1 3205 143 HDAC8, A POTENTIAL THERAPEUTIC TARGET, REGULATES PROLIFERATION AND DIFFERENTIATION OF BONE MARROW STROMAL CELLS IN FIBROUS DYSPLASIA. FIBROUS DYSPLASIA (FD) IS A DISEASE OF POSTNATAL SKELETAL STEM CELLS CAUSED BY ACTIVATING MUTATIONS OF GUANINE NUCLEOTIDE-BINDING PROTEIN ALPHA-STIMULATING ACTIVITY POLYPEPTIDE (GNAS). FD IS CHARACTERIZED BY HIGH PROLIFERATION AND OSTEOGENESIS DISORDER OF BONE MARROW STROMAL CELLS (BMSCS), RESULTING IN BONE PAIN, DEFORMITIES, AND FRACTURES. THE CAMP-CREB PATHWAY, WHICH IS ACTIVATED BY GNAS MUTATIONS, IS KNOWN TO BE CLOSELY ASSOCIATED WITH THE OCCURRENCE OF FD. HOWEVER, SO FAR THERE IS NO AVAILABLE TARGETED THERAPEUTIC STRATEGY FOR FD, AS A CRITICAL ISSUE THAT REMAINS LARGELY UNKNOWN IS HOW THIS PATHWAY IS INVOLVED IN FD. OUR PREVIOUS STUDY REVEALED THAT HISTONE DEACETYLASE 8 (HDAC8) INHIBITED THE OSTEOGENIC DIFFERENTIATION OF BMSCS VIA EPIGENETIC REGULATION. HERE, COMPARED WITH NORMAL BMSCS, FD BMSCS EXHIBITED SIGNIFICANTLY HIGH PROLIFERATION AND WEAK OSTEOGENIC CAPACITY IN RESPONSE TO HDAC8 UPREGULATION AND TUMOR PROTEIN 53 (TP53) DOWNREGULATION. MOREOVER, INHIBITION OF CAMP REDUCED HDAC8 EXPRESSION, INCREASED TP53 EXPRESSION AND RESULTED IN THE IMPROVEMENT OF FD PHENOTYPE. IMPORTANTLY, HDAC8 INHIBITION PREVENTED CAMP-INDUCED CELL PHENOTYPE AND PROMOTED OSTEOGENESIS IN NUDE MICE THAT WERE IMPLANTED WITH FD BMSCS. MECHANISTICALLY, HDAC8 WAS IDENTIFIED AS A TRANSCRIPTIONAL TARGET GENE OF CREB1 AND ITS TRANSCRIPTION WAS DIRECTLY ACTIVATED BY CREB1 IN FD BMSCS. IN SUMMARY, OUR STUDY REVEALS THAT HDAC8 ASSOCIATES WITH FD PHENOTYPE AND DEMONSTRATES THE MECHANISMS REGULATED BY CAMP-CREB1-HDAC8 PATHWAY. THESE RESULTS PROVIDE INSIGHTS INTO THE MOLECULAR REGULATION OF FD PATHOGENESIS, AND OFFER NOVEL CLUES THAT SMALL MOLECULE INHIBITORS TARGETING HDAC8 ARE PROMISING CLINICAL TREATMENT FOR FD. STEM CELLS TRANSLATIONAL MEDICINE 2019;8:148&14. 2019 2 4201 26 METABOLIC REWIRING AND REDOX ALTERATIONS IN MALIGNANT PLEURAL MESOTHELIOMA. MALIGNANT PLEURAL MESOTHELIOMA (MPM) IS A RARE MALIGNANCY OF MESOTHELIAL CELLS WITH INCREASING INCIDENCE, AND IN MANY CASES, DISMAL PROGNOSIS DUE TO ITS AGGRESSIVENESS AND LACK OF EFFECTIVE THERAPIES. ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO ASBESTOS IS CONSIDERED THE MAIN AETIOLOGICAL FACTOR FOR MPM. INHALED ASBESTOS FIBRES ACCUMULATE IN THE LUNGS AND INDUCE THE GENERATION OF REACTIVE OXYGEN SPECIES (ROS) DUE TO THE PRESENCE OF IRON ASSOCIATED WITH THE FIBROUS SILICATES AND TO THE ACTIVATION OF MACROPHAGES AND INFLAMMATION. CHRONIC INFLAMMATION AND A ROS-ENRICHED MICROENVIRONMENT CAN FOSTER THE MALIGNANT TRANSFORMATION OF MESOTHELIAL CELLS. IN ADDITION, MPM CELLS HAVE A HIGHLY GLYCOLYTIC METABOLIC PROFILE AND ARE POSITIVE IN (18)F-FDG PET ANALYSIS. LOSS-OF-FUNCTION MUTATIONS OF BRCA-ASSOCIATED PROTEIN 1 (BAP1) ARE A MAJOR CONTRIBUTOR TO THE METABOLIC REWIRING OF MPM CELLS. A SUBSET OF MPM TUMOURS SHOW LOSS OF THE METHYLADENOSINE PHOSPHORYLASE (MTAP) LOCUS, RESULTING IN PROFOUND ALTERATIONS IN POLYAMINE METABOLISM, ATP AND METHIONINE SALVAGE PATHWAYS, AS WELL AS CHANGES IN EPIGENETIC CONTROL OF GENE EXPRESSION. THIS REVIEW PROVIDES AN OVERVIEW OF THE PERTURBATIONS IN METABOLISM AND ROS HOMOEOSTASIS OF MPM CELLS AND THE ROLE OF THESE ALTERATIONS IN MALIGNANT TRANSFORMATION AND TUMOUR PROGRESSION. 2020 3 1257 33 CURRENT TRENDS IN EPIGENETIC, CELLULAR AND MOLECULAR PATHWAYS IN MANAGEMENT OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS IS A SYSTEMIC CHRONIC POLYARTICULAR AUTOIMMUNE DISORDER OF JOINTS AND JOINT MEMBRANE MAINLY AFFECTING FEET AND HANDS. THE PATHOLOGICAL MANIFESTATION OF THE DISEASE INCLUDES INFILTRATION OF IMMUNE CELLS, HYPERPLASIA OF THE LINING OF SYNOVIUM, FORMATION OF PANNUS AND BONE AND CARTILAGE DESTRUCTION. IF LEFT UNTREATED, THE APPEARANCE OF SMALL FOCAL NECROSIS, ADHESION OF GRANULATION, AND FORMATION OF FIBROUS TISSUE ON THE SURFACE OF ARTICULAR CARTILAGE IS NOTED. THE DISEASE PRIMARILY AFFECTS NEARLY 1% OF THE POPULATION GLOBALLY, WOMEN BEING MORE AFFECTED THAN MEN WITH A RATIO 2:1 AND CAN INITIATE REGARDLESS OF ANY AGE. THE SYNOVIAL FIBROBLAST IN RHEUMATOID ARTHRITIS INDIVIDUALS EXHIBITS AN AGGRESSIVE PHENOTYPE WHICH UPREGULATES THE MANIFESTATION OF PROTOONCOGENES, ADHESIVE COMPOUNDS, INFLAMMATORY CYTOKINES AND MATRIX-DETERIORATING ENZYMES. APART FROM THE INFLAMMATORY EFFECTS OF CYTOKINES, CHEMOKINES ARE ALSO NOTED TO INDUCE SWELLING AND PAIN IN ARTHRITIC INDIVIDUALS BY RESIDING IN SYNOVIAL MEMBRANE AND FORMING PANNUS. THE CURRENT TREATMENT OF RHEUMATOID ARTHRITIS INCLUDES TREATMENT WITH NON-STEROIDAL ANTI-INFLAMMATORY DRUGS, DISEASE-MODIFYING ANTIRHEUMATIC DRUGS, TREATMENT WITH BIOLOGICS SUCH AS INHIBITORS OF TNF-ALPHA, INTERLEUKINS, PLATELET ACTIVATING FACTOR, ETC. WHICH PROVIDES SIGNIFICANT RELIEF FROM SYMPTOMS AND AIDS IN MANAGEMENT OF THE DISEASE. THE CURRENT REVIEW HIGHLIGHTS THE PATHOGENESIS INVOLVED IN THE ONSET OF RHEUMATOID ARTHRITIS AND ALSO COVERS EPIGENETIC, CELLULAR AND MOLECULAR PARAMETERS ASSOCIATED WITH IT TO AID BETTER AND ADVANCED THERAPEUTIC APPROACHES FOR MANAGEMENT OF THE DEBILITATING DISEASE. 2023 4 6214 30 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 5 3245 18 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 6 5939 48 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 7 4501 27 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 8 3931 20 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 9 6741 25 WHERE TO STAND WITH STROMAL CELLS AND CHRONIC SYNOVITIS IN RHEUMATOID ARTHRITIS? THE SYNOVIUM EXERCISES ITS MAIN FUNCTION IN JOINT HOMEOSTASIS THROUGH THE SECRETION OF FACTORS (SUCH AS LUBRICIN AND HYALURONIC ACID) THAT ARE CRITICAL FOR THE JOINT LUBRICATION AND FUNCTION. THE MAIN SYNOVIUM CELL COMPONENTS ARE FIBROBLAST-LIKE SYNOVIOCYTES, MESENCHYMAL STROMAL/STEM CELLS AND MACROPHAGE-LIKE SYNOVIAL CELLS. IN THE SYNOVIUM, CELLS OF MESENCHYMAL ORIGIN MODULATE LOCAL INFLAMMATION AND FIBROSIS, AND INTERACT WITH DIFFERENT FIBROBLAST SUBTYPES AND WITH RESIDENT MACROPHAGES. IN PATHOLOGIC CONDITIONS, SUCH AS RHEUMATOID ARTHRITIS, FIBROBLAST-LIKE SYNOVIOCYTES PROLIFERATE ABNORMALLY, RECRUIT MESENCHYMAL STEM CELLS FROM SUBCHONDRAL BONE MARROW, AND INFLUENCE IMMUNE CELL ACTIVITY THROUGH EPIGENETIC AND METABOLIC ADAPTATIONS. THE RESULTING SYNOVIAL HYPERPLASIA LEADS TO SECONDARY CARTILAGE DESTRUCTION, JOINT SWELLING, AND PAIN. IN THE PRESENT REVIEW, WE SUMMARIZE RECENT FINDINGS ON THE MOLECULAR SIGNATURE AND THE ROLES OF STROMAL CELLS DURING SYNOVIAL PANNUS FORMATION AND RHEUMATOID ARTHRITIS PROGRESSION. 2019 10 699 33 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 11 924 27 CHRONIC INFLAMMATION AS A PROMOTOR OF MUTAGENESIS IN ESSENTIAL THROMBOCYTHEMIA, POLYCYTHEMIA VERA AND MYELOFIBROSIS. A HUMAN INFLAMMATION MODEL FOR CANCER DEVELOPMENT? THE PHILADELPHIA-NEGATIVE CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE ACQUIRED STEM CELL NEOPLASMS, IN WHICH A STEM CELL LESION INDUCES AN AUTONOMOUS PROLIFERATIVE ADVANTAGE. IN ADDITION TO THE JAK2V617 MUTATION SEVERAL OTHER MUTATIONS HAVE BEEN DESCRIBED. RECENTLY CHRONIC INFLAMMATION HAS BEEN PROPOSED AS A TRIGGER AND DRIVER OF CLONAL EVOLUTION IN MPNS. HEREIN, IT IS HYPOTHESIZED THAT SUSTAINED INFLAMMATION MAY ELICIT THE STEM CELL INSULT BY INDUCING A STATE OF CHRONIC OXIDATIVE STRESS WITH ELEVATED LEVELS OF REACTIVE OXYGEN SPECIES (ROS) IN THE BONE MARROW, THEREBY CREATING A HIGH-RISK MICROENVIRONMENT FOR INDUCTION OF MUTATIONS DUE TO THE PERSISTENT INFLAMMATION-INDUCED OXIDATIVE DAMAGE TO DNA IN HEMATOPOIETIC CELLS. ALTERATIONS IN THE EPIGENOME INDUCED BY THE CHRONIC INFLAMMATORY DRIVE MAY LIKELY ELICIT A "EPIGENETIC SWITCH" PROMOTING PERSISTENT INFLAMMATION. THE PERSPECTIVES OF CHRONIC INFLAMMATION AS THE DRIVER OF MUTAGENESIS IN MPNS ARE DISCUSSED, INCLUDING EARLY INTERVENTION WITH INTERFERON-ALPHA2 AND POTENT ANTI-INFLAMMATORY AGENTS (E.G. JAK1-2 INHIBITORS, HISTONE DEACETYLASE INHIBITORS, DNA-HYPOMETHYLATORS AND STATINS) TO DISRUPT THE SELF-PERPETUATING CHRONIC INFLAMMATION STATE AND ACCORDINGLY ELIMINATING A POTENTIAL TRIGGER OF CLONAL EVOLUTION AND DISEASE PROGRESSION WITH MYELOFIBROTIC AND LEUKEMIC TRANSFORMATION. 2013 12 4298 33 MICRORNA-146A GOVERNS FIBROBLAST ACTIVATION AND JOINT PATHOLOGY IN ARTHRITIS. SYNOVIAL FIBROBLASTS ARE KEY CELLS ORCHESTRATING THE INFLAMMATORY RESPONSE IN ARTHRITIS. HERE WE DEMONSTRATE THAT LOSS OF MIR-146A, A KEY EPIGENETIC REGULATOR OF THE INNATE IMMUNE RESPONSE, LEADS TO INCREASED JOINT DESTRUCTION IN A TNF-DRIVEN MODEL OF ARTHRITIS BY SPECIFICALLY REGULATING THE BEHAVIOR OF SYNOVIAL FIBROBLASTS. ABSENCE OF MIR-146A IN SYNOVIAL FIBROBLASTS DISPLAY A HIGHLY DEREGULATED GENE EXPRESSION PATTERN AND ENHANCED PROLIFERATION IN VITRO AND IN VIVO. DEFICIENCY OF MIR-146A INDUCES DEREGULATION OF TUMOR NECROSIS FACTOR (TNF) RECEPTOR ASSOCIATED FACTOR 6 (TRAF6) IN SYNOVIAL FIBROBLASTS, LEADING TO INCREASED PROLIFERATION. IN ADDITION, LOSS OF MIR-146A SHIFTS THE METABOLIC STATE OF FIBROBLASTS TOWARDS GLYCOLYSIS AND AUGMENTS THE ABILITY OF SYNOVIAL FIBROBLASTS TO SUPPORT THE GENERATION OF OSTEOCLASTS BY CONTROLLING THE BALANCE OF OSTEOCLASTOGENIC REGULATORY FACTORS RECEPTOR ACTIVATOR OF NF-KAPPAB LIGAND (RANKL) AND OSTEOPROTEGERIN (OPG). BONE MARROW TRANSPLANTATION EXPERIMENTS CONFIRMED THE IMPORTANCE OF MIR-146A IN THE RADIORESISTANT MESENCHYMAL COMPARTMENT FOR THE CONTROL OF ARTHRITIS SEVERITY, IN PARTICULAR FOR INFLAMMATORY JOINT DESTRUCTION. THIS STUDY THEREFORE IDENTIFIES MICRORNA-146A AS AN IMPORTANT LOCAL EPIGENETIC REGULATOR OF THE INFLAMMATORY RESPONSE IN ARTHRITIS. IT IS A CENTRAL ELEMENT OF AN ANTI-INFLAMMATORY FEEDBACK LOOP IN RESIDENT SYNOVIAL FIBROBLASTS, WHO ARE ORCHESTRATING THE INFLAMMATORY RESPONSE IN CHRONIC ARTHRITIS. MIR-146A RESTRICTS THEIR ACTIVATION, THEREBY PREVENTING EXCESSIVE TISSUE DAMAGE DURING ARTHRITIS. 2017 13 5733 30 SMALL MOLECULES AGAINST THE ORIGIN AND ACTIVATION OF MYOFIBROBLAST FOR RENAL INTERSTITIAL FIBROSIS THERAPY. RENAL INTERSTITIAL FIBROSIS (RIF) IS A COMMON PATHOLOGICAL RESPONSE IN A BROAD RANGE OF PREVALENT CHRONIC KIDNEY DISEASES AND ULTIMATELY LEADS TO RENAL FAILURE AND DEATH. ALTHOUGH RIF CAUSES A HIGH MORBI-MORTALITY WORLDWIDE, EFFECTIVE THERAPEUTIC DRUGS ARE URGENTLY NEEDED. MYOFIBROBLASTS ARE IDENTIFIED AS THE MAIN EFFECTOR DURING THE PROCESS OF RIF. MULTIPLE TYPES OF CELLS, INCLUDING FIBROBLASTS, EPITHELIAL CELLS, ENDOTHELIAL CELLS, MACROPHAGES AND PERICYTES, CONTRIBUTE TO RENAL MYOFIBROBLASTS ORIGIN, AND LOTS OF MEDIATORS, INCLUDING SIGNALING PATHWAYS (TRANSFORMING GROWTH FACTOR-BETA1, MAMMALIAN TARGET OF RAPAMYCIN AND REACTIVE OXYGEN SPECIES) AND EPIGENETIC MODIFICATIONS (HISTONE ACETYLATION, MICRORNA AND LONG NON-CODING RNA) ARE PARTICIPATED IN RENAL MYOFIBROBLASTS ACTIVATION DURING RENAL FIBROGENESIS, SUGGESTING THAT THESE MEDIATORS MAY BE THE PROMISING TARGETS FOR TREATING RIF. IN ADDITION, MANY SMALL MOLECULES SHOW PROFOUND THERAPEUTIC EFFECTS ON RIF BY SUPPRESSING THE ORIGIN AND ACTIVATION OF RENAL MYOFIBROBLASTS. TAKEN TOGETHER, THE REVIEW FOCUSES ON THE MECHANISMS OF THE ORIGIN AND ACTIVATION OF RENAL MYOFIBROBLASTS IN RIF AND THE SMALL MOLECULES AGAINST THEM IMPROVING RIF, WHICH WILL PROVIDE A NEW INSIGHT FOR RIF THERAPY. 2021 14 6757 41 WNT SIGNALING IN LIVER FIBROSIS: PROGRESS, CHALLENGES AND POTENTIAL DIRECTIONS. LIVER FIBROSIS IS A COMMON WOUND-HEALING RESPONSE TO CHRONIC LIVER INJURIES, INCLUDING ALCOHOLIC OR DRUG TOXICITY, PERSISTENT VIRAL INFECTION, AND GENETIC FACTORS. MYOFIBROBLASTIC TRANSDIFFERENTIATION (MTD) IS THE PIVOTAL EVENT DURING LIVER FIBROGENESIS, AND RESEARCH IN THE PAST FEW YEARS HAS IDENTIFIED KEY MEDIATORS AND MOLECULAR MECHANISMS RESPONSIBLE FOR MTD OF HEPATIC STELLATE CELLS (HSCS). HSCS ARE UNDIFFERENTIATED CELLS WHICH PLAY AN IMPORTANT ROLE IN LIVER REGENERATION. RECENT EVIDENCE DEMONSTRATES THAT HSCS DERIVE FROM MESODERM AND AT LEAST IN PART VIA SEPTUM TRANSVERSUM AND MESOTHELIUM, AND HSCS EXPRESS MARKERS FOR DIFFERENT CELL TYPES WHICH DERIVE FROM MULTIPOTENT MESENCHYMAL PROGENITORS. THERE IS A REGULATORY COMMONALITY BETWEEN DIFFERENTIATION OF ADIPOCYTES AND THAT OF HSC, AND THE SHIFT FROM ADIPOGENIC TO MYOGENIC OR NEURONAL PHENOTYPE CHARACTERIZES HSC MTD. CENTRAL OF THIS SHIFT IS A LOSS OF EXPRESSION OF THE MASTER ADIPOGENIC REGULATOR PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR GAMMA (PPARGAMMA). RESTORED EXPRESSION OF PPARGAMMA AND/OR OTHER ADIPOGENIC TRANSCRIPTION GENES CAN REVERSE MYOFIBROBLASTIC HSCS TO DIFFERENTIATED CELLS. VERTEBRATE WNT AND DROSOPHILA WINGLESS ARE HOMOLOGOUS GENES, AND THEIR TRANSLATED PROTEINS HAVE BEEN SHOWN TO PARTICIPATE IN THE REGULATION OF CELL PROLIFERATION, CELL POLARITY, CELL DIFFERENTIATION, AND OTHER BIOLOGICAL ROLES. MORE RECENTLY, WNT SIGNALING IS IMPLICATED IN HUMAN FIBROSING DISEASES, SUCH AS PULMONARY FIBROSIS, RENAL FIBROSIS, AND LIVER FIBROSIS. BLOCKING THE CANONICAL WNT SIGNAL PATHWAY WITH THE CO-RECEPTOR ANTAGONIST DICKKOPF-1 (DKK1) ABROGATES THESE EPIGENETIC REPRESSIONS AND RESTORES THE GENE PPARGAMMA EXPRESSION AND HSC DIFFERENTIATION. THE IDENTIFIED MORPHOGEN MEDIATED EPIGENETIC REGULATION OF PPARGAMMA AND HSC DIFFERENTIATION ALSO SERVES AS NOVEL THERAPEUTIC TARGETS FOR LIVER FIBROSIS AND LIVER REGENERATION. IN CONCLUSION, THE WNT SIGNALING PROMOTES LIVER FIBROSIS BY ENHANCING HSC ACTIVATION AND SURVIVAL, AND WE HEREIN DISCUSS WHAT WE CURRENTLY KNOW AND WHAT WE EXPECT WILL COME IN THIS FIELD IN THE NEXT FUTURE. 2013 15 2378 31 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 16 5013 40 PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AS A THERAPEUTIC TARGET FOR HEPATIC FIBROSIS: FROM BENCH TO BEDSIDE. HEPATIC FIBROSIS IS A DYNAMIC CHRONIC LIVER DISEASE OCCURRING AS A CONSEQUENCE OF WOUND-HEALING RESPONSES TO VARIOUS HEPATIC INJURIES. THIS DISORDER IS ONE OF PRIMARY PREDICTORS FOR LIVER-ASSOCIATED MORBIDITY AND MORTALITY WORLDWIDE. TO DATE, NO PHARMACOLOGICAL AGENT HAS BEEN APPROVED FOR HEPATIC FIBROSIS OR COULD BE RECOMMENDED FOR ROUTINE USE IN CLINICAL CONTEXT. CELLULAR AND MOLECULAR UNDERSTANDING OF HEPATIC FIBROSIS HAS REVEALED THAT PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA), THE FUNCTIONING RECEPTOR FOR ANTIDIABETIC THIAZOLIDINEDIONES, PLAYS A PIVOTAL ROLE IN THE PATHOBIOLOGY OF HEPATIC STELLATE CELLS (HSCS), WHOSE ACTIVATION IS THE CENTRAL EVENT IN THE PATHOGENESIS OF HEPATIC FIBROSIS. ACTIVATION OF PPARGAMMA INHIBITS HSC COLLAGEN PRODUCTION AND MODULATES HSC ADIPOGENIC PHENOTYPE AT TRANSCRIPTIONAL AND EPIGENETIC LEVELS. THESE MOLECULAR INSIGHTS INDICATE PPARGAMMA AS A PROMISING DRUG TARGET FOR ANTIFIBROTIC CHEMOTHERAPY. INTENSIVE ANIMAL STUDIES HAVE DEMONSTRATED THAT STIMULATION OF PPARGAMMA REGULATORY SYSTEM THROUGH GENE THERAPY APPROACHES AND PPARGAMMA LIGANDS HAS THERAPEUTIC PROMISE FOR HEPATIC FIBROSIS INDUCED BY A VARIETY OF ETIOLOGIES. AT THE SAME TIME, THIAZOLIDINEDIONE AGENTS HAVE BEEN INVESTIGATED FOR THEIR CLINICAL BENEFITS PRIMARILY IN PATIENTS WITH NONALCOHOLIC STEATOHEPATITIS, A COMMON METABOLIC LIVER DISORDER WITH HIGH POTENTIAL TO PROGRESS TO FIBROSIS AND LIVER-RELATED DEATH. ALTHOUGH SOME STUDIES HAVE SHOWN INITIAL PROMISE, NONE HAS ESTABLISHED LONG-TERM EFFICACY IN WELL-CONTROLLED RANDOMIZED CLINICAL TRIALS. THIS COMPREHENSIVE REVIEW COVERS THE 10-YEAR DISCOVERIES OF THE MOLECULAR BASIS FOR PPARGAMMA REGULATION OF HSC PATHOPHYSIOLOGY AND THEN FOCUSES ON THE ANIMAL INVESTIGATIONS AND CLINICAL TRIALS OF VARIOUS THERAPEUTIC MODALITIES TARGETING PPARGAMMA FOR HEPATIC FIBROSIS. 2013 17 6910 22 [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 18 4976 29 PATHOPHYSIOLOGICAL MECHANISMS OF HEPATIC STELLATE CELLS ACTIVATION IN LIVER FIBROSIS. LIVER FIBROSIS IS A COMPLEX PATHOLOGICAL PROCESS CONTROLLED BY A VARIETY OF CELLS, MEDIATORS AND SIGNALING PATHWAYS. HEPATIC STELLATE CELLS PLAY A CENTRAL ROLE IN THE DEVELOPMENT OF LIVER FIBROSIS. IN CHRONIC LIVER DISEASE, HEPATIC STELLATE CELLS UNDERGO DRAMATIC PHENOTYPIC ACTIVATION AND ACQUIRE FIBROGENIC PROPERTIES. THIS REVIEW FOCUSES ON THE PATHOPHYSIOLOGICAL MECHANISMS OF HEPATIC STELLATE CELLS ACTIVATION IN LIVER FIBROSIS. THEY ENTER THE CELL CYCLE UNDER THE INFLUENCE OF VARIOUS TRIGGERS. THE "INITIATION" PHASE OF HEPATIC STELLATE CELLS ACTIVATION OVERLAPS AND CONTINUES WITH THE "PERPETUATION" PHASE, WHICH IS CHARACTERIZED BY A PRONOUNCED INFLAMMATORY AND FIBROGENIC REACTION. THIS IS FOLLOWED BY A RESOLUTION PHASE IF THE INJURY SUBSIDES. KNOWLEDGE OF THESE PATHOPHYSIOLOGICAL MECHANISMS PAVED THE WAY FOR DRUGS AIMED AT PREVENTING THE DEVELOPMENT AND PROGRESSION OF LIVER FIBROSIS. IN THIS RESPECT, IMPAIRMENTS IN INTRACELLULAR SIGNALING, EPIGENETIC CHANGES AND CELLULAR STRESS RESPONSE CAN BE THE TARGETS OF THERAPY WHERE THE GOAL IS TO DEACTIVATE HEPATIC STELLATE CELLS. POTENTIAL ANTIFIBROTIC THERAPY MAY FOCUS ON INDUCING HEPATIC STELLATE CELLS TO RETURN TO AN INACTIVE STATE THROUGH CELLULAR AGING, APOPTOSIS, AND/OR CLEARANCE BY IMMUNE CELLS, AND SERVE AS POTENTIAL ANTIFIBROTIC THERAPY. IT IS ESPECIALLY IMPORTANT TO PREVENT THE FORMATION OF LIVER CIRRHOSIS SINCE THE ONLY RADICAL APPROACH TO ITS TREATMENT IS LIVER TRANSPLANTATION WHICH CAN BE PERFORMED IN ONLY A LIMITED NUMBER OF COUNTRIES. 2022 19 6856 29 [NOT AVAILABLE]. BIOLOGICAL ASPECTS OF JAK/STAT SIGNALING IN BCR-ABL-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS: MYELOPROLIFERATIVE DISORDERS MORE RECENTLY NAMED MYELOPROLIFERATIVE NEOPLASMS (MPN) DISPLAY SEVERAL CLINICAL ENTITIES: CHRONIC MYELOID LEUKEMIA (CML), THE CLASSICAL MPN INCLUDING POLYCYTHEMIA VERA (PV), ESSENTIAL THROMBOCYTHEMIA (ET), PRIMARY MYELOFIBROSIS (PMF) AND ATYPICAL AND UNCLASSIFIABLE NMP. THE TERM MPN IS MOSTLY USED FOR CLASSICAL BCR-ABL-NEGATIVE (MYELOPROLIFERATIVE DISORDER) (ET, PV, PMF). THESE ARE CLONAL DISEASES RESULTING FROM THE TRANSFORMATION OF AN HEMATOPOIETIC STEM CELL AND LEADING TO AN ABNORMAL PRODUCTION OF MYELOID CELLS. THE GENETIC DEFECTS RESPONSIBLE FOR THE MYELOPROLIFERATIVE ABNORMALITIES ARE CALLED << DRIVER >> MUTATIONS AND ALL RESULT IN DEREGULATION OF THE CYTOKINE RECEPTOR / JAK2 / STAT AXIS. AMONG THEM, JAK2, THE THROMBOPOIETIN RECEPTOR (MPL) AND CALRETICULIN (CALR) MUTATIONS ARE FOUND IN AROUND 90% OF THE CASES. THESE DRIVER MPN MUTATIONS CAN BE ASSOCIATED WITH OTHER DRIVER MUTATIONS ALSO FOUND IN OTHER HEMATOLOGICAL MALIGNANCIES, ESPECIALLY IN PMFS. THESE ARE CHRONIC DISEASES WITH MAJOR RISKS BEING THROMBOSIS, HEMORRHAGE AND CYTOPENIAS FOR PMF AND THE LONG-TERM PROGRESSION TO MYELOFIBROSIS AND THE TRANSFORMATION TO LEUKEMIA. MOST RECENT THERAPEUTIC HAVE FOCUSED ON TARGETING THE JAK2 SIGNALING PATHWAY DIRECTLY BY INHIBITORS OF JAK2 OR INDIRECTLY. INTERFERON A ALLOWS IN SOME CASES HEMATOLOGIC AND MOLECULAR REMISSION PATIENTS. 2016 20 1764 39 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