1 2294 143 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 2 1608 43 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 6178 40 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 4 783 40 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 5 4842 48 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 6 1136 43 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 7 1565 46 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 4844 40 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 9 4845 31 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 10 6262 57 THE MULTIFACETED FUNCTIONAL ROLE OF DNA METHYLATION IN IMMUNE-MEDIATED RHEUMATIC DISEASES. GENOMIC PREDISPOSITION CANNOT EXPLAIN THE ONSET OF COMPLEX DISEASES, AS WELL ILLUSTRATED BY THE LARGELY INCOMPLETE CONCORDANCE AMONG MONOZYGOTIC TWINS. EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, CHROMATIN REMODELLING AND NON-CODING RNA, ARE CONSIDERED TO BE THE LINK BETWEEN ENVIRONMENTAL STIMULI AND DISEASE ONSET ON A PERMISSIVE GENETIC BACKGROUND IN AUTOIMMUNE AND CHRONIC INFLAMMATORY DISEASES. THE PARADIGMATIC CASES OF RHEUMATOID ARTHRITIS (RA), SYSTEMIC LUPUS ERYTHEMATOSUS (SLE), SYSTEMIC SCLEROSIS (SSC), SJOGREN'S SYNDROME (SJS) AND TYPE-1 DIABETES (T1D) SHARE THE LOSS OF IMMUNOLOGICAL TOLERANCE TO SELF-ANTIGEN INFLUENCED BY SEVERAL FACTORS, WITH A LARGELY INCOMPLETE ROLE OF INDIVIDUAL GENOMIC SUSCEPTIBILITY. THE MOST WIDELY INVESTIGATED EPIGENETIC MECHANISM IS DNA METHYLATION WHICH IS ASSOCIATED WITH GENE SILENCING AND IS DUE TO THE BINDING OF METHYL-CPG BINDING DOMAIN (MBD)-CONTAINING PROTEINS, SUCH AS MECP2, TO 5-METHYLCYTOSINE (5MC). INDEED, A CAUSAL RELATIONSHIP OCCURS BETWEEN DNA METHYLATION AND TRANSCRIPTION FACTORS OCCUPANCY AND RECRUITMENT AT SPECIFIC GENOMIC LOCUS. IN MOST CASES, THE RESULTS OBTAINED IN DIFFERENT STUDIES ARE CONTROVERSIAL IN TERMS OF DNA METHYLATION COMPARISON WHILE FASCINATING EVIDENCE COMES FROM THE COMPARISON OF THE EPIGENOME IN CLINICALLY DISCORDANT MONOZYGOTIC TWINS. IN THIS MANUSCRIPT, WE WILL REVIEW THE MECHANISMS OF EPIGENETICS AND DNA METHYLATION CHANGES IN SPECIFIC IMMUNE-MEDIATED RHEUMATIC DISEASES TO HIGHLIGHT REMAINING UNMET NEEDS AND TO IDENTIFY POSSIBLE SHARED MECHANISMS BEYOND DIFFERENT TISSUE INVOLVEMENTS WITH COMMON THERAPEUTIC OPPORTUNITIES. KEY POINTS * DNA METHYLATION HAS A CRUCIAL ROLE IN REGULATING AND TUNING THE IMMUNE SYSTEM. * EVIDENCES SUGGEST THAT DYSREGULATION OF DNA METHYLATION IS PIVOTAL IN THE CONTEXT OF IMMUNE-MEDIATED RHEUMATIC DISEASES. * DNA METHYLATION DYSREGULATION IN FOXP3 AND INTERFERONS-RELATED GENES IS SHARED WITHIN SEVERAL AUTOIMMUNE DISEASES. * DNA METHYLATION IS AN ATTRACTIVE MARKER FOR DIAGNOSIS AND THERAPY. 2021 11 3039 31 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 12 549 39 AUTOANTIGENS: NOVEL FORMS AND PRESENTATION TO THE IMMUNE SYSTEM. IT IS CLEAR THAT LUPUS AUTOIMMUNITY IS MARKED BY A VARIETY OF ABNORMALITIES, INCLUDING THOSE FOUND AT A MACROSCOPIC SCALE, CELLS AND TISSUES, AS WELL AS MORE MICROENVIRONMENTAL INFLUENCES, ORIGINATING AT THE INDIVIDUAL CELL SURFACE THROUGH TO THE NUCLEUS. THE CONVERGENCE OF GENETIC, EPIGENETIC, AND PERHAPS ENVIRONMENTAL INFLUENCES ALL LEAD TO THE OVERT CLINICAL EXPRESSION OF DISEASE, REFLECTED BY THE PRESENCES OF AUTOANTIBODIES AND TISSUE PATHOLOGY. THIS REVIEW WILL ADDRESS SEVERAL SPECIFIC AREAS THAT FALL AMONG THE NON-GENETIC FACTORS THAT CONTRIBUTE TO LUPUS AUTOIMMUNITY AND RELATED SYNDROMES. IN PARTICULAR, WE WILL DISCUSS THE IMPORTANCE OF UNDERSTANDING VARIOUS PROTEIN POST-TRANSLATIONAL MODIFICATIONS (PTMS), MECHANISMS THAT MEDIATE THE ABILITY OF "MODIFIED SELF" TO TRIGGER AUTOIMMUNITY, AND HOW THESE PTMS INFLUENCE LUPUS DIAGNOSIS. FINALLY, WE WILL DISCUSS ALTERED PATHWAYS OF AUTOANTIGEN PRESENTATION THAT MAY CONTRIBUTE TO THE PERPETUATION OF CHRONIC AUTOIMMUNE DISEASE. 2014 13 5372 48 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 14 5739 30 SMOKING AND RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE CAUSED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. SMOKING HAS BEEN IMPLICATED AS ONE OF THE MOST IMPORTANT EXTRINSIC RISK FACTORS FOR ITS DEVELOPMENT AND SEVERITY. RECENT DEVELOPMENTS HAVE SHED LIGHT ON THE PATHOPHYSIOLOGY OF RA IN SMOKERS, INCLUDING OXIDATIVE STRESS, INFLAMMATION, AUTOANTIBODY FORMATION AND EPIGENETIC CHANGES. THE ASSOCIATION OF SMOKING AND THE DEVELOPMENT OF RA HAVE BEEN DEMONSTRATED THROUGH EPIDEMIOLOGIC STUDIES, AS WELL AS THROUGH IN VIVO AND ANIMAL MODELS OF RA. WITH INCREASED USE OF BIOLOGICAL AGENTS IN ADDITION TO STANDARD DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS), THERE HAS BEEN INTEREST IN HOW SMOKING AFFECTS DRUG RESPONSE IN RA TREATMENT. RECENT EVIDENCE SUGGESTS THE RESPONSE AND DRUG SURVIVAL IN PEOPLE TREATED WITH ANTI-TUMOUR NECROSIS FACTOR (ANTI-TNF) THERAPY IS POORER IN HEAVY SMOKERS, AND POSSIBLE IMMUNOLOGICAL MECHANISMS FOR THIS EFFECT ARE PRESENTED IN THE CURRENT PAPER. 2014 15 398 41 AN UPDATE ON GENETIC SUSCEPTIBILITY IN LUPUS NEPHRITIS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE CHARACTERIZED BY MULTIPLE SYSTEM INVOLVEMENT AND POSITIVE SERUM AUTOANTIBODIES. LUPUS NEPHRITIS (LN) IS THE MOST COMMON AND SERIOUS COMPLICATION OF SLE, AND IT IS THE MAIN CAUSE OF DEATH IN PATIENTS WITH SLE. ABNORMALITIES IN THE IMMUNE SYSTEM LEAD TO LN AND INVOLVE A VARIETY OF CELLS (T CELLS, B CELLS, MACROPHAGES, NK CELLS, ETC.), CYTOKINES (INTERLEUKIN, TUMOR NECROSIS FACTOR ALPHA, ETC.) AND THEIR RELATED PATHWAYS. PREVIOUS STUDIES HAVE SHOWN THAT THE INTERACTIONS OF GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS CONTRIBUTE TO THE PATHOGENESIS AND DEVELOPMENT OF LN. IN RECENT YEARS, ONE GENOME-WIDE ASSOCIATION STUDY (GWAS) AND A NUMBER OF GENE ASSOCIATION STUDIES HAVE EXPLORED THE SUSCEPTIBILITY GENES OF LN, INCLUDING IMMUNIZATION-, INFLAMMATION-, ADHESION- AND OTHER PATHWAY-RELATED GENES. THESE GENES PARTICIPATE IN OR SUGGEST THE PATHOGENESIS AND PROGRESSION OF LN. IN THIS REVIEW, WE SUMMARIZE THE GENETIC SUSCEPTIBILITY OF LN AND DISCUSS THE POSSIBLE MECHANISM UNDERLYING THE SUSCEPTIBILITY GENES OF LN. 2020 16 2591 44 EPIGENETICS OF PSORIASIS. PSORIASIS IS A CHRONIC AND RECURRENT INFLAMMATORY SKIN DISEASE, INVOLVING THE RAPID PROLIFERATION AND ABNORMAL DIFFERENTIATION OF KERATINOCYTES AND ACTIVATION OF T CELLS. IT IS GENERALLY ACCEPTED THAT THE CENTRAL PATHOGENESIS OF PSORIASIS IS A T CELL-DOMINANT IMMUNE DISORDER AFFECTED BY MULTIPLE FACTORS INCLUDING GENETIC SUSCEPTIBILITY, ENVIRONMENTAL FACTORS, INNATE AND ADAPTIVE IMMUNE RESPONSES, ETC. HOWEVER, THE EXACT ETIOLOGY IS LARGELY UNKNOWN. IN RECENT YEARS, EPIGENETIC INVOLVEMENTS, SUCH AS THE DNA METHYLATION, CHROMATIN MODIFICATIONS, AND NONCODING RNA REGULATION ARE REPORTED TO BE CRITICAL FOR THE PATHOGENESIS OF PSORIASIS. HOWEVER, THE INTERPLAY BETWEEN THESE FACTORS HAS ONLY RECENTLY BEEN STARTED TO BE UNRAVELED. NOTABLY, INHIBITORS OF ENZYMES THAT WORK IN EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLTRANSFERASES AND HISTONE DEACETYLASES, ARE BEGINNING TO APPEAR IN THE CLINICAL SETTING TO RESTORE NORMAL EPIGENETIC PATTERNS (GENERALI ET AL. IN J AUTOIMMUN 83:51-61, 2017), PROVIDING NOVEL THERAPEUTIC POTENTIAL AS NOVEL TREATMENT TARGETS FOR PSORIASIS. INDEED, MEDICATIONS PREVIOUSLY USED TO TREAT AUTOIMMUNE DISEASES HAVE LATER BEEN DISCOVERED TO EXERT THEIR ACTION VIA EPIGENETIC MECHANISMS. HEREIN, WE REVIEW THE FINDINGS ON EPIGENETICS ASSOCIATED WITH PSORIASIS, AND DISCUSS FUTURE PERSPECTIVES IN THIS FIELD. 2020 17 2529 32 EPIGENETICS CHANGES ASSOCIATED TO ENVIRONMENTAL TRIGGERS IN AUTOIMMUNITY. AUTOIMMUNE DISEASES (AIDS) ARE CHRONIC CONDITIONS INITIATED BY THE LOSS OF IMMUNOLOGICAL TOLERANCE TO SELF-ANTIGENS AND REPRESENT A HETEROGENEOUS GROUP OF DISORDERS THAT AFFECT SPECIFIC TARGET ORGANS OR MULTIPLE ORGANS IN DIFFERENT SYSTEMS. WHILE THE PATHOGENESIS OF AID REMAINS UNCLEAR, ITS AETIOLOGY IS MULTIFUNCTIONAL AND INCLUDES A COMBINATION OF GENETIC, EPIGENETIC, IMMUNOLOGICAL AND ENVIRONMENTAL FACTORS. IN AIDS, SEVERAL EPIGENETIC MECHANISMS ARE DEFECTIVE INCLUDING DNA DEMETHYLATION, ABNORMAL CHROMATIN POSITIONING ASSOCIATED WITH AUTOANTIBODY PRODUCTION AND ABNORMALITIES IN THE EXPRESSION OF RNA INTERFERENCE (RNAI). IT IS KNOWN THAT ENVIRONMENTAL FACTORS MAY INTERFERE WITH DNA METHYLATION AND HISTONE MODIFICATIONS, HOWEVER, LITTLE IS KNOWN ABOUT EPIGENETIC CHANGES DERIVED OF REGULATION OF RNAI. AN APPROACH TO THE KNOWN ENVIRONMENTAL FACTORS AND THE MECHANISMS THAT ALTER THE EPIGENETIC REGULATION IN AIDS (WITH EMPHASIS IN SYSTEMIC LUPUS ERYTHEMATOSUS, THE PROTOTYPE OF SYSTEMIC AID) ARE SHOWED IN THIS REVIEW. 2016 18 6597 42 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 19 2333 33 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 20 6288 52 THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS ON DIFFERENT FACETS IN THE PERIODONTAL PATHOGENESIS. PERIODONTITIS IS A CHRONIC INFLAMMATORY DISEASE THAT AFFECTS THE SUPPORTING STRUCTURES OF TEETH. IN THE LITERATURE, THE ASSOCIATION BETWEEN THE PATHOGENICITY OF BACTERIA AND ENVIRONMENTAL FACTORS IN THIS REGARD HAVE BEEN EXTENSIVELY EXAMINED. IN THE PRESENT STUDY, WE WILL SHED LIGHT ON THE POTENTIAL ROLE THAT EPIGENETIC CHANGE CAN PLAY ON DIFFERENT FACETS OF ITS PROCESS, MORE PARTICULARLY THE MODIFICATIONS CONCERNING THE GENES INVOLVED IN INFLAMMATION, DEFENSE, AND IMMUNE SYSTEMS. SINCE THE 1960S, THE ROLE OF GENETIC VARIANTS IN THE ONSET AND SEVERITY OF PERIODONTAL DISEASE HAS BEEN WIDELY DEMONSTRATED. THESE MAKE SOME PEOPLE MORE SUSCEPTIBLE TO DEVELOPING IT THAN OTHERS. IT HAS BEEN DOCUMENTED THAT THE WIDE VARIATION IN ITS FREQUENCY FOR VARIOUS RACIAL AND ETHNIC POPULATIONS IS DUE PRIMARILY TO THE COMPLEX INTERPLAY AMONG GENETIC FACTORS WITH THOSE AFFECTING THE ENVIRONMENT AND THE DEMOGRAPHY. IN MOLECULAR BIOLOGY, EPIGENETIC MODIFICATIONS ARE DEFINED AS ANY CHANGE IN THE PROMOTER FOR THE CPG ISLANDS, IN THE STRUCTURE OF THE HISTONE PROTEIN, AS WELL AS POST-TRANSLATIONAL REGULATION BY MICRORNAS (MIRNAS), BEING KNOWN TO CONTRIBUTE TO THE ALTERATION IN GENE EXPRESSION FOR COMPLEX MULTIFACTORIAL DISEASES SUCH AS PERIODONTITIS. THE KEY ROLE OF EPIGENETIC MODIFICATION IS TO UNDERSTAND THE MECHANISM INVOLVED IN THE GENE-ENVIRONMENT INTERACTION, AND THE DEVELOPMENT OF PERIODONTITIS IS NOW THE SUBJECT OF MORE AND MORE STUDIES THAT ATTEMPT TO IDENTIFY WHICH FACTORS ARE STIMULATING IT, BUT ALSO AFFECT THE REDUCED RESPONSE TO THERAPY. 2023