1 313 105 ALCOHOL METABOLISM AND EPIGENETICS CHANGES. METABOLITES, INCLUDING THOSE GENERATED DURING ETHANOL METABOLISM, CAN IMPACT DISEASE STATES BY BINDING TO TRANSCRIPTION FACTORS AND/OR MODIFYING CHROMATIN STRUCTURE, THEREBY ALTERING GENE EXPRESSION PATTERNS. FOR EXAMPLE, THE ACTIVITIES OF ENZYMES INVOLVED IN EPIGENETIC MODIFICATIONS SUCH AS DNA AND HISTONE METHYLATION AND HISTONE ACETYLATION, ARE INFLUENCED BY THE LEVELS OF METABOLITES SUCH AS NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD), ADENOSINE TRIPHOSPHATE (ATP), AND S-ADENOSYLMETHIONINE (SAM). CHRONIC ALCOHOL CONSUMPTION LEADS TO SIGNIFICANT REDUCTIONS IN SAM LEVELS, THEREBY CONTRIBUTING TO DNA HYPOMETHYLATION. SIMILARLY, ETHANOL METABOLISM ALTERS THE RATIO OF NAD+ TO REDUCED NAD (NADH) AND PROMOTES THE FORMATION OF REACTIVE OXYGEN SPECIES AND ACETATE, ALL OF WHICH IMPACT EPIGENETIC REGULATORY MECHANISMS. IN ADDITION TO ALTERED CARBOHYDRATE METABOLISM, INDUCTION OF CELL DEATH, AND CHANGES IN MITOCHONDRIAL PERMEABILITY TRANSITION, THESE METABOLISM-RELATED CHANGES CAN LEAD TO MODULATION OF EPIGENETIC REGULATION OF GENE EXPRESSION. UNDERSTANDING THE NATURE OF THESE EPIGENETIC CHANGES WILL HELP RESEARCHERS DESIGN NOVEL MEDICATIONS TO TREAT OR AT LEAST AMELIORATE ALCOHOL-INDUCED ORGAN DAMAGE. 2013 2 6467 31 TISSUE-SPECIFIC EFFECTS OF EXERCISE AS NAD(+) -BOOSTING STRATEGY: CURRENT KNOWLEDGE AND FUTURE PERSPECTIVES. NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD(+) ) IS AN EVOLUTIONARILY HIGHLY CONSERVED COENZYME WITH MULTI-FACETED CELL FUNCTIONS, INCLUDING ENERGY METABOLISM, MOLECULAR SIGNALING PROCESSES, EPIGENETIC REGULATION, AND DNA REPAIR. SINCE THE DISCOVERY THAT LOWER NAD(+) LEVELS ARE A SHARED CHARACTERISTIC OF VARIOUS DISEASES AND AGING PER SE, SEVERAL NAD(+) -BOOSTING STRATEGIES HAVE EMERGED. OTHER THAN PHARMACOLOGICAL AND NUTRITIONAL APPROACHES, EXERCISE IS THOUGHT TO RESTORE NAD(+) HOMEOSTASIS THROUGH METABOLIC ADAPTION TO CHRONICALLY RECURRING STATES OF INCREASED ENERGY DEMAND. IN THIS REVIEW WE DISCUSS THE IMPACT OF ACUTE EXERCISE AND EXERCISE TRAINING ON TISSUE-SPECIFIC NAD(+) METABOLISM OF RODENTS AND HUMANS TO HIGHLIGHT THE POTENTIAL VALUE AS NAD(+) -BOOSTING STRATEGY. BY INTERCONNECTING RESULTS FROM DIFFERENT INVESTIGATIONS, WE AIM TO DRAW ATTENTION TO TISSUE-SPECIFIC ALTERATIONS IN NAD(+) METABOLISM AND THE ASSOCIATED IMPLICATIONS FOR WHOLE-BODY NAD(+) HOMEOSTASIS. ACUTE EXERCISE LED TO PROFOUND ALTERATIONS OF INTRACELLULAR NAD(+) METABOLISM IN VARIOUS INVESTIGATIONS, WITH THE MAGNITUDE AND DIRECTION OF CHANGES BEING STRONGLY DEPENDENT ON THE APPLIED EXERCISE MODALITY, CELL TYPE, AND INVESTIGATED ANIMAL MODEL OR HUMAN POPULATION. EXERCISE TRAINING ELEVATED NAD(+) LEVELS AND NAD(+) METABOLISM ENZYMES IN VARIOUS TISSUES. BASED ON THESE RESULTS, WE DISCUSS MOLECULAR MECHANISMS THAT MIGHT CONNECT ACUTE EXERCISE-INDUCED DISRUPTIONS OF NAD(+) /NADH HOMEOSTASIS TO CHRONIC EXERCISE ADAPTIONS IN NAD(+) METABOLISM. TAKING THIS HYPOTHESIS-DRIVEN APPROACH, WE HOPE TO INSPIRE FUTURE RESEARCH ON THE MOLECULAR MECHANISMS OF EXERCISE AS NAD(+) -MODIFYING LIFESTYLE INTERVENTION, THEREBY ELUCIDATING THE POTENTIAL THERAPEUTIC VALUE IN NAD(+) -RELATED PATHOLOGIES. 2023 3 558 27 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 4 318 44 ALCOHOL-INDUCED EPIGENETIC CHANGES IN CANCER. CHRONIC, HEAVY ALCOHOL CONSUMPTION IS ASSOCIATED WITH SERIOUS NEGATIVE HEALTH EFFECTS, INCLUDING THE DEVELOPMENT OF SEVERAL CANCER TYPES. ONE OF THE PATHWAYS AFFECTED BY ALCOHOL TOXICITY IS THE ONE-CARBON METABOLISM. THE ALCOHOL-INDUCED IMPAIRMENT OF THIS METABOLIC PATHWAY RESULTS IN EPIGENETIC CHANGES ASSOCIATED WITH CANCER DEVELOPMENT. THESE EPIGENETIC CHANGES ARE INDUCED BY FOLATE DEFICIENCY AND BY PRODUCTS OF THE ETHANOL METABOLISM. THE CHANGES INDUCED BY LONG-TERM HEAVY ETHANOL CONSUMPTION RESULT IN ELEVATIONS OF HOMOCYSTEINE AND S-ADENOSYL-HOMOCYSTEINE (SAH) AND REDUCTIONS IN S-ADENOSYLMETHIONINE (SAM) AND ANTIOXIDANT GLUTATHIONE (GSH) LEVELS, LEADING TO ABNORMAL PROMOTER GENE HYPERMETHYLATION, GLOBAL HYPOMETHYLATION, AND METABOLIC INSUFFICIENCY OF ANTIOXIDANT DEFENSE MECHANISMS. IN ADDITION, REACTIVE OXYGEN SPECIES (ROS) GENERATED DURING THE ETHANOL METABOLISM INDUCE ALTERATIONS IN DNA METHYLATION PATTERNS THAT PLAY A CRITICAL ROLE IN CANCER DEVELOPMENT. SPECIFIC EPIGENETIC CHANGES IN ESOPHAGEAL, HEPATIC, AND COLORECTAL CANCERS HAVE BEEN DETECTED IN BLOOD SAMPLES AND PROPOSED TO BE USED CLINICALLY AS EPIGENETIC BIOMARKERS FOR DIAGNOSIS AND PROGNOSIS OF THESE CANCERS. ALSO, GENETIC VARIANTS OF GENES INVOLVED IN ONE-CARBON METABOLISM AND ETHANOL METABOLISM WERE FOUND TO MODULATE THE RELATIONSHIP BETWEEN ALCOHOL-INDUCED EPIGENETIC CHANGES AND CANCER RISK. FURTHERMORE, ALCOHOL METABOLISM PRODUCTS HAVE BEEN ASSOCIATED WITH AN INCREASE IN NADH LEVELS, WHICH LEAD TO HISTONE MODIFICATIONS AND CHANGES IN GENE EXPRESSION THAT IN TURN INFLUENCE CANCER SUSCEPTIBILITY. CHRONIC EXCESSIVE USE OF ALCOHOL ALSO AFFECTS SELECTED MEMBERS OF THE FAMILY OF MICRORNAS, AND AS MIRNAS COULD ACT AS EPIGENETIC REGULATORS, THIS MAY PLAY AN IMPORTANT ROLE IN CARCINOGENESIS. IN CONCLUSION, TARGETING ALCOHOL-INDUCED EPIGENETIC CHANGES IN SEVERAL CANCER TYPES COULD MAKE AVAILABLE CLINICAL TOOLS FOR THE DIAGNOSIS, PROGNOSIS, AND TREATMENT OF THESE CANCERS, WITH AN IMPORTANT ROLE IN PRECISION MEDICINE. 2018 5 1855 28 ELEVATION IN S-ADENOSYLHOMOCYSTEINE AND DNA HYPOMETHYLATION: POTENTIAL EPIGENETIC MECHANISM FOR HOMOCYSTEINE-RELATED PATHOLOGY. CHRONIC NUTRITIONAL DEFICIENCIES IN FOLATE, CHOLINE, METHIONINE, VITAMIN B-6 AND/OR VITAMIN B-12 CAN PERTURB THE COMPLEX REGULATORY NETWORK THAT MAINTAINS NORMAL ONE-CARBON METABOLISM AND HOMOCYSTEINE HOMEOSTASIS. GENETIC POLYMORPHISMS IN THESE PATHWAYS CAN ACT SYNERGISTICALLY WITH NUTRITIONAL DEFICIENCIES TO ACCELERATE METABOLIC PATHOLOGY ASSOCIATED WITH OCCLUSIVE HEART DISEASE, BIRTH DEFECTS AND DEMENTIA. A MAJOR UNANSWERED QUESTION IS WHETHER HOMOCYSTEINE IS CAUSALLY INVOLVED IN DISEASE PATHOGENESIS OR WHETHER HOMOCYSTEINEMIA IS SIMPLY A PASSIVE AND INDIRECT INDICATOR OF A MORE COMPLEX MECHANISM. S-ADENOSYLMETHIONINE AND S-ADENOSYLHOMOCYSTEINE (SAH), AS THE SUBSTRATE AND PRODUCT OF METHYLTRANSFERASE REACTIONS, ARE IMPORTANT METABOLIC INDICATORS OF CELLULAR METHYLATION STATUS. CHRONIC ELEVATION IN HOMOCYSTEINE LEVELS RESULTS IN PARALLEL INCREASES IN INTRACELLULAR SAH AND POTENT PRODUCT INHIBITION OF DNA METHYLTRANSFERASES. SAH-MEDIATED DNA HYPOMETHYLATION AND ASSOCIATED ALTERATIONS IN GENE EXPRESSION AND CHROMATIN STRUCTURE MAY PROVIDE NEW HYPOTHESES FOR PATHOGENESIS OF DISEASES RELATED TO HOMOCYSTEINEMIA. 2002 6 5538 28 ROLE OF CHRONIC ALCOHOLISM CAUSING CANCER IN OMNIVORES AND VEGETARIANS THROUGH EPIGENETIC MODIFICATIONS. ONE OF THE SIGNIFICANT CONSEQUENCES OF ALCOHOL CONSUMPTION IS CANCER FORMATION VIA SEVERAL CONTRIBUTING FACTORS SUCH AS ACTION OF ALCOHOL METABOLITES, VITAMIN DEFICIENCIES, AND OXIDATIVE STRESS. ALL THESE FACTORS HAVE BEEN SHOWN TO CAUSE EPIGENETIC MODIFICATIONS VIA DNA HYPOMETHYLATION, THUS FORMING A BASIS FOR CANCER DEVELOPMENT. SEVERAL PUBLISHED REVIEWS AND STUDIES WERE SYSTEMATICALLY REVIEWED. OMNIVORES AND VEGETARIANS DIFFER IN TERMS OF NUTRITIONAL INTAKE AND DEFICIENCIES. AS FOLATE DEFICIENCY WAS FOUND TO BE COMMON AMONG THE OMNIVORES, CHRONIC ALCOHOLISM COULD POSSIBLY CAUSE DAMAGE AND EVENTUALLY CANCER IN AN OMNIVOROUS INDIVIDUAL VIA DNA HYPOMETHYLATION DUE TO FOLATE DEFICIENCY. FURTHERMORE, AS NIACIN WAS FOUND TO BE DEFICIENT AMONG VEGETARIANS, DAMAGE IN VEGETARIAN CHRONIC ALCOHOLICS COULD BE DUE TO INCREASED NADH/NAD (+) RATIO, THUS SLOWING ALCOHOL METABOLISM IN LIVER LEADING TO INCREASED ALCOHOL AND ACETALDEHYDE WHICH INHIBIT METHYLTRANSFERASE ENZYMES, EVENTUALLY LEADING TO DNA HYPOMETHYLATION. HENCE CORRECTING THE CONCERNED DEFICIENCY AND SUPPLEMENTATION WITH S-ADENOSYL METHIONINE COULD PROVE TO BE PROTECTIVE IN CHRONIC ALCOHOL USE. 2020 7 870 33 CHRONIC ALCOHOL BINGING INJURES THE LIVER AND OTHER ORGANS BY REDUCING NAD(+) LEVELS REQUIRED FOR SIRTUIN'S DEACETYLASE ACTIVITY. NAD(+) LEVELS ARE MARKEDLY REDUCED WHEN BLOOD ALCOHOL LEVELS ARE HIGH DURING BINGE DRINKING. THIS CAUSES LIVER INJURY TO OCCUR BECAUSE THE ENZYMES THAT REQUIRE NAD(+) AS A COFACTOR SUCH AS THE SIRTUIN DE-ACETYLASES CANNOT DE-ACETYLATE ACETYLATED PROTEINS SUCH AS ACETYLATED HISTONES. THIS PREVENTS THE EPIGENETIC CHANGES THAT REGULATE METABOLIC PROCESSES AND WHICH PREVENT ORGAN INJURY SUCH AS FATTY LIVER IN RESPONSE TO ALCOHOL ABUSE. HYPER ACETYLATION OF NUMEROUS REGULATORY PROTEINS DEVELOPS. SYSTEMIC MULTI-ORGAN INJURY OCCURS WHEN NAD(+) IS REDUCED. FOR INSTANCE THE CIRCADIAN CLOCK IS ALTERED IF NAD(+) IS NOT AVAILABLE. CELL CYCLE ARREST OCCURS DUE TO UP REGULATION OF CELL CYCLE INHIBITORS LEADING TO DNA DAMAGE, MUTATIONS, APOPTOSIS AND TUMORIGENESIS. NAD(+) IS LINKED TO AGING IN THE REGULATION OF TELOMERE STABILITY. NAD(+) IS REQUIRED FOR MITOCHONDRIAL RENEWAL. ALCOHOL DEHYDROGENASE IS PRESENT IN EVERY VISCERAL ORGAN IN THE BODY SO THAT THERE IS A SYSTEMIC REDUCTION OF NAD(+) LEVELS IN ALL OF THESE ORGANS DURING BINGE DRINKING. 2016 8 6726 22 VITAMIN-DEPENDENT METHIONINE METABOLISM AND ALCOHOLIC LIVER DISEASE. EMERGING EVIDENCE INDICATES THAT ETHANOL-INDUCED ALTERATIONS IN HEPATIC METHIONINE METABOLISM PLAY A CENTRAL ROLE IN THE PATHOGENESIS OF ALCOHOLIC LIVER DISEASE (ALD). BECAUSE MALNUTRITION IS A UNIVERSAL CLINICAL FINDING IN THIS DISEASE AND HEPATIC METHIONINE METABOLISM IS DEPENDENT UPON DIETARY FOLATE AND VITAMINS B-6 AND B-12, ALD CAN BE CONSIDERED AN INDUCED NUTRITIONAL DISORDER THAT IS CONDITIONED BY ALCOHOL ABUSE. THE PRESENT REVIEW DESCRIBES THE ETIOLOGIES OF THESE 3 VITAMIN DEFICIENCIES IN ALD AND HOW THEY INTERACT WITH CHRONIC ETHANOL EXPOSURE TO ALTER HEPATIC METHIONINE METABOLISM. SUBSEQUENT SECTIONS FOCUS ON MOLECULAR MECHANISMS FOR THE INTERACTIONS OF ABERRANT METHIONINE METABOLISM WITH ETHANOL IN THE PATHOGENESIS OF ALD, IN PARTICULAR THE ROLE OF S-ADENOSYLMETHIONINE (SAM) IN REGULATING THE EPIGENETIC EXPRESSIONS OF GENES RELEVANT TO PATHWAYS OF LIVER INJURY. THE REVIEW WILL CONCLUDE WITH DESCRIPTIONS OF STUDIES ON THE EFFICACY OF SAM IN THE TREATMENT OF ALD AND WITH DISCUSSION OF POTENTIALLY FRUITFUL FUTURE AVENUES OF RESEARCH. 2011 9 4683 37 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 10 4585 32 NAD(+) AND VASCULAR DYSFUNCTION: FROM MECHANISMS TO THERAPEUTIC OPPORTUNITIES. NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD(+)) IS AN ESSENTIAL AND PLEIOTROPIC COENZYME INVOLVED NOT ONLY IN CELLULAR ENERGY METABOLISM, BUT ALSO IN CELL SIGNALING, EPIGENETIC REGULATION, AND POST-TRANSLATIONAL PROTEIN MODIFICATIONS. VASCULAR DISEASE RISK FACTORS ARE ASSOCIATED WITH ABERRANT NAD(+) METABOLISM. CONVERSELY, THE THERAPEUTIC INCREASE OF NAD(+) LEVELS THROUGH THE ADMINISTRATION OF NAD(+) PRECURSORS OR INHIBITORS OF NAD(+)-CONSUMING ENZYMES REDUCES CHRONIC LOW-GRADE INFLAMMATION, REACTIVATES AUTOPHAGY AND MITOCHONDRIAL BIOGENESIS, AND ENHANCES OXIDATIVE METABOLISM IN VASCULAR CELLS OF HUMANS AND RODENTS WITH VASCULAR PATHOLOGIES. AS SUCH, NAD(+) HAS EMERGED AS A POTENTIAL TARGET FOR COMBATTING AGE-RELATED CARDIOVASCULAR AND CEREBROVASCULAR DISORDERS. THIS REVIEW DISCUSSES NAD(+)-REGULATED MECHANISMS CRITICAL FOR VASCULAR HEALTH AND SUMMARIZES NEW ADVANCES IN NAD(+) RESEARCH DIRECTLY RELATED TO VASCULAR AGING AND DISEASE, INCLUDING HYPERTENSION, ATHEROSCLEROSIS, CORONARY ARTERY DISEASE, AND AORTIC ANEURYSMS. FINALLY, WE ENUMERATE CHALLENGES AND OPPORTUNITIES FOR NAD(+) REPLETION THERAPY WHILE ANTICIPATING THE FUTURE OF THIS EXCITING RESEARCH FIELD, WHICH WILL HAVE A MAJOR IMPACT ON VASCULAR MEDICINE. 2022 11 5587 27 ROLE OF S-ADENOSYLHOMOCYSTEINE IN CARDIOVASCULAR DISEASE AND ITS POTENTIAL EPIGENETIC MECHANISM. TRANSMETHYLATION REACTIONS UTILIZE S-ADENOSYLMETHIONINE (SAM) AS A METHYL DONOR AND ARE CENTRAL TO THE REGULATION OF MANY BIOLOGICAL PROCESSES: MORE THAN FIFTY SAM-DEPENDENT METHYLTRANSFERASES METHYLATE A BROAD SPECTRUM OF CELLULAR COMPOUNDS INCLUDING DNA, HISTONES, PHOSPHOLIPIDS AND OTHER SMALL MOLECULES. COMMON TO ALL SAM-DEPENDENT TRANSMETHYLATION REACTIONS IS THE RELEASE OF THE POTENT INHIBITOR S-ADENOSYLHOMOCYSTEINE (SAH) AS A BY-PRODUCT. SAH IS REVERSIBLY HYDROLYZED TO ADENOSINE AND HOMOCYSTEINE BY SAH HYDROLASE. HYPERHOMOCYSTEINEMIA IS AN INDEPENDENT RISK FACTOR FOR CARDIOVASCULAR DISEASE. HOWEVER, A MAJOR UNANSWERED QUESTION IS IF HOMOCYSTEINE IS CAUSALLY INVOLVED IN DISEASE PATHOGENESIS OR SIMPLY A PASSIVE AND INDIRECT INDICATOR OF A MORE COMPLEX MECHANISM. A CHRONIC ELEVATION IN HOMOCYSTEINE LEVELS RESULTS IN A PARALLEL INCREASE IN INTRACELLULAR OR PLASMA SAH, WHICH IS A MORE SENSITIVE BIOMARKER OF CARDIOVASCULAR DISEASE THAN HOMOCYSTEINE AND SUGGESTS THAT SAH IS A CRITICAL PATHOLOGICAL FACTOR IN HOMOCYSTEINE-ASSOCIATED DISORDERS. PREVIOUS REPORTS INDICATE THAT SUPPLEMENTATION WITH FOLATE AND B VITAMINS EFFICIENTLY LOWERS HOMOCYSTEINE LEVELS BUT NOT PLASMA SAH LEVELS, WHICH POSSIBLY EXPLAINS THE FAILURE OF HOMOCYSTEINE-LOWERING VITAMINS TO REDUCE VASCULAR EVENTS IN SEVERAL RECENT CLINICAL INTERVENTION STUDIES. FURTHERMORE, MORE STUDIES ARE FOCUSING ON THE ROLE AND MECHANISMS OF SAH IN DIFFERENT CHRONIC DISEASES RELATED TO HYPERHOMOCYSTEINEMIA, SUCH AS CARDIOVASCULAR DISEASE, KIDNEY DISEASE, DIABETES, AND OBESITY. THIS REVIEW SUMMARIZES THE CURRENT ROLE OF SAH IN CARDIOVASCULAR DISEASE AND ITS EFFECT ON SEVERAL RELATED RISK FACTORS. IT ALSO EXPLORES POSSIBLE THE MECHANISMS, SUCH AS EPIGENETICS AND OXIDATIVE STRESS, OF SAH. THIS ARTICLE IS PART OF A DIRECTED ISSUE ENTITLED: EPIGENETIC DYNAMICS IN DEVELOPMENT AND DISEASE. 2015 12 872 35 CHRONIC ALCOHOL EXPOSURE DIFFERENTIALLY ALTERS ONE-CARBON METABOLISM IN RAT LIVER AND BRAIN. BACKGROUND: EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION PLAY AN IMPORTANT ROLE IN REGULATING THE PATHOPHYSIOLOGY OF ALCOHOLISM. CHRONIC ALCOHOL EXPOSURE LEADS TO BEHAVIORAL CHANGES AS WELL AS DECREASED EXPRESSION OF GENES ASSOCIATED WITH SYNAPTIC PLASTICITY. IN THE LIVER, IT HAS BEEN DOCUMENTED THAT CHRONIC ALCOHOL EXPOSURE IMPAIRS METHIONINE SYNTHASE (MS) ACTIVITY LEADING TO A DECREASE IN S-ADENOSYL METHIONINE/S-ADENOSYL HOMOCYSTEINE (SAM/SAH) RATIO WHICH RESULTS IN DNA HYPOMETHYLATION; HOWEVER, IT IS NOT KNOWN WHETHER SIMILAR ALTERATIONS OF SAM AND SAH LEVELS ARE ALSO PRODUCED IN BRAIN. METHODS: MALE ADULT SPRAGUE DAWLEY RATS WERE FED CHRONICALLY WITH LIEBER-DECARLI ETHANOL (ETOH) (9% V/V) OR CONTROL DIET. THE ETOH-DIET-FED RATS WERE WITHDRAWN FOR 0 AND 24 HOURS. THE CEREBELLUM AND LIVER TISSUES WERE DISSECTED AND USED TO INVESTIGATE CHANGES IN ONE-CARBON METABOLISM, SAM, AND SAH LEVELS. RESULTS: WE FOUND THAT CHRONIC ETOH EXPOSURE DECREASED SAM LEVELS, SAM/SAH RATIO, MS, METHYLENE TETRAHYDROFOLATE REDUCTASE, AND BETAINE HOMOCYSTEINE METHYLTRANSFERASE (BHMT) EXPRESSION AND INCREASED METHIONINE ADENOSYLTRANSFERASE-2B (MAT2B) BUT NOT MAT2A EXPRESSION IN THE LIVER. IN CONTRAST, CHRONIC ETOH EXPOSURE DECREASED SAH LEVELS, INCREASED SAM/SAH RATIO AND THE EXPRESSION OF MAT2A AND S-ADENOSYL HOMOCYSTEINE HYDROLASE, WHILE THE LEVELS OF SAM OR BHMT EXPRESSION IN CEREBELLUM REMAINED UNALTERED. HOWEVER, IN BOTH LIVER AND CEREBELLUM, CHRONIC ETOH EXPOSURE DECREASED THE EXPRESSION OF MS AND INCREASED MAT2B EXPRESSION. ALL CHRONIC ETOH-INDUCED CHANGES OF ONE-CARBON METABOLISM IN CEREBELLUM, BUT NOT LIVER, RETURNED TO NEAR-NORMAL LEVELS DURING ETOH WITHDRAWAL. CONCLUSIONS: THESE RESULTS INDICATE A DECREASED "METHYLATION INDEX" IN LIVER AND AN INCREASED "METHYLATION INDEX" IN CEREBELLUM. THE OPPOSING CHANGES OF THE "METHYLATION INDEX" SUGGEST ALTERED DNA METHYLATION IN LIVER AND CEREBELLUM, THUS IMPLICATING ONE-CARBON METABOLISM IN THE PATHOPHYSIOLOGY OF ALCOHOLISM. 2017 13 6220 18 THE KIDNEY IS THE MAJOR SITE OF S-ADENOSYLHOMOCYSTEINE DISPOSAL IN HUMANS. S-ADENOSYLHOMOCYSTEINE (SAH), THE METABOLIC PRECURSOR OF HOMOCYSTEINE IN THE BODY, IS A POTENT INHIBITOR OF METHYLATION REACTIONS. SEVERAL METHYLATION REACTIONS PLAY A MAJOR ROLE IN EPIGENETIC REGULATION OF PROTEIN EXPRESSION, ATHEROSCLEROSIS, AND CANCER DEVELOPMENT. HERE WE STUDIED THE MECHANISMS RESPONSIBLE FOR THE MAINTENANCE OF CIRCULATING SAH LEVELS BY MEASUREMENT OF THE ARTERIO-VENOUS DIFFERENCES ACROSS THE KIDNEY, SPLANCHNIC ORGANS, AND THE LUNG IN HUMANS. THE LUNGS DID NOT REMOVE OR ADD ANY CIRCULATING SAH, WHEREAS THE LIVER RELEASED IT INTO THE HEPATIC VEINS. THE KIDNEY EXTRACTED 40% OF SAH AND THE SAH ARTERIO-VENOUS DIFFERENCE ACROSS THE KIDNEY WAS DIRECTLY AND SIGNIFICANTLY RELATED TO ITS ARTERIAL LEVELS. THUS, THE KIDNEY PLAYS A MAJOR ROLE IN MAINTAINING SAH LEVELS AND MAY, INDIRECTLY, CONTROL TISSUE TRANSMETHYLATION REACTIONS. OUR FINDINGS OF A PIVOTAL ROLE FOR THE HUMAN KIDNEY IN SULFUR AMINO ACID METABOLISM MAY ALSO ACCOUNT FOR THE INCREASED PLASMA LEVELS OF SAH IN PATIENTS WITH CHRONIC KIDNEY DISEASES. 2009 14 6166 28 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 15 474 29 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 16 853 27 CHOLINE, OTHER METHYL-DONORS AND EPIGENETICS. CHOLINE DIETARY INTAKE VARIES SUCH THAT MANY PEOPLE DO NOT ACHIEVE ADEQUATE INTAKES. DIET INTAKE OF CHOLINE CAN MODULATE METHYLATION BECAUSE, VIA BETAINE HOMOCYSTEINE METHYLTRANSFERASE (BHMT), THIS NUTRIENT (AND ITS METABOLITE, BETAINE) REGULATE THE CONCENTRATIONS OF S-ADENOSYLHOMOCYSTEINE AND S-ADENOSYLMETHIONINE. SOME OF THE EPIGENETIC MECHANISMS THAT MODIFY GENE EXPRESSION WITHOUT MODIFYING THE GENETIC CODE DEPEND ON THE METHYLATION OF DNA OR OF HISTONES; AND DIET AVAILABILITY OF CHOLINE AND OTHER METHYL-GROUP DONORS INFLUENCES BOTH OF THESE METHYLATIONS. EXAMPLES OF METHYL-DONOR MEDIATED EPIGENETIC EFFECTS INCLUDE THE CHANGES IN COAT COLOR AND BODY WEIGHT IN OFFSPRING WHEN PREGNANT AGOUTI MICE ARE FED HIGH CHOLINE, HIGH METHYL DIETS; THE CHANGES IN TAIL KINKING IN OFFSPRING WHEN PREGNANT AXIN(FU) MICE ARE FED HIGH CHOLINE, HIGH METHYL DIETS; THE CHANGES IN CDKN3 METHYLATION AND ALTERED BRAIN DEVELOPMENT THAT OCCURS IN OFFSPRING WHEN PREGNANT RODENTS ARE FED LOW CHOLINE DIETS. WHEN CHOLINE METABOLISM IS DISRUPTED BY DELETING THE GENE BHMT, DNA METHYLATION IS AFFECTED (ESPECIALLY IN A REGION OF CHROMOSOME 13), EXPRESSION OF SPECIFIC GENES IS SUPPRESSED, AND LIVER CANCERS DEVELOP. BETTER UNDERSTANDING OF HOW NUTRIENTS SUCH AS CHOLINE AND METHYL-DONORS INFLUENCE EPIGENETIC PROGRAMS HAS IMPORTANCE FOR OUR UNDERSTANDING OF NOT ONLY DEVELOPMENTAL ABNORMALITIES BUT ALSO FOR UNDERSTANDING THE ORIGINS OF CHRONIC DISEASES. 2017 17 871 31 CHRONIC ALCOHOL EXPOSURE AFFECTS PANCREATIC ACINAR MITOCHONDRIAL THIAMIN PYROPHOSPHATE UPTAKE: STUDIES WITH MOUSE 266-6 CELL LINE AND PRIMARY CELLS. THIAMIN IS ESSENTIAL FOR NORMAL METABOLIC ACTIVITY OF ALL MAMMALIAN CELLS, INCLUDING THOSE OF THE PANCREAS. CELLS OBTAIN THIAMIN FROM THEIR SURROUNDINGS AND ENZYMATICALLY CONVERT IT INTO THIAMIN PYROPHOSPHATE (TPP) IN THE CYTOPLASM; TPP IS THEN TAKEN UP BY MITOCHONDRIA VIA A SPECIFIC CARRIER THE MITOCHONDRIAL TPP TRANSPORTER (MTPPT; PRODUCT OF THE SLC25A19 GENE). CHRONIC ALCOHOL EXPOSURE NEGATIVELY IMPACTS THE HEALTH OF PANCREATIC ACINAR CELLS (PAC), BUT ITS EFFECT ON PHYSIOLOGICAL/MOLECULAR PARAMETERS OF MTPPT IS NOT KNOWN. WE ADDRESSED THIS ISSUE USING MOUSE PANCREATIC ACINAR TUMOR CELL LINE 266-6 AND PRIMARY PAC OF WILD-TYPE AND TRANSGENIC MICE CARRYING THE SLC25A19 PROMOTER THAT WERE FED ALCOHOL CHRONICALLY. CHRONIC ALCOHOL EXPOSURE OF 266-6 CELLS (BUT NOT TO ITS NONOXIDATIVE METABOLITES ETHYL PALMITATE AND ETHYL OLEATE) LED TO A SIGNIFICANT INHIBITION IN MITOCHONDRIAL TPP UPTAKE, WHICH WAS ASSOCIATED WITH A DECREASED EXPRESSION OF MTPPT PROTEIN, MRNA, AND ACTIVITY OF THE SLC25A19 PROMOTER. SIMILARLY, CHRONIC ALCOHOL FEEDING OF MICE LED TO A SIGNIFICANT INHIBITION IN EXPRESSION OF MTPPT PROTEIN, MRNA, HETEROGENEOUS NUCLEAR RNA, AS WELL AS IN ACTIVITY OF SLC25A19 PROMOTER IN PAC. WHILE CHRONIC ALCOHOL EXPOSURE DID NOT AFFECT DNA METHYLATION OF THE SLC25A19 PROMOTER, A SIGNIFICANT DECREASE IN HISTONE H3 EUCHROMATIN MARKERS AND AN INCREASE IN H3 HETEROCHROMATIN MARKER WERE OBSERVED. THESE FINDINGS SHOW, FOR THE FIRST TIME, THAT CHRONIC ALCOHOL EXPOSURE NEGATIVELY IMPACTS PANCREATIC MTPPT, AND THAT THIS EFFECT IS EXERTED, AT LEAST IN PART, AT THE LEVEL OF SLC25A19 TRANSCRIPTION AND APPEARS TO INVOLVE EPIGENETIC MECHANISM(S). 2015 18 3619 26 IN VIVO ACUTE ON CHRONIC ETHANOL EFFECTS IN LIVER: A MOUSE MODEL EXHIBITING EXACERBATED INJURY, ALTERED METABOLIC AND EPIGENETIC RESPONSES. CHRONIC ALCOHOLICS WHO ALSO BINGE DRINK (I.E., ACUTE ON CHRONIC) ARE PRONE TO AN EXACERBATED LIVER INJURY BUT ITS MECHANISM IS NOT UNDERSTOOD. WE THEREFORE INVESTIGATED THE IN VIVO EFFECTS OF CHRONIC AND BINGE ETHANOL INGESTION AND COMPARED TO CHRONIC ETHANOL FOLLOWED BY THREE REPEAT BINGE ETHANOL ON THE LIVER OF MALE C57/BL6 MICE FED ETHANOL IN LIQUID DIET (4%) FOR FOUR WEEKS FOLLOWED BY BINGE ETHANOL (INTRAGASTRIC ADMINISTRATION, 3.5 G/KG BODY WEIGHT, THREE DOSES, 12H APART). CHRONIC FOLLOWED BY BINGE ETHANOL EXACERBATED FAT ACCUMULATION, NECROSIS, DECREASE IN HEPATIC SAM AND SAM:SAH RATIO, INCREASE IN ADENOSINE LEVELS, AND ELEVATED CYP2E1 LEVELS. HISTONE H3 LYSINE ACETYLATION (H3ACK9), DUALLY MODIFIED PHOSPHOACETYLATED HISTONE H3 (H3ACK9/PS10), AND PHOSPHORYLATED H2AX INCREASED AFTER BINGE WHEREAS PHOSPHORYLATION OF HISTONE H3 SER 10 (H3S10) AND H3 SER 28 (H3S28) INCREASED AFTER CHRONIC ETHANOL-BINGE. HISTONE H3 LYSINE 4 AND 9 DIMETHYLATION INCREASED WITH A MARKED DIMETHYLATION IN H3K9 IN CHRONIC ETHANOL BINGE GROUP. TRIMETHYLATED HISTONE H3 LEVELS DID NOT CHANGE. NUCLEAR LEVELS OF HISTONE ACETYL TRANSFERASE GCN5 AND HISTONE DEACETYLASE HDAC3 WERE ELEVATED WHEREAS PHOSPHO-CREB DECREASED IN A DISTINCTIVE MANNER. TAKEN TOGETHER, ACUTE ON CHRONIC ETHANOL INGESTION CAUSED AMPLIFICATION OF LIVER INJURY AND ELICITED CHARACTERISTIC PROFILES OF HISTONE MODIFICATIONS, METABOLIC ALTERATIONS, AND CHANGES IN NUCLEAR PROTEIN LEVELS. THESE FINDINGS DEMONSTRATE THAT CHRONIC ETHANOL EXPOSURE RENDERS LIVER MORE SUSCEPTIBLE TO REPEAT ACUTE/BINGE ETHANOL INDUCED ACCELERATION OF ALCOHOLIC LIVER DISEASE. 2015 19 4768 34 NUCLEAR EFFECTS OF ETHANOL-INDUCED PROTEASOME INHIBITION IN LIVER CELLS. ALCOHOL INGESTION CAUSES ALTERATION IN SEVERAL CELLULAR MECHANISMS, AND LEADS TO INFLAMMATION, APOPTOSIS, IMMUNOLOGICAL RESPONSE DEFECTS, AND FIBROSIS. THESE PHENOMENA ARE ASSOCIATED WITH SIGNIFICANT CHANGES IN THE EPIGENETIC MECHANISMS, AND SUBSEQUENTLY, TO LIVER CELL MEMORY. THE UBIQUITIN-PROTEASOME PATHWAY IS ONE OF THE VITAL PATHWAYS IN THE CELL THAT BECOMES DYSFUNCTIONAL AS A RESULT OF CHRONIC ETHANOL CONSUMPTION. INHIBITION OF THE PROTEASOME ACTIVITY IN THE NUCLEUS CAUSES CHANGES IN THE TURNOVER OF TRANSCRIPTIONAL FACTORS, HISTONE MODIFYING ENZYMES, AND THEREFORE, AFFECTS EPIGENETIC MECHANISMS. ALCOHOL CONSUMPTION HAS BEEN ASSOCIATED WITH AN INCREASE IN HISTONE ACETYLATION AND A DECREASE IN HISTONE METHYLATION, WHICH LEADS TO GENE EXPRESSION CHANGES. DNA AND HISTONE MODIFICATIONS THAT RESULT FROM ETHANOL-INDUCED PROTEASOME INHIBITION ARE KEY PLAYERS IN REGULATING GENE EXPRESSION, ESPECIALLY GENES INVOLVED IN THE CELL CYCLE, IMMUNOLOGICAL RESPONSES, AND METABOLISM OF ETHANOL. THE PRESENT REVIEW HIGHLIGHTS THE CONSEQUENCES OF ETHANOL-INDUCED PROTEASOME INHIBITION IN THE NUCLEUS OF LIVER CELLS THAT ARE CHRONICALLY EXPOSED TO ETHANOL. 2009 20 315 33 ALCOHOL, DNA METHYLATION, AND CANCER. CANCER IS ONE OF THE MOST SIGNIFICANT DISEASES ASSOCIATED WITH CHRONIC ALCOHOL CONSUMPTION, AND CHRONIC DRINKING IS A STRONG RISK FACTOR FOR CANCER, PARTICULARLY OF THE UPPER AERODIGESTIVE TRACT, LIVER, COLORECTUM, AND BREAST. SEVERAL FACTORS CONTRIBUTE TO ALCOHOL-INDUCED CANCER DEVELOPMENT (I.E., CARCINOGENESIS), INCLUDING THE ACTIONS OF ACETALDEHYDE, THE FIRST AND PRIMARY METABOLITE OF ETHANOL, AND OXIDATIVE STRESS. HOWEVER, INCREASING EVIDENCE SUGGESTS THAT ABERRANT PATTERNS OF DNA METHYLATION, AN IMPORTANT EPIGENETIC MECHANISM OF TRANSCRIPTIONAL CONTROL, ALSO COULD BE PART OF THE PATHOGENETIC MECHANISMS THAT LEAD TO ALCOHOL-INDUCED CANCER DEVELOPMENT. THE EFFECTS OF ALCOHOL ON GLOBAL AND LOCAL DNA METHYLATION PATTERNS LIKELY ARE MEDIATED BY ITS ABILITY TO INTERFERE WITH THE AVAILABILITY OF THE PRINCIPAL BIOLOGICAL METHYL DONOR, S-ADENOSYLMETHIONINE (SAME), AS WELL AS PATHWAYS RELATED TO IT. SEVERAL MECHANISMS MAY MEDIATE THE EFFECTS OF ALCOHOL ON DNA METHYLATION, INCLUDING REDUCED FOLATE LEVELS AND INHIBITION OF KEY ENZYMES IN ONE-CARBON METABOLISM THAT ULTIMATELY LEAD TO LOWER SAME LEVELS, AS WELL AS INHIBITION OF ACTIVITY AND EXPRESSION OF ENZYMES INVOLVED IN DNA METHYLATION (I.E., DNA METHYLTRANSFERASES). FINALLY, VARIATIONS (I.E., POLYMORPHISMS) OF SEVERAL GENES INVOLVED IN ONE-CARBON METABOLISM ALSO MODULATE THE RISK OF ALCOHOL-ASSOCIATED CARCINOGENESIS. 2013