMATORY DISEASES. 2013 13 5423 26 REGULATION OF MACROPHAGE ACTIVATION AND DIFFERENTIATION IN ATHEROSCLEROSIS. CHRONIC INFLAMMATION IS A HALLMARK OF ATHEROSCLEROSIS AND MACROPHAGES PLAY A CENTRAL ROLE IN CONTROLLING INFLAMMATION AT ALL STAGES OF ATHEROSCLEROSIS. IN ATHEROSCLEROSIS, MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES ARE CONTINUOUSLY EXPOSED TO CHOLESTEROL, OXIDIZED LIPIDS, CELL DEBRIS, CYTOKINES, AND CHEMOKINES. NOT ONLY DO THESE STIMULI INDUCE A SPECIFIC MACROPHAGE PHENOTYPE, BUT THEY ALSO INTERACT EXTENSIVELY, LEADING TO MACROPHAGE HETEROGENEITY IN ATHEROSCLEROTIC PLAQUES. HEREIN, WE REVIEW THE DIVERSE PHENOTYPES OF MACROPHAGES, THE MECHANISMS UNDERLYING MACROPHAGE ACTIVATION, AND THE CONTRIBUTIONS OF MACROPHAGES TO ATHEROSCLEROSIS IN THIS CONTEXT. WE ALSO SUMMARIZE RECENT STUDIES ON FOAMY MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES IN PLAQUE DURING DISEASE PROGRESSION. WE PROVIDE A COMPREHENSIVE OVERVIEW OF TRANSCRIPTIONAL, EPIGENETIC, AND METABOLIC REPROGRAMMING OF MACROPHAGES AND DISCUSS THE EMERGING CONCEPTS OF TARGETING CYTOKINES AND MACROPHAGES TO MODULATE ATHEROSCLEROSIS. 2021 14 5629 22 SENESCENCE IN COPD AND ITS COMORBIDITIES. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS REGARDED AS A DISEASE OF ACCELERATED LUNG AGING. THIS AFFLICTION SHOWS ALL OF THE HALLMARKS OF AGING, INCLUDING TELOMERE SHORTENING, CELLULAR SENESCENCE, ACTIVATION OF PI3 KINASE-MTOR SIGNALING, IMPAIRED AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, STEM CELL EXHAUSTION, EPIGENETIC CHANGES, ABNORMAL MICRORNA PROFILES, IMMUNOSENESCENCE, AND A LOW-GRADE CHRONIC INFLAMMATION (INFLAMMAGING). MANY OF THESE PATHWAYS ARE DRIVEN BY CHRONIC EXOGENOUS AND ENDOGENOUS OXIDATIVE STRESS. THERE IS ALSO A REDUCTION IN ANTIAGING MOLECULES, SUCH AS SIRTUINS AND KLOTHO, WHICH FURTHER ACCELERATE THE AGING PROCESS. COPD IS ASSOCIATED WITH SEVERAL COMORBIDITIES (MULTIMORBIDITY), SUCH AS CARDIOVASCULAR AND METABOLIC DISEASES, THAT SHARE THE SAME PATHWAYS OF ACCELERATED AGING. UNDERSTANDING THESE MECHANISMS HAS HELPED IDENTIFY SEVERAL NOVEL THERAPEUTIC TARGETS, AND SEVERAL DRUGS AND DIETARY INTERVENTIONS ARE NOW IN DEVELOPMENT TO TREAT MULTIMORBIDITY. 2017 15 783 28 CELL-SPECIFIC EPIGENETIC DRIVERS OF PATHOGENESIS IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS IS A COMPLEX, INFLAMMATORY AUTOIMMUNE DISEASE, WHICH IS CHARACTERIZED BY PAIN, SWELLING AND JOINT DAMAGE DRIVEN BY THE ALTERED BEHAVIOR OF A NUMBER OF DIFFERENT CELL TYPES SUCH AS SYNOVIAL FIBROBLASTS MACROPHAGES AND LYMPHOCYTES. THE MECHANISM UNDERLYING PATHOGENESIS IS UNCLEAR BUT INCREASING EVIDENCE POINTS TO ALTERED EPIGENETIC REGULATION WITHIN THESE CELL TYPES WHICH PROMOTES THE ACTIVATED DESTRUCTIVE BEHAVIOR THAT UNDERLIES DISEASE PATHOGENESIS. THIS REVIEW SUMMARIZES THE KEY EPIGENETIC MODIFICATIONS IN THE MOST IMPORTANT CELLS TYPES IN RHEUMATOID ARTHRITIS, WHICH ARE ASSOCIATED WITH DISEASE ACTIVITY. WE ALSO DISCUSS EMERGING AVENUES OF RESEARCH FOCUSING ON READERS OF EPIGENETIC MARKERS WHICH MAY SERVE TO BE POTENTIAL THERAPEUTIC TARGETS. 2021 16 733 32 CANCER EPIGENETICS: LINKING BASIC BIOLOGY TO CLINICAL MEDICINE. CANCER EVOLUTION AT ALL STAGES IS DRIVEN BY BOTH EPIGENETIC ABNORMALITIES AS WELL AS GENETIC ALTERATIONS. DYSREGULATION OF EPIGENETIC CONTROL EVENTS MAY LEAD TO ABNORMAL PATTERNS OF DNA METHYLATION AND CHROMATIN CONFIGURATIONS, BOTH OF WHICH ARE CRITICAL CONTRIBUTORS TO THE PATHOGENESIS OF CANCER. THESE EPIGENETIC ABNORMALITIES ARE SET AND MAINTAINED BY MULTIPLE PROTEIN COMPLEXES AND THE INTERPLAY BETWEEN THEIR INDIVIDUAL COMPONENTS INCLUDING DNA METHYLATION MACHINERY, HISTONE MODIFIERS, PARTICULARLY, POLYCOMB (PCG) PROTEINS, AND CHROMATIN REMODELING PROTEINS. RECENT ADVANCES IN GENOME-WIDE TECHNOLOGY HAVE REVEALED THAT THE INVOLVEMENT OF THESE DYSREGULATED EPIGENETIC COMPONENTS APPEARS TO BE EXTENSIVE. MOREOVER, THERE IS A GROWING CONNECTION BETWEEN EPIGENETIC ABNORMALITIES IN CANCER AND CONCEPTS CONCERNING STEM-LIKE CELL SUBPOPULATIONS AS A DRIVING FORCE FOR CANCER. EMERGING DATA SUGGEST THAT ASPECTS OF THE EPIGENETIC LANDSCAPE INHERENT TO NORMAL EMBRYONIC AND ADULT STEM/PROGENITOR CELLS MAY HELP FOSTER, UNDER THE STRESS OF CHRONIC INFLAMMATION OR ACCUMULATING REACTIVE OXYGEN SPECIES, EVOLUTION OF MALIGNANT SUBPOPULATIONS. FINALLY, UNDERSTANDING MOLECULAR MECHANISMS INVOLVED IN INITIATION AND MAINTENANCE OF EPIGENETIC ABNORMALITIES IN ALL TYPES OF CANCER HAS GREAT POTENTIAL FOR TRANSLATIONAL PURPOSES. THIS IS ALREADY EVIDENT FOR EPIGENETIC BIOMARKER DEVELOPMENT, AND FOR PHARMACOLOGICAL TARGETING AIMED AT REVERSING CANCER-SPECIFIC EPIGENETIC ALTERATIONS. 2011 17 4953 30 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 18 2378 27 EPIGENETIC REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING IN ATHEROSCLEROTIC ARTERY REMODELING: A MINI-REVIEW. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY EXTENSIVE REMODELING OF MEDIUM AND LARGE-SIZED ARTERIES. INWARD REMODELING (=LUMEN SHRINKAGE) OF THE VASCULAR WALLS IS THE UNDERLYING CAUSE FOR ISCHEMIA IN TARGET ORGANS. THEREFORE, INWARD REMODELING CAN BE CONSIDERED THE PREDOMINANT FEATURE OF ATHEROSCLEROTIC PATHOLOGY. OUTWARD REMODELING (=LUMEN ENLARGEMENT) IS A PHYSIOLOGICAL RESPONSE COMPENSATING FOR LUMEN SHRINKAGE CAUSED BY NEOINTIMAL HYPERPLASIA, BUT AS A PATHOLOGICAL RESPONSE TO CHANGES IN BLOOD FLOW, OUTWARD REMODELING LEADS TO SUBSTANTIAL ARTERIAL WALL THINNING. THINNED VASCULAR WALLS ARE PRONE TO RUPTURE, AND SUBSEQUENT THROMBUS FORMATION ACCOUNTS FOR THE MAJORITY OF ACUTE CARDIOVASCULAR EVENTS. PATHOLOGICAL REMODELING IS DRIVEN BY INFLAMMATORY CELLS WHICH INDUCE VASCULAR SMOOTH MUSCLE CELLS TO SWITCH FROM QUIESCENT TO A PROLIFERATIVE AND MIGRATORY PHENOTYPE. AFTER DECADES OF INTENSIVE RESEARCH, THE MOLECULAR MECHANISMS OF ARTERIAL REMODELING ARE STARTING TO UNFOLD. IN THIS MINI-REVIEW, WE SUMMARIZE THE CURRENT KNOWLEDGE OF THE EPIGENETIC AND TRANSCRIPTIONAL REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING FROM THE CONTRACTILE TO THE SYNTHETIC PHENOTYPE INVOLVED IN ARTERIAL REMODELING AND DISCUSS POTENTIAL THERAPEUTIC OPTIONS. 2021 19 2344 22 EPIGENETIC REGULATION OF MACROPHAGES: FROM HOMEOSTASIS MAINTENANCE TO HOST DEFENSE. MACROPHAGES ARE CRUCIAL MEMBERS OF THE INNATE IMMUNE RESPONSE AND IMPORTANT REGULATORS. THE DIFFERENTIATION AND ACTIVATION OF MACROPHAGES REQUIRE THE TIMELY REGULATION OF GENE EXPRESSION, WHICH DEPENDS ON THE INTERACTION OF A VARIETY OF FACTORS, INCLUDING TRANSCRIPTION FACTORS AND EPIGENETIC MODIFICATIONS. EPIGENETIC CHANGES ALSO GIVE MACROPHAGES THE ABILITY TO SWITCH RAPIDLY BETWEEN CELLULAR PROGRAMS, INDICATING THE ABILITY OF EPIGENETIC MECHANISMS TO AFFECT PHENOTYPE PLASTICITY. IN THIS REVIEW, WE FOCUS ON KEY EPIGENETIC EVENTS ASSOCIATED WITH MACROPHAGE FATE, HIGHLIGHTING EVENTS RELATED TO THE MAINTENANCE OF TISSUE HOMEOSTASIS, RESPONSES TO DIFFERENT STIMULI AND THE FORMATION OF INNATE IMMUNE MEMORY. FURTHER UNDERSTANDING OF THE EPIGENETIC REGULATION OF MACROPHAGES WILL BE HELPFUL FOR MAINTAINING TISSUE INTEGRITY, PREVENTING CHRONIC INFLAMMATORY DISEASES AND DEVELOPING THERAPIES TO ENHANCE HOST DEFENSE. 2020 20 6621 27 UNDERSTANDING FIBROSIS IN SYSTEMIC SCLEROSIS: SHIFTING PARADIGMS, EMERGING OPPORTUNITIES. FIBROSIS IN MULTIPLE ORGANS IS A PROMINENT PATHOLOGICAL FINDING AND DISTINGUISHING HALLMARK OF SYSTEMIC SCLEROSIS (SSC). FINDINGS DURING THE PAST 5 YEARS HAVE CONTRIBUTED TO A MORE COMPLETE UNDERSTANDING OF THE COMPLEX CELLULAR AND MOLECULAR UNDERPINNING OF FIBROSIS IN SSC. FIBROBLASTS, THE PRINCIPAL EFFECTOR CELLS, ARE ACTIVATED IN THE PROFIBROTIC CELLULAR MILIEU BY CYTOKINES AND GROWTH FACTORS, DEVELOPMENTAL PATHWAYS, ENDOTHELIN 1 AND THROMBIN. INNATE IMMUNE SIGNALING VIA TOLL-LIKE RECEPTORS, MATRIX-GENERATED BIOMECHANICAL STRESS SIGNALING VIA INTEGRINS, HYPOXIA AND OXIDATIVE STRESS SEEM TO BE IMPLICATED IN PERPETUATING THE PROCESS. BEYOND CHRONIC FIBROBLAST ACTIVATION, FIBROSIS REPRESENTS A FAILURE TO TERMINATE TISSUE REPAIR, COUPLED WITH AN EXPANDED POPULATION OF MESENCHYMAL CELLS ORIGINATING FROM BONE MARROW AND TRANSDIFFERENTIATION OF EPITHELIAL CELLS, ENDOTHELIAL CELLS AND PERICYTES. IN ADDITION, STUDIES HAVE IDENTIFIED INTRINSIC ALTERATIONS IN SSC FIBROBLASTS RESULTING FROM EPIGENETIC CHANGES, AS WELL AS ALTERED MICRORNA EXPRESSION THAT MIGHT UNDERLIE THE CELL-AUTONOMOUS, PERSISTENT ACTIVATION PHENOTYPE OF THESE CELLS. PRECISE CHARACTERIZATION OF THE DEREGULATED EXTRACELLULAR AND INTRACELLULAR SIGNALING PATHWAYS, MEDIATORS AND CELLULAR DIFFERENTIATION PROGRAMS THAT CONTRIBUTE TO FIBROSIS IN SSC WILL FACILITATE THE DEVELOPMENT OF SELECTIVE, TARGETED THERAPEUTIC STRATEGIES. EFFECTIVE ANTIFIBROTIC THERAPY WILL ULTIMATELY INVOLVE NOVEL COMPOUNDS AND REPURPOSING OF DRUGS THAT ARE ALREADY APPROVED FOR OTHER INDICATIONS. 2011