1 5145 145 POTENTIAL ROLE OF NUTRACEUTICALS VIA TARGETING A WNT/BETA-CATENIN AND NF-KAPPAB PATHWAY IN TREATMENT OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A DISEASE DUE TO THE AGING OF THE ARTICULAR CARTILAGE, A POST-MITOTIC TISSUE THAT STAYS FUNCTIONING UNTIL PRIMARY HOMEOSTATIC PROCESSES FAIL. BECAUSE OF PAIN AND DISABILITY, OA SIGNIFICANTLY INFLUENCES NATIONAL HEALTHCARE EXPENSES AND PATIENT QUALITY OF LIFE. IT IS A WHOLE-JOINT ILLNESS CHARACTERIZED BY INFLAMMATORY AND OXIDATIVE SIGNALING PATHWAYS AND SIGNIFICANT EPIGENETIC ALTERATIONS THAT CAUSE CARTILAGE EXTRACELLULAR MATRIX DEGRADATION. THE CANONICAL WNT PATHWAY (WNT/BETA-CATENIN PATHWAY) AND NUCLEAR FACTOR KAPPA B (NF-KAPPAB) SIGNALING PATHWAYS MAY FUNCTION IN JOINT TISSUES BY MODULATING THE ACTIVITY OF SYNOVIAL CELLS, OSTEOBLASTS, AND CHONDROCYTES. HOWEVER, FINDING INNOVATIVE WAYS TO TREAT OSTEOARTHRITIS AND GET THE JOINT BACK TO AVERAGE BALANCE IS STILL A STRUGGLE. NUTRACEUTICALS ARE DIETARY SUPPLEMENTS THAT PROMOTE JOINT HEALTH BY BALANCING ANABOLIC AND CATABOLIC SIGNALS. NEW THERAPEUTIC METHODS FOR OA TREATMENT HAVE BEEN DEVELOPED BASED ON MANY RESEARCH FINDINGS THAT SHOW NUTRACEUTICALS HAVE STRONG ANTI-INFLAMMATION, ANTIOXIDANT, ANTI-BONE RESORPTION, AND ANABOLIC PROPERTIES. FOR THE TREATMENT OF OSTEOARTHRITIS, WE EXPLORE THE POSSIBLE INVOLVEMENT OF NUTRACEUTICALS THAT TARGET THE WNT/BETA-CATENIN AND NF-KAPPAB PATHWAYS. PRACTICAL APPLICATIONS: IN KEEPING WITH THE AGING POPULATION, OSTEOARTHRITIS IS BECOMING MORE WIDESPREAD. IN THIS EXTENSIVE RESEARCH, WE STUDIED THE ROLE OF THE WNT/BETA-CATENIN AND NF-KAPPAB PATHWAY IN OA FORMATION AND PROGRESSION. NUTRACEUTICALS THAT TARGET THESE OA-RELATED SIGNALING PATHWAYS ARE A VIABLE THERAPY OPTION. WNT/BETA-CATENIN AND NF-KAPPAB SIGNALING PATHWAY ARE INHIBITED BY POLYPHENOLS, FLAVONOIDS, ALKALOIDS, AND VITAMINS FROM THE NUTRACEUTICAL CATEGORY, MAKING THEM POSSIBLE THERAPEUTIC DRUGS FOR OA THERAPY. 2022 2 1066 31 CLINICAL USE OF AMINO ACIDS AS DIETARY SUPPLEMENT: PROS AND CONS. NITROGEN SUPPLY IS PIVOTAL FOR THE MAINTENANCE OF LIFE. AMINO ACIDS CAN BE UTILIZED TO SYNTHESIZE BOTH GLUCOSE AND LIPIDS. THE OPPOSITE, I.E., PRODUCTION OF AMINO ACIDS FROM EITHER ONE OF THEM, IS NOT POSSIBLE IN THE ABSENCE OF OTHER AMINO ACIDS AS DONORS OF NITROGEN. THE QUALITY OF AMINO ACID CONTENT IN PROTEIN HAS BEEN RE-EVALUATED RECENTLY, AND THE RELEVANCE OF ESSENTIAL AMINO ACIDS HAS BEEN REPEATEDLY UNDERLINED. ESSENTIAL AMINO ACID REQUIREMENTS IN DIFFERENT MAMMALS ARE NOT IDENTICAL, AND RATIOS AMONG THEM SHOULD BE TAKEN INTO ACCOUNT WHEN PROJECTING AN EFFICIENT FORMULATION. RECENT RESEARCH HAS DEMONSTRATED THAT GENES RESPOND TO DIFFERENT QUALITIES AND QUANTITIES OF NUTRITIONAL SUPPLY, AND INCREASED PROVISION OF ESSENTIAL AMINO ACIDS INCREASES LIFESPAN IN ANIMAL EXPERIMENTS THROUGH MITOCHONDRIOGENESIS AND MAINTENANCE OF ELEVATED RATES OF SYNTHESIS OF ANTI-OXIDANT MOLECULES. MOREOVER, GENETIC EXPRESSION OF KEY CONTROLLERS OF SYNTHESIS, LIKE MTOR, MAY BE PARTICULARLY IMPORTANT FOR UNDERSTANDING SKELETAL MUSCLE MAINTENANCE. LOSSES OF MUSCLE MASS AND IMPAIRED IMMUNE FUNCTION ARE RELATED TO REDUCED PROTEIN SUPPLY, AND THERE IS INCREASING EVIDENCE THAT REGULAR ESSENTIAL AMINO ACID INTAKE AS PART OF AN ORAL DIET IS EFFECTIVE IN REVERSING MUSCLE CATABOLISM, PROMOTING MUSCLE ANABOLISM, AND RESTORING IMMUNOLOGICAL FUNCTION. THEREFORE, THE USE OF AMINO ACIDS AS SUPPLEMENTS TO DIET WOULD BE EXPANDING IN THE NEAR FUTURE. IS THIS SAFE? FEW DATA ARE AVAILABLE ON AMINO ACID TOXICITY, AND ONLY ONE ESSENTIAL AMINO ACID MAY BE CONSIDERED TO HAVE CLINICALLY RELEVANT TOXICITY: METHIONINE, BECAUSE IT IS TRANSFORMED INTO A TOXIC INTERMEDIATE, HOMOCYSTEINE, WHEN CYSTEINE SYNTHESIS IS REQUIRED BY METABOLIC NEEDS. MATCHING OF STOICHIOMETRIC RATIOS BETWEEN METHIONINE AND CYSTEINE MAY SOLVE THE PROBLEM OF SUPPLYING SUFFICIENT AMOUNTS OF SULFUR TO THE BODY. ARGININE AND GLUTAMINE ARE TWO NON-ESSENTIAL AMINO ACIDS THAN CAN BECOME "CONDITIONALLY ESSENTIAL" BECAUSE OF ELEVATED NEEDS DURING PATHOLOGICAL CONDITIONS, AND METABOLISM MAY NOT BE ABLE TO MAINTAIN THEIR CONCENTRATIONS AT SUFFICIENT LEVELS TO MATCH METABOLIC REQUIREMENTS. CHRONIC EXOGENOUS ARGININE SUPPLEMENTATION HAS NOT PROVEN TO EXERT POSITIVE CLINICAL EFFECTS IN DIFFERENT TRIALS, AND SEQUENTIAL ARTICULATION OF THE KNOWLEDGE OF INTRODUCTION OF ARGININE-DRIVEN TRANSCRIPTIONAL, TRANSLATIONAL, AND EPIGENETIC ADAPTATIONS MAY GIVE US A KEY FOR INTERPRETING THOSE PUZZLING RESULTS. 2011 3 4296 40 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 4 4776 52 NUTRACEUTICAL ACTIVITY IN OSTEOARTHRITIS BIOLOGY: A FOCUS ON THE NUTRIGENOMIC ROLE. OSTEOARTHRITIS (OA) IS A DISEASE ASSOCIATED TO AGE OR CONDITIONS THAT PRECIPITATE AGING OF ARTICULAR CARTILAGE, A POST-MITOTIC TISSUE THAT REMAINS FUNCTIONAL UNTIL THE FAILURE OF MAJOR HOMEOSTATIC MECHANISMS. OA SEVERELY IMPACTS THE NATIONAL HEALTH SYSTEM COSTS AND PATIENTS' QUALITY OF LIFE BECAUSE OF PAIN AND DISABILITY. IT IS A WHOLE-JOINT DISEASE SUSTAINED BY INFLAMMATORY AND OXIDATIVE SIGNALING PATHWAYS AND MARKED EPIGENETIC CHANGES RESPONSIBLE FOR CATABOLISM OF THE CARTILAGE EXTRACELLULAR MATRIX. OA USUALLY PROGRESSES UNTIL ITS SEVERITY REQUIRES JOINT ARTHROPLASTY. TO DELAY THIS PROGRESSION AND TO IMPROVE SYMPTOMS, A WIDE RANGE OF NATURALLY DERIVED COMPOUNDS HAVE BEEN PROPOSED AND ARE SUMMARIZED IN THIS REVIEW. PRECLINICAL IN VITRO AND IN VIVO STUDIES HAVE PROVIDED PROOF OF PRINCIPLE THAT MANY OF THESE NUTRACEUTICALS ARE ABLE TO EXERT PLEIOTROPIC AND SYNERGISTIC EFFECTS AND EFFECTIVELY COUNTERACT OA PATHOGENESIS BY EXERTING BOTH ANTI-INFLAMMATORY AND ANTIOXIDANT ACTIVITIES AND BY TUNING MAJOR OA-RELATED SIGNALING PATHWAYS. THE LATTER ARE THE BASIS FOR THE NUTRIGENOMIC ROLE PLAYED BY SOME OF THESE COMPOUNDS, GIVEN THE MARKED CHANGES IN THE TRANSCRIPTOME, MIRNOME, AND METHYLOME. ONGOING AND FUTURE CLINICAL TRIALS WILL HOPEFULLY CONFIRM THE DISEASE-MODIFYING ABILITY OF THESE BIOACTIVE MOLECULES IN OA PATIENTS. 2020 5 4928 26 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 6 6224 29 THE LEUCINE CATABOLITE AND DIETARY SUPPLEMENT BETA-HYDROXY-BETA-METHYL BUTYRATE (HMB) AS AN EPIGENETIC REGULATOR IN MUSCLE PROGENITOR CELLS. BETA-HYDROXY-BETA-METHYL BUTYRATE (HMB) IS A NATURAL CATABOLITE OF LEUCINE DEEMED TO PLAY A ROLE IN AMINO ACID SIGNALING AND THE MAINTENANCE OF LEAN MUSCLE MASS. ACCORDINGLY, HMB IS USED AS A DIETARY SUPPLEMENT BY SPORTSMEN AND HAS SHOWN SOME CLINICAL EFFECTIVENESS IN PREVENTING MUSCLE WASTING IN CANCER AND CHRONIC LUNG DISEASE, AS WELL AS IN AGE-DEPENDENT SARCOPENIA. HOWEVER, THE MOLECULAR CASCADES UNDERLYING THESE BENEFICIAL EFFECTS ARE LARGELY UNKNOWN. HMB BEARS A SIGNIFICANT STRUCTURAL SIMILARITY WITH BUTYRATE AND BETA-HYDROXYBUTYRATE (BETAHB), TWO COMPOUNDS RECOGNIZED FOR IMPORTANT EPIGENETIC AND HISTONE-MARKING ACTIVITIES IN MULTIPLE CELL TYPES INCLUDING MUSCLE CELLS. WE ASKED WHETHER SIMILAR CHROMATIN-MODIFYING ACTIONS COULD BE ASSIGNED TO HMB AS WELL. EXPOSURE OF MURINE C2C12 MYOBLASTS TO MILLIMOLAR CONCENTRATIONS OF HMB LED TO AN INCREASE IN GLOBAL HISTONE ACETYLATION, AS MONITORED BY ANTI-ACETYLATED LYSINE IMMUNOBLOTTING, WHILE PREVENTING MYOTUBE DIFFERENTIATION. IN THESE EFFECTS, HMB RESEMBLED, ALTHOUGH WITH LESS POTENCY, THE HISTONE DEACETYLASE (HDAC) INHIBITOR SODIUM BUTYRATE. HOWEVER, INITIAL STUDIES DID NOT CONFIRM A DIRECT INHIBITORY EFFECT OF HMB ON HDACS IN VITRO. BETA-HYDROXYBUTYRATE, A KETONE BODY PRODUCED BY THE LIVER DURING STARVATION OR INTENSE EXERCISE, HAS A MODEST EFFECT ON HISTONE ACETYLATION OF C2C12 CELLS OR IN VITRO HDAC INHIBITOR ACTIVITIES, AND, UNLIKE BUTYRATE AND HMB, DID NOT INTERFERE WITH MYOTUBE FORMATION IN A MYOBLAST DIFFERENTIATION ASSAY. INSTEAD, BETAHB DRAMATICALLY INCREASED LYSINE BETA-HYDROXYBUTYRYLATION (KBHB) OF HISTONE TAILS, AN EPIGENETIC MARK ASSOCIATED WITH FASTING RESPONSES AND MUSCLE CATABOLIC STATES. HOWEVER, WHEN C2C12 CELLS WERE EXPOSED TO BETAHB IN THE PRESENCE OF EQUIMOLAR HMB THIS CHROMATIN MODIFICATION WAS DRASTICALLY REDUCED, POINTING TO A ROLE FOR HMB IN ATTENUATING KETOSIS-ASSOCIATED MUSCLE WASTING. IN CONCLUSION, WHILE THEIR MECHANISTIC UNDERPINNINGS REMAIN TO BE CLARIFIED, THESE PRELIMINARY OBSERVATIONS HIGHLIGHT NOVEL AND POTENTIALLY IMPORTANT ACTIVITIES OF HMB AS AN EPIGENETIC REGULATOR AND BETAHB ANTAGONIST IN MUSCLE PRECURSOR CELLS, TO BE FURTHER EXPLORED IN THEIR BIOMEDICAL IMPLICATIONS. 2021 7 5052 38 PHARMACOLOGICAL TARGETING OF HEME OXYGENASE-1 IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A COMMON AGING-ASSOCIATED DISEASE THAT CLINICALLY MANIFESTS AS JOINT PAIN, MOBILITY LIMITATIONS, AND COMPROMISED QUALITY OF LIFE. TODAY, OA TREATMENT IS LIMITED TO PAIN MANAGEMENT AND JOINT ARTHROPLASTY AT THE LATER STAGES OF DISEASE PROGRESSION. OA PATHOGENESIS IS PREDOMINANTLY MEDIATED BY OXIDATIVE DAMAGE TO JOINT CARTILAGE EXTRACELLULAR MATRIX AND LOCAL CELLS SUCH AS CHONDROCYTES, OSTEOCLASTS, OSTEOBLASTS, AND SYNOVIAL FIBROBLASTS. UNDER NORMAL CONDITIONS, CELLS PREVENT THE ACCUMULATION OF REACTIVE OXYGEN SPECIES (ROS) UNDER OXIDATIVELY STRESSFUL CONDITIONS THROUGH THEIR ADAPTIVE CYTOPROTECTIVE MECHANISMS. HEME OXYGENASE-1 (HO-1) IS AN IRON-DEPENDENT CYTOPROTECTIVE ENZYME THAT FUNCTIONS AS THE INDUCIBLE FORM OF HO. HO-1 AND ITS METABOLITES CARBON MONOXIDE AND BILIVERDIN CONTRIBUTE TOWARDS THE MAINTENANCE OF REDOX HOMEOSTASIS. HO-1 EXPRESSION IS PRIMARILY REGULATED AT THE TRANSCRIPTIONAL LEVEL THROUGH TRANSCRIPTIONAL FACTOR NUCLEAR FACTOR ERYTHROID 2 (NF-E2)-RELATED FACTOR 2 (NRF2), SPECIFICITY PROTEIN 1 (SP1), TRANSCRIPTIONAL REPRESSOR BTB-AND-CNC HOMOLOGY 1 (BACH1), AND EPIGENETIC REGULATION. SEVERAL STUDIES REPORT THAT HO-1 EXPRESSION CAN BE REGULATED USING VARIOUS ANTIOXIDATIVE FACTORS AND CHEMICAL COMPOUNDS, SUGGESTING THERAPEUTIC IMPLICATIONS IN OA PATHOGENESIS AS WELL AS IN THE WIDER CONTEXT OF JOINT DISEASE. HERE, WE REVIEW THE PROTECTIVE ROLE OF HO-1 IN OA WITH A FOCUS ON THE REGULATORY MECHANISMS THAT MEDIATE HO-1 ACTIVITY. 2021 8 3164 29 GREEN TEA PREVENTS NAFLD BY MODULATION OF MIR-34A AND MIR-194 EXPRESSION IN A HIGH-FAT DIET MOUSE MODEL. BACKGROUND/AIMS: NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS CONSIDERED THE HEPATIC MANIFESTATION OF METABOLIC SYNDROME. IT IS CURRENTLY THE MOST COMMON CHRONIC LIVER DISEASE WITH COMPLEX PATHOGENESIS AND CHALLENGING TREATMENT. HERE, WE INVESTIGATED THE HEPATOPROTECTIVE ROLE OF GREEN TEA (GT) AND DETERMINED THE INVOLVEMENT OF MIRNAS AND ITS MECHANISM OF ACTION. METHODS: MALE C57BL/6 MICE WERE FED WITH A HIGH-FAT DIET FOR 4 WEEKS. AFTER THIS PERIOD, THE ANIMALS RECEIVED GAVAGE WITH GT (500 MG/KG BODY WEIGHT) OVER 12 WEEKS (5 DAYS/WEEK). HEPG2 CELL LINES WERE TRANSFECTED WITH MIR-34A OR MIR-194 MIMETICS AND INHIBITORS TO VALIDATE THE IN VIVO RESULTS OR WERE TREATED WITH TNF-ALPHA TO EVALUATE MIRNA REGULATION. RESULTS: GT SUPPLEMENTATION PROTECTS AGAINST NAFLD DEVELOPMENT BY ALTERING LIPID METABOLISM, INCREASING GENE EXPRESSION INVOLVED IN TRIGLYCERIDES AND FATTY ACID CATABOLISM, AND DECREASING UPTAKE AND LIPID ACCUMULATION. THIS PHENOTYPE WAS ACCOMPANIED BY MIR-34A DOWNREGULATION AND AN INCREASE IN THEIR MRNA TARGETS SIRT1, PPARALPHA, AND INSIG2. GT UPREGULATED HEPATIC MIR-194 BY INHIBITING TNF-ALPHA ACTION LEADING TO A DECREASE IN MIR-194 TARGET GENES HMGCS/APOA5. CONCLUSION: OUR STUDY IDENTIFIED FOR THE FIRST TIME THAT THE BENEFICIAL EFFECTS OF GT IN THE LIVER CAN BE DUE TO THE MODULATION OF MIRNAS, OPENING NEW PERSPECTIVES FOR THE TREATMENT OF NAFLD FOCUSING ON EPIGENETIC REGULATION OF MIR-34A AND MIR-194 AS GREEN TEA TARGETS. 2019 9 4577 35 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 10 6441 26 THERAPEUTIC APPROACHES FOR NONALCOHOLIC FATTY LIVER DISEASE: ESTABLISHED TARGETS AND DRUGS. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD), AS A MULTISYSTEMIC DISEASE, IS THE MOST PREVALENT CHRONIC LIVER DISEASE CHARACTERIZED BY EXTREMELY COMPLEX PATHOGENIC MECHANISMS AND MULTIFACTORIAL ETIOLOGY, WHICH OFTEN DEVELOPS AS A CONSEQUENCE OF OBESITY, METABOLIC SYNDROME. PATHOPHYSIOLOGICAL MECHANISMS INVOLVED IN THE DEVELOPMENT OF NAFLD INCLUDE DIET, OBESITY, INSULIN RESISTANCE (IR), GENETIC AND EPIGENETIC DETERMINANTS, INTESTINAL DYSBIOSIS, OXIDATIVE/NITROSATIVE STRESS, AUTOPHAGY DYSREGULATION, HEPATIC INFLAMMATION, GUT-LIVER AXIS, GUT MICROBES, IMPAIRED MITOCHONDRIAL METABOLISM AND REGULATION OF HEPATIC LIPID METABOLISM. SOME OF THE NEW DRUGS FOR THE TREATMENT OF NAFLD ARE INTRODUCED HERE. ALL OF THEM ACHIEVE THERAPEUTIC OBJECTIVES BY INTERFERING WITH CERTAIN PATHOPHYSIOLOGICAL PATHWAYS OF NAFLD, INCLUDING FIBROBLAST GROWTH FACTORS (FGF) ANALOGUES, PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS (PPARS) AGONISTS, GLUCAGON-LIKE PEPTIDE-1 (GLP-1) AGONISTS, G PROTEIN-COUPLED RECEPTORS (GPCRS), SODIUM-GLUCOSE COTRANSPORTER-2 INHIBITORS (SGLT-2I), FARNESOID X RECEPTOR (FXR), FATTY ACID SYNTHASE INHIBITOR (FASNI), ANTIOXIDANTS, ETC. THIS REVIEW DESCRIBES SOME PATHOPHYSIOLOGICAL MECHANISMS OF NAFLD AND ESTABLISHED TARGETS AND DRUGS. 2023 11 5109 44 POLYPHENOL-RELATED EPIGENETIC MODIFICATIONS IN OSTEOARTHRITIS: CURRENT THERAPEUTIC PERSPECTIVES. THE HYALINE CARTILAGE IS AN AVASCULAR, ANEURAL AND ALYMPHATIC TISSUE WITH A LIMITED ABILITY TO REPAIR ITSELF. WHEN THE CARTILAGE IS EXPOSED TO SOME KIND OF INJURY, IT USUALLY TRIGGERS OSTEOARTHRITIS (OA), A PREVALENT AND DEGENERATIVE JOINT DISEASE CLOSELY RELATED TO AGING. OA IS BOTH COMPLEX AND MULTIFACTORIAL, AND IS THE MOST COMMON FORM OF ARTHRITIS, BEING POSITIONED AS A MAJOR CAUSE OF PAIN AND DYSFUNCTION IN THE WORLD. IN ADDITION, HIGH OA PREVALENCE CAN GREATLY AFFECT WORK CAPACITY, MAKING THIS DISEASE A SIGNIFICANT SOCIAL PROBLEM, THEREFORE, ITS PREVENTION AND TREATMENT BECOMES A PRIORITY. AT THIS TIME, THERE ARE NUMEROUS THERAPEUTIC STRATEGIES AVAILABLE TO IMPROVE HYALINE CARTILAGE REPAIR BY USING CHONDROCYTES OR MESENCHYMAL CELLS, BUT NEITHER IS EFFECTIVE ENOUGH TO GENERATE FUNCTIONAL AND DURABLE TISSUE REPARATION OVER TIME. IN OA, CHONDROCYTES HAVE AN ABERRANT GENE EXPRESSION AND PHENOTYPE, RESULTING IN A LOSS OF BALANCE BETWEEN ANABOLIC AND CATABOLIC PROCESSES. ENVIRONMENTAL INFLUENCES SUCH AS RADIATION, INFECTION, SMOKING, NUTRIENTS, TOXINS AND STRESS CAN AFFECT GENE EXPRESSION PATTERNS, WHICH MAY CONSTITUTE RISK FACTORS FOR VARIOUS CHRONIC AND DEGENERATIVE DISEASES, SUCH AS OA. IN ADDITION, CONSIDERABLE EVIDENCE SHOWS THAT EPIGENETIC MECHANISMS PLAY AN IMPORTANT ROLE IN OA CHONDROGENESIS AND PATHOGENESIS. NATURAL PLANT-DERIVED PRODUCTS SUCH AS POLYPHENOLS, WHICH ARE SECONDARY METABOLITES CONSIDERED TO HAVE POTENTIAL ACTIVITY TO BLOCK INFLAMMATION IN SEVERAL DEGENERATIVE DISEASES, CAN STIMULATE EPIGENETIC MODIFICATIONS, AND MAY PROVIDE NEW THERAPEUTIC TARGETS AND COST-EFFECTIVE TREATMENTS. THIS REVIEW AIMS TO PRESENT VARIOUS POLYPHENOLBASED THERAPIES CURRENTLY USED FOR THE TREATMENT OF SEVERAL PROGRESSIVE DISEASES, INCLUDING OA. 2016 12 4679 44 NEW MOLECULAR TARGETS FOR THE TREATMENT OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A CHRONIC DEGENERATIVE JOINT DISORDER CHARACTERIZED BY DESTRUCTION OF THE ARTICULAR CARTILAGE, SUBCHONDRAL BONE ALTERATIONS AND SYNOVITIS. CURRENT TREATMENTS ARE FOCUSED ON SYMPTOMATIC RELIEF BUT THEY LACK EFFICACY TO CONTROL THE PROGRESSION OF THIS DISEASE WHICH IS A LEADING CAUSE OF DISABILITY. THEREFORE, THE DEVELOPMENT OF EFFECTIVE DISEASE-MODIFYING DRUGS IS URGENTLY NEEDED. DIFFERENT INITIATIVES ARE IN PROGRESS TO DEFINE THE MOLECULAR MECHANISMS INVOLVED IN THE INITIATION AND PROGRESSION OF OA. THESE STUDIES SUPPORT THE THERAPEUTIC POTENTIAL OF PATHWAYS RELEVANT IN JOINT METABOLISM SUCH AS WNT/BETA-CATENIN, DISCOIDIN DOMAIN RECEPTOR 2 OR PROTEINASE-ACTIVATED RECEPTOR 2. THE DYSREGULATION IN CARTILAGE CATABOLISM AND SUBCHONDRAL BONE REMODELING COULD BE IMPROVED BY SELECTIVE INHIBITORS OF MATRIX METALLOPROTEINASES, AGGRECANASES AND OTHER PROTEASES. ANOTHER APPROACH WOULD FAVOR THE ACTIVITY OF ANABOLIC PROCESSES BY USING GROWTH FACTORS OR REGULATORY MOLECULES. RECENT STUDIES HAVE ALSO REVEALED THE ROLE OF OXIDATIVE STRESS AND SYNOVITIS IN THE PROGRESSION OF THIS DISEASE, SUPPORTING THE DEVELOPMENT OF A NUMBER OF INHIBITORY STRATEGIES. NOVEL TARGETS IN OA ARE REPRESENTED BY GENES INVOLVED IN OA PATHOPHYSIOLOGY DISCOVERED USING GENE NETWORK, EPIGENETIC AND MICRORNA APPROACHES. FURTHER INSIGHTS INTO THE MOLECULAR MECHANISMS INVOLVED IN OA INITIATION AND PROGRESSION MAY LEAD TO THE DEVELOPMENT OF NEW THERAPIES ABLE TO CONTROL JOINT DESTRUCTION AND REPAIR. 2010 13 3355 34 HISTONE EXTRACTION FROM HUMAN ARTICULAR CARTILAGE FOR THE STUDY OF EPIGENETIC REGULATION IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A CHRONIC DISEASE THAT AFFECTS ARTICULAR CARTILAGE, CAUSING ITS DEGENERATION. ALTHOUGH OA IS ONE OF THE MOST PREVALENT PATHOLOGIES GLOBALLY, THERE ARE NO DEFINITIVE TREATMENTS AVAILABLE. RECENTLY, RESEARCH HAS FOCUSED ON ELUCIDATING THE COMPLEX INTERPLAY THAT TAKES PLACE BETWEEN INFLAMMATORY PROCESSES AND EPIGENETIC REGULATION, SHOWING THAT HISTONE POST-TRANSLATIONAL MODIFICATIONS (PTMS) CAN EXERT A PRONOUNCED EFFECT ON THE EXPRESSION OF OA-RELATED GENES. OA CHONDROCYTES ENHANCE THE PRODUCTION OF INTERLEUKIN 1BETA (IL-1BETA) AND INTERLEUKIN 8 (IL-8), WHICH ARE EPIGENETICALLY REGULATED. THESE CYTOKINES UPREGULATE THE SYNTHESIS OF MATRIX METALLOPROTEINASES (MMPS) AND AGGRECANASES, WHICH PROMOTE THE EXTRACELLULAR MATRIX (ECM) DESTRUCTION. THIS MOTIVATES THE STUDY OF HISTONE PTMS TO INVESTIGATE THE EPIGENETIC REGULATION OF PROINFLAMMATORY MOLECULES, BUT THE ABSENCE OF SPECIFIC PROTOCOLS TO EXTRACT HISTONES FROM HUMAN ARTICULAR CARTILAGE HAS COMPLICATED THIS TASK. THE LACK OF EFFECTIVE METHODS CAN BE EXPLAINED BY THE STRUCTURAL COMPLEXITY AND LOW CELLULARITY OF THIS TISSUE, WHICH ARE RESPONSIBLE FOR THE BIOMECHANICAL PROPERTIES THAT ALLOW THE MOVEMENT OF THE JOINT BUT ALSO COMPLICATE HISTONE ISOLATION. HERE, WE PROVIDE A HISTONE EXTRACTION PROCEDURE SPECIFICALLY ADAPTED FOR CRYOPRESERVED HUMAN ARTICULAR CARTILAGE THAT CAN BE USEFUL TO UNDERSTAND EPIGENETIC REGULATION IN OA AND ACCELERATE THE SEARCH FOR NOVEL STRATEGIES. 2022 14 4880 34 OVERVIEW OF MMP-13 AS A PROMISING TARGET FOR THE TREATMENT OF OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS A COMMON DEGENERATIVE DISEASE CHARACTERIZED BY THE DESTRUCTION OF ARTICULAR CARTILAGE AND CHRONIC INFLAMMATION OF SURROUNDING TISSUES. MATRIX METALLOPROTEINASE-13 (MMP-13) IS THE PRIMARY MMP INVOLVED IN CARTILAGE DEGRADATION THROUGH ITS PARTICULAR ABILITY TO CLEAVE TYPE II COLLAGEN. HENCE, IT IS AN ATTRACTIVE TARGET FOR THE TREATMENT OF OA. HOWEVER, THE DETAILED MOLECULAR MECHANISMS OF OA INITIATION AND PROGRESSION REMAIN ELUSIVE, AND, CURRENTLY, THERE ARE NO INTERVENTIONS AVAILABLE TO RESTORE DEGRADED CARTILAGE. THIS REVIEW FULLY ILLUSTRATES THE INVOLVEMENT OF MMP-13 IN THE INITIATION AND PROGRESSION OF OA THROUGH THE REGULATION OF MMP-13 ACTIVITY AT THE MOLECULAR AND EPIGENETIC LEVELS, AS WELL AS THE STRATEGIES THAT HAVE BEEN EMPLOYED AGAINST MMP-13. THE AIM OF THIS REVIEW IS TO IDENTIFY MMP-13 AS AN ATTRACTIVE TARGET FOR INHIBITOR DEVELOPMENT IN THE TREATMENT OF OA. 2021 15 2701 18 EXCESSIVE BRANCHED-CHAIN AMINO ACID ACCUMULATION RESTRICTS MESENCHYMAL STEM CELL-BASED THERAPY EFFICACY IN MYOCARDIAL INFARCTION. MESENCHYMAL STEM CELLS (MSCS) DELIVERED INTO THE POST-ISCHEMIC HEART MILIEU HAVE A LOW SURVIVAL AND RETENTION RATE, THUS RESTRICTING THE CARDIOREPARATIVE EFFICACY OF MSC-BASED THERAPY. CHRONIC ISCHEMIA RESULTS IN METABOLIC REPROGRAMMING IN THE HEART, BUT LITTLE IS KNOWN ABOUT HOW THESE METABOLIC CHANGES INFLUENCE IMPLANTED MSCS. HERE, WE FOUND THAT EXCESSIVE BRANCHED-CHAIN AMINO ACID (BCAA) ACCUMULATION, A METABOLIC SIGNATURE SEEN IN THE POST-ISCHEMIC HEART, WAS DISADVANTAGEOUS TO THE RETENTION AND CARDIOPROTECTION OF INTRAMYOCARDIALLY INJECTED MSCS. DISCOVERY-DRIVEN EXPERIMENTS REVEALED THAT BCAA AT PATHOLOGICAL LEVELS SENSITIZED MSCS TO STRESS-INDUCED CELL DEATH AND PREMATURE SENESCENCE VIA ACCELERATING THE LOSS OF HISTONE 3 LYSINE 9 TRIMETHYLATION (H3K9ME3). A NOVEL MTORC1/DUX4/KDM4E AXIS WAS IDENTIFIED AS THE CAUSE OF BCAA-INDUCED H3K9ME3 LOSS AND ADVERSE PHENOTYPE ACQUISITION. ENHANCING BCAA CATABOLIC CAPABILITY IN MSCS VIA GENETIC/PHARMACOLOGICAL APPROACHES GREATLY IMPROVED THEIR ADAPTATION TO THE HIGH BCAA MILIEU AND STRENGTHENED THEIR CARDIOPROTECTIVE EFFICACY. WE CONCLUDE THAT ABERRANT BCAA ACCUMULATION IS DETRIMENTAL TO IMPLANTED MSCS VIA A PREVIOUSLY UNKNOWN METABOLITE-SIGNALING-EPIGENETIC MECHANISM, EMPHASIZING THAT THE METABOLIC CHANGES OF THE POST-ISCHEMIC HEART CRUCIALLY INFLUENCE THE FATE OF IMPLANTED MSCS AND THEIR THERAPEUTIC BENEFITS. 2022 16 5334 21 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 17 5724 33 SKELETAL MUSCLE WASTING AND ITS RELATIONSHIP WITH OSTEOARTHRITIS: A MINI-REVIEW OF MECHANISMS AND CURRENT INTERVENTIONS. PURPOSE OF REVIEW: OSTEOARTHRITIS (OA) IS A SUBSET OF JOINT DISORDERS RESULTING IN DEGENERATION OF SYNOVIAL JOINTS. THIS LEADS TO PAIN, DISABILITY AND LOSS OF INDEPENDENCE. KNEE AND HIP OA ARE EXTREMELY PREVALENT, AND THEIR OCCURRENCE INCREASES WITH AGEING. SIMILARLY, LOSS OF MUSCLE MASS AND FUNCTION, SARCOPENIA, OCCURS DURING AGEING. RECENT FINDINGS: LITTLE IS KNOWN ABOUT THE IMPACT OF MUSCLE WASTING ON OA PROGRESSION; NEVERTHELESS, IT HAS BEEN SUGGESTED THAT MUSCLE WASTING DIRECTLY AFFECTS THE STABILITY OF THE JOINTS AND LOSS OF MOBILITY LEADS TO GRADUAL DEGENERATION OF ARTICULAR CARTILAGE. THE MOLECULAR MECHANISMS UNDERLYING MUSCLE WASTING IN OA ARE NOT WELL UNDERSTOOD; HOWEVER, THESE ARE PROBABLY RELATED TO CHANGES IN GENE EXPRESSION, AS WELL AS EPIGENETIC MODIFICATIONS. IT IS BECOMING CLEAR THAT SKELETAL MUSCLE WASTING PLAYS AN IMPORTANT ROLE IN OA DEVELOPMENT AND/OR PROGRESSION. HERE, WE DISCUSS MECHANISMS, CURRENT INTERVENTIONS, SUCH AS EXERCISE, AND POTENTIALLY NOVEL APPROACHES, SUCH AS MODULATION OF MICRORNAS, AIMING AT AMELIORATING OA SYMPTOMS THROUGH MAINTAINING MUSCLE MASS AND FUNCTION. 2019 18 2862 28 FRUCTOSE-MEDIATED EFFECTS ON GENE EXPRESSION AND EPIGENETIC MECHANISMS ASSOCIATED WITH NAFLD PATHOGENESIS. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A CHRONIC, FREQUENTLY PROGRESSIVE CONDITION THAT DEVELOPS IN RESPONSE TO EXCESSIVE HEPATOCYTE FAT ACCUMULATION (I.E., STEATOSIS) IN THE ABSENCE OF SIGNIFICANT ALCOHOL CONSUMPTION. LIVER STEATOSIS DEVELOPS AS A RESULT OF IMBALANCED LIPID METABOLISM, DRIVEN LARGELY BY INCREASED RATES OF DE NOVO LIPOGENESIS AND HEPATIC FATTY ACID UPTAKE AND REDUCED FATTY ACID OXIDATION AND/OR DISPOSAL TO THE CIRCULATION. FRUCTOSE IS A NATURALLY OCCURRING SIMPLE SUGAR, WHICH IS MOST COMMONLY CONSUMED IN MODERN DIETS IN THE FORM OF SUCROSE, A DISACCHARIDE COMPRISED OF ONE MOLECULE OF FRUCTOSE COVALENTLY BONDED WITH ONE MOLECULE OF GLUCOSE. A NUMBER OF OBSERVATIONAL AND EXPERIMENTAL STUDIES HAVE DEMONSTRATED DETRIMENTAL EFFECTS OF DIETARY FRUCTOSE CONSUMPTION NOT ONLY ON DIVERSE METABOLIC OUTCOMES SUCH AS INSULIN RESISTANCE AND OBESITY, BUT ALSO ON HEPATIC STEATOSIS AND NAFLD-RELATED FIBROSIS. DESPITE THE COMPELLING EVIDENCE THAT EXCESSIVE FRUCTOSE CONSUMPTION IS ASSOCIATED WITH THE PRESENCE OF NAFLD AND MAY EVEN PROMOTE THE DEVELOPMENT AND PROGRESSION OF NAFLD TO MORE CLINICALLY SEVERE PHENOTYPES, THE MOLECULAR MECHANISMS BY WHICH FRUCTOSE ELICITS EFFECTS ON DYSREGULATED LIVER METABOLISM REMAIN UNCLEAR. EMERGING DATA SUGGEST THAT DIETARY FRUCTOSE MAY DIRECTLY ALTER THE EXPRESSION OF GENES INVOLVED IN LIPID METABOLISM, INCLUDING THOSE THAT INCREASE HEPATIC FAT ACCUMULATION OR REDUCE HEPATIC FAT REMOVAL. THE AIM OF THIS REVIEW IS TO SUMMARIZE THE CURRENT RESEARCH SUPPORTING A ROLE FOR DIETARY FRUCTOSE INTAKE IN THE MODULATION OF TRANSCRIPTOMIC AND EPIGENETIC MECHANISMS UNDERLYING THE PATHOGENESIS OF NAFLD. 2020 19 484 39 ARTICULAR CARTILAGE CHANGES IN MATURING ATHLETES: NEW TARGETS FOR JOINT REJUVENATION. CONTEXT: ARTICULAR CARTILAGE HAS A UNIQUE FUNCTIONAL ARCHITECTURE CAPABLE OF PROVIDING A LIFETIME OF PAIN-FREE JOINT MOTION. THIS TISSUE, HOWEVER, UNDERGOES SUBSTANTIAL AGE-RELATED PHYSIOLOGIC, MECHANICAL, BIOCHEMICAL, AND FUNCTIONAL CHANGES THAT REDUCE ITS ABILITY TO OVERCOME THE EFFECTS OF MECHANICAL STRESS AND INJURY. MANY FACTORS AFFECT JOINT FUNCTION IN THE MATURING ATHLETE-FROM CHONDROCYTE SURVIVAL AND METABOLISM TO STRUCTURAL COMPOSITION AND GENETIC/EPIGENETIC FACTORS GOVERNING CARTILAGE AND SYNOVIUM. AN EVALUATION OF AGE-RELATED CHANGES FOR JOINT HOMEOSTASIS AND RISK FOR OSTEOARTHRITIS IS IMPORTANT TO THE DEVELOPMENT OF NEW STRATEGIES TO REJUVENATE AGING JOINTS. OBJECTIVE: THIS REVIEW SUMMARIZES THE CURRENT LITERATURE ON THE BIOCHEMICAL, CELLULAR, AND PHYSIOLOGIC CHANGES OCCURRING IN AGING ARTICULAR CARTILAGE. DATA SOURCES: PUBMED (1969-2013) AND PUBLISHED BOOKS IN SPORTS HEALTH, CARTILAGE BIOLOGY, AND AGING. STUDY SELECTION: KEYWORDS INCLUDED AGING, ATHLETE, ARTICULAR CARTILAGE, EPIGENETICS, AND FUNCTIONAL PERFORMANCE WITH AGE. STUDY DESIGN: SYSTEMATIC REVIEW. LEVEL OF EVIDENCE: LEVEL 3. DATA EXTRACTION: TO BE INCLUDED, RESEARCH QUESTIONS ADDRESSED THE EFFECT OF AGE-RELATED CHANGES ON PERFORMANCE, ARTICULAR CARTILAGE BIOLOGY, MOLECULAR MECHANISM, AND MORPHOLOGY. RESULTS: THE MATURE ATHLETE FACES CHALLENGES IN MAINTAINING CARTILAGE HEALTH AND JOINT FUNCTION DUE TO AGE-RELATED CHANGES TO ARTICULAR CARTILAGE BIOLOGY, MORPHOLOGY, AND PHYSIOLOGY. THESE CHANGES INCLUDE CHONDROCYTE LOSS AND A DECLINE IN METABOLIC RESPONSE, ALTERATIONS TO MATRIX AND SYNOVIAL TISSUE COMPOSITION, AND DYSREGULATION OF REPARATIVE RESPONSES. CONCLUSION: ALTHOUGH PHYSICAL DECLINE HAS BEEN REGARDED AS A NORMAL PART OF AGING, MANY INDIVIDUALS MAINTAIN OVERALL FITNESS AND ENJOY TARGETED IMPROVEMENT TO THEIR ATHLETIC CAPACITY THROUGHOUT LIFE. HEALTHY ARTICULAR CARTILAGE AND JOINTS ARE NEEDED TO MAINTAIN ATHLETIC PERFORMANCE AND GENERAL ACTIVITIES. GENETIC AND POTENTIALLY REVERSIBLE EPIGENETIC FACTORS INFLUENCE CARTILAGE PHYSIOLOGY AND ITS RESPONSE TO MECHANICAL AND INJURIOUS STIMULI. IMPROVED UNDERSTANDINGS OF THE PHYSICAL AND MOLECULAR CHANGES TO ARTICULAR CARTILAGE WITH AGING ARE IMPORTANT TO DEVELOP SUCCESSFUL STRATEGIES FOR JOINT REJUVENATION. 2014 20 2361 25 EPIGENETIC REGULATION OF SKELETAL TISSUE INTEGRITY AND OSTEOPOROSIS DEVELOPMENT. BONE TURNOVER IS SOPHISTICATEDLY BALANCED BY A DYNAMIC COUPLING OF BONE FORMATION AND RESORPTION AT VARIOUS RATES. THE ORCHESTRATION OF THIS CONTINUOUS REMODELING OF THE SKELETON FURTHER AFFECTS OTHER SKELETAL TISSUES THROUGH ORGAN CROSSTALK. CHRONIC EXCESSIVE BONE RESORPTION COMPROMISES BONE MASS AND ITS POROUS MICROSTRUCTURE AS WELL AS PROPER BIOMECHANICS. THIS ACCELERATES THE DEVELOPMENT OF OSTEOPOROTIC DISORDERS, A LEADING CAUSE OF SKELETAL DEGENERATION-ASSOCIATED DISABILITY AND PREMATURE DEATH. BONE-FORMING CELLS PLAY IMPORTANT ROLES IN MAINTAINING BONE DEPOSIT AND OSTEOCLASTIC RESORPTION. A POOR ORGANELLE MACHINERY, SUCH AS MITOCHONDRIAL DYSFUNCTION, ENDOPLASMIC RETICULUM STRESS, AND DEFECTIVE AUTOPHAGY, ETC., DYSREGULATES GROWTH FACTOR SECRETION, MINERALIZATION MATRIX PRODUCTION, OR OSTEOCLAST-REGULATORY CAPACITY IN OSTEOBLASTIC CELLS. A PLETHORA OF EPIGENETIC PATHWAYS REGULATE BONE FORMATION, SKELETAL INTEGRITY, AND THE DEVELOPMENT OF OSTEOPOROSIS. MICRORNAS INHIBIT PROTEIN TRANSLATION BY BINDING THE 3'-UNTRANSLATED REGION OF MRNAS OR PROMOTE TRANSLATION THROUGH POST-TRANSCRIPTIONAL PATHWAYS. DNA METHYLATION AND POST-TRANSLATIONAL MODIFICATION OF HISTONES ALTER THE CHROMATIN STRUCTURE, HINDERING HISTONE ENRICHMENT IN PROMOTER REGIONS. MICRORNA-PROCESSING ENZYMES AND DNA AS WELL AS HISTONE MODIFICATION ENZYMES CATALYZE THESE MODIFYING REACTIONS. GAIN AND LOSS OF THESE EPIGENETIC MODIFIERS IN BONE-FORMING CELLS AFFECT THEIR EPIGENETIC LANDSCAPES, INFLUENCING BONE HOMEOSTASIS, MICROARCHITECTURAL INTEGRITY, AND OSTEOPOROTIC CHANGES. THIS ARTICLE CONVEYS PRODUCTIVE INSIGHTS INTO BIOLOGICAL ROLES OF DNA METHYLATION, MICRORNA, AND HISTONE MODIFICATION AND HIGHLIGHTS THEIR INTERACTIONS DURING SKELETAL DEVELOPMENT AND BONE LOSS UNDER PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS. 2020