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 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 5 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 6 273 44 AGE-INDUCED SUPPRESSION OF EZH2 MEDIATES INJURY OF PODOCYTES BY REDUCING H3K27ME3. BACKGROUND: CHRONIC HYPERGLYCEMIA, A PIVOTAL FEATURE OF DIABETES MELLITUS (DM), INITIATES THE FORMATION OF ADVANCED GLYCATION END PRODUCTS (AGES) AND THE DYSREGULATION OF EPIGENETIC MECHANISMS, WHICH MAY CAUSE INJURY TO RENAL PODOCYTES, A CENTRAL FEATURE OF DIABETIC KIDNEY DISEASE (DKD). PREVIOUS DATA OF OUR GROUP SHOWED THAT AGES SIGNIFICANTLY REDUCE THE EXPRESSION OF NIPP1 (NUCLEAR INHIBITOR OF PROTEIN PHOSPHATASE 1) IN PODOCYTES IN VITRO AS WELL AS IN HUMAN AND MURINE DKD. NIPP1 WAS SHOWN BY OTHERS TO INTERACT WITH ENHANCER OF ZESTE HOMOLOG 2 (EZH2), WHICH CATALYZES THE REPRESSIVE METHYLATION OF H3K27ME3 ON HISTONE 3. THEREFORE, WE HYPOTHESIZED THAT AGES CAN DIRECTLY INDUCE EPIGENETIC CHANGES IN PODOCYTES. METHODS: WE ANALYZED THE RELEVANCE OF AGES ON EZH2 EXPRESSION AND ACTIVITY IN A MURINE PODOCYTE CELL LINE. CELLS WERE TREATED WITH 5 MG/ML GLYCATED BSA FOR 24 H. TO DETERMINE THE MEANING OF EZH2 SUPPRESSION, EZH2 ACTIVITY WAS INHIBITED BY INCUBATING THE CELLS WITH THE PHARMACOLOGICAL METHYLTRANSFERASE INHIBITOR 3-DEAZANEPLANOCIN A; EZH2 EXPRESSION WAS REPRESSED WITH SIRNA. MRNA EXPRESSION WAS ANALYZED WITH REAL-TIME PCR, AND PROTEIN EXPRESSION WITH WESTERN BLOT. EZH2 EXPRESSION AND LEVEL OF H3K27 TRIMETHYLATION IN PODOCYTES OF DIABETIC DB/DB MICE, A MOUSE MODEL FOR TYPE 2 DM, WERE ANALYZED USING IMMUNOFLUORESCENCE. RESULTS: OUR DATA DEMONSTRATED THAT AGES DECREASE EZH2 EXPRESSION IN PODOCYTES AND CONSEQUENTLY REDUCE H3K27ME3. THIS SUPPRESSION OF EZH2 MIMICKED THE AGE EFFECTS AND CAUSED AN UPREGULATED EXPRESSION OF PATHOLOGICAL FACTORS THAT CONTRIBUTE TO PODOCYTE INJURY IN DKD. IN ADDITION, ANALYSES OF DB/DB MICE SHOWED SIGNIFICANTLY REDUCED H3K27ME3 AND EZH2 EXPRESSION IN PODOCYTES. MOREOVER, THE SUPPRESSION OF NIPP1 AND EZH2 SHOWED SIMILAR EFFECTS REGARDING PODOCYTE INJURY. CONCLUSIONS: OUR STUDIES PROVIDE A NOVEL PATHWAY HOW AGES CONTRIBUTE TO PODOCYTE INJURY AND THE FORMATION OF THE SO-CALLED METABOLIC MEMORY IN DKD. 2020 7 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 8 3604 35 IMPROVEMENT OF PHYSICAL DECLINE THROUGH COMBINED EFFECTS OF MUSCLE ENHANCEMENT AND MITOCHONDRIAL ACTIVATION BY A GASTRIC HORMONE GHRELIN IN MALE 5/6NX CKD MODEL MICE. BECAUSE A PHYSICAL DECLINE CORRELATES WITH AN INCREASED RISK OF A WIDE RANGE OF DISEASE AND MORBIDITY, AN IMPROVEMENT OF PHYSICAL PERFORMANCE IS EXPECTED TO BRING SIGNIFICANT CLINICAL BENEFITS. THE PRIMARY CAUSE OF PHYSICAL DECLINE IN 5/6 NEPHRECTOMIZED (5/6NX) CHRONIC KIDNEY DISEASE MODEL MICE HAS BEEN REGARDED AS A DECREASE IN MUSCLE MASS; HOWEVER, OUR RECENT STUDY SHOWED THAT A DECREASE IN MUSCLE MITOCHONDRIA PLAYS A CRITICAL ROLE. IN THE PRESENT STUDY, WE EXAMINED THE EFFECTS OF A GASTRIC HORMONE GHRELIN, WHICH HAS BEEN REPORTED TO PROMOTE MUSCLE MITOCHONDRIAL OXIDATION, ON THE PHYSICAL DECLINE IN THE CHRONIC KIDNEY DISEASE MODEL MICE, FOCUSING ON THE EPIGENETIC MODULATIONS OF A MITOCHONDRIAL ACTIVATOR GENE, PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA). GHRELIN TREATMENT IMPROVED A DECLINE IN EXERCISE ENDURANCE OF 5/6NX MICE, ASSOCIATED WITH AN INCREASE IN BOTH OF THE MUSCLE MASS AND MITOCHONDRIAL AMOUNT. THE EXPRESSION LEVEL OF PGC-1ALPHA WAS DECREASED IN THE SKELETAL MUSCLE OF 5/6NX MICE, WHICH WAS ASSOCIATED WITH AN INCREASE IN THE METHYLATION RATIO OF THE CYTOSINE RESIDUE AT 260 BASE PAIRS UPSTREAM OF THE INITIATION POINT. CONVERSELY, GHRELIN TREATMENT DE-METHYLATED THE CYTOSINE RESIDUE AND INCREASED THE EXPRESSION OF PGC-1ALPHA. A REPRESENTATIVE MUSCLE ANABOLIC FACTOR, IGF-1, DID NOT AFFECT THE EXPRESSION OF PGC-1ALPHA AND MUSCLE MITOCHONDRIAL AMOUNT, ALTHOUGH IT INCREASED MUSCLE MASS. AS A RESULT, IGF-1 TREATMENT IN 5/6NX MICE DID NOT INCREASE THE DECREASED EXERCISE ENDURANCE AS EFFECTIVELY AS GHRELIN TREATMENT DID. THESE FINDINGS INDICATE AN ADVANTAGE OF GHRELIN TREATMENT FOR A RECOVERY OF PHYSICAL DECLINE. 2015 9 5305 42 PROTEOMICS ANALYSIS OF HUMAN OBESITY REVEALS THE EPIGENETIC FACTOR HDAC4 AS A POTENTIAL TARGET FOR OBESITY. SEDENTARY LIFESTYLE AND EXCESSIVE ENERGY INTAKE ARE PROMINENT CONTRIBUTORS TO OBESITY; A MAJOR RISK FACTORS FOR THE DEVELOPMENT OF INSULIN RESISTANCE, TYPE 2 DIABETES AND CARDIOVASCULAR DISEASES. ELUCIDATING THE MOLECULAR MECHANISMS UNDERLYING THESE CHRONIC CONDITIONS IS OF RELEVANT IMPORTANCE AS IT MIGHT LEAD TO THE IDENTIFICATION OF NOVEL ANTI-OBESITY TARGETS. THE PURPOSE OF THE CURRENT STUDY IS TO INVESTIGATE DIFFERENTIALLY EXPRESSED PROTEINS BETWEEN LEAN AND OBESE SUBJECTS THROUGH A SHOT-GUN QUANTITATIVE PROTEOMICS APPROACH USING PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) EXTRACTS AS WELL AS POTENTIAL MODULATION OF THOSE PROTEINS BY PHYSICAL EXERCISE. USING THIS APPROACH, A TOTAL OF 47 PROTEINS SHOWED AT LEAST 1.5 FOLD CHANGE BETWEEN LEAN AND OBESE SUBJECTS. IN OBESE, THE PROTEOMIC PROFILING BEFORE AND AFTER 3 MONTHS OF PHYSICAL EXERCISE SHOWED DIFFERENTIAL EXPRESSION OF 38 PROTEINS. THROMBOSPONDIN 1 (TSP1) WAS AMONG THE PROTEINS THAT WERE UPREGULATED IN OBESE SUBJECTS AND THEN DECREASED BY PHYSICAL EXERCISE. CONVERSELY, THE HISTONE DEACETYLASE 4 (HDAC4) WAS DOWNREGULATED IN OBESE SUBJECTS AND THEN INDUCED BY PHYSICAL EXERCISE. THE PROTEOMIC DATA WAS FURTHER VALIDATED BY QRT-PCR, WESTERN BLOT AND IMMUNOHISTOCHEMISTRY IN BOTH PBMCS AND ADIPOSE TISSUE. WE ALSO SHOWED THAT HDAC4 LEVELS CORRELATED POSITIVELY WITH MAXIMUM OXYGEN CONSUMPTION (VO2 MAX) BUT NEGATIVELY WITH BODY MASS INDEX, PERCENT BODY FAT, AND THE INFLAMMATORY CHEMOKINE RANTES. IN FUNCTIONAL ASSAYS, OUR DATA INDICATED THAT ECTOPIC EXPRESSION OF HDAC4 SIGNIFICANTLY IMPAIRED TNF-ALPHA-DEPENDENT ACTIVATION OF NF-KAPPAB, ESTABLISHING THUS A LINK BETWEEN HDAC4 AND REGULATION OF THE IMMUNE SYSTEM. TOGETHER, THE EXPRESSION PATTERN OF HDAC4 IN OBESE SUBJECTS BEFORE AND AFTER PHYSICAL EXERCISE, ITS CORRELATION WITH VARIOUS PHYSICAL, CLINICAL AND METABOLIC PARAMETERS ALONG WITH ITS INHIBITORY EFFECT ON NF-KAPPAB ARE SUGGESTIVE OF A PROTECTIVE ROLE OF HDAC4 AGAINST OBESITY. HDAC4 COULD THEREFORE REPRESENT A POTENTIAL THERAPEUTIC TARGET FOR THE CONTROL AND MANAGEMENT OF OBESITY AND PRESUMABLY INSULIN RESISTANCE. 2013 10 5710 29 SIRT1 DEFICIENCY IN MICROGLIA CONTRIBUTES TO COGNITIVE DECLINE IN AGING AND NEURODEGENERATION VIA EPIGENETIC REGULATION OF IL-1BETA. AGING IS THE PREDOMINANT RISK FACTOR FOR NEURODEGENERATIVE DISEASES. ONE KEY PHENOTYPE AS THE BRAIN AGES IS AN ABERRANT INNATE IMMUNE RESPONSE CHARACTERIZED BY PROINFLAMMATION. HOWEVER, THE MOLECULAR MECHANISMS UNDERLYING AGING-ASSOCIATED PROINFLAMMATION ARE POORLY DEFINED. WHETHER CHRONIC INFLAMMATION PLAYS A CAUSAL ROLE IN COGNITIVE DECLINE IN AGING AND NEURODEGENERATION HAS NOT BEEN ESTABLISHED. HERE WE REPORT A MECHANISTIC LINK BETWEEN CHRONIC INFLAMMATION AND AGING MICROGLIA AND A CAUSAL ROLE OF AGING MICROGLIA IN NEURODEGENERATIVE COGNITIVE DEFICITS. WE SHOWED THAT SIRT1 IS REDUCED WITH THE AGING OF MICROGLIA AND THAT MICROGLIAL SIRT1 DEFICIENCY HAS A CAUSATIVE ROLE IN AGING- OR TAU-MEDIATED MEMORY DEFICITS VIA IL-1BETA UPREGULATION IN MICE. INTERESTINGLY, THE SELECTIVE ACTIVATION OF IL-1BETA TRANSCRIPTION BY SIRT1 DEFICIENCY IS LIKELY MEDIATED THROUGH HYPOMETHYLATING THE SPECIFIC CPG SITES ON IL-1BETA PROXIMAL PROMOTER. IN HUMANS, HYPOMETHYLATION OF IL-1BETA IS STRONGLY ASSOCIATED WITH CHRONOLOGICAL AGE AND WITH ELEVATED IL-1BETA TRANSCRIPTION. OUR FINDINGS REVEAL A NOVEL EPIGENETIC MECHANISM IN AGING MICROGLIA THAT CONTRIBUTES TO COGNITIVE DEFICITS IN AGING AND NEURODEGENERATIVE DISEASES. 2015 11 719 43 CALORIE RESTRICTION-REGULATED MOLECULAR PATHWAYS AND ITS IMPACT ON VARIOUS AGE GROUPS: AN OVERVIEW. CALORIE RESTRICTION (CR) IF PLANNED PROPERLY WITH REGULAR EXERCISE AT DIFFERENT AGES CAN RESULT IN HEALTHY WEIGHT LOSS. CR CAN ALSO HAVE DIFFERENT BENEFICIAL EFFECTS ON IMPROVING LIFESPAN AND DECREASING THE AGE-ASSOCIATED DISEASES BY REGULATING PHYSIOLOGICAL, BIOCHEMICAL, AND MOLECULAR MARKERS. THE DIFFERENT PATHWAYS REGULATED BY CR INCLUDE:(1) AMP-ACTIVATED PROTEIN KINASE (AMPK), WHICH INVOLVES PGC-1ALPHA, SIRT1, AND SIRT3. AMPK ALSO EFFECTS MYOCYTE ENHANCER FACTOR 2 (MEF2), PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR DELTA, AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA, WHICH ARE INVOLVED IN MITOCHONDRIAL BIOGENESIS AND LIPID OXIDATION; (2) FORKHEAD BOX TRANSCRIPTION FACTOR'S SIGNALING IS RELATED TO THE DNA REPAIR, LIPID METABOLISM, PROTECTION OF PROTEIN STRUCTURE, AUTOPHAGY, AND RESISTANCE TO OXIDATIVE STRESS; (3) MAMMALIAN TARGET OF RAPAMYCIN (MTOR) SIGNALING, WHICH INVOLVES KEY FACTORS, SUCH AS S6 PROTEIN KINASE-1 (S6K1), MTOR COMPLEX-1 (MTORC1), AND 4E-BINDING PROTEIN (4E-BP). UNDER CR CONDITIONS, AMPK ACTIVATION AND MTOR INHIBITION HELPS IN THE ACTIVATION OF ULK1 COMPLEX ALONG WITH THE ACETYLTRANSFERASE MEC-17, WHICH IS NECESSARY FOR AUTOPHAGY; (4) INSULIN-LIKE GROWTH FACTOR-1 (IGF-1) PATHWAY DOWNREGULATION PROTECTS AGAINST CANCER AND SLOWS THE AGING PROCESS; (5) NUCLEAR FACTOR KAPPA B PATHWAY DOWNREGULATION DECREASES THE INFLAMMATION; AND (6) C-JUN N-TERMINAL KINASE AND P38 KINASE REGULATION AS A RESPONSE TO THE STRESS. THE ACUTE AND CHRONIC CR BOTH SHOWS ANTIDEPRESSION AND ANXIOLYTIC ACTION BY EFFECTING GHRELIN/GHS-R1A SIGNALING. CR ALSO REGULATES GSK3BETA KINASE AND PROTECTS AGAINST AGE-RELATED BRAIN ATROPHY. CR AT YOUNG AGE MAY SHOW MANY DELETERIOUS EFFECTS BY EFFECTING DIFFERENT MECHANISMS. PARENTAL CR BEFORE OR DURING CONCEPTION WILL ALSO AFFECT THE HEALTH AND DEVELOPMENT OF THE OFFSPRING BY CAUSING MANY EPIGENETIC MODIFICATIONS THAT SHOW TRANSGENERATIONAL TRANSMISSION. MATERNAL CR IS ASSOCIATED WITH INTRAUTERINE GROWTH RETARDATION EFFECTING THE OFFSPRING IN THEIR ADULTHOOD BY DEVELOPING DIFFERENT METABOLIC SYNDROMES. THE EPIGENETIC CHANGES WITH RESPONSE TO PATERNAL FOOD SUPPLY ALSO LINKED TO OFFSPRING HEALTH. CR AT MIDDLE AND OLD AGE PROVIDES A SIGNIFICANT PREVENTIVE IMPACT AGAINST THE DEVELOPMENT OF AGE-ASSOCIATED DISEASES. 2022 12 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 13 4974 29 PATHOPHYSIOLOGICAL MECHANISMS LEADING TO MUSCLE LOSS IN CHRONIC KIDNEY DISEASE. LOSS OF MUSCLE PROTEINS IS A DELETERIOUS CONSEQUENCE OF CHRONIC KIDNEY DISEASE (CKD) THAT CAUSES A DECREASE IN MUSCLE STRENGTH AND FUNCTION, AND CAN LEAD TO A REDUCTION IN QUALITY OF LIFE AND INCREASED RISK OF MORBIDITY AND MORTALITY. THE EFFECTIVENESS OF CURRENT TREATMENT STRATEGIES IN PREVENTING OR REVERSING MUSCLE PROTEIN LOSSES IS LIMITED. THE LIMITATIONS LARGELY STEM FROM THE SYSTEMIC NATURE OF DISEASES SUCH AS CKD, WHICH STIMULATE SKELETAL MUSCLE PROTEIN DEGRADATION PATHWAYS WHILE SIMULTANEOUSLY ACTIVATING MECHANISMS THAT IMPAIR MUSCLE PROTEIN SYNTHESIS AND REPAIR. STIMULI THAT INITIATE MUSCLE PROTEIN LOSS INCLUDE METABOLIC ACIDOSIS, INSULIN AND IGF1 RESISTANCE, CHANGES IN HORMONES, CYTOKINES, INFLAMMATORY PROCESSES AND DECREASED APPETITE. A GROWING BODY OF EVIDENCE SUGGESTS THAT SIGNALLING MOLECULES SECRETED FROM MUSCLE CAN ENTER THE CIRCULATION AND SUBSEQUENTLY INTERACT WITH RECIPIENT ORGANS, INCLUDING THE KIDNEYS, WHILE CONVERSELY, PATHOLOGICAL EVENTS IN THE KIDNEY CAN ADVERSELY INFLUENCE PROTEIN METABOLISM IN SKELETAL MUSCLE, DEMONSTRATING THE EXISTENCE OF CROSSTALK BETWEEN KIDNEY AND MUSCLE. TOGETHER, THESE SIGNALS, WHETHER DIRECT OR INDIRECT, INDUCE CHANGES IN THE LEVELS OF REGULATORY AND EFFECTOR PROTEINS VIA ALTERATIONS IN MRNAS, MICRORNAS AND CHROMATIN EPIGENETIC RESPONSES. ADVANCES IN OUR UNDERSTANDING OF THE SIGNALS AND PROCESSES THAT MEDIATE MUSCLE LOSS IN CKD AND OTHER MUSCLE WASTING CONDITIONS WILL SUPPORT THE FUTURE DEVELOPMENT OF THERAPEUTIC STRATEGIES TO REDUCE MUSCLE LOSS. 2022 14 1900 30 ENERGY SENSING PATHWAYS: BRIDGING TYPE 2 DIABETES AND COLORECTAL CANCER? THE RECENTLY RAPID INCREASE OF OBESITY AND TYPE 2 DIABETES MELLITUS HAS CAUSED GREAT BURDEN TO OUR SOCIETY. A POSITIVE ASSOCIATION BETWEEN TYPE 2 DIABETES AND RISK OF COLORECTAL CANCER HAS BEEN REPORTED BY INCREASING EPIDEMIOLOGICAL STUDIES. THE MOLECULAR MECHANISM OF THIS CONNECTION REMAINS ELUSIVE. HOWEVER, TYPE 2 DIABETES MAY RESULT IN ABNORMAL CARBOHYDRATE AND LIPID METABOLISM, HIGH LEVELS OF CIRCULATING INSULIN, INSULIN GROWTH FACTOR-1, AND ADIPOCYTOKINES, AS WELL AS CHRONIC INFLAMMATION. ALL THESE FACTORS COULD LEAD TO THE ALTERATION OF ENERGY SENSING PATHWAYS SUCH AS THE AMP ACTIVATED KINASE (PRKA), MECHANISTIC (MAMMALIAN) TARGET OF RAPAMYCIN (MTOR), SIRT1, AND AUTOPHAGY SIGNALING PATHWAYS. THE RESULTED IMPAIRED SIRT1 AND AUTOPHAGY SIGNALING PATHWAY COULD INCREASE THE RISK OF GENE MUTATION AND CANCER GENESIS BY DECREASING GENETIC STABILITY AND DNA MISMATCH REPAIR. THE DYSREGULATED MTOR AND PRKA PATHWAY COULD REMODEL CELL METABOLISM DURING THE GROWTH AND METASTASIS OF CANCER IN ORDER FOR THE CANCER CELL TO SURVIVE THE UNFAVORABLE MICROENVIRONMENT SUCH AS HYPOXIA AND LOW BLOOD SUPPLY. MOREOVER, THESE PATHWAYS MAY BE COUPLING METABOLIC AND EPIGENETIC ALTERATIONS THAT ARE CENTRAL TO ONCOGENIC TRANSFORMATION. FURTHER RESEARCHES INCLUDING MOLECULAR PATHOLOGIC EPIDEMIOLOGIC STUDIES ARE WARRANTED TO BETTER ADDRESS THE PRECISE LINKS BETWEEN THESE TWO IMPORTANT DISEASES. 2017 15 133 37 AAV-MEDIATED EXPRESSION OF SECRETED AND TRANSMEMBRANE ALPHAKLOTHO ISOFORMS RESCUES RELEVANT AGING HALLMARKS IN SENESCENT SAMP8 MICE. SENESCENCE REPRESENTS A STAGE IN LIFE ASSOCIATED WITH ELEVATED INCIDENCE OF MORBIDITY AND INCREASED RISK OF MORTALITY DUE TO THE ACCUMULATION OF MOLECULAR ALTERATIONS AND TISSUE DYSFUNCTION, PROMOTING A DECREASE IN THE ORGANISM'S PROTECTIVE SYSTEMS. THUS, AGING PRESENTS MOLECULAR AND BIOLOGICAL HALLMARKS, WHICH INCLUDE CHRONIC INFLAMMATION, EPIGENETIC ALTERATIONS, NEURONAL DYSFUNCTION, AND WORSENING OF PHYSICAL STATUS. IN THIS CONTEXT, WE EXPLORED THE AAV9-MEDIATED EXPRESSION OF THE TWO MAIN ISOFORMS OF THE AGING-PROTECTIVE FACTOR KLOTHO (KL) AS A STRATEGY TO PREVENT THESE GENERAL AGE-RELATED FEATURES USING THE SENESCENCE-ACCELERATED MOUSE PRONE 8 (SAMP8) MODEL. BOTH SECRETED AND TRANSMEMBRANE KL ISOFORMS IMPROVED COGNITIVE PERFORMANCE, PHYSICAL STATE PARAMETERS, AND DIFFERENT MOLECULAR VARIABLES ASSOCIATED WITH AGING. EPIGENETIC LANDSCAPE WAS RECOVERED FOR THE ANALYZED GLOBAL MARKERS DNA METHYLATION (5-MC), HYDROXYMETHYLATION (5-HMC), AND RESTORATION OCCURRED IN THE ACETYLATION LEVELS OF H3 AND H4. GENE EXPRESSION OF PRO- AND ANTI-INFLAMMATORY MEDIATORS IN CENTRAL NERVOUS SYSTEM SUCH AS TNF-ALPHA AND IL-10, RESPECTIVELY, HAD IMPROVED LEVELS, WHICH WERE COMPARABLE TO THE SENESCENCE-ACCELERATED-MOUSE RESISTANT 1 (SAMR1) HEALTHY CONTROL. ADDITIONALLY, THIS IMPROVEMENT IN NEUROINFLAMMATION WAS SUPPORTED BY CHANGES IN THE HISTOLOGICAL MARKERS IBA1, GFAP, AND SA BETA-GAL. FURTHERMORE, BONE TISSUE STRUCTURAL VARIABLES, ESPECIALLY ALTERED DURING SENESCENCE, RECOVERED IN SAMP8 MICE TO SAMR1 CONTROL VALUES AFTER TREATMENT WITH BOTH KL ISOFORMS. THIS WORK PRESENTS EVIDENCE OF THE BENEFICIAL PLEIOTROPIC ROLE OF KLOTHO AS AN ANTI-AGING THERAPY AS WELL AS NEW SPECIFIC FUNCTIONS OF THE KL ISOFORMS FOR THE EPIGENETIC REGULATION AND AGED BONE STRUCTURE ALTERATION IN AN AGING MOUSE MODEL. 2022 16 5438 24 REMOVAL OF EPIGENETIC REPRESSIVE MARK ON INFLAMMATORY GENES IN FAT LIVER. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE MOST COMMON CHRONIC LIVER DISEASE WORLDWIDE. THE DETAILED EPIGENOMIC CHANGES DURING FAT ACCUMULATION IN LIVER ARE NOT CLEAR YET. HERE, WE PERFORMED CHIP-SEQ ANALYSIS IN THE LIVER TISSUES OF HIGH-FAT DIET AND REGULAR CHOW DIET MICE AND INVESTIGATED THE DYNAMIC LANDSCAPES OF H3K27AC AND H3K9ME3 MARKS ON CHROMATIN. WE FIND THAT THE ACTIVATED TYPICAL ENHANCERS MARKED WITH H3K27AC ARE ENRICHED ON LIPID METABOLIC PATHWAYS IN FAT LIVER; HOWEVER, SUPER ENHANCERS DO NOT CHANGE MUCH. THE REGIONS COVERED WITH H3K9ME3 REPRESSIVE MARK SEEM TO UNDERGO GREAT CHANGES, AND ITS PEAK NUMBER AND INTENSITY BOTH DECREASE IN FAT LIVER. THE ENHANCERS LOCATED IN LOST H3K9ME3 REGIONS ARE ENRICHED IN LIPID METABOLISM AND INFLAMMATORY PATHWAYS; AND MOTIF ANALYSIS SHOWS THAT THEY ARE POTENTIAL TARGETS FOR TRANSCRIPTION FACTORS INVOLVED IN METABOLIC AND INFLAMMATORY PROCESSES. OUR STUDY HAS REVEALED THAT H3K9ME3 MAY PLAY AN IMPORTANT ROLE DURING THE PATHOGENESIS OF NAFLD THROUGH REGULATING THE ACCESSIBILITY OF ENHANCERS. 2023 17 476 38 ARSENIC INDUCES FIBROGENIC CHANGES IN HUMAN KIDNEY EPITHELIAL CELLS POTENTIALLY THROUGH EPIGENETIC ALTERATIONS IN DNA METHYLATION. ARSENIC CONTAMINATION IS A SIGNIFICANT PUBLIC HEALTH ISSUE, AND KIDNEY IS ONE OF THE TARGET ORGAN FOR ARSENIC-INDUCED ADVERSE EFFECTS. RENAL FIBROSIS IS A WELL-KNOWN PATHOLOGICAL STAGE FREQUENTLY OBSERVED IN PROGRESSIVE CHRONIC KIDNEY DISEASE (CKD). EPIDEMIOLOGICAL STUDIES IMPLICATE ARSENIC EXPOSURE TO CKD, BUT THE ROLE OF ARSENIC IN KIDNEY FIBROSIS AND THE UNDERLYING MECHANISM IS STILL UNCLEAR. IT IS IN THIS CONTEXT THAT THE CURRENT STUDY EVALUATED THE EFFECTS OF LONG-TERM ARSENIC EXPOSURE ON THE CELLULAR RESPONSE IN MORPHOLOGY, AND MARKER GENES EXPRESSION WITH RESPECT TO FIBROSIS USING HUMAN KIDNEY 2 (HK-2) EPITHELIAL CELLS. RESULTS OF THIS STUDY REVEALED THAT IN ADDITION TO INCREASED GROWTH, HK-2 CELLS UNDERWENT PHENOTYPIC, BIOCHEMICAL AND MOLECULAR CHANGES INDICATIVE OF EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IN RESPONSE TO THE EXPOSURE TO ARSENIC. MOST IMPORTANTLY, THE ARSENIC-EXPOSED CELLS ACQUIRED THE PATHOGENIC FEATURES OF FIBROSIS AS SUPPORTED BY INCREASED EXPRESSION OF MARKERS FOR FIBROSIS, SUCH AS COLLAGEN I, FIBRONECTIN, TRANSFORMING GROWTH FACTOR BETA, AND ALPHA-SMOOTH MUSCLE ACTIN. UPREGULATION OF FIBROSIS ASSOCIATED SIGNALING MOLECULES SUCH AS TISSUE INHIBITOR OF METALLOPROTEINASES-3 AND MATRIX METALLOPROTEINASE-2 AS WELL AS ACTIVATION OF AKT WAS ALSO OBSERVED. ADDITIONALLY, THE EXPRESSION OF EPIGENETIC GENES (DNA METHYLTRANSFERASES 3A AND 3B; METHYL-CPG BINDING DOMAIN 4) WAS INCREASED IN ARSENIC-EXPOSED CELLS. TREATMENT WITH DNA METHYLATION INHIBITOR 5-AZA-2'-DC REVERSED THE EMT PROPERTIES AND RESTORED THE LEVEL OF PHOSPHO-AKT. TOGETHER, THESE DATA FOR THE FIRST TIME SUGGEST THAT LONG-TERM EXPOSURE TO ARSENIC CAN INCREASE THE RISK OF KIDNEY FIBROSIS. ADDITIONALLY, OUR DATA SUGGEST THAT THE ARSENIC-INDUCED FIBROTIC CHANGES ARE, AT LEAST IN PART, MEDIATED BY DNA METHYLATION AND THEREFORE POTENTIALLY CAN BE REVERSED BY EPIGENETIC THERAPEUTICS. 2019 18 4702 25 NICOTINE-INDUCED OXIDATIVE STRESS CONTRIBUTES TO EMT AND STEMNESS DURING NEOPLASTIC TRANSFORMATION THROUGH EPIGENETIC MODIFICATIONS IN HUMAN KIDNEY EPITHELIAL CELLS. NICOTINE IS A COMPONENT OF CIGARETTE SMOKE AND MOUNTING EVIDENCE SUGGESTS TOXICITY AND CARCINOGENICITY OF TOBACCO SMOKE IN KIDNEY. CARCINOGENICITY OF NICOTINE ITSELF IN KIDNEY AND THE UNDERLYING MOLECULAR MECHANISMS ARE NOT WELL-UNDERSTOOD. HENCE, THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE THE CARCINOGENIC EFFECTS OF CHRONIC NICOTINE EXPOSURE IN HK-2 HUMAN KIDNEY EPITHELIAL CELLS. THE EFFECTS OF NICOTINE EXPOSURE ON THE EXPRESSION OF GENES FOR CELLULAR REPROGRAMMING, REDOX STATUS, AND GROWTH SIGNALING PATHWAYS WERE ALSO EVALUATED TO UNDERSTAND THE MOLECULAR MECHANISMS. RESULTS REVEALED THAT CHRONIC EXPOSURE TO NICOTINE INDUCED GROWTH AND NEOPLASTIC TRANSFORMATION IN HK-2 CELLS. INCREASED LEVELS OF INTRACELLULAR REACTIVE OXYGEN SPECIES (ROS), ACQUIRED STEM CELL-LIKE SPHERE FORMATION, AND EPITHELIAL-MESENCHYMAL-TRANSITION (EMT) CHANGES WERE OBSERVED IN NICOTINE EXPOSED CELLS. TREATMENT WITH ANTIOXIDANT N-ACETYL CYSTEINE (NAC) RESULTED IN ABROGATION OF EMT AND STEMNESS IN HK-2 CELLS, INDICATING THE ROLE OF NICOTINE-INDUCED ROS IN THESE MORPHOLOGICAL CHANGES. THE RESULT ALSO SUGGESTS THAT ROS CONTROLS THE STEMNESS THROUGH REGULATION OF AKT PATHWAY DURING EARLY STAGES OF CARCINOGENESIS. ADDITIONALLY, THE EXPRESSION OF EPIGENETIC REGULATORY GENES WAS ALTERED IN NICOTINE-EXPOSED CELLS AND THE CHANGES WERE REVERSED BY NAC. THE EPIGENETIC THERAPEUTICS 5-AZA-2'-DEOXYCYTIDINE AND TRICHOSTATIN A ALSO ABROGATED THE STEMNESS. THIS SUGGESTS THE NICOTINE-INDUCED OXIDATIVE STRESS CAUSED EPIGENETIC ALTERATIONS CONTRIBUTING TO STEMNESS DURING NEOPLASTIC TRANSFORMATION. TO OUR KNOWLEDGE, THIS IS THE FIRST REPORT SHOWING THE ROS-MEDIATED EPIGENETIC MODIFICATIONS AS THE UNDERLYING MECHANISM FOR CARCINOGENICITY OF NICOTINE IN HUMAN KIDNEY EPITHELIAL CELLS. THIS STUDY FURTHER SUGGESTS THE POTENTIAL OF EPIGENETIC THERAPEUTICS FOR PHARMACOLOGICAL INTERVENTION IN NICOTINE-INDUCED KIDNEY CANCER. 2019 19 6564 26 TRANSIENT EXPOSURE TO ELEVATED GLUCOSE LEVELS CAUSES PERSISTENT CHANGES IN DERMAL MICROVASCULAR ENDOTHELIAL CELL RESPONSES TO INJURY. BACKGROUND: THE PURPOSE OF THIS STUDY WAS TO DETERMINE WHETHER ELEVATED GLUCOSE CAN INDUCE A DERMAL MICROVASCULAR ENDOTHELIAL CELL METABOLIC MEMORY, THUS AFFECTING ANGIOGENESIS IN THE REPAIR PROCESS OF MAMMALIAN CUTANEOUS WOUND. WE HYPOTHESIZED THAT TRANSIENT ELEVATED GLUCOSE LEVELS CAUSE SUSTAINED ALTERATION OF ENDOTHELIAL CELL RESPONSES TO INJURY AND PERSISTENT EPIGENETIC CHANGES IN GENE EXPRESSION. METHODS: HUMAN DERMAL MICROVASCULAR ENDOTHELIAL CELLS WERE EXPOSED TO EXPERIMENTAL CONDITIONS WITH OR WITHOUT 30 MM D-GLUCOSE. THE CONTROL GROUP WAS MAINTAINED AT 5 MM D-GLUCOSE; WHILE IN THE TRANSIENT GLUCOSE GROUP, AFTER BEING EXPOSED TO 30 MM D-GLUCOSE FOR TWO DAYS, THEN BEING PUT UNDER THE CONTROL CONDITIONS DURING THE EXPERIMENT. BESIDES, IN THE WHOLE PROCESS OF THE EXPERIMENT, THE CHRONIC GLUCOSE GROUP WAS KEPT IN THE CONDITION WITH 30 MM D-GLUCOSE. PROLIFERATION, MIGRATION, TUBE FORMATION, GENE EXPRESSION AND HISTONE METHYLATION WERE ASSESSED FOR INDIVIDUAL CONDITIONS. RESULTS: TRANSIENT ELEVATED GLUCOSE CAUSED SUSTAINED EFFECTS ON ENDOTHELIAL CELL MIGRATION, TUBE FORMATION AND TIMP3 GENE EXPRESSION. THE EFFECTS ON TIMP3 EXPRESSION WERE ASSOCIATED WITH PERSISTENT CHANGES IN HISTONE MODIFICATION AT THE 5' END OF THE TIMP3 GENE, SUGGESTING AN EPIGENETIC EFFECT. CONCLUSIONS: HYPERGLYCEMIA INDUCED METABOLIC MEMORY COULD PROMOTE THE REGULATION OF TIMP3, AND IT CAN BE USED AS A POSSIBLE INNOVATIVE MOLECULAR TARGET FOR THERAPEUTIC INTERVENTION IN THE TREATMENT OF CHRONIC NON-HEALING DIABETIC WOUNDS. 2021 20 3643 32 INCREASED INFLAMMATORY RESPONSE IN AGED MICE IS ASSOCIATED WITH AGE-RELATED ZINC DEFICIENCY AND ZINC TRANSPORTER DYSREGULATION. AGING IS A COMPLEX PROCESS ASSOCIATED WITH PHYSIOLOGICAL CHANGES IN NUMEROUS ORGAN SYSTEMS. IN PARTICULAR, AGING OF THE IMMUNE SYSTEM IS CHARACTERIZED BY PROGRESSIVE DYSREGULATION OF IMMUNE RESPONSES, RESULTING IN INCREASED SUSCEPTIBILITY TO INFECTIOUS DISEASES, IMPAIRED VACCINATION EFFICACY AND SYSTEMIC LOW-GRADE CHRONIC INFLAMMATION. INCREASING EVIDENCE SUGGEST THAT INTRACELLULAR ZINC HOMEOSTASIS, REGULATED BY ZINC TRANSPORTER EXPRESSION, IS CRITICALLY INVOLVED IN THE SIGNALING AND ACTIVATION OF IMMUNE CELLS. WE HYPOTHESIZE THAT EPIGENETIC ALTERATIONS AND NUTRITIONAL DEFICITS ASSOCIATED WITH AGING MAY LEAD TO ZINC TRANSPORTER DYSREGULATION, RESULTING IN DECREASES IN CELLULAR ZINC LEVELS AND ENHANCED INFLAMMATION WITH AGE. THE GOAL OF THIS STUDY WAS TO EXAMINE THE CONTRIBUTION OF AGE-RELATED ZINC DEFICIENCY AND ZINC TRANSPORTER DYSREGULATION ON THE INFLAMMATORY RESPONSE IN IMMUNE CELLS. THE EFFECTS OF ZINC DEFICIENCY AND AGE ON THE INDUCTION OF INFLAMMATORY RESPONSES WERE DETERMINED USING AN IN VITRO CELL CULTURE SYSTEM AND AN AGED MOUSE MODEL. WE SHOWED THAT ZINC DEFICIENCY, PARTICULARLY THE REDUCTION IN INTRACELLULAR ZINC IN IMMUNE CELLS, WAS ASSOCIATED WITH INCREASED INFLAMMATION WITH AGE. FURTHERMORE, REDUCED ZIP 6 EXPRESSION ENHANCED PROINFLAMMATORY RESPONSE, AND AGE-SPECIFIC ZIP 6 DYSREGULATION CORRELATED WITH AN INCREASE IN ZIP 6 PROMOTER METHYLATION. FURTHERMORE, RESTORING ZINC STATUS VIA DIETARY SUPPLEMENTATION REDUCED AGED-ASSOCIATED INFLAMMATION. OUR DATA SUGGESTED THAT AGE-RELATED EPIGENETIC DYSREGULATION IN ZINC TRANSPORTER EXPRESSION MAY INFLUENCE CELLULAR ZINC LEVELS AND CONTRIBUTE TO INCREASED SUSCEPTIBILITY TO INFLAMMATION WITH AGE. 2013