1 6367 140 THE ROLE OF MICROGLIA IN THE ETIOLOGY AND EVOLUTION OF CHRONIC TRAUMATIC ENCEPHALOPATHY. CHRONIC TRAUMATIC ENCEPHALOPATHY (CTE) IS A PROGRESSIVE NEURODEGENERATIVE DISEASE THAT PRESENTS AS A LATE SEQUELA FROM TRAUMATIC BRAIN INJURY (TBI). TBI IS A GROWING AND UNDER-RECOGNIZED PUBLIC HEALTH CONCERN WITH A HIGH DEGREE OF MORBIDITY AND LARGE ASSOCIATED GLOBAL COSTS. WHILE THE IMMUNE RESPONSE TO TBI IS COMPLEX, ITS CONTRIBUTION TO THE DEVELOPMENT OF CTE REMAINS LARGELY UNKNOWN. IN THIS REVIEW, WE SUMMARIZE THE CURRENT UNDERSTANDING OF THE LINK BETWEEN CTE AND THE RESIDENT INNATE IMMUNE SYSTEM OF THE BRAIN-MICROGLIA. WE DISCUSS THE NEUROPATHOLOGY UNDERLYING CTE INCLUDING THE CREATION AND AGGREGATION OF PHOSPHORYLATED TAU PROTEIN INTO NEUROFIBRILLARY TANGLES AND THE FORMATION OF AMYLOID BETA DEPOSITS. WE ALSO PRESENT HOW MICROGLIA, THE RESIDENT INNATE IMMUNE CELLS OF THE BRAIN, DRIVE THE CONTINUOUS LOW-LEVEL INFLAMMATION ASSOCIATED WITH THE INSIDIOUS ONSET OF CTE. IN THIS REVIEW, WE CONCLUDE THAT THE LATENCY PERIOD BETWEEN THE INDEX BRAIN INJURY AND THE LONG-TERM DEVELOPMENT OF CTE PRESENTS AN OPPORTUNITY FOR THERAPEUTIC INTERVENTION. ENCOURAGING ADVANCES WITH MICROTUBULE STABILIZERS, CIS P-TAU ANTIBODIES, AND THE ABILITY TO THERAPEUTICALLY ALTER THE INFLAMMATORY STATE OF MICROGLIA HAVE SHOWN POSITIVE RESULTS IN BOTH ANIMAL AND HUMAN TRIALS. LOOKING FORWARD, RECENT ADVANCEMENTS IN NEXT-GENERATION SEQUENCING TECHNOLOGY FOR THE STUDY OF GENOMIC, TRANSCRIPTOMIC, AND EPIGENETIC INFORMATION WILL PROVIDE AN OPPORTUNITY FOR SIGNIFICANT ADVANCEMENT IN OUR UNDERSTANDING OF PROREPAIR AND PRO-INJURY GENE SIGNATURES ALLOWING FOR TARGETED INTERVENTION IN THIS HIGHLY MORBID INJURY PROCESS. 2017 2 1459 44 DISORDERED APP METABOLISM AND NEUROVASCULATURE IN TRAUMA AND AGING: COMBINED RISKS FOR CHRONIC NEURODEGENERATIVE DISORDERS. TRAUMATIC BRAIN INJURY (TBI), ADVANCED AGE, AND CEREBRAL VASCULAR DISEASE ARE FACTORS CONFERRING INCREASED RISK FOR LATE ONSET ALZHEIMER'S DISEASE (AD). THESE CONDITIONS ARE ALSO RELATED PATHOLOGICALLY THROUGH MULTIPLE INTERACTING MECHANISMS. THE HALLMARK PATHOLOGY OF AD CONSISTS OF PATHOLOGICAL AGGREGATES OF AMYLOID-BETA (ABETA) PEPTIDES AND TAU PROTEINS. THESE MOLECULES ARE ALSO INVOLVED IN NEUROPATHOLOGY OF SEVERAL OTHER CHRONIC NEURODEGENERATIVE DISEASES, AND ARE UNDER INTENSE INVESTIGATION IN THE AFTERMATH OF TBI AS POTENTIAL CONTRIBUTORS TO THE RISK FOR DEVELOPING AD AND CHRONIC TRAUMATIC ENCEPHALOPATHY (CTE). THE PATHOLOGY OF TBI IS COMPLEX AND DEPENDENT ON INJURY SEVERITY, AGE-AT-INJURY, AND LENGTH OF TIME BETWEEN INJURY AND NEUROPATHOLOGICAL EVALUATION. IN ADDITION, THE MECHANISMS INFLUENCING PATHOLOGY AND RECOVERY AFTER TBI LIKELY INVOLVE GENETIC/EPIGENETIC FACTORS AS WELL AS ADDITIONAL DISORDERS OR COMORBID STATES RELATED TO AGE AND CENTRAL AND PERIPHERAL VASCULAR HEALTH. IN THIS REGARD, DYSFUNCTION OF THE AGING NEUROVASCULAR SYSTEM COULD BE AN IMPORTANT LINK BETWEEN TBI AND CHRONIC NEURODEGENERATIVE DISEASES, EITHER AS A PRECIPITATING EVENT OR RELATED TO ACCUMULATION OF AD-LIKE PATHOLOGY WHICH IS AMPLIFIED IN THE CONTEXT OF AGING. THUS WITH ADVANCED AGE AND VASCULAR DYSFUNCTION, TBI CAN TRIGGER SELF-PROPAGATING CYCLES OF NEURONAL INJURY, PATHOLOGICAL PROTEIN AGGREGATION, AND SYNAPTIC LOSS RESULTING IN CHRONIC NEURODEGENERATIVE DISEASE. IN THIS REVIEW WE DISCUSS EVIDENCE SUPPORTING TBI AND AGING AS DUAL, INTERACTING RISK FACTORS FOR AD, AND THE ROLE OF ABETA AND CEREBRAL VASCULAR DYSFUNCTION IN THIS RELATIONSHIP. EVIDENCE IS DISCUSSED THAT ABETA IS INVOLVED IN CYTO- AND SYNAPTO-TOXICITY AFTER SEVERE TBI, AND THAT ITS CHRONIC EFFECTS ARE POTENTIATED BY AGING AND IMPAIRED CEREBRAL VASCULAR FUNCTION. FROM A THERAPEUTIC PERSPECTIVE, WE EMPHASIZE THAT IN THE FIELDS OF TBI- AND AGING-RELATED NEURODEGENERATION PROTECTIVE STRATEGIES SHOULD INCLUDE PRESERVATION OF NEUROVASCULAR FUNCTION. 2017 3 2227 37 EPIGENETIC MODIFICATIONS OF CHRONIC HYPOXIA-MEDIATED NEURODEGENERATION IN ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS THE MOST COMMON NEURODEGENERATIVE DISORDER AFFECTING THE ELDERLY PEOPLE. AD IS CHARACTERIZED BY PROGRESSIVE AND GRADUAL DECLINE IN COGNITIVE FUNCTION AND MEMORY LOSS. WHILE FAMILIAL EARLY-ONSET AD IS USUALLY ASSOCIATED WITH GENE MUTATIONS, THE ETIOLOGY OF SPORADIC LATE-ONSET FORM OF AD IS LARGELY UNKNOWN. IT HAS BEEN REPORTED THAT ENVIRONMENTAL FACTORS AND EPIGENETIC ALTERATIONS SIGNIFICANTLY CONTRIBUTE TO THE PROCESS OF AD. OUR PREVIOUS STUDIES HAVE DOCUMENTED THAT CHRONIC HYPOXIA IS ONE OF THE ENVIRONMENTAL FACTORS THAT MAY TRIGGER THE AD DEVELOPMENT AND AGGRAVATE THE DISEASE PROGRESSION. IN THIS REVIEW, WE WILL SUMMARIZE THE PATHOLOGICAL EFFECTS OF CHRONIC HYPOXIA ON THE ONSET AND DEVELOPMENT OF AD AND PUT FORWARD THE POSSIBLE MOLECULE MECHANISMS UNDERLYING THE CHRONIC HYPOXIA MEDIATED AD PATHOGENESIS. FINALLY, WE PROPOSE THAT EPIGENETIC REGULATIONS MAY REPRESENT NEW OPPORTUNITY FOR THE THERAPEUTIC INTERVENTION OF THIS DISEASE. 2014 4 4620 31 NEURO-IMMUNE DYSFUNCTION DURING BRAIN AGING: NEW INSIGHTS IN MICROGLIAL CELL REGULATION. MICROGLIA, THE RESIDENT IMMUNE CELLS OF THE BRAIN, ARE AT THE CENTER OF COMMUNICATION BETWEEN THE CENTRAL NERVOUS SYSTEM AND IMMUNE SYSTEM. WHILE THESE BRAIN-IMMUNE INTERACTIONS ARE BALANCED IN HEALTHY ADULTHOOD, THE ABILITY TO MAINTAIN HOMEOSTASIS DURING AGING IS IMPAIRED. MICROGLIA DEVELOP A LOSS OF INTEGRATED REGULATORY NETWORKS INCLUDING ABERRANT SIGNALING FROM OTHER BRAIN CELLS, IMMUNE SENSORS, AND EPIGENETIC MODIFIERS. THE LOW-GRADE CHRONIC NEUROINFLAMMATION ASSOCIATED WITH THIS DYSFUNCTIONAL ACTIVITY LIKELY CONTRIBUTES TO COGNITIVE DEFICITS AND SUSCEPTIBILITY TO AGE-RELATED PATHOLOGIES. A BETTER UNDERSTANDING OF THE UNDERLYING MECHANISMS RESPONSIBLE FOR NEURO-IMMUNE DYSREGULATION WITH AGE IS CRUCIAL FOR PROVIDING TARGETED THERAPEUTIC STRATEGIES TO SUPPORT BRAIN REPAIR AND HEALTHY AGING. 2016 5 5598 41 ROLES OF NON-CODING RNA IN ALZHEIMER'S DISEASE PATHOPHYSIOLOGY. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISORDER THAT IS ACCOMPANIED BY DEFICITS IN MEMORY AND COGNITIVE FUNCTIONS. THE DISEASE IS PATHOLOGICALLY CHARACTERISED BY THE ACCUMULATION AND AGGREGATION OF AN EXTRACELLULAR PEPTIDE REFERRED TO AS AMYLOID-BETA (ABETA) IN THE FORM OF AMYLOID PLAQUES AND THE INTRACELLULAR AGGREGATION OF A HYPERPHOSPHORELATED PROTEIN TAU IN THE FORM OF NEUROFIBRILLARY TANGLES (NFTS) THAT CAUSE NEUROINFLAMMATION, SYNAPTIC DYSFUNCTION, AND OXIDATIVE STRESS. THE SEARCH FOR PATHOMECHANISMS LEADING TO DISEASE ONSET AND PROGRESSION HAS IDENTIFIED MANY KEY PLAYERS THAT INCLUDE GENETIC, EPIGENETIC, BEHAVIOURAL, AND ENVIRONMENTAL FACTORS, WHICH LEND SUPPORT TO THE FACT THAT THIS IS A MULTI-FACETED DISEASE WHERE FAILURE IN VARIOUS SYSTEMS CONTRIBUTES TO DISEASE ONSET AND PROGRESSION. ALTHOUGH THE VAST MAJORITY OF INDIVIDUALS PRESENT WITH THE SPORADIC (NON-GENETIC) FORM OF THE DISEASE, DYSFUNCTIONS IN NUMEROUS PROTEIN-CODING AND NON-CODING GENES HAVE BEEN IMPLICATED IN MECHANISMS CONTRIBUTING TO THE DISEASE. RECENT STUDIES HAVE PROVIDED STRONG EVIDENCE FOR THE ASSOCIATION OF NON-CODING RNAS (NCRNAS) WITH AD. IN THIS REVIEW, WE HIGHLIGHT THE CURRENT FINDINGS ON CHANGES OBSERVED IN CIRCULAR RNA (CIRCRNA), MICRORNA (MIRNA), SHORT INTERFERING RNA (SIRNA), PIWI-INTERACTING RNA (PIRNA), AND LONG NON-CODING RNA (LNCRNA) IN AD. VARIATIONS IN THESE NCRNAS COULD POTENTIALLY SERVE AS BIOMARKERS OR THERAPEUTIC TARGETS FOR THE DIAGNOSIS AND TREATMENT OF ALZHEIMER'S DISEASE. WE ALSO DISCUSS THE RESULTS OF STUDIES THAT HAVE TARGETED THESE NCRNAS IN CELLULAR AND ANIMAL MODELS OF AD WITH A VIEW FOR TRANSLATING THESE FINDINGS INTO THERAPIES FOR ALZHEIMER'S DISEASE. 2023 6 5766 35 SPECIAL ISSUE: ALZHEIMER'S DISEASE. MORE THAN 45 MILLION PEOPLE WORLDWIDE HAVE ALZHEIMER'S DISEASE (AD), A DETERIORATION OF MEMORY AND OTHER COGNITIVE DOMAINS THAT LEADS TO DEATH WITHIN 3 TO 9 YEARS AFTER DIAGNOSIS. THE PRINCIPAL RISK FACTOR FOR AD IS AGE. AS THE AGING POPULATION INCREASES, THE PREVALENCE WILL APPROACH 131 MILLION CASES WORLDWIDE IN 2050. AD IS THEREFORE A GLOBAL PROBLEM CREATING A RAPIDLY GROWING EPIDEMIC AND BECOMING A MAJOR THREAT TO HEALTHCARE IN OUR SOCIETIES. IT HAS BEEN MORE THAN 20 YEARS SINCE IT WAS FIRST PROPOSED THAT THE NEURODEGENERATION IN AD MAY BE CAUSED BY DEPOSITION OF AMYLOID-BETA (ABETA) PEPTIDES IN PLAQUES IN BRAIN TISSUE. ACCORDING TO THE AMYLOID HYPOTHESIS, ACCUMULATION OF ABETA PEPTIDES, RESULTING FROM A CHRONIC IMBALANCE BETWEEN ABETA PRODUCTION AND ABETA CLEARANCE IN THE BRAIN, IS THE PRIMARY INFLUENCE DRIVING AD PATHOGENESIS. CURRENT AVAILABLE MEDICATIONS APPEAR TO BE ABLE TO PRODUCE MODERATE SYMPTOMATIC BENEFITS BUT NOT TO STOP DISEASE PROGRESSION. THE SEARCH FOR BIOMARKERS AS WELL AS NOVEL THERAPEUTIC APPROACHES FOR AD HAS BEEN A MAJOR FOCUS OF RESEARCH. RECENT FINDINGS, HOWEVER, SHOW THAT NEURONAL-INJURY BIOMARKERS ARE INDEPENDENT OF ABETA SUGGESTING EPIGENETIC MODIFICATIONS, GENE-GENE AND/OR GENE-ENVIRONMENT INTERACTIONS IN THE DISEASE ETIOLOGY, AND CALLING FOR RECONSIDERATION OF THE PATHOLOGICAL CASCADE AND ASSESSMENT OF ALTERNATIVE THERAPEUTIC STRATEGIES. IN ADDITION, RECENT RESEARCH RESULTS REGARDING THE EXPRESSION OF THE BETA-AMYLOID PRECURSOR PROTEIN (APP) GENE RESULTING IN THE PRESENCE OF VARIOUS APP-MRNA ISOFORMS AND THEIR QUANTIFICATION, ESPECIALLY FOR IDENTIFYING THE MOST ABUNDANT ONE THAT MAY DECISIVE FOR THE NORMAL STATUS OR DISEASE RISK, HAVE BEEN REPORTED. AS SUCH, A MORE COMPLETE UNDERSTANDING OF AD PATHOGENESIS WILL LIKELY REQUIRE GREATER INSIGHTS INTO THE PHYSIOLOGICAL FUNCTION OF THE BETA-AMYLOID PRECURSOR PROTEIN (APP). 2018 7 676 30 BRAIN AGING: A IANUS-FACED PLAYER BETWEEN HEALTH AND NEURODEGENERATION. NEURODEGENERATIVE DISEASES ARE INCURABLE DEBILITATING DISORDERS CHARACTERIZED BY STRUCTURAL AND FUNCTIONAL NEURONAL LOSS. APPROXIMATELY 30 MILLION PEOPLE ARE AFFECTED WORLDWIDE, AND THIS NUMBER IS PREDICTED TO REACH MORE THAN 150 MILLION BY 2050. NEURODEGENERATIVE DISORDERS INCLUDE ALZHEIMER'S, PARKINSON'S, AND PRION DISEASES AMONG OTHERS. THESE DISORDERS ARE CHARACTERIZED BY THE ACCUMULATION OF AGGREGATING PROTEINS FORMING AMYLOID, RESPONSIBLE FOR THE DISEASE-ASSOCIATED PATHOLOGICAL LESIONS. THE AGGREGATION OF AMYLOIDOGENIC PROTEINS CAN RESULT EITHER IN GAINING OF TOXIC FUNCTIONS, DERIVED FROM THE DAMAGE PROVOKED BY THESE DEPOSITS IN AFFECTED TISSUE, OR IN A LOSS OF FUNCTIONS, DUE TO THE SEQUESTRATION AND THE CONSEQUENT INABILITY OF THE AGGREGATING PROTEIN TO ENSURE ITS PHYSIOLOGICAL ROLE. WHILE IT IS WIDELY ACCEPTED THAT AGING REPRESENTS THE MAIN RISK FACTOR FOR NEURODEGENERATION, THERE IS STILL NO CLEAR CUT-OFF LINE BETWEEN THE TWO CONDITIONS. INDEED, MANY OF THE PATHWAYS THAT ARE COMMONLY ALTERED IN NEURODEGENERATION-MISFOLDED PROTEIN ACCUMULATION, CHRONIC INFLAMMATION, MITOCHONDRIAL DYSFUNCTION, IMPAIRED IRON HOMEOSTASIS, EPIGENETIC MODIFICATIONS-HAVE BEEN OFTEN CORRELATED ALSO WITH HEALTHY AGING. THIS OVERLAP COULD BE EXPLAINED BY THE FACT THAT THE CONTINUOUS ACCUMULATION OF CELLULAR DAMAGES, TOGETHER WITH A PROGRESSIVE DECLINE IN METABOLIC EFFICIENCY DURING AGING, MAKES THE NEURONS MORE VULNERABLE TO TOXIC INJURIES. WHEN A GIVEN THRESHOLD IS EXCEEDED, ALL THESE ALTERATIONS MIGHT GIVE RISE TO PATHOLOGICAL PHENOTYPES THAT ULTIMATELY LEAD TO NEURODEGENERATION. 2020 8 2447 32 EPIGENETIC STUDIES IN ALZHEIMER'S DISEASE: CURRENT FINDINGS, CAVEATS, AND CONSIDERATIONS FOR FUTURE STUDIES. ALZHEIMER'S DISEASE (AD) IS A SPORADIC, CHRONIC NEURODEGENERATIVE DISEASE, USUALLY OCCURRING LATE IN LIFE. THE LAST DECADE HAS WITNESSED TREMENDOUS ADVANCES IN OUR UNDERSTANDING ABOUT THE GENETIC BASIS OF AD, BUT A LARGE AMOUNT OF THE VARIANCE IN DISEASE RISK REMAINS TO BE EXPLAINED. EPIGENETIC MECHANISMS, WHICH DEVELOPMENTALLY REGULATE GENE EXPRESSION VIA MODIFICATIONS TO DNA, HISTONE PROTEINS, AND CHROMATIN, HAVE BEEN HYPOTHESIZED TO PLAY A ROLE IN OTHER COMPLEX NEUROBIOLOGICAL DISEASES, AND STUDIES TO IDENTIFY GENOME-WIDE EPIGENETIC CHANGES IN AD ARE CURRENTLY UNDER WAY. HOWEVER, THE SIMPLE BRUTE-FORCE APPROACH THAT HAS BEEN SUCCESSFULLY EMPLOYED IN GENOME-WIDE ASSOCIATION STUDIES IS UNLIKELY TO BE SUCCESSFUL IN EPIGENOME-WIDE ASSOCIATION STUDIES OF NEURODEGENERATION. A MORE ACADEMIC APPROACH TO UNDERSTANDING THE ROLE OF EPIGENETIC VARIATION IN AD IS REQUIRED, WITH CAREFUL CONSIDERATION OF STUDY DESIGN, METHODOLOGICAL APPROACHES, TISSUE-SPECIFICITY, AND CAUSAL INFERENCE. IN THIS ARTICLE, WE REVIEW THE EMPIRICAL LITERATURE SUPPORTING A ROLE FOR EPIGENETIC PROCESSES IN AD, AND DISCUSS IMPORTANT CONSIDERATIONS AND FUTURE DIRECTIONS FOR THIS NEW AND EMERGING FIELD OF RESEARCH. 2013 9 3540 27 IMMUNE-DERIVED CYTOKINES IN THE NERVOUS SYSTEM: EPIGENETIC INSTRUCTIVE SIGNALS OR NEUROPATHOGENIC MEDIATORS? THE INVESTIGATION OF THE EFFECTS OF INFLAMMATORY CYTOKINES (IC) ON THE GROWTH AND DIFFERENTIATION OF NEURAL CELLS HAS PROVIDED NEW INSIGHTS ON THE ROLE OF SUCH SOLUBLE MEDIATORS IN NERVOUS SYSTEM DEVELOPMENT AND/OR PLASTIC REMODELING AS WELL AS IN THE PATHOGENESIS OF INFLAMMATORY NEURODEGENERATIVE DISORDERS, WHICH ARE CHARACTERIZED BY CHRONIC IC DYSREGULATION IN THE CENTRAL NERVOUS SYSTEM (CNS). THUS, THE STUDY OF THE INTERACTION BETWEEN CNS AND IMMUNE-DERIVED SOLUBLE SIGNALS IN PHYSIOLOGICAL OR PATHOLOGICAL CONDITIONS IS OF INCREASING INTEREST. THIS REVIEW FIRST DISCUSSES EXPERIMENTAL EVIDENCE SUPPORTING THE INSTRUCTIVE/PERMISSIVE ROLE OF IMMUNE-DERIVED CYTOKINES ON CNS DEVELOPMENT AND PLASTICITY. NEXT, WE FOCUS ON HUMAN NEUROLOGICAL DISEASE STATES SUCH AS MULTIPLE SCLEROSIS AND THE NEURODEGENERATION ASSOCIATED TO THE ACQUIRED IMMUNE DEFICIENCY SYNDROME IN WHICH DIFFERENT INFLAMMATORY CYTOKINES HAVE BEEN PROPOSED AS POTENTIAL NEUROPATHOGENIC MEDIATORS. 1999 10 4278 40 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 11 2567 34 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 12 6347 24 THE ROLE OF EPIGENETICS IN NEUROINFLAMMATORY-DRIVEN DISEASES. NEURODEGENERATIVE DISORDERS ARE CHARACTERIZED BY THE PROGRESSIVE LOSS OF CENTRAL AND/OR PERIPHERAL NERVOUS SYSTEM NEURONS. WITHIN THIS CONTEXT, NEUROINFLAMMATION COMES UP AS ONE OF THE MAIN FACTORS LINKED TO NEURODEGENERATION PROGRESSION. IN FACT, NEUROINFLAMMATION HAS BEEN RECOGNIZED AS AN OUTSTANDING FACTOR FOR ALZHEIMER'S DISEASE (AD), AMYOTROPHIC LATERAL SCLEROSIS (ALS), PARKINSON'S DISEASE (PD), AND MULTIPLE SCLEROSIS (MS). INTERESTINGLY, NEUROINFLAMMATORY DISEASES ARE CHARACTERIZED BY DRAMATIC CHANGES IN THE EPIGENETIC PROFILE, WHICH MIGHT PROVIDE NOVEL PROGNOSTIC AND THERAPEUTIC FACTORS TOWARDS NEUROINFLAMMATORY TREATMENT. DEEP CHANGES IN DNA AND HISTONE METHYLATION, ALONG WITH HISTONE ACETYLATION AND ALTERED NON-CODING RNA EXPRESSION, HAVE BEEN REPORTED AT THE ONSET OF INFLAMMATORY DISEASES. THE AIM OF THIS WORK IS TO REVIEW THE CURRENT KNOWLEDGE ON THIS FIELD. 2022 13 4277 31 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 14 2611 28 EPIGENETICS: A PROMISING PARADIGM FOR BETTER UNDERSTANDING AND MANAGING PAIN. EPIGENETIC REGULATION OF GENE EXPRESSION IS A RAPIDLY GROWING AREA OF RESEARCH. CONSIDERING THE LONGEVITY AND PLASTICITY OF NEURONS, THE STUDIES ON EPIGENETIC PATHWAYS IN THE NERVOUS SYSTEM SHOULD BE OF SPECIAL INTEREST FOR BOTH EPIGENETICISTS AND NEUROSCIENTISTS. ACTIVATION OR INACTIVATION OF DIFFERENT EPIGENETIC PATHWAYS BECOMES MORE PRONOUNCED WHEN THE CELLS EXPERIENCE RAPID CHANGES IN THEIR ENVIRONMENT, AND SUCH CHANGES CAN BE EASILY CAUSED BY INJURY AND INFLAMMATION, RESULTING IN PAIN PERCEPTION OR DISTORTION OF PAIN PERCEPTION (EG, HYPERALGESIA). THEREFORE, IN THIS REGARD, THE FIELD OF PAIN IS AT AN ADVANTAGE TO STUDY THE EPIGENETIC PATHWAYS. MORE IMPORTANTLY, UNDERSTANDING PAIN FROM AN EPIGENETICS POINT OF VIEW WOULD PROVIDE A NEW PARADIGM FOR DEVELOPING DRUGS OR STRATEGIES FOR PAIN MANAGEMENT. IN THIS REVIEW, WE INTRODUCE BASIC CONCEPTS OF EPIGENETICS, INCLUDING CHROMATIN DYNAMICS, HISTONE MODIFICATIONS, DNA METHYLATION, AND RNA-INDUCED GENE SILENCING. IN ADDITION, WE PROVIDE EVIDENCE FROM PUBLISHED STUDIES SUGGESTING WIDE IMPLICATION OF DIFFERENT EPIGENETIC PATHWAYS WITHIN PAIN PATHWAYS. PERSPECTIVE: THIS ARTICLE PROVIDES A BRIEF OVERVIEW OF EPIGENETIC PATHWAYS FOR GENE REGULATION AND HIGHLIGHTS THEIR INVOLVEMENT IN PAIN. OUR GOAL IS TO EXPOSE THE READERS TO THESE CONCEPTS SO THAT PAIN-RELATED PHENOTYPES CAN BE INVESTIGATED FROM THE EPIGENETIC POINT OF VIEW. 2013 15 5369 28 RECENT ADVANCES IN UNDERSTANDING NEUROPATHIC PAIN: GLIA, SEX DIFFERENCES, AND EPIGENETICS. NEUROPATHIC PAIN RESULTS FROM DISEASES OR TRAUMA AFFECTING THE NERVOUS SYSTEM. THIS PAIN CAN BE DEVASTATING AND IS POORLY CONTROLLED. THE PATHOPHYSIOLOGY IS COMPLEX, AND IT IS ESSENTIAL TO UNDERSTAND THE UNDERLYING MECHANISMS IN ORDER TO IDENTIFY THE RELEVANT TARGETS FOR THERAPEUTIC INTERVENTION. IN THIS ARTICLE, WE FOCUS ON THE RECENT RESEARCH INVESTIGATING NEURO-IMMUNE COMMUNICATION AND EPIGENETIC PROCESSES, WHICH GAIN PARTICULAR ATTENTION IN THE CONTEXT OF NEUROPATHIC PAIN. SPECIFICALLY, WE ANALYZE THE ROLE OF GLIAL CELLS, INCLUDING MICROGLIA, ASTROCYTES, AND OLIGODENDROCYTES, IN THE MODULATION OF THE CENTRAL NERVOUS SYSTEM INFLAMMATION TRIGGERED BY NEUROPATHY. CONSIDERING EPIGENETICS, WE ADDRESS DNA METHYLATION, HISTONE MODIFICATIONS, AND THE NON-CODING RNAS IN THE REGULATION OF ION CHANNELS, G-PROTEIN-COUPLED RECEPTORS, AND TRANSMITTERS FOLLOWING NEURONAL DAMAGE. THE GOAL WAS NOT ONLY TO HIGHLIGHT THE EMERGING CONCEPTS BUT ALSO TO DISCUSS CONTROVERSIES, METHODOLOGICAL COMPLICATIONS, AND INTRIGUING OPINIONS. 2016 16 5635 33 SEPTIC SHOCK AND THE AGING PROCESS: A MOLECULAR COMPARISON. AGING IS A CONTINUOUS PROCESS PROMOTED BY BOTH INTRINSIC AND EXTRINSIC FACTORS THAT EACH TRIGGER A MULTITUDE OF MOLECULAR EVENTS. INCREASING EVIDENCE SUPPORTS A CENTRAL ROLE FOR INFLAMMATION IN THIS PROGRESSION. HERE, WE DISCUSS HOW THE LOW-GRADE CHRONIC INFLAMMATION THAT CHARACTERIZES AGING IS TIGHTLY INTERCONNECTED WITH OTHER IMPORTANT ASPECTS OF THIS PROCESS, SUCH AS DNA DAMAGE, MITOCHONDRIAL DYSFUNCTION, AND EPIGENETIC CHANGES. SIMILARLY, INFLAMMATION ALSO PLAYS A CRITICAL ROLE IN MANY MORBID CONDITIONS THAT AFFECT PATIENTS WHO ARE ADMITTED TO INTENSIVE CARE. ALTHOUGH THE INFLAMMATORY RESPONSE IS LOW GRADE AND PERSISTENT IN HEALTHY AGING WHILE IT IS ACUTE AND SEVERE IN CRITICALLY ILL STATES, WE HYPOTHESIZE THAT BOTH SITUATIONS HAVE IMPORTANT INTERCONNECTIONS. HERE, WE PERFORMED AN EXTENSIVE REVIEW OF THE LITERATURE TO INVESTIGATE THIS POTENTIAL LINK. BECAUSE SEPSIS IS THE MOST EXTENSIVELY STUDIED DISEASE AND IS THE LEADING CAUSE OF DEATH IN CRITICAL CARE, WE FOCUS OUR DISCUSSION ON COMPARING THE INFLAMMATORY PROFILE OF HEALTHY OLDER PEOPLE WITH THAT OF PATIENTS IN SEPTIC SHOCK TO EXPLAIN WHY WE BELIEVE THAT BOTH SITUATIONS HAVE SYNERGISTIC EFFECTS, LEADING TO CRITICALLY ILL AGED PATIENTS HAVING A WORSE PROGNOSIS WHEN COMPARED WITH CRITICALLY ILL YOUNG PATIENTS. 2017 17 3404 33 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 18 2333 36 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 19 806 34 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 20 6866 36 [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