1 4749 98 NOVEL PROSPECTS FOR SCARLESS WOUND HEALING: THE ROLES OF MYOFIBROBLASTS AND ADIPOCYTES. DISTURBANCES OR DEFECTS IN THE PROCESS OF WOUND REPAIR CAN DISRUPT THE DELICATE BALANCE OF CELLS AND MOLECULES NECESSARY FOR COMPLETE WOUND HEALING, THUS LEADING TO CHRONIC WOUNDS OR FIBROTIC SCARS. MYOFIBROBLASTS ARE ONE OF THE MOST IMPORTANT CELLS INVOLVED IN FIBROTIC SCARS, AND REPROGRAMMING PROVIDES A POTENTIAL AVENUE TO INCREASE MYOFIBROBLAST CLEARANCE. ALTHOUGH MYOFIBROBLASTS HAVE LONG BEEN RECOGNIZED AS TERMINALLY DIFFERENTIATED CELLS, RECENT STUDIES HAVE SHOWN THAT MYOFIBROBLASTS HAVE THE CAPACITY TO BE REPROGRAMMED INTO ADIPOCYTES. THIS REVIEW INTENDS TO SUMMARIZE THE POTENTIAL OF REPROGRAMMING MYOFIBROBLASTS INTO ADIPOCYTES. WE WILL DISCUSS MYOFIBROBLAST LINEAGE TRACING, AS WELL AS THE KNOWN MECHANISMS UNDERLYING ADIPOCYTE REGENERATION FROM MYOFIBROBLASTS. IN ADDITION, WE INVESTIGATED DIFFERENT CHANGES IN MYOFIBROBLAST GENE EXPRESSION, TRANSCRIPTIONAL REGULATORS, SIGNALLING PATHWAYS AND EPIGENETIC REGULATORS DURING SKIN WOUND HEALING. IN THE FUTURE, MYOFIBROBLAST REPROGRAMMING IN WOUND HEALING WILL BE BETTER UNDERSTOOD AND APPRECIATED, WHICH MAY PROVIDE NEW IDEAS FOR THE TREATMENT OF SCARLESS WOUND HEALING. 2022 2 6212 20 THE INTERPLAY OF THE GENETIC ARCHITECTURE, AGING, AND ENVIRONMENTAL FACTORS IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC FIBROSING LUNG DISEASE OF INDETERMINATE ETIOLOGY AND LIMITED THERAPEUTIC OPTIONS. THE INITIATION, DEVELOPMENT, AND PROGRESSION OF IPF ARE INFLUENCED BY GENETIC PREDISPOSITION, AGING, AND HOST AND ENVIRONMENTAL FACTORS, BUT THE MAGNITUDE OF THE CONTRIBUTION OF EACH OF THEM AND THE SEQUENCE OF THE PATHOGENIC EVENTS ARE UNCERTAIN. CURRENT EVIDENCE INDICATES THAT ACCUMULATED ENVIRONMENTAL EXPOSURES IN A GENETICALLY PREDISPOSED INDIVIDUAL, USUALLY OVER 60 YEARS OF AGE, LEADS TO PHENOTYPIC AND FUNCTIONAL ALTERATIONS OF THE LUNG EPITHELIUM. ABERRANT ACTIVATION OF EPITHELIAL CELLS RESULTS, THROUGH A COMPLEX RELEASE OF NUMEROUS MEDIATORS, IN THE LOCAL EXPANSION OF PECULIAR SUBSETS OF AGGRESSIVE FIBROBLASTS AND MYOFIBROBLASTS, WHICH ARE CRUCIAL EFFECTOR CELLS OF FIBROTIC REMODELING AND LOSS OF THE NORMAL LUNG ARCHITECTURE AND FUNCTION. PROGRESSIVE INCREASE OF THE MECHANICAL STIFFNESS ACTIVATES CELL-AUTONOMOUS AND MATRIX-DEPENDENT PROCESSES CONTRIBUTING TO THE PERPETUATION OF THE FIBROTIC RESPONSE. THIS PERSPECTIVE PROVIDES AN INTEGRAL OVERVIEW OF THE MAJOR RISK FACTORS UNDERPINNING THE PATHOGENESIS OF IPF, INCLUDING GENE VARIANTS, AGING ALTERATIONS, ENVIRONMENTAL FACTORS, HOST RISK FACTORS, AND EPIGENETIC REPROGRAMMING. 2021 3 6218 30 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 4 2178 24 EPIGENETIC MECHANISMS OF MACROPHAGE ACTIVATION IN TYPE 2 DIABETES. THE ALARMING RISE OF OBESITY AND TYPE 2 DIABETES (T2D) HAS PUT A TREMENDOUS STRAIN ON GLOBAL HEALTHCARE SYSTEMS. OVER THE PAST DECADE EXTENSIVE RESEARCH HAS FOCUSED ON THE ROLE OF MACROPHAGES AS KEY MEDIATORS OF INFLAMMATION IN T2D. THE INFLAMMATORY ENVIRONMENT IN THE OBESE ADIPOSE TISSUE AND PANCREATIC BETA-CELL ISLETS CREATES AND PERPETUATES IMBALANCED INFLAMMATORY MACROPHAGE ACTIVATION. CONSEQUENCES OF THIS CHRONIC LOW-GRADE INFLAMMATION INCLUDE INSULIN RESISTANCE IN THE ADIPOSE TISSUE AND PANCREATIC BETA-CELL DYSFUNCTION. RECENTLY, THE EMERGING FIELD OF EPIGENETICS HAS PROVIDED NEW INSIGHTS INTO THE PATHOGENESIS OF T2D, WHILE ALSO AFFORDING POTENTIAL NEW OPPORTUNITIES FOR TREATMENT. IN MACROPHAGES, EPIGENETIC MECHANISMS ARE INCREASINGLY BEING RECOGNIZED AS CRUCIAL CONTROLLERS OF THEIR PHENOTYPE. HERE, WE FIRST DESCRIBE THE ROLE OF MACROPHAGES IN T2D. THEN WE ELABORATE ON EPIGENETIC MECHANISMS THAT REGULATE MACROPHAGE ACTIVATION, THEREBY FOCUSING ON T2D. NEXT, WE HIGHLIGHT HOW DIABETIC CONDITIONS SUCH AS HYPERLIPIDEMIA AND HYPERGLYCEMIA COULD INDUCE EPIGENETIC CHANGES THAT PROMOTE AN INFLAMMATORY MACROPHAGE PHENOTYPE. IN CONCLUSION WE DISCUSS POSSIBLE THERAPEUTIC INTERVENTIONS BY TARGETING MACROPHAGE EPIGENETICS AND SPECULATE ON FUTURE RESEARCH DIRECTIONS. 2017 5 5507 21 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 5309 24 PSORIASIS PATHOGENESIS AND TREATMENT. RESEARCH ON PSORIASIS PATHOGENESIS HAS LARGELY INCREASED KNOWLEDGE ON SKIN BIOLOGY IN GENERAL. IN THE PAST 15 YEARS, BREAKTHROUGHS IN THE UNDERSTANDING OF THE PATHOGENESIS OF PSORIASIS HAVE BEEN TRANSLATED INTO TARGETED AND HIGHLY EFFECTIVE THERAPIES PROVIDING FUNDAMENTAL INSIGHTS INTO THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES WITH A DOMINANT IL-23/TH17 AXIS. THIS REVIEW DISCUSSES THE MECHANISMS INVOLVED IN THE INITIATION AND DEVELOPMENT OF THE DISEASE, AS WELL AS THE THERAPEUTIC OPTIONS THAT HAVE ARISEN FROM THE DISSECTION OF THE INFLAMMATORY PSORIATIC PATHWAYS. OUR DISCUSSION BEGINS BY ADDRESSING THE INFLAMMATORY PATHWAYS AND KEY CELL TYPES INITIATING AND PERPETUATING PSORIATIC INFLAMMATION. NEXT, WE DESCRIBE THE ROLE OF GENETICS, ASSOCIATED EPIGENETIC MECHANISMS, AND THE INTERACTION OF THE SKIN FLORA IN THE PATHOPHYSIOLOGY OF PSORIASIS. FINALLY, WE INCLUDE A COMPREHENSIVE REVIEW OF WELL-ESTABLISHED WIDELY AVAILABLE THERAPIES AND NOVEL TARGETED DRUGS. 2019 7 4981 25 PATHOPHYSIOLOGY OF SYSTEMIC SCLEROSIS: CURRENT UNDERSTANDING AND NEW INSIGHTS. INTRODUCTION: SYSTEMIC SCLEROSIS (SSC) IS A COMPLEX AUTOIMMUNE CONNECTIVE TISSUE DISEASE CHARACTERIZED BY CHRONIC AND PROGRESSIVE TISSUE AND ORGAN FIBROSIS WITH BROAD PATIENT-TO-PATIENT VARIABILITY. SOME RISK FACTORS ARE KNOWN AND INCLUDE COMBINATION OF PERSISTENT RAYNAUD'S PHENOMENON, STEROID HORMONE IMBALANCE, SELECTED CHEMICALS, THERMAL, OR OTHER INJURIES. ENDOGENOUS AND/OR EXOGENOUS ENVIRONMENTAL TRIGGER/RISK FACTORS PROMOTE EPIGENETIC MECHANISMS IN GENETICALLY PRIMED SUBJECTS. DISEASE PATHOGENESIS PRESENTS EARLY MICROVASCULAR CHANGES WITH ENDOTHELIAL CELL DYSFUNCTION, FOLLOWED BY THE ACTIVATION OF MECHANISMS PROMOTING THEIR TRANSITION INTO MYOFIBROBLASTS. A COMPLEX AUTOIMMUNE RESPONSE, INVOLVING INNATE AND ADAPTIVE IMMUNITY WITH SPECIFIC/FUNCTIONAL AUTOANTIBODY PRODUCTION, CHARACTERIZES THE DISEASE. PROGRESSIVE FIBROSIS AND ISCHEMIA INVOLVE SKIN AND VISCERAL ORGANS RESULTING IN THEIR IRREVERSIBLE DAMAGE/FAILURE. PROGENITOR CIRCULATING CELLS (MONOCYTES, FIBROCYTES), TOGETHER WITH GROWTH FACTORS AND CYTOKINES PARTICIPATE IN DISEASE DIFFUSION AND EVOLUTION. EPIGENETIC, VASCULAR AND IMMUNOLOGIC MECHANISMS IMPLICATED IN SYSTEMIC FIBROSIS, REPRESENT MAJOR TARGETS FOR INCOMING DISEASE MODIFYING THERAPEUTIC APPROACHES. AREAS COVERED: THIS REVIEW DISCUSSES CURRENT UNDERSTANDING AND NEW INSIGHTS OF SSC PATHOGENESIS, THROUGH AN OVERVIEW OF THE MOST RELEVANT ADVANCEMENTS TO PRESENT ASPECTS AND MECHANISMS INVOLVED IN DISEASE PATHOGENESIS. EXPERT OPINION: CONSIDERING SSC INTRICACY/HETEROGENEITY, EARLY COMBINATION THERAPY WITH VASODILATORS, IMMUNOSUPPRESSIVE AND ANTIFIBROTIC DRUGS SHOULD SUCCESSFULLY DOWNREGULATE THE DISEASE PROGRESSION, ESPECIALLY IF STARTED FROM THE BEGINNING. 2019 8 4488 28 MONOCYTE AND HAEMATOPOIETIC PROGENITOR REPROGRAMMING AS COMMON MECHANISM UNDERLYING CHRONIC INFLAMMATORY AND CARDIOVASCULAR DISEASES. A LARGE NUMBER OF CARDIOVASCULAR EVENTS ARE NOT PREVENTED BY CURRENT THERAPEUTIC REGIMENS. IN SEARCH FOR ADDITIONAL, INNOVATIVE STRATEGIES, IMMUNE CELLS HAVE BEEN RECOGNIZED AS KEY PLAYERS CONTRIBUTING TO ATHEROSCLEROTIC PLAQUE PROGRESSION AND DESTABILIZATION. PARTICULARLY THE ROLE OF INNATE IMMUNE CELLS IS OF MAJOR INTEREST, FOLLOWING THE RECENT PARADIGM SHIFT THAT INNATE IMMUNITY, LONG CONSIDERED TO BE INCAPABLE OF LEARNING, DOES EXHIBIT IMMUNOLOGICAL MEMORY MEDIATED VIA EPIGENETIC REPROGRAMMING. COMPELLING EVIDENCE SHOWS THAT ATHEROSCLEROTIC RISK FACTORS PROMOTE IMMUNE CELL MIGRATION BY PRE-ACTIVATION OF CIRCULATING INNATE IMMUNE CELLS. INNATE IMMUNE CELL ACTIVATION VIA METABOLIC AND EPIGENETIC REPROGRAMMING PERPETUATES A SYSTEMIC LOW-GRADE INFLAMMATORY STATE IN CARDIOVASCULAR DISEASE (CVD) THAT IS ALSO COMMON IN OTHER CHRONIC INFLAMMATORY DISORDERS. THIS OPENS A NEW THERAPEUTIC AREA IN WHICH METABOLIC OR EPIGENETIC MODULATION OF INNATE IMMUNE CELLS MAY RESULT IN DECREASED SYSTEMIC CHRONIC INFLAMMATION, ALLEVIATING CVD, AND ITS CO-MORBIDITIES. 2018 9 6621 32 UNDERSTANDING FIBROSIS IN SYSTEMIC SCLEROSIS: SHIFTING PARADIGMS, EMERGING OPPORTUNITIES. FIBROSIS IN MULTIPLE ORGANS IS A PROMINENT PATHOLOGICAL FINDING AND DISTINGUISHING HALLMARK OF SYSTEMIC SCLEROSIS (SSC). FINDINGS DURING THE PAST 5 YEARS HAVE CONTRIBUTED TO A MORE COMPLETE UNDERSTANDING OF THE COMPLEX CELLULAR AND MOLECULAR UNDERPINNING OF FIBROSIS IN SSC. FIBROBLASTS, THE PRINCIPAL EFFECTOR CELLS, ARE ACTIVATED IN THE PROFIBROTIC CELLULAR MILIEU BY CYTOKINES AND GROWTH FACTORS, DEVELOPMENTAL PATHWAYS, ENDOTHELIN 1 AND THROMBIN. INNATE IMMUNE SIGNALING VIA TOLL-LIKE RECEPTORS, MATRIX-GENERATED BIOMECHANICAL STRESS SIGNALING VIA INTEGRINS, HYPOXIA AND OXIDATIVE STRESS SEEM TO BE IMPLICATED IN PERPETUATING THE PROCESS. BEYOND CHRONIC FIBROBLAST ACTIVATION, FIBROSIS REPRESENTS A FAILURE TO TERMINATE TISSUE REPAIR, COUPLED WITH AN EXPANDED POPULATION OF MESENCHYMAL CELLS ORIGINATING FROM BONE MARROW AND TRANSDIFFERENTIATION OF EPITHELIAL CELLS, ENDOTHELIAL CELLS AND PERICYTES. IN ADDITION, STUDIES HAVE IDENTIFIED INTRINSIC ALTERATIONS IN SSC FIBROBLASTS RESULTING FROM EPIGENETIC CHANGES, AS WELL AS ALTERED MICRORNA EXPRESSION THAT MIGHT UNDERLIE THE CELL-AUTONOMOUS, PERSISTENT ACTIVATION PHENOTYPE OF THESE CELLS. PRECISE CHARACTERIZATION OF THE DEREGULATED EXTRACELLULAR AND INTRACELLULAR SIGNALING PATHWAYS, MEDIATORS AND CELLULAR DIFFERENTIATION PROGRAMS THAT CONTRIBUTE TO FIBROSIS IN SSC WILL FACILITATE THE DEVELOPMENT OF SELECTIVE, TARGETED THERAPEUTIC STRATEGIES. EFFECTIVE ANTIFIBROTIC THERAPY WILL ULTIMATELY INVOLVE NOVEL COMPOUNDS AND REPURPOSING OF DRUGS THAT ARE ALREADY APPROVED FOR OTHER INDICATIONS. 2011 10 6223 28 THE LEADING ROLE OF EPITHELIAL CELLS IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A RELENTLESSLY PROGRESSIVE AND DEVASTATING INTERSTITIAL LUNG DISEASE OF UNKNOWN ETIOLOGY, WHERE THE NORMAL LUNG ARCHITECTURE IS LOST AND REPLACED BY FIBROTIC TISSUE LEADING TO AN IRREVERSIBLE AND PROGRESSIVE RESPIRATORY INSUFFICIENCY. HISTORICALLY, IPF WAS CONSIDERED A CHRONIC INFLAMMATORY DISORDER, WHICH GRADUALLY PROGRESSED TO ESTABLISHED FIBROSIS. HOWEVER, STRONG CLINICAL AND EXPERIMENTAL EVIDENCE INDICATES THAT THE DISEASE REPRESENTS AN EPITHELIAL-DRIVEN DISORDER WHICH RESULTS FROM A COMPLEX INTERPLAY OF GENETIC AND ENVIRONMENTAL RISK FACTORS, AGING-ASSOCIATED PROCESSES AND A PROFIBROTIC EPIGENETIC REPROGRAMMING. THE CONVERGENCE OF THESE FACTORS RESULTS IN THE ABERRANT ACTIVATION OF EPITHELIAL CELLS THAT INITIATE THE DEVELOPMENT OF THE DISEASE, PRODUCING VIRTUALLY ALL THE MEDIATORS THAT PARTICIPATE IN THE MIGRATION, PROLIFERATION AND ACTIVATION OF FIBROBLASTS, THEIR DIFFERENTIATION TO MYOFIBROBLASTS AND THE EXCESSIVE AND CHAOTIC SECRETION OF EXTRACELLULAR MATRIX PROTEINS. ALTHOUGH PROGRESS HAS BEEN MADE IN UNDERSTANDING THE CAUSES AND CONSEQUENCES OF THIS ABNORMAL BEHAVIOR OF DISTAL AIRWAYS AND ALVEOLAR EPITHELIUM, THE MECHANISMS THAT INITIATE AND PERPETUATE THE VICIOUS CIRCLE OF MULTIDIRECTIONAL ABNORMAL COMMUNICATIONS BETWEEN THE EPITHELIUM AND FIBROBLASTS AND OTHER RESIDENT CELLS HAVE NOT BEEN ELUCIDATED. IN THIS REVIEW, WE DISCUSS THE ROLE OF EPITHELIAL CELLS AND THE MECHANISMS UNDERLYING THE FIBROTIC RESPONSE IN IPF, AND HIGHLIGHT SOME PROMISING THERAPEUTIC TARGETS FOR THESE CELLS. 2020 11 3674 29 INFLAMMATION AND DYSREGULATED FIBROBLAST PROLIFERATION--NEW MECHANISMS? IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE MAY PRIMARILY BE DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS AND THE UNDERLYING MESENCHYME. THE MEDIATORS PRODUCED AND PRESENT IN THIS MICROENVIRONMENT INDUCE THE FORMATION OF FIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE DETAILED MECHANISMS THAT LINK IPF WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN, BUT SOME EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES MAY PLAY A ROLE. THIS REVIEW PROVIDES A BRIEF SYNOPSIS OF HIGHLIGHTS IN THE CURRENT UNDERSTANDING OF THE PATHOPHYSIOLOGY OF IPF, AS WELL AS NOVEL THERAPEUTICS BEING EXPLORED IN CLINICAL TRIALS FOR THE TREATMENT OF THIS DEVASTATING DISEASE. 2013 12 6245 30 THE MECHANISMS UNDERLYING CHRONIC INFLAMMATION IN RHEUMATOID ARTHRITIS FROM THE PERSPECTIVE OF THE EPIGENETIC LANDSCAPE. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE THAT IS CHARACTERIZED BY SYNOVIAL HYPERPLASIA AND PROGRESSIVE JOINT DESTRUCTION. THE ACTIVATION OF RA SYNOVIAL FIBROBLASTS (SFS), ALSO CALLED FIBROBLAST-LIKE SYNOVIOCYTES (FLS), CONTRIBUTES SIGNIFICANTLY TO PERPETUATION OF THE DISEASE. GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN REPORTED TO BE INVOLVED IN THE ETIOLOGY OF RA BUT ARE INSUFFICIENT TO EXPLAIN IT. IN RECENT YEARS, ACCUMULATING RESULTS HAVE SHOWN THE POTENTIAL ROLE OF EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS, DNA METHYLATION, AND MICRORNAS, IN THE DEVELOPMENT OF RA. EPIGENETIC MECHANISMS REGULATE CHROMATIN STATE AND GENE TRANSCRIPTION WITHOUT ANY CHANGE IN DNA SEQUENCE, RESULTING IN THE ALTERATION OF PHENOTYPES IN SEVERAL CELL TYPES, ESPECIALLY RASFS. EPIGENETIC CHANGES POSSIBLY PROVIDE RASFS WITH AN ACTIVATED PHENOTYPE. IN THIS PAPER, WE REVIEW THE ROLES OF EPIGENETIC MECHANISMS RELEVANT FOR THE PROGRESSION OF RA. 2016 13 3512 26 IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS IS A DEVASTATING, AGE-RELATED LUNG DISEASE OF UNKNOWN CAUSE THAT HAS FEW TREATMENT OPTIONS. THIS DISEASE WAS ONCE THOUGHT TO BE A CHRONIC INFLAMMATORY PROCESS, BUT CURRENT EVIDENCE INDICATES THAT THE FIBROTIC RESPONSE IS DRIVEN BY ABNORMALLY ACTIVATED ALVEOLAR EPITHELIAL CELLS (AECS). THESE CELLS PRODUCE MEDIATORS THAT INDUCE THE FORMATION OF FIBROBLAST AND MYOFIBROBLAST FOCI THROUGH THE PROLIFERATION OF RESIDENT MESENCHYMAL CELLS, ATTRACTION OF CIRCULATING FIBROCYTES, AND STIMULATION OF THE EPITHELIAL TO MESENCHYMAL TRANSITION. THE FIBROBLAST AND MYOFIBROBLAST FOCI SECRETE EXCESSIVE AMOUNTS OF EXTRACELLULAR MATRIX, MAINLY COLLAGENS, RESULTING IN SCARRING AND DESTRUCTION OF THE LUNG ARCHITECTURE. THE MECHANISMS THAT LINK IDIOPATHIC PULMONARY FIBROSIS WITH AGEING AND ABERRANT EPITHELIAL ACTIVATION ARE UNKNOWN; EVIDENCE SUGGESTS THAT THE ABNORMAL RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND EPIGENETIC CHANGES HAVE A ROLE. IN THIS SEMINAR, WE REVIEW RECENT DATA ON THE CLINICAL COURSE, THERAPEUTIC OPTIONS, AND UNDERLYING MECHANISMS THOUGHT TO BE INVOLVED IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS. 2011 14 6053 18 THE CRUCIAL ROLE OF NLRP3 INFLAMMASOME IN VIRAL INFECTION-ASSOCIATED FIBROSING INTERSTITIAL LUNG DISEASES. IDIOPATHIC PULMONARY FIBROSIS (IPF), ONE OF THE MOST COMMON FIBROSING INTERSTITIAL LUNG DISEASES (ILD), IS A CHRONIC-AGE-RELATED RESPIRATORY DISEASE THAT RISES FROM REPEATED MICRO-INJURY OF THE ALVEOLAR EPITHELIUM. ENVIRONMENTAL INFLUENCES, INTRINSIC FACTORS, GENETIC AND EPIGENETIC RISK FACTORS THAT LEAD TO CHRONIC INFLAMMATION MIGHT BE IMPLICATED IN THE DEVELOPMENT OF IPF. THE EXACT TRIGGERS THAT INITIATE THE FIBROTIC RESPONSE IN IPF REMAIN ENIGMATIC, BUT THERE IS NOW INCREASING EVIDENCE SUPPORTING THE ROLE OF CHRONIC EXPOSURE OF VIRAL INFECTION. DURING VIRAL INFECTION, ACTIVATION OF THE NLRP3 INFLAMMASOME BY INTEGRATING MULTIPLE CELLULAR AND MOLECULAR SIGNALING IMPLICATES ROBUST INFLAMMATION, FIBROBLAST PROLIFERATION, ACTIVATION OF MYOFIBROBLAST, MATRIX DEPOSITION, AND ABERRANT EPITHELIAL-MESENCHYMAL FUNCTION. OVERALL, THE CROSSTALK OF THE NLRP3 INFLAMMASOME AND VIRUSES CAN ACTIVATE IMMUNE RESPONSES AND INFLAMMASOME-ASSOCIATED MOLECULES IN THE DEVELOPMENT, PROGRESSION, AND EXACERBATION OF IPF. 2021 15 5159 19 PRE-RHEUMATOID ARTHRITIS: PREDISPOSITION AND TRANSITION TO CLINICAL SYNOVITIS. MULTIPLE PROVEN AND POTENTIAL RISK FACTORS FOR THE DEVELOPMENT OF RHEUMATOID ARTHRITIS (RA) HAVE BEEN IDENTIFIED, AND REPRESENT INTERACTIONS BETWEEN GENES AND THE ENVIRONMENT. PROVEN RISK FACTORS INCLUDE GENETIC INFLUENCES ON THE FUNCTION OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS, SMOKING, ANTI-CITRULLINATED PROTEIN ANTIBODIES (ACPAS), AND RHEUMATOID FACTORS (RF). POTENTIAL RISK FACTORS INCLUDE EPIGENETIC CONTROL OF GENE EXPRESSION, THE MICROBIOME AND OTHER ENVIRONMENTAL FACTORS, TOLL-LIKE RECEPTORS, CYTOKINES, AND FC RECEPTORS. PRECLINICAL ABNORMALITIES SUCH AS CIRCULATING RF AND ACPAS MAY OCCUR MORE THAN 10 YEARS PRIOR TO THE ONSET OF CLINICAL DISEASE. HOWEVER, THE PRECISE MECHANISMS WHEREBY THESE RISK FACTORS LEAD TO CLINICAL DISEASE REMAIN UNCLEAR. IT IS POSSIBLE THAT, COMBINED WITH ACTIVATION OF THE INNATE IMMUNE SYSTEM, A SUBSET OF ACPAS INITIATES THE DISEASE IN THE CARTILAGE OR SYNOVIUM AFTER BINDING TO ENDOGENOUS CITRULLINATED PROTEINS. SUBSEQUENT ENGAGEMENT OF FC RECEPTORS AND COMPLEMENT ACTIVATION WOULD LEAD TO SECONDARY INFLAMMATION IN THE SYNOVIUM WITH INDUCTION OF A PERPETUATING CYCLE OF CHRONIC SYNOVITIS. 2012 16 4097 24 MATRIX STIFFNESS REGULATES MACROPHAGE POLARIZATION IN ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE AND THE PATHOLOGICAL BASIS OF MANY FATAL CARDIOVASCULAR DISEASES. MACROPHAGES, THE MAIN INFLAMMATORY CELLS IN ATHEROSCLEROTIC PLAQUE, HAVE A PARADOX ROLE IN DISEASE PROGRESSION. IN RESPONSE TO DIFFERENT MICROENVIRONMENTS, MACROPHAGES MAINLY HAVE TWO POLARIZED DIRECTIONS: PRO-INFLAMMATORY MACROPHAGES AND ANTI-INFLAMMATORY MACROPHAGES. MORE AND MORE EVIDENCE SHOWS THAT MACROPHAGE IS MECHANOSENSITIVE AND MATRIX STIFFNESS REGULATE MACROPHAGE PHENOTYPES IN ATHEROSCLEROSIS. HOWEVER, THE MOLECULAR MECHANISM OF MATRIX STIFFNESS REGULATING MACROPHAGE POLARIZATION STILL LACKS IN-DEPTH RESEARCH, WHICH HINDERS THE DEVELOPMENT OF NEW ANTI-ATHEROSCLEROTIC THERAPIES. IN THIS REVIEW, WE DISCUSS THE IMPORTANT ROLE OF MATRIX STIFFNESS IN REGULATING MACROPHAGE POLARIZATION THROUGH MECHANICAL SIGNAL TRANSDUCTION (HIPPO, PIEZO, CYTOSKELETON, AND INTEGRIN) AND EPIGENETIC MECHANISMS (MIRNA, DNA METHYLATION, AND HISTONE). WE HOPE TO PROVIDE A NEW PERSPECTIVE FOR ATHEROSCLEROSIS THERAPY BY TARGETING MATRIX STIFFNESS AND MACROPHAGE POLARIZATION. 2022 17 5423 25 REGULATION OF MACROPHAGE ACTIVATION AND DIFFERENTIATION IN ATHEROSCLEROSIS. CHRONIC INFLAMMATION IS A HALLMARK OF ATHEROSCLEROSIS AND MACROPHAGES PLAY A CENTRAL ROLE IN CONTROLLING INFLAMMATION AT ALL STAGES OF ATHEROSCLEROSIS. IN ATHEROSCLEROSIS, MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES ARE CONTINUOUSLY EXPOSED TO CHOLESTEROL, OXIDIZED LIPIDS, CELL DEBRIS, CYTOKINES, AND CHEMOKINES. NOT ONLY DO THESE STIMULI INDUCE A SPECIFIC MACROPHAGE PHENOTYPE, BUT THEY ALSO INTERACT EXTENSIVELY, LEADING TO MACROPHAGE HETEROGENEITY IN ATHEROSCLEROTIC PLAQUES. HEREIN, WE REVIEW THE DIVERSE PHENOTYPES OF MACROPHAGES, THE MECHANISMS UNDERLYING MACROPHAGE ACTIVATION, AND THE CONTRIBUTIONS OF MACROPHAGES TO ATHEROSCLEROSIS IN THIS CONTEXT. WE ALSO SUMMARIZE RECENT STUDIES ON FOAMY MACROPHAGES AND MONOCYTE-DERIVED MACROPHAGES IN PLAQUE DURING DISEASE PROGRESSION. WE PROVIDE A COMPREHENSIVE OVERVIEW OF TRANSCRIPTIONAL, EPIGENETIC, AND METABOLIC REPROGRAMMING OF MACROPHAGES AND DISCUSS THE EMERGING CONCEPTS OF TARGETING CYTOKINES AND MACROPHAGES TO MODULATE ATHEROSCLEROSIS. 2021 18 6741 21 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 19 5726 22 SKIN WELL-BEING IN DIABETES: ROLE OF MACROPHAGES. MACROPHAGES ARE KEY PLAYERS IN WOUND HEALING- ALONG WITH MEDIATING THE ACUTE INFLAMMATORY RESPONSE, MACROPHAGES ACTIVATE CUTANEOUS EPITHELIAL CELLS AND PROMOTE TISSUE REPAIR. DIABETES COMPLICATIONS, INCLUDING DIABETIC CHRONIC WOUNDS, ARE ACCOMPANIED BY PERSISTENT INFLAMMATION AND MACROPHAGE MALFUNCTION. SEVERAL STUDIES INDICATE THAT HYPERGLYCEMIA INDUCES VARIOUS ALTERATIONS THAT AFFECT MACROPHAGE FUNCTION IN WOUND HEALING INCLUDING EPIGENETIC CHANGES, IMBALANCE BETWEEN PRO- AND ANTI-INFLAMMATORY MODULATORS, AND INSENSITIVITY TO PROLIFERATIVE STIMULI. IN THIS REVIEW, WE BRIEFLY SUMMARIZE RECENT STUDIES REGARDING THOSE ALTERATIONS AND THEIR IMPLICATIONS ON SKIN WELL-BEING IN DIABETES. 2020 20 3930 23 LIVER FIBROGENESIS: UN UPDATE ON ESTABLISHED AND EMERGING BASIC CONCEPTS. LIVER FIBROGENESIS IS DEFINED AS A DYNAMIC AND HIGHLY INTEGRATED PROCESS OCCURRING DURING CHRONIC INJURY TO LIVER PARENCHYMA THAT CAN RESULT IN EXCESS DEPOSITION OF EXTRACELLULAR MATRIX (ECM) COMPONENTS (I.E., LIVER FIBROSIS). LIVER FIBROGENESIS, TOGETHER WITH CHRONIC INFLAMMATORY RESPONSE, IS THEN PRIMARILY INVOLVED IN THE PROGRESSION OF CHRONIC LIVER DISEASES (CLD) IRRESPECTIVE OF THE SPECIFIC ETIOLOGY. IN THE PRESENT REVIEW WE WILL FIRST OFFER A SYNTHETIC AND UPDATED OVERVIEW OF MAJOR BASIC CONCEPTS IN RELATION TO THE ROLE OF MYOFIBROBLASTS (MFS), MACROPHAGES AND OTHER HEPATIC CELL POPULATIONS INVOLVED IN CLD TO THEN OFFER AN OVERVIEW OF ESTABLISHED AND EMERGING ISSUES AND MECHANISMS THAT HAVE BEEN PROPOSED TO FAVOR AND/OR PROMOTE CLD PROGRESSION. A SPECIAL FOCUS WILL BE DEDICATED TO SELECTED ISSUES THAT INCLUDE EMERGING FEATURES IN THE FIELD OF CHOLANGIOPATHIES, THE EMERGING ROLE OF GENETIC AND EPIGENETIC FACTORS AS WELL AS OF HYPOXIA, HYPOXIA-INDUCIBLE FACTORS (HIFS) AND RELATED MEDIATORS. 2020