1 6298 155 THE PROTECTIVE EFFECT OF ZEBULARINE, AN INHIBITOR OF DNA METHYLTRANSFERASE, ON RENAL TUBULOINTERSTITIAL INFLAMMATION AND FIBROSIS. RENAL FIBROSIS, THE FINAL PATHWAY OF CHRONIC KIDNEY DISEASE, IS CAUSED BY GENETIC AND EPIGENETIC MECHANISMS. ALTHOUGH DNA METHYLATION HAS DRAWN ATTENTION AS A DEVELOPING MECHANISM OF RENAL FIBROSIS, ITS CONTRIBUTION TO RENAL FIBROSIS HAS NOT BEEN CLARIFIED. TO ADDRESS THIS ISSUE, THE EFFECT OF ZEBULARINE, A DNA METHYLTRANSFERASE INHIBITOR, ON RENAL INFLAMMATION AND FIBROSIS IN THE MURINE UNILATERAL URETERAL OBSTRUCTION (UUO) MODEL WAS ANALYZED. ZEBULARINE SIGNIFICANTLY ATTENUATED RENAL TUBULOINTERSTITIAL FIBROSIS AND INFLAMMATION. ZEBULARINE DECREASED TRICHROME, ALPHA-SMOOTH MUSCLE ACTIN, COLLAGEN IV, AND TRANSFORMING GROWTH FACTOR-BETA1 STAINING BY 56.2%. 21.3%, 30.3%, AND 29.9%, RESPECTIVELY, AT 3 DAYS, AND BY 54.6%, 41.9%, 45.9%, AND 61.7%, RESPECTIVELY, AT 7 DAYS AFTER UUO. ZEBULARINE DOWNREGULATED MRNA EXPRESSION LEVELS OF MATRIX METALLOPROTEINASE (MMP)-2, MMP-9, FIBRONECTIN, AND SNAIL1 BY 48.6%. 71.4%, 31.8%, AND 42.4%, RESPECTIVELY, AT 7 DAYS AFTER UUO. ZEBULARINE ALSO SUPPRESSED THE ACTIVATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND THE EXPRESSION OF PRO-INFLAMMATORY CYTOKINES, INCLUDING TUMOR NECROSIS FACTOR-ALPHA, INTERLEUKIN (IL)-1BETA, AND IL-6, BY 69.8%, 74.9%, AND 69.6%, RESPECTIVELY, IN OBSTRUCTED KIDNEYS. FURTHERMORE, INHIBITING DNA METHYLTRANSFERASE BUTTRESSED THE NUCLEAR EXPRESSION OF NUCLEAR FACTOR (ERYTHROID-DERIVED 2)-LIKE FACTOR 2, WHICH UPREGULATED DOWNSTREAM EFFECTORS SUCH AS CATALASE (1.838-FOLD INCREASE AT 7 DAYS, P < 0.01), SUPEROXIDE DISMUTASE 1 (1.494-FOLD INCREASE AT 7 DAYS, P < 0.05), AND NAD(P)H: QUINONE OXIDOREDUATE-1 (1.376-FOLD INCREASE AT 7 DAYS, P < 0.05) IN OBSTRUCTED KIDNEYS. COLLECTIVELY, THESE FINDINGS SUGGEST THAT INHIBITING DNA METHYLATION RESTORES THE DISRUPTED BALANCE BETWEEN PRO-INFLAMMATORY AND ANTI-INFLAMMATORY PATHWAYS TO ALLEVIATE RENAL INFLAMMATION AND FIBROSIS. THEREFORE, THESE RESULTS HIGHLIGHT THE POSSIBILITY OF DNA METHYLTRANSFERASES AS THERAPEUTIC TARGETS FOR TREATING RENAL INFLAMMATION AND FIBROSIS. 2022 2 2433 30 EPIGENETIC SILENCING OF NAD(P)H:QUINONE OXIDOREDUCTASE 1 BY HEPATITIS B VIRUS X PROTEIN INCREASES MITOCHONDRIAL INJURY AND CELLULAR SUSCEPTIBILITY TO OXIDATIVE STRESS IN HEPATOMA CELLS. NAD(P)H:QUINONE OXIDOREDUCTASE 1 (NQO1) IS A PHASE II ENZYME THAT PARTICIPATES IN THE DETOXIFICATION OF DOPAMINE-DERIVED QUINONE MOLECULES AND REACTIVE OXYGEN SPECIES. OUR PRIOR WORK USING A PROTEOMIC APPROACH FOUND THAT NQO1 PROTEIN LEVELS WERE SIGNIFICANTLY DECREASED IN STABLE HEPATITIS B VIRUS (HBV)-PRODUCING HEPATOMA CELLS RELATIVE TO THE EMPTY-VECTOR-TRANSFECTED CONTROLS. HOWEVER, THE MECHANISM AND BIOLOGICAL SIGNIFICANCE OF THE NQO1 SUPPRESSION REMAIN ELUSIVE. IN THIS STUDY WE DEMONSTRATE THAT HBV X PROTEIN (HBX) INDUCES EPIGENETIC SILENCING OF NQO1 IN HEPATOMA CELLS THROUGH PROMOTER HYPERMETHYLATION VIA RECRUITMENT OF DNA METHYLTRANSFERASE DNMT3A TO THE PROMOTER REGION OF THE NQO1 GENE. IN HBV-RELATED HEPATOCELLULAR CARCINOMA (HCC) SPECIMENS, HBX EXPRESSION WAS CORRELATED NEGATIVELY TO NQO1 TRANSCRIPTS BUT POSITIVELY TO NQO1 PROMOTER HYPERMETHYLATION. DOWNREGULATION OF NQO1 BY HBX REDUCED INTRACELLULAR GLUTATHIONE LEVELS, IMPAIRED MITOCHONDRIAL FUNCTION, AND INCREASED SUSCEPTIBILITY OF HEPATOMA CELLS TO OXIDATIVE STRESS-INDUCED CELL INJURY. THESE RESULTS SUGGEST A NOVEL MECHANISM FOR HBV-MEDIATED PATHOGENESIS OF CHRONIC LIVER DISEASES, INCLUDING HCC. 2013 3 4894 32 OXIDATIVE STRESS CAUSED BY ACUTE AND CHRONIC EXPOSITION TO ALTITUDE. IN THIS ARTICLE, CURRENT VIEWS ON CELLULAR AND MOLECULAR BIOLOGY (BIOCHEMICAL) MECHANISMS ARE DISCUSSED UNDER THE ASPECT OF ALTITUDE EXPOSITION. THE ANDEAN, TIBETAN, AND ETHIOPIAN PATTERNS OF ADAPTATION TO HIGH-ALTITUDE HYPOXIA ARE KNOWN [BEAL ET AL. (2002) PROC NATL ACAD SCI USA 99: 17215-17218]. THE PHYLOGENETIC TREE OF THE HUMAN SPECIES SUGGESTS THAT THERE ARE GENETIC DIFFERENCES IN ADAPTATION PATTERNS TO CHRONIC HYPOXIC HYPOXIA. FIVE DEFENSE MECHANISMS ARE WELL ESTABLISHED FOR LOWLANDERS WHO ARE EXPOSED TO ACUTE HYPOXIC HYPOXIA. CONSEQUENCES OF THE CELLULAR DECREASE IN ATP ARE THE FORMATION OF HYPOXANTHINE AND XANTHINE, WHICH ARE THE SUBSTRATES FOR THE MASSIVE FORMATION OF SUPEROXIDE ANION RADICALS AND HYDROGEN PEROXIDE VIA THE OXIDASE ACTIVITY OF THE XANTHINE OXIDOREDUCTASE REACTION. UNDER SEVERE HYPOXIA, ABOUT 51 % OF THE TOTAL INHALED OXYGEN IS USED TO FORM SUPEROXIDE ANION RADICALS IN RAT LIVER [GERBER ET AL. (1989) ADV EXP MED BIOL 253B, PLENUM PRESS, NEW YORK, 497-504]. THE REACTIVITY AND SELECTIVITY OF THE SUPEROXIDE ANION RADICAL ARE MODIFIED BY SPECIFIC INTERACTIONS AND ELECTRON EXCHANGE. IT IS COMMONLY ACCEPTED THAT THE SUPEROXIDE ANION RADICAL IN AQUEOUS SOLUTIONS HAS A LIFETIME IN THE MILLISECOND RANGE. HOWEVER, ELECTRON SPIN RESONANCE SPECTROSCOPY STUDIES IN A KO2/H2O/IRON ION SYSTEM REVEALED FOR THE FIRST TIME A STABILIZATION OF A PART OF THE INITIALLY ADDED SUPEROXIDE ANION RADICALS LASTING UP TO HOURS AT ROOM TEMPERATURE [FOLDES-PAPP (1992) GEN PHYSIOL BIOPHYS 11: 3-38]. SUPEROXIDE ANION RADICALS ADSORBED ON AN OXIDIC IRON HYDRATE PHASE IN AQUEOUS SYSTEMS MIGHT FUNCTION AS A STRONG OXIDANT SIMILAR TO THAT SPECIES WHICH HAS BEEN SUGGESTED TO BE A COMPLEX BETWEEN OXYGEN AND DIFFERENT VALENCE STATES OF IRON IN THE INITIATION OF LIPID PEROXIDATION BY FERROUS IRON. THERE WERE SERIOUS DOUBTS ABOUT THE IDENTITY OF ALKOXY RADICALS. FOR THE FIRST TIME, ALKOXY RADICALS WERE DIRECTLY DEMONSTRATED IN SOLUTION BY ELECTRON SPIN RESONANCE SPECTROSCOPY [FOLDES-PAPP ET AL. (1991) ADV SYNTH CATAL 333: 293-301]. THE REDOX STATUS IN MAMMALIAN CELLS IS MAINLY DETERMINED BY THE ANTIOXIDANT GLUTATHIONE, WHICH IS A KEY PLAYER IN MAINTAINING THE INTRACELLULAR REDOX EQUILIBRIUM AND IN THE METABOLIC REGULATION OF THE CELLULAR DEFENSE AGAINST OXIDATIVE STRESS. AS REACTIVE OXYGEN SPECIES OCCUPY AN ESSENTIAL ROLE IN MEMBRANE DAMAGE, THE IDEA OF MEMBRANE-BOUND ENZYMATIC DEFENSE MECHANISMS GETS A NEW DIMENSION [FOLDES-PAPP ET AL. (1981) ACTA BIOL MED GER 40: 1129-1132; FOLDES-PAPP AND MARETZKI (1982) ACTA BIOL MED GER 41: 1003-1008]. THE STEADY-STATE BETWEEN ANTIOXIDANTS AND PRO-OXIDANTS AFFECTS THE GENE EXPRESSION VIA HYPOXIA-INDUCED TRANSCRIPTION ACTIVITIES. THE TRANSCRIPTION FACTOR HYPOXIA-INDUCIBLE FACTOR 1 (HIF-1) IS A GLOBAL REGULATOR OF OXYGEN HOMEOSTASIS. AS DISCUSSED IN THIS ARTICLE, HYPOXIA OR 'OXIDATIVE STRESS' IS ACCOMPANIED BY APPROPRIATE MOLECULAR ADAPTATION MECHANISMS AT THE ENZYMATIC OR EPIGENETIC LEVEL (ENZYMATIC AND NON-ENZYMATIC RADICAL INHIBITORS, POSTTRANSLATIONAL MODIFICATIONS) AND AT THE GENETIC LEVEL (TRANSCRIPTION, TRANSLATION). 2005 4 1980 31 EPIGENETIC ALTERATIONS IN CYTOCHROME P450 OXIDOREDUCTASE (POR) IN SPERM OF RATS EXPOSED TO TETRAHYDROCANNABINOL (THC). AS MARIJUANA LEGALIZATION IS INCREASING, RESEARCH REGARDING POSSIBLE LONG-TERM RISKS FOR USERS AND THEIR OFFSPRING IS NEEDED. LITTLE DATA EXISTS ON EFFECTS OF PATERNAL TETRAHYDROCANNABINOL (THC) EXPOSURE PRIOR TO REPRODUCTION. THIS STUDY DETERMINED IF CHRONIC THC EXPOSURE ALTERS SPERM DNA METHYLATION (DNAM) AND IF SUCH EFFECTS ARE INTERGENERATIONALLY TRANSMITTED. ADULT MALE RATS UNDERWENT ORAL GAVAGE WITH THC OR VEHICLE CONTROL. DIFFERENTIALLY METHYLATED (DM) LOCI IN MOTILE SPERM WERE IDENTIFIED USING REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS). ANOTHER COHORT WAS INJECTED WITH VEHICLE OR THC, AND SPERM DNAM WAS ANALYZED. FINALLY, THC-EXPOSED AND CONTROL ADULT MALE RATS WERE MATED WITH THC-NAIVE FEMALES. DNAM LEVELS OF TARGET GENES IN BRAIN TISSUES OF THE OFFSPRING WERE DETERMINED BY PYROSEQUENCING. RRBS IDENTIFIED 2,940 DM CPGS MAPPING TO 627 GENES. SIGNIFICANT HYPERMETHYLATION WAS CONFIRMED (P < 0.05) FOLLOWING ORAL THC ADMINISTRATION FOR CYTOCHROME P450 OXIDOREDUCTASE (POR), INVOLVED IN TOXIN PROCESSING AND DISORDERS OF SEXUAL DEVELOPMENT. POR HYPERMETHYLATION WAS NOT OBSERVED AFTER THC INJECTION OR IN THE SUBSEQUENT GENERATION. THESE RESULTS SUPPORT THAT THC ALTERS DNAM IN SPERM AND THAT ROUTE OF EXPOSURE CAN HAVE DIFFERENTIAL EFFECTS. ALTHOUGH WE DID NOT OBSERVE EVIDENCE OF INTERGENERATIONAL TRANSMISSION OF THE DNAM CHANGE, LARGER STUDIES ARE REQUIRED TO DEFINITIVELY EXCLUDE THIS POSSIBILITY. 2020 5 6456 42 THYMOSIN BETA4 PREVENTS OXIDATIVE STRESS, INFLAMMATION, AND FIBROSIS IN ETHANOL- AND LPS-INDUCED LIVER INJURY IN MICE. THYMOSIN BETA 4 (TBETA4), AN ACTIN-SEQUESTERING PROTEIN, IS INVOLVED IN TISSUE DEVELOPMENT AND REGENERATION. IT PREVENTS INFLAMMATION AND FIBROSIS IN SEVERAL TISSUES. WE INVESTIGATED THE ROLE OF TBETA4 IN CHRONIC ETHANOL- AND ACUTE LIPOPOLYSACCHARIDE- (LPS-) INDUCED MOUSE LIVER INJURY. C57BL/6 MICE WERE FED 5% ETHANOL IN LIQUID DIET FOR 4 WEEKS PLUS BINGE ETHANOL (5 G/KG, GAVAGE) WITH OR WITHOUT LPS (2 MG/KG, INTRAPERITONEAL) FOR 6 HOURS. TBETA4 (1 MG/KG, INTRAPERITONEAL) WAS ADMINISTERED FOR 1 WEEK. WE DEMONSTRATED THAT TBETA4 PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN LIVER INJURY MARKERS AS WELL AS CHANGES IN LIVER PATHOLOGY. IT ALSO PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN OXIDATIVE STRESS BY DECREASING ROS AND LIPID PEROXIDATION AND INCREASING THE ANTIOXIDANTS, REDUCED GLUTATHIONE AND MANGANESE-DEPENDENT SUPEROXIDE DISMUTASE. IT ALSO PREVENTED THE ACTIVATION OF NUCLEAR FACTOR KAPPA B BY BLOCKING THE PHOSPHORYLATION OF THE INHIBITORY PROTEIN, IKAPPAB, THEREBY PREVENTED PROINFLAMMATORY CYTOKINE PRODUCTION. MOREOVER, TBETA4 PREVENTED FIBROGENESIS BY SUPPRESSING THE EPIGENETIC REPRESSOR, METHYL-CPG-BINDING PROTEIN 2, THAT COORDINATELY REVERSED THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AND DOWNREGULATED FIBROGENIC GENES, PLATELET-DERIVED GROWTH FACTOR-BETA RECEPTOR, ALPHA-SMOOTH MUSCLE ACTIN, COLLAGEN 1, AND FIBRONECTIN, RESULTING IN REDUCED FIBROSIS. OUR DATA SUGGEST THAT TBETA4 HAS ANTIOXIDANT, ANTI-INFLAMMATORY, AND ANTIFIBROTIC POTENTIAL DURING ALCOHOLIC LIVER INJURY. 2018 6 5010 32 PEROXIDATION OF LINOLEIC, ARACHIDONIC AND OLEIC ACID IN RELATION TO THE INDUCTION OF OXIDATIVE DNA DAMAGE AND CYTOGENETIC EFFECTS. IN THE PRESENT STUDY, THE POSSIBLE ROLE OF THE POLYUNSATURATED FATTY ACIDS LINOLEIC AND ARACHIDONIC ACID IN THE CHEMICAL INDUCTION OF CARCINOGENESIS HAS BEEN INVESTIGATED. ANALYSIS OF 7,8-DIHYDRO-8-OXO-2'-DEOXYGUANOSINE (8-OXODG) LEVELS IN 2'-DEOXYGUANOSINE (DG) AND ISOLATED DNA HAS DEMONSTRATED THAT LINOLEIC AND ARACHIDONIC ACID ARE CAPABLE OF INDUCING THIS SPECIFIC GENOTOXIC DAMAGE. THIS EFFECT APPEARS TO BE RELATED TO THE DEGREE OF FATTY ACID UNSATURATION, SINCE IT WAS NOT INDUCED BY MONOUNSATURATED OLEIC ACID. ENZYMATIC PEROXIDATION OF LINOLEIC AND ARACHIDONIC ACID RESULTED IN A SIGNIFICANT INCREASE IN OXIDATIVE DNA DAMAGE. STUDIES ON THE INTERFERENCE OF RADICAL SCAVENGERS WITH THE INDUCTION OF 8-OXODG IN COMBINATION WITH ELECTRON SPIN RESONANCE SPECTROSCOPY DEMONSTRATED THAT THE SUPEROXIDE ANION WAS GENERATED DURING PEROXIDATION OF THESE FATTY ACIDS AND THAT SINGLET OXYGEN IS MOST LIKELY INVOLVED IN THE FORMATION OF OXIDATIVE DNA DAMAGE. THE LEVEL OF OXIDATIVE DAMAGE IN DG AND SINGLE-STRANDED DNA WAS HIGHER AS COMPARED TO THAT IN NATIVE DNA AFTER EQUIMOLAR TREATMENT. EXPOSURE OF HUMAN LYMPHOCYTES TO LINOLEIC OR ARACHIDONIC ACID DID NOT RESULT IN A SIGNIFICANT INCREASE IN LEVELS OF 8-OXODG. THIS MAY INDICATE THAT THE RATE OF INTRACELLULAR PEROXIDATION IS RELATIVELY LOW AND/OR THAT NUCLEAR DNA IN INTACT CELLS IS EFFECTIVELY PROTECTED AGAINST GENETIC DAMAGE INDUCED BY REACTIVE OXYGEN SPECIES. IT IS THEREFORE CONCLUDED THAT RELATIVELY SHORT PERIODS OF LINOLEIC OR ARACHIDONIC ACID ADMINISTRATION ARE NOT LIKELY TO IMPOSE A DIRECT GENOTOXIC RISK. IT CAN, HOWEVER, NOT BE EXCLUDED THAT CHRONIC EXPOSURE TO POLYUNSATURATED FATTY ACIDS INDUCES OXIDATIVE DNA DAMAGE OR IS RELATED TO CANCER RISK BY EPIGENETIC MECHANISMS, AS IS ALSO INDICATED BY THE OBSERVED CYTOTOXIC EFFECTS OF LINOLEIC AND ARACHIDONIC ACID. 1994 7 6166 31 THE GLUTATHIONE SYSTEM: A NEW DRUG TARGET IN NEUROIMMUNE DISORDERS. GLUTATHIONE (GSH) HAS A CRUCIAL ROLE IN CELLULAR SIGNALING AND ANTIOXIDANT DEFENSES EITHER BY REACTING DIRECTLY WITH REACTIVE OXYGEN OR NITROGEN SPECIES OR BY ACTING AS AN ESSENTIAL COFACTOR FOR GSH S-TRANSFERASES AND GLUTATHIONE PEROXIDASES. GSH ACTING IN CONCERT WITH ITS DEPENDENT ENZYMES, KNOWN AS THE GLUTATHIONE SYSTEM, IS RESPONSIBLE FOR THE DETOXIFICATION OF REACTIVE OXYGEN AND NITROGEN SPECIES (ROS/RNS) AND ELECTROPHILES PRODUCED BY XENOBIOTICS. ADEQUATE LEVELS OF GSH ARE ESSENTIAL FOR THE OPTIMAL FUNCTIONING OF THE IMMUNE SYSTEM IN GENERAL AND T CELL ACTIVATION AND DIFFERENTIATION IN PARTICULAR. GSH IS A UBIQUITOUS REGULATOR OF THE CELL CYCLE PER SE. GSH ALSO HAS CRUCIAL FUNCTIONS IN THE BRAIN AS AN ANTIOXIDANT, NEUROMODULATOR, NEUROTRANSMITTER, AND ENABLER OF NEURON SURVIVAL. DEPLETION OF GSH LEADS TO EXACERBATION OF DAMAGE BY OXIDATIVE AND NITROSATIVE STRESS; HYPERNITROSYLATION; INCREASED LEVELS OF PROINFLAMMATORY MEDIATORS AND INFLAMMATORY POTENTIAL; DYSFUNCTIONS OF INTRACELLULAR SIGNALING NETWORKS, E.G., P53, NUCLEAR FACTOR-KAPPAB, AND JANUS KINASES; DECREASED CELL PROLIFERATION AND DNA SYNTHESIS; INACTIVATION OF COMPLEX I OF THE ELECTRON TRANSPORT CHAIN; ACTIVATION OF CYTOCHROME C AND THE APOPTOTIC MACHINERY; BLOCKADE OF THE METHIONINE CYCLE; AND COMPROMISED EPIGENETIC REGULATION OF GENE EXPRESSION. AS SUCH, GSH DEPLETION HAS MARKED CONSEQUENCES FOR THE HOMEOSTATIC CONTROL OF THE IMMUNE SYSTEM, OXIDATIVE AND NITROSATIVE STRESS (O&NS) PATHWAYS, REGULATION OF ENERGY PRODUCTION, AND MITOCHONDRIAL SURVIVAL AS WELL. GSH DEPLETION AND CONCOMITANT INCREASE IN O&NS AND MITOCHONDRIAL DYSFUNCTIONS PLAY A ROLE IN THE PATHOPHYSIOLOGY OF DIVERSE NEUROIMMUNE DISORDERS, INCLUDING DEPRESSION, MYALGIC ENCEPHALOMYELITIS/CHRONIC FATIGUE SYNDROME AND PARKINSON'S DISEASE, SUGGESTING THAT DEPLETED GSH IS AN INTEGRAL PART OF THESE DISEASES. THERAPEUTICAL INTERVENTIONS THAT AIM TO INCREASE GSH CONCENTRATIONS IN VIVO INCLUDE N-ACETYL CYSTEINE; NRF-2 ACTIVATION VIA HYPERBARIC OXYGEN THERAPY; DIMETHYL FUMARATE; PHYTOCHEMICALS, INCLUDING CURCUMIN, RESVERATROL, AND CINNAMON; AND FOLATE SUPPLEMENTATION. 2014 8 4044 27 MACROPHAGES IN OXIDATIVE STRESS AND MODELS TO EVALUATE THE ANTIOXIDANT FUNCTION OF DIETARY NATURAL COMPOUNDS. ANTIOXIDANT TESTING OF NATURAL PRODUCTS HAS ATTRACTED INCREASING INTEREST IN RECENT YEARS, MAINLY DUE TO THE FACT THAT AN ANTIOXIDANT-RICH DIET MIGHT PROVIDE HEALTH BENEFITS. ACTIVATED MACROPHAGES ARE A MAJOR SOURCE OF REACTIVE OXYGEN SPECIES, REACTIVE NITROGEN SPECIES, AND PEROXYNITRITE GENERATED THROUGH THE SO-CALLED RESPIRATORY BURST. CONSTITUTIVELY RELEASED PROINFLAMMATORY CYTOKINE, ESPECIALLY TUMOR NECROSIS FACTOR-ALPHA, TRIGGERS NUCLEAR FACTOR-KAPPAB, AND ACTIVATOR PROTEIN-1 TRANSLOCATION LEADING TO THE OVER PRODUCTION OF REACTIVE OXYGEN SPECIES AND REACTIVE NITROGEN SPECIES IN MACROPHAGES. ACTIVATION OF TRANSCRIPTION FACTORS IN THE LONG-LIVED TISSUE-RESIDENT MACROPHAGES AND/OR MONOCYTE-DERIVED MACROPHAGES, TRIGGER EPIGENETIC MODIFICATIONS LEADING TO THE PATHOGENESIS OF CHRONIC DISEASES. NUTRACEUTICALS INCLUDING LIPID RAFT STRUCTURE DISRUPTION AGENT, CHOLESTEROL DEPLETION AGENT, FARNESYLTRANSFERASE INHIBITOR, NUCLEAR FACTOR-KAPPAB BLOCKER (ALPHA,BETA-UNSATURATED CARBONYL COMPOUNDS), GLUCOCORTICOID RECEPTOR AGONIST, AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AGONIST HAVE LONG BEEN USED TO INACTIVE MACROPHAGE. THE INHIBITION EFFECTS ON THE FORMATION OF NITRIC OXIDE, SUPEROXIDE, AND NITRITE PEROXIDE MAY BE RESPONSIBLE FOR THE ANTI-INFLAMMATORY FUNCTIONALITIES. ACTIVATED MACROPHAGE MODELS COULD BE USED TO IDENTIFY THE ACTIVE COMPONENTS FOR FUNCTIONAL DIETS DEVELOPMENT THROUGH A MULTIPLE TARGETS STRATEGY. 2017 9 6403 30 THE ROLES OF INDUCIBLE CHROMATIN AND TRANSCRIPTIONAL MEMORY IN CELLULAR DEFENSE SYSTEM RESPONSES TO REDOX-ACTIVE POLLUTANTS. PEOPLE ARE EXPOSED TO WIDE RANGE OF REDOX-ACTIVE ENVIRONMENTAL POLLUTANTS. AIR POLLUTION, HEAVY METALS, PESTICIDES, AND ENDOCRINE DISRUPTING CHEMICALS CAN DISRUPT CELLULAR REDOX STATUS. REDOX-ACTIVE POLLUTANTS IN OUR ENVIRONMENT ALL TRIGGER THEIR OWN SETS OF SPECIFIC CELLULAR RESPONSES, BUT THEY ALSO ACTIVATE A COMMON SET OF GENERAL STRESS RESPONSES THAT BUFFER THE CELL AGAINST HOMEOSTATIC INSULTS. THESE CELLULAR DEFENSE SYSTEM (CDS) PATHWAYS INCLUDE THE HEAT SHOCK RESPONSE, THE OXIDATIVE STRESS RESPONSE, THE HYPOXIA RESPONSE, THE UNFOLDED PROTEIN RESPONSE, THE DNA DAMAGE RESPONSE, AND THE GENERAL STRESS RESPONSE MEDIATED BY THE STRESS-ACTIVATED P38 MITOGEN-ACTIVATED PROTEIN KINASE. OVER THE PAST TWO DECADES, THE FIELD OF ENVIRONMENTAL EPIGENETICS HAS INVESTIGATED EPIGENETIC RESPONSES TO ENVIRONMENTAL POLLUTANTS, INCLUDING REDOX-ACTIVE POLLUTANTS. STUDIES OF THESE RESPONSES HIGHLIGHT THE ROLE OF CHROMATIN MODIFICATIONS IN CONTROLLING THE TRANSCRIPTIONAL RESPONSE TO POLLUTANTS AND THE ROLE OF TRANSCRIPTIONAL MEMORY, OFTEN REFERRED TO AS "EPIGENETIC REPROGRAMMING", IN PREDISPOSING PREVIOUSLY EXPOSED INDIVIDUALS TO MORE POTENT TRANSCRIPTIONAL RESPONSES ON SECONDARY CHALLENGE. MY CENTRAL THESIS IN THIS REVIEW IS THAT HIGH DOSE OR CHRONIC EXPOSURE TO REDOX-ACTIVE POLLUTANTS LEADS TO TRANSCRIPTIONAL MEMORIES AT CDS TARGET GENES THAT INFLUENCE THE CELL'S ABILITY TO MOUNT PROTECTIVE RESPONSES. TO SUPPORT THIS THESIS, I WILL: (1) SUMMARIZE THE KNOWN CHROMATIN FEATURES REQUIRED FOR INDUCIBLE GENE ACTIVATION; (2) REVIEW THE KNOWN FORMS OF TRANSCRIPTIONAL MEMORY; (3) DISCUSS THE ROLES OF INDUCIBLE CHROMATIN AND TRANSCRIPTIONAL MEMORY IN CDS RESPONSES THAT ARE ACTIVATED BY REDOX-ACTIVE ENVIRONMENTAL POLLUTANTS; AND (4) PROPOSE A CONCEPTUAL FRAMEWORK FOR CDS PATHWAY RESPONSIVENESS AS A READOUT OF TOTAL CELLULAR EXPOSURE TO REDOX-ACTIVE POLLUTANTS. 2021 10 3843 45 IRON-MEDIATED EPIGENETIC ACTIVATION OF NRF2 TARGETS. THE TOXIC EFFECTS OF EXCESS DIETARY IRON WITHIN THE COLONIC LUMEN ARE WELL DOCUMENTED, PARTICULARLY IN THE CONTEXT OF INFLAMMATORY BOWEL DISEASE (IBD) AND COLORECTAL CANCER (CRC). PROPOSED MECHANISMS THAT UNDERPIN IRON-ASSOCIATED INTESTINAL DISEASE INCLUDE: (1) THE PRO-INFLAMMATORY AND ROS-PROMOTING NATURE OF IRON, (2) GENE-EXPRESSION ALTERATIONS, AND (3) INTESTINAL MICROBIAL DYSBIOSIS. HOWEVER, TO DATE NO STUDIES HAVE EXAMINED THE EFFECT OF IRON ON THE COLONIC EPIGENOME. HERE WE DEMONSTRATE THAT CHRONIC IRON EXPOSURE OF COLONOCYTES LEADS TO SIGNIFICANT HYPOMETHYLATION OF THE EPIGENOME. BIOINFORMATIC ANALYSIS HIGHLIGHTS A SIGNIFICANT EPIGENETIC EFFECT ON NRF2 (NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR 2) PATHWAY TARGETS (INCLUDING NAD(P)H QUINONE DEHYDROGENASE 1 [NQO1] AND GLUTATHIONE PEROXIDASE 2 [GPX2]); THIS DEMETHYLATING EFFECT WAS VALIDATED AND SUBSEQUENT GENE AND PROTEIN EXPRESSION QUANTIFIED. THESE EPIGENETIC MODIFICATIONS WERE NOT OBSERVED UPON THE DIMINISHMENT OF CELLULAR LIPID PEROXIDATION WITH ENDOGENOUS GLUTATHIONE AND THE SUBSEQUENT REMOVAL OF IRON. ADDITIONALLY, THE INDUCTION OF TET1 EXPRESSION WAS FOUND POST-IRON TREATMENT, HIGHLIGHTING THE POSSIBILITY OF AN OXIDATIVE-STRESS INDUCTION OF TET1 AND SUBSEQUENT HYPOMETHYLATION OF NRF2 TARGETS. IN ADDITION, A STRONG TIME DEPENDENCE ON THE ESTABLISHMENT OF IRON-ORCHESTRATED HYPOMETHYLATION WAS FOUND WHICH WAS CONCURRENT WITH THE INCREASE IN THE INTRACELLULAR LABILE IRON POOL (LIP) AND LIPID PEROXIDATION LEVELS. THESE EPIGENETIC CHANGES WERE FURTHER VALIDATED IN MURINE INTESTINAL MUCOSA IN MODELS ADMINISTERED A CHRONIC IRON DIET, PROVIDING EVIDENCE FOR THE LIKELIHOOD OF DIETARY-IRON MEDIATED EPIGENETIC ALTERATIONS IN VIVO. FURTHERMORE, SIGNIFICANT CORRELATIONS WERE FOUND BETWEEN NQO1 AND GPX2 DEMETHYLATION AND HUMAN INTESTINAL TISSUE IRON-STATUS, THUS SUGGESTING THAT THESE IRON-MEDIATED EPIGENETIC MODIFICATIONS ARE LIKELY IN IRON-REPLETE ENTEROCYTES. TOGETHER, THESE DATA DESCRIBE A NOVEL MECHANISM BY WHICH EXCESS DIETARY IRON IS ABLE TO ALTER THE INTESTINAL PHENOTYPE, WHICH COULD HAVE IMPLICATIONS IN IRON-MEDIATED INTESTINAL DISEASE AND THE REGULATION OF FERROPTOSIS. 2022 11 449 19 APOCYNIN PREVENTS ANXIETY-LIKE BEHAVIOR AND HISTONE DEACETYLASES OVEREXPRESSION INDUCED BY SUB-CHRONIC STRESS IN MICE. ANXIETY DISORDERS ARE COMMON MENTAL HEALTH DISEASES AFFECTING UP TO 7% OF PEOPLE AROUND THE WORLD. STRESS IS CONSIDERED ONE OF THE MAJOR ENVIRONMENTAL RISK FACTORS TO PROMOTE ANXIETY DISORDERS THROUGH MECHANISMS INVOLVING EPIGENETIC CHANGES. MOREOVER, ALTERATION IN REDOX BALANCE AND INCREASED REACTIVE OXYGEN SPECIES (ROS) PRODUCTION HAVE BEEN DETECTED IN ANXIETY PATIENTS AND IN STRESSED-ANIMAL MODELS OF ANXIETY. HERE WE TESTED IF THE ADMINISTRATION OF APOCYNIN, A NATURAL ORIGIN ANTIOXIDANT, MAY PREVENT THE ANXIETY-LIKE PHENOTYPE AND REDUCTION OF HISTONE ACETYLATION INDUCED BY A SUBCHRONIC FORCED SWIMMING STRESS (FSS) PARADIGM. WE FOUND THAT APOCYNIN PREVENTED THE ENHANCED LATENCY TIME IN THE NOVELTY-SUPPRESSED FEEDING TEST, AND THE PRODUCTION OF MALONDIALDEHYDE INDUCED BY FSS. MOREOVER, APOCYNIN WAS ABLE TO BLOCK THE UPREGULATION OF P47PHOX, A KEY SUBUNIT OF THE NADPH OXIDASE COMPLEX. FINALLY, APOCYNIN PREVENTED THE RISE OF HIPPOCAMPAL HDAC1, HDAC4 AND HDAC5, AND THE REDUCTION OF HISTONE-3 ACETYLATION LEVELS PROMOTED BY FSS EXPOSURE. IN CONCLUSION, OUR RESULTS PROVIDE EVIDENCE THAT APOCYNIN REDUCES THE DELETERIOUS EFFECT OF STRESS AND SUGGESTS THAT OXIDATIVE STRESS MAY REGULATE EPIGENETIC MECHANISMS. 2021 12 3633 31 INCREASE IN HDAC9 SUPPRESSES MYOBLAST DIFFERENTIATION VIA EPIGENETIC REGULATION OF AUTOPHAGY IN HYPOXIA. EXTREMELY REDUCED OXYGEN (O(2)) LEVELS ARE DETRIMENTAL TO MYOGENIC DIFFERENTIATION AND MULTINUCLEATED MYOTUBE FORMATION, AND CHRONIC EXPOSURE TO HIGH-ALTITUDE HYPOXIA HAS BEEN REPORTED TO BE AN IMPORTANT FACTOR IN SKELETAL MUSCLE ATROPHY. HOWEVER, HOW CHRONIC HYPOXIA CAUSES MUSCLE DYSFUNCTION REMAINS UNKNOWN. IN THE PRESENT STUDY, WE FOUND THAT SEVERE HYPOXIA (1% O(2)) SIGNIFICANTLY INHIBITED THE FUNCTION OF C2C12 CELLS (FROM A MYOBLAST CELL LINE). IMPORTANTLY, THE IMPAIRMENT WAS CONTINUOUSLY MANIFESTED EVEN DURING CULTURE UNDER NORMOXIC CONDITIONS FOR SEVERAL PASSAGES. MECHANISTICALLY, WE REVEALED THAT HISTONE DEACETYLASES 9 (HDAC9), A MEMBER OF THE HISTONE DEACETYLASE FAMILY, WAS SIGNIFICANTLY INCREASED IN C2C12 CELLS UNDER HYPOXIC CONDITIONS, THEREBY INHIBITING INTRACELLULAR AUTOPHAGY LEVELS BY DIRECTLY BINDING TO THE PROMOTER REGIONS OF ATG7, BECLIN1, AND LC3. THIS PHENOMENON RESULTED IN THE SEQUENTIAL DEPHOSPHORYLATION OF GSK3BETA AND INACTIVATION OF THE CANONICAL WNT PATHWAY, IMPAIRING THE FUNCTION OF THE C2C12 CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT HYPOXIA-INDUCED MYOBLAST DYSFUNCTION IS DUE TO ABERRANT EPIGENETIC REGULATION OF AUTOPHAGY, AND OUR EXPERIMENTAL EVIDENCE REVEALS THE POSSIBLE MOLECULAR PATHOGENESIS RESPONSIBLE FOR SOME MUSCLE DISEASES CAUSED BY CHRONIC HYPOXIA AND SUGGESTS A POTENTIAL THERAPEUTIC OPTION. 2019 13 1826 45 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 14 3483 23 IDENTIFICATION OF CERNA NETWORK TO EXPLAIN THE MECHANISM OF COGNITIVE DYSFUNCTIONS INDUCED BY PS NPS IN MICE. PLASTICS BREAKING DOWN OF LARGER PLASTICS INTO SMALLER ONES (MICROPLASTICS AND NANOPLASTIC) AS POTENTIAL THREATS TO THE ECOSYSTEM. PREVIOUS STUDIES DEMONSTRATE THAT THE CENTRAL NERVOUS SYSTEM (CNS) IS A VULNERABLE TARGET OF NANOPLASTICS. HOWEVER, THE POTENTIALLY EPIGENETIC BIOMARKERS OF NANOPLASTIC NEUROTOXICITY IN RODENT MODELS ARE STILL UNKNOWN. THE PRESENT RESEARCH AIMED TO DETERMINE THE ROLE OF COMPETING ENDOGENOUS RNA (CERNA) IN THE PROCESS OF POLYSTYRENE NANOPLASTICS (PS NPS) EXPOSURE-INDUCED NERVE INJURY. THE STUDY WAS DESIGNED TO INVESTIGATE WHETHER 25 NM PS NPS COULD CAUSE LEARNING DYSFUNCTION AND TO ELUCIDATE THE UNDERLYING MECHANISMS IN MICE. A TOTAL OF 40 MICE WERE DIVIDED INTO 4 GROUPS AND WERE EXPOSED TO PS NPS (0, 10, 25, 50 MG/KG). CHRONIC TOXICITY WAS INTRODUCED IN MICE BY ADMINISTRATION OF ORAL GAVAGE FOR 6 MONTHS. THE EVALUATION INCLUDED ASSESSMENT OF THEIR BEHAVIOR, PATHOLOGICAL INVESTIGATION AND DETERMINATION OF THE LEVELS OF REACTIVE OXYGEN SPECIES (ROS) AND DNA DAMAGE. RNA-SEQ WAS PERFORMED TO DETECT THE EXPRESSION LEVELS OF CIRCRNAS, MIRNAS AND MRNAS IN PFC SAMPLES OF MICE TREATED WITH 0 AND 50 MG/KG PS NPS. THE RESULTS INDICATED THAT EXPOSURE OF MICE TO PS NPS CAUSED A DOSE-DEPENDENT COGNITIVE DECLINE. ROS LEVELS AND DNA DAMAGE WERE INCREASED IN THE PFC FOLLOWING EXPOSURE OF THE MICE TO PS NPS. A TOTAL OF 987 MRNAS, 29 MIRNAS AND 67 CIRCRNAS DEMONSTRATED SIGNIFICANT DIFFERENCES BETWEEN THE 0 AND 50 MG/KG PS NPS GROUPS. FUNCTIONAL ENRICHMENT ANALYSES INDICATED THAT PS NPS MAY INDUCE MAJOR INJURY IN THE SYNAPTIC FUNCTION. A TOTAL OF 96 MRNAS, WHICH WERE ASSOCIATED WITH SYNAPTIC DYSFUNCTION WERE IDENTIFIED. A COMPETING ENDOGENOUS RNA (CERNA) NETWORK CONTAINING 27 CIRCRNAS, 19 MIRNAS AND 35 SYNAPTIC DYSFUNCTION-RELATED MRNAS WAS CONSTRUCTED. THE PRESENT STUDY PROVIDED INSIGHT INTO THE MOLECULAR EVENTS ASSOCIATED WITH NANOPLASTIC TOXICITY AND INDUCTION OF COGNITIVE DYSFUNCTION. 2022 15 3981 29 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 16 2300 32 EPIGENETIC REGULATION OF BDNF EXPRESSION IN THE PRIMARY SENSORY NEURONS AFTER PERIPHERAL NERVE INJURY: IMPLICATIONS IN THE DEVELOPMENT OF NEUROPATHIC PAIN. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS KNOWN TO BE UP-REGULATED IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, AND TO CONTRIBUTE TO NEUROPATHIC PAIN. HERE, WE FOUND THAT THERMAL HYPERALGESIA AND MECHANICAL ALLODYNIA AT DAY 7 POST-INJURY WERE INHIBITED ONLY WHEN ANTI-BDNF ANTIBODY WAS INTRATHECALLY ADMINISTRATED AT DAY 2 POST-INJURY. CONSISTENT WITH BEHAVIORAL RESULTS, WESTERN BLOT ANALYSIS SHOWED THAT THE EXPRESSION LEVELS OF BDNF PROTEIN IN THE SPINAL DORSAL HORN WERE MARKEDLY INDUCED DURING EARLY STAGE POST-INJURY. MOREOVER, THE MAXIMAL INCREASE IN BDNF MRNA EXPRESSION IN THE DRG WAS OBSERVED AT DAY 1 POST-INJURY, AND SIGNIFICANTLY ELEVATED LEVELS WERE SUSTAINED FOR AT LEAST 14 DAYS. FOUR OF FIVE BDNF MRNA TRANSCRIPTS WERE UP-REGULATED AFTER NERVE INJURY, AND THE MOST INDUCIBLE TRANSCRIPT WAS EXON I. USING A CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, WE FOUND THAT NERVE INJURY PROMOTES HISTONE H3 AND H4 ACETYLATION, TRANSCRIPTIONALLY ACTIVE MODIFICATIONS, AT BDNF PROMOTER I AT DAY 1 POST-INJURY, AND THE LEVELS OF HISTONE ACETYLATION REMAIN ELEVATED FOR AT LEAST 7 DAYS. TAKEN TOGETHER, OUR FINDINGS SUGGEST THAT AN INITIAL INCREASE IN BDNF EXON I EXPRESSION CONTROLLED BY EPIGENETIC MECHANISMS MIGHT HAVE A CRUCIAL ROLE IN THE DEVELOPMENT OF NEUROPATHIC PAIN. 2013 17 6387 23 THE ROLE OF REACTIVE OXYGEN SPECIES IN ARSENIC TOXICITY. ARSENIC POISONING IS A GLOBAL HEALTH PROBLEM. CHRONIC EXPOSURE TO ARSENIC HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF A WIDE RANGE OF DISEASES AND HEALTH PROBLEMS IN HUMANS. ARSENIC EXPOSURE INDUCES THE GENERATION OF INTRACELLULAR REACTIVE OXYGEN SPECIES (ROS), WHICH MEDIATE MULTIPLE CHANGES TO CELL BEHAVIOR BY ALTERING SIGNALING PATHWAYS AND EPIGENETIC MODIFICATIONS, OR CAUSE DIRECT OXIDATIVE DAMAGE TO MOLECULES. ANTIOXIDANTS WITH THE POTENTIAL TO REDUCE ROS LEVELS HAVE BEEN SHOWN TO AMELIORATE ARSENIC-INDUCED LESIONS. HOWEVER, EMERGING EVIDENCE SUGGESTS THAT CONSTRUCTIVE ACTIVATION OF ANTIOXIDATIVE PATHWAYS AND DECREASED ROS LEVELS CONTRIBUTE TO CHRONIC ARSENIC TOXICITY IN SOME CASES. THIS REVIEW DETAILS THE PATHWAYS INVOLVED IN ARSENIC-INDUCED REDOX IMBALANCE, AS WELL AS CURRENT STUDIES ON PROPHYLAXIS AND TREATMENT STRATEGIES USING ANTIOXIDANTS. 2020 18 2772 29 EXTRACELLULAR ATP AND NEURODEGENERATION. ATP IS A POTENT SIGNALING MOLECULE ABUNDANTLY PRESENT IN THE CNS. IT ELICITS A WIDE ARRAY OF PHYSIOLOGICAL EFFECTS AND IS REGARDED AS THE PHYLOGENETICALLY MOST ANCIENT EPIGENETIC FACTOR PLAYING CRUCIAL BIOLOGICAL ROLES IN SEVERAL DIFFERENT TISSUES. THESE CAN RANGE FROM NEUROTRANSMISSION, SMOOTH MUSCLE CONTRACTION, CHEMOSENSORY SIGNALING, SECRETION AND VASODILATATION, TO MORE COMPLEX PHENOMENA SUCH AS IMMUNE RESPONSES, PAIN, MALE REPRODUCTION, FERTILIZATION AND EMBRYONIC DEVELOPMENT. ATP IS RELEASED INTO THE EXTRACELLULAR SPACE EITHER EXOCYTOTICALLY OR FROM DAMAGED AND DYING CELLS. IT IS OFTEN CO-RELEASED WITH OTHER NEUROTRANSMITTERS AND IT CAN INTERACT WITH GROWTH FACTORS AT BOTH RECEPTOR- AND/OR SIGNAL TRANSDUCTION-LEVEL. ONCE IN THE EXTRACELLULAR ENVIRONMENT, ATP BINDS TO SPECIFIC RECEPTORS TERMED P2. BASED ON PHARMACOLOGICAL PROFILES, ON SELECTIVITY OF COUPLING TO SECOND-MESSENGER PATHWAYS AND ON MOLECULAR CLONING, TWO MAIN SUBCLASSES WITH MULTIPLE SUBTYPES HAVE BEEN DISTINGUISHED. THEY ARE P2X, I.E. FAST CATION-SELECTIVE RECEPTOR CHANNELS (NA+, K+, CA2+), POSSESSING LOW AFFINITY FOR ATP AND RESPONSIBLE FOR FAST EXCITATORY NEUROTRANSMISSION, AND P2Y, I.E. SLOW G PROTEIN-COUPLED METABOTROPIC RECEPTORS, POSSESSING HIGHER AFFINITY FOR THE LIGAND. IN THE NERVOUS SYSTEM, THEY ARE BROADLY EXPRESSED IN BOTH NEURONS AND GLIAL CELLS AND CAN MEDIATE DUAL EFFECTS: SHORT-TERM SUCH AS NEUROTRANSMISSION, AND LONG-TERM SUCH AS TROPHIC ACTIONS. SINCE MASSIVE EXTRACELLULAR RELEASE OF ATP OFTEN OCCURS AFTER METABOLIC STRESS, BRAIN ISCHEMIA AND TRAUMA, PURINERGIC MECHANISMS ARE ALSO CORRELATED TO AND INVOLVED IN THE ETIOPATHOLOGY OF MANY NEURODEGENERATIVE CONDITIONS. FURTHERMORE, EXTRACELLULAR ATP PER SE IS TOXIC FOR PRIMARY NEURONAL DISSOCIATED AND ORGANOTYPIC CNS CULTURES FROM CORTEX, STRIATUM AND CEREBELLUM AND P2 RECEPTORS CAN MEDIATE AND AGGRAVATE HYPOXIC SIGNALING IN MANY CNS NEURONS. CONVERSELY, SEVERAL P2 RECEPTOR ANTAGONISTS ABOLISH THE CELL DEATH FATE OF PRIMARY NEURONAL CULTURES EXPOSED TO EXCESSIVE GLUTAMATE, SERUM/POTASSIUM DEPRIVATION, HYPOGLYCEMIA AND CHEMICAL HYPOXIA. IN PARALLEL WITH THESE DETRIMENTAL EFFECTS, ALSO TROPHIC FUNCTIONS HAVE BEEN EXTENSIVELY DESCRIBED FOR EXTRACELLULAR PURINES (BOTH FOR NEURONAL AND NON-NEURONAL CELLS), BUT THESE MIGHT EITHER AGGRAVATE OR AMELIORATE THE NORMAL CELLULAR CONDITIONS. IN SUMMARY, EXTRACELLULAR ATP PLAYS A VERY COMPLEX ROLE NOT ONLY IN THE REPAIR, REMODELING AND SURVIVAL OCCURRING IN THE NERVOUS SYSTEM, BUT EVEN IN CELL DEATH AND THIS CAN OCCUR EITHER AFTER NORMAL DEVELOPMENTAL CONDITIONS, AFTER INJURY, OR ACUTE AND CHRONIC DISEASES. 2003 19 2950 20 GENETIC AND EPIGENETIC DAMAGE INDUCED BY REACTIVE NITROGEN SPECIES: IMPLICATIONS IN CARCINOGENESIS. CHRONIC INFECTION AND INFLAMMATION ARE RECOGNIZED RISK FACTORS FOR HUMAN CANCER AT VARIOUS SITES. INFECTION AND INFLAMMATION CAN ACTIVATE AND INDUCE A VARIETY OF OXIDANT-GENERATING ENZYMES, INCLUDING NADPH OXIDASE AND INDUCIBLE NITRIC OXIDE SYNTHASE. REACTIVE OXYGEN AND NITROGEN SPECIES PRODUCED BY SUCH ENZYMES REACT WITH EACH OTHER TO GENERATE NEW AND MORE POTENT REACTIVE SPECIES. THESE OXIDANTS NOT ONLY CAN DAMAGE DNA AND INDUCE MUTATIONS, BUT ALSO CAN ACTIVATE ONCOGENE PRODUCTS AND/OR INACTIVATE TUMOR-SUPPRESSOR PROTEINS, THUS CONTRIBUTING TO MOST PROCESSES OF CARCINOGENESIS. APPROPRIATE TREATMENT OF INFLAMMATION SHOULD BE FURTHER EXPLORED FOR CHEMOPREVENTION OF HUMAN CANCERS, ESPECIALLY THOSE ASSOCIATED WITH CHRONIC INFLAMMATION. 2003 20 1632 33 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