1 630 76 BIOLOGICAL AND MECHANICAL FACTORS AND EPIGENETIC REGULATION INVOLVED IN TENDON HEALING. TENDONS ARE AN IMPORTANT PART OF THE MUSCULOSKELETAL SYSTEM. CONNECTING MUSCLES TO BONES, TENDONS CONVERT FORCE INTO MOVEMENT. TENDON INJURY CAN BE ACUTE OR CHRONIC. NOTICEABLY, TENDON HEALING REQUIRES A LONG TIME SPAN AND INCLUDES INFLAMMATION, PROLIFERATION, AND REMODELING PROCESSES. THE MISMATCH BETWEEN ENDOGENOUS AND EXOGENOUS HEALING MAY LEAD TO ADHESION CAUSING FURTHER NEGATIVE EFFECTS. MANAGEMENT OF TENDON INJURIES AND COMPLICATIONS SUCH AS SUBSEQUENT ADHESION FORMATION ARE STILL CHALLENGES FOR CLINICIANS. DUE TO NUMEROUS FACTORS, TENDON HEALING IS A COMPLEX PROCESS. THIS REVIEW INTRODUCES THE ROLE OF VARIOUS BIOLOGICAL AND MECHANICAL FACTORS AND EPIGENETIC REGULATION PROCESSES INVOLVED IN TENDON HEALING. 2023 2 6869 22 [PATHOGENESIS OF RHEUMATOID ARTHRITIS]. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE SYSTEMIC DISEASE THAT PRIMARILY AFFECTS JOINTS. ETIOLOGY AND THE PATHOGENESIS OF RA ARE COMPLEX, INVOLVING MANY TYPES OF CELLS, AMONG OTHERS MACROPHAGES, T AND B CELLS, FIBRO- BLASTS, CHONDROCYTES AND DENDRITIC CELLS. DESPITE WELL DOCUMENTED ROLE OF MANY GENES AND EPIGENETIC MODIFICATIONS IN THE DEVELOPMENT AND EVOLUTION OF THE DISEASE, IN MOST RA PATIENTS THERE IS NO CLEAR PREDISPOSING FACTOR PRESENT. ENVIRONMENTAL FACTORS INVOLVED IN RA PATHOGENESIS ARE CIGARETTE SMOKE, INDUSTRIAL POLLUTANTS LIKE SILICA CRYSTALS, DISTURBANCES OF INTESTINAL, LUNG, AND ORAL MICROBIOTA AND SOME SPECIFIC BACTERIAL AND VIRAL INFECTIOUS AGENTS AND THEIR COMPONENTS. IN THE INITIAL DISEASE STAGE THERE ARE QUALITATIVE AND QUANTITATIVE DISTURBANCES OFPEPTIDE CITRULINATION AS WELL AS OTHER PROTEIN MODIFICATIONS, FOLLOWED BY ANTIGEN PRESENTING CELL (APC) (MACROPHAGES AND DENDRITIC CELLS) AND FIBROBLAST LIKE SYNOVIOCYTES (FLS) ACTIVATION. SOME MICROBES FOSTER THIS PROCESSES BY APC AND FLS DIRECT AND INDIRECT ACTIVATION. IN THE SECOND STAGE APC'S ELICIT SPECIFIC HUMORAL B CELL RE- SPONSE RESULTING IN SPECIFIC ANTIBODIES PRODUCTION AND T CELL AUTOREACTIVITY. INHERITED AND ACQUIRED DEFECTS IN T AND B CELL RESPONSES CAUSED BY REPEATED ACTIVATION OF INNATE IMMUNITY AS WELL AS LOSS OF TOLERANCE, ELICIT CHRONIC AUTOIMMUNE INFLAMMATION, PRIMARILY OF SYNOVIAL MEMBRANES, AND DEVELOPMENT OF CELLULAR PANUS. PATHOLOGIC ACTIVATION OF THE OSTEOCLASTS AND RELEASE OF THE IMMUNE SYSTEM EFFECTOR MOLECULES AND THE PROTEOLYTIC ENZYMES DAMAGE THE CARTILAGE, BONE AND TENDONS COMPOSITION AND STRUCTURE. PERSISTENT INFLAMMATION THROUGH ITS COMPLEX MECHANISMS RESULTS IN MANY SYSTEMIC AND EXTRAARTICULAR RA MANIFESTATIONS OF ALMOST ALL ORGAN SYSTEMS, RESULTING IN SEVERE COMPLICATIONS AND COMORBIDITIES SUCH AS RHEUMATOID LUNG, CARDITIS, VASCULITIS, CAHEXIA, ANEMIA, ACCELERATED ATHEROSCLEROSIS, MYOCARDIAL AND CEREBROVASCULAR VASCULAR DISEASE, LYMPHOMA, OSTEOPOROSIS, DEPRESSION ETC. ACCUMULATED COMPLICATIONS AND COMORBIDITIES FINALLY RESULT IN HANDICAP, SOCIAL DYSFUNCTION AND PREMATURE DEATH. 2014 3 6741 16 WHERE TO STAND WITH STROMAL CELLS AND CHRONIC SYNOVITIS IN RHEUMATOID ARTHRITIS? THE SYNOVIUM EXERCISES ITS MAIN FUNCTION IN JOINT HOMEOSTASIS THROUGH THE SECRETION OF FACTORS (SUCH AS LUBRICIN AND HYALURONIC ACID) THAT ARE CRITICAL FOR THE JOINT LUBRICATION AND FUNCTION. THE MAIN SYNOVIUM CELL COMPONENTS ARE FIBROBLAST-LIKE SYNOVIOCYTES, MESENCHYMAL STROMAL/STEM CELLS AND MACROPHAGE-LIKE SYNOVIAL CELLS. IN THE SYNOVIUM, CELLS OF MESENCHYMAL ORIGIN MODULATE LOCAL INFLAMMATION AND FIBROSIS, AND INTERACT WITH DIFFERENT FIBROBLAST SUBTYPES AND WITH RESIDENT MACROPHAGES. IN PATHOLOGIC CONDITIONS, SUCH AS RHEUMATOID ARTHRITIS, FIBROBLAST-LIKE SYNOVIOCYTES PROLIFERATE ABNORMALLY, RECRUIT MESENCHYMAL STEM CELLS FROM SUBCHONDRAL BONE MARROW, AND INFLUENCE IMMUNE CELL ACTIVITY THROUGH EPIGENETIC AND METABOLIC ADAPTATIONS. THE RESULTING SYNOVIAL HYPERPLASIA LEADS TO SECONDARY CARTILAGE DESTRUCTION, JOINT SWELLING, AND PAIN. IN THE PRESENT REVIEW, WE SUMMARIZE RECENT FINDINGS ON THE MOLECULAR SIGNATURE AND THE ROLES OF STROMAL CELLS DURING SYNOVIAL PANNUS FORMATION AND RHEUMATOID ARTHRITIS PROGRESSION. 2019 4 6218 22 THE JOINT SYNOVIUM: A CRITICAL DETERMINANT OF ARTICULAR CARTILAGE FATE IN INFLAMMATORY JOINT DISEASES. THE SYNOVIUM CONSTITUTES THE ENVELOPE OF ARTICULAR JOINTS AND IS A CRITICAL PROVIDER OF SYNOVIAL FLUID COMPONENTS AND ARTICULAR CARTILAGE NUTRIENTS. ITS INFLAMMATION IS A PREDOMINANT FEATURE AND CAUSE OF JOINT DEGENERATION IN DISEASES AS DIVERSE AS RHEUMATOID, PSORIATIC, JUVENILE AND IDIOPATHIC ARTHRITIS, AND LUPUS, GOUT AND LYME DISEASE. THESE INFLAMMATORY JOINT DISEASES (IJDS) ARE DUE TO A WIDE VARIETY OF GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS THAT TRIGGER, PROMOTE, AND PERPETUATE JOINT DESTABILIZATION. IN SPITE OF THIS VARIETY OF CAUSES, IJDS SHARE MAIN PATHOLOGICAL FEATURES, NAMELY INFLAMMATION OF THE JOINT SYNOVIUM (SYNOVITIS) AND PROGRESSIVE DEGENERATION OF ARTICULAR CARTILAGE. IN ADDITION TO BEING A DRIVING FORCE BEHIND THE DESTRUCTION OF ARTICULAR CARTILAGE IN IJD, SYNOVITIS IS ALSO INCREASINGLY BEING RECOGNIZED AS A SIGNIFICANT CONTRIBUTOR OF ARTICULAR CARTILAGE DEGENERATION IN OSTEOARTHRITIS, A DISEASE PRIMARILY DUE TO AGING- OR TRAUMA-RELATED WEAR AND TEAR OF CARTILAGE SURFACES. IN VIEW OF THIS IMPORTANT ROLE OF THE SYNOVIUM IN DETERMINING THE FATE OF ARTICULAR CARTILAGE, THIS REVIEW FOCUSES ON ITS UNDERLYING MECHANISMS IN THE PATHOLOGY OF IJD. WE ADDRESS THE ROLES OF SYNOVIAL FIBROBLASTS, MACROPHAGES AND ENDOTHELIAL CELLS IN THE MAINTENANCE OF JOINT HEALTH AND IN THE DESTRUCTION OF ARTICULAR CARTILAGE INTEGRITY DURING IJD. MOLECULAR MECHANISMS THAT HAVE BEEN RECENTLY SHOWN TO GOVERN THE PATHOLOGICAL ACTIVITIES OF THE RESIDENT SYNOVIAL CELLS ARE HIGHLIGHTED. FINALLY, ADVANTAGES AND DISADVANTAGES OF TARGETING THESE NEW MOLECULAR MECHANISMS FOR PREVENTING CARTILAGE DEGENERATION DUE TO CHRONIC INFLAMMATION ARE ALSO DISCUSSED. 2017 5 5507 17 RHEUMATOID ARTHRITIS PROGRESSION MEDIATED BY ACTIVATED SYNOVIAL FIBROBLASTS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY SYNOVIAL HYPERPLASIA AND PROGRESSIVE JOINT DESTRUCTION. RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS (RASFS) ARE LEADING CELLS IN JOINT EROSION AND CONTRIBUTE ACTIVELY TO INFLAMMATION. RASFS SHOW AN ACTIVATED PHENOTYPE THAT IS INDEPENDENT OF THE INFLAMMATORY ENVIRONMENT AND REQUIRES THE COMBINATION OF SEVERAL FACTORS. ALTHOUGH NEW ASPECTS REGARDING RASF ACTIVATION VIA MATRIX DEGRADATION PRODUCTS, EPIGENETIC MODIFICATIONS, INFLAMMATORY FACTORS, TOLL-LIKE RECEPTOR (TLR) ACTIVATION AND OTHERS HAVE RECENTLY BEEN UNCOVERED, THE PRIMARY PATHOPHYSIOLOGICAL PROCESSES IN EARLY ARTHRITIS LEADING TO PERMANENT ACTIVATION ARE MOSTLY UNKNOWN. HERE, WE REVIEW NEW FINDINGS REGARDING RASF ACTIVATION AND THEIR ALTERED BEHAVIOR THAT CONTRIBUTE TO MATRIX DESTRUCTION AND INFLAMMATION AS WELL AS THEIR POTENTIAL TO SPREAD RA. 2010 6 6009 24 THE ANTI-INFLAMMATORY MEDIATOR, VASOACTIVE INTESTINAL PEPTIDE, MODULATES THE DIFFERENTIATION AND FUNCTION OF TH SUBSETS IN RHEUMATOID ARTHRITIS. GENETIC BACKGROUND, EPIGENETIC MODIFICATIONS, AND ENVIRONMENTAL FACTORS TRIGGER AUTOIMMUNE RESPONSE IN RHEUMATOID ARTHRITIS (RA). SEVERAL PATHOGENIC INFECTIONS HAVE BEEN RELATED TO THE ONSET OF RA AND MAY CAUSE AN INADEQUATE IMMUNOLOGICAL TOLERANCE TOWARDS CRITICAL SELF-ANTIGENS LEADING TO CHRONIC JOINT INFLAMMATION AND AN IMBALANCE BETWEEN DIFFERENT T HELPER (TH) SUBSETS. VASOACTIVE INTESTINAL PEPTIDE (VIP) IS A MEDIATOR THAT MODULATES ALL THE STAGES COMPRISED BETWEEN THE ARRIVAL OF PATHOGENS AND TH CELL DIFFERENTIATION IN RA THROUGH ITS KNOWN ANTI-INFLAMMATORY AND IMMUNOMODULATORY ACTIONS. THIS "NEUROIMMUNOPEPTIDE" MODULATES THE PATHOGENIC ACTIVITY OF DIVERSE CELL SUBPOPULATIONS INVOLVED IN RA AS LYMPHOCYTES, FIBROBLAST-LIKE SYNOVIOCYTES (FLS), OR MACROPHAGES. IN ADDITION, VIP DECREASES THE EXPRESSION OF PATTERN RECOGNITION RECEPTOR (PRR) SUCH AS TOLL-LIKE RECEPTORS (TLRS) IN FLS FROM RA PATIENTS. THESE RECEPTORS ACT AS SENSORS OF PATHOGEN-ASSOCIATED MOLECULAR PATTERN (PAMP) AND DAMAGE-ASSOCIATED MOLECULAR PATTERN (DAMP) CONNECTING THE INNATE AND ADAPTIVE IMMUNE SYSTEM. MOREOVER, VIP MODULATES THE IMBALANCE BETWEEN TH SUBSETS IN RA, DECREASING PATHOGENIC TH1 AND TH17 SUBSETS AND FAVORING TH2 OR TREG PROFILE DURING THE DIFFERENTIATION/POLARIZATION OF NAIVE OR MEMORY TH CELLS. FINALLY, VIP REGULATES THE PLASTICITY BETWEEN THESES SUBSETS. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF VIP EFFECTS ON THE AFOREMENTIONED FEATURES OF RA PATHOLOGY. 2018 7 1257 24 CURRENT TRENDS IN EPIGENETIC, CELLULAR AND MOLECULAR PATHWAYS IN MANAGEMENT OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS IS A SYSTEMIC CHRONIC POLYARTICULAR AUTOIMMUNE DISORDER OF JOINTS AND JOINT MEMBRANE MAINLY AFFECTING FEET AND HANDS. THE PATHOLOGICAL MANIFESTATION OF THE DISEASE INCLUDES INFILTRATION OF IMMUNE CELLS, HYPERPLASIA OF THE LINING OF SYNOVIUM, FORMATION OF PANNUS AND BONE AND CARTILAGE DESTRUCTION. IF LEFT UNTREATED, THE APPEARANCE OF SMALL FOCAL NECROSIS, ADHESION OF GRANULATION, AND FORMATION OF FIBROUS TISSUE ON THE SURFACE OF ARTICULAR CARTILAGE IS NOTED. THE DISEASE PRIMARILY AFFECTS NEARLY 1% OF THE POPULATION GLOBALLY, WOMEN BEING MORE AFFECTED THAN MEN WITH A RATIO 2:1 AND CAN INITIATE REGARDLESS OF ANY AGE. THE SYNOVIAL FIBROBLAST IN RHEUMATOID ARTHRITIS INDIVIDUALS EXHIBITS AN AGGRESSIVE PHENOTYPE WHICH UPREGULATES THE MANIFESTATION OF PROTOONCOGENES, ADHESIVE COMPOUNDS, INFLAMMATORY CYTOKINES AND MATRIX-DETERIORATING ENZYMES. APART FROM THE INFLAMMATORY EFFECTS OF CYTOKINES, CHEMOKINES ARE ALSO NOTED TO INDUCE SWELLING AND PAIN IN ARTHRITIC INDIVIDUALS BY RESIDING IN SYNOVIAL MEMBRANE AND FORMING PANNUS. THE CURRENT TREATMENT OF RHEUMATOID ARTHRITIS INCLUDES TREATMENT WITH NON-STEROIDAL ANTI-INFLAMMATORY DRUGS, DISEASE-MODIFYING ANTIRHEUMATIC DRUGS, TREATMENT WITH BIOLOGICS SUCH AS INHIBITORS OF TNF-ALPHA, INTERLEUKINS, PLATELET ACTIVATING FACTOR, ETC. WHICH PROVIDES SIGNIFICANT RELIEF FROM SYMPTOMS AND AIDS IN MANAGEMENT OF THE DISEASE. THE CURRENT REVIEW HIGHLIGHTS THE PATHOGENESIS INVOLVED IN THE ONSET OF RHEUMATOID ARTHRITIS AND ALSO COVERS EPIGENETIC, CELLULAR AND MOLECULAR PARAMETERS ASSOCIATED WITH IT TO AID BETTER AND ADVANCED THERAPEUTIC APPROACHES FOR MANAGEMENT OF THE DEBILITATING DISEASE. 2023 8 2221 15 EPIGENETIC MODIFICATIONS IN RHEUMATOID ARTHRITIS, A REVIEW. RHEUMATOID ARTHRITIS IS AN AUTOIMMUNE DISEASE CHARACTERIZED BY CHRONIC JOINT INFLAMMATION AND PROGRESSIVE DESTRUCTION OF CARTILAGE AND BONE WHICH LEADS TO ULTIMATELY LOSS OF FUNCTION AND PAIN. ACTIVATED SYNOVIAL FIBROBLASTS ARE KEY EFFECTOR CELLS IN THE PATHOGENESIS OF RHEUMATOID ARTHRITIS. IN THE RECENT YEARS, EPIGENETIC CHANGES INCLUDING DNA METHYLATION, HISTONE ACETYLATION AND OTHER HISTONE MODIFICATIONS WERE IDENTIFIED THAT ARE ASSOCIATED WITH AN INTRINSIC ACTIVATION AND THE AGGRESSIVE PHENOTYPE OF THESE CELLS. SO FAR, NO THERAPIES TARGETING RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS EXIST. THIS REVIEW COMPRISES RECENT RESEARCH EFFORTS THAT PROPOSE EPIGENETIC MECHANISMS BEHIND THE ACTIVATION OF RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS AND OTHER CELL TYPES. 2013 9 4412 24 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 10 4968 29 PATHOLOGICAL MECHANISMS AND THERAPEUTIC OUTLOOKS FOR ARTHROFIBROSIS. ARTHROFIBROSIS IS A FIBROTIC JOINT DISORDER THAT BEGINS WITH AN INFLAMMATORY REACTION TO INSULTS SUCH AS INJURY, SURGERY AND INFECTION. EXCESSIVE EXTRACELLULAR MATRIX AND ADHESIONS CONTRACT POUCHES, BURSAE AND TENDONS, CAUSE PAIN AND PREVENT A NORMAL RANGE OF JOINT MOTION, WITH DEVASTATING CONSEQUENCES FOR PATIENT QUALITY OF LIFE. ARTHROFIBROSIS AFFECTS PEOPLE OF ALL AGES, WITH PUBLISHED RATES VARYING. THE RISK FACTORS AND BEST MANAGEMENT STRATEGIES ARE LARGELY UNKNOWN DUE TO A POOR UNDERSTANDING OF THE PATHOLOGY AND LACK OF DIAGNOSTIC BIOMARKERS. HOWEVER, CURRENT RESEARCH INTO THE PATHOGENESIS OF FIBROSIS IN ORGANS NOW INFORMS THE UNDERSTANDING OF ARTHROFIBROSIS. THE PROCESS BEGINS WHEN STRESS SIGNALS STIMULATE IMMUNE CELLS. THE RESULTING CASCADE OF CYTOKINES AND MEDIATORS DRIVES FIBROBLASTS TO DIFFERENTIATE INTO MYOFIBROBLASTS, WHICH SECRETE FIBRILLAR COLLAGENS AND TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA). POSITIVE FEEDBACK NETWORKS THEN DYSREGULATE PROCESSES THAT NORMALLY TERMINATE HEALING PROCESSES. WE PROPOSE TWO SUBTYPES OF ARTHROFIBROSIS OCCUR: ACTIVE ARTHROFIBROSIS AND RESIDUAL ARTHROFIBROSIS. IN THE LATTER THE FIBROGENIC PROCESSES HAVE RESOLVED BUT THE JOINT REMAINS STIFF. THE BEST THERAPEUTIC APPROACH FOR EACH SUBTYPE MAY DIFFER SIGNIFICANTLY. TREATMENT TYPICALLY INVOLVES SURGERY, HOWEVER, A PHARMACOLOGICAL APPROACH TO CORRECT DYSREGULATED CELL SIGNALLING COULD BE MORE EFFECTIVE. RECENT RESEARCH SHOWS THAT MYOFIBROBLASTS ARE CAPABLE OF REVERSING DIFFERENTIATION, AND UNDERSTANDING THE MECHANISMS OF PATHOGENESIS AND RESOLUTION WILL BE ESSENTIAL FOR THE DEVELOPMENT OF CELL-BASED TREATMENTS. THERAPIES WITH SIGNIFICANT PROMISE ARE CURRENTLY AVAILABLE, WITH MORE IN DEVELOPMENT, INCLUDING THOSE THAT INHIBIT TGF-BETA SIGNALLING AND EPIGENETIC MODIFICATIONS. THIS REVIEW FOCUSES ON PATHOGENESIS OF STERILE ARTHROFIBROSIS AND THERAPEUTIC TREATMENTS. 2019 11 6328 16 THE ROLE OF CELL ORGANELLES IN RHEUMATOID ARTHRITIS WITH FOCUS ON EXOSOMES. AUTO-IMMUNE DISEASES INVOLVED AT LEAST 25% OF THE POPULATION IN WEALTHY COUNTRIES. SEVERAL FACTORS INCLUDING GENETIC, EPIGENETIC, AND ENVIRONMENTAL ELEMENTS ARE IMPLICATED IN DEVELOPMENT OF RHEUMATOID ARTHRITIS AS AN AUTOIMMUNE DISEASE. AUTOANTIBODIES CAUSE SYNOVIAL INFLAMMATION AND ARTHRITIS, IF LEFT UNTREATED OR BEING UNDER CONTINUAL EXTERNAL STIMULATION, COULD RESULT IN CHRONIC INFLAMMATION, JOINT INJURY, AND DISABILITY. T- AND B-CELLS, SIGNALING MOLECULES, PROINFLAMMATORY MEDIATORS, AND SYNOVIUM-SPECIFIC TARGETS ARE AMONG THE NEW THERAPEUTIC TARGETS. EXOSOMES COULD BE EMPLOYED AS THERAPEUTIC VECTORS IN THE TREATMENT OF AUTOIMMUNE DISEASES. HEREIN, THE ROLE OF CELL ORGANELLE PARTICULARLY EXOSOMES IN RHEUMATOID ARTHRITIS HAD DISCUSSED AND SOME THERAPEUTIC APPLICATIONS OF EXOSOME HIGHLIGHTED. 2021 12 4416 15 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 13 4842 19 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 14 6102 19 THE EMERGING ROLE OF FIBROBLAST-LIKE SYNOVIOCYTES-MEDIATED SYNOVITIS IN OSTEOARTHRITIS: AN UPDATE. OSTEOARTHRITIS (OA), THE MOST UBIQUITOUS DEGENERATIVE DISEASE AFFECTING THE ENTIRE JOINT, IS CHARACTERIZED BY CARTILAGE DEGRADATION AND SYNOVIAL INFLAMMATION. ALTHOUGH THE PATHOGENESIS OF OA REMAINS POORLY UNDERSTOOD, SYNOVIAL INFLAMMATION IS KNOWN TO PLAY AN IMPORTANT ROLE IN OA DEVELOPMENT. HOWEVER, STUDIES ON OA PATHOPHYSIOLOGY HAVE FOCUSED MORE ON CARTILAGE DEGENERATION AND OSTEOPHYTES, RATHER THAN ON THE INFLAMED AND THICKENED SYNOVIUM. FIBROBLAST-LIKE SYNOVIOCYTES (FLS) PRODUCE A SERIES OF PRO-INFLAMMATORY REGULATORS, SUCH AS INFLAMMATORY CYTOKINES, NITRIC OXIDE (NO) AND PROSTAGLANDIN E(2) (PGE(2) ). THESE REGULATORS ARE POSITIVELY ASSOCIATED WITH THE CLINICAL SYMPTOMS OF OA, SUCH AS INFLAMMATORY PAIN, JOINT SWELLING AND DISEASE DEVELOPMENT. A BETTER UNDERSTANDING OF THE INFLAMMATORY IMMUNE RESPONSE IN OA-FLS COULD PROVIDE A NOVEL APPROACH TO COMPREHENSIVE TREATMENT STRATEGIES FOR OA. HERE, WE HAVE SUMMARIZED RECENTLY PUBLISHED LITERATURES REFERRING TO EPIGENETIC MODIFICATIONS, ACTIVATED SIGNALLING PATHWAYS AND INFLAMMATION-ASSOCIATED FACTORS THAT ARE INVOLVED IN OA-FLS-MEDIATED INFLAMMATION. IN ADDITION, THE CURRENT RELATED CLINICAL TRIALS AND FUTURE PERSPECTIVES WERE ALSO SUMMARIZED. 2020 15 5265 19 PROMISING THERAPEUTIC TARGETS FOR TREATMENT OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A SYSTEMIC POLY-ARTICULAR CHRONIC AUTOIMMUNE JOINT DISEASE THAT MAINLY DAMAGES THE HANDS AND FEET, WHICH AFFECTS 0.5% TO 1.0% OF THE POPULATION WORLDWIDE. WITH THE SUSTAINED DEVELOPMENT OF DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS), SIGNIFICANT SUCCESS HAS BEEN ACHIEVED FOR PREVENTING AND RELIEVING DISEASE ACTIVITY IN RA PATIENTS. UNFORTUNATELY, SOME PATIENTS STILL SHOW LIMITED RESPONSE TO DMARDS, WHICH PUTS FORWARD NEW REQUIREMENTS FOR SPECIAL TARGETS AND NOVEL THERAPIES. UNDERSTANDING THE PATHOGENETIC ROLES OF THE VARIOUS MOLECULES IN RA COULD FACILITATE DISCOVERY OF POTENTIAL THERAPEUTIC TARGETS AND APPROACHES. IN THIS REVIEW, BOTH EXISTING AND EMERGING TARGETS, INCLUDING THE PROTEINS, SMALL MOLECULAR METABOLITES, AND EPIGENETIC REGULATORS RELATED TO RA, ARE DISCUSSED, WITH A FOCUS ON THE MECHANISMS THAT RESULT IN INFLAMMATION AND THE DEVELOPMENT OF NEW DRUGS FOR BLOCKING THE VARIOUS MODULATORS IN RA. 2021 16 4684 19 NEW POTENTIAL THERAPEUTIC APPROACHES TARGETING SYNOVIAL FIBROBLASTS IN RHEUMATOID ARTHRITIS. SYNOVIAL CELLS PLAY A KEY ROLE IN JOINT DESTRUCTION DURING CHRONIC INFLAMMATION. IN PARTICULAR, ACTIVATED SYNOVIAL FIBROBLASTS (SFS) UNDERGO INTRINSIC ALTERATIONS LEADING TO AN AGGRESSIVE PHENOTYPE MEDIATING CARTILAGE DESTRUCTION AND BONE EROSION IN RHEUMATOID ARTHRITIS (RA). RECENT RESEARCH HAS REVEALED A NUMBER OF TARGETS TO CONTROL ARTHRITOGENIC CHANGES IN SFS. THEREFORE, IDENTIFICATION OF SF PHENOTYPES, CONTROL OF EPIGENETIC CHANGES, MODULATION OF CELLULAR FUNCTIONS, OR REGULATION OF THE ACTIVITY OF CATION CHANNELS AND DIFFERENT SIGNALING PATHWAYS HAS BEEN INVESTIGATED. ALTHOUGH MANY OF THESE APPROACHES HAVE SHOWN EFFICACY IN VITRO AND IN ANIMAL MODELS OF RA, FURTHER RESEARCH IS NEEDED TO SELECT THE MOST RELEVANT TARGETS FOR DRUG DEVELOPMENT. THIS REVIEW IS FOCUSED ON THE ROLE OF SFS AS A POTENTIAL STRATEGY TO DISCOVER NOVEL THERAPEUTIC TARGETS IN RA AIMED AT PRESERVING JOINT ARCHITECTURE AND FUNCTION. 2021 17 757 22 CARTILAGE REPAIR BY MESENCHYMAL STEM CELLS: CLINICAL TRIAL UPDATE AND PERSPECTIVES. OSTEOARTHRITIS IS A DEGENERATIVE DISEASE OF JOINTS WITH DESTRUCTION OF ARTICULAR CARTILAGE ASSOCIATED WITH SUBCHONDRAL BONE HYPERTROPHY AND INFLAMMATION. OA IS THE LEADING CAUSE OF JOINT PAIN RESULTING IN SIGNIFICANT WORSENING OF THE QUALITY-OF-LIFE IN THE ELDERLY. NUMEROUS EFFORTS HAVE BEEN SPENT TO OVERCOME THE INHERENTLY POOR HEALING ABILITY OF ARTICULAR CARTILAGE. MESENCHYMAL STEM CELLS (MSCS) HAVE BEEN IN THE LIMELIGHT OF CELL-BASED THERAPIES TO PROMOTE CARTILAGE REPAIR. DESPITE PROGRESSIVE ADVANCEMENTS IN MSC MANIPULATION AND THE INTRODUCTION OF VARIOUS BIOACTIVE SCAFFOLDS AND GROWTH FACTORS IN PRECLINICAL STUDIES, CURRENT CLINICAL TRIALS ARE STILL AT EARLY STAGES WITH PRELIMINARY AIMS TO EVALUATE SAFETY, FEASIBILITY AND EFFICACY. THIS REVIEW SUMMARISES RECENTLY REPORTED MSC-BASED CLINICAL TRIALS AND DISCUSSES NEW RESEARCH DIRECTIONS WITH PARTICULAR FOCUS ON THE POTENTIAL APPLICATION OF MSC-DERIVED EXTRACELLULAR VEHICLES, MIRNAS AND ADVANCED GENE EDITING TECHNIQUES WHICH MAY SHED LIGHT ON THE DEVELOPMENT OF NOVEL TREATMENT STRATEGIES. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: THIS REVIEW SUMMARISES RECENT MSC-RELATED CLINICAL RESEARCH THAT FOCUSES ON CARTILAGE REPAIR. WE ALSO PROPOSE A NOVEL POSSIBLE TRANSLATIONAL DIRECTION FOR HYALINE CARTILAGE FORMATION AND A NEW PARADIGM MAKING USE OF EXTRA-CELLULAR SIGNALLING AND EPIGENETIC REGULATION IN THE APPLICATION OF MSCS FOR CARTILAGE REPAIR. 2017 18 6737 22 WHAT MAKES GOUTY INFLAMMATION SO VARIABLE? ACUTE GOUT ARTHRITIS FLARES CONTRIBUTE DOMINANTLY TO GOUT-SPECIFIC IMPAIRED HEALTH-RELATED QUALITY OF LIFE, REPRESENTING A PROGRESSIVELY INCREASING PUBLIC HEALTH PROBLEM. FLARES CAN BE COMPLEX AND EXPENSIVE TO TREAT, PARTLY DUE TO THE FREQUENT COMORBIDITIES. UNMET NEEDS IN GOUT MANAGEMENT ARE MORE PRESSING GIVEN THE MARKEDLY INCREASING GOUT FLARE HOSPITAL ADMISSION RATES. IN ADDITION, CHRONIC GOUTY ARTHRITIS CAN CAUSE JOINT DAMAGE AND FUNCTIONAL IMPAIRMENT. THIS REVIEW ADDRESSES NEW KNOWLEDGE ON THE BASIS FOR THE MARKED, INHERENT VARIABILITY OF RESPONSES TO DEPOSITED URATE CRYSTALS, INCLUDING THE UNPREDICTABLE AND SELF-LIMITED ASPECTS OF MANY GOUT FLARES. SPECIFIC TOPICS REVIEWED INCLUDE HOW INNATE IMMUNITY AND TWO-SIGNAL INFLAMMASOME ACTIVATION INTERSECT WITH DIET, METABOLISM, NUTRITIONAL BIOSENSING, THE MICROBIOME, AND THE PHAGOCYTE CYTOSKELETON AND CELL FATE. THE PAPER DISCUSSES THE ROLES OF ENDOGENOUS CONSTITUTIVE REGULATORS OF INFLAMMATION, INCLUDING CERTAIN NUTRITIONAL BIOSENSORS, AND EMERGING GENETIC AND EPIGENETIC FACTORS. RECENT ADVANCES IN THE BASIS OF VARIABILITY IN RESPONSES TO URATE CRYSTALS IN GOUT PROVIDE INFORMATION ABOUT INFLAMMATORY ARTHRITIS, AND HAVE IDENTIFIED POTENTIAL NEW TARGETS AND STRATEGIES FOR ANTI-INFLAMMATORY PREVENTION AND TREATMENT OF GOUTY ARTHRITIS. 2017 19 5372 25 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 20 3699 17 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