1 4416 113 MOLECULAR AND CELLULAR PATHWAYS CONTRIBUTING TO JOINT DAMAGE IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS IS A CHRONIC AUTOIMMUNE SYNDROME ASSOCIATED WITH SEVERAL GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS AFFECTING THE ARTICULAR JOINTS CONTRIBUTING TO CARTILAGE AND BONE DAMAGE. ALTHOUGH ETIOLOGY OF THIS DISEASE IS NOT CLEAR, SEVERAL IMMUNE PATHWAYS, INVOLVING IMMUNE (T CELLS, B CELLS, DENDRITIC CELLS, MACROPHAGES, AND NEUTROPHILS) AND NONIMMUNE (FIBROBLASTS AND CHONDROCYTES) CELLS, PARTICIPATE IN THE SECRETION OF MANY PROINFLAMMATORY CYTOKINES, CHEMOKINES, PROTEASES (MMPS, ADAMTS), AND OTHER MATRIX LYSING ENZYMES THAT COULD DISTURB THE IMMUNE BALANCE LEADING TO CARTILAGE AND BONE DAMAGE. THE PRESENCE OF AUTOANTIBODIES PRECEDING THE CLINICAL ONSET OF ARTHRITIS AND THE INDUCTION OF BONE EROSION EARLY IN THE DISEASE COURSE CLEARLY SUGGEST THAT INITIATION EVENTS DAMAGING THE CARTILAGE AND BONE START VERY EARLY DURING THE AUTOIMMUNE PHASE OF THE ARTHRITIS DEVELOPMENT. DURING THIS PROCESS, SEVERAL SIGNALING MOLECULES (RANKL-RANK, NF-KAPPAB, MAPK, NFATC1, AND SRC KINASE) ARE ACTIVATED IN THE OSTEOCLASTS, CELLS RESPONSIBLE FOR BONE RESORPTION. HENCE, COMPREHENSIVE KNOWLEDGE ON PATHOGENESIS IS A PREREQUISITE FOR PREVENTION AND DEVELOPMENT OF TARGETED CLINICAL TREATMENT FOR RA PATIENTS THAT CAN RESTORE THE IMMUNE BALANCE IMPROVING CLINICAL THERAPY. 2020 2 6869 43 [PATHOGENESIS OF RHEUMATOID ARTHRITIS]. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE SYSTEMIC DISEASE THAT PRIMARILY AFFECTS JOINTS. ETIOLOGY AND THE PATHOGENESIS OF RA ARE COMPLEX, INVOLVING MANY TYPES OF CELLS, AMONG OTHERS MACROPHAGES, T AND B CELLS, FIBRO- BLASTS, CHONDROCYTES AND DENDRITIC CELLS. DESPITE WELL DOCUMENTED ROLE OF MANY GENES AND EPIGENETIC MODIFICATIONS IN THE DEVELOPMENT AND EVOLUTION OF THE DISEASE, IN MOST RA PATIENTS THERE IS NO CLEAR PREDISPOSING FACTOR PRESENT. ENVIRONMENTAL FACTORS INVOLVED IN RA PATHOGENESIS ARE CIGARETTE SMOKE, INDUSTRIAL POLLUTANTS LIKE SILICA CRYSTALS, DISTURBANCES OF INTESTINAL, LUNG, AND ORAL MICROBIOTA AND SOME SPECIFIC BACTERIAL AND VIRAL INFECTIOUS AGENTS AND THEIR COMPONENTS. IN THE INITIAL DISEASE STAGE THERE ARE QUALITATIVE AND QUANTITATIVE DISTURBANCES OFPEPTIDE CITRULINATION AS WELL AS OTHER PROTEIN MODIFICATIONS, FOLLOWED BY ANTIGEN PRESENTING CELL (APC) (MACROPHAGES AND DENDRITIC CELLS) AND FIBROBLAST LIKE SYNOVIOCYTES (FLS) ACTIVATION. SOME MICROBES FOSTER THIS PROCESSES BY APC AND FLS DIRECT AND INDIRECT ACTIVATION. IN THE SECOND STAGE APC'S ELICIT SPECIFIC HUMORAL B CELL RE- SPONSE RESULTING IN SPECIFIC ANTIBODIES PRODUCTION AND T CELL AUTOREACTIVITY. INHERITED AND ACQUIRED DEFECTS IN T AND B CELL RESPONSES CAUSED BY REPEATED ACTIVATION OF INNATE IMMUNITY AS WELL AS LOSS OF TOLERANCE, ELICIT CHRONIC AUTOIMMUNE INFLAMMATION, PRIMARILY OF SYNOVIAL MEMBRANES, AND DEVELOPMENT OF CELLULAR PANUS. PATHOLOGIC ACTIVATION OF THE OSTEOCLASTS AND RELEASE OF THE IMMUNE SYSTEM EFFECTOR MOLECULES AND THE PROTEOLYTIC ENZYMES DAMAGE THE CARTILAGE, BONE AND TENDONS COMPOSITION AND STRUCTURE. PERSISTENT INFLAMMATION THROUGH ITS COMPLEX MECHANISMS RESULTS IN MANY SYSTEMIC AND EXTRAARTICULAR RA MANIFESTATIONS OF ALMOST ALL ORGAN SYSTEMS, RESULTING IN SEVERE COMPLICATIONS AND COMORBIDITIES SUCH AS RHEUMATOID LUNG, CARDITIS, VASCULITIS, CAHEXIA, ANEMIA, ACCELERATED ATHEROSCLEROSIS, MYOCARDIAL AND CEREBROVASCULAR VASCULAR DISEASE, LYMPHOMA, OSTEOPOROSIS, DEPRESSION ETC. ACCUMULATED COMPLICATIONS AND COMORBIDITIES FINALLY RESULT IN HANDICAP, SOCIAL DYSFUNCTION AND PREMATURE DEATH. 2014 3 6102 32 THE EMERGING ROLE OF FIBROBLAST-LIKE SYNOVIOCYTES-MEDIATED SYNOVITIS IN OSTEOARTHRITIS: AN UPDATE. OSTEOARTHRITIS (OA), THE MOST UBIQUITOUS DEGENERATIVE DISEASE AFFECTING THE ENTIRE JOINT, IS CHARACTERIZED BY CARTILAGE DEGRADATION AND SYNOVIAL INFLAMMATION. ALTHOUGH THE PATHOGENESIS OF OA REMAINS POORLY UNDERSTOOD, SYNOVIAL INFLAMMATION IS KNOWN TO PLAY AN IMPORTANT ROLE IN OA DEVELOPMENT. HOWEVER, STUDIES ON OA PATHOPHYSIOLOGY HAVE FOCUSED MORE ON CARTILAGE DEGENERATION AND OSTEOPHYTES, RATHER THAN ON THE INFLAMED AND THICKENED SYNOVIUM. FIBROBLAST-LIKE SYNOVIOCYTES (FLS) PRODUCE A SERIES OF PRO-INFLAMMATORY REGULATORS, SUCH AS INFLAMMATORY CYTOKINES, NITRIC OXIDE (NO) AND PROSTAGLANDIN E(2) (PGE(2) ). THESE REGULATORS ARE POSITIVELY ASSOCIATED WITH THE CLINICAL SYMPTOMS OF OA, SUCH AS INFLAMMATORY PAIN, JOINT SWELLING AND DISEASE DEVELOPMENT. A BETTER UNDERSTANDING OF THE INFLAMMATORY IMMUNE RESPONSE IN OA-FLS COULD PROVIDE A NOVEL APPROACH TO COMPREHENSIVE TREATMENT STRATEGIES FOR OA. HERE, WE HAVE SUMMARIZED RECENTLY PUBLISHED LITERATURES REFERRING TO EPIGENETIC MODIFICATIONS, ACTIVATED SIGNALLING PATHWAYS AND INFLAMMATION-ASSOCIATED FACTORS THAT ARE INVOLVED IN OA-FLS-MEDIATED INFLAMMATION. IN ADDITION, THE CURRENT RELATED CLINICAL TRIALS AND FUTURE PERSPECTIVES WERE ALSO SUMMARIZED. 2020 4 1608 35 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 5 4412 33 MOLECULAR AND CELLULAR BASIS OF RHEUMATOID JOINT DESTRUCTION. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE ASSOCIATED WITH JOINT DESTRUCTION. SYNOVIAL FIBROBLASTS ARE KEY PLAYERS IN THIS PATHOLOGICAL PROCESS. THEY FAVORISE A PRO-INFLAMMATORY ENVIRONMENT IN THE SYNOVIAL TISSUE, INTERACT WITH THE IMMUNE SYSTEM AND REGULATE THE DIFFERENTIATION OF MONOCYTES INTO OSTEOCLASTS. SYNOVIAL HYPERPLASIA IS ANOTHER CHARACTERISTIC OF RA, REFLECTING NOT ONLY AN IMBALANCE BETWEEN PROLIFERATION AND APOPTOSIS, BUT ALSO THE MIGRATION OF CELLS INTO THE SYNOVIAL TISSUE. GENE TRANSFER EXPERIMENTS HAVE BEEN USED AS IMPORTANT TOOLS FOR THE UNDERSTANDING OF MOLECULAR AND CELLULAR CHANGES THAT CHARACTERIZE THE ACTIVATED RA SYNOVIAL FIBROBLASTS. ACTIVATED SYNOVIAL FIBROBLASTS CAN INVADE CARTILAGE AND BONE. SYNOVIAL ACTIVATION IS DRIVEN BY CYTOKINES, SUCH AS TNFALPHA AND IL-1, AS WELL AS IL-15, 16, 17, 18, 22, 23, BUT ALSO BY CYTOKINE-INDEPENDENT MECHANISMS THAT INVOLVE THE INNATE IMMUNE SYSTEM (I.E. TLRS), A UNIQUE COMMUNICATION NETWORK OF MICROPARTICLES AND EPIGENETIC CHANGES (E.G. L1 RETROELEMENTS). 2006 6 783 25 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 7 3699 31 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 8 6328 27 THE ROLE OF CELL ORGANELLES IN RHEUMATOID ARTHRITIS WITH FOCUS ON EXOSOMES. AUTO-IMMUNE DISEASES INVOLVED AT LEAST 25% OF THE POPULATION IN WEALTHY COUNTRIES. SEVERAL FACTORS INCLUDING GENETIC, EPIGENETIC, AND ENVIRONMENTAL ELEMENTS ARE IMPLICATED IN DEVELOPMENT OF RHEUMATOID ARTHRITIS AS AN AUTOIMMUNE DISEASE. AUTOANTIBODIES CAUSE SYNOVIAL INFLAMMATION AND ARTHRITIS, IF LEFT UNTREATED OR BEING UNDER CONTINUAL EXTERNAL STIMULATION, COULD RESULT IN CHRONIC INFLAMMATION, JOINT INJURY, AND DISABILITY. T- AND B-CELLS, SIGNALING MOLECULES, PROINFLAMMATORY MEDIATORS, AND SYNOVIUM-SPECIFIC TARGETS ARE AMONG THE NEW THERAPEUTIC TARGETS. EXOSOMES COULD BE EMPLOYED AS THERAPEUTIC VECTORS IN THE TREATMENT OF AUTOIMMUNE DISEASES. HEREIN, THE ROLE OF CELL ORGANELLE PARTICULARLY EXOSOMES IN RHEUMATOID ARTHRITIS HAD DISCUSSED AND SOME THERAPEUTIC APPLICATIONS OF EXOSOME HIGHLIGHTED. 2021 9 2221 26 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 10 6884 33 [RHEUMATOID ARTHRITIS]. RHEUMATOID ARTHRITIS ABSTRACT. RHEUMATOID ARTHRITIS (RA) IS THE MOST FREQUENT CHRONIC INFLAMMATORY JOINT DISEASE WITH A PREVALENCE OF APPROXIMATELY 1% WORLDWIDE. THE PATHOGENESIS IS A COMPLEX INTERPLAY OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS, WHICH ARE STILL INCOMPLETELY UNDERSTOOD. THE DISEASE IS CHARACTERIZED BY A POLYARTICULAR SYNOVITIS WITH SYMMETRICAL INVOLVEMENT OF SMALL AND LARGE JOINTS. THE MAJORITY OF PATIENTS HAS DETECTABLE AUTOANTIBODIES IN THE SERUM, RHEUMATOID FACTOR AND ANTI-CCP ANTIBODIES WHICH ARE SPECIFIC FOR RA. THE UNCONTROLLED CHRONIC JOINT INFLAMMATION RESULTS IN DESTRUCTIVE CHANGES OF JOINT CARTILAGE AND BONE. AN EARLY DIAGNOSIS AND INITIATION OF TREATMENT IS THEREFORE OF CENTRAL IMPORTANCE. DISEASE-MODIFYING ANTI-RHEUMATIC DRUGS (DMARD) ARE ABLE TO INHIBIT JOINT DESTRUCTION AND SHOULD BE STARTED AS SOON AS POSSIBLE. THERAPY SHOULD BE TARGETED TO REACH A STATE OF REMISSION. THE INTRODUCTION OF HIGHLY EFFECTIVE BIOLOGIC AND TARGETED SYNTHETIC DMARD HAS ALLOWED TO REACH THIS GOAL OF THERAPY IN MANY PATIENTS AND TO PREVENT DISABILITY. HOWEVER, RISKS OF MEDICATION NEED TO BE CONSIDERED, AS WELL AS COMORBIDITIES. 2023 11 1565 31 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 12 296 27 AGING, CELL SENESCENCE, THE PATHOGENESIS AND TARGETED THERAPIES OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A CHRONIC, DEBILITATING JOINT DISEASE CHARACTERIZED BY PROGRESSIVE DESTRUCTION OF ARTICULAR CARTILAGE. FOR A LONG TIME, OA HAS BEEN CONSIDERED AS A DEGENERATIVE DISEASE, WHILE RECENT OBSERVATIONS INDICATE THE MECHANISMS RESPONSIBLE FOR THE PATHOGENESIS OF OA ARE MULTIFACETED. AGING IS A KEY FACTOR IN ITS DEVELOPMENT. CURRENT TREATMENTS ARE PALLIATIVE AND NO DISEASE MODIFYING ANTI-OSTEOARTHRITIS DRUGS (DMOADS) ARE AVAILABLE. IN ADDITION TO ARTICULAR CARTILAGE DEGRADATION, CELLULAR SENESCENCE, SYNOVIAL INFLAMMATION, AND EPIGENETIC ALTERATIONS MAY ALL HAVE A ROLE IN ITS FORMATION. ACCUMULATING DATA DEMONSTRATE A CLEAR RELATIONSHIP BETWEEN THE SENESCENCE OF ARTICULAR CHONDROCYTES AND OA FORMATION AND PROGRESSION. INHIBITION OF CELL SENESCENCE MAY HELP IDENTIFY NEW AGENTS WITH THE PROPERTIES OF DMOADS. SEVERAL ANTI-CELLULAR SENESCENCE STRATEGIES HAVE BEEN PROPOSED AND THESE INCLUDE SIRTUIN-ACTIVATING COMPOUNDS (STACS), SENOLYTICS, AND SENOMORPHICS DRUGS. THESE AGENTS MAY SELECTIVELY REMOVE SENESCENT CELLS OR AMELIORATE THEIR HARMFUL EFFECTS. THE RESULTS FROM PRECLINICAL EXPERIMENTS AND CLINICAL TRIALS ARE INSPIRING. HOWEVER, MORE STUDIES ARE WARRANTED TO CONFIRM THEIR EFFICACY, SAFETY PROFILES AND ADVERSE EFFECTS OF THESE AGENTS. 2021 13 4842 37 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 14 5505 28 RHEUMATOID ARTHRITIS AND ALZHEIMER'S DISEASE: GENETIC AND EPIGENETIC LINKS IN INFLAMMATORY REGULATION. CONTROVERSIAL DATA ARE AVAILABLE ABOUT THE RELATIONSHIP BETWEEN ALZHEIMER'S DISEASE (AD) AND RHEUMATOID ARTHRITIS (RA). AN INVERSE RELATIONSHIP BETWEEN AD AND RA, DUE TO DIFFERENT FACTORS, WAS PREVIOUSLY DESCRIBED. SIMILARLY TO RA, AD PATHOGENESIS IS MULTIFACTORIAL AND DIFFERENT FINDINGS SUPPORT THE INFLAMMATORY PATHOGENETIC HYPOTHESIS. SEVERAL INFLAMMATORY MEDIATORS ARE INVOLVED IN THE DISEASE ONSET AND PROGRESSION REGULATED BY GENETIC AND EPIGENETIC MECHANISMS. AMONG THEM, INTELEUKIN-6 (IL-6) AND INTERLEUKIN-1 (IL-1) AS PRO-INFLAMMATORY SOLUBLE FACTORS PRODUCED BY MONOCYTES-MACROPHAGES AND TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) PRODUCED BY ACTIVATED MACROPHAGES AND MONONUCLEAR CELLS REPRESENT KEY MOLECULES IN THE INDUCTION AND MAINTENANCE OF CHRONIC INFLAMMATION IN RA. IN PARTICULAR A LINK WITH THE T ALLELE OF THE SNP 3953 T/C IN THE IL-1 GENE AND AN OVEREXPRESSION OF MIR-146A APPEARS TO BE COMMON TO BOTH RA AND AD. IN THIS REVIEW WE WILL DISCUSS THE GENETIC AND EPIGENETIC REGULATION OF THE INFLAMMATORY CASCADE IN RA AND AD TO FIND OUT THE POSSIBLE LINKS BETWEEN RA AND AD ONSET. 2012 15 797 27 CELLULAR SENESCENCE IN OSTEOARTHRITIS PATHOLOGY. CELLULAR SENESCENCE IS A STATE OF STABLE PROLIFERATION ARREST OF CELLS. THE SENESCENCE PATHWAY HAS MANY BENEFICIAL EFFECTS AND IS SEEN TO BE ACTIVATED IN DAMAGED/STRESSED CELLS, AS WELL AS DURING EMBRYONIC DEVELOPMENT AND WOUND HEALING. HOWEVER, THE PERSISTENCE AND ACCUMULATION OF SENESCENT CELLS IN VARIOUS TISSUES CAN ALSO IMPAIR FUNCTION AND HAVE BEEN IMPLICATED IN THE PATHOGENESIS OF MANY AGE-RELATED DISEASES. OSTEOARTHRITIS (OA), A SEVERELY DEBILITATING CHRONIC CONDITION CHARACTERIZED BY PROGRESSIVE TISSUE REMODELING AND LOSS OF JOINT FUNCTION, IS THE MOST PREVALENT DISEASE OF THE SYNOVIAL JOINTS, AND INCREASING AGE IS THE PRIMARY OA RISK FACTOR. THE PROFILE OF INFLAMMATORY AND CATABOLIC MEDIATORS PRESENT DURING THE PATHOGENESIS OF OA IS STRIKINGLY SIMILAR TO THE SECRETORY PROFILE OBSERVED IN 'CLASSICAL' SENESCENT CELLS. DURING OA, CHONDROCYTES (THE SOLE CELL TYPE PRESENT WITHIN ARTICULAR CARTILAGE) EXHIBIT INCREASED LEVELS OF VARIOUS SENESCENCE MARKERS, SUCH AS SENESCENCE-ASSOCIATED BETA-GALACTOSIDASE (SABETAGAL) ACTIVITY, TELOMERE ATTRITION, AND ACCUMULATION OF P16INK4A. THIS SUGGESTS THE HYPOTHESIS THAT SENESCENCE OF CELLS WITHIN JOINT TISSUES MAY PLAY A PATHOLOGICAL ROLE IN THE CAUSATION OF OA. IN THIS REVIEW, WE DISCUSS THE MECHANISMS BY WHICH SENESCENT CELLS MAY PREDISPOSE SYNOVIAL JOINTS TO THE DEVELOPMENT AND/OR PROGRESSION OF OA, AS WELL AS TOUCHING UPON VARIOUS EPIGENETIC ALTERATIONS ASSOCIATED WITH BOTH OA AND SENESCENCE. 2017 16 5476 27 RESTORING T CELL TOLERANCE, EXPLORING THE POTENTIAL OF HISTONE DEACETYLASE INHIBITORS FOR THE TREATMENT OF JUVENILE IDIOPATHIC ARTHRITIS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS CHARACTERIZED BY A LOSS OF IMMUNE TOLERANCE. HERE, THE BALANCE BETWEEN THE ACTIVITY OF EFFECTOR T (TEFF) CELLS AND REGULATORY T (TREG) CELLS IS DISTURBED RESULTING IN CHRONIC INFLAMMATION IN THE JOINTS. PRESENTLY, THERAPEUTIC STRATEGIES ARE PREDOMINANTLY AIMED AT SUPPRESSING IMMUNE ACTIVATION AND PRO-INFLAMMATORY EFFECTOR MECHANISMS, IGNORING THE OPPORTUNITY TO ALSO PROMOTE TOLERANCE BY BOOSTING THE REGULATORY SIDE OF THE IMMUNE BALANCE. HISTONE DEACETYLASES (HDACS) CAN DEACETYLATE BOTH HISTONE AND NON-HISTONE PROTEINS AND HAVE BEEN DEMONSTRATED TO MODULATE EPIGENETIC REGULATION AS WELL AS CELLULAR SIGNALING IN VARIOUS CELL TYPES. IMPORTANTLY, HDACS ARE POTENT REGULATORS OF BOTH TEFF CELL AND TREG CELL FUNCTION AND CAN THUS BE REGARDED AS ATTRACTIVE THERAPEUTIC TARGETS IN CHRONIC INFLAMMATORY ARTHRITIS. HDAC INHIBITORS (HDACI) HAVE PROVEN THERAPEUTIC POTENTIAL IN THE CANCER FIELD, AND ARE PRESENTLY BEING EXPLORED FOR THEIR POTENTIAL IN THE TREATMENT OF AUTOIMMUNE DISEASES. SPECIFIC HDACI HAVE ALREADY BEEN DEMONSTRATED TO REDUCE THE SECRETION OF PRO-INFLAMMATORY CYTOKINES BY TEFF CELLS, AND PROMOTE TREG NUMBERS AND SUPPRESSIVE CAPACITY IN VITRO AND IN VIVO. IN THIS REVIEW, WE OUTLINE THE ROLE OF THE DIFFERENT CLASSES OF HDACS IN BOTH TEFF CELL AND TREG CELL FUNCTION. FURTHERMORE, WE WILL REVIEW THE EFFECT OF DIFFERENT HDACI ON T CELL TOLERANCE AND EXPLORE THEIR POTENTIAL AS A THERAPEUTIC STRATEGY FOR THE TREATMENT OF OLIGOARTICULAR AND POLYARTICULAR JIA. 2019 17 1812 40 EFFECTS OF BIOLOGICAL THERAPIES ON MOLECULAR FEATURES OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE AND CHRONIC INFLAMMATORY DISEASE PRIMARILY AFFECTING THE JOINTS, AND CLOSELY RELATED TO SPECIFIC AUTOANTIBODIES THAT MOSTLY TARGET MODIFIED SELF-EPITOPES. RELEVANT FINDINGS IN THE FIELD OF RA PATHOGENESIS HAVE BEEN DESCRIBED. IN PARTICULAR, NEW INSIGHTS COME FROM STUDIES ON SYNOVIAL FIBROBLASTS AND CELLS BELONGING TO THE INNATE AND ADAPTIVE IMMUNE SYSTEM, WHICH DOCUMENTED THE ABERRANT PRODUCTION OF INFLAMMATORY MEDIATORS, OXIDATIVE STRESS AND NETOSIS, ALONG WITH RELEVANT ALTERATIONS OF THE GENOME AND ON THE REGULATORY EPIGENETIC MECHANISMS. IN RECENT YEARS, THE ADVANCES IN THE UNDERSTANDING OF RA PATHOGENESIS BY IDENTIFYING KEY CELLS AND CYTOKINES ALLOWED THE DEVELOPMENT OF NEW TARGETED DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS). THESE DRUGS CONSIDERABLY IMPROVED TREATMENT OUTCOMES FOR THE MAJORITY OF PATIENTS. MOREOVER, NUMEROUS STUDIES DEMONSTRATED THAT THE PHARMACOLOGICAL THERAPY WITH BIOLOGIC DMARDS (BDMARDS) PROMOTES, IN PARALLEL TO THEIR CLINICAL EFFICACY, SIGNIFICANT IMPROVEMENT IN ALL THESE ALTERED MOLECULAR MECHANISMS. THUS, CONTINUOUS UPDATING OF THE KNOWLEDGE OF MOLECULAR PROCESSES ASSOCIATED WITH THE PATHOGENESIS OF RA, AND ON THE SPECIFIC EFFECTS OF BDMARDS IN THE CORRECTION OF THEIR DYSREGULATION, ARE ESSENTIAL IN THE EARLY AND CORRECT APPROACH TO THE TREATMENT OF THIS COMPLEX AUTOIMMUNE DISORDER. THE PRESENT REVIEW DETAILS BASIC MECHANISMS RELATED TO THE PHYSIOPATHOLOGY OF RA, ALONG WITH THE CORE MECHANISMS OF RESPONSE TO BDMARDS. 2020 18 2054 35 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 19 6906 24 [THE ROLE OF GLYCANS IN CANCER DEVELOPMENT AND PROGRESSION. CLINICAL APPLICATIONS]. CHANGES IN GLYCOSYLATION PATTERN OF CELL SURFACE, BODY FLUIDS AND EXTRACELLULAR MATRIX GLYCOCONJUGATES IS A CHARACTERISTIC FEATURE OF TUMOR CELL MALIGNANCY. THESE CHANGES ARE THE RESULT OF MUTATIONS OF TUMOR-ASSOCIATED GENES AS WELL AS EPIGENETIC CHANGES IN THE TUMOR ENVIRONMENT, INCLUDING NUTRIENT INFLUX, HYPOXIA, CYTOKINE EXPRESSION AND STIMULATION OF CHRONIC INFLAMMATION. THE UNIQUE SET OF CELL SURFACE GLYCOANTIGENS ON NEOPLASTIC CELLS IS RECOGNIZED BY ENDOGENOUS LECTINS LOCATED IN THE EXTRACELLULAR MATRIX, VASCULAR ENDOTHELIUM, ON LEUKOCYTES OR PLATELETS, AND HAS AN IMPACT ON DISRUPTING BASIC CELLULAR PROCESSES, SUCH AS INTERCELLULAR RECOGNITION, CELL-CELL ADHESION OR CELL-ECM INTERACTION. THESE CHANGES HAVE A CRITICAL IMPACT ON THE MIGRATION, INVASIVE AND METASTATIC POTENTIAL OF NEOPLASTIC CELLS AND MODULATE THE IMMUNE RESPONSE. THIS UNIQUE PATTERN OF SUGAR ANTIGENS ON THE CANCER CELLS CAN BE A VAULABLE MARKER TO IDENTIFY THEM, DETERMINE THE STAGE OF THE DISEASE AS WELL AS BE A TARGET OF ANTI-CANCER THERAPY. 2021 20 6597 32 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