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 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 5 5716 38 SIRT6 PROTECTS VASCULAR SMOOTH MUSCLE CELLS FROM OSTEOGENIC TRANSDIFFERENTIATION VIA RUNX2 IN CHRONIC KIDNEY DISEASE. VASCULAR CALCIFICATION (VC) IS REGARDED AS AN IMPORTANT PATHOLOGICAL CHANGE LACKING EFFECTIVE TREATMENT AND ASSOCIATED WITH HIGH MORTALITY. SIRTUIN 6 (SIRT6) IS A MEMBER OF THE SIRTUIN FAMILY, A CLASS III HISTONE DEACETYLASE AND A KEY EPIGENETIC REGULATOR. SIRT6 HAS A PROTECTIVE ROLE IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD). HOWEVER, THE EXACT ROLE AND MOLECULAR MECHANISM OF SIRT6 IN VC IN PATIENTS WITH CKD REMAIN UNCLEAR. HERE, WE DEMONSTRATED THAT SIRT6 WAS MARKEDLY DOWNREGULATED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) AND IN THE RADIAL ARTERY TISSUE OF PATIENTS WITH CKD WITH VC. SIRT6-TRANSGENIC (SIRT6-TG) MICE SHOWED ALLEVIATED VC, WHILE VASCULAR SMOOTH MUSCLE CELL-SPECIFIC (VSMC-SPECIFIC) SIRT6 KNOCKED-DOWN MICE SHOWED SEVERE VC IN CKD. SIRT6 SUPPRESSED THE OSTEOGENIC TRANSDIFFERENTIATION OF VSMCS VIA REGULATION OF RUNT-RELATED TRANSCRIPTION FACTOR 2 (RUNX2). COIMMUNOPRECIPITATION (CO-IP) AND IMMUNOPRECIPITATION (IP) ASSAYS CONFIRMED THAT SIRT6 BOUND TO RUNX2. MOREOVER, RUNX2 WAS DEACETYLATED BY SIRT6 AND FURTHER PROMOTED NUCLEAR EXPORT VIA EXPORTIN 1 (XPO1), WHICH IN TURN CAUSED DEGRADATION OF RUNX2 THROUGH THE UBIQUITIN-PROTEASOME SYSTEM. THESE RESULTS DEMONSTRATED THAT SIRT6 PREVENTED VC BY SUPPRESSING THE OSTEOGENIC TRANSDIFFERENTIATION OF VSMCS, AND AS SUCH TARGETING SIRT6 MAY BE AN APPEALING THERAPEUTIC TARGET FOR VC IN CKD. 2022 6 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 7 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 8 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 9 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 10 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 11 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 12 5675 30 SHIFTS IN PODOCYTE HISTONE H3K27ME3 REGULATE MOUSE AND HUMAN GLOMERULAR DISEASE. HISTONE PROTEIN MODIFICATIONS CONTROL FATE DETERMINATION DURING NORMAL DEVELOPMENT AND DEDIFFERENTIATION DURING DISEASE. HERE, WE SET OUT TO DETERMINE THE EXTENT TO WHICH DYNAMIC CHANGES TO HISTONES AFFECT THE DIFFERENTIATED PHENOTYPE OF ORDINARILY QUIESCENT ADULT GLOMERULAR PODOCYTES. TO DO THIS, WE EXAMINED THE CONSEQUENCES OF SHIFTING THE BALANCE OF THE REPRESSIVE HISTONE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3) MARK IN PODOCYTES. ADRIAMYCIN NEPHROTOXICITY AND SUBTOTAL NEPHRECTOMY (SNX) STUDIES INDICATED THAT DELETION OF THE HISTONE METHYLATING ENZYME EZH2 FROM PODOCYTES DECREASED H3K27ME3 LEVELS AND SENSITIZED MICE TO GLOMERULAR DISEASE. H3K27ME3 WAS ENRICHED AT THE PROMOTER REGION OF THE NOTCH LIGAND JAG1 IN PODOCYTES, AND DEREPRESSION OF JAG1 BY EZH2 INHIBITION OR KNOCKDOWN FACILITATED PODOCYTE DEDIFFERENTIATION. CONVERSELY, INHIBITION OF THE JUMONJI C DOMAIN-CONTAINING DEMETHYLASES JMJD3 AND UTX INCREASED THE H3K27ME3 CONTENT OF PODOCYTES AND ATTENUATED GLOMERULAR DISEASE IN ADRIAMYCIN NEPHROTOXICITY, SNX, AND DIABETES. PODOCYTES IN GLOMERULI FROM HUMANS WITH FOCAL SEGMENTAL GLOMERULOSCLEROSIS OR DIABETIC NEPHROPATHY EXHIBITED DIMINISHED H3K27ME3 AND HEIGHTENED UTX CONTENT. ANALOGOUS TO HUMAN DISEASE, INHIBITION OF JMJD3 AND UTX ABATED NEPHROPATHY PROGRESSION IN MICE WITH ESTABLISHED GLOMERULAR INJURY AND REDUCED H3K27ME3 LEVELS. TOGETHER, THESE FINDINGS INDICATE THAT OSTENSIBLY STABLE CHROMATIN MODIFICATIONS CAN BE DYNAMICALLY REGULATED IN QUIESCENT CELLS AND THAT EPIGENETIC REPROGRAMMING CAN IMPROVE OUTCOMES IN GLOMERULAR DISEASE BY REPRESSING THE REACTIVATION OF DEVELOPMENTAL PATHWAYS. 2018 13 364 30 AMELIORATION OF UREMIC TOXIN INDOXYL SULFATE-INDUCED OSTEOBLASTIC CALCIFICATION BY SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 PROTEIN. BACKGROUND: VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD). IT HAS BEEN REPORTED THAT SOME HISTONE METHYLATION PLAY A ROLE IN VC AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN THAT HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 (SET7/9) IS ONE OF THE IMPORTANT HISTONE METHYLTRANSFERASES. OBJECTIVES: THIS STUDY AIMED TO DETERMINE THE EFFECT OF IS ON THE EXPRESSION OF SET7/9 AND THE ROLE OF SET7/9 IN IS-INDUCED OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VASCULAR SMOOTH MUSCLE CELLS (VSMCS). METHODS: VSMCS WERE INCUBATED WITH VARIOUS CONCENTRATIONS OF IS FOR DIFFERENT DURATIONS TO ASSESS OSTEOBLASTIC DIFFERENTIATION AND EXPRESSION OF SET7/9. WESTERN BLOT ANALYSIS AND QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION WERE PERFORMED TO ASSESS THE PROTEIN AND MRNA LEVELS OF SET7/9 RESPECTIVELY. THE CALCIUM CONTENT WAS MEASURED TO EVALUATE CALCIFICATION. RESULTS: OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VSMCS AND DOWNREGULATION OF THE EXPRESSION OF SET7/9 WERE OBSERVED AFTER IS TREATMENT. THE AUTOPHAGY WAS ACTIVATED AFTER TREATMENT WITH IS, WHEREAS THE INHIBITION OF THE AUTOPHAGY PARTIALLY ATTENUATED THE EFFECT OF IS ON BOTH THE STIMULATION OF THE EXPRESSION OF RUNT-RELATED TRANSCRIPTION FACTOR 2 AND CALCIUM DEPOSITION. CONCLUSIONS: OUR DATA DEMONSTRATED THAT SET7/9 DOWNREGULATION AND AUTOPHAGY ACTIVATION MAY BE THE KEY MECHANISM OF IS-INDUCED VC IN CKD. 2019 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 3240 28 HEPATIC LIPID ACCUMULATION ALTERS GLOBAL HISTONE H3 LYSINE 9 AND 4 TRIMETHYLATION IN THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA NETWORK. RECENT DATA SUGGEST THAT THE ETIOLOGY OF SEVERAL METABOLIC DISEASES IS CLOSELY ASSOCIATED WITH TRANSCRIPTOME ALTERATION BY ABERRANT HISTONE METHYLATION. WE PERFORMED DNA MICROARRAY AND CHIP-ON-CHIP ANALYSES TO EXAMINE TRANSCRIPTOME PROFILING AND TRIMETHYLATION ALTERATIONS TO IDENTIFY THE GENOMIC SIGNATURE OF NONALCOHOLIC FATTY LIVER DISEASE (NAFLD), THE MOST COMMON FORM OF CHRONIC LIVER DISEASE. TRANSCRIPTOME ANALYSIS SHOWED THAT STEATOTIC LIVERS IN HIGH-FAT DIET-FED APOLIPOPROTEIN E2 MICE SIGNIFICANTLY ALTERED THE EXPRESSION OF APPROXIMATELY 70% OF TOTAL GENES COMPARED WITH NORMAL DIET-FED CONTROL LIVERS, SUGGESTING THAT HEPATIC LIPID ACCUMULATION INDUCES DRAMATIC ALTERATIONS IN GENE EXPRESSION IN VIVO. ALSO, PATHWAY ANALYSIS SUGGESTED THAT GENES ENCODING CHROMATIN-REMODELING ENZYMES, SUCH AS JUMONJI C-DOMAIN-CONTAINING HISTONE DEMETHYLASES THAT REGULATE HISTONE H3K9 AND H3K4 TRIMETHYLATION (H3K9ME3, H3K4ME3), WERE SIGNIFICANTLY ALTERED IN STEATOTIC LIVERS. THUS, WE FURTHER INVESTIGATED THE GLOBAL H3K9ME3 AND H3K4ME3 STATUS IN LIPID-ACCUMULATED MOUSE PRIMARY HEPATOCYTES BY CHIP-ON-CHIP ANALYSIS. RESULTS SHOWED THAT HEPATIC LIPID ACCUMULATION INDUCED ABERRANT H3K9ME3 AND H3K4ME3 STATUS IN PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA AND HEPATIC LIPID CATABOLISM NETWORK GENES, REDUCING THEIR MRNA EXPRESSION COMPARED WITH NON-TREATED CONTROL HEPATOCYTES. THIS STUDY PROVIDES THE FIRST EVIDENCE THAT EPIGENETIC REGULATION BY H3K9ME3 AND H3K4ME3 IN HEPATOCYTES MAY BE INVOLVED IN HEPATIC STEATOSIS AND THE PATHOGENESIS OF NAFLD. THUS, CONTROL OF H3K9ME3 AND H3K4ME3 REPRESENTS A POTENTIAL NOVEL NAFLD PREVENTION AND TREATMENT STRATEGY. 2012 16 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 17 5448 33 REPRESSION OF HDAC5 BY ACETATE RESTORES HYPOTHALAMIC-PITUITARY-OVARIAN FUNCTION IN TYPE 2 DIABETES MELLITUS. TYPE 2 DIABETES MELLITUS (T2DM) ACCOUNTS FOR 90-95 % OF WORLDWIDE DIABETES CASES AND IS PRIMARILY CHARACTERIZED BY INSULIN RESISTANCE. ITS PROGRESSION AS A CHRONIC METABOLIC DISEASE HAS BEEN LARGELY ASSOCIATED WITH FEMALE REPRODUCTIVE ABNORMALITIES, INCLUDING OVARIAN DYSFUNCTION WITH CONSEQUENT INFERTILITY. EPIGENETIC MODIFICATIONS HAVE BEEN SUGGESTED AS A POSSIBLE LINK TO METABOLIC COMORBIDITIES. WE THEREFORE HYPOTHESIZED THAT SHORT CHAIN FATTY ACIDS, ACETATE (ACA), A POTENTIAL HISTONE DEACETYLASE INHIBITOR (HDAC) AMELIORATES HYPOTHALAMIC-PITUITARY-OVARIAN (HPO) DYSFUNCTION IN T2DM. FEMALE WISTAR RATS WEIGHING 160-190 G WERE ALLOTTED INTO THREE GROUPS (N = 6/GROUP): CONTROL (VEHICLE; PO), T2D AND T2D + ACA (200 MG/KG; PO). T2DM WAS INDUCED BY FRUCTOSE ADMINISTRATION (10 %; W/V) FOR 6 WEEKS AND SINGLE DOSE OF STREPTOZOTOCIN (35 MG/KG; IP). THE PRESENT DATA SHOWED THAT IN ADDITION TO INSULIN RESISTANCE, INCREASED FASTING BLOOD GLUCOSE AND INSULIN, T2DM INDUCED ELEVATED PLASMA, HYPOTHALAMIC AND OVARIAN TRIGLYCERIDE, LIPID PEROXIDATION, TNF-ALPHA AND GLUTATHIONE DEPLETION. ASIDE, T2DM ALSO LED TO INCREASED PLASMA LACTATE PRODUCTION AND GAMMA-GLUTAMYL TRANSFERASE AS WELL AS DECREASED GONADOTROPINS/17BETA-ESTRADIOL. HISTOLOGICALLY, HYPOTHALAMUS, PITUITARY AND OVARIES REVEALED DISRUPTED NEURONAL CELLS/MODERATE HEMORRHAGE, ALTERED MORPHOLOGY/VASCULAR CONGESTIONS, AND DEGENERATED ANTRAL FOLLICLE/GRAAFIAN FOLLICLE WITH MILD FIBROSIS AND INFILTRATED INFLAMMATORY CELLS RESPECTIVELY IN T2D ANIMALS. INTERESTINGLY, THESE ALTERATIONS WERE ACCOMPANIED BY ELEVATED PLASMA/HYPOTHALAMIC HDAC5 AND ATTENUATED WHEN TREATED WITH ACETATE. THE PRESENT RESULTS DEMONSTRATE THAT T2DM INDUCES HPO DYSFUNCTION, WHICH IS ACCOMPANIED BY ELEVATED CIRCULATING/HYPOTHALAMIC HDAC5. THE RESULTS IN ADDITION SUGGEST THAT ACETATE RESTORES HPO FUNCTION IN T2DM BY SUPPRESSION OF HDAC5 AND ENHANCEMENT OF INSULIN SENSITIVITY. 2021 18 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 19 4017 33 LOW-DOSE HYDRALAZINE REDUCES ALBUMINURIA AND GLOMERULOSCLEROSIS IN A MOUSE MODEL OF OBESITY-RELATED CHRONIC KIDNEY DISEASE. AIM: TO DETERMINE, USING A MOUSE MODEL OF OBESITY, WHETHER LOW-DOSE HYDRALAZINE PREVENTS OBESITY-RELATED CHRONIC KIDNEY DISEASE (CKD). METHODS: FROM 8 WEEKS OF AGE, MALE C57BL/6 MICE RECEIVED A HIGH-FAT DIET (HFD) OR CHOW, WITH OR WITHOUT LOW-DOSE HYDRALAZINE (25 MG/L) IN DRINKING WATER, FOR 24 WEEKS. BIOMETRIC AND METABOLIC VARIABLES, RENAL FUNCTION AND STRUCTURAL CHANGES, RENAL GLOBAL DNA METHYLATION, DNA METHYLATION PROFILE AND MARKERS OF RENAL FIBROSIS, INJURY, INFLAMMATION AND OXIDATIVE STRESS WERE ASSESSED. RESULTS: THE HFD-FED MICE DEVELOPED OBESITY, WITH GLUCOSE INTOLERANCE, HYPERINSULINAEMIA AND DYSLIPIDAEMIA. OBESITY INCREASED ALBUMINURIA AND GLOMERULOSCLEROSIS, WHICH WERE SIGNIFICANTLY AMELIORATED BY LOW-DOSE HYDRALAZINE IN THE ABSENCE OF A BLOOD PRESSURE-LOWERING EFFECT. OBESITY INCREASED RENAL GLOBAL DNA METHYLATION AND THIS WAS ATTENUATED BY LOW-DOSE HYDRALAZINE. HFD-INDUCED CHANGES IN METHYLATION OF INDIVIDUAL LOCI WERE ALSO SIGNIFICANTLY REVERSED BY LOW-DOSE HYDRALAZINE. OBESE MICE DEMONSTRATED INCREASED MARKERS OF KIDNEY FIBROSIS, INFLAMMATION AND OXIDATIVE STRESS, BUT THESE MARKERS WERE NOT SIGNIFICANTLY IMPROVED BY HYDRALAZINE. CONCLUSION: LOW-DOSE HYDRALAZINE AMELIORATED HFD-INDUCED ALBUMINURIA AND GLOMERULOSCLEROSIS, INDEPENDENT OF ALTERATIONS IN BIOMETRIC AND METABOLIC VARIABLES OR BLOOD PRESSURE REGULATION. ALTHOUGH THE PRECISE MECHANISM OF RENOPROTECTION IN OBESITY IS UNCLEAR, AN EPIGENETIC BASIS MAY BE IMPLICATED. THESE DATA SUPPORT REPURPOSING HYDRALAZINE AS A NOVEL THERAPY TO PREVENT CKD PROGRESSION IN OBESE PATIENTS. 2022 20 3295 35 HIGH PHOSPHATE-INDUCED DOWNREGULATION OF PPARGAMMA CONTRIBUTES TO CKD-ASSOCIATED VASCULAR CALCIFICATION. MEDIAL ARTERIAL CALCIFICATION ASSOCIATED WITH HYPERPHOSPHATEMIA IS A MAIN CAUSE OF CARDIOVASCULAR MORTALITY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD), BUT THE MECHANISMS UNDERLYING HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION REMAIN LARGELY UNKNOWN. HERE, WE OBSERVED A SIGNIFICANT DECREASE IN THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) IN CALCIFIED ARTERIES BOTH IN CKD PATIENTS AND IN A MOUSE MODEL OF CKD WITH HYPERPHOSPHATEMIA. IN VITRO, HIGH PHOSPHATE TREATMENT LED TO A DECREASED EXPRESSION OF PPARGAMMA IN MOUSE VASCULAR SMOOTH MUSCLE CELLS (VMSCS), ACCOMPANIED BY APPARENT OSTEOGENIC DIFFERENTIATION AND CALCIFICATION. PRETREATMENT WITH PPARGAMMA AGONIST ROSIGLITAZONE SIGNIFICANTLY REVERSED HIGH PHOSPHATE-INDUCED VSMCS CALCIFICATION. FURTHER INVESTIGATION SHOWED THAT METHYL-CPG BINDING PROTEIN 2 (MECP2)-MEDIATED EPIGENETIC REPRESSION WAS INVOLVED IN HIGH PHOSPHATE-INDUCED PPARGAMMA DOWNREGULATION. MOREOVER, THE EXPRESSION OF KLOTHO THAT HAS THE ABILITY TO INHIBIT VASCULAR CALCIFICATION BY REGULATING PHOSPHATE UPTAKE DECREASED WITH THE PPARGAMMA REDUCTION IN VSMCS AFTER HIGH PHOSPHATE TREATMENT, AND ROSIGLITAZONE FAILED TO INHIBIT HIGH PHOSPHATE-INDUCED CALCIFICATION IN VSMCS WITH KNOCKDOWN OF KLOTHO OR IN AORTIC RINGS FROM KLOTHO-DEFICIENT (KL/KL) MICE. FINALLY, AN IN VIVO STUDY DEMONSTRATED THAT ORAL ADMINISTRATION OF ROSIGLITAZONE COULD INCREASE KLOTHO EXPRESSION AND PROTECT AGAINST HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION IN CKD MICE. THESE FINDINGS SUGGEST THAT THE INHIBITION OF PPARGAMMA EXPRESSION MAY CONTRIBUTE TO THE PATHOGENESIS OF HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION, WHICH MAY PROVIDE A NEW THERAPEUTIC TARGET FOR VASCULAR CALCIFICATION IN CKD PATIENTS. 2018