1 385 114 AN IMMORTALIZED CELL LINE DERIVED FROM RENAL ERYTHROPOIETIN-PRODUCING (REP) CELLS DEMONSTRATES THEIR POTENTIAL TO TRANSFORM INTO MYOFIBROBLASTS. THE ERYTHROID GROWTH FACTOR ERYTHROPOIETIN (EPO) IS PRODUCED BY RENAL INTERSTITIAL FIBROBLASTS, CALLED REP (RENAL EPO-PRODUCING) CELLS, IN A HYPOXIA-INDUCIBLE MANNER. IN CHRONIC KIDNEY DISEASE (CKD), REP CELLS LOSE THEIR EPO-PRODUCTION ABILITY, LEADING TO RENAL ANAEMIA. CONCURRENTLY, REP CELLS ARE SUGGESTED TO BE TRANSFORMED INTO MYOFIBROBLASTS, WHICH ARE THE MAJOR PLAYER OF RENAL FIBROSIS. ALTHOUGH ESTABLISHMENT OF CULTURED CELL LINES DERIVED FROM REP CELLS HAS BEEN A LONG-TERM CHALLENGE, WE HERE SUCCESSFULLY ESTABLISHED A REP-CELL-DERIVED IMMORTALIZED AND CULTIVABLE CELL LINE (REPLIC CELLS) BY USING A GENETICALLY MODIFIED MOUSE LINE. REPLIC CELLS EXHIBITED MYOFIBROBLASTIC PHENOTYPES AND LOST THEIR EPO-PRODUCTION ABILITY, REFLECTING THE SITUATION IN RENAL FIBROSIS. ADDITIONALLY, WE FOUND THAT CELL-AUTONOMOUS TGFBETA SIGNALLING CONTRIBUTES TO MAINTENANCE OF THE MYOFIBROBLASTIC FEATURES OF REPLIC CELLS. FURTHERMORE, THE PROMOTERS OF GENES FOR EPO AND HIF2ALPHA, A MAJOR ACTIVATOR OF EPO GENE EXPRESSION, WERE HIGHLY METHYLATED IN REPLIC CELLS. THUS, THESE RESULTS STRONGLY SUPPORT OUR CONTENTION THAT REP CELLS ARE THE ORIGIN OF MYOFIBROBLASTS IN FIBROTIC KIDNEYS AND DEMONSTRATE THAT CELL-AUTONOMOUS TGFBETA SIGNALLING AND EPIGENETIC SILENCING ARE INVOLVED IN RENAL FIBROSIS AND RENAL ANAEMIA, RESPECTIVELY, IN CKD. THE REPLIC CELL LINE IS A USEFUL TOOL TO FURTHER INVESTIGATE THE MOLECULAR MECHANISMS UNDERLYING RENAL FIBROSIS. 2019 2 5153 26 PPP2R2B HYPERMETHYLATION CAUSES ACQUIRED APOPTOSIS DEFICIENCY IN SYSTEMIC AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION CAUSES TARGET ORGAN DAMAGE IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES. THE FACTORS THAT ALLOW THIS PROTRACTED RESPONSE ARE POORLY UNDERSTOOD. WE ANALYZED THE TRANSCRIPTIONAL REGULATION OF PPP2R2B (B55SS), A MOLECULE NECESSARY FOR THE TERMINATION OF THE IMMUNE RESPONSE, IN PATIENTS WITH AUTOIMMUNE DISEASES. ALTERED EXPRESSION OF B55SS CONDITIONED RESISTANCE TO CYTOKINE WITHDRAWAL-INDUCED DEATH (CWID) IN PATIENTS WITH AUTOIMMUNE DISEASES. THE IMPAIRED UPREGULATION OF B55SS WAS CAUSED BY INFLAMMATION-DRIVEN HYPERMETHYLATION OF SPECIFIC CYTOSINES LOCATED WITHIN A REGULATORY ELEMENT OF PPP2R2B PREVENTING CTCF BINDING. THIS PHENOTYPE COULD BE INDUCED IN HEALTHY T CELLS BY EXPOSURE TO TNF-ALPHA. OUR RESULTS REVEAL A GENE WHOSE EXPRESSION IS AFFECTED BY AN ACQUIRED DEFECT, THROUGH AN EPIGENETIC MECHANISM, IN THE SETTING OF SYSTEMIC AUTOIMMUNITY. BECAUSE FAILURE TO REMOVE ACTIVATED T CELLS THROUGH CWID COULD CONTRIBUTE TO AUTOIMMUNE PATHOLOGY, THIS MECHANISM ILLUSTRATES A VICIOUS CYCLE THROUGH WHICH AUTOIMMUNE INFLAMMATION CONTRIBUTES TO ITS OWN PERPETUATION. 2019 3 6230 26 THE LONG NONCODING RNA LANDSCAPE IN HYPOXIC AND INFLAMMATORY RENAL EPITHELIAL INJURY. LONG NONCODING RNAS (LNCRNAS) ARE EMERGING AS KEY SPECIES-SPECIFIC REGULATORS OF CELLULAR AND DISEASE PROCESSES. TO IDENTIFY POTENTIAL LNCRNAS RELEVANT TO ACUTE AND CHRONIC RENAL EPITHELIAL INJURY, WE PERFORMED UNBIASED WHOLE TRANSCRIPTOME PROFILING OF HUMAN PROXIMAL TUBULAR EPITHELIAL CELLS (PTECS) IN HYPOXIC AND INFLAMMATORY CONDITIONS. RNA SEQUENCING REVEALED THAT THE PROTEIN-CODING AND NONCODING TRANSCRIPTOMIC LANDSCAPE DIFFERED BETWEEN HYPOXIA-STIMULATED AND CYTOKINE-STIMULATED HUMAN PTECS. HYPOXIA- AND INFLAMMATION-MODULATED LNCRNAS WERE PRIORITIZED FOR FOCUSED FOLLOWUP ACCORDING TO THEIR DEGREE OF INDUCTION BY THESE STRESS STIMULI, THEIR EXPRESSION IN HUMAN KIDNEY TISSUE, AND WHETHER EXPOSURE OF HUMAN PTECS TO PLASMA OF CRITICALLY ILL SEPSIS PATIENTS WITH ACUTE KIDNEY INJURY MODULATED THEIR EXPRESSION. FOR THREE LNCRNAS (MIR210HG, LINC-ATP13A4-8, AND LINC-KIAA1737-2) THAT FULFILLED OUR CRITERIA, WE VALIDATED THEIR EXPRESSION PATTERNS, EXAMINED THEIR LOCI FOR CONSERVATION AND SYNTENY, AND DEFINED THEIR ASSOCIATED EPIGENETIC MARKS. THE LNCRNA LANDSCAPE CHARACTERIZED HERE PROVIDES INSIGHTS INTO NOVEL TRANSCRIPTOMIC VARIATIONS IN THE RENAL EPITHELIAL CELL RESPONSE TO HYPOXIC AND INFLAMMATORY STRESS. 2015 4 3049 29 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 5 669 33 BONE MARROW STROMAL CELL ANTIGEN-1 (CD157) REGULATED BY SPHINGOSINE KINASE 2 MEDIATES KIDNEY FIBROSIS. CHRONIC KIDNEY DISEASE IS A PROGRESSIVE DISEASE THAT MAY LEAD TO END-STAGE RENAL DISEASE. INTERSTITIAL FIBROSIS DEVELOPS AS THE DISEASE PROGRESSES. THERAPIES THAT FOCUS ON FIBROSIS TO DELAY OR REVERSE PROGRESSIVE RENAL FAILURE ARE LIMITED. WE AND OTHERS SHOWED THAT SPHINGOSINE KINASE 2-DEFICIENT MICE (SPHK2 (-/-)) DEVELOP LESS FIBROSIS IN MOUSE MODELS OF KIDNEY FIBROSIS. SPHINGOSINE KINASE2 (SPHK2), ONE OF TWO SPHINGOSINE KINASES THAT PRODUCE SPHINGOSINE 1-PHOSPHATE (S1P), IS PRIMARILY LOCATED IN THE NUCLEUS. S1P PRODUCED BY SPHK2 INHIBITS HISTONE DEACETYLASE (HDAC) AND CHANGES HISTONE ACETYLATION STATUS, WHICH CAN LEAD TO ALTERED TARGET GENE EXPRESSION. WE HYPOTHESIZED THAT SPHK2 EPIGENETICALLY REGULATES DOWNSTREAM GENES TO INDUCE FIBROSIS, AND WE PERFORMED A COMPREHENSIVE ANALYSIS USING THE COMBINATION OF RNA-SEQ AND CHIP-SEQ. BST1/CD157 WAS IDENTIFIED AS A GENE THAT IS REGULATED BY SPHK2 THROUGH A CHANGE IN HISTONE ACETYLATION LEVEL, AND BST1 (-/-) MICE WERE FOUND TO DEVELOP LESS RENAL FIBROSIS AFTER UNILATERAL ISCHEMIA-REPERFUSION INJURY, A MOUSE MODEL OF KIDNEY FIBROSIS. ALTHOUGH BST1 IS A CELL-SURFACE MOLECULE THAT HAS A WIDE VARIETY OF FUNCTIONS THROUGH ITS VARIED ENZYMATIC ACTIVITIES AND DOWNSTREAM INTRACELLULAR SIGNALING PATHWAYS, NO STUDIES ON THE ROLE OF BST1 IN KIDNEY DISEASES HAVE BEEN REPORTED PREVIOUSLY. IN THE CURRENT STUDY, WE DEMONSTRATED THAT BST1 IS A GENE THAT IS REGULATED BY SPHK2 THROUGH EPIGENETIC CHANGE AND IS CRITICAL IN KIDNEY FIBROSIS. 2022 6 3468 37 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 7 4233 29 METHYLATION OF SEPTIN9 MEDIATED BY DNMT3A ENHANCES HEPATIC STELLATE CELLS ACTIVATION AND LIVER FIBROGENESIS. LIVER FIBROSIS, RESULTING FROM CHRONIC AND PERSISTENT INJURY TO THE LIVER, IS A WORLDWIDE HEALTH PROBLEM. ADVANCED LIVER FIBROSIS RESULTS IN CIRRHOSIS, LIVER FAILURE AND EVEN HEPATOCELLULAR CANCER (HCC), OFTEN EVENTUALLY REQUIRING LIVER TRANSPLANTATION, POSES A HUGE HEALTH BURDEN ON THE GLOBAL COMMUNITY. HOWEVER, THE SPECIFIC PATHOGENESIS OF LIVER FIBROSIS REMAINS NOT FULLY UNDERSTOOD. NUMEROUS BASIC AND CLINICAL STUDIES HAVE PROVIDED EVIDENCE THAT EPIGENETIC MODIFICATIONS, ESPECIALLY DNA METHYLATION, MIGHT CONTRIBUTE TO THE ACTIVATION OF HEPATIC STELLATE CELLS (HSCS), THE PIVOTAL CELL TYPE RESPONSIBLE FOR THE FIBROUS SCAR IN LIVER. HERE, REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS) AND BISULFITE PYROSEQUENCING PCR (BSP) ANALYSIS IDENTIFIED HYPERMETHYLATION STATUS OF SEPTIN9 (SEPT9) GENE IN LIVER FIBROGENESIS. SEPT9 PROTEIN WAS DRAMATICALLY DECREASED IN LIVERS OF CCL4-TREATED MICE AND IMMORTALIZED HSC-T6 CELLS EXPOSED TO TGF-BETA1. NEVERTHELESS, THE SUPPRESSION OF SEPT9 COULD BE BLOCKED BY DNMT3A-SIRNA AND DNA METHYLTRANSFERASE INHIBITOR, 5-AZA-2'-DEOXYCYTIDINE (5-AZADC). OVEREXPRESSED SEPT9 ATTENUATED TGF-BETA1-INDUCED EXPRESSION OF MYOFIBROBLAST MARKERS ALPHA-SMA AND COL1A1, ACCOMPANIED BY UP-REGULATION OF CELL APOPTOSIS-RELATED PROTEINS. CONVERSELY, RNAI-MEDIATED SILENCING OF SEPT9 ENHANCED ACCUMULATION OF EXTRACELLULAR MATRIX. THESE OBSERVATIONS SUGGESTED THAT SEPT9 CONTRIBUTED TO ALLEVIATE LIVER FIBROSIS MIGHT PARTIALLY THROUGH PROMOTING ACTIVATED HSCS APOPTOSIS AND THIS ANTI-FIBROGENESIS EFFECT MIGHT BE BLOCKED BY DNMT-3A MEDIATED METHYLATION OF SEPT9. THEREFORE, PHARMACOLOGICAL AGENTS THAT INHIBIT SEPT9 METHYLATION AND INCREASE ITS EXPRESSION COULD BE CONSIDERED AS VALUABLE TREATMENTS FOR LIVER FIBROSIS. 2017 8 4143 22 MECHANISMS OF SCARRING IN FOCAL SEGMENTAL GLOMERULOSCLEROSIS. FOCAL SEGMENTAL GLOMERULOSCLEROSIS (FSGS) PRESENTS WITH SCAR IN PARTS OF SOME GLOMERULI AND OFTEN PROGRESSES TO GLOBAL AND DIFFUSE GLOMERULOSCLEROSIS. PODOCYTE INJURY IS THE INITIAL TARGET IN PRIMARY FSGS, INDUCED BY A CIRCULATING FACTOR. SEVERAL GENE VARIANTS, FOR EXAMPLE, APOL1, ARE ASSOCIATED WITH INCREASED SUSCEPTIBILITY TO FSGS. PRIMARY FSGS MAY BE DUE TO GENETIC MUTATION IN KEY PODOCYTE GENES. INCREASED WORK STRESS AFTER LOSS OF NEPHRONS, EPIGENETIC MECHANISMS, AND VARIOUS PROFIBROTIC PATHWAYS CAN CONTRIBUTE TO PROGRESSIVE SCLEROSIS, REGARDLESS OF THE INITIAL INJURY. THE PROGRESSION OF FSGS LESIONS ALSO INVOLVES CROSSTALK BETWEEN PODOCYTES AND OTHER KIDNEY CELLS, SUCH AS PARIETAL EPITHELIAL CELLS, GLOMERULAR ENDOTHELIAL CELLS, AND EVEN TUBULAR EPITHELIAL CELLS. NEW INSIGHTS RELATED TO THESE MECHANISMS COULD POTENTIALLY LEAD TO NEW THERAPEUTIC STRATEGIES TO PREVENT PROGRESSION OF FSGS. 2019 9 5433 22 REL/NF-KAPPA B/I KAPPA B SIGNAL TRANSDUCTION IN THE GENERATION AND TREATMENT OF HUMAN CANCER. THE REL/NF-KAPPA B FAMILY IS A GROUP OF STRUCTURALLY-RELATED, TIGHTLY-REGULATED TRANSCRIPTION FACTORS THAT CONTROL THE EXPRESSION OF A MULTITUDE OF GENES INVOLVED IN KEY CELLULAR AND ORGANISMAL PROCESSES. THE REL/NF-KAPPA B SIGNAL TRANSDUCTION PATHWAY IS MISREGULATED IN A VARIETY OF HUMAN CANCERS, ESPECIALLY ONES OF LYMPHOID CELL ORIGIN, DUE EITHER TO GENETIC CHANGES (SUCH AS CHROMOSOMAL REARRANGEMENTS, AMPLIFICATIONS, AND MUTATIONS) OR TO CHRONIC ACTIVATION OF THE PATHWAY BY EPIGENETIC MECHANISMS. CONSTITUTIVE ACTIVATION OF THE REL/NF-KAPPA B PATHWAY CAN CONTRIBUTE TO THE ONCOGENIC STATE IN SEVERAL WAYS, FOR EXAMPLE, BY DRIVING PROLIFERATION, BY ENHANCING CELL SURVIVAL, OR BY PROMOTING ANGIOGENESIS OR METASTASIS. IN MANY CASES, INHIBITION OF REL/NF-KAPPA B ACTIVITY REVERSES ALL OR PART OF THE MALIGNANT STATE. THUS, THE REL/NF-KAPPA B PATHWAY HAS RECEIVED MUCH ATTENTION AS A FOCAL POINT FOR CLINICAL INTERVENTION. 2002 10 1461 39 DISRUPTION OF RCAN1.4 EXPRESSION MEDIATED BY YY1/HDAC2 MODULATES CHRONIC RENAL ALLOGRAFT INTERSTITIAL FIBROSIS. CHRONIC ALLOGRAFT DYSFUNCTION (CAD) IS A MAJOR FACTOR THAT HINDERS KIDNEY TRANSPLANT SURVIVAL IN THE LONG RUN. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) HAS BEEN CONFIRMED TO SIGNIFICANTLY CONTRIBUTE TO INTERSTITIAL FIBROSIS/TUBULAR ATROPHY (IF/TA), WHICH IS THE MAIN HISTOPATHOLOGICAL FEATURE OF CAD. ABERRANT EXPRESSION OF THE REGULATOR OF CALCINEURIN 1 (RCAN1), RECOGNIZED AS AN ENDOGENOUS INHIBITOR OF THE CALCINEURIN PHOSPHATASE, HAS BEEN SHOWN TO BE EXTENSIVELY INVOLVED IN VARIOUS KIDNEY DISEASES. HOWEVER, IT REMAINS UNCLEAR HOW RCAN1.4 REGULATES IF/TA FORMATION IN CAD PATIENTS. HEREIN, AN IN VIVO MOUSE RENAL TRANSPLANTATION MODEL AND AN IN VITRO MODEL OF HUMAN RENAL TUBULAR EPITHELIAL CELLS (HK-2) TREATED WITH TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) WERE EMPLOYED. OUR RESULTS PROVED THAT RCAN1.4 EXPRESSION WAS DECREASED IN VIVO AND IN VITRO, IN ADDITION TO THE UP-REGULATION OF YIN YANG 1 (YY1), A TRANSCRIPTION FACTOR THAT HAS BEEN REPORTED TO CONVEY MULTIPLE FUNCTIONS IN CHRONIC KIDNEY DISEASE (CKD). KNOCKING IN OF RCAN1.4 EFFICIENTLY ATTENUATED CHRONIC RENAL ALLOGRAFT INTERSTITIAL FIBROSIS IN VIVO AND INHIBITED TNF-ALPHA-INDUCED EMT IN VITRO THROUGH REGULATING ANTI-OXIDATIVE STRESS AND THE CALCINEURIN/NUCLEAR FACTOR OF ACTIVATED T CELLS CYTOPLASMIC 1 (NFATC1) SIGNALING PATHWAY. IN ADDITION, SUPPRESSION OF YY1 MEDIATED BY SHRNA OR SIRNA ALLEVIATED TNF-ALPHA-INDUCED EMT THROUGH ABOLISHING REACTIVE SPECIES PARTLY IN AN RCAN1.4-DEPENDENT MANNER. NOTABLY, WE CONFIRMED THAT YY1 NEGATIVELY REGULATED RCAN1.4 TRANSCRIPTION BY DIRECTLY INTERACTING WITH THE RCAN1.4 PROMOTER. IN ADDITION, HISTONE DEACETYLASE 2 (HDAC2) INTERACTED WITH YY1 TO FORM A MULTI-MOLECULAR COMPLEX, WHICH WAS INVOLVED IN TNF-ALPHA-INDUCED RCAN1.4 TRANSCRIPTIONAL REPRESSION. THEREFORE, RCAN1.4 IS SUGGESTED TO BE MODULATED BY THE YY1/HDAC2 TRANSCRIPTION REPRESSOR COMPLEX IN AN EPIGENETIC MANNER, WHICH IS A MEDIATED NEPHROPROTECTIVE EFFECT PARTLY THROUGH MODULATING O2?- GENERATION AND THE CALCINEURIN/NFATC1 SIGNALING PATHWAY. THUS, THE YY1-RCAN1.4 AXIS CONSTITUTES AN INNOVATIVE TARGET FOR IF/TA TREATMENT IN CAD PATIENTS. 2023 11 662 28 BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME ANALYSES REVEAL LOCI ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. LITTLE IS KNOWN REGARDING THE EPIGENETIC BASIS OF ATHEROSCLEROSIS. HERE WE PRESENT THE CD14+ BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME SIGNATURES ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. THE TRANSCRIPTOME SIGNATURE INCLUDES TRANSCRIPTION COACTIVATOR, ARID5B, WHICH IS KNOWN TO FORM A CHROMATIN DEREPRESSOR COMPLEX WITH A HISTONE H3K9ME2-SPECIFIC DEMETHYLASE AND PROMOTE ADIPOGENESIS AND SMOOTH MUSCLE DEVELOPMENT. ARID5B CPG (CG25953130) METHYLATION IS INVERSELY ASSOCIATED WITH BOTH ARID5B EXPRESSION AND ATHEROSCLEROSIS, CONSISTENT WITH THIS CPG RESIDING IN AN ARID5B ENHANCER REGION, BASED ON CHROMATIN CAPTURE AND HISTONE MARKS DATA. MEDIATION ANALYSIS SUPPORTS ASSUMPTIONS THAT ARID5B EXPRESSION MEDIATES EFFECTS OF CG25953130 METHYLATION AND SEVERAL CARDIOVASCULAR DISEASE RISK FACTORS ON ATHEROSCLEROTIC BURDEN. IN LIPOPOLYSACCHARIDE-STIMULATED HUMAN THP1 MONOCYTES, ARID5B KNOCKDOWN REDUCED EXPRESSION OF GENES INVOLVED IN ATHEROSCLEROSIS-RELATED INFLAMMATORY AND LIPID METABOLISM PATHWAYS, AND INHIBITED CELL MIGRATION AND PHAGOCYTOSIS. THESE DATA SUGGEST THAT ARID5B EXPRESSION, POSSIBLY REGULATED BY AN EPIGENETICALLY CONTROLLED ENHANCER, PROMOTES ATHEROSCLEROSIS BY DYSREGULATING IMMUNOMETABOLISM TOWARDS A CHRONIC INFLAMMATORY PHENOTYPE.THE MOLECULAR MECHANISMS MEDIATING THE IMPACT OF ENVIRONMENTAL FACTORS IN ATHEROSCLEROSIS ARE UNCLEAR. HERE, THE AUTHORS EXAMINE CD14+ BLOOD MONOCYTE'S TRANSCRIPTOME AND EPIGENOME SIGNATURES TO FIND DIFFERENTIAL METHYLATION AND EXPRESSION OF ARID5B TO BE ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. 2017 12 102 21 A REGULATORY ROLE FOR CHD2 IN MYELOPOIESIS. THE TRANSCRIPTIONAL PROGRAM THAT DICTATES HAEMATOPOIETIC CELL FATE AND DIFFERENTIATION REQUIRES AN EPIGENETIC REGULATORY AND MEMORY FUNCTION, PROVIDED BY A NETWORK OF EPIGENETIC FACTORS THAT REGULATE DNA METHYLATION, POST-TRANSLATIONAL HISTONE MODIFICATIONS AND CHROMATIN STRUCTURE. DISTURBED EPIGENETIC REGULATION CAUSES PERTURBATIONS IN THE BLOOD CELL DIFFERENTIATION PROGRAM THAT RESULTS IN VARIOUS TYPES OF HAEMATOPOIETIC DISORDERS. THUS, ACCURATE EPIGENETIC REGULATION IS ESSENTIAL FOR FUNCTIONAL HAEMATOPOIESIS. IN THIS STUDY, WE USED A CRISPR-CAS9 SCREENING APPROACH TO IDENTIFY NEW EPIGENETIC REGULATORS IN MYELOID DIFFERENTIATION. WE DESIGNED A CHROMATIN-UMI CRISPR GUIDE LIBRARY TARGETING 1092 EPIGENETIC REGULATORS. PHORBOL 12-MYRISTATE 13-ACETATE (PMA) TREATMENT OF THE CHRONIC MYELOID LEUKAEMIA CELL LINE K-562 WAS USED AS A MEGAKARYOCYTIC MYELOID DIFFERENTIATION MODEL. BOTH PREVIOUSLY DESCRIBED DEVELOPMENTAL EPIGENETIC REGULATORS AND NOVEL FACTORS WERE IDENTIFIED IN OUR SCREEN. IN THIS STUDY, WE VALIDATED AND CHARACTERIZED A ROLE FOR THE CHROMATIN REMODELLER CHD2 IN MYELOID PROLIFERATION AND MEGAKARYOCYTIC DIFFERENTIATION. 2020 13 5101 31 POLYCOMB FACTOR PHF19 CONTROLS CELL GROWTH AND DIFFERENTIATION TOWARD ERYTHROID PATHWAY IN CHRONIC MYELOID LEUKEMIA CELLS. POLYCOMB GROUP (PCG) OF PROTEINS ARE A GROUP OF HIGHLY CONSERVED EPIGENETIC REGULATORS INVOLVED IN MANY BIOLOGICAL FUNCTIONS, SUCH AS EMBRYONIC DEVELOPMENT, CELL PROLIFERATION, AND ADULT STEM CELL DETERMINATION. PHD FINGER PROTEIN 19 (PHF19) IS AN ASSOCIATED FACTOR OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2), OFTEN UPREGULATED IN HUMAN CANCERS. IN PARTICULAR, MYELOID LEUKEMIA CELL LINES SHOW INCREASED LEVELS OF PHF19, YET LITTLE IS KNOWN ABOUT ITS FUNCTION. HERE, WE HAVE CHARACTERIZED THE ROLE OF PHF19 IN MYELOID LEUKEMIA CELLS. WE DEMONSTRATED THAT PHF19 DEPLETION DECREASES CELL PROLIFERATION AND PROMOTES CHRONIC MYELOID LEUKEMIA (CML) DIFFERENTIATION. MECHANISTICALLY, WE HAVE SHOWN HOW PHF19 REGULATES THE PROLIFERATION OF CML THROUGH A DIRECT REGULATION OF THE CELL CYCLE INHIBITOR P21. FURTHERMORE, WE OBSERVED THAT MTF2, A PHF19 HOMOLOG, PARTIALLY COMPENSATES FOR PHF19 DEPLETION IN A SUBSET OF TARGET GENES, INSTRUCTING SPECIFIC ERYTHROID DIFFERENTIATION. TAKEN TOGETHER, OUR RESULTS SHOW THAT PHF19 IS A KEY TRANSCRIPTIONAL REGULATOR FOR CELL FATE DETERMINATION AND COULD BE A POTENTIAL THERAPEUTIC TARGET FOR MYELOID LEUKEMIA TREATMENT. 2021 14 3327 26 HISTONE DEACETYLASE 4 PROMOTES CHOLESTATIC LIVER INJURY IN THE ABSENCE OF PROHIBITIN-1. PROHIBITIN-1 (PHB1) IS AN EVOLUTIONARILY CONSERVED PLEIOTROPIC PROTEIN THAT PARTICIPATES IN DIVERSE PROCESSES DEPENDING ON ITS SUBCELLULAR LOCALIZATION AND INTERACTOME. RECENT DATA HAVE INDICATED A DIVERSE ROLE FOR PHB1 IN THE PATHOGENESIS OF OBESITY, CANCER, AND INFLAMMATORY BOWEL DISEASE, AMONG OTHERS. DATA PRESENTED HERE SUGGEST THAT PHB1 IS ALSO LINKED TO CHOLESTATIC LIVER DISEASE. EXPRESSION OF PHB1 IS MARKEDLY REDUCED IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS AND BILIARY ATRESIA OR WITH ALAGILLE SYNDROME, TWO MAJOR PEDIATRIC CHOLESTATIC CONDITIONS. IN THE EXPERIMENTAL MODEL OF BILE DUCT LIGATION, SILENCING OF PHB1 INDUCED LIVER FIBROSIS, REDUCED ANIMAL SURVIVAL, AND INDUCED BILE DUCT PROLIFERATION. IMPORTANTLY, THE MODULATORY EFFECT OF PHB1 IS NOT DEPENDENT ON ITS KNOWN MITOCHONDRIAL FUNCTION. ALSO, PHB1 INTERACTS WITH HISTONE DEACETYLASE 4 (HDAC4) IN THE PRESENCE OF BILE ACIDS. HENCE, PHB1 DEPLETION LEADS TO INCREASED NUCLEAR HDAC4 CONTENT AND ITS ASSOCIATED EPIGENETIC CHANGES. REMARKABLY, HDAC4 SILENCING AND THE ADMINISTRATION OF THE HDAC INHIBITOR PARTHENOLIDE DURING OBSTRUCTIVE CHOLESTASIS IN VIVO PROMOTE GENOMIC REPROGRAMMING, LEADING TO REGRESSION OF THE FIBROTIC PHENOTYPE IN LIVER-SPECIFIC PHB1 KNOCKOUT MICE. CONCLUSION: PHB1 IS AN IMPORTANT MEDIATOR OF CHOLESTATIC LIVER INJURY THAT REGULATES THE ACTIVITY OF HDAC4, WHICH CONTROLS SPECIFIC EPIGENETIC MARKERS; THESE RESULTS IDENTIFY POTENTIAL NOVEL STRATEGIES TO TREAT LIVER INJURY AND FIBROSIS, PARTICULARLY AS A CONSEQUENCE OF CHRONIC CHOLESTASIS. 2015 15 984 32 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 16 222 25 ACUTE LIVER STEATOSIS TRANSLATIONALLY CONTROLS THE EPIGENETIC REGULATOR MIER1 TO PROMOTE LIVER REGENERATION IN A STUDY WITH MALE MICE. THE EARLY PHASE LIPID ACCUMULATION IS ESSENTIAL FOR LIVER REGENERATION. HOWEVER, WHETHER THIS ACUTE LIPID ACCUMULATION CAN SERVE AS SIGNALS TO DIRECT LIVER REGENERATION RATHER THAN SIMPLY PROVIDING BUILDING BLOCKS FOR CELL PROLIFERATION REMAINS UNCLEAR. THROUGH IN VIVO CRISPR SCREENING, WE IDENTIFY MIER1 (MESODERM INDUCTION EARLY RESPONSE 1) AS A KEY EPIGENETIC REGULATOR THAT BRIDGES THE ACUTE LIPID ACCUMULATION AND CELL CYCLE GENE EXPRESSION DURING LIVER REGENERATION IN MALE ANIMALS. PHYSIOLOGICALLY, LIVER ACUTE LIPID ACCUMULATION INDUCES THE PHOSPHORYLATION OF EIF2S1(EUKARYOTIC TRANSLATION INITIATION FACTOR 2), WHICH CONSEQUENTLY ATTENUATED MIER1 TRANSLATION. MIER1 DOWNREGULATION IN TURN PROMOTES CELL CYCLE GENE EXPRESSION AND REGENERATION THROUGH CHROMATIN REMODELING. IMPORTANTLY, THE LIPIDS-EIF2S1-MIER1 PATHWAY IS IMPAIRED IN ANIMALS WITH CHRONIC LIVER STEATOSIS; WHEREAS MIER1 DEPLETION SIGNIFICANTLY IMPROVES REGENERATION IN THESE ANIMALS. TAKEN TOGETHER, OUR STUDIES IDENTIFY AN EPIGENETIC MECHANISM BY WHICH THE EARLY PHASE LIPID REDISTRIBUTION FROM ADIPOSE TISSUE TO LIVER DURING REGENERATION IMPACTS HEPATOCYTE PROLIFERATION, AND SUGGEST A POTENTIAL STRATEGY TO BOOST LIVER REGENERATION. 2023 17 4002 24 LOSS OF P120 CATENIN AND LINKS TO MITOTIC ALTERATIONS, INFLAMMATION, AND SKIN CANCER. TUMOR FORMATION INVOLVES EPIGENETIC MODIFICATIONS AND MICROENVIRONMENTAL CHANGES AS WELL AS CUMULATIVE GENETIC ALTERATIONS ENCOMPASSING SOMATIC MUTATIONS, LOSS OF HETEROZYGOSITY, AND ANEUPLOIDY. HERE, WE SHOW THAT CONDITIONAL TARGETING OF P120 CATENIN IN MICE LEADS TO PROGRESSIVE DEVELOPMENT OF SKIN NEOPLASIAS ASSOCIATED WITH INTRINSIC NF-KAPPAB ACTIVATION. WE FIND THAT, SIMILARLY, SQUAMOUS CELL CARCINOMAS IN HUMANS DISPLAY ALTERED P120 AND ACTIVATED NF-KAPPAB. WE SHOW THAT EPIDERMAL HYPERPROLIFERATION ARISING FROM P120 LOSS CAN BE ABROGATED BY IKAPPAB KINASE 2 INHIBITORS. ALTHOUGH THIS UNDERSCORES THE IMPORTANCE OF THIS PATHWAY, THE ROLE OF NF-KAPPAB IN HYPERPROLIFERATION APPEARS ROOTED IN ITS IMPACT ON EPIDERMAL MICROENVIRONMENT BECAUSE AS P120-NULL KERATINOCYTES DISPLAY A GROWTH-ARRESTED PHENOTYPE IN CULTURE. WE TRACE THIS TO A MITOTIC DEFECT, RESULTING IN UNSTABLE, BINUCLEATED CELLS IN VITRO AND IN VIVO. WE SHOW THAT THE ABNORMAL MITOSES CAN BE AMELIORATED BY INHIBITING RHOA, THE ACTIVITY OF WHICH IS ABNORMALLY HIGH. CONVERSELY, WE CAN ELICIT SUCH MITOTIC DEFECTS IN CONTROL KERATINOCYTES BY ELEVATING RHOA ACTIVITY. THE ABILITY OF P120 DEFICIENCY TO ELICIT MITOTIC ALTERATIONS AND CHRONIC INFLAMMATORY RESPONSES, THAT TOGETHER MAY FACILITATE THE DEVELOPMENT OF GENETIC INSTABILITY IN VIVO, PROVIDES INSIGHTS INTO WHY IT FIGURES SO PROMINENTLY IN SKIN CANCER PROGRESSION. 2008 18 4362 36 MIR?152 REGULATES TGF?BETA1?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION BY TARGETING HPIP IN TUBULAR EPITHELIAL CELLS. RENAL FIBROSIS IS A COMMON PATHOLOGICAL FEATURE OF CHRONIC KIDNEY DISEASES, AND THEIR DEVELOPMENT AND PROGRESSION ARE INFLUENCED BY EPIGENETIC MODIFICATIONS INCLUDING ABERRANT MICRORNA (MIRNA OR MIR) EXPRESSION. MIRNAS HAVE BEEN DEMONSTRATED TO MODULATE THE AGGRESSIVENESS OF VARIOUS CANCERS AND HAVE EMERGED AS POSSIBLE THERAPEUTIC AGENTS FOR THE MANAGEMENT OF RENAL FIBROSIS. TRANSFORMING GROWTH FACTOR BETA1 (TGF?BETA1)?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION (EMT) OF TUBULAR EPITHELIAL CELLS SERVES A ROLE IN THE INITIATION AND PROGRESSION OF RENAL FIBROSIS. FURTHERMORE, RECENT RESULTS INDICATED THAT THE PROGRESSION OF EMT IS REVERSIBLE. THE PRESENT STUDY AIMED TO CLARIFY THE ROLE OF MIR?152 IN EMT OF THE TUBULAR EPITHELIAL CELL LINE HK?2, STIMULATED BY TGF?BETA1, USING IN VITRO TRANSFECTION WITH A MIR?152 MIMIC AND TO FURTHER INVESTIGATE THE UNDERLYING MECHANISM OF MIR?152 ACTIVITY. IN THE PRESENT STUDY, MIR?152 EXPRESSION WAS SIGNIFICANTLY REDUCED IN TGF?BETA1?TREATED HK?2 CELLS, ACCOMPANIED BY AN INCREASED EXPRESSION OF HEMATOPOIETIC PRE?B?CELL LEUKEMIA TRANSCRIPTION FACTOR (PBX)?INTERACTING PROTEIN (HPIP). ADDITIONALLY, MIR?152 OVEREXPRESSION INHIBITED TGF?BETA1?INDUCED EMT AND SUPPRESSED HPIP EXPRESSION BY DIRECTLY TARGETING THE 3' UNTRANSLATED REGION OF HPIP IN HK?2 CELLS. FURTHERMORE, UPREGULATION OF HPIP REVERSED MIR?152?MEDIATED INHIBITORY EFFECTS ON THE EMT. COLLECTIVELY, THE RESULTS SUGGEST THAT DOWNREGULATION OF MIR?152 INITIATES THE DEDIFFERENTIATION OF RENAL TUBULES AND PROGRESSION OF RENAL FIBROSIS, WHICH MAY PROVIDE IMPORTANT TARGETS FOR PREVENTION STRATEGIES OF RENAL FIBROSIS. 2018 19 2818 17 FIBROSIS UNDER ARREST. APPROXIMATELY 5% OF PEOPLE THAT ARE HOSPITALIZED FOR ANY REASON DEVELOP ACUTE KIDNEY FAILURE, WHICH, IN SOME CASES, PROGRESSES TO A CHRONIC CONDITION RESULTING IN FIBROSIS OF THE KIDNEY AND PERMANENT CHANGES IN THE ORGAN'S FUNCTION. TWO NEW STUDIES SUGGEST THAT CELL CYCLE ARREST OF EPITHELIAL CELLS AND EPIGENETIC MODIFICATIONS HAVE KEY ROLES IN THE SWITCH TO CHRONIC DISEASE (PAGES 535-543 AND 544-550). 2010 20 5636 34 SERELAXIN ALLEVIATES CARDIAC FIBROSIS THROUGH INHIBITING ENDOTHELIAL-TO-MESENCHYMAL TRANSITION VIA RXFP1. RATIONALE: CARDIAC FIBROSIS IS AN INTEGRAL CONSTITUENT OF EVERY FORM OF CHRONIC HEART DISEASE, AND PERSISTENCE OF FIBROSIS REDUCES TISSUE COMPLIANCE AND ACCELERATES THE PROGRESSION TO HEART FAILURE. RELAXIN-2 IS A HUMAN HORMONE, WHICH HAS VARIOUS PHYSIOLOGICAL FUNCTIONS SUCH AS MEDIATING RENAL VASODILATION IN PREGNANCY. ITS RECOMBINANT FORM SERELAXIN HAS RECENTLY BEEN TESTED IN CLINICAL TRIALS AS A THERAPY FOR ACUTE HEART FAILURE BUT DID NOT MEET ITS PRIMARY ENDPOINTS. THE AIM OF THIS STUDY IS TO EXAMINE WHETHER SERELAXIN HAS AN ANTI-FIBROTIC EFFECT IN THE HEART AND THEREFORE COULD BE BENEFICIAL IN CHRONIC HEART FAILURE. METHODS: WE UTILIZED TWO DIFFERENT CARDIAC FIBROSIS MOUSE MODELS (ASCENDING AORTIC CONSTRICTION (AAC) AND ANGIOTENSIN II (ATII) ADMINISTRATION VIA OSMOTIC MINIPUMPS) TO ASSESS THE ANTI-FIBROTIC POTENTIAL OF SERELAXIN. HISTOLOGICAL ANALYSIS, IMMUNOFLUORESCENCE STAINING AND MOLECULAR ANALYSIS WERE PERFORMED TO ASSESS THE FIBROSIS LEVEL AND INDICATE ENDOTHELIAL CELLS WHICH ARE UNDERGOING ENDMT. IN VITRO TGFBETA1-INDUCED ENDOTHELIAL-TO-MESENCHYMAL TRANSITION (ENDMT) ASSAYS WERE PERFORMED IN HUMAN CORONARY ARTERY ENDOTHELIAL CELLS AND MOUSE CARDIAC ENDOTHELIAL CELLS (MCECS) AND WERE EXAMINED USING MOLECULAR METHODS. CHROMATIN IMMUNOPRECIPITATION-QPCR ASSAY WAS UTILIZED TO IDENTIFY THE SERELAXIN EFFECT ON CHROMATIN REMODELING IN THE RXFP1 PROMOTER REGION IN MCECS. RESULTS: OUR RESULTS DEMONSTRATE A SIGNIFICANT AND DOSE-DEPENDENT ANTI-FIBROTIC EFFECT OF SERELAXIN IN THE HEART IN BOTH MODELS. WE FURTHER SHOW THAT SERELAXIN MEDIATES THIS EFFECT, AT LEAST IN PART, THROUGH INHIBITION OF ENDMT THROUGH THE ENDOTHELIAL RELAXIN FAMILY PEPTIDE RECEPTOR 1 (RXFP1). WE FURTHER DEMONSTRATE THAT SERELAXIN ADMINISTRATION IS ABLE TO INCREASE ITS OWN RECEPTOR EXPRESSION (RXFP1) THROUGH EPIGENETIC REGULATION IN FORM OF HISTONE MODIFICATIONS BY ATTENUATING TGFBETA-PSMAD2/3 SIGNALING IN ENDOTHELIAL CELLS. CONCLUSIONS: THIS STUDY IS THE FIRST TO IDENTIFY THAT SERELAXIN INCREASES THE EXPRESSION OF ITS OWN RECEPTOR RXFP1 AND THAT THIS MEDIATES THE INHIBITION OF ENDMT AND CARDIAC FIBROSIS, SUGGESTING THAT SERELAXIN MAY HAVE A BENEFICIAL EFFECT AS ANTI-FIBROTIC THERAPY IN CHRONIC HEART FAILURE. 2020