1 5002 96 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 2 5739 40 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 3 2558 43 EPIGENETICS IN SUSCEPTIBILITY, PROGRESSION, AND DIAGNOSIS OF PERIODONTITIS. PERIODONTITIS IS CHARACTERIZED BY IRREVERSIBLE DESTRUCTION OF PERIODONTAL TISSUE. AT PRESENT, THE ACCEPTED ETIOLOGY OF PERIODONTITIS IS BASED ON A THREE-FACTOR THEORY INCLUDING PATHOGENIC BACTERIA, HOST FACTORS, AND ACQUIRED FACTORS. PERIODONTITIS DEVELOPMENT USUALLY TAKES A DECADE OR LONGER AND IS THEREFORE CALLED CHRONIC PERIODONTITIS (CP). TO SEARCH FOR GENETIC FACTORS ASSOCIATED WITH CP, SEVERAL GENOME-WIDE ASSOCIATION STUDY (GWAS) ANALYSES WERE CONDUCTED; HOWEVER, POLYMORPHISMS ASSOCIATED WITH CP HAVE NOT BEEN IDENTIFIED. EPIGENETICS, ON THE OTHER HAND, INVOLVES ACQUIRED TRANSCRIPTIONAL REGULATORY MECHANISMS DUE TO REVERSIBLY ALTERED CHROMATIN ACCESSIBILITY. EPIGENETIC STATUS IS A CONDITION SPECIFIC TO EACH TISSUE AND CELL, MOSTLY DETERMINED BY THE RESPONSES OF HOST CELLS TO STIMULATIONS BY LOCAL FACTORS, LIKE BACTERIAL INFLAMMATION, AND SYSTEMIC FACTORS SUCH AS NUTRITION STATUS, METABOLIC DISEASES, AND HEALTH CONDITIONS. SIGNIFICANTLY, EPIGENETIC STATUS HAS BEEN LINKED WITH THE ONSET AND PROGRESSION OF SEVERAL ACQUIRED DISEASES. THUS, EPIGENETIC FACTORS IN PERIODONTAL TISSUES ARE ATTRACTIVE TARGETS FOR PERIODONTITIS DIAGNOSIS AND TREATMENTS. IN THIS REVIEW, WE INTRODUCE ACCUMULATING EVIDENCE TO REVEAL THE EPIGENETIC BACKGROUND EFFECTS RELATED TO PERIODONTITIS CAUSED BY GENETIC FACTORS, SYSTEMIC DISEASES, AND LOCAL ENVIRONMENTAL FACTORS, SUCH AS SMOKING, AND CLARIFY THE UNDERLYING MECHANISMS BY WHICH EPIGENETIC ALTERATION INFLUENCES THE SUSCEPTIBILITY OF PERIODONTITIS. 2022 4 1608 39 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 4844 34 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 6 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 7 4842 37 ONE YEAR IN REVIEW 2017: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. IT HAS BEEN POSTULATED THAT A HIGH-RISK GENETIC BACKGROUND, IN COMBINATION WITH EPIGENETIC MARKS AND ENVIRONMENTAL EXPOSURES, LEADS TO A CASCADE OF EVENTS INDUCING SYNOVITIS AND CONSEQUENT DESTRUCTIVE ARTHRITIS. THE CLINICAL PICTURE OF JOINT INVOLVEMENT IN RA IS THE RESULT OF CHRONIC INFLAMMATION OF THE SYNOVIUM, CHARACTERISED BY INTERACTIONS OF RESIDENT CELLS SUCH AS FIBROBLAST-LIKE SYNOVIOCYTES (FLS) WITH CELLS OF THE INNATE (E.G. MACROPHAGES, DENDRITIC CELLS, MAST CELLS AND NK CELLS, NEUTROPHILS) AND ADAPTIVE IMMUNE SYSTEM (E.G. B AND T LYMPHOCYTES). CURRENTLY, OUR UNDERSTANDING OF THE ROLE OF INNATE AND ADAPTIVE IMMUNITY IN THE PATHOGENESIS OF RA IS EXPANDING. THE CONCEPT OF HOW IMMUNE RESPONSES CONTRIBUTE TO THE DISEASE HAS DRAMATICALLY EVOLVED OVER THE LAST 50 YEARS. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE REPORT NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM A LITERATURE RESEARCH DATE PUBLISHED IN THE LAST YEAR. 2017 8 523 38 ASSOCIATIONS BETWEEN PERIODONTITIS AND SYSTEMIC INFLAMMATORY DISEASES: RESPONSE TO TREATMENT. THERE IS A SIGNIFICANT PREVALENCE OF SUBJECTS WITH PERIODONTITIS PRESENTING WITH OTHER INFLAMMATORY CONDITIONS SUCH AS CORONARY HEART DISEASE, INSULIN RESISTANCE AND ARTHRITIS. THIS PATTERN OF DISEASE PRESENTATION UNDERSCORES THE IMPORTANCE OF INFLAMMATORY LOADING FROM CHRONIC DISEASES, IN DRIVING THEIR PATHOGENESES IN A MULTIDIRECTIONAL MANNER. PRO-INFLAMMATORY CYTOKINES AND OTHER AGENTS PLAY AN IMPORTANT ROLE IN THIS PROCESS; FOR EXAMPLE, A SINGLE NUCLEOTIDE POLYMORPHISM OF THE TNF-ALPHA GENE IS ASSOCIATED WITH SIGNIFICANT PERIODONTAL ATTACHMENT LOSS IN PATIENTS WITH CORONARY HEART DISEASE. CHANGES IN GENE EXPRESSION ASSOCIATED WITH INFLAMMATION AND LIPID METABOLISM IN RESPONSE TO ORAL INFECTION WITH THE PERIODONTAL PATHOGEN PORPHYROMONAS GINGIVALIS (PG) HAVE BEEN DEMONSTRATED IN MOUSE MODELS, INDEPENDENT OF THE DEMONSTRATION OF ATHEROSCLEROTIC LESIONS. INSULIN RESISTANCE IS CONSIDERED TO BE A CHRONIC LOW-GRADE INFLAMMATORY CONDITION, ASSOCIATED WITH ALTERED GLUCOSE TOLERANCE, HYPERTRIGLYCERIDEMIA, CENTRAL OBESITY AND CORONARY HEART DISEASE. IT IS ACCOMPANIED BY ELEVATED LEVELS OF IL-1, IL-6 AND TNF-ALPHA ALSO RELEVANT TO THE PROGRESSION OF PERIODONTITIS. THERE IS EVIDENCE THAT UNCONTROLLED PERIODONTAL DISEASE CONTRIBUTES TO MAINTENANCE OF SYSTEMIC DISEASES, INCLUDING RHEUMATOID ARTHRITIS (RA), WITH INCREASED RISK OF PERIODONTITIS IN SUBJECTS WITH RA. THE PERIODONTAL PATHOGEN PG IS SIGNIFICANT IN CONTRIBUTING TO CITRULLINATION OF PROTEINS RESULTING IN IMMUNE DYSREGULATION AND AUTOIMMUNE RESPONSES, SEEN IN RA. HOWEVER, THEY ARE BOTH MULTIFACTORIAL CHRONIC DISEASES WITH COMPLEX ETIOPATHOGENESES THAT AFFECT THEIR PRESENTATION. CONSISTENT BUT WEAK ASSOCIATIONS ARE SEEN FOR SURROGATE MARKERS OF PERIODONTITIS SUCH AS TOOTH LOSS, WITH MULTIPLE SYSTEMIC CONDITIONS. EFFECTIVE TREATMENT OF PERIODONTITIS WOULD BE IMPORTANT IN REDUCING SYSTEMIC INFLAMMATORY LOADING FROM CHRONIC LOCAL INFLAMMATION AND IN ACHIEVING SYSTEMIC HEALTH. LACK OF A CONSISTENT CAUSE AND EFFECT RELATIONSHIP IN ALL SUBJECTS WOULD BE INFLUENCED BY GENETIC, EPIGENETIC AND OTHER SUBJECT VARIABLES, ALTHOUGH THERE ARE CLEAR MECHANISMS THAT LINK THE ASSOCIATIONS. THIS ARTICLE INCLUDES AN APPRAISAL OF PATENTS AND THEIR APPLICATIONS. 2013 9 2556 29 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 10 5003 37 PERIODONTITIS IS AN INFLAMMATORY DISEASE OF OXIDATIVE STRESS: WE SHOULD TREAT IT THAT WAY. PERIODONTITIS IS A HIGHLY PREVALENT DISEASE. AS IT PROGRESSES, IT CAUSES SERIOUS MORBIDITY IN THE FORM OF PERIODONTAL ABSCESSES AND TOOTH LOSS AND, IN THE LATTER STAGES, PAIN. IT IS ALSO NOW KNOWN THAT PERIODONTITIS IS STRONGLY ASSOCIATED WITH SEVERAL NONORAL DISEASES. THUS, PATIENTS WITH PERIODONTITIS ARE AT GREATER RISK FOR THE DEVELOPMENT AND/OR EXACERBATION OF DIABETES, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND CARDIOVASCULAR DISEASES, AMONG OTHER CONDITIONS. ALTHOUGH IT IS WITHOUT QUESTION THAT SPECIFIC GROUPS OF ORAL BACTERIA WHICH POPULATE DENTAL PLAQUE PLAY A CAUSATIVE ROLE IN THE DEVELOPMENT OF PERIODONTITIS, IT IS NOW THOUGHT THAT ONCE THIS DISEASE HAS BEEN TRIGGERED, OTHER FACTORS PLAY AN EQUAL, AND POSSIBLY MORE IMPORTANT, ROLE IN ITS PROGRESSION, PARTICULARLY IN SEVERE CASES OR IN CASES THAT PROVE DIFFICULT TO TREAT. IN THIS REGARD, WE ALLUDE TO THE HOST RESPONSE, SPECIFICALLY THE NOTION THAT THE HOST, ONCE INFECTED WITH ORAL PERIODONTAL PATHOGENIC BACTERIA, WILL MOUNT A DEFENSE RESPONSE MEDIATED LARGELY THROUGH THE INNATE IMMUNE SYSTEM. THE MOST ABUNDANT CELL TYPE OF THE INNATE IMMUNE SYSTEM - POLYMORPHONUCLEAR NEUTROPHILS - CAN, WHEN PROTECTING THE HOST FROM MICROBIAL INVASION, MOUNT A RESPONSE THAT INCLUDES UPREGULATION OF PROINFLAMMATORY CYTOKINES, MATRIX METALLOPROTEINASES, AND REACTIVE OXYGEN SPECIES, ALL OF WHICH THEN CONTRIBUTE TO THE TISSUE DAMAGE AND LOSS OF TEETH COMMONLY ASSOCIATED WITH PERIODONTITIS. OF THE MECHANISMS REFERRED TO HERE, WE SUGGEST THAT UPREGULATION OF REACTIVE OXYGEN SPECIES MIGHT PLAY ONE OF THE MOST IMPORTANT ROLES IN THE ESTABLISHMENT AND PROGRESSION OF PERIODONTITIS (AS WELL AS IN OTHER DISEASES OF INFLAMMATION) THROUGH THE DEVELOPMENT OF OXIDATIVE STRESS. IN THIS OVERVIEW, WE DISCUSS BOTH INNATE AND EPIGENETIC FACTORS (EG, DIABETES, SMOKING) THAT LEAD TO THE DEVELOPMENT OF OXIDATIVE STRESS. THIS OXIDATIVE STRESS THEN PROVIDES AN ENVIRONMENT CONDUCIVE TO THE DESTRUCTIVE PROCESSES OBSERVED IN PERIODONTITIS. THEREFORE, WE SHALL DESCRIBE SOME OF THE FUNDAMENTAL CHARACTERISTICS OF OXIDATIVE STRESS AND ITS EFFECTS ON THE PERIODONTIUM, DISCUSS THE DISEASES AND OTHER FACTORS THAT CAUSE OXIDATIVE STRESS, AND, FINALLY, REVIEW POTENTIALLY NOVEL THERAPEUTIC APPROACHES FOR THE MANAGEMENT (AND POSSIBLY EVEN THE REVERSAL) OF PERIODONTITIS, WHICH RELY ON THE USE OF THERAPIES, SUCH AS RESVERATROL AND OTHER ANTIOXIDANTS, THAT PROVIDE INCREASED ANTIOXIDANT ACTIVITY IN THE HOST. 2020 11 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 12 5372 33 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 13 783 30 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 14 3031 36 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 15 6288 34 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 16 4392 32 MODIFIABLE RISK FACTORS IN PERIODONTAL DISEASE: EPIGENETIC REGULATION OF GENE EXPRESSION IN THE INFLAMMATORY RESPONSE. EPIGENETICS AS A MODIFIABLE RISK FACTOR IN PERIODONTAL DISEASES HAS BEEN INVESTIGATED IN LIGHT OF THE CURRENT KNOWLEDGE OF HOW CHRONIC INFECTION AND INFLAMMATION CAN AFFECT GENE-SPECIFIC EPIGENETIC REPROGRAMMING IN PERIODONTAL TISSUES. EPIGENOMIC PROGRAMMING MIGHT BE PARTICULARLY SENSITIVE TO ENVIRONMENTAL INFLUENCES, AND A COMBINATION OF PHYSIOLOGICAL STRESSORS AND ENVIRONMENTAL EXPOSURES APPEARS TO AFFECT THE EPIGENOMIC PROGRAM ACQUIRED BY A CELL DURING DIFFERENTIATION AND THROUGHOUT THE CELLULAR LINEAGE LIFESPAN. VIRAL AND BACTERIAL INFECTIONS CAN ESTABLISH SEVERAL TYPES OF EPIGENETIC MODIFICATIONS, WHICH SOMETIMES ENGAGE IN A COMPLEX EPIGENETIC CROSSTALK ALSO REFLECTING IN THE ESTABLISHMENT AND PROGRESS OF PERIODONTAL DISEASES. THE INFLAMMATORY AND METABOLIC STATES OF THE PERIODONTAL TISSUES ARE DRIVEN BY THE INFECTIOUS STIMULI, AND THE MAGNITUDE OF THE CELLULAR AND MOLECULAR SIGNATURE RESPONSE IS FURTHER DICTATED BY THE HOST GENETIC AND EPIGENETIC TRAITS ASSOCIATED WITH VARIOUS SYSTEMIC EXPOSURES, INCLUDING SMOKING, OBESITY AND DIABETES/HYPERGLYCEMIA. THIS REVIEW DISCUSSES THE ADVANCES IN EPIGENETICS, FOCUSING ON THE ROLE OF DNA METHYLATION IN THE PATHOGENESIS OF PERIODONTAL DISEASE AND THE POTENTIAL OF EPIGENETIC THERAPY. 2014 17 1136 33 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 18 1047 30 CLINICAL EFFECT AND BIOLOGICAL MECHANISM OF EXERCISE FOR RHEUMATOID ARTHRITIS: A MINI REVIEW. RHEUMATOID ARTHRITIS (RA) IS A COMMON SYSTEMATIC, CHRONIC INFLAMMATORY, AUTOIMMUNE, AND POLYARTICULAR DISEASE, CAUSING A RANGE OF CLINICAL MANIFESTATIONS, INCLUDING JOINT SWELLING, REDNESS, PAIN, STIFFNESS, FATIGUE, DECREASED QUALITY OF LIFE, PROGRESSIVE DISABILITY, CARDIOVASCULAR PROBLEMS, AND OTHER COMORBIDITIES. STRONG EVIDENCE HAS SHOWN THAT EXERCISE IS EFFECTIVE FOR RA TREATMENT IN VARIOUS CLINICAL DOMAINS. EXERCISE TRAINING FOR RELATIVELY LONGER PERIODS (E.G., >/= 12 WEEKS) CAN DECREASE DISEASE ACTIVITY OF RA. HOWEVER, THE MECHANISM UNDERLYING THE EFFECTIVENESS OF EXERCISE IN REDUCING RA DISEASE ACTIVITY REMAINS UNCLEAR. THIS REVIEW FIRST SUMMARIZES AND HIGHLIGHTS THE EFFECTIVENESS OF EXERCISE IN RA TREATMENT. THEN, WE INTEGRATE CURRENT EVIDENCE AND PROPOSE BIOLOGICAL MECHANISMS RESPONSIBLE FOR THE POTENTIAL EFFECTS OF EXERCISE ON IMMUNE CELLS AND IMMUNITY, INFLAMMATORY RESPONSE, MATRIX METALLOPROTEINASES, OXIDATIVE STRESS, AND EPIGENETIC REGULATION. HOWEVER, A LARGE BODY OF EVIDENCE WAS OBTAINED FROM THE NON-RA POPULATIONS. FUTURE STUDIES ARE NEEDED TO FURTHER EXAMINE THE PROPOSED BIOLOGICAL MECHANISMS RESPONSIBLE FOR THE EFFECTIVENESS OF EXERCISE IN DECREASING DISEASE ACTIVITY IN RA POPULATIONS. SUCH KNOWLEDGE WILL CONTRIBUTE TO THE BASIC SCIENCE AND STRENGTHEN THE SCIENTIFIC BASIS OF THE PRESCRIPTION OF EXERCISE THERAPY FOR RA IN THE CLINICAL ROUTINE. 2022 19 1565 29 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 20 4393 31 MODIFIABLE RISK FACTORS IN PERIODONTITIS: AT THE INTERSECTION OF AGING AND DISEASE. CHRONIC INFLAMMATION IS A PROMINENT FEATURE OF AGING AND OF COMMON AGE-RELATED DISEASES, INCLUDING ATHEROSCLEROSIS, CANCER AND PERIODONTITIS. THIS VOLUME EXAMINES MODIFIABLE RISK FACTORS FOR PERIODONTITIS AND OTHER CHRONIC INFLAMMATORY DISEASES. ORAL BACTERIAL COMMUNITIES AND VIRAL INFECTIONS, PARTICULARLY WITH CYTOMEGALOVIRUS AND OTHER HERPESVIRUSES, ELICIT DISTINCT IMMUNE RESPONSES AND ARE CENTRAL IN THE INITIATION OF PERIODONTAL DISEASES. RISK OF DISEASE IS DYNAMIC AND CHANGES IN RESPONSE TO COMPLEX INTERACTIONS OF GENETIC, ENVIRONMENTAL AND STOCHASTIC FACTORS OVER THE LIFESPAN. MANY MODIFIABLE RISK FACTORS, SUCH AS SMOKING AND EXCESS CALORIC INTAKE, CONTRIBUTE TO INCREASES IN SYSTEMIC MARKERS OF INFLAMMATION AND CAN MODIFY GENE REGULATION THROUGH A VARIETY OF BIOLOGIC MECHANISMS (E.G. EPIGENETIC MODIFICATIONS). PERIODONTITIS AND OTHER COMMON CHRONIC INFLAMMATORY DISEASES SHARE MULTIPLE MODIFIABLE RISK FACTORS, SUCH AS TOBACCO SMOKING, PSYCHOLOGICAL STRESS AND DEPRESSION, ALCOHOL CONSUMPTION, OBESITY, DIABETES, METABOLIC SYNDROME AND OSTEOPOROSIS. INTERVENTIONS THAT TARGET MODIFIABLE RISK FACTORS HAVE THE POTENTIAL TO IMPROVE RISK PROFILES FOR PERIODONTITIS AS WELL AS FOR OTHER COMMON CHRONIC DISEASES. 2014