1 83 127 A NOVEL EPIGENETIC MARKER, TEN-ELEVEN TRANSLOCATION FAMILY MEMBER 2 (TET2), IS IDENTIFIED IN THE INTRACTABLE EPILEPTIC BRAIN AND REGULATES ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) IN THE BLOOD-BRAIN BARRIER. DRUG-RESISTANT EPILEPSY (DRE) IS A CHRONIC CONDITION DERIVED FROM SPONTANEOUS CHANGES AND REGULATORY EFFECTS IN THE EPILEPTIC BRAIN. AS DEMETHYLATION FACTORS, TEN-ELEVEN TRANSLOCATION (TET) FAMILY MEMBERS HAVE BECOME A FOCUS IN RECENT STUDIES OF NEUROLOGICAL DISORDERS. HERE, WE QUANTIFIED AND LOCALIZED TET1, TET2 AND 5-HYDROXYMETHYLCYTOSINE (5-HMC) IN THE TEMPORAL LOBE CORTEX OF DRE PATIENTS (N = 27) AND TRAUMATIC BRAIN HEMORRHAGE CONTROLS (N = 10) BY IMMUNOCHEMICAL STAINING. TET2 AND ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) EXPRESSION PATTERNS WERE DETERMINED IN THE ISOLATED BRAIN CAPILLARIES OF DRE PATIENTS. TET2 EXPRESSION WAS SIGNIFICANTLY INCREASED IN THE TEMPORAL CORTICAL TISSUE OF DRE PATIENTS WITH OR WITHOUT HIPPOCAMPAL SCLEROSIS (HS) COMPARED TO CONTROL PATIENTS, WHILE TET1 AND 5-HMC SHOWED NO DIFFERENCES IN EXPRESSION. WE ALSO FOUND THAT A PARTICULARLY STRONG EXPRESSION OF TET2 IN THE VASCULAR TISSUE OF DRE PATIENTS. ABCB1 AND TET2 HAVE EVIDENTLY HIGHER EXPRESSION IN THE VASCULAR ENDOTHELIUM FROM THE NEOCORTEX OF DRE PATIENTS. IN BLOOD-BRAIN BARRIER (BBB) MODEL, TET2 DEPLETION CAN CAUSE ATTENUATED EXPRESSION AND FUNCTION OF ABCB1. DATA FROM A COHORT STUDY AND EXPERIMENTS IN A BBB MODEL SUGGEST THAT TET2 HAS A SPECIFIC REGULATORY EFFECT ON ABCB1, WHICH MAY SERVE AS A POTENTIAL MECHANISM AND TARGET IN DRE. 2022 2 1301 31 DEEP SEQUENCING REVEALS INCREASED DNA METHYLATION IN CHRONIC RAT EPILEPSY. EPILEPSY IS A FREQUENT NEUROLOGICAL DISORDER, ALTHOUGH ONSET AND PROGRESSION OF SEIZURES REMAIN DIFFICULT TO PREDICT IN AFFECTED PATIENTS, IRRESPECTIVE OF THEIR EPILEPTOGENIC CONDITION. PREVIOUS STUDIES IN ANIMAL MODELS AS WELL AS HUMAN EPILEPTIC BRAIN TISSUE REVEALED A REMARKABLY DIVERSE PATTERN OF GENE EXPRESSION IMPLICATING EPIGENETIC CHANGES TO CONTRIBUTE TO DISEASE PROGRESSION. HERE WE MAPPED FOR THE FIRST TIME GLOBAL DNA METHYLATION PATTERNS IN CHRONIC EPILEPTIC RATS AND CONTROLS. USING METHYL-CPG CAPTURE ASSOCIATED WITH MASSIVE PARALLEL SEQUENCING (METHYL-SEQ) WE REPORT THE GENOMIC METHYLATION SIGNATURE OF THE CHRONIC EPILEPTIC STATE. WE OBSERVED A PREDOMINANT INCREASE, RATHER THAN LOSS OF DNA METHYLATION IN CHRONIC RAT EPILEPSY. ABERRANT METHYLATION PATTERNS WERE INVERSELY CORRELATED WITH GENE EXPRESSION CHANGES USING MRNA SEQUENCING FROM SAME ANIMALS AND TISSUE SPECIMENS. ADMINISTRATION OF A KETOGENIC, HIGH-FAT, LOW-CARBOHYDRATE DIET ATTENUATED SEIZURE PROGRESSION AND AMELIORATED DNA METHYLATION MEDIATED CHANGES IN GENE EXPRESSION. THIS IS THE FIRST REPORT OF UNSUPERVISED CLUSTERING OF AN EPIGENETIC MARK BEING USED IN EPILEPSY RESEARCH TO SEPARATE EPILEPTIC FROM NON-EPILEPTIC ANIMALS AS WELL AS FROM ANIMALS RECEIVING ANTI-CONVULSIVE DIETARY TREATMENT. WE FURTHER DISCUSS THE POTENTIAL IMPACT OF EPIGENETIC CHANGES AS A PATHOGENIC MECHANISM OF EPILEPTOGENESIS. 2013 3 2111 35 EPIGENETIC FUNCTION OF TET FAMILY, 5-METHYLCYTOSINE, AND 5-HYDROXYMETHYLCYTOSINE IN HEMATOLOGIC MALIGNANCIES. DNA METHYLATION PLAYS SIGNIFICANT ROLES IN A VARIETY OF BIOLOGICAL AND PATHOLOGICAL PROCESSES INCLUDING MAMMALIAN DEVELOPMENT, GENOMIC IMPRINTING, RETROTRANSPOSON SILENCING, AND X-CHROMOSOME INACTIVATION. RECENT DISCOVERIES INDICATED THAT TEN-ELEVEN TRANSLOCATION (TET) FAMILY OF DIOXYGENASES CAN CONVERT 5-METHYLCYTOSINE (5-MC) INTO 5-HYDROXYMETHYLCYTOSINE (5-HMC). THE TET FAMILY INCLUDES THREE MEMBERS: TET1, TET2, AND TET3. WITH INCREASING EVIDENCE, MORE AND MORE BIOLOGICAL AND PATHOLOGICAL PROCESSES IN WHICH 5-HMC AND TET FAMILY SERVE UNPARALLELED BIOLOGICAL ROLES ARE NOTICED, FOR EXAMPLE, DNA DEMETHYLATION AND TRANSCRIPTIONAL REGULATION OF DIFFERENT TARGET GENES, WHICH ARE INVOLVED IN MANY HUMAN DISEASES, ESPECIALLY HEMATOLOGIC MALIGNANCIES, RESEMBLING CHRONIC MYELOMONOCYTIC LEUKEMIA, MYELODYSPLASTIC SYNDROMES, AND SO ON. IN THIS REVIEW, WE FOCUS ON THE DIVERSE FUNCTIONS OF TET FAMILY AND THE NOVEL EPIGENETIC MARKS, 5-MC AND 5-HMC, IN HEMATOLOGIC MALIGNANCIES. THIS REVIEW WILL PROVIDE VALUABLE INSIGHTS INTO THE POTENTIAL TARGETS OF HEMATOLOGIC MALIGNANCIES. FURTHER UNDERSTANDING OF THE NORMAL AND PATHOLOGICAL FUNCTIONS OF TET FAMILY MAY PROVIDE NEW METHODS TO DEVELOP NOVEL EPIGENETIC THERAPIES FOR TREATING HEMATOLOGIC MALIGNANCIES. 2019 4 4879 21 OVERLAPPING SIGNATURES OF CHRONIC PAIN IN THE DNA METHYLATION LANDSCAPE OF PREFRONTAL CORTEX AND PERIPHERAL T CELLS. WE TESTED THE HYPOTHESIS THAT EPIGENETIC MECHANISMS IN THE BRAIN AND THE IMMUNE SYSTEM ARE ASSOCIATED WITH CHRONIC PAIN. GENOME-WIDE DNA METHYLATION ASSESSED IN 9 MONTHS POST NERVE-INJURY (SNI) AND SHAM RATS, IN THE PREFRONTAL CORTEX (PFC) AS WELL AS IN T CELLS REVEALED A VAST DIFFERENCE IN THE DNA METHYLATION LANDSCAPE IN THE BRAIN BETWEEN THE GROUPS AND A REMARKABLE OVERLAP (72%) BETWEEN DIFFERENTIALLY METHYLATED PROBES IN T CELLS AND PREFRONTAL CORTEX. DNA METHYLATION STATES IN THE PFC SHOWED ROBUST CORRELATION WITH PAIN SCORE OF ANIMALS IN SEVERAL GENES INVOLVED IN PAIN. FINALLY, ONLY 11 DIFFERENTIALLY METHYLATED PROBES IN T CELLS WERE SUFFICIENT TO DISTINGUISH SNI OR SHAM INDIVIDUAL RATS. THIS STUDY SUPPORTS THE PLAUSIBILITY OF DNA METHYLATION INVOLVEMENT IN CHRONIC PAIN AND DEMONSTRATES THE POTENTIAL FEASIBILITY OF DNA METHYLATION MARKERS IN T CELLS AS NONINVASIVE BIOMARKERS OF CHRONIC PAIN SUSCEPTIBILITY. 2016 5 808 29 CHANGED HISTONE ACETYLATION PATTERNS IN NORMAL-APPEARING WHITE MATTER AND EARLY MULTIPLE SCLEROSIS LESIONS. THE EPIGENETIC IDENTITY OF OLIGODENDROCYTES IS MODULATED BY POSTTRANSLATIONAL MODIFICATIONS OF HISTONES. ACETYLATION OF HISTONE H3 RESULTS FROM THE BALANCE BETWEEN THE ACTIVITY OF HISTONE ACETYLTRANSFERASES (HATS) AND HISTONE DEACETYLASES AND MODULATES TRANSCRIPTIONAL ACTIVATION. WE HAVE PREVIOUSLY SHOWN THAT, IN RODENTS, HISTONE DEACETYLATION FAVORS OLIGODENDROCYTE DIFFERENTIATION, WHEREAS ACETYLATION IS ASSOCIATED WITH INCREASED LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION. HERE, WE REPORT, IN HUMANS BRAINS, A SHIFT TOWARD HISTONE ACETYLATION IN THE WHITE MATTER OF THE FRONTAL LOBES OF AGED SUBJECTS AND IN PATIENTS WITH CHRONIC MULTIPLE SCLEROSIS (MS). INCREASED IMMUNOREACTIVITY FOR ACETYLATED HISTONE H3 WAS OBSERVED IN THE NUCLEI OF NOGOA+ OLIGODENDROCYTES IN A SUBSET OF MS SAMPLES. THESE CHANGES WERE ASSOCIATED WITH HIGH LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION (I.E., TCF7L2, ID2, AND SOX2) AND HIGHER HAT TRANSCRIPT LEVELS (I.E., CBP, P300) IN FEMALE MS PATIENTS COMPARED WITH NON-NEUROLOGICAL CONTROLS AND CORRELATED WITH DISEASE DURATION. CHROMATIN IMMUNOPRECIPITATION FROM SAMPLES OF MS PATIENTS REVEALED ENRICHMENT OF ACETYL-HISTONE H3 AT THE PROMOTER OF THE INCREASED TARGET GENES (I.E., TCF7L2). THE DATA IN CHRONIC LESIONS CONTRASTED WITH FINDINGS IN EARLY MS LESIONS, WHERE A MARKED OLIGODENDROGLIAL HISTONE DEACETYLATION WAS OBSERVED. TOGETHER, THESE DATA SUGGEST THAT HISTONE DEACETYLATION IS A PROCESS THAT OCCURS AT THE EARLY STAGES OF THE DISEASE AND WHOSE EFFICIENCY DECREASES WITH DISEASE DURATION. 2011 6 1794 38 EFFECT OF DIABETES STATUS AND HYPERGLYCEMIA ON GLOBAL DNA METHYLATION AND HYDROXYMETHYLATION. TYPE 2 DIABETES MELLITUS (T2DM) IS CHARACTERIZED BY OXIDATIVE STRESS THAT COULD LEAD TO CHRONIC MICRO- AND MACROVASCULAR COMPLICATIONS. WE HYPOTHESIZED THAT SOME OF THE TARGET ORGAN DAMAGE IS MEDIATED BY OXIDATIVE ALTERATIONS IN EPIGENETIC MECHANISMS INVOLVING DNA METHYLATION (5MC) AND DNA HYDROXYMETHYLATION (5HMC). WE ANALYZED GLOBAL DNA METHYLATION AND HYDROXYMETHYLATION IN PERIPHERAL BLOOD CELLS IN WELL-CONTROLLED AND POORLY CONTROLLED PATIENTS WITH T2DM AND COMPARED THEM WITH HEALTHY CONTROLS. WE ALSO ANALYZED MICROARRAYS OF DNA METHYLATION AND GENE EXPRESSION OF OTHER IMPORTANT TISSUES IN THE CONTEXT OF DIABETES FROM THE GEO DATABASE REPOSITORY AND THEN COMPARED THESE RESULTS WITH OUR EXPERIMENTAL GENE EXPRESSION DATA. DNA METHYLATION AND, MORE IMPORTANTLY, DNA HYDROXYMETHYLATION LEVELS WERE INCREASED IN POORLY CONTROLLED PATIENTS COMPARED TO WELL-CONTROLLED AND HEALTHY INDIVIDUALS. BOTH 5MC AND 5HMC MEASUREMENTS WERE CORRELATED WITH THE PERCENTAGE OF GLYCATED HEMOGLOBIN, INDICATING A DIRECT IMPACT OF HYPERGLYCEMIA ON CHANGES OVER THE EPIGENOME. THE ANALYSIS OF METHYLATION MICROARRAYS WAS CONCORDANT, AND 5MC LEVELS WERE INCREASED IN THE PERIPHERAL BLOOD OF T2DM PATIENTS. HOWEVER, THE DNA METHYLATION LEVELS WERE THE OPPOSITE OF THOSE IN OTHER TISSUES, SUCH AS THE PANCREAS, ADIPOSE TISSUE AND SKELETAL MUSCLE. WE HYPOTHESIZE THAT A PROCESS OF DNA OXIDATION ASSOCIATED WITH HYPERGLYCEMIA MAY EXPLAIN THE DNA DEMETHYLATION IN WHICH THE ACTIVITY OF TEN-ELEVEN TRANSLOCATION (TET) PROTEINS IS NOT SUFFICIENT TO COMPLETE THE PROCESS. HIGH LEVELS OF GLUCOSE LEAD TO CELLULAR OXIDATION, WHICH TRIGGERS THE PROCESS OF DNA DEMETHYLATION AIDED BY TET ENZYMES, RESULTING IN EPIGENETIC DYSREGULATION OF THE DAMAGED TISSUES. 2017 7 531 38 ASTROCYTE REACTIVITY FOLLOWING BLAST EXPOSURE INVOLVES ABERRANT HISTONE ACETYLATION. BLAST INDUCED NEUROTRAUMA (BINT) IS A PREVALENT INJURY WITHIN MILITARY AND CIVILIAN POPULATIONS. THE INJURY IS CHARACTERIZED BY PERSISTENT INFLAMMATION AT THE CELLULAR LEVEL WHICH MANIFESTS AS A MULTITUDE OF COGNITIVE AND FUNCTIONAL IMPAIRMENTS. EPIGENETIC REGULATION OF TRANSCRIPTION OFFERS AN IMPORTANT CONTROL MECHANISM FOR GENE EXPRESSION AND CELLULAR FUNCTION WHICH MAY UNDERLIE CHRONIC INFLAMMATION AND RESULT IN NEURODEGENERATION. WE HYPOTHESIZE THAT ALTERED HISTONE ACETYLATION PATTERNS MAY BE INVOLVED IN BLAST INDUCED INFLAMMATION AND THE CHRONIC ACTIVATION OF GLIAL CELLS. THIS STUDY AIMED TO ELUCIDATE CHANGES TO HISTONE ACETYLATION OCCURRING FOLLOWING INJURY AND THE ROLES THESE CHANGES MAY HAVE WITHIN THE PATHOLOGY. SPRAGUE DAWLEY RATS WERE SUBJECTED TO EITHER A 10 OR 17 PSI BLAST OVERPRESSURE WITHIN AN ADVANCED BLAST SIMULATOR (ABS). SHAM ANIMALS UNDERWENT THE SAME PROCEDURES WITHOUT BLAST EXPOSURE. MEMORY IMPAIRMENTS WERE MEASURED USING THE NOVEL OBJECT RECOGNITION (NOR) TEST AT 2 AND 7 DAYS POST-INJURY. TISSUES WERE COLLECTED AT 7 DAYS FOR WESTERN BLOT AND IMMUNOHISTOCHEMISTRY (IHC) ANALYSIS. SHAM ANIMALS SHOWED INTACT MEMORY AT EACH TIME POINT. THE NOVEL OBJECT DISCRIMINATION DECREASED SIGNIFICANTLY BETWEEN TWO AND 7 DAYS FOR EACH INJURY GROUP (P < 0.05). THIS IS INDICATIVE OF THE ONSET OF MEMORY IMPAIRMENT. WESTERN BLOT ANALYSIS SHOWED GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP), A KNOWN MARKER OF ACTIVATED ASTROCYTES, WAS ELEVATED IN THE PREFRONTAL CORTEX (PFC) FOLLOWING BLAST EXPOSURE FOR BOTH INJURY GROUPS. ANALYSIS OF HISTONE PROTEIN EXTRACT SHOWED NO CHANGES IN THE LEVEL OF ANY TOTAL HISTONE PROTEINS WITHIN THE PFC. HOWEVER, ACETYLATION LEVELS OF HISTONE H2B, H3, AND H4 WERE DECREASED IN BOTH GROUPS (P < 0.05). CO-LOCALIZATION IMMUNOFLUORESCENCE WAS USED TO FURTHER INVESTIGATE ANY POTENTIAL CORRELATION BETWEEN DECREASED HISTONE ACETYLATION AND ASTROCYTE ACTIVATION. THESE EXPERIMENTS SHOWED A SIMILAR DECREASE IN H3 ACETYLATION IN ASTROCYTES EXPOSED TO A 17 PSI BLAST BUT NOT A 10 PSI BLAST. FURTHER INVESTIGATION OF GENE EXPRESSION BY POLYMERASE CHAIN REACTION (PCR) ARRAY, SHOWED DYSREGULATION OF SEVERAL CYTOKINE AND CYTOKINE RECEPTORS THAT ARE INVOLVED IN NEUROINFLAMMATORY PROCESSES. WE HAVE SHOWN ABERRANT HISTONE ACETYLATION PATTERNS INVOLVED IN BLAST INDUCED ASTROGLIOSIS AND COGNITIVE IMPAIRMENTS. FURTHER UNDERSTANDING OF THEIR ROLE IN THE INJURY PROGRESSION MAY LEAD TO NOVEL THERAPEUTIC TARGETS. 2016 8 22 24 5-HYDROXYMETHYLCYTOSINE AS A CLINICAL BIOMARKER: FLUORESCENCE-BASED ASSAY FOR HIGH-THROUGHPUT EPIGENETIC QUANTIFICATION IN HUMAN TISSUES. EPIGENETIC TRANSFORMATIONS MAY PROVIDE EARLY INDICATORS FOR CANCER AND OTHER DISEASE. SPECIFICALLY, THE AMOUNT OF GENOMIC 5-HYDROXYMETHYLCYTOSINE (5-HMC) WAS SHOWN TO BE GLOBALLY REDUCED IN A WIDE RANGE OF CANCERS. THE INTEGRATION OF THIS GLOBAL BIOMARKER INTO DIAGNOSTIC WORKFLOWS IS HAMPERED BY THE LIMITATIONS OF CURRENT 5-HMC QUANTIFICATION METHODS. HERE WE PRESENT AND VALIDATE A FLUORESCENCE-BASED PLATFORM FOR HIGH-THROUGHPUT AND COST-EFFECTIVE QUANTIFICATION OF GLOBAL GENOMIC 5-HMC LEVELS. WE UTILIZED THE ASSAY TO CHARACTERIZE CANCEROUS TISSUES BASED ON THEIR 5-HMC CONTENT, AND OBSERVED A PRONOUNCED REDUCTION IN 5-HMC LEVEL IN VARIOUS CANCER TYPES. WE PRESENT DATA FOR GLIOBLASTOMA, COLORECTAL CANCER, MULTIPLE MYELOMA, CHRONIC LYMPHOCYTIC LEUKEMIA AND PANCREATIC CANCER, COMPARED TO CORRESPONDING CONTROLS. POTENTIALLY, THE TECHNIQUE COULD ALSO BE USED TO FOLLOW RESPONSE TO TREATMENT FOR PERSONALIZED TREATMENT SELECTION. WE PRESENT INITIAL PROOF-OF-CONCEPT DATA FOR TREATMENT OF FAMILIAL ADENOMATOUS POLYPOSIS. 2020 9 5617 44 SARCOSINE SUPPRESSES EPILEPTOGENESIS IN RATS WITH EFFECTS ON HIPPOCAMPAL DNA METHYLATION. EPILEPTOGENESIS IS A COMMON CONSEQUENCE OF BRAIN INSULTS, HOWEVER, THE PREVENTION OR DELAY OF THE EPILEPTOGENIC PROCESS REMAINS AN IMPORTANT UNMET MEDICAL CHALLENGE. OVEREXPRESSION OF GLYCINE TRANSPORTER 1 (GLYT1) IS PROPOSED AS A PATHOLOGICAL HALLMARK IN THE HIPPOCAMPUS OF PATIENTS WITH TEMPORAL LOBE EPILEPSY (TLE), AND WE PREVIOUSLY DEMONSTRATED IN RODENT EPILEPSY MODELS THAT AUGMENTATION OF GLYCINE SUPPRESSED CHRONIC SEIZURES AND ALTERED ACUTE SEIZURE THRESHOLDS. IN THE PRESENT STUDY WE EVALUATED THE EFFECT OF THE GLYT1 INHIBITOR, SARCOSINE (AKA N-METHYLGLYCINE), ON EPILEPTOGENESIS AND ALSO INVESTIGATED POSSIBLE MECHANISMS. WE DEVELOPED A MODIFIED RAPID KINDLING MODEL OF EPILEPTOGENESIS IN RATS COMBINED WITH SEIZURE SCORE MONITORING TO EVALUATE THE ANTIEPILEPTOGENIC EFFECT OF SARCOSINE. WE USED IMMUNOHISTOCHEMISTRY AND WESTERN BLOT ANALYSIS FOR THE EVALUATION OF GLYT1 EXPRESSION AND EPIGENETIC CHANGES OF 5-METHYLCYTOSINE (5MC) AND 5-HYDROXYMETHYLCYTOSINE (5HMC) IN THE EPILEPTOGENIC HIPPOCAMPI OF RATS, AND FURTHER EVALUATED EXPRESSION CHANGES IN ENZYMES INVOLVED IN THE REGULATION OF DNA METHYLATION, TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1), DNA-METHYLTRANSFERASE 1 (DNMT1), AND DNMT3A. OUR RESULTS DEMONSTRATED: (I) EXPERIMENTAL EVIDENCE THAT SARCOSINE (3 G/KG, I.P. DAILY) SUPPRESSED KINDLING EPILEPTOGENESIS IN RATS; (II) THE SARCOSINE-INDUCED ANTIEPILEPTOGENIC EFFECT WAS ACCOMPANIED BY A SUPPRESSED HIPPOCAMPAL GLYT1 EXPRESSION AS WELL AS A REDUCTION OF HIPPOCAMPAL 5MC LEVELS AND A CORRESPONDING INCREASE IN 5HMC; AND (III) SARCOSINE TREATMENT CAUSED DIFFERENTIAL EXPRESSION CHANGES OF TET1 AND DNMTS. TOGETHER, THESE FINDINGS SUGGEST THAT SARCOSINE HAS UNPRECEDENTED DISEASE-MODIFYING PROPERTIES IN A KINDLING MODEL OF EPILEPTOGENESIS IN RATS, WHICH WAS ASSOCIATED WITH ALTERED HIPPOCAMPAL DNA METHYLATION. THUS, MANIPULATION OF THE GLYCINE SYSTEM IS A POTENTIAL THERAPEUTIC APPROACH TO ATTENUATE THE DEVELOPMENT OF EPILEPSY. 2020 10 1425 37 DIFFERENTIAL DNA METHYLATION PROFILES OF CODING AND NON-CODING GENES DEFINE HIPPOCAMPAL SCLEROSIS IN HUMAN TEMPORAL LOBE EPILEPSY. TEMPORAL LOBE EPILEPSY IS ASSOCIATED WITH LARGE-SCALE, WIDE-RANGING CHANGES IN GENE EXPRESSION IN THE HIPPOCAMPUS. EPIGENETIC CHANGES TO DNA ARE ATTRACTIVE MECHANISMS TO EXPLAIN THE SUSTAINED HYPEREXCITABILITY OF CHRONIC EPILEPSY. HERE, THROUGH METHYLATION ANALYSIS OF ALL ANNOTATED C-PHOSPHATE-G ISLANDS AND PROMOTER REGIONS IN THE HUMAN GENOME, WE REPORT A PILOT STUDY OF THE METHYLATION PROFILES OF TEMPORAL LOBE EPILEPSY WITH OR WITHOUT HIPPOCAMPAL SCLEROSIS. FURTHERMORE, BY COMPARATIVE ANALYSIS OF EXPRESSION AND PROMOTER METHYLATION, WE IDENTIFY METHYLATION SENSITIVE NON-CODING RNA IN HUMAN TEMPORAL LOBE EPILEPSY. A TOTAL OF 146 PROTEIN-CODING GENES EXHIBITED ALTERED DNA METHYLATION IN TEMPORAL LOBE EPILEPSY HIPPOCAMPUS (N = 9) WHEN COMPARED TO CONTROL (N = 5), WITH 81.5% OF THE PROMOTERS OF THESE GENES DISPLAYING HYPERMETHYLATION. UNIQUE METHYLATION PROFILES WERE EVIDENT IN TEMPORAL LOBE EPILEPSY WITH OR WITHOUT HIPPOCAMPAL SCLEROSIS, IN ADDITION TO A COMMON METHYLATION PROFILE REGARDLESS OF PATHOLOGY GRADE. GENE ONTOLOGY TERMS ASSOCIATED WITH DEVELOPMENT, NEURON REMODELLING AND NEURON MATURATION WERE OVER-REPRESENTED IN THE METHYLATION PROFILE OF WATSON GRADE 1 SAMPLES (MILD HIPPOCAMPAL SCLEROSIS). IN ADDITION TO GENES ASSOCIATED WITH NEURONAL, NEUROTRANSMITTER/SYNAPTIC TRANSMISSION AND CELL DEATH FUNCTIONS, DIFFERENTIAL HYPERMETHYLATION OF GENES ASSOCIATED WITH TRANSCRIPTIONAL REGULATION WAS EVIDENT IN TEMPORAL LOBE EPILEPSY, BUT OVERALL FEW GENES PREVIOUSLY ASSOCIATED WITH EPILEPSY WERE AMONG THE DIFFERENTIALLY METHYLATED. FINALLY, A PANEL OF 13, METHYLATION-SENSITIVE MICRORNA WERE IDENTIFIED IN TEMPORAL LOBE EPILEPSY INCLUDING MIR27A, MIR-193A-5P (MIR193A) AND MIR-876-3P (MIR876), AND THE DIFFERENTIAL METHYLATION OF LONG NON-CODING RNA DOCUMENTED FOR THE FIRST TIME. THE PRESENT STUDY THEREFORE REPORTS SELECT, GENOME-WIDE DNA METHYLATION CHANGES IN HUMAN TEMPORAL LOBE EPILEPSY THAT MAY CONTRIBUTE TO THE MOLECULAR ARCHITECTURE OF THE EPILEPTIC BRAIN. 2015 11 6419 36 THE TET2-UPF1 COMPLEX MODULATES MRNA STABILITY UNDER STRESS CONDITIONS. INTRODUCTION: ENVIRONMENTAL STRESS PROMOTES EPIGENETIC ALTERATIONS THAT IMPACT GENE EXPRESSION AND SUBSEQUENTLY PARTICIPATE IN THE PATHOLOGICAL PROCESSES OF THE DISORDER. AMONG EPIGENETIC REGULATIONS, TEN-ELEVEN TRANSLOCATION (TET) ENZYMES OXIDIZE 5-METHYLCYTOSINE (5MC) TO 5-HYDROXYMETHYLCYTOSINE (5HMC) IN DNA AND RNA AND FUNCTION AS CRITICAL PLAYERS IN THE PATHOGENESIS OF DISEASES. OUR PREVIOUS RESULTS SHOWED THAT CHRONIC STRESS INCREASES THE EXPRESSION OF CYTOPLASMIC TET2 IN THE HIPPOCAMPUS OF MICE EXPOSED TO CHRONIC MILD STRESS (CMS). WHETHER THE CYTOPLASMIC TET2 ALTERS RNA 5HMC MODIFICATION IN CHRONIC STRESS-RELATED PROCESSES REMAINS LARGELY UNKNOWN. METHODS: TO EXPLORE THE ROLE OF CYTOPLASMIC TET2 UNDER CMS CONDITIONS, WE ESTABLISHED CMS MICE MODEL AND DETECTED THE EXPRESSION OF RNA 5HMC BY DOT BLOT. WE VERIFIED THE INTERACTION OF TET2 AND ITS INTERACTING PROTEIN BY CO-IMMUNOPRECIPITATION COMBINED WITH MASS SPECTROMETRY AND SCREENED DOWNSTREAM TARGET GENES BY CLUSTER ANALYSIS OF TET2 AND UPSTREAM FRAMESHIFT 1 (UPF1) INTERACTING RNA. THE EXPRESSION OF PROTEIN WAS DETECTED BY WESTERN BLOT AND THE EXPRESSION OF THE SCREENED TARGET GENES WAS DETECTED BY QRT-PCR. RESULTS: IN THIS STUDY, WE FOUND THAT INCREASED CYTOPLASMIC TET2 EXPRESSION UNDER CMS CONDITIONS LEADS TO INCREASE IN TOTAL RNA 5HMC MODIFICATION. TET2 INTERACTED WITH THE KEY NON-SENSE-MEDIATED MRNA DECAY (NMD) FACTOR UPF1, REGULATED THE STABILITY OF STRESS-RELATED GENES SUCH AS UNC5B MRNA, AND MIGHT THEREBY AFFECT NEURODEVELOPMENT. DISCUSSION: IN SUMMARY, THIS STUDY REVEALED THAT TET2-MEDIATED RNA 5HMC MODIFICATION IS INVOLVED IN STRESS-RELATED MRNA STABILITY REGULATION AND MAY SERVE AS A POTENTIAL THERAPEUTIC TARGET FOR CHRONIC STRESS-RELATED DISEASES SUCH AS DEPRESSION. 2023 12 5975 27 TET1 IS AN IMPORTANT TRANSCRIPTIONAL ACTIVATOR OF TNFALPHA EXPRESSION IN MACROPHAGES. ACTIVATION OF MACROPHAGES AND OVEREXPRESSION OF TNFALPHA IS ASSOCIATED WITH THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES. HOWEVER, THE MECHANISMS LEADING TO TNFALPHA OVEREXPRESSION ARE STILL UNKNOWN. 5-METHYLOCYTOSINE (5-MC) IS AN EPIGENETIC MODIFICATION THAT IS ASSOCIATED WITH SILENCED GENES. RECENT STUDIES SHOWED THAT IT IS CONVERTED TO 5-HYDROXYLMETHYLOCYTOSINE (5-HMC) AND REACTIVATES GENE EXPRESSION THROUGH THE ACTION OF THE FAMILY OF TEN-ELEVEN-TRANSLOCATION (TET1-3) ENZYMES. IN THIS STUDY, WE SHOW THAT 5-HMC LEVELS ARE INCREASED GLOBALLY AND SPECIFICALLY IN THE TNFALPHA PROMOTER DURING THE DIFFERENTIATION OF MONOCYTES TO MACROPHAGES. IN ADDITION, THE LEVELS OF 5-HMC ARE INCREASED UPON LPS STIMULATION OF MACROPHAGES. FURTHERMORE, CRIPSR STABLE KNOCKOUT OF TET1 DECREASES THE EXPRESSION OF TNFALPHA AND OTHER PRO-INFLAMMATORY CYTOKINES. IN CONCLUSION, WE SHOWED THAT TET1 CONTRIBUTES TO THE ACTIVATION OF MACROPHAGES POSSIBLY THROUGH REGULATION OF 5-HYDROXYMETHYLATION IN THE PROMOTER OF PRO-INFLAMMATORY CYTOKINE GENES. THE TET1 ENZYME COULD BE A PROMISING THERAPEUTIC TARGET TO INHIBIT THE PERSISTENT INFLAMMATION CAUSED BY MACROPHAGES IN CHRONIC INFLAMMATORY DISEASES. 2019 13 3135 29 GLOBAL DNA METHYLATION AND HYDROXYMETHYLATION LEVELS IN PBMCS ARE ALTERED IN RRMS PATIENTS TREATED WITH IFN-BETA AND GA-A PRELIMINARY STUDY. MULTIPLE SCLEROSIS (MS) IS A CHRONIC DISEASE AFFECTING THE CENTRAL NERVOUS SYSTEM (CNS) DUE TO AN AUTOIMMUNE ATTACK ON AXONAL MYELIN SHEATHS. EPIGENETICS IS AN OPEN RESEARCH TOPIC ON MS, WHICH HAS BEEN INVESTIGATED IN SEARCH OF BIOMARKERS AND TREATMENT TARGETS FOR THIS HETEROGENEOUS DISEASE. IN THIS STUDY, WE QUANTIFIED GLOBAL LEVELS OF EPIGENETIC MARKS USING AN ELISA-LIKE APPROACH IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM 52 PATIENTS WITH MS, TREATED WITH INTERFERON BETA (IFN-BETA) AND GLATIRAMER ACETATE (GA) OR UNTREATED, AND 30 HEALTHY CONTROLS. WE PERFORMED MEDIA COMPARISONS AND CORRELATION ANALYSES OF THESE EPIGENETIC MARKERS WITH CLINICAL VARIABLES IN SUBGROUPS OF PATIENTS AND CONTROLS. WE OBSERVED THAT DNA METHYLATION (5-MC) DECREASED IN TREATED PATIENTS COMPARED WITH UNTREATED AND HEALTHY CONTROLS. MOREOVER, 5-MC AND HYDROXYMETHYLATION (5-HMC) CORRELATED WITH CLINICAL VARIABLES. IN CONTRAST, HISTONE H3 AND H4 ACETYLATION DID NOT CORRELATE WITH THE DISEASE VARIABLES CONSIDERED. GLOBALLY QUANTIFIED EPIGENETIC DNA MARKS 5-MC AND 5-HMC CORRELATE WITH DISEASE AND WERE ALTERED WITH TREATMENT. HOWEVER, TO DATE, NO BIOMARKER HAS BEEN IDENTIFIED THAT CAN PREDICT THE POTENTIAL RESPONSE TO THERAPY BEFORE TREATMENT INITIATION. 2023 14 5706 28 SINGLE-MOLECULE QUANTIFICATION OF 5-HYDROXYMETHYLCYTOSINE FOR DIAGNOSIS OF BLOOD AND COLON CANCERS. BACKGROUND: THE DNA MODIFICATION 5-HYDROXYMETHYLCYTOSINE (5HMC) IS NOW REFERRED TO AS THE SIXTH BASE OF DNA WITH EVIDENCE OF TISSUE-SPECIFIC PATTERNS AND CORRELATION WITH GENE REGULATION AND EXPRESSION. THIS EPIGENETIC MARK WAS RECENTLY REPORTED AS A POTENTIAL BIOMARKER FOR MULTIPLE TYPES OF CANCER, BUT ITS APPLICATION IN THE CLINIC IS LIMITED BY THE UTILITY OF RECENT 5HMC QUANTIFICATION ASSAYS. WE USE A RECENTLY DEVELOPED, ULTRA-SENSITIVE, FLUORESCENCE-BASED SINGLE-MOLECULE METHOD FOR GLOBAL QUANTIFICATION OF 5HMC IN GENOMIC DNA. THE HIGH SENSITIVITY OF THE METHOD GIVES ACCESS TO PRECISE QUANTIFICATION OF EXTREMELY LOW 5HMC LEVELS COMMON IN MANY CANCERS. METHODS: WE ASSESSED 5HMC LEVELS IN DNA EXTRACTED FROM A SET OF COLON AND BLOOD CANCER SAMPLES AND COMPARED 5HMC LEVELS WITH HEALTHY CONTROLS, IN A SINGLE-MOLECULE APPROACH. RESULTS: USING OUR METHOD, WE OBSERVED A SIGNIFICANTLY REDUCED LEVEL OF 5HMC IN BLOOD AND COLON CANCERS AND COULD DISTINGUISH BETWEEN COLON TUMOR AND COLON TISSUE ADJACENT TO THE TUMOR BASED ON THE GLOBAL LEVELS OF THIS MOLECULAR BIOMARKER. CONCLUSIONS: SINGLE-MOLECULE DETECTION OF 5HMC ALLOWS DISTINGUISHING BETWEEN MALIGNANT AND HEALTHY TISSUE IN CLINICALLY RELEVANT AND ACCESSIBLE TISSUE SUCH AS BLOOD AND COLON. THE PRESENTED METHOD OUTPERFORMS CURRENT COMMERCIALLY AVAILABLE QUANTIFICATION KITS AND MAY POTENTIALLY BE DEVELOPED INTO A WIDELY USED, 5HMC QUANTIFICATION ASSAY FOR RESEARCH AND CLINICAL DIAGNOSTICS. FURTHERMORE, USING THIS METHOD, WE CONFIRM THAT 5HMC IS A GOOD MOLECULAR BIOMARKER FOR DIAGNOSING COLON AND VARIOUS TYPES OF BLOOD CANCER. 2017 15 5345 39 RAPID CHANGES IN EXPRESSION OF CLASS I AND IV HISTONE DEACETYLASES DURING EPILEPTOGENESIS IN MOUSE MODELS OF TEMPORAL LOBE EPILEPSY. A PROMINENT ROLE OF EPIGENETIC MECHANISMS IN MANIFESTATION OF EPILEPSY HAS BEEN PROPOSED. THUS ALTERED HISTONE H3 AND H4 ACETYLATION HAS BEEN DEMONSTRATED IN EXPERIMENTAL MODELS OF TEMPORAL LOBE EPILEPSY (TLE). WE NOW INVESTIGATED CHANGES IN THE EXPRESSION OF THE CLASS I AND CLASS IV HISTONE DEACETYLASES (HDAC) IN TWO COMPLEMENTARY MOUSE TLE MODELS. UNILATERAL INTRAHIPPOCAMPAL INJECTION OF KAINIC ACID (KA) INDUCED A STATUS EPILEPTICUS LASTING 6 TO 24H, DEVELOPMENT OF SPONTANEOUS LIMBIC SEIZURES (2 TO 3 DAYS AFTER KA INJECTION) AND CHRONIC EPILEPSY, AS REVEALED BY TELEMETRIC RECORDINGS OF THE EEGS. MICE WERE KILLED AT DIFFERENT INTERVALS AFTER KA INJECTION AND EXPRESSION OF HDAC MRNAS WAS INVESTIGATED BY IN SITU HYBRIDIZATION. WE OBSERVED MARKED DECREASES IN THE EXPRESSION OF HDACS 1, 2 AND 11 (BY UP TO 75%) IN THE GRANULE CELL AND PYRAMIDAL CELL LAYERS OF THE HIPPOCAMPUS DURING THE ACUTE STATUS EPILEPTICUS (2 TO 6H AFTER KA INJECTION). THIS WAS FOLLOWED BY INCREASED EXPRESSION OF ALL CLASS I HDAC MRNAS IN ALL PRINCIPAL CELL LAYERS OF THE HIPPOCAMPUS AFTER 12 TO 48 H. IN THE CHRONIC PHASE, 14 AND 28 DAYS AFTER KA, ONLY MODEST INCREASES IN THE EXPRESSION OF HDAC1 MRNA WERE OBSERVED IN GRANULE AND PYRAMIDAL CELLS. IMMUNOHISTOCHEMISTRY USING AN ANTIBODY DETECTING HDAC2 REVEALED RESULTS CONSISTENT WITH THE MRNA DATA AND INDICATES ALSO EXPRESSION IN GLIAL CELLS ON THE INJECTION SIDE. SIMILAR CHANGES AS SEEN IN THE KA MODEL WERE OBSERVED AFTER A PILOCARPINE-INDUCED STATUS EPILEPTICUS EXCEPT THAT DECREASES IN HDACS 2, 3 AND 8 WERE ALSO SEEN AT THE CHRONIC 28 DAY INTERVAL. THE PROMINENT DECREASES IN HDAC EXPRESSION DURING STATUS EPILEPTICUS ARE CONSISTENT WITH THE PREVIOUSLY DEMONSTRATED INCREASED EXPRESSION OF NUMEROUS PROTEINS AND WITH THE AUGMENTED ACETYLATION OF HISTONE H4. IT IS SUGGESTED THAT RESPECTIVE PUTATIVE GENE PRODUCTS COULD FACILITATE PROCONVULSIVE AS WELL AS ANTICONVULSIVE MECHANISMS. THE INCREASED EXPRESSION OF ALL CLASS I HDACS DURING THE "SILENT PHASE", ON THE OTHER HAND, MAY BE RELATED TO DECREASED HISTONE ACETYLATION, WHICH COULD CAUSE A DECREASE IN EXPRESSION OF CERTAIN PROTEINS, A MECHANISM THAT COULD ALSO PROMOTE EPILEPTOGENESIS. THUS, ADDRESSING HDAC EXPRESSION MAY HAVE A THERAPEUTIC POTENTIAL IN INTERFERING WITH A STATUS EPILEPTICUS AND WITH THE MANIFESTATION OF TLE. 2015 16 4604 30 NEGATIVE EVIDENCE FOR A FUNCTIONAL ROLE OF NEURONAL DNMT3A IN PERSISTENT PAIN. TRADITIONALLY, NEUROSCIENCE HAS HAD TO RELY ON MIXED TISSUE ANALYSIS TO EXAMINE TRANSCRIPTIONAL AND EPIGENETIC CHANGES IN THE CONTEXT OF NERVOUS SYSTEM FUNCTION OR PATHOLOGY. HOWEVER, PARTICULARLY WHEN STUDYING CHRONIC PAIN CONDITIONS, THIS APPROACH CAN BE FLAWED, SINCE IT NEGLECTS TO TAKE INTO ACCOUNT THE SHIFTING CONTRIBUTION OF DIFFERENT CELL TYPES ACROSS EXPERIMENTAL CONDITIONS. HERE, WE DEMONSTRATE THIS USING THE EXAMPLE OF DNA METHYLTRANSFERASES (DNMTS) - A GROUP OF EPIGENETIC MODIFIERS CONSISTING OF DNMT1, DNMT3A, AND DNMT3B IN MAMMALIAN CELLS. WE USED SENSORY NEURON-SPECIFIC KNOCKOUT MICE FOR DNMT3A/3B AS WELL AS PHARMACOLOGICAL BLOCKADE OF DNMT1 TO STUDY THEIR ROLE IN NOCICEPTION. IN CONTRAST TO PREVIOUS ANALYSES ON WHOLE TISSUE, WE FIND THAT DNMT3A AND 3B PROTEIN IS NOT EXPRESSED IN ADULT DRG NEURONS, THAT NONE OF THE DNA METHYLTRANSFERASES ARE REGULATED WITH INJURY AND THAT INTERFERING WITH THEIR FUNCTION HAS NO EFFECT ON NOCICEPTION. OUR RESULTS THEREFORE CURRENTLY DO NOT SUPPORT A ROLE FOR NEURONAL DNA METHYLTRANSFERASES IN PAIN PROCESSING IN ADULT ANIMALS. 2018 17 2489 25 EPIGENETICALLY MODIFIED NUCLEOTIDES IN CHRONIC HEROIN AND COCAINE TREATED MICE. EPIGENETIC CHANGES INCLUDE THE ADDITION OF A METHYL GROUP TO THE 5' CARBON OF THE CYTOSINE RING, KNOWN AS DNA METHYLATION, WHICH RESULTS IN THE GENERATION OF THE FIFTH DNA BASE, NAMELY 5-METHYLCYTOSINE. DURING ACTIVE OR PASSIVE DEMETHYLATION, AN INTERMEDIATE MODIFIED BASE IS FORMED, 5-HYDROXYMETHYLCYTOSINE. WE HAVE CURRENTLY QUANTIFIED 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE IN THE LIVER AND BRAIN OF MICE TREATED WITH COCAINE OR HEROIN, USING LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC-MS/MS). OUR RESULTS SHOW THAT GLOBAL 5-METHYLCYTOSINE LEVELS ARE NOT AFFECTED BY HEROIN OR COCAINE ADMINISTRATION, NEITHER IN THE LIVER NOR IN THE BRAIN. HOWEVER, 5-HYDROXYMETHYLCYTOSINE LEVELS ARE REDUCED IN THE LIVER FOLLOWING COCAINE ADMINISTRATION, WHILE THEY ARE NOT AFFECTED BY COCAINE IN THE BRAIN OR BY HEROIN ADMINISTRATION IN THE LIVER AND THE BRAIN. ELUCIDATION OF THE EPIGENETIC PHENOMENA THAT TAKES PLACE WITH RESPECT TO DRUG ABUSE AND ADDICTION, VIA QUANTITATIVE ANALYSIS OF DIFFERENT MODIFIED BASES, MAY ENABLE A BETTER UNDERSTANDING OF THE UNDERLYING MECHANISMS AND MAY LEAD TO MORE PERSONALIZED AND EFFECTIVE TREATMENT OPTIONS. 2014 18 344 30 ALTERED BDNF METHYLATION IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN AND HIGH BIOPSYCHOSOCIAL COMPLEXITY. PURPOSE: THE INTERMED INSTRUMENT, WHICH WAS DEVELOPED TO MEASURE PATIENT'S BIOPSYCHOSOCIAL (BPS) COMPLEXITY, REPRESENTS A POWERFUL DIAGNOSTIC AND THERAPEUTIC TOOL. EPIGENETIC CHANGES ARE THE INTERFACE BETWEEN SIGNALS FROM THE ENVIRONMENT AND GENETIC MODIFICATIONS, AFFECTING GENE EXPRESSION, IN PARTICULAR, BY DNA METHYLATION OF CPG DINUCLEOTIDES IN PROMOTOR REGIONS OF THE CORRESPONDING GENES. THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) GENE PLAYS A CRUCIAL ROLE IN THE CENTRAL SENSITIZATION (CS) OF PAIN. IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC PAIN MODIFIES THE METHYLATION LEVELS OF THE BDNF GENE IN A MANNER THAT IS INTERCONNECTED WITH THE BPS STATUS. PATIENTS AND METHODS: FIFTY-EIGHT CHRONIC MUSCULOSKELETAL PAIN PATIENTS (CMSP) WERE ENROLLED IN THE STUDY. DNA WAS EXTRACTED FROM BLOOD SAMPLES, THE METHYLATION LEVELS OF 13 CPG SITES IN THE BDNF PROMOTER WERE MEASURED BY PYROSEQUENCING, AND ASSOCIATION STUDIES WITH VARIOUS PATIENT PARAMETERS AND THE INTERMED SCORES WERE PERFORMED. RESULTS: INTERESTINGLY, A NEGATIVE CORRELATION (-0.40) WAS FOUND BETWEEN THE TOTAL INTERMED SCORES AND THE AVERAGE CPG METHYLATION VALUES OF THE BDNF GENE, BUT NO CORRELATION WAS OBSERVED WITH THE SEVERITY OF PAIN, DEGREE OF ANXIETY, DEPRESSION, OR KINESIOPHOBIA AND CATASTROPHISM. MOREOVER, THE ASSOCIATION WAS INDEPENDENT OF AGE, SEX AND LEVEL OF COMORBIDITIES. CONCLUSION: THIS RESULT SHOWS THAT CMSP, IN ASSOCIATION WITH ITS BIOPSYCHOSOCIAL CONTEXT, EPIGENETICALLY DECREASES THE DEGREE OF METHYLATION OF THE BDNF PROMOTER AND SHOULD THEREFORE INCREASE THE LEVEL OF BDNF TRANSCRIPTION. IT ALSO SUGGESTS A ROLE OF THE INTERMED TOOL TO DETECT A RELATIONSHIP BETWEEN THE BPS COMPLEXITY AND THE EPIGENETIC CONTROL OF A TARGET GENE. THE POSSIBLE UPREGULATION OF BDNF EXPRESSION MIGHT BE, AT LEAST IN PART, THE SIGNAL FOR CHRONIC PAIN-INDUCED CENTRAL SENSITIZATION (CS). THIS COULD PARTLY EXPLAIN WHY PATIENTS WITH A HIGHER LEVEL OF COMPLEXITY FEEL MORE PAIN THAN THOSE WITH LOWER COMPLEXITY. 2020 19 4236 30 METHYLATION OF THE TYROSINE HYDROXYLASE GENE IS DYSREGULATED BY COCAINE DEPENDENCE IN THE HUMAN STRIATUM. COCAINE DEPENDENCE IS A CHRONIC, RELAPSING DISORDER CAUSED BY LASTING CHANGES IN THE BRAIN. ANIMAL STUDIES HAVE IDENTIFIED COCAINE-RELATED ALTERATIONS IN STRIATAL DNA METHYLATION; HOWEVER, IT IS UNCLEAR HOW METHYLATION IS RELATED TO COCAINE DEPENDENCE IN HUMANS. WE GENERATED METHYLOMIC PROFILES OF THE NUCLEUS ACCUMBENS USING HUMAN POSTMORTEM BRAINS FROM A COHORT OF INDIVIDUALS WITH COCAINE DEPENDENCE AND HEALTHY CONTROLS (N = 25 PER GROUP). WE FOUND HYPERMETHYLATION IN A CLUSTER OF CPGS WITHIN THE GENE BODY OF TYROSINE HYDROXYLASE (TH), CONTAINING A PUTATIVE BINDING SITE FOR THE EARLY GROWTH RESPONSE 1 (EGR1) TRANSCRIPTION FACTOR, WHICH IS HYPERMETHYLATED IN THE CAUDATE NUCLEUS OF COCAINE-DEPENDENT INDIVIDUALS. WE REPLICATED THIS FINDING AND FOUND IT TO BE SPECIFIC TO STRIATAL NEURONAL NUCLEI. FURTHERMORE, THIS LOCUS DEMONSTRATES ENHANCER ACTIVITY WHICH IS ATTENUATED BY METHYLATION AND ENHANCED BY EGR1 OVEREXPRESSION. THESE RESULTS SUGGEST THAT COCAINE DEPENDENCE ALTERS THE EPIGENETIC REGULATION OF DOPAMINERGIC SIGNALING GENES. 2021 20 4628 30 NEUROEPIGENETIC ALTERATIONS IN THE PREFRONTAL CORTEX OF TYPE 2 DIABETIC MICE THROUGH DNA HYPERMETHYLATION. BACKGROUND: DNA METHYLATION CHANGES HAVE KNOWN TO DOWNREGULATE SEVERAL REGULATORY PROTEINS EPIGENETICALLY DURING VARIOUS NEURODEGENERATIVE DISORDERS. OUR STUDY AIMS TO UNDERSTAND THE EFFECT OF THIS GLOBAL DNA METHYLATION ON THE CEREBRAL COMPLICATIONS OF TYPE 2 DIABETES MICE, AND ITS NOTABLE EFFECT ON MAINTAINING THE SYNAPTIC FIDELITY. METHODS AND RESULTS: CHRONIC HIGH FAT DIET AND STREPTOZOTOCIN-INDUCED DIABETIC MICE WERE STUDIED FOR THE NEUROBEHAVIORAL AND NEUROANATOMIC PARAMETERS PERTAINING TO PREFRONTAL CORTEX, SUBSEQUENTLY ELUCIDATING THE ASSOCIATED CHANGES IN DNA METHYLATION WITHIN THESE DIABETIC BRAINS. FURTHER, THE IMPACT OF THIS EPIGENETIC DYSREGULATION ON HSF1, BDNF AND PSD95 WERE STUDIED BY ASSESSING THE BINDING AFFINITY AND LEVEL OF % METHYLATION WITHIN THE PROMOTER SITE OF THEIR RESPECTIVE GENES. OUR STUDY SUGGEST INCREASED DNMT ABERRATIONS WITHIN THE PREFRONTAL CORTEX, WITH INCREASED MECP2 LEVELS, CONFIRMING DNA HYPERMETHYLATION. THIS WAS IN ACCORDANCE WITH THE ALTERED NEUROBEHAVIORAL CHANGES. FURTHER, THE HYPERMETHYLATION WAS FOUND TO PARTICIPATE IN GENE SILENCING OF HSF1, BDNF AND PSD95 PROTEINS, RESPONSIBLE FOR MAINTAINING THE SYNAPTIC FIDELITY. CONCLUSION: OVERALL, OUR STUDY CONCLUDES THE PLAUSIBLE INVOLVEMENT OF NEUROEPIGENETIC ALTERATIONS IN THE PREFRONTAL CORTEX (PFC) OF THE TYPE 2 DIABETES MICE, SPECIFICALLY DNA HYPERMETHYLATION. PFC PLAYS A CENTRAL ROLE IN MODULATING COGNITIVE AND OTHER EXECUTIVE FUNCTIONS THROUGH ITS CONNECTION WITH SEVERAL BRAIN REGIONS, AND THUS THERAPEUTIC STRATEGIES TARGETING EPIGENETIC MODULATIONS IN IT, CAN PAVE A WAY IN CONTROLLING SEVERAL NEUROLOGICAL ALTERATIONS IN THE BRAIN. 2022