1 1806 184 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 2 1334 30 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 3 3390 32 HOPX PLAYS A CRITICAL ROLE IN ANTIRETROVIRAL DRUGS INDUCED EPIGENETIC MODIFICATION AND CARDIAC HYPERTROPHY. PEOPLE LIVING WITH HIV (PLWH) HAVE TO TAKE AN ANTIRETROVIRAL THERAPY (ART) FOR LIFE AND SHOW NONCOMMUNICABLE ILLNESSES SUCH AS CHRONIC INFLAMMATION, IMMUNE ACTIVATION, AND MULTIORGAN DYSREGULATION. RECENT STUDIES SUGGEST THAT LONG-TERM USE OF ART INDUCES COMORBID CONDITIONS AND IS ONE OF THE LEADING CAUSES OF HEART FAILURE IN PLWH. HOWEVER, THE MOLECULAR MECHANISM OF ANTIRETROVIRAL DRUGS (ARVS) INDUCED HEART FAILURE IS UNCLEAR. TO DETERMINE THE MECHANISM OF ARVS INDUCED CARDIAC DYSFUNCTION, WE PERFORMED GLOBAL TRANSCRIPTOMIC PROFILING OF ARVS TREATED NEONATAL RAT VENTRICULAR CARDIOMYOCYTES IN CULTURE. DIFFERENTIALLY EXPRESSED GENES WERE IDENTIFIED BY RNA-SEQUENCING. OUR DATA SHOW THAT ARVS TREATMENT CAUSES UPREGULATION OF SEVERAL BIOLOGICAL FUNCTIONS ASSOCIATED WITH CARDIOTOXICITY, HYPERTROPHY, AND HEART FAILURE. GLOBAL GENE EXPRESSION DATA WERE VALIDATED IN CARDIAC TISSUE ISOLATED FROM HIV PATIENTS HAVING A HISTORY OF ART. INTERESTINGLY, WE FOUND THAT HOMEODOMAIN-ONLY PROTEIN HOMEOBOX (HOPX) EXPRESSION WAS SIGNIFICANTLY INCREASED IN CARDIOMYOCYTES TREATED WITH ARVS AND IN THE HEART TISSUE OF HIV PATIENTS. FURTHERMORE, WE FOUND THAT HOPX PLAYS A CRUCIAL ROLE IN ARVS MEDIATED CELLULAR HYPERTROPHY. MECHANISTICALLY, WE FOUND THAT HOPX PLAYS A CRITICAL ROLE IN EPIGENETIC REGULATION, THROUGH DEACETYLATION OF HISTONE, WHILE THE HDAC INHIBITOR, TRICHOSTATIN A, CAN RESTORE THE ACETYLATION LEVEL OF HISTONE 3 IN THE PRESENCE OF ARVS. 2021 4 3049 23 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 3128 39 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 6 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 7 2763 33 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 8 35 30 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 6659 32 UPREGULATION OF AKT3 CONFERS RESISTANCE TO THE AKT INHIBITOR MK2206 IN BREAST CANCER. ACQUIRED RESISTANCE TO MOLECULAR TARGETED THERAPY REPRESENTS A MAJOR CHALLENGE FOR THE EFFECTIVE TREATMENT OF CANCER. HYPERACTIVATION OF THE PI3K/AKT PATHWAY IS FREQUENTLY OBSERVED IN VIRTUALLY ALL HUMAN MALIGNANCIES, AND NUMEROUS PI3K AND AKT INHIBITORS ARE CURRENTLY UNDER CLINICAL EVALUATION. HOWEVER, MECHANISMS OF ACQUIRED RESISTANCE TO AKT INHIBITORS HAVE YET TO BE DESCRIBED. HERE, WE USE A BREAST CANCER PRECLINICAL MODEL TO IDENTIFY RESISTANCE MECHANISMS TO A SMALL MOLECULE ALLOSTERIC AKT INHIBITOR, MK2206. USING A STEP-WISE AND CHRONIC HIGH-DOSE EXPOSURE, BREAST CANCER CELL LINES HARBORING ONCOGENIC PI3K RESISTANT TO MK2206 WERE ESTABLISHED. USING THIS MODEL, WE REVEAL THAT AKT3 EXPRESSION IS MARKEDLY UPREGULATED IN AKT INHIBITOR-RESISTANT CELLS. INDUCTION OF AKT3 IS REGULATED EPIGENETICALLY BY THE BROMODOMAIN AND EXTRA TERMINAL DOMAIN PROTEINS. IMPORTANTLY, KNOCKDOWN OF AKT3, BUT NOT AKT1 OR AKT2, IN RESISTANT CELLS RESTORES SENSITIVITY TO MK2206. AKT INHIBITOR-RESISTANT CELLS ALSO DISPLAY AN EPITHELIAL TO MESENCHYMAL TRANSITION PHENOTYPE AS ASSESSED BY ALTERATIONS IN THE LEVELS OF E-CADHERIN, N-CADHERIN, AND VIMENTIN, AS WELL AS ENHANCED INVASIVENESS OF TUMOR SPHEROIDS. NOTABLY, THE INVASIVE MORPHOLOGY OF RESISTANT SPHEROIDS IS DIMINISHED UPON AKT3 DEPLETION. WE ALSO SHOW THAT RESISTANCE TO MK2206 IS REVERSIBLE BECAUSE UPON DRUG REMOVAL RESISTANT CELLS REGAIN SENSITIVITY TO AKT INHIBITION, ACCOMPANIED BY REEXPRESSION OF EPITHELIAL MARKERS AND REDUCTION OF AKT3 EXPRESSION, IMPLYING THAT EPIGENETIC REPROGRAMMING CONTRIBUTES TO ACQUISITION OF RESISTANCE. THESE FINDINGS PROVIDE A RATIONALE FOR DEVELOPING THERAPEUTICS TARGETING AKT3 TO CIRCUMVENT ACQUIRED RESISTANCE IN BREAST CANCER. MOL CANCER THER; 15(8); 1964-74. (C)2016 AACR. 2016 10 1121 32 COMPARISON OF EPIGENETIC PROFILES OF HUMAN ORAL EPITHELIAL CELLS FROM HIV-POSITIVE (ON HAART) AND HIV-NEGATIVE SUBJECTS. HIV-INFECTED SUBJECTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) ARE SUSCEPTIBLE TO COMORBID MICROBIAL INFECTIONS IN THE ORAL CAVITY. WE OBSERVED THAT PRIMARY ORAL EPITHELIAL CELLS (POECS) ISOLATED FROM HIV+ SUBJECTS ON HAART GROW MORE SLOWLY AND ARE LESS INNATE IMMUNE RESPONSIVE TO MICROBIAL CHALLENGE WHEN COMPARED WITH POECS FROM NORMAL SUBJECTS. THESE ABERRANT CELLS ALSO DEMONSTRATE EPIGENETIC DIFFERENCES THAT INCLUDE REDUCTION IN HISTONE DEACETYLASE 1 (HDAC-1) LEVELS AND REDUCED TOTAL DNA METHYLTRANSFERASE (DNMT) ACTIVITY SPECIFIC TO ENZYMES DNMT1 AND DNMT3A. THE DNMT ACTIVITY CORRELATES WELL WITH GLOBAL DNA METHYLATION, INDICATING THAT ABERRANT DNMT ACTIVITY IN HIV+ (ON HAART) POECS LEADS TO AN ABERRANTLY METHYLATED EPITHELIAL CELL PHENOTYPE. OVERALL, OUR RESULTS LEAD US TO HYPOTHESIZE THAT, IN PATIENTS WITH CHRONIC HIV INFECTION ON HAART, EPIGENETIC CHANGES IN KEY GENES RESULT IN INCREASED VULNERABILITY TO MICROBIAL INFECTION IN THE ORAL CAVITY. 2013 11 1668 42 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 12 5636 44 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 13 5153 31 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 14 984 30 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 15 5788 28 SREBP1 DRIVES KERATIN-80-DEPENDENT CYTOSKELETAL CHANGES AND INVASIVE BEHAVIOR IN ENDOCRINE-RESISTANT ERALPHA BREAST CANCER. APPROXIMATELY 30% OF ERALPHA BREAST CANCER PATIENTS RELAPSE WITH METASTATIC DISEASE FOLLOWING ADJUVANT ENDOCRINE THERAPIES. THE CONNECTION BETWEEN ACQUISITION OF DRUG RESISTANCE AND INVASIVE POTENTIAL IS POORLY UNDERSTOOD. IN THIS STUDY, WE DEMONSTRATE THAT THE TYPE II KERATIN TOPOLOGICAL ASSOCIATING DOMAIN UNDERGOES EPIGENETIC REPROGRAMMING IN AROMATASE INHIBITORS (AI)-RESISTANT CELLS, LEADING TO KERATIN-80 (KRT80) UPREGULATION. KRT80 EXPRESSION IS DRIVEN BY DE NOVO ENHANCER ACTIVATION BY STEROL REGULATORY ELEMENT-BINDING PROTEIN 1 (SREBP1). KRT80 UPREGULATION DIRECTLY PROMOTES CYTOSKELETAL REARRANGEMENTS AT THE LEADING EDGE, INCREASED FOCAL ADHESION AND CELLULAR STIFFENING, COLLECTIVELY PROMOTING CANCER CELL INVASION. SHEARWAVE ELASTICITY IMAGING PERFORMED ON PROSPECTIVELY RECRUITED PATIENTS CONFIRMS KRT80 LEVELS CORRELATE WITH STIFFER TUMORS. IMMUNOHISTOCHEMISTRY SHOWED INCREASED KRT80-POSITIVE CELLS AT RELAPSE AND, USING SEVERAL CLINICAL ENDPOINTS, KRT80 EXPRESSION ASSOCIATES WITH POOR SURVIVAL. COLLECTIVELY, OUR DATA UNCOVER AN UNPREDICTED AND POTENTIALLY TARGETABLE DIRECT LINK BETWEEN EPIGENETIC AND CYTOSKELETAL REPROGRAMMING PROMOTING CELL INVASION IN RESPONSE TO CHRONIC AI TREATMENT. 2019 16 136 33 ABERRANT DNA HYPERMETHYLATION PATTERNS LEAD TO TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS OF MICE. OVEREXPOSURE OF THE HUMAN SKIN TO SOLAR ULTRAVIOLET (UV) RADIATION IS THE MAJOR ETIOLOGIC FACTOR FOR DEVELOPMENT OF SKIN CANCERS. HERE, WE REPORT THE RESULTS OF EPIGENETIC MODIFICATIONS IN UV-EXPOSED SKIN AND SKIN TUMORS IN A SYSTEMATIC MANNER. THE SKIN AND TUMOR SAMPLES WERE COLLECTED AFTER CHRONIC EXPOSURE OF THE SKIN OF SKH-1 HAIRLESS MICE TO UVB RADIATION USING A WELL-ESTABLISHED PHOTOCARCINOGENESIS PROTOCOL. WE FOUND A DISTINCT DNA HYPERMETHYLATION PATTERN IN THE UVB-EXPOSED EPIDERMAL SKIN AND UVB-INDUCED SKIN TUMORS THAT WAS ASSOCIATED WITH THE ELEVATED EXPRESSION AND ACTIVITY OF THE DNA METHYLTRANSFERASES (DNMT) 1, DNMT3A AND DNMT3B. TO EXPLORE THE ROLE OF HYPERMETHYLATION IN SKIN PHOTOCARCINOGENESIS, WE FOCUSED ON THE P16(INK4A) AND RASSF1A TUMOR SUPPRESSOR GENES, WHICH ARE TRANSCRIPTIONALLY SILENCED ON METHYLATION. WE ESTABLISHED THAT THE SILENCING OF THESE GENES IN UVB-EXPOSED EPIDERMIS AND UVB-INDUCED SKIN TUMORS IS ASSOCIATED WITH A NETWORK OF EPIGENETIC MODIFICATIONS, INCLUDING HYPOACETYLATION OF HISTONE H3 AND H4 AND INCREASED HISTONE DEACETYLATION, AS WELL AS RECRUITMENT OF METHYL-BINDING PROTEINS, INCLUDING MECP2 AND MBD1, TO THE METHYLATED CPGS. HIGHER LEVELS OF DNA METHYLATION AND DNMT ACTIVITY IN HUMAN SQUAMOUS CELL CARCINOMA SPECIMENS THAN IN NORMAL HUMAN SKIN SUGGEST THAT THE DATA ARE RELEVANT CLINICALLY. OUR DATA INDICATE FOR THE FIRST TIME THAT UVB-INDUCED DNA HYPERMETHYLATION, ENHANCED DNMT ACTIVITY AND HISTONE MODIFICATIONS OCCUR IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS AND SUGGEST THAT THESE EVENTS ARE INVOLVED IN THE SILENCING OF TUMOR SUPPRESSOR GENES AND IN SKIN TUMOR DEVELOPMENT. 2011 17 4696 34 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 18 669 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 19 370 39 AN APICOMPLEXAN BROMODOMAIN PROTEIN, TGBDP1, ASSOCIATES WITH DIVERSE EPIGENETIC FACTORS TO REGULATE ESSENTIAL TRANSCRIPTIONAL PROCESSES IN TOXOPLASMA GONDII. THE PROTOZOAN PATHOGEN TOXOPLASMA GONDII RELIES ON TIGHT REGULATION OF GENE EXPRESSION TO INVADE AND ESTABLISH INFECTION IN ITS HOST. THE DIVERGENT GENE REGULATORY MECHANISMS OF TOXOPLASMA AND RELATED APICOMPLEXAN PATHOGENS RELY HEAVILY ON REGULATORS OF CHROMATIN STRUCTURE AND HISTONE MODIFICATIONS. THE IMPORTANT CONTRIBUTION OF HISTONE ACETYLATION FOR TOXOPLASMA IN BOTH ACUTE AND CHRONIC INFECTION HAS BEEN DEMONSTRATED, WHERE HISTONE ACETYLATION INCREASES AT ACTIVE GENE LOCI. HOWEVER, THE DIRECT CONSEQUENCES OF SPECIFIC HISTONE ACETYLATION MARKS AND THE CHROMATIN PATHWAY THAT INFLUENCES TRANSCRIPTIONAL REGULATION IN RESPONSE TO THE MODIFICATION ARE UNCLEAR. AS A READER OF LYSINE ACETYLATION, THE BROMODOMAIN SERVES AS A MEDIATOR BETWEEN THE ACETYLATED HISTONE AND TRANSCRIPTIONAL REGULATORS. HERE WE SHOW THAT THE BROMODOMAIN PROTEIN, TGBDP1, WHICH IS CONSERVED AMONG APICOMPLEXA AND WITHIN THE ALVEOLATA SUPERPHYLUM, IS ESSENTIAL FOR TOXOPLASMA ASEXUAL PROLIFERATION. USING CLEAVAGE UNDER TARGETS AND TAGMENTATION, WE DEMONSTRATE THAT TGBDP1 IS RECRUITED TO TRANSCRIPTIONAL START SITES OF A LARGE PROPORTION OF PARASITE GENES. TRANSCRIPTIONAL PROFILING DURING TGBDP1 KNOCKDOWN REVEALED THAT LOSS OF TGBDP1 LEADS TO MAJOR DYSREGULATION OF GENE EXPRESSION, IMPLYING MULTIPLE ROLES FOR TGBDP1 IN BOTH GENE ACTIVATION AND REPRESSION. THIS IS SUPPORTED BY INTERACTOME ANALYSIS OF TGBDP1 DEMONSTRATING THAT TGBDP1 FORMS A CORE COMPLEX WITH TWO OTHER BROMODOMAIN PROTEINS AND AN APIAP2 FACTOR. THIS CORE COMPLEX APPEARS TO INTERACT WITH OTHER EPIGENETIC FACTORS SUCH AS NUCLEOSOME REMODELING COMPLEXES. WE CONCLUDE THAT TGBDP1 INTERACTS WITH DIVERSE EPIGENETIC REGULATORS TO EXERT OPPOSING INFLUENCES ON GENE EXPRESSION IN THE TOXOPLASMA TACHYZOITE. IMPORTANCE HISTONE ACETYLATION IS CRITICAL FOR PROPER REGULATION OF GENE EXPRESSION IN THE SINGLE-CELLED EUKARYOTIC PATHOGEN TOXOPLASMA GONDII. BROMODOMAIN PROTEINS ARE "READERS" OF HISTONE ACETYLATION AND MAY LINK THE MODIFIED CHROMATIN TO TRANSCRIPTION FACTORS. HERE, WE SHOW THAT THE BROMODOMAIN PROTEIN TGBDP1 IS ESSENTIAL FOR PARASITE SURVIVAL AND THAT LOSS OF TGBDP1 RESULTS IN GLOBAL DYSREGULATION OF GENE EXPRESSION. TGBDP1 IS RECRUITED TO THE PROMOTER REGION OF A LARGE PROPORTION OF PARASITE GENES, FORMS A CORE COMPLEX WITH TWO OTHER BROMODOMAIN PROTEINS, AND INTERACTS WITH DIFFERENT TRANSCRIPTIONAL REGULATORY COMPLEXES. WE CONCLUDE THAT TGBDP1 IS A KEY FACTOR FOR SENSING SPECIFIC HISTONE MODIFICATIONS TO INFLUENCE MULTIPLE FACETS OF TRANSCRIPTIONAL REGULATION IN TOXOPLASMA GONDII. 2023 20 2758 27 EXPRESSION OF HORMONAL CARCINOGENESIS GENES AND RELATED REGULATORY MICRORNAS IN UTERUS AND OVARIES OF DDT-TREATED FEMALE RATS. THE INSECTICIDE DICHLORODIPHENYLTRICHLOROETHANE (DDT) IS A NONMUTAGENIC XENOBIOTIC COMPOUND ABLE TO EXERT ESTROGEN-LIKE EFFECTS RESULTING IN ACTIVATION OF ESTROGEN RECEPTOR-ALPHA (ERALPHA) FOLLOWED BY CHANGED EXPRESSION OF ITS DOWNSTREAM TARGET GENES. IN ADDITION, STUDIES PERFORMED OVER RECENT YEARS SUGGEST THAT DDT MAY ALSO INFLUENCE EXPRESSION OF MICRORNAS. HOWEVER, AN IMPACT OF DDT ON EXPRESSION OF ER, MICRORNAS, AND RELATED TARGET GENES HAS NOT BEEN FULLY ELUCIDATED. HERE, USING REAL-TIME PCR, WE ASSESSED CHANGES IN EXPRESSION OF KEY GENES INVOLVED IN HORMONAL CARCINOGENESIS AS WELL AS POTENTIALLY RELATED REGULATORY ONCOGENIC/TUMOR SUPPRESSOR MICRORNAS AND THEIR TARGET GENES IN THE UTERUS AND OVARIES OF FEMALE WISTAR RATS DURING SINGLE AND CHRONIC MULTIPLE-DOSE DDT EXPOSURE. WE FOUND THAT APPLYING DDT RESULTS IN ALTERED EXPRESSION OF MICRORNAS-221, -222, -205, -126A, AND -429, THEIR TARGET GENES (PTEN, DICER1), AS WELL AS GENES INVOLVED IN HORMONAL CARCINOGENESIS (ESR1, PGR, CCND1, CYP19A1). NOTABLY, CYP19A1 EXPRESSION SEEMS TO BE ALSO REGULATED BY MICRORNAS-221, -222, AND -205. THE DATA SUGGEST THAT EPIGENETIC EFFECTS INDUCED BY DDT AS A POTENTIAL CARCINOGEN MAY BE BASED ON AT LEAST TWO MECHANISMS: (I) ACTIVATION OF ERALPHA FOLLOWED BY ALTERED EXPRESSION OF THE TARGET GENES ENCODING RECEPTOR PGR AND CCND1 AS WELL AS IMPAIRED EXPRESSION OF CYP19A1, AFFECTING, THEREBY, CELL HORMONE BALANCE; AND (II) CHANGED EXPRESSION OF MICRORNAS RESULTING IN IMPAIRED EXPRESSION OF RELATED TARGET GENES INCLUDING REDUCED LEVEL OF CYP19A1 MRNA. 2017