1 4577 112 MYOSTATIN: BASIC BIOLOGY TO CLINICAL APPLICATION. MYOSTATIN IS A MEMBER OF THE TRANSFORMING GROWTH FACTOR (TGF)-BETA SUPERFAMILY. IT IS EXPRESSED BY ANIMAL AND HUMAN SKELETAL MUSCLE CELLS WHERE IT LIMITS MUSCLE GROWTH AND PROMOTES PROTEIN BREAKDOWN. ITS EFFECTS ARE INFLUENCED BY COMPLEX MECHANISMS INCLUDING TRANSCRIPTIONAL AND EPIGENETIC REGULATION AND MODULATION BY EXTRACELLULAR BINDING PROTEINS. DUE TO ITS ACTIONS IN PROMOTING MUSCLE ATROPHY AND CACHEXIA, MYOSTATIN HAS BEEN INVESTIGATED AS A PROMISING THERAPEUTIC TARGET TO COUNTERACT MUSCLE MASS LOSS IN EXPERIMENTAL MODELS AND PATIENTS AFFECTED BY DIFFERENT MUSCLE-WASTING CONDITIONS. MOREOVER, GROWING EVIDENCE INDICATES THAT MYOSTATIN, BEYOND TO REGULATE SKELETAL MUSCLE GROWTH, MAY HAVE A ROLE IN MANY PHYSIOLOGIC AND PATHOLOGIC PROCESSES, SUCH AS OBESITY, INSULIN RESISTANCE, CARDIOVASCULAR AND CHRONIC KIDNEY DISEASE. IN THIS CHAPTER, WE REVIEW MYOSTATIN BIOLOGY, INCLUDING INTRACELLULAR AND EXTRACELLULAR REGULATORY PATHWAYS, AND THE ROLE OF MYOSTATIN IN MODULATING PHYSIOLOGIC PROCESSES, SUCH AS MUSCLE GROWTH AND AGING. MOREOVER, WE DISCUSS THE MOST RELEVANT EXPERIMENTAL AND CLINICAL EVIDENCE SUPPORTING THE EXTRA-MUSCLE EFFECTS OF MYOSTATIN. FINALLY, WE CONSIDER THE MAIN STRATEGIES DEVELOPED AND TESTED TO INHIBIT MYOSTATIN IN CLINICAL TRIALS AND DISCUSS THE LIMITS AND FUTURE PERSPECTIVES OF THE RESEARCH ON MYOSTATIN. 2022 2 5334 33 QUADRICEPS MUSCLE WEAKNESS AND ATROPHY ARE ASSOCIATED WITH A DIFFERENTIAL EPIGENETIC PROFILE IN ADVANCED COPD. EPIGENETIC MECHANISMS REGULATE MUSCLE MASS AND FUNCTION IN MODELS OF MUSCLE DYSFUNCTION AND ATROPHY. WE ASSESSED WHETHER QUADRICEPS MUSCLE WEAKNESS AND ATROPHY ARE ASSOCIATED WITH A DIFFERENTIAL EXPRESSION PROFILE OF EPIGENETIC EVENTS IN PATIENTS WITH ADVANCED COPD (CHRONIC OBSTRUCTIVE PULMONARY DISEASE). IN VASTUS LATERALIS (VL) OF SEDENTARY SEVERE COPD PATIENTS (N=41), WHO WERE FURTHER SUBDIVIDED INTO THOSE WITH (N=25) AND WITHOUT (N=16) MUSCLE WEAKNESS AND HEALTHY CONTROLS (N=19), EXPRESSION OF MUSCLE-ENRICHED MIRNAS, HISTONE ACETYLTRANSFERASES (HATS) AND DEACETYLASES (HDACS), GROWTH AND ATROPHY SIGNALLING MARKERS, TOTAL PROTEIN AND HISTONE ACETYLATION, TRANSCRIPTION FACTORS, SMALL UBIQUITIN-RELATED MODIFIER (SUMO) LIGASES AND MUSCLE STRUCTURE WERE EXPLORED. ALL SUBJECTS WERE CLINICALLY EVALUATED. COMPARED WITH CONTROLS, IN VL OF ALL COPD TOGETHER AND IN MUSCLE-WEAKNESS PATIENTS, EXPRESSION OF MIR-1, MIR-206 AND MIR-27A, LEVELS OF LYSINE-ACETYLATED PROTEINS AND HISTONES AND ACETYLATED HISTONE 3 WERE INCREASED, WHEREAS EXPRESSION OF HDAC3, HDAC4, SIRTUIN-1 (SIRT-1), IGF-1 (INSULIN-LIKE GROWTH FACTOR-1) WERE DECREASED, AKT (V-AKT MURINE THYMOMA VIRAL ONCOGENE HOMOLOGUE 1) EXPRESSION DID NOT DIFFER, FOLLISTATIN EXPRESSION WAS GREATER, WHEREAS MYOSTATIN EXPRESSION WAS LOWER, SERUM REPONSE FACTOR (SRF) EXPRESSION WAS INCREASED AND FIBRE SIZE OF FAST-TWITCH FIBRES WAS SIGNIFICANTLY REDUCED. IN VL OF SEVERE COPD PATIENTS WITH MUSCLE WEAKNESS AND ATROPHY, EPIGENETIC EVENTS REGULATE MUSCLE DIFFERENTIATION RATHER THAN PROLIFERATION AND MUSCLE GROWTH AND ATROPHY SIGNALLING, PROBABLY AS FEEDBACK MECHANISMS TO PREVENT THOSE MUSCLES FROM UNDERGOING FURTHER ATROPHY. LYSINE-HYPERACETYLATION OF HISTONES MAY DRIVE ENHANCED PROTEIN CATABOLISM IN THOSE MUSCLES. THESE FINDINGS MAY HELP DESIGN NOVEL THERAPEUTIC STRATEGIES (ENHANCERS OF MIRNAS PROMOTING MYOGENESIS AND ACETYLATION INHIBITORS) TO SELECTIVELY TARGET MUSCLE WEAKNESS AND ATROPHY IN SEVERE COPD. 2015 3 3090 32 GENOMIC AND EPIGENOMIC EVALUATION OF ELECTRICALLY INDUCED EXERCISE IN PEOPLE WITH SPINAL CORD INJURY: APPLICATION TO PRECISION REHABILITATION. OBJECTIVE: PHYSICAL THERAPISTS DEVELOP PATIENT-CENTERED EXERCISE PRESCRIPTIONS TO HELP OVERCOME THE PHYSICAL, EMOTIONAL, PSYCHOSOCIAL, AND ENVIRONMENTAL STRESSORS THAT UNDERMINE A PERSON'S HEALTH. OPTIMALLY PRESCRIBING MUSCLE ACTIVITY FOR PEOPLE WITH DISABILITY, SUCH AS A SPINAL CORD INJURY, IS CHALLENGING BECAUSE OF THEIR LOSS OF VOLITIONAL MOVEMENT CONTROL AND THE DETERIORATION OF THEIR UNDERLYING SKELETAL SYSTEMS. THIS REPORT SUMMARIZES SPINAL CORD INJURY-SPECIFIC FACTORS THAT SHOULD BE CONSIDERED IN PATIENT-CENTERED, PRECISION PRESCRIPTION OF MUSCLE ACTIVITY FOR PEOPLE WITH SPINAL CORD INJURY. THIS REPORT ALSO PRESENTS A MUSCLE GENOMIC AND EPIGENOMIC ANALYSIS TO EXAMINE THE REGULATION OF THE PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR 1ALPHA (PGC-1ALPHA) (OXIDATIVE) AND MYOSTATIN (HYPERTROPHY) SIGNALING PATHWAYS IN SKELETAL MUSCLE DURING LOW-FREQUENCY (LOWER-FORCE) ELECTRICALLY INDUCED EXERCISE VERSUS HIGHER-FREQUENCY (HIGHER-FORCE) ELECTRICALLY INDUCED EXERCISE UNDER CONSTANT MUSCLE RECRUITMENT (INTENSITY). METHODS: SEVENTEEN PEOPLE WITH SPINAL CORD INJURY PARTICIPATED IN 1 OR MORE UNILATERAL ELECTRICALLY INDUCED EXERCISE SESSIONS USING A LOWER-FORCE (1-, 3-, OR 5-HZ) OR HIGHER-FORCE (20-HZ) PROTOCOL. THREE HOURS AFTER THE EXERCISE SESSION, PERCUTANEOUS MUSCLE BIOPSIES WERE PERFORMED ON EXERCISED AND NONEXERCISED MUSCLES FOR GENOMIC AND EPIGENOMIC ANALYSIS. RESULTS: WE FOUND THAT LOW-FREQUENCY (LOW-FORCE) ELECTRICALLY INDUCED EXERCISE SIGNIFICANTLY INCREASED THE EXPRESSION OF PGC-1ALPHA AND DECREASED THE EXPRESSION OF MYOSTATIN, CONSISTENT WITH THE EXPRESSION CHANGES OBSERVED WITH HIGH-FREQUENCY (HIGHER-FORCE) ELECTRICALLY INDUCED EXERCISE. FURTHER, WE FOUND THAT LOW-FREQUENCY (LOWER-FORCE) ELECTRICALLY INDUCED EXERCISE SIGNIFICANTLY DEMETHYLATED, OR EPIGENETICALLY PROMOTED, THE PGC-1ALPHA SIGNALING PATHWAY. A GLOBAL EPIGENETIC ANALYSIS SHOWED THAT >70 PATHWAYS WERE REGULATED WITH LOW-FREQUENCY (LOWER-FORCE) ELECTRICALLY INDUCED EXERCISE. CONCLUSION: THESE NOVEL RESULTS SUPPORT THE NOTION THAT LOW-FREQUENCY (LOW-FORCE) ELECTRICALLY INDUCED EXERCISE MAY OFFER A MORE PRECISE REHABILITATION STRATEGY FOR PEOPLE WITH CHRONIC PARALYSIS AND SEVERE OSTEOPOROSIS. FUTURE CLINICAL TRIALS ARE WARRANTED TO EXPLORE WHETHER LOW-FREQUENCY (LOWER-FORCE) ELECTRICALLY INDUCED EXERCISE TRAINING AFFECTS THE OVERALL HEALTH OF PEOPLE WITH CHRONIC SPINAL CORD INJURY. 2022 4 1633 37 DO EPIGENETIC EVENTS TAKE PLACE IN THE VASTUS LATERALIS OF PATIENTS WITH MILD CHRONIC OBSTRUCTIVE PULMONARY DISEASE? MUSCLE DYSFUNCTION IS A MAJOR COMORBIDITY IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). SEVERAL BIOLOGICAL MECHANISMS INCLUDING EPIGENETIC EVENTS REGULATE MUSCLE MASS AND FUNCTION IN MODELS OF MUSCLE ATROPHY. INVESTIGATIONS CONDUCTED SO FAR HAVE FOCUSED ON THE ELUCIDATION OF BIOLOGICAL MECHANISMS INVOLVED IN MUSCLE DYSFUNCTION IN ADVANCED COPD. WE ASSESSED WHETHER THE EPIGENETIC PROFILE MAY BE ALTERED IN THE VASTUS LATERALIS OF PATIENTS WITH MILD COPD, NORMAL BODY COMPOSITION, AND MILDLY IMPAIRED MUSCLE FUNCTION AND EXERCISE CAPACITY. IN VASTUS LATERALIS (VL) OF MILD COPD PATIENTS WITH WELL-PRESERVED BODY COMPOSITION AND IN HEALTHY AGE-MATCHED CONTROLS, EXPRESSION OF DNA METHYLATION, MUSCLE-ENRICHED MICRORNAS, HISTONE ACETYLTRANSFERASES (HTAS) AND DEACETYLASES (HDACS), PROTEIN ACETYLATION, SMALL UBIQUITIN-RELATED MODIFIER (SUMO) LIGASES, AND MUSCLE STRUCTURE WERE EXPLORED. ALL SUBJECTS WERE CLINICALLY EVALUATED. COMPARED TO HEALTHY CONTROLS, IN THE VL OF MILD COPD PATIENTS, MUSCLE FUNCTION AND EXERCISE CAPACITY WERE MODERATELY REDUCED, DNA METHYLATION LEVELS DID NOT DIFFER, MIR-1 EXPRESSION LEVELS WERE INCREASED AND POSITIVELY CORRELATED WITH BOTH FORCED EXPIRATORY VOLUME IN ONE SECOND (FEV1) AND QUADRICEPS FORCE, HDAC4 PROTEIN LEVELS WERE INCREASED, AND MUSCLE FIBER TYPES AND SIZES WERE NOT DIFFERENT. MODERATE SKELETAL MUSCLE DYSFUNCTION IS A RELEVANT FEATURE IN PATIENTS WITH MILD COPD AND PRESERVED BODY COMPOSITION. SEVERAL EPIGENETIC EVENTS ARE DIFFERENTIALLY EXPRESSED IN THE LIMB MUSCLES OF THESE PATIENTS, PROBABLY AS AN ATTEMPT TO COUNTERBALANCE THE UNDERLYING MECHANISMS THAT ALTER MUSCLE FUNCTION AND MASS. THE STUDY OF PATIENTS AT EARLY STAGES OF THEIR DISEASE IS OF INTEREST AS THEY ARE A TARGET FOR TIMELY THERAPEUTIC INTERVENTIONS THAT MAY SLOW DOWN THE COURSE OF THE DISEASE AND PREVENT THE DELETERIOUS EFFECTS OF MAJOR COMORBIDITIES. 2014 5 5679 24 SHORT- AND LONG-TERM HINDLIMB IMMOBILIZATION AND RELOADING: PROFILE OF EPIGENETIC EVENTS IN GASTROCNEMIUS. SKELETAL MUSCLE DYSFUNCTION AND ATROPHY ARE CHARACTERISTIC FEATURES ACCOMPANYING CHRONIC CONDITIONS. EPIGENETIC EVENTS REGULATE MUSCLE MASS AND FUNCTION MAINTENANCE. WE HYPOTHESIZED THAT THE PATTERN OF EPIGENETIC EVENTS (MUSCLE-ENRICHED MICRORNAS AND HISTONE ACETYLATION) AND ACETYLATION OF TRANSCRIPTION FACTORS KNOWN TO SIGNAL MUSCLE WASTING MAY DIFFER BETWEEN EARLY- AND LATE-TIME POINTS IN SKELETAL MUSCLES OF MICE EXPOSED TO HINDLIMB IMMOBILIZATION (I) AND RECOVERY FOLLOWING I. BODY AND MUSCLE WEIGHTS, GRIP STRENGTH, MUSCLE-ENRICHED MICRORNAS, HISTONE DEACETYLASES (HDACS), ACETYLATION OF PROTEINS, HISTONES, AND TRANSCRIPTION FACTORS (TF), MYOGENIC TF FACTORS, AND MUSCLE PHENOTYPE WERE ASSESSED IN GASTROCNEMIUS OF MICE EXPOSED TO PERIODS (1, 2, 3, 7, 15, AND 30 DAYS, I GROUPS) OF HINDLIMB IMMOBILIZATION, AND IN THOSE EXPOSED TO RELOADING FOR DIFFERENT PERIODS OF TIME (1, 3, 7, 15, AND 30 DAYS, R GROUPS) FOLLOWING 7-DAY IMMOBILIZATION. COMPARED TO NON-IMMOBILIZED CONTROLS, MUSCLE WEIGHT, LIMB STRENGTH, MICRORNAS, ESPECIALLY MIR-486, SIRT1 LEVELS, AND SLOW- AND FAST-TWITCH CROSS-SECTIONAL AREAS WERE DECREASED IN MICE OF I GROUPS, WHEREAS PAX7 AND ACETYLATED FOXO1 AND FOXO3 LEVELS WERE INCREASED. MUSCLE RELOADING FOLLOWING SPLINT REMOVAL IMPROVED MUSCLE MASS LOSS, STRENGTH, AND FIBER ATROPHY, BY INCREASING MICRORNAS, PARTICULARLY MIR-486, AND SIRT1 CONTENT, WHILE DECREASING ACETYLATED FOXO1 AND FOXO3 LEVELS. IN THIS MOUSE MODEL OF DISUSE MUSCLE ATROPHY, MUSCLE-ENRICHED MICRORNAS, ESPECIALLY MIR-486, THROUGH PAX7 REGULATION DELAYED MUSCLE CELL DIFFERENTIATION FOLLOWING UNLOADING OF GASTROCNEMIUS MUSCLE. ACETYLATION OF FOXO1 AND 3 SEEMED TO DRIVE MUSCLE MASS LOSS AND ATROPHY, WHILE DEACETYLATION OF THESE FACTORS THROUGH SIRT1 WOULD ENABLE THE MUSCLE FIBERS TO REGENERATE. J. CELL. PHYSIOL. 232: 1415-1427, 2017. (C) 2016 WILEY PERIODICALS, INC. 2017 6 2170 34 EPIGENETIC MECHANISMS IN RESPIRATORY MUSCLE DYSFUNCTION OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE. EPIGENETIC EVENTS ARE DIFFERENTIALLY EXPRESSED IN THE LUNGS AND AIRWAYS OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). MOREOVER, EPIGENETIC MECHANISMS ARE INVOLVED IN THE SKELETAL (PERIPHERAL) MUSCLE DYSFUNCTION OF COPD PATIENTS. WHETHER EPIGENETIC EVENTS MAY ALSO REGULATE RESPIRATORY MUSCLE DYSFUNCTION IN COPD REMAINS UNKNOWN. WE HYPOTHESIZED THAT EPIGENETIC MECHANISMS WOULD BE DIFFERENTIALLY EXPRESSED IN THE MAIN INSPIRATORY MUSCLE (DIAPHRAGM) OF PATIENTS WITH COPD OF A WIDE RANGE OF DISEASE SEVERITY COMPARED TO HEALTHY CONTROLS. IN DIAPHRAGM MUSCLE SPECIMENS (THORACOTOMY DUE TO LUNG LOCALIZED NEOPLASMS) OF SEDENTARY PATIENTS WITH MILD-TO-MODERATE AND SEVERE COPD, WITH PRESERVED BODY COMPOSITION, AND SEDENTARY HEALTHY CONTROLS, EXPRESSION OF MUSCLE-ENRICHED MICRORNAS, HISTONE ACETYLTRANSFERASES (HATS) AND DEACETYLASES (HDACS), TOTAL DNA METHYLATION AND PROTEIN ACETYLATION, SMALL UBIQUITIN-RELATED MODIFIER (SUMO) LIGASES, MUSCLE-SPECIFIC TRANSCRIPTION FACTORS, AND MUSCLE STRUCTURE WERE EXPLORED. ALL SUBJECTS WERE ALSO CLINICALLY EVALUATED: LUNG AND MUSCLE FUNCTIONS AND EXERCISE CAPACITY. COMPARED TO HEALTHY CONTROLS, PATIENTS EXHIBITED MODERATE AIRFLOW LIMITATION AND DIFFUSION CAPACITY, AND REDUCED EXERCISE TOLERANCE AND TRANSDIAPHRAGMATIC STRENGTH. MOREOVER, IN THE DIAPHRAGM OF THE COPD PATIENTS, MUSCLE-SPECIFIC MICRORNA EXPRESSION WAS DOWNREGULATED, WHILE HDAC4 AND MYOCYTE ENHANCER FACTOR (MEF)2C PROTEIN LEVELS WERE HIGHER, AND DNA METHYLATION LEVELS, MUSCLE FIBER TYPES AND SIZES DID NOT DIFFER BETWEEN PATIENTS AND CONTROLS. IN THE MAIN RESPIRATORY MUSCLE OF COPD PATIENTS WITH A WIDE RANGE OF DISEASE SEVERITY AND NORMAL BODY COMPOSITION, MUSCLE-SPECIFIC MICRORNAS WERE DOWNREGULATED, WHILE HDAC4 AND MEF2C LEVELS WERE UPREGULATED. IT IS LIKELY THAT THESE EPIGENETIC EVENTS ACT AS BIOLOGICAL ADAPTIVE MECHANISMS TO BETTER OVERCOME THE CONTINUOUS INSPIRATORY LOADS OF THE RESPIRATORY SYSTEM IN COPD. THESE FINDINGS MAY OFFER NOVEL THERAPEUTIC STRATEGIES TO SPECIFICALLY TARGET RESPIRATORY MUSCLE DYSFUNCTION IN PATIENTS WITH COPD. 2014 7 3519 27 IGF-1 SIGNALING IN NEONATAL HYPOXIA-INDUCED PULMONARY HYPERTENSION: ROLE OF EPIGENETIC REGULATION. PULMONARY HYPERTENSION IS A FATAL DISEASE CHARACTERIZED BY A PROGRESSIVE INCREASE IN PULMONARY ARTERY PRESSURE ACCOMPANIED BY PULMONARY VASCULAR REMODELING AND INCREASED VASOMOTOR TONE. ALTHOUGH SOME BIOLOGICAL PATHWAYS HAVE BEEN IDENTIFIED IN NEONATAL HYPOXIA-INDUCED PULMONARY HYPERTENSION (PH), LITTLE IS KNOWN REGARDING THE ROLE OF GROWTH FACTORS IN THE PATHOGENESIS OF PH IN NEONATES. IN THIS STUDY, USING A MODEL OF HYPOXIA-INDUCED PH IN NEONATAL MICE, WE DEMONSTRATE THAT THE GROWTH FACTOR INSULIN-LIKE GROWTH FACTOR-1 (IGF-1), A POTENT ACTIVATOR OF THE AKT SIGNALING PATHWAY, IS INVOLVED IN NEONATAL PH. AFTER EXPOSURE TO HYPOXIA, IGF-1 SIGNALING IS ACTIVATED IN PULMONARY ENDOTHELIAL AND SMOOTH MUSCLE CELLS IN VITRO, AND THE IGF-1 DOWNSTREAM SIGNAL PAKT(S473) IS UPREGULATED IN LUNGS OF NEONATAL MICE. WE FOUND THAT IGF-1 REGULATES ET-1 EXPRESSION IN PULMONARY ENDOTHELIAL CELLS AND THAT IGF-1 EXPRESSION IS REGULATED BY HISTONE DEACETYLASES (HDACS). IN ADDITION, THERE IS A DIFFERENTIAL CYTOSINE METHYLATION SITE IN THE IGF-1 PROMOTER REGION IN RESPONSE TO NEONATAL HYPOXIA. MOREOVER, INHIBITION OF HDACS WITH APICIDIN DECREASES NEONATAL HYPOXIA-INDUCED GLOBAL DNA METHYLATION LEVELS IN LUNGS AND SPECIFIC CYTOSINE METHYLATION LEVELS AROUND THE PULMONARY IGF-1 PROMOTER REGION. FINALLY, HDAC INHIBITION WITH APICIDIN REDUCES CHRONIC HYPOXIA-INDUCED ACTIVATION OF IGF-1/PAKT SIGNALING IN LUNGS AND ATTENUATES RIGHT VENTRICULAR HYPERTROPHY AND PULMONARY VASCULAR REMODELING. TAKEN TOGETHER, WE CONCLUDE THAT IGF-1, WHICH IS EPIGENETICALLY REGULATED, IS INVOLVED IN THE PATHOGENESIS OF PULMONARY HYPERTENSION IN NEONATAL MICE. THIS STUDY IMPLICATES A NOVEL HDAC/IGF-1 EPIGENETIC PATHWAY IN THE REGULATION OF HYPOXIA-INDUCED PH AND WARRANTS FURTHER STUDY OF THE ROLE OF IGF-1 IN NEONATAL PULMONARY HYPERTENSIVE DISEASE. 2015 8 4544 30 MUSCLE HYPERTROPHY IN HYPOXIA WITH INFLAMMATION IS CONTROLLED BY BROMODOMAIN AND EXTRA-TERMINAL DOMAIN PROTEINS. SOME OF THE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS ENGAGED IN EXERCISE-BASED MUSCLE REHABILITATION PROGRAMS ARE UNRESPONSIVE. TO UNRAVEL THE RESPECTIVE ROLE OF CHRONIC HYPOXIA AND PULMONARY INFLAMMATION ON SOLEUS MUSCLE HYPERTROPHIC CAPACITIES, WE CHALLENGED MALE WISTAR RATS TO REPEATED LIPOPOLYSACCHARIDE INSTILLATIONS, ASSOCIATED OR NOT WITH A CHRONIC HYPOXIA EXPOSURE. MUSCLE HYPERTROPHY WAS INITIATED BY BILATERAL ABLATION OF SOLEUS AGONISTS 1 WEEK BEFORE SACRIFICE. TO UNDERSTAND THE ROLE PLAYED BY THE HISTONE ACETYLATION, WE ALSO TREATED OUR ANIMALS WITH AN INHIBITOR OF BROMODOMAINS AND EXTRA TERMINAL PROTEINS (I-BET) DURING THE WEEK AFTER SURGERY. PULMONARY INFLAMMATION TOTALLY INHIBITED THIS HYPERTROPHY RESPONSE UNDER BOTH NORMOXIC AND HYPOXIC CONDITIONS (26% LOWER THAN CONTROL SURGERY, P < 0.05), CONSISTENT WITH THE S6K1 AND MYOGENIN MEASUREMENTS. CHANGES IN HISTONE ACETYLATION AND CLASS IIA HISTONE DEACETYLASES EXPRESSION, FOLLOWING PULMONARY INFLAMMATION, SUGGESTED A PUTATIVE ROLE FOR HISTONE ACETYLATION SIGNALING IN THE ALTERED HYPERTROPHY RESPONSE. THE I-BET DRUG RESTORED THE HYPERTROPHY RESPONSE SUGGESTING THAT THE NON-RESPONSE OF MUSCLE TO A HYPERTROPHIC STIMULUS COULD BE MODULATED BY EPIGENETIC MECHANISMS, INCLUDING HISTONE-ACETYLATION DEPENDANT PATHWAYS. DRUGS TARGETING SUCH EPIGENETIC MECHANISMS MAY OPEN THERAPEUTIC PERSPECTIVES FOR COPD PATIENTS WITH SYSTEMIC INFLAMMATION WHO ARE UNRESPONSIVE TO REHABILITATION. 2017 9 2681 26 EVALUATION OF MUSCLE-SPECIFIC AND METABOLISM REGULATING MICRORNAS IN A CHRONIC SWIMMING RAT MODEL. MAKING BENEFIT FROM THE EPIGENETIC EFFECTS OF ENVIRONMENTAL FACTORS SUCH AS PHYSICAL ACTIVITY MAY RESULT IN A CONSIDERABLE IMPROVEMENT IN THE PREVENTION OF CHRONIC CIVILIZATION DISEASES. IN OUR CHRONIC SWIMMING RAT MODEL, THE EXPRESSION LEVELS OF SUCH MICRORNAS WERE CHARACTERIZED, THAT ARE INVOLVED IN SKELETAL MUSCLE DIFFERENTIATION, HYPERTROPHY AND FINE-TUNING OF METABOLISM, WHICH PROCESSES ARE INFLUENCED BY CHRONIC ENDURANCE TRAINING, CONTRIBUTING TO THE METABOLIC ADAPTATION OF SKELETAL MUSCLE DURING PHYSICAL ACTIVITY. AFTER CHRONIC SWIMMING, THE LEVEL OF MIR-128A INCREASED SIGNIFICANTLY IN EDL MUSCLES, WHICH MAY INFLUENCE METABOLIC ADAPTATION AND STRESS RESPONSE AS WELL. IN SOL, THE EXPRESSION LEVEL OF MIR-15B AND MIR-451 DECREASED SIGNIFICANTLY AFTER CHRONIC SWIMMING, WHICH CHANGES ARE OPPOSITE TO THEIR PREVIOUSLY DESCRIBED INCREMENT IN INSULIN RESISTANT SKELETAL MUSCLE. MIR-451 ALSO TARGETS PGC-1ALPHA MRNA, WHICHES EXPRESSION LEVEL SIGNIFICANTLY INCREASED IN SOL MUSCLES, RESULTING IN ENHANCED BIOGENESIS AND OXIDATIVE CAPACITY OF MITOCHONDRIA. IN SUMMARY, THE MICRORNA EXPRESSION CHANGES THAT WERE OBSERVED DURING OUR EXPERIMENTS SUGGEST THAT CHRONIC SWIM TRAINING CONTRIBUTES TO A BENEFICIAL METABOLIC PROFILE OF SKELETAL MUSCLE. 2022 10 3604 28 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 11 4928 37 PARP-1 AND PARP-2 ACTIVITY IN CANCER-INDUCED CACHEXIA: POTENTIAL THERAPEUTIC IMPLICATIONS. SKELETAL MUSCLE DYSFUNCTION AND MASS LOSS IS A CHARACTERISTIC FEATURE IN PATIENTS WITH CHRONIC DISEASES INCLUDING CANCER AND ACUTE CONDITIONS SUCH AS CRITICAL ILLNESS. MAINTENANCE OF AN ADEQUATE MUSCLE MASS IS CRUCIAL FOR THE PATIENTS' PROGNOSIS IRRESPECTIVE OF THE UNDERLYING CONDITION. MOREOVER, AGING-RELATED SARCOPENIA MAY FURTHER AGGRAVATE THE MUSCLE WASTING PROCESS ASSOCIATED WITH CHRONIC DISEASES AND CANCER. POLY(ADENOSINE DIPHOSPHATE-RIBOSE) POLYMERASE (PARP) ACTIVATION HAS BEEN DEMONSTRATED TO CONTRIBUTE TO THE PATHOPHYSIOLOGY OF MUSCLE MASS LOSS AND DYSFUNCTION IN ANIMAL MODELS OF CANCER-INDUCED CACHEXIA. GENETIC INHIBITION OF PARP ACTIVITY ATTENUATED THE DELETERIOUS EFFECTS SEEN ON DEPLETED MUSCLES IN MOUSE MODELS OF ONCOLOGIC CACHEXIA. IN THE PRESENT MINIREVIEW THE MECHANISMS WHEREBY PARP ACTIVITY INHIBITION MAY IMPROVE MUSCLE MASS AND PERFORMANCE IN MODELS OF CANCER-INDUCED CACHEXIA ARE DISCUSSED. SPECIFICALLY, THE BENEFICIAL EFFECTS OF INHIBITION OF PARP ACTIVITY ON ATTENUATION OF INCREASED OXIDATIVE STRESS, PROTEIN CATABOLISM, POOR MUSCLE ANABOLISM AND MITOCHONDRIAL CONTENT AND EPIGENETIC MODULATION OF MUSCLE PHENOTYPE ARE REVIEWED IN THIS ARTICLE. FINALLY, THE POTENTIAL THERAPEUTIC STRATEGIES OF PHARMACOLOGICAL PARP ACTIVITY INHIBITION FOR THE TREATMENT OF CANCER-INDUCED CACHEXIA ARE ALSO BEING DESCRIBED IN THIS REVIEW. 2018 12 4841 27 ONE WEEK, BUT NOT 12 HOURS, OF CAST IMMOBILIZATION ALTERS PROMOTOR DNA METHYLATION PATTERNS IN THE NNOS GENE IN MOUSE SKELETAL MUSCLE. KEY POINTS: DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN REGULATING GENE EXPRESSION IN SKELETAL MUSCLE TO ADAPT TO PHYSICAL ACTIVITY AND INACTIVITY. NEURONAL NITRIC OXIDE SYNTHASE (NNOS) IN SKELETAL MUSCLE IS A KEY REGULATOR OF SKELETAL MUSCLE MASS; HOWEVER, IT IS UNCLEAR WHETHER NNOS EXPRESSION IS REGULATED BY DNA METHYLATION. WE FOUND THAT 1 WEEK OF CAST IMMOBILIZATION INCREASED NNOS DNA METHYLATION LEVELS AND DOWNREGULATED NNOS GENE EXPRESSION IN ATROPHIC SLOW-TWITCH SOLEUS MUSCLE FROM THE MOUSE LEG. THESE CHANGES WERE NOT DETECTED IN NON-ATROPHIC FAST-TWITCH EXTENSOR DIGITORUM LONGUS MUSCLE. TWELVE HOURS OF CAST IMMOBILIZATION DECREASED NNOS GENE EXPRESSION, WHEREAS NNOS DNA METHYLATION LEVELS WERE UNCHANGED, SUGGESTING THAT DOWNREGULATION OF NNOS GENE EXPRESSION BY SHORT-TERM MUSCLE INACTIVITY IS INDEPENDENT OF THE DNA METHYLATION PATTERN. THESE FINDINGS CONTRIBUTE TO A BETTER UNDERSTANDING OF THE MAINTENANCE OF SKELETAL MUSCLE MASS AND PREVENTION OF MUSCLE ATROPHY BY EPIGENETIC MECHANISMS VIA THE NNOS/NO PATHWAY. ABSTRACT: DNA METHYLATION IS A MECHANISM THAT CONTROLS GENE EXPRESSION IN SKELETAL MUSCLE UNDER VARIOUS ENVIRONMENTAL STIMULI, SUCH AS PHYSICAL ACTIVITY AND INACTIVITY. NEURONAL NITRIC OXIDE SYNTHASE (NNOS) REGULATES MUSCLE ATROPHY IN SKELETAL MUSCLE. HOWEVER, THE MECHANISMS REGULATING NNOS EXPRESSION IN ATROPHIC MUSCLE REMAIN UNCLEAR. WE HYPOTHESIZED THAT NNOS EXPRESSION IN ATROPHIC MUSCLE IS REGULATED BY DNA METHYLATION OF THE NNOS PROMOTOR IN SOLEUS (SOL; SLOW-TWITCH FIBRE DOMINANT) AND EXTENSOR DIGITORUM LONGUS (EDL; FAST-TWITCH FIBRE DOMINANT) MUSCLES. ONE WEEK OF CAST IMMOBILIZATION INDUCED SIGNIFICANT MUSCLE ATROPHY IN SOL BUT NOT IN EDL. WE SHOWED THAT 1 WEEK OF CAST IMMOBILIZATION INCREASED NNOS DNA METHYLATION LEVELS IN SOL, ALTHOUGH ONLY A MINOR CHANGE WAS DETECTED IN EDL. CONSISTENT WITH THE INCREASED DNA METHYLATION LEVELS IN ATROPHIC SOL, THE GENE EXPRESSION LEVELS OF TOTAL NNOS AND NNOSMICRO (I.E. THE MAJOR SPLICING VARIANT OF NNOS IN SKELETAL MUSCLE) DECREASED. THE ABUNDANCE OF THE NNOS PROTEIN AND CELL MEMBRANE (ESPECIALLY TYPE IIA FIBRE) IMMUNOREACTIVITY ALSO DECREASED IN ATROPHIC SOL. THESE CHANGES WERE NOT OBSERVED IN EDL AFTER 1 WEEK OF CAST IMMOBILIZATION. FURTHERMORE, DESPITE THE LACK OF SIGNIFICANT ATROPHY, 12 H OF CAST IMMOBILIZATION DECREASED GENE EXPRESSION LEVELS OF TOTAL NNOS AND NNOSMICRO IN SOL. HOWEVER, NO ASSOCIATION WAS DETECTED BETWEEN NNOS DNA METHYLATION AND GENE EXPRESSION. THE EXPRESSION OF THE NNOSBETA GENE, ANOTHER SPLICING VARIANT OF NNOS, IN EDL WAS UNCHANGED BY CAST IMMOBILIZATION, WHEREAS ITS EXPRESSION WAS NOT DETECTED IN SOL. WE CONCLUDED THAT CHRONIC ADAPTATION OF NNOS GENE EXPRESSION IN CAST IMMOBILIZED MUSCLE MAY INVOLVE NNOS DNA METHYLATION. 2019 13 4296 28 MICRORNA-1 MODULATES CHONDROCYTE PHENOTYPE BY REGULATING FZD7 OF WNT/ BETA-CATENIN SIGNALING PATHWAY. OBJECTIVE: OSTEOARTHRITIS (OA) IS AN INCURABLE JOINT DISEASE CHARACTERIZED BY PRONOUNCED PAIN. MICRORNAS CONSTITUTE EPIGENETIC MECHANISMS THAT MAY AFFECT OA PROGRESSION BY CONTRIBUTING TO CHANGES IN CHONDROCYTE PHENOTYPE. THIS STUDY INVESTIGATES FOR THE FIRST TIME WHETHER THERE IS A LINK BETWEEN MIRNA-1 (MIR-1) AND OA PATHOGENESIS, AND THE MOLECULAR MECHANISMS INVOLVED. DESIGN: OA-ASSOCIATED GENE EXPRESSION, INCLUDING MMP-13, ADAMTS5, AND COL2A1 WAS COMPARED IN CHONDROCYTES FROM NON-OA AND OA CARTILAGE, AND IN SW1353 CELLS OVER- AND UNDEREXPRESSING MIR-1. BIOINFORMATICS AND LUCIFERASE REPORTER ASSAY WERE CONDUCTED TO CONFIRM WHETHER FZD7 WAS A TARGET OF MIR-1. THE EFFECTS OF MIR-1 ON FZD7 EXPRESSION AND DOWNSTREAM WNT/BETA-CATENIN SIGNALLING WERE INVESTIGATED. RESULTS: NON-OA AND OA CHONDROCYTES DIFFERED SIGNIFICANTLY IN THE EXPRESSION OF MIR-1 AND OA-ASSOCIATED GENES. MIR-1 OVER- AND UNDEREXPRESSION IN SW1353 CELLS, RESPECTIVELY, REDUCED AND ENHANCED GENE EXPRESSION ASSOCIATED WITH CARTILAGE CATABOLISM. FZD7, WHICH HAS AN IMPORTANT ROLE IN THE WNT/BETA-CATENIN SIGNALING PATHWAY, WAS SHOWN TO BE A POTENTIAL TARGET OF MIR-1. MIR-1 BINDING TO FZD7 INCREASED THE LEVELS OF PHOSPHORYLATED (INACTIVATED) BETA-CATENIN, THEREBY PREVENTING DOWNSTREAM BETA-CATENIN SIGNALING. CONCLUSIONS: INHIBITION OF WNT/BETA-CATENIN SIGNALING BY MIR-1 IN CHONDROCYTES MAY ATTENUATE THE EXPRESSION OF GENES THAT REGULATE THE ACTIVITY OF CATABOLIC ENZYMES. THIS FINDING MAY BE USEFUL FOR FUTURE INVESTIGATIONS OF MOLECULAR TARGETS FOR OA TREATMENT. 2021 14 3124 21 GHRELIN TREATMENT IMPROVES PHYSICAL DECLINE IN SARCOPENIA MODEL MICE THROUGH MUSCULAR ENHANCEMENT AND MITOCHONDRIAL ACTIVATION. CHRONIC KIDNEY DISEASE (CKD) IMPAIRS PHYSICAL PERFORMANCE IN HUMANS, WHICH LEADS TO A RISK OF ALL-CAUSE MORTALITY. IN OUR PREVIOUS STUDY, WE DEMONSTRATED THAT A REDUCTION IN MUSCLE MITOCHONDRIA RATHER THAN MUSCLE MASS WAS A MAJOR CAUSE OF PHYSICAL DECLINE IN 5/6 NEPHRECTOMIZED CKD MODEL MICE. BECAUSE GHRELIN ADMINISTRATION HAS BEEN REPORTED TO ENHANCE OXYGEN UTILIZATION IN SKELETAL MUSCLE, WE EXAMINED THE USEFULNESS OF GHRELIN FOR A RECOVERY OF PHYSICAL DECLINE IN 5/6 NEPHRECTOMIZED C57BL/6 MICE, FOCUSING ON THE EPIGENETIC MODIFICATION OF PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA), A MASTER REGULATOR OF MITOCHONDRIAL BIOGENESIS. THE MICE WERE INTRAPERITONEALLY ADMINISTERED ACYLATED GHRELIN (0.1 NMOL/GBW; THREE TIMES PER WEEK) FOR A MONTH. MUSCLE STRENGTH AND EXERCISE ENDURANCE WERE MEASURED BY USING A DYNAMOMETER AND TREADMILL, RESPECTIVELY. MITOCHONDRIAL DNA COPY NUMBER WAS DETERMINED BY QUANTITATIVE PCR. THE METHYLATION LEVELS OF THE CYTOSINE RESIDUE AT 260 BASE PAIRS UPSTREAM OF THE TRANSLATION INITIATION POINT (C-260) OF PGC-1ALPHA, WHICH HAS BEEN DEMONSTRATED TO DECREASE THE EXPRESSION, WAS EVALUATED BY METHYLATION-SPECIFIC PCR AND BISULFITE GENOMIC SEQUENCING METHODS AFTER THE GHRELIN ADMINISTRATION. GHRELIN ADMINISTRATION IMPROVED BOTH MUSCLE STRENGTH AND EXERCISE ENDURANCE IN THE MICE AND WAS ASSOCIATED WITH AN INCREASE IN MUSCLE MASS AND MUSCLE MITOCHONDRIAL CONTENT. GHRELIN ADMINISTRATION DECREASED THE METHYLATION RATIO OF C-260 OF PGC-1ALPHA IN THE SKELETAL MUSCLE AND INCREASED THE EXPRESSION. THEREFORE, GHRELIN ADMINISTRATION EFFECTIVELY REDUCED THE PHYSICAL DECLINE IN 5/6 NEPHRECTOMIZED MICE AND WAS ACCOMPANIED WITH AN INCREASED MITOCHONDRIAL CONTENT THROUGH DE-METHYLATION OF THE PROMOTER REGION OF PGC-1ALPHA IN THE MUSCLE. 2017 15 4303 27 MICRORNA-223 INHIBITS TISSUE FACTOR EXPRESSION IN VASCULAR ENDOTHELIAL CELLS. OBJECTIVE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY PROCESS, IN WHICH VASCULAR ENDOTHELIAL CELLS (ECS) BECOME DYSFUNCTIONAL OWING TO THE EFFECTS OF CHEMICAL SUBSTANCES, SUCH AS INFLAMMATORY FACTOR AND GROWTH FACTORS. TISSUE FACTOR (TF) EXPRESSION IS INDUCED BY THE ABOVE CHEMICAL SUBSTANCES IN ACTIVATED ECS. TF INITIATES THROMBOSIS ON DISRUPTED ATHEROSCLEROTIC PLAQUES WHICH PLAYS AN ESSENTIAL ROLE DURING THE ONSET OF ACUTE CORONARY SYNDROMES (ACS). INCREASING EVIDENCES SUGGEST THE IMPORTANT ROLE OF MICRORNAS AS EPIGENETIC REGULATORS OF ATHEROSCLEROTIC DISEASE. THE AIM OF OUR STUDY IS TO IDENTIFY IF MICRORNA-223 (MIR-223) TARGETS TF IN ECS. METHODS AND RESULTS: BIOINFORMATIC ANALYSIS SHOWED THAT TF IS A TARGET CANDIDATE OF MIR-223. WESTERN BLOTTING ANALYSIS REVEALED THAT TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) INCREASED TF EXPRESSION IN AORTA OF C57BL/6J MICE AND CULTURED ECS (EA.HY926 CELLS AND HUVEC) AFTER 4 H TREATMENT. IN TNF-ALPHA TREATED ECS, TF MRNA WAS ALSO INCREASED MEASURED BY REAL-TIME PCR. REAL-TIME PCR RESULTS SHOWED THAT MIR-223 LEVELS WERE DOWNREGULATED IN TNF-ALPHA-TREATED AORTA OF C57BL/6J MICE AND CULTURED ECS. TRANSFECTION OF ECS WITH MIR-223 MIMIC OR MIR-223 INHIBITOR MODIFIED TF EXPRESSION BOTH IN MRNA AND PROTEIN LEVELS. LUCIFERASE ASSAYS CONFIRMED THAT MIR-223 SUPPRESSED TF EXPRESSION BY BINDING TO THE SEQUENCE OF TF 3'-UNTRANSLATED REGIONS (3'UTR). TF PROCOAGULANT ACTIVITY WAS INHIBITED BY OVEREXPRESSING MIR-223 WITH OR WITHOUT TNF-ALPHA STIMULATION. CONCLUSIONS: MIR-223-MEDIATED SUPPRESSION OF TF EXPRESSION PROVIDES A NOVEL MOLECULAR MECHANISM FOR THE REGULATION OF COAGULATION CASCADE, AND SUGGESTS A CLUE AGAINST THROMBOGENESIS DURING THE PROCESS OF ATHEROSCLEROTIC PLAQUE RUPTURE. 2014 16 4543 31 MUSCLE DYSFUNCTION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE: UPDATE ON CAUSES AND BIOLOGICAL FINDINGS. RESPIRATORY AND/OR LIMB MUSCLE DYSFUNCTION, WHICH ARE FREQUENTLY OBSERVED IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS, CONTRIBUTE TO THEIR DISEASE PROGNOSIS IRRESPECTIVE OF THE LUNG FUNCTION. MUSCLE DYSFUNCTION IS CAUSED BY THE INTERACTION OF LOCAL AND SYSTEMIC FACTORS. THE KEY DELETERIOUS ETIOLOGIC FACTORS ARE PULMONARY HYPERINFLATION FOR THE RESPIRATORY MUSCLES AND DECONDITIONING SECONDARY TO REDUCED PHYSICAL ACTIVITY FOR LIMB MUSCLES. NONETHELESS, CIGARETTE SMOKE, SYSTEMIC INFLAMMATION, NUTRITIONAL ABNORMALITIES, EXERCISE, EXACERBATIONS, ANABOLIC INSUFFICIENCY, DRUGS AND COMORBIDITIES ALSO SEEM TO PLAY A RELEVANT ROLE. ALL THESE FACTORS MODIFY THE PHENOTYPE OF THE MUSCLES, THROUGH THE INDUCTION OF SEVERAL BIOLOGICAL PHENOMENA IN PATIENTS WITH COPD. WHILE RESPIRATORY MUSCLES IMPROVE THEIR AEROBIC PHENOTYPE (PERCENTAGE OF OXIDATIVE FIBERS, CAPILLARIZATION, MITOCHONDRIAL DENSITY, ENZYME ACTIVITY IN THE AEROBIC PATHWAYS, ETC.), LIMB MUSCLES EXHIBIT THE OPPOSITE PHENOTYPE. IN ADDITION, BOTH MUSCLE GROUPS SHOW OXIDATIVE STRESS, SIGNS OF DAMAGE AND EPIGENETIC CHANGES. HOWEVER, FIBER ATROPHY, INCREASED NUMBER OF INFLAMMATORY CELLS, ALTERED REGENERATIVE CAPACITY; SIGNS OF APOPTOSIS AND AUTOPHAGY, AND AN IMBALANCE BETWEEN PROTEIN SYNTHESIS AND BREAKDOWN ARE RATHER CHARACTERISTIC FEATURES OF THE LIMB MUSCLES, MOSTLY IN PATIENTS WITH REDUCED BODY WEIGHT. DESPITE THAT SIGNIFICANT PROGRESS HAS BEEN ACHIEVED IN THE LAST DECADES, FULL ELUCIDATION OF THE SPECIFIC ROLES OF THE TARGET BIOLOGICAL MECHANISMS INVOLVED IN COPD MUSCLE DYSFUNCTION IS STILL REQUIRED. SUCH AN ACHIEVEMENT WILL BE CRUCIAL TO ADEQUATELY TACKLE WITH THIS RELEVANT CLINICAL PROBLEM OF COPD PATIENTS IN THE NEAR-FUTURE. 2015 17 5716 31 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 18 446 35 APABETALONE DOWNREGULATES FIBROTIC, INFLAMMATORY AND CALCIFIC PROCESSES IN RENAL MESANGIAL CELLS AND PATIENTS WITH RENAL IMPAIRMENT. EPIGENETIC MECHANISMS ARE IMPLICATED IN TRANSCRIPTIONAL PROGRAMS DRIVING CHRONIC KIDNEY DISEASE (CKD). APABETALONE IS AN ORALLY AVAILABLE INHIBITOR OF BROMODOMAIN AND EXTRATERMINAL (BET) PROTEINS, WHICH ARE EPIGENETIC READERS THAT MODULATE GENE EXPRESSION. IN THE PHASE 3 BETONMACE TRIAL, APABETALONE REDUCED RISK OF MAJOR ADVERSE CARDIAC EVENTS (MACE) BY 50% IN THE CKD SUBPOPULATION, INDICATING FAVORABLE EFFECTS ALONG THE KIDNEY-HEART AXIS. ACTIVATION OF HUMAN RENAL MESANGIAL CELLS (HRMCS) TO A CONTRACTILE PHENOTYPE THAT OVERPRODUCES EXTRACELLULAR MATRIX (ECM) AND INFLAMMATORY CYTOKINES, AND PROMOTES CALCIFICATION, FREQUENTLY ACCOMPANIES CKD TO DRIVE PATHOLOGY. HERE, WE SHOW APABETALONE DOWNREGULATED HRMC ACTIVATION WITH TGF-BETA1 STIMULATION BY SUPPRESSING TGF-BETA1-INDUCED ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION, ALPHA-SMA ASSEMBLY INTO STRESS FIBERS, ENHANCED CONTRACTION, COLLAGEN OVERPRODUCTION, AND EXPRESSION OF KEY DRIVERS OF FIBROSIS, INFLAMMATION, OR CALCIFICATION INCLUDING THROMBOSPONDIN, FIBRONECTIN, PERIOSTIN, SPARC, INTERLEUKIN 6, AND ALKALINE PHOSPHATASE. LIPOPOLYSACCHARIDE-STIMULATED EXPRESSION OF INFLAMMATORY GENES IL6, IL1B, AND PTGS2 WAS ALSO SUPPRESSED. TRANSCRIPTOMICS CONFIRMED APABETALONE AFFECTED GENE SETS OF ECM REMODELING AND INTEGRINS. CLINICAL TRANSLATION OF IN VITRO RESULTS WAS INDICATED IN CKD PATIENTS WHERE A SINGLE DOSE OF APABETALONE REDUCED PLASMA LEVELS OF KEY PRO-FIBROTIC AND INFLAMMATORY MARKERS, AND INDICATED INHIBITION OF TGF-BETA1 SIGNALING. WHILE PLASMA PROTEINS CANNOT BE TRACED TO THE KIDNEY ALONE, ANTI-FIBROTIC AND ANTI-INFLAMMATORY EFFECTS OF APABETALONE IDENTIFIED IN THIS STUDY ARE CONSISTENT WITH THE OBSERVED DECREASE IN CARDIOVASCULAR RISK IN CKD PATIENTS. 2023 19 2505 43 EPIGENETICS AND MUSCLE DYSFUNCTION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMMON, PREVENTABLE, AND TREATABLE DISEASE AND A MAJOR LEADING CAUSE OF MORBIDITY AND MORTALITY WORLDWIDE. IN COPD, COMORBIDITIES, ACUTE EXACERBATIONS, AND SYSTEMIC MANIFESTATIONS NEGATIVELY INFLUENCE DISEASE SEVERITY AND PROGRESSION REGARDLESS OF THE RESPIRATORY CONDITION. SKELETAL MUSCLE DYSFUNCTION, WHICH IS ONE OF THE COMMONEST SYSTEMIC MANIFESTATIONS IN PATIENTS WITH COPD, HAS A TREMENDOUS IMPACT ON THEIR EXERCISE CAPACITY AND QUALITY OF LIFE. SEVERAL PATHOPHYSIOLOGICAL AND MOLECULAR UNDERLYING MECHANISMS INCLUDING EPIGENETICS (THE PROCESS WHEREBY GENE EXPRESSION IS REGULATED BY HERITABLE MECHANISMS THAT DO NOT AFFECT DNA SEQUENCE) HAVE BEEN SHOWN TO PARTICIPATE IN THE ETIOLOGY OF COPD MUSCLE DYSFUNCTION. THE EPIGENETIC MODIFICATIONS IDENTIFIED SO FAR IN CELLS INCLUDE DNA METHYLATION, HISTONE ACETYLATION AND METHYLATION, AND NONCODING RNAS SUCH AS MICRORNAS. HEREIN, WE FIRST REVIEW THE ROLE OF EPIGENETIC MECHANISMS IN MUSCLE DEVELOPMENT AND ADAPTATION TO ENVIRONMENTAL FACTORS IN SEVERAL MODELS. MOREOVER, THE EPIGENETIC EVENTS REPORTED SO FAR TO BE POTENTIALLY INVOLVED IN MUSCLE DYSFUNCTION AND MASS LOSS OF PATIENTS WITH COPD ARE ALSO DISCUSSED. FURTHERMORE, THE DIFFERENT EXPRESSION PROFILE OF SEVERAL MUSCLE-ENRICHED MICRORNAS IN THE DIAPHRAGM AND VASTUS LATERALIS MUSCLES OF PATIENTS WITH COPD ARE ALSO REVIEWED FROM RESULTS RECENTLY OBTAINED IN OUR GROUP. THE ROLE OF PROTEIN HYPERACETYLATION IN ENHANCED MUSCLE PROTEIN CATABOLISM OF LIMB MUSCLES IS ALSO DISCUSSED. FUTURE RESEARCH SHOULD FOCUS ON THE FULL ELUCIDATION OF THE TRIGGERS OF EPIGENETIC MECHANISMS AND THEIR SPECIFIC DOWNSTREAM BIOLOGICAL PATHWAYS IN COPD MUSCLE DYSFUNCTION AND WASTING. 2015 20 664 22 BLOOD REFLUX-INDUCED EPIGENETIC FACTORS HDACS AND DNMTS ARE ASSOCIATED WITH THE DEVELOPMENT OF HUMAN CHRONIC VENOUS DISEASE. BLOOD REFLUX AND METABOLIC REGULATION PLAY IMPORTANT ROLES IN CHRONIC VENOUS DISEASE (CVD) DEVELOPMENT. HISTONE DEACETYLASES (HDACS) AND DNA METHYLTRANSFERASES (DNMTS) SERVE AS REPRESSORS THAT INHIBIT METABOLIC SIGNALING, WHICH IS INDUCED BY PROATHEROGENIC FLOW TO PROMOTE AORTIC ENDOTHELIAL CELL (EC) DYSFUNCTION AND ATHEROSCLEROSIS. THE AIM OF THIS STUDY WAS TO ELUCIDATE THE RELATIONSHIP BETWEEN BLOOD REFLUX AND EPIGENETIC FACTORS HDACS AND DNMTS IN CVD. HUMAN VARICOSE VEINS WITH DIFFERENT LEVELS OF BLOOD REFLUX VERSUS NORMAL VEINS WITH NORMAL VENOUS FLOW WERE EXAMINED. THE RESULTS SHOW THAT HDAC-1, -2, -3, -5, AND -7 ARE OVEREXPRESSED IN THE ENDOTHELIUM OF VARICOSE VEINS WITH BLOOD REFLUX. BLOOD REFLUX-INDUCED HDACS ARE ENHANCED IN THE VARICOSE VEINS WITH A LONGER DURATION TIME OF BLOOD REFLUX. IN CONTRAST, THESE HDACS ARE RARELY EXPRESSED IN THE ENDOTHELIUM OF THE NORMAL VEIN WITH NORMAL VENOUS FLOW. SIMILAR RESULTS ARE OBTAINED FOR DNMT1 AND DNMT3A. OUR FINDINGS SUGGEST THAT THE EPIGENETIC FACTORS, HDACS AND DNMTS, ARE INDUCED IN VENOUS ECS IN RESPONSE TO BLOOD REFLUX BUT ARE INHIBITED IN RESPONSE TO NORMAL VENOUS FLOW. BLOOD REFLUX-INDUCED HDACS AND DNMTS COULD INHIBIT METABOLIC REGULATION AND PROMOTE VENOUS EC DYSFUNCTION, WHICH IS HIGHLY CORRELATED WITH CVD PATHOGENESIS. 2022