1 6374 156 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 2 2702 33 EXCITOTOXICITY AND OVERNUTRITION ADDITIVELY IMPAIR METABOLIC FUNCTION AND IDENTITY OF PANCREATIC BETA-CELLS. A SUSTAINED INCREASE IN INTRACELLULAR CA(2+) CONCENTRATION (REFERRED TO HEREAFTER AS EXCITOTOXICITY), BROUGHT ON BY CHRONIC METABOLIC STRESS, MAY CONTRIBUTE TO PANCREATIC BETA-CELL FAILURE. TO DETERMINE THE ADDITIVE EFFECTS OF EXCITOTOXICITY AND OVERNUTRITION ON BETA-CELL FUNCTION AND GENE EXPRESSION, WE ANALYZED THE IMPACT OF A HIGH-FAT DIET (HFD) ON ABCC8 KNOCKOUT MICE. EXCITOTOXICITY CAUSED BETA-CELLS TO BE MORE SUSCEPTIBLE TO HFD-INDUCED IMPAIRMENT OF GLUCOSE HOMEOSTASIS, AND THESE EFFECTS WERE MITIGATED BY VERAPAMIL, A CA(2+) CHANNEL BLOCKER. EXCITOTOXICITY, OVERNUTRITION, AND THE COMBINATION OF BOTH STRESSES CAUSED SIMILAR BUT DISTINCT ALTERATIONS IN THE BETA-CELL TRANSCRIPTOME, INCLUDING ADDITIVE INCREASES IN GENES ASSOCIATED WITH MITOCHONDRIAL ENERGY METABOLISM, FATTY ACID BETA-OXIDATION, AND MITOCHONDRIAL BIOGENESIS AND THEIR KEY REGULATOR PPARGC1A OVERNUTRITION WORSENED EXCITOTOXICITY-INDUCED MITOCHONDRIAL DYSFUNCTION, INCREASING METABOLIC INFLEXIBILITY AND MITOCHONDRIAL DAMAGE. IN ADDITION, EXCITOTOXICITY AND OVERNUTRITION, INDIVIDUALLY AND TOGETHER, IMPAIRED BOTH BETA-CELL FUNCTION AND IDENTITY BY REDUCING EXPRESSION OF GENES IMPORTANT FOR INSULIN SECRETION, CELL POLARITY, CELL JUNCTION, CILIA, CYTOSKELETON, VESICULAR TRAFFICKING, AND REGULATION OF BETA-CELL EPIGENETIC AND TRANSCRIPTIONAL PROGRAM. SEX HAD AN IMPACT ON ALL BETA-CELL RESPONSES, WITH MALE ANIMALS EXHIBITING GREATER METABOLIC STRESS-INDUCED IMPAIRMENTS THAN FEMALES. TOGETHER, THESE FINDINGS INDICATE THAT A SUSTAINED INCREASE IN INTRACELLULAR CA(2+), BY ALTERING MITOCHONDRIAL FUNCTION AND IMPAIRING BETA-CELL IDENTITY, AUGMENTS OVERNUTRITION-INDUCED BETA-CELL FAILURE. 2020 3 5381 41 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 4 1665 44 DOWNREGULATION OF KIDNEY PROTECTIVE FACTORS BY INFLAMMATION: ROLE OF TRANSCRIPTION FACTORS AND EPIGENETIC MECHANISMS. CHRONIC KIDNEY DISEASE (CKD) IS ASSOCIATED TO AN INCREASED RISK OF DEATH, CKD PROGRESSION, AND ACUTE KIDNEY INJURY (AKI) EVEN FROM EARLY STAGES, WHEN GLOMERULAR FILTRATION RATE (GFR) IS PRESERVED. THE LINK BETWEEN EARLY CKD AND THESE RISKS IS UNCLEAR, SINCE THERE IS NO ACCUMULATION OF UREMIC TOXINS. HOWEVER, PATHOLOGICAL ALBUMINURIA AND KIDNEY INFLAMMATION ARE FREQUENT FEATURES OF EARLY CKD, AND THE PRODUCTION OF KIDNEY PROTECTIVE FACTORS MAY BE DECREASED. INDEED, KLOTHO EXPRESSION IS ALREADY DECREASED IN CKD CATEGORY G1 (NORMAL GFR). KLOTHO HAS ANTI-AGING AND NEPHROPROTECTIVE PROPERTIES, AND DECREASED KLOTHO LEVELS MAY CONTRIBUTE TO INCREASE THE RISK OF DEATH, CKD PROGRESSION, AND AKI. IN THIS REVIEW, WE DISCUSS THE DOWNREGULATION BY MEDIATORS OF INFLAMMATION OF MOLECULES WITH SYSTEMIC AND/OR RENAL LOCAL PROTECTIVE FUNCTIONS, EXEMPLIFIED BY KLOTHO AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA), A TRANSCRIPTION FACTOR THAT PROMOTES MITOCHONDRIAL BIOGENESIS. CYTOKINES SUCH AS TWEAK, TNF-ALPHA, OR TRANSFORMING GROWTH FACTOR -BETA1 PRODUCED LOCALLY DURING KIDNEY INJURY OR RELEASED FROM INFLAMMATORY SITES AT OTHER ORGANS MAY DECREASE KIDNEY EXPRESSION OF KLOTHO AND PGC-1ALPHA OR LEAD TO SUBOPTIMAL RECRUITMENT OF THESE NEPHROPROTECTIVE PROTEINS. TRANSCRIPTION FACTORS (E.G., SMAD3 AND NF-KAPPAB) AND EPIGENETIC MECHANISMS (E.G., HISTONE ACETYLATION OR METHYLATION) CONTRIBUTE TO DOWNREGULATE THE EXPRESSION OF KLOTHO AND/OR PGC-1ALPHA, WHILE HISTONE CROTONYLATION PROMOTES PGC-1ALPHA EXPRESSION. NF-KAPPABIZ FACILITATES THE REPRESSIVE EFFECT OF NF-KAPPAB ON KLOTHO EXPRESSION. A DETAILED UNDERSTANDING OF THESE MEDIATORS MAY CONTRIBUTE TO THE DEVELOPMENT OF NOVEL THERAPEUTIC APPROACHES TO PREVENT CKD PROGRESSION AND ITS NEGATIVE IMPACT ON MORTALITY AND AKI. 2016 5 3640 34 INCREASED EXTRACELLULAR MATRIX PROTEIN PRODUCTION IN CHRONIC DIABETIC COMPLICATIONS: IMPLICATIONS OF NON-CODING RNAS. MANAGEMENT OF CHRONIC DIABETIC COMPLICATIONS REMAINS A MAJOR MEDICAL CHALLENGE WORLDWIDE. ONE OF THE CHARACTERISTIC FEATURES OF ALL CHRONIC DIABETIC COMPLICATIONS IS AUGMENTED PRODUCTION OF EXTRACELLULAR MATRIX (ECM) PROTEINS. SUCH ECM PROTEINS ARE DEPOSITED IN ALL TISSUES AFFECTED BY CHRONIC COMPLICATIONS, ULTIMATELY CAUSING ORGAN DAMAGE AND DYSFUNCTION. A CONTRIBUTING FACTOR TO THIS PATHOGENETIC PROCESS IS GLUCOSE-INDUCED ENDOTHELIAL DAMAGE, WHICH INVOLVES PHENOTYPIC TRANSFORMATION OF ENDOTHELIAL CELLS (ECS). THIS PHENOTYPIC TRANSITION OF ECS, FROM A QUIESCENT STATE TO AN ACTIVATED DYSFUNCTIONAL STATE, CAN BE MEDIATED THROUGH ALTERATIONS IN THE SYNTHESIS OF CELLULAR PROTEINS. IN THIS REVIEW, WE DISCUSSED THE ROLES OF NON-CODING RNAS, SPECIFICALLY MICRORNAS (MIRNAS) AND LONG NON-CODING RNAS (LNCRNAS), IN SUCH PROCESSES. WE FURTHER OUTLINED OTHER EPIGENETIC MECHANISMS REGULATING THE BIOGENESIS AND/OR FUNCTION OF NON-CODING RNAS. OVERALL, WE BELIEVE THAT BETTER UNDERSTANDING OF SUCH MOLECULAR PROCESSES MAY LEAD TO THE DEVELOPMENT OF NOVEL BIOMARKERS AND THERAPEUTIC STRATEGIES IN THE FUTURE. 2019 6 1872 32 EMERGING ROLE OF LONG NON-CODING RNAS IN ENDOTHELIAL DYSFUNCTION AND THEIR MOLECULAR MECHANISMS. LONG NON-CODING RNAS (LNCRNAS) ARE THE NOVEL CLASS OF TRANSCRIPTS INVOLVED IN TRANSCRIPTIONAL, POST-TRANSCRIPTIONAL, TRANSLATIONAL, AND POST-TRANSLATIONAL REGULATION OF PHYSIOLOGY AND THE PATHOLOGY OF DISEASES. STUDIES HAVE EVIDENCED THAT THE IMPAIRMENT OF ENDOTHELIUM IS A CRITICAL EVENT IN THE PATHOGENESIS OF ATHEROSCLEROSIS AND ITS COMPLICATIONS. ENDOTHELIAL DYSFUNCTION IS CHARACTERIZED BY AN IMBALANCE IN VASODILATION AND VASOCONSTRICTION, OXIDATIVE STRESS, PROINFLAMMATORY FACTORS, AND NITRIC OXIDE BIOAVAILABILITY. DISRUPTION OF THE ENDOTHELIAL BARRIER PERMEABILITY, THE FIRST STEP IN DEVELOPING ATHEROSCLEROTIC LESIONS IS A CONSEQUENCE OF ENDOTHELIAL DYSFUNCTION. THOUGH SEVERAL FACTORS INTERFERE WITH THE NORMAL FUNCTIONING OF THE ENDOTHELIUM, INTRINSIC EPIGENETIC MECHANISMS GOVERNING ENDOTHELIAL FUNCTION ARE REGULATED BY LNCRNAS AND PERTURBATIONS CONTRIBUTE TO THE PATHOGENESIS OF THE DISEASE. THIS REVIEW COMPREHENSIVELY ADDRESSES THE BIOGENESIS OF LNCRNA AND MOLECULAR MECHANISMS UNDERLYING AND REGULATION IN ENDOTHELIAL FUNCTION. AN INSIGHT CORRELATING LNCRNAS AND ENDOTHELIAL DYSFUNCTION-ASSOCIATED DISEASES CAN POSITIVELY IMPACT THE DEVELOPMENT OF NOVEL BIOMARKERS AND THERAPEUTIC TARGETS IN ENDOTHELIAL DYSFUNCTION-ASSOCIATED DISEASES AND TREATMENT STRATEGIES. 2022 7 5826 35 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 8 2681 26 EVALUATION OF MUSCLE-SPECIFIC AND METABOLISM REGULATING MICRORNAS IN A CHRONIC SWIMMING RAT MODEL. MAKING BENEFIT FROM THE EPIGENETIC EFFECTS OF ENVIRONMENTAL FACTORS SUCH AS PHYSICAL ACTIVITY MAY RESULT IN A CONSIDERABLE IMPROVEMENT IN THE PREVENTION OF CHRONIC CIVILIZATION DISEASES. IN OUR CHRONIC SWIMMING RAT MODEL, THE EXPRESSION LEVELS OF SUCH MICRORNAS WERE CHARACTERIZED, THAT ARE INVOLVED IN SKELETAL MUSCLE DIFFERENTIATION, HYPERTROPHY AND FINE-TUNING OF METABOLISM, WHICH PROCESSES ARE INFLUENCED BY CHRONIC ENDURANCE TRAINING, CONTRIBUTING TO THE METABOLIC ADAPTATION OF SKELETAL MUSCLE DURING PHYSICAL ACTIVITY. AFTER CHRONIC SWIMMING, THE LEVEL OF MIR-128A INCREASED SIGNIFICANTLY IN EDL MUSCLES, WHICH MAY INFLUENCE METABOLIC ADAPTATION AND STRESS RESPONSE AS WELL. IN SOL, THE EXPRESSION LEVEL OF MIR-15B AND MIR-451 DECREASED SIGNIFICANTLY AFTER CHRONIC SWIMMING, WHICH CHANGES ARE OPPOSITE TO THEIR PREVIOUSLY DESCRIBED INCREMENT IN INSULIN RESISTANT SKELETAL MUSCLE. MIR-451 ALSO TARGETS PGC-1ALPHA MRNA, WHICHES EXPRESSION LEVEL SIGNIFICANTLY INCREASED IN SOL MUSCLES, RESULTING IN ENHANCED BIOGENESIS AND OXIDATIVE CAPACITY OF MITOCHONDRIA. IN SUMMARY, THE MICRORNA EXPRESSION CHANGES THAT WERE OBSERVED DURING OUR EXPERIMENTS SUGGEST THAT CHRONIC SWIM TRAINING CONTRIBUTES TO A BENEFICIAL METABOLIC PROFILE OF SKELETAL MUSCLE. 2022 9 375 22 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 10 4372 37 MIRNAS, OXIDATIVE STRESS, AND CANCER: A COMPREHENSIVE AND UPDATED REVIEW. OXIDATIVE STRESS REFERS TO ELEVATED LEVELS OF INTRACELLULAR REACTIVE OXYGEN SPECIES (ROS). ROS HOMEOSTASIS FUNCTIONS AS A SIGNALING PATHWAY FOR NORMAL CELL SURVIVAL AND APPROPRIATE CELL SIGNALING. CHRONIC INFLAMMATION INDUCED BY IMBALANCED LEVELS OF ROS CONTRIBUTES TO MANY DISEASES AND DIFFERENT TYPES OF CANCER. ROS CAN ALTER THE EXPRESSION OF ONCOGENES AND TUMOR SUPPRESSOR GENES THROUGH EPIGENETIC MODIFICATIONS, TRANSCRIPTION FACTORS, AND NON-CODING RNAS. MICRORNAS (MIRNAS) ARE SMALL NON-CODING RNAS THAT PLAY A KEY ROLE IN MOST BIOLOGICAL PATHWAYS. EACH MIRNA REGULATES HUNDREDS OF TARGET GENES BY INHIBITING PROTEIN TRANSLATION AND/OR PROMOTING MESSENGER RNA DEGRADATION. IN NORMAL CONDITIONS, MIRNAS PLAY A PHYSIOLOGICAL ROLE IN CELL PROLIFERATION, DIFFERENTIATION, AND APOPTOSIS. HOWEVER, DIFFERENT FACTORS THAT CAN DYSREGULATE CELL SIGNALING AND CELLULAR HOMEOSTASIS CAN ALSO AFFECT MIRNA EXPRESSION. THE ALTERATION OF MIRNA EXPRESSION CAN WORK AGAINST DISTURBING FACTORS OR MEDIATE THEIR EFFECTS. OXIDATIVE STRESS IS ONE OF THESE FACTORS. CONSIDERING THE COMPLEX INTERPLAY BETWEEN ROS LEVEL AND MIRNA REGULATION AND BOTH OF THESE WITH CANCER DEVELOPMENT, WE REVIEW THE ROLE OF MIRNAS IN CANCER, FOCUSING ON THEIR FUNCTION IN OXIDATIVE STRESS. 2020 11 2723 37 EXOSOMES: NOMENCLATURE, ISOLATION, AND BIOLOGICAL ROLES IN LIVER DISEASES. THE BIOGENESIS AND BIOLOGICAL ROLES OF EXTRACELLULAR VESICLES (EVS) IN THE PROGRESSION OF LIVER DISEASES HAVE ATTRACTED CONSIDERABLE ATTENTION IN RECENT YEARS. EVS ARE MEMBRANE-BOUND NANOSIZED VESICLES FOUND IN DIFFERENT TYPES OF BODY FLUIDS AND CONTAIN VARIOUS BIOACTIVE MATERIALS, INCLUDING PROTEINS, LIPIDS, NUCLEIC ACIDS, AND MITOCHONDRIAL DNA. BASED ON THEIR ORIGIN AND BIOGENESIS, EVS CAN BE CLASSIFIED AS APOPTOTIC BODIES, MICROVESICLES, AND EXOSOMES. AMONG THESE, EXOSOMES ARE THE SMALLEST EVS (30-150 NM IN DIAMETER), WHICH PLAY A SIGNIFICANT ROLE IN CELL-TO-CELL COMMUNICATION AND EPIGENETIC REGULATION. MOREOVER, EXOSOMAL CONTENT ANALYSIS CAN REVEAL THE FUNCTIONAL STATE OF THE PARENTAL CELL. THEREFORE, EXOSOMES CAN BE APPLIED TO VARIOUS PURPOSES, INCLUDING DISEASE DIAGNOSIS AND TREATMENT, DRUG DELIVERY, CELL-FREE VACCINES, AND REGENERATIVE MEDICINE. HOWEVER, EXOSOME-RELATED RESEARCH FACES TWO MAJOR LIMITATIONS: ISOLATION OF EXOSOMES WITH HIGH YIELD AND PURITY AND DISTINCTION OF EXOSOMES FROM OTHER EVS (ESPECIALLY MICROVESICLES). NO STANDARDIZED EXOSOME ISOLATION METHOD HAS BEEN ESTABLISHED TO DATE; HOWEVER, VARIOUS EXOSOME ISOLATION STRATEGIES HAVE BEEN PROPOSED TO INVESTIGATE THEIR BIOLOGICAL ROLES. EXOSOME-MEDIATED INTERCELLULAR COMMUNICATIONS ARE KNOWN TO BE INVOLVED IN ALCOHOLIC LIVER DISEASE AND NONALCOHOLIC FATTY LIVER DISEASE DEVELOPMENT. DAMAGED HEPATOCYTES OR NONPARENCHYMAL CELLS RELEASE LARGE NUMBERS OF EXOSOMES THAT PROMOTE THE PROGRESSION OF INFLAMMATION AND FIBROGENESIS THROUGH INTERACTIONS WITH NEIGHBORING CELLS. EXOSOMES ARE EXPECTED TO PROVIDE INSIGHT ON THE PROGRESSION OF LIVER DISEASE. HERE, WE REVIEW THE BIOGENESIS OF EXOSOMES, EXOSOME ISOLATION TECHNIQUES, AND BIOLOGICAL ROLES OF EXOSOMES IN ALCOHOLIC LIVER DISEASE AND NONALCOHOLIC FATTY LIVER DISEASE. 2023 12 4384 34 MITOCHONDRIAL EPIGENETICS REGULATING INFLAMMATION IN CANCER AND AGING. INFLAMMATION IS A DEFINING FACTOR IN DISEASE PROGRESSION; EPIGENETIC MODIFICATIONS OF THIS FIRST LINE OF DEFENCE PATHWAY CAN AFFECT MANY PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS, LIKE AGING AND TUMORIGENESIS. INFLAMMAGEING, ONE OF THE HALLMARKS OF AGING, REPRESENTS A CHRONIC, LOW KEY BUT A PERSISTENT INFLAMMATORY STATE. OXIDATIVE STRESS, ALTERATIONS IN MITOCHONDRIAL DNA (MTDNA) COPY NUMBER AND MIS-LOCALIZED EXTRA-MITOCHONDRIAL MTDNA ARE SUGGESTED TO DIRECTLY INDUCE VARIOUS IMMUNE RESPONSE PATHWAYS. THIS COULD ULTIMATELY PERTURB CELLULAR HOMEOSTASIS AND LEAD TO PATHOLOGICAL CONSEQUENCES. EPIGENETIC REMODELLING OF MTDNA BY DNA METHYLATION, POST-TRANSLATIONAL MODIFICATIONS OF MTDNA BINDING PROTEINS AND REGULATION OF MITOCHONDRIAL GENE EXPRESSION BY NUCLEAR DNA OR MTDNA ENCODED NON-CODING RNAS, ARE SUGGESTED TO DIRECTLY CORRELATE WITH THE ONSET AND PROGRESSION OF VARIOUS TYPES OF CANCER. MITOCHONDRIA ARE ALSO CAPABLE OF REGULATING IMMUNE RESPONSE TO VARIOUS INFECTIONS AND TISSUE DAMAGE BY PRODUCING PRO- OR ANTI-INFLAMMATORY SIGNALS. THIS OCCURS BY ALTERING THE LEVELS OF MITOCHONDRIAL METABOLITES AND REACTIVE OXYGEN SPECIES (ROS) LEVELS. SINCE MITOCHONDRIA ARE KNOWN AS THE GUARDIANS OF THE INFLAMMATORY RESPONSE, IT IS PLAUSIBLE THAT MITOCHONDRIAL EPIGENETICS MIGHT PLAY A PIVOTAL ROLE IN INFLAMMATION. HENCE, THIS REVIEW FOCUSES ON THE INTRICATE DYNAMICS OF EPIGENETIC ALTERATIONS OF INFLAMMATION, WITH EMPHASIS ON MITOCHONDRIA IN CANCER AND AGING. 2022 13 799 33 CELLULAR SIGNALING AND POTENTIAL NEW TREATMENT TARGETS IN DIABETIC RETINOPATHY. DYSFUNCTION AND DEATH OF MICROVASCULAR CELLS AND IMBALANCE BETWEEN THE PRODUCTION AND THE DEGRADATION OF EXTRACELLULAR MATRIX (ECM) PROTEINS ARE A CHARACTERISTIC FEATURE OF DIABETIC RETINOPATHY (DR). GLUCOSE-INDUCED BIOCHEMICAL ALTERATIONS IN THE VASCULAR ENDOTHELIAL CELLS MAY ACTIVATE A CASCADE OF SIGNALING PATHWAYS LEADING TO INCREASED PRODUCTION OF ECM PROTEINS AND CELLULAR DYSFUNCTION/DEATH. CHRONIC DIABETES LEADS TO THE ACTIVATION OF A NUMBER OF SIGNALING PROTEINS INCLUDING PROTEIN KINASE C, PROTEIN KINASE B, AND MITOGEN-ACTIVATED PROTEIN KINASES. THESE SIGNALING CASCADES ARE ACTIVATED IN RESPONSE TO HYPERGLYCEMIA-INDUCED OXIDATIVE STRESS, POLYOL PATHWAY, AND ADVANCED GLYCATION END PRODUCT FORMATION AMONG OTHERS. THE ABERRANT SIGNALING PATHWAYS ULTIMATELY LEAD TO ACTIVATION OF TRANSCRIPTION FACTORS SUCH AS NUCLEAR FACTOR-KAPPAB AND ACTIVATING PROTEIN-1. THE ACTIVITY OF THESE TRANSCRIPTION FACTORS IS ALSO REGULATED BY EPIGENETIC MECHANISMS THROUGH TRANSCRIPTIONAL COACTIVATOR P300. THESE COMPLEX SIGNALING PATHWAYS MAY BE INVOLVED IN GLUCOSE-INDUCED ALTERATIONS OF ENDOTHELIAL CELL PHENOTYPE LEADING TO THE PRODUCTION OF INCREASED ECM PROTEINS AND VASOACTIVE EFFECTOR MOLECULES CAUSING FUNCTIONAL AND STRUCTURAL CHANGES IN THE MICROVASCULATURE. UNDERSTANDING OF SUCH MECHANISTIC PATHWAYS WILL HELP TO DEVELOP FUTURE ADJUVANT THERAPIES FOR DIABETIC RETINOPATHY. 2007 14 719 36 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 15 4211 37 METFORMIN FOR CARDIOVASCULAR PROTECTION, INFLAMMATORY BOWEL DISEASE, OSTEOPOROSIS, PERIODONTITIS, POLYCYSTIC OVARIAN SYNDROME, NEURODEGENERATION, CANCER, INFLAMMATION AND SENESCENCE: WHAT IS NEXT? DIABETES IS ACCOMPANIED BY SEVERAL COMPLICATIONS. HIGHER PREVALENCE OF CANCERS, CARDIOVASCULAR DISEASES, CHRONIC KIDNEY DISEASE (CKD), OBESITY, OSTEOPOROSIS, AND NEURODEGENERATIVE DISEASES HAS BEEN REPORTED AMONG PATIENTS WITH DIABETES. METFORMIN IS THE OLDEST ORAL ANTIDIABETIC DRUG AND CAN IMPROVE COEXISTING COMPLICATIONS OF DIABETES. CLINICAL TRIALS AND OBSERVATIONAL STUDIES UNCOVERED THAT METFORMIN CAN REMARKABLY PREVENT OR ALLEVIATE CARDIOVASCULAR DISEASES, OBESITY, POLYCYSTIC OVARIAN SYNDROME (PCOS), OSTEOPOROSIS, CANCER, PERIODONTITIS, NEURONAL DAMAGE AND NEURODEGENERATIVE DISEASES, INFLAMMATION, INFLAMMATORY BOWEL DISEASE (IBD), TUBERCULOSIS, AND COVID-19. IN ADDITION, METFORMIN HAS BEEN PROPOSED AS AN ANTIAGING AGENT. NUMEROUS MECHANISMS WERE SHOWN TO BE INVOLVED IN THE PROTECTIVE EFFECTS OF METFORMIN. METFORMIN ACTIVATES THE LKB1/AMPK PATHWAY TO INTERACT WITH SEVERAL INTRACELLULAR SIGNALING PATHWAYS AND MOLECULAR MECHANISMS. THE DRUG MODIFIES THE BIOLOGIC FUNCTION OF NF-KAPPAB, PI3K/AKT/MTOR, SIRT1/PGC-1ALPHA, NLRP3, ERK, P38 MAPK, WNT/BETA-CATENIN, NRF2, JNK, AND OTHER MAJOR MOLECULES IN THE INTRACELLULAR SIGNALING NETWORK. IT ALSO REGULATES THE EXPRESSION OF NONCODING RNAS. THEREBY, METFORMIN CAN REGULATE METABOLISM, GROWTH, PROLIFERATION, INFLAMMATION, TUMORIGENESIS, AND SENESCENCE. ADDITIONALLY, METFORMIN MODULATES IMMUNE RESPONSE, AUTOPHAGY, MITOPHAGY, ENDOPLASMIC RETICULUM (ER) STRESS, AND APOPTOSIS AND EXERTS EPIGENETIC EFFECTS. FURTHERMORE, METFORMIN PROTECTS AGAINST OXIDATIVE STRESS AND GENOMIC INSTABILITY, PRESERVES TELOMERE LENGTH, AND PREVENTS STEM CELL EXHAUSTION. IN THIS REVIEW, THE PROTECTIVE EFFECTS OF METFORMIN ON EACH DISEASE WILL BE DISCUSSED USING THE RESULTS OF RECENT META-ANALYSES, CLINICAL TRIALS, AND OBSERVATIONAL STUDIES. THEREAFTER, IT WILL BE METICULOUSLY EXPLAINED HOW METFORMIN REPROGRAMS INTRACELLULAR SIGNALING PATHWAYS AND ALTERS MOLECULAR AND CELLULAR INTERACTIONS TO MODIFY THE CLINICAL PRESENTATIONS OF SEVERAL DISEASES. 2021 16 293 38 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 17 4383 44 MITOCHONDRIAL EPIGENETICS AND ENVIRONMENTAL HEALTH: MAKING A CASE FOR ENDOCRINE DISRUPTING CHEMICALS. RECENT STUDIES IMPLICATE MITOCHONDRIAL DYSFUNCTION IN THE DEVELOPMENT AND PROGRESSION OF NUMEROUS CHRONIC DISEASES, WHICH MAY BE PARTIALLY DUE TO MODIFICATIONS IN MITOCHONDRIAL DNA (MTDNA). THERE IS ALSO MOUNTING EVIDENCE THAT EPIGENETIC MODIFICATIONS TO MTDNA MAY BE AN ADDITIONAL LAYER OF REGULATION THAT CONTROLS MITOCHONDRIAL BIOGENESIS AND FUNCTION. SEVERAL ENVIRONMENTAL FACTORS (EG, SMOKING, AIR POLLUTION) HAVE BEEN ASSOCIATED WITH ALTERED MTDNA METHYLATION IN A HANDFUL OF MECHANISTIC STUDIES AND IN OBSERVATIONAL HUMAN STUDIES. HOWEVER, LITTLE IS UNDERSTOOD ABOUT OTHER ENVIRONMENTAL CONTAMINANTS THAT INDUCE MTDNA EPIGENETIC CHANGES. NUMEROUS ENVIRONMENTAL TOXICANTS ARE CLASSIFIED AS ENDOCRINE DISRUPTING CHEMICALS (EDCS). BEYOND THEIR ACTIONS ON HORMONAL PATHWAYS, EDC EXPOSURE IS ASSOCIATED WITH ELEVATED OXIDATIVE STRESS, WHICH MAY OCCUR THROUGH OR RESULT IN MITOCHONDRIAL DYSFUNCTION. ALTHOUGH ONLY A FEW STUDIES HAVE ASSESSED THE IMPACTS OF EDCS ON MTDNA METHYLATION, THE CURRENT REVIEW PROVIDES REASONS TO CONSIDER MTDNA EPIGENETIC DISRUPTION AS A MECHANISM OF ACTION OF EDCS AND REVIEWS POTENTIAL LIMITATIONS RELATED TO CURRENTLY AVAILABLE EVIDENCE. FIRST, THERE IS SUFFICIENT EVIDENCE THAT EDCS (INCLUDING BISPHENOLS AND PHTHALATES) DIRECTLY TARGET MITOCHONDRIAL FUNCTION, AND MORE DIRECT EVIDENCE IS NEEDED TO CONNECT THIS TO MTDNA METHYLATION. SECOND, THESE AND OTHER EDCS ARE POTENT MODULATORS OF NUCLEAR DNA EPIGENETICS, INCLUDING DNA METHYLATION AND HISTONE MODIFICATIONS. FINALLY, EDCS HAVE BEEN SHOWN TO DISRUPT SEVERAL MODULATORS OF MTDNA METHYLATION, INCLUDING DNA METHYLTRANSFERASES AND THE MITOCHONDRIAL TRANSCRIPTION FACTOR A/NUCLEAR RESPIRATORY FACTOR 1 PATHWAY. TAKEN TOGETHER, THESE STUDIES HIGHLIGHT THE NEED FOR FUTURE RESEARCH EVALUATING MTDNA EPIGENETIC DISRUPTION BY EDCS AND TO DETAIL SPECIFIC MECHANISMS RESPONSIBLE FOR SUCH DISRUPTIONS. 2020 18 4585 38 NAD(+) AND VASCULAR DYSFUNCTION: FROM MECHANISMS TO THERAPEUTIC OPPORTUNITIES. NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD(+)) IS AN ESSENTIAL AND PLEIOTROPIC COENZYME INVOLVED NOT ONLY IN CELLULAR ENERGY METABOLISM, BUT ALSO IN CELL SIGNALING, EPIGENETIC REGULATION, AND POST-TRANSLATIONAL PROTEIN MODIFICATIONS. VASCULAR DISEASE RISK FACTORS ARE ASSOCIATED WITH ABERRANT NAD(+) METABOLISM. CONVERSELY, THE THERAPEUTIC INCREASE OF NAD(+) LEVELS THROUGH THE ADMINISTRATION OF NAD(+) PRECURSORS OR INHIBITORS OF NAD(+)-CONSUMING ENZYMES REDUCES CHRONIC LOW-GRADE INFLAMMATION, REACTIVATES AUTOPHAGY AND MITOCHONDRIAL BIOGENESIS, AND ENHANCES OXIDATIVE METABOLISM IN VASCULAR CELLS OF HUMANS AND RODENTS WITH VASCULAR PATHOLOGIES. AS SUCH, NAD(+) HAS EMERGED AS A POTENTIAL TARGET FOR COMBATTING AGE-RELATED CARDIOVASCULAR AND CEREBROVASCULAR DISORDERS. THIS REVIEW DISCUSSES NAD(+)-REGULATED MECHANISMS CRITICAL FOR VASCULAR HEALTH AND SUMMARIZES NEW ADVANCES IN NAD(+) RESEARCH DIRECTLY RELATED TO VASCULAR AGING AND DISEASE, INCLUDING HYPERTENSION, ATHEROSCLEROSIS, CORONARY ARTERY DISEASE, AND AORTIC ANEURYSMS. FINALLY, WE ENUMERATE CHALLENGES AND OPPORTUNITIES FOR NAD(+) REPLETION THERAPY WHILE ANTICIPATING THE FUTURE OF THIS EXCITING RESEARCH FIELD, WHICH WILL HAVE A MAJOR IMPACT ON VASCULAR MEDICINE. 2022 19 4381 42 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 20 5471 38 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