1 2884 111 G9A IS ESSENTIAL FOR EPIGENETIC SILENCING OF K(+) CHANNEL GENES IN ACUTE-TO-CHRONIC PAIN TRANSITION. NEUROPATHIC PAIN IS A DEBILITATING CLINICAL PROBLEM AND DIFFICULT TO TREAT. NERVE INJURY CAUSES A LONG-LASTING REDUCTION IN K(+) CHANNEL EXPRESSION IN THE DORSAL ROOT GANGLION (DRG), BUT LITTLE IS KNOWN ABOUT THE EPIGENETIC MECHANISMS INVOLVED. WE FOUND THAT NERVE INJURY INCREASED DIMETHYLATION OF LYS9 ON HISTONE H3 (H3K9ME2) AT KCNA4, KCND2, KCNQ2 AND KCNMA1 PROMOTERS BUT DID NOT AFFECT LEVELS OF DNA METHYLATION ON THESE GENES IN DRGS. NERVE INJURY INCREASED ACTIVITY OF EUCHROMATIC HISTONE-LYSINE N-METHYLTRANSFERASE-2 (G9A), HISTONE DEACETYLASES AND ENHANCER OF ZESTE HOMOLOG-2 (EZH2), BUT ONLY G9A INHIBITION CONSISTENTLY RESTORED K(+) CHANNEL EXPRESSION. SELECTIVE KNOCKOUT OF THE GENE ENCODING G9A IN DRG NEURONS COMPLETELY BLOCKED K(+) CHANNEL SILENCING AND CHRONIC PAIN DEVELOPMENT AFTER NERVE INJURY. REMARKABLY, RNA SEQUENCING ANALYSIS REVEALED THAT G9A INHIBITION NOT ONLY REACTIVATED 40 OF 42 SILENCED GENES ASSOCIATED WITH K(+) CHANNELS BUT ALSO NORMALIZED 638 GENES DOWN- OR UPREGULATED BY NERVE INJURY. THUS G9A HAS A DOMINANT FUNCTION IN TRANSCRIPTIONAL REPRESSION OF K(+) CHANNELS AND IN ACUTE-TO-CHRONIC PAIN TRANSITION AFTER NERVE INJURY. 2015 2 2885 42 G9A PARTICIPATES IN NERVE INJURY-INDUCED KCNA2 DOWNREGULATION IN PRIMARY SENSORY NEURONS. NERVE INJURY-INDUCED DOWNREGULATION OF VOLTAGE-GATED POTASSIUM CHANNEL SUBUNIT KCNA2 IN THE DORSAL ROOT GANGLION (DRG) IS CRITICAL FOR DRG NEURONAL EXCITABILITY AND NEUROPATHIC PAIN GENESIS. HOWEVER, HOW NERVE INJURY CAUSES THIS DOWNREGULATION IS STILL ELUSIVE. EUCHROMATIC HISTONE-LYSINE N-METHYLTRANSFERASE 2, ALSO KNOWN AS G9A, METHYLATES HISTONE H3 ON LYSINE RESIDUE 9 TO PREDOMINANTLY PRODUCE A DYNAMIC HISTONE DIMETHYLATION, RESULTING IN CONDENSED CHROMATIN AND GENE TRANSCRIPTIONAL REPRESSION. WE SHOWED HERE THAT BLOCKING NERVE INJURY-INDUCED INCREASE IN G9A RESCUED KCNA2 MRNA AND PROTEIN EXPRESSION IN THE AXOTOMIZED DRG AND ATTENUATED THE DEVELOPMENT OF NERVE INJURY-INDUCED PAIN HYPERSENSITIVITY. MIMICKING THIS INCREASE DECREASED KCNA2 MRNA AND PROTEIN EXPRESSION, REDUCED KV CURRENT, AND INCREASED EXCITABILITY IN THE DRG NEURONS AND LED TO SPINAL CORD CENTRAL SENSITIZATION AND NEUROPATHIC PAIN-LIKE SYMPTOMS. G9A MRNA IS CO-LOCALIZED WITH KCNA2 MRNA IN THE DRG NEURONS. THESE FINDINGS INDICATE THAT G9A CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT THROUGH EPIGENETIC SILENCING OF KCNA2 IN THE AXOTOMIZED DRG. 2016 3 3303 23 HIGH-FREQUENCY P16(INK) (4A) PROMOTER METHYLATION IS ASSOCIATED WITH HISTONE METHYLTRANSFERASE SETDB1 EXPRESSION IN SPORADIC CUTANEOUS MELANOMA. EPIGENETIC MECHANISMS PARTICIPATE IN MELANOMA DEVELOPMENT AND PROGRESSION. THE EFFECT OF HISTONE MODIFICATIONS AND THEIR CATALYSING ENZYMES OVER EUCHROMATIC PROMOTER DNA METHYLATION IN MELANOMA REMAINS UNCLEAR. THIS STUDY INVESTIGATED THE POTENTIAL ASSOCIATION OF P16(INK) (4A) PROMOTER METHYLATION WITH HISTONE METHYLTRANSFERASE SETDB1 EXPRESSION IN GREEK PATIENTS WITH SPORADIC MELANOMA AND THEIR CORRELATION WITH CLINICOPATHOLOGICAL CHARACTERISTICS. PROMOTER METHYLATION WAS DETECTED BY METHYLATION-SPECIFIC PCR IN 100 PERIPHERAL BLOOD SAMPLES AND 58 MELANOMA TISSUES FROM THE SAME PATIENTS. CELL PROLIFERATION (KI-67 INDEX), P16(INK) (4A) AND SETDB1 EXPRESSION WERE EVALUATED BY IMMUNOHISTOCHEMISTRY. HIGH-FREQUENCY PROMOTER METHYLATION (25.86%) WAS OBSERVED IN TISSUE SAMPLES AND CORRELATED WITH INCREASED CELL PROLIFERATION (P = 0.0514). P16(INK) (4A) PROMOTER METHYLATION WAS HIGHER IN VERTICAL GROWTH-PHASE (60%) MELANOMAS THAN IN RADIAL (40%, P = 0.063) AND THOSE DISPLAYING EPIDERMAL INVOLVEMENT (P = 0.046). IMPORTANTLY, P16(INK) (4A) METHYLATION CORRELATED WITH INCREASED MELANOMA THICKNESS ACCORDING TO BRESLOW INDEX (P = 0.0495) AND MARGINALLY WITH INCREASED CLARK LEVEL (I/II VS III/IV/V, P = 0.070). LOW (1-30%) P16(INK) (4A) EXPRESSION WAS DETECTED AT THE MAJORITY (19 OF 54) OF MELANOMA CASES (35.19%), BEING MARGINALLY CORRELATED WITH TUMOR LYMPHOCYTIC INFILTRATION (P = 0.078). SETDB1 NUCLEAR IMMUNOREACTIVITY WAS OBSERVED IN 47 OF 57 (82.46%) CASES, WHEREAS 27 OF 57 (47.37%) SHOWED CYTOPLASMIC IMMUNOEXPRESSION. CYTOPLASMIC SETDB1 EXPRESSION CORRELATED WITH HIGHER FREQUENCY OF P16(INK) (4A) METHYLATION AND P16(INK) (4A) EXPRESSION (P = 0.033, P = 0.011, RESPECTIVELY). INCREASED NUCLEAR SETDB1 LEVELS WERE ASSOCIATED WITH HIGHER MITOTIC COUNT (0-5/MM(2) VS >5/MM(2) , P = 0.0869), ADVANCED CLARK LEVEL (III-V, P = 0.0380), EPIDERMAL INVOLVEMENT (P = 0.0331) AND THE NON-CHRONIC SUN EXPOSURE-ASSOCIATED MELANOMA TYPE (P = 0.0664). OUR DATA DEMONSTRATE FOR THE FIRST TIME THE ASSOCIATION OF HISTONE METHYLTRANSFERASE SETDB1 WITH FREQUENT METHYLATION OF THE EUCHROMATIC P16(INK) (4A) PROMOTER AND SEVERAL PROGNOSTIC PARAMETERS IN MELANOMAS. 2014 4 3368 39 HISTONE METHYLTRANSFERASE G9A DIMINISHES EXPRESSION OF CANNABINOID CB(1) RECEPTORS IN PRIMARY SENSORY NEURONS IN NEUROPATHIC PAIN. TYPE 1 CANNABINOID RECEPTORS (CB(1)RS) ARE EXPRESSED IN THE DORSAL ROOT GANGLION (DRG) AND CONTRIBUTE TO THE ANALGESIC EFFECT OF CANNABINOIDS. HOWEVER, THE EPIGENETIC MECHANISM REGULATING THE EXPRESSION OF CB(1)RS IN NEUROPATHIC PAIN IS UNKNOWN. G9A (ENCODED BY THE EHMT2 GENE), A HISTONE 3 AT LYSINE 9 METHYLTRANSFERASE, IS A KEY CHROMATIN REGULATOR RESPONSIBLE FOR GENE SILENCING. IN THIS STUDY, WE DETERMINED G9A'S ROLE IN REGULATING CB(1)R EXPRESSION IN THE DRG AND IN CB(1)R-MEDIATED ANALGESIC EFFECTS IN AN ANIMAL MODEL OF NEUROPATHIC PAIN. WE SHOW THAT NERVE INJURY PROFOUNDLY REDUCED MRNA LEVELS OF CB(1)RS BUT INCREASED THE EXPRESSION OF CB(2) RECEPTORS IN THE RAT DRG. CHIP RESULTS INDICATED INCREASED ENRICHMENT OF HISTONE 3 AT LYSINE 9 DIMETHYLATION, A G9A-CATALYZED REPRESSIVE HISTONE MARK, AT THE PROMOTER REGIONS OF THE CB(1)R GENES. G9A INHIBITION IN NERVE-INJURED RATS NOT ONLY UP-REGULATED THE CB(1)R EXPRESSION LEVEL IN THE DRG BUT ALSO POTENTIATED THE ANALGESIC EFFECT OF A CB(1)R AGONIST ON NERVE INJURY-INDUCED PAIN HYPERSENSITIVITY. FURTHERMORE, IN MICE LACKING EHMT2 IN DRG NEURONS, NERVE INJURY FAILED TO REDUCE CB(1)R EXPRESSION IN THE DRG AND TO DECREASE THE ANALGESIC EFFECT OF THE CB(1)R AGONIST. MOREOVER, NERVE INJURY DIMINISHED THE INHIBITORY EFFECT OF THE CB(1)R AGONIST ON SYNAPTIC GLUTAMATE RELEASE FROM PRIMARY AFFERENT NERVES TO SPINAL CORD DORSAL HORN NEURONS IN WT MICE BUT NOT IN MICE LACKING EHMT2 IN DRG NEURONS. OUR FINDINGS REVEAL THAT NERVE INJURY DIMINISHES THE ANALGESIC EFFECT OF CB(1)R AGONISTS THROUGH G9A-MEDIATED CB(1)R DOWN-REGULATION IN PRIMARY SENSORY NEURONS. 2020 5 4919 42 PANNEXIN-1 UP-REGULATION IN THE DORSAL ROOT GANGLION CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT. PANNEXIN-1 (PANX1) IS A LARGE-PORE MEMBRANE CHANNEL INVOLVED IN THE RELEASE OF ATP AND OTHER SIGNALING MEDIATORS. LITTLE IS KNOWN ABOUT THE EXPRESSION AND FUNCTIONAL ROLE OF PANX1 IN THE DORSAL ROOT GANGLION (DRG) IN THE DEVELOPMENT OF CHRONIC NEUROPATHIC PAIN. IN THIS STUDY, WE DETERMINED THE EPIGENETIC MECHANISM INVOLVED IN INCREASED PANX1 EXPRESSION IN THE DRG AFTER NERVE INJURY. SPINAL NERVE LIGATION IN RATS SIGNIFICANTLY INCREASED THE MRNA AND PROTEIN LEVELS OF PANX1 IN THE DRG BUT NOT IN THE SPINAL CORD. IMMUNOCYTOCHEMICAL LABELING SHOWED THAT PANX1 WAS PRIMARILY EXPRESSED IN A SUBSET OF MEDIUM AND LARGE DRG NEURONS IN CONTROL RATS AND THAT NERVE INJURY MARKEDLY INCREASED THE NUMBER OF PANX1-IMMUNOREACTIVE DRG NEURONS. NERVE INJURY SIGNIFICANTLY INCREASED THE ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME2 AND H3K9AC) AND DECREASED THE OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AROUND THE PROMOTER REGION OF PANX1 IN THE DRG. HOWEVER, NERVE INJURY HAD NO EFFECT ON THE DNA METHYLATION LEVEL AROUND THE PANX1 PROMOTER IN THE DRG. FURTHERMORE, INTRATHECAL INJECTION OF THE PANX1 BLOCKERS OR PANX1-SPECIFIC SIRNA SIGNIFICANTLY REDUCED PAIN HYPERSENSITIVITY INDUCED BY NERVE INJURY. IN ADDITION, SIRNA KNOCKDOWN OF PANX1 EXPRESSION IN A DRG CELL LINE SIGNIFICANTLY REDUCED CASPASE-1 RELEASE INDUCED BY NEURONAL DEPOLARIZATION. OUR FINDINGS SUGGEST THAT NERVE INJURY INCREASES PANX1 EXPRESSION LEVELS IN THE DRG THROUGH ALTERED HISTONE MODIFICATIONS. PANX1 UP-REGULATION CONTRIBUTES TO THE DEVELOPMENT OF NEUROPATHIC PAIN AND STIMULATION OF INFLAMMASOME SIGNALING. 2015 6 4637 38 NEURON-RESTRICTIVE SILENCER FACTOR CAUSES EPIGENETIC SILENCING OF KV4.3 GENE AFTER PERIPHERAL NERVE INJURY. PERIPHERAL NERVE INJURY CAUSES A VARIETY OF ALTERATIONS IN PAIN-RELATED GENE EXPRESSION IN PRIMARY AFFERENT, WHICH UNDERLIE THE NEURONAL PLASTICITY IN NEUROPATHIC PAIN. ONE OF THE CHARACTERISTIC ALTERATIONS IS A LONG-LASTING DOWNREGULATION OF VOLTAGE-GATED POTASSIUM (K(V)) CHANNEL, INCLUDING K(V)4.3, IN THE DORSAL ROOT GANGLION (DRG). THE PRESENT STUDY SHOWED THAT NERVE INJURY REDUCES THE MESSENGER RNA (MRNA) EXPRESSION LEVEL OF K(V)4.3 GENE, WHICH CONTAINS A CONSERVED NEURON-RESTRICTIVE SILENCER ELEMENT (NRSE), A BINDING SITE FOR NEURON-RESTRICTIVE SILENCER FACTOR (NRSF). MOREOVER, WE FOUND THAT INJURY CAUSES AN INCREASE IN DIRECT NRSF BINDING TO K(V)4.3-NRSE IN THE DRG, USING CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY. CHIP ASSAY FURTHER REVEALED THAT ACETYLATION OF HISTONE H4, BUT NOT H3, AT K(V)4.3-NRSE IS MARKEDLY REDUCED AT DAY 7 POST-INJURY. FINALLY, THE INJURY-INDUCED K(V)4.3 DOWNREGULATION WAS SIGNIFICANTLY BLOCKED BY ANTISENSE-KNOCKDOWN OF NRSF. TAKEN TOGETHER, THESE DATA SUGGEST THAT NERVE INJURY CAUSES AN EPIGENETIC SILENCING OF K(V)4.3 GENE MEDIATED THROUGH TRANSCRIPTIONAL SUPPRESSOR NRSF IN THE DRG. 2010 7 6424 41 THE TRANSCRIPTION FACTOR C/EBPBETA IN THE DORSAL ROOT GANGLION CONTRIBUTES TO PERIPHERAL NERVE TRAUMA-INDUCED NOCICEPTIVE HYPERSENSITIVITY. CHANGES IN GENE TRANSCRIPTION IN THE DORSAL ROOT GANGLION (DRG) AFTER NERVE TRAUMA CONTRIBUTE TO THE GENESIS OF NEUROPATHIC PAIN. WE REPORT THAT PERIPHERAL NERVE TRAUMA CAUSED BY CHRONIC CONSTRICTION INJURY (CCI) INCREASED THE ABUNDANCE OF THE TRANSCRIPTION FACTOR C/EBPBETA (CCAAT/ENHANCER BINDING PROTEIN BETA) IN THE DRG. BLOCKING THIS INCREASE MITIGATED THE DEVELOPMENT AND MAINTENANCE OF CCI-INDUCED MECHANICAL, THERMAL, AND COLD PAIN HYPERSENSITIVITIES WITHOUT AFFECTING BASAL RESPONSES TO ACUTE PAIN AND LOCOMOTOR ACTIVITY. CONVERSELY, MIMICKING THIS INCREASE PRODUCED HYPERSENSITIVITY TO MECHANICAL, THERMAL, OR COLD PAIN. IN THE IPSILATERAL DRG, C/EBPBETA PROMOTED A DECREASE IN THE ABUNDANCE OF THE VOLTAGE-GATED POTASSIUM CHANNEL SUBUNIT KV1.2 AND MU OPIOID RECEPTOR (MOR) AT THE MRNA AND PROTEIN LEVELS, WHICH WOULD BE PREDICTED TO INCREASE EXCITABILITY IN THE IPSILATERAL DRG NEURONS AND REDUCE THE EFFICACY OF MORPHINE ANALGESIA. THESE EFFECTS REQUIRED C/EPBBETA-MEDIATED TRANSCRIPTIONAL ACTIVATION OF EHMT2 (EUCHROMATIC HISTONE-LYSINE N-METHYLTRANSFERASE 2), WHICH ENCODES G9A, AN EPIGENETIC SILENCER OF THE GENES ENCODING KV1.2 AND MOR. BLOCKING THE INCREASE IN C/EBPBETA IN THE DRG IMPROVED MORPHINE ANALGESIA AFTER CCI. THESE RESULTS SUGGEST THAT C/EBPBETA IS AN ENDOGENOUS INITIATOR OF NEUROPATHIC PAIN AND COULD BE A POTENTIAL TARGET FOR THE PREVENTION AND TREATMENT OF THIS DISORDER. 2017 8 3727 28 INHIBITION OF PANCREATIC ACINAR MITOCHONDRIAL THIAMIN PYROPHOSPHATE UPTAKE BY THE CIGARETTE SMOKE COMPONENT 4-(METHYLNITROSAMINO)-1-(3-PYRIDYL)-1-BUTANONE. THIAMIN IS ESSENTIAL FOR NORMAL METABOLISM IN PANCREATIC ACINAR CELLS (PAC) AND IS OBTAINED FROM THEIR MICROENVIRONMENT THROUGH SPECIFIC PLASMA-MEMBRANE TRANSPORTERS, CONVERTED TO THIAMIN PYROPHOSPHATE (TPP) IN THE CYTOPLASM, FOLLOWED BY UPTAKE OF TPP BY MITOCHONDRIA THROUGH THE MITOCHONDRIAL TPP (MTPP) TRANSPORTER (MTPPT; PRODUCT OF SLC25A19 GENE). TPP IS ESSENTIAL FOR NORMAL MITOCHONDRIAL FUNCTION. WE EXAMINED THE EFFECT OF LONG-TERM/CHRONIC EXPOSURE OF PAC IN VITRO (PANCREATIC ACINAR 266-6 CELLS) AND IN VIVO (WILD-TYPE OR TRANSGENIC MICE CARRYING THE SLC25A19 PROMOTER) OF THE CIGARETTE SMOKE TOXIN, 4-(METHYLNITROSAMINO)-1-(3-PYRIDYL)-1-BUTANONE (NNK), ON THE MTPP UPTAKE PROCESS. OUR IN VITRO AND IN VIVO FINDINGS DEMONSTRATE THAT NNK NEGATIVELY AFFECTS MTPP UPTAKE AND REDUCED EXPRESSION OF MTPPT PROTEIN, MTPPT MRNA, AND HETEROGENOUS NUCLEAR RNA, AS WELL AS SLC25A19 PROMOTER ACTIVITY. THE EFFECT OF NNK ON SLC25A19 TRANSCRIPTION WAS NEITHER MEDIATED BY CHANGES IN EXPRESSION OF TRANSCRIPTIONAL FACTOR NFY-1 (KNOWN TO DRIVE SLC25A19 TRANSCRIPTION), NOR DUE TO CHANGES IN METHYLATION PROFILE OF THE SLC25A19 PROMOTER. RATHER, IT APPEARS TO BE DUE TO CHANGES IN HISTONE MODIFICATIONS THAT INVOLVE SIGNIFICANT DECREASES IN HISTONE H3K4-TRIMETHYLATION AND H3K9-ACETYLATION (ACTIVATION MARKERS). THE EFFECT OF NNK ON MTPPT FUNCTION IS MEDIATED THROUGH THE NONNEURONAL ALPHA7-NICOTINIC ACETYLCHOLINE RECEPTOR (ALPHA7-NACHR), AS INDICATED BY BOTH IN VITRO (USING THE NACHR ANTAGONIST MECAMYLAMINE) AND IN VIVO (USING AN ALPHA7-NACHR(-/-) MOUSE MODEL) STUDIES. THESE FINDINGS DEMONSTRATE THAT CHRONIC EXPOSURE OF PAC TO NNK NEGATIVELY IMPACTS PAC MTPP UPTAKE. THIS EFFECT APPEARS TO BE EXERTED AT THE LEVEL OF SLC25A19 TRANSCRIPTION, INVOLVE EPIGENETIC MECHANISM(S), AND IS MEDIATED THROUGH THE ALPHA7-NACHR. 2016 9 5354 49 RE1-SILENCING TRANSCRIPTION FACTOR CONTROLS THE ACUTE-TO-CHRONIC NEUROPATHIC PAIN TRANSITION AND CHRM2 RECEPTOR GENE EXPRESSION IN PRIMARY SENSORY NEURONS. NEUROPATHIC PAIN IS ASSOCIATED WITH PERSISTENT CHANGES IN GENE EXPRESSION IN PRIMARY SENSORY NEURONS, BUT THE UNDERLYING EPIGENETIC MECHANISMS THAT CAUSE THESE CHANGES REMAIN UNCLEAR. THE MUSCARINIC CHOLINERGIC RECEPTORS (MACHRS), PARTICULARLY THE M2 SUBTYPE (ENCODED BY THE CHOLINERGIC RECEPTOR MUSCARINIC 2 (CHRM2) GENE), ARE CRITICALLY INVOLVED IN THE REGULATION OF SPINAL NOCICEPTIVE TRANSMISSION. HOWEVER, LITTLE IS KNOWN ABOUT HOW CHRM2 EXPRESSION IS TRANSCRIPTIONALLY REGULATED. HERE WE SHOW THAT NERVE INJURY PERSISTENTLY INCREASED THE EXPRESSION OF RE1-SILENCING TRANSCRIPTION FACTOR (REST, ALSO KNOWN AS NEURON-RESTRICTIVE SILENCING FACTOR [NRSF]), A GENE-SILENCING TRANSCRIPTION FACTOR, IN THE DORSAL ROOT GANGLION (DRG). REMARKABLY, NERVE INJURY-INDUCED CHRONIC BUT NOT ACUTE PAIN HYPERSENSITIVITY WAS ATTENUATED IN MICE WITH REST KNOCKOUT IN DRG NEURONS. ALSO, SIRNA-MEDIATED REST KNOCKDOWN REVERSED NERVE INJURY-INDUCED CHRONIC PAIN HYPERSENSITIVITY IN RATS. NERVE INJURY PERSISTENTLY REDUCED CHRM2 EXPRESSION IN THE DRG AND DIMINISHED THE ANALGESIC EFFECT OF MUSCARINE. THE RE1 BINDING SITE ON THE CHRM2 PROMOTER IS REQUIRED FOR REST-MEDIATED CHRM2 REPRESSION, AND NERVE INJURY INCREASED THE ENRICHMENT OF REST IN THE CHRM2 PROMOTER IN THE DRG. FURTHERMORE, REST KNOCKDOWN OR GENETIC ABLATION IN DRG NEURONS NORMALIZED CHRM2 EXPRESSION AND AUGMENTED MUSCARINE'S ANALGESIC EFFECT ON NEUROPATHIC PAIN AND FULLY REVERSED THE NERVE INJURY-INDUCED REDUCTION IN THE INHIBITORY EFFECT OF MUSCARINE ON GLUTAMATERGIC INPUT TO SPINAL DORSAL HORN NEURONS. OUR FINDINGS INDICATE THAT NERVE INJURY-INDUCED REST UP-REGULATION IN DRG NEURONS PLAYS AN IMPORTANT ROLE IN THE ACUTE-TO-CHRONIC PAIN TRANSITION AND IS ESSENTIAL FOR THE TRANSCRIPTIONAL REPRESSION OF CHRM2 IN NEUROPATHIC PAIN. 2018 10 5298 28 PROTEIN ARGININE METHYLTRANSFERASE 5 SUPPRESSES THE TRANSCRIPTION OF THE RB FAMILY OF TUMOR SUPPRESSORS IN LEUKEMIA AND LYMPHOMA CELLS. THE PROPER EPIGENETIC MODIFICATION OF CHROMATIN BY PROTEIN ARGININE METHYLTRANSFERASES (PRMTS) IS CRUCIAL FOR NORMAL CELL GROWTH AND HEALTH. THE HUMAN SWI/SNF-ASSOCIATED PRMT5 IS INVOLVED IN THE TRANSCRIPTIONAL REPRESSION OF TARGET GENES BY DIRECTLY METHYLATING H3R8 AND H4R3. TO FURTHER UNDERSTAND THE IMPACT OF PRMT5-MEDIATED HISTONE METHYLATION ON CANCER, WE ANALYZED ITS EXPRESSION IN NORMAL AND TRANSFORMED HUMAN B LYMPHOCYTES. OUR FINDINGS REVEAL THAT PRMT5 PROTEIN LEVELS ARE ENHANCED IN VARIOUS HUMAN LYMPHOID CANCER CELLS, INCLUDING TRANSFORMED CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) CELL LINES. PRMT5 OVEREXPRESSION IS CAUSED BY THE ALTERED EXPRESSION OF THE PRMT5-SPECIFIC MICRORNAS 19A, 25, 32, 92, 92B, AND 96 AND RESULTS IN THE INCREASED GLOBAL SYMMETRIC METHYLATION OF H3R8 AND H4R3. AN EVALUATION OF BOTH EPIGENETIC MARKS AT PRMT5 TARGET GENES SUCH AS RB1 (P105), RBL1 (P107), AND RBL2 (P130) SHOWED THAT PROMOTERS H3R8 AND H4R3 ARE HYPERMETHYLATED, WHICH IN TURN TRIGGERS POCKET PROTEIN TRANSCRIPTIONAL REPRESSION. FURTHERMORE, REDUCING PRMT5 EXPRESSION IN WAC3CD5 B-CLL CELLS ABOLISHES H3R8 AND H4R3 HYPERMETHYLATION, RESTORES RBL2 EXPRESSION, AND INHIBITS CANCER CELL PROLIFERATION. THESE RESULTS INDICATE THAT PRMT5 OVEREXPRESSION EPIGENETICALLY ALTERS THE TRANSCRIPTION OF KEY TUMOR SUPPRESSOR GENES AND SUGGEST A CAUSAL ROLE OF THE ELEVATED SYMMETRIC METHYLATION OF H3R8 AND H4R3 AT THE RBL2 PROMOTER IN TRANSFORMED B-LYMPHOCYTE PATHOLOGY. 2008 11 1167 33 CONTRIBUTION OF DORSAL ROOT GANGLION OCTAMER TRANSCRIPTION FACTOR 1 TO NEUROPATHIC PAIN AFTER PERIPHERAL NERVE INJURY. NEUROPATHIC PAIN GENESIS IS RELATED TO GENE ALTERATIONS IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY. TRANSCRIPTION FACTORS CONTROL GENE EXPRESSION. IN THIS STUDY, WE INVESTIGATED WHETHER OCTAMER TRANSCRIPTION FACTOR 1 (OCT1), A TRANSCRIPTION FACTOR, CONTRIBUTED TO NEUROPATHIC PAIN CAUSED BY CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE. CHRONIC CONSTRICTION INJURY PRODUCED A TIME-DEPENDENT INCREASE IN THE LEVEL OF OCT1 PROTEIN IN THE IPSILATERAL L4/5 DRG, BUT NOT IN THE SPINAL CORD. BLOCKING THIS INCREASE THROUGH MICROINJECTION OF OCT1 SIRNA INTO THE IPSILATERAL L4/5 DRG ATTENUATED THE INITIATION AND MAINTENANCE OF CCI-INDUCED MECHANICAL ALLODYNIA, HEAT HYPERALGESIA, AND COLD ALLODYNIA AND IMPROVED MORPHINE ANALGESIA AFTER CCI, WITHOUT AFFECTING BASAL RESPONSES TO ACUTE MECHANICAL, HEAT, AND COLD STIMULI AS WELL AS LOCOMOTOR FUNCTIONS. MIMICKING THIS INCREASE THROUGH MICROINJECTION OF RECOMBINANT ADENO-ASSOCIATED VIRUS 5 HARBORING FULL-LENGTH OCT1 INTO THE UNILATERAL L4/5 DRG LED TO MARKED MECHANICAL ALLODYNIA, HEAT HYPERALGESIA, AND COLD ALLODYNIA IN NAIVE RATS. MECHANISTICALLY, OCT1 PARTICIPATED IN CCI-INDUCED INCREASES IN DNMT3A MRNA AND ITS PROTEIN AND DNMT3A-MEDIATED DECREASES IN OPRM1 AND KCNA2 MRNAS AND THEIR PROTEINS IN THE INJURED DRG. THESE FINDINGS INDICATE THAT OCT1 MAY PARTICIPATE IN NEUROPATHIC PAIN AT LEAST IN PART BY TRANSCRIPTIONALLY ACTIVATING DNMT3A AND SUBSEQUENTLY EPIGENETIC SILENCING OF OPRM1 AND KCAN2 IN THE DRG. OCT1 MAY SERVE AS A POTENTIAL TARGET FOR THERAPEUTIC TREATMENTS AGAINST NEUROPATHIC PAIN. 2019 12 6056 40 THE CYTIDINE N-ACETYLTRANSFERASE NAT10 PARTICIPATES IN PERIPHERAL NERVE INJURY-INDUCED NEUROPATHIC PAIN BY STABILIZING SYT9 EXPRESSION IN PRIMARY SENSORY NEURONS. RNA N4-ACETYLCYTIDINE (AC4C) MODIFICATION IS INCREASINGLY RECOGNIZED AS AN IMPORTANT LAYER OF GENE REGULATION; HOWEVER, THE INVOLVEMENT OF AC4C IN PAIN REGULATION HAS NOT BEEN STUDIED. HERE, WE REPORT THAT N-ACETYLTRANSFERASE 10 PROTEIN (NAT10; THE ONLY KNOWN AC4C "WRITER") CONTRIBUTES TO THE INDUCTION AND DEVELOPMENT OF NEUROPATHIC PAIN IN AN AC4C-DEPENDENT MANNER. PERIPHERAL NERVE INJURY INCREASES THE LEVELS OF NAT10 EXPRESSION AND OVERALL AC4C IN INJURED DORSAL ROOT GANGLIA (DRGS). THIS UPREGULATION IS TRIGGERED BY THE ACTIVATION OF UPSTREAM TRANSCRIPTION FACTOR 1 (USF1), A TRANSCRIPTION FACTOR THAT BINDS TO THE NAT10 PROMOTER. KNOCK-DOWN OR GENETIC DELETION OF NAT10 IN THE DRG ABOLISHES THE GAIN OF AC4C SITES IN SYT9 MRNA AND THE AUGMENTATION OF SYT9 PROTEIN, RESULTING IN A MARKED ANTINOCICEPTIVE EFFECT IN NERVE-INJURED MALE MICE. CONVERSELY, MIMICKING NAT10 UPREGULATION IN THE ABSENCE OF INJURY EVOKES THE ELEVATION OF SYT9 AC4C AND SYT9 PROTEIN AND INDUCES THE GENESIS OF NEUROPATHIC-PAIN-LIKE BEHAVIORS. THESE FINDINGS DEMONSTRATE THAT USF1-GOVERNED NAT10 REGULATES NEUROPATHIC PAIN BY TARGETING SYT9 AC4C IN PERIPHERAL NOCICEPTIVE SENSORY NEURONS. OUR FINDINGS ESTABLISH NAT10 AS A CRITICAL ENDOGENOUS INITIATOR OF NOCICEPTIVE BEHAVIOR AND A PROMISING NEW TARGET FOR TREATING NEUROPATHIC PAIN.SIGNIFICANCE STATEMENT THE CYTIDINE N4-ACETYLCYTIDINE (AC4C), A NEW EPIGENETIC RNA MODIFICATION, IS CRUCIAL FOR THE TRANSLATION AND STABILITY OF MRNA, BUT ITS ROLE FOR CHRONIC PAIN REMAINS UNCLEAR. HERE, WE DEMONSTRATE THAT N-ACETYLTRANSFERASE 10 (NAT10) ACTS AS AC4C N-ACETYLTRANSFERASE AND PLAYS AN IMPORTANT ROLE IN THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN. NAT10 WAS UPREGULATED VIA THE ACTIVATION OF THE TRANSCRIPTION FACTOR UPSTREAM TRANSCRIPTION FACTOR 1 (USF1) IN THE INJURED DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY. SINCE PHARMACOLOGICAL OR GENETIC DELETING NAT10 IN THE DRG ATTENUATED THE NERVE INJURY-INDUCED NOCICEPTIVE HYPERSENSITIVITIES PARTIALLY THROUGH SUPPRESSING SYT9 MRNA AC4C AND STABILIZING SYT9 PROTEIN LEVEL, NAT10 MAY SERVE AS AN EFFECTIVE AND NOVEL THERAPEUTIC TARGET FOR NEUROPATHIC PAIN. 2023 13 5297 54 PROTEIN ARGININE METHYLTRANSFERASE 5 CONTRIBUTES TO PACLITAXEL-INDUCED NEUROPATHIC PAIN BY ACTIVATING TRANSIENT RECEPTOR POTENTIAL VANILLOID 1 EPIGENETIC MODIFICATION IN DORSAL ROOT GANGLION. BACKGROUND: PACLITAXEL (PTX), WHICH IS A FIRST-LINE CHEMOTHERAPY DRUG USED TO TREAT VARIOUS TYPES OF CANCERS, EXHIBITS PERIPHERAL NEUROPATHY AS A COMMON SIDE EFFECT THAT IS DIFFICULT TO TREAT. PROTEIN ARGININE METHYLTRANSFERASE 5 (PRMT 5) IS A KEY REGULATOR OF THE CHEMOTHERAPY RESPONSE, AS CHEMOTHERAPY DRUGS INDUCE PRMT5 EXPRESSION. HOWEVER, LITTLE IS KNOWN ABOUT THE PRMT5-MEDIATED EPIGENETIC MECHANISMS INVOLVED IN PTX-INDUCED NEUROPATHIC ALLODYNIA. METHODS: SPRAGUE-DAWLEY RATS WERE INTRAPERITONEALLY GIVEN PTX TO INDUCE NEUROPATHIC PAIN. BIOCHEMICAL ANALYSES WERE CONDUCTED TO MEASURE THE PROTEIN EXPRESSION LEVELS IN THE DORSAL ROOT GANGLION (DRG) OF THE ANIMALS. THE VON FREY TEST AND HOT PLATE TEST WERE USED TO EVALUATE NOCICEPTIVE BEHAVIORS. RESULTS: PTX INCREASED THE PRMT5 (MEAN DIFFERENCE [MD]: 0.68, 95% CONFIDENCE INTERVAL [CI], 0.88-0.48; P < .001 FOR VEHICLE)-MEDIATED DEPOSITION OF HISTONE H3R2 DIMETHYL SYMMETRIC (H3R2ME2S) AT THE TRANSIENT RECEPTOR POTENTIAL VANILLOID 1 (TRPV1) PROMOTER IN THE DRG. PRMT5-INDUCED H3R2ME2S RECRUITED WD REPEAT DOMAIN 5 (WDR5) TO INCREASE TRIMETHYLATION OF LYSINE 4 ON HISTONE H3 (H3K4ME3) AT TRPV1 PROMOTERS, THUS RESULTING IN TRPV1 TRANSCRIPTIONAL ACTIVATION (MD: 0.65, 95% CI, 0.82-0.49; P < .001 FOR VEHICLE) IN DRG IN PTX-INDUCED NEUROPATHIC PAIN. MOREOVER, PTX INCREASED THE ACTIVITY OF NADPH OXIDASE 4 (NOX4) (MD: 0.66, 95% CI, 0.81-0.51; P < .001 FOR VEHICLE), PRMT5-INDUCED H3R2ME2S, AND WDR5-MEDIATED H3K4ME3 IN THE DRG IN PTX-INDUCED NEUROPATHIC PAIN. PHARMACOLOGICAL ANTAGONISM AND THE SELECTIVE KNOCKDOWN OF PRMT5 IN DRG NEURONS COMPLETELY BLOCKED PRMT5-MEDIATED H3R2ME2S, WDR5-MEDIATED H3K4ME3, OR TRPV1 EXPRESSION AND NEUROPATHIC PAIN DEVELOPMENT AFTER PTX INJECTION. REMARKABLY, NOX4 INHIBITION NOT ONLY ATTENUATED ALLODYNIA BEHAVIOR AND REVERSED THE ABOVE-MENTIONED SIGNALING BUT ALSO REVERSED NOX4 UPREGULATION VIA PTX. CONCLUSIONS: THUS, THE NOX4/PRMT5-ASSOCIATED EPIGENETIC MECHANISM IN DRG HAS A DOMINANT FUNCTION IN THE TRANSCRIPTIONAL ACTIVATION OF TRPV1 IN PTX-INDUCED NEUROPATHIC PAIN. 2023 14 2127 28 EPIGENETIC INACTIVATION OF MIR-9 FAMILY MICRORNAS IN CHRONIC LYMPHOCYTIC LEUKEMIA--IMPLICATIONS ON CONSTITUTIVE ACTIVATION OF NFKAPPAB PATHWAY. BACKGROUND: THE MIR-9 FAMILY MICRORNAS HAVE BEEN IDENTIFIED AS A TUMOR SUPPRESSOR MIRNA IN CANCERS. WE POSTULATED THAT MIR-9-1, MIR-9-2 AND MIR-9-3 MIGHT BE INACTIVATED BY DNA HYPERMETHYLATION IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). METHODS: METHYLATION OF MIR-9-1, MIR-9-2 AND MIR-9-3 WAS STUDIED IN EIGHT NORMAL CONTROLS INCLUDING NORMAL BONE MARROW, BUFFY COAT, AND CD19-SORTED PERIPHERAL BLOOD B-CELLS FROM HEALTHY INDIVIDUALS, SEVEN CLL CELL LINES, AND SEVENTY-EIGHT DIAGNOSTIC CLL SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. RESULTS: THE PROMOTERS OF MIR-9-3 AND MIR-9-1 WERE BOTH UNMETHYLATED IN NORMAL CONTROLS, BUT METHYLATED IN FIVE (71.4%) AND ONE OF SEVEN CLL CELL LINES RESPECTIVELY. HOWEVER, MIR-9-2 PROMOTER WAS METHYLATED IN NORMAL CONTROLS INCLUDING CD19 + VE B-CELLS, HENCE SUGGESTIVE OF A TISSUE-SPECIFIC BUT NOT TUMOR-SPECIFIC METHYLATION, AND THUS NOT FURTHER STUDIED. DIFFERENT MSP STATUSES OF MIR-9-3, INCLUDING COMPLETE METHYLATION, PARTIAL METHYLATION, AND COMPLETE UNMETHYLATION, WERE VERIFIED BY QUANTITATIVE BISULFITE METHYLATION ANALYSIS. 5-AZA-2'-DEOXYCYTIDINE TREATMENT RESULTED IN MIR-9-3 PROMOTER DEMETHYLATION AND RE-EXPRESSION OF PRI-MIR-9-3 IN I83-E95 AND WAC3CD5+ CELLS, WHICH WERE HOMOZYGOUSLY METHYLATED FOR MIR-9-3. MOREOVER, OVEREXPRESSION OF MIR-9 LED TO SUPPRESSED CELL PROLIFERATION AND ENHANCED APOPTOSIS TOGETHER WITH DOWNREGULATION OF NFKAPPAB1 IN I83-E95 CELLS, SUPPORTING A TUMOR SUPPRESSOR ROLE OF MIR-9-3 IN CLL. IN PRIMARY CLL SAMPLES, MIR-9-3 WAS DETECTED IN 17% AND MIR-9-1 METHYLATION IN NONE OF THE PATIENTS AT DIAGNOSIS. MOREOVER, MIR-9-3 METHYLATION WAS ASSOCIATED WITH ADVANCED RAI STAGE (>/= STAGE 2) (P = 0.04). CONCLUSIONS: OF THE MIR-9 FAMILY, MIR-9-3 IS A TUMOR SUPPRESSOR MIRNA RELATIVELY FREQUENTLY METHYLATED, AND HENCE SILENCED IN CLL; WHEREAS MIR-9-1 METHYLATION IS RARE IN CLL. THE ROLE OF MIR-9-3 METHYLATION IN THE CONSTITUTIVE ACTIVATION OF NFKAPPAB SIGNALING PATHWAY IN CLL WARRANTS FURTHER STUDY. 2013 15 2863 29 FUNCTION OF DNA METHYLTRANSFERASE 3A IN LEAD (PB(2+) )-INDUCED CYCLOOXYGENASE-2 GENE. LEAD IONS (PB(2+) ) ARE TOXIC INDUSTRIAL POLLUTANTS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES IN HUMANS AND ANIMALS. PREVIOUSLY, WE FOUND THAT PB(2+) IONS INDUCE COX-2 GENE EXPRESSION VIA THE EGF RECEPTOR/NUCLEAR FACTOR-KAPPAB SIGNAL TRANSDUCTION PATHWAY IN EPIDERMOID CARCINOMA CELL LINE A431. IN THIS STUDY, TO SEE WHETHER PB(2+) IONS AFFECT COX-2 EXPRESSION BY EPIGENETIC MECHANISMS, WE LOOKED AT THE MRNAS OF DNA METHYLTRANSFERASES (DNMTS) USING REAL-TIME PCR OF TOTAL RNA FROM THESE CELLS. CELLS EXPOSED TO PB(2+) HAD LOW LEVELS OF DNMT3A MRNA, WHEREAS THE LEVELS OF DNMT1 AND DNMT3B MRNAS REMAINED UNCHANGED. PRETREATMENT OF CELLS WITH DNMT INHIBITOR 5-AZA-2'-DEOXYCYTIDINE (5 MUM) FOLLOWED BY PB(2+) (1 MUM) SIGNIFICANTLY INCREASED LEVELS OF COX-2 MRNA COMPARED WITH CELLS TREATED WITH PB(2+) ALONE. OVEREXPRESSION OF TUMOR SUPPRESSOR GENE RB CORRELATED WITH AN INCREASE IN COX-2 MRNA AND A DECREASE IN DNMT3A MRNA. CONVERSELY, OVEREXPRESSION OF TRANSCRIPTION FACTOR E2F1 CORRELATED WITH A DECREASE IN COX-2 MRNA AND AN INCREASE IN DMNT3A MRNA. PRETREATMENT WITH EGFR INHIBITORS AG1478 AND PD153035 SIGNIFICANTLY LIMITED PB(2+) -INDUCED REDUCTION IN DNMT3A MRNA. IN ADDITION, GENE KNOCKDOWN OF DNMT3A WITH SHORT HAIRPIN RNA CORRELATED WITH INCREASED COX-2 MRNA INDUCED BY PB(2+) . OUR FINDINGS SUGGEST PB(2+) IONS INDUCE COX-2 EXPRESSION INDIRECTLY BY REDUCING DNMT3A METHYLATION OF THE COX-2 PROMOTER VIA TRANSCRIPTION FACTORS RB AND E2F1. 2015 16 5229 28 PRO-APOPTOTIC TP53 HOMOLOG TAP63 IS REPRESSED VIA EPIGENETIC SILENCING AND B-CELL RECEPTOR SIGNALLING IN CHRONIC LYMPHOCYTIC LEUKAEMIA. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS AN ACCUMULATIVE DISORDER MARKED BY DEFICIENT APOPTOSIS. THE TP53 HOMOLOG TAP63 PROMOTES APOPTOSIS AND CHEMOSENSITIVITY IN SOLID TUMOURS AND ITS DEREGULATION MAY CONTRIBUTE TO CLL CELL SURVIVAL. WE FOUND THAT TAP63ALPHA WAS THE MOST PREVALENT TP63 ISOFORM IN CLL. COMPARED TO HEALTHY B CELLS, TAP63 MRNA WAS REPRESSED IN 55.7% OF CLL SAMPLES. TP63 PROMOTER METHYLATION WAS HIGH IN CLL AND INVERSELY CORRELATED WITH TP63 PROTEIN EXPRESSION IN B-CELL LYMPHOMA CELL LINES. SIRNA-MEDIATED KNOCKDOWN OF TP63 RESULTED IN PARTIAL PROTECTION FROM SPONTANEOUS APOPTOSIS ACCOMPANIED BY REDUCTIONS IN PMAIP1 (NOXA), BBC3 (PUMA), AND BAX MRNA IN CLL CELLS AND INCREASED PROLIFERATION OF RAJI LYMPHOMA CELLS. TAP63 MRNA LEVELS WERE HIGHER IN CLL WITH UNMUTATED IGHV. B-CELL RECEPTOR (BCR) ENGAGEMENT LED TO REPRESSION OF TP63 MRNA EXPRESSION IN MALIGNANT B CELLS, WHILE PHARMACOLOGICAL INHIBITION OF BCR SIGNALLING PREVENTED TP63 DOWNREGULATION. MIR21, KNOWN TO TARGET TAP63, CORRELATED INVERSELY WITH TAP63 EXPRESSION IN CLL, AND BCR-MEDIATED DOWNREGULATION OF TP63 WAS ACCOMPANIED BY MIR21 UPREGULATION IN MOST CLL SAMPLES. OUR DATA ILLUSTRATE THE PRO-APOPTOTIC FUNCTION OF TP63, PROVIDE INSIGHTS INTO THE MECHANISMS OF BCR-TARGETING AGENTS, AND ESTABLISH A RATIONALE FOR DESIGNING NOVEL APPROACHES TO INDUCE TP63 IN CLL AND B-CELL LYMPHOMA. 2013 17 2134 27 EPIGENETIC INACTIVATION OF THE MIR129-2 IN HEMATOLOGICAL MALIGNANCIES. BACKGROUND: MIR129-2 HAS BEEN SHOWN TO BE A TUMOR SUPPRESSOR MICRORNA HYPERMETHYLATED IN EPITHELIAL CANCERS. PATIENTS AND METHODS: EPIGENETIC INACTIVATION OF MIR129-2 WAS STUDIED BY METHYLATION-SPECIFIC PCR (MSP) IN 13 CELL LINES (EIGHT MYELOMA AND FIVE LYMPHOMA), 15 NORMAL CONTROLS AND 344 PRIMARY SAMPLES INCLUDING ACUTE MYELOID LEUKEMIA (AML), ACUTE LYMPHOBLASTIC LEUKEMIA (ALL), CHRONIC MYELOID LEUKEMIA (CML), CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), NON-HODGKIN'S LYMPHOMA (NHL), MULTIPLE MYELOMA (MM) AT DIAGNOSIS, MM AT RELAPSE/PROGRESSION, AND MONOCLONAL GAMMOPATHY OF UNDETERMINED SIGNIFICANCE (MGUS). EXPRESSION OF MIR129 AND ITS TARGET, SOX4, IN CELL LINES WAS MEASURED BEFORE AND AFTER HYPOMETHYLATING TREATMENT AND MIR129 OVEREXPRESSION. MIR129 EXPRESSION WAS CORRELATED WITH MIR129-2 METHYLATION STATUS IN PRIMARY LYMPHOMA SAMPLES. TUMOR SUPPRESSOR FUNCTION OF MIR129 WAS DEMONSTRATED BY MTT AND TRYPAN BLUE EXCLUSION ASSAY AFTER MIR129 OVEREXPRESSION. RESULTS: THE SENSITIVITY OF THE METHYLATED-MSP WAS ONE IN 10(3). DIFFERENT MSP STATUSES, INCLUDING COMPLETE METHYLATION, PARTIAL METHYLATION, AND COMPLETE UNMETHYLATION, WERE VERIFIED BY QUANTITATIVE BISULFITE PYROSEQUENCING. ALL FIVE LYMPHOMA AND SEVEN OF EIGHT MYELOMA CELL LINES SHOWED COMPLETE AND PARTIAL MIR129-2 METHYLATION. IN PRIMARY SAMPLES, MIR129-2 METHYLATION WAS ABSENT IN AML AND CML, BUT DETECTED IN 5% ALL, 45.9% CLL, 49.5% MM AT DIAGNOSIS, AND 59.1% NHL. IN CLL, MIR129-2 METHYLATION ADVERSELY IMPACTED ON SURVIVAL (P=0.004). IN MM, MIR129-2 METHYLATION INCREASED FROM 27.5% MGUS TO 49.5% MM AT DIAGNOSIS AND 41.5% AT RELAPSE/PROGRESSION (P=0.023). IN NHL, MIR129-2 METHYLATION WAS ASSOCIATED WITH MIR124-1 AND MIR203 METHYLATION (P<0.001), AND LOWER MIR129 EXPRESSION (P=0.009). HYPOMETHYLATION TREATMENT OF JEKO-1, HOMOZYGOUSLY METHYLATED FOR MIR129-2, LED TO MIR129-2 DEMETHYLATION AND MIR129 RE-EXPRESSION, WITH DOWNREGULATION OF SOX4 MRNA. MOREOVER, MIR129 OVEREXPRESSION IN BOTH MANTLE CELL LINES, JEKO-1 AND GRANTA-519, INHIBITED CELLULAR PROLIFERATION AND ENHANCED CELL DEATH, WITH CONCOMITANT SOX4 MRNA DOWNREGULATION. CONCLUSIONS: MIR129-2 IS A TUMOR SUPPRESSIVE MICRORNA FREQUENTLY METHYLATED IN LYMPHOID BUT NOT MYELOID MALIGNANCIES, LEADING TO REVERSIBLE MIR129-2 SILENCING. IN CLL, MIR129-2 METHYLATION WAS ASSOCIATED WITH AN INFERIOR SURVIVAL. IN MM, MIR129-2 METHYLATION MIGHT BE ACQUIRED DURING PROGRESSION FROM MGUS TO SYMPTOMATIC MM. IN NHL, MIR129-2 METHYLATION MIGHT COLLABORATE WITH MIR124-1 AND MIR203 METHYLATION IN LYMPHOMAGENESIS. 2013 18 1334 27 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 19 5062 37 PHOSPHATE NIMA-RELATED KINASE 2-DEPENDENT EPIGENETIC PATHWAYS IN DORSAL ROOT GANGLION NEURONS MEDIATES PACLITAXEL-INDUCED NEUROPATHIC PAIN. BACKGROUND: THE MICROTUBULE-STABILIZING DRUG PACLITAXEL (PTX) IS AN IMPORTANT CHEMOTHERAPEUTIC AGENT FOR CANCER TREATMENT AND CAUSES PERIPHERAL NEUROPATHY AS A COMMON SIDE EFFECT THAT SUBSTANTIALLY IMPACTS THE FUNCTIONAL STATUS AND QUALITY OF LIFE OF PATIENTS. THE MECHANISTIC ROLE FOR NIMA-RELATED KINASE 2 (NEK2) IN THE PROGRESSION OF PTX-INDUCED NEUROPATHIC PAIN HAS NOT BEEN ESTABLISHED. METHODS: ADULT MALE SPRAGUE-DAWLEY RATS INTRAPERITONEALLY RECEIVED PTX TO INDUCE NEUROPATHIC PAIN. THE PROTEIN EXPRESSION LEVELS IN THE DORSAL ROOT GANGLION (DRG) OF ANIMALS WERE MEASURED BY BIOCHEMICAL ANALYSES. NOCICEPTIVE BEHAVIORS WERE EVALUATED BY VON FREY TESTS AND HOT PLATE TESTS. RESULTS: PTX INCREASED PHOSPHORYLATION OF THE IMPORTANT MICROTUBULE DYNAMICS REGULATOR NEK2 IN DRG NEURONS AND INDUCED PROFOUND NEUROPATHIC ALLODYNIA. PTX-ACTIVATED PHOSPHORYLATED NEK2 (PNEK2) INCREASED JUMONJI DOMAIN-CONTAINING 3 (JMJD3) PROTEIN, A HISTONE DEMETHYLASE PROTEIN, TO SPECIFICALLY CATALYZE THE DEMETHYLATION OF THE REPRESSIVE HISTONE MARK H3 LYSINE 27 TRIMETHYLATION (H3K27ME3) AT THE TRPV1 GENE, THEREBY ENHANCING TRANSIENT RECEPTOR POTENTIAL VANILLOID SUBTYPE-1 (TRPV1) EXPRESSION IN DRG NEURONS. MOREOVER, THE PNEK2-DEPENDENT PTX RESPONSE PROGRAM IS REGULATED BY ENHANCING P90 RIBOSOMAL S6 KINASE 2 (RSK2) PHOSPHORYLATION. CONVERSELY, INTRATHECAL INJECTIONS OF KAEMPFEROL (A SELECTIVE RSK2 ACTIVATION ANTAGONIST), NCL 00017509 (A SELECTIVE NEK2 INHIBITOR), NEK2-TARGETED SIRNA, GSK-J4 (A SELECTIVE JMJD3 INHIBITOR), OR CAPSAZEPINE (AN ANTAGONIST OF TRPV1 RECEPTOR) INTO PTX-TREATED RATS REVERSED NEUROPATHIC ALLODYNIA AND RESTORED SILENCING OF THE TRPV1 GENE, SUGGESTING THE HIERARCHY AND INTERACTION AMONG PHOSPHORYLATED RSK2 (PRSK2), PNEK2, JMJD3, H3K27ME3, AND TRPV1 IN THE DRG NEURONS IN PTX-INDUCED NEUROPATHIC PAIN. CONCLUSIONS: PRSK2/JMJD3/H3K27ME3/TRPV1 SIGNALING IN THE DRG NEURONS PLAYS AS A KEY REGULATOR FOR PTX THERAPEUTIC APPROACHES. 2023 20 1318 32 DEMETHYLATION OF G-PROTEIN-COUPLED RECEPTOR 151 PROMOTER FACILITATES THE BINDING OF KRUPPEL-LIKE FACTOR 5 AND ENHANCES NEUROPATHIC PAIN AFTER NERVE INJURY IN MICE. G-PROTEIN-COUPLED RECEPTORS ARE CONSIDERED TO BE CELL-SURFACE SENSORS OF EXTRACELLULAR SIGNALS, THEREBY HAVING A CRUCIAL ROLE IN SIGNAL TRANSDUCTION AND BEING THE MOST FRUITFUL TARGETS FOR DRUG DISCOVERY. G-PROTEIN-COUPLED RECEPTOR 151 (GPR151) WAS REPORTED TO BE EXPRESSED SPECIFICALLY IN THE HABENULAR AREA. HERE WE REPORT THE EXPRESSION AND THE EPIGENETIC REGULATION OF GRP151 IN THE SPINAL CORD AFTER SPINAL NERVE LIGATION (SNL) AND THE CONTRIBUTION OF GPR151 TO NEUROPATHIC PAIN IN MALE MICE. SNL DRAMATICALLY INCREASED GPR151 EXPRESSION IN SPINAL NEURONS. GPR151 MUTATION OR SPINAL INHIBITION BY SHRNA ALLEVIATED SNL-INDUCED MECHANICAL ALLODYNIA AND HEAT HYPERALGESIA. INTERESTINGLY, THE CPG ISLAND IN THE GPR151 GENE PROMOTER REGION WAS DEMETHYLATED, THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) WAS DECREASED, AND THE BINDING OF DNMT3B WITH GPR151 PROMOTER WAS REDUCED AFTER SNL. OVEREXPRESSION OF DNMT3B IN THE SPINAL CORD DECREASED GPR151 EXPRESSION AND ATTENUATED SNL-INDUCED NEUROPATHIC PAIN. FURTHERMORE, KRUPPEL-LIKE FACTOR 5 (KLF5), A TRANSCRIPTIONAL FACTOR OF THE KLF FAMILY, WAS UPREGULATED IN SPINAL NEURONS, AND THE BINDING AFFINITY OF KLF5 WITH GPR151 PROMOTER WAS INCREASED AFTER SNL. INHIBITION OF KLF5 REDUCED GPR151 EXPRESSION AND ATTENUATED SNL-INDUCED PAIN HYPERSENSITIVITY. FURTHER MRNA MICROARRAY ANALYSIS REVEALED THAT MUTATION OF GPR151 REDUCED THE EXPRESSION OF A VARIETY OF PAIN-RELATED GENES IN RESPONSE TO SNL, ESPECIALLY MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) SIGNALING PATHWAY-ASSOCIATED GENES. THIS STUDY REVEALS THAT GPR151, INCREASED BY DNA DEMETHYLATION AND THE ENHANCED INTERACTION WITH KLF5, CONTRIBUTES TO THE MAINTENANCE OF NEUROPATHIC PAIN VIA INCREASING MAPK PATHWAY-RELATED GENE EXPRESSION.SIGNIFICANCE STATEMENT G-PROTEIN-COUPLED RECEPTORS (GPCRS) ARE TARGETS OF VARIOUS CLINICALLY APPROVED DRUGS. HERE WE REPORT THAT SNL INCREASED GPR151 EXPRESSION IN THE SPINAL CORD, AND MUTATION OR INHIBITION OF GPR151 ALLEVIATED SNL-INDUCED NEUROPATHIC PAIN. IN ADDITION, SNL DOWNREGULATED THE EXPRESSION OF DNMT3B, WHICH CAUSED DEMETHYLATION OF GPR151 GENE PROMOTER, FACILITATED THE BINDING OF TRANSCRIPTIONAL FACTOR KLF5 WITH THE GPR151 PROMOTER, AND FURTHER INCREASED GPR151 EXPRESSION IN SPINAL NEURONS. THE INCREASED GPR151 MAY CONTRIBUTE TO THE PATHOGENESIS OF NEUROPATHIC PAIN VIA ACTIVATING MAPK SIGNALING AND INCREASING PAIN-RELATED GENE EXPRESSION. OUR STUDY REVEALS AN EPIGENETIC MECHANISM UNDERLYING GPR151 EXPRESSION AND SUGGESTS THAT TARGETING GPR151 MAY OFFER A NEW STRATEGY FOR THE TREATMENT OF NEUROPATHIC PAIN. 2018