1 719 188 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 2 1900 44 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 3 4526 41 MULTIFUNCTIONAL TARGETS OF DIETARY POLYPHENOLS IN DISEASE: A CASE FOR THE CHEMOKINE NETWORK AND ENERGY METABOLISM. CHRONIC, NON-ACUTE INFLAMMATION IS BEHIND CONDITIONS THAT REPRESENT MOST OF THE DISEASE BURDEN IN HUMANS AND IS CLEARLY LINKED TO IMMUNE AND METABOLIC MECHANISMS. THE CONVERGENCE OF PATHWAYS INVOLVING THE IMMUNE RESPONSE, OXIDATIVE STRESS, INCREASED CIRCULATING LIPIDS AND ABERRANT INSULIN SIGNALING RESULTS IN CCL2-ASSOCIATED MACROPHAGE RECRUITMENT AND ALTERED ENERGY METABOLISM. THE CCL2/CCR2 PATHWAY AND THE ENERGY SENSOR AMP-ACTIVATED PROTEIN KINASE (AMPK) ARE ATTRACTIVE THERAPEUTIC TARGETS AS A PART OF PREVENTIVE MANAGEMENT OF DISEASE. SEVERAL EFFECTS OF POLYPHENOLS ARE USEFUL IN THIS SCENARIO, INCLUDING A REDUCTION IN THE ACTIVITIES OF CYTOKINES AND MODULATION OF CELLULAR METABOLISM THROUGH HISTONE DEACETYLASE INHIBITORS, AMPK ACTIVATORS, CALORIE-RESTRICTION MIMETICS OR EPIGENETIC REGULATORS. RESEARCH IS CURRENTLY UNDERWAY TO DEVELOP ORALLY ACTIVE DRUGS WITH THESE EFFECTS, BUT IT IS CONVENIENT TO EXAMINE MORE CLOSELY WHAT WE ARE EATING. IF A LACK OF RELEVANCE IN TERMS OF TOXICITY AND SUBSTANTIAL EFFECTIVENESS ARE CONFIRMED, PLANT-DERIVED COMPONENTS MAY PROVIDE USEFUL DRUGGABLE COMPONENTS AND DIETARY SUPPLEMENTS. WE CONSIDER THERAPEUTIC ACTIONS AS A COMBINATION OF SYNERGISTIC AND/OR ANTAGONISTIC INTERACTIONS IN A MULTI-TARGET STRATEGY. HENCE, IMPROVEMENT IN FOOD THROUGH ENRICHMENT WITH POLYPHENOLS WITH DEMONSTRATED ACTIVITY MAY REPRESENT A MAJOR ADVANCE IN THE DESIGN OF DIETS WITH BOTH INDUSTRIAL AND SANITARY VALUE. 2013 4 1394 49 DIET AND AGING. NUTRITION HAS IMPORTANT LONG-TERM CONSEQUENCES FOR HEALTH THAT ARE NOT ONLY LIMITED TO THE INDIVIDUAL BUT CAN BE PASSED ON TO THE NEXT GENERATION. IT CAN CONTRIBUTE TO THE DEVELOPMENT AND PROGRESSION OF CHRONIC DISEASES THUS EFFECTING LIFE SPAN. CALORIC RESTRICTION (CR) CAN EXTEND THE AVERAGE AND MAXIMUM LIFE SPAN AND DELAY THE ONSET OF AGE-ASSOCIATED CHANGES IN MANY ORGANISMS. CR ELICITS COORDINATED AND ADAPTIVE STRESS RESPONSES AT THE CELLULAR AND WHOLE-ORGANISM LEVEL BY MODULATING EPIGENETIC MECHANISMS (E.G., DNA METHYLATION, POSTTRANSLATIONAL HISTONE MODIFICATIONS), SIGNALING PATHWAYS THAT REGULATE CELL GROWTH AND AGING (E.G., TOR, AMPK, P53, AND FOXO), AND CELL-TO-CELL SIGNALING MOLECULES (E.G., ADIPONECTIN). THE OVERALL EFFECT OF THESE ADAPTIVE STRESS RESPONSES IS AN INCREASED RESISTANCE TO SUBSEQUENT STRESS, THUS DELAYING AGE-RELATED CHANGES AND PROMOTING LONGEVITY. IN HUMAN, CR COULD DELAY MANY DISEASES ASSOCIATED WITH AGING INCLUDING CANCER, DIABETES, ATHEROSCLEROSIS, CARDIOVASCULAR DISEASE, AND NEURODEGENERATIVE DISEASES. AS AN ALTERNATIVE TO CR, SEVERAL CR MIMETICS HAVE BEEN TESTED ON ANIMALS AND HUMANS. AT PRESENT, THE MOST PROMISING ALTERNATIVES TO THE USE OF CR IN HUMANS SEEM TO BE EXERCISE, ALONE OR IN COMBINATION WITH REDUCED CALORIE INTAKE, AND THE USE OF PLANT-DERIVED POLYPHENOL RESVERATROL AS A FOOD SUPPLEMENT. 2012 5 4987 45 PATTERNS OF CALCIUM SIGNALING: A LINK BETWEEN CHRONIC EMOTIONS AND CANCER. INTRA AND INTER-CELLULAR CALCIUM SIGNALING IS PRESENT IN ALL TYPES OF CELLS AND BODY TISSUES. IN THE HUMAN BRAIN, CALCIUM CURRENTS AND WAVES ARE RELATED TO MENTAL ACTIVITIES, INCLUDING EMOTIONS. WE PRESENT A THEORETICAL INTERPRETATION OF THESE PHENOMENA SUGGESTING THEIR INVOLVEMENT IN CHRONIC EMOTIONAL PATTERNS AND IN THE PATHOLOGY OF CANCER. RECENT DEVELOPMENTS ON BIOPHYSICS, TRANSLATIONAL BIOLOGY AND PSYCHONEUROENDOCRINOIMMUNOLOGY (PNEI) CAN SUPPORT EXPLANATORY HYPOTHESES ABOUT THE LINK BETWEEN EMOTIONAL STRESSES AND THE ORIGIN AND DEVELOPMENT OF DIFFERENT TYPES OF TUMOR CELLS. CHRONIC STRESSES MAY CAUSE PERTURBATIONS OF RHYTHMS OF THE PNEI SYSTEM, EXCESSIVE ACTIVATION OF HPA AXIS AND ABNORMAL ACTIVATION OF CALCIUM SIGNALS IN SOMATIC TISSUES, WITH DELETERIOUS EFFECTS ON DIFFERENT PARTS OF THE BODY. THE INCREASING OF CALCIUM SIGNALING INSIDE CELLS MAY LEAD TO A DEREGULATION OF DIFFERENT PATHWAYS AND EPIGENETIC SYSTEMS THAT PROMOTE THE PRODUCTION OF GENOMIC MUTATIONS IN A SECOND PHASE. IN PARTICULAR, THE HYPERACTIVATION OF THE TRANSCRIPTION NUCLEAR FACTOR KAPPAB (NF-KAPPAB), IF IS NOT COUNTERBALANCED BY THE FOLLOWING ACTIVATION OF THE NUCLEAR FACTOR (ERYTHROID-DERIVED 2)-LIKE 2 (NFE2L2 OR NRF2), INCREASES THE PRODUCTION OF OXIDATIVE CATABOLITES, AS THE ADVANCED GLYCATION END PRODUCTS (AGE), WHICH PLAY A KEY ROLE IN THE PROGRESSION OF DIFFERENT TYPES OF CANCER AND OTHER DEGENERATIVE DISEASES. CORTISOL BINDING TO GLUCOCORTICOID RECEPTOR (GR) REDUCES THE ACTIVITY OF BOTH NF-KAPPAB AND NRF2 INSIDE THE CELLS BUT INHIBITS THE CELLULAR IMMUNITY AND THE ANABOLIC PROCESSES OF TISSUE REGENERATION. THE TISSUE ATROPHY AND THE DEFECTIVE ANTI-AGEING MECHANISMS PROMOTES THE TUMORAL CELLS GROWTH AND THEIR ESCAPE FROM THE IMMUNE-SURVEILLANCE. 2017 6 4597 32 NATURAL PRODUCTS WITH ANTI-AGING POTENTIAL: AFFECTED TARGETS AND MOLECULAR MECHANISMS. IN RECENT YEARS, THERE HAS BEEN A GREAT DEAL OF ATTENTION TOWARD THE MOLECULAR MACHINERY RELEVANT TO AGE-RELATED PROGRESSION CONTROLLED THROUGH THE EXTERNAL INTERVENTION OF POLYPHENOLS- AN EPIGENETIC-MODULATING DIET. NATURAL PRODUCTS MODULATE CELLULAR LONGEVITY THROUGH HISTONE POST-TRANSLATIONAL MODIFICATION AND CAN ALSO INDUCE THE UPREGULATION OF AUTOPHAGY, THUS REDUCING THE LEVEL OF ACETYL COENZYME A (ACCOA). IN ADDITION, THE EFFECT OF CALORIC RESTRICTION (CR) ON CANCER-RELATED CHRONIC INFLAMMATION IS OF GREAT SIGNIFICANCE IN AGING. IN LINE WITH THIS, SIRT1 PROTEIN LEVELS ARE EXPANDED IN RESPONSE TO CALORIE RESTRICTION MIMETICS (CRM), IN THIS WAY ACTING AS AUTOPHAGY INDUCERS RELEVANT TO CANCER PREVENTION. 2018 7 2346 38 EPIGENETIC REGULATION OF METABOLISM AND INFLAMMATION BY CALORIE RESTRICTION. CHRONIC CALORIC RESTRICTION (CR) WITHOUT MALNUTRITION IS KNOWN TO AFFECT DIFFERENT CELLULAR PROCESSES SUCH AS STEM CELL FUNCTION, CELL SENESCENCE, INFLAMMATION, AND METABOLISM. DESPITE THE DIFFERENCES IN THE IMPLEMENTATION OF CR, THE REDUCTION OF CALORIES PRODUCES A WIDESPREAD BENEFICIAL EFFECT IN NONCOMMUNICABLE CHRONIC DISEASES, WHICH CAN BE EXPLAINED BY IMPROVEMENTS IN IMMUNO-METABOLIC ADAPTATION. CELLULAR ADAPTATION THAT OCCURS IN RESPONSE TO DIETARY PATTERNS CAN BE EXPLAINED BY ALTERATIONS IN EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNA. IN THIS REVIEW, WE DEFINE THESE MODIFICATIONS AND SYSTEMATICALLY SUMMARIZE THE CURRENT EVIDENCE RELATED TO CR AND THE EPIGENOME. WE THEN EXPLAIN THE SIGNIFICANCE OF GENOME-WIDE EPIGENETIC MODIFICATIONS IN THE CONTEXT OF DISEASE DEVELOPMENT. ALTHOUGH SUBSTANTIAL EVIDENCE EXISTS FOR THE WIDESPREAD EFFECT OF CR ON LONGEVITY, THERE IS NO CONSENSUS REGARDING THE EPIGENETIC REGULATIONS OF THE UNDERLYING CELLULAR MECHANISMS THAT LEAD TO IMPROVED HEALTH. WE PROVIDE COMPELLING EVIDENCE THAT CR PRODUCES LONG-LASTING EPIGENETIC EFFECTS THAT MEDIATE EXPRESSION OF GENES RELATED TO IMMUNO-METABOLIC PROCESSES. EPIGENETIC REPROGRAMMING OF THE UNDERLYING CHRONIC LOW-GRADE INFLAMMATION BY CR CAN LEAD TO IMMUNO-METABOLIC ADAPTATIONS THAT ENHANCE QUALITY OF LIFE, EXTEND LIFESPAN, AND DELAY CHRONIC DISEASE ONSET. 2019 8 4391 41 MODERATE EXERCISE INDUCES TRAINED IMMUNITY IN MACROPHAGES. DESPITE ITS IMPORTANCE IN PROTECTING THE HOST FROM INFECTIONS AND INJURY, EXCESSIVE INFLAMMATION MAY LEAD TO SERIOUS HUMAN DISEASES INCLUDING AUTOIMMUNE DISORDERS, CARDIOVASCULAR DISEASES, DIABETES, AND CANCER. EXERCISE IS A KNOWN IMMUNOMODULATOR; HOWEVER, WHETHER EXERCISE CAUSES LONG-TERM CHANGES IN INFLAMMATORY RESPONSES AND HOW THESE CHANGES OCCUR ARE LACKING. HERE, WE SHOW THAT CHRONIC MODERATE-INTENSITY TRAINING OF MICE LEADS TO PERSISTENT METABOLIC REWIRING AND CHANGES TO CHROMATIN ACCESSIBILITY IN BONE MARROW-DERIVED MACROPHAGES (BMDMS), WHICH, IN TURN, TEMPERS THEIR INFLAMMATORY RESPONSES. WE SHOW THAT BMDMS FROM EXERCISED MICE EXHIBITED A DECREASE IN LIPOPOLYSACCHARIDE (LPS)-INDUCED NF-KAPPAB ACTIVATION AND PROINFLAMMATORY GENE EXPRESSION ALONG WITH AN INCREASE IN M2-LIKE-ASSOCIATED GENES WHEN COMPARED WITH BMDMS FROM SEDENTARY MICE. THIS WAS ASSOCIATED WITH IMPROVED MITOCHONDRIAL QUALITY AND INCREASED RELIANCE ON OXIDATIVE PHOSPHORYLATION ACCOMPANIED WITH REDUCED MITOCHONDRIAL REACTIVE OXYGEN SPECIES (ROS) PRODUCTION. MECHANISTICALLY, ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN (ATAC)-SEQ ANALYSIS SHOWED CHANGES IN CHROMATIN ACCESSIBILITY OF GENES ASSOCIATED WITH INFLAMMATORY AND METABOLIC PATHWAYS. OVERALL, OUR DATA SUGGEST THAT CHRONIC MODERATE EXERCISE CAN INFLUENCE THE INFLAMMATORY RESPONSES OF MACROPHAGES BY REPROGRAMMING THEIR METABOLIC AND EPIGENETIC LANDSCAPE.NEW & NOTEWORTHY IN THIS STUDY, WE EXPLAIN HOW LONG-TERM MODERATE EXERCISE TRAINING CAN REDUCE INFLAMMATION IN MOUSE MACROPHAGES BY REPROGRAMMING THE WAY THEY SENSE AND RESPOND TO THE PRESENCE OF PATHOGENS. WE COMPLETED A THOROUGH ANALYSIS AND SHOWED THAT THESE CHANGES PERSIST IN MACROPHAGES BECAUSE EXERCISE IMPROVES THE ABILITY OF CELLS TO UTILIZE OXYGEN WITHOUT PRODUCING DAMAGING COMPOUNDS, AND CHANGES THE WAY THEY ACCESS THEIR DNA. 2023 9 5318 39 PSYCHONEUROENDOCRINE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE: A REVIEW. THERE IS EVIDENCE SUGGESTING THAT IMMUNOSENESCENCE CAN BE ACCELERATED BY EXTERNAL FACTORS SUCH AS CHRONIC STRESS. HERE WE REVIEW POTENTIAL PSYCHONEUROENDOCRINE DETERMINANTS OF PREMATURE AGING OF THE IMMUNE SYSTEM AND DISCUSS AVAILABLE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE. CHRONIC STRESS MAY ACCELERATE VARIOUS FEATURES OF IMMUNOSENESCENCE BY ACTIVATING KEY ALLOSTATIC SYSTEMS, NOTABLY THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. THE IMMUNOLOGICAL IMPACT OF SUCH NEUROENDOCRINE DYSREGULATION MAY BE FURTHER AMPLIFIED BY A DRAMATIC DECLINE IN DEHYDROEPIANDROSTERONE (DHEA) LEVELS, ACTING IN PART AS AN ENDOGENOUS GLUCOCORTICOID ANTAGONIST. STRESS-BUFFERING STRATEGIES SHOW BENEFICIAL EFFECTS ON VARIOUS BIOMARKERS IN ELDERLY POPULATIONS. LIKEWISE, SUPPLEMENTATION OF DHEA, MELATONIN OR GROWTH HORMONE HAS YIELDED SIGNIFICANT BENEFICIAL EFFECTS IN A NUMBER OF STUDIES, INCLUDING: INCREASED WELL-BEING, MEMORY PERFORMANCE, BONE MINERAL DENSITY AND IMPROVED IMMUNOCOMPETENCE AS EVIDENCED BY RESULTS OF IN VITRO (T CELL PROLIFERATION, CYTOTOXICITY, CYTOKINE PRODUCTION), AND IN VIVO IMMUNE CHALLENGES. HOWEVER, THE SIDE-EFFECTS OF HORMONAL SUPPLEMENTATION ARE ALSO DISCUSSED. FINALLY, MODERATE EXERCISE VIA THE PROMOTION OF CORTISOL/DHEA BALANCE OR EPIGENETIC MODIFICATIONS, IS ASSOCIATED WITH LOWER SERUM PRO-INFLAMMATORY CYTOKINES, GREATER LYMPHOPROLIFERATIVE RESPONSES AND LOWER COUNTS OF SENESCENT T CELLS. TAKEN TOGETHER, THESE DATA SUGGEST THAT IMMUNE SYSTEM IS PLASTIC AND IMMUNOSENESCENCE CAN BE ATTENUATED PSYCHONEUROENDOCRINE INTERVENTIONS. 2013 10 4117 54 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 11 5581 46 ROLE OF NF-KAPPAB IN AGEING AND AGE-RELATED DISEASES: LESSONS FROM GENETICALLY MODIFIED MOUSE MODELS. AGEING IS A COMPLEX PROCESS, INDUCED BY MULTIFACETED INTERACTION OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. IT IS MANIFESTED BY A DECLINE IN THE PHYSIOLOGICAL FUNCTIONS OF ORGANISMS AND ASSOCIATED TO THE DEVELOPMENT OF AGE-RELATED CHRONIC DISEASES AND CANCER DEVELOPMENT. IT IS CONSIDERED THAT AGEING FOLLOWS A STRICTLY-REGULATED PROGRAM, IN WHICH SOME SIGNALING PATHWAYS CRITICALLY CONTRIBUTE TO THE ESTABLISHMENT AND MAINTENANCE OF THE AGED STATE. CHRONIC INFLAMMATION IS A MAJOR MECHANISM THAT PROMOTES THE BIOLOGICAL AGEING PROCESS AND COMORBIDITY, WITH THE TRANSCRIPTION FACTOR NF-KAPPAB (NUCLEAR FACTOR KAPPA-LIGHT-CHAIN-ENHANCER OF ACTIVATED B CELLS) AS A CRUCIAL MEDIATOR OF INFLAMMATORY RESPONSES. THIS, TOGETHER WITH THE FINDING THAT THE ACTIVATION OR INHIBITION OF NF-KAPPAB CAN INDUCE OR REVERSE RESPECTIVELY THE MAIN FEATURES OF AGED ORGANISMS, HAS BROUGHT IT UNDER CONSIDERATION AS A KEY TRANSCRIPTION FACTOR THAT ACTS AS A DRIVER OF AGEING. IN THIS REVIEW, WE FOCUSED ON THE DATA OBTAINED ENTIRELY THROUGH THE GENERATION OF KNOCKOUT AND TRANSGENIC MOUSE MODELS OF EITHER PROTEIN INVOLVED IN THE NF-KAPPAB SIGNALING PATHWAY THAT HAVE PROVIDED RELEVANT INFORMATION ABOUT THE INTRICATE PROCESSES OR MOLECULAR MECHANISMS THAT CONTROL AGEING. WE HAVE REVIEWED THE RELATIONSHIP OF NF-KAPPAB AND PREMATURE AGEING; THE DEVELOPMENT OF CANCER ASSOCIATED WITH AGEING AND THE IMPLICATION OF NF-KAPPAB ACTIVATION IN THE DEVELOPMENT OF AGE-RELATED DISEASES, SOME OF WHICH GREATLY INCREASE THE RISK OF DEVELOPING CANCER. 2021 12 3403 33 HOW EPIGENETIC MODIFICATIONS DRIVE THE EXPRESSION AND MEDIATE THE ACTION OF PGC-1ALPHA IN THE REGULATION OF METABOLISM. EPIGENETIC CHANGES ARE A HALLMARK OF SHORT- AND LONG-TERM TRANSCRIPTIONAL REGULATION, AND HENCE INSTRUMENTAL IN THE CONTROL OF CELLULAR IDENTITY AND PLASTICITY. EPIGENETIC MECHANISMS LEADING TO CHANGES IN CHROMATIN STRUCTURE, ACCESSIBILITY FOR RECRUITMENT OF TRANSCRIPTIONAL COMPLEXES, AND INTERACTION OF ENHANCERS AND PROMOTERS ALL CONTRIBUTE TO ACUTE AND CHRONIC ADAPTATIONS OF CELLS, TISSUES AND ORGANS TO INTERNAL AND EXTERNAL PERTURBATIONS. SIMILARLY, THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR 1ALPHA (PGC-1ALPHA) IS ACTIVATED BY STIMULI THAT ALTER THE CELLULAR ENERGETIC DEMAND, AND SUBSEQUENTLY CONTROLS COMPLEX TRANSCRIPTIONAL NETWORKS RESPONSIBLE FOR CELLULAR PLASTICITY. IT THUS IS OF NO SURPRISE THAT PGC-1ALPHA IS UNDER THE CONTROL OF EPIGENETIC MECHANISMS, AND CONSTITUTES A MEDIATOR OF EPIGENETIC CHANGES IN VARIOUS TISSUES AND CONTEXTS. IN THIS REVIEW, WE SUMMARIZE THE CURRENT KNOWLEDGE OF THE LINK BETWEEN EPIGENETICS AND PGC-1ALPHA IN HEALTH AND DISEASE. 2019 13 4974 37 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 2499 32 EPIGENETICS AND EXERCISE. EPIGENETICS CAN BE DEFINED AS 'THE STRUCTURAL ADAPTATION OF CHROMOSOMAL REGIONS SO AS TO REGISTER, SIGNAL, OR PERPETUATE ALTERED ACTIVITY STATES.' INCREASED TRANSCRIPTION OF KEY REGULATORY, METABOLIC, AND MYOGENIC GENES IS AN EARLY RESPONSE TO EXERCISE AND IS IMPORTANT IN MEDIATING SUBSEQUENT ADAPTATIONS IN SKELETAL MUSCLE. DNA HYPOMETHYLATION AND HISTONE HYPERACETYLATION ARE EMERGING AS IMPORTANT CRUCIAL EVENTS FOR INCREASED TRANSCRIPTION. THE COMPLEX INTERACTIONS BETWEEN MULTIPLE EPIGENETIC MODIFICATIONS AND THEIR REGULATION BY METABOLIC CHANGES AND SIGNALING EVENTS DURING EXERCISE, WITH IMPLICATIONS FOR ENHANCED UNDERSTANDING OF THE ACUTE AND CHRONIC ADAPTATIONS TO EXERCISE, ARE QUESTIONS FOR FURTHER INVESTIGATION. 2019 15 5710 34 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 16 3287 52 HIERARCHICAL AND CYBERNETIC NATURE OF BIOLOGIC SYSTEMS AND THEIR RELEVANCE TO HOMEOSTATIC ADAPTATION TO LOW-LEVEL EXPOSURES TO OXIDATIVE STRESS-INDUCING AGENTS. DURING EVOLUTION IN AN AEROBIC ENVIRONMENT, MULTICELLULAR ORGANISMS SURVIVED BY ADAPTIVE RESPONSES TO BOTH THE ENDOGENOUS OXIDATIVE METABOLISM IN THE CELLS OF THE ORGANISM AND THE CHEMICALS AND LOW-LEVEL RADIATION TO WHICH THEY HAD BEEN EXPOSED. THE DEFENSE REPERTOIRE EXISTS AT ALL LEVELS OF THE BIOLOGICAL HIERARCHY--FROM THE MOLECULAR AND BIOCHEMICAL LEVEL TO THE CELLULAR AND TISSUE LEVEL TO THE ORGAN AND ORGAN SYSTEM LEVEL. CELLS CONTAIN PREVENTIVE ANTIOXIDANTS TO SUPPRESS OXIDATIVE DAMAGE TO MEMBRANES. CELLS ALSO CONTAIN PROTEINS AND DNA; BUILT-IN REDUNDANCIES FOR DAMAGED MOLECULES AND ORGANELLES; TIGHTLY COUPLED REDOX SYSTEMS; POOLS OF REDUCTANTS; ANTIOXIDANTS; DNA REPAIR MECHANISMS AND SENSITIVE SENSOR MOLECULES SUCH AS NUCLEAR FACTOR KAPPA BETA; AND SIGNAL TRANSDUCTION MECHANISMS AFFECTING BOTH TRANSCRIPTION AND POST-TRANSLATIONAL MODIFICATION OF PROTEINS NEEDED TO COPE WITH OXIDATIVE STRESS. THE BIOLOGIC CONSEQUENCES OF THE LOW-LEVEL RADIATION THAT EXCEEDS THE BACKGROUND LEVEL OF OXIDATIVE DAMAGE COULD BE NECROSIS OR APOPTOSIS, CELL PROLIFERATION, OR CELL DIFFERENTIATION. THESE EFFECTS ARE TRIGGERED BY OXIDATIVE STRESS-INDUCED SIGNAL TRANSDUCTION MECHANISMS--AN EPIGENETIC, NOT GENOTOXIC, PROCESS. IF THE END POINTS OF CELL PROLIFERATION, DIFFERENTIATION, OR CELL DEATH ARE NOT SEEN AT FREQUENCIES ABOVE BACKGROUND LEVELS IN AN ORGANISM, IT IS UNLIKELY THAT LOW-LEVEL RADIATION WOULD PLAY A ROLE IN THE MULTISTEP PROCESSES OF CHRONIC DISEASES SUCH AS CANCER. THE MECHANISM LINKED TO HOMEOSTATIC REGULATION OF PROLIFERATION AND ADAPTIVE FUNCTIONS IN A MULTICELLULAR ORGANISM COULD PROVIDE PROTECTION OF ANY ONE CELL RECEIVING DEPOSITED ENERGY BY THE RADIATION TRACT THROUGH THE SHARING OF REDUCTANTS AND BY TRIGGERING APOPTOSIS OF TARGET STEM CELLS. EXAMPLES OF THE ROLE OF GAP JUNCTIONAL INTERCELLULAR COMMUNICATION IN THE ADAPTIVE RESPONSE OF CELLS AND THE BYSTANDER EFFECT ILLUSTRATE HOW THE INTERACTION OF CELLS CAN MODULATE THE EFFECT OF RADIATION ON THE SINGLE CELL. 1998 17 3837 36 IONIZING RADIATION-INDUCED OXIDATIVE STRESS, EPIGENETIC CHANGES AND GENOMIC INSTABILITY: THE PIVOTAL ROLE OF MITOCHONDRIA. PURPOSE: TO REVIEW THE DATA CONCERNING THE ROLE OF ENDOGENOUSLY GENERATED REACTIVE OXYGEN SPECIES (ROS) IN THE NON-TARGETED IONIZING RADIATION (IR) EFFECTS AND IN DETERMINATION OF THE CELL POPULATION'S FATE, BOTH EARLY AFTER EXPOSURE AND AFTER MANY GENERATIONS. CONCLUSIONS: THE SHORT-TERM AS WELL AS CHRONIC OXIDATIVE STRESS RESPONSES MAINLY ARE PRODUCED DUE TO ROS GENERATION BY THE ELECTRON TRANSPORT CHAIN (ETC) OF THE MITOCHONDRIA AND BY THE CYTOPLASMIC NADPH OXIDASES. WHETHER THE INDUCTION OF THE OXIDATIVE STRESS AND ITS CONSEQUENCES OCCUR OR ARE HAMPERED IN A SINGLE CELL LARGELY DEPENDS ON THE INTERACTION BETWEEN THE NUCLEUS AND THE CELLULAR POPULATION OF SEVERAL HUNDRED OR THOUSANDS OF MITOCHONDRIA THAT ARE GENETICALLY HETEROGENEOUS. HIGH INTRA-MITOCHONDRIAL ROS LEVEL IS DAMAGING THE MITOCHONDRIAL (MT) DNA AND ITS MUTATIONS AFFECT THE EPIGENETIC CONTROL MECHANISMS OF THE NUCLEAR (N) DNA, BY DECREASING THE ACTIVITY OF METHYLTRANSFERASES AND THUS, CAUSING GLOBAL DNA HYPOMETHYLATION. THESE CHANGES ARE TRANSMITTED TO THE PROGENY OF THE IRRADIATED CELLS. THE CHRONIC OXIDATIVE STRESS IS THE MAIN CAUSE OF THE LATE POST-RADIATION EFFECTS, INCLUDING CANCER, AND THIS MAKES IT AN IMPORTANT ADVERSE EFFECT OF EXPOSURE TO IR AND A TARGET FOR RADIOLOGICAL PROTECTION. 2015 18 5711 39 SIRT1 IS A HIGHLY NETWORKED PROTEIN THAT MEDIATES THE ADAPTATION TO CHRONIC PHYSIOLOGICAL STRESS. SIRT1 IS A NAD(+)-DEPENDENT PROTEIN DEACETYLASE THAT HAS A VERY LARGE NUMBER OF ESTABLISHED PROTEIN SUBSTRATES AND AN EQUALLY IMPRESSIVE LIST OF BIOLOGICAL FUNCTIONS THOUGHT TO BE REGULATED BY ITS ACTIVITY. PERHAPS AS NOTABLE IS THE REMARKABLE NUMBER OF POINTS OF CONFLICT CONCERNING THE ROLE OF SIRT1 IN BIOLOGICAL PROCESSES. FOR EXAMPLE, EVIDENCE EXISTS SUGGESTING THAT SIRT1 IS A TUMOR SUPPRESSOR, IS AN ONCOGENE, OR HAS NO EFFECT ON ONCOGENESIS. SIMILARLY, SIRT1 IS VARIABLY REPORTED TO INDUCE, INHIBIT, OR HAVE NO EFFECT ON AUTOPHAGY. WE BELIEVE THAT THE RESOLUTION OF MANY CONFLICTING RESULTS IS POSSIBLE BY CONSIDERING RECENT REPORTS INDICATING THAT SIRT1 IS AN IMPORTANT HUB INTERACTING WITH A COMPLEX NETWORK OF PROTEINS THAT COLLECTIVELY REGULATE A WIDE VARIETY OF BIOLOGICAL PROCESSES INCLUDING CANCER AND AUTOPHAGY. A NUMBER OF THE INTERACTING PROTEINS ARE THEMSELVES HUBS THAT, LIKE SIRT1, UTILIZE INTRINSICALLY DISORDERED REGIONS FOR THEIR PROMISCUOUS INTERACTIONS. MANY STUDIES INVESTIGATING SIRT1 FUNCTION HAVE BEEN CARRIED OUT ON CELL LINES CARRYING UNDETERMINED NUMBERS OF ALTERATIONS TO THE PROTEINS COMPRISING THE SIRT1 NETWORK OR ON INBRED MOUSE STRAINS CARRYING FIXED MUTATIONS AFFECTING SOME OF THESE PROTEINS. THUS, THE EFFECTS OF MODULATING SIRT1 AMOUNT AND/OR ACTIVITY ARE IMPORTANTLY DETERMINED BY THE GENETIC BACKGROUND OF THE CELL (OR THE INBRED STRAIN OF MICE), AND THE EFFECTS ATTRIBUTED TO SIRT1 ARE SYNTHETIC WITH THE BACKGROUND OF MUTATIONS AND EPIGENETIC DIFFERENCES BETWEEN CELLS AND ORGANISMS. WORK ON MICE CARRYING ALTERATIONS TO THE SIRT1 GENE SUGGESTS THAT THE NETWORK IN WHICH SIRT1 FUNCTIONS PLAYS AN IMPORTANT ROLE IN MEDIATING PHYSIOLOGICAL ADAPTATION TO VARIOUS SOURCES OF CHRONIC STRESS SUCH AS CALORIE RESTRICTION AND CALORIE OVERLOAD. WHETHER THE CATALYTIC ACTIVITY OF SIRT1 AND THE NUCLEAR CONCENTRATION OF THE CO-FACTOR, NAD(+), ARE RESPONSIBLE FOR MODULATING THIS ACTIVITY REMAINS TO BE DETERMINED. HOWEVER, THE EFFECT OF MODULATING SIRT1 ACTIVITY MUST BE INTERPRETED IN THE CONTEXT OF THE CELL OR TISSUE UNDER INVESTIGATION. INDEED, FOR SIRT1, WE ARGUE THAT CONTEXT IS EVERYTHING. 2013 19 2002 31 EPIGENETIC AND POST-TRANSCRIPTIONAL REPRESSION SUPPORT METABOLIC SUPPRESSION IN CHRONICALLY HYPOXIC GOLDFISH. GOLDFISH ENTER A HYPOMETABOLIC STATE TO SURVIVE CHRONIC HYPOXIA. WE RECENTLY DESCRIBED TISSUE-SPECIFIC CONTRIBUTIONS OF MEMBRANE LIPID COMPOSITION REMODELING AND MITOCHONDRIAL FUNCTION TO METABOLIC SUPPRESSION ACROSS DIFFERENT GOLDFISH TISSUES. HOWEVER, THE MOLECULAR AND ESPECIALLY EPIGENETIC FOUNDATIONS OF HYPOXIA TOLERANCE IN GOLDFISH UNDER METABOLIC SUPPRESSION ARE NOT WELL UNDERSTOOD. HERE WE SHOW THAT COMPONENTS OF THE MOLECULAR OXYGEN-SENSING MACHINERY ARE ROBUSTLY ACTIVATED ACROSS TISSUES IRRESPECTIVE OF HYPOXIA DURATION. INDUCTION OF GENE EXPRESSION OF ENZYMES INVOLVED IN DNA METHYLATION TURNOVER AND MICRORNA BIOGENESIS SUGGEST A ROLE FOR EPIGENETIC TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL SUPPRESSION OF GENE EXPRESSION IN THE HYPOXIA-ACCLIMATED BRAIN. CONVERSELY, MECHANISTIC TARGET OF RAPAMYCIN-DEPENDENT TRANSLATIONAL MACHINERY ACTIVITY IS NOT REDUCED IN LIVER AND WHITE MUSCLE, SUGGESTING THIS PATHWAY DOES NOT CONTRIBUTE TO LOWERING CELLULAR ENERGY EXPENDITURE. FINALLY, MOLECULAR EVIDENCE SUPPORTS PREVIOUSLY REPORTED CHRONIC HYPOXIA-DEPENDENT CHANGES IN MEMBRANE CHOLESTEROL, LIPID METABOLISM AND MITOCHONDRIAL FUNCTION VIA CHANGES IN TRANSCRIPTS INVOLVED IN CHOLESTEROL BIOSYNTHESIS, BETA-OXIDATION, AND MITOCHONDRIAL FUSION IN MULTIPLE TISSUES. OVERALL, THIS STUDY SHOWS THAT CHRONIC HYPOXIA ROBUSTLY INDUCES EXPRESSION OF OXYGEN-SENSING MACHINERY ACROSS TISSUES, INDUCES REPRESSIVE TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL EPIGENETIC MARKS ESPECIALLY IN THE CHRONIC HYPOXIA-ACCLIMATED BRAIN AND SUPPORTS A ROLE FOR MEMBRANE REMODELING AND MITOCHONDRIAL FUNCTION AND DYNAMICS IN PROMOTING METABOLIC SUPPRESSION. 2022 20 5471 43 RESPIRATORY MUSCLE SENESCENCE IN AGEING AND CHRONIC LUNG DISEASES. AGEING IS A PROGRESSIVE CONDITION THAT USUALLY LEADS TO THE LOSS OF PHYSIOLOGICAL PROPERTIES. THIS PROCESS IS ALSO PRESENT IN RESPIRATORY MUSCLES, WHICH ARE AFFECTED BY BOTH SENESCENT CHANGES OCCURRING IN THE WHOLE ORGANISM AND THOSE THAT ARE MORE SPECIFIC FOR MUSCLES. THE MECHANISMS OF THE LATTER CHANGES INCLUDE OXIDATIVE STRESS, DECREASE IN NEUROTROPHIC FACTORS AND DNA ABNORMALITIES. AGEING NORMALLY COEXISTS WITH COMORBIDITIES, INCLUDING RESPIRATORY DISEASES, WHICH FURTHER DETERIORATE THE STRUCTURE AND FUNCTION OF RESPIRATORY MUSCLES. IN THIS CONTEXT, CHANGES INTRINSIC TO AGEING BECOME ENHANCED BY MORE SPECIFIC FACTORS SUCH AS THE IMPAIRMENT IN LUNG MECHANICS AND GAS EXCHANGE, EXACERBATIONS AND HYPOXIA. HYPOXIA IN PARTICULAR HAS A DIRECT EFFECT ON MUSCLES, MAINLY THROUGH THE EXPRESSION OF INDUCIBLE FACTORS (HYPOXIC-INDUCIBLE FACTOR), AND CAN RESULT IN OXIDATIVE STRESS AND CHANGES IN DNA, DECREASE IN MITOCHONDRIAL BIOGENESIS AND DEFECTS IN THE TISSUE REPAIR MECHANISMS. INTENSE EXERCISE CAN ALSO CAUSE DAMAGE IN RESPIRATORY MUSCLES OF ELDERLY RESPIRATORY PATIENTS, BUT THIS CAN BE FOLLOWED BY TISSUE REPAIR AND REMODELLING. HOWEVER, AGEING INTERFERES WITH MUSCLE REPAIR BY TAMPERING WITH THE FUNCTION OF SATELLITE CELLS, MAINLY DUE TO OXIDATIVE STRESS, DNA DAMAGE AND EPIGENETIC MECHANISMS. IN ADDITION TO THE NORMAL PROCESS OF AGEING, STRESS-INDUCED PREMATURE SENESCENCE CAN ALSO OCCUR, INVOLVING CHANGES IN THE EXPRESSION OF MULTIPLE GENES BUT WITHOUT MODIFICATIONS IN TELOMERE LENGTH. 2020