1 2979 80 GENETIC BACKGROUND OF JUVENILE IDIOPATHIC ARTHRITIS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS THE MOST COMMON CHRONIC RHEUMATOLOGIC DISEASE IN CHILDREN. JIA IS A GROUP OF DISORDERS THAT SHARE THE CLINICAL MANIFESTATION OF CHRONIC JOINT INFLAMMATION. THE HUMAN LEUKOCYTE ANTIGEN REGION (HLA) SEEMS TO BE A MAJOR SUSCEPTIBILITY LOCUS FOR JIA THAT IS ESTIMATED TO ACCOUNT FOR 17% OF FAMILIAL SEGREGATION OF THE DISEASE. TO DATE, AROUND 20 NON-HLA LOCI CONFERRING SUSCEPTIBILITY TO JIA WERE FOUND. AT LEAST A HALF OF THOSE ARE SHARED BETWEEN JIA AND RHEUMATOID ARTHRITIS (RA), AN ADULT RHEUMATIC DISEASE, THEREBY SUGGESTING FOR SIMILARITY OF PATHOGENIC MECHANISMS OF BOTH DISEASES. NEW FINDINGS ALSO SUGGEST FOR A LIKELY ROLE OF EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF JIA THAT SHOULD BE INVESTIGATED IN THE FUTURE. 2014 2 555 23 AXIAL SPONDYLOARTHRITIS: RESHAPE THE FUTURE-FROM THE "2022 GISEA INTERNATIONAL SYMPOSIUM". THE TERM "AXIAL SPONDYLOARTHRITIS" (AXSPA) REFERS TO A GROUP OF CHRONIC RHEUMATIC DISEASES THAT PREDOMINANTLY INVOLVE THE AXIAL SKELETON AND CONSIST OF ANKYLOSING SPONDYLITIS, REACTIVE ARTHRITIS, ARTHRITIS/SPONDYLITIS ASSOCIATED WITH PSORIASIS (PSA) AND ARTHRITIS/SPONDYLITIS ASSOCIATED WITH INFLAMMATORY BOWEL DISEASES (IBD). MOREOVER, PAIN IS AN IMPORTANT AND COMMON SYMPTOM OF AXSPA. IT MAY PROGRESS TO CHRONIC PAIN, A MORE COMPLICATED BIO-PSYCHOSOCIAL PHENOMENA, LEADING TO A SIGNIFICANT WORSENING OF QUALITY OF LIFE. THE DEVELOPMENT OF THE AXSPA INFLAMMATORY PROCESS IS GROUNDED IN THE COMPLEX INTERACTION BETWEEN GENETIC (SUCH AS HLA B27), EPIGENETIC, AND ENVIRONMENTAL FACTORS ASSOCIATED WITH A DYSREGULATED IMMUNE RESPONSE. CONSIDERING THE PIVOTAL CONTRIBUTION OF IL-23 AND IL-17 IN AXSPA INFLAMMATION, THE INHIBITION OF THESE CYTOKINES HAS BEEN EVALUATED AS A POTENTIAL THERAPEUTIC STRATEGY. WITH THIS CONTEXT, HERE WE DISCUSS THE MAIN PATHOGENETIC MECHANISMS, THERAPEUTIC APPROACHES AND THE ROLE OF PAIN IN AXSPA FROM THE 2022 INTERNATIONAL GISEA/OEG SYMPOSIUM. 2022 3 6787 73 [CONTRIBUTION OF NON-HLA GENES TO JUVENILE IDIOPATHIC ARTHRITIS SUSCEPTIBILITY]. JUVENILE IDIOPATHIC ARTHRITIS (JAL4) IS THE MOST COMMON CHRONIC RHEUMATOLOGIC DISEASE IN CHILDREN. JIA IS A GROUP OF DISORDERS THAT SHARE THE CLINICAL MANIFESTATION OF CHRONIC JOINT INFLAMMATION. THE HUMAN LEUKOCYTE ANTIGEN REGION (HLA) SEEMS TO BE A MAJOR SUSCEPTIBILITY LOCUS FOR JIA THAT IS ESTIMATED TO ACCOUNT FOR 17% OF FAMILIAL SEGREGATION OF THE DISEASE. GENOME-WIDE ASSOCIATION STUDIES (GWAS), CASE-CONTROL STUDIES AND META-ANALYSES OF THE POST-GWAS ERA REVEALED OVER 20 NON-HLA LOCI CONFERRING SUSCEPTIBILITY TO JIA. AT LEAST A HALF OF THOSE ARE SHARED BETWEEN JIA AND RHEUMATOID ARTHRITIS, AN ADULT RHEUMATIC DISEASE, THEREBY SUGGESTING FOR SIMILARITY OF PATHOGENIC MECHANISMS OF BOTH DISEASES. NEW FINDINGS ALSO SUGGEST FOR A LIKELY ROLE OF EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF JIA THAT SHOULD BE INVESTIGATED IN THE FUTURE. 2014 4 3507 27 IDENTIFICATION OF TARGET GENES AT JUVENILE IDIOPATHIC ARTHRITIS GWAS LOCI IN HUMAN NEUTROPHILS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS THE MOST COMMON CHRONIC RHEUMATIC DISEASE AMONG CHILDREN WHICH COULD CAUSE SEVERE DISABILITY. GENOMIC STUDIES HAVE DISCOVERED SUBSTANTIAL NUMBER OF RISK LOCI FOR JIA, HOWEVER, THE MECHANISM OF HOW THESE LOCI AFFECT JIA DEVELOPMENT IS NOT FULLY UNDERSTOOD. NEUTROPHIL IS AN IMPORTANT CELL TYPE INVOLVED IN AUTOIMMUNE DISEASES. TO BETTER UNDERSTAND THE BIOLOGICAL FUNCTION OF GENETIC LOCI IN NEUTROPHILS DURING JIA DEVELOPMENT, WE TOOK AN INTEGRATED MULTI-OMICS APPROACH TO IDENTIFY TARGET GENES AT JIA RISK LOCI IN NEUTROPHILS AND CONSTRUCTED A PROTEIN-PROTEIN INTERACTION NETWORK VIA A MACHINE LEARNING APPROACH. WE IDENTIFIED GENES LIKELY TO BE JIA RISK LOCI TARGETED GENES IN NEUTROPHILS WHICH COULD CONTRIBUTE TO JIA DEVELOPMENT. 2019 5 3173 21 GUT MICROBIOTA-MICRORNA INTERACTIONS IN ANKYLOSING SPONDYLITIS. ANKYLOSING SPONDYLITIS (AS) IS A CHRONIC AUTOIMMUNE INFLAMMATORY DISABILITY THAT IS PART OF THE RHEUMATIC DISEASE GROUP OF SPONDYLOARTHROPATHIES. AS COMMONLY INFLUENCES THE JOINTS OF THE AXIAL SKELETON. THE CONTRIBUTIONS TO AS PATHOGENESIS OF GENETIC SUSCEPTIBILITY (PARTICULARLY HLA-B27 AND ERAP-1) AND EPIGENETIC MODIFICATIONS, LIKE NON-CODING RNAS, AS WELL AS ENVIRONMENTAL FACTORS, HAVE BEEN INVESTIGATED OVER THE LAST FEW YEARS. BUT THE FUNDAMENTAL ETIOLOGY OF AS REMAINS ELUSIVE TO DATE. THE EVIDENCE SUMMARIZED HERE INDICATES THAT IN THE IMMUNOPATHOGENESIS OF AS, MICRORNAS AND THE GUT MICROBIOME PERFORM CRITICAL FUNCTIONS. WE DISCUSS SIGNIFICANT ADVANCES IN THE IMMUNOLOGICAL MECHANISMS UNDERLYING AS AND ADDRESS POTENTIAL CROSS-TALK BETWEEN THE GUT MICROBIOME AND HOST MICRORNAS. THIS CRITICAL INTERACTION IMPLICATES A CO-EVOLUTIONARY SYMBIOTIC LINK BETWEEN HOST IMMUNITY AND THE GUT MICROBIOME. 2021 6 6289 23 THE POTENTIAL ROLE OF GENETICS, ENVIRONMENTAL FACTORS, AND GUT DYSBIOSIS IN THE ABERRANT NON-CODING RNA EXPRESSION TO MEDIATE INFLAMMATION AND OSTEOCLASTOGENIC/OSTEOGENIC DIFFERENTIATION IN ANKYLOSING SPONDYLITIS. ANKYLOSING SPONDYLITIS (AS) OR RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS IS A CHRONIC IMMUNE-MEDIATED RHEUMATIC DISORDER CHARACTERIZED BY THE INFLAMMATION IN THE AXIAL SKELETON, PERIPHERAL JOINTS, AND SOFT TISSUES (ENTHESIS, FASCIA, AND LIGAMENT). IN ADDITION, THE EXTRA-SKELETAL COMPLICATIONS INCLUDING ANTERIOR UVEITIS, INTERSTITIAL LUNG DISEASES AND AORTITIS ARE FOUND. THE PATHOGENESIS OF AS IMPLICATES AN INTRICATE INTERACTION AMONG HLA (HLA-B27) AND NON-HLA LOCI [ENDOPLASMIC RETICULUM AMINOPEPTIDASE 1 (ERAP1), AND INTERLEUKIN-23 RECEPTOR (IL23R), GUT DYSBIOSIS, IMMUNE PLASTICITY, AND NUMEROUS ENVIRONMENTAL FACTORS (INFECTIONS, HEAVY METALS, STRESS, CIGARETTE SMOKING, ETC.) THE LATTER MULTIPLE NON-GENETIC FACTORS MAY EXERT A POWERFUL STRESS ON EPIGENETIC REGULATIONS. THESE EPIGENETIC REGULATIONS OF GENE EXPRESSION CONTAIN DNA METHYLATION/DEMETHYLATION, HISTONE MODIFICATIONS AND ABERRANT NON-CODING RNAS (NCRNAS) EXPRESSION, LEADING TO INFLAMMATION AND IMMUNE DYSFUNCTIONS. IN THE PRESENT REVIEW, WE SHALL DISCUSS THESE CONTRIBUTORY FACTORS THAT ARE INVOLVED IN AS PATHOGENESIS, ESPECIALLY THE ABERRANT NCRNA EXPRESSION AND ITS EFFECTS ON THE PROINFLAMMATORY CYTOKINE PRODUCTIONS (TNF-ALPHA, IL-17 AND IL-23), T CELL SKEWING TO TH1/TH17, AND OSTEOCLASTOGENIC/OSTEOGENIC DIFFERENTIATION. FINALLY, SOME POTENTIAL INVESTIGATORY APPROACHES ARE RAISED FOR SOLVING THE PUZZLES IN AS PATHOGENESIS. 2021 7 4656 27 NEW ADVANCES IN JUVENILE IDIOPATHIC ARTHRITIS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) COMPRISES A GROUP OF HETEROGENEOUS DISORDERS OF CHRONIC ARTHRITIS IN CHILDHOOD WITH NO APPARENT ETIOLOGY. JUVENILE IDIOPATHIC ARTHRITIS IS THE MOST COMMON PEDIATRIC RHEUMATIC DISEASE AND IS ASSOCIATED WITH SIGNIFICANT LONG-TERM MORBIDITY AND MORTALITY. THERE HAVE BEEN MAJOR ADVANCES IN RECENT YEARS IN OUR UNDERSTANDING OF THE PATHOGENESIS OF JIA, THE DEFINITION OF DISEASE CONTROL, AND BIOLOGICAL TREATMENTS FOR JIA. MULTIPLE ENVIRONMENTAL AND GENETIC FACTORS HAVE BEEN LINKED WITH THE ONSET AND / OR THE EXACERBATION OF JIA, INCLUDING PERINATAL FACTORS, VIRAL AND BACTERIAL INFECTIONS, EPIGENETIC FACTORS, AND MALNUTRITION. HOWEVER, NO SINGLE CAUSATIVE FACTOR HAS BEEN IDENTIFIED TO DATE. AS OUR UNDERSTANDING OF THE COMPLEX NETWORK OF IMMUNE CELLS AND INFLAMMATORY CYTOKINES HAS IMPROVED, BIOLOGICS HAVE BEEN DEVELOPED TO MODULATE THE INFLAMMATORY PROCESSES. INDEED, A NUMBER OF SUCH BIOLOGICS HAVE BEEN DEMONSTRATED EFFECTIVE FOR THE TREATMENT OF JIA. ALTHOUGH BIOLOGIC AGENTS MAY ALLEVIATE THE INFLAMMATION ASSOCIATED WITH JIA AND PREVENT DISABILITY CAUSED BY JOINT DESTRUCTION, CONTINUED AND COMPREHENSIVE OBSERVATION IS REQUIRED TO DETERMINE THE LONG-TERM OUTCOMES ASSOCIATED WITH SUCH TREATMENT. 2012 8 5473 31 RESPONSES OF PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS TO METHOTREXATE: A GENOMIC OUTLOOK. INTRODUCTION: JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS A CHRONIC DISEASE CHARACTERIZED BY PERSISTENT JOINT INFLAMMATION. JIA IS THE MOST COMMON PEDIATRIC CHRONIC RHEUMATIC DISEASE AND NO CURATIVE THERAPY IS CURRENTLY AVAILABLE. METHOTREXATE (MTX) IS AN IMPORTANT TREATMENT FOR JIA EVEN THOUGH A HIGH INTER-INDIVIDUAL VARIABILITY IN RESPONSE IS OBSERVED IN PATIENTS. AMONG THE FACTORS OF THIS VARIABILITY, GENETICS AND EPIGENETICS MIGHT PLAY AN IMPORTANT ROLE. AREAS COVERED: THIS REVIEW SUMMARIZES THE RESULTS OF PHARMACOGENETIC AND PHARMACOEPIGENETIC STUDIES REGARDING MTX RESPONSE IN JIA. STUDIES CONSIDERING EPIGENETIC FACTORS IN JIA PATIENTS ARE STILL VERY LIMITED, THEREFORE THIS REVIEW INCLUDES ALSO STUDIES PERFORMED IN ADULT PATIENTS WITH RHEUMATOID ARTHRITIS. MOREOVER, THE RELEVANCE OF BIOMARKERS MEASURED IN BLOOD OR URINE OF JIA PATIENTS IN RELATION TO MTX TREATMENT IS DISCUSSED. EXPERT OPINION: NOWADAYS, EVEN THOUGH MANY PHARMACOGENOMICS STUDIES HAVE BEEN PUBLISHED, A SPECIFIC GENETIC MARKER PREDICTOR OF MTX EFFICACY OR ADVERSE EVENTS HAS NOT YET BEEN IDENTIFIED. ENCOURAGING RESULTS ARE AVAILABLE AND GREAT EXPECTATIONS RELY ON THE STUDY OF EPIGENETICS. FUTURE STUDIES ARE NEEDED IN ORDER TO IDENTIFY GENETIC AND EPIGENETIC BIOMARKERS THAT CAN BE IMPLEMENTED IN THE CLINICAL PRACTICE. 2021 9 6152 20 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 10 2556 20 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 11 6218 27 THE JOINT SYNOVIUM: A CRITICAL DETERMINANT OF ARTICULAR CARTILAGE FATE IN INFLAMMATORY JOINT DISEASES. THE SYNOVIUM CONSTITUTES THE ENVELOPE OF ARTICULAR JOINTS AND IS A CRITICAL PROVIDER OF SYNOVIAL FLUID COMPONENTS AND ARTICULAR CARTILAGE NUTRIENTS. ITS INFLAMMATION IS A PREDOMINANT FEATURE AND CAUSE OF JOINT DEGENERATION IN DISEASES AS DIVERSE AS RHEUMATOID, PSORIATIC, JUVENILE AND IDIOPATHIC ARTHRITIS, AND LUPUS, GOUT AND LYME DISEASE. THESE INFLAMMATORY JOINT DISEASES (IJDS) ARE DUE TO A WIDE VARIETY OF GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS THAT TRIGGER, PROMOTE, AND PERPETUATE JOINT DESTABILIZATION. IN SPITE OF THIS VARIETY OF CAUSES, IJDS SHARE MAIN PATHOLOGICAL FEATURES, NAMELY INFLAMMATION OF THE JOINT SYNOVIUM (SYNOVITIS) AND PROGRESSIVE DEGENERATION OF ARTICULAR CARTILAGE. IN ADDITION TO BEING A DRIVING FORCE BEHIND THE DESTRUCTION OF ARTICULAR CARTILAGE IN IJD, SYNOVITIS IS ALSO INCREASINGLY BEING RECOGNIZED AS A SIGNIFICANT CONTRIBUTOR OF ARTICULAR CARTILAGE DEGENERATION IN OSTEOARTHRITIS, A DISEASE PRIMARILY DUE TO AGING- OR TRAUMA-RELATED WEAR AND TEAR OF CARTILAGE SURFACES. IN VIEW OF THIS IMPORTANT ROLE OF THE SYNOVIUM IN DETERMINING THE FATE OF ARTICULAR CARTILAGE, THIS REVIEW FOCUSES ON ITS UNDERLYING MECHANISMS IN THE PATHOLOGY OF IJD. WE ADDRESS THE ROLES OF SYNOVIAL FIBROBLASTS, MACROPHAGES AND ENDOTHELIAL CELLS IN THE MAINTENANCE OF JOINT HEALTH AND IN THE DESTRUCTION OF ARTICULAR CARTILAGE INTEGRITY DURING IJD. MOLECULAR MECHANISMS THAT HAVE BEEN RECENTLY SHOWN TO GOVERN THE PATHOLOGICAL ACTIVITIES OF THE RESIDENT SYNOVIAL CELLS ARE HIGHLIGHTED. FINALLY, ADVANTAGES AND DISADVANTAGES OF TARGETING THESE NEW MOLECULAR MECHANISMS FOR PREVENTING CARTILAGE DEGENERATION DUE TO CHRONIC INFLAMMATION ARE ALSO DISCUSSED. 2017 12 6884 24 [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 13 4676 37 NEW INSIGHTS TOWARD THE PATHOGENESIS OF ANKYLOSING SPONDYLITIS; GENETIC VARIATIONS AND EPIGENETIC MODIFICATIONS. ANKYLOSING SPONDYLITIS (AS) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE, CHARACTERIZED BY TYPICALLY AN AXIAL ARTHRITIS. AS IS THE PROTOTYPE OF A GROUP OF DISORDERS CALLED SPONDYLOARTHROPATHIES, WHICH IS BELIEVED TO HAVE COMMON CLINICAL MANIFESTATIONS AND GENETIC PREDISPOSITION. TO DATE, THE EXACT ETIOLOGY OF AS REMAINS UNCLEAR. OVER THE PAST FEW YEARS, HOWEVER, THE ROLE OF GENETIC SUSCEPTIBILITY AND EPIGENETIC MODIFICATIONS CAUSED THROUGH ENVIRONMENTAL FACTORS HAVE BEEN EXTENSIVELY SURVEYED WITH RESPECT TO THE PATHOGENESIS OF AS, RESULTED IN IMPORTANT ADVANCES. THIS REVIEW ARTICLE FOCUSES ON THE RECENT ADVANCES IN THE FIELD OF AS RESEARCH, INCLUDING HLA AND NON-HLA SUSCEPTIBILITY GENES IDENTIFIED IN GENOME-WIDE ASSOCIATION STUDIES (GWAS), AND ABERRANT EPIGENETIC MODIFICATIONS OF GENE LOCI ASSOCIATED WITH AS. HLA GENES MOST SIGNIFICANTLY LINKED WITH AS SUSCEPTIBILITY INCLUDE HLA-B27 AND ITS SUBTYPES. NUMEROUS NON-HLA GENES SUCH AS THOSE IN UBIQUITINATION, AMINOPEPTIDASES AND MHC CLASS I PRESENTATION MOLECULES LIKE ERAP-1 WERE ALSO REPORTED. MOREOVER, EPIGENETIC MODIFICATIONS OCCURRED IN AS HAS BEEN SUMMARIZED. TAKEN TOGETHER, THE FINDINGS PRESENTED IN THIS REVIEW ATTEMPT TO EXPLAIN THE CIRCUMSTANCE BY WHICH BOTH GENETIC VARIATIONS AND EPIGENETIC MODIFICATIONS ARE INVOLVED IN TRIGGERING AND DEVELOPMENT OF AS. NONETHELESS, SEVERAL UNANSWERED DARK SIDES CONTINUE TO CLOG OUR EXHAUSTIVE UNDERSTANDING OF AS. FUTURE RESEARCHES IN THE FIELD OF EPIGENETICS SHOULD BE CARRIED OUT TO EXTEND OUR VISION OF AS ETIOPATHOGENESIS. 2017 14 2221 20 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 15 6147 25 THE EXPRESSION OF NON-CODING RNAS AND THEIR TARGET MOLECULES IN RHEUMATOID ARTHRITIS: A MOLECULAR BASIS FOR RHEUMATOID PATHOGENESIS AND ITS POTENTIAL CLINICAL APPLICATIONS. RHEUMATOID ARTHRITIS (RA) IS A TYPICAL AUTOIMMUNE-MEDIATED RHEUMATIC DISEASE PRESENTING AS A CHRONIC SYNOVITIS IN THE JOINT. THE CHRONIC SYNOVIAL INFLAMMATION IS CHARACTERIZED BY HYPER-VASCULARITY AND EXTRAVASATION OF VARIOUS IMMUNE-RELATED CELLS TO FORM LYMPHOID AGGREGATES WHERE AN INTIMATE CROSS-TALK AMONG INNATE AND ADAPTIVE IMMUNE CELLS TAKES PLACE. THESE INTERACTIONS FACILITATE PRODUCTION OF ABUNDANT PROINFLAMMATORY CYTOKINES, CHEMOKINES AND GROWTH FACTORS FOR THE PROLIFERATION/MATURATION/DIFFERENTIATION OF B LYMPHOCYTES TO BECOME PLASMA CELLS. FINALLY, THE AUTOANTIBODIES AGAINST DENATURED IMMUNOGLOBULIN G (RHEUMATOID FACTORS), EB VIRUS NUCLEAR ANTIGENS (EBNAS) AND CITRULLINATED PROTEIN (ACPAS) ARE PRODUCED TO TRIGGER THE DEVELOPMENT OF RA. FURTHERMORE, IT IS DOCUMENTED THAT GENE MUTATIONS, ABNORMAL EPIGENETIC REGULATION OF PEPTIDYLARGININE DEIMINASE GENES 2 AND 4 (PADI2 AND PADI4), AND THEREBY THE INDUCED AUTOANTIBODIES AGAINST PAD2 AND PAD4 ARE IMPLICATED IN ACPA PRODUCTION IN RA PATIENTS. THE ABERRANT EXPRESSIONS OF NON-CODING RNAS (NCRNAS) INCLUDING MICRORNAS (MIRS) AND LONG NON-CODING RNAS (LNCRNAS) IN THE IMMUNE SYSTEM UNDOUBTEDLY DERANGE THE MRNA EXPRESSIONS OF CYTOKINES/CHEMOKINES/GROWTH FACTORS. IN THE PRESENT REVIEW, WE WILL DISCUSS IN DETAIL THE EXPRESSION OF THESE NCRNAS AND THEIR TARGET MOLECULES PARTICIPATING IN DEVELOPING RA, AND THE POTENTIAL BIOMARKERS FOR THE DISEASE, ITS DIAGNOSIS, CARDIOVASCULAR COMPLICATIONS AND THERAPEUTIC RESPONSE. FINALLY, WE PROPOSE SOME PROSPECTIVE INVESTIGATIONS FOR UNRAVELING THE CONUNDRUMS OF RHEUMATOID PATHOGENESIS. 2021 16 5372 28 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 17 2238 21 EPIGENETIC MODULATION AS A THERAPEUTIC PROSPECT FOR TREATMENT OF AUTOIMMUNE RHEUMATIC DISEASES. SYSTEMIC INFLAMMATORY RHEUMATIC DISEASES ARE CONSIDERED AS AUTOIMMUNE DISEASES, MEANING THAT THE BALANCE BETWEEN RECOGNITION OF PATHOGENS AND AVOIDANCE OF SELF-ATTACK IS IMPAIRED AND THE IMMUNE SYSTEM ATTACKS AND DESTROYS ITS OWN HEALTHY TISSUE. TREATMENT WITH CONVENTIONAL DISEASE MODIFYING ANTIRHEUMATIC DRUGS (DMARDS) AND/OR NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) IS OFTEN ASSOCIATED WITH VARIOUS ADVERSE REACTIONS DUE TO UNSPECIFIC AND TOXIC PROPERTIES OF THOSE DRUGS. ALTHOUGH BIOLOGIC DRUGS HAVE LARGELY IMPROVED THE OUTCOME IN MANY PATIENTS, SUCH DRUGS STILL POSE SIGNIFICANT PROBLEMS AND FAIL TO PROVIDE A SOLUTION TO ALL PATIENTS. THEREFORE, DEVELOPMENT OF MORE EFFECTIVE TREATMENTS AND IMPROVEMENTS IN EARLY DIAGNOSIS OF RHEUMATIC DISEASES ARE BADLY NEEDED IN ORDER TO INCREASE PATIENT'S FUNCTIONING AND QUALITY OF LIFE. THE REVERSIBLE NATURE OF EPIGENETIC MECHANISMS OFFERS A NEW CLASS OF DRUGS THAT MODULATE THE IMMUNE SYSTEM AND INFLAMMATION. IN FACT, EPIGENETIC DRUGS ARE ALREADY IN USE IN SOME TYPES OF CANCER OR CARDIOVASCULAR DISEASES. THEREFORE, EPIGENETIC-BASED THERAPEUTICS THAT CONTROL AUTOIMMUNITY AND CHRONIC INFLAMMATORY PROCESS HAVE BROAD IMPLICATIONS FOR THE PATHOGENESIS, DIAGNOSIS, AND MANAGEMENT OF RHEUMATIC DISEASES. THIS REVIEW SUMMARISES THE LATEST INFORMATION ABOUT POTENTIAL THERAPEUTIC APPLICATION OF EPIGENETIC MODIFICATION IN TARGETING IMMUNE ABNORMALITIES AND INFLAMMATION OF RHEUMATIC DISEASES. 2016 18 5159 20 PRE-RHEUMATOID ARTHRITIS: PREDISPOSITION AND TRANSITION TO CLINICAL SYNOVITIS. MULTIPLE PROVEN AND POTENTIAL RISK FACTORS FOR THE DEVELOPMENT OF RHEUMATOID ARTHRITIS (RA) HAVE BEEN IDENTIFIED, AND REPRESENT INTERACTIONS BETWEEN GENES AND THE ENVIRONMENT. PROVEN RISK FACTORS INCLUDE GENETIC INFLUENCES ON THE FUNCTION OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS, SMOKING, ANTI-CITRULLINATED PROTEIN ANTIBODIES (ACPAS), AND RHEUMATOID FACTORS (RF). POTENTIAL RISK FACTORS INCLUDE EPIGENETIC CONTROL OF GENE EXPRESSION, THE MICROBIOME AND OTHER ENVIRONMENTAL FACTORS, TOLL-LIKE RECEPTORS, CYTOKINES, AND FC RECEPTORS. PRECLINICAL ABNORMALITIES SUCH AS CIRCULATING RF AND ACPAS MAY OCCUR MORE THAN 10 YEARS PRIOR TO THE ONSET OF CLINICAL DISEASE. HOWEVER, THE PRECISE MECHANISMS WHEREBY THESE RISK FACTORS LEAD TO CLINICAL DISEASE REMAIN UNCLEAR. IT IS POSSIBLE THAT, COMBINED WITH ACTIVATION OF THE INNATE IMMUNE SYSTEM, A SUBSET OF ACPAS INITIATES THE DISEASE IN THE CARTILAGE OR SYNOVIUM AFTER BINDING TO ENDOGENOUS CITRULLINATED PROTEINS. SUBSEQUENT ENGAGEMENT OF FC RECEPTORS AND COMPLEMENT ACTIVATION WOULD LEAD TO SECONDARY INFLAMMATION IN THE SYNOVIUM WITH INDUCTION OF A PERPETUATING CYCLE OF CHRONIC SYNOVITIS. 2012 19 4845 22 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 20 5265 24 PROMISING THERAPEUTIC TARGETS FOR TREATMENT OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A SYSTEMIC POLY-ARTICULAR CHRONIC AUTOIMMUNE JOINT DISEASE THAT MAINLY DAMAGES THE HANDS AND FEET, WHICH AFFECTS 0.5% TO 1.0% OF THE POPULATION WORLDWIDE. WITH THE SUSTAINED DEVELOPMENT OF DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS), SIGNIFICANT SUCCESS HAS BEEN ACHIEVED FOR PREVENTING AND RELIEVING DISEASE ACTIVITY IN RA PATIENTS. UNFORTUNATELY, SOME PATIENTS STILL SHOW LIMITED RESPONSE TO DMARDS, WHICH PUTS FORWARD NEW REQUIREMENTS FOR SPECIAL TARGETS AND NOVEL THERAPIES. UNDERSTANDING THE PATHOGENETIC ROLES OF THE VARIOUS MOLECULES IN RA COULD FACILITATE DISCOVERY OF POTENTIAL THERAPEUTIC TARGETS AND APPROACHES. IN THIS REVIEW, BOTH EXISTING AND EMERGING TARGETS, INCLUDING THE PROTEINS, SMALL MOLECULAR METABOLITES, AND EPIGENETIC REGULATORS RELATED TO RA, ARE DISCUSSED, WITH A FOCUS ON THE MECHANISMS THAT RESULT IN INFLAMMATION AND THE DEVELOPMENT OF NEW DRUGS FOR BLOCKING THE VARIOUS MODULATORS IN RA. 2021