1   853 117 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
2  4398  31 MODULATION OF DNA METHYLTRANSFERASE PROFILE BY METHYL DONOR STARVATION FOLLOWED BY GAMMA IRRADIATION. DNA METHYLATION IS AN IMPORTANT EPIGENETIC MECHANISM OF TRANSCRIPTIONAL CONTROL, WHICH PLAYS AN ESSENTIAL ROLE IN MAINTAINING CELLULAR FUNCTION. ROLE OF ONE-CARBON TRANSFER AGENTS/METHYL DONORS NAMELY FOLATE, CHOLINE AND METHIONINE IN DNA METHYLATION HAS BEEN THE SUBJECT OF EXTENSIVE INVESTIGATION. THE METHYLATION PATTERN OF DNA IS ESTABLISHED DURING EMBRYOGENESIS BY DNA METHYLTRANSFERASE 3 (DNMT3) AND IS SUBSEQUENTLY MAINTAINED BY MAINTENANCE METHYLATION ACTIVITY OF THE ENZYME DNA METHYLTRANSFERASE 1 (DNMT1). IONIZING RADIATION IS KNOWN TO EXTENSIVELY DAMAGE THE DNA. SUFFICIENT DIETARY AVAILABILITY OF METHYL DONORS IS KNOWN TO CONTRIBUTE TOWARDS ONE-CARBON TRANSFER MEDIATED REPAIR OF DAMAGED DNA WHERE FOLATE IS INVOLVED IN NUCLEOTIDE BASE SYNTHESIS. IN THE PRESENT STUDY, MODIFICATION IN ACTIVITIES OF DNMT1 AND DNMT3 BY METHYL DONOR STARVATION FOLLOWED BY GAMMA-IRRADIATION WAS OBSERVED. ASSAYS WERE BASED ON THE CATALYTIC TRANSFER OF (3)H-METHYL GROUPS FROM S-ADENOSYL-L: -METHIONINE TO A DNA SUBSTRATE. EXPERIMENTS SHOWED A DOSE AND METHYL DONORS STARVATION DEPENDENT ATTENUATION IN DNMT1 ACTIVITY. ATTENUATION OF DNMT1 ACTIVITY WAS MOST SIGNIFICANT FOR DIET DEPRIVED OF ALL THE THREE-METHYL DONORS. NO SIGNIFICANT CHANGE IN NUCLEAR OR CYTOPLASMIC DNMT3 ACTIVITY WAS OBSERVED WHEN EITHER OR ALL THE THREE POSSIBLE SOURCE OF DIETARY METHYL GROUP SUPPLY WERE REMOVED. IONIZING RADIATION AND METHYL DONOR DEFICIENCY WERE OBSERVED TO ACT SYNERGISTICALLY TOWARDS INHIBITING DNMT1 ACTIVITY. PRESENT RESULTS SUGGESTED POSSIBILITY OF INTERACTION AMONG FOLATE, METHIONINE AND CHOLINE DEFICIENCY TO POTENTIATE SYMPTOMS OF IONIZING RADIATION STRESS. THESE ENZYMATIC MODIFICATIONS MIGHT CONTRIBUTE TO ALTERED DNA METHYLATION AFTER CHRONIC FEEDING OF METHYL DONOR FREE DIETS FOLLOWED BY GAMMA IRRADIATION. THESE RESULTS SUGGESTED THAT DIETARY AVAILABILITY OF METHYL DONORS AND GAMMA-RADIATION STRESS MIGHT SIGNIFICANTLY ALTER THE DNMT1 PROFILE.	2007	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
3   558  31 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  1855  29 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
5  4214  43 METHIONINE METABOLISM IN YUCATAN MINIATURE SWINE. METHIONINE IS AN ESSENTIAL AMINO ACID WHICH WHEN NOT INCORPORATED INTO PROTEIN, CAN BE CONVERTED TO S-ADENOSYLMETHIONINE, THE UNIVERSAL METHYL DONOR IN OVER 200 TRANSMETHYLATION REACTIONS, WHICH INCLUDE CREATINE AND PHOSPHATIDYLCHOLINE (PC) SYNTHESIS, AS WELL AS DEOXYRIBONUCLEIC ACID (DNA) METHYLATION. FOLLOWING TRANSMETHYLATION, HOMOCYSTEINE IS FORMED, WHICH CAN BE CONVERTED TO CYSTEINE VIA TRANSSULFURATION OR REMETHYLATED TO METHIONINE BY RECEIVING A METHYL GROUP FROM FOLATE OR BETAINE. CHANGES TO METHYL GROUP AVAILABILITY IN UTERO CAN LEAD TO PERMANENT CHANGES IN EPIGENETIC PATTERNS OF DNA METHYLATION, WHICH HAS BEEN IMPLICATED IN "FETAL PROGRAMMING", A PHENOMENON ASSOCIATED WITH POOR NUTRITION DURING FETAL DEVELOPMENT THAT RESULTS IN LOW BIRTH WEIGHT AND DISEASE IN LATER LIFE. IT HAS BEEN SHOWN THAT PROGRAMMING CAN ALSO OCCUR IN THE NEONATE. OUR GLOBAL OBJECTIVE WAS TO UNDERSTAND HOW THE VARIABILITY OF NUTRIENTS INVOLVED IN METHIONINE METABOLISM CAN AFFECT METHIONINE AND METHYL GROUP AVAILABILITY. WE HYPOTHESIZE THAT NUTRIENTS THAT CONVERGE ON METHIONINE METABOLISM CAN AFFECT METHIONINE AVAILABILITY FOR ITS VARIOUS FUNCTIONS. IN THIS THESIS, WE USED INTRAUTERINE GROWTH RESTRICTED (IUGR) PIGLETS TO INVESTIGATE WHETHER A GLOBAL NUTRITIONAL INSULT IN UTERO CAN LEAD TO A PERTURBED METHIONINE METABOLISM. OUR RESULTS DEMONSTRATE THAT IUGR PIGLETS HAVE A LOWER CAPACITY TO DISPOSE OF HOMOCYSTEINE VIA BOTH TRANSSULFURATION AND REMETHYLATION PATHWAYS, AS WELL AS A LOWER INCORPORATION OF METHYL GROUPS INTO PC. THE SECOND OBJECTIVE OF THIS THESIS WAS TO DETERMINE WHETHER VARIATION IN METHIONINE SUPPLY AND DEMAND CAN AFFECT METHIONINE AVAILABILITY. WE DEMONSTRATED THAT STIMULATING EITHER ACUTE OR CHRONIC CREATINE SYNTHESIS LEADS TO LOWER METHYL INCORPORATION INTO PROTEIN AND PC IN PIGS. FURTHERMORE, WHEN METHIONINE IS LIMITING, SUPPLEMENTATION WITH EITHER FOLATE OR BETAINE LEADS TO HIGHER METHIONINE AVAILABILITY FOR PROTEIN SYNTHESIS. FINALLY, BECAUSE CREATINE IS INCREASINGLY BEING UTILIZED AS AN ERGOGENIC AND NEUROPROTECTIVE SUPPLEMENT, WE WANTED TO DETERMINE WHETHER PROVISION OF THE CREATINE PRECURSOR, GUANIDINOACETATE (GAA), COULD EFFECTIVELY INCREASE TISSUE CREATINE STORES. WE SHOWED THAT 2.5 WEEKS OF SUPPLEMENTATION WITH GAA IS MORE EFFECTIVE THAN CREATINE AT INCREASING HEPATIC AND MUSCLE CREATINE STORES. THE RESULTS OF THIS THESIS DEMONSTRATE THAT THE PRESENCE OF IUGR, AN INCREASED DEMAND FOR CREATINE SYNTHESIS, OR THE SUPPLEMENTATION WITH REMETHYLATION NUTRIENTS CAN EACH AFFECT METHIONINE AVAILABILITY; ALL ARE IMPORTANT WHEN CONSIDERING NEONATAL NUTRIENT REQUIREMENTS. FURTHERMORE, ALTHOUGH GAA IS EFFECTIVE AT INCREASING LEVELS OF TISSUE CREATINE, HIGHER GAA METHYLATION CAN LIMIT METHIONINE AVAILABILITY FOR GROWTH AND SYNTHESIS OF PC.	2016	
                                                                                                                                                                                                                                        
6  1833  33 EFFECTS OF METHYL DONOR DIETS ON INCISIONAL PAIN IN MICE. BACKGROUND: DIETARY SUPPLEMENTATION WITH METHYL DONORS CAN INFLUENCE THE PROGRAMMING OF EPIGENETIC PATTERNS RESULTING IN PERSISTENT ALTERATIONS IN DISEASE SUSCEPTIBILITY AND BEHAVIOR. HOWEVER, THE DIETARY EFFECTS OF METHYL DONORS ON PAIN HAVE NOT BEEN EXPLORED. IN THIS STUDY, WE EVALUATED THE EFFECTS OF DIETARY METHYL DONOR CONTENT ON PAIN RESPONSES IN MICE. METHODS: MALE AND FEMALE C57BL/6J MICE WERE TREATED WITH HIGH OR LOW METHYL DONOR DIETS EITHER IN THE PERINATAL PERIOD OR AFTER WEANING. MECHANICAL AND THERMAL NOCICEPTIVE SENSITIVITY WERE MEASURED BEFORE AND AFTER INCISION. RESULTS: MICE FED HIGH OR LOW METHYL DONOR DIETS DISPLAYED EQUAL WEIGHT GAIN OVER THE COURSE OF THE EXPERIMENTS. WHEN EXPOSED TO THESE DIETARY MANIPULATIONS IN THE PERINATAL PERIOD, ONLY MALE OFFSPRING OF DAMS FED A HIGH METHYL DONOR DIET DISPLAYED INCREASED MECHANICAL ALLODYNIA. HINDPAW INCISION IN THESE ANIMALS CAUSED ENHANCED NOCICEPTIVE SENSITIZATION, BUT DIETARY HISTORY DID NOT AFFECT THE DURATION OF SENSITIZATION. FOR MICE EXPOSED TO HIGH OR LOW METHYL DONOR DIETS AFTER WEANING, NO SIGNIFICANT DIFFERENCES WERE OBSERVED IN MECHANICAL OR THERMAL NOCICEPTIVE SENSITIVITY EITHER AT BASELINE OR IN RESPONSE TO HINDPAW INCISION. CONCLUSIONS: PERINATAL DIETARY FACTORS SUCH AS METHYL DONOR CONTENT MAY IMPACT PAIN EXPERIENCES IN LATER LIFE. THESE EFFECTS, HOWEVER, MAY BE SPECIFIC TO SEX AND PAIN MODALITY.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
7   872  39 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
8  4683  42 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	

9  4219  38 METHYL-DONOR DEFICIENCY IN ADOLESCENCE AFFECTS MEMORY AND EPIGENETIC STATUS IN THE MOUSE HIPPOCAMPUS. DNA METHYLATION IS ONE OF THE ESSENTIAL FACTORS IN THE CONTROL OF GENE EXPRESSION. ALTERATION OF THE DNA METHYLATION PATTERN HAS BEEN LINKED TO VARIOUS NEUROLOGICAL, BEHAVIORAL AND NEUROCOGNITIVE DYSFUNCTIONS. RECENT STUDIES HAVE POINTED OUT THE IMPORTANCE OF EPIGENETICS IN BRAIN DEVELOPMENT AND FUNCTIONS INCLUDING LEARNING AND MEMORY. NUTRIENTS RELATED TO ONE-CARBON METABOLISM ARE KNOWN TO PLAY IMPORTANT ROLES IN THE MAINTENANCE OF GENOMIC DNA METHYLATION. PREVIOUS STUDIES HAVE SHOWN THAT THE LONG-TERM ADMINISTRATION OF A DIET LACKING ESSENTIAL ONE-CARBON NUTRIENTS SUCH AS METHIONINE, CHOLINE AND FOLIC ACID (METHYL DONORS) CAUSED GLOBAL DNA HYPERMETHYLATION IN THE BRAIN. THEREFORE, THE LONG-TERM FEEDING OF A METHYL-DONOR-DEFICIENT DIET MAY CAUSE ABNORMAL BRAIN DEVELOPMENT INCLUDING LEARNING AND MEMORY. TO CONFIRM THIS HYPOTHESIS, 3-WEEK-OLD MICE WERE MAINTAINED ON A FOLATE-, METHIONINE- AND CHOLINE-DEFICIENT (FMCD) OR CONTROL (CON) DIET FOR 3 WEEKS. WE FOUND THAT THE METHYL-DONOR DEFICIENCY IMPAIRED BOTH NOVEL OBJECT RECOGNITION AND FEAR EXTINCTION AFTER 3 WEEKS OF TREATMENT. THE FMCD GROUP SHOWED SPONTANEOUS RECOVERY OF FEAR THAT DIFFERED FROM THAT IN CON. IN ADDITION, WE FOUND DECREASED GRIA1 GENE EXPRESSION AND SPECIFIC CPG HYPERMETHYLATION OF THE GRIA1 PROMOTER REGION IN THE FMCD HIPPOCAMPUS. OUR DATA SUGGEST THAT A CHRONIC DIETARY LACK OF METHYL DONORS IN THE DEVELOPMENTAL PERIOD AFFECTS LEARNING, MEMORY AND GENE EXPRESSIONS IN THE HIPPOCAMPUS.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
10  1781  24 EFFECT OF 1 YEAR B AND D VITAMIN SUPPLEMENTATION ON LINE-1 REPETITIVE ELEMENT METHYLATION IN OLDER SUBJECTS. BACKGROUND: DISTURBED DNA METHYLATION IS CAUSALLY RELATED TO CHRONIC DISEASES LIKE CANCER AND ATHEROSCLEROSIS. B VITAMINS ARE COFACTORS REQUIRED FOR METHYL GROUP SYNTHESIS AND MAY THEREFORE AFFECT DNA METHYLATION. VITAMIN D HAS EPIGENETIC EFFECTS. WE TESTED IF B AND D VITAMIN SUPPLEMENTATION HAS AN EFFECT ON GENOMIC LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) METHYLATION AND THE METABOLITES S-ADENOSYLMETHIONINE (SAM) AND S-ADENOSYLHOMOCYSTEINE (SAH). METHODS: FIFTY SUBJECTS (MEDIAN AGE 68.0 YEARS) WERE SUPPLEMENTED WITH A DAILY ORAL DOSE OF B VITAMINS (500 MICROG FOLIC ACID, 500 MICROG VITAMIN B12 AND 50 MG VITAMIN B6), 1200 IU VITAMIN D AND 456 MG CALCIUM. FASTING BLOOD SAMPLES WERE COLLECTED BEFORE AND AFTER 1 YEAR OF SUPPLEMENTATION. LINE-1 METHYLATION WAS DETERMINED IN GENOMIC DNA FROM BLOOD CELLS AS A SURROGATE FOR WHOLE GENOME METHYLATION. IN ADDITION, SAM, SAH AND TOTAL HOMOCYSTEINE (THCY) WERE MEASURED IN PLASMA SAMPLES. RESULTS: PLASMA HOMOCYSTEINE DECREASED SIGNIFICANTLY AFTER SUPPLEMENTATION (12.8 VS. 9.1 MICROMOL/L; P<0.05), WHEREAS SAM, SAH, THE SAM/SAH RATIO AND LINE-1 METHYLATION DID NOT CHANGE SIGNIFICANTLY. LINE-1 METHYLATION WAS NOT SIGNIFICANTLY CORRELATED WITH SAH, HOMOCYSTEINE OR B VITAMINS. CONCLUSIONS: LONG-TERM VITAMIN B SUPPLEMENTATION HAD NO EFFECT ON LINE-1 METHYLATION IN BLOOD CELLS NOR ON PLASMA LEVELS OF SAM AND SAH. VITAMIN B AND D SUPPLEMENTATION SEEMS TO HAVE NO EFFECT ON DNA METHYLATION, ESPECIALLY IN CASES WHERE NO SEVERE DEFICIENCY EXISTS.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
11  6445  29 THERAPEUTIC BENEFITS OF THE METHYL DONOR S-ADENOSYLMETHIONINE ON NERVE INJURY-INDUCED MECHANICAL HYPERSENSITIVITY AND COGNITIVE IMPAIRMENT IN MICE. DESPITE CONSIDERABLE ADVANCES IN UNDERSTANDING MECHANISMS INVOLVED IN CHRONIC PAIN, EFFECTIVE TREATMENT REMAINS ELUSIVE. COMORBID CONDITIONS INCLUDING ANXIETY, DEPRESSION, AND COGNITIVE IMPAIRMENT FURTHER IMPACT QUALITY OF LIFE. CHRONIC PAIN IS ASSOCIATED WITH REVERSIBLE CHANGES IN BRAIN ANATOMY AND FUNCTION AND WITH LONG-TERM CHANGES IN GENE EXPRESSION. EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, CONTRIBUTE TO WIDE-SPREAD AND LONG-LASTING REPROGRAMMING OF GENE EXPRESSION. WE PREVIOUSLY REPORTED DECREASES IN GLOBAL DNA METHYLATION IN THE MOUSE FRONTAL CORTEX 6 MONTHS AFTER INDUCTION OF NEUROPATHIC PAIN USING THE SPARED NERVE INJURY (SNI) MODEL. HERE, WE EXAMINED THE THERAPEUTIC EFFECT OF INCREASING DNA METHYLATION USING THE METHYL DONOR S-ADENOSYLMETHIONINE (SAM). S-ADENOSYLMETHIONINE IS MARKETED AS A NUTRITIONAL SUPPLEMENT FOR A RANGE OF CONDITIONS INCLUDING LIVER DISEASE, DEPRESSION, OSTEOARTHRITIS, FIBROMYALGIA, AND DEMENTIA. THREE MONTHS AFTER SNI OR SHAM SURGERY, ANIMALS WERE TREATED WITH SAM (20 MG/KG, 3X/WEEK) OR SALINE ORALLY FOR 4 MONTHS, AND THE IMPACT ON SENSORY, MOTOR, MOTIVATIONAL, AND COGNITIVE INDICES WAS MEASURED. S-ADENOSYLMETHIONINE ATTENUATED SNI-INDUCED MECHANICAL HYPERSENSITIVITY AND REDUCED ACTIVE AVOIDANCE OF MECHANICAL STIMULI BUT HAD NO EFFECT ON COLD SENSITIVITY OR MOTOR CAPACITY. S-ADENOSYLMETHIONINE COMPLETELY BLOCKED NERVE INJURY-INDUCED COGNITIVE IMPAIRMENT AND ATTENUATED SNI-INDUCED DECREASES IN GLOBAL DNA METHYLATION IN THE FRONTAL CORTEX. IN SUMMARY, CHRONIC ORAL ADMINISTRATION OF THE METHYL DONOR, SAM, ATTENUATED SENSORY AND COGNITIVE SYMPTOMS ASSOCIATED WITH NERVE INJURY IN MICE. THESE EFFECTS MAY BE MEDIATED, IN PART, THROUGH MODULATION OF DNA METHYLATION IN THE CENTRAL NERVOUS SYSTEM BY SYSTEMIC ADMINISTRATION OF THE METHYL DONOR SAM.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
12  5609  28 S-ADENOSYLMETHIONINE DECREASES THE PEAK BLOOD ALCOHOL LEVELS 3 H AFTER AN ACUTE BOLUS OF ETHANOL BY INDUCING ALCOHOL METABOLIZING ENZYMES IN THE LIVER. INTRODUCTION: AN ALCOHOL BOLUS CAUSES THE BLOOD ALCOHOL LEVEL (BAL) TO PEAK AT 1-2 H POST INGESTION. THE ETHANOL ELIMINATION RATE IS REGULATED BY ALCOHOL METABOLIZING ENZYMES, PRIMARILY ALCOHOL DEHYDROGENASE (ADH1), ACETALDEHYDE DEHYDROGENASE (ALDH), AND CYTOCHROME P450 (CYP2E1). RECENTLY, S-ADENOSYLMETHIONINE (SAME) WAS FOUND TO REDUCE ACUTE BALS 3 H AFTER AN ALCOHOL BOLUS. THE QUESTION, THEN, WAS: WHAT IS THE MECHANISM INVOLVED IN THIS REDUCTION OF BAL BY FEEDING SAME? TO ANSWER THIS QUESTION, WE INVESTIGATED THE CHANGES IN ETHANOL METABOLIZING ENZYMES AND THE EPIGENETIC CHANGES THAT REGULATE THE EXPRESSION OF THESE ENZYMES DURING ACUTE BINGE DRINKING AND CHRONIC DRINKING. METHODS: RATS WERE FED A BOLUS OF ETHANOL WITH OR WITHOUT SAME, AND WERE SACRIFICED AT 3 H OR 12 H AFTER THE BOLUS. RESULTS: RT-PCR AND WESTERN BLOT ANALYSES SHOWED THAT SAME SIGNIFICANTLY INDUCED ADH1 LEVELS IN THE 3 H LIVER SAMPLES. HOWEVER, SAME DID NOT AFFECT THE CHANGES IN ADH1 PROTEIN LEVELS 12 H POST BOLUS. SINCE SAME IS A METHYL DONOR, IT WAS POSTULATED THAT THE ADH1 GENE EXPRESSION UP REGULATION AT 3 H WAS DUE TO A HISTONE MODIFICATION INDUCED BY METHYLATION FROM METHYL TRANSFERASES. DIMETHYLATED HISTONE 3 LYSINE 4 (H3K4ME2), A MODIFICATION RESPONSIBLE FOR GENE EXPRESSION ACTIVATION, WAS FOUND TO BE SIGNIFICANTLY INCREASED BY SAME AT 3 H POST BOLUS. CONCLUSION: THESE RESULTS CORRELATED WITH THE LOW BAL FOUND AT 3 H POST BOLUS, AND SUPPORT THE CONCEPT THAT SAME INCREASED THE GENE EXPRESSION TO INCREASE THE ELIMINATION RATE OF ETHANOL IN BINGE DRINKING BY INCREASING H3K4ME2.	2010	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
13  5587  34 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
14  4086  37 MATERNAL OBESITY DISRUPTS THE METHIONINE CYCLE IN BABOON PREGNANCY. MATERNAL INTAKE OF DIETARY METHYL-MICRONUTRIENTS (E.G. FOLATE, CHOLINE, BETAINE AND VITAMIN B-12) DURING PREGNANCY IS ESSENTIAL FOR NORMAL MATERNAL AND FETAL METHIONINE METABOLISM, AND IS CRITICAL FOR IMPORTANT METABOLIC PROCESSES INCLUDING THOSE INVOLVED IN DEVELOPMENTAL PROGRAMMING. MATERNAL OBESITY AND NUTRIENT EXCESS DURING PREGNANCY INFLUENCE DEVELOPMENTAL PROGRAMMING POTENTIALLY PREDISPOSING ADULT OFFSPRING TO A VARIETY OF CHRONIC HEALTH PROBLEMS. IN THE PRESENT STUDY, WE HYPOTHESIZED THAT MATERNAL OBESITY WOULD DYSREGULATE THE MATERNAL AND FETAL METHIONINE CYCLE. TO TEST THIS HYPOTHESIS, WE DEVELOPED A NULLIPAROUS BABOON OBESITY MODEL FED A HIGH FAT, HIGH ENERGY DIET (HF-HED) PRIOR TO AND DURING GESTATION, AND EXAMINED METHIONINE CYCLE BIOMARKERS (E.G., CIRCULATING CONCENTRATIONS OF HOMOCYSTEINE, METHIONINE, CHOLINE, BETAINE, KEY AMINO ACIDS, FOLATE, AND VITAMIN B-12). ANIMALS WERE GROUP HOUSED ALLOWING FULL PHYSICAL ACTIVITY AND SOCIAL INTERACTION. MATERNAL PREPREGNANCY PERCENT BODY FAT WAS 5% IN CONTROLS AND 19% IN HF-HED MOTHERS, WHILE FETAL WEIGHT WAS 16% LOWER IN OFFSPRING OF HF-HED MOTHERS AT TERM. MATERNAL AND FETAL HOMOCYSTEINE WERE HIGHER, WHILE MATERNAL AND FETAL VITAMIN B-12 AND BETAINE WERE LOWER IN THE HF-HED GROUP. ELEVATIONS IN CIRCULATING MATERNAL FOLATE WERE EVIDENT IN THE HF-HED GROUP INDICATING IMPAIRED FOLATE METABOLISM (METHYL-TRAP) AS A CONSEQUENCE OF MATERNAL VITAMIN B-12 DEPLETION. FINALLY, FETAL METHIONINE, GLYCINE, SERINE, AND TAURINE WERE LOWER IN THE HF-HED FETUSES. THESE DATA SHOW THAT MATERNAL OBESITY DISTURBS THE METHIONINE CYCLE IN PRIMATE PREGNANCY, PROVIDING A MECHANISM FOR THE EPIGENETIC CHANGES OBSERVED AMONG OBESE PREGNANT WOMEN AND SUGGESTING DIAGNOSTIC AND THERAPEUTIC OPPORTUNITIES IN HUMAN PREGNANCIES COMPLICATED BY OBESITY.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
15  6717  35 VITAMIN B SUPPLEMENTATION AND NUTRITIONAL INTAKE OF METHYL DONORS IN PATIENTS WITH CHRONIC KIDNEY DISEASE: A CRITICAL REVIEW OF THE IMPACT ON EPIGENETIC MACHINERY. CARDIOVASCULAR MORBIDITY AND MORTALITY ARE SEVERAL-FOLD HIGHER IN PATIENTS WITH ADVANCED CHRONIC KIDNEY DISEASE (CKD) AND END-STAGE RENAL DISEASE (ESRD) THAN IN THE GENERAL POPULATION. HYPERHOMOCYSTEINEMIA HAS UNDOUBTEDLY A CENTRAL ROLE IN SUCH A PROMINENT CARDIOVASCULAR BURDEN. THE LEVELS OF HOMOCYSTEINE ARE REGULATED BY METHYL DONORS (FOLATE, METHIONINE, CHOLINE, BETAINE), AND COFACTORS (VITAMIN B6, VITAMIN B12,). UREMIA-INDUCED HYPERHOMOCYSTEINEMIA HAS AS ITS MAIN TARGETS DNA METHYLTRANSFERASES, AND THIS LEADS TO AN ALTERED EPIGENETIC CONTROL OF GENES REGULATED THROUGH METHYLATION. IN RENAL PATIENTS, THE EPIGENETIC LANDSCAPE IS STRICTLY CORRELATED WITH THE UREMIC PHENOTYPE AND DEPENDENT ON DIETARY INTAKE OF MICRONUTRIENTS, INFLAMMATION, GUT MICROBIOME, INFLAMMATORY STATUS, OXIDATIVE STRESS, AND LIFESTYLE HABITS. ALL THESE FACTORS ARE KEY CONTRIBUTORS IN METHYLOME MAINTENANCE AND IN THE MODULATION OF GENE TRANSCRIPTION THROUGH DNA HYPO- OR HYPERMETHYLATION IN CKD. THIS IS AN OVERVIEW OF THE EPIGENETIC CHANGES RELATED TO DNA METHYLATION IN PATIENTS WITH ADVANCED CKD AND ESRD. WE EXPLORED THE CURRENTLY AVAILABLE DATA ON THE MOLECULAR DYSREGULATIONS RESULTING FROM ALTERED GENE EXPRESSION IN UREMIA. SPECIAL ATTENTION WAS PAID TO THE EFFICACY OF B-VITAMINS SUPPLEMENTATION AND DIETARY INTAKE OF METHYL DONORS ON HOMOCYSTEINE LOWERING AND CARDIOVASCULAR PROTECTION.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
16  6246  27 THE METHYL DONOR S-ADENOSYL METHIONINE REVERSES THE DNA METHYLATION SIGNATURE OF CHRONIC NEUROPATHIC PAIN IN MOUSE FRONTAL CORTEX. CHRONIC PAIN IS ASSOCIATED WITH PERSISTENT BUT REVERSIBLE STRUCTURAL AND FUNCTIONAL CHANGES IN THE PREFRONTAL CORTEX (PFC). THIS STABLE YET MALLEABLE PLASTICITY IMPLICATES EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, AS A POTENTIAL MEDIATOR OF CHRONIC PAIN-INDUCED CORTICAL PATHOLOGY. WE PREVIOUSLY DEMONSTRATED THAT CHRONIC ORAL ADMINISTRATION OF THE METHYL DONOR S-ADENOSYL METHIONINE (SAM) ATTENUATES LONG-TERM PERIPHERAL NEUROPATHIC PAIN AND ALTERS GLOBAL FRONTAL CORTICAL DNA METHYLATION. HOWEVER, THE SPECIFIC GENES AND PATHWAYS ASSOCIATED WITH THE RESOLUTION OF CHRONIC PAIN BY SAM REMAIN UNEXPLORED. OBJECTIVE: TO DETERMINE THE EFFECT OF LONG-TERM THERAPEUTIC EXPOSURE TO SAM ON THE DNA METHYLATION OF INDIVIDUAL GENES AND PATHWAYS IN A MOUSE NEUROPATHIC PAIN MODEL. METHODS: MALE CD-1 MICE RECEIVED SPARED NERVE INJURY OR SHAM SURGERY. THREE MONTHS AFTER INJURY, ANIMALS RECEIVED SAM (20 MG/KG, ORAL, 3X A WEEK) OR VEHICLE FOR 16 WEEKS FOLLOWED BY EPIGENOME-WIDE ANALYSIS OF FRONTAL CORTEX. RESULTS: PERIPHERAL NEUROPATHIC PAIN WAS ASSOCIATED WITH 4000 DIFFERENTIALLY METHYLATED GENOMIC REGIONS THAT WERE ENRICHED IN INTRACELLULAR SIGNALING, CELL MOTILITY AND MIGRATION, CYTOSKELETAL STRUCTURE, AND CELL ADHESION PATHWAYS. A THIRD OF THESE DIFFERENTIALLY METHYLATED REGIONS WERE REVERSED BY SAM TREATMENT (1415 REGIONS REPRESENTING 1013 GENES). MORE THAN 100 GENES WITH KNOWN PAIN-RELATED FUNCTION WERE DIFFERENTIALLY METHYLATED AFTER NERVE INJURY; 29 OF THESE WERE REVERSED BY SAM TREATMENT INCLUDING SCN10A, TRPA1, NTRK1, AND GFAP. CONCLUSION: THESE RESULTS SUGGEST A ROLE FOR THE EPIGENOME IN THE MAINTENANCE OF CHRONIC PAIN AND ADVANCE EPIGENETIC MODULATORS SUCH AS SAM AS A NOVEL APPROACH TO TREAT CHRONIC PAIN.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
17   339  36 ALTERATIONS IN HOMOCYSTEINE METABOLISM AMONG ALCOHOL DEPENDENT PATIENTS--CLINICAL, PATHOBIOCHEMICAL AND GENETIC ASPECTS. ADDICTION RESEARCH FOCUSING ON HOMOCYSTEINE METABOLISM AND ITS ASSOCIATION WITH ASPECTS OF ALCOHOL DEPENDENCE HAS REVEALED IMPORTANT FINDINGS. RECENT LITERATURE ON THIS TOPIC HAS BEEN TAKEN INTO ACCOUNT FOR THE REVIEW PROVIDED. METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) IS A KEY ENZYME IN THE HOMOCYSTEINE METABOLISM. PLASMA HOMOCYSTEINE LEVELS ARE INFLUENCED BY THE SINGLE-NUCLEOTIDE POLYMORPHISM (SNP) MTHFR C677T. BESIDES GENETIC FACTORS, ENVIRONMENTAL FACTORS HAVE AN IMPACT ON HOMOCYSTEINE PLASMA LEVELS TOO. THUS, CHRONIC ALCOHOL INTAKE IS ASSOCIATED WITH ELEVATED HOMOCYSTEINE PLASMA CONCENTRATIONS. ELEVATION OF PLASMA HOMOCYSTEINE CONCENTRATION IS CONSIDERED AS A PREDICTOR FOR THE OCCURRENCE OF ALCOHOL WITHDRAWAL SEIZURES AND--AS HOMOCYSTEINE IS A CARDIOVASCULAR RISK FACTOR--MIGHT CONTRIBUTE TO THE HIGHER RISK FOR MYOCARDIAL INFARCTION AMONG ALCOHOL DEPENDENT PATIENTS. HOMOCYSTEINE ACTS AS AN N-METHYL-D-ASPARTATE (NMDA) RECEPTOR AGONIST AND HAS EXCITOTOXIC EFFECTS. FURTHERMORE, IT HAS BEEN DEMONSTRATED THAT HOMOCYSTEINE HAS NEUROTOXIC EFFECTS ESPECIALLY ON DOPAMINERGIC NEURONS. AS THE REWARDING EFFECTS OF ALCOHOL ARE MEDIATED BY THE DOPAMINERGIC SYSTEM, A HOMOCYSTEINE-DEPENDENT IMPAIRMENT OF THE REWARD SYSTEM POSSIBLY LEADS TO AN ALTERED DRINKING BEHAVIOUR ACCORDING TO THE DEFICIT HYPOTHESIS OF ADDICTION. HOMOCYSTEINE IS INVOLVED IN THE METABOLISM OF METHYL GROUPS AND DNA-METHYLATION PLAYS A ROLE IN REGULATION OF GENE EXPRESSION. THEREFORE IT HAS BEEN SUGGESTED THAT HOMOCYSTEINE IS AN IMPORTANT EPIGENETIC FACTOR. IT REMAINS TO BE DETERMINED WHETHER ALCOHOL DEPENDENT PATIENTS BENEFIT FROM HOMOCYSTEINE LOWERING STRATEGIES, E.G., VIA SUPPLEMENTATION OF FOLATE, VITAMIN B6 AND B12. IN THIS RESPECT IT IS NOT CLEAR YET, IF A SUPPLEMENTATION THERAPY CAN REDUCE THE RISK FOR THE OCCURRENCE OF ALCOHOL WITHDRAWAL SEIZURES.	2008	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
18  4406  25 MOLECULAR ALTERATIONS IN HEPATOCARCINOGENESIS INDUCED BY DIETARY METHYL DEFICIENCY. A CHRONIC DEFICIENCY OF MAJOR DIETARY METHYL GROUP DONORS--METHIONINE, CHOLINE, FOLIC ACID, AND VITAMIN B12--CAN INDUCE THE DEVELOPMENT OF LIVER CANCER IN RODENTS. FEEDING METHYL-DEFICIENT DIETS CAUSES SEVERAL MOLECULAR ALTERATIONS, INCLUDING ALTERED LIPID METABOLISM, OXIDATIVE STRESS, DEREGULATED ONE-CARBON METABOLISM, AND A NUMBER OF EPIGENETIC ABNORMALITIES THAT RESULT IN PROGRESSIVE LIVER INJURY CULMINATING IN THE DEVELOPMENT OF PRIMARY LIVER TUMORS. IMPORTANTLY, THIS METHYL-DEFICIENT MODEL OF ENDOGENOUS HEPATOCARCINOGENESIS IS ONE OF THE MOST RELEVANT MODELS OF HUMAN LIVER CARCINOGENESIS THAT ALLOWS STUDYING LIVER CANCER PATHOGENESIS BY SUBSTANTIALLY COMPLEMENTING MANY SHORTCOMINGS OF HUMANS-ONLY STUDIES. IN THIS REVIEW, WE DESCRIBE MOLECULAR CHANGES AND THEIR ROLE IN PATHOGENESIS OF LIVER CARCINOGENESIS INDUCED BY METHYL DEFICIENCY.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
19  5485  25 REVERSAL OF COCAINE-CONDITIONED PLACE PREFERENCE THROUGH METHYL SUPPLEMENTATION IN MICE: ALTERING GLOBAL DNA METHYLATION IN THE PREFRONTAL CORTEX. ANALYSIS OF GLOBAL METHYLATION IN CELLS HAS REVEALED CORRELATIONS BETWEEN OVERALL DNA METHYLATION STATUS AND SOME BIOLOGICAL STATES. RECENT STUDIES SUGGEST THAT EPIGENETIC REGULATION THROUGH DNA METHYLATION COULD BE RESPONSIBLE FOR NEUROADAPTATIONS INDUCED BY ADDICTIVE DRUGS. HOWEVER, THERE IS NO INVESTIGATION TO DETERMINE GLOBAL DNA METHYLATION STATUS FOLLOWING REPEATED EXPOSURE TO ADDICTIVE DRUGS. USING MICE CONDITIONED PLACE PREFERENCE (CPP) PROCEDURE, WE MEASURED GLOBAL DNA METHYLATION LEVEL IN THE NUCLEUS ACCUMBENS (NAC) AND THE PREFRONTAL CORTEX (PFC) ASSOCIATED WITH DRUG REWARDING EFFECTS. WE FOUND THAT COCAINE-, BUT NOT MORPHINE- OR FOOD-CPP TRAINING DECREASED GLOBAL DNA METHYLATION IN THE PFC. CHRONIC TREATMENT WITH METHIONINE, A METHYL DONOR, FOR 25 CONSECUTIVE DAYS PRIOR TO AND DURING CPP TRAINING INHIBITED THE ESTABLISHMENT OF COCAINE, BUT NOT MORPHINE OR FOOD CPP. WE ALSO FOUND THAT BOTH MRNA AND PROTEIN LEVEL OF DNMT (DNA METHYTRANSFERASE) 3B IN THE PFC WERE DOWNREGULATED FOLLOWING THE ESTABLISHMENT OF COCAINE CPP, AND THE DOWNREGULATION COULD BE REVERSED BY REPEATED ADMINISTRATION OF METHIONINE. OUR STUDY INDICATES A CRUCIAL ROLE OF GLOBAL PFC DNA HYPOMETHYLATION IN THE REWARDING EFFECTS OF COCAINE. REVERSAL OF GLOBAL DNA HYPOMETHYLATION COULD SIGNIFICANTLY ATTENUATE THE REWARDING EFFECTS INDUCED BY COCAINE. OUR RESULTS SUGGEST THAT METHIONINE MAY HAVE BECOME A POTENTIAL THERAPEUTIC TARGET TO TREAT COCAINE ADDICTION.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
20  2158  50 EPIGENETIC MECHANISMS FOR NUTRITION DETERMINANTS OF LATER HEALTH OUTCOMES. EPIGENETIC MARKING ON GENES CAN DETERMINE WHETHER OR NOT GENES ARE EXPRESSED. EPIGENETIC REGULATION IS MEDIATED BY THE ADDITION OF METHYL GROUPS TO DNA CYTOSINE BASES, OF METHYL AND ACETYL GROUPS TO PROTEINS (HISTONES) AROUND WHICH DNA IS WRAPPED, AND BY SMALL INTERFERING RNA MOLECULES. SOME COMPONENTS OF EPIGENETIC REGULATION HAVE EVOLVED TO PERMIT CONTROL OF WHETHER MATERNAL OR PATERNAL GENES ARE EXPRESSED. THE EPIGENETIC IMPRINTING OF IGF2 EXPRESSION IS AN EXAMPLE OF MATERNAL AND PATERNAL EPIGENETIC MARKING THAT MODULATES FETAL GROWTH AND FETAL SIZE. HOWEVER, EPIGENETIC REGULATION ALSO PERMITS THE FETUS AND THE INFANT TO ADAPT GENE EXPRESSION TO THE ENVIRONMENT IN WHICH IT IS GROWING; SOMETIMES WHEN THIS ADJUSTMENT GOES AWRY, THE RISK OF CHRONIC DISEASE IS INCREASED. RECENT PROGRESS IN THE UNDERSTANDING OF NUTRITIONAL INFLUENCES ON EPIGENETICS SUGGESTS THAT NUTRIENTS THAT ARE PART OF METHYL-GROUP METABOLISM CAN SIGNIFICANTLY INFLUENCE EPIGENETICS. DURING CRITICAL PERIODS IN DEVELOPMENT, DIETARY METHYL-GROUP INTAKE (CHOLINE, METHIONINE, AND FOLATE) CAN ALTER DNA AND HISTONE METHYLATION, WHICH RESULTS IN LIFELONG CHANGES IN GENE EXPRESSION. IN RODENT MODELS, PREGNANT DAMS THAT WERE FED DIETS HIGH IN METHIONINE, FOLIC ACID, AND CHOLINE PRODUCED OFFSPRING WITH DIFFERENT COAT COLORS OR WITH KINKED TAILS. A NUMBER OF SYNDROMES IN HUMANS CAN BE CAUSED BY DEFECTIVE EPIGENETIC REGULATION, INCLUDING RETT SYNDROME. THERE ARE INTERESTING EXAMPLES OF THE EFFECTS OF NUTRITION IN EARLY LIFE THAT RESULT IN ALTERED HEALTH IN ADULTS, AND SOME OF THESE COULD BE THE RESULT OF ALTERED EPIGENETIC REGULATION OF GENE EXPRESSION.	2009