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 5939 31 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 3 699 24 BROMODOMAIN PROTEIN 4 IS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HEPATIC STELLATE CELL ACTIVATION. LIVER FIBROSIS IS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX IN LIVER. CHRONIC LIVER INJURY INDUCES THE ACTIVATION OF HEPATIC STELLATE CELL (HSCS), A KEY STEP IN LIVER FIBROGENESIS. THE ACTIVATED HSC IS THE PRIMARY SOURCE OF ECM AND CONTRIBUTES SIGNIFICANTLY TO LIVER FIBROSIS. TGFBETA1 IS THE MOST POTENT PRO-FIBROTIC CYTOKINE. BROMODOMAIN PROTEIN 4 (BRD4), AN EPIGENETIC READER OF HISTONE ACETYLATION MARKS, WAS CRUCIAL FOR PROFIBROTIC GENE EXPRESSION IN HSCS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLES OF BRD4 IN TGFBETA1-DEPENDENT HSC ACTIVATION AND LIVER FIBROSIS, FOCUSING ON TGFBETA1-INDUCED ALTERATIONS OF THE LEVELS OF THE FIBROTIC-RELATED IMPORTANT PROTEINS IN HSCS BY EMPLOYING THE HETEROZYGOUS TGFBETA1 KNOCKOUT MICE AND BRD4 KNOCKDOWN IN VIVO AND IN VITRO. RESULTS REVEALED THAT BRD4 PROTEIN LEVEL WAS SIGNIFICANTLY UPREGULATED BY TGFBETA1 AND BRD4 KNOCKDOWN REDUCED TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. BRD4 WAS REQUIRED FOR THE INFLUENCES OF TGFBETA1 ON PDGFBETA RECEPTOR AND ON THE PATHWAYS OF SMAD3, STAT3, AND AKT. BRD4 ALSO MEDIATED TGFBETA1-INDUCED INCREASES IN HISTONE ACETYLTRANSFERASE P300, THE PIVOTAL PRO-INFLAMMATORY NFKB P65, AND TISSUE INHIBITOR OF METALLOPROTEINASE 1 WHEREAS BRD4 REDUCED CASPASE-3 PROTEIN LEVELS IN HSCS DURING LIVER INJURY, INDEPENDENT OF TGFBETA1. FURTHER EXPERIMENTS INDICATED THE INTERACTION BETWEEN TGFBETA1-INDUCED BRD4 AND NFKB P65 IN HSCS AND IN LIVER OF TAA-INDUCED LIVER INJURY. HUMAN CIRRHOTIC LIVERS WERE DEMONSTRATED A PARALLEL INCREASE IN THE PROTEIN LEVELS OF BRD4 AND NFKB P65 IN HSCS. THIS STUDY REVEALED THAT BRD4 WAS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. 2023 4 4501 25 MORPHOGENS AND HEPATIC STELLATE CELL FATE REGULATION IN CHRONIC LIVER DISEASE. HEPATIC STELLATE CELLS (HSC) ARE THE LIVER MESENCHYMAL CELL TYPE WHICH RESPONDS TO HEPATOCELLULAR DAMAGE AND PARTICIPATES IN WOUND HEALING. ALTHOUGH HSC MYOFIBROBLASTIC TRANS-DIFFERENTIATION (ACTIVATION) IS IMPLICATED IN EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION, MOLECULAR UNDERSTANDING OF THIS PHENOTYPIC SWITCH FROM THE VIEWPOINT OF CELL FATE REGULATION IS LIMITED. RECENT STUDIES DEMONSTRATE THE ROLES OF ANTI-ADIPOGENIC MORPHOGENS (WNT, NECDIN, SHH) IN EPIGENETIC REPRESSION OF THE HSC DIFFERENTIATION GENE PPARGAMMA AS A CAUSAL EVENT IN HSC ACTIVATION. THESE MORPHOGENS HAVE POSITIVE CROSS-INTERACTIONS WHICH CONVERGE TO EPIGENETIC REPRESSION OF PPARGAMMA INVOLVING THE METHYL-CPG BINDING PROTEIN MECP2. HOWEVER, THESE MORPHOGENS EXPRESSED BY ACTIVATED HSC MAY ALSO PARTICIPATE IN CROSS-TALK BETWEEN HSC AND HEPATOBLASTS/HEPATOCYTES TO SUPPORT LIVER REGENERATION, AND THEIR ABERRANT REGULATION MAY CONTRIBUTE TO LIVER TUMORIGENESIS. IMPLICATIONS OF HSC-DERIVED MORPHOGENS IN THESE POSSIBILITIES ARE DISCUSSED. 2012 5 692 27 BRD4 PROMOTES HEPATIC STELLATE CELLS ACTIVATION AND HEPATIC FIBROSIS VIA MEDIATING P300/H3K27AC/PLK1 AXIS. HEPATIC FIBROSIS (HF) IS A REVERSIBLE WOUND-HEALING RESPONSE CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX (ECM) DEPOSITION AND SECONDARY TO PERSISTENT CHRONIC INJURY. BROMODOMAIN PROTEIN 4 (BRD4) COMMONLY FUNCTIONS AS A "READER" TO REGULATE EPIGENETIC MODIFICATIONS INVOLVED IN VARIOUS BIOLOGICAL AND PATHOLOGICAL EVENTS, BUT THE MECHANISM OF HF REMAINS UNCLEAR. IN THIS STUDY, WE ESTABLISHED A CCL(4)-INDUCED HF MODEL AND SPONTANEOUS RECOVERY MODEL IN MICE AND FOUND ABERRANT BRD4 EXPRESSION, WHICH WAS CONSISTENT WITH THE RESULTS IN HUMAN HEPATIC STELLATE CELLS (HSCS)- LX2 CELLS IN VITRO. SUBSEQUENTLY, WE FOUND THAT DISTRICTION AND INHIBITION OF BRD4 RESTRAINED TGFBETA-INDUCED TRANS-DIFFERENTIATION OF LX2 CELLS INTO ACTIVATED, PROLIFERATIVE MYOFIBROBLASTS AND ACCELERATED APOPTOSIS, AND BRD4 OVEREXPRESSION BLOCKED MDI-INDUCED LX2 CELLS INACTIVATION AND PROMOTED THE PROLIFERATION AND INHIBITED APOPTOSIS OF INACTIVATED CELLS. ADDITIONALLY, ADENO-ASSOCIATED VIRUS SEROTYPE 8-LOADED SHORT HAIRPIN RNA-MEDIATED BRD4 KNOCKDOWN IN MICE SIGNIFICANTLY ATTENUATED CCL(4)-INDUCED FIBROTIC RESPONSES INCLUDING HSCS ACTIVATION AND COLLAGEN DEPOSITION. MECHANISTICALLY, BRD4 DEFICIENCY INHIBITED PLK1 EXPRESSION IN ACTIVATED LX2 CELLS, AND CHIP AND CO-IP ASSAYS REVEALED THAT BRD4 REGULATION OF PLK1 WAS DEPENDENT ON P300-MEDIATED ACETYLATION MODIFICATION FOR H3K27 ON THE PLK1 PROMOTER. IN CONCLUSION, BRD4 DEFICIENCY IN THE LIVER ALLEVIATES CCL(4)-INDUCED HF IN MICE, AND BRD4 PARTICIPATES IN THE ACTIVATION AND REVERSAL OF HSCS THROUGH POSITIVELY REGULATING THE P300/H3K27AC/PLK1 AXIS, PROVIDING A POTENTIAL INSIGHT FOR HF THERAPY. 2023 6 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 7 4563 17 MYELOID DNA METHYLTRANSFERASE3B DEFICIENCY AGGRAVATES PULMONARY FIBROSIS BY ENHANCING PROFIBROTIC MACROPHAGE ACTIVATION. BACKGROUND: IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE AND SEVERE DISEASE CHARACTERIZED BY EXCESSIVE MATRIX DEPOSITION IN THE LUNGS. MACROPHAGES PLAY CRUCIAL ROLES IN MAINTAINING LUNG HOMEOSTASIS BUT ARE ALSO CENTRAL IN THE PATHOGENESIS OF LUNG DISEASES LIKE PULMONARY FIBROSIS. ESPECIALLY, MACROPHAGE POLARIZATION/ACTIVATION SEEMS TO PLAY A CRUCIAL ROLE IN PATHOLOGY AND EPIGENETIC REPROGRAMING IS WELL-KNOWN TO REGULATE MACROPHAGE POLARIZATION. DNA METHYLATION ALTERATIONS IN IPF LUNGS HAVE BEEN WELL DOCUMENTED, BUT THE ROLE OF DNA METHYLATION IN SPECIFIC CELL TYPES, ESPECIALLY MACROPHAGES, IS POORLY DEFINED. METHODS: IN ORDER TO DETERMINE THE ROLE OF DNA METHYLATION IN MACROPHAGES DURING PULMONARY FIBROSIS, WE SUBJECTED MACROPHAGE SPECIFIC DNA METHYLTRANSFERASE (DNMT)3B, WHICH MEDIATES THE DE NOVO DNA METHYLATION, DEFICIENT MICE TO THE BLEOMYCIN-INDUCED PULMONARY FIBROSIS MODEL. MACROPHAGE POLARIZATION AND FIBROTIC PARAMETERS WERE EVALUATED AT 21 DAYS AFTER BLEOMYCIN ADMINISTRATION. DNMT3B KNOCKOUT AND WILD TYPE BONE MARROW-DERIVED MACROPHAGES WERE STIMULATED WITH EITHER INTERLEUKIN (IL)4 OR TRANSFORMING GROWTH FACTOR BETA 1 (TGFB1) IN VITRO, AFTER WHICH PROFIBROTIC GENE EXPRESSION AND DNA METHYLATION AT THE ARG1 PROMOTOR WERE DETERMINED. RESULTS: WE SHOW THAT DNMT3B DEFICIENCY PROMOTES ALTERNATIVE MACROPHAGE POLARIZATION INDUCED BY IL4 AND TGFB1 IN VITRO AND ALSO ENHANCES PROFIBROTIC MACROPHAGE POLARIZATION IN THE ALVEOLAR SPACE DURING PULMONARY FIBROSIS IN VIVO. MOREOVER, MYELOID SPECIFIC DELETION OF DNMT3B PROMOTED THE DEVELOPMENT OF EXPERIMENTAL PULMONARY FIBROSIS. CONCLUSIONS: IN SUMMARY, THESE DATA SUGGEST THAT MYELOID DNMT3B REPRESSES FIBROTIC MACROPHAGE POLARIZATION AND PROTECTS AGAINST BLEOMYCIN INDUCED PULMONARY FIBROSIS. 2022 8 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 9 793 30 CELLULAR RE- AND DE-PROGRAMMING BY MICROENVIRONMENTAL MEMORY: WHY SHORT TGF-BETA1 PULSES CAN HAVE LONG EFFECTS. BACKGROUND: FIBROSIS POSES A SUBSTANTIAL SETBACK IN REGENERATIVE MEDICINE. HISTOPATHOLOGICALLY, FIBROSIS IS AN EXCESSIVE ACCUMULATION OF COLLAGEN AFFECTED BY MYOFIBROBLASTS AND THIS CAN OCCUR IN ANY TISSUE THAT IS EXPOSED TO CHRONIC INJURY OR INSULT. TRANSFORMING GROWTH FACTOR (TGF)-BETA1, A CRUCIAL MEDIATOR OF FIBROSIS, DRIVES DIFFERENTIATION OF FIBROBLASTS INTO MYOFIBROBLASTS. THESE CELLS EXHIBIT ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) AND SYNTHESIZE HIGH AMOUNTS OF COLLAGEN I, THE MAJOR EXTRACELLULAR MATRIX (ECM) COMPONENT OF FIBROSIS. WHILE HORMONES STIMULATE CELLS IN A PULSATILE MANNER, LITTLE IS KNOWN ABOUT CELLULAR RESPONSE KINETICS UPON GROWTH FACTOR IMPACT. WE THEREFORE STUDIED THE EFFECTS OF SHORT TGF-BETA1 PULSES IN TERMS OF THE INDUCTION AND MAINTENANCE OF THE MYOFIBROBLAST PHENOTYPE. RESULTS: TWENTY-FOUR HOURS AFTER A SINGLE 30 MIN TGF-BETA1 PULSE, TRANSCRIPTION OF FIBROGENIC GENES WAS UPREGULATED, BUT SUBSIDED 7 DAYS LATER. IN PARALLEL, COLLAGEN I SECRETION RATE AND ALPHA-SMA PRESENCE WERE ELEVATED FOR 7 DAYS. A SECOND PULSE 24 H LATER EXTENDED THE DURATION OF EFFECTS TO 14 DAYS. WE COULD NOT ESTABLISH EPIGENETIC CHANGES ON FIBROGENIC TARGET GENES TO EXPLAIN THE LONG-LASTING EFFECTS. HOWEVER, ECM DEPOSITED UNDER SINGLY PULSED TGF-BETA1 WAS ABLE TO INDUCE MYOFIBROBLAST FEATURES IN PREVIOUSLY UNTREATED FIBROBLASTS. DEPENDENT ON THE AGE OF THE ECM (1 DAY VERSUS 7 DAYS' FORMATION TIME), THIS PROPERTY WAS DIMINISHED. VICE VERSA, MYOFIBROBLASTS WERE CULTURED ON FIBROBLAST ECM AND CELLS OBSERVED TO EXPRESS REDUCED (IN COMPARISON WITH MYOFIBROBLASTS) LEVELS OF COLLAGEN I. CONCLUSIONS: WE DEMONSTRATED THAT SHORT TGF-BETA1 PULSES CAN EXERT LONG-LASTING EFFECTS ON FIBROBLASTS BY CHANGING THEIR MICROENVIRONMENT, THUS LEAVING AN IMPRINT AND CREATING A RECIPROCAL FEED-BACK LOOP. THEREFORE, THE ECM MIGHT ACT AS MID-TERM MEMORY FOR PATHOBIOCHEMICAL EVENTS. WE WOULD EXPECT THIS MICROENVIRONMENTAL MEMORY TO BE DEPENDENT ON MATRIX TURNOVER AND, AS SUCH, TO BE ERASABLE. OUR FINDINGS CONTRIBUTE TO THE CURRENT UNDERSTANDING OF FIBROBLAST INDUCTION AND MAINTENANCE, AND HAVE BEARING ON THE DEVELOPMENT OF ANTIFIBROTIC DRUGS. 2013 10 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 11 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 12 6910 21 [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 13 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 14 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 15 5992 25 TGF-BETA: THE MASTER REGULATOR OF FIBROSIS. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS THE PRIMARY FACTOR THAT DRIVES FIBROSIS IN MOST, IF NOT ALL, FORMS OF CHRONIC KIDNEY DISEASE (CKD). INHIBITION OF THE TGF-BETA ISOFORM, TGF-BETA1, OR ITS DOWNSTREAM SIGNALLING PATHWAYS SUBSTANTIALLY LIMITS RENAL FIBROSIS IN A WIDE RANGE OF DISEASE MODELS WHEREAS OVEREXPRESSION OF TGF-BETA1 INDUCES RENAL FIBROSIS. TGF-BETA1 CAN INDUCE RENAL FIBROSIS VIA ACTIVATION OF BOTH CANONICAL (SMAD-BASED) AND NON-CANONICAL (NON-SMAD-BASED) SIGNALLING PATHWAYS, WHICH RESULT IN ACTIVATION OF MYOFIBROBLASTS, EXCESSIVE PRODUCTION OF EXTRACELLULAR MATRIX (ECM) AND INHIBITION OF ECM DEGRADATION. THE ROLE OF SMAD PROTEINS IN THE REGULATION OF FIBROSIS IS COMPLEX, WITH COMPETING PROFIBROTIC AND ANTIFIBROTIC ACTIONS (INCLUDING IN THE REGULATION OF MESENCHYMAL TRANSITIONING), AND WITH COMPLEX INTERPLAY BETWEEN TGF-BETA/SMADS AND OTHER SIGNALLING PATHWAYS. STUDIES OVER THE PAST 5 YEARS HAVE IDENTIFIED ADDITIONAL MECHANISMS THAT REGULATE THE ACTION OF TGF-BETA1/SMAD SIGNALLING IN FIBROSIS, INCLUDING SHORT AND LONG NONCODING RNA MOLECULES AND EPIGENETIC MODIFICATIONS OF DNA AND HISTONE PROTEINS. ALTHOUGH DIRECT TARGETING OF TGF-BETA1 IS UNLIKELY TO YIELD A VIABLE ANTIFIBROTIC THERAPY DUE TO THE INVOLVEMENT OF TGF-BETA1 IN OTHER PROCESSES, GREATER UNDERSTANDING OF THE VARIOUS PATHWAYS BY WHICH TGF-BETA1 CONTROLS FIBROSIS HAS IDENTIFIED ALTERNATIVE TARGETS FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS TO HALT THIS MOST DAMAGING PROCESS IN CKD. 2016 16 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 17 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 18 5054 25 PHARMACOPROTEOMICS REVEAL NOVEL PROTECTIVE ACTIVITY OF BROMODOMAIN CONTAINING 4 INHIBITORS ON VASCULAR HOMEOSTASIS IN TLR3-MEDIATED AIRWAY REMODELING. SMALL MOLECULE INHIBITORS OF THE EPIGENETIC REGULATOR BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) ARE POTENTIAL THERAPEUTICS FOR VIRAL AND ALLERGEN-INDUCED AIRWAY REMODELING. A LIMITATION OF THEIR PRECLINICAL ADVANCEMENT IS THE LACK OF DETAILED UNDERSTANDING OF MECHANISMS OF ACTION AND BIOMARKERS OF EFFECT. WE REPORT A SYSTEMS-LEVEL PHARMACOPROTEOMICS IN A STANDARDIZED MURINE MODEL OF TOLL-LIKE RECEPTOR TLR3-NFKAPPAB/RELA INNATE INFLAMMATION IN THE ABSENCE OR PRESENCE OF A HIGHLY SELECTIVE BRD4 INHIBITOR (ZL0454) OR NONSELECTIVE BROMODOMAIN AND EXTRATERMINAL DOMAIN INHIBITOR (JQ1). PROTEOMICS OF BRONCHOALVEOLAR LAVAGE FLUID (BALF) SECRETOME AND EXOSOMAL PROTEINS FROM THIS MURINE MODEL REVEALED INCREASED, SELECTIVE, CAPILLARY LEAK ASSOCIATED WITH PERICYTE-MYOFIBROBLAST TRANSITION, A PHENOMENON BLOCKED BY BRD4 INHIBITORS. BALF PROTEOMICS ALSO SUGGESTED THAT ZL0454 BETTER REDUCED THE VASCULAR LEAKAGE AND EXTRACELLULAR MATRIX DEPOSITION THAN JQ1. A SIGNIFICANT SUBSET OF INFLAMMATION-MEDIATED REMODELING FACTORS WAS ALSO IDENTIFIED IN A MOUSE MODEL OF IDIOPATHIC PULMONARY FIBROSIS PRODUCED BY BLEOMYCIN. BALF EXOSOME ANALYSIS INDICATED THAT BRD4 INHIBITORS REDUCED THE INDUCTION OF EXOSOMES ENRICHED IN COAGULATION FACTORS WHOSE PRESENCE CORRELATED WITH INTERSTITIAL FIBRIN DEPOSITION. FINALLY, BALF SAMPLES FROM HUMANS WITH SEVERE ASTHMA DEMONSTRATED SIMILAR UPREGULATIONS OF ORM2, APCS, SPARCL1, FGA, AND FN1, SUGGESTING THEIR POTENTIAL AS BIOMARKERS FOR EARLY DETECTION OF AIRWAY REMODELING AND/OR MONITORING OF THERAPY RESPONSE. SIGNIFICANCE: REPETITIVE AND CHRONIC VIRAL UPPER RESPIRATORY TRACT INFECTIONS TRIGGER TOLL-LIKE RECEPTOR (TLR)3-NFKAPPAB/RELA MEDIATED AIRWAY REMODELING WHICH IS LINKED TO A PROGRESSIVE DECLINE IN PULMONARY FUNCTION IN PATIENTS WITH ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. SMALL MOLECULE INHIBITORS OF THE EPIGENETIC REGULATOR BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) ARE POTENTIAL THERAPEUTICS FOR VIRAL AND ALLERGEN-INDUCED AIRWAY REMODELING. A LIMITATION OF THEIR PRECLINICAL ADVANCEMENT IS THE LACK OF DETAILED UNDERSTANDING OF MECHANISMS OF ACTION AND BIOMARKERS OF EFFECT. OUR STUDY REVEALED THAT THE ACTIVATION OF (TLR)3-NFKAPPAB/RELA PATHWAY IN THE LUNG INDUCED AN ELEVATION IN COAGULATION, COMPLEMENT, AND PLATELET FACTORS, INDICATING THE INCREASED VASCULAR LEAK DURING AIRWAY REMODELING. THE MECHANISM OF VASCULAR LEAKAGE WAS CHRONIC INFLAMMATION-INDUCED PERICYTE-MYOFIBROBLAST TRANSITION, WHICH WAS BLOCKED BY BRD4 INHIBITORS. FINALLY, PROTEOMICS ANALYSIS OF THE BRONCHOALVEOLAR LAVAGE FLUID SAMPLES FROM HUMANS WITH SEVERE ASTHMA DEMONSTRATED SIMILAR FINDINGS THAT WE OBSERVED IN THE ANIMAL MODEL. 2019 19 1764 23 EARLY-IMMEDIATE GENE EGR1 IS ASSOCIATED WITH TGFBETA1 REGULATION OF EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 VIA THE CANONICAL SMAD3 SIGNALING IN HEPATIC STELLATE CELLS IN VITRO AND IN VIVO. UPON CHRONIC DAMAGE TO THE LIVER, MULTIPLE CYTOKINES STIMULATE HEPATIC STELLATE CELLS (HSCS), CAUSING THE ALTERATIONS OF GENE EXPRESSION PROFILES AND THUS LEADING TO HSC ACTIVATION, A KEY STEP IN LIVER FIBROGENESIS. ACTIVATED HSCS ARE THE DOMINANT CONTRIBUTORS TO LIVER FIBROSIS. BROMODOMAIN CONTAINING PROTEIN 4 (BRD4), AN IMPORTANT EPIGENETIC READER, WAS DEMONSTRATED TO CONCENTRATE ON HUNDREDS OF ENHANCERS ASSOCIATED WITH GENES INVOLVED IN MULTIPLE PROFIBROTIC PATHWAYS, THEREBY DIRECTING HSC ACTIVATION AND THE FIBROTIC RESPONSES. THE PRESENT STUDIES WERE DESIGNED TO EXAMINE THE EFFECT OF TRANSFORMING GROWTH FACTOR BETA-1 (TGFBETA1), THE MOST POTENT PRO-FIBROTIC CYTOKINE, ON BRD4 EXPRESSION IN HSCS AND, IF SO, ELUCIDATED THE UNDERLYING MECHANISMS IN VITRO AND IN VIVO. THE EXPERIMENTS EMPLOYED THE HETEROGENEOUS TGFBETA1 KNOCKOUT (TGFBETA1(+/-) ) MICE, GENE KNOCKDOWN IN VIVO, AND A MODEL OF THIOACETAMIDE (TAA)-INDUCED LIVER INJURY. THE RESULTS REVEALED THAT TGFBETA1 ENHANCED BRD4 EXPRESSION IN HSCS, WHICH WAS MEDIATED, AT LEAST, BY SMAD3 SIGNALING AND EARLY-IMMEDIATE GENE EGR1 (EARLY GROWTH RESPONSE-1). TGFBETA1-INDUCED SMAD3 SIGNALING INCREASED EGR1 EXPRESSION AND PROMOTED EGR1 BINDING TO BRD4 PROMOTER AT A SITE AROUND -111 BP, PROMOTING BRD4 EXPRESSION. EGR1 KNOCKDOWN REDUCED BRD4 EXPRESSION IN HSCS IN A MOUSE MODEL OF TAA-INDUCED LIVER INJURY AND LESSENED LIVER FIBROSIS. DOUBLE FLUORESCENCE STAINING DEMONSTRATED A STRONG INCREASE IN BRD4 EXPRESSION IN ACTIVATED HSCS IN FIBROTIC AREAS OF THE HUMAN LIVERS, PARALLELING THE UPREGULATION OF P-SMAD3 AND EGR1. THIS RESEARCH SUGGESTED NOVEL MOLECULAR EVENTS UNDERLYING THE ROLES OF THE MASTER PRO-FIBROTIC CYTOKINE TGFBETA1 IN HSC ACTIVATION AND LIVER FIBROGENESIS. 2022 20 2554 24 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