1 788 121 CELLULAR ALLOSTATIC LOAD IS LINKED TO INCREASED ENERGY EXPENDITURE AND ACCELERATED BIOLOGICAL AGING. STRESS TRIGGERS ANTICIPATORY PHYSIOLOGICAL RESPONSES THAT PROMOTE SURVIVAL, A PHENOMENON TERMED ALLOSTASIS. HOWEVER, THE CHRONIC ACTIVATION OF ENERGY-DEPENDENT ALLOSTATIC RESPONSES RESULTS IN ALLOSTATIC LOAD, A DYSREGULATED STATE THAT PREDICTS FUNCTIONAL DECLINE, ACCELERATES AGING, AND INCREASES MORTALITY IN HUMANS. THE ENERGETIC COST AND CELLULAR BASIS FOR THE DAMAGING EFFECTS OF ALLOSTATIC LOAD HAVE NOT BEEN DEFINED. HERE, BY LONGITUDINALLY PROFILING THREE UNRELATED PRIMARY HUMAN FIBROBLAST LINES ACROSS THEIR LIFESPAN, WE FIND THAT CHRONIC GLUCOCORTICOID EXPOSURE INCREASES CELLULAR ENERGY EXPENDITURE BY APPROXIMATELY 60%, ALONG WITH A METABOLIC SHIFT FROM GLYCOLYSIS TO MITOCHONDRIAL OXIDATIVE PHOSPHORYLATION (OXPHOS). THIS STATE OF STRESS-INDUCED HYPERMETABOLISM IS LINKED TO MTDNA INSTABILITY, NON-LINEARLY AFFECTS AGE-RELATED CYTOKINES SECRETION, AND ACCELERATES CELLULAR AGING BASED ON DNA METHYLATION CLOCKS, TELOMERE SHORTENING RATE, AND REDUCED LIFESPAN. PHARMACOLOGICALLY NORMALIZING OXPHOS ACTIVITY WHILE FURTHER INCREASING ENERGY EXPENDITURE EXACERBATES THE ACCELERATED AGING PHENOTYPE, POINTING TO TOTAL ENERGY EXPENDITURE AS A POTENTIAL DRIVER OF AGING DYNAMICS. TOGETHER, OUR FINDINGS DEFINE BIOENERGETIC AND MULTI-OMIC RECALIBRATIONS OF STRESS ADAPTATION, UNDERSCORING INCREASED ENERGY EXPENDITURE AND ACCELERATED CELLULAR AGING AS INTERRELATED FEATURES OF CELLULAR ALLOSTATIC LOAD. 2023 2 375 26 AN ENERGETIC VIEW OF STRESS: FOCUS ON MITOCHONDRIA. ENERGY IS REQUIRED TO SUSTAIN LIFE AND ENABLE STRESS ADAPTATION. AT THE CELLULAR LEVEL, ENERGY IS LARGELY DERIVED FROM MITOCHONDRIA - UNIQUE MULTIFUNCTIONAL ORGANELLES WITH THEIR OWN GENOME. FOUR MAIN ELEMENTS CONNECT MITOCHONDRIA TO STRESS: (1) ENERGY IS REQUIRED AT THE MOLECULAR, (EPI)GENETIC, CELLULAR, ORGANELLAR, AND SYSTEMIC LEVELS TO SUSTAIN COMPONENTS OF STRESS RESPONSES; (2) GLUCOCORTICOIDS AND OTHER STEROID HORMONES ARE PRODUCED AND METABOLIZED BY MITOCHONDRIA; (3) RECIPROCALLY, MITOCHONDRIA RESPOND TO NEUROENDOCRINE AND METABOLIC STRESS MEDIATORS; AND (4) EXPERIMENTALLY MANIPULATING MITOCHONDRIAL FUNCTIONS ALTERS PHYSIOLOGICAL AND BEHAVIORAL RESPONSES TO PSYCHOLOGICAL STRESS. THUS, MITOCHONDRIA ARE ENDOCRINE ORGANELLES THAT PROVIDE BOTH THE ENERGY AND SIGNALS THAT ENABLE AND DIRECT STRESS ADAPTATION. NEURAL CIRCUITS REGULATING SOCIAL BEHAVIOR - AS WELL AS PSYCHOPATHOLOGICAL PROCESSES - ARE ALSO INFLUENCED BY MITOCHONDRIAL ENERGETICS. AN INTEGRATIVE VIEW OF STRESS AS AN ENERGY-DRIVEN PROCESS OPENS NEW OPPORTUNITIES TO STUDY MECHANISMS OF ADAPTATION AND REGULATION ACROSS THE LIFESPAN. 2018 3 6629 23 UNDERSTANDING THE HUMAN AGING PROTEOME USING EPIDEMIOLOGICAL MODELS. HUMAN AGING IS A COMPLEX MULTIFACTORIAL PROCESS ASSOCIATED WITH A DECLINE OF PHYSICAL AND COGNITIVE FUNCTION AND HIGH SUSCEPTIBILITY TO CHRONIC DISEASES, INFLUENCED BY GENETIC, EPIGENETIC, ENVIRONMENTAL, AND DEMOGRAPHIC FACTORS. THIS CHAPTER WILL PROVIDE AN OVERVIEW ON THE USE OF EPIDEMIOLOGICAL MODELS WITH PROTEOMICS DATA AS A METHOD THAT CAN BE USED TO IDENTIFY FACTORS THAT MODULATE THE AGING PROCESS IN HUMANS. THIS IS DEMONSTRATED WITH PROTEOMICS DATA FROM HUMAN PLASMA AND SKELETAL MUSCLE, WHERE THE COMBINATION WITH EPIDEMIOLOGICAL MODELS IDENTIFIED A SET OF MITOCHONDRIAL, SPLICEOSOME, AND SENESCENCE PROTEINS AS WELL AS THE ROLE OF ENERGETIC PATHWAYS SUCH AS GLYCOLYSIS, AND ELECTRON TRANSPORT PATHWAYS THAT REGULATE THE AGING PROCESS. 2022 4 6034 30 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 5 5543 30 ROLE OF ENDOGENOUS GLUCOCORTICOIDS IN CANCER IN THE ELDERLY. ALTHOUGH NOT A DISEASE ITSELF, AGING REPRESENTS A RISK FACTOR FOR MANY AGING-RELATED ILLNESSES, INCLUDING CANCER. NUMEROUS CAUSES UNDERLIE THE INCREASED INCIDENCE OF MALIGNANCIES IN THE ELDERLY, FOR EXAMPLE, GENOMIC INSTABILITY AND EPIGENETIC ALTERATIONS THAT OCCUR AT CELLULAR LEVEL, WHICH ALSO INVOLVE THE IMMUNE CELLS. THE PROGRESSIVE DECLINE OF THE IMMUNE SYSTEM FUNCTIONS THAT OCCURS IN AGING DEFINES IMMUNOSENESCENCE, AND INCLUDES BOTH INNATE AND ADAPTIVE IMMUNITY; THE LATTER UNDERGOES MAJOR ALTERATIONS. AGING AND CHRONIC STRESS SHARE THE ABNORMAL HYPOTHALAMIC(-)PITUITARY(-)ADRENAL AXIS ACTIVATION, WHERE ALTERED PERIPHERAL GLUCOCORTICOIDS (GC) LEVELS AND CHRONIC STRESS HAVE BEEN ASSOCIATED WITH ACCELERATED CELLULAR AGING, PREMATURE IMMUNOSENESCENCE, AND AGING-RELATED DISEASES. CONSEQUENTLY, CHANGES IN GC LEVELS AND SENSITIVITY CONTRIBUTE TO THE SIGNS OF IMMUNOSENESCENCE, NAMELY FEWER NAIVE T CELLS, POOR IMMUNE RESPONSE TO NEW ANTIGENS, DECREASED CELL-MEDIATED IMMUNITY, AND THYMIC INVOLUTION. GC SIGNALING ALTERATIONS ALSO INVOLVE EPIGENETIC ALTERATIONS IN DNA METHYLATION, WITH TRANSCRIPTION MODIFICATIONS THAT MAY CONTRIBUTE TO IMMUNOSENESCENCE. IMMUNE CELL AGING LEADS TO DECREASED LEVELS OF IMMUNOSURVEILLANCE, THEREBY PROVIDING TUMOR CELLS ONE MORE ROUTE FOR IMMUNE SYSTEM ESCAPE. HERE, THE CONTRIBUTION OF GC SECRETION AND SIGNALING DYSREGULATION TO THE INCREASED INCIDENCE OF TUMORIGENESIS IN THE ELDERLY IS REVIEWED. 2018 6 3102 31 GENOMIC INSTABILITIES, CELLULAR SENESCENCE, AND AGING: IN VITRO, IN VIVO AND AGING-LIKE HUMAN SYNDROMES. AS AVERAGE LIFE SPAN AND ELDERLY PEOPLE PREVALENCE IN THE WESTERN WORLD POPULATION IS GRADUALLY INCREASING, THE INCIDENCE OF AGE-RELATED DISEASES SUCH AS CANCER, HEART DISEASES, DIABETES, AND DEMENTIA IS INCREASING, BEARING SOCIAL AND ECONOMIC CONSEQUENCES WORLDWIDE. UNDERSTANDING THE MOLECULAR BASIS OF AGING-RELATED PROCESSES CAN HELP EXTEND THE ORGANISM'S HEALTH SPAN, I.E., THE LIFE PERIOD IN WHICH THE ORGANISM IS FREE OF CHRONIC DISEASES OR DECREASE IN BASIC BODY FUNCTIONS. DURING THE LAST FEW DECADES, IMMENSE PROGRESS WAS MADE IN THE UNDERSTANDING OF MAJOR COMPONENTS OF AGING AND HEALTHY AGING BIOLOGY, INCLUDING GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC CHANGES, PROTEOSTASIS, NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND INTRACELLULAR COMMUNICATIONS. THIS PROGRESS HAS BEEN MADE BY THREE SPEAR-HEADED STRATEGIES: IN VITRO (CELL AND TISSUE CULTURE FROM VARIOUS SOURCES), IN VIVO (INCLUDES DIVERSE MODEL AND NON-MODEL ORGANISMS), BOTH CAN BE MANIPULATED AND TRANSLATED TO HUMAN BIOLOGY, AND THE STUDY OF AGING-LIKE HUMAN SYNDROMES AND HUMAN POPULATIONS. HEREIN, WE WILL FOCUS ON CURRENT REPOSITORY OF GENOMIC "SENESCENCE" STAGE OF AGING, WHICH INCLUDES HEALTH DECLINE, STRUCTURAL CHANGES OF THE GENOME, FAULTY DNA DAMAGE RESPONSE AND DNA DAMAGE, TELOMERE SHORTENING, AND EPIGENETIC ALTERATIONS. ALTHOUGH AGING IS A COMPLEX PROCESS, MANY OF THE "HALLMARKS" OF AGING ARE DIRECTLY RELATED TO DNA STRUCTURE AND FUNCTION. THIS REVIEW WILL ILLUSTRATE THE VARIETY OF THESE STUDIES, DONE IN IN VITRO, IN VIVO AND HUMAN LEVELS, AND HIGHLIGHT THE UNIQUE POTENTIAL AND CONTRIBUTION OF EACH RESEARCH LEVEL AND EVENTUALLY THE LINK BETWEEN THEM. 2018 7 6189 31 THE IMPACT OF LIFE STRESS ON HALLMARKS OF AGING AND ACCELERATED SENESCENCE: CONNECTIONS IN SICKNESS AND IN HEALTH. CHRONIC STRESS IS A RISK FACTOR FOR NUMEROUS AGING-RELATED DISEASES AND HAS BEEN SHOWN TO SHORTEN LIFESPAN IN HUMANS AND OTHER SOCIAL MAMMALS. YET HOW LIFE STRESS CAUSES SUCH A VAST RANGE OF DISEASES IS STILL LARGELY UNCLEAR. IN RECENT YEARS, THE IMPACT OF STRESS ON HEALTH AND AGING HAS BEEN INCREASINGLY ASSOCIATED WITH THE DYSREGULATION OF THE SO-CALLED HALLMARKS OF AGING. THESE ARE BASIC BIOLOGICAL MECHANISMS THAT INFLUENCE INTRINSIC CELLULAR FUNCTIONS AND WHOSE ALTERATION CAN LEAD TO ACCELERATED AGING. HERE, WE REVIEW CORRELATIONAL AND EXPERIMENTAL LITERATURE (PRIMARILY FOCUSING ON EVIDENCE FROM HUMANS AND MURINE MODELS) ON THE CONTRIBUTION OF LIFE STRESS - PARTICULARLY STRESS DERIVED FROM ADVERSE SOCIAL ENVIRONMENTS - TO TRIGGER HALLMARKS OF AGING, INCLUDING CELLULAR SENESCENCE, STERILE INFLAMMATION, TELOMERE SHORTENING, PRODUCTION OF REACTIVE OXYGEN SPECIES, DNA DAMAGE, AND EPIGENETIC CHANGES. WE ALSO EVALUATE THE VALIDITY OF STRESS-INDUCED SENESCENCE AND ACCELERATED AGING AS AN ETIOPATHOLOGICAL PROPOSITION. FINALLY, WE HIGHLIGHT CURRENT GAPS OF KNOWLEDGE AND FUTURE DIRECTIONS FOR THE FIELD, AND DISCUSS PERSPECTIVES FOR TRANSLATIONAL GEROSCIENCE. 2023 8 5318 32 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 9 996 26 CHRONIC STRESS, EPIGENETICS, AND ADIPOSE TISSUE METABOLISM IN THE OBESE STATE. IN OBESITY, ENDOCRINE AND METABOLIC PERTURBATIONS, INCLUDING THOSE INDUCED BY CHRONIC ACTIVATION OF THE HYPOTHALAMUS-PITUITARY-ADRENAL AXIS, ARE ASSOCIATED WITH THE ACCUMULATION OF ADIPOSE TISSUE AND INFLAMMATION. SUCH CHANGES ARE ATTRIBUTABLE TO A COMBINATION OF GENETIC AND EPIGENETIC FACTORS THAT ARE INFLUENCED BY THE ENVIRONMENT AND EXACERBATED BY CHRONIC ACTIVATION OF THE HYPOTHALAMUS-PITUITARY-ADRENAL AXIS. STRESS EXPOSURE AT DIFFERENT LIFE STAGES CAN ALTER ADIPOSE TISSUE METABOLISM DIRECTLY THROUGH EPIGENETIC MODIFICATION OR INDIRECTLY THROUGH THE MANIPULATION OF HYPOTHALAMIC APPETITE REGULATION, AND THEREBY CONTRIBUTE TO ENDOCRINE CHANGES THAT FURTHER DISRUPT WHOLE-BODY ENERGY BALANCE. THIS REVIEW SYNTHESIZES CURRENT KNOWLEDGE, WITH AN EMPHASIS ON HUMAN CLINICAL TRIALS, TO DESCRIBE METABOLIC CHANGES IN ADIPOSE TISSUE AND ASSOCIATED ENDOCRINE, GENETIC AND EPIGENETIC CHANGES IN THE OBESE STATE. IN PARTICULAR, WE DISCUSS EPIGENETIC CHANGES INDUCED BY STRESS EXPOSURE AND THEIR CONTRIBUTION TO APPETITE AND ADIPOCYTE DYSFUNCTION, WHICH COLLECTIVELY PROMOTE THE PATHOGENESIS OF OBESITY. SUCH KNOWLEDGE IS CRITICAL FOR PROVIDING FUTURE DIRECTIONS OF METABOLISM RESEARCH AND TARGETS FOR TREATING METABOLIC DISORDERS. 2020 10 2916 29 GENE VARIANTS AS DETERMINANTS OF LONGEVITY: FOCUS ON THE INFLAMMATORY FACTORS. HUMAN LONGEVITY IS AN EXTREMELY COMPLEX TRAIT WITH VARIOUS GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS ACTING UPON THE LONGEVITY PHENOTYPE. IT IS NOW BECOMING EVIDENT THAT WHILST THE GENETIC DIFFERENCES CONTRIBUTE ONLY MODESTLY TO LIFE EXPECTANCY BEFORE THE AGE OF 60 YEARS, THEIR IMPACT ON SURVIVAL BECOMES MORE PROMINENT AT THE EXTREME AGES. SEVERAL LONGEVITY GENE CANDIDATES HAVE EMERGED DURING THE PAST DECADE; THE MAJORITY OF THEM ARE RELATED EITHER TO INFLAMMATORY FUNCTIONS, STRESS RESPONSE OR TO LIPID AND GLUCOSE METABOLISM. THE VARIANTS OF INFLAMMATORY AND IMMUNE RESPONSE GENES ARE OF SPECIAL INTEREST SINCE ADVANCING AGES IS ACCOMPANIED BY A DECLINE IN SEVERAL IMMUNE FUNCTIONS--A PHENOMENON CALLED IMMUNOSENESCENCE. PARADOXICALLY, AGEING IS ALSO CHARACTERISED BY CHRONIC LOW-GRADE INFLAMMATION TERMED "INFLAMMAGING", WHICH MANIFESTS AS A TWO- TO FOURFOLD INCREASE IN THE PRODUCTION OF PROINFLAMMATORY CYTOKINES AND ACUTE PHASE PROTEINS. THESE CONTRASTING PHENOMENA PROVIDE A FUNCTIONAL RATIONALE OF HOW THE GENETIC DIFFERENCES IN INFLAMMATORY MEDIATORS MAY MODIFY THE LIFE SPAN OF THE ELDERLY. BESIDES DESCRIBING THE PRE-EXISTING INFLAMMATORY AND IMMUNE-RELATED LONGEVITY GENE VARIANTS, IN THIS REVIEW, WE ALSO EXPLAIN SOME OF THE THEORETICAL AND PRACTICAL CHALLENGES THAT GENETIC LONGEVITY STUDIES OFTEN ENCOUNTER. 2010 11 6656 29 UPDATED UNDERSTANDING OF CANCER AS A METABOLIC AND TELOMERE-DRIVEN DISEASE, AND PROPOSAL FOR COMPLEX PERSONALIZED TREATMENT, A HYPOTHESIS. IN THIS REVIEW, WE PROPOSE A HOLISTIC APPROACH TO UNDERSTANDING CANCER AS A METABOLIC DISEASE. OUR SEARCH FOR RELEVANT STUDIES IN MEDICAL DATABASES CONCLUDES THAT CANCER CELLS DO NOT EVOLVE DIRECTLY FROM NORMAL HEALTHY CELLS. WE HYPOTHESIZE THAT ABERRANT DNA DAMAGE ACCUMULATES OVER TIME-AVOIDING THE NATURAL DNA CONTROLS THAT OTHERWISE REPAIR OR REPLACE THE RAPIDLY REPLICATING CELLS. DNA DAMAGE STARTS TO ACCUMULATE IN NON-REPLICATING CELLS, LEADING TO SENESCENCE AND AGING. DNA DAMAGE IS LINKED WITH GENETIC AND EPIGENETIC FACTORS, BUT THE DEVELOPMENT OF CANCER IS FAVORED BY TELOMERASE ACTIVITY. EVIDENCE INDICATES THAT TELOMERE LENGTH IS AFFECTED BY CHRONIC INFLAMMATIONS, ALTERATIONS OF MITOCHONDRIAL DNA, AND VARIOUS ENVIRONMENTAL FACTORS. EMOTIONAL STRESS ALSO INFLUENCES TELOMERE LENGTH. CHRONIC INFLAMMATION CAN CAUSE OXIDATIVE DNA DAMAGE. OXIDATIVE STRESS, IN TURN, CAN TRIGGER MITOCHONDRIAL CHANGES, WHICH ULTIMATELY ALTER NUCLEAR GENE EXPRESSION. THIS VICIOUS CYCLE HAS LED SEVERAL SCIENTISTS TO VIEW CANCER AS A METABOLIC DISEASE. WE HAVE PROPOSED COMPLEX PERSONALIZED TREATMENTS THAT SEEK TO CORRECT MULTIPLE CHANGES SIMULTANEOUSLY USING A PSYCHOLOGICAL APPROACH TO REDUCE CHRONIC STRESS, IMMUNE CHECKPOINT THERAPY WITH REDUCED DOSES OF CHEMO AND RADIOTHERAPY, MINIMAL SURGICAL INTERVENTION, IF ANY, AND MITOCHONDRIAL METABOLIC REPROGRAMMING PROTOCOLS SUPPLEMENTED BY INTERMITTENT FASTING AND PERSONALIZED DIETARY PLANS WITHOUT INTERFERING WITH THE OTHER THERAPIES. 2020 12 625 24 BIOLOGICAL AGE AND ENVIRONMENTAL RISK FACTORS FOR DEMENTIA AND STROKE: MOLECULAR MECHANISMS. SINCE THE DEVELOPMENT OF ANTIBIOTICS AND VACCINATION, AS WELL AS MAJOR IMPROVEMENTS IN PUBLIC HYGIENE, THE MAIN RISK FACTORS FOR MORBIDITY AND MORTALITY ARE AGE AND CHRONIC EXPOSURE TO ENVIRONMENTAL FACTORS, BOTH OF WHICH CAN INTERACT WITH GENETIC PREDISPOSITIONS. AS THE AVERAGE AGE OF THE POPULATION INCREASES, THE PREVALENCE AND COSTS OF CHRONIC DISEASES, ESPECIALLY NEUROLOGICAL CONDITIONS, ARE RAPIDLY INCREASING. THE DELETERIOUS EFFECTS OF AGE AND ENVIRONMENTAL RISK FACTORS, DEVELOP CHRONICALLY OVER RELATIVELY LONG PERIODS OF TIME, IN CONTRAST TO THE RELATIVELY RAPID DELETERIOUS EFFECTS OF INFECTIOUS DISEASES OR ACCIDENTS. OF PARTICULAR INTEREST IS THE HYPOTHESIS THAT THE DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS MAY BE MEDIATED BY ACCELERATION OF BIOLOGICAL AGE. THIS HYPOTHESIS IS SUPPORTED BY EVIDENCE THAT DIETARY RESTRICTION, WHICH UNIVERSALLY DELAYS AGE-RELATED DISEASES, ALSO AMELIORATES DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS. CONVERSELY, BOTH AGE AND ENVIRONMENTAL RISK FACTORS ARE ASSOCIATED WITH THE ACCUMULATION OF SOMATIC MUTATIONS IN MITOTIC CELLS AND EPIGENETIC MODIFICATIONS THAT ARE A MEASURE OF "BIOLOGICAL AGE", A BETTER PREDICTOR OF AGE-RELATED MORBIDITY AND MORTALITY THAN CHRONOLOGICAL AGE. HERE WE REVIEW EVIDENCE THAT ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING AND AIR POLLUTION MAY ALSO DRIVE NEUROLOGICAL CONDITIONS, INCLUDING ALZHEIMER'S DISEASE, BY THE ACCELERATION OF BIOLOGICAL AGE, MEDIATED BY CUMULATIVE AND PERSISTENT EPIGENETIC EFFECTS AS WELL AS SOMATIC MUTATIONS. ELUCIDATION OF SUCH MECHANISMS COULD PLAUSIBLY ALLOW THE DEVELOPMENT OF INTERVENTIONS WHICH DELAY DELETERIOUS EFFECTS OF BOTH AGING AND ENVIRONMENTAL RISK FACTORS. 2022 13 285 26 AGING AND AGING-RELATED DISEASES: FROM MOLECULAR MECHANISMS TO INTERVENTIONS AND TREATMENTS. AGING IS A GRADUAL AND IRREVERSIBLE PATHOPHYSIOLOGICAL PROCESS. IT PRESENTS WITH DECLINES IN TISSUE AND CELL FUNCTIONS AND SIGNIFICANT INCREASES IN THE RISKS OF VARIOUS AGING-RELATED DISEASES, INCLUDING NEURODEGENERATIVE DISEASES, CARDIOVASCULAR DISEASES, METABOLIC DISEASES, MUSCULOSKELETAL DISEASES, AND IMMUNE SYSTEM DISEASES. ALTHOUGH THE DEVELOPMENT OF MODERN MEDICINE HAS PROMOTED HUMAN HEALTH AND GREATLY EXTENDED LIFE EXPECTANCY, WITH THE AGING OF SOCIETY, A VARIETY OF CHRONIC DISEASES HAVE GRADUALLY BECOME THE MOST IMPORTANT CAUSES OF DISABILITY AND DEATH IN ELDERLY INDIVIDUALS. CURRENT RESEARCH ON AGING FOCUSES ON ELUCIDATING HOW VARIOUS ENDOGENOUS AND EXOGENOUS STRESSES (SUCH AS GENOMIC INSTABILITY, TELOMERE DYSFUNCTION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, COMPROMISE OF AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, ALTERED INTERCELLULAR COMMUNICATION, DEREGULATED NUTRIENT SENSING) PARTICIPATE IN THE REGULATION OF AGING. FURTHERMORE, THOROUGH RESEARCH ON THE PATHOGENESIS OF AGING TO IDENTIFY INTERVENTIONS THAT PROMOTE HEALTH AND LONGEVITY (SUCH AS CALORIC RESTRICTION, MICROBIOTA TRANSPLANTATION, AND NUTRITIONAL INTERVENTION) AND CLINICAL TREATMENT METHODS FOR AGING-RELATED DISEASES (DEPLETION OF SENESCENT CELLS, STEM CELL THERAPY, ANTIOXIDATIVE AND ANTI-INFLAMMATORY TREATMENTS, AND HORMONE REPLACEMENT THERAPY) COULD DECREASE THE INCIDENCE AND DEVELOPMENT OF AGING-RELATED DISEASES AND IN TURN PROMOTE HEALTHY AGING AND LONGEVITY. 2022 14 282 29 AGEING AND LOW-LEVEL CHRONIC INFLAMMATION: THE ROLE OF THE BIOLOGICAL CLOCK. AGEING IS A MULTIFACTORIAL PHYSIOLOGICAL MANIFESTATION THAT OCCURS INEXORABLY AND GRADUALLY IN ALL FORMS OF LIFE. THIS PROCESS IS LINKED TO THE DECAY OF HOMEOSTASIS DUE TO THE PROGRESSIVE DECREASE IN THE REPARATIVE AND REGENERATIVE CAPACITY OF TISSUES AND ORGANS, WITH REDUCED PHYSIOLOGICAL RESERVE IN RESPONSE TO STRESS. AGEING IS CLOSELY RELATED TO OXIDATIVE DAMAGE AND INVOLVES IMMUNOSENESCENCE AND TISSUE IMPAIRMENT OR METABOLIC IMBALANCES THAT TRIGGER INFLAMMATION AND INFLAMMASOME FORMATION. ONE OF THE MAIN AGEING-RELATED ALTERATIONS IS THE DYSREGULATION OF THE IMMUNE RESPONSE, WHICH RESULTS IN CHRONIC LOW-LEVEL, SYSTEMIC INFLAMMATION, TERMED "INFLAMMAGING". GENETIC AND EPIGENETIC CHANGES, AS WELL AS ENVIRONMENTAL FACTORS, PROMOTE AND/OR MODULATE THE MECHANISMS OF AGEING AT THE MOLECULAR, CELLULAR, ORGAN, AND SYSTEM LEVELS. MOST OF THESE MECHANISMS ARE CHARACTERIZED BY TIME-DEPENDENT PATTERNS OF VARIATION DRIVEN BY THE BIOLOGICAL CLOCK. IN THIS REVIEW, WE DESCRIBE THE INVOLVEMENT OF AGEING-RELATED PROCESSES WITH INFLAMMATION IN RELATION TO THE FUNCTIONING OF THE BIOLOGICAL CLOCK AND THE MECHANISMS OPERATING THIS INTRICATE INTERACTION. 2022 15 5635 28 SEPTIC SHOCK AND THE AGING PROCESS: A MOLECULAR COMPARISON. AGING IS A CONTINUOUS PROCESS PROMOTED BY BOTH INTRINSIC AND EXTRINSIC FACTORS THAT EACH TRIGGER A MULTITUDE OF MOLECULAR EVENTS. INCREASING EVIDENCE SUPPORTS A CENTRAL ROLE FOR INFLAMMATION IN THIS PROGRESSION. HERE, WE DISCUSS HOW THE LOW-GRADE CHRONIC INFLAMMATION THAT CHARACTERIZES AGING IS TIGHTLY INTERCONNECTED WITH OTHER IMPORTANT ASPECTS OF THIS PROCESS, SUCH AS DNA DAMAGE, MITOCHONDRIAL DYSFUNCTION, AND EPIGENETIC CHANGES. SIMILARLY, INFLAMMATION ALSO PLAYS A CRITICAL ROLE IN MANY MORBID CONDITIONS THAT AFFECT PATIENTS WHO ARE ADMITTED TO INTENSIVE CARE. ALTHOUGH THE INFLAMMATORY RESPONSE IS LOW GRADE AND PERSISTENT IN HEALTHY AGING WHILE IT IS ACUTE AND SEVERE IN CRITICALLY ILL STATES, WE HYPOTHESIZE THAT BOTH SITUATIONS HAVE IMPORTANT INTERCONNECTIONS. HERE, WE PERFORMED AN EXTENSIVE REVIEW OF THE LITERATURE TO INVESTIGATE THIS POTENTIAL LINK. BECAUSE SEPSIS IS THE MOST EXTENSIVELY STUDIED DISEASE AND IS THE LEADING CAUSE OF DEATH IN CRITICAL CARE, WE FOCUS OUR DISCUSSION ON COMPARING THE INFLAMMATORY PROFILE OF HEALTHY OLDER PEOPLE WITH THAT OF PATIENTS IN SEPTIC SHOCK TO EXPLAIN WHY WE BELIEVE THAT BOTH SITUATIONS HAVE SYNERGISTIC EFFECTS, LEADING TO CRITICALLY ILL AGED PATIENTS HAVING A WORSE PROGNOSIS WHEN COMPARED WITH CRITICALLY ILL YOUNG PATIENTS. 2017 16 5164 31 PRECLINICAL AND CLINICAL EVIDENCE OF DNA METHYLATION CHANGES IN RESPONSE TO TRAUMA AND CHRONIC STRESS. EXPOSURE TO CHRONIC STRESS, EITHER REPEATED SEVERE ACUTE OR MODERATE SUSTAINED STRESS, IS ONE OF THE STRONGEST RISK FACTORS FOR THE DEVELOPMENT OF PSYCHOPATHOLOGIES SUCH AS POST-TRAUMATIC STRESS DISORDER AND DEPRESSION. CHRONIC STRESS IS LINKED WITH SEVERAL LASTING BIOLOGICAL CONSEQUENCES, PARTICULARLY TO THE STRESS ENDOCRINE SYSTEM BUT ALSO AFFECTING INTERMEDIATE PHENOTYPES SUCH AS BRAIN STRUCTURE AND FUNCTION, IMMUNE FUNCTION, AND BEHAVIOR. ALTHOUGH GENETIC PREDISPOSITION CONFERS A PROPORTION OF THE RISK, THE MOST RELEVANT MOLECULAR MECHANISMS DETERMINING THOSE SUSCEPTIBLE AND RESILIENT TO THE EFFECTS OF STRESS AND TRAUMA MAY BE EPIGENETIC. EPIGENETICS REFERS TO THE MECHANISMS THAT REGULATE GENOMIC INFORMATION BY DYNAMICALLY CHANGING THE PATTERNS OF TRANSCRIPTION AND TRANSLATION OF GENES. MOUNTING EVIDENCE FROM PRECLINICAL RODENT AND CLINICAL POPULATION STUDIES STRONGLY SUPPORT THAT EPIGENETIC MODIFICATIONS CAN OCCUR IN RESPONSE TO TRAUMATIC AND CHRONIC STRESS. HERE, WE DISCUSS THIS LITERATURE EXAMINING STRESS-INDUCED EPIGENETIC CHANGES IN PRECLINICAL MODELS AND CLINICAL COHORTS OF STRESS AND TRAUMA OCCURRING EARLY IN LIFE OR IN ADULTHOOD. WE HIGHLIGHT THAT A COMPLEX RELATIONSHIP BETWEEN THE TIMING OF ENVIRONMENTAL STRESSORS AND GENETIC PREDISPOSITIONS LIKELY MEDIATE THE RESPONSE TO CHRONIC STRESS OVER TIME, AND THAT A BETTER UNDERSTANDING OF EPIGENETIC CHANGES IS NEEDED BY FURTHER INVESTIGATIONS IN LONGITUDINAL AND POSTMORTEM BRAIN CLINICAL COHORTS. 2017 17 2855 40 FROM INFLAMMAGING TO HEALTHY AGING BY DIETARY LIFESTYLE CHOICES: IS EPIGENETICS THE KEY TO PERSONALIZED NUTRITION? THE PROGRESSIVELY OLDER POPULATION IN DEVELOPED COUNTRIES IS REFLECTED IN AN INCREASE IN THE NUMBER OF PEOPLE SUFFERING FROM AGE-RELATED CHRONIC INFLAMMATORY DISEASES SUCH AS METABOLIC SYNDROME, DIABETES, HEART AND LUNG DISEASES, CANCER, OSTEOPOROSIS, ARTHRITIS, AND DEMENTIA. THE HETEROGENEITY IN BIOLOGICAL AGING, CHRONOLOGICAL AGE, AND AGING-ASSOCIATED DISORDERS IN HUMANS HAVE BEEN ASCRIBED TO DIFFERENT GENETIC AND ENVIRONMENTAL FACTORS (I.E., DIET, POLLUTION, STRESS) THAT ARE CLOSELY LINKED TO SOCIOECONOMIC FACTORS. THE COMMON DENOMINATOR OF THESE FACTORS IS THE INFLAMMATORY RESPONSE. CHRONIC LOW-GRADE SYSTEMIC INFLAMMATION DURING PHYSIOLOGICAL AGING AND IMMUNOSENESCENCE ARE INTERTWINED IN THE PATHOGENESIS OF PREMATURE AGING ALSO DEFINED AS 'INFLAMMAGING.' THE LATTER HAS BEEN ASSOCIATED WITH FRAILTY, MORBIDITY, AND MORTALITY IN ELDERLY SUBJECTS. HOWEVER, IT IS UNKNOWN TO WHAT EXTENT INFLAMMAGING OR LONGEVITY IS CONTROLLED BY EPIGENETIC EVENTS IN EARLY LIFE. TODAY, HUMAN DIET IS BELIEVED TO HAVE A MAJOR INFLUENCE ON BOTH THE DEVELOPMENT AND PREVENTION OF AGE-RELATED DISEASES. MOST PLANT-DERIVED DIETARY PHYTOCHEMICALS AND MACRO- AND MICRONUTRIENTS MODULATE OXIDATIVE STRESS AND INFLAMMATORY SIGNALING AND REGULATE METABOLIC PATHWAYS AND BIOENERGETICS THAT CAN BE TRANSLATED INTO STABLE EPIGENETIC PATTERNS OF GENE EXPRESSION. THEREFORE, DIET INTERVENTIONS DESIGNED FOR HEALTHY AGING HAVE BECOME A HOT TOPIC IN NUTRITIONAL EPIGENOMIC RESEARCH. INCREASING EVIDENCE HAS REVEALED THAT COMPLEX INTERACTIONS BETWEEN FOOD COMPONENTS AND HISTONE MODIFICATIONS, DNA METHYLATION, NON-CODING RNA EXPRESSION, AND CHROMATIN REMODELING FACTORS INFLUENCE THE INFLAMMAGING PHENOTYPE AND AS SUCH MAY PROTECT OR PREDISPOSE AN INDIVIDUAL TO MANY AGE-RELATED DISEASES. REMARKABLY, HUMANS PRESENT A BROAD RANGE OF RESPONSES TO SIMILAR DIETARY CHALLENGES DUE TO BOTH GENETIC AND EPIGENETIC MODULATIONS OF THE EXPRESSION OF TARGET PROTEINS AND KEY GENES INVOLVED IN THE METABOLISM AND DISTRIBUTION OF THE DIETARY CONSTITUENTS. HERE, WE WILL SUMMARIZE THE EPIGENETIC ACTIONS OF DIETARY COMPONENTS, INCLUDING PHYTOCHEMICALS, AND MACRO- AND MICRONUTRIENTS AS WELL AS METABOLITES, THAT CAN ATTENUATE INFLAMMAGING. WE WILL DISCUSS THE CHALLENGES FACING PERSONALIZED NUTRITION TO TRANSLATE HIGHLY VARIABLE INTERINDIVIDUAL EPIGENETIC DIET RESPONSES TO POTENTIAL INDIVIDUAL HEALTH BENEFITS/RISKS RELATED TO AGING DISEASE. 2015 18 6287 31 THE POTENTIAL ROLE OF ENVIRONMENTAL FACTORS IN MODULATING MITOCHONDRIAL DNA EPIGENETIC MARKS. MANY STUDIES IMPLICATE MITOCHONDRIAL DYSFUNCTION IN THE DEVELOPMENT AND PROGRESSION OF NUMEROUS CHRONIC DISEASES. MITOCHONDRIA ARE RESPONSIBLE FOR MOST CELLULAR ENERGY PRODUCTION, AND UNLIKE OTHER CYTOPLASMIC ORGANELLES, MITOCHONDRIA CONTAIN THEIR OWN GENOME. MOST RESEARCH TO DATE, THROUGH INVESTIGATING MITOCHONDRIAL DNA COPY NUMBER, HAS FOCUSED ON LARGER STRUCTURAL CHANGES OR ALTERATIONS TO THE ENTIRE MITOCHONDRIAL GENOME AND THEIR ROLE IN HUMAN DISEASE. USING THESE METHODS, MITOCHONDRIAL DYSFUNCTION HAS BEEN LINKED TO CANCERS, CARDIOVASCULAR DISEASE, AND METABOLIC HEALTH. HOWEVER, LIKE THE NUCLEAR GENOME, THE MITOCHONDRIAL GENOME MAY EXPERIENCE EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION THAT MAY PARTIALLY EXPLAIN SOME OF THE HEALTH EFFECTS OF VARIOUS EXPOSURES. RECENTLY, THERE HAS BEEN A MOVEMENT TO UNDERSTAND HUMAN HEALTH AND DISEASE WITHIN THE CONTEXT OF THE EXPOSOME, WHICH AIMS TO DESCRIBE AND QUANTIFY THE ENTIRETY OF ALL EXPOSURES PEOPLE ENCOUNTER THROUGHOUT THEIR LIVES. THESE INCLUDE, AMONG OTHERS, ENVIRONMENTAL POLLUTANTS, OCCUPATIONAL EXPOSURES, HEAVY METALS, AND LIFESTYLE AND BEHAVIORAL FACTORS. IN THIS CHAPTER, WE SUMMARIZE THE CURRENT RESEARCH ON MITOCHONDRIA AND HUMAN HEALTH, PROVIDE AN OVERVIEW OF THE CURRENT KNOWLEDGE ON MITOCHONDRIAL EPIGENETICS, AND DESCRIBE THE EXPERIMENTAL AND EPIDEMIOLOGIC STUDIES THAT HAVE INVESTIGATED PARTICULAR EXPOSURES AND THEIR RELATIONSHIPS WITH MITOCHONDRIAL EPIGENETIC MODIFICATIONS. WE CONCLUDE THE CHAPTER WITH SUGGESTIONS FOR FUTURE DIRECTIONS IN EPIDEMIOLOGIC AND EXPERIMENTAL RESEARCH THAT IS NEEDED TO ADVANCE THE GROWING FIELD OF MITOCHONDRIAL EPIGENETICS. 2023 19 1931 24 ENVIRONMENTAL EXPOSURES, THE EPIGENOME, AND AFRICAN AMERICAN WOMEN'S HEALTH. STRESS IS A COMMON FEATURE OF MODERN LIFE, BUT BOTH THE EXTENT OF EXPOSURE TO STRESSORS AND THE DOWNSTREAM EFFECTS OF THESE STRESS EXPOSURES CAN VARY CONSIDERABLY AMONG INDIVIDUALS, COMMUNITIES, AND POPULATIONS. WHEN INDIVIDUALS ARE EXPOSED TO REPEATED OR CHRONIC STRESS, WEAR AND TEAR ON THE BODY CAN ACCUMULATE AND MANIFEST IN MANY WAYS. THE TERM "ALLOSTATIC LOAD" REPRESENTS THE PHYSIOLOGICAL CONSEQUENCES OF REPEATED OR CHRONIC EXPOSURE TO ENVIRONMENTAL STRESSORS AND IS LINKED TO FLUCTUATING AND/OR HEIGHTENED NEURAL OR NEUROENDOCRINE RESPONSES. AFRICAN AMERICAN WOMEN ARE ONE POPULATION SUBGROUP THAT HAS BEEN IDENTIFIED AS POTENTIALLY HAVING BOTH AN ELEVATED ALLOSTATIC LOAD AND AN ENHANCED RESILIENCE TO EXTERNAL FACTORS. ONE MECHANISM BY WHICH ENVIRONMENTAL STRESSORS MAY IMPACT HUMAN HEALTH IS VIA EPIGENETIC REMODELING OF THE GENOME. THIS REVIEW WILL FOCUS ON WHAT IS KNOWN ABOUT HOW DIFFERENT TYPES OF ENVIRONMENTAL STRESSORS MAY AFFECT THE EPIGENOME AND EXPLORE LINKS BETWEEN EPIGENETIC REPROGRAMMING AND ALTERED ALLOSTATIC LOAD AND RESILIENCE AS IT PERTAINS TO AFRICAN AMERICAN WOMEN'S HEALTH. 2019 20 1360 25 DEVELOPMENTAL ASPECTS OF A LIFE COURSE APPROACH TO HEALTHY AGEING. WE EXAMINE THE MECHANISTIC BASIS AND WIDER IMPLICATIONS OF ADOPTING A DEVELOPMENTAL PERSPECTIVE ON HUMAN AGEING. PREVIOUS MODELS OF AGEING HAVE CONCENTRATED ON ITS GENETIC BASIS, OR THE DETRIMENTAL EFFECTS OF ACCUMULATED DAMAGE, BUT ALSO HAVE RAISED ISSUES ABOUT WHETHER AGEING CAN BE VIEWED AS ADAPTIVE ITSELF, OR IS A CONSEQUENCE OF OTHER ADAPTIVE PROCESSES, FOR EXAMPLE IF MAINTENANCE AND REPAIR PROCESSES IN THE PERIOD UP TO REPRODUCTION ARE TRADED OFF AGAINST LATER DECLINE IN FUNCTION. A LIFE COURSE MODEL PLACES AGEING IN THE CONTEXT OF THE ATTAINMENT OF PEAK CAPACITY FOR A BODY SYSTEM, STARTING IN EARLY DEVELOPMENT WHEN PLASTICITY PERMITS CHANGES IN STRUCTURE AND FUNCTION INDUCED BY A RANGE OF ENVIRONMENTAL STIMULI, FOLLOWED BY A PERIOD OF DECLINE, THE RATE OF WHICH DEPENDS ON THE PEAK ATTAINED AS WELL AS THE LATER LIFE CONDITIONS. SUCH PATH DEPENDENCY IN THE RATE OF AGEING MAY OFFER NEW INSIGHTS INTO ITS MODIFICATION. FOCUSING ON MUSCULOSKELETAL AND CARDIOVASCULAR FUNCTION, WE DISCUSS THIS MODEL AND THE POSSIBLE UNDERLYING MECHANISMS, INCLUDING ENDOTHELIAL FUNCTION, OXIDATIVE STRESS, STEM CELLS AND NUTRITIONAL FACTORS SUCH AS VITAMIN D STATUS. EPIGENETIC CHANGES INDUCED DURING DEVELOPMENTAL PLASTICITY, AND IMMUNE FUNCTION MAY PROVIDE A COMMON MECHANISTIC PROCESS UNDERLYING A LIFE COURSE MODEL OF AGEING. THE LIFE COURSE TRAJECTORY DIFFERS IN HIGH AND LOW RESOURCE SETTINGS. NEW INSIGHTS INTO THE DEVELOPMENTAL COMPONENTS OF THE LIFE COURSE MODEL OF AGEING MAY LEAD TO THE DESIGN OF BIOMARKERS OF LATER CHRONIC DISEASE RISK AND TO NEW INTERVENTIONS TO PROMOTE HEALTHY AGEING, WITH IMPORTANT IMPLICATIONS FOR PUBLIC HEALTH. 2016