1 3931 84 LIVER INJURY AND THE ACTIVATION OF THE HEPATIC MYOFIBROBLASTS. LIVER FIBROSIS IS A WOUND HEALING PROCESS, THE END RESULT OF CHRONIC LIVER INJURY ELICITED BY DIFFERENT NOXIOUS STIMULI. ACTIVATED HEPATIC STELLATE CELLS OR MYOFIBROBLASTS AND PORTAL MYOFIBROBLASTS ARE CONSIDERED AS THE MAIN PRODUCERS OF THE EXTRACELLULAR MATRIX IN THE LIVER. UPON LIVER INJURY THE QUIESCENT STELLATE CELLS TRANSDIFFERENTIATE INTO MYOFIBROBLASTS A PROCESS HIGHLIGHTED BY THE LOSS OF VITAMIN A STORES, UPREGULATION OF INTERSTITIAL TYPE COLLAGENS, SMOOTH MUSCLE ALPHA ACTIN, MATRIX METALLOPROTEINASES, PROTEOGLYCANS, AND THE INDUCTION OF CELL SURVIVAL PATHWAYS. ACTIVATION OF HEPATIC STELLATE CELLS IS A RESULT OF A COMPLEX INTERPLAY BETWEEN THE PARENCHYMAL CELLS, IMMUNE CELLS, EXTRACELLULAR MATRIX MECHANICS AND EXTRAHEPATIC MILIEU SUCH AS THE GUT MICROBIOME. IN THIS REVIEW WE WILL FOCUS ON THE PATHOMECHANISM OF STELLATE CELL ACTIVATION FOLLOWING CHRONIC LIVER INJURY; WITH THE AIM OF IDENTIFYING POSSIBLE TREATMENT TARGETS FOR ANTI-FIBROGENIC AGENTS. 2013 2 3512 25 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 3 3885 32 KIDNEY FIBROSIS: FROM MECHANISMS TO THERAPEUTIC MEDICINES. CHRONIC KIDNEY DISEASE (CKD) IS ESTIMATED TO AFFECT 10-14% OF GLOBAL POPULATION. KIDNEY FIBROSIS, CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION LEADING TO SCARRING, IS A HALLMARK MANIFESTATION IN DIFFERENT PROGRESSIVE CKD; HOWEVER, AT PRESENT NO ANTIFIBROTIC THERAPIES AGAINST CKD EXIST. KIDNEY FIBROSIS IS IDENTIFIED BY TUBULE ATROPHY, INTERSTITIAL CHRONIC INFLAMMATION AND FIBROGENESIS, GLOMERULOSCLEROSIS, AND VASCULAR RAREFACTION. FIBROTIC NICHE, WHERE ORGAN FIBROSIS INITIATES, IS A COMPLEX INTERPLAY BETWEEN INJURED PARENCHYMA (LIKE TUBULAR CELLS) AND MULTIPLE NON-PARENCHYMAL CELL LINEAGES (IMMUNE AND MESENCHYMAL CELLS) LOCATED SPATIALLY WITHIN SCARRING AREAS. ALTHOUGH THE MECHANISMS OF KIDNEY FIBROSIS ARE COMPLICATED DUE TO THE KINDS OF CELLS INVOLVED, WITH THE HELP OF SINGLE-CELL TECHNOLOGY, MANY KEY QUESTIONS HAVE BEEN EXPLORED, SUCH AS WHAT KIND OF RENAL TUBULES ARE PROFIBROTIC, WHERE MYOFIBROBLASTS ORIGINATE, WHICH IMMUNE CELLS ARE INVOLVED, AND HOW CELLS COMMUNICATE WITH EACH OTHER. IN ADDITION, GENETICS AND EPIGENETICS ARE DEEPER MECHANISMS THAT REGULATE KIDNEY FIBROSIS. AND THE REVERSIBLE NATURE OF EPIGENETIC CHANGES INCLUDING DNA METHYLATION, RNA INTERFERENCE, AND CHROMATIN REMODELING, GIVES AN OPPORTUNITY TO STOP OR REVERSE KIDNEY FIBROSIS BY THERAPEUTIC STRATEGIES. MORE MARKETED (E.G., RAS BLOCKAGE, SGLT2 INHIBITORS) HAVE BEEN DEVELOPED TO DELAY CKD PROGRESSION IN RECENT YEARS. FURTHERMORE, A BETTER UNDERSTANDING OF RENAL FIBROSIS IS ALSO FAVORED TO DISCOVER BIOMARKERS OF FIBROTIC INJURY. IN THE REVIEW, WE UPDATE RECENT ADVANCES IN THE MECHANISM OF RENAL FIBROSIS AND SUMMARIZE NOVEL BIOMARKERS AND ANTIFIBROTIC TREATMENT FOR CKD. 2023 4 3674 27 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 5 3930 26 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 6 2502 26 EPIGENETICS AND LIVER FIBROSIS. LIVER FIBROSIS ARISES BECAUSE PROLONGED INJURY COMBINED WITH EXCESSIVE SCAR DEPOSITION WITHIN HEPATIC PARENCHYMA ARISING FROM OVERACTIVE WOUND HEALING RESPONSE MEDIATED BY ACTIVATED MYOFIBROBLASTS. FIBROSIS IS THE COMMON END POINT FOR ANY TYPE OF CHRONIC LIVER INJURY INCLUDING ALCOHOLIC LIVER DISEASE, NONALCOHOLIC FATTY LIVER DISEASE, VIRAL HEPATITIS, AND CHOLESTATIC LIVER DISEASES. ALTHOUGH GENETIC INFLUENCES ARE IMPORTANT, IT IS EPIGENETIC MECHANISMS THAT HAVE BEEN SHOWN TO ORCHESTRATE MANY ASPECTS OF FIBROGENESIS IN THE LIVER. NEW DISCOVERIES IN THE FIELD ARE LEADING TOWARD THE DEVELOPMENT OF EPIGENETIC BIOMARKERS AND TARGETED THERAPIES. THIS REVIEW CONSIDERS EPIGENETIC MECHANISMS AS WELL AS RECENT ADVANCES IN EPIGENETIC PROGRAMMING IN THE CONTEXT OF HEPATIC FIBROSIS. 2017 7 3245 23 HEPATIC STELLATE CELLS AS KEY TARGET IN LIVER FIBROSIS. PROGRESSIVE LIVER FIBROSIS, INDUCED BY CHRONIC VIRAL AND METABOLIC DISORDERS, LEADS TO MORE THAN ONE MILLION DEATHS ANNUALLY VIA DEVELOPMENT OF CIRRHOSIS, ALTHOUGH NO ANTIFIBROTIC THERAPY HAS BEEN APPROVED TO DATE. TRANSDIFFERENTIATION (OR "ACTIVATION") OF HEPATIC STELLATE CELLS IS THE MAJOR CELLULAR SOURCE OF MATRIX PROTEIN-SECRETING MYOFIBROBLASTS, THE MAJOR DRIVER OF LIVER FIBROGENESIS. PARACRINE SIGNALS FROM INJURED EPITHELIAL CELLS, FIBROTIC TISSUE MICROENVIRONMENT, IMMUNE AND SYSTEMIC METABOLIC DYSREGULATION, ENTERIC DYSBIOSIS, AND HEPATITIS VIRAL PRODUCTS CAN DIRECTLY OR INDIRECTLY INDUCE STELLATE CELL ACTIVATION. DYSREGULATED INTRACELLULAR SIGNALING, EPIGENETIC CHANGES, AND CELLULAR STRESS RESPONSE REPRESENT CANDIDATE TARGETS TO DEACTIVATE STELLATE CELLS BY INDUCING REVERSION TO INACTIVATED STATE, CELLULAR SENESCENCE, APOPTOSIS, AND/OR CLEARANCE BY IMMUNE CELLS. CELL TYPE- AND TARGET-SPECIFIC PHARMACOLOGICAL INTERVENTION TO THERAPEUTICALLY INDUCE THE DEACTIVATION WILL ENABLE MORE EFFECTIVE AND LESS TOXIC PRECISION ANTIFIBROTIC THERAPIES. 2017 8 5988 22 TGF-BETA/SMAD AND RENAL FIBROSIS. RENAL FIBROSIS IS CHARACTERIZED BY EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX (ECM) THAT DISRUPTS AND REPLACES FUNCTIONAL PARENCHYMA, WHICH LEADS TO ORGAN FAILURE. IT IS KNOWN AS THE MAJOR PATHOLOGICAL MECHANISM OF CHRONIC KIDNEY DISEASE (CKD). ALTHOUGH CKD HAS AN IMPACT ON NO LESS THAN 10% OF THE WORLD POPULATION, THERAPEUTIC OPTIONS ARE STILL LIMITED. REGARDLESS OF ETIOLOGY, ELEVATED TGF-BETA LEVELS ARE HIGHLY CORRELATED WITH THE ACTIVATED PRO-FIBROTIC PATHWAYS AND DISEASE PROGRESSION. TGF-BETA, THE KEY DRIVER OF RENAL FIBROSIS, IS INVOLVED IN A DYNAMIC PATHOPHYSIOLOGICAL PROCESS THAT LEADS TO CKD AND END-STAGE RENAL DISEASE (ESRD). IT IS BECOMING CLEAR THAT EPIGENETICS REGULATES RENAL PROGRAMMING, AND THEREFORE, THE DEVELOPMENT AND PROGRESSION OF RENAL DISEASE. INDEED, RECENT EVIDENCE SHOWS TGF-BETA1/SMAD SIGNALING REGULATES RENAL FIBROSIS VIA EPIGENETIC-CORRELATED MECHANISMS. THIS REVIEW FOCUSES ON THE FUNCTION OF TGF-BETA/SMADS IN RENAL FIBROGENESIS, AND THE ROLE OF EPIGENETICS AS A REGULATOR OF PRO-FIBROTIC GENE EXPRESSION. 2019 9 6053 14 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 10 1143 23 CONCISE REVIEW: CLINICAL PROSPECTS FOR TREATING CHRONIC OBSTRUCTIVE PULMONARY DISEASE WITH REGENERATIVE APPROACHES. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS BECOMING A MAJOR CAUSE OF DEATH WORLDWIDE. COPD IS CHARACTERIZED BY A PROGRESSIVE AND NOT FULLY REVERSIBLE AIRFLOW LIMITATION CAUSED BY CHRONIC SMALL AIRWAY DISEASE AND LUNG PARENCHYMAL DESTRUCTION. CLINICALLY AVAILABLE DRUGS IMPROVE AIRFLOW OBSTRUCTION AND RESPIRATORY SYMPTOMS BUT CANNOT CURE THE DISEASE. SLOWING THE PROGRESSIVE LUNG DESTRUCTION OR REBUILDING THE DESTROYED LUNG STRUCTURE IS A PROMISING STRATEGY TO CURE COPD. IN CONTRAST TO SMALL ANIMAL MODELS, PHARMACOLOGICAL LUNG REGENERATION IS DIFFICULT IN HUMAN COPD. MATURATION, AGING, AND SENESCENCE IN COPD LUNG CELLS, INCLUDING ENDOGENOUS STEM CELLS, MAY AFFECT THE REGENERATIVE CAPACITY FOLLOWING PHARMACOLOGICAL THERAPY. THE LUNG IS A COMPLEX ORGAN COMPOSED OF MORE THAN 40 DIFFERENT CELL TYPES; THEREFORE, DETAILED ANALYSES, SUCH AS EPIGENETIC MODIFICATION ANALYSIS, IN EACH SPECIFIC CELL TYPE HAVE NOT BEEN PERFORMED IN LUNGS WITH COPD. RECENTLY, A METHOD FOR THE DIRECT ISOLATION OF INDIVIDUAL CELL TYPES FROM HUMAN LUNG HAS BEEN DEVELOPED, AND FINGERPRINTS OF EACH CELL TYPE IN COPD LUNGS CAN BE ANALYZED. RESEARCH USING THIS TECHNIQUE COMBINED WITH THE RECENTLY DISCOVERED LUNG ENDOGENOUS STEM-PROGENITOR POPULATIONS WILL GIVE A BETTER UNDERSTANDING ABOUT THE FATE OF COPD LUNG CELLS AND PROVIDE A FUTURE FOR CELL-BASED THERAPY TO TREAT THIS INTRACTABLE DISEASE. 2012 11 5950 26 TARGETING THE PROGRESSION OF CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS A DEVASTATING CONDITION THAT IS REACHING EPIDEMIC LEVELS OWING TO THE INCREASING PREVALENCE OF DIABETES MELLITUS, HYPERTENSION AND OBESITY, AS WELL AS AGEING OF THE POPULATION. REGARDLESS OF THE UNDERLYING AETIOLOGY, CKD IS SLOWLY PROGRESSIVE AND LEADS TO IRREVERSIBLE NEPHRON LOSS, END-STAGE RENAL DISEASE AND/OR PREMATURE DEATH. FACTORS THAT CONTRIBUTE TO CKD PROGRESSION INCLUDE PARENCHYMAL CELL LOSS, CHRONIC INFLAMMATION, FIBROSIS AND REDUCED REGENERATIVE CAPACITY OF THE KIDNEY. CURRENT THERAPIES HAVE LIMITED EFFECTIVENESS AND ONLY DELAY DISEASE PROGRESSION, UNDERSCORING THE NEED TO DEVELOP NOVEL THERAPEUTIC APPROACHES TO EITHER STOP OR REVERSE PROGRESSION. PRECLINICAL STUDIES HAVE IDENTIFIED SEVERAL APPROACHES THAT REDUCE FIBROSIS IN EXPERIMENTAL MODELS, INCLUDING TARGETING CYTOKINES, TRANSCRIPTION FACTORS, DEVELOPMENTAL AND SIGNALLING PATHWAYS AND EPIGENETIC MODULATORS, PARTICULARLY MICRORNAS. SOME OF THESE NEPHROPROTECTIVE STRATEGIES ARE NOW BEING TESTED IN CLINICAL TRIALS. LESSONS LEARNED FROM THE FAILURE OF CLINICAL STUDIES OF TRANSFORMING GROWTH FACTOR BETA1 (TGFBETA1) BLOCKADE UNDERSCORE THE NEED FOR ALTERNATIVE APPROACHES TO CKD THERAPY, AS STRATEGIES THAT TARGET A SINGLE PATHOGENIC PROCESS MAY RESULT IN UNEXPECTED NEGATIVE EFFECTS ON SIMULTANEOUSLY OCCURRING PROCESSES. ADDITIONAL PROMISING AVENUES INCLUDE PREVENTING TUBULAR CELL INJURY AND ANTI-FIBROTIC THERAPIES THAT TARGET ACTIVATED MYOFIBROBLASTS, THE MAIN COLLAGEN-PRODUCING CELLS. 2020 12 5769 25 SPECIFIC EPIGENETIC REGULATORS SERVE AS POTENTIAL THERAPEUTIC TARGETS IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF), A DISORDER OBSERVED MOSTLY IN OLDER HUMAN BEINGS, IS CHARACTERISED BY CHRONIC AND PROGRESSIVE LUNG SCARRING LEADING TO AN IRREVERSIBLE DECLINE IN LUNG FUNCTION. THIS HEALTH CONDITION HAS A DISMAL PROGNOSIS AND THE CURRENTLY AVAILABLE DRUGS ONLY DELAY BUT FAIL TO REVERSE THE PROGRESSION OF LUNG DAMAGE. CONSEQUENTLY, IT BECOMES IMPERATIVE TO DISCOVER IMPROVED THERAPEUTIC COMPOUNDS AND THEIR CELLULAR TARGETS TO CURE IPF. IN THIS REGARD, A NUMBER OF RECENT STUDIES HAVE TARGETED THE EPIGENETIC REGULATION BY HISTONE DEACETYLASES (HDACS) TO DEVELOP AND CATEGORISE ANTIFIBROTIC DRUGS FOR LUNGS. THEREFORE, THIS REVIEW FOCUSES ON HOW ABERRANT EXPRESSION OR ACTIVITY OF CLASSES I, II AND III HDACS ALTER TGF-BETA SIGNALLING TO PROMOTE EVENTS SUCH AS EPITHELIAL-MESENCHYMAL TRANSITION, DIFFERENTIATION OF ACTIVATED FIBROBLASTS INTO MYOFIBROBLASTS, AND EXCESS DEPOSITION OF THE EXTRACELLULAR MATRIX TO PROPEL LUNG FIBROSIS. FURTHER, THIS STUDY DESCRIBES HOW CERTAIN CHEMICAL COMPOUNDS OR DIETARY CHANGES MODULATE DYSREGULATED HDACS TO ATTENUATE FIVE FAULTY TGF-BETA-DEPENDENT PROFIBROTIC PROCESSES, BOTH IN ANIMAL MODELS AND CELL LINES REPLICATING IPF, THEREBY IDENTIFYING PROMISING MEANS TO TREAT THIS LUNG DISORDER. 2022 13 4882 24 OVERVIEW OF THE CELLULAR AND MOLECULAR BASIS OF KIDNEY FIBROSIS. THE COMMON PATHOGENETIC PATHWAY OF PROGRESSIVE INJURY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) IS EPITOMIZED AS NORMAL KIDNEY PARENCHYMAL DESTRUCTION DUE TO SCARRING (FIBROSIS). UNDERSTANDING THE FUNDAMENTAL PATHWAYS THAT LEAD TO RENAL FIBROSIS IS ESSENTIAL IN ORDER TO DEVELOP BETTER THERAPEUTIC OPTIONS FOR HUMAN CKD. ALTHOUGH COMPLEX, FOUR CELLULAR RESPONSES ARE PIVOTAL. (1) AN INTERSTITIAL INFLAMMATORY RESPONSE THAT HAS MULTIPLE CONSEQUENCES-SOME HARMFUL AND OTHERS HEALING. (2) THE APPEARANCE OF A UNIQUE INTERSTITIAL CELL POPULATION OF MYOFIBROBLASTS, PRIMARILY DERIVED FROM KIDNEY STROMAL CELLS (FIBROBLASTS AND PERICYTES), THAT ARE THE PRIMARY SOURCE OF THE VARIOUS EXTRACELLULAR MATRIX PROTEINS THAT FORM INTERSTITIAL SCARS. (3) TUBULAR EPITHELIAL CELLS THAT HAVE VARIABLE AND TIME-DEPENDENT ROLES AS EARLY RESPONDERS TO INJURY AND LATER AS VICTIMS OF FIBROSIS DUE TO THE LOSS OF THEIR REGENERATIVE ABILITIES. (4) LOSS OF INTERSTITIAL CAPILLARY INTEGRITY THAT COMPROMISES OXYGEN DELIVERY AND LEADS TO A VICIOUS CASCADE OF HYPOXIA-OXIDANT STRESS THAT ACCENTUATES INJURY AND FIBROSIS. IN THE ABSENCE OF ADEQUATE ANGIOGENIC RESPONSES, A HEALTHY INTERSTITIAL CAPILLARY NETWORK IS NOT MAINTAINED. THE FIBROTIC 'SCAR' THAT TYPIFIES CKD IS AN INTERESTING CONSORTIUM OF MULTIFUNCTIONAL MACROMOLECULES THAT NOT ONLY CHANGE IN COMPOSITION AND STRUCTURE OVER TIME, BUT CAN BE DEGRADED VIA EXTRACELLULAR AND INTRACELLULAR PROTEASES. ALTHOUGH TRANSFORMING GROWTH FACTOR BETA APPEARS TO BE THE PRIMARY DRIVER OF KIDNEY FIBROSIS, A VAST ARRAY OF ADDITIONAL MOLECULES MAY HAVE MODULATING ROLES. THE IMPORTANCE OF GENETIC AND EPIGENETIC FACTORS IS INCREASINGLY APPRECIATED. AN INTRIGUING BUT INCOMPLETELY UNDERSTOOD CARDIORENAL SYNDROME UNDERLIES THE HIGH MORBIDITY AND MORTALITY RATES THAT DEVELOP IN ASSOCIATION WITH PROGRESSIVE KIDNEY FIBROSIS. 2014 14 2817 23 FIBROSIS IN THE LIVER: ACUTE PROTECTION AND CHRONIC DISEASE. THE UNDERSTANDING OF THE CELLULAR AND MOLECULAR MECHANISMS OF THE FIBROTIC WOUND-HEALING RESPONSE OF THE LIVER HAS MADE DRAMATIC PROGRESS IN THE PAST 20 YEARS. HEPATIC STELLATE CELLS (HSCS), WHICH AFTER LIVER INJURY PROLIFERATE AND TRANSDIFFERENTIATE TO MYOFIBROBLASTS, HAVE EMERGED AS THE PRIMARY SOURCE OF THE FIBROTIC RESPONSE, EVEN THOUGH OTHER FIBROGENIC CELLS MAY ALSO CONTRIBUTE TO THE PRODUCTION OF EXTRACELLULAR MATRIX (ECM). ADVANCES IN THE UNDERSTANDING OF HSC REGULATION INCLUDE APOPTOTIC SIGNALING, ANGIOGENIC SIGNALING, AND RESPONSES TO OXIDATIVE STRESS. THE ECM HAS EMERGED NOT ONLY AS A STRUCTURAL SCAFFOLD, BUT ALSO AS A DYNAMIC AND INTERACTIVE MATRIX REGULATING STELLATE CELL ACTIVATION. ADDITIONALLY, THE INNATE IMMUNE SYSTEM AND IMMUNE SIGNALING, AS WELL AS A BROADENING UNDERSTANDING OF THE TRANSCRIPTIONAL REGULATION INCLUDING MICRORNAS AND EPIGENETIC EVENTS OFFER POTENTIAL THERAPEUTIC TARGETS. UNRAVELING GENETIC DETERMINANTS RELATED TO MECHANISMS OF HEPATIC FIBROGENESIS PROMISE INDIVIDUALIZED THERAPY OR PREVENTION. HEPATIC FIBROSIS AND CIRRHOSIS HAVE EMERGED AS TREATABLE AND POTENTIALLY REVERSIBLE CONSEQUENCE OF CHRONIC LIVER DISEASE. 2010 15 4658 15 NEW ANTI-INFLAMMATORY TARGETS FOR CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS ASSOCIATED WITH CHRONIC INFLAMMATION OF THE PERIPHERAL AIRWAYS AND LUNG PARENCHYMA, WHICH LEADS TO PROGRESSIVE OBSTRUCTION OF THE AIRWAYS. CURRENT MANAGEMENT WITH LONG-ACTING BRONCHODILATORS DOES NOT REDUCE DISEASE PROGRESSION, AND THERE ARE NO TREATMENTS THAT EFFECTIVELY SUPPRESS CHRONIC INFLAMMATION IN COPD. AN INCREASED UNDERSTANDING OF THE INFLAMMATORY PROCESSES THAT ARE INVOLVED IN THE PATHOPHYSIOLOGY OF COPD HAS IDENTIFIED SEVERAL NEW THERAPEUTIC TARGETS. THIS REVIEW DISCUSSES SOME OF THE MOST PROMISING OF THESE TARGETS, INCLUDING NEW ANTIOXIDANTS, KINASE INHIBITORS AND DRUGS THAT TARGET CELLULAR SENESCENCE, MICROBIAL COLONIZATION, EPIGENETIC REGULATION OF INFLAMMATORY GENE EXPRESSION AND CORTICOSTEROID RESISTANCE. 2013 16 2169 25 EPIGENETIC MECHANISMS IN PARENCHYMAL LUNG DISEASES: BYSTANDERS OR THERAPEUTIC TARGETS? EPIGENETIC RESPONSES DUE TO ENVIRONMENTAL CHANGES ALTER CHROMATIN STRUCTURE, WHICH IN TURN MODIFIES THE PHENOTYPE, GENE EXPRESSION PROFILE, AND ACTIVITY OF EACH CELL TYPE THAT HAS A ROLE IN THE PATHOPHYSIOLOGY OF A DISEASE. PULMONARY DISEASES ARE ONE OF THE MAJOR CAUSES OF DEATH IN THE WORLD, INCLUDING LUNG CANCER, IDIOPATHIC PULMONARY FIBROSIS (IPF), CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), PULMONARY HYPERTENSION (PH), LUNG TUBERCULOSIS, PULMONARY EMBOLISM, AND ASTHMA. SEVERAL LINES OF EVIDENCE INDICATE THAT EPIGENETIC MODIFICATIONS MAY BE ONE OF THE MAIN FACTORS TO EXPLAIN THE INCREASING INCIDENCE AND PREVALENCE OF LUNG DISEASES INCLUDING IPF AND COPD. INTERESTINGLY, ISOLATED FIBROBLASTS AND SMOOTH MUSCLE CELLS FROM PATIENTS WITH PULMONARY DISEASES SUCH AS IPF AND PH THAT WERE CULTURED EX VIVO MAINTAINED THE DISEASE PHENOTYPE. THE CELLS OFTEN SHOW A HYPER-PROLIFERATIVE, APOPTOSIS-RESISTANT PHENOTYPE WITH INCREASED EXPRESSION OF EXTRACELLULAR MATRIX (ECM) AND ACTIVATED FOCAL ADHESIONS SUGGESTING THE PRESENCE OF AN EPIGENETICALLY IMPRINTED PHENOTYPE. MOREOVER, MANY ABNORMALITIES OBSERVED IN MOLECULAR PROCESSES IN IPF PATIENTS ARE SHOWN TO BE EPIGENETICALLY REGULATED, SUCH AS INNATE IMMUNITY, CELLULAR SENESCENCE, AND APOPTOTIC CELL DEATH. DNA METHYLATION, HISTONE MODIFICATION, AND MICRORNA REGULATION CONSTITUTE THE MOST COMMON EPIGENETIC MODIFICATION MECHANISMS. 2022 17 3513 26 IDIOPATHIC PULMONARY FIBROSIS: PATHOGENESIS AND MANAGEMENT. BACKGROUND: IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE DISEASE CHARACTERIZED BY THE ABERRANT ACCUMULATION OF FIBROTIC TISSUE IN THE LUNGS PARENCHYMA, ASSOCIATED WITH SIGNIFICANT MORBIDITY AND POOR PROGNOSIS. THIS REVIEW WILL PRESENT THE SUBSTANTIAL ADVANCES ACHIEVED IN THE UNDERSTANDING OF IPF PATHOGENESIS AND IN THE THERAPEUTIC OPTIONS THAT CAN BE OFFERED TO PATIENTS, AND WILL ADDRESS THE ISSUES REGARDING DIAGNOSIS AND MANAGEMENT THAT ARE STILL OPEN. MAIN BODY: OVER THE LAST TWO DECADES MUCH HAS BEEN CLARIFIED ABOUT THE PATHOGENIC PATHWAYS UNDERLYING THE DEVELOPMENT AND PROGRESSION OF THE LUNG SCARRING IN IPF. SUSTAINED ALVEOLAR EPITHELIAL MICRO-INJURY AND ACTIVATION HAS BEEN RECOGNISED AS THE TRIGGER OF SEVERAL BIOLOGICAL EVENTS OF DISORDERED REPAIR OCCURRING IN GENETICALLY SUSCEPTIBLE AGEING INDIVIDUALS. DESPITE MULTIDISCIPLINARY TEAM DISCUSSION HAS DEMONSTRATED TO INCREASE DIAGNOSTIC ACCURACY, PATIENTS CAN STILL REMAIN UNCLASSIFIED WHEN THE CURRENT DIAGNOSTIC CRITERIA ARE STRICTLY APPLIED, REQUIRING THE IDENTIFICATION OF A USUAL INTERSTITIAL PATTERN EITHER ON HIGH-RESOLUTION COMPUTED TOMOGRAPHY SCAN OR LUNG BIOPSY. OUTSTANDING ACHIEVEMENTS HAVE BEEN MADE IN THE MANAGEMENT OF THESE PATIENTS, AS NINTEDANIB AND PIRFENIDONE CONSISTENTLY PROVED TO REDUCE THE RATE OF PROGRESSION OF THE FIBROTIC PROCESS. HOWEVER, MANY UNCERTAINTIES STILL LIE IN THE CORRECT USE OF THESE DRUGS, RANGING FROM THE INITIAL CHOICE OF THE DRUG, THE APPROPRIATE TIMING FOR TREATMENT AND THE BENEFIT-RISK RATIO OF A COMBINED TREATMENT REGIMEN. SEVERAL NOVEL COMPOUNDS ARE BEING DEVELOPED IN THE PERSPECTIVE OF A MORE TARGETED THERAPEUTIC APPROACH; IN THE MEANTIME, THE SUPPORTIVE CARE OF THESE PATIENTS AND THEIR CARERS SHOULD BE APPROPRIATELY PRIORITIZED, AND GREATER EFFORTS SHOULD BE MADE TOWARD THE PROMPT IDENTIFICATION AND MANAGEMENT OF RELEVANT COMORBIDITIES. CONCLUSIONS: BUILDING ON THE ADVANCES IN THE UNDERSTANDING OF IPF PATHOBIOLOGY, THE FURTHER INVESTIGATION OF THE ROLE OF GENE VARIANTS, EPIGENETIC ALTERATIONS AND OTHER MOLECULAR BIOMARKERS REFLECTING DISEASE ACTIVITY AND BEHAVIOUR WILL HOPEFULLY ENABLE EARLIER AND MORE CONFIDENT DIAGNOSIS, IMPROVE DISEASE PHENOTYPING AND SUPPORT THE DEVELOPMENT OF NOVEL AGENTS FOR PERSONALIZED TREATMENT OF IPF. 2018 18 6223 27 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 19 6621 24 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 20 5322 17 PULMONARY DISEASES AND AGEING. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND IDIOPATHIC PULMONARY FIBROSIS ARE REGARDED AS A DISEASES OF ACCELERATED LUNG AGEING AND SHOW ALL OF THE HALLMARKS OF AGEING, INCLUDING TELOMERE SHORTENING, CELLULAR SENESCENCE, ACTIVATION OF PI3 KINASE-MTOR SIGNALING, IMPAIRED AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, STEM CELL EXHAUSTION, EPIGENETIC CHANGES, ABNORMAL MICRORNA PROFILES, IMMUNOSENESCENCE AND A LOW GRADE CHRONIC INFLAMMATION DUE TO SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). MANY OF THESE AGEING MECHANISMS ARE DRIVEN BY EXOGENOUS AND ENDOGENOUS OXIDATIVE STRESS. THERE IS ALSO A REDUCTION IN ANTI-AGEING MOLECULES, SUCH AS SIRTUINS AND KLOTHO, WHICH FURTHER ACCELERATE THE AGEING PROCESS. UNDERSTANDING THESE MOLECULAR MECHANISMS HAS IDENTIFIED SEVERAL NOVEL THERAPEUTIC TARGETS AND SEVERAL DRUGS AND DIETARY INTERVENTIONS ARE NOW IN DEVELOPMENT TO TREAT CHRONIC LUNG DISEASE. 2019