1 5010 136 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 2 4894 48 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 3 2840 41 FRAMEWORK ANALYSIS FOR THE CARCINOGENIC MODE OF ACTION OF NITROBENZENE. NITROBENZENE (CASRN: 98-95-3) HAS BEEN SHOWN TO INDUCE CANCERS IN MANY TISSUES INCLUDING KIDNEY, LIVER, AND THYROID, FOLLOWING CHRONIC INHALATION IN ANIMALS. HOWEVER, WITH A FEW EXCEPTIONS, GENOTOXICITY ASSAYS USING NITROBENZENE HAVE GIVEN NEGATIVE RESULTS. SOME DNA BINDING/ADDUCT STUDIES HAVE BROUGHT FORTH QUESTIONABLE RESULTS AND, CONSIDERING THE AVAILABLE WEIGHT OF EVIDENCE, IT DOES NOT APPEAR THAT NITROBENZENE CAUSES CANCER VIA A GENOTOXIC MODE OF ACTION. NITROBENZENE PRODUCES A NUMBER OF FREE RADICALS DURING ITS REDUCTIVE METABOLISM, IN THE GUT AS WELL AS AT THE CELLULAR LEVEL, AND GENERATES SUPEROXIDE ANION AS A BY-PRODUCT DURING OXIDATIVE MELABOLISM. THE REACTIVE SPECIES GENERATED DURING NITROBENZENE METABOLISM ARE CONSIDERED CANDIDATES FOR CARCINOGENICITY. FURTHERMORE, SEVERAL LINES OF EVIDENCE SUGGEST THAT NITROBENZENE EXERTS ITS CARCINOGENICITY THROUGH A NON-DNA REACTIVE (EPIGENETIC) FASHION, SUCH AS A STRONG TEMPORAL RELATIONSHIP BETWEEN NON-, PRE-, AND NEOPLASTIC LESIONS LEADING TO CARCINOGENESIS. IN THIS REPORT, WE FIRST DESCRIBE THE ABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION OF NITROBENZENE FOLLOWED BY A SUMMARY OF THE AVAILABLE GENOTOXICITY STUDIES AND THE ONLY AVAILABLE CANCER BIOASSAY. WE SUBSEQUENTLY REFER TO THE MODE OF ACTION FRAMEWORK OF THE U.S. ENVIRONMENTAL PROTECTION AGENCY'S 2005 GUIDELINES FOR CARCINOGEN RISK ASSESSMENT AS A BASIS FOR PRESENTING POSSIBLE MODES OF ACTION FOR NITROBENZENE-INDUCED CANCERS OF THE LIVER, THYROID, AND KIDNEY, AS SUPPORTED BY THE AVAILABLE EXPERIMENTAL DATA. THE RATIONALE(S) REGARDING HUMAN RELEVANCE OF EACH MODE OF ACTION IS ALSO PRESENTED. FINALLY, WE HYPOTHESIZE THAT THE CARCINOGENIC MODE OF ACTION FOR NITROBENZENE IS MULTIFACTORIAL IN NATURE AND REFLECTIVE OF FREE RADICALS, INFLAMMATION, AND/OR ALTERED METHYLATION. 2007 4 5714 31 SIRT3 OVEREXPRESSION AND EPIGENETIC SILENCING OF CATALASE REGULATE ROS ACCUMULATION IN CLL CELLS ACTIVATING AXL SIGNALING AXIS. MITOCHONDRIAL METABOLISM IS THE KEY SOURCE FOR ABUNDANT ROS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS. HERE, WE DETECTED SIGNIFICANTLY LOWER SUPEROXIDE ANION (O(2)(-)) LEVELS WITH INCREASED ACCUMULATION OF HYDROGEN PEROXIDE (H(2)O(2)) IN CLL CELLS VS. NORMAL B-CELLS. FURTHER ANALYSIS INDICATED THAT MITOCHONDRIAL SUPEROXIDE DISMUTASE (SOD)2, WHICH CONVERTS O(2)(-) INTO H(2)O(2) REMAINED DEACETYLATED IN CLL CELLS DUE TO SIRT3 OVEREXPRESSION RESULTING ITS CONSTITUTIVE ACTIVATION. IN ADDITION, CATALASE EXPRESSION WAS ALSO REDUCED IN CLL CELLS SUGGESTING IMPAIRMENT OF H(2)O(2)-CONVERSION INTO WATER AND O(2) WHICH MAY CAUSE H(2)O(2)-ACCUMULATION. IMPORTANTLY, WE IDENTIFIED TWO CPG-ISLANDS IN THE CATALASE PROMOTER AND DISCOVERED THAT WHILE THE DISTAL CPG-ISLAND (-3619 TO -3765) REMAINED METHYLATED IN BOTH NORMAL B-CELLS AND CLL CELLS, VARIABLE DEGREES OF METHYLATION WERE DISCERNIBLE IN THE PROXIMAL CPG-ISLAND (-174 TO -332) ONLY IN CLL CELLS. FINALLY, TREATMENT OF CLL CELLS WITH A DEMETHYLATING AGENT INCREASED CATALASE MRNA LEVELS. FUNCTIONALLY, ROS ACCUMULATION IN CLL CELLS ACTIVATED THE AXL SURVIVAL AXIS WHILE UPREGULATED SIRT3, SUGGESTING THAT CLL CELLS RAPIDLY REMOVE HIGHLY REACTIVE O(2)(-) TO AVOID ITS CYTOTOXIC EFFECT BUT MAINTAIN INCREASED H(2)O(2)-LEVEL TO PROMOTE CELL SURVIVAL. THEREFORE, ABROGATION OF ABERRANTLY ACTIVATED CELL SURVIVAL PATHWAYS USING ANTIOXIDANTS CAN BE AN EFFECTIVE INTERVENTION IN CLL THERAPY IN COMBINATION WITH CONVENTIONAL AGENTS. 2021 5 4683 34 NEW PERSPECTIVES ON FOLATE TRANSPORT IN RELATION TO ALCOHOLISM-INDUCED FOLATE MALABSORPTION--ASSOCIATION WITH EPIGENOME STABILITY AND CANCER DEVELOPMENT. FOLATES ARE MEMBERS OF THE B-CLASS OF VITAMINS, WHICH ARE REQUIRED FOR THE SYNTHESIS OF PURINES AND PYRIMIDINES, AND FOR THE METHYLATION OF ESSENTIAL BIOLOGICAL SUBSTANCES, INCLUDING PHOSPHOLIPIDS, DNA, AND NEUROTRANSMITTERS. FOLATES CANNOT BE SYNTHESIZED DE NOVO BY MAMMALS; HENCE, AN EFFICIENT INTESTINAL ABSORPTION PROCESS IS REQUIRED. INTESTINAL FOLATE TRANSPORT IS CARRIER-MEDIATED, PH-DEPENDENT AND ELECTRONEUTRAL, WITH SIMILAR AFFINITY FOR OXIDIZED AND REDUCED FOLIC ACID DERIVATIVES. THE VARIOUS TRANSPORTERS, I.E. REDUCED FOLATE CARRIER, PROTON-COUPLED FOLATE TRANSPORTER, FOLATE-BINDING PROTEIN, AND ORGANIC ANION TRANSPORTERS, ARE INVOLVED IN THE FOLATE TRANSPORT PROCESS IN VARIOUS TISSUES. ANY IMPAIRMENT IN UPTAKE OF FOLATE CAN LEAD TO A STATE OF FOLATE DEFICIENCY, THE MOST PREVALENT VITAMIN DEFICIENCY IN WORLD, AFFECTING 10% OF THE POPULATION IN THE USA. SUCH IMPAIRMENTS IN FOLATE TRANSPORT OCCUR IN A VARIETY OF CONDITIONS, INCLUDING CHRONIC USE OF ETHANOL, SOME INBORN HEREDITARY DISORDERS, AND CERTAIN DISEASES. AMONG THESE, ETHANOL INGESTION HAS BEEN THE MAJOR CONTRIBUTOR TO FOLATE DEFICIENCY. ETHANOL-ASSOCIATED FOLATE DEFICIENCY CAN DEVELOP BECAUSE OF DIETARY INADEQUACY, INTESTINAL MALABSORPTION, ALTERED HEPATOBILIARY METABOLISM, ENHANCED COLONIC METABOLISM, AND INCREASED RENAL EXCRETION. ETHANOL REDUCES THE INTESTINAL AND RENAL UPTAKE OF FOLATE BY ALTERING THE BINDING AND TRANSPORT KINETICS OF FOLATE TRANSPORT SYSTEMS. ALSO, ETHANOL REDUCES THE EXPRESSION OF FOLATE TRANSPORTERS IN BOTH INTESTINE AND KIDNEY, AND THIS MIGHT BE A CONTRIBUTING FACTOR FOR FOLATE MALABSORPTION, LEADING TO FOLATE DEFICIENCY. THE MAINTENANCE OF INTRACELLULAR FOLATE HOMEOSTASIS IS ESSENTIAL FOR THE ONE-CARBON TRANSFER REACTIONS NECESSARY FOR DNA SYNTHESIS AND BIOLOGICAL METHYLATION REACTIONS. DNA METHYLATION IS AN IMPORTANT EPIGENETIC DETERMINANT IN GENE EXPRESSION, IN THE MAINTENANCE OF DNA INTEGRITY AND STABILITY, IN CHROMOSOMAL MODIFICATIONS, AND IN THE DEVELOPMENT OF MUTATIONS. ETHANOL, A TOXIN THAT IS CONSUMED REGULARLY, HAS BEEN FOUND TO AFFECT THE METHYLATION OF DNA. IN ADDITION TO ITS EFFECT ON DNA METHYLATION DUE TO FOLATE DEFICIENCY, ETHANOL COULD DIRECTLY EXERT ITS EFFECT THROUGH ITS INTERACTION WITH ONE-CARBON METABOLISM, IMPAIRMENT OF METHYL GROUP SYNTHESIS, AND AFFECTING THE ENZYMES REGULATING THE SYNTHESIS OF S-ADENOSYLMETHIONINE, THE PRIMARY METHYL GROUP DONOR FOR MOST BIOLOGICAL METHYLATION REACTIONS. THUS, ETHANOL PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF SEVERAL DISEASES THROUGH ITS POTENTIAL ABILITY TO MODULATE THE METHYLATION OF BIOLOGICAL MOLECULES. THIS REVIEW DISCUSSES THE UNDERLYING MECHANISM OF FOLATE MALABSORPTION IN ALCOHOLISM, THE MECHANISM OF METHYLATION-ASSOCIATED SILENCING OF GENES, AND HOW THE INTERACTION BETWEEN ETHANOL AND FOLATE DEFICIENCY AFFECTS THE METHYLATION OF GENES, THEREBY MODULATING EPIGENOME STABILITY AND THE RISK OF CANCER. 2009 6 474 30 ARSENIC BIOTRANSFORMATION AS A CANCER PROMOTING FACTOR BY INDUCING DNA DAMAGE AND DISRUPTION OF REPAIR MECHANISMS. CHRONIC EXPOSURE TO ARSENIC IN DRINKING WATER POSES A MAJOR GLOBAL HEALTH CONCERN. POPULATIONS EXPOSED TO HIGH CONCENTRATIONS OF ARSENIC-CONTAMINATED DRINKING WATER SUFFER SERIOUS HEALTH CONSEQUENCES, INCLUDING ALARMING CANCER INCIDENCE AND DEATH RATES. ARSENIC IS BIOTRANSFORMED THROUGH SEQUENTIAL ADDITION OF METHYL GROUPS, ACQUIRED FROM S-ADENOSYLMETHIONINE (SAM). METABOLISM OF ARSENIC GENERATES A VARIETY OF GENOTOXIC AND CYTOTOXIC SPECIES, DAMAGING DNA DIRECTLY AND INDIRECTLY, THROUGH THE GENERATION OF REACTIVE OXIDATIVE SPECIES AND INDUCTION OF DNA ADDUCTS, STRAND BREAKS AND CROSS LINKS, AND INHIBITION OF THE DNA REPAIR PROCESS ITSELF. SINCE SAM IS THE METHYL GROUP DONOR USED BY DNA METHYLTRANSFERASES TO MAINTAIN NORMAL EPIGENETIC PATTERNS IN ALL HUMAN CELLS, ARSENIC IS ALSO POSTULATED TO AFFECT MAINTENANCE OF NORMAL DNA METHYLATION PATTERNS, CHROMATIN STRUCTURE, AND GENOMIC STABILITY. THE BIOLOGICAL PROCESSES UNDERLYING THE CANCER PROMOTING FACTORS OF ARSENIC METABOLISM, RELATED TO DNA DAMAGE AND REPAIR, WILL BE DISCUSSED HERE. 2011 7 6166 30 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 1066 33 CLINICAL USE OF AMINO ACIDS AS DIETARY SUPPLEMENT: PROS AND CONS. NITROGEN SUPPLY IS PIVOTAL FOR THE MAINTENANCE OF LIFE. AMINO ACIDS CAN BE UTILIZED TO SYNTHESIZE BOTH GLUCOSE AND LIPIDS. THE OPPOSITE, I.E., PRODUCTION OF AMINO ACIDS FROM EITHER ONE OF THEM, IS NOT POSSIBLE IN THE ABSENCE OF OTHER AMINO ACIDS AS DONORS OF NITROGEN. THE QUALITY OF AMINO ACID CONTENT IN PROTEIN HAS BEEN RE-EVALUATED RECENTLY, AND THE RELEVANCE OF ESSENTIAL AMINO ACIDS HAS BEEN REPEATEDLY UNDERLINED. ESSENTIAL AMINO ACID REQUIREMENTS IN DIFFERENT MAMMALS ARE NOT IDENTICAL, AND RATIOS AMONG THEM SHOULD BE TAKEN INTO ACCOUNT WHEN PROJECTING AN EFFICIENT FORMULATION. RECENT RESEARCH HAS DEMONSTRATED THAT GENES RESPOND TO DIFFERENT QUALITIES AND QUANTITIES OF NUTRITIONAL SUPPLY, AND INCREASED PROVISION OF ESSENTIAL AMINO ACIDS INCREASES LIFESPAN IN ANIMAL EXPERIMENTS THROUGH MITOCHONDRIOGENESIS AND MAINTENANCE OF ELEVATED RATES OF SYNTHESIS OF ANTI-OXIDANT MOLECULES. MOREOVER, GENETIC EXPRESSION OF KEY CONTROLLERS OF SYNTHESIS, LIKE MTOR, MAY BE PARTICULARLY IMPORTANT FOR UNDERSTANDING SKELETAL MUSCLE MAINTENANCE. LOSSES OF MUSCLE MASS AND IMPAIRED IMMUNE FUNCTION ARE RELATED TO REDUCED PROTEIN SUPPLY, AND THERE IS INCREASING EVIDENCE THAT REGULAR ESSENTIAL AMINO ACID INTAKE AS PART OF AN ORAL DIET IS EFFECTIVE IN REVERSING MUSCLE CATABOLISM, PROMOTING MUSCLE ANABOLISM, AND RESTORING IMMUNOLOGICAL FUNCTION. THEREFORE, THE USE OF AMINO ACIDS AS SUPPLEMENTS TO DIET WOULD BE EXPANDING IN THE NEAR FUTURE. IS THIS SAFE? FEW DATA ARE AVAILABLE ON AMINO ACID TOXICITY, AND ONLY ONE ESSENTIAL AMINO ACID MAY BE CONSIDERED TO HAVE CLINICALLY RELEVANT TOXICITY: METHIONINE, BECAUSE IT IS TRANSFORMED INTO A TOXIC INTERMEDIATE, HOMOCYSTEINE, WHEN CYSTEINE SYNTHESIS IS REQUIRED BY METABOLIC NEEDS. MATCHING OF STOICHIOMETRIC RATIOS BETWEEN METHIONINE AND CYSTEINE MAY SOLVE THE PROBLEM OF SUPPLYING SUFFICIENT AMOUNTS OF SULFUR TO THE BODY. ARGININE AND GLUTAMINE ARE TWO NON-ESSENTIAL AMINO ACIDS THAN CAN BECOME "CONDITIONALLY ESSENTIAL" BECAUSE OF ELEVATED NEEDS DURING PATHOLOGICAL CONDITIONS, AND METABOLISM MAY NOT BE ABLE TO MAINTAIN THEIR CONCENTRATIONS AT SUFFICIENT LEVELS TO MATCH METABOLIC REQUIREMENTS. CHRONIC EXOGENOUS ARGININE SUPPLEMENTATION HAS NOT PROVEN TO EXERT POSITIVE CLINICAL EFFECTS IN DIFFERENT TRIALS, AND SEQUENTIAL ARTICULATION OF THE KNOWLEDGE OF INTRODUCTION OF ARGININE-DRIVEN TRANSCRIPTIONAL, TRANSLATIONAL, AND EPIGENETIC ADAPTATIONS MAY GIVE US A KEY FOR INTERPRETING THOSE PUZZLING RESULTS. 2011 9 558 28 B-VITAMIN DEPENDENT METHIONINE METABOLISM AND ALCOHOLIC LIVER DISEASE. CONVINCING EVIDENCE LINKS ABERRANT B-VITAMIN DEPENDENT HEPATIC METHIONINE METABOLISM TO THE PATHOGENESIS OF ALCOHOLIC LIVER DISEASE (ALD). THIS REVIEW FOCUSES ON THE ESSENTIAL ROLES OF FOLATE AND VITAMINS B6 AND B12 IN HEPATIC METHIONINE METABOLISM, THE CAUSES OF THEIR DEFICIENCIES AMONG CHRONIC ALCOHOLIC PERSONS, AND HOW THEIR DEFICIENCIES TOGETHER WITH CHRONIC ALCOHOL EXPOSURE IMPACT ON ABERRANT METHIONINE METABOLISM IN THE PATHOGENESIS OF ALD. FOLATE IS THE DIETARY TRANSMETHYLATION DONOR FOR THE PRODUCTION OF S-ADENOSYLMETHIONINE (SAM), WHICH IS THE SUBSTRATE FOR ALL METHYLTRANSFERASES THAT REGULATE GENE EXPRESSIONS IN PATHWAYS OF LIVER INJURY, AS WELL AS A REGULATOR OF THE TRANSSULFURATION PATHWAY THAT IS ESSENTIAL FOR PRODUCTION OF GLUTATHIONE (GSH), THE PRINCIPAL ANTIOXIDANT FOR DEFENSE AGAINST OXIDATIVE LIVER INJURY. VITAMIN B12 REGULATES TRANSMETHYLATION REACTIONS FOR SAM PRODUCTION AND VITAMIN B6 REGULATES TRANSSULFURATION REACTIONS FOR GSH PRODUCTION. FOLATE DEFICIENCY ACCELERATES THE EXPERIMENTAL DEVELOPMENT OF ALD IN ETHANOL-FED ANIMALS WHILE REDUCING LIVER SAM LEVELS WITH RESULTANT ABNORMAL GENE EXPRESSION AND DECREASED PRODUCTION OF ANTIOXIDANT GSH. THROUGH ITS EFFECTS ON FOLATE METABOLISM, REDUCED SAM ALSO IMPAIRS NUCLEOTIDE BALANCE WITH RESULTANT INCREASED DNA STRAND BREAKS, OXIDATION, HEPATOCELLULAR APOPTOSIS, AND RISK OF CARCINOGENESIS. THE REVIEW ENCOMPASSES REFERENCED STUDIES ON MECHANISMS FOR PERTURBATIONS OF METHIONINE METABOLISM IN ALD, EVIDENCE FOR ALTERED GENE EXPRESSIONS AND THEIR EPIGENETIC REGULATION IN THE PATHOGENESIS OF ALD, AND CLINICAL STUDIES ON POTENTIAL PREVENTION AND TREATMENT OF ALD BY CORRECTION OF METHIONINE METABOLISM WITH SAM. 2013 10 6086 40 THE EFFECTS OF ACETALDEHYDE EXPOSURE ON HISTONE MODIFICATIONS AND CHROMATIN STRUCTURE IN HUMAN LUNG BRONCHIAL EPITHELIAL CELLS. AS THE PRIMARY METABOLITE OF ALCOHOL AND THE MOST ABUNDANT CARCINOGEN IN TOBACCO SMOKE, ACETALDEHYDE IS LINKED TO A NUMBER OF HUMAN DISEASES ASSOCIATED WITH CHRONIC ALCOHOL CONSUMPTION AND SMOKING INCLUDING CANCERS. IN ADDITION TO DIRECT DNA DAMAGE AS A RESULT OF THE FORMATION OF ACETALDEHYDE-DNA ADDUCTS, ACETALDEHYDE MAY ALSO INDIRECTLY IMPACT PROPER GENOME FUNCTION THROUGH THE FORMATION OF PROTEIN ADDUCTS. HISTONE PROTEINS ARE THE MAJOR COMPONENT OF THE CHROMATIN. POST-TRANSLATIONAL HISTONE MODIFICATIONS (PTMS) ARE CRITICALLY IMPORTANT FOR THE MAINTENANCE OF GENETIC AND EPIGENETIC STABILITY. HOWEVER, LITTLE IS KNOWN ABOUT HOW ACETALDEHYDE-HISTONE ADDUCTS AFFECT HISTONE MODIFICATIONS AND CHROMATIN STRUCTURE. THE RESULTS OF PROTEIN CARBONYL ASSAYS SUGGEST THAT ACETALDEHYDE FORMS ADDUCTS WITH HISTONE PROTEINS IN HUMAN BRONCHIAL EPITHELIAL BEAS-2B CELLS. THE LEVEL OF ACETYLATION FOR N-TERMINAL TAILS OF CYTOSOLIC HISTONES H3 AND H4, AN IMPORTANT MODIFICATION FOR HISTONE NUCLEAR IMPORT AND CHROMATIN ASSEMBLY, IS SIGNIFICANTLY DOWNREGULATED FOLLOWING ACETALDEHYDE EXPOSURE IN BEAS-2B CELLS, POSSIBLY DUE TO THE FORMATION OF HISTONE ADDUCTS AND/OR THE DECREASE IN THE EXPRESSION OF HISTONE ACETYLTRANSFERASES. NOTABLY, THE LEVEL OF NUCLEOSOMAL HISTONES IN THE CHROMATIN FRACTION AND AT MOST OF THE GENOMIC LOCI WE TESTED ARE LOW IN ACETALDEHYDE-TREATED CELLS AS COMPARED WITH THE CONTROL CELLS, WHICH IS SUGGESTIVE OF INHIBITION OF CHROMATIN ASSEMBLY. MOREOVER, ACETALDEHYDE EXPOSURE PERTURBS CHROMATIN STRUCTURE AS EVIDENCED BY THE INCREASE IN GENERAL CHROMATIN ACCESSIBILITY AND THE DECREASE IN NUCLEOSOME OCCUPANCY AT GENOMIC LOCI FOLLOWING ACETALDEHYDE TREATMENT. OUR RESULTS INDICATE THAT REGULATION OF HISTONE MODIFICATIONS AND CHROMATIN ACCESSIBILITY MAY PLAY IMPORTANT ROLES IN ACETALDEHYDE-INDUCED PATHOGENESIS. ENVIRON. MOL. MUTAGEN. 59:375-385, 2018. (C) 2018 WILEY PERIODICALS, INC. 2018 11 6909 35 [TOXIC COMPONENTS OF PM(2.5) AND THEIR TOXICITY MECHANISMS-ON THE TOXICITY OF SULFATE AND CARBON COMPONENTS]. RECENTLY, THE MAIN AIR POLLUTANT HAS BEEN FINE PARTICULATE MATTER (PM(2.5)), WHICH IS TAKEN UP BY THE WHOLE BODY WITH SEVERE ADVERSE HEALTH EFFECTS. THE MAIN CHEMICAL COMPONENTS OF PM(2.5) ARE SALTS OF SULFATE (AND NITRATE) AND CARBONS. HOWEVER, IT REMAINS UNKNOWN WHICH COMPONENTS ARE TOXIC. HERE, THE AUTHOR REVIEWED THE LITERATURES TO DETERMINE WHICH COMPONENTS ARE TOXIC AND THE MAIN MECHANISMS UNDERLYING THEIR TOXICITY. MANY EPIDEMIOLOGICAL STUDIES HAVE SHOWN THAT SULFATE CONCENTRATION IS STRONGLY RELATED TO MORTALITY. HOWEVER, THERE IS NO EXPERIMENTAL EVIDENCE SHOWING THAT SULFATE AT ENVIRONMENTAL CONCENTRATIONS OF PM(2.5) CAUSES CARDIOVASCULAR DISEASE OR OTHER DISEASE. ON THE OTHER HAND, CARBON COMPONENTS SUCH AS ELEMENTARY CARBON (EC) PRODUCES HIGH CONCENTRATIONS OF REACTIVE OXYGEN SPECIES (ROS) VIA ITS PHAGOCYTOSIS BY MACROPHAGES, AND ORGANIC CARBON (OC) ALSO PRODUCES HIGH CONCENTRATIONS OF ROS DURING ITS METABOLIC PROCESSES, AND THE ROS CAUSE ACUTE AND CHRONIC INFLAMMATION. THEY CAUSE MANY DISEASES INCLUDING CARDIOVASCULAR DISEASE, ASTHMA AND CANCER. FURTHERMORE, THERE ARE MANY LINES OF EVIDENCE SHOWING THAT EPIGENETIC CHANGES SUCH AS DNA METHYLATION OR MICRORNA EXPRESSION INDUCED BY PARTICULATE MATTERS ALSO INDUCE THE DEVELOPMENT OF MANY DISEASES SUCH AS THOSE MENTIONED ABOVE. IT HAS BEEN REPORTED THAT CARBON COMPONENTS ARE INCORPORATED INTO THE BRAIN AND PRODUCE ROS, AND THAT THE ROS CAUSE DAMAGE TO BRAIN CELLS AND ALZHEIMER'S DISEASE AND COGNITIVE DISORDERS IN THE ELDERLY.FROM THESE LINES OF EVIDENCE, THE AUTHOR WOULD LIKE TO EMPHASIZE THAT THE MAIN TOXICITY OF PM(2.5) IS DUE TO CARBON COMPONENTS, AND IT IS IMPORTANT TO TAKE COUNTERMEASURES TO DECREASE THE CONCENTRATION OF CARBON COMPONENTS IN AMBIENT AIR. 2019 12 3633 32 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 6387 34 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 14 567 35 BASIC PROPERTIES AND MOLECULAR MECHANISMS OF EXOGENOUS CHEMICAL CARCINOGENS. EXOGENOUS CHEMICAL CARCINOGENESIS IS AN EXTREMELY COMPLEX MULTIFACTORIAL PROCESS DURING WHICH GENE-ENVIRONMENT INTERACTIONS INVOLVING CHRONIC EXPOSURE TO EXOGENOUS CHEMICAL CARCINOGENS (ECCS) AND POLYMORPHISMS OF CANCER SUSCEPTIBILITY GENES ADD FURTHER COMPLEXITY. WE DESCRIBE THE PROPERTIES AND MOLECULAR MECHANISMS OF ECCS THAT CONTRIBUTE TO INDUCE AND GENERATE CANCER. A BASIC AND SPECIFIC PROPERTY OF MANY LIPOPHILIC ORGANIC ECCS INCLUDING POLYCYCLIC AROMATIC HYDROCARBONS AND POLYHALOGENATED AROMATIC HYDROCARBONS IS THEIR ABILITY TO BIOACCUMULATE IN THE ADIPOSE TISSUE FROM WHERE THEY MAY BE RELEASED IN THE BLOOD CIRCULATION AND TARGET PERIPHERAL TISSUES FOR CARCINOGENESIS. MANY ORGANIC ECCS ARE PROCARCINOGENS AND CONSEQUENTLY NEED TO BE ACTIVATED BY THE CYTOCHROME P450 (CYP) SYSTEM AND/OR OTHER ENZYMES BEFORE THEY CAN ADDUCT DNA AND PROTEINS. BECAUSE THEY CONTRIBUTE NOT ONLY TO THE COCARCINOGENIC AND PROMOTING EFFECTS OF MANY AROMATIC POLLUTANTS BUT ALSO TO THEIR MUTAGENIC EFFECTS, THE ARYL HYDROCARBON RECEPTOR-ACTIVATING AND THE INDUCIBLE CYP SYSTEMS ARE CENTRAL TO EXOGENOUS CHEMICAL CARCINOGENESIS. ANOTHER BASIC PROPERTY OF ECCS IS THEIR ABILITY TO INDUCE STABLE AND BULKY DNA ADDUCTS THAT CANNOT BE SIMPLY REPAIRED BY THE DIFFERENT REPAIR SYSTEMS. IN ADDITION, FOLLOWING ECC EXPOSURE, MUTAGENESIS MAY ALSO BE CAUSED INDIRECTLY BY FREE-RADICAL PRODUCTION AND BY EPIGENETIC ALTERATIONS. AS A RESULT OF COMPLEX MOLECULAR INTERPLAYS, DIRECT AND/OR INDIRECT MUTAGENESIS MAY ESPECIALLY ACCOUNT FOR THE CARCINOGENIC EFFECTS OF MANY EXOGENOUS METALS AND METALLOIDS. BECAUSE OF THESE MOLECULAR PROPERTIES AND ACTION MECHANISMS, WE CONCLUDE THAT ECCS COULD BE MAJOR CONTRIBUTORS TO HUMAN CANCER, WITH OBVIOUSLY GREAT PUBLIC HEALTH CONSEQUENCES. 2010 15 2961 45 GENETIC AND EPIGENETIC MECHANISMS IN METAL CARCINOGENESIS AND COCARCINOGENESIS: NICKEL, ARSENIC, AND CHROMIUM. CHRONIC EXPOSURE TO NICKEL(II), CHROMIUM(VI), OR INORGANIC ARSENIC (IAS) HAS LONG BEEN KNOWN TO INCREASE CANCER INCIDENCE AMONG AFFECTED INDIVIDUALS. RECENT EPIDEMIOLOGICAL STUDIES HAVE FOUND THAT CARCINOGENIC RISKS ASSOCIATED WITH CHROMATE AND IAS EXPOSURES WERE SUBSTANTIALLY HIGHER THAN PREVIOUSLY THOUGHT, WHICH LED TO MAJOR REVISIONS OF THE FEDERAL STANDARDS REGULATING AMBIENT AND DRINKING WATER LEVELS. GENOTOXIC EFFECTS OF CR(VI) AND IAS ARE STRONGLY INFLUENCED BY THEIR INTRACELLULAR METABOLISM, WHICH CREATES SEVERAL REACTIVE INTERMEDIATES AND BYPRODUCTS. TOXIC METALS ARE CAPABLE OF POTENT AND SURPRISINGLY SELECTIVE ACTIVATION OF STRESS-SIGNALING PATHWAYS, WHICH ARE KNOWN TO CONTRIBUTE TO THE DEVELOPMENT OF HUMAN CANCERS. DEPENDING ON THE METAL, ASCORBATE (VITAMIN C) HAS BEEN FOUND TO ACT EITHER AS A STRONG ENHANCER OR SUPPRESSOR OF TOXIC RESPONSES IN HUMAN CELLS. IN ADDITION TO GENETIC DAMAGE VIA BOTH OXIDATIVE AND NONOXIDATIVE (DNA ADDUCTS) MECHANISMS, METALS CAN ALSO CAUSE SIGNIFICANT CHANGES IN DNA METHYLATION AND HISTONE MODIFICATIONS, LEADING TO EPIGENETIC SILENCING OR REACTIVATION OF GENE EXPRESSION. IN VITRO GENOTOXICITY EXPERIMENTS AND RECENT ANIMAL CARCINOGENICITY STUDIES PROVIDED STRONG SUPPORT FOR THE IDEA THAT METALS CAN ACT AS COCARCINOGENS IN COMBINATION WITH NONMETAL CARCINOGENS. COCARCINOGENIC AND COMUTAGENIC EFFECTS OF METALS ARE LIKELY TO STEM FROM THEIR ABILITY TO INTERFERE WITH DNA REPAIR PROCESSES. OVERALL, METAL CARCINOGENESIS APPEARS TO REQUIRE THE FORMATION OF SPECIFIC METAL COMPLEXES, CHROMOSOMAL DAMAGE, AND ACTIVATION OF SIGNAL TRANSDUCTION PATHWAYS PROMOTING SURVIVAL AND EXPANSION OF GENETICALLY/EPIGENETICALLY ALTERED CELLS. 2008 16 6038 29 THE CHEMICAL DEFENSIVE SYSTEM IN THE PATHOBIOLOGY OF IDIOPATHIC ENVIRONMENT-ASSOCIATED DISEASES. CHEMICAL DEFENSIVE SYSTEM CONSISTING OF BIO-SENSORING, TRANSMITTING, AND RESPONSIVE ELEMENTS HAS BEEN EVOLVED TO PROTECT MULTI-CELLULAR ORGANISMS AGAINST ENVIRONMENTAL CHEMICAL INSULTS (XENOBIOTICS) AND TO MAINTAIN HOMEOSTASIS OF ENDOGENOUS LOW MOLECULAR WEIGHT METABOLITES (ENDOBIOTICS). BOTH GENETIC AND EPIGENETIC DEFECTS OF THE SYSTEM IN ASSOCIATION WITH CARCINOGENESIS AND INDIVIDUAL SENSITIVITY TO ANTI-TUMOR THERAPIES HAVE BEEN INTENSELY STUDIED. RECENTLY, SEVERAL NON-TUMOR HUMAN PATHOLOGIES WITH EVIDENT ENVIRONMENTAL COMPONENTS SUCH AS RATHER RARE FUNCTIONAL SYNDROMES (MULTIPLE CHEMICAL SENSITIVITY, CHRONIC FATIGUE, PERSIAN GULF, AND FIBROMYALGIA NOW COLLECTIVELY LABELED AS IDIOPATHIC ENVIRONMENTAL INTOLERANCES) AND COMMON DISEASES (VITILIGO AND SYSTEMIC LUPUS ERYTHEMATOSUS) HAVE BECOME SUBJECTS OF THE RESEARCH ON THE IMPAIRED METABOLISM AND DETOXIFICATION OF XENOBIOTICS AND ENDOGENOUS TOXINS. HERE, WE COLLECTED AND CRITICALLY REVIEWED EPIDEMIOLOGICAL, GENETIC, AND BIOCHEMICAL DATA ON THE INVOLVEMENT AND POSSIBLE ROLE OF CYTOCHROME P450 SUPER FAMILY ENZYMES, GLUTATHIONE-S-TRANSFERASE ISOZYMES, CATECHOL-O-METHYL-TRANSFERASE, UDP-GLUCURONOSYL TRANSFERASES, AND PROTEINS DETOXIFYING INORGANIC AND ORGANIC PEROXIDES (CATALASE, GLUTATHIONE PEROXIDASE, AND PEROXIREDOXIN) IN THE ABOVE PATHOLOGIES. GENETIC PREDISPOSITION ASSESSED MAINLY BY SINGLE NUCLEOTIDE POLYMORPHISM AND GENE EXPRESSION ANALYSES REVEALED CORRELATIONS BETWEEN DEFECTS IN GENES ENCODING XENOBIOTIC-METABOLIZING AND/OR DETOXIFYING ENZYMES AND RISK/SEVERITY OF THESE SYNDROMES/DISEASES. PROTEOME ANALYSIS IDENTIFIED ABNORMAL EXPRESSION OF THE ENZYMES. THEIR FUNCTIONS WERE AFFECTED EPIGENETICALLY LEADING TO METABOLIC IMPAIRMENT AND, AS A CONSEQUENCE, TO THE NEGATIVE HEALTH OUTCOMES SHARED BY SOME OF THESE PATHOLOGIES. DATA OBTAINED SO FAR SUGGEST THAT DISTINCT COMPONENTS OF THE CHEMICAL DEFENSIVE SYSTEM COULD BE SUITABLE MOLECULAR TARGETS FOR FUTURE PATHOGENIC THERAPIES. 2009 17 5590 22 ROLE OF THE BICARBONATE-RESPONSIVE SOLUBLE ADENYLYL CYCLASE IN CHOLANGIOCYTE APOPTOSIS IN PRIMARY BILIARY CHOLANGITIS; A NEW HYPOTHESIS. PRIMARY BILIARY CHOLANGITIS (PBC) IS A CHRONIC FIBROSING CHOLANGIOPATHY CHARACTERIZED BY AN AUTOIMMUNE STEREOTYPE AND DEFECTIVE BILIARY BICARBONATE SECRETION DUE TO DOWN-REGULATION OF ANION EXCHANGER 2 (AE2). DESPITE THE AUTOIMMUNE FEATURES, IMMUNOSUPPRESSANTS ARE INEFFECTIVE WHILE TWO BILE ACID-BASED THERAPIES (URSODEOXYCHOLIC ACID AND OBETICHOLIC ACID) HAVE BEEN SHOWN TO IMPROVE BIOCHEMICAL AND HISTOLOGICAL FEATURES OF CHOLESTASIS AND LONG-TERM PROGNOSIS. HOWEVER, THE ETIOLOGY AND PATHOGENESIS OF PBC IS LARGELY UNKNOWN. RECENTLY, IT HAS BEEN SHOWN THAT MICRORNA-506 (MIR-506) ON CHROMOSOME X IS UP-REGULATED IN PBC CHOLANGIOCYTES AND SUPPRESSES AE2 EXPRESSION, WHICH SENSITIZES CHOLANGIOCYTES TO BILE SALT-INDUCED APOPTOSIS BY ACTIVATING SOLUBLE ADENYLYL CYCLASE (SAC), AN EVOLUTIONARILY CONSERVED BICARBONATE SENSOR. IN THIS REVIEW, WE DISCUSS THE EXPERIMENTAL EVIDENCE FOR THE EMERGING ROLE OF THE MIR-506-AE2-SAC AXIS IN PBC PATHOGENESIS. WE FURTHER HYPOTHESIZE THAT THE INITIAL DISEASE TRIGGER INDUCES AN X-LINKED EPIGENETIC CHANGE, LEADING TO A FEMALE-BIASED ACTIVATION OF THE MIR-506-AE2-SAC AXIS. THIS ARTICLE IS PART OF A SPECIAL ISSUE ENTITLED: CHOLANGIOCYTES IN HEALTH AND DISEASEEDITED BY JESUS BANALES, MARCO MARZIONI AND PETER JANSEN. 2018 18 6078 41 THE EFFECT OF CHRONIC ARSENIC EXPOSURE IN ZEBRAFISH. ARSENIC IS A PREVALENT ENVIRONMENTAL TOXIN AND A GROUP ONE HUMAN CARCINOGENIC AGENT. CHRONIC ARSENIC EXPOSURE HAS BEEN ASSOCIATED WITH MANY HUMAN DISEASES. THE AIM OF THIS STUDY IS TO EVALUATE ZEBRAFISH AS AN ANIMAL MODEL TO ASSESS ARSENIC TOXICITY IN ELEVATED LONG-TERM ARSENIC EXPOSURE. WITH PROLONGED EXPOSURE (6 MONTHS) TO VARIOUS CONCENTRATIONS OF ARSENIC FROM 50 PPB TO 300 PPB, EFFECTS OF ARSENIC ACCUMULATION IN ZEBRAFISH TISSUES, AND PHENOTYPES WERE INVESTIGATED. RESULTS SHOWED THAT THERE ARE NO SIGNIFICANT CHANGES OF ARSENIC RETENTION IN ZEBRAFISH TISSUES, AND ZEBRAFISH DID NOT EXHIBIT ANY VISIBLE TUMOR FORMATION UNDER ARSENIC EXPOSURE CONDITIONS. HOWEVER, THE ZEBRAFISH DEMONSTRATE A DYSFUNCTION IN THEIR NEUROLOGICAL SYSTEM, WHICH IS REFLECTED BY A REDUCTION OF LOCOMOTIVE ACTIVITY. MOREOVER, ELEVATED LEVELS OF THE SUPEROXIDE DISMUTASE (SOD2) PROTEIN WERE DETECTED IN THE EYE AND LIVER, SUGGESTING INCREASED OXIDATIVE STRESS. IN ADDITION, THE PROGENIES OF ARSENIC-TREATED PARENTS DISPLAYED A SMALLER BIOMASS (FOUR-FOLD REDUCTION IN BODY WEIGHT) COMPARED WITH THOSE FROM THEIR PARENTAL CONTROLS. THIS RESULT INDICATES THAT ARSENIC MAY INDUCE GENETIC OR EPIGENETIC CHANGES THAT ARE THEN PASSED ON TO THE NEXT GENERATION. OVERALL, THIS STUDY DEMONSTRATES THAT ZEBRAFISH IS A CONVENIENT VERTEBRATE MODEL WITH ADVANTAGES IN THE EVALUATION OF ARSENIC-ASSOCIATED NEUROLOGICAL DISORDERS AS WELL AS ITS INFLUENCES ON THE OFFSPRING. 2016 19 1504 27 DNA METHYLATION AND HISTONE DEACETYLATION REGULATING INSULIN SENSITIVITY DUE TO CHRONIC COLD EXPOSURE. IN THIS STUDY, WE INVESTIGATED THE CAUSAL RELATIONSHIP BETWEEN CHRONIC COLD EXPOSURE AND INSULIN RESISTANCE AND THE MECHANISMS OF HOW DNA METHYLATION AND HISTONE DEACETYLATION REGULATE COLD-REDUCED INSULIN RESISTANCE. 46 ADULT MALE MICE FROM POSTNATAL DAY 90-180 WERE RANDOMLY ASSIGNED TO CONTROL GROUP AND COLD-EXPOSURE GROUP. MICE IN COLD-EXPOSURE GROUP WERE PLACED AT TEMPERATURE FROM -1 TO 4 DEGREES C FOR 30 DAYS TO MIMIC CHRONIC COLD ENVIRONMENT. THEN, FASTING BLOOD GLUCOSE, BLOOD INSULIN LEVEL AND INSULIN RESISTANCE INDEX WERE MEASURED WITH ENZYMATIC METHODS. IMMUNOFLUORESCENT LABELING WAS CARRIED OUT TO VISUALIZE THE INSULIN RECEPTOR SUBSTRATE 2 (IRS2), OBESE RECEPTOR (OB-R, A LEPTIN RECEPTOR), VOLTAGE-DEPENDENT ANION CHANNEL PROTEIN 1 (VDAC1), CYTOCHROME C (CYTC), 5-METHYLCYTOSINE (5-MC) POSITIVE CELLS IN HIPPOCAMPAL CA1 AREA. FURTHERMORE, THE EXPRESSIONS OF SOME PROTEINS MENTIONED ABOVE WERE DETECTED WITH WESTERN BLOT. THE RESULTS SHOWED: 1 IN CIRCLE CHRONIC COLD EXPOSURE COULD REDUCE THE INSULIN RESISTANCE INDEX (P < 0.01) AND INCREASE THE NUMBER OF IRS2 POSITIVE CELLS AND OB-R POSITIVE CELLS IN HIPPOCAMPUS (P < 0.01). 2 IN CIRCLE THE EXPRESSIONS OF MITOCHONDRIAL ENERGY-RELATIVE PROTEINS, VDAC1 AND CYTC, WERE HIGHER IN COLD-EXPOSURE GROUP THAN IN CONTROL GROUP WITH BOTH IMMUNOHISTOCHEMICAL STAINING AND WESTERN BLOT (P < 0.01). 3 IN CIRCLE CHRONIC COLD EXPOSURE INCREASED DNA METHYLATION AND HISTONE DEACETYLATION IN THE PYRAMIDAL CELLS OF CA1 AREA AND LED TO AN INCREASE IN THE EXPRESSION OF HISTONE DEACETYLASE 1 (HDAC1) AND DNA METHYLATION RELATIVE ENZYMES (P < 0.01). IN CONCLUSION, CHRONIC COLD EXPOSURE CAN IMPROVE INSULIN SENSITIVITY, WITH THE INVOLVEMENT OF DNA METHYLATION, HISTONE DEACETYLATION AND THE REGULATION OF MITOCHONDRIAL ENERGY METABOLISM. THESE EPIGENETIC MODIFICATIONS PROBABLY FORM THE BASIC MECHANISM OF COLD-REDUCED INSULIN RESISTANCE. 2017 20 4044 25 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