1 3807 149 INTRACELLULAR PROTONS ACCELERATE AGING AND SWITCH ON AGING HALLMARKS IN MICE. DIET-INDUCED METABOLIC ACIDOSIS IS ASSOCIATED WITH THE IMPAIRMENT OF BONE METABOLISM AND AN INCREASED RISK OF A NUMBER OF CHRONIC NONCOMMUNICABLE DISEASES, SUCH AS TYPE 2 DIABETES MELLITUS AND HYPERTENSION. THE SERUM BICARBONATE LEVEL IS AN INDEPENDENT PREDICTOR OF CHRONIC KIDNEY DISEASE PROGRESSION. WE INVESTIGATED WHETHER PROTON ACCELERATES AGING BY ANALYZING BOTH COUPLING FACTOR 6-OVEREXPRESSING TRANSGENIC (TG) AND HIGH SALT-FED MICE WHICH DISPLAY SUSTAINED INTRACELLULAR ACIDOSIS, DUE TO ENHANCED PROTON IMPORT THROUGH ECTO-F(1) F(O) COMPLEX AND/OR REDUCED PROTON EXPORT THROUGH NA(+) -K(+) ATPASE INHIBITION. BOTH TYPES OF MICE DISPLAYED SHORTENED LIFESPAN AND EARLY SENESCENCE-ASSOCIATED PHENOTYPES SUCH AS SIGNS OF HAIR GREYING AND ALOPECIA, WEIGHT LOSS, AND/OR REDUCED ORGAN MASS. IN CHRONIC INTRACELLULAR ACIDOSIS MICE, AUTOPHAGY WAS IMPAIRED BY REGRESSION OF ATG7, AN INCREASE IN NUCLEAR ACETYLATED LC3 II, AND ACETYLATION OF ATG7. THE INCREASE IN HISTONE 3 TRIMETHYLATION AT LYSINE 4 (H3K4ME3) AND H4K20ME3 AND THE DECREASE IN H3K9ME3 AND H3K27ME3 WERE OBSERVED IN THE HEART AND KIDNEY OBTAINED FROM BOTH TG AND HIGH SALT-FED MICE. THE DECREASE IN LAMIN A/C, EMERIN, AND HETEROCHROMATIN PROTEIN 1ALPHA WITHOUT CHANGES IN BARRIER-TO-AUTOINTEGRATION FACTOR AND HIGH-MOBILITY GROUP BOX 1 WAS CONFIRMED IN TG AND HIGH SALT-FED MICE. SUPPRESSION OF NUCLEAR HISTONE DEACETYLASE 3-EMERIN SYSTEM IS ATTRIBUTABLE TO EPIGENETIC REGRESSION OF ATG7 AND H4K5 ACETYLATION. THESE FINDINGS WILL SHED LIGHT ON NOVEL AGING AND IMPAIRED AUTOPHAGY MECHANISM, AND PROVIDE IMPLICATIONS IN A TARGET FOR ANTIAGING THERAPY. 2018 2 4731 103 NOVEL ANTI-AGING GENE NM_026333 CONTRIBUTES TO PROTON-INDUCED AGING VIA NCX1-PATHWAY. DIET-INDUCED METABOLIC ACIDOSIS IS ASSOCIATED WITH THE IMPAIRMENT OF BONE METABOLISM AND AN INCREASED RISK OF A NUMBER OF CHRONIC NONCOMMUNICABLE DISEASES, SUCH AS TYPE 2 DIABETES MELLITUS AND HYPERTENSION. LOW SERUM BICARBONATE IS ASSOCIATED WITH HIGH MORTALITY IN HEALTHY OLDER INDIVIDUALS. RECENTLY, WE DEMONSTRATED THAT BOTH COUPLING FACTOR 6 (CF6)-OVEREXPRESSING TRANSGENIC (TG) AND HIGH SALT-FED MICE WHICH HAD SUSTAINED INTRACELLULAR ACIDOSIS, DUE TO ENHANCED PROTON IMPORT THROUGH ECTO-F(1)F(O) COMPLEX AND/OR REDUCED PROTON EXPORT THROUGH NA(+)-K(+) ATPASE INHIBITION, DISPLAYED SHORTENED LIFESPAN AND EARLY SENESCENCE-ASSOCIATED PHENOTYPES SUCH AS SIGNS OF HAIR GREYING AND ALOPECIA, WEIGHT LOSS, AND/OR REDUCED ORGAN MASS. IN THIS STUDY, WE SEARCHED CAUSATIVE GENES OF PROTON-INDUCED AGING IN CF6-OVEREXPRESSING TG AND HIGH SALT-FED MICE. WE DISCOVERED NM_026333 AS A NOVEL ANTI-AGING GENE WHICH WAS DOWNREGULATED IN THE HEART AND KIDNEY IN BOTH TYPES OF MICE. NM_026333 PROTEIN CONSISTS OF 269 AMINO ACIDS WITH TRANSMEMBRANE REGION (90-193AA). INDUCTION OF NM_026333 OR RECOMBINANT PROTEIN RESCUED TG CELLS AND CF6-TREATED HUMAN CELLS FROM AGING HALLMARKS OF IMPAIRED AUTOPHAGY, GENOMIC INSTABILITY, AND EPIGENETIC ALTERATION. NM_026333 PROTEIN DIRECTLY BOUND PLASMA MEMBRANE NA(+)-CA(2+) EXCHANGER 1 (NCX1) TO SUPPRESS ITS REVERSE MODE, AND CANCELLED PROTON-INDUCED EPIGENETIC REGRESSION OF ATG7 THAT WAS CAUSED BY H3K4 AND H4K20 TRI-METHYLATION VIA SUPPRESSION OF DEMETHYLASE AND H4K5 ACETYLATION VIA SUPPRESSION OF NUCLEAR HDAC3-HDAC4-EMERIN SYSTEM. NM_026333 ALSO ATTENUATED PROTON-INDUCED IMPAIRED FORMATION OF AUTOLYSOSOME, AN INCREASE IN NUCLEAR ACETYLATED LC3 II, AND ACETYLATION OF ATG7. THESE EFFECTS REAPPEARED BY NCX1 INHIBITOR. FURTHERMORE, NCX1 INHIBITOR EXTENDED LIFESPAN COMPARED WITH VEHICLE-TREATMENT IN TG MICE. THIS STUDY WILL SHED LIGHT ON NOVEL AGING MECHANISM AND PROVIDE IMPLICATIONS IN A TARGET FOR ANTI-AGING THERAPY. 2018 3 1104 29 COMBINED EXPOSURE TO PROTONS AND (56)FE LEADS TO OVEREXPRESSION OF IL13 AND REACTIVATION OF REPETITIVE ELEMENTS IN THE MOUSE LUNG. INTEREST IN DEEP SPACE EXPLORATION UNDERLINES THE NEEDS TO INVESTIGATE THE EFFECTS OF EXPOSURE TO COMBINED SOURCES OF SPACE RADIATION. THE LUNG IS A TARGET ORGAN FOR RADIATION, AND EXPOSURE TO PROTONS AND HEAVY IONS AS RADIATION SOURCES MAY LEAD TO THE DEVELOPMENT OF DEGENERATIVE DISEASE AND CANCER. IN THIS STUDY, WE EVALUATED THE PRO-FIBROTIC AND EPIGENETIC EFFECTS OF EXPOSURE TO PROTONS (150 MEV/NUCLEON, 0.1 GY) AND HEAVY IRON IONS ((56)FE, 600 MEV/NUCLEON, 0.5 GY) ALONE OR IN COMBINATION (PROTONS ON DAY 1 AND (56)FE ON DAY 2) IN C57BL/6 MALE MICE 4 WEEKS AFTER IRRADIATION. EXPOSURE TO (56)FE, PROTON OR IN COMBINATION, DID NOT RESULT IN HISTOPATHOLOGICAL CHANGES IN THE MURINE LUNG. AT THE SAME TIME, COMBINED EXPOSURE TO PROTONS AND (56)FE RESULTED IN PRONOUNCED MOLECULAR ALTERATIONS IN COMPARISON WITH EITHER SOURCE OF RADIATION ALONE. SPECIFICALLY, WE OBSERVED A SUBSTANTIAL INCREASE IN THE EXPRESSION OF CYTOKINE IL13, LOSS OF EXPRESSION OF DNA METHYLTRANSFERASE DNMT1, AND REACTIVATION OF LINE-1, SINE B1 RETROTRANSPOSONS, AND MAJOR AND MINOR SATELLITES. GIVEN THE DELETERIOUS POTENTIAL OF THE OBSERVED EFFECTS THAT MAY LEAD TO DEVELOPMENT OF CHRONIC LUNG INJURY, PULMONARY FIBROSIS, AND CANCER, FUTURE STUDIES DEVOTED TO THE INVESTIGATION OF THE LONG-TERM EFFECTS OF COMBINED EXPOSURES TO PROTON AND HEAVY IONS ARE CLEARLY NEEDED. 2015 4 4683 34 NEW PERSPECTIVES ON FOLATE TRANSPORT IN RELATION TO ALCOHOLISM-INDUCED FOLATE MALABSORPTION--ASSOCIATION WITH EPIGENOME STABILITY AND CANCER DEVELOPMENT. FOLATES ARE MEMBERS OF THE B-CLASS OF VITAMINS, WHICH ARE REQUIRED FOR THE SYNTHESIS OF PURINES AND PYRIMIDINES, AND FOR THE METHYLATION OF ESSENTIAL BIOLOGICAL SUBSTANCES, INCLUDING PHOSPHOLIPIDS, DNA, AND NEUROTRANSMITTERS. FOLATES CANNOT BE SYNTHESIZED DE NOVO BY MAMMALS; HENCE, AN EFFICIENT INTESTINAL ABSORPTION PROCESS IS REQUIRED. INTESTINAL FOLATE TRANSPORT IS CARRIER-MEDIATED, PH-DEPENDENT AND ELECTRONEUTRAL, WITH SIMILAR AFFINITY FOR OXIDIZED AND REDUCED FOLIC ACID DERIVATIVES. THE VARIOUS TRANSPORTERS, I.E. REDUCED FOLATE CARRIER, PROTON-COUPLED FOLATE TRANSPORTER, FOLATE-BINDING PROTEIN, AND ORGANIC ANION TRANSPORTERS, ARE INVOLVED IN THE FOLATE TRANSPORT PROCESS IN VARIOUS TISSUES. ANY IMPAIRMENT IN UPTAKE OF FOLATE CAN LEAD TO A STATE OF FOLATE DEFICIENCY, THE MOST PREVALENT VITAMIN DEFICIENCY IN WORLD, AFFECTING 10% OF THE POPULATION IN THE USA. SUCH IMPAIRMENTS IN FOLATE TRANSPORT OCCUR IN A VARIETY OF CONDITIONS, INCLUDING CHRONIC USE OF ETHANOL, SOME INBORN HEREDITARY DISORDERS, AND CERTAIN DISEASES. AMONG THESE, ETHANOL INGESTION HAS BEEN THE MAJOR CONTRIBUTOR TO FOLATE DEFICIENCY. ETHANOL-ASSOCIATED FOLATE DEFICIENCY CAN DEVELOP BECAUSE OF DIETARY INADEQUACY, INTESTINAL MALABSORPTION, ALTERED HEPATOBILIARY METABOLISM, ENHANCED COLONIC METABOLISM, AND INCREASED RENAL EXCRETION. ETHANOL REDUCES THE INTESTINAL AND RENAL UPTAKE OF FOLATE BY ALTERING THE BINDING AND TRANSPORT KINETICS OF FOLATE TRANSPORT SYSTEMS. ALSO, ETHANOL REDUCES THE EXPRESSION OF FOLATE TRANSPORTERS IN BOTH INTESTINE AND KIDNEY, AND THIS MIGHT BE A CONTRIBUTING FACTOR FOR FOLATE MALABSORPTION, LEADING TO FOLATE DEFICIENCY. THE MAINTENANCE OF INTRACELLULAR FOLATE HOMEOSTASIS IS ESSENTIAL FOR THE ONE-CARBON TRANSFER REACTIONS NECESSARY FOR DNA SYNTHESIS AND BIOLOGICAL METHYLATION REACTIONS. DNA METHYLATION IS AN IMPORTANT EPIGENETIC DETERMINANT IN GENE EXPRESSION, IN THE MAINTENANCE OF DNA INTEGRITY AND STABILITY, IN CHROMOSOMAL MODIFICATIONS, AND IN THE DEVELOPMENT OF MUTATIONS. ETHANOL, A TOXIN THAT IS CONSUMED REGULARLY, HAS BEEN FOUND TO AFFECT THE METHYLATION OF DNA. IN ADDITION TO ITS EFFECT ON DNA METHYLATION DUE TO FOLATE DEFICIENCY, ETHANOL COULD DIRECTLY EXERT ITS EFFECT THROUGH ITS INTERACTION WITH ONE-CARBON METABOLISM, IMPAIRMENT OF METHYL GROUP SYNTHESIS, AND AFFECTING THE ENZYMES REGULATING THE SYNTHESIS OF S-ADENOSYLMETHIONINE, THE PRIMARY METHYL GROUP DONOR FOR MOST BIOLOGICAL METHYLATION REACTIONS. THUS, ETHANOL PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF SEVERAL DISEASES THROUGH ITS POTENTIAL ABILITY TO MODULATE THE METHYLATION OF BIOLOGICAL MOLECULES. THIS REVIEW DISCUSSES THE UNDERLYING MECHANISM OF FOLATE MALABSORPTION IN ALCOHOLISM, THE MECHANISM OF METHYLATION-ASSOCIATED SILENCING OF GENES, AND HOW THE INTERACTION BETWEEN ETHANOL AND FOLATE DEFICIENCY AFFECTS THE METHYLATION OF GENES, THEREBY MODULATING EPIGENOME STABILITY AND THE RISK OF CANCER. 2009 5 3359 29 HISTONE H4 LYSINE 16 ACETYLATION CONTROLS CENTRAL CARBON METABOLISM AND DIET-INDUCED OBESITY IN MICE. NONCOMMUNICABLE DISEASES (NCDS) ACCOUNT FOR OVER 70% OF DEATHS WORLD-WIDE. PREVIOUS WORK HAS LINKED NCDS SUCH AS TYPE 2 DIABETES (T2D) TO DISRUPTION OF CHROMATIN REGULATORS. HOWEVER, THE EXACT MOLECULAR ORIGINS OF THESE CHRONIC CONDITIONS REMAIN ELUSIVE. HERE, WE IDENTIFY THE H4 LYSINE 16 ACETYLTRANSFERASE MOF AS A CRITICAL REGULATOR OF CENTRAL CARBON METABOLISM. HIGH-THROUGHPUT METABOLOMICS UNVEIL A SYSTEMIC AMINO ACID AND CARBOHYDRATE IMBALANCE IN MOF DEFICIENT MICE, MANIFESTING IN T2D PREDISPOSITION. ORAL GLUCOSE TOLERANCE TESTING (OGTT) REVEALS DEFECTS IN GLUCOSE ASSIMILATION AND INSULIN SECRETION IN THESE ANIMALS. FURTHERMORE, MOF DEFICIENT MICE ARE RESISTANT TO DIET-INDUCED FAT GAIN DUE TO DEFECTS IN GLUCOSE UPTAKE IN ADIPOSE TISSUE. MOF-MEDIATED H4K16AC DEPOSITION CONTROLS EXPRESSION OF THE MASTER REGULATOR OF GLUCOSE METABOLISM, PPARG AND THE ENTIRE DOWNSTREAM TRANSCRIPTIONAL NETWORK. GLUCOSE UPTAKE AND LIPID STORAGE CAN BE RECONSTITUTED IN MOF-DEPLETED ADIPOCYTES IN VITRO BY ECTOPIC GLUT4 EXPRESSION, PPARGAMMA AGONIST THIAZOLIDINEDIONE (TZD) TREATMENT OR SIRT1 INHIBITION. HENCE, CHRONIC IMBALANCE IN H4K16AC PROMOTES A DESTABILISATION OF METABOLISM TRIGGERING THE DEVELOPMENT OF A METABOLIC DISORDER, AND ITS MAINTENANCE PROVIDES AN UNPRECEDENTED REGULATORY EPIGENETIC MECHANISM CONTROLLING DIET-INDUCED OBESITY. 2021 6 6456 31 THYMOSIN BETA4 PREVENTS OXIDATIVE STRESS, INFLAMMATION, AND FIBROSIS IN ETHANOL- AND LPS-INDUCED LIVER INJURY IN MICE. THYMOSIN BETA 4 (TBETA4), AN ACTIN-SEQUESTERING PROTEIN, IS INVOLVED IN TISSUE DEVELOPMENT AND REGENERATION. IT PREVENTS INFLAMMATION AND FIBROSIS IN SEVERAL TISSUES. WE INVESTIGATED THE ROLE OF TBETA4 IN CHRONIC ETHANOL- AND ACUTE LIPOPOLYSACCHARIDE- (LPS-) INDUCED MOUSE LIVER INJURY. C57BL/6 MICE WERE FED 5% ETHANOL IN LIQUID DIET FOR 4 WEEKS PLUS BINGE ETHANOL (5 G/KG, GAVAGE) WITH OR WITHOUT LPS (2 MG/KG, INTRAPERITONEAL) FOR 6 HOURS. TBETA4 (1 MG/KG, INTRAPERITONEAL) WAS ADMINISTERED FOR 1 WEEK. WE DEMONSTRATED THAT TBETA4 PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN LIVER INJURY MARKERS AS WELL AS CHANGES IN LIVER PATHOLOGY. IT ALSO PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN OXIDATIVE STRESS BY DECREASING ROS AND LIPID PEROXIDATION AND INCREASING THE ANTIOXIDANTS, REDUCED GLUTATHIONE AND MANGANESE-DEPENDENT SUPEROXIDE DISMUTASE. IT ALSO PREVENTED THE ACTIVATION OF NUCLEAR FACTOR KAPPA B BY BLOCKING THE PHOSPHORYLATION OF THE INHIBITORY PROTEIN, IKAPPAB, THEREBY PREVENTED PROINFLAMMATORY CYTOKINE PRODUCTION. MOREOVER, TBETA4 PREVENTED FIBROGENESIS BY SUPPRESSING THE EPIGENETIC REPRESSOR, METHYL-CPG-BINDING PROTEIN 2, THAT COORDINATELY REVERSED THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AND DOWNREGULATED FIBROGENIC GENES, PLATELET-DERIVED GROWTH FACTOR-BETA RECEPTOR, ALPHA-SMOOTH MUSCLE ACTIN, COLLAGEN 1, AND FIBRONECTIN, RESULTING IN REDUCED FIBROSIS. OUR DATA SUGGEST THAT TBETA4 HAS ANTIOXIDANT, ANTI-INFLAMMATORY, AND ANTIFIBROTIC POTENTIAL DURING ALCOHOLIC LIVER INJURY. 2018 7 558 24 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 8 3360 30 HISTONE H4K20 TRIMETHYLATION IS DECREASED IN MURINE MODELS OF HEART DISEASE. HEART DISEASE IS THE LEADING CAUSE OF DEATH IN THE DEVELOPED WORLD, AND ITS COMORBIDITIES SUCH AS HYPERTENSION, DIABETES, AND HEART FAILURE ARE ACCOMPANIED BY MAJOR TRANSCRIPTOMIC CHANGES IN THE HEART. DURING CARDIAC DYSFUNCTION, WHICH LEADS TO HEART FAILURE, THERE ARE GLOBAL EPIGENETIC ALTERATIONS TO CHROMATIN THAT OCCUR CONCOMITANTLY WITH MORPHOLOGICAL CHANGES IN THE HEART IN RESPONSE TO ACUTE AND CHRONIC STRESS. THESE EPIGENETIC ALTERATIONS INCLUDE THE REVERSIBLE METHYLATION OF LYSINE RESIDUES ON HISTONE PROTEINS. LYSINE METHYLATIONS ON HISTONES H3K4 AND H3K9 WERE AMONG THE FIRST METHYLATED LYSINE RESIDUES IDENTIFIED AND HAVE BEEN LINKED TO GENE ACTIVATION AND SILENCING, RESPECTIVELY. HOWEVER, MUCH LESS IS KNOWN REGARDING OTHER METHYLATED HISTONE RESIDUES, INCLUDING HISTONE H4K20. TRIMETHYLATION OF HISTONE H4K20 HAS BEEN SHOWN TO REPRESS GENE EXPRESSION; HOWEVER, THIS MODIFICATION HAS NEVER BEEN EXAMINED IN THE HEART. HERE, WE UTILIZED IMMUNOBLOTTING AND MASS SPECTROMETRY TO QUANTIFY HISTONE H4K20 TRIMETHYLATION IN THREE MODELS OF CARDIAC DYSFUNCTION. OUR RESULTS SHOW THAT LYSINE METHYLATION AT THIS SITE IS DIFFERENTIALLY REGULATED IN THE CARDIOMYOCYTE, LEADING TO INCREASED H4K20 TRIMETHYLATION DURING ACUTE HYPERTROPHIC STRESS IN CELL MODELS AND DECREASED H4K20 TRIMETHYLATION DURING SUSTAINED ISCHEMIC INJURY AND CARDIAC DYSFUNCTION IN ANIMAL MODELS. IN ADDITION, WE EXAMINED PUBLICLY AVAILABLE DATA SETS TO ANALYZE ENZYMES THAT REGULATE H4K20 METHYLATION AND IDENTIFIED TWO DEMETHYLASES (KDM7B AND KDM7C) AND TWO METHYLTRANSFERASES (KMT5A AND SMYD5) THAT WERE ALL DIFFERENTIALLY EXPRESSED IN HEART FAILURE PATIENTS. THIS IS THE FIRST STUDY TO EXAMINE HISTONE H4K20 TRIMETHYLATION IN THE HEART AND TO DETERMINE HOW THIS POST-TRANSLATIONAL MODIFICATION IS DIFFERENTIALLY REGULATED IN MULTIPLE MODELS OF CARDIAC DISEASE. 2022 9 3203 26 HDAC3 ACTIVITY WITHIN THE NUCLEUS ACCUMBENS REGULATES COCAINE-INDUCED PLASTICITY AND BEHAVIOR IN A CELL-TYPE-SPECIFIC MANNER. EPIGENETIC MECHANISMS REGULATE PROCESSES OF NEUROPLASTICITY CRITICAL TO COCAINE-INDUCED BEHAVIORS. THIS INCLUDES THE CLASS I HISTONE DEACETYLASE (HDAC) HDAC3, KNOWN TO ACT AS A NEGATIVE REGULATOR OF COCAINE-ASSOCIATED MEMORY FORMATION WITHIN THE NUCLEUS ACCUMBENS (NAC). DESPITE THIS, IT REMAINS UNKNOWN HOW COCAINE ALTERS HDAC3-DEPENDENT MECHANISMS. HERE, WE PROFILED HDAC3 EXPRESSION AND ACTIVITY IN TOTAL NAC MOUSE TISSUE FOLLOWING COCAINE EXPOSURE. ALTHOUGH CHRONIC COCAINE DID NOT AFFECT EXPRESSION OF HDAC3 WITHIN THE NAC, CHRONIC COCAINE DID AFFECT PROMOTER-SPECIFIC CHANGES IN HDAC3 AND H4K8AC OCCUPANCY. THESE CHANGES IN PROMOTER OCCUPANCY CORRELATED WITH COCAINE-INDUCED CHANGES IN EXPRESSION OF PLASTICITY-RELATED GENES. TO CAUSALLY DETERMINE WHETHER COCAINE-INDUCED PLASTICITY IS MEDIATED BY HDAC3'S DEACETYLASE ACTIVITY, WE OVEREXPRESSED A DEACETYLASE-DEAD HDAC3 POINT MUTANT (HDAC3-Y298H-V5) WITHIN THE NAC OF ADULT MALE MICE. WE FOUND THAT DISRUPTING HDAC3'S ENZYMATIC ACTIVITY ALTERED SELECTIVE CHANGES IN GENE EXPRESSION AND SYNAPTIC PLASTICITY FOLLOWING COCAINE EXPOSURE, DESPITE HAVING NO EFFECTS ON COCAINE-INDUCED BEHAVIORS. IN FURTHER ASSESSING HDAC3'S ROLE WITHIN THE NAC, WE OBSERVED THAT CHRONIC COCAINE INCREASES HDAC3 EXPRESSION IN DRD1 BUT NOT DRD2-CELLS OF THE NAC. MOREOVER, WE DISCOVERED THAT HDAC3 ACTS SELECTIVELY WITHIN D1R CELL-TYPES TO REGULATE COCAINE-ASSOCIATED MEMORY FORMATION AND COCAINE-SEEKING. OVERALL, THESE RESULTS SUGGEST THAT COCAINE INDUCES CELL-TYPE-SPECIFIC CHANGES IN EPIGENETIC MECHANISMS TO PROMOTE PLASTICITY IMPORTANT FOR DRIVING COCAINE-RELATED BEHAVIORS.SIGNIFICANCE STATEMENT DRUGS OF ABUSE ALTER MOLECULAR MECHANISMS THROUGHOUT THE REWARD CIRCUITRY THAT CAN LEAD TO PERSISTENT DRUG-ASSOCIATED BEHAVIORS. EPIGENETIC REGULATORS ARE CRITICAL DRIVERS OF DRUG-INDUCED CHANGES IN GENE EXPRESSION. HERE, WE DEMONSTRATE THAT THE ACTIVITY OF AN EPIGENETIC ENZYME PROMOTES NEUROPLASTICITY WITHIN THE NUCLEUS ACCUMBENS (NAC) CRITICAL TO COCAINE ACTION. IN ADDITION, WE DEMONSTRATE THAT THESE CHANGES IN EPIGENETIC ACTIVITY DRIVE COCAINE-SEEKING BEHAVIORS IN A CELL-TYPE-SPECIFIC MANNER. THESE FINDINGS ARE KEY IN UNDERSTANDING AND TARGETING COCAINE'S IMPACT OF NEURAL CIRCUITRY AND BEHAVIOR. 2021 10 4215 36 METHYL DEFICIENCY, ALTERATIONS IN GLOBAL HISTONE MODIFICATIONS, AND CARCINOGENESIS. THE METHYL-DEFICIENT MODEL OF ENDOGENOUS HEPATOCARCINOGENESIS IN RODENTS IS UNIQUE IN THAT DIETARY OMISSION RATHER THAN THE ADDITION OF CHEMICAL CARCINOGENS LEADS TO TUMOR FORMATION. THUS, THE BIOCHEMICAL AND MOLECULAR EVENTS PREDISPOSING TO CANCER IN THIS MODEL RESULT FROM CHRONIC METABOLIC STRESS AND PROVIDE AN IDEAL MODEL SYSTEM TO STUDY PROGRESSIVE ALTERATIONS THAT OCCUR DURING CARCINOGENESIS. MOREOVER, EPIGENETIC ALTERATIONS IMPOSED BY THIS DIET ARE BELIEVED TO BE 1 OF THE MAIN MECHANISMS RESPONSIBLE FOR MALIGNANT TRANSFORMATION OF RAT LIVER CELLS. IN THIS STUDY WE EXAMINED THE CHANGES IN GLOBAL HISTONE MODIFICATION PATTERNS IN LIVER DURING HEPATOCARCINOGENESIS INDUCED BY METHYL DEFICIENCY. FEEDING ANIMALS THE METHYL-DEFICIENT DIET (MDD) LED TO PROGRESSIVE LOSS OF HISTONE H4 LYSINE 20 TRIMETHYLATION (H4K20ME3), H3 LYSINE 9 TRIMETHYLATION (H3K9ME3), AND HISTONE H3 LYSINE 9 (H3K9AC) AND HISTONE H4 LYSINE 16 (H4K16AC) ACETYLATION. A CONSIDERABLE DECREASE OF H4K20ME3 AND H3K9AC WAS ALSO DETECTED IN LIVER TUMORS INDUCED BY MDD. IN CONTRAST, LIVER TUMORS DISPLAYED AN INCREASE IN H3K9ME3 AND H4K16AC. TO DETERMINE THE POSSIBLE MECHANISM OF ALTERATIONS OF HISTONE MODIFICATIONS, WE ANALYZED THE EXPRESSION OF HISTONE-MODIFYING ENZYMES IN LIVER DURING HEPATOCARCINOGENESIS. THE EXPRESSION OF SUV4-20H2 AND RIZ1 HISTONE METHYLTRANSFERASES (HMTS) STEADILY DECREASED ALONG WITH THE DEVELOPMENT OF LIVER TUMORS AND REACHED ITS LOWEST LEVEL IN TUMOR TISSUE, WHEREAS THE EXPRESSION OF SUV39-H1 HMT AND HISTONE ACETYLTRANSFERASE 1 (HAT1) SUBSTANTIALLY INCREASED IN TUMORS. THESE RESULTS ILLUSTRATE THE COMPLEXITY AND IMPORTANCE OF HISTONE MODIFICATION CHANGES IN THE ETIOLOGY OF HEPATOCARCINOGENESIS INDUCED BY MDD. 2007 11 3894 21 LAMIN B1 REGULATES SOMATIC MUTATIONS AND PROGRESSION OF B-CELL MALIGNANCIES. SOMATIC HYPERMUTATION (SHM) IS A PIVOTAL PROCESS IN ADAPTIVE IMMUNITY THAT OCCURS IN THE GERMINAL CENTRE AND ALLOWS B CELLS TO CHANGE THEIR PRIMARY DNA SEQUENCE AND DIVERSIFY THEIR ANTIGEN RECEPTORS. HERE, WE REPORT THAT GENOME BINDING OF LAMIN B1, A COMPONENT OF THE NUCLEAR ENVELOPE INVOLVED IN EPIGENETIC CHROMATIN REGULATION, IS REDUCED DURING B-CELL ACTIVATION AND FORMATION OF LYMPHOID GERMINAL CENTRES. CHROMATIN IMMUNOPRECIPITATION-SEQ ANALYSIS SHOWED THAT KAPPA AND HEAVY VARIABLE IMMUNOGLOBULIN DOMAINS WERE RELEASED FROM THE LAMIN B1 SUPPRESSIVE ENVIRONMENT WHEN SHM WAS INDUCED IN B CELLS. RNA INTERFERENCE-MEDIATED REDUCTION OF LAMIN B1 RESULTED IN SPONTANEOUS SHM AS WELL AS KAPPA-LIGHT CHAIN ABERRANT SURFACE EXPRESSION. FINALLY, LAMIN B1 EXPRESSION LEVEL CORRELATED WITH PROGRESSION-FREE AND OVERALL SURVIVAL IN CHRONIC LYMPHOCYTIC LEUKAEMIA, AND WAS STRONGLY INVOLVED IN THE TRANSFORMATION OF FOLLICULAR LYMPHOMA. IN SUMMARY, HERE WE REPORT THAT LAMIN B1 IS A NEGATIVE EPIGENETIC REGULATOR OF SHM IN NORMAL B-CELLS AND A 'MUTATIONAL GATEKEEPER', SUPPRESSING THE ABERRANT MUTATIONS THAT DRIVE LYMPHOID MALIGNANCY. 2018 12 1125 37 COMPLEX INHIBITION OF AUTOPHAGY BY MITOCHONDRIAL ALDEHYDE DEHYDROGENASE SHORTENS LIFESPAN AND EXACERBATES CARDIAC AGING. AUTOPHAGY, A CONSERVATIVE DEGRADATION PROCESS FOR LONG-LIVED AND DAMAGED PROTEINS, PARTICIPATES IN A CASCADE OF BIOLOGICAL PROCESSES INCLUDING AGING. A NUMBER OF AUTOPHAGY REGULATORS HAVE BEEN IDENTIFIED. HERE WE DEMONSTRATED THAT MITOCHONDRIAL ALDEHYDE DEHYDROGENASE (ALDH2), AN ENZYME WITH THE MOST COMMON SINGLE POINT MUTATION IN HUMANS, GOVERNS CARDIAC AGING THROUGH REGULATION OF AUTOPHAGY. MYOCARDIAL MECHANICAL AND AUTOPHAGY PROPERTIES WERE EXAMINED IN YOUNG (4MONTHS) AND OLD (26-28MONTHS) WILD-TYPE (WT) AND GLOBAL ALDH2 TRANSGENIC MICE. ALDH2 OVEREXPRESSION SHORTENED LIFESPAN BY 7.7% WITHOUT AFFECTING AGING-ASSOCIATED CHANGES IN PLASMA METABOLIC PROFILES. MYOCARDIAL FUNCTION WAS COMPROMISED WITH AGING ASSOCIATED WITH CARDIAC HYPERTROPHY, THE EFFECTS WERE ACCENTUATED BY ALDH2. AGING OVERTLY SUPPRESSED AUTOPHAGY AND COMPROMISED AUTOPHAGY FLUX, THE EFFECTS WERE EXACERBATED BY ALDH2. AGING DAMPENED PHOSPHORYLATION OF JNK, BCL-2, IKKBETA, AMPK AND TSC2 WHILE PROMOTING PHOSPHORYLATION OF MTOR, THE EFFECTS OF WHICH WERE EXAGGERATED BY ALDH2. CO-IMMUNOPRECIPITATION REVEALED INCREASED DISSOCIATION BETWEEN BCL-2 AND BECLIN-1 (RESULT OF DECREASED BCL-2 PHOSPHORYLATION) IN AGING, THE EFFECT OF WHICH WAS EXACERBATED WITH ALDH2. CHRONIC TREATMENT OF THE AUTOPHAGY INDUCER RAPAMYCIN ALLEVIATED AGING-INDUCED CARDIAC DYSFUNCTION IN BOTH WT AND ALDH2 MICE. MOREOVER, ACTIVATION OF JNK AND INHIBITION OF EITHER BCL-2 OR IKKBETA OVERTLY ATTENUATED ALDH2 ACTIVATION-INDUCED ACCENTUATION OF CARDIOMYOCYTE AGING. EXAMINATION OF THE OTHERWISE ELDERLY INDIVIDUALS REVEALED A POSITIVE CORRELATION BETWEEN CARDIAC FUNCTION/GEOMETRY AND ALDH2 GENE MUTATION. TAKEN TOGETHER, OUR DATA REVEALED THAT ALDH2 ENZYME MAY SUPPRESS MYOCARDIAL AUTOPHAGY POSSIBLY THROUGH A COMPLEX JNK-BCL-2 AND IKKBETA-AMPK-DEPENDENT MECHANISM EN ROUTE TO ACCENTUATION OF MYOCARDIAL REMODELING AND CONTRACTILE DYSFUNCTION IN AGING. THIS ARTICLE IS PART OF A SPECIAL ISSUE ENTITLED: GENETIC AND EPIGENETIC CONTROL OF HEART FAILURE - EDITED BY JUN REN & MEGAN YINGMEI ZHANG. 2017 13 1066 25 CLINICAL USE OF AMINO ACIDS AS DIETARY SUPPLEMENT: PROS AND CONS. NITROGEN SUPPLY IS PIVOTAL FOR THE MAINTENANCE OF LIFE. AMINO ACIDS CAN BE UTILIZED TO SYNTHESIZE BOTH GLUCOSE AND LIPIDS. THE OPPOSITE, I.E., PRODUCTION OF AMINO ACIDS FROM EITHER ONE OF THEM, IS NOT POSSIBLE IN THE ABSENCE OF OTHER AMINO ACIDS AS DONORS OF NITROGEN. THE QUALITY OF AMINO ACID CONTENT IN PROTEIN HAS BEEN RE-EVALUATED RECENTLY, AND THE RELEVANCE OF ESSENTIAL AMINO ACIDS HAS BEEN REPEATEDLY UNDERLINED. ESSENTIAL AMINO ACID REQUIREMENTS IN DIFFERENT MAMMALS ARE NOT IDENTICAL, AND RATIOS AMONG THEM SHOULD BE TAKEN INTO ACCOUNT WHEN PROJECTING AN EFFICIENT FORMULATION. RECENT RESEARCH HAS DEMONSTRATED THAT GENES RESPOND TO DIFFERENT QUALITIES AND QUANTITIES OF NUTRITIONAL SUPPLY, AND INCREASED PROVISION OF ESSENTIAL AMINO ACIDS INCREASES LIFESPAN IN ANIMAL EXPERIMENTS THROUGH MITOCHONDRIOGENESIS AND MAINTENANCE OF ELEVATED RATES OF SYNTHESIS OF ANTI-OXIDANT MOLECULES. MOREOVER, GENETIC EXPRESSION OF KEY CONTROLLERS OF SYNTHESIS, LIKE MTOR, MAY BE PARTICULARLY IMPORTANT FOR UNDERSTANDING SKELETAL MUSCLE MAINTENANCE. LOSSES OF MUSCLE MASS AND IMPAIRED IMMUNE FUNCTION ARE RELATED TO REDUCED PROTEIN SUPPLY, AND THERE IS INCREASING EVIDENCE THAT REGULAR ESSENTIAL AMINO ACID INTAKE AS PART OF AN ORAL DIET IS EFFECTIVE IN REVERSING MUSCLE CATABOLISM, PROMOTING MUSCLE ANABOLISM, AND RESTORING IMMUNOLOGICAL FUNCTION. THEREFORE, THE USE OF AMINO ACIDS AS SUPPLEMENTS TO DIET WOULD BE EXPANDING IN THE NEAR FUTURE. IS THIS SAFE? FEW DATA ARE AVAILABLE ON AMINO ACID TOXICITY, AND ONLY ONE ESSENTIAL AMINO ACID MAY BE CONSIDERED TO HAVE CLINICALLY RELEVANT TOXICITY: METHIONINE, BECAUSE IT IS TRANSFORMED INTO A TOXIC INTERMEDIATE, HOMOCYSTEINE, WHEN CYSTEINE SYNTHESIS IS REQUIRED BY METABOLIC NEEDS. MATCHING OF STOICHIOMETRIC RATIOS BETWEEN METHIONINE AND CYSTEINE MAY SOLVE THE PROBLEM OF SUPPLYING SUFFICIENT AMOUNTS OF SULFUR TO THE BODY. ARGININE AND GLUTAMINE ARE TWO NON-ESSENTIAL AMINO ACIDS THAN CAN BECOME "CONDITIONALLY ESSENTIAL" BECAUSE OF ELEVATED NEEDS DURING PATHOLOGICAL CONDITIONS, AND METABOLISM MAY NOT BE ABLE TO MAINTAIN THEIR CONCENTRATIONS AT SUFFICIENT LEVELS TO MATCH METABOLIC REQUIREMENTS. CHRONIC EXOGENOUS ARGININE SUPPLEMENTATION HAS NOT PROVEN TO EXERT POSITIVE CLINICAL EFFECTS IN DIFFERENT TRIALS, AND SEQUENTIAL ARTICULATION OF THE KNOWLEDGE OF INTRODUCTION OF ARGININE-DRIVEN TRANSCRIPTIONAL, TRANSLATIONAL, AND EPIGENETIC ADAPTATIONS MAY GIVE US A KEY FOR INTERPRETING THOSE PUZZLING RESULTS. 2011 14 3889 33 KLOTHO RECOVERY BY GENISTEIN VIA PROMOTER HISTONE ACETYLATION AND DNA DEMETHYLATION MITIGATES RENAL FIBROSIS IN MICE. RENAL FIBROSIS IS A COMMON HISTOMORPHOLOGICAL FEATURE OF RENAL AGING AND CHRONIC KIDNEY DISEASES OF ALL ETIOLOGIES, AND ITS INITIATION AND PROGRESSION ARE SUBSTANTIALLY INFLUENCED BY ABERRANT EPIGENETIC MODIFICATIONS OF FIBROSIS-SUSCEPTIBLE GENES, YET WITHOUT EFFECTIVE THERAPY. "EPIGENETIC DIETS" EXHIBIT TISSUE-PROTECTIVE AND EPIGENETIC-MODULATING PROPERTIES; HOWEVER, THEIR ANTI-RENAL FIBROSIS FUNCTIONS AND THE UNDERLYING MECHANISMS ARE LESS UNDERSTOOD. IN THIS STUDY, WE SHOW THAT GENISTEIN, A PHYTOESTROGENIC ISOFLAVONE ENRICHED IN DIETARY SOY PRODUCTS, EXHIBITS IMPRESSIVE ANTI-RENAL FIBROSIS ACTIVITIES BY RECOVERING EPIGENETIC LOSS OF KLOTHO, A KIDNEY-ENRICHED ANTI-AGING AND FIBROSIS-SUPPRESSING PROTEIN. MOUSE FIBROTIC KIDNEYS INDUCED BY UUO (UNILATERAL URETERAL OCCLUSION) DISPLAYED SEVERER KLOTHO SUPPRESSION AND ADVERSE EXPRESSION OF RENAL FIBROSIS-ASSOCIATED PROTEINS, BUT GENISTEIN ADMINISTRATION MARKEDLY RECOVERED THE KLOTHO LOSS AND ATTENUATED RENAL FIBROSIS AND THE PROTEIN EXPRESSION ABNORMALITIES. THE EXAMINATION OF POSSIBLE CAUSES OF THE KLOTHO RECOVERY REVEALED THAT GENISTEIN SIMULTANEOUSLY INHIBITED HISTONE 3 DEACETYLATION OF KLOTHO PROMOTER AND NORMALIZED THE PROMOTER DNA HYPERMETHYLATION BY SUPPRESSING ELEVATED DNA METHYLTRANSFERASE DNMT1 AND DNMT3A. MORE IMPORTANTLY, GENISTEIN'S ANTI-RENAL FIBROSIS EFFECTS ON THE RENAL FIBROTIC LESIONS AND THE ABNORMAL EXPRESSIONS OF FIBROSIS-ASSOCIATED PROTEINS WERE ABROGATED WHEN KLOTHO IS KNOCKDOWN BY RNA INTERFERENCES IN UUO MICE. THUS, OUR RESULTS IDENTIFY KLOTHO RESTORATION VIA EPIGENETIC HISTONE ACETYLATION AND DNA DEMETHYLATION AS A CRITICAL MECHANISM OF GENISTEIN'S ANTI-FIBROSIS FUNCTION AND SHED NEW LIGHTS ON THE POTENTIALS OF EPIGENETIC DIETS IN PREVENTING OR TREATING AGING OR RENAL FIBROSIS-ASSOCIATED KIDNEY DISEASES. KEY MESSAGES: GENISTEIN PREVENTS RENAL FIBROSIS AND THE ASSOCIATED KLOTHO SUPPRESSION IN UUO MICE. GENISTEIN UPREGULATES KLOTHO IN PART BY REVERSING THE PROMOTER HISTONE 3 HYPOACETYLATION. GENISTEIN ALSO PRESERVES KLOTHO VIA RELIEVING KLOTHO PROMOTER HYPERMETHYLATION. GENISTEIN DEMETHYLATES KLOTHO PROMOTER BY INHIBITING ABERRANT DNMT1/3A EXPRESSION. GENISTEIN RESTORATION OF KLOTHO IS ESSENTIAL FOR ITS ANTI-RENAL FIBROSIS FUNCTION. 2019 15 4117 36 MECHANISMS OF AUTOPHAGIC RESPONSES TO ALTERED NUTRITIONAL STATUS. AUTOPHAGY IS A DYNAMIC PROCESS AND CRITICAL FOR CELLULAR REMODELING AND ORGANELLE QUALITY CONTROL. IN RESPONSE TO ALTERED NUTRITIONAL STATUS (E.G., FASTING AND FEEDING), AUTOPHAGIC ACTIVITY IS FINELY TUNED BY TRANSCRIPTIONAL, POSTTRANSLATIONAL, AND EPIGENETIC REGULATIONS VIA VARIOUS SIGNALING PATHWAYS, INCLUDING ENERGY SENSORS (E.G., MECHANISTIC TARGET OF RAPAMYCIN (MTOR)/ AMP-ACTIVATED PROTEIN KINASE - UNC-51 LIKE AUTOPHAGY ACTIVATING KINASE 1, MTORC1- WD REPEAT DOMAIN, PHOSPHOINOSITIDE INTERACTING 2, MTORC1- TRANSCRIPTION FACTOR EB, PERILIPIN 5- SIRTUIN 1, AND SIRTUIN 1-MEDIATED DEACETYLATION OF AUTOPHAGY PROTEINS), FASTING OR FEEDING INDUCED HORMONES (E.G., FIBROBLAST GROWTH FACTOR [FGF21]- PROTEIN KINASE A - JUMONJI DOMAIN-CONTAINING PROTEIN D3, FGF21- DOWNSTREAM REGULATORY ELEMENT ANTAGONIST MODULATOR - E3 LIGASE MIDLINE-1- TRANSCRIPTION FACTOR EB, FGF19-SHP- LYSINE-SPECIFIC DEMETHYLASE, INSULIN- INSULIN RECEPTOR SUBSTRATE - PROTEIN KINASE B - FORKHEAD BOX O, GLUCAGON- PROTEIN KINASE A - CAMP RESPONSE BINDING PROTEIN), AND LYSOSOMAL ENZYMES (E.G., CATHEPSIN B AND CATHEPSIN L). IN CONTRAST TO FASTING THAT INDUCES AUTOPHAGY AND HEALTH BENEFITS, NUTRIENT OVERSUPPLY (OVERFEEDING OR FEEDING ON HIGH ENERGY DIETS) DYSREGULATES AUTOPHAGY, WHICH HAS BEEN INCREASINGLY OBSERVED IN ANIMAL MODELS OF HUMAN CHRONIC DISEASES SUCH AS OBESITY, DIABETES, NON-ALCOHOLIC FATTY LIVER DISEASE, AND CARDIOVASCULAR DISEASE. STUDIES HAVE REVEALED MULTIFACETED EFFECTS OF HIGH ENERGY DIETS ON AUTOPHAGY, BEING EITHER AN INHIBITOR OR ENHANCER OF AUTOPHAGY. THE CONUNDRUM MAY ARISE FROM THE VARIATIONS IN METHODS FOR AUTOPHAGY ANALYSIS, COMPONENTS OF HIGH ENERGY DIETS AND CONTROL DIETS FOR TREATMENTS, TREATMENT DURATIONS, AND THE AGES OF GENETIC BACKGROUNDS OF LABORATORY ANIMALS. IN THIS ARTICLE, WE REVIEWED THE EVIDENCE FROM BOTH HUMAN AND ANIMAL STUDIES, PRESENTING THE MOLECULAR MECHANISM OF AUTOPHAGIC RESPONSE TO ALTERED NUTRITIONAL STATUS AND DISCUSSING THE CONTRIBUTING FACTORS OF AND POSSIBLE SOLUTION TO THE CURRENT CONUNDRUM CONCERNING THE EXACT ROLE OF HIGH ENERGY DIETS IN AUTOPHAGIC REGULATION. 2022 16 3633 33 INCREASE IN HDAC9 SUPPRESSES MYOBLAST DIFFERENTIATION VIA EPIGENETIC REGULATION OF AUTOPHAGY IN HYPOXIA. EXTREMELY REDUCED OXYGEN (O(2)) LEVELS ARE DETRIMENTAL TO MYOGENIC DIFFERENTIATION AND MULTINUCLEATED MYOTUBE FORMATION, AND CHRONIC EXPOSURE TO HIGH-ALTITUDE HYPOXIA HAS BEEN REPORTED TO BE AN IMPORTANT FACTOR IN SKELETAL MUSCLE ATROPHY. HOWEVER, HOW CHRONIC HYPOXIA CAUSES MUSCLE DYSFUNCTION REMAINS UNKNOWN. IN THE PRESENT STUDY, WE FOUND THAT SEVERE HYPOXIA (1% O(2)) SIGNIFICANTLY INHIBITED THE FUNCTION OF C2C12 CELLS (FROM A MYOBLAST CELL LINE). IMPORTANTLY, THE IMPAIRMENT WAS CONTINUOUSLY MANIFESTED EVEN DURING CULTURE UNDER NORMOXIC CONDITIONS FOR SEVERAL PASSAGES. MECHANISTICALLY, WE REVEALED THAT HISTONE DEACETYLASES 9 (HDAC9), A MEMBER OF THE HISTONE DEACETYLASE FAMILY, WAS SIGNIFICANTLY INCREASED IN C2C12 CELLS UNDER HYPOXIC CONDITIONS, THEREBY INHIBITING INTRACELLULAR AUTOPHAGY LEVELS BY DIRECTLY BINDING TO THE PROMOTER REGIONS OF ATG7, BECLIN1, AND LC3. THIS PHENOMENON RESULTED IN THE SEQUENTIAL DEPHOSPHORYLATION OF GSK3BETA AND INACTIVATION OF THE CANONICAL WNT PATHWAY, IMPAIRING THE FUNCTION OF THE C2C12 CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT HYPOXIA-INDUCED MYOBLAST DYSFUNCTION IS DUE TO ABERRANT EPIGENETIC REGULATION OF AUTOPHAGY, AND OUR EXPERIMENTAL EVIDENCE REVEALS THE POSSIBLE MOLECULAR PATHOGENESIS RESPONSIBLE FOR SOME MUSCLE DISEASES CAUSED BY CHRONIC HYPOXIA AND SUGGESTS A POTENTIAL THERAPEUTIC OPTION. 2019 17 951 40 CHRONIC MILD STRESS MODIFIED EPIGENETIC MECHANISMS LEADING TO ACCELERATED SENESCENCE AND IMPAIRED COGNITIVE PERFORMANCE IN MICE. COGNITIVE AND BEHAVIOURAL DISTURBANCES ARE A GROWING PUBLIC HEALTHCARE ISSUE FOR THE MODERN SOCIETY, AS STRESSFUL LIFESTYLE IS BECOMING MORE AND MORE COMMON. BESIDES, SEVERAL PIECES OF EVIDENCE STATE THAT ENVIRONMENT IS CRUCIAL IN THE DEVELOPMENT OF SEVERAL DISEASES AS WELL AS COMPROMISING HEALTHY AGING. THEREFORE, IT IS IMPORTANT TO STUDY THE EFFECTS OF STRESS ON COGNITION AND ITS RELATIONSHIP WITH AGING. TO ADDRESS THESE QUERIES, CHRONIC MILD STRESS (CMS) PARADIGM WAS USED IN THE SENESCENCE-ACCELERATED MOUSE PRONE 8 (SAMP8) AND RESISTANT 1 (SAMR1). ON ONE HAND, WE DETERMINED THE CHANGES PRODUCED IN THE THREE MAIN EPIGENETIC MARKS AFTER 4 WEEKS OF CMS TREATMENT, SUCH AS A REDUCTION IN HISTONE POSTTRANSLATIONAL MODIFICATIONS AND DNA METHYLATION, AND UP-REGULATION OR DOWN-REGULATION OF SEVERAL MIRNA INVOLVED IN DIFFERENT CELLULAR PROCESSES IN MICE. IN ADDITION, CMS TREATMENT INDUCED REACTIVE OXYGEN SPECIES (ROS) DAMAGE ACCUMULATION AND LOSS OF ANTIOXIDANT DEFENCE MECHANISMS, AS WELL AS INFLAMMATORY SIGNALLING ACTIVATION THROUGH NF-KAPPAB PATHWAY AND ASTROGLIOSIS MARKERS, LIKE GFAP. REMARKABLY, CMS ALTERED MTORC1 SIGNALLING IN BOTH STRAINS, DECREASING AUTOPHAGY ONLY IN SAMR1 MICE. WE FOUND A DECREASE IN GLYCOGEN SYNTHASE KINASE 3 BETA (GSK-3BETA) INACTIVATION, HYPERPHOSPHORYLATION OF TAU AND AN INCREASE IN SAPPBETA PROTEIN LEVELS IN MICE UNDER CMS. MOREOVER, REDUCTION IN THE NON-AMYLOIDOGENIC SECRETASE ADAM10 PROTEIN LEVELS WAS FOUND IN SAMR1 CMS GROUP. CONSEQUENTLY, DETRIMENTAL EFFECTS ON BEHAVIOUR AND COGNITIVE PERFORMANCE WERE DETECTED IN CMS TREATED MICE, AFFECTING MAINLY SAMR1 MICE, PROMOTING A TURNING TO SAMP8 PHENOTYPE. IN CONCLUSION, CMS IS A FEASIBLE INTERVENTION TO UNDERSTAND THE INFLUENCE OF STRESS ON EPIGENETIC MECHANISMS UNDERLYING COGNITION AND ACCELERATING SENESCENCE. 2020 18 1906 36 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 19 3242 30 HEPATIC NCOR1 DELETION EXACERBATES ALCOHOL-INDUCED LIVER INJURY IN MICE BY PROMOTING CCL2-MEDIATED MONOCYTE-DERIVED MACROPHAGE INFILTRATION. NUCLEAR RECEPTOR COREPRESSOR 1 (NCOR1) IS A COREPRESSOR OF THE EPIGENETIC REGULATION OF GENE TRANSCRIPTION THAT HAS IMPORTANT FUNCTIONS IN METABOLISM AND INFLAMMATION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN ALCOHOL-ASSOCIATED LIVER DISEASE (ALD). IN THIS STUDY, WE DEVELOPED MICE WITH HEPATOCYTE-SPECIFIC NCOR1 KNOCKOUT (NCOR1(HEP-/-)) USING THE ALBUMIN-CRE/LOXP SYSTEM AND INVESTIGATED THE ROLE OF NCOR1 IN THE PATHOGENESIS OF ALD AND THE UNDERLYING MECHANISMS. THE TRADITIONAL ALCOHOL FEEDING MODEL AND NIAAA MODEL OF ALD WERE BOTH ESTABLISHED IN WILD-TYPE AND NCOR1(HEP-/-) MICE. WE SHOWED THAT AFTER ALD WAS ESTABLISHED, NCOR1(HEP-/-) MICE HAD WORSE LIVER INJURY BUT LESS STEATOSIS THAN WILD-TYPE MICE. WE DEMONSTRATED THAT HEPATOCYTE-SPECIFIC LOSS OF NCOR1 ATTENUATED LIVER STEATOSIS BY PROMOTING FATTY ACID OXIDATION BY UPREGULATING BMAL1 (A CIRCADIAN CLOCK COMPONENT THAT HAS BEEN REPORTED TO PROMOTE PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR ALPHA (PPARALPHA)-MEDIATED FATTY BETA-OXIDATION BY UPREGULATING DE NOVO LIPID SYNTHESIS). ON THE OTHER HAND, HEPATOCYTE-SPECIFIC LOSS OF NCOR1 EXACERBATED ALCOHOL-INDUCED LIVER INFLAMMATION AND OXIDATIVE STRESS BY RECRUITING MONOCYTE-DERIVED MACROPHAGES VIA C-C MOTIF CHEMOKINE LIGAND 2 (CCL2). IN THE MOUSE HEPATOCYTE LINE AML12, NCOR1 KNOCKDOWN SIGNIFICANTLY INCREASED ETHANOL-INDUCED CCL2 RELEASE. THESE RESULTS SUGGEST THAT HEPATOCYTE NCOR1 PLAYS DISTINCT ROLES IN CONTROLLING LIVER INFLAMMATION AND STEATOSIS, WHICH PROVIDES NEW INSIGHTS INTO THE DEVELOPMENT OF TREATMENTS FOR STEATOHEPATITIS INDUCED BY CHRONIC ALCOHOL CONSUMPTION. 2022 20 4214 33 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