1 5240 115 PROGESTERONE EFFECTS ON OLIGODENDROCYTE DIFFERENTIATION IN INJURED SPINAL CORD. SPINAL CORD LESIONS RESULT IN CHRONIC DEMYELINATION AS A CONSEQUENCE OF SECONDARY INJURY. ALTHOUGH OLIGODENDROCYTE PRECURSOR CELLS PROLIFERATE THE DIFFERENTIATION PROGRAM FAILS. SUCCESSFUL DIFFERENTIATION IMPLIES PROGRESSIVE DECREASE OF TRANSCRIPTIONAL INHIBITORS FOLLOWED BY UPREGULATION OF ACTIVATORS. PROGESTERONE EMERGES AS AN ANTI-INFLAMMATORY AND PRO-MYELINATING AGENT WHICH IMPROVES LOCOMOTOR OUTCOME AFTER SPINAL CORD INJURY. IN THIS STUDY, WE HAVE DEMONSTRATED THAT SPINAL CORD INJURY ENHANCED OLIGODENDROCYTE PRECURSOR CELL NUMBER AND DECREASED MRNA EXPRESSION OF TRANSCRIPTIONAL INHIBITORS (ID2, ID4, HES5). HOWEVER, MRNA EXPRESSION OF TRANSCRIPTIONAL ACTIVATORS (OLIG2, NKX2.2, SOX10 AND MASH1) WAS DOWN-REGULATED 3 DAYS POST INJURY. INTERESTINGLY, A DIFFERENTIATION FACTOR SUCH AS PROGESTERONE INCREASED TRANSCRIPTIONAL ACTIVATOR MRNA LEVELS AND THE DENSITY OF OLIG2- EXPRESSING OLIGODENDROCYTE PRECURSOR CELLS. THE DIFFERENTIATION PROGRAM IS REGULATED BY EXTRACELLULAR SIGNALS WHICH MODIFY TRANSCRIPTIONAL FACTORS AND EPIGENETIC PLAYERS. AS TGFBETA1 IS A KNOWN OLIGODENDROCYTE DIFFERENTIATION FACTOR WHICH IS REGULATED BY PROGESTERONE IN REPRODUCTIVE TISSUES, WE ASSESSED WHETHER TGFBETA1 COULD MEDIATE PROGESTERONE REMYELINATING ACTIONS AFTER THE LESION. NOTWITHSTANDING THAT ASTROCYTE, OLIGODENDROCYTE PRECURSOR AND MICROGLIAL CELL DENSITY INCREASED AFTER SPINAL CORD INJURY, THE NUMBER OF THESE CELLS WHICH EXPRESSED TGFBETA1 REMAINED UNCHANGED REGARDING SHAM OPERATED RATS. HOWEVER, PROGESTERONE TREATMENT INCREASED TGFBETA1 MRNA EXPRESSION AND THE NUMBER OF ASTROCYTES AND MICROGLIAL TGFBETA1 EXPRESSING CELLS WHICH WOULD INDIRECTLY ENHANCE OLIGODENDROCYTE DIFFERENTIATION. THEREFORE, TGFBETA1 ARISES AS A POTENTIAL MEDIATOR OF PROGESTERONE DIFFERENTIATING EFFECTS ON OLIGODENDROCYTE LINAGE. 2019 2 1868 24 EMERGING NEUROTOXIC MECHANISMS IN ENVIRONMENTAL FACTORS-INDUCED NEURODEGENERATION. EXPOSURE TO ENVIRONMENTAL NEUROTOXIC METALS, PESTICIDES AND OTHER CHEMICALS IS INCREASINGLY RECOGNIZED AS A KEY RISK FACTOR IN THE PATHOGENESIS OF CHRONIC NEURODEGENERATIVE DISORDERS SUCH AS PARKINSON'S AND ALZHEIMER'S DISEASES. OXIDATIVE STRESS AND APOPTOSIS HAVE BEEN ACTIVELY INVESTIGATED AS NEUROTOXIC MECHANISMS OVER THE PAST TWO DECADES, RESULTING IN A GREATER UNDERSTANDING OF NEUROTOXIC PROCESSES. NEVERTHELESS, EMERGING EVIDENCE INDICATES THAT EPIGENETIC CHANGES, PROTEIN AGGREGATION AND AUTOPHAGY ARE IMPORTANT CELLULAR AND MOLECULAR CORRELATES OF NEURODEGENERATIVE DISEASES RESULTING FROM CHRONIC NEUROTOXIC CHEMICAL EXPOSURE. DURING THE JOINT CONFERENCE OF THE 13TH INTERNATIONAL NEUROTOXICOLOGY ASSOCIATION AND THE 11TH INTERNATIONAL SYMPOSIUM ON NEUROBEHAVIORAL METHODS AND EFFECTS IN OCCUPATIONAL AND ENVIRONMENTAL HEALTH, THE RECENT PROGRESS MADE TOWARD UNDERSTANDING EPIGENETIC MECHANISMS, PROTEIN AGGREGATION, AUTOPHAGY, AND DEREGULATED KINASE ACTIVATION FOLLOWING NEUROTOXIC CHEMICAL EXPOSURE AND THE RELEVANCE TO NEURODEGENERATIVE CONDITIONS WERE ONE OF THE THEMES OF THE SYMPOSIUM. DR. ANUMANTHA G. KANTHASAMY DESCRIBED THE ROLE OF ACETYLATION OF HISTONES AND NON-HISTONE PROTEINS IN NEUROTOXICANT-INDUCED NEURODEGENERATIVE PROCESSES IN THE NIGRAL DOPAMINERGIC NEURONAL SYSTEM. DR. ARTHI KANTHASAMY ILLUSTRATED THE ROLE OF AUTOPHAGY AS A KEY DETERMINANT IN CELL DEATH EVENTS DURING NEUROTOXIC INSULTS. DR. AJAY RANA PROVIDED EVIDENCE FOR POSTTRANSLATIONAL MODIFICATION OF ALPHA-SYNUCLEIN PROTEIN BY THE MIXED LINAGE KINASE (MLK) GROUP OF KINASES TO INITIATE PROTEIN AGGREGATION IN CELL CULTURE AND ANIMAL MODELS OF PARKINSON'S DISEASE. THESE PRESENTATIONS OUTLINED EMERGING CUTTING EDGE MECHANISMS THAT MIGHT SET THE STAGE FOR FUTURE MECHANISTIC INVESTIGATIONS INTO NEW FRONTIERS OF MOLECULAR NEUROTOXICOLOGY. THIS REPORT SUMMARIZES THE VIEWS OF SYMPOSIUM PARTICIPANTS, WITH EMPHASIS ON FUTURE DIRECTIONS FOR STUDY OF ENVIRONMENTALLY AND OCCUPATIONALLY LINKED CHRONIC NEURODEGENERATIVE DISEASES. 2012 3 2087 31 EPIGENETIC DYSREGULATION OF ID4 PREDICTS DISEASE PROGRESSION AND TREATMENT OUTCOME IN MYELOID MALIGNANCIES. PROMOTER HYPERMETHYLATION-MEDIATED INACTIVATION OF ID4 PLAYS A CRUCIAL ROLE IN THE DEVELOPMENT OF SOLID TUMOURS. THIS STUDY AIMED TO INVESTIGATE ID4 METHYLATION AND ITS CLINICAL RELEVANCE IN MYELOID MALIGNANCIES. ID4 HYPERMETHYLATION WAS ASSOCIATED WITH HIGHER IPSS SCORES, BUT WAS NOT AN INDEPENDENT PROGNOSTIC BIOMARKER AFFECTING OVERALL SURVIVAL (OS) IN MYELODYSPLASTIC SYNDROME (MDS). HOWEVER, ID4 HYPERMETHYLATION CORRELATED WITH SHORTER OS AND LEUKAEMIA-FREE SURVIVAL (LFS) TIME AND ACTED AS AN INDEPENDENT RISK FACTOR AFFECTING OS IN ACUTE MYELOID LEUKAEMIA (AML). MOREOVER, ID4 METHYLATION WAS SIGNIFICANTLY DECREASED IN THE FOLLOW-UP PAIRED AML PATIENTS WHO ACHIEVED COMPLETE REMISSION (CR) AFTER INDUCTION THERAPY. IMPORTANTLY, ID4 METHYLATION WAS INCREASED DURING MDS PROGRESSION TO AML AND CHRONIC PHASE (CP) PROGRESSION TO BLAST CRISIS (BC) IN CHRONIC MYELOID LEUKAEMIA (CML). EPIGENETIC STUDIES SHOWED THAT ID4 METHYLATION MIGHT BE ONE OF THE MECHANISMS SILENCING ID4 EXPRESSION IN MYELOID LEUKAEMIA. FUNCTIONAL STUDIES IN VITRO SHOWED THAT RESTORATION OF ID4 EXPRESSION COULD INHIBIT CELL PROLIFERATION AND PROMOTE APOPTOSIS IN BOTH K562 AND HL60 CELLS. THESE FINDINGS INDICATE THAT ID4 ACTS AS A TUMOUR SUPPRESSOR IN MYELOID MALIGNANCIES, AND ID4 METHYLATION IS A POTENTIAL BIOMARKER IN PREDICTING DISEASE PROGRESSION AND TREATMENT OUTCOME. 2017 4 1205 34 COULD THE INHIBITOR OF DNA BINDING 2 AND 4 PLAY A ROLE IN WHITE MATTER INJURY? WHITE MATTER INJURY (WMI) PREVENTS THE NORMAL DEVELOPMENT OF MYELINATION, LEADING TO CENTRAL NERVOUS SYSTEM MYELINATION DISORDERS AND THE PRODUCTION OF CHRONIC SEQUELAE ASSOCIATED WITH WMI, SUCH AS CHRONIC DYSKINESIA, COGNITIVE IMPAIRMENT AND CEREBRAL PALSY. THIS RESULTS IN A LARGE EMOTIONAL AND SOCIOECONOMIC BURDEN. DECREASED MYELINATION IN PRETERM INFANT WMI IS ASSOCIATED WITH THE DELAYED DEVELOPMENT OR DESTRUCTION OF OLIGODENDROCYTE (OL) LINEAGE CELLS, PARTICULARLY OLIGODENDROCYTE PRECURSOR CELLS (OPCS). THE DEVELOPMENT OF CELLS FROM THE OL LINEAGE INVOLVES THE MIGRATION, PROLIFERATION AND DIFFERENT STAGES OF OL DIFFERENTIATION, FINALLY LEADING TO MYELINATION. A SERIES OF COMPLEX INTRINSIC, EXTRINSIC AND EPIGENETIC FACTORS REGULATE THE OPC CELL CYCLE WITHDRAWAL, OL LINEAGE PROGRESSION AND MYELINATION. WE FOCUS ON THE INHIBITOR OF DNA BINDING 2 (ID2), BECAUSE IT IS WIDELY INVOLVED IN THE DIFFERENT STAGES OF OL DIFFERENTIATION AND GENESIS. ID2 IS A KEY TRANSCRIPTION FACTOR FOR THE NORMAL DEVELOPMENT OF OL LINEAGE CELLS, AND THE PATHOGENESIS OF WMI IS CLOSELY LINKED WITH OL DEVELOPMENTAL DISORDERS. ID4, ANOTHER FAMILY MEMBER OF THE IDS PROTEIN, ALSO PLAYS A SIMILAR ROLE IN OL DIFFERENTIATION AND GENESIS. ID2 AND ID4 BELONG TO THE HELIX-LOOP-HELIX FAMILY; THEY LACK THE DNA-BINDING SEQUENCES AND INHIBIT OLIGODENDROGENESIS AND OPC DIFFERENTIATION. IN THIS REVIEW, WE MAINLY DISCUSS THE ROLES OF ID2 IN OL DEVELOPMENT, ESPECIALLY DURING OPC DIFFERENTIATION, AND SUMMARIZE THE ID2-MEDIATED INTRACELLULAR AND EXTRACELLULAR SIGNALING PATHWAYS THAT REGULATE THESE PROCESSES. WE ALSO DISCUSS ID4 IN RELATION TO BONE MORPHOGENETIC PROTEIN SIGNALING AND OLIGODENDROGENESIS. IT IS LIKELY THAT THESE DEVELOPMENTAL MECHANISMS ARE ALSO INVOLVED IN THE MYELIN REPAIR OR REMYELINATION IN HUMAN NEUROLOGICAL DISEASES. 2019 5 4635 26 NEUROINFLAMMATORY MECHANISMS IN PARKINSON'S DISEASE: POTENTIAL ENVIRONMENTAL TRIGGERS, PATHWAYS, AND TARGETS FOR EARLY THERAPEUTIC INTERVENTION. MOST ACUTE AND CHRONIC NEURODEGENERATIVE CONDITIONS ARE ACCOMPANIED BY NEUROINFLAMMATION; YET THE EXACT NATURE OF THE INFLAMMATORY PROCESSES AND WHETHER THEY MODIFY DISEASE PROGRESSION IS NOT WELL UNDERSTOOD. IN THIS REVIEW, WE DISCUSS THE KEY EPIDEMIOLOGICAL, CLINICAL, AND EXPERIMENTAL EVIDENCE IMPLICATING INFLAMMATORY PROCESSES IN THE PROGRESSIVE DEGENERATION OF THE DOPAMINERGIC (DA) NIGROSTRIATAL PATHWAY AND THEIR POTENTIAL CONTRIBUTION TO THE PATHOPHYSIOLOGY OF PARKINSON'S DISEASE (PD). GIVEN THAT INTERPLAY BETWEEN GENETICS AND ENVIRONMENT ARE LIKELY TO CONTRIBUTE TO RISK FOR DEVELOPMENT OF IDIOPATHIC PD, RECENT DATA SHOWING INTERACTIONS BETWEEN PRODUCTS OF GENES LINKED TO HERITABLE PD THAT FUNCTION TO PROTECT DA NEURONS AGAINST OXIDATIVE OR PROTEOLYTIC STRESS AND INFLAMMATION PATHWAYS WILL BE DISCUSSED. CELLULAR MECHANISMS ACTIVATED OR ENHANCED BY INFLAMMATORY PROCESSES THAT MAY CONTRIBUTE TO MITOCHONDRIAL DYSFUNCTION, OXIDATIVE STRESS, OR APOPTOSIS OF DOPAMINERGIC (DA) NEURONS WILL BE REVIEWED, WITH SPECIAL EMPHASIS ON TUMOR NECROSIS FACTOR (TNF) AND INTERLEUKIN-1-BETA (IL-1BETA) SIGNALING PATHWAYS. EPIGENETIC FACTORS WHICH HAVE THE POTENTIAL TO TRIGGER NEUROINFLAMMATION, INCLUDING ENVIRONMENTAL EXPOSURES AND AGE-ASSOCIATED CHRONIC INFLAMMATORY CONDITIONS, WILL BE DISCUSSED AS POSSIBLE 'SECOND-HIT' TRIGGERS THAT MAY AFFECT DISEASE ONSET OR PROGRESSION OF IDIOPATHIC PD. IF INFLAMMATORY PROCESSES HAVE AN ACTIVE ROLE IN NIGROSTRIATAL PATHWAY DEGENERATION, THEN EVIDENCE SHOULD EXIST TO INDICATE THAT SUCH PROCESSES BEGIN IN THE EARLY STAGES OF DISEASE AND THAT THEY CONTRIBUTE TO NEURONAL DYSFUNCTION AND/OR HASTEN NEURODEGENERATION OF THE NIGROSTRIATAL PATHWAY. THERAPEUTICALLY, IF ANTI-INFLAMMATORY INTERVENTIONS CAN BE SHOWN TO RESCUE NIGRAL DA NEURONS FROM DEGENERATION AND LOWER PD RISK, THEN TIMELY USE OF ANTI-INFLAMMATORY THERAPIES SHOULD BE INVESTIGATED FURTHER IN WELL-DESIGNED CLINICAL TRIALS FOR THEIR ABILITY TO PREVENT OR DELAY THE PROGRESSIVE LOSS OF NIGRAL DA NEURONS IN GENETICALLY SUSCEPTIBLE POPULATIONS. 2007 6 5541 27 ROLE OF DIETARY PHENOLS IN MITIGATING MICROGLIA-MEDIATED NEUROINFLAMMATION. CHRONIC NEUROINFLAMMATION IS A PATHOLOGICAL FEATURE OF A NUMBER OF CENTRAL NERVOUS SYSTEM (CNS) DISEASES AND IS MEDIATED BY SUSTAINED ACTIVATION OF MICROGLIAL CELLS, THE INNATE IMMUNE CELLS OF THE CNS. STUDIES HAVE MAINLY FOCUSED ON IDENTIFYING THE MOLECULAR AND EPIGENETIC MECHANISMS OF MICROGLIAL ACTIVATION. THIS IS CRUCIAL IN DESIGNING THERAPEUTIC STRATEGIES FOR NEUROPATHOLOGIES IN WHICH PROLONGED MICROGLIAL ACTIVATION IS KNOWN TO EXACERBATE DISEASE CONDITION. IN RECENT YEARS, INCREASING EVIDENCE SHOW THAT NATURALLY OCCURRING COMPOUNDS PRESENT IN REGULAR DIET COULD FUNCTION AS "NUTRACEUTICALS," ARRESTING MICROGLIAL ACTIVATION, AND THUS CONFERRING NEUROPROTECTION. THIS REVIEW SUMMARIZES OUR UNDERSTANDING OF THE ROLE OF DIETARY PHENOLIC NUTRACEUTICALS IN MITIGATING MICROGLIA-MEDIATED NEUROINFLAMMATION. STUDIES SHOW THAT THESE NATURAL PHENOLS INHIBIT KEY SIGNALING PATHWAYS IN ACTIVATED MICROGLIA SUCH AS THE NFKAPPAB, MAPK AND JAK-STAT THAT TRIGGER MICROGLIA-MEDIATED INFLAMMATION IN VARIOUS NEUROPATHOLOGICAL CONDITIONS SUCH AS INJURY, INFECTION, STROKE, AUTISM AND NEURODEGENERATIVE DISEASES, I.E., ALZHEIMER'S DISEASE AND PARKINSON'S DISEASE. THE ANTI-INFLAMMATORY AND ANTIOXIDANT EFFECT EXERTED BY THESE NATURAL PHENOLS HAVE SHOWN CONSIDERABLE SUCCESS IN IMPROVING DISEASE CONDITION IN ANIMAL MODELS OF NEUROPATHOLOGIES, AND THUS SEEM TO BE SUITABLE CANDIDATES FOR DEVELOPING THERAPEUTIC STRATEGIES. 2016 7 6425 23 THE TRANSCRIPTION FACTOR REST UP-REGULATES TYROSINE HYDROXYLASE AND ANTIAPOPTOTIC GENES AND PROTECTS DOPAMINERGIC NEURONS AGAINST MANGANESE TOXICITY. DOPAMINERGIC FUNCTIONS ARE IMPORTANT FOR VARIOUS BIOLOGICAL ACTIVITIES, AND THEIR IMPAIRMENT LEADS TO NEURODEGENERATION, A HALLMARK OF PARKINSON'S DISEASE (PD). CHRONIC MANGANESE (MN) EXPOSURE CAUSES THE NEUROLOGICAL DISORDER MANGANISM, PRESENTING SYMPTOMS SIMILAR TO THOSE OF PD. EMERGING EVIDENCE HAS LINKED THE TRANSCRIPTION FACTOR RE1-SILENCING TRANSCRIPTION FACTOR (REST) TO PD AND ALSO ALZHEIMER'S DISEASE. BUT REST'S ROLE IN DOPAMINERGIC NEURONS IS UNCLEAR. HERE, WE INVESTIGATED WHETHER REST PROTECTS DOPAMINERGIC NEURONS AGAINST MN-INDUCED TOXICITY AND ENHANCES EXPRESSION OF THE DOPAMINE-SYNTHESIZING ENZYME TYROSINE HYDROXYLASE (TH). WE REPORT THAT REST BINDS TO RE1 CONSENSUS SITES IN THE TH GENE PROMOTER, STIMULATES TH TRANSCRIPTION, AND INCREASES TH MRNA AND PROTEIN LEVELS IN DOPAMINERGIC CELLS. REST BINDING TO THE TH PROMOTER RECRUITED THE EPIGENETIC MODIFIER CAMP-RESPONSE ELEMENT-BINDING PROTEIN-BINDING PROTEIN/P300 AND THEREBY UP-REGULATED TH EXPRESSION. REST RELIEVED MN-INDUCED REPRESSION OF TH PROMOTER ACTIVITY, MRNA, AND PROTEIN LEVELS AND ALSO REDUCED MN-INDUCED OXIDATIVE STRESS, INFLAMMATION, AND APOPTOSIS IN DOPAMINERGIC NEURONS. REST REDUCED MN-INDUCED PROINFLAMMATORY CYTOKINES, INCLUDING TUMOR NECROSIS FACTOR ALPHA, INTERLEUKIN 1BETA (IL-1BETA), IL-6, AND INTERFERON GAMMA. MOREOVER, REST INHIBITED THE MN-INDUCED PROAPOPTOTIC PROTEINS BCL-2-ASSOCIATED X PROTEIN (BAX) AND DEATH-ASSOCIATED PROTEIN 6 (DAXX) AND ATTENUATED AN MN-INDUCED DECREASE IN THE ANTIAPOPTOTIC PROTEINS BCL-2 AND BCL-XL. REST ALSO ENHANCED THE EXPRESSION OF ANTIOXIDANT PROTEINS, INCLUDING CATALASE, NF-E2-RELATED FACTOR 2 (NRF2), AND HEME OXYGENASE 1 (HO-1). OUR FINDINGS INDICATE THAT REST ACTIVATES TH EXPRESSION AND THEREBY PROTECTS NEURONS AGAINST MN-INDUCED TOXICITY AND NEUROLOGICAL DISORDERS ASSOCIATED WITH DOPAMINERGIC NEURODEGENERATION. 2020 8 5143 20 POTENTIAL ROLE OF EPIGENETIC MECHANISM IN MANGANESE INDUCED NEUROTOXICITY. MANGANESE IS A VITAL NUTRIENT AND IS MAINTAINED AT AN OPTIMAL LEVEL (2.5-5 MG/DAY) IN HUMAN BODY. CHRONIC EXPOSURE TO MANGANESE IS ASSOCIATED WITH NEUROTOXICITY AND CORRELATED WITH THE DEVELOPMENT OF VARIOUS NEUROLOGICAL DISORDERS SUCH AS PARKINSON'S DISEASE. OXIDATIVE STRESS MEDIATED APOPTOTIC CELL DEATH HAS BEEN WELL ESTABLISHED MECHANISM IN MANGANESE INDUCED TOXICITY. OXIDATIVE STRESS HAS A POTENTIAL TO ALTER THE EPIGENETIC MECHANISM OF GENE REGULATION. EPIGENETIC INSIGHT OF MANGANESE NEUROTOXICITY IN CONTEXT OF ITS CORRELATION WITH THE DEVELOPMENT OF PARKINSONISM IS POORLY UNDERSTOOD. PARKINSON'S DISEASE IS CHARACTERIZED BY THE ALPHA-SYNUCLEIN AGGREGATION IN THE FORM OF LEWY BODIES IN NEURONAL CELLS. RECENT FINDINGS ILLUSTRATE THAT MANGANESE CAN CAUSE OVEREXPRESSION OF ALPHA-SYNUCLEIN. ALPHA-SYNUCLEIN ACTS EPIGENETICALLY VIA INTERACTION WITH HISTONE PROTEINS IN REGULATING APOPTOSIS. ALPHA-SYNUCLEIN ALSO CAUSES GLOBAL DNA HYPOMETHYLATION THROUGH SEQUESTRATION OF DNA METHYLTRANSFERASE IN CYTOPLASM. AN INDIVIDUAL GENETIC DIFFERENCE MAY ALSO HAVE AN INFLUENCE ON EPIGENETIC SUSCEPTIBILITY TO MANGANESE NEUROTOXICITY AND THE DEVELOPMENT OF PARKINSON'S DISEASE. THIS REVIEW PRESENTS THE CURRENT STATE OF FINDINGS IN RELATION TO ROLE OF EPIGENETIC MECHANISM IN MANGANESE INDUCED NEUROTOXICITY, WITH A SPECIAL EMPHASIS ON THE DEVELOPMENT OF PARKINSON'S DISEASE. 2016 9 4130 19 MECHANISMS OF FERROPTOSIS AND EMERGING LINKS TO THE PATHOLOGY OF NEURODEGENERATIVE DISEASES. NEURODEGENERATIVE DISEASES ARE A DIVERSE CLASS OF DISEASES ATTRIBUTED TO CHRONIC PROGRESSIVE NEURONAL DEGENERATION AND SYNAPTIC LOSS IN THE BRAIN AND/OR SPINAL CORD, INCLUDING ALZHEIMER'S DISEASE, PARKINSON'S DISEASE, HUNTINGTON'S DISEASE, AMYOTROPHIC LATERAL SCLEROSIS AND MULTIPLE SCLEROSIS. THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES IS COMPLEX AND DIVERSE, OFTEN INVOLVING MITOCHONDRIAL DYSFUNCTION, NEUROINFLAMMATION, AND EPIGENETIC CHANGES. HOWEVER, THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES HAS NOT BEEN FULLY ELUCIDATED. RECENTLY, ACCUMULATING EVIDENCE REVEALED THAT FERROPTOSIS, A NEWLY DISCOVERED IRON-DEPENDENT AND LIPID PEROXIDATION-DRIVEN TYPE OF PROGRAMMED CELL DEATH, PROVIDES ANOTHER EXPLANATION FOR THE OCCURRENCE AND PROGRESSION OF NEURODEGENERATIVE DISEASES. HERE, WE PROVIDE AN OVERVIEW OF THE PROCESS AND REGULATION MECHANISMS OF FERROPTOSIS, AND SUMMARIZE CURRENT RESEARCH PROGRESSES THAT SUPPORT THE CONTRIBUTION OF FERROPTOSIS TO THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES. A COMPREHENSIVE UNDERSTANDING OF THE EMERGING ROLES OF FERROPTOSIS IN NEURODEGENERATIVE DISEASES WILL SHED LIGHT ON THE DEVELOPMENT OF NOVEL THERAPEUTIC TECHNOLOGIES AND STRATEGIES FOR SLOWING DOWN THE PROGRESSION OF THESE DISEASES. 2022 10 6904 17 [THE ROLE OF ALUMINUM AND LEAD IN THE DEVELOPMENT OF ALZHEIMER'S AND PARKINSON'S DISEASES]. THE ARTICLE SUMMARIZES THE DATA AVAILABLE IN THE LITERATURE ON THE TOXIC EFFECTS OF ALUMINUM AND LEAD ON THE HUMAN BRAIN AND ASSESSES THE RELATIONSHIP OF THESE EFFECTS TO THE ETIOPATHOGENESIS OF THE MOST COMMON NEURODEGENERATIVE DISEASES, SUCH AS ALZHEIMER'S AND PARKINSON'S DISEASES. THE ACCUMULATION OF IONS OF THESE METALS IN THE BRAIN STRUCTURES LEADS TO CHRONIC INTOXICATION THAT IS MANIFESTED BY THE MORPHOLOGICAL SIGNS THAT ARE TYPICAL FOR ALZHEIMER'S DISEASE, SUCH AS DEPOSITS OF BETA-AMYLOID AND TAU-PROTEIN MAINLY IN THE FRONTAL AND TEMPORAL REGIONS OF THE CORTEX, AND FOR PARKINSON'S DISEASE, SUCH AS DEGENERATION OF DOPAMINE NEURONS IN THE SUBSTANTIA NIGRA AND THEIR ACCUMULATION OF ALPHA-SYNUCLEIN. THE MOST LIKELY FORMS OF PARTICIPATION OF ALUMINUM AND LEAD IONS IN THE MECHANISMS OF NEURODEGENERATION ARE THE REPLACEMENT OF BIVALENT METAL IONS NECESSARY FOR BRAIN FUNCTIONING, OXIDATIVE STRESS INITIATION, EPIGENETIC MODIFICATIONS OF HISTONES, AND INCREASED EXPRESSION OF NONCODING RIBONUCLEIC ACIDS. 2021 11 4136 22 MECHANISMS OF MANGANESE-INDUCED NEUROTOXICITY AND THE PURSUIT OF NEUROTHERAPEUTIC STRATEGIES. CHRONIC EXPOSURE TO ELEVATED LEVELS OF MANGANESE VIA OCCUPATIONAL OR ENVIRONMENTAL SETTINGS CAUSES A NEUROLOGICAL DISORDER KNOWN AS MANGANISM, RESEMBLING THE SYMPTOMS OF PARKINSON'S DISEASE, SUCH AS MOTOR DEFICITS AND COGNITIVE IMPAIRMENT. NUMEROUS STUDIES HAVE BEEN CONDUCTED TO CHARACTERIZE MANGANESE'S NEUROTOXICITY MECHANISMS IN SEARCH OF EFFECTIVE THERAPEUTICS, INCLUDING NATURAL AND SYNTHETIC COMPOUNDS TO TREAT MANGANESE TOXICITY. SEVERAL POTENTIAL MOLECULAR TARGETS OF MANGANESE TOXICITY AT THE EPIGENETIC AND TRANSCRIPTIONAL LEVELS HAVE BEEN IDENTIFIED RECENTLY, WHICH MAY CONTRIBUTE TO DEVELOP MORE PRECISE AND EFFECTIVE GENE THERAPIES. THIS REVIEW UPDATES FINDINGS ON MANGANESE-INDUCED NEUROTOXICITY MECHANISMS ON INTRACELLULAR INSULTS SUCH AS OXIDATIVE STRESS, INFLAMMATION, EXCITOTOXICITY, AND MITOPHAGY, AS WELL AS TRANSCRIPTIONAL DYSREGULATIONS INVOLVING YIN YANG 1, RE1-SILENCING TRANSCRIPTION FACTOR, TRANSCRIPTION FACTOR EB, AND NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR 2 THAT COULD BE TARGETS OF MANGANESE NEUROTOXICITY THERAPIES. THIS REVIEW ALSO FEATURES INTRACELLULAR PROTEINS SUCH AS PTEN-INDUCIBLE KINASE 1, PARKIN, SIRTUINS, LEUCINE-RICH REPEAT KINASE 2, AND ALPHA-SYNUCLEIN, WHICH ARE ASSOCIATED WITH MANGANESE-INDUCED DYSREGULATION OF AUTOPHAGY/MITOPHAGY. IN ADDITION, NEWER THERAPEUTIC APPROACHES TO TREAT MANGANESE'S NEUROTOXICITY INCLUDING NATURAL AND SYNTHETIC COMPOUNDS MODULATING EXCITOTOXICITY, AUTOPHAGY, AND MITOPHAGY, WERE REVIEWED. TAKEN TOGETHER, IN-DEPTH MECHANISTIC KNOWLEDGE ACCOMPANIED BY ADVANCES IN GENE AND DRUG DELIVERY STRATEGIES WILL MAKE SIGNIFICANT PROGRESS IN THE DEVELOPMENT OF RELIABLE THERAPEUTIC INTERVENTIONS AGAINST MANGANESE-INDUCED NEUROTOXICITY. 2022 12 4646 16 NEUROPATHOLOGICAL MECHANISMS ASSOCIATED WITH PESTICIDES IN ALZHEIMER'S DISEASE. ENVIRONMENTAL TOXICANTS HAVE BEEN IMPLICATED IN NEURODEGENERATIVE DISEASES, AND PESTICIDE EXPOSURE IS A SUSPECTED ENVIRONMENTAL RISK FACTOR FOR ALZHEIMER'S DISEASE (AD). SEVERAL EPIDEMIOLOGICAL ANALYSES HAVE AFFIRMED A LINK BETWEEN PESTICIDES AND INCIDENCE OF SPORADIC AD. MEANWHILE, IN VITRO AND ANIMAL MODELS OF AD HAVE SHED LIGHT ON POTENTIAL NEUROPATHOLOGICAL MECHANISMS. IN THIS PAPER, A PERSPECTIVE ON NEUROPATHOLOGICAL MECHANISMS UNDERLYING PESTICIDES' INDUCTION OF AD IS PROVIDED. PROPOSED MECHANISMS RANGE FROM GENERIC OXIDATIVE STRESS INDUCTION IN NEURONS TO MORE AD-SPECIFIC PROCESSES INVOLVING AMYLOID-BETA (ABETA) AND HYPERPHOSPHORYLATED TAU (P-TAU). MECHANISMS THAT ARE MORE SPECULATIVE OR INDIRECT IN NATURE, INCLUDING SOMATIC MUTATION, EPIGENETIC MODULATION, IMPAIRMENT OF ADULT NEUROGENESIS, AND MICROBIOTA DYSBIOSIS, ARE ALSO DISCUSSED. CHRONIC TOXICITY MECHANISMS OF ENVIRONMENTAL PESTICIDE EXPOSURE CROSSTALKS IN COMPLEX WAYS AND COULD POTENTIALLY BE MUTUALLY ENHANCING, THUS MAKING THE DECIPHERING OF SIMPLISTIC CAUSAL RELATIONSHIPS DIFFICULT. 2020 13 5580 25 ROLE OF NEUROTOXICANTS IN THE PATHOGENESIS OF ALZHEIMER'S DISEASE: A MECHANISTIC INSIGHT. ALZHEIMER'S DISEASE (AD) IS THE MOST CONSPICUOUS CHRONIC NEURODEGENERATIVE SYNDROME, WHICH HAS BECOME A SIGNIFICANT CHALLENGE FOR THE GLOBAL HEALTHCARE SYSTEM. MULTIPLE STUDIES HAVE CORROBORATED A CLEAR ASSOCIATION OF NEUROTOXICANTS WITH AD PATHOGENICITY, SUCH AS AMYLOID BETA (ABETA) PROTEINS AND NEUROFIBRILLARY TANGLES (NFTS), SIGNALLING PATHWAY MODIFICATIONS, CELLULAR STRESS, COGNITIVE DYSFUNCTIONS, NEURONAL APOPTOSIS, NEUROINFLAMMATION, EPIGENETIC MODIFICATION, AND SO ON. THIS REVIEW, THEREFORE, AIMED TO ADDRESS SEVERAL ESSENTIAL MECHANISMS AND SIGNALLING CASCADES, INCLUDING WNT (WINGLESS AND INT.) SIGNALLING PATHWAY, AUTOPHAGY, MAMMALIAN TARGET OF RAPAMYCIN (MTOR), PROTEIN KINASE C (PKC) SIGNALLING CASCADES, CELLULAR REDOX STATUS, ENERGY METABOLISM, GLUTAMATERGIC NEUROTRANSMISSIONS, IMMUNE CELL STIMULATIONS (E.G. MICROGLIA, ASTROCYTES) AS WELL AS AN AMYLOID PRECURSOR PROTEIN (APP), PRESENILIN-1 (PSEN1), PRESENILIN-2 (PSEN2) AND OTHER AD-RELATED GENE EXPRESSIONS THAT HAVE BEEN PRETENTIOUS AND MODULATED BY THE VARIOUS NEUROTOXICANTS. THIS REVIEW CONCLUDED THAT NEUROTOXICANTS PLAY A MOMENTOUS ROLE IN DEVELOPING AD THROUGH MODULATING VARIOUS SIGNALLING CASCADES. NEVERTHELESS, COMPREHENSION OF THIS RISK AGENT-INDUCED NEUROTOXICITY IS FAR TOO LITTLE. MORE IN-DEPTH EPIDEMIOLOGICAL AND SYSTEMATIC INVESTIGATIONS ARE NEEDED TO UNDERSTAND THE POTENTIAL MECHANISMS BETTER TO ADDRESS THESE NEUROTOXICANTS AND IMPROVE APPROACHES TO THEIR RISK EXPOSURE THAT AID IN AD PATHOGENESIS.KEY MESSAGESINEVITABLE CASCADE MECHANISMS OF HOW ALZHEIMER'S DISEASE-RELATED (AD-RELATED) GENE EXPRESSIONS ARE MODULATED BY NEUROTOXICANTS HAVE BEEN DISCUSSED.INVOLVEMENT OF THE NEUROTOXICANTS-INDUCED PATHWAYS CAUSED AN EXTENDED RISK OF AD IS EXPLICITED.INTEGRATION OF CELL CULTURE, ANIMALS AND POPULATION-BASED ANALYSIS ON THE CLINICAL SEVERITY OF AD IS ADDRESSED. 2021 14 4682 23 NEW PATHWAYS IDENTIFY NOVEL DRUG TARGETS FOR THE PREVENTION AND TREATMENT OF ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS AN INCURABLE, PROGRESSIVE NEURODEGENERATIVE DISORDER. AD IS A COMPLEX AND MULTIFACTORIAL DISEASE THAT IS RESPONSIBLE FOR 60-80% OF DEMENTIA CASES. AGING, GENETIC FACTORS, AND EPIGENETIC CHANGES ARE THE MAIN RISK FACTORS FOR AD. TWO AGGREGATION-PRONE PROTEINS PLAY A DECISIVE ROLE IN AD PATHOGENESIS: BETA-AMYLOID (ABETA) AND HYPERPHOSPHORYLATED TAU (PTAU). BOTH OF THEM FORM DEPOSITS AND DIFFUSIBLE TOXIC AGGREGATES IN THE BRAIN. THESE PROTEINS ARE THE BIOMARKERS OF AD. DIFFERENT HYPOTHESES HAVE TRIED TO EXPLAIN AD PATHOGENESIS AND SERVED AS PLATFORMS FOR AD DRUG RESEARCH. EXPERIMENTS DEMONSTRATED THAT BOTH ABETA AND PTAU MIGHT START NEURODEGENERATIVE PROCESSES AND ARE NECESSARY FOR COGNITIVE DECLINE. THE TWO PATHOLOGIES ACT IN SYNERGY. INHIBITION OF THE FORMATION OF TOXIC ABETA AND PTAU AGGREGATES HAS BEEN AN OLD DRUG TARGET. RECENTLY, SUCCESSFUL ABETA CLEARANCE BY MONOCLONAL ANTIBODIES HAS RAISED NEW HOPES FOR AD TREATMENTS IF THE DISEASE IS DETECTED AT EARLY STAGES. MORE RECENTLY, NOVEL TARGETS, E.G., IMPROVEMENTS IN AMYLOID CLEARANCE FROM THE BRAIN, APPLICATION OF SMALL HEAT SHOCK PROTEINS (HSPS), MODULATION OF CHRONIC NEUROINFLAMMATION BY DIFFERENT RECEPTOR LIGANDS, MODULATION OF MICROGLIAL PHAGOCYTOSIS, AND INCREASE IN MYELINATION HAVE BEEN REVEALED IN AD RESEARCH. 2023 15 533 30 ASTROCYTIC TRANSCRIPTION FACTOR REST UPREGULATES GLUTAMATE TRANSPORTER EAAT2, PROTECTING DOPAMINERGIC NEURONS FROM MANGANESE-INDUCED EXCITOTOXICITY. CHRONIC EXPOSURE TO HIGH LEVELS OF MANGANESE (MN) LEADS TO MANGANISM, A NEUROLOGICAL DISORDER WITH SIMILAR SYMPTOMS TO THOSE INHERENT TO PARKINSON'S DISEASE. HOWEVER, THE UNDERLYING MECHANISMS OF THIS PATHOLOGICAL CONDITION HAVE YET TO BE ESTABLISHED. SINCE THE HUMAN EXCITATORY AMINO ACID TRANSPORTER 2 (EAAT2) (GLUTAMATE TRANSPORTER 1 IN RODENTS) IS PREDOMINANTLY EXPRESSED IN ASTROCYTES AND ITS DYSREGULATION IS INVOLVED IN MN-INDUCED EXCITOTOXIC NEURONAL INJURY, CHARACTERIZATION OF THE MECHANISMS THAT MEDIATE THE MN-INDUCED IMPAIRMENT IN EAAT2 FUNCTION IS CRUCIAL FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS AGAINST MN NEUROTOXICITY. REPRESSOR ELEMENT 1-SILENCING TRANSCRIPTION FACTOR (REST) EXERTS PROTECTIVE EFFECTS IN MANY NEURODEGENERATIVE DISEASES. BUT THE EFFECTS OF REST ON EAAT2 EXPRESSION AND ENSUING NEUROPROTECTION ARE UNKNOWN. GIVEN THAT THE EAAT2 PROMOTER CONTAINS REST BINDING SITES, THE PRESENT STUDY INVESTIGATED THE ROLE OF REST IN EAAT2 EXPRESSION AT THE TRANSCRIPTIONAL LEVEL IN ASTROCYTES AND MN-INDUCED NEUROTOXICITY IN AN ASTROCYTE-NEURON COCULTURE SYSTEM. THE RESULTS REVEAL THAT ASTROCYTIC REST POSITIVELY REGULATES EAAT2 EXPRESSION WITH THE RECRUITMENT OF AN EPIGENETIC MODIFIER, CAMP RESPONSE ELEMENT-BINDING PROTEIN-BINDING PROTEIN/P300, TO ITS CONSENSUS BINDING SITES IN THE EAAT2 PROMOTER. MOREOVER, ASTROCYTIC OVEREXPRESSION OF REST ATTENUATES MN-INDUCED REDUCTION IN EAAT2 EXPRESSION, LEADING TO ATTENUATION OF GLUTAMATE-INDUCED NEUROTOXICITY IN THE ASTROCYTE-NEURON COCULTURE SYSTEM. OUR FINDINGS DEMONSTRATE THAT ASTROCYTIC REST PLAYS A CRITICAL ROLE IN PROTECTION AGAINST MN-INDUCED NEUROTOXICITY BY ATTENUATING MN-INDUCED EAAT2 REPRESSION AND THE ENSUING EXCITOTOXIC DOPAMINERGIC NEURONAL INJURY. THIS INDICATES THAT ASTROCYTIC REST COULD BE A POTENTIAL MOLECULAR TARGET FOR THE TREATMENT OF MN TOXICITY AND OTHER NEUROLOGICAL DISORDERS ASSOCIATED WITH EAAT2 DYSREGULATION. 2021 16 2350 26 EPIGENETIC REGULATION OF NEUROINFLAMMATION IN PARKINSON'S DISEASE. NEUROINFLAMMATION IS ONE OF THE MOST SIGNIFICANT FACTORS INVOLVED IN THE INITIATION AND PROGRESSION OF PARKINSON'S DISEASE. PD IS A NEURODEGENERATIVE DISORDER WITH A MOTOR DISABILITY LINKED WITH VARIOUS COMPLEX AND DIVERSIFIED RISK FACTORS. THESE FACTORS TRIGGER MYRIADS OF CELLULAR AND MOLECULAR PROCESSES, SUCH AS MISFOLDING DEFECTIVE PROTEINS, OXIDATIVE STRESS, MITOCHONDRIAL DYSFUNCTION, AND NEUROTOXIC SUBSTANCES THAT INDUCE SELECTIVE NEURODEGENERATION OF DOPAMINE NEURONS. THIS NEURONAL DAMAGE ACTIVATES THE NEURONAL IMMUNE SYSTEM, INCLUDING GLIAL CELLS AND INFLAMMATORY CYTOKINES, TO TRIGGER NEUROINFLAMMATION. THE TRANSITION OF ACUTE TO CHRONIC NEUROINFLAMMATION ENHANCES THE SUSCEPTIBILITY OF INFLAMMATION-INDUCED DOPAMINERGIC NEURON DAMAGE, FORMING A VICIOUS CYCLE AND PROMPTING AN INDIVIDUAL TO PD DEVELOPMENT. EPIGENETIC MECHANISMS RECENTLY HAVE BEEN AT THE FOREFRONT OF THE REGULATION OF NEUROINFLAMMATORY FACTORS IN PD, PROPOSING A NEW DAWN FOR BREAKING THIS VICIOUS CYCLE. THIS REVIEW EXAMINED THE CORE EPIGENETIC MECHANISMS INVOLVED IN THE ACTIVATION AND PHENOTYPIC TRANSFORMATION OF GLIAL CELLS MEDIATED NEUROINFLAMMATION IN PD. WE FOUND THAT EPIGENETIC MECHANISMS DO NOT WORK INDEPENDENTLY, DESPITE BEING COORDINATED WITH EACH OTHER TO ACTIVATE NEUROINFLAMMATORY PATHWAYS. IN THIS REGARD, WE ATTEMPTED TO FIND THE SYNERGIC CORRELATION AND CONTRIBUTION OF THESE EPIGENETIC MODIFICATIONS WITH VARIOUS NEUROINFLAMMATORY PATHWAYS TO BROADEN THE CANVAS OF UNDERLYING PATHOLOGICAL MECHANISMS INVOLVED IN PD DEVELOPMENT. MOREOVER, THIS STUDY HIGHLIGHTED THE DUAL CHARACTERISTICS (NEUROPROTECTIVE/NEUROTOXIC) OF THESE EPIGENETIC MARKS, WHICH MAY COUNTERACT PD PATHOGENESIS AND MAKE THEM POTENTIAL CANDIDATES FOR DEVISING FUTURE PD DIAGNOSIS AND TREATMENT. 2021 17 676 19 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 18 4333 33 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 19 4969 32 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 20 4129 25 MECHANISMS OF ENDOMETRIAL PROGESTERONE RESISTANCE. THROUGHOUT THE REPRODUCTIVE YEARS, THE RISE AND FALL IN OVARIAN HORMONES ELICIT IN THE ENDOMETRIUM WAVES OF CELL PROLIFERATION, DIFFERENTIATION, RECRUITMENT OF INFLAMMATORY CELLS, APOPTOSIS, TISSUE BREAKDOWN AND REGENERATION. THE ACTIVATED PROGESTERONE RECEPTOR, A MEMBER OF THE SUPERFAMILY OF LIGAND-DEPENDENT TRANSCRIPTION FACTORS, IS THE MASTER REGULATOR OF THIS INTENSE TISSUE REMODELLING PROCESS IN THE UTERUS. ITS ACTIVITY IS TIGHTLY REGULATED BY INTERACTION WITH CELL-SPECIFIC TRANSCRIPTION FACTORS AND COREGULATORS AS WELL AS BY SPECIFIC POSTTRANSLATIONAL MODIFICATIONS THAT RESPOND DYNAMICALLY TO A VARIETY OF ENVIRONMENTAL AND INFLAMMATORY SIGNALS. ENDOMETRIOSIS, A CHRONIC INFLAMMATORY DISORDER, DISRUPTS COORDINATED PROGESTERONE RESPONSES THROUGHOUT THE REPRODUCTIVE TRACT, INCLUDING IN THE ENDOMETRIUM. THIS PHENOMENON IS INCREASINGLY REFERRED TO AS 'PROGESTERONE RESISTANCE'. EMERGING EVIDENCE SUGGESTS THAT PROGESTERONE RESISTANCE IN ENDOMETRIOSIS IS NOT JUST A CONSEQUENCE OF PERTURBED PROGESTERONE SIGNAL TRANSDUCTION CAUSED BY CHRONIC INFLAMMATION BUT ASSOCIATED WITH EPIGENETIC CHROMATIN CHANGES THAT DETERMINE THE INTRINSIC RESPONSIVENESS OF ENDOMETRIAL CELLS TO DIFFERENTIATION CUES. 2012