1 3736 137 INNATE IMMUNE TOLERANCE IN MICROGLIA DOES NOT IMPACT ON CENTRAL NERVOUS SYSTEM PRION DISEASE. PRION DISEASES SUCH AS CREUTZFELDT-JAKOB DISEASE IN HUMANS, BOVINE SPONGIFORM ENCEPHALOPATHY IN CATTLE, AND SCRAPIE IN SHEEP, ARE INFECTIOUS AND CHRONIC NEURODEGENERATIVE DISEASES TO WHICH THERE ARE NO CURES. INFECTION WITH PRIONS IN THE CENTRAL NERVOUS SYSTEM (CNS) ULTIMATELY CAUSES EXTENSIVE NEURODEGENERATION, AND THIS IS ACCOMPANIED BY PROMINENT MICROGLIAL AND ASTROCYTIC ACTIVATION IN AFFECTED REGIONS. THE MICROGLIA ARE THE CNS MACROPHAGES AND HELP MAINTAIN NEURONAL HOMEOSTASIS, CLEAR DEAD OR DYING CELLS AND PROVIDE DEFENSE AGAINST PATHOGENS. THE MICROGLIA ALSO PROVIDE NEUROPROTECTION DURING CNS PRION DISEASE, BUT THEIR PRO-INFLAMMATORY ACTIVATION MAY EXACERBATE THE DEVELOPMENT OF THE NEUROPATHOLOGY. INNATE IMMUNE TOLERANCE INDUCED BY CONSECUTIVE SYSTEMIC BACTERIAL LIPOPOLYSACCHARIDE (LPS) TREATMENT CAN INDUCE LONG-TERM EPIGENETIC CHANGES IN THE MICROGLIA IN THE BRAIN THAT SEVERAL MONTHS LATER CAN DAMPEN THEIR RESPONSIVENESS TO SUBSEQUENT LPS TREATMENT AND IMPEDE THE DEVELOPMENT OF NEURITIC DAMAGE IN A TRANSGENIC MOUSE MODEL OF ALZHEIMER'S DISEASE-LIKE PATHOLOGY. WE THEREFORE REASONED THAT INNATE IMMUNE TOLERANCE IN MICROGLIA MIGHT SIMILARLY IMPEDE THE SUBSEQUENT DEVELOPMENT OF CNS PRION DISEASE. TO TEST THIS HYPOTHESIS GROUPS OF MICE WERE FIRST INFECTED WITH PRIONS BY INTRACEREBRAL INJECTION, AND 35 DAYS LATER GIVEN FOUR CONSECUTIVE SYSTEMIC INJECTIONS WITH LPS TO INDUCE INNATE IMMUNE TOLERANCE. OUR DATA SHOW THAT CONSECUTIVE SYSTEMIC LPS TREATMENT DID NOT AFFECT THE SUBSEQUENT DEVELOPMENT OF CNS PRION DISEASE. OUR DATA SUGGESTS INNATE IMMUNE TOLERANCE IN MICROGLIA DOES NOT INFLUENCE THE SUBSEQUENT ONSET OF PRION DISEASE-INDUCED NEUROPATHOLOGY IN MICE, DESPITE PREVIOUSLY PUBLISHED EVIDENCE OF THIS EFFECT IN AN ALZHEIMER'S DISEASE MOUSE MODEL. 2022 2 4278 47 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 3 4969 41 PATHOLOGICAL NEUROINFLAMMATORY CONVERSION OF REACTIVE ASTROCYTES IS INDUCED BY MICROGLIA AND INVOLVES CHROMATIN REMODELING. FOLLOWING BRAIN INJURY OR IN NEURODEGENERATIVE DISEASES, ASTROCYTES BECOME REACTIVE AND MAY SUFFER PATHOLOGICAL REMODELING, FEATURES OF WHICH ARE THE LOSS OF THEIR HOMEOSTATIC FUNCTIONS AND A PRO-INFLAMMATORY GAIN OF FUNCTION THAT FACILITATES NEURODEGENERATION. PHARMACOLOGICAL INTERVENTION TO MODULATE THIS ASTROGLIAL RESPONSE AND NEUROINFLAMMATION IS AN INTERESTING NEW THERAPEUTIC RESEARCH STRATEGY, BUT IT STILL REQUIRES A DEEPER UNDERSTANDING OF THE UNDERLYING CELLULAR AND MOLECULAR MECHANISMS OF THE PHENOMENON. BASED ON THE KNOWN MICROGLIAL-ASTROGLIAL INTERACTION, THE PROMINENT ROLE OF THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY IN MEDIATING ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION, AND ITS ABILITY TO RECRUIT CHROMATIN-REMODELING ENZYMES, WE FIRST EXPLORED THE MICROGLIAL ROLE IN THE INITIATION OF ASTROGLIAL PRO-INFLAMMATORY CONVERSION AND THEN MONITORED THE PROGRESSION OF EPIGENETIC CHANGES IN THE ASTROCYTIC CHROMATIN. DIFFERENT CONFIGURATIONS OF PRIMARY GLIAL CULTURE WERE USED TO MODULATE MICROGLIA-ASTROCYTE CROSSTALK WHILE INDUCING PRO-INFLAMMATORY GAIN OF FUNCTION BY LIPOPOLYSACCHARIDE (LPS) EXPOSURE. IN VIVO, BRAIN ISCHEMIA BY CORTICAL DEVASCULARIZATION (PIAL DISRUPTION) WAS PERFORMED TO VERIFY THE PRESENCE OF EPIGENETIC MARKS IN REACTIVE ASTROCYTES. OUR RESULTS SHOWED THAT 1) MICROGLIA IS REQUIRED TO INITIATE THE PATHOLOGICAL CONVERSION OF ASTROCYTES BY TRIGGERING THE NF-KAPPAB SIGNALING PATHWAY; 2) THIS INTERACTION IS MEDIATED BY SOLUBLE FACTORS AND INDUCES STABLE ASTROGLIAL PHENOTYPIC CHANGES; 3) THE PATHOLOGICAL CONVERSION PROMOTES CHROMATIN REMODELING WITH STABLE INCREASE IN H3K9K14AC, TEMPORARY INCREASE IN H3K27AC, AND TEMPORARY REDUCTION IN HETEROCHROMATIN MARK H3K9ME3; AND 4) IN VIVO REACTIVE ASTROCYTES SHOW INCREASED H3K27AC MARK IN THE NEUROINFLAMMATORY MILIEU FROM THE ISCHEMIC PENUMBRA. OUR FINDINGS INDICATE THAT ASTROGLIAL PATHOLOGICAL PRO-INFLAMMATORY GAIN OF FUNCTION IS ASSOCIATED WITH PROFOUND CHANGES IN THE CONFIGURATION OF ASTROCYTIC CHROMATIN, WHICH IN TURN ARE INITIATED BY MICROGLIA-DERIVED CUES. THESE RESULTS OPEN A NEW AVENUE IN THE STUDY OF POTENTIAL PHARMACOLOGICAL INTERVENTIONS THAT MODIFY THE INITIATION AND STABILIZATION OF ASTROGLIAL PATHOLOGICAL REMODELING, WHICH WOULD BE USEFUL IN ACUTE AND CHRONIC CNS INJURY. EPIGENETIC CHANGES REPRESENT A PLAUSIBLE PHARMACOLOGICAL TARGET TO INTERFERE WITH THE STABILIZATION OF THE PATHOLOGICAL ASTROGLIAL PHENOTYPE. 2021 4 6527 34 TRANSCRIPTIONAL CONTROL OF MALADAPTIVE AND PROTECTIVE RESPONSES IN ALCOHOLICS: A ROLE OF THE NF-KAPPAB SYSTEM. ALCOHOL DEPENDENCE AND ASSOCIATED COGNITIVE IMPAIRMENT APPEAR TO RESULT FROM MALADAPTIVE NEUROPLASTICITY IN RESPONSE TO CHRONIC ALCOHOL CONSUMPTION, NEUROINFLAMMATION AND NEURODEGENERATION. THE INHERENT STABILITY OF BEHAVIORAL ALTERATIONS ASSOCIATED WITH THE ADDICTED STATE SUGGESTS THAT TRANSCRIPTIONAL AND EPIGENETIC MECHANISMS ARE OPERATIVE. NF-KAPPAB TRANSCRIPTION FACTORS ARE REGULATORS OF SYNAPTIC PLASTICITY AND INFLAMMATION, AND RESPONSIVE TO A VARIETY OF STIMULI INCLUDING ALCOHOL. THESE FACTORS ARE ABUNDANT IN THE BRAIN WHERE THEY HAVE DIVERSE FUNCTIONS THAT DEPEND ON THE COMPOSITION OF THE NF-KAPPAB COMPLEX AND CELLULAR CONTEXT. IN NEURON CELL BODIES, NF-KAPPAB IS CONSTITUTIVELY ACTIVE, AND INVOLVED IN NEURONAL INJURY AND NEUROPROTECTION. HOWEVER, AT THE SYNAPSE, NF-KAPPAB IS PRESENT IN A LATENT FORM AND UPON ACTIVATION IS TRANSPORTED TO THE CELL NUCLEUS. IN GLIA, NF-KAPPAB IS INDUCIBLE AND REGULATES INFLAMMATORY PROCESSES THAT EXACERBATE ALCOHOL-INDUCED NEURODEGENERATION. ANIMAL STUDIES DEMONSTRATE THAT ACUTE ALCOHOL EXPOSURE TRANSIENTLY ACTIVATES NF-KAPPAB, WHICH INDUCES NEUROINFLAMMATORY RESPONSES AND NEURODEGENERATION. POSTMORTEM STUDIES OF BRAINS OF HUMAN ALCOHOLICS SUGGEST THAT REPEATED CYCLES OF ALCOHOL CONSUMPTION AND WITHDRAWAL CAUSE ADAPTIVE CHANGES IN THE NF-KAPPAB SYSTEM THAT MAY PERMIT THE SYSTEM TO BETTER TOLERATE EXCESSIVE STIMULATION. THIS TYPE OF TOLERANCE, ENSURING A LOW DEGREE OF RESPONSIVENESS TO APPLIED STIMULI, APPARENTLY DIFFERS FROM THAT IN THE IMMUNE SYSTEM, AND MAY REPRESENT A COMPENSATORY RESPONSE THAT PROTECTS BRAIN CELLS AGAINST ALCOHOL NEUROTOXICITY. THIS VIEW IS SUPPORTED BY FINDINGS SHOWING PREFERENTIAL DOWNREGULATION OF PRO-APOPTOTIC GENE EXPRESSION IN THE AFFECTED BRAIN AREAS IN HUMAN ALCOHOLICS. ALTHOUGH FURTHER VERIFICATION IS NEEDED, WE SPECULATE THAT NF-KAPPAB-DRIVEN NEUROINFLAMMATION AND DISRUPTION TO NEUROPLASTICITY PLAY A SIGNIFICANT ROLE IN REGULATING ALCOHOL DEPENDENCE AND COGNITIVE IMPAIRMENT. 2011 5 5710 30 SIRT1 DEFICIENCY IN MICROGLIA CONTRIBUTES TO COGNITIVE DECLINE IN AGING AND NEURODEGENERATION VIA EPIGENETIC REGULATION OF IL-1BETA. AGING IS THE PREDOMINANT RISK FACTOR FOR NEURODEGENERATIVE DISEASES. ONE KEY PHENOTYPE AS THE BRAIN AGES IS AN ABERRANT INNATE IMMUNE RESPONSE CHARACTERIZED BY PROINFLAMMATION. HOWEVER, THE MOLECULAR MECHANISMS UNDERLYING AGING-ASSOCIATED PROINFLAMMATION ARE POORLY DEFINED. WHETHER CHRONIC INFLAMMATION PLAYS A CAUSAL ROLE IN COGNITIVE DECLINE IN AGING AND NEURODEGENERATION HAS NOT BEEN ESTABLISHED. HERE WE REPORT A MECHANISTIC LINK BETWEEN CHRONIC INFLAMMATION AND AGING MICROGLIA AND A CAUSAL ROLE OF AGING MICROGLIA IN NEURODEGENERATIVE COGNITIVE DEFICITS. WE SHOWED THAT SIRT1 IS REDUCED WITH THE AGING OF MICROGLIA AND THAT MICROGLIAL SIRT1 DEFICIENCY HAS A CAUSATIVE ROLE IN AGING- OR TAU-MEDIATED MEMORY DEFICITS VIA IL-1BETA UPREGULATION IN MICE. INTERESTINGLY, THE SELECTIVE ACTIVATION OF IL-1BETA TRANSCRIPTION BY SIRT1 DEFICIENCY IS LIKELY MEDIATED THROUGH HYPOMETHYLATING THE SPECIFIC CPG SITES ON IL-1BETA PROXIMAL PROMOTER. IN HUMANS, HYPOMETHYLATION OF IL-1BETA IS STRONGLY ASSOCIATED WITH CHRONOLOGICAL AGE AND WITH ELEVATED IL-1BETA TRANSCRIPTION. OUR FINDINGS REVEAL A NOVEL EPIGENETIC MECHANISM IN AGING MICROGLIA THAT CONTRIBUTES TO COGNITIVE DEFICITS IN AGING AND NEURODEGENERATIVE DISEASES. 2015 6 4333 39 MICRORNAS: KEY PLAYERS IN MICROGLIA AND ASTROCYTE MEDIATED INFLAMMATION IN CNS PATHOLOGIES. THE SIGNIFICANCE OF MICROGLIA AND ASTROCYTES IN NEURAL DEVELOPMENT, IN MAINTAINING SYNAPTIC CONNECTIONS AND HOMEOSTASIS IN THE HEALTHY BRAIN IS WELL ESTABLISHED. MICROGLIA ARE DYNAMIC IMMUNE CELLS OF THE BRAIN THAT ELICIT AN IMMUNE RESPONSE DURING BRAIN DAMAGE AND ALSO PARTICIPATE IN TISSUE REPAIR AND REGENERATION, WHILE ASTROCYTES CONTRIBUTE TO THE LOCAL INFLAMMATORY RESPONSE BY PRODUCING PROINFLAMMATORY CYTOKINES AND RESOLVING NEURONAL DAMAGE THROUGH PRODUCTION OF ANTI-INFLAMMATORY CYTOKINES AND NEUROTROPHIC FACTORS. RECENT EFFORTS HAVE FOCUSED ON ELUCIDATING THE EPIGENETIC MECHANISMS WHICH REGULATE GLIAL CELL BEHAVIOR IN NORMAL AND PATHOLOGIC STATES. AN IMPORTANT CLASS OF EPIGENETIC REGULATORS IS MICRORNAS (MIRNAS) WHICH ARE SMALL NON-CODING RNA MOLECULES THAT REGULATE GENE EXPRESSION POSTTRANSCRIPTIONALLY. CERTAIN DYSREGULATED MIRNAS CONTRIBUTE TO CHRONIC MICROGLIAL INFLAMMATION IN THE BRAIN, THEREBY LEADING TO PROGRESSION OF NEUROLOGICAL DISEASES LIKE ALZHEIMER'S DISEASE, TRAUMATIC INJURY, AMYOTROPHIC LATERAL SCLEROSIS AND STROKE. FURTHER, SEVERAL MIRNAS ARE DIFFERENTIALLY EXPRESSED IN ASTROCYTES AFTER ISCHEMIA AND SPINAL CORD INJURY. DESPITE KNOWLEDGE ABOUT MIRNAS IN NEUROINFLAMMATION, LITTLE IS KNOWN ABOUT EFFECTIVE DELIVERY ROUTES AND PHARMACOKINETIC DATA FOR MIRNA BASED THERAPEUTICS. THIS REVIEW SUMMARIZES THE CURRENT RESEARCH ON THE ROLE OF MIRNAS IN PROMOTING AND INHIBITING INFLAMMATORY RESPONSE OF MICROGLIA AND ASTROCYTES IN A DISEASE-SPECIFIC MANNER. IN ADDITION, MIRNA DELIVERY AS A THERAPEUTIC STRATEGY TO TREAT NEUROINFLAMMATION IS DISCUSSED. 2016 7 4620 24 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 8 6257 30 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 9 3540 31 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 4439 37 MOLECULAR GENETIC AND EPIGENETIC BASIS OF MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC IMMUNE-MEDIATED DISEASE OF SPINAL CORD AND BRAIN. THE INITIAL EVENT IN MS OCCURS WHEN ACTIVATED CD4(+) T CELLS IN PERIPHERY EXACERBATES IMMUNE RESPONSES BY STIMULATING IMMUNE CELLS SUCH AS B CELLS, CD8(+) CELLS, MAST CELLS, GRANULOCYTES AND MONOCYTES. THESE PROINFLAMMATORY CELLS PASS BLOOD BRAIN BARRIER BY SECRETING PROINFLAMMATORY CYTOKINES INCLUDING TNF-ALPHA AND INF-(GAMMA) WHICH ACTIVATE ADHESION FACTORS. APCS (ANTIGEN-PRESENTING CELLS) REACTIVATE CD4(+) T CELLS AFTER INFILTRATING THE CNS AND CD4(+) T CELLS PRODUCE CYTOKINES AND CHEMOKINES. THESE PROINFLAMMATORY CYTOKINES AGGRAVATE INFLAMMATION BY INDUCING MYELIN PHAGOCYTOSIS THROUGH MICROGLIA AND ASTROCYTES ACTIVATION. MS IS BELIEVED TO HAVE A MULTIFACTORIAL ORIGIN THAT INCLUDES A COMBINATION OF MULTIPLE GENETIC, ENVIRONMENTAL AND STOCHASTIC FACTORS. ALTHOUGH THE EXACT COMPONENT OF MS RISKS THAT CAN BE EXPLAINED BY THESE FACTORS IS DIFFICULT TO DETERMINE, ESTIMATES BASED ON GENETIC AND EPIDEMIOLOGICAL STUDIES SUGGEST THAT UP TO 60-70 % OF THE TOTAL RISK OF MS MAY BE CONTRIBUTE TO GENETIC FACTORS. IN CONTINUE, FIRSTLY WE PROVIDE AN OVERVIEW OF THE CURRENT UNDERSTANDING OF EPIGENETIC MECHANISMS, AND SO PRESENT EVIDENCE OF HOW THE EPIGENETIC MODIFICATIONS CONTRIBUTE TO INCREASED SUSCEPTIBILITY OF MS. WE ALSO EXPLAIN HOW SPECIFIED EPIGENETIC MODIFICATIONS MAY INFLUENCE THE PATHOPHYSIOLOGY AND KEY ASPECTS OF DISEASE IN MS (DEMYELINATION, REMYELINATION, INFLAMMATION, AND NEURODEGENERATION). FINALLY, WE TEND TO DISCUSS HOW ENVIRONMENTAL FACTORS AND EPIGENETIC MECHANISMS MAY INTERACT TO HAVE AN EFFECT ON MS RISK AND CLINICAL OUTCOME AND RECOMMEND NEW THERAPEUTIC INTERVENTIONS THAT MIGHT MODULATE PATIENTS' EPIGENETIC PROFILES. 2017 11 676 35 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 12 4391 40 MODERATE EXERCISE INDUCES TRAINED IMMUNITY IN MACROPHAGES. DESPITE ITS IMPORTANCE IN PROTECTING THE HOST FROM INFECTIONS AND INJURY, EXCESSIVE INFLAMMATION MAY LEAD TO SERIOUS HUMAN DISEASES INCLUDING AUTOIMMUNE DISORDERS, CARDIOVASCULAR DISEASES, DIABETES, AND CANCER. EXERCISE IS A KNOWN IMMUNOMODULATOR; HOWEVER, WHETHER EXERCISE CAUSES LONG-TERM CHANGES IN INFLAMMATORY RESPONSES AND HOW THESE CHANGES OCCUR ARE LACKING. HERE, WE SHOW THAT CHRONIC MODERATE-INTENSITY TRAINING OF MICE LEADS TO PERSISTENT METABOLIC REWIRING AND CHANGES TO CHROMATIN ACCESSIBILITY IN BONE MARROW-DERIVED MACROPHAGES (BMDMS), WHICH, IN TURN, TEMPERS THEIR INFLAMMATORY RESPONSES. WE SHOW THAT BMDMS FROM EXERCISED MICE EXHIBITED A DECREASE IN LIPOPOLYSACCHARIDE (LPS)-INDUCED NF-KAPPAB ACTIVATION AND PROINFLAMMATORY GENE EXPRESSION ALONG WITH AN INCREASE IN M2-LIKE-ASSOCIATED GENES WHEN COMPARED WITH BMDMS FROM SEDENTARY MICE. THIS WAS ASSOCIATED WITH IMPROVED MITOCHONDRIAL QUALITY AND INCREASED RELIANCE ON OXIDATIVE PHOSPHORYLATION ACCOMPANIED WITH REDUCED MITOCHONDRIAL REACTIVE OXYGEN SPECIES (ROS) PRODUCTION. MECHANISTICALLY, ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN (ATAC)-SEQ ANALYSIS SHOWED CHANGES IN CHROMATIN ACCESSIBILITY OF GENES ASSOCIATED WITH INFLAMMATORY AND METABOLIC PATHWAYS. OVERALL, OUR DATA SUGGEST THAT CHRONIC MODERATE EXERCISE CAN INFLUENCE THE INFLAMMATORY RESPONSES OF MACROPHAGES BY REPROGRAMMING THEIR METABOLIC AND EPIGENETIC LANDSCAPE.NEW & NOTEWORTHY IN THIS STUDY, WE EXPLAIN HOW LONG-TERM MODERATE EXERCISE TRAINING CAN REDUCE INFLAMMATION IN MOUSE MACROPHAGES BY REPROGRAMMING THE WAY THEY SENSE AND RESPOND TO THE PRESENCE OF PATHOGENS. WE COMPLETED A THOROUGH ANALYSIS AND SHOWED THAT THESE CHANGES PERSIST IN MACROPHAGES BECAUSE EXERCISE IMPROVES THE ABILITY OF CELLS TO UTILIZE OXYGEN WITHOUT PRODUCING DAMAGING COMPOUNDS, AND CHANGES THE WAY THEY ACCESS THEIR DNA. 2023 13 4633 34 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 14 2303 29 EPIGENETIC REGULATION OF CANNABINOID-MEDIATED ATTENUATION OF INFLAMMATION AND ITS IMPACT ON THE USE OF CANNABINOIDS TO TREAT AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION IS CONSIDERED TO BE A SILENT KILLER BECAUSE IT IS THE UNDERLYING CAUSE OF A WIDE RANGE OF CLINICAL DISORDERS, FROM CARDIOVASCULAR TO NEUROLOGICAL DISEASES, AND FROM CANCER TO OBESITY. IN ADDITION, THERE ARE OVER 80 DIFFERENT TYPES OF DEBILITATING AUTOIMMUNE DISEASES FOR WHICH THERE ARE NO CURE. CURRENTLY, THE DRUGS THAT ARE AVAILABLE TO SUPPRESS CHRONIC INFLAMMATION ARE EITHER INEFFECTIVE OR OVERTLY SUPPRESS THE INFLAMMATION, THEREBY CAUSING INCREASED SUSCEPTIBILITY TO INFECTIONS AND CANCER. THUS, THE DEVELOPMENT OF A NEW CLASS OF DRUGS THAT CAN SUPPRESS CHRONIC INFLAMMATION IS IMPERATIVE. CANNABINOIDS ARE A GROUP OF COMPOUNDS PRODUCED IN THE BODY (ENDOCANNABINOIDS) OR FOUND IN CANNABIS (PHYTOCANNABINOIDS) THAT ACT THROUGH CANNABINOID RECEPTORS AND VARIOUS OTHER RECEPTORS EXPRESSED WIDELY IN THE BRAIN AND IMMUNE SYSTEM. IN THE LAST DECADE, CANNABINOIDS HAVE BEEN WELL ESTABLISHED EXPERIMENTALLY TO MEDIATE ANTI-INFLAMMATORY PROPERTIES. RESEARCH HAS SHOWN THAT THEY SUPPRESS INFLAMMATION THROUGH MULTIPLE PATHWAYS, INCLUDING APOPTOSIS AND INDUCING IMMUNOSUPPRESSIVE T REGULATORY CELLS (TREGS) AND MYELOID-DERIVED SUPPRESSOR CELLS (MDSCS). INTERESTINGLY, CANNABINOIDS ALSO MEDIATE EPIGENETIC ALTERATIONS IN GENES THAT REGULATE INFLAMMATION. IN THE CURRENT REVIEW, WE HIGHLIGHT HOW THE EPIGENETIC MODULATIONS CAUSED BY CANNABINOIDS LEAD TO THE SUPPRESSION OF INFLAMMATION AND HELP IDENTIFY NOVEL PATHWAYS THAT CAN BE USED TO TARGET AUTOIMMUNE DISEASES. 2021 15 3587 43 IMPACT OF TLR4 ON BEHAVIORAL AND COGNITIVE DYSFUNCTIONS ASSOCIATED WITH ALCOHOL-INDUCED NEUROINFLAMMATORY DAMAGE. TOLL-LIKE RECEPTORS (TLRS) PLAY AN IMPORTANT ROLE IN THE INNATE IMMUNE RESPONSE, AND EMERGING EVIDENCE INDICATES THEIR ROLE IN BRAIN INJURY AND NEURODEGENERATION. OUR RECENT RESULTS HAVE DEMONSTRATED THAT ETHANOL IS CAPABLE OF ACTIVATING GLIAL TLR4 RECEPTORS AND THAT THE ELIMINATION OF THESE RECEPTORS IN MICE PROTECTS AGAINST ETHANOL-INDUCED GLIAL ACTIVATION, INDUCTION OF INFLAMMATORY MEDIATORS AND APOPTOSIS. THIS STUDY WAS DESIGNED TO ASSESS WHETHER ETHANOL-INDUCED INFLAMMATORY DAMAGE CAUSES BEHAVIORAL AND COGNITIVE CONSEQUENCES, AND IF BEHAVIORAL ALTERATIONS ARE DEPENDENT OF TLR4 FUNCTIONS. HERE WE SHOW IN MICE DRINKING ALCOHOL FOR 5MONTHS, FOLLOWED BY A 15-DAY WITHDRAWAL PERIOD, THAT ACTIVATION OF THE ASTROGLIAL AND MICROGLIAL CELLS IN FRONTAL CORTEX AND STRIATUM IS MAINTAINED AND THAT THESE EVENTS ARE ASSOCIATED WITH COGNITIVE AND ANXIETY-RELATED BEHAVIORAL IMPAIRMENTS IN WILD-TYPE (WT) MICE, AS DEMONSTRATED BY TESTING THE ANIMALS WITH OBJECT MEMORY RECOGNITION, CONDITIONED TASTE AVERSION AND DARK AND LIGHT BOX ANXIETY TASKS. MICE LACKING TLR4 RECEPTORS ARE PROTECTED AGAINST ETHANOL-INDUCED INFLAMMATORY DAMAGE, AND BEHAVIORAL ASSOCIATED EFFECTS. WE FURTHER ASSESS THE POSSIBILITY OF THE EPIGENETIC MODIFICATIONS PARTICIPATING IN SHORT- OR LONG-TERM BEHAVIORAL EFFECTS ASSOCIATED WITH NEUROINFLAMMATORY DAMAGE. WE SHOW THAT CHRONIC ALCOHOL TREATMENT DECREASES H4 HISTONE ACETYLATION AND HISTONE ACETYLTRANSFERASES ACTIVITY IN FRONTAL CORTEX, STRIATUM AND HIPPOCAMPUS OF WT MICE. ALTERATIONS IN CHROMATIN STRUCTURE WERE NOT OBSERVED IN TLR4(-/-) MICE. THESE RESULTS PROVIDE THE FIRST EVIDENCE OF THE ROLE THAT TLR4 FUNCTIONS PLAY IN THE BEHAVIORAL CONSEQUENCES OF ALCOHOL-INDUCED INFLAMMATORY DAMAGE AND SUGGEST THAT THE EPIGENETIC MODIFICATIONS MEDIATED BY TLR4 COULD CONTRIBUTE TO SHORT- OR LONG-TERM ALCOHOL-INDUCED BEHAVIORAL OR COGNITIVE DYSFUNCTIONS. 2011 16 4036 26 MACROPHAGE EPIGENETIC MEMORIES OF EARLY LIFE INJURY DRIVE NEONATAL NOCICEPTIVE PRIMING. THE DEVELOPING PERIPHERAL NERVOUS AND IMMUNE SYSTEMS ARE FUNCTIONALLY DISTINCT FROM ADULTS. THESE SYSTEMS ARE VULNERABLE TO EFFECTS OF EARLY LIFE INJURY WHICH CAN INFLUENCE OUTCOMES RELATED TO NOCICEPTION FOLLOWING SUBSEQUENT INJURY LATER IN LIFE (I.E. "NEONATAL NOCICEPTIVE PRIMING"). THE UNDERPINNINGS OF THIS PHENOMENON ARE LARGELY UNKNOWN, ALTHOUGH MACROPHAGES CAN BE EPIGENETICALLY TRAINED BY INJURY. WE FOUND THAT MACROPHAGES ARE BOTH NECESSARY AND PARTIALLY SUFFICIENT TO DRIVE NEONATAL NOCICEPTIVE PRIMING POSSIBLY DUE TO A LONG-LASTING EPIGENETIC REMODELING OF PERIPHERAL MACROPHAGES. THE P75 NEUROTROPHIC FACTOR RECEPTOR (NTR) WAS OBSERVED TO BE AN IMPORTANT EFFECTOR IN REGULATING NEONATAL NOCICEPTIVE PRIMING. P75NTR MODULATES THE INFLAMMATORY PROFILE AND RESPONSES OF RODENT AND HUMAN MACROPHAGES. THIS "PAIN MEMORY" WAS ABLE TO BE TRANSFERRED TO A NAIVE HOST TO ALTER SEX-SPECIFIC PAIN-RELATED BEHAVIORS. THIS STUDY REVEALS A NOVEL MECHANISM BY WHICH ACUTE POST-SURGICAL PAIN MAY TRANSITION TO CHRONIC PAIN IN CHILDREN. 2023 17 6520 44 TRANSCRIPTIONAL AND EPIGENETIC REGULATION OF MONOCYTE AND MACROPHAGE DYSFUNCTION BY CHRONIC ALCOHOL CONSUMPTION. DRINKING ALCOHOL, EVEN IN MODERATION, CAN AFFECT THE IMMUNE SYSTEM. STUDIES HAVE SHOWN DISPROPORTIONATE EFFECTS OF ALCOHOL ON CIRCULATING AND TISSUE-RESIDENT MYELOID CELLS (GRANULOCYTES, MONOCYTES, MACROPHAGES, DENDRITIC CELLS). THESE CELLS ORCHESTRATE THE BODY'S FIRST LINE OF DEFENSE AGAINST MICROBIAL CHALLENGES AS WELL AS MAINTAIN TISSUE HOMEOSTASIS AND REPAIR. ALCOHOL'S EFFECTS ON THESE CELLS ARE DEPENDENT ON EXPOSURE PATTERN, WITH ACUTE DRINKING DAMPENING BUT CHRONIC DRINKING ENHANCING PRODUCTION OF INFLAMMATORY MEDIATORS. ALTHOUGH CHRONIC DRINKING IS ASSOCIATED WITH HEIGHTENED SYSTEMIC INFLAMMATION, STUDIES ON TISSUE RESIDENT MACROPHAGE POPULATIONS IN SEVERAL ORGANS INCLUDING THE SPLEEN, LIVER, BRAIN, AND LUNG HAVE ALSO SHOWN COMPROMISED FUNCTIONAL AND METABOLIC CAPACITIES OF THESE CELLS. MANY OF THESE EFFECTS ARE THOUGHT TO BE MEDIATED BY OXIDATIVE STRESS CAUSED BY ALCOHOL AND ITS METABOLITES WHICH CAN DIRECTLY IMPACT THE CELLULAR EPIGENETIC LANDSCAPES. IN ADDITION, SINCE MYELOID CELLS ARE RELATIVELY SHORT-LIVED IN CIRCULATION AND ARE UNDER CONSTANT REPOPULATION FROM THE BONE MARROW COMPARTMENT, ALCOHOL'S EFFECTS ON BONE MARROW PROGENITORS AND HEMATOPOIESIS ARE IMPORTANT FOR UNDERSTANDING THE IMPACT OF ALCOHOL SYSTEMICALLY ON THESE MYELOID POPULATIONS. ALCOHOL-INDUCED DISRUPTION OF PROGENITOR, CIRCULATING, AND TISSUE RESIDENT MYELOID POPULATIONS CONTRIBUTE TO THE INCREASED SUSCEPTIBILITY OF PATIENTS WITH ALCOHOL USE DISORDERS TO VIRAL AND BACTERIAL INFECTIONS. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF THE IMPACT OF CHRONIC ALCOHOL CONSUMPTION ON THE FUNCTION OF MONOCYTES AND MACROPHAGES IN HOST DEFENSE, TISSUE REPAIR AND INFLAMMATION. WE THEN SUMMARIZE OUR CURRENT UNDERSTANDING OF THE MECHANISMS UNDERLYING ALCOHOL-INDUCED DISRUPTION AND EXAMINE CHANGES IN TRANSCRIPTOME AND EPIGENOME OF MONOCYTES AND MCROPHAGES. OVERALL, CHRONIC ALCOHOL CONSUMPTION LEADS TO HYPER-INFLAMMATION CONCOMITANT WITH DECREASED MICROBIAL AND WOUND HEALING RESPONSES BY MONOCYTES/MACROPHAGES DUE TO A REWIRING OF THE EPIGENTIC AND TRANSCRIPTIONAL LANDSCAPE. HOWEVER, IN ADVANCED ALCOHOLIC LIVER DISEASE, MYELOID CELLS BECOME IMMUNOSUPPRESSED AS A RESPONSE TO THE SURROUNDING HYPER-INFLAMMATORY MILIEU. THEREFORE, THE EFFECT OF CHRONIC ALCOHOL ON THE INFLAMMATORY RESPONSE DEPENDS ON DISEASE STATE AND THE IMMUNE CELL POPULATION. 2022 18 4277 39 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 19 6866 31 [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 20 534 29 ASTROGLIA IN THE VULNERABILITY TO AND MAINTENANCE OF STRESS-MEDIATED NEUROPATHOLOGY AND DEPRESSION. SIGNIFICANT STRESS EXPOSURE AND PSYCHIATRIC DEPRESSION ARE ASSOCIATED WITH MORPHOLOGICAL, BIOCHEMICAL, AND PHYSIOLOGICAL DISTURBANCES OF ASTROCYTES IN SPECIFIC BRAIN REGIONS RELEVANT TO THE PATHOPHYSIOLOGY OF THOSE DISORDERS, SUGGESTING THAT ASTROCYTES ARE INVOLVED IN THE MECHANISMS UNDERLYING THE VULNERABILITY TO OR MAINTENANCE OF STRESS-RELATED NEUROPATHOLOGY AND DEPRESSION. TO UNDERSTAND THOSE MECHANISMS A VARIETY OF STUDIES HAVE PROBED THE EFFECT OF VARIOUS MODALITIES OF STRESS EXPOSURE ON THE METABOLISM, GENE EXPRESSION AND PLASTICITY OF ASTROCYTES. THESE STUDIES HAVE UNCOVERED THE PARTICIPATION OF VARIOUS CELLULAR PATHWAYS, SUCH AS THOSE FOR INTRACELLULAR CALCIUM REGULATION, NEUROIMMUNE RESPONSES, EXTRACELLULAR IONIC REGULATION, GAP JUNCTIONS-BASED CELLULAR COMMUNICATION, AND REGULATION OF NEUROTRANSMITTER AND GLIOTRANSMITTER RELEASE AND UPTAKE. MORE RECENTLY EPIGENETIC MODIFICATIONS RESULTING FROM EXPOSURE TO CHRONIC FORMS OF STRESS OR TO EARLY LIFE ADVERSITY HAVE BEEN SUGGESTED TO AFFECT NOT ONLY NEURONAL MECHANISMS BUT ALSO GENE EXPRESSION AND PHYSIOLOGY OF ASTROCYTES AND OTHER GLIAL CELLS. HOWEVER, MUCH REMAINS TO BE LEARNED TO UNDERSTAND THE SPECIFIC ROLE OF THOSE AND OTHER MODIFICATIONS IN THE ASTROGLIAL CONTRIBUTION TO THE VULNERABILITY TO AND MAINTENANCE OF STRESS-RELATED DISORDERS AND DEPRESSION, AND FOR LEVERAGING THAT KNOWLEDGE TO ACHIEVE MORE EFFECTIVE PSYCHIATRIC THERAPIES. 2022