1 4282 113 MICRORNA AND EXOSOME: KEY PLAYERS IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS KNOWN AS ONE OF IMPORTANT AUTOIMMUNE DISORDERS WHICH CAN LEAD TO JOINT PAIN AND DAMAGE THROUGHOUT BODY. GIVEN THAT INTERNAL (IE, GENETIC AND EPIGENETIC ALTERATIONS) AND EXTERNAL FACTORS (IE, LIFESTYLE CHANGES, AGE, HORMONES, SMOKING, STRESS, AND OBESITY) INVOLVED IN RA PATHOGENESIS. INCREASING EVIDENCE INDICATED THAT CELLULAR AND MOLECULAR ALTERATIONS PLAY CRITICAL ROLES IN THE INITIATION AND PROGRESSION OF RA. AMONG VARIOUS TARGETS AND MOLECULAR SIGNALING PATHWAYS, MICRORNAS (MIRNAS) AND THEIR REGULATORY NETWORKS HAVE KEY ROLES IN THE RA PATHOGENESIS. IT HAS BEEN SHOWED THAT DEREGULATION OF MANY MIRNAS INVOLVED IN DIFFERENT STAGES OF RA. HENCE, IDENTIFICATION OF MIRNAS AND THEIR SIGNALING PATHWAYS IN RA, COULD CONTRIBUTE TO NEW KNOWLEDGE WHICH HELP TO BETTER TREATMENT OF PATIENTS WITH RA. BESIDES MIRNAS, EXOSOMES HAVE BEEN EMERGED AS KEY MESSENGERS IN RA PATHOGENESIS. EXSOSOMES ARE NANOCARRIERS WHICH COULD BE RELEASED FROM VARIOUS CELLS AND LEAD TO CHANGING OF BEHAVIORS RECIPIENT CELLS VIA TARGETING THEIR CARGOS (EG, PROTEINS, MESSENGER RNAS, MIRNAS, LONG NONCODING RNAS, DNAS). HERE, WE SUMMARIZED SEVERAL MIRNAS INVOLVED IN RA PATHOGENESIS. MOREOVER, WE HIGHLIGHTED THE ROLES OF EXOSOMES IN RA PATHOGENESIS. 2019 2 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 3 1726 33 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 4 1608 37 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 6328 28 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 6 783 31 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 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 2224 25 EPIGENETIC MODIFICATIONS IN THE PATHOGENESIS OF SYSTEMIC SCLEROSIS. SYSTEMIC SCLEROSIS IS A RARE CHRONIC AUTOIMMUNE DISEASE, WHICH MAINLY MANIFESTS AS IMMUNE DISORDERS, VASCULAR DAMAGE, AND PROGRESSIVE FIBROSIS. THE ETIOLOGY OF SSC IS COMPLEX AND INVOLVES MULTIPLE FACTORS. BOTH GENETIC AND ENVIRONMENTAL FACTORS ARE INVOLVED IN ITS PATHOGENESIS. AS ONE OF THE MOLECULAR MECHANISMS OF ENVIRONMENTAL FACTORS, EPIGENETIC REGULATION PLAYS AN IMPORTANT ROLE IN THE OCCURRENCE AND DEVELOPMENT OF SYSTEMIC SCLEROSIS, WHICH INVOLVES DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNA REGULATION. THIS REVIEW SUMMARIZES RESEARCH ADVANCES IN EPIGENETICS, INCLUDING EXOSOMES, LNCRNA, AND MENTIONS POSSIBLE BIOMARKERS AND THERAPEUTIC TARGETS AMONG THEM. 2022 9 5372 37 RECENT ADVANCES IN UNDERSTANDING THE PATHOGENESIS OF RHEUMATOID ARTHRITIS: NEW TREATMENT STRATEGIES. RHEUMATOID ARTHRITIS (RA) IS CONSIDERED A CHRONIC SYSTEMIC, MULTI-FACTORIAL, INFLAMMATORY, AND PROGRESSIVE AUTOIMMUNE DISEASE AFFECTING MANY PEOPLE WORLDWIDE. WHILE PATIENTS SHOW VERY INDIVIDUAL COURSES OF DISEASE, WITH RA FOCUSING ON THE MUSCULOSKELETAL SYSTEM, JOINTS ARE OFTEN SEVERELY AFFECTED, LEADING TO LOCAL INFLAMMATION, CARTILAGE DESTRUCTION, AND BONE EROSION. TO PREVENT JOINT DAMAGE AND PHYSICAL DISABILITY AS ONE OF MANY SYMPTOMS OF RA, EARLY DIAGNOSIS IS CRITICAL. AUTO-ANTIBODIES PLAY A PIVOTAL CLINICAL ROLE IN PATIENTS WITH SYSTEMIC RA. AS BIOMARKERS, THEY COULD HELP TO MAKE A MORE EFFICIENT DIAGNOSIS, PROGNOSIS, AND TREATMENT DECISION. BESIDES AUTO-ANTIBODIES, SEVERAL OTHER FACTORS ARE INVOLVED IN THE PROGRESSION OF RA, SUCH AS EPIGENETIC ALTERATIONS, POST-TRANSLATIONAL MODIFICATIONS, GLYCOSYLATION, AUTOPHAGY, AND T-CELLS. UNDERSTANDING THE INTERPLAY BETWEEN THESE FACTORS WOULD CONTRIBUTE TO A DEEPER INSIGHT INTO THE CAUSES, MECHANISMS, PROGRESSION, AND TREATMENT OF THE DISEASE. IN THIS REVIEW, THE LATEST RA RESEARCH FINDINGS ARE DISCUSSED TO BETTER UNDERSTAND THE PATHOGENESIS, AND FINALLY, TREATMENT STRATEGIES FOR RA THERAPY ARE PRESENTED, INCLUDING BOTH CONVENTIONAL APPROACHES AND NEW METHODS THAT HAVE BEEN DEVELOPED IN RECENT YEARS OR ARE CURRENTLY UNDER INVESTIGATION. 2021 10 4845 28 ONE YEAR IN REVIEW 2020: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. THE DISCOVERY OF NEW GENE POLYMORPHISMS AND THEIR ASSOCIATION WITH DISEASE SUSCEPTIBILITY HAVE ADDED NEW ELEMENTS TO BETTER CLARIFY RA PATHOGENESIS. IN THE LAST YEAR, IMPORTANT ELEMENTS HAVE BEEN ADDED TO THE CURRENT KNOWLEDGE OF MECHANISMS REGULATING INNATE AND ADAPTIVE IMMUNITY IN RA, LEADING TO DISCOVERING NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS RESULTING FROM A LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2020 11 3699 26 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 12 4318 28 MICRORNAS IN ANKYLOSING SPONDYLITIS: FUNCTION, POTENTIAL AND CHALLENGES. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNA, ARE CONSIDERED THE ESSENTIAL CONNECTION BETWEEN A DISORDER'S ONSET AND THE ENVIRONMENT, ON A PERMISSIVE GENETIC BACKGROUND. AMONG AUTOIMMUNE AND INFLAMMATORY-MEDIATED DISORDERS, ANKYLOSING SPONDYLITIS (AS), A CHRONIC ARTHRITIS OF THE SPINE, IS A VERY GOOD EXAMPLE FOR THE WEIGHT OF EPIGENETICS' CONTRIBUTION. MICRORNAS (MIRNAS) ARE SINGLE-STRANDED NUCLEOTIDES WHICH REGULATE GENE EXPRESSION AND ARE INVOLVED IN PATHOLOGICAL AND PHYSIOLOGICAL PROCESSES. IN THIS MANUSCRIPT WE PROVIDE A CLARIFICATION ON THE ROLE OF MICRORNAS IN AS, WITH A FOCUS ON THE MECHANISMS OF PATHOGENESIS. IN SPECIFIC, WE HAVE EXAMINED THE CONTRIBUTION OF MIRNAS IN THE PROCESSES OF INFLAMMATION, NEW BONE FORMATION AND T-CELL FUNCTION, AND THE PATHWAYS (I.E. WNT, BMP, TGFBETA SIGNALLING ETC.) THEY REGULATE. THE UTILITY OF MIRNAS IN BETTER UNDERSTANDING AS PATHOGENESIS IS UNDISPUTED AND THEIR UTILITY AS THERAPEUTIC OPPORTUNITY IS STRONGLY INCREASING. 2020 13 4289 29 MICRORNA IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS THE MOST PREVALENT DEGENERATIVE JOINT DISEASE AND IS ACCOMPANIED BY PAIN AND JOINT DYSFUNCTION. ITS CLINICAL TREATMENT TENDS TO BE UNSATISFACTORY. NOVEL TARGETS IN OA INCLUDE GENES THAT ARE INVOLVED IN OA PATHOPHYSIOLOGY AND HAVE BEEN DISCOVERED USING GENE NETWORK, EPIGENETIC AND MICRORNA (MIRNA) APPROACHES. MIRNA HAS BEEN IMPLICATED IN IMPORTANT CELLULAR PROCESSES SUCH AS LIPID METABOLISM, APOPTOSIS, DIFFERENTIATION AND ORGAN DEVELOPMENT. THE IMPORTANCE OF MIRNA REGULATION IN CELLULAR FUNCTION IS BECOMING INCREASINGLY CLEAR AS NEW MIRNA TARGETS ARE REVEALED. THE PRESENT REVIEW SUMMARIZES THE CURRENT EVIDENCE OF THE IMPORTANT ROLE PLAYED BY MIRNA IN DETERMINING THE COMPLEX GENE EXPRESSION PATTERNS OF OA CHONDROCYTES AND THEIR ROLE IN THE REGULATION OF TRANSCRIPTION, AND POSSIBLE DEMETHYLATION MECHANISMS THAT MIGHT BE APPLICABLE IN OA. IN SUMMARY, MIRNA MAY HAVE IMPORTANT DIAGNOSTIC AND THERAPEUTIC POTENTIAL, AND MIGHT PROVIDE A NOVEL MEANS OF TREATING OA. 2011 14 4842 32 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 15 2294 43 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 16 6152 24 THE FUNCTION OF NCRNAS IN RHEUMATIC DISEASES. RHEUMATIC DISEASES ARE A GROUP OF CHRONIC HETEROGENEOUS AUTOIMMUNE DISORDERS CHARACTERIZED BY ABNORMAL REGULATION OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS. DESPITE EXTENSIVE EFFORTS, THE FULL SPECTRUM OF MOLECULAR FACTORS THAT CONTRIBUTE TO THE PATHOGENESIS OF RHEUMATIC DISEASES REMAINS UNCLEAR. NCRNAS CAN GOVERN GENE EXPRESSION AT THE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL LEVELS IN MULTIPLE DISEASES. RECENT STUDIES HAVE DEMONSTRATED AN IMPORTANT ROLE FOR NCRNAS, SUCH AS MIRNAS AND LNCRNAS, IN THE DEVELOPMENT OF IMMUNE CELLS AND RHEUMATIC DISEASES. HERE, WE FOCUS ON THE EPIGENETIC REGULATORY ROLES OF NCRNAS IN THE PATHOGENESIS OF RHEUMATIC DISEASES AND AS BIOMARKERS OF DISEASE STATE. 2019 17 4324 41 MICRORNAS IN RHEUMATOID ARTHRITIS: FROM PATHOGENESIS TO CLINICAL IMPACT. OVER THE LAST DECADE, MANY EPIGENETIC MECHANISMS THAT CONTRIBUTE IN THE PATHOGENESIS OF AUTOIMMUNE DISORDERS HAVE BEEN REVEALED. MICRORNAS (MIRNAS) ARE SMALL, NON-CODING, RNA MOLECULES THAT BIND TO MESSENGER RNAS AND DISRUPT THE TRANSCRIPTION OF TARGET GENES. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC SYSTEMIC AUTOIMMUNE DISEASE IN WHICH A PLETHORA OF EPIGENETIC CHANGES TAKE PLACE. CURRENT RESEARCH ON RA EPIGENETICS HAS FOCUSED MAINLY ON MIRNAS. GENETIC VARIANCE OF SOME MIRNA GENES, ESPECIALLY MIR-499, MIGHT PREDISPOSE AN INDIVIDUAL TO RA DEVELOPMENT. ADDITIONALLY, ALTERED EXPRESSION OF MANY MIRNAS HAS BEEN DISCOVERED IN SEVERAL CELLS, TISSUES AND BODY FLUIDS IN PATIENTS WITH RA. MIRNAS EXPRESSION ALSO DIFFERS DEPENDING ON DISEASE'S STAGE AND ACTIVITY. SERUM MIR-22 AND MIR-103A MIGHT PREDICT RA DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS (PRE-RA), WHILE SERUM MIR-16, MIR-24, MIR-125A AND MIR-223 LEVELS ARE ALTERED IN EARLY RA (DISEASE DURATION <12 MONTHS) PATIENTS COMPARED TO ESTABLISHED RA OR HEALTHY INDIVIDUALS. MOREOVER, SERUM MIR-223 LEVELS HAVE BEEN ASSOCIATED WITH RA ACTIVITY AND DISEASE RELAPSE. WHAT IS MORE, SERUM LEVELS OF SEVERAL MIRNAS, INCLUDING MIR-125B AND MIR-223, COULD BE USED TO PREDICT RESPONSE TO RA TREATMENT. FINALLY, MIRNA ANALOGS OR ANTAGONISTS HAVE BEEN USED AS THERAPEUTIC REGIMENS IN EXPERIMENTAL ARTHRITIS MODELS AND HAVE DEMONSTRATED PROMISING RESULTS. IN CONCLUSION, THE RESEARCH ON THE MIRNA ALTERATIONS IN RA SHEDS LIGHT TO SEVERAL ASPECTS OF RA PATHOGENESIS, INTRODUCES NEW BIOMARKERS FOR RA DIAGNOSIS AND TREATMENT RESPONSE PREDICTION AND OFFERS THE OPPORTUNITY TO DISCOVER NEW, TARGETED DRUGS FOR PATIENTS WITH RA. 2019 18 2557 37 EPIGENETICS IN RHEUMATOID ARTHRITIS; FIBROBLAST-LIKE SYNOVIOCYTES AS AN EMERGING PARADIGM IN THE PATHOGENESIS OF THE DISEASE. RHEUMATOID ARTHRITIS (RA) IS CHARACTERIZED BY IMMUNE DYSFUNCTIONS AND CHRONIC INFLAMMATION THAT MAINLY AFFECTS DIARTHRODIAL JOINTS. GENETICS HAS LONG BEEN SURVEYED IN SEARCHING FOR THE ETIOPATHOGENESIS OF THE DISEASE AND PARTIALLY CLARIFIED THE CONUNDRUMS WITHIN THIS CONTEXT. EPIGENETIC ALTERATIONS, SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND NONCODING RNAS, WHICH HAVE BEEN CONSIDERED TO BE INVOLVED IN RA PATHOGENESIS, LIKELY EXPLAIN THE NONGENETIC RISK FACTORS. EPIGENETIC MODIFICATIONS MAY INFLUENCE RA THROUGH FIBROBLAST-LIKE SYNOVIOCYTES (FLSS). IT HAS BEEN SHOWN THAT FLSS PLAY AN ESSENTIAL ROLE IN THE ONSET AND EXACERBATION OF RA, AND THEREFORE, THEY MAY ILLUSTRATE SOME ASPECTS OF RA PATHOGENESIS. THESE CELLS EXHIBIT A UNIQUE DNA METHYLATION PROFILE IN THE EARLY STAGE OF THE DISEASE THAT CHANGES WITH DISEASE PROGRESSION. HISTONE ACETYLATION PROFILE IN RA FLSS IS DISRUPTED THROUGH THE IMBALANCE OF HISTONE ACETYLTRANSFERASES AND HISTONE DEACETYLASE ACTIVITY. FURTHERMORE, DYSREGULATION OF MICRORNAS (MIRNAS) IS IMMENSE. MOST OF THESE MIRNAS HAVE SHOWN AN ABERRANT EXPRESSION IN FLSS THAT ARE INVOLVED IN PROLIFERATION AND CYTOKINE PRODUCTION. BESIDES, DYSREGULATION OF LONG NONCODING RNAS IN FLSS HAS BEEN REVEALED AND ATTRIBUTED TO RA PATHOGENESIS. FURTHER INVESTIGATIONS ARE NEEDED TO GET A BETTER VIEW OF EPIGENETIC ALTERATIONS AND THEIR INTERACTIONS. WE ALSO DISCUSS THE ROLE OF THESE EPIGENETIC ALTERATIONS IN RA PATHOGENESIS AND THEIR THERAPEUTIC POTENTIAL. 2020 19 4844 31 ONE YEAR IN REVIEW 2019: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. OVER THE LAST FEW YEARS, PARTICULAR ATTENTION HAS BEEN GIVEN TO NOVEL GENES AND TO THE CLOSE INTERACTION BETWEEN GENETIC FACTORS AND EPIGENETIC MECHANISMS. RESEARCH HAS ALSO FOCUSED ON THE INFLUENCE OF ENVIRONMENTAL FACTORS ON DISEASE DEVELOPMENT, AND ON NEW MECHANISMS OF THE INNATE AND ADAPTIVE IMMUNE SYSTEM THAT CAN INFLUENCE THE DIFFERENT STAGES OF RA. HOWEVER, THERE ARE STILL SEVERAL ASPECTS OF THE DISEASE THAT NEED FURTHER INVESTIGATION. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IMPROVE THE CURRENT DIAGNOSTIC TOOLS AND TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2019 20 2556 21 EPIGENETICS IN RHEUMATOID ARTHRITIS. EPIGENETICS IS A STEADILY GROWING RESEARCH AREA. IN MANY HUMAN DISEASES, ESPECIALLY IN CANCERS, BUT ALSO IN AUTOIMMUNE DISEASES, EPIGENETIC ABERRATIONS HAVE BEEN FOUND. RHEUMATOID ARTHRITIS IS AN AUTOIMMUNE DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION AND DESTRUCTION OF SYNOVIAL JOINTS. EVEN THOUGH THE ETIOLOGY IS NOT YET FULLY UNDERSTOOD, RHEUMATOID ARTHRITIS IS GENERALLY CONSIDERED TO BE CAUSED BY A COMBINATION OF GENETIC PREDISPOSITION, DEREGULATED IMMUNOMODULATION, AND ENVIRONMENTAL INFLUENCES. TO GAIN A BETTER UNDERSTANDING OF THIS DISEASE, RESEARCHERS HAVE BECOME INTERESTED IN STUDYING EPIGENETIC CHANGES IN RHEUMATOID ARTHRITIS. HERE, WE WANT TO REVIEW THE CURRENT KNOWLEDGE ON EPIGENETICS IN RHEUMATOID ARTHRITIS. 2010