1 555 98 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 2 3173 33 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 3 6289 38 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 4 4676 34 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 5 4319 25 MICRORNAS IN AXIAL SPONDYLARTHRITIS: AN OVERVIEW OF THE RECENT PROGRESSES IN THE FIELD WITH A FOCUS ON ANKYLOSING SPONDYLITIS AND PSORIATIC ARTHRITIS. PURPOSE OF REVIEW: TO HIGHLIGHT THE RECENT DISCOVERIES AND LINES OF EVIDENCE ON THE ROLE OF MICRORNAS IN ANKYLOSING SPONDYLITIS (AS) AND PSORIATIC ARTHRITIS (PSA), FOCUSING ON THEIR EXPRESSION PROFILING AND MECHANISMS OF ACTION. RECENT FINDINGS: AS AND PSA ARE CHRONIC INFLAMMATORY MUSCULOSKELETAL DISEASES WITH AXIAL MANIFESTATIONS AND REPRESENT AN EXCELLENT MODEL FOR STUDYING MICRORNAS CONTRIBUTION TO THE DISEASE PATHOGENESIS, PARTICULARLY THROUGH IMMUNOMODULATION, INFLAMMATION, AND BONE REMODELLING, OR THEIR VALUE AS CANDIDATE DIAGNOSTIC AND PROGNOSTIC BIOMARKERS. MICRORNAS ARE SINGLE-STRANDED NUCLEOTIDES ABLE TO REGULATE GENE EXPRESSION. THEY ARE A KEY COMPONENT OF THE EPIGENETIC MACHINERY, INVOLVED IN PHYSIOLOGICAL AND PATHOLOGICAL PROCESSES. THE CONTRIBUTION OF MICRORNAS IN AS AND PSA (SUCH AS MIR-29A IN REGULATING BONE METABOLISM) IS HIGHLIGHTED BY SEVERAL WORKS IN THE FIELD BUT THEIR UTILITY AS POSSIBLE MARKERS MUST BE STILL CONFIRMED, PARTICULARLY IN LARGER PATIENTS' COHORTS. 2021 6 3033 39 GENETICS, EPIGENETICS, AND GENDER IMPACT IN AXIAL-SPONDYLOARTHRITIS SUSCEPTIBILITY: AN UPDATE ON GENETIC POLYMORPHISMS AND THEIR SEX RELATED ASSOCIATIONS. SPONDYLOARTHRITIS (SPA) IS A GROUP OF CHRONIC INFLAMMATORY RHEUMATIC DISEASE THAT CAN BE DIVIDED INTO PREDOMINANTLY AXIAL OR PREDOMINANTLY PERIPHERAL INVOLVEMENT, WITH OR WITHOUT ASSOCIATED PSORIASIS, INFLAMMATORY BOWEL DISEASE OR PREVIOUS INFECTION. AXIAL SPA (AXSPA) ENCOMPASSES ANKYLOSING SPONDYLITIS (AS) WITH RADIOLOGICAL SACROILIITIS, AND A TYPE WITHOUT RADIOGRAPHIC SACROILIITIS, CALLED "NON-RADIOGRAPHIC AXIAL SPA" (NR-AXSPA). MALES AND FEMALES SHOW LARGE DIFFERENCES IN THEIR SUSCEPTIBILITY TO SPA, SUCH AS DISTINCTIONS IN CLINICAL PATTERNS, PHENOTYPES AND IN THERAPEUTICAL RESPONSE, PARTICULARLY TO TNF INHIBITORS (TNFI). SEVERAL STUDIES INDICATE THAT AS WOMEN HAVE DOUBLED RISK TO FAILURE TNFI COMPARED WITH MALES. THIS DIVERSITY IN DRUGS' EFFICACY AMONG WOMEN AND MEN MAY BE CAUSED BY DIFFERENCES IN THE BALANCE OF SEX HORMONES AND IN GENE-SPECIFIC EXPRESSION LIKELY TRIGGERED BY X-CHROMOSOME INSTABILITY AND GENE-SPECIFIC EPIGENETIC MODIFICATIONS. EVIDENCE REPORTED THAT POLYMORPHISMS IN MICRORNAS ON X- AND OTHER CHROMOSOMES, SUCH AS MIR-146A, MIR-155, MIR-125A-5P, MIR-151A-3P AND MIR-22-3P, MIR-199A-5P COULD BE INVOLVED IN THE DIFFERENT CLINICAL PRESENTATION OF SPA, AS WELL AS DISEASE ACTIVITY. IN ADDITION, ASSOCIATION WITH NON-RESPONSE TO TNFI TREATMENT AND PRESENCE OF IRAK3 AND CHUCK GENES IN SPA PATIENTS WAS RECENTLY DETECTED. FINALLY, POLYMORPHISMS IN GENES INVOLVED IN IL-23/IL-17 PATHWAY, SUCH AS IN DRUG PHARMACODYNAMICS AND PHARMACOKINETICS MAY HAVE A ROLE IN RESPONSE TO TNFI, IL17I, AND IL23I. A MAJOR UNDERSTANDING OF GENOMIC VARIABILITY COULD HELP IN THE DEVELOPMENT OF NEW THERAPEUTIC TARGETS OR IN TAKING ADVANTAGES OF DIFFERENT MECHANISMS OF ACTION OF BIOLOGICAL DRUGS. MOVING FROM THE MULTIFACTORIAL ETIOLOGY OF DISEASE, THE PRESENT REVIEW AIMS AT EVALUATING GENETIC AND EPIGENETIC FACTORS AND THEIR RELATIONSHIP WITH SEX AND BDMARDS RESPONSE, HELPING TO INVESTIGATE THE DIFFERENT EXPRESSION AMONG MALES AND FEMALES OF GENES ON X- AND OTHER CHROMOSOMES, AS WELL AS MI-RNA, TO HIGHLIGHT RELATIONSHIPS BETWEEN SEX AND OCCURRENCE OF SPECIFIC PHENOTYPES AND SYMPTOMS OF THE DISEASE. MOREOVER, THE ROLE OF THE EPIGENETIC MODIFICATION IN RELATION TO IMMUNE-REGULATORY MECHANISMS WILL BE EVALUATED. 2021 7 2989 35 GENETIC FACTORS INVOLVED IN THE CO?OCCURRENCE OF ENDOMETRIOSIS WITH ANKYLOSING SPONDYLITIS (REVIEW). PREVIOUS RESEARCH HAS REVEALED AN ASSOCIATION BETWEEN ENDOMETRIOSIS AND VARIOUS AUTOIMMUNE DISEASES, WHILE RECENT DATA SUGGEST, FOR THE FIRST TIME, AN ASSOCIATION BETWEEN ENDOMETRIOSIS AND THE RISK OF DEVELOPING ANKYLOSING SPONDYLITIS (AS). AS, THE PROTOTYPE OF SPONDYLOARTHRITIDES DISEASES, IS A SYSTEMIC, CHRONIC, IMMUNE?MEDIATED INFLAMMATORY ARTHRITIS, WHICH PRIMARILY AFFECTS THE SPINE AND SACROILIAC JOINTS, AS WELL AS THE AXIAL SKELETON WITH OR WITHOUT EXTRASPINAL MANIFESTATIONS. AS IS OF POLYGENIC INHERITANCE AND NUMEROUS IMMUNOLOGICALLY RELEVANT GENES CONTRIBUTE TO ITS DEVELOPMENT. ENDOMETRIOSIS IS AN ENIGMATIC, RELATIVELY COMMON, BENIGN, ESTROGEN?DEPENDENT, HETEROGENEOUS GYNECOLOGICAL DISEASE, INFLUENCED BY MULTIPLE GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. IT IS CHARACTERIZED BY THE GROWTH OF ENDOMETRIAL TISSUE OCCURRING IN SITES OTHER THAN THE UTERINE CAVITY, MOST COMMONLY IN THE PELVIC CAVITY, INCLUDING THE OVARIES AND THE UTEROSACRAL LIGAMENTS, AFFECTING UP TO 10% OF THE FEMALE POPULATION OF CHILDBEARING AGE, CAUSING PAIN AND INFERTILITY. THE PRESENT REVIEW DISCUSSES WHETHER A PARTIALLY SHARED GENETIC BACKGROUND MAY EXPLAIN THE CO?OCCURRENCE OF THESE DISORDERS, AS WELL AS POTENTIAL SIMILARITIES REGARDING THE UNDERLYING PATHOGENETIC MECHANISMS AND SPECIFIC MOLECULAR AND CELLULAR PATHWAYS. 2023 8 986 31 CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS (CRMO) AND JUVENILE SPONDYLOARTHRITIS (JSPA): TO WHAT EXTENT ARE THEY RELATED? CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS (CRMO) IS AN AUTOINFLAMMATORY DISEASE OCCURRING MAINLY IN THE PEDIATRIC AGE GROUP (BEFORE 16 YEARS) AND GENERALLY PRESENTS AS A SEPARATE ENTITY. SYNOVITIS, ACNE, PUSTULOSIS, HYPEROSTOSIS AND OSTEITIS (SAPHO) SYNDROME COMBINES OSTEOARTICULAR AND CUTANEOUS INVOLVEMENT, SIMILAR TO CRMO, AND FALLS INTO THE SPECTRUM OF SPONDYLOARTHRITIS (SPA). THE FACT THAT A PATIENT CAN PROGRESS FROM ONE DISEASE TO ANOTHER RAISES THE QUESTION OF WHETHER CRMO, LIKE SAPHO, COULD FALL WITHIN THE SPECTRUM OF SPA, RANGING FROM A PREDOMINANTLY OSTEOARTICULAR FORM TO AN ENTHESITIC FORM WITH MORE OR LESS MARKED SKIN INVOLVEMENT. IN THIS REVIEW, WE SET OUT TO DISCUSS THIS HYPOTHESIS BY HIGHLIGHTING THE DIFFERENCES AND SIMILARITIES BETWEEN CRMO AND JUVENILE SPA IN CLINICAL, RADIOLOGICAL AND PATHOPHYSIOLOGICAL ASPECTS. A COMMON HYPOTHESIS COULD POTENTIALLY CONSIDER INTESTINAL DYSBIOSIS AS THE ORIGIN OF THESE DIFFERENT INFLAMMATORY DISEASES. INTERINDIVIDUAL FACTORS SUCH AS GENDER, ENVIRONMENT, GENETICS AND/OR EPIGENETIC BACKGROUND COULD ACT AS COMBINED DISEASE MODIFIERS. THIS IS WHY WE SUGGEST THAT PATHOPHYSIOLOGY, RATHER THAN CLINICAL PHENOTYPE, BE USED TO RECLASSIFY THESE DISEASES. 2023 9 3057 29 GENOME-WIDE DNA METHYLATION ANALYSIS IN ANKYLOSING SPONDYLITIS IDENTIFIES HLA-B*27 DEPENDENT AND INDEPENDENT DNA METHYLATION CHANGES IN WHOLE BLOOD. BACKGROUND AND OBJECTIVE: ANKYLOSING SPONDYLITIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY INFLAMMATION OF THE SACROILIAC JOINTS AND THE SPINE THAT CAN LEAD TO SIGNIFICANT PAIN, IMMOBILITY, AND DISABILITY. THE ETIOLOGY AND PATHOGENESIS OF ANKYLOSING SPONDYLITIS ARE INCOMPLETELY UNDERSTOOD, THOUGH MOST PATIENTS CARRY THE HLA-B*27 ALLELE. THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE DNA METHYLATION CHANGES IN ANKYLOSING SPONDYLITIS WITH THE GOAL OF REVEALING NOVEL MECHANISTIC INSIGHTS INTO THIS DISEASE. METHODS: GENOME-WIDE DNA METHYLATION ANALYSIS WAS PERFORMED IN WHOLE BLOOD DNA SAMPLES USING THE INFINIUM METHYLATIONEPIC ARRAY IN PATIENTS WITH ANKYLOSING SPONDYLITIS COMPARED TO AGE, SEX, AND RACE MATCHED PATIENTS WITH OSTEOARTHRITIS AS A NON-INFLAMMATORY DISEASE CONTROL. WE STUDIED 24 PATIENTS WITH ANKYLOSING SPONDYLITIS, INCLUDING 12 PATIENTS WHO CARRY HLA-B*27 AND 12 PATIENTS WHO ARE HLA-B*27 NEGATIVE. DNA METHYLATION ANALYSIS WAS PERFORMED WITH ADJUSTMENT FOR BLOOD CELL COMPOSITION IN EACH SAMPLE. RESULTS: WE IDENTIFIED A TOTAL OF 67 DIFFERENTIALLY METHYLATED SITES BETWEEN ANKYLOSING SPONDYLITIS PATIENTS AND OSTEOARTHRITIS CONTROLS. HYPERMETHYLATED GENES FOUND INCLUDED GTPASE-RELATED GENES, WHILE HYPOMETHYLATED GENES INCLUDED HCP5, WHICH ENCODES A LNCRNA WITHIN THE MHC REGION, PREVIOUSLY ASSOCIATED WITH GENETIC RISK FOR PSORIASIS AND TOXIC EPIDERMAL NECROLYSIS. CARRYING HLA-B*27 WAS ASSOCIATED WITH ROBUST HYPOMETHYLATION OF HCP5, TUBULIN FOLDING COFACTOR A (TBCA) AND PHOSPHOLIPASE D FAMILY MEMBER 6 (PLD6) IN ANKYLOSING SPONDYLITIS PATIENTS. HYPOMETHYLATION WITHIN HCP5 INVOLVES A CPG SITE THAT CONTAINS A SINGLE NUCLEOTIDE POLYMORPHISM IN LINKAGE DISEQUILIBRIUM WITH HLA-B*27 AND THAT CONTROLS DNA METHYLATION AT THIS LOCUS IN AN ALLELE-SPECIFIC MANNER. CONCLUSIONS: A GENOME-WIDE DNA METHYLATION ANALYSIS IN ANKYLOSING SPONDYLITIS IDENTIFIED DNA METHYLATION PATTERNS THAT COULD PROVIDE POTENTIAL NOVEL INSIGHTS INTO THIS DISEASE. OUR FINDINGS SUGGEST THAT HLA-B*27 MIGHT PLAY A ROLE IN ANKYLOSING SPONDYLITIS IN PART THROUGH INDUCING EPIGENETIC DYSREGULATION. 2019 10 2569 30 EPIGENETICS OF ANKYLOSING SPONDYLITIS: RECENT DEVELOPMENTS. ANKYLOSING SPONDYLITIS (AS) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE WHICH MAINLY AFFECTS THE SPINE, SACROILIAC JOINT AND PERIPHERAL JOINTS. TO DATE, THE EXACT CAUSES AND PATHOGENESIS OF AS STILL REMAIN UNKNOWN. IT IS CONSIDERED THAT THE PATHOGENESIS OF AS IS ASSOCIATED WITH GENETIC, INFECTION, ENVIRONMENT, IMMUNITY AND OTHER FACTORS. AMONG THEM, THE ROLE OF GENETIC FACTORS IN THE PATHOGENESIS OF AS HAS BEEN STUDIED MOST DEEPLY. HOWEVER, OVER THE PAST FEW YEARS, THE FUNCTION OF ENVIRONMENTAL PREDISPOSITION AND EPIGENETIC MODIFICATION IN THE PATHOGENESIS OF AS HAS RECEIVED EXTENSIVE ATTENTION. THIS PAPER SUMMARIZES THE RECENT PROGRESS IN THE EPIGENETICS OF AS, INCLUDING ABNORMAL EPIGENETIC MODIFICATIONS AT AS-ASSOCIATED GENOMIC LOCI, SUCH AS DNA METHYLATION, HISTONE MODIFICATION, MICRORNA, AND SO ON. IN SUMMARY, THE FINDINGS OF THIS REVIEW ATTEMPT TO EXPLAIN THE ROLE OF EPIGENETIC MODIFICATION IN THE OCCURRENCE AND DEVELOPMENT OF AS. NEVERTHELESS, THERE ARE STILL UNKNOWN AND COMPLICATED ASPECTS WORTH EXPLORING TO DEEPEN OUR UNDERSTANDING OF THE PATHOGENESIS OF AS. 2021 11 5655 33 SEX-BASED MEDICINE MEETS PSORIATIC ARTHRITIS: LESSONS LEARNED AND TO LEARN. HUMORALLY ASSOCIATED AUTOIMMUNE DISEASES GENERALLY SHOW A FEMALE PREDOMINANCE WHEREAS ANKYLOSING SPONDYLITIS, A DISEASE THAT OVERLAPS WITH PSORIATIC ARTHRITIS (PSA), SHOWS A MALE PREDOMINANCE. THE PRESENT REVIEW ASCERTAINS THE CURRENT KNOWLEDGE OF SEX-SPECIFIC DIFFERENCES RELATED TO PSORIATIC ARTHRITIS (PSA), A CHRONIC, INFLAMMATORY CONDITION ASSOCIATED WITH PSORIASIS. SEX DIFFERENCES MAY HAVE IMPORTANT IMPLICATIONS FOR CLINICAL RESEARCH IN PSA AND IN TERMS OF EPIDEMIOLOGY (INCIDENCE, PREVALENCE, LIFETIME RISK, SURVIVAL, AND MORTALITY), CLINICAL, RADIOLOGICAL, AND LABORATORY FEATURES, AND RESPONSE TO TREATMENT. WHILE NATIONWIDE SURVEYS AND LARGE-SCALE DATABASES AND REGISTRIES SHOW NO SEX-SPECIFIC DIFFERENCES, VARYING MALE/FEMALE RATIOS HAVE BEEN REPORTED, RANGING FROM 0.42 TO 2.75 (COMPARABLE WITH THOSE REPORTED FOR PSORIASIS VULGARIS: RANGING FROM 0.28 TO 2.38). THIS MAY REFLECT SUBTLE, COMPLEX, NONLINEAR INTERACTIONS BETWEEN THE BIOLOGICAL MAKE-UP OF THE INDIVIDUAL (GENETIC AND EPIGENETIC DIFFERENCES), HORMONAL COMPONENTS INCLUDING MENOPAUSAL STATUS, ENVIRONMENTAL EXPOSURES INCLUDING SKELETAL PHYSICAL STRESSING, AND PSYCHOLOGICAL VARIABLES. THERE EXISTS METHODOLOGICAL HETEROGENEITY AND PAUCITY OF DATA CONCERNING SEX-SPECIFIC DIFFERENCES, IN TERMS OF THE SPECIFIC POPULATION STUDIED, STUDY DESIGN, AND THE DIAGNOSTIC CRITERIA UTILIZED. HARMONIZING AND RECONCILING THESE DISCREPANCIES WOULD BE OF CRUCIAL IMPORTANCE IN ACHIEVING THE AMBITIOUS GOALS OF PERSONALIZED/INDIVIDUALIZED MEDICINE AND FURTHER STANDARDIZED META-DATA AND BIG DATA COULD HELP DISENTANGLE AND ELUCIDATE THE PRECISE MECHANISMS OF UNDERLYING POTENTIAL PSA SEX-SPECIFIC DIFFERENCES. 2022 12 4962 34 PATHOGENESIS OF PSORIATIC ARTHRITIS. PSORIATIC ARTHRITIS (PSA) IS A CHRONIC INFLAMMATORY ARTHROPATHY INVOLVING SYNOVIAL AND ENTHESEAL STRUCTURES, ASSOCIATED WITH PSORIASIS OR SIMILAR CONDITIONS. THE ETIOPATHOGENETIC MECHANISMS UNDERLYING PSA REMAIN UNCLARIFIED. THE MOST ACCREDITED HYPOTHESIS INVOLVES A COMPLEX INTERACTION AMONG GENETIC, ENVIRONMENTAL, AND IMMUNOLOGICAL FACTORS. ENVIRONMENTAL AGENTS, PARTICULARLY TRAUMA, MECHANICAL STRESS, AND SMOKE HAVE BEEN CITED AS POSSIBLE FACTORS IN TRIGGERING THE DISEASE IN GENETICALLY PREDISPOSED SUBJECTS. LIKE OTHER FORMS OF SPONDYLOARTHROPATHIES, PSA SHOWS SEVERAL GENETIC ASSOCIATIONS WITH THE MAJOR HISTOCOMPATIBILITY COMPLEX (MHC) CLASS I ALLELES LOCATED ON CHROMOSOME 6P21.3, PARTICULARLY THE HUMAN LEUKOCYTE ANTIGEN (HLA)-B27 IN AXIAL PHENOTYPES. RECENT STUDIES HAVE DEMONSTRATED THAT THE MOST COMMON EPIGENETIC MECHANISMS THAT REGULATE GENE EXPRESSION IN PSA ARE REPRESENTED BY DNA METHYLATION, PARENT OF ORIGIN EFFECT OR GENOMIC IMPRINTING, EXPRESSION OR ACTIVITY OF EPIGENETIC MODIFYING ENZYMES, AND RNA INTERFERENCE (RNAI) BY MICRORNAS (MIRNAS). THE MECHANISMS UNDERLYING PSA PATHOGENESIS ACTIVATE THE INNATE AND ADAPTIVE IMMUNE SYSTEM AND OVEREXPRESSION OF TNF ASSOCIATED WITH AMPLIFICATION OF THE IL-23/IL-17 AXIS. IN RECENT YEARS, MORE PSA SUSCEPTIBILITY GENES AND EPIGENETIC MECHANISMS HAVE BEEN IDENTIFIED. ADVANCES IN THE KNOWLEDGE OF INNATE AND ADAPTIVE IMMUNE MECHANISMS UNDERLYING PSA HAVE CONTRIBUTED TO A BETTER UNDERSTANDING OF THE HETEROGENEOUS CLINICAL EXPRESSION OF THE DISEASE AND, THUS, TO THERAPY STRATEGIES. THE COMPLEXITY OF THE PATHOGENETIC ASPECTS INVOLVING MULTIPLE CYTOKINES, CELL LINES, AND MOLECULES NEEDS TO BE FURTHER INVESTIGATED TO ADVANCE PERSONALIZED THERAPEUTIC STRATEGIES AND TO IMPROVE OUTCOMES OF PATIENTS AFFECTED BY PSA. 2019 13 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 14 4318 27 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 15 2979 23 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 16 2595 35 EPIGENETICS OF SPONDYLOARTHRITIS. SPONDYLOARTHRITIS (SPA) IS A CHRONIC INFLAMMATORY DISORDER RESULTING FROM A COMBINATION OF GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. DESPITE RECENT ADVANCES, A SUBSTANTIAL FRACTION OF ITS GENETIC BASIS REMAINS POORLY UNDERSTOOD. SEVERAL MECHANISMS HAVE BEEN PROPOSED TO ACCOUNT FOR THIS UNEXPLAINED HERITABILITY, INCLUDING EPIGENETICS WHICH CAN PLAY A ROLE AT THE INTERFACE BETWEEN GENETIC AND ENVIRONMENTAL SUSCEPTIBILITY FACTORS. EPIGENETICS REFERS TO CHANGES IN GENE EXPRESSION THAT ARE NOT ENCODED IN THE DNA SEQUENCE ITSELF. SUCH MECHANISMS MAY INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS. DISRUPTION OF ONE OF THESE SYSTEMS CAN LEAD TO INAPPROPRIATE GENE EXPRESSION, WHICH IN TURN MIGHT FAVOUR THE DEVELOPMENT OF DISEASE. THANKS TO RECENT TECHNOLOGICAL PROGRESS, THERE HAS BEEN A GROWING INTEREST IN THE FIELD OF EPIGENETICS IN COMPLEX DISEASES, INCLUDING SPA. HOWEVER, EPIGENETIC STUDIES FACE SOME METHODOLOGICAL LIMITATIONS THAT HAMPER INTERPRETATION OF THEIR RESULTS: SMALL SAMPLE SIZE, ABSENCE OF BIOLOGICAL REPLICATION, LACK OF ADEQUATE CONTROLS FOR POTENTIAL CONFOUNDERS, STUDIES NOT PERFORMED IN THE MOST RELEVANT CELL/TISSUES. IN THE FUTURE, INTEGRATION OF EPIGENETICS WITH OTHER "OMICS" DATA WILL PROBABLY BE NECESSARY TO IMPROVE OUR UNDERSTANDING OF SPA PATHOGENESIS. THESE ISSUES NEED TO BE ADDRESSED BEFORE CONSIDERING THE USE OF EPIGENETIC MARKS IN CLINICAL ROUTINE, AS BIOMARKERS OR AS DRUG TARGETS. 2020 17 6787 24 [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 18 302 36 AIR POLLUTION EXPOSURE AND AUTO-INFLAMMATORY AND AUTOIMMUNE DISEASES OF THE MUSCULOSKELETAL SYSTEM: A REVIEW OF EPIDEMIOLOGIC AND MECHANISTIC EVIDENCE. AUTO-INFLAMMATORY AND AUTOIMMUNE DISEASES OF THE MUSCULOSKELETAL SYSTEM CAN BE PERCEIVED AS A SPECTRUM OF RHEUMATIC DISEASES, WITH THE JOINTS AND CONNECTIVE TISSUES ARE ERODED SEVERELY THAT PROGRESSIVELY DEVELOP CHRONIC INFLAMMATION AND LESION. A WIDE RANGE OF RISK FACTORS REPRESENTED BY GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN UNCOVERED BY POPULATION-BASED SURVEYS AND EXPERIMENTAL STUDIES. LATELY, THE EXPOSURE TO AIR POLLUTION HAS BEEN FOUND TO BE POTENTIALLY INVOLVED IN THE MECHANISMS OF OCCURRENCE OR DEVELOPMENT OF SUCH DISEASES, PRINCIPALLY MANIFEST IN OXIDATIVE STRESS, LOCAL AND SYSTEMIC INFLAMMATION, AND EPIGENETIC MODIFICATIONS, AS WELL AS THE MITOCHONDRIAL DYSFUNCTION, WHICH HAS BEEN REPORTED TO PARTICIPATE IN THE INTERMEDIATE LINKS. THE LUNGS MIGHT SERVE AS A STARTING AREA OF AIR POLLUTANTS, WHICH WOULD CAUSE OXIDATIVE STRESS-INDUCED BRONCHIAL-ASSOCIATED LYMPHOID TISSUE (IBALT) TO FURTHER TO INFLUENCE T, B CELLS, AND THE SECRETION OF PRO-INFLAMMATORY CYTOKINES. THE BINDING OF AROMATIC HYDROCARBON RECEPTOR (AHR) TO THE CORRESPONDING CONTAMINANT LIGANDS TENDS TO REGULATE THE REACTION OF TH17 AND TREGS. FURTHERMORE, AIR POLLUTION COMPONENTS MIGHT SPUR ON IMMUNE AND INFLAMMATORY RESPONSES BY DAMAGING MITOCHONDRIA THAT COULD INTERACT WITH AND EXACERBATE OXIDATIVE STRESS AND PRO-INFLAMMATORY CYTOKINES. IN THIS REVIEW, WE FOCUSED ON THE ASSOCIATION BETWEEN AIR POLLUTION AND TYPICAL AUTO-INFLAMMATORY AND AUTOIMMUNE DISEASES OF THE MUSCULOSKELETAL SYSTEM, MAINLY INCLUDING OSTEOARTHRITIS (OA), RHEUMATOID ARTHRITIS (RA), SPONDYLOARTHRITIS (SPA) AND JUVENILE IDIOPATHIC ARTHRITIS (JIA), AND AIM TO COLLATE THE MECHANISMS INVOLVED AND THE POTENTIAL CHANNELS. A COMPLETE SUMMARY AND IN-DEPTH UNDERSTANDING OF THE AUTOIMMUNE AND INFLAMMATORY EFFECTS OF AIR POLLUTION EXPOSURE SHOULD HOPEFULLY CONTRIBUTE NEW PERSPECTIVES ON HOW TO FORMULATE BETTER PUBLIC HEALTH POLICIES TO ALLEVIATE THE ADVERSE HEALTH EFFECTS OF AIR POLLUTANTS. 2023 19 6152 24 THE FUNCTION OF NCRNAS IN RHEUMATIC DISEASES. RHEUMATIC DISEASES ARE A GROUP OF CHRONIC HETEROGENEOUS AUTOIMMUNE DISORDERS CHARACTERIZED BY ABNORMAL REGULATION OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS. DESPITE EXTENSIVE EFFORTS, THE FULL SPECTRUM OF MOLECULAR FACTORS THAT CONTRIBUTE TO THE PATHOGENESIS OF RHEUMATIC DISEASES REMAINS UNCLEAR. NCRNAS CAN GOVERN GENE EXPRESSION AT THE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL LEVELS IN MULTIPLE DISEASES. RECENT STUDIES HAVE DEMONSTRATED AN IMPORTANT ROLE FOR NCRNAS, SUCH AS MIRNAS AND LNCRNAS, IN THE DEVELOPMENT OF IMMUNE CELLS AND RHEUMATIC DISEASES. HERE, WE FOCUS ON THE EPIGENETIC REGULATORY ROLES OF NCRNAS IN THE PATHOGENESIS OF RHEUMATIC DISEASES AND AS BIOMARKERS OF DISEASE STATE. 2019 20 5002 27 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