1 783 79 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 2 1608 38 DNA METHYLATION-GOVERNED GENE EXPRESSION IN AUTOIMMUNE ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE HALLMARKED BY PROGRESSIVE AND IRREVERSIBLE JOINT DESTRUCTION. RA PATHOGENESIS IS A T CELL-REGULATED AND B CELL-MEDIATED PROCESS IN WHICH ACTIVATED LYMPHOCYTE-PRODUCED CHEMOKINES AND CYTOKINES PROMOTE LEUKOCYTE INFILTRATION THAT ULTIMATELY LEADS TO DESTRUCTION OF THE JOINTS. THERE IS AN OBVIOUS NEED TO DISCOVER NEW DRUGS FOR RA TREATMENT THAT HAVE DIFFERENT BIOLOGICAL TARGETS OR MODES OF ACTION THAN THE CURRENTLY EMPLOYED THERAPEUTICS. ENVIRONMENTAL FACTORS SUCH AS CIGARETTE SMOKE, CERTAIN DIET COMPONENTS, AND ORAL PATHOGENS CAN SIGNIFICANTLY AFFECT GENE REGULATION VIA EPIGENETIC FACTORS. EPIGENETICS OPENED A NEW FIELD FOR PHARMACOLOGY, AND DNA METHYLATION AND HISTONE MODIFICATION-IMPLICATED FACTORS ARE FEASIBLE TARGETS FOR RA THERAPY. EXPLORING RA PATHOGENESIS INVOLVED EPIGENETIC FACTORS AND MECHANISMS IS CRUCIAL FOR DEVELOPING MORE EFFICIENT RA THERAPIES. HERE WE REVIEW EPIGENETIC ALTERATIONS ASSOCIATED WITH RA PATHOGENESIS INCLUDING DNA METHYLATION AND INTERACTING FACTORS. ADDITIONALLY, WE WILL SUMMARIZE THE LITERATURE REVEALING THE INVOLVED MOLECULAR STRUCTURES AND INTERACTIONS. FINALLY, POTENTIAL EPIGENETIC FACTOR-BASED THERAPIES WILL BE DISCUSSED THAT MAY HELP IN BETTER MANAGEMENT OF RA IN THE FUTURE. 2019 3 1136 37 COMPREHENSIVE OVERVIEW OF MICRORNA FUNCTION IN RHEUMATOID ARTHRITIS. MICRORNAS (MIRNAS), A CLASS OF ENDOGENOUS SINGLE-STRANDED SHORT NONCODING RNAS, HAVE EMERGED AS VITAL EPIGENETIC REGULATORS OF BOTH PATHOLOGICAL AND PHYSIOLOGICAL PROCESSES IN ANIMALS. THEY DIRECT FUNDAMENTAL CELLULAR PATHWAYS AND PROCESSES BY FINE-TUNING THE EXPRESSION OF MULTIPLE GENES AT THE POSTTRANSCRIPTIONAL LEVEL. GROWING EVIDENCE SUGGESTS THAT MIRNAS ARE IMPLICATED IN THE ONSET AND DEVELOPMENT OF RHEUMATOID ARTHRITIS (RA). RA IS A CHRONIC INFLAMMATORY DISEASE THAT MAINLY AFFECTS SYNOVIAL JOINTS. THIS COMMON AUTOIMMUNE DISORDER IS CHARACTERIZED BY A COMPLEX AND MULTIFACETED PATHOGENESIS, AND ITS MORBIDITY, DISABILITY AND MORTALITY RATES REMAIN CONSISTENTLY HIGH. MORE IN-DEPTH INSIGHTS INTO THE UNDERLYING MECHANISMS OF RA ARE REQUIRED TO ADDRESS UNMET CLINICAL NEEDS AND OPTIMIZE TREATMENT. HEREIN, WE COMPREHENSIVELY REVIEW THE DEREGULATED MIRNAS AND IMPAIRED CELLULAR FUNCTIONS IN RA TO SHED LIGHT ON SEVERAL ASPECTS OF RA PATHOGENESIS, WITH A FOCUS ON EXCESSIVE INFLAMMATION, SYNOVIAL HYPERPLASIA AND PROGRESSIVE JOINT DAMAGE. THIS REVIEW ALSO PROVIDES PROMISING TARGETS FOR INNOVATIVE THERAPIES OF RA. IN ADDITION, WE DISCUSS THE REGULATORY ROLES AND CLINICAL POTENTIAL OF EXTRACELLULAR MIRNAS IN RA, HIGHLIGHTING THEIR PROSPECTIVE APPLICATIONS AS DIAGNOSTIC AND PREDICTIVE BIOMARKERS. 2023 4 3699 33 INFLAMMATORY MEMORIES: IS EPIGENETICS THE MISSING LINK TO PERSISTENT STROMAL CELL ACTIVATION IN RHEUMATOID ARTHRITIS? RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE LEADING TO JOINT DESTRUCTION. SYNOVIAL FIBROBLASTS ARE RECOGNIZED AS KEY CELLS IN THE PATHOGENESIS OF RA SINCE THEY ATTRACT AND ACTIVATE IMMUNE CELLS AND PRODUCE MATRIX DEGRADING ENZYMES. MOST NOTABLY SYNOVIAL FIBROBLASTS FROM PATIENTS WITH RA ARE STABLY ACTIVATED AND PRODUCE HIGH LEVELS OF DISEASE-PROMOTING MOLECULES WITHOUT FURTHER STIMULATION BY IMMUNE CELLS. ACCUMULATING DATA SUGGEST THAT EPIGENETIC CHANGES IN STROMAL CELL POPULATIONS MIGHT BE CRUCIALLY INVOLVED IN THE PATHOLOGY OF RA AND OTHER CHRONIC INFLAMMATORY DISEASES. IN THE CURRENT REVIEW, WE DISCUSS THE MECHANISMS BY WHICH EPIGENETIC CHANGES MIGHT CAUSE THE STABLE ACTIVATION OF SYNOVIAL FIBROBLASTS IN RA AND HOW CHANGES IN THE EPIGENOME MIGHT ALTER IMMUNE FUNCTION AND INFLAMMATORY RESPONSE AND THEREBY PROMOTE THE DEVELOPMENT OF CHRONIC DISEASES. 2011 5 2221 38 EPIGENETIC MODIFICATIONS IN RHEUMATOID ARTHRITIS, A REVIEW. RHEUMATOID ARTHRITIS IS AN AUTOIMMUNE DISEASE CHARACTERIZED BY CHRONIC JOINT INFLAMMATION AND PROGRESSIVE DESTRUCTION OF CARTILAGE AND BONE WHICH LEADS TO ULTIMATELY LOSS OF FUNCTION AND PAIN. ACTIVATED SYNOVIAL FIBROBLASTS ARE KEY EFFECTOR CELLS IN THE PATHOGENESIS OF RHEUMATOID ARTHRITIS. IN THE RECENT YEARS, EPIGENETIC CHANGES INCLUDING DNA METHYLATION, HISTONE ACETYLATION AND OTHER HISTONE MODIFICATIONS WERE IDENTIFIED THAT ARE ASSOCIATED WITH AN INTRINSIC ACTIVATION AND THE AGGRESSIVE PHENOTYPE OF THESE CELLS. SO FAR, NO THERAPIES TARGETING RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS EXIST. THIS REVIEW COMPRISES RECENT RESEARCH EFFORTS THAT PROPOSE EPIGENETIC MECHANISMS BEHIND THE ACTIVATION OF RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS AND OTHER CELL TYPES. 2013 6 4842 35 ONE YEAR IN REVIEW 2017: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. IT HAS BEEN POSTULATED THAT A HIGH-RISK GENETIC BACKGROUND, IN COMBINATION WITH EPIGENETIC MARKS AND ENVIRONMENTAL EXPOSURES, LEADS TO A CASCADE OF EVENTS INDUCING SYNOVITIS AND CONSEQUENT DESTRUCTIVE ARTHRITIS. THE CLINICAL PICTURE OF JOINT INVOLVEMENT IN RA IS THE RESULT OF CHRONIC INFLAMMATION OF THE SYNOVIUM, CHARACTERISED BY INTERACTIONS OF RESIDENT CELLS SUCH AS FIBROBLAST-LIKE SYNOVIOCYTES (FLS) WITH CELLS OF THE INNATE (E.G. MACROPHAGES, DENDRITIC CELLS, MAST CELLS AND NK CELLS, NEUTROPHILS) AND ADAPTIVE IMMUNE SYSTEM (E.G. B AND T LYMPHOCYTES). CURRENTLY, OUR UNDERSTANDING OF THE ROLE OF INNATE AND ADAPTIVE IMMUNITY IN THE PATHOGENESIS OF RA IS EXPANDING. THE CONCEPT OF HOW IMMUNE RESPONSES CONTRIBUTE TO THE DISEASE HAS DRAMATICALLY EVOLVED OVER THE LAST 50 YEARS. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE REPORT NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM A LITERATURE RESEARCH DATE PUBLISHED IN THE LAST YEAR. 2017 7 1565 32 DNA METHYLATION OF T LYMPHOCYTES AS A THERAPEUTIC TARGET: IMPLICATIONS FOR RHEUMATOID ARTHRITIS ETIOLOGY. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE DISEASE THAT CAN CAUSE JOINT DAMAGE AND DISABILITY. EPIGENETIC VARIATION, ESPECIALLY DNA METHYLATION, HAS BEEN SHOWN TO BE INVOLVED IN ALMOST ALL THE STAGES OF THE PATHOLOGY OF RA, FROM AUTOANTIBODY PRODUCTION TO VARIOUS SELF-EFFECTOR T CELLS AND THE DEFECTS OF PROTECTIVE T CELLS THAT CAN LEAD TO CHRONIC INFLAMMATION AND EROSION OF BONES AND JOINTS. GIVEN THE CRITICAL ROLE OF T CELLS IN THE PATHOLOGY OF RA, THE REGULATORY FUNCTIONS OF DNA METHYLATION IN T CELL BIOLOGY REMAIN UNCLEAR. IN THIS REVIEW, WE ELABORATE ON THE RELATIONSHIP BETWEEN RA PATHOGENESIS AND DNA METHYLATION IN THE CONTEXT OF DIFFERENT T CELL POPULATIONS. WE SUMMARIZE THE RELEVANT METHYLATION EVENTS IN T CELL DEVELOPMENT, DIFFERENTIATION, AND T CELL-RELATED GENES IN DISEASE PREDICTION AND DRUG EFFICACY. UNDERSTANDING THE EPIGENETIC REGULATION OF T CELLS HAS THE POTENTIAL TO PROFOUNDLY TRANSLATE PRECLINICAL RESULTS INTO CLINICAL PRACTICE AND PROVIDE A FRAMEWORK FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED RA THERAPEUTICS. 2022 8 6597 34 TUNING MONOCYTES AND MACROPHAGES FOR PERSONALIZED THERAPY AND DIAGNOSTIC CHALLENGE IN RHEUMATOID ARTHRITIS. MONOCYTES/MACROPHAGES PLAY A CENTRAL ROLE IN CHRONIC INFLAMMATORY DISORDERS, INCLUDING RHEUMATOID ARTHRITIS (RA). ACTIVATION OF THESE CELLS RESULTS IN THE PRODUCTION OF VARIOUS MEDIATORS RESPONSIBLE FOR INFLAMMATION AND RA PATHOGENESIS. ON THE OTHER HAND, THE DEPLETION OF MACROPHAGES USING SPECIFIC ANTIBODIES OR CHEMICAL AGENTS CAN PREVENT THEIR SYNOVIAL TISSUE INFILTRATION AND SUBSEQUENTLY ATTENUATES INFLAMMATION. THEIR PLASTICITY IS A MAJOR FEATURE THAT HELPS THE SWITCH FROM A PRO-INFLAMMATORY PHENOTYPE (M1) TO AN ANTI-INFLAMMATORY STATE (M2). THEREFORE, UNDERSTANDING THE PRECISE STRATEGY TARGETING PRO-INFLAMMATORY MONOCYTES/MACROPHAGES SHOULD BE A POWERFUL WAY OF INHIBITING CHRONIC INFLAMMATION AND BONE EROSION. IN THIS REVIEW, WE DEMONSTRATE POTENTIAL CONSEQUENCES OF DIFFERENT EPIGENETIC REGULATIONS ON INFLAMMATORY CYTOKINES PRODUCTION BY MONOCYTES. IN ADDITION, WE PRESENT UNIQUE PROFILES OF MONOCYTES/MACROPHAGES CONTRIBUTING TO IDENTIFICATION OF NEW BIOMARKERS OF DISEASE ACTIVITY OR PREDICTING TREATMENT RESPONSE IN RA. WE ALSO OUTLINE NOVEL APPROACHES OF TUNING MONOCYTES/MACROPHAGES BY BIOLOGIC DRUGS, SMALL MOLECULES OR BY OTHER THERAPEUTIC MODALITIES TO REDUCE ARTHRITIS. FINALLY, THE IMPORTANCE OF CELLULAR HETEROGENEITY OF MONOCYTES/MACROPHAGES IS HIGHLIGHTED BY SINGLE-CELL TECHNOLOGIES, WHICH LEADS TO THE DESIGN OF CELL-SPECIFIC THERAPEUTIC PROTOCOLS FOR PERSONALIZED MEDICINE IN RA IN THE FUTURE. 2021 9 2054 47 EPIGENETIC CONTRIBUTIONS IN THE DEVELOPMENT OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE DISEASE, CHARACTERIZED BY CHRONIC INFLAMMATION OF THE JOINTS WITH SEVERE PAIN AND SWELLING, JOINT DAMAGE AND DISABILITY, WHICH LEADS TO JOINT DESTRUCTION AND LOSS OF FUNCTION. DESPITE EXTENSIVE RESEARCH EFFORTS, THE UNDERLYING CAUSE FOR RA IS STILL UNKNOWN AND CURRENT THERAPIES ARE MORE OR LESS EFFECTIVE IN CONTROLLING SYMPTOMS BUT STILL FAIL TO CURE THE DISEASE. IN RECENT YEARS, EPIGENETIC MODIFICATIONS WERE FOUND TO STRONGLY CONTRIBUTE TO THE DEVELOPMENT OF RA BY AFFECTING DIVERSE ASPECTS OF THE DISEASE AND MODIFYING GENE EXPRESSION LEVELS AND BEHAVIOR OF SEVERAL CELL TYPES, FIRST AND FOREMOST JOINT RESIDENT SYNOVIAL FIBROBLASTS (SF). RASF ARE THE MOST COMMON CELL TYPE AT THE SITE OF INVASION. OWING TO THEIR AGGRESSIVE, INTRINSICALLY ACTIVATED PHENOTYPE, RASF ARE ACTIVE CONTRIBUTORS IN JOINT DAMAGE. RASF ARE CHARACTERIZED BY THEIR ABILITY TO SECRETE CYTOKINES, CHEMOKINES AND JOINT-DAMAGING ENZYMES. FURTHERMORE, THESE CELLS ARE RESISTANT TO APOPTOSIS, LEADING TO HYPERPLASIA OF THE SYNOVIUM. IN ADDITION, RASF HAVE INVASIVE AND MIGRATORY PROPERTIES THAT COULD LEAD TO SPREADING OF THE DISEASE TO UNAFFECTED JOINTS. EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION AND POST-TRANSLATIONAL HISTONE MODIFICATIONS, SUCH AS HISTONE (DE)ACETYLATION, HISTONE METHYLATION AND HISTONE SUMOYLATION WERE IDENTIFIED AS REGULATORY MECHANISMS IN CONTROLLING AGGRESSIVE CELL ACTIVATION IN VITRO AND IN DISEASE OUTCOME IN ANIMAL MODELS IN VIVO. IN THE LAST 5 YEARS, THE FIELD OF EPIGENETICS IN RA HAS IMPRESSIVELY INCREASED. IN THIS REVIEW WE CONSIDER THE ROLE OF DIVERSE EPIGENETIC MODIFICATIONS IN THE DEVELOPMENT OF RA, WITH A SPECIAL FOCUS ON EPIGENETIC MODIFICATIONS IN RASF. 2012 10 1726 39 DYSREGULATION OF LNCRNAS IN RHEUMATOID ARTHRITIS: BIOMARKERS, PATHOGENESIS AND POTENTIAL THERAPEUTIC TARGETS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC AUTOIMMUNE DISEASE OF UNKNOWN ETIOLOGY, MAINLY MANIFESTED BY PERSISTENT ABNORMAL PROLIFERATION OF FIBROBLAST-LIKE SYNOVIOCYTES (FLSS), INFLAMMATION, SYNOVIAL HYPERPLASIA AND CARTILAGE EROSION, ACCOMPANIED BY JOINT SWELLING AND JOINT DESTRUCTION. ABNORMAL EXPRESSION OR FUNCTION OF LONG NONCODING RNAS (LNCRNAS) ARE CLOSELY RELATED TO HUMAN DISEASES, INCLUDING CANCERS, MENTAL DISEASES, AUTOIMMUNE DISEASES AND OTHERS. THE ABNORMAL SEQUENCE AND SPATIAL STRUCTURE OF LNCRNAS, THE DISORDER EXPRESSION AND THE ABNORMAL INTERACTION WITH THE BINDING PROTEIN WILL LEAD TO THE CHANGE OF GENE EXPRESSION IN THE WAY OF EPIGENETIC MODIFICATION. INCREASING EVIDENCE DEMONSTRATED THAT LNCRNAS WERE INVOLVED IN THE ACTIVATION OF FLSS, WHICH PLAYED A KEY ROLE IN THE PATHOGENESIS OF RA. IN THIS REVIEW, THE RESEARCH PROGRESS OF LNCRNAS IN THE PATHOGENESIS OF RA WAS SYSTEMATICALLY SUMMARIZED, INCLUDING THE ROLE OF LNCRNAS IN THE DIAGNOSIS OF RA, THE REGULATORY MECHANISM OF LNCRNAS IN THE PATHOGENESIS OF RA, AND THE INTERVENTION ROLE OF LNCRNAS IN THE TREATMENT OF RA. FURTHERMORE, THE ACTIVATED SIGNAL PATHWAYS, THE ROLE OF DNA METHYLATION AND OTHER MECHANISM HAVE ALSO BEEN OVERVIEW IN THIS REVIEW. 2021 11 6178 32 THE HISTONE MODIFICATION CODE IN THE PATHOGENESIS OF AUTOIMMUNE DISEASES. AUTOIMMUNE DISEASES ARE CHRONIC INFLAMMATORY DISORDERS CAUSED BY A LOSS OF SELF-TOLERANCE, WHICH IS CHARACTERIZED BY THE APPEARANCE OF AUTOANTIBODIES AND/OR AUTOREACTIVE LYMPHOCYTES AND THE IMPAIRED SUPPRESSIVE FUNCTION OF REGULATORY T CELLS. THE PATHOGENESIS OF AUTOIMMUNE DISEASES IS EXTREMELY COMPLEX AND REMAINS LARGELY UNKNOWN. RECENT ADVANCES INDICATE THAT ENVIRONMENTAL FACTORS TRIGGER AUTOIMMUNE DISEASES IN GENETICALLY PREDISPOSED INDIVIDUALS. IN ADDITION, ACCUMULATING RESULTS HAVE INDICATED A POTENTIAL ROLE OF EPIGENETIC MECHANISMS, SUCH AS HISTONE MODIFICATIONS, IN THE DEVELOPMENT OF AUTOIMMUNE DISEASES. HISTONE MODIFICATIONS REGULATE THE CHROMATIN STATES AND GENE TRANSCRIPTION WITHOUT ANY CHANGE IN THE DNA SEQUENCE, POSSIBLY RESULTING IN PHENOTYPE ALTERATION IN SEVERAL DIFFERENT CELL TYPES. IN THIS PAPER, WE DISCUSS THE SIGNIFICANT ROLES OF HISTONE MODIFICATIONS INVOLVED IN THE PATHOGENESIS OF AUTOIMMUNE DISEASES, INCLUDING RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS, SYSTEMIC SCLEROSIS, PRIMARY BILIARY CIRRHOSIS, AND TYPE 1 DIABETES. 2017 12 4657 37 NEW ADVANCES OF DNA METHYLATION AND HISTONE MODIFICATIONS IN RHEUMATOID ARTHRITIS, WITH SPECIAL EMPHASIS ON MECP2. EPIGENETICS IS A STEADILY GROWING RESEARCH AREA IN MANY HUMAN DISEASES, ESPECIALLY IN AUTOIMMUNE DISEASES SUCH AS RHEUMATOID ARTHRITIS (RA). RA IS AN AUTOIMMUNE DISEASE WITH UNCLEAR ETIOLOGY CHARACTERIZED BY CHRONIC INFLAMMATION AND JOINT DESTRUCTION AND FIBROBLAST-LIKE SYNOVIOCYTES (FLS) DISPLAY A CRUCIAL ROLE IN THE PATHOGENESIS OF RA. EVEN THOUGH THE ETIOLOGY IS NOT YET FULLY UNDERSTOOD, RA IS GENERALLY CONSIDERED TO BE CAUSED BY A COMBINATION OF EPIGENETIC MODIFICATION, DEREGULATED IMMUNOMODULATION, AND ENVIRONMENTAL FACTORS. EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION AND POST-TRANSLATIONAL HISTONE MODIFICATIONS, SUCH AS HISTONE METHYLATION AND HISTONE (DE)ACETYLATION ARE IDENTIFIED AS REGULATORY MECHANISMS IN CONTROLLING AGGRESSIVE FLS ACTIVATION IN PATIENTS AND ANIMAL MODELS. IN THE LAST 3YEARS, THE FIELD OF EPIGENETICS IN RA HAS IMPRESSIVELY INCREASED. METHYL-CPG-BINDING PROTEIN 2 (MECP2) IS FIRST IDENTIFIED AS A TRANSCRIPTIONAL REPRESSOR THAT INHIBITS GENE EXPRESSION THROUGH THE INTERPRETATION OF TWO EPIGENETIC MARKERS, DNA METHYLATION AND HISTONE MODIFICATION. THE COOPERATIVE ACTION AMONG MECP2, DNA METHYLATION AND HISTONE MODIFICATIONS INDICATES THAT MECP2 SHOULD PARTICIPATE IN THE PATHOGENESIS OF RA THROUGH SILENCE OF CERTAIN GENE TRANSCRIPTION. IN THIS REVIEW, WE CONSIDER THE ROLE OF DNA METHYLATION AND HISTONE MODIFICATIONS IN THE DEVELOPMENT OF RA, WITH A SPECIAL FOCUS ON INCREASED MECP2 EXPRESSION IN RA ANIMAL MODELS. 2013 13 2550 33 EPIGENETICS IN OSTEOARTHRITIS: POTENTIAL OF HDAC INHIBITORS AS THERAPEUTICS. OSTEOARTHRITIS (OA) IS THE MOST COMMON JOINT DISEASE AND THE LEADING CAUSE OF CHRONIC DISABILITY IN MIDDLE-AGED AND OLDER POPULATIONS WORLDWIDE. THE DEVELOPMENT OF DISEASE MODIFYING THERAPY FOR OA IS IN ITS INFANCY LARGELY BECAUSE THE REGULATORY MECHANISMS FOR THE MOLECULAR EFFECTORS OF OA PATHOGENESIS ARE POORLY UNDERSTOOD. RECENT STUDIES IDENTIFIED EPIGENETIC EVENTS AS A CRITICAL REGULATOR OF MOLECULAR PLAYERS INVOLVED IN THE INDUCTION AND DEVELOPMENT OF OA. EPIGENETIC MECHANISMS INCLUDE DNA METHYLATION, NON-CODING RNA AND HISTONE MODIFICATIONS. THE AIM OF THIS REVIEW IS TO BRIEFLY HIGHLIGHT THE RECENT ADVANCES IN THE EPIGENETICS OF CARTILAGE AND POTENTIAL OF HDACS (HISTONE DEACETYLASES) INHIBITORS IN THE THERAPEUTIC MANAGEMENT OF OA. WE SUMMARIZE THE RECENT STUDIES UTILIZING HDAC INHIBITORS AS POTENTIAL THERAPEUTICS FOR INHIBITING DISEASE PROGRESSION AND PREVENTING THE CARTILAGE DESTRUCTION IN OA. HDACS CONTROL NORMAL CARTILAGE DEVELOPMENT AND HOMEOSTASIS AND UNDERSTANDING THE IMPACT OF HDACS INHIBITORS ON THE DISEASE PATHOGENESIS IS OF INTEREST BECAUSE OF ITS IMPORTANCE IN AFFECTING OVERALL CARTILAGE HEALTH AND HOMEOSTASIS. THESE FINDINGS ALSO SHED NEW LIGHT ON CARTILAGE DISEASE PATHOPHYSIOLOGY AND PROVIDE SUBSTANTIAL EVIDENCE THAT HDACS MAY BE POTENTIAL NOVEL THERAPEUTIC TARGETS IN OA. 2018 14 2294 40 EPIGENETIC REGULATION IN THE PATHOGENESIS OF SJOGREN SYNDROME AND RHEUMATOID ARTHRITIS. AUTOIMMUNE RHEUMATIC DISEASES, SUCH AS SJOGREN SYNDROME (SS) AND RHEUMATOID ARTHRITIS (RA), ARE CHARACTERIZED BY CHRONIC INFLAMMATION AND AUTOIMMUNITY, WHICH CAUSE JOINT TISSUE DAMAGE AND DESTRUCTION BY TRIGGERING REDUCED MOBILITY AND DEBILITATION IN PATIENTS WITH THESE DISEASES. INITIATION AND MAINTENANCE OF CHRONIC INFLAMMATORY STAGES ACCOUNT FOR SEVERAL MECHANISMS THAT INVOLVE IMMUNE CELLS AS KEY PLAYERS AND THE INTERACTION OF THE IMMUNE CELLS WITH OTHER TISSUES. INDEED, THE OVERLAPPING OF CERTAIN CLINICAL AND SEROLOGIC MANIFESTATIONS BETWEEN SS AND RA MAY INDICATE THAT NUMEROUS IMMUNOLOGIC-RELATED MECHANISMS ARE INVOLVED IN THE PHYSIOPATHOLOGY OF BOTH THESE DISEASES. IT IS WIDELY ACCEPTED THAT EPIGENETIC PATHWAYS PLAY AN ESSENTIAL ROLE IN THE DEVELOPMENT AND FUNCTION OF THE IMMUNE SYSTEM. ALTHOUGH MANY PUBLISHED STUDIES HAVE ATTEMPTED TO ELUCIDATE THE RELATION BETWEEN EPIGENETIC MODIFICATIONS (E.G. DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS, MIRNAS) AND AUTOIMMUNE DISORDERS, THE CONTRIBUTION OF EPIGENETIC REGULATION TO THE PATHOGENESIS OF SS AND RA IS AT PRESENT POORLY UNDERSTOOD. THIS REVIEW ATTEMPTS TO SHED LIGHT FROM A CRITICAL POINT OF VIEW ON THE IDENTIFICATION OF THE MOST RELEVANT EPIGENETIC MECHANISMS RELATED TO RA AND SS BY EXPLAINING INTRICATE REGULATORY PROCESSES AND PHENOTYPIC FEATURES OF BOTH AUTOIMMUNE DISEASES. MOREOVER, WE POINT OUT SOME EPIGENETIC MARKERS WHICH CAN BE USED TO MONITOR THE INFLAMMATION STATUS AND THE DYSREGULATED IMMUNITY IN SS AND RA. FINALLY, WE DISCUSS THE INCONVENIENCE OF USING EPIGENETIC DATA OBTAINED FROM BULK IMMUNE CELL POPULATIONS INSTEAD SPECIFIC IMMUNE CELL SUBPOPULATIONS. 2019 15 2508 27 EPIGENETICS AND OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS THE MOST COMMON FORM OF JOINT DISEASE AND THE LEADING CAUSE OF CHRONIC DISABILITY IN MIDDLE-AGED AND OLDER POPULATIONS. THE DEVELOPMENT OF DISEASE-MODIFYING THERAPY FOR OA CURRENTLY FACES MAJOR OBSTACLES LARGELY BECAUSE THE REGULATORY MECHANISMS FOR THE FUNCTION OF JOINT TISSUE CELLS REMAIN UNCLEAR. PREVIOUS STUDIES HAVE FOUND THAT THE ALTERATIONS IN GENE EXPRESSION OF SPECIFIC TRANSCRIPTION FACTORS (TFS), PRO- OR ANTI-INFLAMMATORY CYTOKINES, MATRIX PROTEINASES AND EXTRACELLULAR MATRIX (ECM) PROTEINS IN ARTICULAR CARTILAGE MAY BE INVOLVED IN THE DEVELOPMENT OF OA. HOWEVER, THE REGULATORY MECHANISMS FOR THE EXPRESSION OF THOSE GENES IN OA CHONDROCYTES ARE LARGELY UNKNOWN. THE RECENT ADVANCES IN EPIGENETIC STUDIES HAVE SHED LIGHTS ON THE IMPORTANCE OF EPIGENETIC REGULATION OF GENE EXPRESSION IN THE DEVELOPMENT OF OA. IN THIS REVIEW, WE SUMMARIZE AND DISCUSS THE RECENT STUDIES ON THE REGULATORY ROLES OF VARIOUS EPIGENETIC MECHANISMS IN THE EXPRESSION OF GENES FOR SPECIFIC TFS, CYTOKINES, ECM PROTEINS AND MATRIX PROTEINASES, AS WELL THE SIGNIFICANCE OF THESE EPIGENETIC MECHANISMS IN THE PATHOGENESIS OF OA. 2015 16 4679 33 NEW MOLECULAR TARGETS FOR THE TREATMENT OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A CHRONIC DEGENERATIVE JOINT DISORDER CHARACTERIZED BY DESTRUCTION OF THE ARTICULAR CARTILAGE, SUBCHONDRAL BONE ALTERATIONS AND SYNOVITIS. CURRENT TREATMENTS ARE FOCUSED ON SYMPTOMATIC RELIEF BUT THEY LACK EFFICACY TO CONTROL THE PROGRESSION OF THIS DISEASE WHICH IS A LEADING CAUSE OF DISABILITY. THEREFORE, THE DEVELOPMENT OF EFFECTIVE DISEASE-MODIFYING DRUGS IS URGENTLY NEEDED. DIFFERENT INITIATIVES ARE IN PROGRESS TO DEFINE THE MOLECULAR MECHANISMS INVOLVED IN THE INITIATION AND PROGRESSION OF OA. THESE STUDIES SUPPORT THE THERAPEUTIC POTENTIAL OF PATHWAYS RELEVANT IN JOINT METABOLISM SUCH AS WNT/BETA-CATENIN, DISCOIDIN DOMAIN RECEPTOR 2 OR PROTEINASE-ACTIVATED RECEPTOR 2. THE DYSREGULATION IN CARTILAGE CATABOLISM AND SUBCHONDRAL BONE REMODELING COULD BE IMPROVED BY SELECTIVE INHIBITORS OF MATRIX METALLOPROTEINASES, AGGRECANASES AND OTHER PROTEASES. ANOTHER APPROACH WOULD FAVOR THE ACTIVITY OF ANABOLIC PROCESSES BY USING GROWTH FACTORS OR REGULATORY MOLECULES. RECENT STUDIES HAVE ALSO REVEALED THE ROLE OF OXIDATIVE STRESS AND SYNOVITIS IN THE PROGRESSION OF THIS DISEASE, SUPPORTING THE DEVELOPMENT OF A NUMBER OF INHIBITORY STRATEGIES. NOVEL TARGETS IN OA ARE REPRESENTED BY GENES INVOLVED IN OA PATHOPHYSIOLOGY DISCOVERED USING GENE NETWORK, EPIGENETIC AND MICRORNA APPROACHES. FURTHER INSIGHTS INTO THE MOLECULAR MECHANISMS INVOLVED IN OA INITIATION AND PROGRESSION MAY LEAD TO THE DEVELOPMENT OF NEW THERAPIES ABLE TO CONTROL JOINT DESTRUCTION AND REPAIR. 2010 17 6245 36 THE MECHANISMS UNDERLYING CHRONIC INFLAMMATION IN RHEUMATOID ARTHRITIS FROM THE PERSPECTIVE OF THE EPIGENETIC LANDSCAPE. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE THAT IS CHARACTERIZED BY SYNOVIAL HYPERPLASIA AND PROGRESSIVE JOINT DESTRUCTION. THE ACTIVATION OF RA SYNOVIAL FIBROBLASTS (SFS), ALSO CALLED FIBROBLAST-LIKE SYNOVIOCYTES (FLS), CONTRIBUTES SIGNIFICANTLY TO PERPETUATION OF THE DISEASE. GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN REPORTED TO BE INVOLVED IN THE ETIOLOGY OF RA BUT ARE INSUFFICIENT TO EXPLAIN IT. IN RECENT YEARS, ACCUMULATING RESULTS HAVE SHOWN THE POTENTIAL ROLE OF EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS, DNA METHYLATION, AND MICRORNAS, IN THE DEVELOPMENT OF RA. EPIGENETIC MECHANISMS REGULATE CHROMATIN STATE AND GENE TRANSCRIPTION WITHOUT ANY CHANGE IN DNA SEQUENCE, RESULTING IN THE ALTERATION OF PHENOTYPES IN SEVERAL CELL TYPES, ESPECIALLY RASFS. EPIGENETIC CHANGES POSSIBLY PROVIDE RASFS WITH AN ACTIVATED PHENOTYPE. IN THIS PAPER, WE REVIEW THE ROLES OF EPIGENETIC MECHANISMS RELEVANT FOR THE PROGRESSION OF RA. 2016 18 2460 31 EPIGENETIC THERAPIES FOR OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS AN AGE-ASSOCIATED DISEASE CHARACTERIZED BY CHRONIC JOINT PAIN RESULTING FROM DEGRADATION OF ARTICULAR CARTILAGE, INFLAMMATION OF THE SYNOVIAL LINING, AND CHANGES TO THE SUBCHONDRAL BONE. DESPITE THE WIDE PREVALENCE, NO FDA-APPROVED DISEASE-MODIFYING DRUGS EXIST. RECENT EVIDENCE HAS DEMONSTRATED THAT EPIGENETIC DYSREGULATION OF MULTIPLE MOLECULAR PATHWAYS UNDERLIES OA PATHOGENESIS, PROVIDING A NEW MECHANISTIC AND THERAPEUTIC AXIS WITH THE ADVANTAGE OF TARGETING MULTIPLE DEREGULATED PATHWAYS SIMULTANEOUSLY. IN THIS REVIEW, WE FOCUS ON THE EPIGENETIC REGULATORS THAT HAVE BEEN IMPLICATED IN OA, THEIR INDIVIDUAL ROLES, AND POTENTIAL CROSSTALK. FINALLY, WE DISCUSS THE PHARMACOLOGICAL MOLECULES THAT CAN MODULATE THEIR ACTIVITIES AND DISCUSS THE POTENTIAL ADVANTAGES AND CHALLENGES ASSOCIATED WITH EPIGENOME-BASED THERAPEUTICS FOR OA. 2020 19 3039 32 GENOME ENGINEERING FOR PERSONALIZED ARTHRITIS THERAPEUTICS. ARTHRITIS REPRESENTS A FAMILY OF COMPLEX JOINT PATHOLOGIES RESPONSIBLE FOR THE MAJORITY OF MUSCULOSKELETAL CONDITIONS. NEARLY ALL DISEASES WITHIN THIS FAMILY, INCLUDING OSTEOARTHRITIS, RHEUMATOID ARTHRITIS, AND JUVENILE IDIOPATHIC ARTHRITIS, ARE CHRONIC CONDITIONS WITH FEW OR NO DISEASE-MODIFYING THERAPEUTICS AVAILABLE. ADVANCES IN GENOME ENGINEERING TECHNOLOGY, MOST RECENTLY WITH CRISPR-CAS9, HAVE REVOLUTIONIZED OUR ABILITY TO INTERROGATE AND VALIDATE GENETIC AND EPIGENETIC ELEMENTS ASSOCIATED WITH CHRONIC DISEASES SUCH AS ARTHRITIS. THESE TECHNOLOGIES, TOGETHER WITH CELL REPROGRAMMING METHODS, INCLUDING THE USE OF INDUCED PLURIPOTENT STEM CELLS, PROVIDE A PLATFORM FOR HUMAN DISEASE MODELING. WE SUMMARIZE NEW EVIDENCE FROM GENOME-WIDE ASSOCIATION STUDIES AND GENOMICS THAT SUBSTANTIATES A GENETIC BASIS FOR ARTHRITIS PATHOGENESIS. WE ALSO REVIEW THE POTENTIAL CONTRIBUTIONS OF GENOME ENGINEERING IN THE DEVELOPMENT OF NEW ARTHRITIS THERAPEUTICS. 2017 20 5932 29 TARGETING EPIGENETIC REGULATORS FOR INFLAMMATION: MECHANISMS AND INTERVENTION THERAPY. EMERGING EVIDENCE INDICATES THAT RESOLUTION OF INFLAMMATION IS A CRITICAL AND DYNAMIC ENDOGENOUS PROCESS FOR HOST TISSUES DEFENDING AGAINST EXTERNAL INVASIVE PATHOGENS OR INTERNAL TISSUE INJURY. IT HAS LONG BEEN KNOWN THAT AUTOIMMUNE DISEASES AND CHRONIC INFLAMMATORY DISORDERS ARE CHARACTERIZED BY DYSREGULATED IMMUNE RESPONSES, LEADING TO EXCESSIVE AND UNCONTROL TISSUE INFLAMMATION. THE DYSREGULATION OF EPIGENETIC ALTERATIONS INCLUDING DNA METHYLATION, POSTTRANSLATIONAL MODIFICATIONS TO HISTONE PROTEINS, AND NONCODING RNA EXPRESSION HAS BEEN IMPLICATED IN A HOST OF INFLAMMATORY DISORDERS AND THE IMMUNE SYSTEM. THE INFLAMMATORY RESPONSE IS CONSIDERED AS A CRITICAL TRIGGER OF EPIGENETIC ALTERATIONS THAT IN TURN INTERCEDE INFLAMMATORY ACTIONS. THUS, UNDERSTANDING THE MOLECULAR MECHANISM THAT DICTATES THE OUTCOME OF TARGETING EPIGENETIC REGULATORS FOR INFLAMMATORY DISEASE IS REQUIRED FOR INFLAMMATION RESOLUTION. IN THIS ARTICLE, WE ELUCIDATE THE CRITICAL ROLE OF THE NUCLEAR FACTOR-KAPPAB SIGNALING PATHWAY, JAK/STAT SIGNALING PATHWAY, AND THE NLRP3 INFLAMMASOME IN CHRONIC INFLAMMATORY DISEASES. AND WE FORMULATE THE RELATIONSHIP BETWEEN INFLAMMATION, CORONAVIRUS DISEASE 2019, AND HUMAN CANCERS. ADDITIONALLY, WE REVIEW THE MECHANISM OF EPIGENETIC MODIFICATIONS INVOLVED IN INFLAMMATION AND INNATE IMMUNE CELLS. ALL THAT MATTERS IS THAT WE PROPOSE AND DISCUSS THE REJUVENATION POTENTIAL OF INTERVENTIONS THAT TARGET EPIGENETIC REGULATORS AND REGULATORY MECHANISMS FOR CHRONIC INFLAMMATION-ASSOCIATED DISEASES TO IMPROVE THERAPEUTIC OUTCOMES. 2022