1 5505 96 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 2 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 3 1565 28 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 4 783 29 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 4657 31 NEW ADVANCES OF DNA METHYLATION AND HISTONE MODIFICATIONS IN RHEUMATOID ARTHRITIS, WITH SPECIAL EMPHASIS ON MECP2. EPIGENETICS IS A STEADILY GROWING RESEARCH AREA IN MANY HUMAN DISEASES, ESPECIALLY IN AUTOIMMUNE DISEASES SUCH AS RHEUMATOID ARTHRITIS (RA). RA IS AN AUTOIMMUNE DISEASE WITH UNCLEAR ETIOLOGY CHARACTERIZED BY CHRONIC INFLAMMATION AND JOINT DESTRUCTION AND FIBROBLAST-LIKE SYNOVIOCYTES (FLS) DISPLAY A CRUCIAL ROLE IN THE PATHOGENESIS OF RA. EVEN THOUGH THE ETIOLOGY IS NOT YET FULLY UNDERSTOOD, RA IS GENERALLY CONSIDERED TO BE CAUSED BY A COMBINATION OF EPIGENETIC MODIFICATION, DEREGULATED IMMUNOMODULATION, AND ENVIRONMENTAL FACTORS. EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION AND POST-TRANSLATIONAL HISTONE MODIFICATIONS, SUCH AS HISTONE METHYLATION AND HISTONE (DE)ACETYLATION ARE IDENTIFIED AS REGULATORY MECHANISMS IN CONTROLLING AGGRESSIVE FLS ACTIVATION IN PATIENTS AND ANIMAL MODELS. IN THE LAST 3YEARS, THE FIELD OF EPIGENETICS IN RA HAS IMPRESSIVELY INCREASED. METHYL-CPG-BINDING PROTEIN 2 (MECP2) IS FIRST IDENTIFIED AS A TRANSCRIPTIONAL REPRESSOR THAT INHIBITS GENE EXPRESSION THROUGH THE INTERPRETATION OF TWO EPIGENETIC MARKERS, DNA METHYLATION AND HISTONE MODIFICATION. THE COOPERATIVE ACTION AMONG MECP2, DNA METHYLATION AND HISTONE MODIFICATIONS INDICATES THAT MECP2 SHOULD PARTICIPATE IN THE PATHOGENESIS OF RA THROUGH SILENCE OF CERTAIN GENE TRANSCRIPTION. IN THIS REVIEW, WE CONSIDER THE ROLE OF DNA METHYLATION AND HISTONE MODIFICATIONS IN THE DEVELOPMENT OF RA, WITH A SPECIAL FOCUS ON INCREASED MECP2 EXPRESSION IN RA ANIMAL MODELS. 2013 6 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 7 4416 28 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 8 5421 25 REGULATION OF INTERLEUKIN-23 EXPRESSION IN HEALTH AND DISEASE. INTERLEUKIN (IL)-23 PLAYS A CENTRAL ROLE IN THE ORCHESTRATION OF INFLAMMATORY RESPONSES. PRODUCED BY DENDRITIC CELLS AND MACROPHAGES, THIS CYTOKINE PROMOTES THE PROTECTION OF THE HOST AGAINST MUCOSAL PATHOGENS THROUGH THE INDUCTION OF IL-17 AND RELATED CYTOKINES BY LYMPHOID CELLS. PRECLINICAL DISEASE MODELS AND ASSOCIATION STUDIES IN HUMANS HAVE ALSO CLEARLY DEMONSTRATED THE IMPLICATION OF IL-23 SIGNALLING PATHWAY IN INFLAMMATORY DISEASES. INDEED, THIS CYTOKINE IS NOW CONSIDERED AS A MAJOR THERAPEUTIC TARGET IN IMMUNE-BASED PATHOLOGIES SUCH AS PSORIASIS, ANKYLOSING SPONDYLITIS OR CROHN'S DISEASE. FURTHERMORE, IN THE CONTEXT OF INFLAMMATION-RELATED CANCER, IL-23 IS THOUGHT TO CONTRIBUTE TO TUMORIGENESIS AND PROGRESSION TO METASTATIC DISEASE. HEREIN, WE REVIEW OUR CURRENT UNDERSTANDING OF IL-23 REGULATION AT THE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL LEVELS. WE DISCUSS THE RELEVANCE OF THESE FINDINGS IN THE CONTEXT OF INFECTION, CHRONIC INFLAMMATION AND CANCER. 2016 9 4439 29 MOLECULAR GENETIC AND EPIGENETIC BASIS OF MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC IMMUNE-MEDIATED DISEASE OF SPINAL CORD AND BRAIN. THE INITIAL EVENT IN MS OCCURS WHEN ACTIVATED CD4(+) T CELLS IN PERIPHERY EXACERBATES IMMUNE RESPONSES BY STIMULATING IMMUNE CELLS SUCH AS B CELLS, CD8(+) CELLS, MAST CELLS, GRANULOCYTES AND MONOCYTES. THESE PROINFLAMMATORY CELLS PASS BLOOD BRAIN BARRIER BY SECRETING PROINFLAMMATORY CYTOKINES INCLUDING TNF-ALPHA AND INF-(GAMMA) WHICH ACTIVATE ADHESION FACTORS. APCS (ANTIGEN-PRESENTING CELLS) REACTIVATE CD4(+) T CELLS AFTER INFILTRATING THE CNS AND CD4(+) T CELLS PRODUCE CYTOKINES AND CHEMOKINES. THESE PROINFLAMMATORY CYTOKINES AGGRAVATE INFLAMMATION BY INDUCING MYELIN PHAGOCYTOSIS THROUGH MICROGLIA AND ASTROCYTES ACTIVATION. MS IS BELIEVED TO HAVE A MULTIFACTORIAL ORIGIN THAT INCLUDES A COMBINATION OF MULTIPLE GENETIC, ENVIRONMENTAL AND STOCHASTIC FACTORS. ALTHOUGH THE EXACT COMPONENT OF MS RISKS THAT CAN BE EXPLAINED BY THESE FACTORS IS DIFFICULT TO DETERMINE, ESTIMATES BASED ON GENETIC AND EPIDEMIOLOGICAL STUDIES SUGGEST THAT UP TO 60-70 % OF THE TOTAL RISK OF MS MAY BE CONTRIBUTE TO GENETIC FACTORS. IN CONTINUE, FIRSTLY WE PROVIDE AN OVERVIEW OF THE CURRENT UNDERSTANDING OF EPIGENETIC MECHANISMS, AND SO PRESENT EVIDENCE OF HOW THE EPIGENETIC MODIFICATIONS CONTRIBUTE TO INCREASED SUSCEPTIBILITY OF MS. WE ALSO EXPLAIN HOW SPECIFIED EPIGENETIC MODIFICATIONS MAY INFLUENCE THE PATHOPHYSIOLOGY AND KEY ASPECTS OF DISEASE IN MS (DEMYELINATION, REMYELINATION, INFLAMMATION, AND NEURODEGENERATION). FINALLY, WE TEND TO DISCUSS HOW ENVIRONMENTAL FACTORS AND EPIGENETIC MECHANISMS MAY INTERACT TO HAVE AN EFFECT ON MS RISK AND CLINICAL OUTCOME AND RECOMMEND NEW THERAPEUTIC INTERVENTIONS THAT MIGHT MODULATE PATIENTS' EPIGENETIC PROFILES. 2017 10 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 11 6476 23 TOLL-LIKE RECEPTORS, INFECTIONS, AND RHEUMATOID ARTHRITIS. TOLL-LIKE RECEPTORS (TLR) THAT BELONG TO THE GROUP OF PROTEIN RECOGNITION RECEPTOR (PPR) PROVIDE AN INNATE IMMUNE RESPONSE FOLLOWING THE SENSING OF CONSERVED PATHOGEN-ASSOCIATED MICROBIAL PATTERNS (PAMPS) AND CHANGES IN DANGER-ASSOCIATED MOLECULAR PATTERNS (DAMPS) THAT ARE GENERATED AS A CONSEQUENCE OF CELLULAR INJURY. ANALYSIS OF THE TLR PATHWAY HAS MOREOVER OFFERED NEW INSIGHTS INTO THE PATHOGENESIS OF RHEUMATOID ARTHRITIS (RA). INDEED, A DYSFUNCTIONAL TLR-MEDIATED RESPONSE CHARACTERIZES RA PATIENTS AND PARTICIPATES IN ESTABLISHMENT OF A CHRONIC INFLAMMATORY STATE. SUCH AN INAPPROPRIATE TLR RESPONSE HAS BEEN ATTRIBUTED (I) TO THE REPORT OF IMPORTANT ALTERATIONS IN THE MICROBIOTA AND ABNORMAL RESPONSES TO INFECTIOUS AGENTS AS PART OF RA; (II) TO THE ABNORMAL PRESENCE OF TLR-LIGANDS IN THE SERUM AND SYNOVIAL FLUID OF RA PATIENTS; (III) TO THE OVEREXPRESSION OF TLR MOLECULES; (IV) TO THE PRODUCTION OF A LARGE PANEL OF PRO-INFLAMMATORY CYTOKINES DOWNSTREAM OF THE TLR PATHWAY; AND (V) TO GENETIC VARIANTS AND EPIGENETIC FACTORS IN SUSCEPTIBLE RA PATIENTS PROMOTING A HYPER TLR RESPONSE. AS A CONSEQUENCE, THE DEVELOPMENT OF PROMISING THERAPEUTIC STRATEGIES TARGETING TLRS FOR THE TREATMENT AND PREVENTION OF RA IS EMERGING. 2020 12 6136 29 THE EPIGENETICS OF MULTIPLE SCLEROSIS AND OTHER RELATED DISORDERS. MULTIPLE SCLEROSIS (MS) IS A DEMYELINATING DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION OF THE CENTRAL NERVOUS SYSTEM (CNS) GRAY AND WHITE MATTER. ALTHOUGH THE CAUSE OF MS IS UNKNOWN, IT IS WIDELY APPRECIATED THAT INNATE AND ADAPTIVE IMMUNE PROCESSES CONTRIBUTE TO ITS PATHOGENESIS. THESE INCLUDE MICROGLIA/MACROPHAGE ACTIVATION, PRO-INFLAMMATORY T-CELL (TH1) RESPONSES AND HUMORAL RESPONSES. ADDITIONALLY, THERE IS EVIDENCE INDICATING THAT MS HAS A NEURODEGENERATIVE COMPONENT SINCE NEURONAL AND AXONAL LOSS OCCURS EVEN IN THE ABSENCE OF OVERT INFLAMMATION. THESE ASPECTS ALSO FORM THE RATIONALE FOR CLINICAL MANAGEMENT OF THE DISEASE. HOWEVER, THE CURRENTLY AVAILABLE THERAPIES TO CONTROL THE DISEASE ARE ONLY PARTIALLY EFFECTIVE AT BEST INDICATING THAT MORE EFFECTIVE THERAPEUTIC SOLUTIONS ARE URGENTLY NEEDED. IT IS APPRECIATED THAT IN THE IMMUNE-DRIVEN AND NEURODEGENERATIVE PROCESSES MS-SPECIFIC DEREGULATION OF GENE EXPRESSIONS AND RESULTING PROTEIN DYSFUNCTION ARE THOUGHT TO PLAY A CENTRAL ROLE. THESE DEVIATIONS IN GENE EXPRESSION PATTERNS CONTRIBUTE TO THE INFLAMMATORY RESPONSE IN THE CNS, AND TO NEURONAL OR AXONAL LOSS. EPIGENETIC MECHANISMS CONTROL TRANSCRIPTION OF MOST, IF NOT ALL GENES, IN NUCLEATED CELLS INCLUDING CELLS OF THE CNS AND IN HAEMATOPOIETIC CELLS. MS-SPECIFIC ALTERATIONS IN EPIGENETIC REGULATION OF GENE EXPRESSION MAY THEREFORE LIE AT THE HEART OF THE DEREGULATION OF GENE EXPRESSION IN MS. AS SUCH, EPIGENETIC MECHANISMS MOST LIKELY PLAY AN IMPORTANT ROLE IN DISEASE PATHOGENESIS. IN THIS REVIEW WE DISCUSS A ROLE FOR MS-SPECIFIC DEREGULATION OF EPIGENETIC FEATURES THAT CONTROL GENE EXPRESSION IN THE CNS AND IN THE PERIPHERY. FURTHERMORE, WE DISCUSS THE APPLICATION OF SMALL MOLECULE INHIBITORS THAT TARGET THE EPIGENETIC MACHINERY TO AMELIORATE DISEASE IN EXPERIMENTAL ANIMAL MODELS, INDICATING THAT SUCH APPROACHES MAY BE APPLICABLE TO MS PATIENTS. 2014 13 2591 33 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 14 2294 37 EPIGENETIC REGULATION IN THE PATHOGENESIS OF SJOGREN SYNDROME AND RHEUMATOID ARTHRITIS. AUTOIMMUNE RHEUMATIC DISEASES, SUCH AS SJOGREN SYNDROME (SS) AND RHEUMATOID ARTHRITIS (RA), ARE CHARACTERIZED BY CHRONIC INFLAMMATION AND AUTOIMMUNITY, WHICH CAUSE JOINT TISSUE DAMAGE AND DESTRUCTION BY TRIGGERING REDUCED MOBILITY AND DEBILITATION IN PATIENTS WITH THESE DISEASES. INITIATION AND MAINTENANCE OF CHRONIC INFLAMMATORY STAGES ACCOUNT FOR SEVERAL MECHANISMS THAT INVOLVE IMMUNE CELLS AS KEY PLAYERS AND THE INTERACTION OF THE IMMUNE CELLS WITH OTHER TISSUES. INDEED, THE OVERLAPPING OF CERTAIN CLINICAL AND SEROLOGIC MANIFESTATIONS BETWEEN SS AND RA MAY INDICATE THAT NUMEROUS IMMUNOLOGIC-RELATED MECHANISMS ARE INVOLVED IN THE PHYSIOPATHOLOGY OF BOTH THESE DISEASES. IT IS WIDELY ACCEPTED THAT EPIGENETIC PATHWAYS PLAY AN ESSENTIAL ROLE IN THE DEVELOPMENT AND FUNCTION OF THE IMMUNE SYSTEM. ALTHOUGH MANY PUBLISHED STUDIES HAVE ATTEMPTED TO ELUCIDATE THE RELATION BETWEEN EPIGENETIC MODIFICATIONS (E.G. DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS, MIRNAS) AND AUTOIMMUNE DISORDERS, THE CONTRIBUTION OF EPIGENETIC REGULATION TO THE PATHOGENESIS OF SS AND RA IS AT PRESENT POORLY UNDERSTOOD. THIS REVIEW ATTEMPTS TO SHED LIGHT FROM A CRITICAL POINT OF VIEW ON THE IDENTIFICATION OF THE MOST RELEVANT EPIGENETIC MECHANISMS RELATED TO RA AND SS BY EXPLAINING INTRICATE REGULATORY PROCESSES AND PHENOTYPIC FEATURES OF BOTH AUTOIMMUNE DISEASES. MOREOVER, WE POINT OUT SOME EPIGENETIC MARKERS WHICH CAN BE USED TO MONITOR THE INFLAMMATION STATUS AND THE DYSREGULATED IMMUNITY IN SS AND RA. FINALLY, WE DISCUSS THE INCONVENIENCE OF USING EPIGENETIC DATA OBTAINED FROM BULK IMMUNE CELL POPULATIONS INSTEAD SPECIFIC IMMUNE CELL SUBPOPULATIONS. 2019 15 5739 26 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 16 6178 28 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 17 3031 33 GENETICS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS AN INFLAMMATORY AUTOIMMUNE DISEASE INVOLVING SYMMETRIC JOINTS AND IS GENERALLY CHARACTERIZED BY PERSISTENT PAIN, TENDERNESS, AND DESTRUCTION OF JOINTS. THE VAST MAJORITY OF RA PATIENTS PRODUCE AUTOANTIBODIES, AND IMMUNE CELL INVOLVEMENT IN DISEASE DEVELOPMENT IS WELL RECOGNIZED, AS IS THE CONTRIBUTION OF OTHER TYPES OF CELLS IN SYNOVIAL TISSUE, LIKE FIBROBLASTS. IT IS KNOWN THAT THERE ARE MAJOR GENETIC ASSOCIATIONS WITH THE HLA LOCUS, WHILE MULTIPLE NON-HLA GENETIC VARIANTS DISPLAY RELATIVELY LOW RISK OF RA. BOTH HLA AND NON-HLA ASSOCIATIONS SUGGEST THAT THE PROFILES OF GENETIC ASSOCIATIONS FOR AUTOANTIBODY-POSITIVE VS. AUTOANTIBODY-NEGATIVE RA ARE DIFFERENT. SEVERAL ALLELES OF HLA-DRB1 ARE ASSOCIATED WITH HIGH RISK FOR AUTOANTIBODY-POSITIVE RA, WITH THE STRONGEST RISK CHARACTERIZED BY VALINE AT POSITION 11 OF THE PROTEIN SEQUENCE (HLA-DRB1*04 AND *10 ALLELES). THERE IS A STRONG PROTECTIVE EFFECT FOR THE RISK OF AUTOANTIBODY-POSITIVE RA ASSOCIATED WITH HLA-DRB1*13 ALLELES. ALTHOUGH MAJOR GENETIC ASSOCIATIONS HAVE BEEN KNOWN FOR SEVERAL YEARS, UNDERSTANDING OF THE SPECIFIC MECHANISMS IN THE DEVELOPMENT OF INCREASED RISK OF RA FOR THESE VARIATIONS IS WORK IN PROGRESS. CURRENT STUDIES FOCUS ON THE BINDING OF IMMUNE RECEPTORS INVOLVED IN RECOGNITION OF PUTATIVE PEPTIDES IN ACTIVATION OF T CELLS, AS WELL AS INVESTIGATION OF CELL SIGNALING MECHANISMS. AT LEAST A PART OF RA RISK COULD BE EXPLAINED BY GENE-GENE AND GENE-ENVIRONMENT INTERACTIONS. THERE ARE CURRENTLY MORE THAN 150 CANDIDATE LOCI WITH POLYMORPHISMS THAT ASSOCIATE WITH RA, MAINLY RELATED TO SEROPOSITIVE DISEASE, AND NEW DISCOVERIES ARE ANTICIPATED IN THE FUTURE FROM INVESTIGATION OF DIVERSE HUMAN POPULATIONS. THIS NEW RESEARCH WILL HELP CREATE A STRONG FOUNDATION FOR THE CONTINUING PROCESS OF INTEGRATING GENETIC, EPIGENETIC, TRANSCRIPTOMIC, AND PROTEOMIC DATA IN STUDIES OF RA. 2022 18 4412 32 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 19 4318 24 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 20 5002 28 PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AS RISK FACTORS FOR RHEUMATOID ARTHRITIS: A REVIEW OF THE LAST 10 YEARS. RHEUMATOID ARTHRITIS (RA) IS CHARACTERIZED BY CHRONIC INFLAMMATORY DESTRUCTION OF JOINT TISSUE AND IS CAUSED BY AN ABNORMAL AUTOIMMUNE RESPONSE TRIGGERED BY INTERACTIONS BETWEEN GENETICS, ENVIRONMENTAL FACTORS, AND EPIGENETIC AND POSTTRANSLATIONAL MODIFICATIONS. RA HAS BEEN SUGGESTED TO BE INTERRELATED WITH PERIODONTITIS, A SERIOUS FORM OR STAGE OF CHRONIC INFLAMMATORY PERIODONTAL DISEASE ASSOCIATED WITH PERIODONTOPATHIC BACTERIAL INFECTIONS, GENETIC PREDISPOSITION, ENVIRONMENTAL FACTORS, AND EPIGENETIC INFLUENCES. OVER THE LAST DECADE, A NUMBER OF ANIMAL AND CLINICAL STUDIES HAVE BEEN CONDUCTED TO ASSESS WHETHER OR NOT PERIODONTITIS AND ASSOCIATED PERIODONTOPATHIC BACTERIA CONSTITUTE RISK FACTORS FOR RA. THE PRESENT REVIEW INTRODUCES RECENT ACCUMULATING EVIDENCE TO SUPPORT THE ASSOCIATIONS OF PERIODONTITIS AND PERIODONTOPATHIC BACTERIA WITH THE RISK OF RA OR THE OUTCOME OF RA PHARMACOLOGICAL TREATMENT WITH DISEASE-MODIFYING ANTIRHEUMATIC DRUGS. IN ADDITION, THE RESULTS FROM INTERVENTION STUDIES HAVE SUGGESTED AN IMPROVEMENT IN RA CLINICAL PARAMETERS AFTER NONSURGICAL PERIODONTAL TREATMENT. FURTHERMORE, THE POTENTIAL CAUSAL MECHANISMS UNDERLYING THE LINK BETWEEN PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AND RA ARE SUMMARIZED. 2023