1 5510 132 RIBAVIRIN RESTORES IFNALPHA RESPONSIVENESS IN HCV-INFECTED LIVERS BY EPIGENETIC REMODELLING AT INTERFERON STIMULATED GENES. OBJECTIVES: CAVEATS IN THE UNDERSTANDING OF RIBAVIRIN (RBV) MECHANISMS OF ACTION HAS SOMEHOW PREVENTED THE DEVELOPMENT OF BETTER ANALOGUES ABLE TO FURTHER IMPROVE ITS THERAPEUTIC CONTRIBUTION IN INTERFERON (IFN)-BASED AND DIRECT ANTIVIRAL AGENT-BASED REGIMENS FOR CHRONIC HCV OR OTHER INDICATIONS. HERE, WE DESCRIBE A NEW MECHANISM BY WHICH RBV MODULATES IFN-STIMULATED GENES (ISGS) AND CONTRIBUTES TO RESTORE HEPATIC IMMUNE RESPONSIVENESS. DESIGN: RBV EFFECT ON ISG EXPRESSION WAS MONITORED IN VITRO AND IN VIVO, THAT IS, IN NON-TRANSFORMED HEPATOCYTES AND IN THE LIVER OF RBV MONO-TREATED PATIENTS, RESPECTIVELY. MODULATION OF HISTONE MODIFICATIONS AND RECRUITMENT OF HISTONE-MODIFYING ENZYMES AT TARGET PROMOTERS WAS ANALYSED BY CHROMATIN IMMUNOPRECIPITATION IN RBV-TREATED PRIMARY HUMAN HEPATOCYTES AND IN PATIENTS' LIVER BIOPSIES. RESULTS: RBV DECREASES THE MRNA LEVELS OF SEVERAL ABNORMALLY PREACTIVATED ISGS IN PATIENTS WITH HCV, WHO ARE NON-RESPONDERS TO IFN THERAPY. RBV INCREASES G9A HISTONE METHYLTRANSFERASE RECRUITMENT AND HISTONE-H3 LYSINE-9 DIMETHYLATION/TRIMETHYLATION AT SELECTED ISG PROMOTERS IN VITRO AND IN VIVO. G9A PHARMACOLOGICAL BLOCKADE ABOLISHES RBV-INDUCED ISG DOWNREGULATION AND SEVERELY IMPAIRS RBV ABILITY TO POTENTIATE IFN ANTIVIRAL ACTION AND INDUCTION OF ISGS FOLLOWING HCV INFECTION OF PRIMARY HUMAN HEPATOCYTES. CONCLUSIONS: RBV-INDUCED EPIGENETIC CHANGES, LEADING TO DECREASED ISG EXPRESSION, RESTORE AN IFN-RESPONSIVE HEPATIC ENVIRONMENT IN PATIENTS WITH HCV, WHICH MAY ALSO PROVE USEFUL IN IFN-FREE REGIMENS. 2016 2 1668 45 DOWNREGULATION OF SOCS1 INCREASES INTERFERON-INDUCED ISGYLATION DURING DIFFERENTIATION OF INDUCED-PLURIPOTENT STEM CELLS TO HEPATOCYTES. BACKGROUND & AIMS: INCREASED EXPRESSION OF IFN-STIMULATED GENE 15 (ISG15) AND SUBSEQUENTLY INCREASED ISGYLATION ARE KEY FACTORS IN THE HOST RESPONSE TO VIRAL INFECTION. IN THIS STUDY, WE SOUGHT TO CHARACTERIZE THE EXPRESSION OF ISG15, ISGYLATION, AND ASSOCIATED ENZYMES AT EACH STAGE OF DIFFERENTIATION FROM INDUCED PLURIPOTENT STEM CELLS (IPSCS) TO HEPATOCYTES. METHODS: TO STUDY THE REGULATION OF ISGYLATION, WE UTILIZED PATIENT SAMPLES AND IN VITRO CELL CULTURE MODELS INCLUDING IPSCS, HEPATOCYTES-LIKE CELLS, IMMORTALIZED CELL LINES, AND PRIMARY HUMAN HEPATOCYTES. PROTEIN/MRNA EXPRESSION WERE MEASURED FOLLOWING TREATMENT WITH POLY(I:C), IFNALPHA AND HCV INFECTION. RESULTS: WHEN COMPARED TO HLCS, WE OBSERVED SEVERAL NOVEL ASPECTS OF THE ISGYLATION PATHWAY IN IPSCS. THESE INCLUDE A LOWER BASELINE EXPRESSION OF THE ISGYLATION-ACTIVATING ENZYME, UBE1L, A LACK OF IFN-INDUCED EXPRESSION OF THE ISGYLATION-CONJUGATION ENZYME UBE2L6, AN ATTENUATED ACTIVATION OF THE TRANSCRIPTION FACTOR STAT1 AND CONSTITUTIVE EXPRESSION OF SOCS1. ISGYLATION WAS OBSERVED IN IPSCS FOLLOWING DOWNREGULATION OF SOCS1, WHICH FACILITATED STAT1 ACTIVATION AND SUBSEQUENTLY INCREASED EXPRESSION OF UBE2L6. INTRIGUINGLY, HCV PERMISSIVE TRANSFORMED HEPATOMA CELL LINES DEMONSTRATED HIGHER INTRINSIC EXPRESSION OF SOCS1 AND WEAKER ISGYLATION FOLLOWING IFN TREATMENT. SOCS1 DOWNREGULATION IN HCV-INFECTED HUH 7.5.1 CELLS LED TO INCREASED ISGYLATION. CONCLUSIONS: HEREIN, WE SHOW THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. FURTHERMORE, AS IPSCS DIFFERENTIATE INTO HEPATOCYTES, EPIGENETIC MECHANISMS REGULATE ISGYLATION BY MODIFYING UBE1L AND SOCS1 EXPRESSION LEVELS. OVERALL, THIS STUDY DEMONSTRATES THAT THE DEVELOPMENT OF CELL-INTRINSIC INNATE IMMUNITY DURING THE DIFFERENTIATION OF IPSCS TO HEPATOCYTES PROVIDES INSIGHT INTO CELL TYPE-SPECIFIC REGULATION OF HOST DEFENSE RESPONSES AND RELATED ONCOGENIC PROCESSES. IMPACT AND IMPLICATIONS: TO ELUCIDATE THE MECHANISM UNDERLYING REGULATION OF ISGYLATION, A KEY PROCESS IN THE INNATE IMMUNE RESPONSE, WE STUDIED CHANGES IN ISGYLATION-ASSOCIATED GENES AT THE DIFFERENT STAGES OF DIFFERENTIATION FROM IPSCS TO HEPATOCYTES. WE FOUND THAT HIGH BASAL LEVELS OF SOCS1 INHIBIT STAT1 ACTIVATION AND SUBSEQUENTLY IFN-INDUCED UBE2L6 AND ISGYLATION IN IPSCS. IMPORTANTLY, EPIGENETIC REGULATION OF SOCS1 AND SUBSEQUENTLY ISGYLATION MAY BE IMPORTANT FACTORS IN THE DEVELOPMENT OF CELL TYPE-SPECIFIC HOST DEFENSE RESPONSES IN HEPATOCYTES THAT SHOULD BE CONSIDERED WHEN STUDYING CHRONIC INFECTIONS AND ONCOGENIC PROCESSES IN THE LIVER. 2022 3 3249 32 HEPATITIS B VIRUS HIJACKS CTHRC1 TO EVADE HOST IMMUNITY AND MAINTAIN REPLICATION. HEPATITIS B VIRUS (HBV) INFECTION CAUSES ACUTE AND CHRONIC LIVER DISEASES, BUT IS NOT DIRECTLY CYTOPATHIC. LIVER INJURY RESULTS FROM REPEATED ATTEMPTS OF THE CELLULAR IMMUNE RESPONSE SYSTEM TO CONTROL THE VIRAL INFECTION. HERE, WE INVESTIGATE THE ROLES OF CELLULAR FACTORS AND SIGNALING PATHWAYS INVOLVED IN THE REGULATION OF HBV REPLICATION TO REVEAL THE MECHANISM UNDERLYING HBV INFECTION AND PATHOGENESIS. WE SHOW THAT COLLAGEN TRIPLE HELIX REPEAT CONTAINING 1 (CTHRC1) EXPRESSION IS ELEVATED IN HBV-INFECTED PATIENTS AND IN HBV-TRANSFECTED CELLS THROUGH EPIGENETIC MODIFICATION AND TRANSCRIPTIONAL REGULATION. CTHRC1 FACILITATES HBV REPLICATION IN CULTURED CELLS AND BALB/C MICE BY ACTIVATING THE PKCALPHA/ERK/JNK/C-JUN CASCADE TO REPRESS THE IFN/JAK/STAT PATHWAY. HBV-ACTIVATED CTHRC1 DOWNREGULATES THE ACTIVITY OF TYPE I INTERFERON (IFN), THE PRODUCTION OF IFN-STIMULATED GENES (ISGS), AND THE PHOSPHORYLATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 1/2 (STAT1/2), WHEREAS IT UPREGULATES THE PHOSPHORYLATION AND UBIQUITINATION OF TYPE I IFN RECEPTORS (IFNARALPHA/BETA). THUS, OUR RESULTS SHOW THAT HBV USES A NOVEL MECHANISM TO HIJACK CELLULAR FACTORS AND SIGNAL CASCADES IN ORDER TO EVADE HOST ANTIVIRAL IMMUNITY AND MAINTAIN PERSISTENT INFECTION. WE ALSO DEMONSTRATE THAT CTHRC1 HAS A NOVEL ROLE IN VIRAL INFECTION. 2015 4 2155 38 EPIGENETIC MECHANISMS AND METABOLIC REPROGRAMMING IN FIBROGENESIS: DUAL TARGETING OF G9A AND DNMT1 FOR THE INHIBITION OF LIVER FIBROSIS. OBJECTIVE: HEPATIC STELLATE CELLS (HSC) TRANSDIFFERENTIATION INTO MYOFIBROBLASTS IS CENTRAL TO FIBROGENESIS. EPIGENETIC MECHANISMS, INCLUDING HISTONE AND DNA METHYLATION, PLAY A KEY ROLE IN THIS PROCESS. CONCERTED ACTION BETWEEN HISTONE AND DNA-MEHYLTRANSFERASES LIKE G9A AND DNMT1 IS A COMMON THEME IN GENE EXPRESSION REGULATION. WE AIMED TO STUDY THE EFFICACY OF CM272, A FIRST-IN-CLASS DUAL AND REVERSIBLE G9A/DNMT1 INHIBITOR, IN HALTING FIBROGENESIS. DESIGN: G9A AND DNMT1 WERE ANALYSED IN CIRRHOTIC HUMAN LIVERS, MOUSE MODELS OF LIVER FIBROSIS AND CULTURED MOUSE HSC. G9A AND DNMT1 EXPRESSION WAS KNOCKED DOWN OR INHIBITED WITH CM272 IN HUMAN HSC (HHSC), AND TRANSCRIPTOMIC RESPONSES TO TRANSFORMING GROWTH FACTOR-BETA1 (TGFBETA1) WERE EXAMINED. GLYCOLYTIC METABOLISM AND MITOCHONDRIAL FUNCTION WERE ANALYSED WITH SEAHORSE-XF TECHNOLOGY. GENE EXPRESSION REGULATION WAS ANALYSED BY CHROMATIN IMMUNOPRECIPITATION AND METHYLATION-SPECIFIC PCR. ANTIFIBROGENIC ACTIVITY AND SAFETY OF CM272 WERE STUDIED IN MOUSE CHRONIC CCL(4) ADMINISTRATION AND BILE DUCT LIGATION (BDL), AND IN HUMAN PRECISION-CUT LIVER SLICES (PCLSS) IN A NEW BIOREACTOR TECHNOLOGY. RESULTS: G9A AND DNMT1 WERE DETECTED IN STROMAL CELLS IN AREAS OF ACTIVE FIBROSIS IN HUMAN AND MOUSE LIVERS. G9A AND DNMT1 EXPRESSION WAS INDUCED DURING MOUSE HSC ACTIVATION, AND TGFBETA1 TRIGGERED THEIR CHROMATIN RECRUITMENT IN HHSC. G9A/DNMT1 KNOCKDOWN AND CM272 INHIBITED TGFBETA1 FIBROGENIC RESPONSES IN HHSC. TGFBETA1-MEDIATED PROFIBROGENIC METABOLIC REPROGRAMMING WAS ABROGATED BY CM272, WHICH RESTORED GLUCONEOGENIC GENE EXPRESSION AND MITOCHONDRIAL FUNCTION THROUGH ON-TARGET EPIGENETIC EFFECTS. CM272 INHIBITED FIBROGENESIS IN MICE AND PCLSS WITHOUT TOXICITY. CONCLUSIONS: DUAL G9A/DNMT1 INHIBITION BY COMPOUNDS LIKE CM272 MAY BE A NOVEL THERAPEUTIC STRATEGY FOR TREATING LIVER FIBROSIS. 2021 5 1806 34 EFFECT OF TRANSCRIPTION INHIBITION AND GENERATION OF SUPPRESSIVE VIRAL NON-CODING RNAS. BACKGROUND: HIV-1 PATIENTS RECEIVING COMBINATION ANTIRETROVIRAL THERAPY (CART) SURVIVE INFECTION BUT REQUIRE LIFE-LONG ADHERENCE AT HIGH EXPENSE. IN CHRONIC CART-TREATED PATIENTS WITH UNDETECTABLE VIRAL TITERS, CELL-ASSOCIATED VIRAL RNA IS STILL DETECTABLE, POINTING TO LOW-LEVEL VIRAL TRANSCRIPTIONAL LEAKINESS. TO DATE, THERE ARE NO FDA-APPROVED DRUGS AGAINST HIV-1 TRANSCRIPTION. WE HAVE PREVIOUSLY SHOWN THAT F07#13, A THIRD GENERATION TAT PEPTIDE MIMETIC WITH COMPETITIVE ACTIVITY AGAINST CDK9/T1-TAT BINDING SITES, INHIBITS HIV-1 TRANSCRIPTION IN VITRO AND IN VIVO. RESULTS: HERE, WE DEMONSTRATE THAT INCREASING CONCENTRATIONS OF F07#13 (0.01, 0.1, 1 MICROM) CAUSE A DECREASE IN TAT LEVELS IN A DOSE-DEPENDENT MANNER BY INHIBITING THE CDK9/T1-TAT COMPLEX FORMATION AND SUBSEQUENT UBIQUITIN-MEDIATED TAT SEQUESTRATION AND DEGRADATION. OUR DATA INDICATE THAT COMPLEXES I AND IV CONTAIN DISTINCT PATTERNS OF UBIQUITINATED TAT AND THAT TRANSCRIPTIONAL INHIBITION INDUCED BY F07#13 CAUSES AN OVERALL REDUCTION IN TAT LEVELS. THIS REDUCTION MAY BE TRIGGERED BY F07#13 BUT ULTIMATELY IS MEDIATED BY TAR-GAG VIRAL RNAS THAT BIND SUPPRESSIVE TRANSCRIPTION FACTORS (SIMILAR TO 7SK, NRON, HOTAIR, AND XIST LNCRNAS) TO ENHANCE TRANSCRIPTIONAL GENE SILENCING AND LATENCY. THESE RNAS COMPLEX WITH PRC2, SIN3A, AND CUL4B, RESULTING IN EPIGENETIC MODIFICATIONS. FINALLY, WE OBSERVED AN F07#13-MEDIATED DECREASE OF VIRAL BURDEN BY TARGETING THE R REGION OF THE LONG TERMINAL REPEAT (HIV-1 PROMOTER REGION, LTR), PROMOTING BOTH PAUSED POLYMERASES AND INCREASED EFFICIENCY OF CRISPR/CAS9 EDITING IN INFECTED CELLS. THIS IMPLIES THAT GENE EDITING MAY BE BEST PERFORMED UNDER A REPRESSED TRANSCRIPTIONAL STATE. CONCLUSIONS: COLLECTIVELY, OUR RESULTS INDICATE THAT F07#13, WHICH CAN TERMINATE RNA POLYMERASE II AT DISTINCT SITES, CAN GENERATE SCAFFOLD RNAS, WHICH MAY ASSEMBLE INTO SPECIFIC SETS OF "RNA MACHINES" THAT CONTRIBUTE TO GENE REGULATION. IT REMAINS TO BE SEEN WHETHER THESE EFFECTS CAN ALSO BE SEEN IN VARIOUS CLADES THAT HAVE VARYING PROMOTER STRENGTH, MUTANT LTRS, AND IN PATIENT SAMPLES. 2019 6 2316 34 EPIGENETIC REGULATION OF FRUCTOSE-1,6-BISPHOSPHATASE 1 BY HOST TRANSCRIPTION FACTOR SPECKLED 110 KDA DURING HEPATITIS B VIRUS INFECTION. HEPATITIS B VIRUS (HBV) IS THE LEADING CAUSE OF LIVER DISEASE RANGING FROM ACUTE AND CHRONIC HEPATITIS TO LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC). STUDIES HAVE REVEALED THAT HBV INFECTION BROADLY REPROGRAMMES THE HOST CELLULAR METABOLIC PROCESSES FOR VIRAL PATHOGENESIS. PREVIOUS REPORTS HAVE SHOWN THAT GLYCOLYSIS AND GLUCONEOGENESIS ARE AMONG THE MOST DEREGULATED PATHWAYS DURING HBV INFECTION. WE NOTED THAT DESPITE BEING ONE OF THE RATE-LIMITING ENZYMES OF GLUCONEOGENESIS, THE ROLE AND REGULATION OF FRUCTOSE-1,6-BISPHOSPHATASE 1 (FBP1) DURING HBV INFECTION IS NOT MUCH EXPLORED. IN THIS STUDY, WE REPORT FBP1 UPREGULATION UPON HBV INFECTION AND UNRAVEL A NOVEL MECHANISM OF EPIGENETIC REPROGRAMMING OF FBP1 BY HBV VIA UTILIZING HOST FACTOR SPECKLED 110 KDA (SP110). HERE, WE IDENTIFIED ACETYLATED LYSINE 18 OF HISTONE H3 (H3K18AC) AS A SELECTIVE INTERACTOR OF SP110 BROMODOMAIN. FURTHERMORE, WE FOUND THAT SP110 GETS RECRUITED ON H3K18AC-ENRICHED FBP1 PROMOTER, AND FACILITATES RECRUITMENT OF DEACETYLASE SIRTUIN 2 (SIRT2) ON THAT SITE IN THE PRESENCE OF HBV. SIRT2 IN TURN BRINGS ITS INTERACTOR AND TRANSCRIPTIONAL ACTIVATOR HEPATOCYTE NUCLEAR FACTOR 4-ALPHA TO THE PROMOTER, WHICH ULTIMATELY LEADS TO A LOSS OF DNA METHYLATION NEAR THE COGNATE SITE. INTERESTINGLY, THIS SP110 DRIVEN FBP1 REGULATION DURING INFECTION WAS FOUND TO PROMOTE VIRAL-BORNE HCC PROGRESSION. MOREOVER, SP110 CAN BE USED AS A PROGNOSTIC MARKER FOR THE HEPATITIS-MEDIATED HCC PATIENTS, WHERE HIGH SP110 EXPRESSION SIGNIFICANTLY LOWERED THEIR SURVIVAL. THUS, THE EPIGENETIC READER PROTEIN SP110 HAS POTENTIAL TO BE A THERAPEUTIC TARGET TO CHALLENGE HBV-INDUCED HCCS. 2022 7 3128 45 GIPC-REGULATED IGFBP-3 PROMOTES HSC MIGRATION IN VITRO AND PORTAL HYPERTENSION IN VIVO THROUGH A BETA1-INTEGRIN PATHWAY. BACKGROUND & AIMS: TRANSFORMING GROWTH FACTOR (TGF-BETA)-INDUCED ACTIVATION OF QUIESCENT HEPATIC STELLATE CELLS (HSCS) AND THEIR TRANSFORMATION TO MYOFIBROBLASTS IS A KEY EVENT IN LIVER FIBROSIS AND PORTAL HYPERTENSION. GIPC (ALSO REFERRED TO AS SYNECTIN) IS A DOWNSTREAM SIGNAL ACTIVATION MOLECULE OF TGF-BETA AND OTHER RECEPTORS. IN THIS STUDY, WE SOUGHT TO IDENTIFY NOVEL GENES TARGETED BY TGF-BETA AND GIPC AND ELUCIDATE IF AND HOW THEY MAY CONTRIBUTE TO LIVER FIBROSIS. METHODS: WE PERFORMED SEQUENTIAL MESSENGER RNA SEQUENCING ANALYSIS ON TGF-BETA-STIMULATED HSCS AND THEN ON TGF-BETA-STIMULATED HSCS IN THE PRESENCE AND ABSENCE OF GIPC ALSO REFERRED TO AS SYNECTIN (GIPC) KNOCKDOWN. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-3 (IGFBP-3) TRANSPORT PROTEIN EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC. QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, TARGETED CHROMATIN IMMUNOPRECIPITATION, AND WESTERN BLOT ANALYSIS WERE DONE FOR FURTHER CONFIRMATION. RESULTS: IGFBP-3, AN INSULIN GROWTH FACTOR TRANSPORT PROTEIN, EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC, WHICH WAS CONFIRMED BY QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, AND WESTERN BLOT ANALYSIS. TARGETED CHROMATIN IMMUNOPRECIPITATION SHOWED THAT GIPC INCREASES THE HISTONE 3 LYSINE 27 (H3K27) ACETYLATION ACTIVATING MARK AND CONCURRENTLY DECREASES THE H3K27 INHIBITORY TRIMETHYLATION (H3K27M3) MARK, PROVIDING AN EPIGENETIC CORRELATE TO THE GENE REGULATION CHANGES. IN VIVO, GLOBAL KNOCKOUT OF IGFBP-3 MICE RESULTED IN ATTENUATION OF HSC ACTIVATION MARKERS AND ATTENUATION OF PORTAL PRESSURE IN RESPONSE TO CHRONIC LIVER INJURY MODELS. ANALYSIS OF SERUM LEVELS FROM CIRRHOTIC PATIENTS ALSO SHOWED AN IGFBP-3 INCREASE OF MORE THAN 2-FOLD COMPARED WITH HEALTHY CONTROLS. FINALLY, IN VITRO MECHANISM STUDIES SHOWED THAT IGFBP-3 PROMOTES HSC MIGRATION THROUGH INTEGRIN-DEPENDENT PHOSPHORYLATION OF PROTEIN KINASE B. CONCLUSIONS: TGF-BETA UP-REGULATES IGFBP-3 THROUGH GIPC, LEADING TO INCREASED HSC MIGRATION IN VITRO AND PROMOTES PORTAL HYPERTENSION IN VIVO. THESE STUDIES SUPPORT THE ROLE OF IGFBP-3 AS A POTENTIAL PATHOPHYSIOLOGIC TARGET OR BIOMARKER IN CHRONIC LIVER DISEASE. 2020 8 35 31 A CHROMATIN ACTIVITY-BASED CHEMOPROTEOMIC APPROACH REVEALS A TRANSCRIPTIONAL REPRESSOME FOR GENE-SPECIFIC SILENCING. IMMUNE CELLS DEVELOP ENDOTOXIN TOLERANCE (ET) AFTER PROLONGED STIMULATION. ET INCREASES THE LEVEL OF A REPRESSION MARK H3K9ME2 IN THE TRANSCRIPTIONALLY SILENT CHROMATIN SPECIFICALLY ASSOCIATED WITH PRO-INFLAMMATORY GENES. HOWEVER, IT IS NOT CLEAR WHAT PROTEINS ARE FUNCTIONALLY INVOLVED IN THIS PROCESS. HERE WE SHOW THAT A NOVEL CHROMATIN ACTIVITY-BASED CHEMOPROTEOMIC (CHAC) APPROACH CAN DISSECT THE FUNCTIONAL CHROMATIN PROTEIN COMPLEXES THAT REGULATE ET-ASSOCIATED INFLAMMATION. USING UNC0638 THAT BINDS THE ENZYMATICALLY ACTIVE H3K9-SPECIFIC METHYLTRANSFERASE G9A/GLP, CHAC REVEALS THAT G9A IS CONSTITUTIVELY ACTIVE AT A G9A-DEPENDENT MEGA-DALTON REPRESSOME IN PRIMARY ENDOTOXIN-TOLERANT MACROPHAGES. G9A/GLP BROADLY IMPACTS THE ET-SPECIFIC REPROGRAMMING OF THE HISTONE CODE LANDSCAPE, CHROMATIN REMODELLING AND THE ACTIVITIES OF SELECT TRANSCRIPTION FACTORS. WE DISCOVER THAT THE G9A-DEPENDENT EPIGENETIC ENVIRONMENT PROMOTES THE TRANSCRIPTIONAL REPRESSION ACTIVITY OF C-MYC FOR GENE-SPECIFIC CO-REGULATION OF CHRONIC INFLAMMATION. CHAC MAY ALSO BE APPLICABLE TO DISSECT OTHER FUNCTIONAL PROTEIN COMPLEXES IN THE CONTEXT OF PHENOTYPIC CHROMATIN ARCHITECTURES. 2014 9 5004 28 PERIPHERAL B CELLS FROM PATIENTS WITH HEPATITIS C VIRUS-ASSOCIATED LYMPHOMA EXHIBIT CLONAL EXPANSION AND AN ANERGIC-LIKE TRANSCRIPTIONAL PROFILE. CHRONIC HCV INFECTION REMAINS A GLOBAL HEALTH CONCERN DUE TO ITS INVOLVEMENT IN HEPATIC AND EXTRAHEPATIC DISEASES, INCLUDING B CELL NON-HODGKIN LYMPHOMA (BNHL). CLINICAL AND EPIDEMIOLOGICAL EVIDENCE SUPPORT A CAUSAL ROLE FOR HCV IN BNHL DEVELOPMENT, ALTHOUGH MECHANISTIC INSIGHT IS LACKING. WE PERFORMED RNA-SEQUENCING ON PERIPHERAL B CELLS FROM PATIENTS WITH HCV ALONE, BNHL ALONE, AND HCV-ASSOCIATED BNHL TO IDENTIFY UNIQUE AND SHARED TRANSCRIPTIONAL PROFILES ASSOCIATED WITH TRANSFORMATION. IN PATIENTS WITH HCV-ASSOCIATED BNHL, WE OBSERVED THE ENRICHMENT OF AN ANERGIC-LIKE GENE SIGNATURE AND EVIDENCE OF CLONAL EXPANSION THAT WAS CORRELATED WITH THE EXPRESSION OF EPIGENETIC REGULATORY GENES. OUR DATA SUPPORT A ROLE FOR VIRAL-MEDIATED CLONAL EXPANSION OF ANERGIC-LIKE B CELLS IN HCV-ASSOCIATED BNHL DEVELOPMENT AND SUGGEST EPIGENETIC DYSREGULATION AS A POTENTIAL MECHANISM DRIVING EXPANSION. WE PROPOSE EPIGENETIC MECHANISMS MAY BE INVOLVED IN BOTH HCV-ASSOCIATED LYMPHOMA AND REGULATION OF B CELL ANERGY, REPRESENTING AN ATTRACTIVE TARGET FOR CLINICAL INTERVENTIONS. 2023 10 1334 26 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 11 3049 25 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 12 4696 26 NF-KAPPAB REPRESSES RETINOIC ACID RECEPTOR-MEDIATED GPRC5A TRANSACTIVATION IN LUNG EPITHELIAL CELLS TO PROMOTE NEOPLASIA. CHRONIC INFLAMMATION IS ASSOCIATED WITH LUNG TUMORIGENESIS, IN WHICH NF-KAPPAB-MEDIATED EPIGENETIC REGULATION PLAYS A CRITICAL ROLE. LUNG TUMOR SUPPRESSOR G PROTEIN-COUPLED RECEPTOR, FAMILY C, MEMBER 5A (GPRC5A), IS REPRESSED IN MOST NON-SMALL CELL LUNG CANCER (NSCLC); HOWEVER, THE MECHANISMS REMAIN UNCLEAR. HERE, WE SHOW THAT NF-KAPPAB ACTS AS A TRANSCRIPTIONAL REPRESSOR IN SUPPRESSION OF GPRC5A. NF-KAPPAB INDUCED GPRC5A REPRESSION BOTH IN VITRO AND IN VIVO. INTRIGUINGLY, TRANSACTIVATION OF NF-KAPPAB DOWNSTREAM TARGETS WAS NOT REQUIRED, BUT THE TRANSACTIVATION DOMAIN OF RELA/P65 WAS REQUIRED FOR GPRC5A REPRESSION. NF-KAPPAB DID NOT BIND TO ANY POTENTIAL CIS-ELEMENT IN THE GPRC5A PROMOTER. INSTEAD, P65 WAS COMPLEXED WITH RETINOIC ACID RECEPTOR ALPHA/BETA (RARALPHA/BETA) AND RECRUITED TO THE RA RESPONSE ELEMENT SITE AT THE GPRC5A PROMOTER, RESULTING IN DISRUPTED RNA POLYMERASE II COMPLEXING AND SUPPRESSED TRANSCRIPTION. NOTABLY, PHOSPHORYLATION ON SERINE 276 OF P65 WAS REQUIRED FOR INTERACTION WITH RARALPHA/BETA AND REPRESSION OF GPRC5A. MOREOVER, NF-KAPPAB-MEDIATED EPIGENETIC REPRESSION WAS THROUGH SUPPRESSION OF ACETYLATED HISTONE H3K9 (H3K9AC), BUT NOT DNA METHYLATION OF THE CPG ISLANDS, AT THE GPRC5A PROMOTER. CONSISTENTLY, A HISTONE DEACETYLASE INHIBITOR, BUT NOT DNA METHYLATION INHIBITOR, RESTORED GPRC5A EXPRESSION IN NSCLC CELLS. THUS, NF-KAPPAB INDUCES TRANSCRIPTIONAL REPRESSION OF GPRC5A VIA A COMPLEX WITH RARALPHA/BETA AND MEDIATES EPIGENETIC REPRESSION VIA SUPPRESSION OF H3K9AC. 2023 13 4233 30 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 14 3327 34 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 6385 30 THE ROLE OF PROMYELOCYTIC LEUKEMIA PROTEIN IN STEATOSIS-ASSOCIATED HEPATIC TUMORS RELATED TO CHRONIC HEPATITIS B VIRUS INFECTION. THE PERSISTENCE OF HEPATITIS B SURFACE ANTIGEN (HBSAG) IS A RISK FACTOR FOR THE DEVELOPMENT OF STEATOSIS-ASSOCIATED TUMORS IN CHRONIC HEPATITIS B VIRUS (HBV) INFECTION, YET LITTLE IS KNOWN ABOUT THE METABOLIC LINK WITH THIS FACTOR. WE CORRELATED HBV-RELATED PATHOGENESIS IN GENETICALLY ENGINEERED MICE AND HUMAN CARRIERS WITH METABOLIC PROTEOMICS AND LIPOGENIC GENE EXPRESSION PROFILES. THE IMMUNOHISTOCHEMISTRY SHOWED THAT THE PROMYELOCYTIC LEUKEMIA PROTEIN (PML, A TUMOR SUPPRESSOR INVOLVED IN GENOME MAINTENANCE AND FATTY ACID OXIDATION), BEING INVERSELY INFLUENCED BY THE DYNAMIC HBSAG LEVELS FROM ACUTE PHASE TO SEROCLEARANCE, APPEARED AS A LIPO-METABOLIC SWITCH LINKING HBSAG-INDUCED STEATOSIS (LIPOGENESIS) TO HBSAG-LOST FAT-BURNING HEPATOCARCINOGENESIS (LIPOLYSIS). KNOCKDOWN OF PML IN HBSAG-TRANSGENIC MICE PREDISPOSED TO OBESITY AND DROVE EARLY STEATOSIS-SPECIFIC LIVER TUMORIGENESIS. PROTEOME ANALYSIS REVEALED THAT THE SIGNALING PATHWAYS CORRESPONDING TO ENERGY METABOLISM AND ITS REGULATORS WERE FREQUENTLY ALTERED BY SUPPRESSION OR DEPLETION OF PML IN THE HBSAG-TRANSGENIC MICE, MAINLY INCLUDING OXIDATIVE PHOSPHORYLATION AND FATTY ACID METABOLISM. EXPRESSION PROFILING FURTHER IDENTIFIED UPREGULATION OF STEAROYL-COA DESATURASE 1 (SCD1) AND EPIGENETIC METHYLATION OF NDUFA13 IN THE MITOCHONDRIAL RESPIRATORY CHAIN AND THE CELL CYCLE INHIBITOR CDKN1C IN CONCORDANCE TO THE INCREASED SEVERITY OF LIPODYSTROPHY AND NEOPLASIA IN THE LIVERS OF HBSAG-TRANSGENIC MICE WITH PML INSUFFICIENCY. THE DEFECT IN LIPOLYSIS IN PML-DEFICIENT HBSAG-TRANSGENIC MICE MADE THE HBSAG-INDUCED ADIPOSE-LIKE LIVER TUMORS VULNERABLE TO SYNTHETIC LETHALITY FROM TOXIC SATURATED FAT ACCUMULATION WITH A SCD1 INHIBITOR. OUR FINDINGS PROVIDE MECHANISTIC INSIGHTS INTO THE EVOLUTION OF STEATOSIS-ASSOCIATED HEPATIC TUMORS DRIVEN BY RECIPROCAL INTERACTIONS OF HBSAG AND PML, AND A POTENTIAL UTILITY OF LIPID METABOLIC REPROGRAMMING AS A TREATMENT TARGET. 2018 16 4443 27 MOLECULAR INSIGHTS INTO SPINDLIN1-HBX INTERPLAY AND ITS IMPACT ON HBV TRANSCRIPTION FROM CCCDNA MINICHROMOSOME. MOLECULAR INTERPLAY BETWEEN HOST EPIGENETIC FACTORS AND VIRAL PROTEINS CONSTITUTES AN INTRIGUING MECHANISM FOR SUSTAINING HEPATITIS B VIRUS (HBV) LIFE CYCLE AND ITS CHRONIC INFECTION. HBV ENCODES A REGULATORY PROTEIN, HBX, WHICH ACTIVATES TRANSCRIPTION AND REPLICATION OF HBV GENOME ORGANIZED AS COVALENTLY CLOSED CIRCULAR (CCC) DNA MINICHROMOSOME. HERE WE ILLUSTRATE HOW HBX ACCOMPLISHES ITS TASK BY HIJACKING SPINDLIN1, AN EPIGENETIC READER COMPRISING THREE CONSECUTIVE TUDOR DOMAINS. OUR BIOCHEMICAL AND STRUCTURAL STUDIES HAVE REVEALED THAT THE HIGHLY CONSERVED N-TERMINAL 2-21 SEGMENT OF HBX (HBX(2-21)) ASSOCIATES INTIMATELY WITH TUDOR 3 OF SPINDLIN1, ENHANCING HISTONE H3 "K4ME3-K9ME3" READOUT BY TUDORS 2 AND 1. FUNCTIONALLY, SPINDLIN1-HBX ENGAGEMENT PROMOTES GENE EXPRESSION FROM THE CHROMATINIZED CCCDNA, ACCOMPANIED BY AN EPIGENETIC SWITCH FROM AN H3K9ME3-ENRICHED REPRESSIVE STATE TO AN H3K4ME3-MARKED ACTIVE STATE, AS WELL AS A CONFORMATIONAL SWITCH OF HBX THAT MAY OCCUR IN COORDINATION WITH OTHER HBX-BINDING FACTORS, SUCH AS DDB1. DESPITE A PROPOSED TRANSREPRESSION ACTIVITY OF HBX(2-21), OUR STUDY REVEALS A KEY ROLE OF SPINDLIN1 IN DEREPRESSING THIS CONSERVED MOTIF, THEREBY PROMOTING HBV TRANSCRIPTION FROM ITS CHROMATINIZED GENOME. 2023 17 669 27 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 18 5636 39 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 19 5153 28 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 20 5863 28 SUPPRESSION OF ALLERGIC ASTHMA BY LOSS OF FUNCTION OF MIZ1-MEDIATED TH1 SKEWING. ASTHMA IS THE MOST PREVALENT CHRONIC RESPIRATORY DISEASE WORLDWIDE. THERE IS CURRENTLY NO CURE, AND IT REMAINS AN IMPORTANT CAUSE OF MORBIDITY AND MORTALITY. HERE WE REPORT THAT LUNG-SPECIFIC LOSS OF FUNCTION OF THE TRANSCRIPTION FACTOR MIZ1 (C-MYC-INTERACTING ZINC FINGER PROTEIN-1) UPREGULATES THE PRO-T-HELPER CELL TYPE 1 CYTOKINE IL-12. UPREGULATION OF IL-12 IN TURN STIMULATES A TH1 RESPONSE, THEREBY COUNTERACTING T-HELPER CELL TYPE 2 RESPONSE AND PREVENTING THE ALLERGIC RESPONSE IN MOUSE MODELS OF HOUSE DUST MITE- AND OVA (OVALBUMIN)-INDUCED ASTHMA. USING TRANSGENIC MICE EXPRESSING CRE UNDER A CELL-SPECIFIC PROMOTER, WE DEMONSTRATE THAT MIZ1 ACTS IN LUNG EPITHELIAL CELLS AND DENDRITIC CELLS IN ASTHMA. CHROMATIN IMMUNOPRECIPITATION COUPLED WITH HIGH-THROUGHPUT DNA SEQUENCING OR QUANTITATIVE PCR REVEALS THE BINDING OF MIZ1 ON THE IL12 PROMOTER INDICATING DIRECT REPRESSION OF IL-12 BY MIZ1. IN ADDITION, HDAC1 (HISTONE DEACETYLASE 1) IS RECRUITED TO THE IL12 PROMOTER IN A MIZ1-DEPDENENT MANNER, SUGGESTING EPIGENETIC REPRESSION OF IL12 BY MIZ1. FURTHERMORE, MIZ1 IS UPREGULATED IN THE LUNGS OF ASTHMATIC MICE. OUR DATA TOGETHER SUGGEST THAT MIZ1 IS UPREGULATED DURING ASTHMA, WHICH IN TURN PROMOTES ASTHMA PATHOGENESIS BY PREVENTING TH1 SKEWING THROUGH THE TRANSCRIPTIONAL REPRESSION OF IL-12. 2022