1 2770 148 EXTENDING INJURY- AND DISEASE-RESISTANT CNS PHENOTYPES BY REPETITIVE EPIGENETIC CONDITIONING. SIGNIFICANT REDUCTIONS IN THE EXTENT OF ACUTE INJURY IN THE CNS CAN BE ACHIEVED BY EXPOSURE TO DIFFERENT PRECONDITIONING STIMULI, BUT THE DURATION OF THE INDUCED PROTECTIVE PHENOTYPE IS TYPICALLY SHORT-LASTING, AND THUS IS DEEMED AS LIMITING ITS CLINICAL APPLICABILITY. EXTENDING THE PERIOD OVER WHICH SUCH ADAPTIVE EPIGENETIC CHANGES PERSIST - IN EFFECT, EXPANDING CONDITIONING'S "THERAPEUTIC WINDOW" - WOULD SIGNIFICANTLY BROADEN THE POTENTIAL APPLICATIONS OF SUCH A TREATMENT APPROACH IN PATIENTS. THE FREQUENCY OF THE CONDITIONING STIMULUS MAY HOLD THE KEY. WHILE TRANSIENT (1-3 DAYS) PROTECTION AGAINST CNS ISCHEMIC INJURY IS WELL ESTABLISHED PRECLINICALLY FOLLOWING A SINGLE PRECONDITIONING STIMULUS, REPETITIVELY PRESENTING PRECONDITIONING STIMULI EXTENDS THE DURATION OF ISCHEMIC TOLERANCE BY MANY WEEKS. MOREOVER, REPETITIVE INTERMITTENT POSTCONDITIONING ENHANCES POST-ISCHEMIC RECOVERY METRICS AND IMPROVES LONG-TERM SURVIVAL. INTERMITTENT CONDITIONING IS ALSO EFFICACIOUS FOR PREVENTING OR DELAYING INJURY IN PRECLINICAL MODELS OF CHRONIC NEURODEGENERATIVE DISEASE, AND FOR PROMOTING LONG-LASTING FUNCTIONAL IMPROVEMENTS IN A NUMBER OF OTHER PATHOLOGIES AS WELL. ALTHOUGH THE DETAILED MECHANISMS UNDERLYING THESE PROTRACTED KINDS OF NEUROPLASTICITY REMAIN LARGELY UNSTUDIED, ACCUMULATING EMPIRICAL EVIDENCE SUPPORTS THE CONTENTION THAT ALL OF THESE ADAPTIVE PHENOTYPES ARE EPIGENETICALLY MEDIATED. GOING FORWARD, ADDITIONAL PRECLINICAL DEMONSTRATIONS OF THE ABILITY TO INDUCE SUSTAINED BENEFICIAL PHENOTYPES THAT REDUCE THE BURDEN OF ACUTE AND CHRONIC NEURODEGENERATION, AND EXPERIMENTAL INTERROGATIONS OF THE REGULATORY CONSTRUCTS RESPONSIBLE FOR THESE EPIGENETIC RESPONSES, WILL ACCELERATE THE IDENTIFICATION OF NOT ONLY EFFICACIOUS BUT ALSO PRACTICAL, ADAPTIVE EPIGENETICS-BASED TREATMENTS FOR INDIVIDUALS WITH NEUROLOGICAL DISEASE. 2015 2 6257 32 THE MOLECULAR BASIS OF TOLERANCE. TOLERANCE IS DEFINED AS THE DIMINISHED RESPONSE TO ALCOHOL OR OTHER DRUGS OVER THE COURSE OF REPEATED OR PROLONGED EXPOSURE. THIS MECHANISM ALLOWS PHYSIOLOGICAL PROCESSES TO ACHIEVE STABILITY IN A CONSTANTLY CHANGING ENVIRONMENT. THE ONSET OF TOLERANCE MAY OCCUR WITHIN MINUTES, DURING A SINGLE EXPOSURE TO ALCOHOL (I.E., ACUTE TOLERANCE), OR OVER LONGER TIMEFRAMES AND WITH PROLONGED EXPOSURE TO ALCOHOL (I.E., RAPID OR CHRONIC TOLERANCE). CHANGES IN TOLERANCE INDUCED BY ALCOHOL MAY AFFECT SEVERAL PROCESSES AT THE MOLECULAR, CELLULAR, OR BEHAVIORAL LEVEL. THESE EFFECTS OFTEN ARE INTERRELATED AND MAY BE DIFFICULT TO SEPARATE. THIS ARTICLE DESCRIBES CHANGES AT THE MOLECULAR LEVEL THAT ARE RELATED TO THE ONSET OF ACUTE, RAPID, OR CHRONIC TOLERANCE. IT FOCUSES ON NEURONAL MEMBRANE-BOUND CHANNELS AND THE FACTORS THAT AFFECT THEIR FUNCTION AND PRODUCTION, SUCH AS MODIFICATION OF PROTEIN SYNTHESIS AND ACTIVITY, INTERACTION WITH THE MEMBRANE LIPID MICROENVIRONMENT, EPIGENETIC EFFECTS ON CYTOPLASMIC REGULATION, AND GENE TRANSCRIPTION. ALSO CONSIDERED IS THE GENETICS OF TOLERANCE. 2008 3 6414 37 THE STRESSED SYNAPSE 2.0: PATHOPHYSIOLOGICAL MECHANISMS IN STRESS-RELATED NEUROPSYCHIATRIC DISORDERS. STRESS IS A PRIMARY RISK FACTOR FOR SEVERAL NEUROPSYCHIATRIC DISORDERS. EVIDENCE FROM PRECLINICAL MODELS AND CLINICAL STUDIES OF DEPRESSION HAVE REVEALED AN ARRAY OF STRUCTURAL AND FUNCTIONAL MALADAPTIVE CHANGES, WHEREBY ADVERSE ENVIRONMENTAL FACTORS SHAPE THE BRAIN. THESE CHANGES, OBSERVED FROM THE MOLECULAR AND TRANSCRIPTIONAL LEVELS THROUGH TO LARGE-SCALE BRAIN NETWORKS, TO THE BEHAVIOURS REVEAL A COMPLEX MATRIX OF INTERRELATED PATHOPHYSIOLOGICAL PROCESSES THAT DIFFER BETWEEN SEXES, PROVIDING INSIGHT INTO THE POTENTIAL UNDERPINNINGS OF THE SEX BIAS OF NEUROPSYCHIATRIC DISORDERS. ALTHOUGH MANY PRECLINICAL STUDIES USE CHRONIC STRESS PROTOCOLS, LONG-TERM CHANGES ARE ALSO INDUCED BY ACUTE EXPOSURE TO TRAUMATIC STRESS, OPENING A PATH TO IDENTIFY DETERMINANTS OF RESILIENT VERSUS SUSCEPTIBLE RESPONSES TO BOTH ACUTE AND CHRONIC STRESS. EPIGENETIC REGULATION OF GENE EXPRESSION HAS EMERGED AS A KEY PLAYER UNDERLYING THE PERSISTENT IMPACT OF STRESS ON THE BRAIN. INDEED, HISTONE MODIFICATION, DNA METHYLATION AND MICRORNAS ARE CLOSELY INVOLVED IN MANY ASPECTS OF THE STRESS RESPONSE AND REVEAL THE GLUTAMATE SYSTEM AS A KEY PLAYER. THE SUCCESS OF KETAMINE HAS STIMULATED A WHOLE LINE OF RESEARCH AND DEVELOPMENT ON DRUGS DIRECTLY OR INDIRECTLY TARGETING GLUTAMATE FUNCTION. HOWEVER, THE CHALLENGE OF TRANSLATING THE EMERGING UNDERSTANDING OF STRESS PATHOPHYSIOLOGY INTO EFFECTIVE CLINICAL TREATMENTS REMAINS A MAJOR CHALLENGE. 2022 4 2567 42 EPIGENETICS MODIFIERS: POTENTIAL HUB FOR UNDERSTANDING AND TREATING NEURODEVELOPMENTAL DISORDERS FROM HYPOXIC INJURY. BACKGROUND: THE FETAL BRAIN IS ADAPTED TO THE HYPOXIC CONDITIONS PRESENT DURING NORMAL IN UTERO DEVELOPMENT. RELATIVELY MORE HYPOXIC STATES, EITHER CHRONIC OR ACUTE, ARE PATHOLOGIC AND CAN LEAD TO SIGNIFICANT LONG-TERM NEURODEVELOPMENTAL SEQUELAE. IN UTERO HYPOXIC INJURY IS ASSOCIATED WITH NEONATAL MORTALITY AND MILLIONS OF LIVES LIVED WITH VARYING DEGREES OF DISABILITY. MAIN BODY: GENETIC STUDIES OF CHILDREN WITH NEURODEVELOPMENTAL DISEASE INDICATE THAT EPIGENETIC MODIFIERS REGULATING DNA METHYLATION AND HISTONE REMODELING ARE CRITICAL FOR NORMAL BRAIN DEVELOPMENT. EPIGENETIC MODIFIERS ARE ALSO REGULATED BY ENVIRONMENTAL STIMULI, SUCH AS HYPOXIA. INDEED, EPIGENETIC MODIFIERS THAT ARE MUTATED IN CHILDREN WITH GENETIC NEURODEVELOPMENTAL DISEASES ARE REGULATED BY HYPOXIA IN A NUMBER OF PRECLINICAL MODELS AND MAY BE PART OF THE MECHANISM FOR THE LONG-TERM NEURODEVELOPMENTAL SEQUELAE SEEM IN CHILDREN WITH HYPOXIC BRAIN INJURY. THUS, A COMPREHENSIVE UNDERSTANDING THE ROLE OF DNA METHYLATION AND HISTONE MODIFICATIONS IN HYPOXIC INJURY IS CRITICAL FOR DEVELOPING NOVEL STRATEGIES TO TREAT CHILDREN WITH HYPOXIC INJURY. CONCLUSIONS: THIS REVIEW FOCUSES ON OUR CURRENT UNDERSTANDING OF THE INTERSECTION BETWEEN EPIGENETICS, BRAIN DEVELOPMENT, AND HYPOXIA. OPPORTUNITIES FOR THE USE OF EPIGENETICS AS BIOMARKERS OF NEURODEVELOPMENTAL DISEASE AFTER HYPOXIC INJURY AND POTENTIAL CLINICAL EPIGENETICS TARGETS TO IMPROVE OUTCOMES AFTER INJURY ARE ALSO DISCUSSED. WHILE THERE HAVE BEEN MANY PUBLISHED STUDIES ON THE EPIGENETICS OF HYPOXIA, MORE ARE NEEDED IN THE DEVELOPING BRAIN IN ORDER TO DETERMINE WHICH EPIGENETIC PATHWAYS MAY BE MOST IMPORTANT FOR MITIGATING THE LONG-TERM CONSEQUENCES OF HYPOXIC BRAIN INJURY. 2020 5 4277 29 MICROGLIA SEQUELAE: BRAIN SIGNATURE OF INNATE IMMUNITY IN SCHIZOPHRENIA. SCHIZOPHRENIA IS A PSYCHIATRIC DISORDER WITH SIGNIFICANT IMPACT ON INDIVIDUALS AND SOCIETY. THE CURRENT PHARMACOLOGIC TREATMENT, WHICH PRINCIPALLY ALLEVIATES PSYCHOSIS, IS FOCUSED ON NEUROTRANSMITTERS MODULATION, RELYING ON DRUGS WITH SEVERE SIDE EFFECTS AND INEFFECTIVENESS IN A SIGNIFICANT PERCENTAGE OF CASES. THEREFORE, AND DUE TO DIFFICULTIES INHERENT TO DIAGNOSIS AND TREATMENT, IT IS VITAL TO REASSESS ALTERNATIVE CELLULAR AND MOLECULAR DRUG TARGETS. DISTINCT RISK FACTORS - GENETIC, DEVELOPMENTAL, EPIGENETIC, AND ENVIRONMENTAL - HAVE BEEN ASSOCIATED WITH DISEASE ONSET AND PROGRESSION, GIVING RISE TO THE PROPOSAL OF DIFFERENT PATHOPHYSIOLOGICAL MECHANISMS AND PUTATIVE PHARMACOLOGICAL TARGETS. IMMUNITY IS INVOLVED AND, PARTICULARLY MICROGLIA - INNATE IMMUNE CELLS OF THE CENTRAL NERVOUS SYSTEM, CRITICALLY INVOLVED IN BRAIN DEVELOPMENT - HAVE CAPTURED ATTENTION AS CELLULAR PLAYERS. MICROGLIA UNDERGO MARKED MORPHOLOGIC AND FUNCTIONAL ALTERATIONS IN THE HUMAN DISEASE, AS WELL AS IN ANIMAL MODELS OF SCHIZOPHRENIA, AS REPORTED IN SEVERAL ORIGINAL PAPERS. WE CLUSTER THE MAIN FINDINGS OF CLINICAL STUDIES BY GROUPS OF PATIENTS: (1) AT ULTRA-HIGH RISK OF PSYCHOSIS, (2) WITH A FIRST EPISODE OF PSYCHOSIS OR RECENT-ONSET SCHIZOPHRENIA, AND (3) WITH CHRONIC SCHIZOPHRENIA; IN TRANSLATIONAL STUDIES, WE HIGHLIGHT THE TIME WINDOW OF APPEARANCE OF PARTICULAR MICROGLIA ALTERATIONS IN THE MOST WELL STUDIED ANIMAL MODEL IN THE FIELD (MATERNAL IMMUNE ACTIVATION). THE ORGANIZATION OF CLINICAL AND TRANSLATIONAL FINDINGS BASED ON SCHIZOPHRENIA-ASSOCIATED MICROGLIA CHANGES IN DIFFERENT PHASES OF THE DISEASE COURSE MAY HELP DEFINING A TEMPORAL PATTERN OF MICROGLIA CHANGES AND MAY DRIVE THE DESIGN OF NOVEL THERAPEUTIC STRATEGIES. 2022 6 806 31 CHALLENGES FOR MODELING AND INTERPRETING THE COMPLEX BIOLOGY OF SEVERE INJURY AND INFLAMMATION. HUMAN INJURY IS ASSOCIATED WITH INFLAMMATORY RESPONSES THAT ARE MODULATED BY THE ACUTE AND CHRONIC ACTIVITY OF ENDOGENOUS FACTORS AND EXOGENOUS INTERVENTIONS. A CHARACTERISTIC FEATURE OF CHRONIC, SEVERE INFLAMMATORY STATES IS THE DIMINISHED SIGNAL OUTPUT VARIABILITY OF MANY ORGAN SYSTEMS, INCLUDING INNATE IMMUNE RESPONSIVENESS AND ENDOGENOUS NEURAL AND ENDOCRINE-MEDIATED FUNCTIONS. THE ATTENUATION OF SIGNAL/RESPONSE VARIABILITY AND INTEGRATION OF FEEDBACK CAPACITY MAY CONTRIBUTE TO SYSTEMIC AND TISSUE-SPECIFIC DETERIORATION OF FUNCTION. SOME WELL-INTENTIONED THERAPIES DIRECTED TOWARD SUPPORT OF SYSTEMIC AND TISSUE FUNCTIONS MAY ACTUALLY PROMOTE THE LOSS OF SYSTEM(S) ADAPTABILITY AND CONTRIBUTE TO ADVERSE OUTCOMES IN SEVERELY STRESSED PATIENTS. IN VIVO AND IN SILICO MODELS OF STRESS, INJURY, AND INFECTION HAVE YET TO FULLY DEFINE THE INFLUENCES OF ONGOING STRESSFUL STIMULAE AS WELL AS GENETIC VARIATION AND EPIGENETIC FACTORS IN THE CONTEXT OF AN EVOLVING INFLAMMATORY STATE. EXPERIMENTAL AND HUMAN MODELS INCORPORATING VARIABLE, ANTECEDENT STRESS(ES) AND ALTERED NEUROENDOCRINE RHYTHMS MIGHT APPROXIMATE THE ALTERED ADAPTABILITY IN IMMUNE AND ORGAN FUNCTION RESPONSES. SUCH MODELS MAY ALSO PROVIDE INSIGHTS INTO THE SALIENT MECHANISMS OF RISK AND OUTCOME MORE PRECISELY THAN DO THE CONSTRAINED STUDY CONDITIONS OF CURRENT ANIMAL OR HUMAN MODELS OF SYSTEMIC INFLAMMATION. 2008 7 6866 35 [PAIN AND EMOTIONAL DYSREGULATION: CELLULAR MEMORY DUE TO PAIN]. GENETIC FACTORS ARE INVOLVED IN DETERMINANTS FOR THE RISK OF PSYCHIATRIC DISORDERS, AND NEUROLOGICAL AND NEURODEGENERATIVE DISEASES. CHRONIC PAIN STIMULI AND INTENSE PAIN HAVE EFFECTS AT A CELLULAR AND/OR GENE EXPRESSION LEVEL, AND WILL EVENTUALLY INDUCE "CELLULAR MEMORY DUE TO PAIN", WHICH MEANS THAT TISSUE DAMAGE, EVEN IF ONLY TRANSIENT, CAN ELICIT EPIGENETICALLY ABNORMAL TRANSCRIPTION/TRANSLATION AND POST-TRANSLATIONAL MODIFICATION IN RELATED CELLS DEPENDING ON THE DEGREE OR KIND OF INJURY OR ASSOCIATED CONDITIONS. SUCH CELL MEMORY/TRANSFORMATION DUE TO PAIN CAN CAUSE AN ABNORMALITY IN A FUNDAMENTAL INTRACELLULAR RESPONSE, SUCH AS A CHANGE IN THE THREE-DIMENSIONAL STRUCTURE OF DNA, TRANSCRIPTION, OR TRANSLATION. ON THE OTHER HAND, PAIN IS A MULTIDIMENSIONAL EXPERIENCE WITH SENSORY-DISCRIMINATIVE AND MOTIVATIONAL-AFFECTIVE COMPONENTS. RECENT HUMAN BRAIN IMAGING STUDIES HAVE EXAMINED DIFFERENCES IN ACTIVITY IN THE NUCLEUS ACCUMBENS BETWEEN CONTROLS AND PATIENTS WITH CHRONIC PAIN, AND HAVE REVEALED THAT THE NUCLEUS ACCUMBENS PLAYS A ROLE IN PREDICTING THE VALUE OF A NOXIOUS STIMULUS AND ITS OFFSET, AND IN THE CONSEQUENT CHANGES IN THE MOTIVATIONAL STATE. IN THIS REVIEW, WE PROVIDE A VERY BRIEF OVERVIEW OF A COMPREHENSIVE UNDERSTANDING OF CHRONIC PAIN ASSOCIATED WITH EMOTIONAL DYSREGULATION DUE TO TRANSCRIPTIONAL REGULATION, EPIGENETIC MODIFICATION AND MIRNA REGULATION. 2015 8 5313 33 PSYCHOLOGICAL STRESS AS A MODULATOR OF FUNCTIONAL RECOVERY FOLLOWING SPINAL CORD INJURY. THERE IS STRONG EVIDENCE INDICATING THAT THE SOCIAL ENVIRONMENT TRIGGERS CHANGES TO THE PSYCHOLOGICAL STRESS RESPONSE AND GLUCOCORTICOID RECEPTOR FUNCTION. CONSIDERABLE LITERATURE LINKS THE SUBSEQUENT CHANGES IN STRESS RESILIENCY TO PHYSICAL HEALTH. HERE, CONVERGING EVIDENCE FOR THE MODULATORY ROLE OF CHRONIC PSYCHOLOGICAL STRESS IN THE RECOVERY PROCESS FOLLOWING SPINAL CORD INJURY (SCI) IS PRESENTED. DESPITE THE CONSIDERABLE ADVANCES IN SCI RESEARCH, WE ARE STILL UNABLE TO IDENTIFY THE CAUSES OF VARIABILITY IN PATIENTS' RECOVERY FOLLOWING INJURY. WE PROPOSE THAT INDIVIDUALS' PAST AND PRESENT LIFE EXPERIENCES (IN THE FORM OF STRESS EXPOSURE) MAY SIGNIFICANTLY MODULATE PATIENTS' OUTCOME POST-SCI. WE PROPOSE A THEORETICAL MODEL TO EXPLAIN THE NEGATIVE IMPACT OF CHRONIC PSYCHOLOGICAL STRESS ON PHYSICAL AND PSYCHOLOGICAL RECOVERY. THE STRESS EXPERIENCED IN LIFE PRIOR TO SCI AND ALSO AS A RESULT OF THE TRAUMATIC INJURY, COULD COMPROMISE GLUCOCORTICOID RECEPTOR SENSITIVITY AND FUNCTION, AND CONTRIBUTE TO HIGH LEVELS OF INFLAMMATION AND APOPTOSIS POST-SCI, DECREASING THE TISSUE REMAINING AT THE INJURY SITE AND UNDERMINING RECOVERY OF FUNCTION. BOTH STRESS-INDUCED GLUCOCORTICOID RESISTANCE AND STRESS-INDUCED EPIGENETIC CHANGES TO THE GLUCOCORTICOID RECEPTOR CAN MODULATE THE NUCLEAR FACTOR-KAPPA B REGULATED INFLAMMATORY PATHWAYS AND THE BCL-2 REGULATED APOPTOSIS PATHWAYS. THIS MODEL NOT ONLY CONTRIBUTES TO THE THEORETICAL UNDERSTANDING OF THE RECOVERY PROCESS FOLLOWING INJURY, BUT ALSO PROVIDES CONCRETE TESTABLE HYPOTHESES FOR FUTURE STUDIES. 2014 9 4633 32 NEUROIMMUNE ACTIVATION DRIVES MULTIPLE BRAIN STATES. NEUROIMMUNE SIGNALING IS INCREASINGLY IDENTIFIED AS A CRITICAL COMPONENT OF NEURONAL PROCESSES UNDERLYING MEMORY, EMOTION AND COGNITION. THE INTERACTIONS OF MICROGLIA AND ASTROCYTES WITH NEURONS AND SYNAPSES, AND THE INDIVIDUAL CYTOKINES AND IMMUNE SIGNALING MOLECULES THAT MEDIATE THESE INTERACTIONS ARE A CURRENT FOCUS OF MUCH RESEARCH. HERE, WE DISCUSS NEUROIMMUNE ACTIVATION AS A MECHANISM TRIGGERING DIFFERENT STATES THAT MODULATE COGNITIVE AND AFFECTIVE PROCESSES TO ALLOW FOR APPROPRIATE BEHAVIOR DURING AND AFTER ILLNESS OR INJURY. WE PROPOSE THAT THESE STATES LIE ON A CONTINUUM FROM A NAIVE HOMEOSTATIC BASELINE STATE IN THE ABSENCE OF STIMULATION, TO ACUTE NEUROIMMUNE ACTIVITY AND CHRONIC ACTIVATION. IMPORTANTLY, CONSEQUENCES OF ILLNESS OR INJURY INCLUDING COGNITIVE DEFICITS AND MOOD IMPAIRMENTS CAN PERSIST LONG AFTER RESOLUTION OF IMMUNE SIGNALING. THIS SUGGESTS THAT NEUROIMMUNE ACTIVATION ALSO RESULTS IN AN ENDURING SHIFT IN THE HOMEOSTATIC BASELINE STATE WITH LONG LASTING CONSEQUENCES FOR NEURAL FUNCTION AND BEHAVIOR. SUCH DIFFERENT STATES CAN BE IDENTIFIED IN A MULTIDIMENSIONAL WAY, USING PATTERNS OF CYTOKINE AND GLIAL ACTIVATION, BEHAVIORAL AND COGNITIVE CHANGES, AND EPIGENETIC SIGNATURES. IDENTIFYING DISTINCT NEUROIMMUNE STATES AND THEIR CONSEQUENCES FOR NEURAL FUNCTION WILL PROVIDE A FRAMEWORK FOR PREDICTING VULNERABILITY TO DISORDERS OF MEMORY, COGNITION AND EMOTION BOTH DURING AND LONG AFTER RECOVERY FROM ILLNESS. 2018 10 38 30 A COMMON ROLE FOR PSYCHOTROPIC MEDICATIONS: MEMORY IMPAIRMENT. THE PSYCHOPATHOLOGIC PROFILE OF MENTAL DISORDERS IS VERY DIVERSE AND PSYCHOTROPIC MEDICATIONS USED TO TREAT THEM DIFFER IN THEIR CHEMICAL STRUCTURE. NEVERTHELESS, THESE DRUGS SHARE THESE FOUR CHARACTERISTICS: DELAYED ONSET OF CLINICAL RESPONSE, NOT ONE OF THEM CAN BE SAID TO CURE, THERE IS A HIGH NUMBER OF NON-RESPONDERS, AND THE MECHANISM RESPONSIBLE FOR THEIR THERAPEUTIC ACTION IS NOT KNOWN. IT IS HYPOTHESIZED THAT THE ACTION OF PSYCHOTROPIC MEDICATIONS IS MEMORY IMPAIRMENT, UNDERSTANDING MEMORY AS THE TRACE LEFT IN THE NERVOUS SYSTEM NOT ONLY BY INDIVIDUAL EXPERIENCES BUT ALSO BY GENETIC AND EPIGENETIC PHENOMENA. IT IS SUGGESTED THAT IT WOULD BE BENEFICIAL TO TRANSLATE SOME RESEARCH STRATEGIES FROM THE NEUROBIOLOGY OF LEARNING AND MEMORY TO THE STUDY OF THE EFFECTS OF PSYCHOTROPIC MEDICATIONS. THE HYPOTHESIS IS BRIEFLY ASSESSED ACCORDING TO THE FOLLOWING THREE CRITERIA: (A). THE COMPARISON BETWEEN THE MOLECULAR EFFECTS OF PSYCHOTROPIC MEDICATIONS AND THE SO-CALLED MOLECULAR BIOLOGY OF LEARNING AND MEMORY, (B). THE EFFECTS OF THESE DRUGS, PREFERENTIALLY AFTER CHRONIC USE, ON MEMORY TESTS, AND (C). THE EFFECTS OF DRUGS THAT IMPAIR MEMORY ON TESTS USED FOR SCREENING PSYCHOTROPIC MEDICATIONS. FINALLY, SOME GENERAL SUGGESTIONS FOR FUTURE RESEARCH ARE POINTED OUT. 2003 11 232 37 ADAPTIVE PLASTICITY IN THE RETINA: PROTECTION AGAINST ACUTE INJURY AND NEURODEGENERATIVE DISEASE BY CONDITIONING STIMULI. ALTHOUGH BOTH PRECLINICAL AND CLINICAL CONDITIONING STUDIES IN HEART AND BRAIN LEAD THE FIELD OF CONDITIONING MEDICINE, INVESTIGATIONS OF RETINAL CONDITIONING STILL NUMBER MORE THAN 100. IN THIS BRIEF REVIEW, WE HIGHLIGHT FINDINGS TO DATE FROM ANIMAL AND CELL CULTURE MODELS OF CONDITIONING THAT PROVIDE DEMONSTRATED PROTECTION IN ACUTE AND CHRONIC RETINAL INJURY AND DISEASE MODELS. THE MULTITUDE OF STIMULI USED TO CONDITION THE RETINA, THE SIGNALING MEDIATORS AND PATHWAYS IDENTIFIED, AND THE INJURY- AND DISEASE-RESILIENT PHENOTYPES DOCUMENTED ARE DISCUSSED HEREIN, ALONG WITH OUR RECOMMENDATIONS FOR THE KINDS OF STUDIES NEEDED TO CONTINUE TO ADVANCE THIS PROMISING FIELD. IN OUR VIEW, THE ROBUST PROTECTION AFFORDED BY THESE ADAPTIVE EPIGENETIC RESPONSES TO CONDITIONING STRESS PROVIDES SIGNIFICANT INCENTIVES FOR BOTH FURTHERING OUR INVESTMENT IN BENCH RESEARCH AND UNDERWRITING CLINICAL TRIALS, SO THAT THE FULL POTENTIAL OF THIS THERAPY CAN BE REALIZED. 2018 12 4278 35 MICROGLIAL INNATE MEMORY AND EPIGENETIC REPROGRAMMING IN NEUROLOGICAL DISORDERS. MICROGLIA ARE MYELOID-DERIVED CELLS RECOGNIZED AS BRAIN-RESIDENT MACROPHAGES. THEY ACT AS THE FIRST AND MAIN LINE OF IMMUNE DEFENSE IN THE CENTRAL NERVOUS SYSTEM (CNS). MICROGLIA HAVE HIGH PHENOTYPIC PLASTICITY AND ARE ESSENTIAL FOR REGULATING HEALTHY BRAIN HOMEOSTASIS, AND THEIR DYSREGULATION UNDERLIES THE ONSET AND PROGRESSION OF SEVERAL CNS PATHOLOGIES THROUGH IMPAIRED INFLAMMATORY RESPONSES. ABERRANT MICROGLIAL ACTIVATION, FOLLOWING AN INFLAMMATORY INSULT, IS ASSOCIATED WITH EPIGENETIC DYSREGULATION IN VARIOUS CNS PATHOLOGIES. EMERGING DATA SUGGEST THAT CERTAIN STIMULI TO MYELOID CELLS DETERMINE ENHANCED OR ATTENUATED RESPONSES TO SUBSEQUENT STIMULI. THESE PHENOMENA, GENERALLY TERMED INNATE IMMUNE MEMORY (IIM), ARE HIGHLY DEPENDENT ON EPIGENETIC REPROGRAMMING. MICROGLIAL PRIMING HAS BEEN REPORTED IN SEVERAL NEUROLOGICAL DISEASES AND CORRESPONDS TO A STATE OF INCREASED PERMISSIVENESS OR EXACERBATED RESPONSE, PROMOTED BY CONTINUOUS EXPOSURE TO A CHRONIC PRO-INFLAMMATORY ENVIRONMENT. IN THIS ARTICLE, WE PROVIDE EXTENSIVE EVIDENCE OF THESE EPIGENETIC-MEDIATED PHENOMENA UNDER NEUROLOGICAL CONDITIONS AND DISCUSS THEIR CONTRIBUTION TO PATHOGENESIS AND THEIR CLINICAL IMPLICATIONS, INCLUDING THOSE CONCERNING POTENTIAL NOVEL THERAPEUTIC APPROACHES. 2021 13 2346 34 EPIGENETIC REGULATION OF METABOLISM AND INFLAMMATION BY CALORIE RESTRICTION. CHRONIC CALORIC RESTRICTION (CR) WITHOUT MALNUTRITION IS KNOWN TO AFFECT DIFFERENT CELLULAR PROCESSES SUCH AS STEM CELL FUNCTION, CELL SENESCENCE, INFLAMMATION, AND METABOLISM. DESPITE THE DIFFERENCES IN THE IMPLEMENTATION OF CR, THE REDUCTION OF CALORIES PRODUCES A WIDESPREAD BENEFICIAL EFFECT IN NONCOMMUNICABLE CHRONIC DISEASES, WHICH CAN BE EXPLAINED BY IMPROVEMENTS IN IMMUNO-METABOLIC ADAPTATION. CELLULAR ADAPTATION THAT OCCURS IN RESPONSE TO DIETARY PATTERNS CAN BE EXPLAINED BY ALTERATIONS IN EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNA. IN THIS REVIEW, WE DEFINE THESE MODIFICATIONS AND SYSTEMATICALLY SUMMARIZE THE CURRENT EVIDENCE RELATED TO CR AND THE EPIGENOME. WE THEN EXPLAIN THE SIGNIFICANCE OF GENOME-WIDE EPIGENETIC MODIFICATIONS IN THE CONTEXT OF DISEASE DEVELOPMENT. ALTHOUGH SUBSTANTIAL EVIDENCE EXISTS FOR THE WIDESPREAD EFFECT OF CR ON LONGEVITY, THERE IS NO CONSENSUS REGARDING THE EPIGENETIC REGULATIONS OF THE UNDERLYING CELLULAR MECHANISMS THAT LEAD TO IMPROVED HEALTH. WE PROVIDE COMPELLING EVIDENCE THAT CR PRODUCES LONG-LASTING EPIGENETIC EFFECTS THAT MEDIATE EXPRESSION OF GENES RELATED TO IMMUNO-METABOLIC PROCESSES. EPIGENETIC REPROGRAMMING OF THE UNDERLYING CHRONIC LOW-GRADE INFLAMMATION BY CR CAN LEAD TO IMMUNO-METABOLIC ADAPTATIONS THAT ENHANCE QUALITY OF LIFE, EXTEND LIFESPAN, AND DELAY CHRONIC DISEASE ONSET. 2019 14 2703 37 EXERCISE ADAPTATIONS: MOLECULAR MECHANISMS AND POTENTIAL TARGETS FOR THERAPEUTIC BENEFIT. EXERCISE IS FUNDAMENTAL FOR GOOD HEALTH, WHEREAS PHYSICAL INACTIVITY UNDERPINS MANY CHRONIC DISEASES OF MODERN SOCIETY. IT IS WELL APPRECIATED THAT REGULAR EXERCISE IMPROVES METABOLISM AND THE METABOLIC PHENOTYPE IN A NUMBER OF TISSUES. THE PHENOTYPIC ALTERATIONS OBSERVED IN SKELETAL MUSCLE ARE PARTLY MEDIATED BY TRANSCRIPTIONAL RESPONSES THAT OCCUR FOLLOWING EACH INDIVIDUAL BOUT OF EXERCISE. THIS ADAPTIVE RESPONSE INCREASES OXIDATIVE CAPACITY AND INFLUENCES THE FUNCTION OF MYOKINES AND EXTRACELLULAR VESICLES THAT SIGNAL TO OTHER TISSUES. OUR UNDERSTANDING OF THE EPIGENETIC AND TRANSCRIPTIONAL MECHANISMS THAT MEDIATE THE SKELETAL MUSCLE GENE EXPRESSION RESPONSE TO EXERCISE AS WELL AS OF THEIR UPSTREAM SIGNALLING PATHWAYS HAS ADVANCED SUBSTANTIALLY IN THE PAST 10 YEARS. WITH THIS KNOWLEDGE ALSO COMES THE OPPORTUNITY TO DESIGN NEW THERAPEUTIC STRATEGIES BASED ON THE BIOLOGY OF EXERCISE FOR A VARIETY OF CHRONIC CONDITIONS WHERE REGULAR EXERCISE MIGHT BE A CHALLENGE. THIS REVIEW PROVIDES AN OVERVIEW OF THE BENEFICIAL ADAPTIVE RESPONSES TO EXERCISE AND DETAILS THE MOLECULAR MECHANISMS INVOLVED. THE POSSIBILITY OF DESIGNING THERAPEUTIC INTERVENTIONS BASED ON THESE MOLECULAR MECHANISMS IS ADDRESSED, USING RELEVANT EXAMPLES THAT HAVE EXPLOITED THIS APPROACH. 2020 15 3988 30 LONG-TERM WINDOW OF ISCHEMIC TOLERANCE: AN EVOLUTIONARILY CONSERVED FORM OF METABOLIC PLASTICITY REGULATED BY EPIGENETIC MODIFICATIONS? IN THE ABSENCE OF EFFECTIVE NEUROPROTECTIVE AGENTS IN THE CLINIC, ISCHEMIC AND PHARMACOLOGICAL PRECONDITIONING ARE GAINING INCREASED INTEREST IN THE FIELD OF CEREBRAL ISCHEMIA. OUR LAB RECENTLY REPORTED THAT RESVERATROL PRECONDITIONING AFFORDS TOLERANCE AGAINST A FOCAL CEREBRAL ISCHEMIC INSULT IN MICE THAT CAN LAST FOR AT LEAST 14 DAYS IN VIVO MAKING IT THE LONGEST WINDOW OF ISCHEMIC TOLERANCE DISCOVERED TO DATE BY A SINGLE ADMINISTRATION OF A PHARMACOLOGICAL AGENT. THE MECHANISM BEHIND THIS NOVEL EXTENDED WINDOW OF ISCHEMIC TOLERANCE REMAINS ELUSIVE. IN THE BELOW COMMENTARY WE DISCUSS POTENTIAL MECHANISMS THAT COULD EXPLAIN THIS NOVEL EXTENDED WINDOW OF ISCHEMIC TOLERANCE IN THE CONTEXT OF PREVIOUSLY IDENTIFIED WINDOWS AND THE KNOWN MECHANISMS BEHIND THEM. WE ALSO DRAW PARALLELS FROM THE FIELDS OF HIBERNATION AND HYPOXIA-TOLERANCE, WHICH ARE CHRONIC ADAPTATIONS TO SEVERE CONDITIONS OF HYPOXIA AND ISCHEMIA KNOWN TO BE MEDIATED BY A FORM OF METABOLIC DEPRESSION. WE ALSO BRIEFLY DISCUSS THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN MAINTAINING THIS DEPRESSED STATE OF METABOLISM. 2016 16 6715 27 VITAMIN A AND THE EPIGENOME. THE EPIGENETIC PHENOMENA REFER TO HERITABLE CHANGES IN GENE EXPRESSION OTHER THAN THOSE IN THE DNA SEQUENCE, SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS. MAJOR RESEARCH PROGRESS IN THE LAST FEW YEARS HAS PROVIDED FURTHER PROOF THAT ENVIRONMENTAL FACTORS, INCLUDING DIET AND NUTRITION, CAN INFLUENCE PHYSIOLOGIC AND PATHOLOGIC PROCESSES THROUGH EPIGENETIC ALTERATIONS, WHICH IN TURN INFLUENCE GENE EXPRESSION. THIS INFLUENCE IS TERMED NUTRITIONAL EPIGENETICS, AND ONE PROMINENT EXAMPLE IS THE REGULATION OF GENE TRANSCRIPTION BY VITAMIN A THROUGH INTERACTION TO ITS NUCLEAR RECEPTOR. VITAMIN A IS CRITICAL THROUGHOUT LIFE. TOGETHER WITH ITS DERIVATIVES, IT REGULATES DIVERSE PROCESSES INCLUDING REPRODUCTION, EMBRYOGENESIS, VISION, GROWTH, CELLULAR DIFFERENTIATION AND PROLIFERATION, MAINTENANCE OF EPITHELIAL CELLULAR INTEGRITY AND IMMUNE FUNCTION. HERE WE REVIEW THE EPIGENETIC ROLE OF VITAMIN A IN CANCER, STEM CELLS DIFFERENTIATION, PROLIFERATION, AND IMMUNITY. THE DATA PRESENTED HERE SHOW THAT RETINOIC ACID IS A POTENT AGENT CAPABLE OF INDUCING ALTERATIONS IN EPIGENETIC MODIFICATIONS THAT PRODUCE VARIOUS EFFECTS ON THE PHENOTYPE. MEDICAL BENEFITS OF VITAMIN A AS AN EPIGENETIC MODULATOR, ESPECIALLY WITH RESPECT TO ITS CHRONIC USE AS NUTRITIONAL SUPPLEMENT, SHOULD RELY ON OUR FURTHER UNDERSTANDING OF ITS EPIGENETIC EFFECTS DURING HEALTH AND DISEASE, AS WELL AS THROUGH DIFFERENT GENERATIONS. 2017 17 5164 37 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 18 2523 38 EPIGENETICS AND THE TRANSITION FROM ACUTE TO CHRONIC PAIN. OBJECTIVE: THE OBJECTIVE OF THIS STUDY WAS TO REVIEW THE EPIGENETIC MODIFICATIONS INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN AND TO IDENTIFY POTENTIAL TARGETS FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED PAIN THERAPEUTICS. BACKGROUND: EPIGENETICS IS THE STUDY OF HERITABLE MODIFICATIONS IN GENE EXPRESSION AND PHENOTYPE THAT DO NOT REQUIRE A CHANGE IN GENETIC SEQUENCE TO MANIFEST THEIR EFFECTS. ENVIRONMENTAL TOXINS, MEDICATIONS, DIET, AND PSYCHOLOGICAL STRESSES CAN ALTER EPIGENETIC PROCESSES SUCH AS DNA METHYLATION, HISTONE ACETYLATION, AND RNA INTERFERENCE. AS EPIGENETIC MODIFICATIONS POTENTIALLY PLAY AN IMPORTANT ROLE IN INFLAMMATORY CYTOKINE METABOLISM, STEROID RESPONSIVENESS, AND OPIOID SENSITIVITY, THEY ARE LIKELY KEY FACTORS IN THE DEVELOPMENT OF CHRONIC PAIN. ALTHOUGH OUR KNOWLEDGE OF THE HUMAN GENETIC CODE AND DISEASE-ASSOCIATED POLYMORPHISMS HAS GROWN SIGNIFICANTLY IN THE PAST DECADE, WE HAVE NOT YET BEEN ABLE TO ELUCIDATE THE MECHANISMS THAT LEAD TO THE DEVELOPMENT OF PERSISTENT PAIN AFTER NERVE INJURY OR SURGERY. DESIGN: THIS IS A FOCUSED LITERATURE REVIEW OF EPIGENETIC SCIENCE AND ITS RELATIONSHIP TO CHRONIC PAIN. RESULTS: SIGNIFICANT LABORATORY AND CLINICAL DATA SUPPORT THE NOTION THAT EPIGENETIC MODIFICATIONS ARE AFFECTED BY THE ENVIRONMENT AND LEAD TO DIFFERENTIAL GENE EXPRESSION. SIMILAR TO MECHANISMS INVOLVED IN THE DEVELOPMENT OF CANCER, NEURODEGENERATIVE DISEASE, AND INFLAMMATORY DISORDERS, THE LITERATURE ENDORSES AN IMPORTANT POTENTIAL ROLE FOR EPIGENETICS IN CHRONIC PAIN. CONCLUSIONS: EPIGENETIC ANALYSIS MAY IDENTIFY MECHANISMS CRITICAL TO THE DEVELOPMENT OF CHRONIC PAIN AFTER INJURY, AND MAY PROVIDE NEW PATHWAYS AND TARGET MECHANISMS FOR FUTURE DRUG DEVELOPMENT AND INDIVIDUALIZED MEDICINE. 2012 19 6211 36 THE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IN HEALTH AND DISEASE: POTENTIAL ROLE OF AUTONOMIC REGULATION AND EPIGENETIC MECHANISMS. OXIDATIVE STRESS CAN BE INDUCED BY VARIOUS STIMULI AND ALTERED IN CERTAIN CONDITIONS, INCLUDING EXERCISE AND PAIN. ALTHOUGH MANY STUDIES HAVE INVESTIGATED OXIDATIVE STRESS IN RELATION TO EITHER EXERCISE OR PAIN, THE LITERATURE PRESENTS CONFLICTING RESULTS. THEREFORE, THIS REVIEW CRITICALLY DISCUSSES EXISTING LITERATURE ABOUT THIS TOPIC, AIMING TO PROVIDE A CLEAR OVERVIEW OF KNOWN INTERACTIONS BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IN HEALTHY PEOPLE AS WELL AS IN PEOPLE WITH CHRONIC PAIN, AND TO HIGHLIGHT POSSIBLE CONFOUNDING FACTORS TO KEEP IN MIND WHEN REFLECTING ON THESE INTERACTIONS. IN ADDITION, AUTONOMIC REGULATION AND EPIGENETIC MECHANISMS ARE PROPOSED AS POTENTIAL MECHANISMS OF ACTION UNDERLYING THE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN. THIS REVIEW HIGHLIGHTS THAT THE RELATION BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IS POORLY UNDERSTOOD AND NOT STRAIGHTFORWARD, AS IT IS DEPENDENT ON THE CHARACTERISTICS OF EXERCISE, BUT ALSO ON WHICH POPULATION IS INVESTIGATED. TO BE ABLE TO COMPARE STUDIES ON THIS TOPIC, STRICT GUIDELINES SHOULD BE DEVELOPED TO LIMIT THE EFFECT OF SEVERAL CONFOUNDING FACTORS. THIS WAY, THE TRUE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN, AND THE UNDERLYING MECHANISMS OF ACTION CAN BE REVEALED AND VALIDATED VIA INDEPENDENT STUDIES. 2020 20 3404 34 HOW EPIGENETICS IMPACTS ON HUMAN DISEASES. EPIGENETICS IS A RAPIDLY GROWING FIELD OF BIOLOGY THAT STUDIES THE CHANGES IN GENE EXPRESSION THAT ARE NOT DUE TO ALTERATIONS IN THE DNA SEQUENCE BUT RATHER THE CHEMICAL MODIFICATIONS OF DNA AND ITS ASSOCIATED PROTEINS. EPIGENETIC MECHANISMS CAN PROFOUNDLY INFLUENCE GENE EXPRESSION, CELL DIFFERENTIATION, TISSUE DEVELOPMENT, AND DISEASE SUSCEPTIBILITY. UNDERSTANDING EPIGENETIC CHANGES IS ESSENTIAL TO ELUCIDATE THE MECHANISMS UNDERLYING THE INCREASINGLY RECOGNIZED ROLE OF ENVIRONMENTAL AND LIFESTYLE FACTORS IN HEALTH AND DISEASE AND THE INTERGENERATIONAL TRANSMISSION OF PHENOTYPES. RECENT STUDIES SUGGEST EPIGENETICS MAY BE CRITICAL IN VARIOUS DISEASES, FROM CARDIOVASCULAR DISEASE AND CANCER TO NEURODEVELOPMENTAL AND NEURODEGENERATIVE DISORDERS. EPIGENETIC MODIFICATIONS ARE POTENTIALLY REVERSIBLE AND COULD PROVIDE NEW THERAPEUTIC AVENUES FOR TREATING THESE DISEASES USING EPIGENETIC MODULATORS. MOREOVER, EPIGENETICS PROVIDE INSIGHT INTO DISEASE PATHOGENESIS AND BIOMARKERS FOR DISEASE DIAGNOSIS AND RISK STRATIFICATION. NEVERTHELESS, EPIGENETIC INTERVENTIONS HAVE THE POTENTIAL FOR UNINTENDED CONSEQUENCES AND MAY POTENTIALLY LEAD TO INCREASED RISKS OF UNEXPECTED OUTCOMES, SUCH AS ADVERSE DRUG REACTIONS, DEVELOPMENTAL ABNORMALITIES, AND CANCER. THEREFORE, RIGOROUS STUDIES ARE ESSENTIAL TO MINIMIZE THE RISKS ASSOCIATED WITH EPIGENETIC THERAPIES AND TO DEVELOP SAFE AND EFFECTIVE INTERVENTIONS FOR IMPROVING HUMAN HEALTH. THIS ARTICLE PROVIDES A SYNTHETIC AND HISTORICAL VIEW OF THE ORIGIN OF EPIGENETICS AND SOME OF THE MOST RELEVANT ACHIEVEMENTS. 2023