1 1620 116 DNA METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL SILENCING IN MALIGNANT GLIOMA: A COMBINED WHOLE-GENOME MICROARRAY AND PROMOTER ARRAY ANALYSIS. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS A COMMON FEATURE IN HUMAN CANCER. PROMOTER HYPERMETHYLATION AND HISTONE DEACETYLATION ARE REVERSIBLE EPIGENETIC MECHANISMS ASSOCIATED WITH TRANSCRIPTIONAL REGULATION. DNA METHYLTRANSFERASES (DNMT1 AND DNMT3B) REGULATE AND MAINTAIN PROMOTER METHYLATION AND ARE OVEREXPRESSED IN HUMAN CANCER. WE PERFORMED WHOLE-GENOME MICROARRAY ANALYSIS TO IDENTIFY GENES WITH ALTERED EXPRESSION AFTER RNAI-INDUCED SUPPRESSION OF DNMT IN A GLIOBLASTOMA MULTIFORME (GBM) CELL LINE. WE THEN IDENTIFIED GENES WITH BOTH DECREASED EXPRESSION AND EVIDENCE OF PROMOTER CPG ISLAND HYPERMETHYLATION IN GBM TISSUE SAMPLES USING A COMBINED WHOLE-GENOME MICROARRAY TRANSCRIPTOME ANALYSIS IN CONJUNCTION WITH A PROMOTER ARRAY ANALYSIS AFTER DNA IMMUNOPRECIPITATION WITH ANTI-5-METHYLCYTIDINE. DNMT1 AND 3B KNOCKDOWN RESULTED IN THE RESTORED EXPRESSION OF 308 GENES THAT ALSO CONTAINED PROMOTER REGION HYPERMETHYLATION. OF THESE, 43 WERE ALSO FOUND TO BE DOWNREGULATED IN GBM TISSUE SAMPLES. THREE DOWNREGULATED GENES WITH HYPERMETHYLATED PROMOTERS AND RESTORED EXPRESSION IN RESPONSE TO ACUTE DNMT SUPPRESSION WERE ASSAYED FOR METHYLATION CHANGES USING BISULFITE SEQUENCE ANALYSIS OF THE PROMOTER REGION AFTER CHRONIC DNMT SUPPRESSION. RESTORATION OF GENE EXPRESSION WAS NOT ASSOCIATED WITH CHANGES IN PROMOTER REGION METHYLATION, BUT RATHER WITH CHANGES IN HISTONE METHYLATION AND CHROMATIN CONFORMATION. TWO OF THE IDENTIFIED GENES EXHIBITED GROWTH SUPPRESSIVE ACTIVITY IN IN VITRO ASSAYS. COMBINING TARGETED GENETIC MANIPULATIONS WITH COMPREHENSIVE GENOMIC AND EXPRESSION ANALYSES PROVIDES A POTENTIALLY POWERFUL NEW APPROACH FOR IDENTIFYING EPIGENETICALLY REGULATED GENES IN GBM. 2009 2 3323 29 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 3 4309 33 MICRORNAS 29B AND 181A DOWN-REGULATE THE EXPRESSION OF THE NOREPINEPHRINE TRANSPORTER AND GLUCOCORTICOID RECEPTORS IN PC12 CELLS. MICRORNAS ARE SHORT NON-CODING RNAS THAT PROVIDE GLOBAL REGULATION OF GENE EXPRESSION AT THE POST-TRANSCRIPTIONAL LEVEL. SUCH REGULATION HAS BEEN FOUND TO PLAY A ROLE IN STRESS-INDUCED EPIGENETIC RESPONSES IN THE BRAIN. THE NOREPINEPHRINE TRANSPORTER (NET) AND GLUCOCORTICOID RECEPTORS ARE CLOSELY RELATED TO THE HOMEOSTATIC INTEGRATION AND REGULATION AFTER STRESS. OUR PREVIOUS STUDIES DEMONSTRATED THAT NET MRNA AND PROTEIN LEVELS IN RATS ARE REGULATED BY CHRONIC STRESS AND BY ADMINISTRATION OF CORTICOSTERONE, WHICH IS MEDIATED THROUGH GLUCOCORTICOID RECEPTORS. WHETHER MIRNAS ARE INTERMEDIARIES IN THE REGULATION OF THESE PROTEINS REMAINS TO BE ELUCIDATED. THIS STUDY WAS UNDERTAKEN TO DETERMINE POSSIBLE REGULATORY EFFECTS OF MIRNAS ON THE EXPRESSION OF NET AND GLUCOCORTICOID RECEPTORS IN THE NORADRENERGIC NEURONAL CELL LINE. USING COMPUTATIONAL TARGET PREDICTION, WE IDENTIFIED SEVERAL CANDIDATE MIRNAS POTENTIALLY TARGETING NET AND GLUCOCORTICOID RECEPTORS. WESTERN BLOT RESULTS SHOWED THAT OVER-EXPRESSION OF MIR-181A AND MIR-29B SIGNIFICANTLY REPRESSED PROTEIN LEVELS OF NET, WHICH IS ACCOMPANIED BY A REDUCED [(3) H] NOREPINEPHRINE UPTAKE, AND GLUCOCORTICOID RECEPTORS IN PC12 CELLS. LUCIFERASE REPORTER ASSAYS VERIFIED THAT BOTH MIR-181A AND MIR-29B BIND THE 3'UTR OF MRNA OF NET AND GLUCOCORTICOID RECEPTORS. FURTHERMORE, EXPOSURE OF PC12 CELLS TO CORTICOSTERONE MARKEDLY REDUCED THE ENDOGENOUS LEVELS OF MIR-29B, WHICH WAS NOT REVERSED BY THE APPLICATION OF GLUCOCORTICOID RECEPTOR ANTAGONIST MIFEPRISTONE. THESE OBSERVATIONS INDICATE THAT MIR-181A AND MIR-29B CAN FUNCTION AS THE NEGATIVE REGULATORS OF NET AND GLUCOCORTICOID RECEPTOR TRANSLATION IN VITRO. THIS REGULATORY EFFECT MAY BE RELATED TO STRESS-INDUCED UP-REGULATION OF THE NORADRENERGIC PHENOTYPE, A PHENOMENON OBSERVED IN STRESS MODELS AND DEPRESSIVE PATIENTS. THIS STUDY DEMONSTRATED THAT MIR-29B AND MIR-181A, TWO SHORT NON-CODING RNAS THAT PROVIDE GLOBAL REGULATION OF GENE EXPRESSION, MARKEDLY REPRESSED PROTEIN LEVELS OF NOREPINEPHRINE (NE) TRANSPORTER AND GLUCOCORTICOID RECEPTOR (GR), AS WELL AS NE UPTAKE BY BINDING THE 3'UTR OF THEIR MRNAS IN PC12 CELLS. ALSO, EXPOSURE OF CELLS TO CORTICOSTERONE SIGNIFICANTLY REDUCED MIR-29B LEVELS THROUGH A GR-INDEPENDENT WAY. 2016 4 1632 32 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 5 6069 37 THE DIOXIN RECEPTOR IS SILENCED BY PROMOTER HYPERMETHYLATION IN HUMAN ACUTE LYMPHOBLASTIC LEUKEMIA THROUGH INHIBITION OF SP1 BINDING. THE TRANSCRIPTION FACTOR ARYL HYDROCARBON RECEPTOR (AHR) HAS RELEVANT FUNCTIONS IN CELL PROLIFERATION. INTERESTINGLY, THE AHR CAN EITHER PROMOTE OR INHIBIT PROLIFERATION DEPENDING ON THE CELL PHENOTYPE. ALTHOUGH RECENT DATA REVEAL POTENTIAL PATHWAYS FOR AHR SIGNALING IN CELL PROLIFERATION, THE MECHANISMS THAT REGULATE ITS ACTIVITY IN TUMOR CELLS REMAIN UNKNOWN. HERE, WE HAVE ANALYZED PROMOTER HYPERMETHYLATION AS A POTENTIAL MECHANISM CONTROLLING AHR EXPRESSION IN HUMAN TUMOR CELLS. AHR PROMOTER CPG METHYLATION WAS SPORADIC IN A PANEL OF 19 TUMOR CELL LINES EXCEPT FOR THE CHRONIC MYELOID LEUKEMIA (CML) K562 AND THE ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) REH. WHEN COMPARED WITH NORMAL LYMPHOCYTES, REH HAD VERY LOW CONSTITUTIVE AHR EXPRESSION THAT COULD BE ATTRIBUTED TO PROMOTER HYPERMETHYLATION SINCE TREATMENT WITH THE DNA DEMETHYLATING AGENT 5-AZA-2'-DEOXYCITIDINE (AZA) SIGNIFICANTLY INCREASED AHR MRNA AND PROTEIN. THESE RESULTS IN LEUKEMIA-DERIVED CELL LINES WERE FURTHER CONFIRMED IN PRIMARY ALL, WHERE 33% OF THE PATIENTS (7/21) HAD AHR PROMOTER HYPERMETHYLATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) SHOWED THAT METHYLATION IMPAIRED BINDING OF THE TRANSCRIPTION FACTOR SP1 TO THE AHR PROMOTER, THUS PROVIDING A MECHANISM FOR AHR DOWNREGULATION IN REH CELLS. THEREFORE, PROMOTER HYPERMETHYLATION REPRESENTS A NOVEL EPIGENETIC MECHANISM DOWNREGULATING AHR ACTIVITY IN HEMATOLOGICAL MALIGNANCIES SUCH AS ALL. 2006 6 6660 39 UPREGULATION OF CXCR4 THROUGH PROMOTER DEMETHYLATION CONTRIBUTES TO INFLAMMATORY HYPERALGESIA IN RATS. AIM AND METHODS: CHRONIC PAIN ASSOCIATED WITH INFLAMMATION IS A COMMON CLINICAL PROBLEM, AND THE UNDERLYING MECHANISMS YET ARE INCOMPLETELY DEFINED. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER INFLAMMATORY PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE, WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR4 EXPRESSION IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO INFLAMMATORY PAIN INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA) IN RATS. RESULTS: INTRAPLANTAR INJECTION OF CFA COULD NOT ONLY INDUCE SIGNIFICANT HYPERALGESIA IN RATS, BUT ALSO SIGNIFICANTLY INCREASE THE EXPRESSION OF CXCR4 MRNA AND PROTEIN IN THE DORSAL ROOT GANGLION (DRG). INTRATHECAL INJECTION OF CXCR4 ANTAGONIST AMD3100 SIGNIFICANTLY RELIEVED HYPERALGESIA IN INFLAMMATORY RATS IN A TIME- AND DOSE-DEPENDENT MANNER. BISULFITE SEQUENCING AND METHYLATION-SPECIFIC PCR DEMONSTRATE THAT CFA INJECTION LED TO A SIGNIFICANT DEMETHYLATION OF CPG ISLAND AT CXCR4 GENE PROMOTER. CONSISTENTLY, THE EXPRESSION OF DNMT3B WAS SIGNIFICANTLY DOWNREGULATED AFTER CFA INJECTION. ONLINE SOFTWARE PREDICTION REVEALS THREE BINDING SITES OF P65 IN THE CPG ISLAND OF CXCR4 GENE PROMOTER, WHICH HAS CONFIRMED BY THE CHROMATIN IMMUNOPRECIPITATION ASSAY, CFA TREATMENT SIGNIFICANTLY INCREASES THE RECRUITMENT OF P65 TO CXCR4 GENE PROMOTER. INHIBITION OF NF-KB SIGNALING USING P65 INHIBITOR PYRROLIDINE DITHIOCARBAMATE SIGNIFICANTLY PREVENTED THE INCREASES OF THE CXCR4 EXPRESSION. CONCLUSION: UPREGULATION OF CXCR4 EXPRESSION DUE TO PROMOTER DEMETHYLATION FOLLOWED BY INCREASED RECRUITMENT OF P65 TO PROMOTER OF CXCR4 GENE CONTRIBUTES TO INFLAMMATORY HYPERALGESIA. THESE FINDINGS PROVIDE A THEORETICAL BASIS FOR THE TREATMENT OF CHRONIC PAIN FROM AN EPIGENETIC PERSPECTIVE. 2018 7 141 31 ABERRANT DNA METHYLATION OF MTOR PATHWAY GENES PROMOTES INFLAMMATORY ACTIVATION OF IMMUNE CELLS IN DIABETIC KIDNEY DISEASE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE (DKD), BUT THE UNDERLYING MECHANISMS REMAIN UNCLEAR. IN THIS STUDY, WE TESTED THE HYPOTHESIS THAT ABERRANT DNA METHYLATION IN PERIPHERAL IMMUNE CELLS CONTRIBUTES TO DKD PROGRESSION. WE SHOWED THAT LEVELS OF DNA METHYLTRANSFERASE 1 (DNMT1), A KEY ENZYME FOR DNA METHYLATION, WERE INCREASED ALONG WITH INFLAMMATORY ACTIVITY OF PERIPHERAL BLOOD MONONUCLEAR CELLS IN DKD PATIENTS. INHIBITION OF DNMT1 WITH 5-AZA-2'-DEOXYCYTIDINE (5-AZA) MARKEDLY INCREASED THE PROPORTION OF CD4(+)CD25(+) REGULATORY T CELLS IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN CULTURE AND IN DIABETIC ANIMALS. ADOPTIVE TRANSFER OF IMMUNE CELLS FROM 5-AZA-TREATED ANIMALS SHOWED BENEFICIAL EFFECTS ON THE HOST IMMUNE SYSTEM, RESULTING IN A SIGNIFICANT IMPROVEMENT OF DKD. USING GENOME-WIDE DNA METHYLATION ASSAYS, WE IDENTIFIED THE DIFFERENTIALLY METHYLATED CYTOSINES IN THE PROMOTER REGIONS OF MAMMALIAN TARGET OF RAPAMYCIN (MTOR) REGULATORS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF DIABETIC PATIENTS. FURTHER, MRNA ARRAYS CONFIRMED THE CONSISTENT INDUCTION OF GENES EXPRESSED IN THE MTOR PATHWAY. IMPORTANTLY, DOWN-REGULATION OF DNMT1 EXPRESSION VIA RNA INTERFERENCE RESULTED IN PROMINENT CYTOSINE DEMETHYLATION OF MTOR NEGATIVE REGULATORS AND SUBSEQUENT DECREASE OF MTOR ACTIVITY. LASTLY, MODULATION OF MTOR RESULTED IN CHANGES IN THE EFFECT OF 5-AZA ON DIABETIC IMMUNE CELLS. THUS, UP-REGULATION OF DNMT1 IN DIABETIC IMMUNE CELLS INDUCES ABERRANT CYTOSINE METHYLATION OF THE UPSTREAM REGULATORS OF MTOR, LEADING TO PATHOGENIC ACTIVATION OF THE MTOR PATHWAY AND CONSEQUENT INFLAMMATION IN DIABETIC KIDNEYS. HENCE, THIS STUDY HIGHLIGHTS THERAPEUTIC POTENTIAL OF TARGETING EPIGENETIC EVENTS IN IMMUNE SYSTEM FOR TREATING DKD. 2019 8 920 26 CHRONIC HYPOXIA FACILITATES ALZHEIMER'S DISEASE THROUGH DEMETHYLATION OF GAMMA-SECRETASE BY DOWNREGULATING DNA METHYLTRANSFERASE 3B. INTRODUCTION: ENVIRONMENTAL FACTORS AND EPIGENETIC MECHANISMS ARE BELIEVED TO CONTRIBUTE TO ALZHEIMER'S DISEASE (AD). WE PREVIOUSLY DOCUMENTED THAT PRENATAL HYPOXIA AGGRAVATED THE COGNITIVE IMPAIRMENT AND NEUROPATHOLOGY IN OFFSPRING MICE. HERE, WE INVESTIGATE THE CHRONIC HYPOXIA-INDUCED EPIGENETIC MODIFICATIONS IN AD. METHODS: THE 3-MONTH-OLD APP(SWE)/PS1(DE9) MICE WERE EXPOSED TO HYPOXIC ENVIRONMENT 6 HOUR/DAY FOR 30 DAYS, FOLLOWED BY LEARNING AND MEMORY TESTS AND BIOCHEMICAL AND NEUROPATHOLOGY MEASUREMENT AT THE AGE OF 4, 6, AND 9 MONTHS. RESULTS: WE FOUND HYPOXIA EXAGGERATED THE NEUROPATHOLOGY AND COGNITIVE IMPAIRMENT IN AD MICE. CHRONIC HYPOXIA INDUCED DEMETHYLATION ON GENOMIC DNA AND DECREASED THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) IN VIVO. WE FURTHER FOUND THAT DNMTS INHIBITION ELEVATED THE PROTEIN LEVELS OF AMYLOID PRECURSOR PROTEIN, BETA- AND GAMMA-SECRETASES, WHEREAS OVEREXPRESSION OF DNMT3B SUPPRESSED THE LEVELS OF THEM IN VITRO. DISCUSSION: OUR STUDY SUGGESTS CHRONIC HYPOXIA CAN AGGRAVATE AD PROGRESSION THROUGH DEMETHYLATION OF GENES ENCODING GAMMA-SECRETASE COMPONENTS BY DOWNREGULATION OF DNMT3B. 2016 9 3636 32 INCREASED DNA METHYLTRANSFERASE ACTIVITY AND DNA METHYLATION FOLLOWING EPIDERMAL GROWTH FACTOR STIMULATION IN OVARIAN CANCER CELLS. OVARIAN CANCER PROGRESSION IS CORRELATED WITH ACCUMULATION OF ABERRANT CPG ISLAND METHYLATION. IN OVARIAN CANCER, ASCITES FLUID CONTAINS NUMEROUS EPIDERMAL-GROWTH-FACTOR-RECEPTOR (EGFR) ACTIVATORS, WHICH COULD RESULT IN A TUMOR MICROENVIRONMENT OF CONSTANT EGFR ACTIVATION. SIGNALING PATHWAYS DOWNSTREAM OF EGFR, SUCH AS RAS, REGULATE DNA METHYLATION. WE HYPOTHESIZED THAT CHRONIC EGFR ACTIVATION COULD ALTER DNA METHYLATION. WE FOUND THAT EGFR ACTIVATION INCREASED DNA METHYLTRANSFERASE (DNMT) ACTIVITY ACUTELY, AS WELL AS AFTER LONG-TERM EGF TREATMENT OR EXPRESSION OF A MUTATIONALLY ACTIVATED EGFR. FURTHERMORE, THIS INCREASE IN DNMT ACTIVITY WAS DEPENDENT ON EGFR CATALYTIC ACTIVITY AND RESULTED IN INCREASED GLOBAL DNA METHYLATION. ADDITIONALLY, TREATMENT WITH THE DNMT INHIBITOR/HYPOMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE (AZA) INHIBITED THE EGF INDUCED INCREASE OF BOTH DNMT ACTIVITY AND GLOBAL METHYLATION. THESE DATA SUPPORT A ROLE FOR EGFR IN THE PROCESS OF ACCUMULATED DNA METHYLATION DURING OVARIAN CANCER PROGRESSION AND SUGGEST THAT EPIGENETIC THERAPY MAY BE BENEFICIAL FOR THE TREATMENT OF OVARIAN CANCER. 2012 10 5345 31 RAPID CHANGES IN EXPRESSION OF CLASS I AND IV HISTONE DEACETYLASES DURING EPILEPTOGENESIS IN MOUSE MODELS OF TEMPORAL LOBE EPILEPSY. A PROMINENT ROLE OF EPIGENETIC MECHANISMS IN MANIFESTATION OF EPILEPSY HAS BEEN PROPOSED. THUS ALTERED HISTONE H3 AND H4 ACETYLATION HAS BEEN DEMONSTRATED IN EXPERIMENTAL MODELS OF TEMPORAL LOBE EPILEPSY (TLE). WE NOW INVESTIGATED CHANGES IN THE EXPRESSION OF THE CLASS I AND CLASS IV HISTONE DEACETYLASES (HDAC) IN TWO COMPLEMENTARY MOUSE TLE MODELS. UNILATERAL INTRAHIPPOCAMPAL INJECTION OF KAINIC ACID (KA) INDUCED A STATUS EPILEPTICUS LASTING 6 TO 24H, DEVELOPMENT OF SPONTANEOUS LIMBIC SEIZURES (2 TO 3 DAYS AFTER KA INJECTION) AND CHRONIC EPILEPSY, AS REVEALED BY TELEMETRIC RECORDINGS OF THE EEGS. MICE WERE KILLED AT DIFFERENT INTERVALS AFTER KA INJECTION AND EXPRESSION OF HDAC MRNAS WAS INVESTIGATED BY IN SITU HYBRIDIZATION. WE OBSERVED MARKED DECREASES IN THE EXPRESSION OF HDACS 1, 2 AND 11 (BY UP TO 75%) IN THE GRANULE CELL AND PYRAMIDAL CELL LAYERS OF THE HIPPOCAMPUS DURING THE ACUTE STATUS EPILEPTICUS (2 TO 6H AFTER KA INJECTION). THIS WAS FOLLOWED BY INCREASED EXPRESSION OF ALL CLASS I HDAC MRNAS IN ALL PRINCIPAL CELL LAYERS OF THE HIPPOCAMPUS AFTER 12 TO 48 H. IN THE CHRONIC PHASE, 14 AND 28 DAYS AFTER KA, ONLY MODEST INCREASES IN THE EXPRESSION OF HDAC1 MRNA WERE OBSERVED IN GRANULE AND PYRAMIDAL CELLS. IMMUNOHISTOCHEMISTRY USING AN ANTIBODY DETECTING HDAC2 REVEALED RESULTS CONSISTENT WITH THE MRNA DATA AND INDICATES ALSO EXPRESSION IN GLIAL CELLS ON THE INJECTION SIDE. SIMILAR CHANGES AS SEEN IN THE KA MODEL WERE OBSERVED AFTER A PILOCARPINE-INDUCED STATUS EPILEPTICUS EXCEPT THAT DECREASES IN HDACS 2, 3 AND 8 WERE ALSO SEEN AT THE CHRONIC 28 DAY INTERVAL. THE PROMINENT DECREASES IN HDAC EXPRESSION DURING STATUS EPILEPTICUS ARE CONSISTENT WITH THE PREVIOUSLY DEMONSTRATED INCREASED EXPRESSION OF NUMEROUS PROTEINS AND WITH THE AUGMENTED ACETYLATION OF HISTONE H4. IT IS SUGGESTED THAT RESPECTIVE PUTATIVE GENE PRODUCTS COULD FACILITATE PROCONVULSIVE AS WELL AS ANTICONVULSIVE MECHANISMS. THE INCREASED EXPRESSION OF ALL CLASS I HDACS DURING THE "SILENT PHASE", ON THE OTHER HAND, MAY BE RELATED TO DECREASED HISTONE ACETYLATION, WHICH COULD CAUSE A DECREASE IN EXPRESSION OF CERTAIN PROTEINS, A MECHANISM THAT COULD ALSO PROMOTE EPILEPTOGENESIS. THUS, ADDRESSING HDAC EXPRESSION MAY HAVE A THERAPEUTIC POTENTIAL IN INTERFERING WITH A STATUS EPILEPTICUS AND WITH THE MANIFESTATION OF TLE. 2015 11 5279 26 PROMOTER-SPECIFIC RELEVANCE OF HISTONE MODIFICATIONS INDUCED BY DEXAMETHASONE DURING THE REGULATION OF PRO-INFLAMMATORY MEDIATORS. GLUCOCORTICOSTEROIDS (GCS) ARE WIDELY USED TO TREAT DIFFERENT KINDS OF CHRONIC INFLAMMATORY AND IMMUNE DISEASES THROUGH TRANSCRIPTIONAL REGULATION OF INFLAMMATORY GENES. MODULATION OF GENE EXPRESSION BY GCS IS KNOWN TO OCCUR THROUGH DIVERSE MECHANISMS OF VARYING RELEVANCE TO SPECIFIC CLASSES OF GENES. EPIGENETIC MODIFICATIONS ARE INDEED A PIVOTAL REGULATORY FEATURE OF GLUCOCORTICOID RECEPTOR AND OTHER TRANSCRIPTION FACTORS. IN THIS STUDY, HISTONE POST-TRANSLATIONAL MODIFICATIONS WERE INVESTIGATED FOR THEIR INVOLVEMENT IN THE REGULATION OF SELECTED PRO-INFLAMMATORY GENES - EXPRESSED IN HUMAN MONOCYTE-DERIVED MACROPHAGES - IN RESPONSE TO TREATMENT WITH SYNTHETIC GC DEXAMETHASONE (DEX). WE SHOW THAT HISTONE TAIL ACETYLATION STATUS IS MODIFIED FOLLOWING DEX ADMINISTRATION, THROUGH DISTINCT AND ALTERNATIVE MECHANISMS AT THE PROMOTERS OF INTERLEUKIN-8 AND INTERLEUKIN-23. IN ADDITION TO HISTONE H3 ACETYLATION, OUR RESULTS DEMONSTRATE THAT H3 LYSINE 4 TRIMETHYLATION IS AFFECTED FOLLOWING DRUG TREATMENT. 2014 12 3720 26 INHIBITION OF CLASS I HISTONE DEACETYLASES ABROGATES TUMOR GROWTH FACTOR BETA EXPRESSION AND DEVELOPMENT OF FIBROSIS DURING CHRONIC PANCREATITIS. PANCREATIC FIBROSIS IS THE HALLMARK OF CHRONIC PANCREATITIS, A HIGHLY DEBILITATING DISEASE FOR WHICH THERE IS CURRENTLY NO CURE. THE KEY EVENT AT THE BASIS OF PANCREATIC FIBROSIS IS THE DEPOSITION OF EXTRACELLULAR MATRIX PROTEINS BY ACTIVATED PANCREATIC STELLATE CELLS (PSCS). TRANSFORMING GROWTH FACTOR BETA (TGFBETA) IS A POTENT PROFIBROTIC FACTOR IN THE PANCREAS AS IT PROMOTES THE ACTIVATION OF PSC; THUS, PHARMACOLOGIC INTERVENTIONS THAT EFFECTIVELY REDUCE TGFBETA EXPRESSION HARBOR CONSIDERABLE THERAPEUTIC POTENTIAL IN THE TREATMENT OF CHRONIC PANCREATITIS. IN THIS STUDY, WE INVESTIGATED WHETHER TGFBETA EXPRESSION IS REDUCED BY PHARMACOLOGIC INHIBITION OF THE EPIGENETIC MODIFIERS HISTONE DEACETYLASES (HDACS). TO ADDRESS THIS AIM, CHRONIC PANCREATITIS WAS INDUCED IN C57BL/6 MICE WITH SERIAL INJECTIONS OF CERULEIN, AND THE SELECTIVE CLASS 1 HDAC INHIBITOR MS-275 WAS ADMINISTERED IN VIVO IN A PREVENTIVE AND THERAPEUTIC MANNER. BOTH MS-275 REGIMENS POTENTLY REDUCED DEPOSITION OF EXTRACELLULAR MATRIX AND DEVELOPMENT OF FIBROSIS IN THE PANCREAS AFTER 4 WEEKS OF CHRONIC PANCREATITIS. REDUCED PANCREATIC FIBROSIS WAS CONCOMITANT WITH LOWER EXPRESSION OF PANCREATIC TGFBETA AND CONSEQUENT REDUCED PSC ACTIVATION. IN SEARCH OF THE CELL TYPES TARGETED BY THE INHIBITOR, WE FOUND THAT MS-275 TREATMENT ABROGATED THE EXPRESSION OF TGFBETA IN ACINAR CELLS STIMULATED BY CERULEIN TREATMENT. OUR STUDY DEMONSTRATES THAT MS-275 IS AN EFFECTIVE ANTIFIBROTIC AGENT IN THE CONTEXT OF EXPERIMENTAL CHRONIC PANCREATITIS AND THUS MAY CONSTITUTE A VALID THERAPEUTIC INTERVENTION FOR THIS SEVERE DISEASE. 2018 13 3341 24 HISTONE DEACETYLASE-2 IS INVOLVED IN STRESS-INDUCED COGNITIVE IMPAIRMENT VIA HISTONE DEACETYLATION AND PI3K/AKT SIGNALING PATHWAY MODIFICATION. EXPOSURE TO CHRONIC STRESS UPREGULATES BLOOD GLUCOCORTICOID LEVELS AND IMPAIRS COGNITION VIA DIVERSE EPIGENETIC MECHANISMS, SUCH AS HISTONE DEACETYLATION. HISTONE DEACETYLATION CAN LEAD TO TRANSCRIPTIONAL SILENCING OF MANY PROTEINS INVOLVED IN COGNITION AND MAY ALSO CAUSE LEARNING AND MEMORY DYSFUNCTION. HISTONE DEACETYLASE?2 (HDAC2) HAS BEEN DEMONSTRATED TO EPIGENETICALLY BLOCK COGNITION VIA A REDUCTION IN THE HISTONE ACETYLATION LEVEL; HOWEVER, IT IS UNKNOWN WHETHER HDAC2 IS INVOLVED IN THE COGNITIVE DECLINE INDUCED BY CHRONIC STRESS. TO THE BEST OF AUTHORS' KNOWLEDGE, THIS IS THE FIRST STUDY TO DEMONSTRATE THAT THE STRESS HORMONE CORTICOSTEROID UPREGULATE HDAC2 PROTEIN LEVELS IN NEURO?2A CELLS AND CAUSE CELL INJURIES. HDAC2 KNOCKDOWN RESULTED IN A SIGNIFICANT AMELIORATION OF THE PATHOLOGICAL CHANGES IN N2A CELLS VIA THE UPREGULATION OF HISTONE ACETYLATION AND MODIFICATIONS IN THE PHOSPHOINOSITIDE 3?KINASE/PROTEIN KINASE B SIGNALING PATHWAY. IN ADDITION, THE HDAC2 PROTEIN LEVELS WERE UPREGULATED IN 12?MONTH?OLD FEMALE C57BL/6J MICE UNDER CHRONIC STRESS IN VIVO. TAKEN TOGETHER, THESE FINDINGS SUGGESTED THAT HDAC2 MAY BE AN IMPORTANT NEGATIVE REGULATOR INVOLVED IN CHRONIC STRESS?INDUCED COGNITIVE IMPAIRMENT. 2017 14 3795 37 INTERLEUKIN-6 CONTRIBUTES TO GROWTH IN CHOLANGIOCARCINOMA CELLS BY ABERRANT PROMOTER METHYLATION AND GENE EXPRESSION. THE ASSOCIATION BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT AND PROGRESSION OF MALIGNANCY IS EXEMPLIFIED IN THE BILIARY TRACT WHERE PERSISTENT INFLAMMATION STRONGLY PREDISPOSES TO CHOLANGIOCARCINOMA. THE INFLAMMATORY CYTOKINE INTERLEUKIN-6 (IL-6) ENHANCES TUMOR GROWTH IN CHOLANGIOCARCINOMA BY ALTERED GENE EXPRESSION VIA AUTOCRINE MECHANISMS. IL-6 CAN REGULATE THE ACTIVITY OF DNA METHYLTRANSFERASES, AND MOREOVER, ABERRANT DNA METHYLATION CAN CONTRIBUTE TO CARCINOGENESIS. WE THEREFORE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO IL-6 ON METHYLATION-DEPENDENT GENE EXPRESSION AND TRANSFORMED CELL GROWTH IN HUMAN CHOLANGIOCARCINOMA. THE RELATIONSHIP BETWEEN AUTOCRINE IL-6 PATHWAYS, DNA METHYLATION, AND TRANSFORMED CELL GROWTH WAS ASSESSED USING MALIGNANT CHOLANGIOCYTES STABLY TRANSFECTED TO OVEREXPRESS IL-6. TREATMENT WITH THE DNA METHYLATION INHIBITOR 5-AZA-2'-DEOXYCYTIDINE DECREASED CELL PROLIFERATION, GROWTH IN SOFT AGAR, AND METHYLCYTOSINE CONTENT OF MALIGNANT CHOLANGIOCYTES. HOWEVER, THIS EFFECT WAS NOT OBSERVED IN IL-6-OVEREXPRESSING CELLS. IL-6 OVEREXPRESSION RESULTED IN THE ALTERED EXPRESSION AND PROMOTER METHYLATION OF SEVERAL GENES, INCLUDING THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). EGFR PROMOTER METHYLATION WAS DECREASED AND GENE AND PROTEIN EXPRESSION WAS INCREASED BY IL-6. THUS, EPIGENETIC REGULATION OF GENE EXPRESSION BY IL-6 CAN CONTRIBUTE TO TUMOR PROGRESSION BY ALTERING PROMOTER METHYLATION AND GENE EXPRESSION OF GROWTH-REGULATORY PATHWAYS, SUCH AS THOSE INVOLVING EGFR. MOREOVER, ENHANCED IL-6 EXPRESSION MAY DECREASE THE SENSITIVITY OF TUMOR CELLS TO THERAPEUTIC TREATMENTS USING METHYLATION INHIBITORS. THESE OBSERVATIONS HAVE IMPORTANT IMPLICATIONS FOR CANCER TREATMENT AND PROVIDE A MECHANISM BY WHICH PERSISTENT CYTOKINE STIMULATION CAN PROMOTE TUMOR GROWTH. 2006 15 4173 27 MELATONIN INDUCES HISTONE HYPERACETYLATION IN THE RAT BRAIN. WE HAVE REPORTED THAT MELATONIN INDUCES HISTONE HYPERACETYLATION IN MOUSE NEURAL STEM CELLS, SUGGESTING AN EPIGENETIC ROLE FOR THIS PLEIOTROPIC HORMONE. TO SUPPORT SUCH A ROLE, IT IS NECESSARY TO DEMONSTRATE THAT MELATONIN PRODUCES SIMILAR EFFECTS IN VIVO. HISTONE ACETYLATION, FOLLOWING CHRONIC TREATMENT WITH MELATONIN (4MUG/ML IN DRINKING WATER FOR 17 DAYS), WAS EXAMINED BY WESTERN BLOTTING IN SELECTED RAT BRAIN REGIONS. MELATONIN INDUCED SIGNIFICANT INCREASES IN HISTONE H3 AND HISTONE H4 ACETYLATION IN THE HIPPOCAMPUS. HISTONE H4 WAS ALSO HYPERACETYLATED IN THE STRIATUM, BUT THERE WERE NO SIGNIFICANT CHANGES IN HISTONE H3 ACETYLATION IN THIS BRAIN REGION. NO SIGNIFICANT CHANGES IN THE ACETYLATION OF EITHER HISTONE H3 OR H4 WERE OBSERVED IN THE MIDBRAIN AND CEREBELLUM. AN EXAMINATION OF KINASE ACTIVATION, WHICH MAY BE RELATED TO THESE CHANGES, REVEALED THAT MELATONIN TREATMENT INCREASED THE LEVELS OF PHOSPHO-ERK (EXTRACELLULAR SIGNAL-REGULATED KINASE) IN THE HIPPOCAMPUS AND STRIATUM, BUT PHOSPHO-AKT (PROTEIN KINASE B) LEVELS WERE UNCHANGED. THESE FINDINGS SUGGEST THAT CHROMATIN REMODELING AND ASSOCIATED CHANGES IN THE EPIGENETIC REGULATION OF GENE EXPRESSION UNDERLIE THE MULTIPLE PHYSIOLOGICAL EFFECTS OF MELATONIN. 2013 16 1035 35 CLASS I HISTONE DEACETYLASE INHIBITION IMPROVES PANCREATITIS OUTCOME BY LIMITING LEUKOCYTE RECRUITMENT AND ACINAR-TO-DUCTAL METAPLASIA. BACKGROUND AND PURPOSE: PANCREATITIS IS A COMMON INFLAMMATION OF THE PANCREAS WITH RISING INCIDENCE IN MANY COUNTRIES. DESPITE IMPROVEMENTS IN DIAGNOSTIC TECHNIQUES, THE DISEASE IS ASSOCIATED WITH HIGH RISK OF SEVERE MORBIDITY AND MORTALITY AND THERE IS AN URGENT NEED FOR NEW THERAPEUTIC INTERVENTIONS. IN THIS STUDY, WE EVALUATED WHETHER HISTONE DEACETYLASES (HDACS), KEY EPIGENETIC REGULATORS OF GENE TRANSCRIPTION, ARE INVOLVED IN THE DEVELOPMENT OF THE DISEASE. EXPERIMENTAL APPROACH: WE ANALYSED HDAC REGULATION DURING CERULEIN-INDUCED ACUTE, CHRONIC AND AUTOIMMUNE PANCREATITIS USING DIFFERENT TRANSGENIC MOUSE MODELS. THE FUNCTIONAL RELEVANCE OF CLASS I HDACS WAS TESTED WITH THE SELECTIVE INHIBITOR MS-275 IN VIVO UPON PANCREATITIS INDUCTION AND IN VITRO IN ACTIVATED MACROPHAGES AND PRIMARY ACINAR CELL EXPLANTS. KEY RESULTS: HDAC EXPRESSION AND ACTIVITY WERE UP-REGULATED IN A TIME-DEPENDENT MANNER FOLLOWING INDUCTION OF PANCREATITIS, WITH THE HIGHEST ABUNDANCE OBSERVED FOR CLASS I HDACS. CLASS I HDAC INHIBITION DID NOT PREVENT THE INITIAL ACINAR CELL DAMAGE. HOWEVER, IT EFFECTIVELY REDUCED THE INFILTRATION OF INFLAMMATORY CELLS, INCLUDING MACROPHAGES AND T CELLS, IN BOTH ACUTE AND CHRONIC PHASES OF THE DISEASE, AND DIRECTLY DISRUPTED MACROPHAGE ACTIVATION. IN ADDITION, MS-275 TREATMENT REDUCED DNA DAMAGE IN ACINAR CELLS AND LIMITED ACINAR DE-DIFFERENTIATION INTO ACINAR-TO-DUCTAL METAPLASIA IN A CELL-AUTONOMOUS MANNER BY IMPEDING THE EGF RECEPTOR SIGNALLING AXIS. CONCLUSIONS AND IMPLICATIONS: THESE RESULTS DEMONSTRATE THAT CLASS I HDACS ARE CRITICALLY INVOLVED IN THE DEVELOPMENT OF ACUTE AND CHRONIC FORMS OF PANCREATITIS AND SUGGEST THAT BLOCKADE OF CLASS I HDAC ISOFORMS IS A PROMISING TARGET TO IMPROVE THE OUTCOME OF THE DISEASE. 2017 17 3470 26 HYPOXIA-INDUCIBLE KDM3A ADDICTION IN MULTIPLE MYELOMA. IN MULTIPLE MYELOMA (MM), THE BONE MARROW (BM) MICROENVIRONMENT MAY CONTAIN A MYELOMA CELL FRACTION THAT HAS ACQUIRED TREATMENT RESISTANCE BY UNDERGOING AN EPIGENETIC GENE EXPRESSION CHANGE. HYPOXIC STRESS IS AN IMPORTANT FACTOR IN THE BM MICROENVIRONMENT. RECENTLY, WE DEMONSTRATED THAT MIR-210 WAS UPREGULATED IN HYPOXIA AND DOWNREGULATED IRF4, WHICH IS KNOWN AS AN ESSENTIAL FACTOR IN MYELOMA ONCOGENESIS IN NORMOXIA. IN THE STUDY, WE DEMONSTRATED THAT MYELOMA CELLS STILL SHOWED A STRONG ANTIAPOPTOTIC PHENOTYPE DESPITE IRF4 DOWNREGULATION, SUGGESTING THAT ANOTHER ANTIAPOPTOTIC FACTOR MIGHT BE INVOLVED UNDER HYPOXIC STRESS. TO DETERMINE THE FACTOR OR FACTORS, WE CONDUCTED GENE EXPRESSION ANALYSIS ON MYELOMA CELLS (PRIMARY SAMPLES AND CELL LINES) THAT WERE EXPOSED TO CHRONIC HYPOXIA AND OBSERVED UPREGULATION OF GLYCOLYTIC GENES AND GENES ENCODING H3K9 DEMETHYLASES IN MYELOMA CELLS WITH HYPOXIA. AMONG THESE, KDM3A WAS MOST SIGNIFICANTLY UPREGULATED IN ALL EXAMINED CELLS, AND ITS KNOCKDOWN INDUCED APOPTOSIS OF MYELOMA CELLS IN CHRONIC HYPOXIA. EXPRESSION OF KDM3A WAS DEPENDENT ON HIF-1ALPHA, WHICH IS A TRANSCRIPTION FACTOR SPECIFICALLY UPREGULATED IN HYPOXIA. WE FURTHER DEMONSTRATED THAT AN ESSENTIAL TARGET OF KDM3A WAS A NONCODING GENE, MALAT1, WHOSE UPREGULATION CONTRIBUTED TO ACQUISITION OF AN ANTIAPOPTOTIC PHENOTYPE BY ACCUMULATION OF HIF-1ALPHA, LEADING TO UPREGULATION OF GLYCOLYTIC GENES UNDER HYPOXIA. THIS PROCESS WAS INDEPENDENT FROM IRF4. THESE RESULTS LED US TO CONCLUDE THAT THE HYPOXIA-INDUCIBLE HIF-1ALPHA-KDM3A-MALAT1 AXIS ALSO CONTRIBUTES TO ACQUISITION OF THE ANTIAPOPTOTIC PHENOTYPE VIA UPREGULATION OF GLYCOLYSIS-PROMOTING GENES. THUS, THIS AXIS IS A PROMISING THERAPEUTIC TARGET AGAINST MYELOMA CELLS IN THE BM MICROENVIRONMENT. 2018 18 6020 33 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 19 4236 32 METHYLATION OF THE TYROSINE HYDROXYLASE GENE IS DYSREGULATED BY COCAINE DEPENDENCE IN THE HUMAN STRIATUM. COCAINE DEPENDENCE IS A CHRONIC, RELAPSING DISORDER CAUSED BY LASTING CHANGES IN THE BRAIN. ANIMAL STUDIES HAVE IDENTIFIED COCAINE-RELATED ALTERATIONS IN STRIATAL DNA METHYLATION; HOWEVER, IT IS UNCLEAR HOW METHYLATION IS RELATED TO COCAINE DEPENDENCE IN HUMANS. WE GENERATED METHYLOMIC PROFILES OF THE NUCLEUS ACCUMBENS USING HUMAN POSTMORTEM BRAINS FROM A COHORT OF INDIVIDUALS WITH COCAINE DEPENDENCE AND HEALTHY CONTROLS (N = 25 PER GROUP). WE FOUND HYPERMETHYLATION IN A CLUSTER OF CPGS WITHIN THE GENE BODY OF TYROSINE HYDROXYLASE (TH), CONTAINING A PUTATIVE BINDING SITE FOR THE EARLY GROWTH RESPONSE 1 (EGR1) TRANSCRIPTION FACTOR, WHICH IS HYPERMETHYLATED IN THE CAUDATE NUCLEUS OF COCAINE-DEPENDENT INDIVIDUALS. WE REPLICATED THIS FINDING AND FOUND IT TO BE SPECIFIC TO STRIATAL NEURONAL NUCLEI. FURTHERMORE, THIS LOCUS DEMONSTRATES ENHANCER ACTIVITY WHICH IS ATTENUATED BY METHYLATION AND ENHANCED BY EGR1 OVEREXPRESSION. THESE RESULTS SUGGEST THAT COCAINE DEPENDENCE ALTERS THE EPIGENETIC REGULATION OF DOPAMINERGIC SIGNALING GENES. 2021 20 1566 35 DNA METHYLATION OF TH1/TH2 CYTOKINE GENES AFFECTS SENSITIZATION AND PROGRESS OF EXPERIMENTAL ASTHMA. BACKGROUND: EPIGENETIC CHANGES IN DNA METHYLATION HAVE RECENTLY BEEN DEMONSTRATED TO BE INVOLVED IN EFFECTOR T-CELL POLARIZATION, RESULTING IN DIFFERENTIAL SECRETION OF T(H)1 AND T(H)2 CYTOKINES. HOWEVER, THE CONTRIBUTION TO THE DEVELOPMENT OF A CHRONIC INFLAMMATORY PHENOTYPE REMAINS STILL UNCLEAR. OBJECTIVE: WE SOUGHT TO INVESTIGATE CHANGES IN DNA METHYLATION IN MARKER GENES OF T-CELL SUBSETS DURING ALLERGEN SENSITIZATION/CHALLENGE AND THEIR INFLUENCE ON THE DEVELOPMENT OF AN ALLERGIC AIRWAY INFLAMMATORY RESPONSE. METHODS: THE RELATIONSHIP BETWEEN CHANGES IN DNA METHYLATION AND PHENOTYPE DEVELOPMENT WERE EXAMINED IN A WELL-ESTABLISHED MODEL OF EXPERIMENTAL ASTHMA. DNA METHYLATION WAS INVESTIGATED AT GENOMIC LOCI ASSOCIATED WITH T(H)1 (IFNG PROMOTER) OR T(H)2 (CONSERVED NONCODING SEQUENCE 1 [CNS1]) CYTOKINE PRODUCTION BY USING BISULFITE PYROSEQUENCING. RESULTS: ANALYSIS OF CD4(+) T CELLS REVEALED A SIGNIFICANT INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER AFTER ALLERGEN SENSITIZATION/CHALLENGE, WHICH CORRELATED WITH DECREASED IFN-GAMMA CYTOKINE EXPRESSION, WHEREAS ONLY MINOR CHANGES WERE OBSERVED AT THE CNS1 LOCUS. FURTHERMORE, THE INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER COULD BE REVERSED WITH A DNA METHYLTRANSFERASE (DNMT) INHIBITOR IN VITRO AND IN VIVO WITH BENEFICIAL EFFECTS ON SENSITIZATION STATUS AND ALLERGIC PHENOTYPE. THE SPECIFIC IMPORTANCE OF THE DNA METHYLATION STATUS IN CD4(+) T CELLS COULD BE CONFIRMED BY USING ADOPTIVE TRANSFER EXPERIMENTS. CONCLUSION: WE HERE REPORT THE NOVEL FINDING THAT EPIGENETIC REGULATION IN T CELLS CONTRIBUTES TO THE DEVELOPMENT OF EXPERIMENTAL ASTHMA AND CAN BE TARGETED PHARMACOLOGICALLY. 2012