1 2554 145 EPIGENETICS IN REACTIVE AND REPARATIVE CARDIAC FIBROGENESIS: THE PROMISE OF EPIGENETIC THERAPY. EPIGENETIC CHANGES PLAY A PIVOTAL ROLE IN THE DEVELOPMENT OF A WIDE SPECTRUM OF HUMAN DISEASES INCLUDING CARDIOVASCULAR DISEASES, CANCER, DIABETES, AND INTELLECTUAL DISABILITIES. CARDIAC FIBROGENESIS IS A COMMON PATHOPHYSIOLOGICAL PROCESS SEEN DURING CHRONIC AND STRESS-INDUCED ACCELERATED CARDIAC AGING. WHILE ADEQUATE PRODUCTION OF EXTRACELLULAR MATRIX (ECM) PROTEINS IS NECESSARY FOR POST-INJURY WOUND HEALING, EXCESSIVE SYNTHESIS AND ACCUMULATION OF EXTRACELLULAR MATRIX PROTEIN IN THE STRESSED OR INJURED HEARTS CAUSES DECREASED OR LOSS OF LUSITROPY THAT LEADS TO CARDIAC FAILURE. THIS SELF-PERPETUATING DEPOSITION OF COLLAGEN AND OTHER MATRIX PROTEINS EVENTUALLY ALTER CELLULAR HOMEOSTASIS; IMPAIR TISSUE ELASTICITY AND LEADS TO MULTI-ORGAN FAILURE, AS SEEN DURING PATHOGENESIS OF CARDIOVASCULAR DISEASES, CHRONIC KIDNEY DISEASES, CIRRHOSIS, IDIOPATHIC PULMONARY FIBROSIS, AND SCLERODERMA. IN THE LAST 25 YEARS, MULTIPLE STUDIES HAVE INVESTIGATED THE MOLECULAR BASIS OF ORGAN FIBROSIS AND HIGHLIGHTED ITS MULTI-FACTORIAL GENETIC, EPIGENETIC, AND ENVIRONMENTAL REGULATION. IN THIS MINIREVIEW, WE FOCUS ON FIVE MAJOR EPIGENETIC REGULATORS AND DISCUSS THEIR CENTRAL ROLE IN CARDIAC FIBROGENESIS. ADDITIONALLY, WE COMPARE AND CONTRAST THE EPIGENETIC REGULATION OF HYPERTENSION-INDUCED REACTIVE FIBROGENESIS AND MYOCARDIAL INFARCTION-INDUCED REPARATIVE OR REPLACEMENT CARDIAC FIBROGENESIS. AS MICRORNAS-ONE OF THE MAJOR EPIGENETIC REGULATORS-CIRCULATE IN PLASMA, WE ALSO ADVOCATE THEIR POTENTIAL DIAGNOSTIC ROLE IN CARDIAC FIBROSIS. LASTLY, WE DISCUSS THE EVOLUTION OF NOVEL EPIGENETIC-REGULATING DRUGS AND PREDICT THEIR CLINICAL ROLE IN THE SUPPRESSION OF PATHOLOGICAL CARDIAC REMODELING, CARDIAC AGING, AND HEART FAILURE. J. CELL. PHYSIOL. 232: 1941-1956, 2017. (C) 2016 WILEY PERIODICALS, INC. 2017 2 2791 38 FAT-FREE P300 IS GOOD FOR SCAR-FREE TISSUE REPAIR. FIBROSIS, THE DEADLY PATHOLOGICAL MANIFESTATION OF AN ABNORMAL TISSUE REMODELING IN ANY ORGAN DUE TO EXCESSIVE COLLAGEN DEPOSITION, IS ASSOCIATED WITH A WIDE VARIETY OF ORGAN FAILURE-RELATED HUMAN DISEASES. CHRONIC STRESS OR REPEATED INJURY IN A PARTICULAR ORGAN INDUCES ABNORMAL MOLECULAR SIGNALS THAT LEAD TO SUPER-ACTIVATION OF MATRIX PROTEIN PRODUCING FIBROBLASTS, EXCESSIVE MATRIX PROTEINS ACCUMULATION, LOSS OF PHYSIOLOGICAL TISSUE ARCHITECTURE OR ELASTICITY, AND ULTIMATELY LEADING TO ORGAN FAILURE. THERE IS NO EFFECTIVE THERAPY FOR FIBROSIS. FACTOR ACETYLTRANSFERASE P300 (FATP300), A MAJOR EPIGENETIC REGULATOR THAT ACETYLATES SPECIFIC LYSINES IN HISTONES AND TRANSCRIPTION FACTORS, IS ESSENTIAL FOR ELEVATED COLLAGEN SYNTHESIS AND THE LEVELS OF FATP300 ARE SIGNIFICANTLY ELEVATED IN DIFFERENT FIBROTIC TISSUES. PHARMACOLOGICAL INHIBITION OF FAT ACTIVITY OF P300 IS ASSOCIATED WITH DECREASED COLLAGEN SYNTHESIS BY FIBROBLASTS IN TISSUES AND AMELIORATION OF ORGAN FIBROSIS. THEREFORE, FAT-FREE P300 IS SUPERIOR FOR PHYSIOLOGICAL TISSUE REPAIR AND MUST BE EXPLOITED AS A VIABLE THERAPEUTIC TARGET AGAINST MULTI-ORGAN FIBROSIS. 2014 3 2218 35 EPIGENETIC MODIFICATIONS IN FIBROTIC DISEASES: IMPLICATIONS FOR PATHOGENESIS AND PHARMACOLOGICAL TARGETS. ORGAN FIBROSIS IS A COMPLEX AND CHRONIC DISORDER THAT RESULTS FROM A VARIETY OF ACUTE INJURIES AND CONTRIBUTES TO THIRTY PERCENT OF NATURALLY OCCURRING DEATHS WORLDWIDE. THE MAIN FEATURE OF ORGAN FIBROSIS IS THE EXCESSIVE ACCUMULATION AND DEPOSIT OF EXTRACELLULAR MATRIX, THEREBY LEADING TO ORGAN DYSFUNCTION, LOSS OF ELASTICITY, AND DEVELOPMENT OF A RIGID ORGAN. ACCUMULATING EVIDENCE SHOWS THAT EPIGENETIC REMODELING, INCLUDING ABERRANT DNA METHYLATION AND NONCODING RNA EXPRESSION AS WELL AS HISTONE POST-TRANSLATIONAL MODIFICATIONS, PLAY IMPORTANT ROLES IN THE PATHOGENESIS OF FIBROSIS THROUGH THE REGULATION OF FIBROBLAST ACTIVATION, DIFFERENTIATION, AND APOPTOSIS, AS WELL AS COLLAGEN SYNTHESIS AND PROFIBROTIC GENE TRANSCRIPTION. IN THIS REVIEW, WE DISCUSS THE BASIC REGULATION OF DNA METHYLATION, NONCODING RNA EXPRESSION, AND HISTONE POST-TRANSLATIONAL MODIFICATION, AND THEIR PARTICIPATION IN THE PATHOGENESIS AND DEVELOPMENT OF ORGAN FIBROSIS. THIS REVIEW ALSO PROVIDES THE LATEST INSIGHTS INTO THE NOVEL BIOMARKERS AND THERAPEUTIC TARGETS FOR FIBROSIS THROUGH MODULATION OF EPIGENETIC REMODELING. 2015 4 4873 31 OVER-EXPRESSION OF PROTHYMOSIN-ALPHA ANTAGONIZES TGFBETA SIGNALLING TO PROMOTE THE DEVELOPMENT OF EMPHYSEMA. EMPHYSEMA, A MAJOR CONSEQUENCE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IS CHARACTERIZED BY THE PERMANENT AIRFLOW RESTRICTION RESULTING FROM ENLARGEMENT OF ALVEOLAR AIRSPACE AND LOSS OF LUNG ELASTICITY. TRANSFORMING GROWTH FACTOR-BETA (TGFBETA) SIGNALLING REGULATES THE BALANCE OF MATRIX METALLOPROTEINASE (MMP)/TISSUE INHIBITOR OF MATRIX METALLOPROTEINASE (TIMP) TO CONTROL MATRIX HOMEOSTASIS. PATIENTS WITH COPD HAVE DYSREGULATED TGFBETA SIGNALLING AND REDUCED HISTONE DEACETYLASE (HDAC) ACTIVITY THROUGH EPIGENETIC UP-REGULATION OF HISTONE ACETYLATION IN THE PROMOTERS OF PRO-INFLAMMATORY GENES. HOWEVER, THE POTENTIAL LINK BETWEEN DECREASED HDAC ACTIVITY AND DYSREGULATED TGFBETA SIGNALLING IN EMPHYSEMA PATHOGENESIS REMAINS TO BE DETERMINED. PROTHYMOSIN ALPHA (PROT), A HIGHLY CONSERVED ACIDIC NUCLEAR PROTEIN, PLAYS A ROLE IN THE ACETYLATION OF HISTONE AND NON-HISTONE PROTEINS. THE AIM OF THIS STUDY WAS TO TEST THE HYPOTHESIS THAT PROT INHIBITS TGFBETA-SMAD SIGNALLING THROUGH SMAD7, THEREBY CONTRIBUTING TO EMPHYSEMA PATHOGENESIS. WE SHOW THAT PROT ENHANCES SMAD7 ACETYLATION BY DECREASING ITS ASSOCIATION WITH HDAC AND THEREBY DOWN-REGULATES TGFBETA-SMAD SIGNALLING. PROT CAUSED AN IMBALANCE BETWEEN MMP AND TIMP THROUGH ACETYLATED SMAD7 IN FAVOUR OF MMP EXPRESSION. IN ADDITION TO INTERFERING WITH R-SMAD ACTIVATION AND TARGETING RECEPTORS FOR DEGRADATION IN THE CYTOPLASM, ACETYLATED SMAD7 POTENTIATED BY PROT COMPETITIVELY ANTAGONIZED BINDING OF THE PSMAD2/3-SMAD4 COMPLEX TO THE TIMP-3 PROMOTER, RESULTING IN REDUCED TIMP-3 EXPRESSION. THESE EFFECTS WERE DETECTED IN PROT-OVER-EXPRESSING CELLS, LUNGS OF PROT TRANSGENIC MICE DISPLAYING AN EMPHYSEMA PHENOTYPE AND IN EMPHYSEMA PATIENTS. IMPORTANTLY, INCREASED SMAD7 AND REDUCED TIMP-3 WERE FOUND IN THE LUNGS OF EMPHYSEMA PATIENTS AND MICE WITH CIGARETTE SMOKE EXTRACT (CSE)-INDUCED EMPHYSEMA. SUCH EFFECTS COULD BE ABROGATED BY SILENCING ENDOGENOUS PROT EXPRESSION. COLLECTIVELY, OUR RESULTS UNCOVER ACETYLATED SMAD7 REGULATED BY PROT AS AN IMPORTANT DETERMINANT IN DYSREGULATED TGFBETA SIGNALLING THAT CONTRIBUTES TO EMPHYSEMA PATHOGENESIS. 2016 5 383 30 AN EPIGENOME-WIDE STUDY OF DNA METHYLATION PROFILES AND LUNG FUNCTION AMONG AMERICAN INDIANS IN THE STRONG HEART STUDY. BACKGROUND: EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION (DNAM), ARE OFTEN RELATED TO ENVIRONMENTAL EXPOSURES, AND ARE INCREASINGLY RECOGNIZED AS KEY PROCESSES IN THE PATHOGENESIS OF CHRONIC LUNG DISEASE. AMERICAN INDIAN COMMUNITIES HAVE A HIGH BURDEN OF LUNG DISEASE COMPARED TO THE NATIONAL AVERAGE. THE OBJECTIVE OF THIS STUDY WAS TO INVESTIGATE THE ASSOCIATION OF DNAM AND LUNG FUNCTION IN THE STRONG HEART STUDY (SHS). WE CONDUCTED A CROSS-SECTIONAL STUDY OF AMERICAN INDIAN ADULTS, 45-74 YEARS OF AGE WHO PARTICIPATED IN THE SHS. DNAM WAS MEASURED USING THE ILLUMINA INFINIUM HUMAN METHYLATIONEPIC PLATFORM AT BASELINE (1989-1991). LUNG FUNCTION WAS MEASURED VIA SPIROMETRY, INCLUDING FORCED EXPIRATORY VOLUME IN 1 S (FEV1) AND FORCED VITAL CAPACITY (FVC), AT VISIT 2 (1993-1995). AIRFLOW LIMITATION WAS DEFINED AS FEV1 < 70% PREDICTED AND FEV1/FVC < 0.7, RESTRICTION WAS DEFINED AS FEV1/FVC > 0.7 AND FVC < 80% PREDICTED, AND NORMAL SPIROMETRY WAS DEFINED AS FEV1/FVC > 0.7, FEV1 > 70% PREDICTED, FVC > 80% PREDICTED. WE USED ELASTIC-NET MODELS TO SELECT RELEVANT CPGS FOR LUNG FUNCTION AND SPIROMETRY-DEFINED LUNG DISEASE. WE ALSO CONDUCTED BIOINFORMATIC ANALYSES TO EVALUATE THE BIOLOGICAL PLAUSIBILITY OF THE FINDINGS. RESULTS: AMONG 1677 PARTICIPANTS, 21.2% HAD SPIROMETRY-DEFINED AIRFLOW LIMITATION AND 13.6% HAD SPIROMETRY-DEFINED RESTRICTIVE PATTERN LUNG FUNCTION. ELASTIC-NET MODELS SELECTED 1118 DIFFERENTIALLY METHYLATED POSITIONS (DMPS) AS PREDICTORS OF AIRFLOW LIMITATION AND 1385 FOR RESTRICTIVE PATTERN LUNG FUNCTION. A TOTAL OF 12 DMPS OVERLAPPED BETWEEN AIRFLOW LIMITATION AND RESTRICTIVE PATTERN. EGFR, MAPK1 AND PRPF8 GENES WERE THE MOST CONNECTED NODES IN THE PROTEIN-PROTEIN INTERACTION NETWORK. MANY OF THE DMPS TARGETED GENES WITH BIOLOGICAL ROLES RELATED TO LUNG FUNCTION SUCH AS PROTEIN KINASES. CONCLUSION: WE FOUND MULTIPLE DIFFERENTIALLY METHYLATED CPG SITES ASSOCIATED WITH CHRONIC LUNG DISEASE. THESE SIGNALS COULD CONTRIBUTE TO BETTER UNDERSTAND MOLECULAR MECHANISMS INVOLVED IN LUNG DISEASE, AS ASSESSED SYSTEMICALLY, AS WELL AS TO IDENTIFY PATTERNS THAT COULD BE USEFUL FOR DIAGNOSTIC PURPOSES. FURTHER EXPERIMENTAL AND LONGITUDINAL STUDIES ARE NEEDED TO ASSESS WHETHER DNA METHYLATION HAS A CAUSAL ROLE IN LUNG DISEASE. 2022 6 292 36 AGING AND SUSCEPTIBILITY TO PULMONARY DISEASE. THE LUNGS ARE CONTINUALLY SUBJECTED TO NOXIOUS AND INERT SUBSTANCES, ARE IMMUNOLOGICALLY ACTIVE, AND ARE IN A CONSTANT STATE OF DAMAGE AND REPAIR. THIS MAKES THE PULMONARY SYSTEM PARTICULARLY VULNERABLE TO DISEASES OF AGING. AGING CAN BE UNDERSTOOD AS RANDOM MOLECULAR DAMAGE THAT IS UNREPAIRED AND ACCUMULATES OVER TIME, RESULTING IN CELLULAR DEFECTS AND TISSUE DYSFUNCTION. THE BREAKDOWN OF CELLULAR MECHANISMS, INCLUDING STEM CELL EXHAUSTION, GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATION, LOSS OF PROTEOSTASIS, DEREGULATED NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, ALTERED INTERCELLULAR COMMUNICATION, AND CHANGES IN THE EXTRACELLULAR MATRIX IS THOUGHT TO ADVANCE THE AGING PROCESS ITSELF. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IDIOPATHIC PULMONARY FIBROSIS (IPF), AND CANCERS ILLUSTRATE A PATHOLOGIC BREAKDOWN IN THESE MECHANISMS BEYOND NORMAL AGING. THE IMMUNE SYSTEM BECOMES LESS EFFECTIVE WITH ADVANCING AGE. THERE IS A LOW-LEVEL STATE OF CHRONIC INFLAMMATION TERMED INFLAMMAGING WHICH IS THOUGHT TO BE DRIVEN BY IMMUNOSENESCENCE, THE CHANGES IN THE INNATE AND ADAPTIVE IMMUNE SYSTEMS WITH ADVANCING AGE THAT LEAD TO DYSREGULATION AND DECREASED EFFECTIVENESS OF THE IMMUNE SYSTEM. THESE PROCESSES OF AGING LEAD TO EXPECTED CHANGES IN THE FORM AND FUNCTION OF THE RESPIRATORY SYSTEM, MOST NOTABLY A LOSS OF LUNG ELASTICITY, DECREASE IN RESPIRATORY MUSCLE STRENGTH, INCREASE IN VENTILATION-PERFUSION MISMATCHING, AND STIFFENING OF THE VASCULATURE. THE ASTUTE CLINICIAN IS AWARE OF THESE EXPECTED FINDINGS AND DOES NOT OFTEN ATTRIBUTE DYSPNEA TO AGING ALONE. MAINTAINING A LOW THRESHOLD TO INVESTIGATE FOR COMORBID DISEASE AND UNDERSTANDING HOW PULMONARY DISEASE PRESENTS DIFFERENTLY IN THE ELDERLY THAN IN YOUNGER ADULTS CAN IMPROVE CLINICAL OUTCOMES. (C) 2022 AMERICAN PHYSIOLOGICAL SOCIETY. COMPR PHYSIOL 12:3509-3522, 2022. 2022 7 3628 25 INACTIVATION OF NUCLEAR HISTONE DEACETYLASES BY EP300 DISRUPTS THE MICEE COMPLEX IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE, AND HIGHLY LETHAL LUNG DISEASE WITH UNKNOWN ETIOLOGY AND POOR PROGNOSIS. IPF PATIENTS DIE WITHIN 2 YEARS AFTER DIAGNOSIS MOSTLY DUE TO RESPIRATORY FAILURE. CURRENT TREATMENTS AGAINST IPF AIM TO AMELIORATE PATIENT SYMPTOMS AND TO DELAY DISEASE PROGRESSION. UNFORTUNATELY, THERAPIES TARGETING THE CAUSES OF OR REVERTING IPF HAVE NOT YET BEEN DEVELOPED. HERE WE SHOW THAT REDUCED LEVELS OF MIRNA LETHAL 7D (MIRLET7D) IN IPF COMPROMISE EPIGENETIC GENE SILENCING MEDIATED BY THE RIBONUCLEOPROTEIN COMPLEX MICEE. IN ADDITION, WE FIND THAT HYPERACTIVE EP300 REDUCES NUCLEAR HDAC ACTIVITY AND INTERFERES WITH MICEE FUNCTION IN IPF. REMARKABLY, EP300 INHIBITION REDUCES FIBROTIC HALLMARKS OF IN VITRO (PATIENT-DERIVED PRIMARY FIBROBLAST), IN VIVO (BLEOMYCIN MOUSE MODEL), AND EX VIVO (PRECISION-CUT LUNG SLICES, PCLS) IPF MODELS. OUR WORK PROVIDES THE MOLECULAR BASIS FOR THERAPIES AGAINST IPF USING EP300 INHIBITION. 2019 8 2020 32 EPIGENETIC CHANGES AND FUNCTIONS IN PNEUMOCONIOSIS. PNEUMOCONIOSIS IS ONE OF THE MOST COMMON OCCUPATIONAL DISEASES IN THE WORLD, AND SPECIFIC TREATMENT METHODS OF PNEUMOCONIOSIS ARE LACKING AT PRESENT, SO IT CARRIES GREAT SOCIAL AND ECONOMIC BURDENS. PNEUMOCONIOSIS, CORONAVIRUS DISEASE 2019, AND IDIOPATHIC PULMONARY FIBROSIS ALL HAVE SIMILAR TYPICAL PATHOLOGICAL CHANGES-PULMONARY FIBROSIS. PULMONARY FIBROSIS IS A CHRONIC LUNG DISEASE CHARACTERIZED BY EXCESSIVE DEPOSITION OF THE EXTRACELLULAR MATRIX AND REMODELING OF THE LUNG TISSUE STRUCTURE. CLARIFYING THE PATHOGENESIS OF PNEUMOCONIOSIS PLAYS AN IMPORTANT GUIDING ROLE IN ITS TREATMENT. THE OCCURRENCE AND DEVELOPMENT OF PNEUMOCONIOSIS ARE ACCOMPANIED BY EPIGENETIC FACTORS (E.G., DNA METHYLATION AND NONCODING RNA) CHANGES, WHICH IN TURN CAN PROMOTE OR INHIBIT THE PROCESS OF PNEUMOCONIOSIS. HERE, WE SUMMARIZE EPIGENETIC CHANGES AND FUNCTIONS IN THE SEVERAL KINDS OF EVIDENCE CLASSIFICATION (EPIDEMIOLOGICAL INVESTIGATION, IN VIVO, AND IN VITRO EXPERIMENTS) AND MAIN TYPES OF CELLS (MACROPHAGES, FIBROBLASTS, AND ALVEOLAR EPITHELIAL CELLS) TO PROVIDE SOME CLUES FOR FINDING SPECIFIC THERAPEUTIC TARGETS FOR PNEUMOCONIOSIS AND EVEN FOR PULMONARY FIBROSIS. 2022 9 5575 39 ROLE OF MICRORNAS IN SIGNALING PATHWAYS ASSOCIATED WITH THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS: A FOCUS ON EPITHELIAL-MESENCHYMAL TRANSITION. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC AND PROGRESSIVE DISEASE WITH HIGH MORTALITY AND UNCLEAR ETIOLOGY. PREVIOUS EVIDENCE SUPPORTS THAT THE ORIGIN OF THIS DISEASE IS ASSOCIATED WITH EPIGENETIC ALTERATIONS, AGE, AND ENVIRONMENTAL FACTORS. IPF INITIATES WITH CHRONIC EPITHELIAL LUNG INJURIES, FOLLOWED BY BASAL MEMBRANE DESTRUCTION, WHICH PROMOTES THE ACTIVATION OF MYOFIBROBLASTS AND EXCESSIVE SYNTHESIS OF EXTRACELLULAR MATRIX (ECM) PROTEINS, AS WELL AS EPITHELIAL-MESENCHYMAL TRANSITION (EMT). DUE TO MIRNAS' ROLE AS REGULATORS OF APOPTOSIS, PROLIFERATION, DIFFERENTIATION, AND CELL-CELL INTERACTION PROCESSES, SOME STUDIES HAVE INVOLVED MIRNAS IN THE BIOGENESIS AND PROGRESSION OF IPF. IN THIS CONTEXT, THE ANALYSIS AND DISCUSSION OF THE PROBABLE ASSOCIATION OF MIRNAS WITH THE SIGNALING PATHWAYS INVOLVED IN THE DEVELOPMENT OF IPF WOULD IMPROVE OUR KNOWLEDGE OF THE ASSOCIATED MOLECULAR MECHANISMS, THEREBY FACILITATING ITS EVALUATION AS A THERAPEUTIC TARGET FOR THIS SEVERE LUNG DISEASE. IN THIS WORK, THE MOST RECENT PUBLICATIONS EVALUATING THE ROLE OF MIRNAS AS REGULATORS OR ACTIVATORS OF SIGNAL PATHWAYS ASSOCIATED WITH THE PATHOGENESIS OF IPF WERE ANALYZED. THE SEARCH IN PUBMED WAS MADE USING THE FOLLOWING TERMS: "MIRNAS AND IDIOPATHIC PULMONARY FIBROSIS (IPF)"; "MIRNAS AND IPF AND SIGNALING PATHWAYS (SP)"; AND "MIRNAS AND IPF AND SP AND IPF PATHOGENESIS". ADDITIONALLY, WE FOCUS MAINLY ON THOSE WORKS WHERE THE SIGNALING PATHWAYS INVOLVED WITH EMT, FIBROBLAST DIFFERENTIATION, AND SYNTHESIS OF ECM COMPONENTS WERE ASSESSED. FINALLY, THE IMPORTANCE AND SIGNIFICANCE OF MIRNAS AS POTENTIAL THERAPEUTIC OR DIAGNOSTIC TOOLS FOR THE TREATMENT OF IPF ARE DISCUSSED. 2022 10 3512 27 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 11 4661 21 NEW ASPECTS OF THE EPIGENETIC REGULATION OF EMT RELATED TO PULMONARY FIBROSIS. PULMONARY FIBROSIS IS A CHRONIC AND PROGRESSIVE FIBROTIC DISEASE THAT RESULTS IN IMPAIRED GAS EXCHANGE, VENTILATION, AND EVENTUAL DEATH. THE PRO-FIBROTIC ENVIRONMENT IS INSTIGATED BY VARIOUS FACTORS, LEADING TO THE TRANSFORMATION OF EPITHELIAL CELLS INTO MYOFIBROBLASTS AND/OR FIBROBLASTS THAT TRIGGER FIBROSIS. EPITHELIAL MESENCHYMAL TRANSITION (EMT) IS A BIOLOGICAL PROCESS THAT PLAYS A CRITICAL ROLE IN THE PATHOGENESIS OF PULMONARY FIBROSIS. EPIGENETIC REGULATION OF TISSUE-STROMAL CROSSTALK INVOLVING DNA METHYLATION, HISTONE MODIFICATIONS, NON-CODING RNA, AND CHROMATIN REMODELING PLAYS A KEY ROLE IN THE CONTROL OF EMT. THE REVIEW INVESTIGATES THE EPIGENETIC REGULATION OF EMT AND ITS SIGNIFICANCE IN PULMONARY FIBROSIS. 2023 12 5769 32 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 2169 34 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 14 5993 24 TGFBETA PROMOTES FIBROSIS BY MYST1-DEPENDENT EPIGENETIC REGULATION OF AUTOPHAGY. ACTIVATION OF FIBROBLASTS IS ESSENTIAL FOR PHYSIOLOGICAL TISSUE REPAIR. UNCONTROLLED ACTIVATION OF FIBROBLASTS, HOWEVER, MAY LEAD TO TISSUE FIBROSIS WITH ORGAN DYSFUNCTION. ALTHOUGH SEVERAL PATHWAYS CAPABLE OF PROMOTING FIBROBLAST ACTIVATION AND TISSUE REPAIR HAVE BEEN IDENTIFIED, THEIR INTERPLAY IN THE CONTEXT OF CHRONIC FIBROTIC DISEASES REMAINS INCOMPLETELY UNDERSTOOD. HERE, WE PROVIDE EVIDENCE THAT TRANSFORMING GROWTH FACTOR-BETA (TGFBETA) ACTIVATES AUTOPHAGY BY AN EPIGENETIC MECHANISM TO AMPLIFY ITS PROFIBROTIC EFFECTS. TGFBETA INDUCES AUTOPHAGY IN FIBROTIC DISEASES BY SMAD3-DEPENDENT DOWNREGULATION OF THE H4K16 HISTONE ACETYLTRANSFERASE MYST1, WHICH REGULATES THE EXPRESSION OF CORE COMPONENTS OF THE AUTOPHAGY MACHINERY SUCH AS ATG7 AND BECLIN1. ACTIVATION OF AUTOPHAGY IN FIBROBLASTS PROMOTES COLLAGEN RELEASE AND IS BOTH, SUFFICIENT AND REQUIRED, TO INDUCE TISSUE FIBROSIS. FORCED EXPRESSION OF MYST1 ABROGATES THE STIMULATORY EFFECTS OF TGFBETA ON AUTOPHAGY AND RE-ESTABLISHES THE EPIGENETIC CONTROL OF AUTOPHAGY IN FIBROTIC CONDITIONS. INTERFERENCE WITH THE ABERRANT ACTIVATION OF AUTOPHAGY INHIBITS TGFBETA-INDUCED FIBROBLAST ACTIVATION AND AMELIORATES EXPERIMENTAL DERMAL AND PULMONARY FIBROSIS. THESE FINDINGS LINK UNCONTROLLED TGFBETA SIGNALING TO ABERRANT AUTOPHAGY AND DEREGULATED EPIGENETICS IN FIBROTIC DISEASES AND MAY CONTRIBUTE TO THE DEVELOPMENT OF THERAPEUTIC INTERVENTIONS IN FIBROTIC DISEASES. 2021 15 6910 26 [TRANSFORMING GROWTH FACTOR-BETA AND RENAL FIBROSIS]. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS A DRIVING FORCE OF RENAL FIBROSIS, WHICH MAY LEAD TO CHRONIC KIDNEY DISEASES AND EVEN END STAGE RENAL DISEASES. BY ACTIVATING CANONICAL AND NON-CANONICAL SIGNALING PATHWAYS, TGF-BETA PROMOTES THE SYNTHESIS OF EXTRACELLULAR MATRIX WHILE PREVENTING THEIR DEGRADATION. IN THE INJURED KIDNEY, TGF-BETA INDUCES APOPTOSIS, PROLIFERATION AND FIBROTIC RESPONSE OF RENAL CELLS INCLUDING EPITHELIAL CELLS, ENDOTHELIAL CELLS, PODOCYTES, FIBROBLASTS, PERICYTES AND MACROPHAGES, AND IT ALSO PROMOTES TRANSDIFFERENTIATION, ACTIVATION AND PROLIFERATION OF MYOFIBROBLASTS. ADDITIONALLY, TGF-BETA EXERTS PROFIBROTIC EFFECTS BY INTERPLAYING WITH OTHER SIGNALING PATHWAYS LIKE BMP-7, WNT/BETA-CATENIN AND MAP KINASE. SMAD3 IS THE CENTRAL PATHOLOGICAL GENE IN RENAL FIBROSIS, AND EPIGENETIC REGULATION OF TGF-BETA/SMAD3 IS A HOT TOPIC IN KIDNEY FIELD. ALTHOUGH DIRECT TARGETING TGF-BETA MAY CAUSE SIDE EFFECTS INCLUDING TUMORIGENESIS AND IMMUNE DISEASES, THE THERAPEUTIC STRATEGIES TARGETING THE BALANCE OF DOWNSTREAM SMAD3 AND SMAD7 MAY PREVENT OR DELAY THE PROGRESSION OF FIBROTIC KIDNEY DISEASE. 2018 16 6546 36 TRANSCRIPTOMIC AND EPIGENETIC PROFILING OF FIBROBLASTS IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF), A DEVASTATING, FIBROPROLIFERATIVE, CHRONIC LUNG DISORDER, IS ASSOCIATED WITH EXPANSION OF FIBROBLASTS/MYOFIBROBLASTS, WHICH LEADS TO EXCESSIVE PRODUCTION AND DEPOSITION OF EXTRACELLULAR MATRIX. IPF IS TYPICALLY CLINICALLY IDENTIFIED AS END-STAGE LUNG DISEASE, AFTER FIBROTIC PROCESSES ARE WELL-ESTABLISHED AND ADVANCED. FIBROBLASTS HAVE BEEN SHOWN TO BE CRITICALLY IMPORTANT IN THE DEVELOPMENT AND PROGRESSION OF IPF. WE HYPOTHESIZE THAT DIFFERENTIAL CHROMATIN ACCESS CAN DRIVE GENETIC DIFFERENCES IN IPF FIBROBLASTS RELATIVE TO HEALTHY FIBROBLASTS. TO THIS END, WE PERFORMED ASSAY OF TRANSPOSASE-ACCESSIBLE CHROMATIN SEQUENCING TO IDENTIFY DIFFERENTIALLY ACCESSIBLE REGIONS WITHIN THE GENOMES OF FIBROBLASTS FROM HEALTHY AND IPF LUNGS. MULTIPLE MOTIFS WERE IDENTIFIED TO BE ENRICHED IN IPF FIBROBLASTS COMPARED WITH HEALTHY FIBROBLASTS, INCLUDING BINDING MOTIFS FOR TWIST1 AND FOXA1. RNA SEQUENCING IDENTIFIED 93 GENES THAT COULD BE ANNOTATED TO DIFFERENTIALLY ACCESSIBLE REGIONS. PATHWAY ANALYSIS OF THE ANNOTATED GENES IDENTIFIED CELLULAR ADHESION, CYTOSKELETAL ANCHORING, AND CELL DIFFERENTIATION AS IMPORTANT BIOLOGICAL PROCESSES. IN ADDITION, SINGLE NUCLEOTIDE POLYMORPHISM ANALYSIS SHOWED THAT LINKAGE DISEQUILIBRIUM BLOCKS OF IPF RISK SINGLE NUCLEOTIDE POLYMORPHISMS WITH IPF-ACCESSIBLE REGIONS THAT HAVE BEEN IDENTIFIED TO BE LOCATED IN GENES THAT ARE IMPORTANT IN IPF, INCLUDING MUC5B, TERT, AND TOLLIP. VALIDATION STUDIES IN ISOLATED LUNG TISSUE CONFIRMED INCREASED EXPRESSION FOR TWIST1 AND FOXA1 IN ADDITION TO REVEALING SHANK2 AND CSPR2 AS NOVEL TARGETS. THUS, MODULATION OF DIFFERENTIAL CHROMATIN ACCESS MAY BE AN IMPORTANT MECHANISM IN THE PATHOGENESIS OF LUNG FIBROSIS. 2022 17 3640 31 INCREASED EXTRACELLULAR MATRIX PROTEIN PRODUCTION IN CHRONIC DIABETIC COMPLICATIONS: IMPLICATIONS OF NON-CODING RNAS. MANAGEMENT OF CHRONIC DIABETIC COMPLICATIONS REMAINS A MAJOR MEDICAL CHALLENGE WORLDWIDE. ONE OF THE CHARACTERISTIC FEATURES OF ALL CHRONIC DIABETIC COMPLICATIONS IS AUGMENTED PRODUCTION OF EXTRACELLULAR MATRIX (ECM) PROTEINS. SUCH ECM PROTEINS ARE DEPOSITED IN ALL TISSUES AFFECTED BY CHRONIC COMPLICATIONS, ULTIMATELY CAUSING ORGAN DAMAGE AND DYSFUNCTION. A CONTRIBUTING FACTOR TO THIS PATHOGENETIC PROCESS IS GLUCOSE-INDUCED ENDOTHELIAL DAMAGE, WHICH INVOLVES PHENOTYPIC TRANSFORMATION OF ENDOTHELIAL CELLS (ECS). THIS PHENOTYPIC TRANSITION OF ECS, FROM A QUIESCENT STATE TO AN ACTIVATED DYSFUNCTIONAL STATE, CAN BE MEDIATED THROUGH ALTERATIONS IN THE SYNTHESIS OF CELLULAR PROTEINS. IN THIS REVIEW, WE DISCUSSED THE ROLES OF NON-CODING RNAS, SPECIFICALLY MICRORNAS (MIRNAS) AND LONG NON-CODING RNAS (LNCRNAS), IN SUCH PROCESSES. WE FURTHER OUTLINED OTHER EPIGENETIC MECHANISMS REGULATING THE BIOGENESIS AND/OR FUNCTION OF NON-CODING RNAS. OVERALL, WE BELIEVE THAT BETTER UNDERSTANDING OF SUCH MOLECULAR PROCESSES MAY LEAD TO THE DEVELOPMENT OF NOVEL BIOMARKERS AND THERAPEUTIC STRATEGIES IN THE FUTURE. 2019 18 5484 34 REVEALING THE PATHOGENIC AND AGING-RELATED MECHANISMS OF THE ENIGMATIC IDIOPATHIC PULMONARY FIBROSIS. AN INTEGRAL MODEL. A GROWING BODY OF EVIDENCE INDICATES THAT ABERRANT ACTIVATION OF ALVEOLAR EPITHELIAL CELLS AND FIBROBLASTS IN AN AGING LUNG PLAYS A CRITICAL ROLE IN THE PATHOGENESIS OF IDIOPATHIC PULMONARY FIBROSIS (IPF). HOWEVER, THE BIOPATHOLOGICAL PROCESSES LINKING AGING WITH IPF AND THE MECHANISMS RESPONSIBLE FOR THE ABNORMAL ACTIVATION OF EPITHELIAL CELLS AND FIBROBLASTS HAVE NOT BEEN ELUCIDATED. MANY OF THE HALLMARKS OF AGING (E.G., GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, MITOCHONDRIAL DYSFUNCTION, AND CELLULAR SENESCENCE) HAVE BEEN PROPOSED AS ESSENTIAL MECHANISMS FOR THE DEVELOPMENT OF IPF; HOWEVER, THESE DISTURBANCES ARE NOT RESTRICTED TO IPF AND ALSO OCCUR IN OTHER AGING-RELATED LUNG DISORDERS, PRIMARILY CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THEREFORE, AN UNANSWERED QUESTION IS WHY A CURRENT/FORMER SMOKER OF ABOUT 60 YEARS OF AGE WITH SHORTER TELOMERES, ALVEOLAR EPITHELIAL SENESCENCE, EXCESSIVE OXIDATIVE STRESS, AND MITOCHONDRIAL DYSFUNCTION DEVELOPS IPF AND NOT COPD; IN OTHER WORDS, WHAT MAKES OLD LUNGS SPECIFICALLY SUSCEPTIBLE TO DEVELOP IPF? IN THIS PERSPECTIVE, WE PROPOSE AN INTEGRAL MODEL IN WHICH THE COMBINATION OF SOME GENE VARIANTS AND/OR GENE EXPRESSION IN THE AGING LUNG RESULTS IN THE LOSS OF EPITHELIAL INTEGRITY AND CONSEQUENTLY IN THE FAILURE OF THE ALVEOLI TO CORRECTLY RESPOND TO INJURY AND TO FACE THE STRESS ASSOCIATED WITH MECHANICAL STRETCH. AFTERWARD, A DISTINCTIVE EPIGENETIC "REPROGRAMMING" THAT AFFECTS BOTH EPITHELIAL CELLS AND FIBROBLASTS PROVOKES, AMONG OTHERS, THE RECAPITULATION OF DEVELOPMENTAL PATHWAYS AND THE ABERRANT ACTIVATION AND MISCOMMUNICATION BETWEEN BOTH CELL TYPES, RESULTING IN THE EXAGGERATED PRODUCTION AND ACCUMULATION OF EXTRACELLULAR MATRIX AND THE SUBSEQUENT DESTRUCTION OF THE LUNG ARCHITECTURE. 2014 19 5939 41 TARGETING MECHANOTRANSDUCTION AT THE TRANSCRIPTIONAL LEVEL: YAP AND BRD4 ARE NOVEL THERAPEUTIC TARGETS FOR THE REVERSAL OF LIVER FIBROSIS. LIVER FIBROSIS IS THE RESULT OF A DEREGULATED WOUND HEALING PROCESS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX. HEPATIC STELLATE CELLS (HSCS), WHICH ARE ACTIVATED IN RESPONSE TO LIVER INJURY, ARE THE MAJOR SOURCE OF EXTRACELLULAR MATRIX AND DRIVE THE WOUND HEALING PROCESS. HOWEVER, CHRONIC LIVER DAMAGE LEADS TO PERPETUAL HSC ACTIVATION, PROGRESSIVE FORMATION OF PATHOLOGICAL SCAR TISSUE AND ULTIMATELY, CIRRHOSIS AND ORGAN FAILURE. HSC ACTIVATION IS TRIGGERED LARGELY IN RESPONSE TO MECHANOSIGNALING FROM THE MICROENVIRONMENT, WHICH INDUCES A PROFIBROTIC NUCLEAR TRANSCRIPTION PROGRAM THAT PROMOTES HSC PROLIFERATION AND EXTRACELLULAR MATRIX SECRETION THEREBY SETTING UP A POSITIVE FEEDBACK LOOP LEADING TO MATRIX STIFFENING AND SELF-SUSTAINED, PATHOLOGICAL, HSC ACTIVATION. DESPITE THE SIGNIFICANT PROGRESS IN OUR UNDERSTANDING OF LIVER FIBROSIS, THE MOLECULAR MECHANISMS THROUGH WHICH THE EXTRACELLULAR MATRIX PROMOTES HSC ACTIVATION ARE NOT WELL UNDERSTOOD AND NO EFFECTIVE THERAPIES HAVE BEEN APPROVED TO DATE THAT CAN TARGET THIS EARLY, REVERSIBLE, STAGE IN LIVER FIBROSIS. SEVERAL NEW LINES OF INVESTIGATION NOW PROVIDE IMPORTANT INSIGHT INTO THIS AREA OF STUDY AND IDENTIFY TWO NUCLEAR TARGETS WHOSE INHIBITION HAS THE POTENTIAL OF REVERSING LIVER FIBROSIS BY INTERFERING WITH HSC ACTIVATION: YES-ASSOCIATED PROTEIN (YAP), A TRANSCRIPTIONAL CO-ACTIVATOR AND EFFECTOR OF THE MECHANOSENSITIVE HIPPO PATHWAY, AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4), AN EPIGENETIC REGULATOR OF GENE EXPRESSION. YAP AND BRD4 ACTIVITY IS INDUCED IN RESPONSE TO MECHANICAL STIMULATION OF HSCS AND EACH PROTEIN INDEPENDENTLY CONTROLS WAVES OF EARLY GENE EXPRESSION NECESSARY FOR HSC ACTIVATION. SIGNIFICANTLY, INHIBITION OF EITHER PROTEIN CAN REVERT THE CHRONIC ACTIVATION OF HSCS AND IMPEDE PATHOLOGICAL PROGRESSION OF LIVER FIBROSIS IN CLINICALLY RELEVANT MODEL SYSTEMS. IN THIS REVIEW WE WILL DISCUSS THE ROLES OF THESE NUCLEAR CO-ACTIVATORS IN HSC ACTIVATION, THEIR MECHANISM OF ACTION IN THE FIBROTIC PROCESS IN THE LIVER AND OTHER ORGANS, AND THE POTENTIAL OF TARGETING THEIR ACTIVITY WITH SMALL MOLECULE DRUGS FOR FIBROSIS REVERSAL. 2016 20 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