1 1001 151 CHRONIC TCDD EXPOSURE RESULTS IN THE DYSREGULATION OF GENE EXPRESSION IN SPLENIC B-LYMPHOCYTES AND IN THE IMPAIRMENTS IN T-CELL AND B-CELL DIFFERENTIATION IN MOUSE MODEL. 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) EXPOSURE IN HUMANS IS ASSOCIATED WITH MARKED IMMUNE SUPPRESSIONS AND INCREASED INCIDENCE OF LYMPHOBLASTIC DISEASES. TO ELUCIDATE MECHANISMS OF IMPAIRMENTS IN HUMORAL IMMUNE RESPONSES, WE USED A MURINE MODEL. FOLLOWING A 20-WEEK ADMINISTRATION OF LOW DOSES OF TCDD, WE OBSERVED SEVERELY REDUCED ANTIBODY TITERS, DRAMATICALLY DECREASED NUMBER OF SPLENIC TH1 AND TH2 CELLS AND AN INCREASE IN CD19(+) B CELLS. TRANSCRIPTIONAL PROFILING OF CD19(+) B CELLS SHOWED THAT MARKERS OF PRE-B CELLS WERE SIGNIFICANTLY ELEVATED, INDICATING DELAYED B CELL MATURATION. THESE CHANGES IN B CELLS WERE ACCOMPANIED BY DECREASES OF T HELPER CELL NUMBERS AND REDUCED IGM AND IGG TITERS. A TRANSCRIPTOME ANALYSIS OF SPLENIC B CELLS FOLLOWED BY INGENUITY PATHWAY ANALYSIS (IPA) REVEALED A SET OF DIFFERENTIALLY EXPRESSED GENES KNOWN TO PLAY ROLES IN TUMORIGENESIS, CELL-PROLIFERATION AND CELL-MIGRATION. THE MOST UP-REGULATED TRANSCRIPT GENE WAS EPH RECEPTOR A2 (EPHA2), A KNOWN ONCOGENE, AND THE MOST DOWN-REGULATED TRANSCRIPT WAS ZBTB16 THAT CODES FOR A NEGATIVE TRANSCRIPTIONAL REGULATOR IMPORTANT IN EPIGENETIC CHROMATIN REMODELING. IPA IDENTIFIED CAMP-RESPONSIVE ELEMENT MODULATOR (CREM) AND CAMP-RESPONSIVE ELEMENT BINDING PROTEIN 1 (CREB1) AS TOP UPSTREAM REGULATORS. CONSISTENTLY, A MAPPER PROMOTER DATABASE ANALYSIS SHOWED THAT ALL TOP DYSREGULATED GENES HAD CREM AND/OR CREB1 BINDING SITES IN THEIR PROMOTER REGIONS. IN SUMMARY, OUR DATA SHOWED THAT CHRONIC TCDD EXPOSURE IN MICE CAUSED SUPPRESSED HUMORAL IMMUNITY ACCOMPANIED WITH PROFOUND DYSREGULATION OF GENE EXPRESSION IN SPLENIC B-LYMPHOCYTES, LIKELY THROUGH CAMP-DEPENDENT PATHWAYS. THIS DYSREGULATION RESULTED IN IMPAIRMENTS IN T-CELL AND B-CELL DIFFERENTIATION AND ACTIVATION OF THE TUMORIGENIC TRANSCRIPTION PROGRAM. 2016 2 1458 43 DISORDER OF G2-M CHECKPOINT CONTROL IN ANILINE-INDUCED CELL PROLIFERATION IN RAT SPLEEN. ANILINE, A TOXIC AROMATIC AMINE, IS KNOWN TO CAUSE HEMOPOIETIC TOXICITY BOTH IN HUMANS AND ANIMALS. ANILINE EXPOSURE ALSO LEADS TO TOXIC RESPONSE IN SPLEEN WHICH IS CHARACTERIZED BY SPLENOMEGALY, HYPERPLASIA, FIBROSIS AND THE EVENTUAL FORMATION OF TUMORS ON CHRONIC IN VIVO EXPOSURE. PREVIOUSLY, WE HAVE SHOWN THAT ANILINE EXPOSURE LEADS TO IRON OVERLOAD, OXIDATIVE DNA DAMAGE, AND INCREASED CELL PROLIFERATION, WHICH COULD EVENTUALLY CONTRIBUTE TO A TUMORIGENIC RESPONSE IN THE SPLEEN. DESPITE OUR DEMONSTRATION THAT CELL PROLIFERATION WAS ASSOCIATED WITH DEREGULATION OF G1 PHASE CYCLINS AND INCREASED EXPRESSION OF G1 PHASE CYCLIN-DEPENDENT KINASES (CDKS), MOLECULAR MECHANISMS, ESPECIALLY THE REGULATION OF G2 PHASE AND CONTRIBUTION OF EPIGENETIC MECHANISMS IN ANILINE-INDUCED SPLENIC CELLULAR PROLIFERATION REMAIN LARGELY UNCLEAR. THIS STUDY THEREFORE, MAINLY FOCUSED ON THE REGULATION OF G2 PHASE IN AN ANIMAL MODEL PRECEDING A TUMORIGENIC RESPONSE. MALE SPRAGUE-DAWLEY RATS WERE GIVEN ANILINE (0.5 MMOL/KG/DAY) IN DRINKING WATER OR DRINKING WATER ONLY (CONTROLS) FOR 30 DAYS, AND EXPRESSION OF G2 PHASE CYCLINS, CDK1, CDK INHIBITORS AND MIRNAS WERE MEASURED IN THE SPLEEN. ANILINE TREATMENT RESULTED IN SIGNIFICANT INCREASES IN CELL CYCLE REGULATORY PROTEINS, INCLUDING CYCLINS A, B AND CDK1, PARTICULARLY PHOSPHOR-CDK1, AND DECREASES IN CDK INHIBITORS P21 AND P27, WHICH COULD PROMOTE THE SPLENOCYTES TO GO THROUGH G2/M TRANSITION. OUR DATA ALSO SHOWED UPREGULATION OF TUMOR MARKERS TRX-1 AND REF-1 IN RATS TREATED WITH ANILINE. MORE IMPORTANTLY, WE OBSERVED LOWER EXPRESSION OF MIRNAS INCLUDING LET-7A, MIR-15B, MIR24, MIR-100 AND MIR-125, AND GREATER EXPRESSION OF CDK INHIBITOR REGULATORY MIRNAS SUCH AS MIR-181A, MIR-221 AND MIR-222 IN THE SPLEENS OF ANILINE-TREATED ANIMALS. OUR FINDINGS SUGGEST THAT SIGNIFICANT INCREASES IN THE EXPRESSION OF CYCLINS, CDK1 AND ABERRANT REGULATION OF MIRNAS COULD LEAD TO AN ACCELERATED G2/M TRANSITION OF THE SPLENOCYTES, AND POTENTIALLY TO A TUMORIGENIC RESPONSE ON CHRONIC ANILINE EXPOSURE. 2015 3 4466 42 MOLECULAR MECHANISMS OF REPEATED SOCIAL DEFEAT-INDUCED GLUCOCORTICOID RESISTANCE: ROLE OF MICRORNA. GLUCOCORTICOID (GC) RESISTANCE IS A SEVERE PROBLEM ASSOCIATED WITH VARIOUS INFLAMMATORY DISEASES. PREVIOUS STUDIES HAVE SHOWN THAT REPEATED SOCIAL STRESS INDUCES GC RESISTANCE IN INNATE IMMUNE CELLS, BUT THE UNDERLYING MOLECULAR MECHANISMS HAVE NOT BEEN FULLY ELUCIDATED. THEREFORE, THE PURPOSE OF THIS STUDY WAS TO EXAMINE POTENTIAL UNDERLYING MOLECULAR MECHANISM(S) OF REPEATED SOCIAL DEFEAT (RSD) STRESS ON GC RESISTANCE IN SPLENIC MACROPHAGES. IT WAS HYPOTHESIZED THAT MRNA EXPRESSION OF RECEPTORS FOR GC AND NUCLEAR TRANSLOCATING-ASSOCIATED REGULATORS IN SPLENIC MACROPHAGES WOULD BE AFFECTED BY RSD, AND THAT THESE CHANGES WOULD BE ASSOCIATED WITH EPIGENETIC MODIFICATION. THE DATA SHOWED THAT THE MRNA EXPRESSION OF GC AND MINERALOCORTICOID RECEPTORS WERE SIGNIFICANTLY DECREASED IN SPLENIC MACROPHAGES BY RSD. RSD ALSO INDUCED A SIGNIFICANTLY DECREASED MRNA EXPRESSION IN FK506-BINDING PROTEIN 52 (FKBP52), CONSEQUENTLY RESULTING IN A SIGNIFICANTLY INCREASED RATIO OF FKBP51 TO FKBP52. MOREOVER, DNA METHYLTRANSFERASES 3A AND 3B SHOWED A SIGNIFICANT DECREASE IN THEIR MRNA EXPRESSION IN THE RSD GROUP AS DID MRNA EXPRESSION OF HISTONE DEACETYLTRANSFERASE 2. THE RSD GROUP ALSO SHOWED A SIGNIFICANTLY REDUCED QUANTITY OF METHYLATED DNA IN SPLENIC MACROPHAGES. BASED ON MICRORNA (MIRNA) PROFILING DATA, IT WAS DETERMINED THAT RSD INDUCED SIGNIFICANTLY INCREASED EXPRESSION OF 9 DIFFERENT MIRNAS THAT WERE PREDICTED TO INTERACT WITH MRNAS OF THE GC RECEPTOR (6 MIRNAS), MINERALOCORTICOID RECEPTOR (3 MIRNAS) AND FKBP52 (2 MIRNAS). SPEARMAN CORRELATION ANALYSIS REVEALED SIGNIFICANTLY STRONG CORRELATIONS BETWEEN THE EXPRESSION OF 2 MIRNAS AND THEIR TARGET MRNA EXPRESSION FOR GC RECEPTORS. AMONG THESE MIRNAS, WE VERIFIED DIRECT EFFECTS OF MIRNA-29B AND -340 OVEREXPRESSION ON MRNA EXPRESSION OF GC RECEPTORS IN L929 CELLS. THE OVEREXPRESSION OF MIRNA-29B OR -340 IN L929 CELLS SIGNIFICANTLY REDUCED LPS-INDUCED OVEREXPRESSION OF GC RECEPTORS. IN CONCLUSION, THIS STUDY PROVIDES EVIDENCE THAT EPIGENETIC REGULATION, SUCH AS DNA METHYLATION AND MIRNA EXPRESSION, MAY PLAY A ROLE IN THE RSD-INDUCED GC RESISTANCE THAT WE HAVE OBSERVED IN SPLENIC MACROPHAGES. 2015 4 6020 43 THE ATTENUATION OF RENAL FIBROSIS BY HISTONE DEACETYLASE INHIBITORS IS ASSOCIATED WITH THE PLASTICITY OF FOXP3(+)IL-17(+) T CELLS. BACKGROUND: THE HISTONE DEACETYLASE (HDAC) INHIBITOR, WHICH HAS POTENTIAL EFFECTS ON EPIGENETIC MODIFICATIONS, HAD BEEN REPORTED TO ATTENUATE RENAL FIBROSIS. CD4(+) FORKHEAD BOX P3 (FOXP3)(+) T REGULATORY (TREG) CELLS MAY BE CONVERTED TO INFLAMMATION-ASSOCIATED T HELPER 17 CELLS (TH17) WITH TISSUE FIBROSIS PROPERTIES. THE ASSOCIATION BETWEEN FOXP3(+)IL-17(+) T CELLS AND THE ATTENUATION OF RENAL FIBROSIS BY THE HDAC INHIBITOR IS NOT CLEAR. METHODS: THIS STUDY EVALUATED THE ROLES OF THE HDAC INHIBITOR, TREG CELLS AND THEIR DIFFERENTIATION INTO TH17 CELLS, WHICH AGGRAVATE CHRONIC INFLAMMATION AND RENAL FIBROSIS IN A UNILATERAL URETERAL OBSTRUCTION (UUO) MOUSE MODEL. THE STUDY GROUPS INCLUDED CONTROL AND UUO MICE THAT WERE MONITORED FOR 7, 14 OR 21 DAYS. RESULTS: JUXTAGLOMERULAR (JG) HYPERPLASIA, ANGIOTENSIN II TYPE 1 RECEPTOR (AT1R) EXPRESSION AND LYMPHOCYTE INFILTRATION WERE OBSERVED IN RENAL TISSUES AFTER UUO BUT WERE DECREASED AFTER TRICHOSTATIN A (TSA) TREATMENT, A HDAC INHIBITOR. THE NUMBER OF CD4(+)FOXP3(+) T CELLS INCREASED PROGRESSIVELY, ALONG WITH THE NUMBER OF FOXP3(+)INTERLEUKIN (IL)-17(+) T CELLS, AFTER 14 DAYS, AND THEIR NUMBERS THEN PROGRESSIVELY DECREASED WITH INCREASING CD4(+)IL-17(+) T CELL NUMBERS, AS DEMONSTRATED BY DOUBLE IMMUNOHISTOCHEMISTRY. PROGRESSIVE RENAL FIBROSIS WAS ASSOCIATED WITH THE LOSS OF CD4(+)FOXP3(+)IL-17(+) T CELLS IN SPLENIC SINGLE-CELL SUSPENSIONS. FOXP3(+)IL-17(+) T CELLS EXPRESSED TGF-BETA1 BOTH IN VITRO AND IN VIVO, AND TGF-BETA1 EXPRESSION WAS SIGNIFICANTLY KNOCKDOWN BY IL-17 SIRNA IN VITRO. THESE CELLS WERE FOUND TO PLAY A ROLE IN CONVERTING TREGS INTO IL-17- AND TGF-BETA1-PRODUCING CELLS. CONCLUSIONS: TSA TREATMENT DECREASED JG HYPERPLASIA, THE PERCENTAGE OF FOXP3(+)IL-17(+) CELLS AND THE DEGREE OF FIBROSIS, SUGGESTING THAT THERAPEUTIC BENEFITS MAY RESULT FROM EPIGENETIC MODIFICATIONS. 2017 5 914 32 CHRONIC HEAVY DRINKING DRIVES DISTINCT TRANSCRIPTIONAL AND EPIGENETIC CHANGES IN SPLENIC MACROPHAGES. BACKGROUND: CHRONIC HEAVY ALCOHOL DRINKING (CHD) LEADS TO SIGNIFICANT ORGAN DAMAGE, INCREASED SUSCEPTIBILITY TO INFECTIONS, AND DELAYED WOUND HEALING. THESE ADVERSE OUTCOMES ARE BELIEVED TO BE MEDIATED BY ALTERATIONS IN THE FUNCTION OF MYELOID CELLS; HOWEVER, THE MECHANISMS UNDERLYING THESE CHANGES ARE POORLY UNDERSTOOD. METHODS: WE DETERMINED THE IMPACT OF CHD ON THE PHENOTYPE OF SPLENIC MACROPHAGES USING FLOW CYTOMETRY. CHANGES IN FUNCTIONAL RESPONSES TO LPS WERE MEASURED USING LUMINEX AND RNA-SEQ. FINALLY, ALTERATIONS IN CHROMATIN ACCESSIBILITY WERE UNCOVERED USING ATAC-SEQ. FINDINGS: A HISTORY OF CHD LED TO INCREASED FREQUENCY OF SPLENIC MACROPHAGES THAT EXHIBITED A HEIGHTENED ACTIVATION STATE AT RESTING. ADDITIONALLY, SPLENIC MACROPHAGES FROM CHD ANIMALS GENERATED A LARGER INFLAMMATORY RESPONSE TO LPS, BOTH AT PROTEIN AND GENE EXPRESSION LEVELS. FINALLY, CHD RESULTED IN INCREASED LEVELS OF H3K4ME3, A HISTONE MARK OF ACTIVE PROMOTERS, AS WELL AS CHROMATIN ACCESSIBILITY AT PROMOTERS AND INTERGENIC REGIONS THAT REGULATE INFLAMMATORY RESPONSES. INTERPRETATION: THESE FINDINGS SUGGEST THAT A HISTORY OF CHD ALTERS THE IMMUNE FITNESS OF TISSUE-RESIDENT MACROPHAGES VIA EPIGENETIC MECHANISMS. FUND: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM (NIAAA), NATIONAL INSTITUTES OF HEALTH (NIH) - R24AA019431, U01 AA13641, U01 AA13510, R21AA021947, AND R21AA025839. 2019 6 5333 23 PYRUVATE KINASE DEFICIENCY: THE GENOTYPE-PHENOTYPE ASSOCIATION. RED CELL PYRUVATE KINASE (PK) DEFICIENCY IS THE MOST FREQUENT ENZYME ABNORMALITY OF GLYCOLYSIS CAUSING CHRONIC NON-SPHEROCYTIC HAEMOLYTIC ANAEMIA. THE DISEASE IS TRANSMITTED AS AN AUTOSOMAL RECESSIVE TRAIT, CLINICAL SYMPTOMS USUALLY OCCURRING IN COMPOUND HETEROZYGOTES FOR TWO MUTANT ALLELES AND IN HOMOZYGOTES. THE SEVERITY OF HAEMOLYSIS IS HIGHLY VARIABLE, RANGING FROM VERY MILD OR FULLY COMPENSATED FORMS TO LIFE-THREATENING NEONATAL ANAEMIA NECESSITATING EXCHANGE TRANSFUSIONS. ERYTHROCYTE PK IS SYNTHESISED UNDER THE CONTROL OF THE PK-LR GENE LOCATED ON CHROMOSOME 1. ONE HUNDRED EIGHTY DIFFERENT MUTATIONS IN PK-LR GENE, MOSTLY MISSENSE, HAVE BEEN SO FAR REPORTED ASSOCIATED TO PK DEFICIENCY. FIRST ATTEMPTS TO DELINEATE THE GENOTYPE-PHENOTYPE ASSOCIATION WERE MAINLY BASED ON THE ANALYSIS OF THE ENZYME'S THREE-DIMENSIONAL STRUCTURE AND THE OBSERVATION OF THE FEW HOMOZYGOUS PATIENTS. MORE RECENTLY, THE COMPARISON OF THE RECOMBINANT MUTANTS OF HUMAN RED CELL PK WITH THE WILD-TYPE ENZYME HAS ENABLED THE EFFECTS OF AMINO ACID REPLACEMENTS ON THE ENZYME MOLECULAR PROPERTIES TO BE DETERMINED. HOWEVER, THE CLINICAL MANIFESTATIONS OF RED CELL ENZYME DEFECTS ARE NOT MERELY DEPENDENT ON THE MOLECULAR PROPERTIES OF THE MUTANT PROTEIN BUT RATHER REFLECT THE COMPLEX INTERACTIONS OF ADDITIONAL FACTORS, INCLUDING GENETIC BACKGROUND, CONCOMITANT FUNCTIONAL POLYMORPHISMS OF OTHER ENZYMES, POSTTRANSLATIONAL OR EPIGENETIC MODIFICATIONS, INEFFECTIVE ERYTHROPOIESIS AND DIFFERENCES IN SPLENIC FUNCTION. 2007 7 597 32 BET-BROMODOMAIN AND EZH2 INHIBITOR-TREATED CHRONIC GVHD MICE HAVE BLUNTED GERMINAL CENTERS WITH DISTINCT TRANSCRIPTOMES. DESPITE ADVANCES IN THE FIELD, CHRONIC GRAFT-VERSUS-HOST-DISEASE (CGVHD) REMAINS A LEADING CAUSE OF MORBIDITY AND MORTALITY FOLLOWING ALLOGENIC HEMATOPOIETIC STEM CELL TRANSPLANT. BECAUSE TREATMENT OPTIONS REMAIN LIMITED, WE TESTED EFFICACY OF ANTICANCER, CHROMATIN-MODIFYING ENZYME INHIBITORS IN A CLINICALLY RELEVANT MURINE MODEL OF CGVHD WITH BRONCHIOLITIS OBLITERANS (BO). WE OBSERVED THAT THE NOVEL ENHANCER OF ZESTE HOMOLOG 2 (EZH2) INHIBITOR JQ5 AND THE BET-BROMODOMAIN INHIBITOR JQ1 EACH IMPROVED PULMONARY FUNCTION; IMPAIRED THE GERMINAL CENTER (GC) REACTION, A PREREQUISITE IN CGVHD/BO PATHOGENESIS; AND JQ5 REDUCED EZH2-MEDIATED H3K27ME3 IN DONOR T CELLS. USING CONDITIONAL EZH2 KNOCKOUT DONOR CELLS, WE DEMONSTRATED THAT EZH2 IS OBLIGATORY FOR THE INITIATION OF CGVHD/BO. IN A SCLERODERMATOUS CGVHD MODEL, JQ5 REDUCED THE SEVERITY OF CUTANEOUS LESIONS. TO DETERMINE HOW THE 2 DRUGS COULD LEAD TO THE SAME PHYSIOLOGICAL IMPROVEMENTS WHILE TARGETING UNIQUE EPIGENETIC PROCESSES, WE ANALYZED THE TRANSCRIPTOMES OF SPLENIC GCB CELLS (GCBS) FROM TRANSPLANTED MICE TREATED WITH EITHER DRUG. MULTIPLE INFLAMMATORY AND SIGNALING PATHWAYS ENRICHED IN CGVHD/BO GCBS WERE REDUCED BY EACH DRUG. GCBS FROM JQ5- BUT NOT JQ1-TREATED MICE WERE ENRICHED FOR PROPROLIFERATIVE PATHWAYS ALSO SEEN IN GCBS FROM BONE MARROW-ONLY TRANSPLANTED MICE, LIKELY REFLECTING THEIR UNDERLYING BIOLOGY IN THE UNPERTURBED STATE. IN CONJUNCTION WITH IN VIVO DATA, THESE INSIGHTS LED US TO CONCLUDE THAT EPIGENETIC TARGETING OF THE GC IS A VIABLE CLINICAL APPROACH FOR THE TREATMENT OF CGVHD, AND THAT THE EZH2 INHIBITOR JQ5 AND THE BET-BROMODOMAIN INHIBITOR JQ1 DEMONSTRATED CLINICAL POTENTIAL FOR EZH2I AND BETI IN PATIENTS WITH CGVHD/BO. 2022 8 2787 45 EZH2-MEDIATED EPIGENETIC MODIFICATION IS REQUIRED FOR ALLOGENEIC T CELL-INDUCED LUPUS DISEASE. BACKGROUND: THE MECHANISMS INVOLVED IN THE PATHOGENESIS OF AUTOIMMUNE DISORDERS, INCLUDING SYSTEMIC LUPUS ERYTHEMATOSUS (SLE), HAVE NOT BEEN FULLY ELUCIDATED. SOME OF THESE MECHANISMS INVOLVE EPIGENETIC REGULATION OF GENE EXPRESSION. THE HISTONE METHYLTRANSFERASE EZH2 CONTRIBUTES TO EPIGENETIC REGULATION OF GENE EXPRESSION, IS HIGHLY EXPRESSED IN GERMINAL CENTER (GC) B CELLS AND FOLLICULAR T HELPER (T(FH)) CELLS, AND MAY BE INVOLVED IN LUPUS PATHOGENESIS. METHODS: THE MURINE BM12 MODEL OF LUPUS-LIKE CHRONIC GRAFT VERSUS HOST DISEASE (CGVHD) WAS INDUCED BY INTRA-PERITONEAL INJECTION OF NEGATIVELY ISOLATED ALLOGENEIC CD4(+) T CELLS. LUPUS-LIKE DISEASE DEVELOPMENT WAS MONITORED BY ELISA DETERMINATION OF SERUM ANTI-DSDNA AND ANTI-CHROMATIN ANTIBODY TITERS. IMMUNE CELL ACTIVATION AND EZH2 EXPRESSION WERE EVALUATED BY FLOW CYTOMETRY AND WESTERN BLOTTING. RESULTS: DECREASED AUTOANTIBODY PRODUCTION AND GC FORMATION ARE OBSERVED WHEN EZH2-DEFICIENT CD4(+) T CELLS ARE USED INSTEAD OF WILD-TYPE (WT) TO INDUCE CGVHD AND WHEN MICE THAT RECEIVE ALLOGENEIC WT DONOR T CELLS TO INDUCE CGVHD ARE TREATED WITH GSK503, AN EZH2-SPECIFIC INHIBITOR. IN THE BM12 CGVHD MODEL, WT DONOR T CELLS ARE NORMALLY FULLY ACTIVATED 1 WEEK AFTER INFUSION INTO AN ALLOGENEIC HOST, EXHIBIT A T(FH) CELL (PD-1(HI)/CXCR5(HI)) PHENOTYPE WITH UPREGULATED EZH2, AND ACTIVATE B CELLS TO FORM GERMINAL CENTERS (GCS). IN CONTRAST, EZH2-DEFICIENT DONOR T CELLS GENERATE FEWER T(FH) CELLS THAT FAIL TO ACTIVATE B CELLS OR PROMOTE GC FORMATION. DESPITE SIMILAR T-INDEPENDENT, LPS-INDUCED B CELL RESPONSES, OVA-IMMUNIZED CD4.EZH2-KO MICE HAD A SKEWED LOW-AFFINITY IGM PHENOTYPE IN COMPARISON TO SIMILARLY TREATED WT MICE. IN ADDITION, EARLY AFTER OVA IMMUNIZATION, MORE CD4(+) T CELLS FROM B6.CD4.EZH2-KO MICE HAD A CD44(LO)/CD62L(LO) PHENOTYPE, WHICH SUGGESTS ARRESTED OR DELAYED ACTIVATION, THAN CD4(+) T CELLS FROM OVALBUMIN-IMMUNIZED B6.WT MICE. CONCLUSION: EZH2 GENE DELETION OR PHARMACOLOGICAL EZH2 INHIBITION SUPPRESSES AUTOANTIBODY PRODUCTION AND GC FORMATION IN BM12 LUPUS-LIKE CGVHD AND DECREASES AFFINITY MATURATION AND ISOTYPE SWITCHING IN RESPONSE TO IMMUNIZATION WITH A T CELL-DEPENDENT ANTIGEN. EZH2 INHIBITION MAY BE USEFUL FOR THE TREATMENT OF LUPUS AND OTHER AUTOIMMUNE DISORDERS. 2020 9 3760 32 INTEGRATED SINGLE CELL ANALYSIS SHOWS CHRONIC ALCOHOL DRINKING DISRUPTS MONOCYTE DIFFERENTIATION IN THE BONE MARROW. CHRONIC HEAVY ALCOHOL DRINKING (CHD) REWIRES MONOCYTES AND MACROPHAGES TOWARD HEIGHTENED INFLAMMATORY STATES WITH COMPROMISED ANTIMICROBIAL DEFENSES THAT PERSIST AFTER 1-MONTH ABSTINENCE. TO DETERMINE WHETHER THESE CHANGES ARE MEDIATED THROUGH ALTERATIONS IN THE BONE MARROW NICHE, WE PROFILED MONOCYTES AND HEMATOPOIETIC STEM CELL PROGENITORS (HSCPS) FROM CHD RHESUS MACAQUES USING A COMBINATION OF FUNCTIONAL ASSAYS AND SINGLE CELL GENOMICS. CHD RESULTED IN TRANSCRIPTIONAL PROFILES CONSISTENT WITH INCREASED ACTIVATION AND INFLAMMATION WITHIN BONE MARROW RESIDENT MONOCYTES AND MACROPHAGES. FURTHERMORE, CHD RESULTED IN TRANSCRIPTIONAL SIGNATURES ASSOCIATED WITH INCREASED OXIDATIVE AND CELLULAR STRESS IN HSCP. DIFFERENTIATION OF HSCP IN VITRO REVEALED SKEWING TOWARD MONOCYTES EXPRESSING "NEUTROPHIL-LIKE" MARKERS WITH GREATER INFLAMMATORY RESPONSES TO BACTERIAL AGONISTS. FURTHER ANALYSES OF HSCPS SHOWED BROAD EPIGENETIC CHANGES THAT WERE IN LINE WITH EXACERBATED INFLAMMATORY RESPONSES WITHIN MONOCYTES AND THEIR PROGENITORS. IN SUMMARY, CHD ALTERS HSCPS IN THE BONE MARROW LEADING TO THE PRODUCTION OF MONOCYTES POISED TO GENERATE DYSREGULATED HYPER-INFLAMMATORY RESPONSES. 2023 10 1906 35 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 11 5319 35 PTEN IS FUNDAMENTAL FOR ELIMINATION OF LEUKEMIA STEM CELLS MEDIATED BY GSK126 TARGETING EZH2 IN CHRONIC MYELOGENOUS LEUKEMIA. PURPOSE: LEUKEMIA STEM CELLS (LSCS) ARE AN IMPORTANT SOURCE OF TYROSINE KINASE INHIBITOR RESISTANCE AND DISEASE RELAPSE IN PATIENTS WITH CHRONIC MYELOGENOUS LEUKEMIA (CML). TARGETING LSCS MAY BE AN ATTRACTIVE STRATEGY TO OVERRIDE THIS THORNY PROBLEM. GIVEN THAT EZH2 WAS OVEREXPRESSED IN PRIMARY CML CD34(+) CELLS, OUR PURPOSE IN THIS STUDY WAS TO EVALUATE THE EFFECTS OF TARGETING EZH2 ON CML LSCS AND CLARIFY ITS UNDERLYING MECHANISM.EXPERIMENTAL DESIGN: HUMAN PRIMARY CML CD34(+) CELLS AND RETROVIRALLY BCR-ABL-DRIVEN CML MOUSE MODELS WERE EMPLOYED TO EVALUATE THE EFFECTS OF SUPPRESSION OF EZH2 BY GSK126- OR EZH2-SPECIFIC SHRNA IN VITRO AND IN VIVO RECRUITMENT OF EZH2 AND H3K27ME3 ON THE PROMOTER OF TUMOR-SUPPRESSOR GENE PTEN IN CML CELLS WAS MEASURED BY CHROMATIN IMMUNOPRECIPITATION ASSAY.RESULTS: OUR RESULTS SHOWED THAT PHARMACOLOGIC INHIBITION OF EZH2 BY GSK126 NOT ONLY ELICITED APOPTOSIS AND RESTRICTED CELL GROWTH IN CML BULK LEUKEMIA CELLS, BUT ALSO DECREASED LSCS IN CML CD34(+) CELLS WHILE SPARING THOSE FROM NORMAL BONE MARROW CD34(+) CELLS. SUPPRESSION OF EZH2 BY GSK126 OR SPECIFIC SHRNA PROLONGED SURVIVAL OF CML MICE AND REDUCED THE NUMBER OF LSCS IN MICE. EZH2 KNOCKDOWN RESULTED IN ELEVATION OF PTEN AND LED TO IMPAIRED RECRUITMENT OF EZH2 AND H3K27ME3 ON THE PROMOTER OF PTEN GENE. THE EFFECT OF EZH2 KNOCKDOWN IN THE CML MICE WAS AT LEAST PARTIALLY REVERSED BY PTEN KNOCKDOWN.CONCLUSIONS: THESE FINDINGS IMPROVE THE UNDERSTANDING OF THE EPIGENETIC REGULATION OF STEMNESS IN CML LSCS AND WARRANT CLINICAL TRIAL OF GSK126 IN REFRACTORY PATIENTS WITH CML. CLIN CANCER RES; 24(1); 145-57. (C)2017 AACR. 2018 12 3373 38 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018 13 5918 35 TARGETING BMI-1 IN B CELLS RESTORES EFFECTIVE HUMORAL IMMUNE RESPONSES AND CONTROLS CHRONIC VIRAL INFECTION. INEFFECTIVE ANTIBODY-MEDIATED RESPONSES ARE A KEY CHARACTERISTIC OF CHRONIC VIRAL INFECTION. HOWEVER, OUR UNDERSTANDING OF THE INTRINSIC MECHANISMS THAT DRIVE THIS DYSREGULATION ARE UNCLEAR. HERE, WE IDENTIFY THAT TARGETING THE EPIGENETIC MODIFIER BMI-1 IN MICE IMPROVES HUMORAL RESPONSES TO CHRONIC LYMPHOCYTIC CHORIOMENINGITIS VIRUS. BMI-1 WAS UPREGULATED BY GERMINAL CENTER B CELLS IN CHRONIC VIRAL INFECTION, CORRELATING WITH CHANGES TO THE ACCESSIBLE CHROMATIN LANDSCAPE, COMPARED TO ACUTE INFECTION. B CELL-INTRINSIC DELETION OF BMI1 ACCELERATED VIRAL CLEARANCE, REDUCED SPLENOMEGALY AND RESTORED SPLENIC ARCHITECTURE. DELETION OF BMI1 RESTORED C-MYC EXPRESSION IN B CELLS, CONCOMITANT WITH IMPROVED QUALITY OF ANTIBODY AND COUPLED WITH REDUCED ANTIBODY-SECRETING CELL NUMBERS. SPECIFICALLY, BMI-1-DEFICIENCY INDUCED ANTIBODY WITH INCREASED NEUTRALIZING CAPACITY AND ENHANCED ANTIBODY-DEPENDENT EFFECTOR FUNCTION. USING A SMALL MOLECULE INHIBITOR TO MURINE BMI-1, WE COULD DEPLETE ANTIBODY-SECRETING CELLS AND PROHIBIT DETRIMENTAL IMMUNE COMPLEX FORMATION IN VIVO. THIS STUDY DEFINES BMI-1 AS A CRUCIAL IMMUNE MODIFIER THAT CONTROLS ANTIBODY-MEDIATED RESPONSES IN CHRONIC INFECTION. 2022 14 3953 43 LOCUS-SPECIFIC REVERSIBLE DNA METHYLATION REGULATES TRANSIENT IL-10 EXPRESSION IN TH1 CELLS. IL-10 IS A PLEIOTROPIC CYTOKINE WITH MULTIFACETED FUNCTIONS IN ESTABLISHING IMMUNE HOMEOSTASIS. ALTHOUGH EXPRESSED BY TH1 AND TH2 CELLS, CONVENTIONAL TH1 CELLS PRODUCE MARGINAL LEVELS OF IL-10 COMPARED WITH THEIR TH2 COUNTERPARTS. IN THIS STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISMS OF IL-10 GENE EXPRESSION IN TH1 CELLS. BIOINFORMATICS EMBOSS CPG PLOT ANALYSIS AND BISULFITE PYROSEQUENCING REVEALED THREE CPG DNA METHYLATION SITES IN THE IL-10 GENE LOCUS. PROGRESSIVE DNA METHYLATION AT ALL OF THE CPG REGIONS OF INTEREST (ROIS) ESTABLISHED A REPRESSIVE PROGRAM OF IL-10 GENE EXPRESSION IN TH1 CELLS. INTERESTINGLY, TH1 CELLS TREATED WITH IL-12 AND IL-27 CYTOKINES, THEREBY MIMICKING A CHRONIC INFLAMMATORY CONDITION IN VIVO, DISPLAYED A SIGNIFICANT INCREASE IN IL-10 PRODUCTION THAT WAS ACCOMPANIED BY SELECTIVE DNA DEMETHYLATION AT ROI 3 LOCATED IN INTRON 3. IL-10-PRODUCING T CELLS ISOLATED FROM LYMPHOCYTIC CHORIOMENINGITIS VIRUS-INFECTED MICE ALSO SHOWED ENHANCED DNA DEMETHYLATION AT ROI 3. BINDING OF STAT1 AND STAT3 TO DEMETHYLATED ROI 3 ENHANCED IL-10 EXPRESSION IN AN IL-12/IL-27-DEPENDENT MANNER. ACCORDINGLY, CD4(+) T CELLS ISOLATED FROM STAT1- OR STAT3-KNOCKOUT MICE WERE SIGNIFICANTLY DEFECTIVE IN IL-10 PRODUCTION. OUR DATA SUGGEST THAT, ALTHOUGH STABLY MAINTAINED DNA METHYLATION AT THE PROMOTER MAY REPRESS IL-10 EXPRESSION IN TH1 CELLS, LOCUS-SPECIFIC REVERSIBLE DNA DEMETHYLATION MAY SERVE AS A THRESHOLD PLATFORM TO CONTROL TRANSIENT IL-10 GENE EXPRESSION. 2018 15 6540 41 TRANSCRIPTIONAL, EPIGENETIC, AND FUNCTIONAL REPROGRAMMING OF MONOCYTES FROM NON-HUMAN PRIMATES FOLLOWING CHRONIC ALCOHOL DRINKING. CHRONIC HEAVY DRINKING (CHD) OF ALCOHOL IS A KNOWN RISK FACTOR FOR INCREASED SUSCEPTIBILITY TO BACTERIAL AND VIRAL INFECTION AS WELL AS IMPAIRED WOUND HEALING. EVIDENCE SUGGESTS THAT THESE DEFECTS ARE MEDIATED BY A DYSREGULATED INFLAMMATORY RESPONSE ORIGINATING FROM MYELOID CELLS, NOTABLY MONOCYTES AND MACROPHAGES, BUT THE MECHANISMS REMAIN POORLY UNDERSTOOD. OUR ABILITY TO STUDY CHD IS IMPACTED BY THE COMPLEXITIES OF HUMAN DRINKING PATTERNS AND BEHAVIOR AS WELL AS COMORBIDITIES AND CONFOUNDING RISK FACTORS FOR PATIENTS WITH ALCOHOL USE DISORDERS. TO OVERCOME THESE CHALLENGES, WE UTILIZED A TRANSLATIONAL RHESUS MACAQUE MODEL OF VOLUNTARY ETHANOL SELF-ADMINISTRATION THAT CLOSELY RECAPITULATES HUMAN DRINKING PATTERNS AND CHRONICITY. IN THIS STUDY, WE EXAMINED THE EFFECTS OF CHD ON BLOOD MONOCYTES IN CONTROL AND CHD FEMALE MACAQUES AFTER 12 MONTHS OF DAILY ETHANOL CONSUMPTION. WHILE MONOCYTES FROM CHD FEMALE MACAQUES GENERATED A HYPER-INFLAMMATORY RESPONSE TO EX VIVO LPS STIMULATION, THEIR RESPONSE TO E. COLI WAS DAMPENED. IN DEPTH SCRNA-SEQ ANALYSIS OF PURIFIED MONOCYTES REVEALED SIGNIFICANT SHIFTS IN CLASSICAL MONOCYTE SUBSETS WITH ACCUMULATION OF CELLS EXPRESSING MARKERS OF HYPOXIA (HIF1A) AND INFLAMMATION (NFKB SIGNALING PATHWAY) IN CHD MACAQUES. THE INCREASED PRESENCE OF MONOCYTE SUBSETS SKEWED TOWARDS INFLAMMATORY PHENOTYPES WAS COMPLEMENTED BY EPIGENETIC ANALYSIS, WHICH REVEALED HIGHER ACCESSIBILITY OF PROMOTER REGIONS THAT REGULATE GENES INVOLVED IN CYTOKINE SIGNALING PATHWAYS. COLLECTIVELY, DATA PRESENTED IN THIS MANUSCRIPT DEMONSTRATE THAT CHD SHIFTS CLASSICAL MONOCYTE SUBSET COMPOSITION AND PRIMES THE MONOCYTES TOWARDS A MORE HYPER-INFLAMMATORY RESPONSE TO LPS, BUT COMPROMISED PATHOGEN RESPONSE. 2021 16 1905 36 ENHANCER OF ZESTE HOMOLOG 2 CONTRIBUTES TO APOPTOSIS BY INACTIVATING JANUS KINASE 2/ SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION SIGNALING IN INFLAMMATORY BOWEL DISEASE. BACKGROUND: INFLAMMATORY BOWEL DISEASE (IBD) IS A PREVALENT WORLDWIDE HEALTH PROBLEM FEATURED BY RELAPSING, CHRONIC GASTROINTESTINAL INFLAMMATION. ENHANCER OF ZESTE HOMOLOG 2 (EZH2) IS A CRITICAL EPIGENETIC REGULATOR IN DIFFERENT PATHOLOGICAL MODELS, SUCH AS CANCER AND INFLAMMATION. HOWEVER, THE ROLE OF EZH2 IN THE IBD DEVELOPMENT IS STILL OBSCURE. AIM: TO EXPLORE THE EFFECT OF EZH2 ON IBD PROGRESSION AND THE UNDERLYING MECHANISM. METHODS: THE IBD MOUSE MODEL WAS CONDUCTED BY ADDING DEXTRAN SODIUM SULFATE (DSS), AND THE EFFECT OF EZH2 ON DSS-INDUCED COLITIS WAS ASSESSED IN THE MODEL. THE FUNCTION OF EZH2 IN REGULATING APOPTOSIS AND PERMEABILITY WAS EVALUATED BY ANNEXIN V-FITC APOPTOSIS DETECTION KIT, TRANSEPITHELIAL ELECTRICAL RESISTANCE ANALYSIS, AND WESTERN BLOT ANALYSIS OF RELATED MARKERS, INCLUDING ZONA OCCLUDENS 1, CLAUDIN-5, AND OCCLUDIN, IN NCM460 AND FETAL HUMAN COLON (FHC) CELLS. THE MECHANICAL INVESTIGATION WAS PERFORMED BY QUANTITATIVE REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION, WESTERN BLOT ANALYSIS, AND CHROMATIN IMMUNOPRECIPITATION ASSAYS. RESULTS: THE COLON LENGTH WAS INHIBITED IN THE DSS-TREATED MICE AND WAS ENHANCED BY THE EZH2 DEPLETION IN THE SYSTEM. DSS TREATMENT CAUSED A DECREASED HISTOLOGICAL SCORE IN THE MICE, WHICH WAS REVERSED BY EZH2 DEPLETION. THE INFLAMMATORY CYTOKINES, SUCH AS TUMOR NECROSIS FACTOR-ALPHA, INTERLEUKIN-6, AND INTERLEUKIN-1BETA, WERE INDUCED IN THE DSS-TREATED MICE, IN WHICH THE DEPLETION OF EZH2 COULD REVERSE THIS EFFECT. MOREOVER, THE TUMOR NECROSIS FACTOR-ALPHA TREATMENT INDUCED THE APOPTOSIS OF NCM460 AND FHC CELLS, IN WHICH EZH2 DEPLETION COULD REVERSE THIS EFFECT IN THE CELLS. MOREOVER, THE DEPLETION OF EZH2 ATTENUATED PERMEABILITY OF COLONIC EPITHELIAL CELLS. MECHANICALLY, THE DEPLETION OF EZH2 OR EZH2 INHIBITOR GSK343 WAS ABLE TO ENHANCE THE EXPRESSION AND THE PHOSPHORYLATION OF JANUS KINASE 2 (JK2) AND SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION IN THE NCM460 AND FHC CELLS. SPECIFICALLY, EZH2 INACTIVATED JAK2 EXPRESSION BY REGULATING HISTONE H3K27ME3. JAK2 INHIBITOR TG101348 WAS ABLE TO REVERSE EZH2 KNOCKDOWN-MEDIATED COLONIC EPITHELIAL CELL PERMEABILITY AND APOPTOSIS. CONCLUSION: THUS, WE CONCLUDED THAT EZH2 CONTRIBUTED TO APOPTOSIS AND INFLAMMATORY RESPONSE BY INACTIVATING JAK2/ SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION SIGNALING IN IBD. EZH2 MAY BE APPLIED AS A POTENTIAL TARGET FOR IBD THERAPY. 2021 17 3759 36 INTEGRATED SINGLE CELL ANALYSIS SHOWS CHRONIC ALCOHOL DRINKING DISRUPTS MONOCYTE DIFFERENTIATION IN THE BONE MARROW NICHE. CHRONIC ALCOHOL DRINKING REWIRES CIRCULATING MONOCYTES AND TISSUE-RESIDENT MACROPHAGES TOWARDS HEIGHTENED INFLAMMATORY STATES WITH COMPROMISED ANTI-MICROBIAL DEFENSES. AS THESE EFFECTS REMAIN CONSISTENT IN SHORT-LIVED MONOCYTES AFTER A 1-MONTH ABSTINENCE PERIOD IT IS UNCLEAR WHETHER THESE CHANGES ARE RESTRICTED TO THE PERIPHERY OR MEDIATED THROUGH ALTERATIONS IN THE PROGENITOR NICHE. TO TEST THIS HYPOTHESIS, WE PROFILED MONOCYTES/MACROPHAGES AND HEMATOPOIETIC STEM CELL PROGENITORS (HSCP) OF THE BONE MARROW COMPARTMENT FROM RHESUS MACAQUES AFTER 12 MONTHS OF ETHANOL CONSUMPTION USING A COMBINATION OF FUNCTIONAL ASSAYS AND SINGLE CELL GENOMICS. BONE MARROW-RESIDENT MONOCYTES/MACROPHAGES FROM ETHANOL-CONSUMING ANIMALS EXHIBITED HEIGHTENED INFLAMMATION. DIFFERENTIATION OF HSCP IN VITRO REVEALED SKEWING TOWARDS MONOCYTES EXPRESSING NEUTROPHIL-LIKE MARKERS WITH HEIGHTENED INFLAMMATORY RESPONSES TO BACTERIAL AGONISTS. SINGLE CELL TRANSCRIPTIONAL ANALYSIS OF HSCPS SHOWED REDUCED PROLIFERATION BUT INCREASED INFLAMMATORY MARKERS IN MATURE MYELOID PROGENITORS. WE OBSERVED TRANSCRIPTIONAL SIGNATURES ASSOCIATED WITH INCREASED OXIDATIVE AND CELLULAR STRESS AS WELL AS OXIDATIVE PHOSPHORYLATION IN IMMATURE AND MATURE MYELOID PROGENITORS. SINGLE CELL ANALYSIS OF THE CHROMATIN LANDSCAPE SHOWED ALTERED DRIVERS OF DIFFERENTIATION IN MONOCYTES AND PROGENITORS. COLLECTIVELY, THESE DATA INDICATE THAT CHRONIC ETHANOL DRINKING RESULTS IN REMODELING OF THE TRANSCRIPTIONAL AND EPIGENETIC LANDSCAPES OF THE BONE MARROW COMPARTMENT LEADING TO ALTERED FUNCTIONS IN THE PERIPHERY. 2023 18 2185 36 EPIGENETIC MECHANISMS UNDERLYING HIV-INFECTION INDUCED SUSCEPTIBILITY OF CD4+ T CELLS TO ENHANCED ACTIVATION-INDUCED FASL EXPRESSION AND CELL DEATH. BACKGROUND: CHRONIC IMMUNE ACTIVATION AND CD4 T CELL DEPLETION ARE SIGNIFICANT PATHOGENIC FEATURES OF HIV INFECTION. EXPRESSION OF FAS LIGAND (FASL), A KEY MEDIATOR OF ACTIVATION-INDUCED CELL DEATH IN T CELLS, IS ELEVATED IN PEOPLE LIVING WITH HIV-1 INFECTION (PLWH). HOWEVER, THE EPIGENETIC MECHANISMS UNDERLYING THE ENHANCED INDUCTION OF FASL EXPRESSION IN CD4 T LYMPHOCYTES IN PLWH ARE NOT COMPLETELY ELUCIDATED. HENCE, THE CURRENT WORK EXAMINED THE EFFECT OF HIV INFECTION ON FASL PROMOTER-ASSOCIATED HISTONE MODIFICATIONS AND TRANSCRIPTIONAL REGULATION IN CD4 T LYMPHOCYTES IN PLWH. METHOD: FLOW CYTOMETRIC ANALYSIS WAS PERFORMED TO EXAMINE THE FAS-FASL EXPRESSION ON TOTAL CD4 T CELLS AND NAIVE/MEMORY CD4 T CELL SUBSETS. EPIGENETIC FASL PROMOTER HISTONE MODIFICATIONS WERE INVESTIGATED BY CHROMATIN IMMUNOPRECIPITATION-QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION ANALYSIS USING FRESHLY ISOLATED TOTAL CD4 T LYMPHOCYTES FROM HIV-1 INFECTED AND NONINFECTED INDIVIDUALS. RESULTS: ALL NAIVE/MEMORY CD4 T CELL SUBSETS FROM PLWH SHOWED MARKEDLY GREATER FREQUENCY OF FASL EXPRESSION. NOTABLY, EXAMINATION OF FUNCTIONAL OUTCOME OF FASL/FAS CO-EXPRESSION DEMONSTRATED THE PREFERENTIAL SUSCEPTIBILITY OF TCM AND TEM SUBSETS TO ACTIVATION-INDUCED APOPTOSIS. IMPORTANTLY, THESE CD4 T CELLS COLLECTIVELY DEMONSTRATED A DISTINCT FASL PROMOTER HISTONE PROFILE INVOLVING A COORDINATED CROSS-TALK BETWEEN HISTONE H3 MODIFICATIONS LEADING TO ENHANCED FASL GENE EXPRESSION. SPECIFICALLY, LEVELS OF TRANSCRIPTIONALLY PERMISSIVE HISTONE H3K4-TRIMETHYLATION (H3K4ME3) AND HISTONE H3K9-ACETYLATION (H3K9AC) WERE INCREASED, WITH A CONCOMITANT DECREASE IN THE REPRESSIVE H3K9-TRIMETHYLATION (H3K9ME3). CONCLUSION: THE PRESENT WORK DEMONSTRATES THAT EPIGENETIC MECHANISMS INVOLVING PROMOTER-HISTONE MODIFICATIONS REGULATE TRANSCRIPTIONAL COMPETENCE AND FASL EXPRESSION IN CD4 T CELLS FROM PLWH AND RENDER THEM SUSCEPTIBLE TO ACTIVATION-INDUCED CELL DEATH. 2021 19 5868 34 SUPPRESSIVE EFFECTS OF METFORMIN ON T-HELPER 1-RELATED CHEMOKINES EXPRESSION IN THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1. PURPOSE OF THE STUDY: TYPE 1 AND TYPE 2 DIABETES MELLITUS (DM) ARE CHRONIC T-CELL-MEDIATED INFLAMMATORY DISEASES. METFORMIN IS A WIDELY USED DRUG FOR TYPE 2 DM THAT REDUCES THE NEED FOR INSULIN IN TYPE 1 DM. HOWEVER, WHETHER METFORMIN HAS AN ANTI-INFLAMMATORY EFFECT FOR TREATING DM IS UNKNOWN. WE INVESTIGATED THE ANTI-INFLAMMATORY MECHANISM OF METFORMIN IN THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1. MATERIALS AND METHODS: THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1 WAS PRETREATED WITH METFORMIN AND STIMULATED WITH LIPOPOLYSACCHARIDE (LPS). THE PRODUCTION OF T-HELPER (TH)-1-RELATED CHEMOKINES INCLUDING INTERFERON-GAMMA-INDUCED PROTEIN-10 (IP-10) AND MONOCYTE CHEMOATTRACTANT PROTEIN-1 (MCP-1), TH2-RELATED CHEMOKINE MACROPHAGE-DERIVED CHEMOKINE, AND THE PROINFLAMMATORY CHEMOKINE TUMOR NECROSIS FACTOR-ALPHA WAS MEASURED USING ENZYME-LINKED IMMUNOSORBENT ASSAY. INTRACELLULAR SIGNALING PATHWAYS WERE INVESTIGATED USING WESTERN BLOT ANALYSIS AND CHROMATIN IMMUNOPRECIPITATION ASSAY. RESULTS: METFORMIN SUPPRESSED LPS-INDUCED IP-10 AND MCP-1 PRODUCTION AS WELL AS LPS-INDUCED PHOSPHORYLATION OF C-JUN N-TERMINAL KINASE (JNK), P38, EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK), AND NUCLEAR FACTOR-KAPPA B (NF-KAPPAB). MOREOVER, METFORMIN SUPPRESSED LPS-INDUCED ACETYLATION OF HISTONES H3 AND H4 AT THE IP-10 PROMOTER. CONCLUSIONS: METFORMIN SUPPRESSED THE PRODUCTION OF TH1-RELATED CHEMOKINES IP-10 AND MCP-1 IN THP-1 CELLS. SUPPRESSIVE EFFECTS OF METFORMIN ON IP-10 PRODUCTION MIGHT BE ATTRIBUTED AT LEAST PARTIALLY TO THE JNK, P38, ERK, AND NF-KAPPAB PATHWAYS AS WELL AS TO EPIGENETIC REGULATION THROUGH THE ACETYLATION OF HISTONES H3 AND H4. THESE RESULTS INDICATED THE THERAPEUTIC ANTI-INFLAMMATORY POTENTIAL OF METFORMIN. 2018 20 3323 40 HISTONE DEACETYLASE 1 (HDAC1): A KEY PLAYER OF T CELL-MEDIATED ARTHRITIS. RHEUMATOID ARTHRITIS (RA) REPRESENTS A CHRONIC T CELL-MEDIATED INFLAMMATORY AUTOIMMUNE DISEASE. STUDIES HAVE SHOWN THAT EPIGENETIC MECHANISMS CONTRIBUTE TO THE PATHOGENESIS OF RA. HISTONE DEACETYLASES (HDACS) REPRESENT ONE IMPORTANT GROUP OF EPIGENETIC REGULATORS. HOWEVER, THE ROLE OF INDIVIDUAL HDAC MEMBERS FOR THE PATHOGENESIS OF ARTHRITIS IS STILL UNKNOWN. IN THIS STUDY WE DEMONSTRATE THAT MICE WITH A T CELL-SPECIFIC DELETION OF HDAC1 (HDAC1-CKO) ARE RESISTANT TO THE DEVELOPMENT OF COLLAGEN-INDUCED ARTHRITIS (CIA), WHEREAS THE ANTIBODY RESPONSE TO COLLAGEN TYPE II WAS UNDISTURBED, INDICATING AN UNALTERED T CELL-MEDIATED B CELL ACTIVATION. THE INFLAMMATORY CYTOKINES IL-17 AND IL-6 WERE SIGNIFICANTLY DECREASED IN SERA OF HDAC1-CKO MICE. IL-6 TREATED HDAC1-DEFICIENT CD4(+) T CELLS SHOWED AN IMPAIRED UPREGULATION OF CCR6. SELECTIVE INHIBITION OF CLASS I HDACS WITH THE HDAC INHIBITOR MS-275 UNDER TH17-SKEWING CONDITIONS INHIBITED THE UPREGULATION OF CHEMOKINE RECEPTOR 6 (CCR6) IN MOUSE AND HUMAN CD4(+) T CELLS. ACCORDINGLY, ANALYSIS OF HUMAN RNA-SEQUENCING (RNA-SEQ) DATA AND HISTOLOGICAL ANALYSIS OF SYNOVIAL TISSUE SAMPLES FROM HUMAN RA PATIENTS REVEALED THE EXISTENCE OF CD4(+)CCR6(+) CELLS WITH ENHANCED HDAC1 EXPRESSION. OUR DATA INDICATE A KEY ROLE FOR HDAC1 FOR THE PATHOGENESIS OF CIA AND SUGGEST THAT HDAC1 AND OTHER CLASS I HDACS MIGHT BE PROMISING TARGETS OF SELECTIVE HDAC INHIBITORS (HDACI) FOR THE TREATMENT OF RA. 2020