1 1826 149 EFFECTS OF HISTONE DEACETYLASE INHIBITOR ON EXTRACELLULAR MATRIX PRODUCTION IN HUMAN NASAL POLYP ORGAN CULTURES. BACKGROUND: NASAL POLYPOSIS IS ASSOCIATED WITH A CHRONIC INFLAMMATORY CONDITION OF THE SINONASAL MUCOSA AND INVOLVES MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION. EPIGENETIC MODULATION BY HISTONE DEACETYLASE (HDAC) INHIBITORS INCLUDING TRICHOSTATIN A (TSA) HAS BEEN REPORTED TO HAVE INHIBITORY EFFECTS ON MYOFIBROBLAST DIFFERENTIATION IN LUNG AND RENAL FIBROBLASTS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE INHIBITORY EFFECT OF TSA ON MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION IN NASAL POLYP ORGAN CULTURES. METHODS: NASAL POLYP TISSUES FROM 18 PATIENTS WERE ACQUIRED DURING ENDOSCOPIC SINUS SURGERY. AFTER ORGAN CULTURE, NASAL POLYPS WERE STIMULATED WITH TGF-BETA1 AND THEN TREATED WITH TSA. ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), FIBRONECTIN, AND COLLAGEN TYPE I EXPRESSION LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (PCR), REAL-TIME PCR, WESTERN BLOT, AND IMMUNOFLUORESCENT STAINING. HDAC2, HDAC4, AND ACETYLATED H4 EXPRESSION LEVELS WERE ASSAYED BY WESTERN BLOT. CYTOTOXICITY WAS ANALYZED BY THE TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING ASSAY. RESULTS: THE EXPRESSION LEVELS OF ALPHA-SMA, FIBRONECTIN, AND COLLAGEN TYPE 1 WERE INCREASED IN NASAL POLYP AFTER TRANSFORMING GROWTH FACTOR (TGF) BETA1 TREATMENT. TSA-INHIBITED TGF-BETA1 INDUCED THESE GENE AND PROTEIN EXPRESSION LEVELS. FURTHERMORE, TSA SUPPRESSED PROTEIN EXPRESSION LEVELS OF HDAC2 AND HDAC4. HOWEVER, TSA INDUCED HYPERACETYLATION OF HISTONES H4. TREATMENT WITH TGF-BETA1 WITH OR WITHOUT TSA DID NOT HAVE CYTOTOXIC EFFECT. CONCLUSION: THESE FINDINGS PROVIDE NOVEL INSIGHTS INTO THE EPIGENETIC REGULATION IN MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION OF NASAL POLYP. TSA COULD BE A CANDIDATE OF A THERAPEUTIC AGENT FOR REVERSING THE TGF-BETA1-INDUCED ECM SYNTHESIS THAT LEADS TO NASAL POLYP DEVELOPMENT. 2013 2 2349 85 EPIGENETIC REGULATION OF MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX PRODUCTION IN NASAL POLYP-DERIVED FIBROBLASTS. BACKGROUND: NASAL POLYPOSIS IS A MULTI-FACTORIAL DISEASE ASSOCIATED WITH CHRONIC INFLAMMATORY CONDITION OF THE PARANASAL SINUSES. MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION ARE INVOLVED IN THE PATHOGENESIS OF NASAL POLYPOSIS. OBJECTIVE: THE AIM OF THIS STUDY WAS TO STUDY THE EFFECT OF TRICHOSTATIN A (TSA), A HISTONE DEACETYLASE (HDAC) INHIBITOR, ON TRANSFORMING GROWTH FACTOR (TGF)-BETA1-INDUCED MYOFIBROBLAST DIFFERENTIATION AND ECM ACCUMULATION IN NASAL POLYP-DERIVED FIBROBLASTS (NPDFS). METHODS: NASAL POLYP-DERIVED FIBROBLASTS WERE ISOLATED FROM NASAL POLYPS OF PATIENTS WHO HAVE CHRONIC RHINOSINUSITIS WITH NASAL POLYP. TSA WAS TREATED IN TGF-BETA1-INDUCED NPDFS. EXPRESSION LEVELS OF HDAC2, ALPHA-SMOOTH MUSCLE ACTIN (SMA), TGF-BETA1, COLLAGEN TYPE I, ACETYLATED HISTONE H3, ACETYLATED HISTONE H4, PHOSPHORYLATED SMAD2/3 AND SMAD7 WERE DETERMINED BY RT-PCR, WESTERN BLOT AND/OR IMMUNOFLUORESCENT STAINING. THE TOTAL COLLAGEN AMOUNT PRODUCTION WAS ANALYSED BY SIRCOL SOLUBLE COLLAGEN ASSAY AND CONTRACTILE ACTIVITY WAS MEASURED BY COLLAGEN GEL CONTRACTION ASSAY. HDAC2 INHIBITION BY TSA OR HDAC2 SILENCING WAS ESTABLISHED BY RT-PCR AND WESTERN BLOT. THE EPIGENETIC EFFECT ON ALPHA-SMA GENE INACTIVATION WAS EXAMINED BY CHROMATIN IMMUNOPRECIPITATION ASSAY. PROLIFERATION WAS DETERMINED BY KI67-POSITIVE CELL STAINING AND CYTOTOXICITY WAS ASSESSED BY 3-(4,5- DIMETHYLTHIAZOL-2YL)-2,5-DIPHENYL-2H-TETRAZOLIUM BROMIDE (MTT) ASSAY. RESULTS: THE EXPRESSION LEVELS OF HDAC2, ALPHA-SMA AND TGF-BETA1 WERE INCREASED IN NASAL POLYP TISSUES COMPARED TO NORMAL INFERIOR TURBINATE TISSUES. TSA AND HDAC2 SILENCING INHIBITED EXPRESSION LEVELS ALPHA-SMA, COLLAGEN AND HDAC2. TSA INDUCED HYPERACETYLATION OF HISTONE AND SUPPRESSED OPENING OF ALPHA-SMA GENE PROMOTER IN TGF-BETA1-INDUCED NPDFS. TSA INHIBITED TGF-BETA1-INDUCED SMAD 2/3 AND RESCUED TGF-BETA1-SUPPRESSED SMAD7 SIGNALLING PATHWAY. FINALLY, TSA BLOCKED PROLIFERATION IN TGF-BETA1-INDUCED NPDFS AND HAS NO CYTOTOXIC EFFECT IN NPDFS. CONCLUSIONS AND CLINICAL RELEVANCE: THESE RESULTS SUGGEST THAT HDAC INHIBITION IS ASSOCIATED WITH MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLUAR MATRIX ACCUMULATION IN NASAL POLYPOSIS. TSA MAY BE USEFUL AS AN INHIBITOR OF NASAL POLYP GROWTH, AND THUS HAS POTENTIAL TO BE USED AS A NOVEL TREATMENT OPTION FOR NASAL POLYPOSIS. 2012 3 1632 43 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 4 2748 42 EXPRESSION AND FUNCTION OF EZH2 IN SYNOVIAL FIBROBLASTS: EPIGENETIC REPRESSION OF THE WNT INHIBITOR SFRP1 IN RHEUMATOID ARTHRITIS. OBJECTIVES: TO STUDY THE EXPRESSION, REGULATION AND FUNCTION OF THE HISTONE METHYLTRANSFERASE ENHANCER OF ZESTE HOMOLOGUE 2 (EZH2) IN SYNOVIAL FIBROBLASTS (SF) FROM PATIENTS WITH RHEUMATOID ARTHRITIS (RA) AND OSTEOARTHRITIS (OA). METHODS: SF WERE OBTAINED FROM RA AND OA PATIENTS UNDERGOING JOINT SURGERY. EXPRESSION LEVELS WERE ASSESSED BY QUANTITATIVE REAL-TIME PCR AND WESTERN BLOT. KINASE INHIBITORS AND REPORTER GENE ASSAYS WERE EMPLOYED TO STUDY SIGNALLING PATHWAYS. FUNCTIONAL ANALYSES INCLUDED EZH2 OVEREXPRESSION BY PLASMID TRANSFECTION AND GENE SILENCING BY SMALL INTERFERING RNA. CHROMATIN IMMUNOPRECIPITATION ASSAY WAS USED TO ANALYSE HISTONE METHYLATION WITHIN DISTINCT PROMOTER REGIONS. RESULTS: BY STUDYING THE EXPRESSION AND FUNCTION OF EZH2 IN SF THE AUTHORS FOUND THAT EZH2 IS OVEREXPRESSED IN RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS (RASF) AND FURTHER INDUCED BY TUMOUR NECROSIS FACTOR ALPHA THROUGH THE NUCLEAR FACTOR KAPPA B AND JUN KINASE PATHWAYS. AS A TARGET GENE OF EZH2 THE AUTHORS IDENTIFIED SECRETED FRIZZLED-RELATED PROTEIN 1 (SFRP1), AN INHIBITOR OF WNT SIGNALLING, WHICH IS ASSOCIATED WITH THE ACTIVATION OF RASF, AND SHOW THAT SFRP1 EXPRESSION CORRELATES WITH THE OCCUPATION OF ITS PROMOTER WITH ACTIVATING AND SILENCING HISTONE MARKS. CONCLUSIONS: THESE DATA STRONGLY SUGGEST THAT THE CHRONIC INFLAMMATORY ENVIRONMENT OF THE RA JOINT INDUCES EZH2 AND THUS MIGHT CAUSE CHANGES IN THE EPIGENETIC PROGRAMMES OF SF. 2011 5 531 45 ASTROCYTE REACTIVITY FOLLOWING BLAST EXPOSURE INVOLVES ABERRANT HISTONE ACETYLATION. BLAST INDUCED NEUROTRAUMA (BINT) IS A PREVALENT INJURY WITHIN MILITARY AND CIVILIAN POPULATIONS. THE INJURY IS CHARACTERIZED BY PERSISTENT INFLAMMATION AT THE CELLULAR LEVEL WHICH MANIFESTS AS A MULTITUDE OF COGNITIVE AND FUNCTIONAL IMPAIRMENTS. EPIGENETIC REGULATION OF TRANSCRIPTION OFFERS AN IMPORTANT CONTROL MECHANISM FOR GENE EXPRESSION AND CELLULAR FUNCTION WHICH MAY UNDERLIE CHRONIC INFLAMMATION AND RESULT IN NEURODEGENERATION. WE HYPOTHESIZE THAT ALTERED HISTONE ACETYLATION PATTERNS MAY BE INVOLVED IN BLAST INDUCED INFLAMMATION AND THE CHRONIC ACTIVATION OF GLIAL CELLS. THIS STUDY AIMED TO ELUCIDATE CHANGES TO HISTONE ACETYLATION OCCURRING FOLLOWING INJURY AND THE ROLES THESE CHANGES MAY HAVE WITHIN THE PATHOLOGY. SPRAGUE DAWLEY RATS WERE SUBJECTED TO EITHER A 10 OR 17 PSI BLAST OVERPRESSURE WITHIN AN ADVANCED BLAST SIMULATOR (ABS). SHAM ANIMALS UNDERWENT THE SAME PROCEDURES WITHOUT BLAST EXPOSURE. MEMORY IMPAIRMENTS WERE MEASURED USING THE NOVEL OBJECT RECOGNITION (NOR) TEST AT 2 AND 7 DAYS POST-INJURY. TISSUES WERE COLLECTED AT 7 DAYS FOR WESTERN BLOT AND IMMUNOHISTOCHEMISTRY (IHC) ANALYSIS. SHAM ANIMALS SHOWED INTACT MEMORY AT EACH TIME POINT. THE NOVEL OBJECT DISCRIMINATION DECREASED SIGNIFICANTLY BETWEEN TWO AND 7 DAYS FOR EACH INJURY GROUP (P < 0.05). THIS IS INDICATIVE OF THE ONSET OF MEMORY IMPAIRMENT. WESTERN BLOT ANALYSIS SHOWED GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP), A KNOWN MARKER OF ACTIVATED ASTROCYTES, WAS ELEVATED IN THE PREFRONTAL CORTEX (PFC) FOLLOWING BLAST EXPOSURE FOR BOTH INJURY GROUPS. ANALYSIS OF HISTONE PROTEIN EXTRACT SHOWED NO CHANGES IN THE LEVEL OF ANY TOTAL HISTONE PROTEINS WITHIN THE PFC. HOWEVER, ACETYLATION LEVELS OF HISTONE H2B, H3, AND H4 WERE DECREASED IN BOTH GROUPS (P < 0.05). CO-LOCALIZATION IMMUNOFLUORESCENCE WAS USED TO FURTHER INVESTIGATE ANY POTENTIAL CORRELATION BETWEEN DECREASED HISTONE ACETYLATION AND ASTROCYTE ACTIVATION. THESE EXPERIMENTS SHOWED A SIMILAR DECREASE IN H3 ACETYLATION IN ASTROCYTES EXPOSED TO A 17 PSI BLAST BUT NOT A 10 PSI BLAST. FURTHER INVESTIGATION OF GENE EXPRESSION BY POLYMERASE CHAIN REACTION (PCR) ARRAY, SHOWED DYSREGULATION OF SEVERAL CYTOKINE AND CYTOKINE RECEPTORS THAT ARE INVOLVED IN NEUROINFLAMMATORY PROCESSES. WE HAVE SHOWN ABERRANT HISTONE ACETYLATION PATTERNS INVOLVED IN BLAST INDUCED ASTROGLIOSIS AND COGNITIVE IMPAIRMENTS. FURTHER UNDERSTANDING OF THEIR ROLE IN THE INJURY PROGRESSION MAY LEAD TO NOVEL THERAPEUTIC TARGETS. 2016 6 793 55 CELLULAR RE- AND DE-PROGRAMMING BY MICROENVIRONMENTAL MEMORY: WHY SHORT TGF-BETA1 PULSES CAN HAVE LONG EFFECTS. BACKGROUND: FIBROSIS POSES A SUBSTANTIAL SETBACK IN REGENERATIVE MEDICINE. HISTOPATHOLOGICALLY, FIBROSIS IS AN EXCESSIVE ACCUMULATION OF COLLAGEN AFFECTED BY MYOFIBROBLASTS AND THIS CAN OCCUR IN ANY TISSUE THAT IS EXPOSED TO CHRONIC INJURY OR INSULT. TRANSFORMING GROWTH FACTOR (TGF)-BETA1, A CRUCIAL MEDIATOR OF FIBROSIS, DRIVES DIFFERENTIATION OF FIBROBLASTS INTO MYOFIBROBLASTS. THESE CELLS EXHIBIT ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) AND SYNTHESIZE HIGH AMOUNTS OF COLLAGEN I, THE MAJOR EXTRACELLULAR MATRIX (ECM) COMPONENT OF FIBROSIS. WHILE HORMONES STIMULATE CELLS IN A PULSATILE MANNER, LITTLE IS KNOWN ABOUT CELLULAR RESPONSE KINETICS UPON GROWTH FACTOR IMPACT. WE THEREFORE STUDIED THE EFFECTS OF SHORT TGF-BETA1 PULSES IN TERMS OF THE INDUCTION AND MAINTENANCE OF THE MYOFIBROBLAST PHENOTYPE. RESULTS: TWENTY-FOUR HOURS AFTER A SINGLE 30 MIN TGF-BETA1 PULSE, TRANSCRIPTION OF FIBROGENIC GENES WAS UPREGULATED, BUT SUBSIDED 7 DAYS LATER. IN PARALLEL, COLLAGEN I SECRETION RATE AND ALPHA-SMA PRESENCE WERE ELEVATED FOR 7 DAYS. A SECOND PULSE 24 H LATER EXTENDED THE DURATION OF EFFECTS TO 14 DAYS. WE COULD NOT ESTABLISH EPIGENETIC CHANGES ON FIBROGENIC TARGET GENES TO EXPLAIN THE LONG-LASTING EFFECTS. HOWEVER, ECM DEPOSITED UNDER SINGLY PULSED TGF-BETA1 WAS ABLE TO INDUCE MYOFIBROBLAST FEATURES IN PREVIOUSLY UNTREATED FIBROBLASTS. DEPENDENT ON THE AGE OF THE ECM (1 DAY VERSUS 7 DAYS' FORMATION TIME), THIS PROPERTY WAS DIMINISHED. VICE VERSA, MYOFIBROBLASTS WERE CULTURED ON FIBROBLAST ECM AND CELLS OBSERVED TO EXPRESS REDUCED (IN COMPARISON WITH MYOFIBROBLASTS) LEVELS OF COLLAGEN I. CONCLUSIONS: WE DEMONSTRATED THAT SHORT TGF-BETA1 PULSES CAN EXERT LONG-LASTING EFFECTS ON FIBROBLASTS BY CHANGING THEIR MICROENVIRONMENT, THUS LEAVING AN IMPRINT AND CREATING A RECIPROCAL FEED-BACK LOOP. THEREFORE, THE ECM MIGHT ACT AS MID-TERM MEMORY FOR PATHOBIOCHEMICAL EVENTS. WE WOULD EXPECT THIS MICROENVIRONMENTAL MEMORY TO BE DEPENDENT ON MATRIX TURNOVER AND, AS SUCH, TO BE ERASABLE. OUR FINDINGS CONTRIBUTE TO THE CURRENT UNDERSTANDING OF FIBROBLAST INDUCTION AND MAINTENANCE, AND HAVE BEARING ON THE DEVELOPMENT OF ANTIFIBROTIC DRUGS. 2013 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 6020 53 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 9 1236 42 CURCUMIN AMELIORATES NEPHROSCLEROSIS VIA SUPPRESSION OF HISTONE ACETYLATION INDEPENDENT OF HYPERTENSION. BACKGROUND: ALTHOUGH HISTONE ACETYLATION, AN EPIGENETIC MODIFICATION, HAS BEEN REPORTED TO BE RELATED TO THE PROGRESSION OF VARIOUS DISEASES, ITS INVOLVEMENT IN NEPHROSCLEROSIS IS UNCLEAR. METHODS: DAHL SALT-SENSITIVE RATS WERE USED AS A MODEL OF NEPHROSCLEROSIS IN THIS STUDY. THE RATS WERE DIVIDED INTO THREE GROUPS: (I) NORMAL-SALT DIET GROUP, (II) HIGH-SALT DIET GROUP (HS), AND (III) HS ADMINISTERED DAILY WITH CURCUMIN, A HISTONE ACETYLTRANSFERASE INHIBITOR (HS+C). AT 6 WEEKS AFTER THE TREATMENT, THE KIDNEYS WERE DISSECTED. MORPHOLOGIC CHANGES WERE ASSESSED BY MASSON'S TRICHROME STAINING. THE NUMBER OF MACROPHAGES, FIBROBLASTS AND THE CELLS EXPRESSING ACETYLATED HISTONE H3 AT LYS 9 (H3K9) WERE ASSESSED BY IMMUNOHISTOCHEMISTRY. RESULTS: ALTHOUGH BOTH HS AND HS+C RATS REVEALED A MARKED INCREASE IN SYSTOLIC BLOOD PRESSURE, SERUM CREATININE WAS INCREASED ONLY IN HS RATS AT 6 WEEKS. IN THE HS RATS, NEPHROSCLEROSIS WAS INDUCED, ACCOMPANYING A SIGNIFICANT ACCUMULATION OF MACROPHAGES AND FIBROBLASTS. THE INFLAMMATION AND FIBROSIS WAS MARKEDLY SUPPRESSED IN THE HS+C GROUP. THE LEVEL OF HISTONE ACETYLATION AT LYS 9 WAS ENHANCED IN THE HS RATS, WHEREAS CURCUMIN ADMINISTRATION SUPPRESSED THE HISTONE ACETYLATION. MOREOVER, IN THE HS RATS, INTERLEUKIN-6 GENE EXPRESSION WAS ASSOCIATED WITH ACETYLATED H3K9, AS REVEALED BY CHROMATIN IMMUNOPRECIPITATION ASSAY. CONCLUSIONS: OUR RESULTS SUGGESTED THAT CURCUMIN AMELIORATES NEPHROSCLEROSIS VIA SUPPRESSION OF HISTONE ACETYLATION, INDEPENDENTLY OF HYPERTENSION. 2016 10 3720 37 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 11 3935 50 LIVER-SPECIFIC KNOCKDOWN OF CLASS IIA HDACS HAS LIMITED EFFICACY ON GLUCOSE METABOLISM BUT ENTAILS SEVERE ORGAN SIDE EFFECTS IN MICE. HISTONE DEACETYLASES (HDACS) ARE IMPORTANT REGULATORS OF EPIGENETIC GENE MODIFICATION THAT ARE INVOLVED IN THE TRANSCRIPTIONAL CONTROL OF METABOLISM. IN PARTICULAR CLASS IIA HDACS HAVE BEEN SHOWN TO AFFECT HEPATIC GLUCONEOGENESIS AND PREVIOUS APPROACHES REVEALED THAT THEIR INHIBITION REDUCES BLOOD GLUCOSE IN TYPE 2 DIABETIC MICE. IN THE PRESENT STUDY, WE AIMED TO EVALUATE THE POTENTIAL OF CLASS IIA HDAC INHIBITION AS A THERAPEUTIC OPPORTUNITY FOR THE TREATMENT +OF METABOLIC DISEASES. FOR THAT, SIRNAS SELECTIVELY TARGETING HDAC4, 5 AND 7 WERE SELECTED AND USED TO ACHIEVE A COMBINATORIAL KNOCKDOWN OF THESE THREE CLASS IIA HDAC ISOFORMS. SUBSEQUENTLY, THE HEPATOCELLULAR EFFECTS AS WELL AS THE IMPACT ON GLUCOSE AND LIPID METABOLISM WERE ANALYZED IN VITRO AND IN VIVO. THE TRIPLE KNOCKDOWN RESULTED IN A STATISTICALLY SIGNIFICANT DECREASE OF GLUCONEOGENIC GENE EXPRESSION IN MURINE AND HUMAN HEPATOCYTE CELL MODELS. A SIMILAR HDAC-INDUCED DOWNREGULATION OF HEPATIC GLUCONEOGENESIS GENES COULD BE ACHIEVED IN MICE USING A LIVER-SPECIFIC LIPID NANOPARTICLE SIRNA FORMULATION. HOWEVER, THE EFFICACY ON WHOLE BODY GLUCOSE METABOLISM ASSESSED BY PYRUVATE-TOLERANCE TESTS WERE ONLY LIMITED AND DID NOT OUTWEIGH THE SAFETY FINDINGS OBSERVED BY HISTOPATHOLOGICAL ANALYSIS IN SPLEEN AND KIDNEY. MECHANISTICALLY, AFFYMETRIX GENE EXPRESSION STUDIES PROVIDE EVIDENCE THAT CLASS IIA HDACS DIRECTLY TARGET OTHER KEY FACTORS BEYOND THE DESCRIBED FORKHEAD BOX (FOXP) TRANSCRIPTION REGULATORS, SUCH AS HEPATOCYTE NUCLEAR FACTOR 4 ALPHA (HNF4A). DOWNSTREAM OF THESE FACTORS SEVERAL ADDITIONAL PATHWAYS WERE REGULATED NOT MERELY INCLUDING GLUCOSE AND LIPID METABOLISM AND TRANSPORT. IN CONCLUSION, THE LIVER-DIRECTED COMBINATORIAL KNOCKDOWN OF HDAC4, 5 AND 7 BY THERAPEUTIC SIRNAS AFFECTED MULTIPLE PATHWAYS IN VITRO, LEADING IN VIVO TO THE DOWNREGULATION OF GENES INVOLVED IN GLUCONEOGENESIS. HOWEVER, THE EFFECTS ON GENE EXPRESSION LEVEL WERE NOT PARALLELED BY A SIGNIFICANT REDUCTION OF GLUCONEOGENESIS IN MICE. COMBINED KNOCKDOWN OF HDAC ISOFORMS WAS ASSOCIATED WITH SEVERE ADVERSE EFFECTS IN VIVO, CHALLENGING THIS APPROACH AS A TREATMENT OPTION FOR CHRONIC METABOLIC DISORDERS LIKE TYPE 2 DIABETES. 2020 12 3795 40 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 13 4899 33 OXIDATIVE STRESS MEDIATES THE APOPTOSIS AND EPIGENETIC MODIFICATION OF THE BCL-2 PROMOTER VIA DNMT1 IN A CIGARETTE SMOKE-INDUCED EMPHYSEMA MODEL. BACKGROUND: EMPHYSEMA IS A CRUCIAL PATHOLOGICAL CHARACTERISTIC OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). OXIDATIVE STRESS, APOPTOSIS AND EPIGENETIC MECHANISMS CONTRIBUTE TO THE PATHOGENESIS OF EMPHYSEMA. HOWEVER, AN ATTEMPT TO ACCURATELY IDENTIFY WHETHER THESE MECHANISMS INTERACT WITH EACH OTHER AND HOW THEY ARE TRIGGERED HAS NEVER BEEN CONDUCTED. METHOD: THE TOTAL REACTIVE OXYGEN SPECIES (ROS) LEVEL, PULMONARY APOPTOSIS AND B-CELL LYMPHOMA/LEUKEMIA-2 (BCL-2) EXPRESSION, AN APOPTOSIS REGULATOR, WERE DETECTED IN SAMPLES FROM COPD PATIENTS. BISULFITE SEQUENCING PCR (BSP) WAS CONDUCTED TO OBSERVE THE ALTERATIONS IN THE METHYLATION OF THE BCL-2 PROMOTER IN SPECIMENS. THE DYSREGULATION OF DNA METHYLTRANSFERASE ENZYME 1 (DNMT1), A VITAL DNA METHYLTRANSFERASE ENZYME, IN THE LUNGS OF PATIENTS WAS CONFIRMED THROUGH WESTERN BLOTTING. TO FIND OUT INTERACTIONS BETWEEN OXIDATIVE STRESS AND DNA METHYLATION IN EMPHYSEMA, MOUSE MODELS WERE BUILT WITH ANTIOXIDANT TREATMENT AND DNMT1 SILENCING, AND WERE EXAMINED WITH THE PULMONARY APOPTOSIS, BCL-2 AND DNMT1 LEVELS, AND EPIGENETIC ALTERATIONS OF BCL-2. RESULTS: HIGHER ROS LEVELS AND PULMONARY APOPTOSIS WERE OBSERVED IN COPD PATIENTS THAN IN HEALTHY CONTROLS. DOWNREGULATED BCL-2 EXPRESSION WITH INCREASED PROMOTER METHYLATION AND DNMT1 PROTEIN EXPRESSION WAS FOUND IN COPD PATIENTS. ANTIOXIDANT TREATMENT REDUCED THE LEVEL OF ROS, DNMT1 PROTEIN AND EMPHYSEMATOUS PROGRESSION IN THE SMOKING MODELS. FOLLOWING DNMT1 BLOCKADE, SMOKING MODELS SHOWED IMPROVED LUNG FUNCTION, PULMONARY APOPTOSIS, EMPHYSEMATOUS PROGRESSION, AND INCREASED BCL-2 PROTEIN LEVEL WITH LESS PROMOTER METHYLATION THAN EMPHYSEMA MICE. CONCLUSION: CIGARETTE-INDUCED OXIDATIVE STRESS MEDIATES PULMONARY APOPTOSIS AND HYPERMETHYLATION OF THE BCL-2 PROMOTER IN EMPHYSEMA MODELS THROUGH DNMT1. 2020 14 808 31 CHANGED HISTONE ACETYLATION PATTERNS IN NORMAL-APPEARING WHITE MATTER AND EARLY MULTIPLE SCLEROSIS LESIONS. THE EPIGENETIC IDENTITY OF OLIGODENDROCYTES IS MODULATED BY POSTTRANSLATIONAL MODIFICATIONS OF HISTONES. ACETYLATION OF HISTONE H3 RESULTS FROM THE BALANCE BETWEEN THE ACTIVITY OF HISTONE ACETYLTRANSFERASES (HATS) AND HISTONE DEACETYLASES AND MODULATES TRANSCRIPTIONAL ACTIVATION. WE HAVE PREVIOUSLY SHOWN THAT, IN RODENTS, HISTONE DEACETYLATION FAVORS OLIGODENDROCYTE DIFFERENTIATION, WHEREAS ACETYLATION IS ASSOCIATED WITH INCREASED LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION. HERE, WE REPORT, IN HUMANS BRAINS, A SHIFT TOWARD HISTONE ACETYLATION IN THE WHITE MATTER OF THE FRONTAL LOBES OF AGED SUBJECTS AND IN PATIENTS WITH CHRONIC MULTIPLE SCLEROSIS (MS). INCREASED IMMUNOREACTIVITY FOR ACETYLATED HISTONE H3 WAS OBSERVED IN THE NUCLEI OF NOGOA+ OLIGODENDROCYTES IN A SUBSET OF MS SAMPLES. THESE CHANGES WERE ASSOCIATED WITH HIGH LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION (I.E., TCF7L2, ID2, AND SOX2) AND HIGHER HAT TRANSCRIPT LEVELS (I.E., CBP, P300) IN FEMALE MS PATIENTS COMPARED WITH NON-NEUROLOGICAL CONTROLS AND CORRELATED WITH DISEASE DURATION. CHROMATIN IMMUNOPRECIPITATION FROM SAMPLES OF MS PATIENTS REVEALED ENRICHMENT OF ACETYL-HISTONE H3 AT THE PROMOTER OF THE INCREASED TARGET GENES (I.E., TCF7L2). THE DATA IN CHRONIC LESIONS CONTRASTED WITH FINDINGS IN EARLY MS LESIONS, WHERE A MARKED OLIGODENDROGLIAL HISTONE DEACETYLATION WAS OBSERVED. TOGETHER, THESE DATA SUGGEST THAT HISTONE DEACETYLATION IS A PROCESS THAT OCCURS AT THE EARLY STAGES OF THE DISEASE AND WHOSE EFFICIENCY DECREASES WITH DISEASE DURATION. 2011 15 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 16 1035 44 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 3342 36 HISTONE DEACETYLASE9 REPRESENTS THE EPIGENETIC PROMOTION OF M1 MACROPHAGE POLARIZATION AND INFLAMMATORY RESPONSE VIA TLR4 REGULATION. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY RESPONSE MEDIATED BY VARIOUS FACTORS, WHERE EPIGENETIC REGULATION INVOLVING HISTONE DEACETYLATION IS ENVISAGED TO MODULATE THE EXPRESSION OF RELATED PROTEINS BY REGULATING THE BINDING OF TRANSCRIPTION FACTORS TO DNA, THEREBY INFLUENCING THE DEVELOPMENT OF ATHEROSCLEROSIS. THE MECHANISM OF ATHEROSCLEROSIS BY HISTONE DEACETYLATION IS PARTLY KNOWN; HENCE, THIS PROJECT AIMED AT INVESTIGATING THE ROLE OF HISTONE DEACETYLASE 9 (HDAC9) IN ATHEROSCLEROSIS. FOR THIS PURPOSE, SERUM WAS SEPARATED FROM BLOOD SAMPLES FOLLOWING CLOTTING AND CENTRIFUGATION FROM ATHEROSCLEROTIC AND HEALTHY PATIENTS (N = 40 EACH), AND THEN, VARIOUS TESTS WERE PERFORMED. THE RESULTS INDICATED THAT TOLL-LIKE RECEPTOR 4 (TLR4) WAS NOT ONLY POSITIVELY CORRELATED TO THE HDAC9 GENE, BUT WAS ALSO UPREGULATED IN ATHEROSCLEROSIS, WHERE IT WAS ALSO SIGNIFICANTLY UPREGULATED IN THE ATHEROSCLEROSIS CELL MODEL OF OXIDIZED LOW-DENSITY LIPOPROTEIN-INDUCED MACROPHAGES. CONVERSELY, THE TLR4 WAS SIGNIFICANTLY DOWNREGULATED IN INSTANCES OF LOSS OF HDAC9 FUNCTION, CEMENTING THE BRIDGING RELATIONSHIP BETWEEN HDAC9 AND MACROPHAGE POLARIZATION, WHERE THE HDAC9 WAS FOUND TO UPREGULATE M1 MACROPHAGE POLARIZATION WHICH TRANSLATED INTO THE RELEASE OF HIGHER CONTENT OF PROINFLAMMATORY CYTOKINES SUCH AS INTERLEUKIN-1BETA (IL-1BETA) AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), WHICH TEND TO SIGNIFICANTLY DECREASE FOLLOWING THE DELETION OF TLR4. HENCE, THIS STUDY REPORTS NOVEL RELATION BETWEEN EPIGENETIC CONTROL AND ATHEROSCLEROSIS, WHICH COULD PARTLY BE EXPLAINED BY HISTONE DEACETYLATION. 2022 18 3981 37 LONG-TERM EPIGENETIC THERAPY WITH ORAL ZEBULARINE HAS MINIMAL SIDE EFFECTS AND PREVENTS INTESTINAL TUMORS IN MICE. RECENT SUCCESSES IN THE APPLICATION OF EPIGENETIC DRUGS FOR THE TREATMENT OF MYELODYSPLASTIC SYNDROME HAVE RAISED QUESTIONS ON THE SAFETY OF LONG-TERM ADMINISTRATION OF DNA METHYLATION INHIBITORS. WE TREATED PREWEANED CANCER PRONE APC(MIN/+) (MIN) MICE CONTINUOUSLY WITH THE DNA METHYLATION INHIBITOR ZEBULARINE IN THEIR DRINKING WATER TO DETERMINE THE EFFECTS OF THE DRUG ON NORMAL MOUSE DEVELOPMENT AS WELL AS CANCER PREVENTION. ZEBULARINE CAUSED A TISSUE-SPECIFIC REDUCTION IN DNA METHYLATION AT B1 SHORT INTERSPERSED NUCLEOTIDE ELEMENTS IN THE SMALL AND LARGE INTESTINES OF FEMALE MIN MICE BUT NOT IN OTHER ORGANS EXAMINED AFTER CHRONIC ORAL TREATMENT. NO SIGNIFICANT DIFFERENCE IN THE AVERAGE WEIGHTS OF MICE WAS OBSERVED DURING THE TREATMENT. IN ADDITION, ANALYSIS OF GLOBAL GENE EXPRESSION OF COLONIC EPITHELIAL CELLS FROM THE FEMALES INDICATED THAT ONLY 3% TO 6% OF THE GENES WERE AFFECTED IN THEIR EXPRESSION. WE DID NOT DETECT TOXICITY AND ABNORMALITIES FROM THE HISTOPATHOLOGIC ANALYSIS OF LIVER AND INTESTINAL TISSUES. LASTLY, WE TESTED WHETHER PREVENTION OF TUMORIGENESIS CAN BE ACHIEVED WITH CHRONIC ORAL ADMINISTRATION OF ZEBULARINE IN MIN MICE. THE AVERAGE NUMBER OF POLYPS IN MIN FEMALES DECREASED FROM 58 TO 1, WHEREAS THE AVERAGE POLYP NUMBER REMAINED UNAFFECTED IN MIN MALES POSSIBLY DUE TO DIFFERENTIAL ACTIVITY OF ALDEHYDE OXIDASE. TAKEN TOGETHER, OUR RESULTS SHOW FOR THE FIRST TIME THAT LONG-TERM ORAL ADMINISTRATION OF ZEBULARINE CAUSES A GENDER-SPECIFIC ABROGATION OF INTESTINAL TUMORS WHILE CAUSING A TISSUE-SPECIFIC DNA DEMETHYLATION. IMPORTANTLY, PROLONGED TREATMENT OF MICE WITH EPIGENETIC DRUGS RESULTED IN ONLY MINOR DEVELOPMENTAL AND HISTOLOGIC CHANGES. 2008 19 2590 35 EPIGENETICS OF PROTEASOME INHIBITION IN THE LIVER OF RATS FED ETHANOL CHRONICALLY. AIM: TO EXAMINE THE EFFECTS OF ETHANOL-INDUCED PROTEASOME INHIBITION, AND THE EFFECTS OF PROTEASOME INHIBITION IN THE REGULATION OF EPIGENETIC MECHANISMS. METHODS: RATS WERE FED ETHANOL FOR 1 MO USING THE TSUKAMOTO-FRENCH MODEL AND WERE COMPARED TO RATS GIVEN THE PROTEASOME INHIBITOR PS-341 (BORTEZOMIB, VELCADE(TM)) BY INTRAPERITONEAL INJECTION. MICROARRAY ANALYSIS AND REAL TIME PCR WERE PERFORMED AND PROTEASOME ACTIVITY ASSAYS AND WESTERN BLOT ANALYSIS WERE PERFORMED USING ISOLATED NUCLEI. RESULTS: CHRONIC ETHANOL FEEDING CAUSED A SIGNIFICANT INHIBITION OF THE UBIQUITIN PROTEASOME PATHWAY IN THE NUCLEUS, WHICH LED TO CHANGES IN THE TURNOVER OF TRANSCRIPTIONAL FACTORS, HISTONE-MODIFYING ENZYMES, AND, THEREFORE, AFFECTED EPIGENETIC MECHANISMS. CHRONIC ETHANOL FEEDING WAS RELATED TO AN INCREASE IN HISTONE ACETYLATION, AND IT IS HYPOTHESIZED THAT THE PROTEASOME PROTEOLYTIC ACTIVITY REGULATED HISTONE MODIFICATIONS BY CONTROLLING THE STABILITY OF HISTONE MODIFYING ENZYMES, AND, THEREFORE, REGULATED THE CHROMATIN STRUCTURE, ALLOWING EASY ACCESS TO CHROMATIN BY RNA POLYMERASE, AND, THUS, PROPER GENE EXPRESSION. PROTEASOME INHIBITION BY PS-341 INCREASED HISTONE ACETYLATION SIMILAR TO CHRONIC ETHANOL FEEDING. IN ADDITION, PROTEASOME INHIBITION CAUSED DRAMATIC CHANGES IN HEPATIC REMETHYLATION REACTIONS AS THERE WAS A SIGNIFICANT DECREASE IN THE ENZYMES RESPONSIBLE FOR THE REGENERATION OF S-ADENOSYLMETHIONINE, AND, IN PARTICULAR, A SIGNIFICANT DECREASE IN THE BETAINE-HOMOCYSTEINE METHYLTRANSFERASE ENZYME. THIS SUGGESTED THAT HYPOMETHYLATION WAS ASSOCIATED WITH PROTEASOME INHIBITION, AS INDICATED BY THE DECREASE IN HISTONE METHYLATION. CONCLUSION: THE ROLE OF PROTEASOME INHIBITION IN REGULATING EPIGENETIC MECHANISMS, AND ITS LINK TO LIVER INJURY IN ALCOHOLIC LIVER DISEASE, IS THUS A PROMISING APPROACH TO STUDY LIVER INJURY DUE TO CHRONIC ETHANOL CONSUMPTION. 2009 20 476 42 ARSENIC INDUCES FIBROGENIC CHANGES IN HUMAN KIDNEY EPITHELIAL CELLS POTENTIALLY THROUGH EPIGENETIC ALTERATIONS IN DNA METHYLATION. ARSENIC CONTAMINATION IS A SIGNIFICANT PUBLIC HEALTH ISSUE, AND KIDNEY IS ONE OF THE TARGET ORGAN FOR ARSENIC-INDUCED ADVERSE EFFECTS. RENAL FIBROSIS IS A WELL-KNOWN PATHOLOGICAL STAGE FREQUENTLY OBSERVED IN PROGRESSIVE CHRONIC KIDNEY DISEASE (CKD). EPIDEMIOLOGICAL STUDIES IMPLICATE ARSENIC EXPOSURE TO CKD, BUT THE ROLE OF ARSENIC IN KIDNEY FIBROSIS AND THE UNDERLYING MECHANISM IS STILL UNCLEAR. IT IS IN THIS CONTEXT THAT THE CURRENT STUDY EVALUATED THE EFFECTS OF LONG-TERM ARSENIC EXPOSURE ON THE CELLULAR RESPONSE IN MORPHOLOGY, AND MARKER GENES EXPRESSION WITH RESPECT TO FIBROSIS USING HUMAN KIDNEY 2 (HK-2) EPITHELIAL CELLS. RESULTS OF THIS STUDY REVEALED THAT IN ADDITION TO INCREASED GROWTH, HK-2 CELLS UNDERWENT PHENOTYPIC, BIOCHEMICAL AND MOLECULAR CHANGES INDICATIVE OF EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IN RESPONSE TO THE EXPOSURE TO ARSENIC. MOST IMPORTANTLY, THE ARSENIC-EXPOSED CELLS ACQUIRED THE PATHOGENIC FEATURES OF FIBROSIS AS SUPPORTED BY INCREASED EXPRESSION OF MARKERS FOR FIBROSIS, SUCH AS COLLAGEN I, FIBRONECTIN, TRANSFORMING GROWTH FACTOR BETA, AND ALPHA-SMOOTH MUSCLE ACTIN. UPREGULATION OF FIBROSIS ASSOCIATED SIGNALING MOLECULES SUCH AS TISSUE INHIBITOR OF METALLOPROTEINASES-3 AND MATRIX METALLOPROTEINASE-2 AS WELL AS ACTIVATION OF AKT WAS ALSO OBSERVED. ADDITIONALLY, THE EXPRESSION OF EPIGENETIC GENES (DNA METHYLTRANSFERASES 3A AND 3B; METHYL-CPG BINDING DOMAIN 4) WAS INCREASED IN ARSENIC-EXPOSED CELLS. TREATMENT WITH DNA METHYLATION INHIBITOR 5-AZA-2'-DC REVERSED THE EMT PROPERTIES AND RESTORED THE LEVEL OF PHOSPHO-AKT. TOGETHER, THESE DATA FOR THE FIRST TIME SUGGEST THAT LONG-TERM EXPOSURE TO ARSENIC CAN INCREASE THE RISK OF KIDNEY FIBROSIS. ADDITIONALLY, OUR DATA SUGGEST THAT THE ARSENIC-INDUCED FIBROTIC CHANGES ARE, AT LEAST IN PART, MEDIATED BY DNA METHYLATION AND THEREFORE POTENTIALLY CAN BE REVERSED BY EPIGENETIC THERAPEUTICS. 2019