1 4097 80 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 2 5939 37 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 1220 21 CRISPR/CAS9-BASED MUTAGENESIS OF HISTONE H3.1 IN SPINAL DYNORPHINERGIC NEURONS ATTENUATES THERMAL SENSITIVITY IN MICE. BURN INJURY IS A TRAUMA RESULTING IN TISSUE DEGRADATION AND SEVERE PAIN, WHICH IS PROCESSED FIRST BY NEURONAL CIRCUITS IN THE SPINAL DORSAL HORN. WE HAVE RECENTLY SHOWN THAT IN MICE, EXCITATORY DYNORPHINERGIC (PDYN) NEURONS PLAY A PIVOTAL ROLE IN THE RESPONSE TO BURN-INJURY-ASSOCIATED TISSUE DAMAGE VIA HISTONE H3.1 PHOSPHORYLATION-DEPENDENT SIGNALING. AS PDYN NEURONS WERE MOSTLY ASSOCIATED WITH MECHANICAL ALLODYNIA, THEIR INVOLVEMENT IN THERMONOCICEPTION HAD TO BE FURTHER ELUCIDATED. USING A CUSTOM-MADE AAV9_MUTH3.1 VIRUS COMBINED WITH THE CRISPR/CAS9 SYSTEM, HERE WE PROVIDE EVIDENCE THAT BLOCKING HISTONE H3.1 PHOSPHORYLATION AT POSITION SERINE 10 (S10) IN SPINAL PDYN NEURONS SIGNIFICANTLY INCREASES THE THERMAL NOCICEPTIVE THRESHOLD IN MICE. IN CONTRAST, NEITHER MECHANOSENSATION NOR ACUTE CHEMONOCICEPTION WAS AFFECTED BY THE TRANSGENIC MANIPULATION OF HISTONE H3.1. THESE RESULTS SUGGEST THAT BLOCKING RAPID EPIGENETIC TAGGING OF S10H3 IN SPINAL PDYN NEURONS ALTERS ACUTE THERMOSENSATION AND THUS EXPLAINS THE INVOLVEMENT OF PDYN CELLS IN THE IMMEDIATE RESPONSE TO BURN-INJURY-ASSOCIATED TISSUE DAMAGE. 2022 4 172 26 ABSENCE OF HDAC3 BY MATRIX STIFFNESS PROMOTES CHROMATIN REMODELING AND FIBROBLAST ACTIVATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC AND FATAL DISEASE CHARACTERIZED BY PROGRESSIVE AND IRREVERSIBLE LUNG SCARRING ASSOCIATED WITH PERSISTENT ACTIVATION OF FIBROBLASTS. EPIGENETICS COULD INTEGRATE DIVERSE MICROENVIRONMENTAL SIGNALS, SUCH AS STIFFNESS, TO DIRECT PERSISTENT FIBROBLAST ACTIVATION. HISTONE MODIFICATIONS BY DEACETYLASES (HDAC) MAY PLAY AN ESSENTIAL ROLE IN THE GENE EXPRESSION CHANGES INVOLVED IN THE PATHOLOGICAL REMODELING OF THE LUNG. PARTICULARLY, HDAC3 IS CRUCIAL FOR MAINTAINING CHROMATIN AND REGULATING GENE EXPRESSION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN IPF. IN THE STUDY, CONTROL AND IPF-DERIVED FIBROBLASTS WERE USED TO DETERMINE THE INFLUENCE OF HDAC3 ON CHROMATIN REMODELING AND GENE EXPRESSION ASSOCIATED WITH IPF SIGNATURE. ADDITIONALLY, THE CELLS WERE GROWN ON HYDROGELS TO MIMIC THE STIFFNESS OF A FIBROTIC LUNG. OUR RESULTS SHOWED A DECREASED HDAC3 IN THE NUCLEUS OF IPF FIBROBLASTS, WHICH CORRELATES WITH CHANGES IN NUCLEUS SIZE AND HETEROCHROMATIN LOSS. THE INHIBITION OF HDAC3 WITH A PHARMACOLOGICAL INHIBITOR CAUSES HYPERACETYLATION OF H3K9 AND PROVOKES AN INCREASED EXPRESSION OF COL1A1, ACTA2, AND P21. COMPARABLE RESULTS WERE FOUND IN HYDROGELS, WHERE MATRIX STIFFNESS PROMOTES THE LOSS OF NUCLEAR HDAC3 AND INCREASES THE PROFIBROTIC SIGNATURE. FINALLY, LATRUNCULIN B WAS USED TO CONFIRM THAT CHANGES BY STIFFNESS DEPEND ON THE MECHANOTRANSDUCTION SIGNALS. TOGETHER, THESE RESULTS SUGGEST THAT HDAC3 COULD BE A LINK BETWEEN EPIGENETIC MECHANISMS AND THE FIBROTIC MICROENVIRONMENT. 2023 5 2825 31 FLOW-DEPENDENT EPIGENETIC REGULATION OF IGFBP5 EXPRESSION BY H3K27ME3 CONTRIBUTES TO ENDOTHELIAL ANTI-INFLAMMATORY EFFECTS. RATIONALE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY AND EPIGENETIC DISEASE THAT IS INFLUENCED BY DIFFERENT PATTERNS OF BLOOD FLOW. HOWEVER, THE EPIGENETIC MECHANISM WHEREBY ATHEROPROTECTIVE FLOW CONTROLS ENDOTHELIAL GENE PROGRAMMING REMAINS ELUSIVE. HERE, WE INVESTIGATED THE POSSIBILITY THAT FLOW ALTERS ENDOTHELIAL GENE EXPRESSION THROUGH EPIGENETIC MECHANISMS. METHODS: EN FACE STAINING AND WESTERN BLOT WERE USED TO DETECT PROTEIN EXPRESSION. REAL-TIME PCR WAS USED TO DETERMINE RELATIVE GENE EXPRESSION. RNA-SEQUENCING OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS TREATED WITH SIRNA OF ENHANCER OF ZESTE HOMOLOG 2 (EZH2) OR LAMINAR FLOW WAS USED FOR TRANSCRIPTIONAL PROFILING. RESULTS: WE FOUND THAT TRIMETHYLATION OF HISTONE 3 LYSINE 27 (H3K27ME3), A REPRESSIVE EPIGENETIC MARK THAT ORCHESTRATES GENE REPRESSION, WAS REDUCED IN LAMINAR FLOW AREAS OF MOUSE AORTA AND FLOW-TREATED HUMAN ENDOTHELIAL CELLS. THE DECREASE OF H3K27ME3 PARALLELED A REDUCTION IN THE EPIGENETIC "WRITER"-EZH2, THE CATALYTIC SUBUNIT OF THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). MOREOVER, LAMINAR FLOW DECREASED EXPRESSION OF EZH2 VIA MECHANOSENSITIVE MIR101. GENOME-WIDE TRANSCRIPTOME PROFILING STUDIES IN ENDOTHELIAL CELLS TREATED WITH EZH2 SIRNA AND FLOW REVEALED THE UPREGULATION OF NOVEL MECHANOSENSITIVE GENE IGFBP5 (INSULIN-LIKE GROWTH FACTOR-BINDING PROTEIN 5), WHICH IS EPIGENETICALLY SILENCED BY H3K27ME3. FUNCTIONALLY, INHIBITION OF H3K27ME3 BY EZH2 SIRNA OR GSK126 (A SPECIFIC EZH2 INHIBITOR) REDUCED H3K27ME3 LEVELS AND MONOCYTE ADHESION TO ENDOTHELIAL CELLS. ADENOVIRAL OVEREXPRESSION OF IGFBP5 ALSO RECAPITULATED THE ANTI-INFLAMMATORY EFFECTS OF H3K27ME3 INHIBITION. MORE IMPORTANTLY, WE OBSERVED EZH2 UPREGULATION, AND IGFBP5 DOWNREGULATION, IN ADVANCED ATHEROSCLEROTIC PLAQUES FROM HUMAN PATIENTS. CONCLUSION: TAKEN TOGETHER, OUR FINDINGS REVEAL THAT ATHEROPROTECTIVE FLOW REDUCES H3K27ME3 AS A CHROMATIN-BASED MECHANISM TO AUGMENT THE EXPRESSION OF GENES THAT CONFER AN ANTI-INFLAMMATORY RESPONSE IN THE ENDOTHELIUM. OUR STUDY EXEMPLIFIES FLOW-DEPENDENT EPIGENETIC REGULATION OF ENDOTHELIAL GENE EXPRESSION, AND ALSO SUGGESTS THAT TARGETING THE EZH2/H3K27ME3/IGFBP5 PATHWAY MAY OFFER NOVEL THERAPEUTICS FOR INFLAMMATORY DISORDERS SUCH AS ATHEROSCLEROSIS. 2018 6 2378 28 EPIGENETIC REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING IN ATHEROSCLEROTIC ARTERY REMODELING: A MINI-REVIEW. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY EXTENSIVE REMODELING OF MEDIUM AND LARGE-SIZED ARTERIES. INWARD REMODELING (=LUMEN SHRINKAGE) OF THE VASCULAR WALLS IS THE UNDERLYING CAUSE FOR ISCHEMIA IN TARGET ORGANS. THEREFORE, INWARD REMODELING CAN BE CONSIDERED THE PREDOMINANT FEATURE OF ATHEROSCLEROTIC PATHOLOGY. OUTWARD REMODELING (=LUMEN ENLARGEMENT) IS A PHYSIOLOGICAL RESPONSE COMPENSATING FOR LUMEN SHRINKAGE CAUSED BY NEOINTIMAL HYPERPLASIA, BUT AS A PATHOLOGICAL RESPONSE TO CHANGES IN BLOOD FLOW, OUTWARD REMODELING LEADS TO SUBSTANTIAL ARTERIAL WALL THINNING. THINNED VASCULAR WALLS ARE PRONE TO RUPTURE, AND SUBSEQUENT THROMBUS FORMATION ACCOUNTS FOR THE MAJORITY OF ACUTE CARDIOVASCULAR EVENTS. PATHOLOGICAL REMODELING IS DRIVEN BY INFLAMMATORY CELLS WHICH INDUCE VASCULAR SMOOTH MUSCLE CELLS TO SWITCH FROM QUIESCENT TO A PROLIFERATIVE AND MIGRATORY PHENOTYPE. AFTER DECADES OF INTENSIVE RESEARCH, THE MOLECULAR MECHANISMS OF ARTERIAL REMODELING ARE STARTING TO UNFOLD. IN THIS MINI-REVIEW, WE SUMMARIZE THE CURRENT KNOWLEDGE OF THE EPIGENETIC AND TRANSCRIPTIONAL REGULATION OF VASCULAR SMOOTH MUSCLE CELL PHENOTYPE SWITCHING FROM THE CONTRACTILE TO THE SYNTHETIC PHENOTYPE INVOLVED IN ARTERIAL REMODELING AND DISCUSS POTENTIAL THERAPEUTIC OPTIONS. 2021 7 4158 30 MECHANOTRANSDUCTION DETERMINES THE STRUCTURE AND FUNCTION OF LUNG AND BONE: A THEORETICAL MODEL FOR THE PATHOPHYSIOLOGY OF CHRONIC DISEASE. MULTICELLULAR ORGANISMS HAVE EVOLVED IN ADAPTATION TO THE EARTH'S GRAVITATIONAL AND OXYGEN ENVIRONMENT. THIS EPIGENETIC PROCESS IS DEPENDENT ON THE CAPACITY OF MESODERMAL CELLS TO ACT AS MECHANOSENSORS THAT CAN CONFORM, DEFORM, AND REFORM IN ADAPTATION TO THE ORGANISM'S PHYSICAL ENVIRONMENT. MECHANICAL FORCES, SUCH AS HYDROSTATIC PRESSURE AND GRAVITY, PLAY IMPORTANT ROLES IN THE EMBRYONIC DEVELOPMENT, HOMEOSTASIS, AND REPAIR OF LUNG AND BONE. WE DISCUSS THE ROLE OF PARATHYROID HORMONE-RELATED PROTEIN (PTHRP) AS A MECHANOTRANSDUCER FOR STRETCH IN THESE ORGANS DURING NORMAL DEVELOPMENT, PARTICULARLY AS IT LENDS ITSELF TO HOMEOSTASIS; WE FURTHER DEMONSTRATE THAT "UNCOUPLING" OF SUCH MECHANISMS MAY PLAY A CENTRAL ROLE IN INJURY REPAIR, PARTICULARLY AS IT RELATES TO CHRONIC DISEASES OF LUNG AND BONE. ENDOTHERMAL PTHRP SIGNALING THROUGH ITS G-PROTEIN COUPLED RECEPTOR PROMOTES NORMAL CELL-CELL SIGNALING THAT MAINTAINS THE HOMEOSTATIC PHENOTYPES OF LUNG AND BONE. MOLECULAR DISRUPTION OF THE PTHRP/PTHRP RECEPTOR PATHWAY FROM ENDODERM TO MESODERM, BECAUSE OF SUCH FACTORS AS VOLUTRAUMA, HYPEROXIA, INFLAMMATION, AND MICROGRAVITY, ALTERS INTRACELLULAR SIGNALING, CAUSING MALADAPTIVE CELLULAR CHANGES, RESULTING IN MYOFIBROBLAST PROLIFERATION AND GRANULATION. EXAMPLES OF SUCH PATHOLOGIC CHANGES SPECIFICALLY RELATED TO THIS CELLULAR/MOLECULAR MECHANISM OF MALADAPTATION ARE CHRONIC LUNG DISEASE AND OSTEOPOROSIS. WE SUGGEST A NEW PARADIGM THAT MAY HELP IN THE FUTURE CREATION OF DIAGNOSTIC AND THERAPEUTIC MODALITIES FOR A WIDE RANGE OF DEVELOPMENTAL AND CHRONIC DISEASES RANGING FROM BRONCHOPULMONARY DYSPLASIA IN NEWBORNS TO IDIOPATHIC PULMONARY FIBROSIS AND OSTEOPOROSIS AS A RESULT OF AGING OR MICROGRAVITY. 2003 8 1654 20 DORSAL ROOT GANGLIA COACTIVATOR-ASSOCIATED ARGININE METHYLTRANSFERASE 1 CONTRIBUTES TO PERIPHERAL NERVE INJURY-INDUCED PAIN HYPERSENSITIVITIES. NEUROPATHIC PAIN IS ASSOCIATED WITH GENE EXPRESSION CHANGES WITHIN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, WHICH INVOLVES EPIGENETIC MECHANISMS. COACTIVATOR-ASSOCIATED ARGININE METHYLTRANSFERASE 1 (CARM1), AN EPIGENETIC ACTIVATOR, REGULATES GENE TRANSCRIPTIONAL ACTIVITY BY PROTEIN POSTTRANSLATIONAL MODIFICATIONS. HOWEVER, WHETHER CARM1 PLAYS AN ESSENTIAL ROLE IN THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN IS UNKNOWN. WE REPORT HERE THAT PERIPHERAL NERVE INJURY INDUCED THE UPREGULATION OF THE MRNA AND PROTEIN EXPRESSION OF CARM1 IN THE INJURED DRG, AND BLOCKING ITS EXPRESSION THROUGH SMALL INTERFERING RNA (SIRNA) IN THE INJURED DRG ATTENUATED THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN. FURTHERMORE, PHARMACOLOGICAL INHIBITION OF CARM1 MITIGATED PERIPHERAL NERVE INJURY-INDUCED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA. GIVEN THAT CARM1 INHIBITION OR KNOCKDOWN ATTENUATED THE INDUCTION AND MAINTENANCE OF NEUROPATHIC PAIN AFTER PERIPHERAL NERVE INJURY, OUR FINDINGS SUGGEST THAT CARM1 MAY SERVE AS A PROMISING THERAPEUTIC TARGET FOR NEUROPATHIC PAIN TREATMENT IN CLINICAL APPLICATIONS. 2018 9 4563 26 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 10 4358 22 MIR-338-3P BLOCKS TGFBETA-INDUCED MYOFIBROBLAST DIFFERENTIATION THROUGH THE INDUCTION OF PTEN. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC INTERSTITIAL LUNG DISEASE. THE PATHOGENESIS OF IPF IS NOT COMPLETELY UNDERSTOOD. HOWEVER, NUMEROUS GENES ARE ASSOCIATED WITH THE DEVELOPMENT AND PROGRESSION OF PULMONARY FIBROSIS, INDICATING THERE IS A SIGNIFICANT GENETIC COMPONENT TO THE PATHOGENESIS OF IPF. EPIGENETIC INFLUENCES ON THE DEVELOPMENT OF HUMAN DISEASE, INCLUDING PULMONARY FIBROSIS, REMAIN TO BE FULLY ELUCIDATED. IN THIS PAPER, WE IDENTIFY MIR-338-3P AS A MICRORNA SEVERELY DOWNREGULATED IN THE LUNGS OF PATIENTS WITH PULMONARY FIBROSIS AND IN EXPERIMENTAL MODELS OF PULMONARY FIBROSIS. TREATMENT OF PRIMARY HUMAN LUNG FIBROBLASTS WITH MIR-338-3P INHIBITS MYOFIBROBLAST DIFFERENTIATION AND MATRIX PROTEIN PRODUCTION. PUBLISHED AND PROPOSED TARGETS OF MIR-338-3P SUCH AS TGFBETA RECEPTOR 1, MEK/ERK 1/2, CDK4, AND CYCLIN D ARE ALSO NOT RESPONSIBLE FOR THE REGULATION OF PULMONARY FIBROBLAST BEHAVIOR BY MIR-338-3P. MIR-338-3P INHIBITS MYOFIBROBLAST DIFFERENTIATION BY PREVENTING TGFBETA-MEDIATED DOWNREGULATION OF PHOSPHATASE AND TENSIN HOMOLOG (PTEN), A KNOWN ANTIFIBROTIC MEDIATOR. 2022 11 5995 19 TGFBETA-INDUCED FIBROBLAST ACTIVATION REQUIRES PERSISTENT AND TARGETED HDAC-MEDIATED GENE REPRESSION. TISSUE FIBROSIS IS A CHRONIC DISEASE DRIVEN BY PERSISTENT FIBROBLAST ACTIVATION THAT HAS RECENTLY BEEN LINKED TO EPIGENETIC MODIFICATIONS. HERE, WE SCREENED A SMALL LIBRARY OF EPIGENETIC SMALL-MOLECULE MODULATORS TO IDENTIFY COMPOUNDS CAPABLE OF INHIBITING OR REVERSING TGFBETA-MEDIATED FIBROBLAST ACTIVATION. WE IDENTIFIED PRACINOSTAT, AN HDAC INHIBITOR, AS A POTENT ATTENUATOR OF LUNG FIBROBLAST ACTIVATION AND CONFIRMED ITS EFFICACY IN PATIENT-DERIVED FIBROBLASTS ISOLATED FROM FIBROTIC LUNG TISSUE. MECHANISTICALLY, WE FOUND THAT HDAC-DEPENDENT TRANSCRIPTIONAL REPRESSION WAS AN EARLY AND ESSENTIAL EVENT IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION. TREATMENT OF LUNG FIBROBLASTS WITH PRACINOSTAT BROADLY ATTENUATED TGFBETA-MEDIATED EPIGENETIC REPRESSION AND PROMOTED FIBROBLAST QUIESCENCE. WE CONFIRMED A SPECIFIC ROLE FOR HDAC-DEPENDENT HISTONE DEACETYLATION IN THE PROMOTER REGION OF THE ANTI-FIBROTIC GENE PPARGC1A (PGC1ALPHA) IN RESPONSE TO TGFBETA STIMULATION. FINALLY, WE IDENTIFIED HDAC7 AS A KEY FACTOR WHOSE SIRNA-MEDIATED KNOCKDOWN ATTENUATES FIBROBLAST ACTIVATION WITHOUT ALTERING GLOBAL HISTONE ACETYLATION. TOGETHER, THESE RESULTS PROVIDE NOVEL MECHANISTIC INSIGHT INTO THE ESSENTIAL ROLE HDACS PLAY IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION VIA TARGETED GENE REPRESSION. 2019 12 6214 28 THE INTRACELLULAR SIGNALING PATHWAYS GOVERNING MACROPHAGE ACTIVATION AND FUNCTION IN HUMAN ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY LIPID ACCUMULATION AND PLAQUE FORMATION IN ARTERIAL VESSEL WALLS. ATHEROSCLEROTIC PLAQUES NARROW THE ARTERIAL LUMEN TO INCREASE THE RISK OF HEART ATTACKS, ISCHEMIC STROKE AND PERIPHERAL VASCULAR DISEASE, WHICH ARE MAJOR AND WORLDWIDE HEALTH AND ECONOMIC BURDENS. MACROPHAGE ACCUMULATION WITHIN PLAQUES IS CHARACTERISTIC OF ALL STAGES OF ATHEROSCLEROSIS AND THEIR PRESENCE IS A POTENTIAL MARKER OF DISEASE ACTIVITY AND PLAQUE STABILITY. MACROPHAGES ENGULF LIPIDS AND MODIFIED LIPOPROTEINS TO FORM FOAM CELLS THAT EXPRESS PRO-INFLAMMATORY AND CHEMOTACTIC EFFECTOR MOLECULES, STRESS INDUCING FACTORS AND REACTIVE OXYGEN SPECIES. THEY CONTROL PLAQUE STABILITY AND RUPTURE THROUGH SECRETION OF METALLOPROTEINASES AND EXTRACELLULAR MATRIX DEGRADATION. ALTHOUGH MACROPHAGES CAN WORSEN DISEASE BY PROPAGATING INFLAMMATION, THEY CAN STABILIZE ATHEROSCLEROTIC PLAQUES THROUGH TISSUE REMODELING, PROMOTING THE FORMATION OF A FIBROUS CAP, CLEARING APOPTOTIC CELLS TO PREVENT NECROTIC CORE FORMATION AND THROUGH VASCULAR REPAIR. IN ATHEROSCLEROSIS, MACROPHAGES RESPOND TO DYSLIPIDAEMIA, CYTOKINES, DYING CELLS, METABOLIC FACTORS, LIPIDS, PHYSICAL STIMULI AND EPIGENETIC FACTORS AND EXHIBIT HETEROGENEITY IN THEIR ACTIVATION DEPENDING ON THE STIMULI THEY RECEIVE. UNDERSTANDING THESE SIGNALS AND THE PATHWAYS DRIVING MACROPHAGE FUNCTION WITHIN DEVELOPING AND ESTABLISHED PLAQUES AND HOW THEY CAN BE PHARMACOLOGICALLY MODULATED, REPRESENTS A STRATEGY FOR THE PREVENTION AND TREATMENT OF ATHEROSCLEROSIS. THIS REVIEW FOCUSSES ON THE CURRENT UNDERSTANDING OF FACTORS CONTROLLING MACROPHAGE HETEROGENEITY AND FUNCTION IN ATHEROSCLEROSIS. PARTICULAR ATTENTION IS GIVEN TO THE MACROPHAGE INTRACELLULAR SIGNALING PATHWAYS AND TRANSCRIPTION FACTORS ACTIVATED BY BIOCHEMICAL AND BIOPHYSICAL STIMULI WITHIN PLAQUES, AND HOW THEY ARE INTEGRATED TO REGULATE PLAQUE FORMATION AND STABILITY. 2022 13 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 14 5933 42 TARGETING EPIGENETICS AND NON-CODING RNAS IN ATHEROSCLEROSIS: FROM MECHANISMS TO THERAPEUTICS. ATHEROSCLEROSIS, THE PRINCIPAL CAUSE OF CARDIOVASCULAR DEATH WORLDWIDE, IS A PATHOLOGICAL DISEASE CHARACTERIZED BY FIBRO-PROLIFERATION, CHRONIC INFLAMMATION, LIPID ACCUMULATION, AND IMMUNE DISORDER IN THE VESSEL WALL. AS THE ATHEROMATOUS PLAQUES DEVELOP INTO ADVANCED STAGE, THE VULNERABLE PLAQUES ARE PRONE TO RUPTURE, WHICH CAUSES ACUTE CARDIOVASCULAR EVENTS, INCLUDING ISCHEMIC STROKE AND MYOCARDIAL INFARCTION. EMERGING EVIDENCE HAS SUGGESTED THAT ATHEROSCLEROSIS IS ALSO AN EPIGENETIC DISEASE WITH THE INTERPLAY OF MULTIPLE EPIGENETIC MECHANISMS. THE EPIGENETIC BASIS OF ATHEROSCLEROSIS HAS TRANSFORMED OUR KNOWLEDGE OF EPIGENETICS FROM AN IMPORTANT BIOLOGICAL PHENOMENON TO A BURGEONING FIELD IN CARDIOVASCULAR RESEARCH. HERE, WE PROVIDE A SYSTEMATIC AND UP-TO-DATE OVERVIEW OF THE CURRENT KNOWLEDGE OF THREE DISTINCT BUT INTERRELATED EPIGENETIC PROCESSES (INCLUDING DNA METHYLATION, HISTONE METHYLATION/ACETYLATION, AND NON-CODING RNAS), IN ATHEROSCLEROTIC PLAQUE DEVELOPMENT AND INSTABILITY. MECHANISTIC AND CONCEPTUAL ADVANCES IN UNDERSTANDING THE BIOLOGICAL ROLES OF VARIOUS EPIGENETIC MODIFIERS IN REGULATING GENE EXPRESSION AND FUNCTIONS OF ENDOTHELIAL CELLS (VASCULAR HOMEOSTASIS, LEUKOCYTE ADHESION, ENDOTHELIAL-MESENCHYMAL TRANSITION, ANGIOGENESIS, AND MECHANOTRANSDUCTION), SMOOTH MUSCLE CELLS (PROLIFERATION, MIGRATION, INFLAMMATION, HYPERTROPHY, AND PHENOTYPIC SWITCH), AND MACROPHAGES (DIFFERENTIATION, INFLAMMATION, FOAM CELL FORMATION, AND POLARIZATION) ARE DISCUSSED. THE INHERENTLY DYNAMIC NATURE AND REVERSIBILITY OF EPIGENETIC REGULATION, ENABLES THE POSSIBILITY OF EPIGENETIC THERAPY BY TARGETING EPIGENETIC "WRITERS", "READERS", AND "ERASERS". SEVERAL FOOD DRUG ADMINISTRATION-APPROVED SMALL-MOLECULE EPIGENETIC DRUGS SHOW PROMISE IN PRE-CLINICAL STUDIES FOR THE TREATMENT OF ATHEROSCLEROSIS. FINALLY, WE DISCUSS POTENTIAL THERAPEUTIC IMPLICATIONS AND CHALLENGES FOR FUTURE RESEARCH INVOLVING CARDIOVASCULAR EPIGENETICS, WITH AN AIM TO PROVIDE A TRANSLATIONAL PERSPECTIVE FOR IDENTIFYING NOVEL BIOMARKERS OF ATHEROSCLEROSIS, AND TRANSFORMING PRECISION CARDIOVASCULAR RESEARCH AND DISEASE THERAPY IN MODERN ERA OF EPIGENETICS. 2019 15 4906 27 P300 EXERTS AN EPIGENETIC ROLE IN CHRONIC NEUROPATHIC PAIN THROUGH ITS ACETYLTRANSFERASE ACTIVITY IN RATS FOLLOWING CHRONIC CONSTRICTION INJURY (CCI). BACKGROUND: NEUROPATHIC PAIN IS DETRIMENTAL TO HUMAN HEALTH; HOWEVER, ITS PATHOGENESIS STILL REMAINS LARGELY UNKNOWN. OVEREXPRESSION OF PAIN-ASSOCIATED GENES AND INCREASED NOCICEPTIVE SOMATO-SENSITIVITY ARE WELL OBSERVED IN NEUROPATHIC PAIN. THE IMPORTANCE OF EPIGENETIC MECHANISMS IN REGULATING THE EXPRESSION OF PRO- OR ANTI-NOCICEPTIVE GENES HAS BEEN REVEALED BY STUDIES RECENTLY, AND WE HYPOTHESIZE THAT THE TRANSCRIPTIONAL COACTIVATOR AND THE HISTONE ACETYLTRANSFERASE E1A BINDING PROTEIN P300 (P300), AS A PART OF THE EPIGENETIC MECHANISMS OF GENE REGULATION, MAY BE INVOLVED IN THE PATHOGENESIS OF NEUROPATHIC PAIN INDUCED BY CHRONIC CONSTRICTION INJURY (CCI). TO TEST THIS HYPOTHESIS, TWO DIFFERENT APPROACHES WERE USED IN THIS STUDY: (I) DOWN-REGULATING P300 WITH SPECIFIC SMALL HAIRPIN RNA (SHRNA) AND (II) CHEMICAL INHIBITION OF P300 ACETYLTRANSFERASE ACTIVITY BY A SMALL MOLECULE INHIBITOR, C646. RESULTS: USING THE CCI RAT MODEL, WE FOUND THAT THE P300 EXPRESSION WAS INCREASED IN THE LUMBAR SPINAL CORD ON DAY 14 AFTER CCI. THE TREATMENT WITH INTRATHECAL P300 SHRNA REVERSED CCI-INDUCED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA, AND SUPPRESSED THE EXPRESSION OF CYCLOOXYGENASE-2 (COX-2), A NEUROPATHIC PAIN-ASSOCIATED FACTOR. FURTHERMORE, C646, AN INHIBITOR OF P300 ACETYLTRANSFERASE, ALSO ATTENUATED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA, ACCOMPANIED BY A SUPPRESSED COX-2 EXPRESSION, IN THE SPINAL CORD. CONCLUSIONS: THE RESULTS SUGGEST THAT, THROUGH ITS ACETYLTRANSFERASE ACTIVITY IN THE SPINAL CORD AFTER CCI, P300 EPIGENETICALLY PLAYS AN IMPORTANT ROLE IN NEUROPATHIC PAIN. INHIBITING P300, USING INTERFERING RNA OR C646, MAY BE A PROMISING APPROACH TO THE DEVELOPMENT OF NEW NEUROPATHIC PAIN THERAPIES. 2012 16 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 17 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 18 1862 23 EMERGENCE OF FIBROBLASTS WITH A PROINFLAMMATORY EPIGENETICALLY ALTERED PHENOTYPE IN SEVERE HYPOXIC PULMONARY HYPERTENSION. PERSISTENT ACCUMULATION OF MONOCYTES/MACROPHAGES IN THE PULMONARY ARTERY ADVENTITIAL/PERIVASCULAR AREAS OF ANIMALS AND HUMANS WITH PULMONARY HYPERTENSION HAS BEEN DOCUMENTED. THE CELLULAR MECHANISMS CONTRIBUTING TO CHRONIC INFLAMMATORY RESPONSES REMAIN UNCLEAR. WE HYPOTHESIZED THAT PERIVASCULAR INFLAMMATION IS PERPETUATED BY ACTIVATED ADVENTITIAL FIBROBLASTS, WHICH, THROUGH SUSTAINED PRODUCTION OF PROINFLAMMATORY CYTOKINES/CHEMOKINES AND ADHESION MOLECULES, INDUCE ACCUMULATION, RETENTION, AND ACTIVATION OF MONOCYTES/MACROPHAGES. WE FURTHER HYPOTHESIZED THAT THIS PROINFLAMMATORY PHENOTYPE IS THE RESULT OF THE ABNORMAL ACTIVITY OF HISTONE-MODIFYING ENZYMES, SPECIFICALLY, CLASS I HISTONE DEACETYLASES (HDACS). PULMONARY ADVENTITIAL FIBROBLASTS FROM CHRONICALLY HYPOXIC HYPERTENSIVE CALVES (TERMED PH-FIBS) EXPRESSED A CONSTITUTIVE AND PERSISTENT PROINFLAMMATORY PHENOTYPE DEFINED BY HIGH EXPRESSION OF IL-1BETA, IL-6, CCL2(MCP-1), CXCL12(SDF-1), CCL5(RANTES), CCR7, CXCR4, GM-CSF, CD40, CD40L, AND VCAM-1. THE PROINFLAMMATORY PHENOTYPE OF PH-FIBS WAS ASSOCIATED WITH EPIGENETIC ALTERATIONS AS DEMONSTRATED BY INCREASED ACTIVITY OF HDACS AND THE FINDINGS THAT CLASS I HDAC INHIBITORS MARKEDLY DECREASED CYTOKINE/CHEMOKINE MRNA EXPRESSION LEVELS IN THESE CELLS. PH-FIBS INDUCED INCREASED ADHESION OF THP-1 MONOCYTES AND PRODUCED SOLUBLE FACTORS THAT INDUCED INCREASED MIGRATION OF THP-1 AND MURINE BONE MARROW-DERIVED MACROPHAGES AS WELL AS ACTIVATED MONOCYTES/MACROPHAGES TO EXPRESS PROINFLAMMATORY CYTOKINES AND PROFIBROGENIC MEDIATORS (TIMP1 AND TYPE I COLLAGEN) AT THE TRANSCRIPTIONAL LEVEL. CLASS I HDAC INHIBITORS MARKEDLY REDUCED THE ABILITY OF PH-FIBS TO INDUCE MONOCYTE MIGRATION AND PROINFLAMMATORY ACTIVATION. THE EMERGENCE OF A DISTINCT ADVENTITIAL FIBROBLAST POPULATION WITH AN EPIGENETICALLY ALTERED PROINFLAMMATORY PHENOTYPE CAPABLE OF RECRUITING, RETAINING, AND ACTIVATING MONOCYTES/MACROPHAGES CHARACTERIZES PULMONARY HYPERTENSION-ASSOCIATED VASCULAR REMODELING AND THUS COULD CONTRIBUTE SIGNIFICANTLY TO CHRONIC INFLAMMATORY PROCESSES IN THE PULMONARY ARTERY WALL. 2011 19 6910 23 [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 20 4506 25 MRTF-A MEDIATES LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION BY INTERACTING WITH THE COMPASS COMPLEX. CHRONIC INFLAMMATION UNDERSCORES THE PATHOGENESIS OF A RANGE OF HUMAN DISEASES. LIPOPOLYSACCHARIDE (LPS) ELICITS STRONG PRO-INFLAMMATORY RESPONSES IN MACROPHAGES THROUGH THE TRANSCRIPTION FACTOR NF-KAPPAB. THE EPIGENETIC MECHANISM UNDERLYING LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION IS NOT FULLY UNDERSTOOD. HEREIN, WE DESCRIBE A ROLE FOR MYOCARDIN-RELATED TRANSCRIPTION FACTOR A (MRTF-A, ALSO KNOWN AS MKL1) IN THIS PROCESS. MRTF-A OVEREXPRESSION ENHANCED NF-KAPPAB-DEPENDENT PRO-INFLAMMATORY TRANSCRIPTION, WHEREAS MRTF-A SILENCING INHIBITED THIS PROCESS. MRTF-A DEFICIENCY ALSO REDUCED THE SYNTHESIS OF PRO-INFLAMMATORY MEDIATORS IN A MOUSE MODEL OF COLITIS. LPS PROMOTED THE RECRUITMENT OF MRTF-A TO THE PROMOTERS OF PRO-INFLAMMATORY GENES IN AN NF-KAPPAB-DEPENDENT MANNER. RECIPROCALLY, MRTF-A INFLUENCED THE NUCLEAR ENRICHMENT AND TARGET BINDING OF NF-KAPPAB. MECHANISTICALLY, MRTF-A WAS NECESSARY FOR THE ACCUMULATION OF ACTIVE HISTONE MODIFICATIONS ON NF-KAPPAB TARGET PROMOTERS BY COMMUNICATING WITH THE HISTONE H3K4 METHYLTRANSFERASE COMPLEX (COMPASS). SILENCING OF INDIVIDUAL MEMBERS OF COMPASS, INCLUDING ASH2, WDR5 AND SET1 (ALSO KNOWN AS SETD1A), DOWNREGULATED THE PRODUCTION OF PRO-INFLAMMATORY MEDIATORS AND IMPAIRED THE NF-KAPPAB KINETICS. IN SUMMARY, OUR WORK HAS UNCOVERED A PREVIOUSLY UNKNOWN FUNCTION FOR MRTF-A AND PROVIDED INSIGHTS INTO THE RATIONALIZED DEVELOPMENT OF ANTI-INFLAMMATORY THERAPEUTIC STRATEGIES. 2014