1 375 91 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 2 2468 21 EPIGENETIC TOXICOLOGY AS TOXICANT-INDUCED CHANGES IN INTRACELLULAR SIGNALLING LEADING TO ALTERED GAP JUNCTIONAL INTERCELLULAR COMMUNICATION. COMMUNICATION MECHANISMS [EXTRA-, INTRA-, AND GAP JUNCTIONAL INTER-CELLULAR COMMUNICATION (GJIC)] CONTROL, FROM THE FERTILIZED EGG, THROUGH EMBRYOGENESIS TO MATURITY AND AGING, WHETHER A CELL PROLIFERATES, DIFFERENTIATES, DIES BY APOPTOSIS, OR IF DIFFERENTIATED, ADAPTIVELY RESPONDS TO ENDOGENOUS AND EXOGENOUS SIGNALS. FROM THE EGG TO THE 100 TRILLION CELLS IN THE HUMAN BODY, HEALTH IS MAINTAINED WHEN THESE COMMUNICATION PROCESSES BETWEEN STEM, PROGENITOR AND TERMINALLY DIFFERENTIATED CELLS ARE INTEGRATED. EACH CELL CHOICE INVOLVES 'EPIGENETIC' MECHANISMS TO ALTER THE EXPRESSION OF GENES AT THE TRANSCRIPTIONAL, TRANSLATIONAL OR POST-TRANSLATIONAL LEVELS. DISRUPTION OF THE COMMUNICATION MECHANISMS CAN BE EITHER ADAPTIVE OR MALADAPTIVE. MODULATION OF EXTRA-CELLULAR COMMUNICATION, EITHER BY GENETIC IMBALANCES OF GROWTH FACTORS, HORMONES OR NEUROTRANSMITTERS OR BY ENVIRONMENTAL, EXOGENOUS CHEMICALS CAN TRIGGER SIGNAL TRANSDUCING INTRA-CELLULAR MECHANISMS. THESE INTRA-CELLULAR SIGNALS CAN MODULATE GENE EXPRESSION AT THE TRANSCRIPTIONAL, TRANSLATIONAL OR POST-TRANSLATIONAL LEVELS WHILE ALSO MODULATING GJIC. UNTIMELY OR CHRONIC DISRUPTION OF GJIC DURING EMBRYONIC OR FETAL DEVELOPMENT COULD LEAD TO EMBRYONIC LETHALITY OR TERATOGENESIS. BY MODULATION OF GJIC, HOMEOSTATIC CONTROL OF CELL GROWTH, DIFFERENTIATION OR APOPTOSIS COULD LEAD TO SPECIFIC DISEASES, SUCH AS NEUROLOGICAL, CARDIOVASCULAR, REPRODUCTIVE OR ENDOCRINOLOGICAL DYSFUNCTION. CHEMICAL MODULATION OR ONCOGENE DOWN-REGULATION OF GJIC IN INITIATED TISSUES HAS BEEN SHOWN TO LEAD TO TUMOR PROMOTION. GENETIC SYNDROMES CARRYING A MUTATED GAP JUNCTION GENE, TOGETHER WITH SOME TRANSGENIC AND KNOCK-OUT GAP JUNCTION GENE MICE, PROVIDE EVIDENCE FOR THE IMPORTANCE OF THIS ORGANELLE FOUND ONLY IN METAZOANS. IMPLICATIONS FOR 'THRESHOLDS' TO TOXICANTS AND FOR RISK ASSESSMENT ARE EVIDENT. 1998 3 293 20 AGING HALLMARKS AND THE ROLE OF OXIDATIVE STRESS. AGING IS A COMPLEX BIOLOGICAL PROCESS ACCOMPANIED BY A PROGRESSIVE DECLINE IN THE PHYSICAL FUNCTION OF THE ORGANISM AND AN INCREASED RISK OF AGE-RELATED CHRONIC DISEASES SUCH AS CARDIOVASCULAR DISEASES, CANCER, AND NEURODEGENERATIVE DISEASES. STUDIES HAVE ESTABLISHED THAT THERE EXIST NINE HALLMARKS OF THE AGING PROCESS, INCLUDING (I) TELOMERE SHORTENING, (II) GENOMIC INSTABILITY, (III) EPIGENETIC MODIFICATIONS, (IV) MITOCHONDRIAL DYSFUNCTION, (V) LOSS OF PROTEOSTASIS, (VI) DYSREGULATED NUTRIENT SENSING, (VII) STEM CELL EXHAUSTION, (VIII) CELLULAR SENESCENCE, AND (IX) ALTERED CELLULAR COMMUNICATION. ALL THESE ALTERATIONS HAVE BEEN LINKED TO SUSTAINED SYSTEMIC INFLAMMATION, AND THESE MECHANISMS CONTRIBUTE TO THE AGING PROCESS IN TIMING NOT CLEARLY DETERMINED YET. NEVERTHELESS, MITOCHONDRIAL DYSFUNCTION IS ONE OF THE MOST IMPORTANT MECHANISMS CONTRIBUTING TO THE AGING PROCESS. MITOCHONDRIA IS THE PRIMARY ENDOGENOUS SOURCE OF REACTIVE OXYGEN SPECIES (ROS). DURING THE AGING PROCESS, THERE IS A DECLINE IN ATP PRODUCTION AND ELEVATED ROS PRODUCTION TOGETHER WITH A DECLINE IN THE ANTIOXIDANT DEFENSE. ELEVATED ROS LEVELS CAN CAUSE OXIDATIVE STRESS AND SEVERE DAMAGE TO THE CELL, ORGANELLE MEMBRANES, DNA, LIPIDS, AND PROTEINS. THIS DAMAGE CONTRIBUTES TO THE AGING PHENOTYPE. IN THIS REVIEW, WE SUMMARIZE RECENT ADVANCES IN THE MECHANISMS OF AGING WITH AN EMPHASIS ON MITOCHONDRIAL DYSFUNCTION AND ROS PRODUCTION. 2023 4 4381 19 MITOCHONDRIAL DYSFUNCTION AND THE AKI-TO-CKD TRANSITION. ACUTE KIDNEY INJURY (AKI) HAS BEEN WIDELY RECOGNIZED AS AN IMPORTANT RISK FACTOR FOR THE OCCURRENCE AND DEVELOPMENT OF CHRONIC KIDNEY DISEASE (CKD). EVEN MILDER AKI HAS ADVERSE CONSEQUENCES AND COULD PROGRESS TO RENAL FIBROSIS, WHICH IS THE ULTIMATE COMMON PATHWAY FOR VARIOUS TERMINAL KIDNEY DISEASES. THUS, IT IS URGENT TO DEVELOP A STRATEGY TO HINDER THE TRANSITION FROM AKI TO CKD. SOME MECHANISMS OF THE AKI-TO-CKD TRANSITION HAVE BEEN REVEALED, SUCH AS NEPHRON LOSS, CELL CYCLE ARREST, PERSISTENT INFLAMMATION, ENDOTHELIAL INJURY WITH VASCULAR RAREFACTION, AND EPIGENETIC CHANGES. PREVIOUS STUDIES HAVE ELUCIDATED THE PIVOTAL ROLE OF MITOCHONDRIA IN ACUTE INJURIES AND DEMONSTRATED THAT THE FITNESS OF THIS ORGANELLE IS A MAJOR DETERMINANT IN BOTH THE PATHOGENESIS AND RECOVERY OF ORGAN FUNCTION. RECENT RESEARCH HAS SUGGESTED THAT DAMAGE TO MITOCHONDRIAL FUNCTION IN EARLY AKI IS A CRUCIAL FACTOR LEADING TO TUBULAR INJURY AND PERSISTENT RENAL INSUFFICIENCY. DYSREGULATION OF MITOCHONDRIAL HOMEOSTASIS, ALTERATIONS IN BIOENERGETICS, AND ORGANELLE STRESS CROSS TALK CONTRIBUTE TO THE AKI-TO-CKD TRANSITION. IN THIS REVIEW, WE FOCUS ON THE PATHOPHYSIOLOGY OF MITOCHONDRIA IN RENAL RECOVERY AFTER AKI AND PROGRESSION TO CKD, CONFIRMING THAT TARGETING MITOCHONDRIA REPRESENTS A POTENTIALLY EFFECTIVE THERAPEUTIC STRATEGY FOR THE PROGRESSION OF AKI TO CKD. 2020 5 4170 18 MEETING REPORT: ISN FOREFRONTS IN NEPHROLOGY ON ENDOTHELIAL BIOLOGY AND RENAL DISEASE: FROM BENCH TO PREVENTION. THIS ISN-SPONSORED FOREFRONT IN NEPHROLOGY MEETING, WHICH HAS BROUGHT TOGETHER 120 SCIENTISTS FROM 21 COUNTRIES, HAS BEEN CONCERNED WITH VARIOUS ASPECTS OF ENDOTHELIAL FUNCTION AND DYSFUNCTION AND THEIR CONTRIBUTION TO PROGRESSION OF CHRONIC KIDNEY DISEASE AND/OR ITS CARDIOVASCULAR COMPLICATIONS. THE FOLLOWING THEMES WERE DISCUSSED IN GREAT DEPTH: (1) PHENOTYPICAL CHANGES IN THE VASCULAR ENDOTHELIUM - PERMEABILITY, SENESCENCE, AND APOPTOSIS; (2) REGULATION OF ENDOTHELIAL NITRIC OXIDE (NO) SYNTHASE FUNCTION - CAVEOLAR AND SHEAR STRESS MECHANISMS, EPIGENETIC REGULATION, S-NITROSYLATION, AND RHO-KINASE REGULATION; (3) OXIDATIVE STRESS AND HYPOXIA-INDUCED CHANGES; (4) ORGANELLAR DYSFUNCTION - LYSOSOMES, MITOCHONDRIA, AND ENDOPLASMIC RETICULUM; (5) NO-INDEPENDENT MECHANISMS OF VASOMOTION - EPOXIDES, HEME OXYGENASE-1 AND CARBON MONOXIDE, THROMBOXANE, TUMOR NECROSIS FACTOR-ALPHA, AND URIC ACID; (6) ENDOTHELIAL CROSSTALK WITH PODOCYTES, MONOCYTES, SMOOTH MUSCLE CELLS, AND PLATELETS; (7) CANDIDATE CLINICAL BIOMARKERS OF ENDOTHELIAL DYSFUNCTION - FUNCTIONAL TESTING OF MACRO- AND MICRO-VASCULAR FUNCTIONS, SURROGATE MARKERS, CIRCULATING DETACHED ENDOTHELIAL CELLS, AND ENDOTHELIAL PRECURSOR CELLS; AND CULMINATED IN ROUND TABLE DISCUSSION ON THE DIAGNOSIS OF ENDOTHELIAL DYSFUNCTION AND ITS TREATMENT OPTIONS. IN CONCLUSION, THIS MEETING HAS FOCUSED ON SEVERAL KEY PROBLEMS OF ENDOTHELIAL CELL PATHOBIOLOGY RELEVANT TO CHRONIC KIDNEY DISEASE. 2006 6 5826 18 STRESS SIGNAL NETWORK BETWEEN HYPOXIA AND ER STRESS IN CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS CHARACTERIZED BY AN IRREVERSIBLE DECREASE IN KIDNEY FUNCTION AND INDUCTION OF VARIOUS METABOLIC DYSFUNCTIONS. ACCUMULATED FINDINGS REVEAL THAT CHRONIC HYPOXIC STRESS AND ENDOPLASMIC RETICULUM (ER) STRESS ARE INVOLVED IN A RANGE OF PATHOGENIC CONDITIONS, INCLUDING THE PROGRESSION OF CKD. BECAUSE OF THE PRESENCE OF AN ARTERIOVENOUS OXYGEN SHUNT, THE KIDNEY IS THOUGHT TO BE SUSCEPTIBLE TO HYPOXIA. CHRONIC KIDNEY HYPOXIA IS INDUCED BY A NUMBER OF PATHOGENIC CONDITIONS, INCLUDING RENAL ISCHEMIA, REDUCED PERITUBULAR CAPILLARY, AND TUBULOINTERSTITIAL FIBROSIS. THE ER IS AN ORGANELLE WHICH HELPS MAINTAIN THE QUALITY OF PROTEINS THROUGH THE UNFOLDED PROTEIN RESPONSE (UPR) PATHWAY, AND ER DYSFUNCTION ASSOCIATED WITH MALADAPTIVE UPR ACTIVATION IS NAMED ER STRESS. ER STRESS IS REPORTED TO BE RELATED TO SOME OF THE EFFECTS OF PATHOGENESIS IN KIDNEY, PARTICULARLY IN THE PODOCYTE SLIT DIAPHRAGM AND TUBULOINTERSTITIUM. FURTHERMORE, CHRONIC HYPOXIA MEDIATES ER STRESS IN BLOOD VESSEL ENDOTHELIAL CELLS AND TUBULOINTERSTITIUM VIA SEVERAL MECHANISMS, INCLUDING OXIDATIVE STRESS, EPIGENETIC ALTERATION, LIPID METABOLISM, AND THE AKT PATHWAY. IN SUMMARY, A GROWING CONSENSUS CONSIDERS THAT THESE STRESSES INTERACT VIA COMPLICATED STRESS SIGNAL NETWORKS, WHICH LEADS TO THE EXACERBATION OF CKD (FIGURE 1). THIS STRESS SIGNAL NETWORK MIGHT BE A TARGET FOR INTERVENTIONS AIMED AT AMELIORATING CKD. 2017 7 3181 22 HALLMARKS OF AGING: AN EXPANDING UNIVERSE. AGING IS DRIVEN BY HALLMARKS FULFILLING THE FOLLOWING THREE PREMISES: (1) THEIR AGE-ASSOCIATED MANIFESTATION, (2) THE ACCELERATION OF AGING BY EXPERIMENTALLY ACCENTUATING THEM, AND (3) THE OPPORTUNITY TO DECELERATE, STOP, OR REVERSE AGING BY THERAPEUTIC INTERVENTIONS ON THEM. WE PROPOSE THE FOLLOWING TWELVE HALLMARKS OF AGING: GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, DISABLED MACROAUTOPHAGY, DEREGULATED NUTRIENT-SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, ALTERED INTERCELLULAR COMMUNICATION, CHRONIC INFLAMMATION, AND DYSBIOSIS. THESE HALLMARKS ARE INTERCONNECTED AMONG EACH OTHER, AS WELL AS TO THE RECENTLY PROPOSED HALLMARKS OF HEALTH, WHICH INCLUDE ORGANIZATIONAL FEATURES OF SPATIAL COMPARTMENTALIZATION, MAINTENANCE OF HOMEOSTASIS, AND ADEQUATE RESPONSES TO STRESS. 2023 8 6374 22 THE ROLE OF MITOCHONDRIA IN MYOCARDIAL DAMAGE CAUSED BY ENERGY METABOLISM DISORDERS: FROM MECHANISMS TO THERAPEUTICS. MYOCARDIAL DAMAGE IS THE MOST SERIOUS PATHOLOGICAL CONSEQUENCE OF CARDIOVASCULAR DISEASES AND AN IMPORTANT REASON FOR THEIR HIGH MORTALITY. IN RECENT YEARS, BECAUSE OF THE HIGH PREVALENCE OF SYSTEMIC ENERGY METABOLISM DISORDERS (E.G., OBESITY, DIABETES MELLITUS, AND METABOLIC SYNDROME), COMPLICATIONS OF MYOCARDIAL DAMAGE CAUSED BY THESE DISORDERS HAVE ATTRACTED WIDESPREAD ATTENTION. ENERGY METABOLISM DISORDERS ARE INDEPENDENT OF TRADITIONAL INJURY-RELATED RISK FACTORS, SUCH AS ISCHEMIA, HYPOXIA, TRAUMA, AND INFECTION. AN IMBALANCE OF MYOCARDIAL METABOLIC FLEXIBILITY AND MYOCARDIAL ENERGY DEPLETION ARE USUALLY THE INITIAL CHANGES OF MYOCARDIAL INJURY CAUSED BY ENERGY METABOLISM DISORDERS, AND ABNORMAL MORPHOLOGY AND FUNCTIONAL DESTRUCTION OF THE MITOCHONDRIA ARE THEIR IMPORTANT FEATURES. SPECIFICALLY, MITOCHONDRIA ARE THE CENTERS OF ENERGY METABOLISM, AND RECENT EVIDENCE HAS SHOWN THAT DECREASED MITOCHONDRIAL FUNCTION, CAUSED BY AN IMBALANCE IN MITOCHONDRIAL QUALITY CONTROL, MAY PLAY A KEY ROLE IN MYOCARDIAL INJURY CAUSED BY ENERGY METABOLISM DISORDERS. UNDER CHRONIC ENERGY STRESS, MITOCHONDRIA UNDERGO PATHOLOGICAL FISSION, WHILE MITOPHAGY, MITOCHONDRIAL FUSION, AND BIOGENESIS ARE INHIBITED, AND MITOCHONDRIAL PROTEIN BALANCE AND TRANSFER ARE DISTURBED, RESULTING IN THE ACCUMULATION OF NONFUNCTIONAL AND DAMAGED MITOCHONDRIA. CONSEQUENTLY, DAMAGED MITOCHONDRIA LEAD TO MYOCARDIAL ENERGY DEPLETION AND THE ACCUMULATION OF LARGE AMOUNTS OF REACTIVE OXYGEN SPECIES, FURTHER AGGRAVATING THE IMBALANCE IN MITOCHONDRIAL QUALITY CONTROL AND FORMING A VICIOUS CYCLE. IN ADDITION, IMPAIRED MITOCHONDRIA COORDINATE CALCIUM HOMEOSTASIS IMBALANCE, AND EPIGENETIC ALTERATIONS PARTICIPATE IN THE PATHOGENESIS OF MYOCARDIAL DAMAGE. THESE PATHOLOGICAL CHANGES INDUCE RAPID PROGRESSION OF MYOCARDIAL DAMAGE, EVENTUALLY LEADING TO HEART FAILURE OR SUDDEN CARDIAC DEATH. TO INTERVENE MORE SPECIFICALLY IN THE MYOCARDIAL DAMAGE CAUSED BY METABOLIC DISORDERS, WE NEED TO UNDERSTAND THE SPECIFIC ROLE OF MITOCHONDRIA IN THIS CONTEXT IN DETAIL. ACCORDINGLY, PROMISING THERAPEUTIC STRATEGIES HAVE BEEN PROPOSED. WE ALSO SUMMARIZE THE EXISTING THERAPEUTIC STRATEGIES TO PROVIDE A REFERENCE FOR CLINICAL TREATMENT AND DEVELOPING NEW THERAPIES. 2023 9 4985 24 PATHWAYS TO AGING: THE MITOCHONDRION AT THE INTERSECTION OF BIOLOGICAL AND PSYCHOSOCIAL SCIENCES. COMPELLING EVIDENCE SUGGESTS THAT BOTH BIOLOGICAL AND PSYCHOSOCIAL FACTORS IMPACT THE PROCESS OF AGING. HOWEVER, OUR UNDERSTANDING OF THE DYNAMIC INTERPLAY AMONG BIOLOGICAL AND PSYCHOSOCIAL FACTORS ACROSS THE LIFE COURSE IS STILL FRAGMENTARY. FOR EXAMPLE, IT NEEDS TO BE ESTABLISHED HOW THE INTERACTION OF INDIVIDUAL FACTORS (E.G., GENETIC AND EPIGENETIC ENDOWMENT AND PERSONALITY), BEHAVIORAL FACTORS (E.G., PHYSICAL ACTIVITY, DIET, AND STRESS MANAGEMENT), AND PSYCHOSOCIAL EXPERIENCES (E.G., SOCIAL SUPPORT, WELL-BEING, SOCIOECONOMIC STATUS, AND MARRIAGE) IN PERINATAL, CHILDHOOD, AND ADULTHOOD INFLUENCE HEALTH ACROSS THE AGING CONTINUUM. THIS PAPER AIMS TO OUTLINE POTENTIAL INTERSECTION POINTS SERVING AS AN INTERFACE BETWEEN BIOLOGICAL AND PSYCHOSOCIAL FACTORS, WITH AN EMPHASIS ON THE MITOCHONDRION. MITOCHONDRIA ARE CELLULAR ORGANELLES WHICH PLAY A CRITICAL ROLE IN CELLULAR SENESCENCE. BOTH CHRONIC EXPOSURE TO PSYCHOSOCIAL STRESS AND GENETIC-BASED MITOCHONDRIAL DYSFUNCTION HAVE STRIKINGLY SIMILAR BIOLOGICAL CONSEQUENCES; BOTH PREDISPOSE INDIVIDUALS TO ADVERSE AGE-RELATED HEALTH DISORDERS AND EARLY MORTALITY. EXPLORING THE INTERACTIVE NATURE OF THE FACTORS RESULTING IN PATHWAYS TO NORMAL HEALTHY AGING, AS WELL AS THOSE LEADING TO MORBIDITY AND EARLY MORTALITY, WILL CONTINUE TO ENHANCE OUR ABILITY TO TRANSLATE RESEARCH INTO EFFECTIVE PRACTICES THAT CAN BE IMPLEMENTED THROUGHOUT THE LIFE COURSE TO OPTIMISE THE AGING PROCESS. 2011 10 5381 20 RECONSIDERING THE ROLE OF MITOCHONDRIA IN AGING. BACKGROUND: MITOCHONDRIAL DYSFUNCTION HAS LONG BEEN CONSIDERED A MAJOR CONTRIBUTOR TO AGING AND AGE-RELATED DISEASES. HARMAN'S MITOCHONDRIAL FREE RADICAL THEORY OF AGING POSTULATED THAT SOMATIC MITOCHONDRIAL DNA MUTATIONS THAT ACCUMULATE OVER THE LIFE SPAN CAUSE EXCESSIVE PRODUCTION OF REACTIVE OXYGEN SPECIES THAT DAMAGE MACROMOLECULES AND IMPAIR CELL AND TISSUE FUNCTION. INDEED, STUDIES HAVE SHOWN THAT MAXIMAL OXIDATIVE CAPACITY DECLINES WITH AGE WHILE REACTIVE OXYGEN SPECIES PRODUCTION INCREASES. HARMAN'S HYPOTHESIS HAS BEEN SERIOUSLY CHALLENGED BY RECENT STUDIES SHOWING THAT REACTIVE OXYGEN SPECIES EVOKE METABOLIC HEALTH AND LONGEVITY, PERHAPS THROUGH HORMETIC MECHANISMS THAT INCLUDE AUTOPHAGY. THE PURPOSE OF THIS REVIEW IS TO SCAN THE EVER-GROWING LITERATURE ON MITOCHONDRIA FROM THE PERSPECTIVE OF AGING RESEARCH AND TRY TO IDENTIFY PRIORITY QUESTIONS THAT SHOULD BE ADDRESSED IN FUTURE RESEARCH. METHODS: A SYSTEMATIC SEARCH OF PEER-REVIEWED STUDIES WAS PERFORMED USING PUBMED. SEARCH TERMS INCLUDED (I) MITOCHONDRIA OR MITOCHONDRIAL; (II) AGING, AGEING, OLDER ADULTS OR ELDERLY; AND (III) REACTIVE OXYGEN SPECIES, MITOCHONDRIA DYNAMICS, MITOCHONDRIAL PROTEOSTASIS, CYTOSOL, MITOCHONDRIAL-ASSOCIATED MEMBRANES, REDOX HOMEOSTASIS, ELECTRON TRANSPORT CHAIN, ELECTRON TRANSPORT CHAIN EFFICIENCY, EPIGENETIC REGULATION, DNA HETEROPLASMY. RESULTS: THE IMPORTANCE OF MITOCHONDRIAL BIOLOGY AS A TRAIT D'UNION BETWEEN THE BASIC BIOLOGY OF AGING AND THE PATHOGENESIS OF AGE-RELATED DISEASES IS STRONGER THAN EVER, ALTHOUGH THE EMPHASIS HAS MOVED FROM REACTIVE OXYGEN SPECIES PRODUCTION TO OTHER ASPECTS OF MITOCHONDRIAL PHYSIOLOGY, INCLUDING MITOCHONDRIAL BIOGENESIS AND TURNOVER, ENERGY SENSING, APOPTOSIS, SENESCENCE, AND CALCIUM DYNAMICS. CONCLUSIONS: MITOCHONDRIA COULD PLAY A KEY ROLE IN THE PATHOPHYSIOLOGY OF AGING OR IN THE EARLIER STAGES OF SOME EVENTS THAT LEAD TO THE AGING PHENOTYPE. THEREFORE, MITOCHONDRIA WILL INCREASINGLY BE TARGETED TO PREVENT AND TREAT CHRONIC DISEASES AND TO PROMOTE HEALTHY AGING. 2015 11 5879 20 SYNTHETIC MITOCHONDRIA AS THERAPEUTICS AGAINST SYSTEMIC AGING: A HYPOTHESIS. WE HYPOTHESIZE HEREIN THAT SYNTHETIC MITOCHONDRIA, ENGINEERED, OR REPROGRAMMED TO BE MORE ENERGETICALLY EFFICIENT AND TO HAVE MILDLY ELEVATED LEVELS OF REACTIVE OXYGEN SPECIES (ROS) PRODUCTION, WOULD BE AN EFFECTIVE FORM OF THERAPEUTICS AGAINST SYSTEMIC AGING. THE FREE RADICAL AND MITOCHONDRIA THEORIES OF AGING HOLD THAT MITOCHONDRIA-GENERATED ROS UNDERLIES CHRONIC ORGANELLE, CELL AND TISSUES DAMAGES THAT CONTRIBUTE TO SYSTEMIC AGING. MORE RECENT FINDINGS, HOWEVER, COLLECTIVELY SUGGEST THAT WHILE ACUTE AND MASSIVE ROS GENERATION DURING EVENTS SUCH AS TISSUE INJURY IS INDEED DETRIMENTAL, SUBACUTE STRESSES, AND CHRONIC ELEVATION IN ROS PRODUCTION MAY INSTEAD INDUCE A STATE OF MITOCHONDRIAL HORMESIS (OR "MITOHORMESIS") THAT COULD EXTEND LIFESPAN. MITOHORMESIS APPEARS TO BE A CONVERGENT MECHANISM FOR SEVERAL KNOWN ANTI-AGING SIGNALING PATHWAYS. IMPORTANTLY, MITOHORMETIC SIGNALING COULD ALSO OCCUR IN A NON-CELL AUTONOMOUS MANNER, WITH ITS INDUCTION IN NEURONS AFFECTING GUT CELLS, FOR EXAMPLE. TECHNOLOGIES ARE OUTLINED THAT COULD LEAD TOWARDS TESTING OF THE HYPOTHESIS, WHICH INCLUDE GENETIC AND EPIGENETIC ENGINEERING OF THE MITOCHONDRIA, AS WELL AS INTERCELLULAR TRANSFER OF MITOCHONDRIA FROM TRANSPLANTED HELPER CELLS TO TARGET TISSUES. 2015 12 4663 24 NEW HORIZONS: NOVEL APPROACHES TO ENHANCE HEALTHSPAN THROUGH TARGETING CELLULAR SENESCENCE AND RELATED AGING MECHANISMS. THE ELDERLY POPULATION IS INCREASING FASTER THAN OTHER SEGMENTS OF THE POPULATION THROUGHOUT THE WORLD. AGE IS THE LEADING PREDICTOR FOR MOST CHRONIC DISEASES AND DISORDERS, MULTIMORBIDITY, GERIATRIC SYNDROMES, AND IMPAIRED ABILITY TO RECOVER FROM ACCIDENTS OR ILLNESSES. ENHANCING THE DURATION OF HEALTH AND INDEPENDENCE, TERMED HEALTHSPAN, WOULD BE MORE DESIRABLE THAN EXTENDING LIFESPAN MERELY BY PROLONGING THE PERIOD OF MORBIDITY TOWARD THE END OF LIFE. THE GEROSCIENCE HYPOTHESIS POSITS THAT HEALTHSPAN CAN BE EXTENDED BY TARGETING FUNDAMENTAL AGING MECHANISMS, RATHER THAN ATTEMPTING TO ADDRESS EACH AGE-RELATED DISEASE ONE AT A TIME, ONLY SO THE AFFLICTED INDIVIDUAL SURVIVES DISABLED AND DIES SHORTLY AFTERWARD OF ANOTHER AGE-RELATED DISEASE. THESE FUNDAMENTAL AGING MECHANISMS INCLUDE, AMONG OTHERS, CHRONIC INFLAMMATION, FIBROSIS, STEM CELL/ PROGENITOR DYSFUNCTION, DNA DAMAGE, EPIGENETIC CHANGES, METABOLIC SHIFTS, DESTRUCTIVE METABOLITE GENERATION, MITOCHONDRIAL DYSFUNCTION, MISFOLDED OR AGGREGATED PROTEIN ACCUMULATION, AND CELLULAR SENESCENCE. THESE PROCESSES APPEAR TO BE TIGHTLY INTERLINKED, AS TARGETING ANY ONE APPEARS TO AFFECT MANY OF THE REST, UNDERLYING OUR UNITARY THEORY OF FUNDAMENTAL AGING MECHANISMS. INTERVENTIONS TARGETING MANY FUNDAMENTAL AGING PROCESSES ARE BEING DEVELOPED, INCLUDING DIETARY MANIPULATIONS, METFORMIN, MTOR (MECHANISTIC TARGET OF RAPAMYCIN) INHIBITORS, AND SENOLYTICS, WHICH ARE IN EARLY HUMAN TRIALS. THESE INTERVENTIONS COULD LEAD TO GREATER HEALTHSPAN BENEFITS THAN TREATING AGE-RELATED DISEASES ONE AT A TIME. TO ILLUSTRATE THESE POINTS, WE FOCUS ON CELLULAR SENESCENCE AND THERAPIES IN DEVELOPMENT TO TARGET SENESCENT CELLS. COMBINING INTERVENTIONS TARGETING AGING MECHANISMS WITH DISEASE-SPECIFIC DRUGS COULD RESULT IN MORE THAN ADDITIVE BENEFITS FOR CURRENTLY DIFFICULT-TO-TREAT OR INTRACTABLE DISEASES. MORE RESEARCH ATTENTION NEEDS TO BE DEVOTED TO TARGETING FUNDAMENTAL AGING PROCESSES. 2021 13 6287 23 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 14 5391 23 REDOX-RELATED BIOMARKERS IN HUMAN CARDIOVASCULAR DISEASE - CLASSICAL FOOTPRINTS AND BEYOND. GLOBAL EPIDEMIOLOGICAL STUDIES SHOW THAT CHRONIC NON-COMMUNICABLE DISEASES SUCH AS ATHEROSCLEROSIS AND METABOLIC DISORDERS REPRESENT THE LEADING CAUSE OF PREMATURE MORTALITY AND MORBIDITY. CARDIOVASCULAR DISEASE SUCH AS ISCHEMIC HEART DISEASE IS A MAJOR CONTRIBUTOR TO THE GLOBAL BURDEN OF DISEASE AND THE SOCIOECONOMIC HEALTH COSTS. CLINICAL AND EPIDEMIOLOGICAL DATA SHOW AN ASSOCIATION OF TYPICAL OXIDATIVE STRESS MARKERS SUCH AS LIPID PEROXIDATION PRODUCTS, 3-NITROTYROSINE OR OXIDIZED DNA/RNA BASES WITH ALL MAJOR CARDIOVASCULAR DISEASES. THIS SUPPORTS THE CONCEPT THAT THE FORMATION OF REACTIVE OXYGEN AND NITROGEN SPECIES BY VARIOUS SOURCES (NADPH OXIDASES, XANTHINE OXIDASE AND MITOCHONDRIAL RESPIRATORY CHAIN) REPRESENTS A HALLMARK OF THE LEADING CARDIOVASCULAR COMORBIDITIES SUCH AS HYPERLIPIDEMIA, HYPERTENSION AND DIABETES. THESE REACTIVE OXYGEN AND NITROGEN SPECIES CAN LEAD TO OXIDATIVE DAMAGE BUT ALSO ADVERSE REDOX SIGNALING AT THE LEVEL OF KINASES, CALCIUM HANDLING, INFLAMMATION, EPIGENETIC CONTROL, CIRCADIAN CLOCK AND PROTEASOMAL SYSTEM. THE IN VIVO FOOTPRINTS OF THESE ADVERSE PROCESSES (REDOX BIOMARKERS) ARE DISCUSSED IN THE PRESENT REVIEW WITH FOCUS ON THEIR CLINICAL RELEVANCE, WHEREAS THE DETAILS OF THEIR MECHANISMS OF FORMATION AND TECHNICAL ASPECTS OF THEIR DETECTION ARE ONLY BRIEFLY MENTIONED. THE MAJOR CATEGORIES OF REDOX BIOMARKERS ARE SUMMARIZED AND EXPLAINED ON THE BASIS OF SUITABLE EXAMPLES. ALSO THE POTENTIAL PROGNOSTIC VALUE OF REDOX BIOMARKERS IS CRITICALLY DISCUSSED TO UNDERSTAND WHAT KIND OF INFORMATION THEY CAN PROVIDE BUT ALSO WHAT THEY CANNOT ACHIEVE. 2021 15 2361 16 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 16 303 26 AIR POLLUTION STRESS AND THE AGING PHENOTYPE: THE TELOMERE CONNECTION. AGING IS A COMPLEX PHYSIOLOGICAL PHENOMENON. THE QUESTION WHY SOME SUBJECTS GROW OLD WHILE REMAINING FREE FROM DISEASE WHEREAS OTHERS PREMATURELY DIE REMAINS LARGELY UNANSWERED. WE FOCUS HERE ON THE ROLE OF AIR POLLUTION IN BIOLOGICAL AGING. HALLMARKS OF AGING CAN BE GROUPED INTO THREE MAIN CATEGORIES: GENOMIC INSTABILITY, TELOMERE ATTRITION, AND EPIGENETIC ALTERATIONS LEADING TO ALTERED MITOCHONDRIAL FUNCTION AND CELLULAR SENESCENCE. AT BIRTH, THE INITIAL TELOMERE LENGTH OF A PERSON IS LARGELY DETERMINED BY ENVIRONMENTAL FACTORS. TELOMERE LENGTH SHORTENS WITH EACH CELL DIVISION AND EXPOSURE TO AIR POLLUTION AS WELL AS LOW RESIDENTIAL GREENS SPACE EXPOSURE IS ASSOCIATED WITH SHORTER TELOMERE LENGTH. RECENT STUDIES SHOW THAT THE ESTIMATED EFFECTS OF PARTICULATE AIR POLLUTION EXPOSURE ON THE TELOMERE MITOCHONDRIAL AXIS OF AGING MAY PLAY AN IMPORTANT ROLE IN CHRONIC HEALTH EFFECTS OF AIR POLLUTION. THE EXPOSOME ENCOMPASSES ALL EXPOSURES OVER AN ENTIRE LIFE. AS TELOMERES CAN BE CONSIDERED AS THE CELLULAR MEMORIES OF EXPOSURE TO OXIDATIVE STRESS AND INFLAMMATION, TELOMERE MAINTENANCE MAY BE A PROXY FOR ASSESSING THE "EXPOSOME". IF TELOMERES ARE CAUSALLY RELATED TO THE AGING PHENOTYPE AND ENVIRONMENTAL AIR POLLUTION IS AN IMPORTANT DETERMINANT OF TELOMERE LENGTH, THIS MIGHT PROVIDE NEW AVENUES FOR FUTURE PREVENTIVE STRATEGIES. 2016 17 3287 32 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 18 5416 17 REGULATION OF CELLULAR METABOLISM: PROGRAMMING AND MAINTAINING METABOLIC HOMEOSTASIS. MITOCHONDRIAL OXIDATIVE PHOSPHORYLATION IS PROGRAMMED TO SET AND MAINTAIN METABOLIC HOMEOSTASIS. THIS IS ACCOMPLISHED THROUGH AN INTRINSIC PROGRAM THAT DETERMINES THE METABOLIC [ATP]/[ADP]/[PI], WHERE [PI] IS THE CONCENTRATION OF INORGANIC PHOSPHATE (ENERGY STATE) AND MAINTAINS IT THROUGH A BIDIRECTIONAL SENSORY/SIGNALING CONTROL NETWORK THAT REACHES EVERY ASPECT OF CELLULAR METABOLISM. THE PROGRAM SETS THE ENERGY STATE WITH HIGH PRECISION (TO BETTER THAN ONE PART IN 10(9)) AND CAN RESPOND TO TRANSIENT CHANGES IN ENERGY DEMAND (ATP USE) TO MORE THAN 100 TIMES THE RESTING RATE. EPIGENETIC AND ENVIRONMENTAL FACTORS ARE ABLE TO "FINE TUNE" THE PROGRAMMED SET POINT OVER A NARROW RANGE TO MEET THE SPECIAL NEEDS ASSOCIATED WITH CELL DIFFERENTIATION AND CHRONIC CHANGES IN METABOLIC REQUIREMENTS. THE RESULT IS ROBUST, ACROSS PLATFORM CONTROL OF METABOLISM, ESSENTIAL TO CELLULAR DIFFERENTIATION AND THE EVOLUTION OF COMPLEX ORGANISMS. 2013 19 285 19 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 20 3596 23 IMPLICATIONS OF SPHINGOLIPIDS ON AGING AND AGE-RELATED DISEASES. AGING IS A PROCESS LEADING TO A PROGRESSIVE LOSS OF PHYSIOLOGICAL INTEGRITY AND HOMEOSTASIS, AND A PRIMARY RISK FACTOR FOR MANY LATE-ONSET CHRONIC DISEASES. THE MECHANISMS UNDERLYING AGING HAVE LONG PIQUED THE CURIOSITY OF SCIENTISTS. HOWEVER, THE IDEA THAT AGING IS A BIOLOGICAL PROCESS SUSCEPTIBLE TO GENETIC MANIPULATION WAS NOT WELL ESTABLISHED UNTIL THE DISCOVERY THAT THE INHIBITION OF INSULIN/IGF-1 SIGNALING EXTENDED THE LIFESPAN OF C. ELEGANS. ALTHOUGH AGING IS A COMPLEX MULTISYSTEM PROCESS, LOPEZ-OTIN ET AL. DESCRIBED AGING IN REFERENCE TO NINE HALLMARKS OF AGING. THESE NINE HALLMARKS INCLUDE: GENOMIC INSTABILITY, TELOMERE ATTRITION, EPIGENETIC ALTERATIONS, LOSS OF PROTEOSTASIS, DEREGULATED NUTRIENT SENSING, MITOCHONDRIAL DYSFUNCTION, CELLULAR SENESCENCE, STEM CELL EXHAUSTION, AND ALTERED INTERCELLULAR COMMUNICATION. DUE TO RECENT ADVANCES IN LIPIDOMIC, INVESTIGATION INTO THE ROLE OF LIPIDS IN BIOLOGICAL AGING HAS INTENSIFIED, PARTICULARLY THE ROLE OF SPHINGOLIPIDS (SL). SLS ARE A DIVERSE GROUP OF LIPIDS ORIGINATING FROM THE ENDOPLASMIC RETICULUM (ER) AND CAN BE MODIFIED TO CREATE A VASTLY DIVERSE GROUP OF BIOACTIVE METABOLITES THAT REGULATE ALMOST EVERY MAJOR CELLULAR PROCESS, INCLUDING CELL CYCLE REGULATION, SENESCENCE, PROLIFERATION, AND APOPTOSIS. ALTHOUGH SL BIOLOGY REACHES ALL NINE HALLMARKS OF AGING, ITS CONTRIBUTION TO EACH HALLMARK IS DISPROPORTIONATE. IN THIS REVIEW, WE WILL DISCUSS IN DETAIL THE MAJOR CONTRIBUTIONS OF SLS TO THE HALLMARKS OF AGING AND AGE-RELATED DISEASES WHILE ALSO SUMMARIZING THE IMPORTANCE OF THEIR OTHER MINOR BUT INTEGRAL CONTRIBUTIONS. 2021