1 3815 176 INTRAUTERINE PROGRAMMING MECHANISM FOR HYPERCHOLESTEROLEMIA IN PRENATAL CAFFEINE-EXPOSED FEMALE ADULT RAT OFFSPRING. CLINICAL AND ANIMAL STUDIES HAVE INDICATED THAT HYPERCHOLESTEROLEMIA AND ITS ASSOCIATED DISEASES HAVE INTRAUTERINE DEVELOPMENTAL ORIGINS. OUR PREVIOUS STUDIES SHOWED THAT PRENATAL CAFFEINE EXPOSURE (PCE) LED TO FETAL OVEREXPOSURE TO MATERNAL GLUCOCORTICOIDS (GCS) AND INCREASED SERUM TOTAL CHOLESTEROL LEVELS IN ADULT RAT OFFSPRING. THIS STUDY FURTHER CONFIRMS THE INTRAUTERINE PROGRAMMING OF PCE-INDUCED HYPERCHOLESTEROLEMIA IN FEMALE ADULT RAT OFFSPRING. PREGNANT WISTAR RATS WERE INTRAGASTRICALLY ADMINISTERED CAFFEINE (30, 60, AND 120 MG/KG/D) FROM GESTATIONAL DAY (GD)9 TO 20. FEMALE RAT OFFSPRING WERE EUTHANIZED AT GD20 AND POSTNATAL WK 12; SEVERAL ADULT RAT OFFSPRING WERE ADDITIONALLY SUBJECTED TO ICE-WATER SWIMMING STIMULATION TO INDUCE CHRONIC STRESS PRIOR TO DEATH. THE EFFECTS OF GCS ON CHOLESTEROL METABOLISM AND EPIGENETIC REGULATION WERE VERIFIED USING THE L02 CELL LINE. THE RESULTS SHOWED THAT PCE INDUCED HYPERCHOLESTEROLEMIA IN ADULT OFFSPRING, WHICH MANIFESTED AS SIGNIFICANTLY HIGHER LEVELS OF SERUM TOTAL CHOLESTEROL AND LDL CHOLESTEROL (LDL-C) AS WELL AS HIGHER RATIOS OF LDL-C/HDL CHOLESTEROL. WE FURTHER FOUND THAT THE CHOLESTEROL LEVELS WERE INCREASED IN FETAL LIVERS BUT WERE DECREASED IN FETAL BLOOD, ACCOMPANIED BY INCREASED MATERNAL BLOOD CHOLESTEROL LEVELS AND REDUCED PLACENTAL CHOLESTEROL TRANSPORT. FURTHERMORE, ANALYSIS OF PCE OFFSPRING IN THE UTERUS AND IN A POSTNATAL BASAL/CHRONIC STRESS STATE AND THE RESULTS OF IN VITRO EXPERIMENTS SHOWED THAT HEPATIC CHOLESTEROL METABOLISM UNDERWENT GC-DEPENDENT CHANGES AND WAS ASSOCIATED WITH CHOLESTEROL SYNTHASE VIA ABNORMALITIES IN 3-HYDROXY-3-METHYLGLUTARYL-COA REDUCTASE (HMGCR) HISTONE ACETYLATION. WE CONCLUDED THAT, TO COMPENSATE FOR INTRAUTERINE PLACENTALLY DERIVED DECREASES IN FETAL BLOOD CHOLESTEROL LEVELS, HIGH INTRAUTERINE GC LEVELS ACTIVATED FETAL HEPATIC CCAAT ENHANCER BINDING PROTEIN ALPHA SIGNALING AND DOWN-REGULATED SIRTUIN1 EXPRESSION, WHICH MEDIATED THE HIGH LEVELS OF HISTONE ACETYLATION ( VIA H3K9AC AND H3K14AC) AND EXPRESSION OF HMGCR. THIS GC-DEPENDENT CHOLESTEROL METABOLISM PROGRAMMING EFFECT WAS SUSTAINED THROUGH ADULTHOOD, LEADING TO THE OCCURRENCE OF HYPERCHOLESTEROLEMIA.-XU, D., LUO, H. W., HU, W., HU, S. W., YUAN, C., WANG, G. H., ZHANG, L., YU, H., MAGDALOU, J., CHEN, L. B., WANG, H. INTRAUTERINE PROGRAMMING MECHANISM FOR HYPERCHOLESTEROLEMIA IN PRENATAL CAFFEINE-EXPOSED FEMALE ADULT RAT OFFSPRING. 2018 2 1839 59 EFFECTS OF PRENATAL NICOTINE EXPOSURE ON HEPATIC GLUCOSE AND LIPID METABOLISM IN OFFSPRING RATS AND ITS HEREDITABILITY. PRENATAL NICOTINE EXPOSURE (PNE) COULD INDUCE AN INCREASED SUSCEPTIBILITY TO MULTIPLE CHRONIC DISEASES IN ADULT OFFSPRING, THAT MAINLY CAUSED BY INTRAUTERINE MATERNAL GLUCOCORTICOID (GC) OVER-EXPOSURE. WE INVESTIGATED THE CHANGES AND INHERITABILITY OF HEPATIC GLUCOSE AND LIPID METABOLISM CAUSED BY PNE, TO DECIPHER THE POSSIBLE INTRAUTERINE PROGRAMMING MECHANISM. PREGNANT WISTAR RATS WERE ADMINISTERED SUBCUTANEOUSLY WITH 2 MG/KG.D NICOTINE FROM GESTATIONAL DAY (GD) 9 APPROXIMATELY 20, AND SECOND-GENERATION (F2) WERE SET ACCORDING TO THE MATING BETWEEN CONTROL FEMALES AND PNE MALES. THE RESULTS SHOWED THAT SERUM PHENOTYPES AND HEPATIC ENZYMES OF GLUCOSE AND LIPID METABOLISM WERE LOWER IN F1 FETAL RATS OF PNE BUT HIGHER IN THE F1 ADULT RATS. MEANWHILE, THE ACTIVATED STATES OF HEPATIC GLUCOCORTICOID-ACTIVATION SYSTEM, INCLUDING TYPE 1 AND TYPE 2 11BETA-HYDROXYSTEROID DEHYDROGENASES (HSD11B1/2), NUCLEAR RECEPTOR SUBFAMILY 3, GROUP C, MEMBER 1 (NR3C1) AND CCAAT ENHANCER BINDING PROTEIN ALPHA (CEBPA), WERE POSITIVELY CORRELATED WITH SERUM CORTICOSTERONE LEVELS BUT NEGATIVELY CORRELATED WITH THE HISTONE ACETYLATION (H3K27AC) AND EXPRESSION LEVELS OF INSULIN-LIKE GROWTH FACTOR 1 (IGF1) BEFORE AND AFTER BIRTH. FURTHERMORE, SERUM PHENOTYPES AND HEPATIC ENZYMES OF GLUCOSE AND LIPID METABOLISM WERE LOWER IN BOTH F2 FETAL AND ADULT RATS OF PNE, WHICH WERE CONSISTENT WITH THE HEPATIC CHANGES OF GC-IGF1 AXIS AND THE GLUCOCORTICOID-ACTIVATION SYSTEM. IN CONCLUSION, PNE COULD LEAD TO INHERITABLE CHANGES OF HEPATIC GLUCOSE AND LIPID METABOLISM, WHICH ARE RELATED TO THE INTRAUTERINE PROGRAMMING OF GC-IGF1 AXIS INDUCED BY THE GLUCOCORTICOID-ACTIVATION SYSTEM. 2020 3 5266 37 PROMOTED INTERACTION OF C/EBPALPHA WITH DEMETHYLATED CXCR3 GENE PROMOTER CONTRIBUTES TO NEUROPATHIC PAIN IN MICE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER NEUROPATHIC PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR3 IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY SPINAL NERVE LIGATION (SNL) IN MICE. SNL INCREASED CXCR3 MRNA AND PROTEIN EXPRESSION IN THE NEURONS OF THE SPINAL CORD. MEANWHILE, THE CPG (5'-CYTOSINE-PHOSPHATE-GUANINE-3') ISLAND IN THE CXCR3 GENE PROMOTER REGION WAS DEMETHYLATED, AND THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) WAS DECREASED. SNL ALSO INCREASED THE BINDING OF CCAAT (CYTIDINE-CYTIDINE-ADENOSINE-ADENOSINE-THYMIDINE)/ENHANCER BINDING PROTEIN ALPHA (C/EBPALPHA) WITH CXCR3 PROMOTER AND DECREASED THE BINDING OF DNMT3B WITH CXCR3 PROMOTER IN THE SPINAL CORD. C/EBPALPHA EXPRESSION WAS INCREASED IN SPINAL NEURONS AFTER SNL, AND INHIBITION OF C/EBPALPHA BY INTRATHECAL SMALL INTERFERING RNA ATTENUATED SNL-INDUCED PAIN HYPERSENSITIVITY AND REDUCED CXCR3 EXPRESSION. FURTHERMORE, SNL-INDUCED MECHANICAL ALLODYNIA AND HEAT HYPERALGESIA WERE MARKEDLY REDUCED IN CXCR3(-/-) MICE. SPINAL INHIBITION OF CXCR3 BY SHRNA OR CXCR3 ANTAGONIST ALSO ATTENUATED ESTABLISHED NEUROPATHIC PAIN. MOREOVER, CXCL10, THE LIGAND OF CXCR3, WAS INCREASED IN SPINAL NEURONS AND ASTROCYTES AFTER SNL. SUPERFUSING SPINAL CORD SLICES WITH CXCL10 ENHANCED SPONTANEOUS EPSCS AND POTENTIATED NMDA-INDUCED AND AMPA-INDUCED CURRENTS OF LAMINA II NEURONS. FINALLY, INTRATHECAL INJECTION OF CXCL10 INDUCED CXCR3-DEPENDENT PAIN HYPERSENSITIVITY IN NAIVE MICE. COLLECTIVELY, OUR RESULTS DEMONSTRATED THAT CXCR3, INCREASED BY DNA DEMETHYLATION AND THE ENHANCED INTERACTION WITH C/EBPALPHA, CAN BE ACTIVATED BY CXCL10 TO FACILITATE EXCITATORY SYNAPTIC TRANSMISSION AND CONTRIBUTE TO THE MAINTENANCE OF NEUROPATHIC PAIN. SIGNIFICANCE STATEMENT: PERIPHERAL NERVE INJURY INDUCES CHANGES OF GENE EXPRESSION IN THE SPINAL CORD THAT MAY CONTRIBUTE TO THE PATHOGENESIS OF NEUROPATHIC PAIN. CXCR3 IS A CHEMOKINE RECEPTOR. WHETHER IT IS INVOLVED IN NEUROPATHIC PAIN AND HOW IT IS REGULATED AFTER NERVE INJURY REMAIN LARGELY UNKNOWN. OUR STUDY DEMONSTRATES THAT SPINAL NERVE LIGATION DOWNREGULATES THE EXPRESSION OF DNMT3B, WHICH MAY CAUSE DEMETHYLATION OF CXCR3 GENE PROMOTER AND FACILITATE THE BINDING OF CCAAT/ENHANCER BINDING PROTEIN ALPHA WITH CXCR3 PROMOTER AND FURTHER INCREASE CXCR3 EXPRESSION IN SPINAL NEURONS. THE UPREGULATED CXCR3 MAY CONTRIBUTE TO NEUROPATHIC PAIN BY FACILITATING CENTRAL SENSITIZATION. OUR STUDY REVEALS AN EPIGENETIC MECHANISM UNDERLYING CXCR3 EXPRESSION AND ALSO SUGGESTS THAT TARGETING THE EXPRESSION OR ACTIVATION OF CXCR3 SIGNALING MAY OFFER NEW THERAPEUTICS FOR NEUROPATHIC PAIN. 2017 4 3816 58 INTRAUTERINE PROGRAMMING OF CARTILAGINOUS 11BETA-HSD2 INDUCED BY CORTICOSTERONE AND CAFFEINE MEDIATED SUSCEPTIBILITY TO ADULT OSTEOARTHRITIS. OUR PREVIOUS STUDY REPORTED THAT PRENATAL CAFFEINE EXPOSURE (PCE) COULD INDUCE CHONDRODYSPLASIA AND INCREASE THE SUSCEPTIBILITY TO OSTEOARTHRITIS IN OFFSPRING RATS. HOWEVER, THE POTENTIAL MECHANISMS AND INITIATING FACTORS REMAIN UNKNOWN. THIS STUDY AIMS TO INVESTIGATE WHETHER 11BETA-HSD2, A GLUCOCORTICOID-METABOLIZING ENZYME, IS INVOLVED IN THE SUSCEPTIBILITY OF OSTEOARTHRITIS INDUCED BY PCE AND TO FURTHER EXPLORE ITS POTENTIAL MECHANISMS AND INITIATING FACTORS. FIRSTLY, WE FOUND THAT PCE REDUCED CARTILAGE MATRIX SYNTHESIS (AGGRECAN/COL2A1 EXPRESSION) IN MALE ADULT OFFSPRING RATS AND EXHIBITED AN OSTEOARTHRITIS PHENOTYPE FOLLOWING CHRONIC STRESS, WHICH WAS ASSOCIATED WITH PERSISTENTLY REDUCED H3K9AC AND H3K27AC LEVELS AT THE PROMOTER OF 11BETA-HSD2 AS WELL AS ITS EXPRESSION IN THE CARTILAGE FROM FETUS TO ADULTHOOD. THE EXPRESSION OF 11BETA-HSD2, AGGRECAN AND COL2A1 WERE ALL DECREASED BY CORTICOSTERONE IN THE FETAL CHONDROCYTES, WHILE OVEREXPRESSION OF 11BETA-HSD2 COULD PARTIALLY ALLEVIATE THE DECREASE OF MATRIX SYNTHESIS INDUCED BY CORTICOSTERONE IN VITRO. FURTHERMORE, THE GLUCOCORTICOID RECEPTOR (GR) ACTIVATED BY GLUCOCORTICOIDS DIRECTLY BONDED TO THE PROMOTER REGION OF 11BETA-HSD2 TO INHIBIT ITS EXPRESSION. MEANWHILE, THE ACTIVATED GR REDUCED THE H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2 BY RECRUITING HDAC4 AND PROMOTING GR-HDAC4 PROTEIN INTERACTION TO INHIBIT THE 11BETA-HSD2 EXPRESSION. MOREOVER, CAFFEINE COULD REDUCE THE EXPRESSION OF 11BETA-HSD2 BY INHIBITING THE CAMP/PKA SIGNALING PATHWAY BUT WITHOUT REDUCING THE H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2, THEREBY SYNERGISTICALLY ENHANCING THE CORTICOSTERONE EFFECT. IN CONCLUSION, THE PERSISTENTLY REDUCED H3K9AC AND H3K27AC LEVELS OF 11BETA-HSD2 FROM FETUS TO ADULTHOOD MEDIATED THE INHIBITION OF CARTILAGE MATRIX SYNTHESIS AND THE INCREASED SUSCEPTIBILITY TO OSTEOARTHRITIS. THIS EPIGENETIC PROGRAMMING CHANGE IN UTERO WAS INDUCED BY GLUCOCORTICOIDS WITH SYNERGISTIC EFFECT OF CAFFEINE. 2022 5 3812 67 INTRAUTERINE ENDOGENOUS HIGH GLUCOCORTICOIDS PROGRAM OVARIAN DYSFUNCTION IN FEMALE OFFSPRING SECONDARY TO PRENATAL CAFFEINE EXPOSURE. OVARIAN DYSFUNCTION HAS AN INTRAUTERINE ORIGIN, AND PRENATAL CAFFEINE EXPOSURE (PCE) COULD LEAD TO ABNORMAL FOLLICLE COUNTS IN OFFSPRING AFTER BIRTH. HOWEVER, THE EFFECT OF PCE ON OFFSPRING OVARIAN FUNCTION AND ITS MECHANISM OF INTRAUTERINE PROGRAMMING HAVE NOT BEEN REPORTED THUS FAR. IN THIS STUDY, PREGNANT WISTAR RATS WERE INTRAGASTRICALLY ADMINISTERED CAFFEINE (30 AND 120 MG/KG.D) AT GESTATIONAL DAYS 9-20 (GD9-20). CERTAIN TESTS WERE PERFORMED ON THE BLOOD, OVARIES AND HYPOTHALAMUS OF FEMALE OFFSPRING AT DIFFERENT TIME POINTS. PCE FEMALE OFFSPRING HAD OVARIAN DYSFUNCTION IN ADULTHOOD COMPARED WITH THE CONTROL. FURTHER RESULTS SHOWED THAT IN UTERO OVARIAN MORPHOLOGICAL DEVELOPMENT AND ESTRADIOL SYNTHESIS WERE INHIBITED BUT RAPIDLY INCREASED DURING PUBERTY IN THE PCE GROUP. THE HISTONE 3 LYSINE 27 ACETYLATION (H3K27AC) LEVEL OF THE INSULIN-LIKE GROWTH FACTOR 1 (IGF1) PROMOTER REGION AND ITS EXPRESSION WERE DECREASED IN THE OVARY, WHICH WAS DUE TO EXPOSURE TO HIGH LEVELS OF FETAL BLOOD CORTICOSTERONE, AND THE H3K27AC LEVEL OF IGF1 AND ITS EXPRESSION SHIFTED TO INCREASE AFTER BIRTH WITH A DECREASE IN SERUM CORTICOSTERONE LEVELS. CHRONIC STRESS LED TO INCREASED SERUM CORTICOSTERONE LEVELS IN ADULT OFFSPRING, WHEREAS OVARIAN MORPHOLOGICAL DEVELOPMENT, THE H3K27AC LEVEL OF IGF1 AND ITS EXPRESSION, AND ESTRADIOL SYNTHESIS WERE SIGNIFICANTLY INHIBITED. MOREOVER, THE ACTIVITY OF THE HYPOTHALAMIC-PITUITARY-OVARIAN (HPO) AXIS WAS INCREASED IN THE EARLY POSTNATAL PERIOD OF PCE OFFSPRING, AND CHRONIC STRESS REVERSED THESE CHANGES. IN THE KGN CELL LINE, IT WAS FOUND THAT CORTISOL COULD PROMOTE THE TRANSLOCATION OF THE GLUCOCORTICOID RECEPTOR (GR) INTO THE NUCLEUS AND UPREGULATE HISTONE DEACETYLASE 10 (HDAC10) TO INHIBIT THE H3K27AC LEVEL OF IGF1 AND ITS EXPRESSION AND ESTRADIOL SYNTHESIS. IN SUMMARY, PCE IS ASSOCIATED WITH OVARIAN DYSFUNCTION IN FEMALE ADULT OFFSPRING, AND THE POTENTIAL MECHANISM IS RELATED TO INTRAUTERINE HIGH GLUCOCORTICOID EXPOSURE BY ACTIVATING THE GR AND RECRUITING HDAC10 TO AFFECT OVARIAN GLUCOCORTICOID-IGF1 AXIS PROGRAMMING AND TO INHIBIT ESTRADIOL SYNTHESIS. 2021 6 5191 58 PRENATAL DEXAMETHASONE EXPOSURE PROGRAMS THE DECREASED TESTOSTERONE SYNTHESIS IN OFFSPRING RATS BY LOW LEVEL OF ENDOGENOUS GLUCOCORTICOIDS. PRENATAL DEXAMETHASONE EXPOSURE (PDE) CAN DECREASE MATERNAL ENDOGENOUS GLUCOCORTICOID LEVEL AND INDUCE TESTICULAR DYSPLASIA IN MALE OFFSPRING RATS. IN THIS STUDY WE INVESTIGATED LOW LEVEL ENDOGENOUS GLUCOCORTICOID-MEDIATED TESTICULAR DYSPLASIA IN PDE OFFSPRING AND ELUCIDATED THE INTRAUTERINE EPIGENETIC PROGRAMMING MECHANISMS. PREGNANT RATS WERE INJECTED WITH DEXAMETHASONE (0.2 MG.KG(-1).D(-1), SC) ON GESTATIONAL DAY (GD) 9-20. THE OFFSPRING RAT BLOOD AND TESTIS WERE COLLECTED AFTER EUTHANASIA ON GD20, POSTNATAL WEEK (PW) 12 OR PW28. WE SHOWED THAT PDE INDUCED ABNORMAL MORPHOLOGY OF TESTIS AND SIGNIFICANTLY DECREASED THE EXPRESSION OF TESTOSTERONE SYNTHESIS-RELATED GENES AS WELL AS TESTOSTERONE PRODUCTION BEFORE AND AFTER BIRTH. MEANWHILE, SERUM CORTICOSTERONE, THE EXPRESSION AND HISTONE 3 LYSINE 14 ACETYLATION (H3K14AC) OF TESTICULAR INSULIN-LIKE GROWTH FACTOR 1 (IGF1) WERE SIGNIFICANTLY DECREASED. AFTER THE PREGNANT RATS WERE SUBJECTED TO CHRONIC STRESS FOR 2 WEEKS (PW10-12), SERUM CORTICOSTERONE LEVEL WAS INCREASED IN THE ADULT PDE OFFSPRING, AND THE ABOVE-MENTIONED OTHER INDICATORS WERE ALSO IMPROVED. CULTURED LEYDIG CELLS (TM3) WERE TREATED WITH CORTICOSTERONE (62.5-500 NM) IN VITRO. WE SHOWED THAT CORTICOSTERONE CONCENTRATION-DEPENDENTLY INHIBITED GLUCOCORTICOID RECEPTOR ALPHA (GRALPHA) AND MIR-124-3P EXPRESSION, INCREASED HISTONE DEACETYLASE 5 (HDAC5) EXPRESSION, AND DECREASED IGF1 H3K14AC LEVEL AND THE EXPRESSION OF IGF1/STEROIDOGENIC ACUTE REGULATORY PROTEIN (STAR), SUGGESTING THAT CORTICOSTERONE AT LOWER THAN PHYSIOLOGICAL LEVEL (<500 NM) INHIBITED TESTOSTERONE SYNTHESIS BY REDUCING H3K14AC AND THE EXPRESSION LEVEL OF IGF1 THROUGH GRALPHA/MIR-124-3P/HDAC5 PATHWAY. IN CONCLUSION, PDE CAN CAUSE PERSISTENT INHIBITION OF TESTOSTERONE SYNTHESIS BEFORE AND AFTER BIRTH IN THE OFFSPRING RATS BY LOW LEVEL OF ENDOGENOUS GLUCOCORTICOIDS. 2022 7 6601 61 TWO INTRAUTERINE PROGRAMMING MECHANISMS OF ADULT HYPERCHOLESTEROLEMIA INDUCED BY PRENATAL NICOTINE EXPOSURE IN MALE OFFSPRING RATS. EPIDEMIOLOGIC STUDIES SHOWED THAT LOW BIRTH WEIGHT IS ASSOCIATED WITH HIGH CHOLESTEROL AND AN INCREASED RISK OF CARDIOVASCULAR DISEASES IN ADULTHOOD. THIS STUDY AIMED TO ELUCIDATE THE INTRAUTERINE PROGRAMMING MECHANISMS OF ADULT HYPERCHOLESTEROLEMIA. THE RESULTS SHOWED THAT PRENATAL NICOTINE EXPOSURE (PNE) CAUSED INTRAUTERINE GROWTH RETARDATION AND HYPERCHOLESTEROLEMIA IN MALE ADULT OFFSPRING RATS. HEPATIC CHOLESTEROL SYNTHESIS AND OUTPUT WERE DECEASED IN UTERO BUT INCREASED IN ADULTS; HEPATIC REVERSE CHOLESTEROL TRANSPORT (RCT) PERSISTENTLY DECEASED BEFORE AND AFTER BIRTH. MEANWHILE, PNE ELEVATED SERUM CORTICOSTERONE LEVEL AND DECREASED HEPATIC IGF1 PATHWAY ACTIVITY IN MALE FETUSES, WHEREAS CONVERSE CHANGES WERE OBSERVED IN MALE ADULTS. THE CHRONIC STRESS MODEL AND CORTISOL-TREATED HEPG2 CELLS VERIFIED THAT EXCESSIVE GLUCOCORTICOID (GC)-INDUCED GC-IGF1 AXIS PROGRAMMING ENHANCED HEPATIC CHOLESTEROL SYNTHESIS AND OUTPUT. IN ADDITION, PNE DECREASED THE EXPRESSION OF SPECIFIC PROTEIN 1 AND P300 ENRICHMENT AND H3K27 ACETYLATION AT THE PROMOTER REGION OF GENES RESPONSIBLE FOR RCT BOTH IN FETAL AND ADULT, MALE LIVERS AND REDUCED EXPRESSION OF THOSE GENES, SIMILAR ALTERATIONS WERE ALSO CONFIRMED IN CORTISOL-TREATED HEPG2 CELLS, SUGGESTING THAT EXCESSIVE GC-RELATED PROGRAMMING INDUCED CONTINUOUS RCT REDUCTION BY EPIGENETIC MODIFICATION. TAKEN TOGETHER, THE "2-PROGRAMMING" APPROACH DISCUSSED ABOVE MAY ULTIMATELY CONTRIBUTE TO THE DEVELOPMENT OF HYPERCHOLESTEROLEMIA IN MALE ADULT OFFSPRING.-ZHOU, J., ZHU, C., LUO, H., SHEN, L., GONG, J., WU, Y., MAGDALOU, J., CHEN, L., GUO, Y., WANG, H. TWO INTRAUTERINE PROGRAMMING MECHANISMS OF ADULT HYPERCHOLESTEROLEMIA INDUCED BY PRENATAL NICOTINE EXPOSURE IN MALE OFFSPRING RATS. 2019 8 742 37 CANNABINOID CB2 RECEPTORS ARE UPREGULATED VIA BIVALENT HISTONE MODIFICATIONS AND CONTROL PRIMARY AFFERENT INPUT TO THE SPINAL CORD IN NEUROPATHIC PAIN. TYPE-2 CANNABINOID RECEPTORS (CB2, ENCODED BY THE CNR2 GENE) ARE MAINLY EXPRESSED IN IMMUNE CELLS, AND CB2 AGONISTS NORMALLY HAVE NO ANALGESIC EFFECT. HOWEVER, NERVE INJURY UPREGULATES CB2 IN THE DORSAL ROOT GANGLION (DRG), FOLLOWING WHICH CB2 STIMULATION REDUCES NEUROPATHIC PAIN. IT IS UNCLEAR HOW NERVE INJURY INCREASES CB2 EXPRESSION OR HOW CB2 ACTIVITY IS TRANSFORMED IN NEUROPATHIC PAIN. IN THIS STUDY, IMMUNOBLOTTING SHOWED THAT SPINAL NERVE LIGATION (SNL) INDUCED A DELAYED AND SUSTAINED INCREASE IN CB2 EXPRESSION IN THE DRG AND DORSAL SPINAL CORD SYNAPTOSOMES. RNASCOPE IN SITU HYBRIDIZATION ALSO SHOWED THAT SNL SUBSTANTIALLY INCREASED CB2 MRNA LEVELS, MOSTLY IN MEDIUM AND LARGE DRG NEURONS. FURTHERMORE, WE FOUND THAT THE SPECIFIC CB2 AGONIST JWH-133 SIGNIFICANTLY INHIBITS THE AMPLITUDE OF DORSAL ROOT-EVOKED GLUTAMATERGIC EXCITATORY POSTSYNAPTIC CURRENTS IN SPINAL DORSAL HORN NEURONS IN SNL RATS, BUT NOT IN SHAM CONTROL RATS; INTRATHECAL INJECTION OF JWH-133 REVERSED PAIN HYPERSENSITIVITY IN SNL RATS, BUT HAD NO EFFECT IN SHAM CONTROL RATS. IN ADDITION, CHROMATIN IMMUNOPRECIPITATION-QPCR ANALYSIS SHOWED THAT SNL INCREASED ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME3 AND H3K9AC) AND DIMINISHED OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AT THE CNR2 PROMOTER IN THE DRG. IN CONTRAST, SNL HAD NO EFFECT ON DNA METHYLATION LEVELS AROUND THE CNR2 PROMOTER. OUR FINDINGS SUGGEST THAT PERIPHERAL NERVE INJURY PROMOTES CB2 EXPRESSION IN PRIMARY SENSORY NEURONS VIA EPIGENETIC BIVALENT HISTONE MODIFICATIONS AND THAT CB2 ACTIVATION REDUCES NEUROPATHIC PAIN BY ATTENUATING NOCICEPTIVE TRANSMISSION FROM PRIMARY AFFERENT NERVES TO THE SPINAL CORD. 2022 9 2272 34 EPIGENETIC REDUCTION OF MIR-214-3P UPREGULATES ASTROCYTIC COLONY-STIMULATING FACTOR-1 AND CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY NERVE INJURY. EMERGING EVIDENCE HAS INDICATED THAT COLONY-STIMULATING FACTOR-1 (CSF1) MODULATES NEUROINFLAMMATION IN THE CENTRAL NERVOUS SYSTEM AND THE DEVELOPMENT OF NEUROPATHIC PAIN, WHILE THE UNDERLYING MECHANISM REMAINS UNKNOWN. HERE, WE IDENTIFIED THE INCREASED EXPRESSION OF CSF1 DERIVED FROM ACTIVATED ASTROCYTES IN THE IPSILATERAL DORSAL HORN IN RATS WITH SPINAL NERVE LIGATION (SNL). SUPPRESSION OF CSF1 EXPRESSION ALLEVIATED NEUROINFLAMMATION, NEURONAL HYPEREXCITABILITY, AND GLUTAMATERGIC RECEPTOR SUBUNIT UPREGULATION IN THE DORSAL HORN AND IMPROVED SNL-INDUCED PAIN BEHAVIOR. WE ALSO FOUND REDUCED MIR-214-3P EXPRESSION IN THE IPSILATERAL DORSAL HORN FOLLOWING AN SNL PROCEDURE; MIR-214-3P DIRECTLY BOUND TO THE 3'-UTR OF CSF1 MRNA AND NEGATIVELY REGULATED CSF1 EXPRESSION. INTRATHECAL DELIVERY OF MIR-214-3P MIMIC REVERSED THE ENHANCED EXPRESSION OF CSF1 AND ASTROCYTE OVERACTIVITY AND ALLEVIATED THE IL-6 UPREGULATION AND PAIN BEHAVIOR INDUCED BY SNL. MOREOVER, SUPPRESSION OF SPINAL MIR-214-3P INCREASED ASTROCYTE REACTIVITY, PROMOTED CSF1 AND IL-6 PRODUCTION, AND INDUCED PAIN HYPERSENSITIVITY IN NAIVE ANIMALS. FURTHERMORE, SNL INDUCED THE EXPRESSION OF DNA METHYLTRANSFERASE 3A (DNMT3A) THAT WAS ASSOCIATED WITH THE HYPERMETHYLATION OF THE MIR-214-3P PROMOTER, LEADING TO REDUCED MIR-214-3P EXPRESSION IN THE MODEL RODENTS. TREATMENT WITH THE DNMT INHIBITOR ZEBULARINE SIGNIFICANTLY REDUCED CYTOSINE METHYLATION IN THE MIR-214-3P PROMOTER; THIS REDUCED METHYLATION CONSEQUENTLY INCREASED THE EXPRESSION OF MIR-214-3P AND DECREASED THE CONTENT OF CSF1 IN THE IPSILATERAL DORSAL HORN AND, FURTHER, ATTENUATED IL-6 PRODUCTION AND PAIN BEHAVIOR IN RATS WITH SNL. TOGETHER, OUR DATA INDICATE THAT THE DNMT3A-MEDIATED EPIGENETIC SUPPRESSION OF MIR-214-3P ENHANCED CSF1 PRODUCTION IN ASTROCYTES, WHICH SUBSEQUENTLY INDUCED NEUROINFLAMMATION AND PAIN BEHAVIOR IN SNL MODEL RATS. 2020 10 5253 64 PROGRAMMING CHANGES OF HIPPOCAMPAL MIR-134-5P/SOX2 SIGNAL MEDIATE THE SUSCEPTIBILITY TO DEPRESSION IN PRENATAL DEXAMETHASONE-EXPOSED FEMALE OFFSPRING. DEPRESSION IS A NEUROPSYCHIATRIC DISORDER AND HAS INTRAUTERINE DEVELOPMENTAL ORIGINS. THIS STUDY AIMED TO CONFIRM THE DEPRESSION SUSCEPTIBILITY IN OFFSPRING RATS INDUCED BY PRENATAL DEXAMETHASONE EXPOSURE (PDE) AND TO FURTHER EXPLORE THE INTRAUTERINE PROGRAMMING MECHANISM. WISTAR RATS WERE INJECTED WITH DEXAMETHASONE (0.2 MG/KG.D) SUBCUTANEOUSLY DURING THE GESTATIONAL DAYS 9-20 AND PART OF THE OFFSPRING WAS GIVEN CHRONIC STRESS AT POSTNATAL WEEKS 10-12. BEHAVIORAL RESULTS SHOWED THAT THE ADULT PDE FEMALE OFFSPRING WAS SUSCEPTIBLE TO DEPRESSION, ACCOMPANIED BY INCREASED HIPPOCAMPAL MIR-134-5P EXPRESSION AND DECREASED SEX-DETERMINING REGION Y-BOX 2 (SOX2) EXPRESSION, AS WELL AS DISORDERS OF NEURAL PROGENITOR CELLS PROLIFERATION AND HIPPOCAMPAL NEUROGENESIS. THE PDE FEMALE FETAL RATS PRESENTED CONSISTENT CHANGES WITH THE ADULT OFFSPRING, ACCOMPANIED BY THE UPREGULATION OF GLUCOCORTICOID RECEPTOR (GR) EXPRESSION AND DECREASED SIRTUIN 1 (SIRT1) EXPRESSION. WE FURTHER FOUND THAT THE H3K9AC LEVEL OF THE MIR-134-5P PROMOTER WAS SIGNIFICANTLY INCREASED IN THE PDE FETAL HIPPOCAMPUS, AS WELL AS IN ADULT OFFSPRING BEFORE AND AFTER CHRONIC STRESS. IN VITRO, THE CHANGES OF GR/SIRT1/MIR-134-5P/SOX2 SIGNAL BY DEXAMETHASONE WERE CONSISTENT WITH IN VIVO EXPERIMENTS, WHICH COULD BE REVERSED BY GR RECEPTOR ANTAGONIST, SIRT1 AGONIST, AND MIR-134-5P INHIBITOR. THIS STUDY CONFIRMED THAT PDE LED TO AN INCREASED EXPRESSION LEVEL AS WELL AS H3K9AC LEVEL OF MIR-134-5P BY ACTIVATING THE GR/SIRT1 PATHWAY IN THE FETAL HIPPOCAMPUS AND THEN INHIBITED THE SOX2 EXPRESSION. THE PROGRAMMING EFFECT MEDIATED BY THE ABNORMAL EPIGENETIC MODIFICATION COULD LAST FROM INTRAUTERINE TO ADULTHOOD, WHICH CONSTITUTES THE INTRAUTERINE PROGRAMMING MECHANISM LEADING TO HIPPOCAMPAL NEUROGENESIS DISORDERS AND DEPRESSION SUSCEPTIBILITY IN FEMALE OFFSPRING. INTRAUTERINE PROGRAMMING MECHANISM FOR THE INCREASED DEPRESSIVE SUSCEPTIBILITY IN ADULT FEMALE OFFSPRING BY PRENATAL DEXAMETHASONE EXPOSURE (PDE). GR, GLUCOCORTICOID RECEPTOR; SIRT1, SIRTUIN 1; SOX2, SEX-DETERMINING REGION Y-BOX 2; NPCS, NEUROPROGENITOR CELLS; H3K9AC, HISTONE 3 LYSINE 9 ACETYLATION; GRE, GLUCOCORTICOID RESPONSE ELEMENT. 2022 11 5657 36 SEX-DEPENDENT PRONOCICEPTIVE ROLE OF SPINAL ALPHA(5) -GABA(A) RECEPTOR AND ITS EPIGENETIC REGULATION IN NEUROPATHIC RODENTS. EXTRASYNAPTIC ALPHA(5) -SUBUNIT CONTAINING GABA(A) (ALPHA(5) -GABA(A) ) RECEPTORS PARTICIPATE IN CHRONIC PAIN. PREVIOUSLY, WE REPORTED A SEX DIFFERENCE IN THE ACTION OF ALPHA(5) -GABA(A) RECEPTORS IN DYSFUNCTIONAL PAIN. HOWEVER, THE UNDERLYING MECHANISMS REMAIN UNKNOWN. THE AIM OF THIS STUDY WAS TO EXAMINE THIS SEXUAL DIMORPHISM IN NEUROPATHIC RODENTS AND THE MECHANISMS INVOLVED. FEMALE AND MALE WISTAR RATS OR ICR MICE WERE SUBJECTED TO NERVE INJURY FOLLOWED BY ALPHA(5) -GABA(A) RECEPTOR INVERSE AGONIST INTRATHECAL ADMINISTRATION, L-655,708. THE DRUG PRODUCED AN ANTIALLODYNIC EFFECT IN NERVE-INJURED FEMALE RATS AND MICE, AND A LOWER EFFECT IN MALES. WE HYPOTHESIZED THAT CHANGES IN ALPHA(5) -GABA(A) RECEPTOR, PROBABLY INFLUENCED BY HORMONAL AND EPIGENETIC STATUS, MIGHT UNDERLIE THIS SEX DIFFERENCE. THUS, WE PERFORMED QPCR AND WESTERN BLOT. NERVE INJURY INCREASED ALPHA(5) -GABA(A) MRNA AND PROTEIN IN FEMALE DORSAL ROOT GANGLIA (DRG) AND DECREASED THEM IN DRG AND SPINAL CORD OF MALES. TO INVESTIGATE THE HORMONAL INFLUENCE OVER ALPHA(5) -GABA(A) RECEPTOR ACTIONS, WE PERFORMED NERVE INJURY TO OVARIECTOMIZED RATS AND RECONSTITUTED THEM WITH 17BETA-ESTRADIOL (E2). OVARIECTOMY ABROGATED L-655,708 ANTIALLODYNIC EFFECT AND E2 RESTORED IT. OVARIECTOMY DECREASED ALPHA(5) -GABA(A) RECEPTOR AND ESTROGEN RECEPTOR ALPHA PROTEIN IN DRG OF NEUROPATHIC FEMALE RATS, WHILE E2 ENHANCED THEM. SINCE DNA METHYLATION MIGHT CONTRIBUTE TO ALPHA(5) -GABA(A) RECEPTOR DOWN-REGULATION IN MALES, WE EXAMINED CPG ISLAND DNA METHYLATION OF ALPHA(5) -GABA(A) RECEPTOR CODING GENE THROUGH PYROSEQUENCING. NERVE INJURY INCREASED METHYLATION IN MALE, BUT NOT FEMALE RATS. PHARMACOLOGICAL INHIBITION OF DNA METHYLTRANSFERASES INCREASED ALPHA(5) -GABA(A) RECEPTOR AND ENABLED L-655,708 ANTINOCICEPTIVE EFFECT IN MALE RATS. THESE RESULTS SUGGEST THAT ALPHA(5) -GABA(A) RECEPTOR IS A SUITABLE TARGET TO TREAT CHRONIC PAIN IN FEMALES. 2021 12 4172 29 MELATONIN IMPEDES TET1-DEPENDENT MGLUR5 PROMOTER DEMETHYLATION TO RELIEVE PAIN. MELATONIN (N-ACETYL-5-METHOXYTRYPTAMINE)/MT2 RECEPTOR-DEPENDENT EPIGENETIC MODIFICATION REPRESENTS A NOVEL PATHWAY IN THE TREATMENT OF NEUROPATHIC PAIN. BECAUSE SPINAL TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1)-DEPENDENT EPIGENETIC DEMETHYLATION HAS RECENTLY BEEN LINKED TO PAIN HYPERSENSITIVITY, WE HYPOTHESIZED THAT MELATONIN/MT2-DEPENDENT ANALGESIA INVOLVES SPINAL TET1-DEPENDENT DEMETHYLATION. HERE, WE SHOWED THAT SPINAL TET1 GENE TRANSFER BY INTRATHECAL DELIVERY OF TET1-ENCODING VECTORS TO NAIVE RATS PRODUCED PROFOUND AND LONG-LASTING NOCICEPTIVE HYPERSENSITIVITY. IN ADDITION, ENHANCED TET1 EXPRESSION, TET1-METABOTROPIC GLUTAMATE RECEPTOR SUBTYPE 5 (MGLUR5) PROMOTER COUPLING, DEMETHYLATION AT THE MGLUR5 PROMOTER, AND MGLUR5 EXPRESSION IN DORSAL HORN NEURONS WERE OBSERVED. RATS SUBJECTED TO SPINAL NERVE LIGATION AND INTRAPLANTAR COMPLETE FREUND'S ADJUVANT INJECTION DISPLAYED TACTILE ALLODYNIA AND BEHAVIORAL HYPERALGESIA ASSOCIATED WITH SIMILAR CHANGES IN THE DORSAL HORN. NOTABLY, INTRATHECAL MELATONIN INJECTION REVERSED THE PROTEIN EXPRESSION, PROTEIN-PROMOTER COUPLING, PROMOTER DEMETHYLATION, AND PAIN HYPERSENSITIVITY INDUCED BY TET1 GENE TRANSFER, SPINAL NERVE LIGATION, AND INTRAPLANTAR COMPLETE FREUND'S ADJUVANT INJECTION. ALL THE EFFECTS CAUSED BY MELATONIN WERE BLOCKED BY PRETREATMENT WITH A MT2 RECEPTOR-SELECTIVE ANTAGONIST. IN CONCLUSION, MELATONIN RELIEVES PAIN BY IMPEDING TET1-DEPENDENT DEMETHYLATION OF MGLUR5 IN DORSAL HORN NEURONS THROUGH THE MT2 RECEPTOR. OUR FINDINGS LINK MELATONIN/MT2 SIGNALING TO TET1-DEPENDENT EPIGENETIC DEMETHYLATION OF NOCICEPTIVE GENES FOR THE FIRST TIME AND SUGGEST MELATONIN AS A PROMISING THERAPY FOR THE TREATMENT OF PAIN. 2017 13 5574 23 ROLE OF MICRORNA-143 IN NERVE INJURY-INDUCED UPREGULATION OF DNMT3A EXPRESSION IN PRIMARY SENSORY NEURONS. PERIPHERAL NERVE INJURY INCREASED THE EXPRESSION OF THE DNA METHYLTRANSFERASE 3A (DNMT3A) MRNA AND ITS ENCODING DNMT3A PROTEIN IN INJURED DORSAL ROOT GANGLIA (DRG). THIS INCREASE IS CONSIDERED AS AN ENDOGENOUS INSTIGATOR IN NEUROPATHIC PAIN GENESIS THROUGH EPIGENETIC SILENCING OF PAIN-ASSOCIATED GENES (SUCH AS OPRM1) IN INJURED DRG. HOWEVER, HOW DRG DNMT3A IS INCREASED FOLLOWING PERIPHERAL NERVE INJURY IS STILL ELUSIVE. WE REPORTED HERE THAT PERIPHERAL NERVE INJURY CAUSED BY THE FIFTH SPINAL NERVE LIGATION (SNL) DOWNREGULATED MICRORNA (MIR)-143 EXPRESSION IN INJURED DRG. THIS DOWNREGULATION WAS REQUIRED FOR SNL-INDUCED DRG DNMT3A INCREASE AS RESCUING MIR-143 DOWNREGULATION THROUGH MICROINJECTION OF MIR-143 MIMICS INTO INJURED DRG BLOCKED THE SNL-INDUCED INCREASE IN DNMT3A AND RESTORED THE SNL-INDUCED DECREASES IN OPRM1 MRNA AND ITS ENCODING MU OPIOID RECEPTOR (MOR) IN INJURED DRG, IMPAIRED SPINAL CORD CENTRAL SENSITIZATION AND NEUROPATHIC PAIN, AND IMPROVED MORPHINE ANALGESIC EFFECTS FOLLOWING SNL. MIMICKING SNL-INDUCED DRG MIR-143 DOWNREGULATION THROUGH DRG MICROINJECTION OF MIR143 INHIBITORS IN NAIVE RATS INCREASED THE EXPRESSION OF DNMT3A AND REDUCED THE EXPRESSION OF OPRM1 MRNA AND MOR IN INJECTED DRG AND PRODUCED NEUROPATHIC PAIN-LIKE SYMPTOMS. THESE FINDINGS SUGGEST THAT MIR-143 IS A NEGATIVE REGULATOR IN DNMT3A EXPRESSION IN THE DRG UNDER NEUROPATHIC PAIN CONDITIONS AND MAY BE A POTENTIAL TARGET FOR THERAPEUTIC MANAGEMENT OF NEUROPATHIC PAIN. 2017 14 3201 35 HDAC2 IN PRIMARY SENSORY NEURONS CONSTITUTIVELY RESTRAINS CHRONIC PAIN BY REPRESSING ALPHA2DELTA-1 EXPRESSION AND ASSOCIATED NMDA RECEPTOR ACTIVITY. ALPHA2DELTA-1 (ENCODED BY THE CACNA2D1 GENE) IS A NEWLY DISCOVERED NMDA RECEPTOR-INTERACTING PROTEIN AND IS THE THERAPEUTIC TARGET OF GABAPENTINOIDS (E.G., GABAPENTIN AND PREGABALIN) FREQUENTLY USED FOR TREATING PATIENTS WITH NEUROPATHIC PAIN. NERVE INJURY CAUSES SUSTAINED ALPHA2DELTA-1 UPREGULATION IN THE DORSAL ROOT GANGLION (DRG), WHICH PROMOTES NMDA RECEPTOR SYNAPTIC TRAFFICKING AND ACTIVATION IN THE SPINAL DORSAL HORN, A HALLMARK OF CHRONIC NEUROPATHIC PAIN. HOWEVER, LITTLE IS KNOWN ABOUT HOW NERVE INJURY INITIATES AND MAINTAINS THE HIGH EXPRESSION LEVEL OF ALPHA2DELTA-1 TO SUSTAIN CHRONIC PAIN. HERE, WE SHOW THAT NERVE INJURY CAUSED HISTONE HYPERACETYLATION AND DIMINISHED ENRICHMENT OF HISTONE DEACETYLASE-2 (HDAC2), BUT NOT HDAC3, AT THE CACNA2D1 PROMOTER IN THE DRG. STRIKINGLY, HDAC2 KNOCKDOWN OR CONDITIONAL KNOCKOUT IN DRG NEURONS IN MALE AND FEMALE MICE CONSISTENTLY INDUCED LONG-LASTING MECHANICAL PAIN HYPERSENSITIVITY, WHICH WAS READILY REVERSED BY BLOCKING NMDA RECEPTORS, INHIBITING ALPHA2DELTA-1 WITH GABAPENTIN OR DISRUPTING THE ALPHA2DELTA-1-NMDA RECEPTOR INTERACTION AT THE SPINAL CORD LEVEL. HDAC2 DELETION IN DRG NEURONS INCREASED HISTONE ACETYLATION LEVELS AT THE CACNA2D1 PROMOTER, UPREGULATED ALPHA2DELTA-1 IN THE DRG, AND POTENTIATED ALPHA2DELTA-1-DEPENDENT NMDA RECEPTOR ACTIVITY AT PRIMARY AFFERENT CENTRAL TERMINALS IN THE SPINAL DORSAL HORN. CORRESPONDINGLY, HDAC2 KNOCKDOWN-INDUCED PAIN HYPERSENSITIVITY WAS BLUNTED IN CACNA2D1 KNOCKOUT MICE. THUS, OUR FINDINGS REVEAL THAT HDAC2 FUNCTIONS AS A PIVOTAL TRANSCRIPTIONAL REPRESSOR OF NEUROPATHIC PAIN VIA CONSTITUTIVELY SUPPRESSING ALPHA2DELTA-1 EXPRESSION AND ENSUING PRESYNAPTIC NMDA RECEPTOR ACTIVITY IN THE SPINAL CORD. HDAC2 ENRICHMENT LEVELS AT THE CACNA2D1 PROMOTER IN DRG NEURONS CONSTITUTE A UNIQUE EPIGENETIC MECHANISM THAT GOVERNS ACUTE-TO-CHRONIC PAIN TRANSITION.SIGNIFICANCE STATEMENT EXCESS ALPHA2DELTA-1 PROTEINS PRODUCED AFTER NERVE INJURY DIRECTLY INTERACT WITH GLUTAMATE NMDA RECEPTORS TO POTENTIATE SYNAPTIC NMDA RECEPTOR ACTIVITY IN THE SPINAL CORD, A PROMINENT MECHANISM OF NERVE PAIN. BECAUSE ALPHA2DELTA-1 UPREGULATION AFTER NERVE INJURY IS LONG LASTING, GABAPENTINOIDS RELIEVE PAIN SYMPTOMS ONLY TEMPORARILY. OUR STUDY DEMONSTRATES FOR THE FIRST TIME THE UNEXPECTED ROLE OF INTRINSIC HDAC2 ACTIVITY AT THE ALPHA2DELTA-1 GENE PROMOTER IN LIMITING ALPHA2DELTA-1 GENE TRANSCRIPTION, NMDA RECEPTOR-DEPENDENT SYNAPTIC PLASTICITY, AND CHRONIC PAIN DEVELOPMENT AFTER NERVE INJURY. THESE FINDINGS CHALLENGE THE PREVAILING VIEW ABOUT THE ROLE OF GENERAL HDAC ACTIVITY IN PROMOTING CHRONIC PAIN. RESTORING THE REPRESSIVE HDAC2 FUNCTION AND/OR REDUCING HISTONE ACETYLATION AT THE ALPHA2DELTA-1 GENE PROMOTER IN PRIMARY SENSORY NEURONS COULD LEAD TO LONG-LASTING RELIEF OF NERVE PAIN. 2022 15 2365 31 EPIGENETIC REGULATION OF SPINAL CXCR2 SIGNALING IN INCISIONAL HYPERSENSITIVITY IN MICE. BACKGROUND: THE REGULATION OF GENE EXPRESSION IN NOCICEPTIVE PATHWAYS CONTRIBUTES TO THE INDUCTION AND MAINTENANCE OF PAIN SENSITIZATION. HISTONE ACETYLATION IS A KEY EPIGENETIC MECHANISM CONTROLLING CHROMATIN STRUCTURE AND GENE EXPRESSION. CHEMOKINE CC MOTIF RECEPTOR 2 (CXCR2) IS A PROINFLAMMATORY RECEPTOR IMPLICATED IN NEUROPATHIC AND INFLAMMATORY PAIN AND IS KNOWN TO BE REGULATED BY HISTONE ACETYLATION IN SOME SETTINGS. THE AUTHORS SOUGHT TO INVESTIGATE THE ROLE OF HISTONE ACETYLATION ON SPINAL CXCR2 SIGNALING AFTER INCISION. METHODS: GROUPS OF 5-8 MICE UNDERWENT HIND PAW INCISION. SUBEROYLANILIDE HYDROXAMIC ACID AND ANACARDIC ACID WERE USED TO INHIBIT HISTONE DEACETYLASE AND HISTONE ACETYLTRANSFERASE, RESPECTIVELY. BEHAVIORAL MEASURES OF THERMAL AND MECHANICAL SENSITIZATION AS WELL AS HYPERALGESIC PRIMING WERE USED. BOTH MESSAGE RNA QUANTIFICATION AND CHROMATIN IMMUNOPRECIPITATION ANALYSIS WERE USED TO STUDY THE REGULATION OF CXCR2 AND LIGAND EXPRESSION. FINALLY, THE SELECTIVE CXCR2 ANTAGONIST SB225002 WAS ADMINISTERED INTRATHECALLY TO REVEAL THE FUNCTION OF SPINAL CXCR2 RECEPTORS AFTER HIND PAW INCISION. RESULTS: SUBEROYLANILIDE HYDROXAMIC ACID SIGNIFICANTLY EXACERBATED MECHANICAL SENSITIZATION AFTER INCISION. CONVERSELY, ANACARDIC ACID REDUCED INCISIONAL SENSITIZATION AND ALSO ATTENUATED INCISION-INDUCED HYPERALGESIC PRIMING. OVERALL, ACETYLATED HISTONE H3 AT LYSINE 9 WAS INCREASED IN SPINAL CORD TISSUES AFTER INCISION, AND ENHANCED ASSOCIATION OF ACETYLATED HISTONE H3 AT LYSINE 9 WITH THE PROMOTER REGIONS OF CXCR2 AND KERATINOCYTE-DERIVED CHEMOKINE (CXCL1) WAS OBSERVED AS WELL. BLOCKING CXCR2 REVERSED MECHANICAL HYPERSENSITIVITY AFTER HIND PAW INCISION. CONCLUSIONS: HISTONE MODIFICATION IS AN IMPORTANT EPIGENETIC MECHANISM REGULATING INCISION-INDUCED NOCICEPTIVE SENSITIZATION. THE SPINAL CXCR2 SIGNALING PATHWAY IS ONE EPIGENETICALLY REGULATED PATHWAY CONTROLLING EARLY AND LATENT SENSITIZATION AFTER INCISION. 2013 16 2482 34 EPIGENETIC UPREGULATION OF METABOTROPIC GLUTAMATE RECEPTOR 2 IN THE SPINAL CORD ATTENUATES OESTROGEN-INDUCED VISCERAL HYPERSENSITIVITY. OBJECTIVE: EPIGENETIC MECHANISMS ARE POTENTIAL TARGETS TO RELIEVE SOMATIC PAIN. HOWEVER, LITTLE IS KNOWN WHETHER EPIGENETIC REGULATION INTERFERES WITH VISCERAL PAIN. PREVIOUS STUDIES SHOW THAT OESTROGEN FACILITATES VISCERAL PAIN. THIS STUDY AIMED TO DETERMINE WHETHER HISTONE HYPERACETYLATION IN THE SPINAL CORD COULD ATTENUATE OESTROGEN-FACILITATED VISCERAL PAIN. DESIGN: THE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ON THE MAGNITUDE OF THE VISCEROMOTOR RESPONSE (VMR) TO COLORECTAL DISTENTION WAS EXAMINED IN OVARIECTOMISED RATS WITH/WITHOUT OESTROGEN REPLACEMENT. AN ADDITIONAL INTERACTION WITH THE METABOTROPIC GLUTAMATE RECEPTOR 2/3 (MGLUR2/3) ANTAGONIST LY341495 WAS TESTED. THE LEVELS OF ACETYLATED HISTONE AND MGLUR2 MRNA AND PROTEIN WERE ANALYSED. THE BINDING OF ACETYLATED H3 AND OESTROGEN RECEPTOR ALPHA (ERALPHA) TO THE GRM2 PROMOTER WAS MEASURED BY CHROMATIN IMMUNOPRECIPITATION COUPLED WITH QPCR. RESULTS: IN OVARIECTOMISED RATS, 17BETA-ESTRADIOL (E2), BUT NOT SAFFLOWER OIL, INCREASED THE MAGNITUDE OF THE VMR TO COLORECTAL DISTENTION. SAHA ATTENUATED THE E2-FACILITATED VMR, BUT HAD NO EFFECT IN SAFFLOWER OIL-TREATED RATS. SUBSEQUENT SPINAL ADMINISTRATION OF LY341495 REVERSED THE ANTINOCICEPTIVE EFFECT OF SAHA IN E2 RATS. IN ADDITION, SAHA INCREASED MGLUR2 MRNA AND PROTEIN IN THE SPINAL DORSAL HORN FOLLOWING E2, BUT NOT VEHICLE, TREATMENT. IN CONTRAST, NEITHER E2 NOR SAHA ALONE ALTERED MGLUR2 MRNA. SAHA INCREASED BINDING OF H3K9AC AND ERALPHA TO THE SAME REGIONS OF THE GRM2 PROMOTER IN E2-SAHA-TREATED ANIMALS. CONCLUSIONS: HISTONE HYPERACETYLATION IN THE SPINAL CORD ATTENUATES THE PRONOCICEPTIVE EFFECTS OF OESTROGEN ON VISCERAL SENSITIVITY, SUGGESTING THAT EPIGENETIC REGULATION MAY BE A POTENTIAL APPROACH TO RELIEVE VISCERAL PAIN. 2015 17 6612 35 ULTRA-LOW-DOSE NALOXONE ENHANCES THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN PTX-TREATED RATS: REGULATION ON GLOBAL HISTONE METHYLATION. OBJECTIVE: EPIGENETIC REPROGRAMMING MAY HAVE A POSSIBLE ROLE IN NEUROPATHIC PAIN DEVELOPMENT; THE PRESENT STUDY EXAMINED THE GLOBAL PATTERNS OF LYSINE HISTONE MODIFICATION. IN THIS SERIAL STUDY WE ANALYZED THE LEVELS OF HISTONE 3 LYSINE 4 MONOMETHYLATION, HISTONE 3 LYSINE 4 DIMETHYLATION, AND HISTONE 3 LYSINE 9 TRIMETHYLATION IN PERTUSSIS TOXIN (PTX)-INDUCED THERMAL HYPERALGESIC RAT SPINAL CORDS. METHODS: MALE WISTAR RATS IMPLANTED WITH AN INTRATHECAL CATHETER RECEIVED A SINGLE INTRATHECAL PTX (1 MUG IN 5 MUL SALINE) INJECTION. FOUR DAYS LATER, THEY WERE RANDOMLY ASSIGNED TO RECEIVE EITHER A SINGLE INJECTION OF SALINE, OR ULTRA-LOW-DOSE NALOXONE (15 NG IN 5 MUL SALINE), FOLLOWED BY MORPHINE (10 MUG IN 5 MUL SALINE) INJECTION 30 MINUTES LATER. RESULTS: THE RESULTS SHOWED THAT PTX INJECTION INDUCED THERMAL HYPERALGESIA AND SIGNIFICANT INCREASE OF GLOBAL HISTONE METHYLATION IN THE SPINAL CORDS. INTRATHECAL MORPHINE ALONE DID NOT AFFECT THE THERMAL HYPERALGESIA AND GLOBAL HISTONE METHYLATION. IN CONTRAST, INTRATHECAL ADMINISTRATION OF ULTRA-LOW-DOSE NALOXONE PLUS MORPHINE SIGNIFICANTLY ATTENUATED THE PTX-INDUCED THERMAL HYPERALGESIA AND DOWN-REGULATED THE GLOBAL HISTONE METHYLATION. CONCLUSION: THE RESULTS SUGGEST THAT ULTRA-LOW-DOSE NALOXONE MIGHT BE CLINICAL VALUABLE FOR NEUROPATHIC PAIN MANAGEMENT VIA REGULATING GLOBAL HISTONE MODIFICATION. 2012 18 5651 39 SEX DIFFERENCES IN THE EPIGENETIC REGULATION OF CHRONIC VISCERAL PAIN FOLLOWING UNPREDICTABLE EARLY LIFE STRESS. BACKGROUND: WE PREVIOUSLY REPORTED THAT EARLY LIFE STRESS (ELS) DYSREGULATED GLUCOCORTICOID RECEPTOR (GR) AND CORTICOTROPHIN-RELEASING HORMONE (CRH) EXPRESSION IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA). EPIGENETIC MODIFICATIONS SERVE AS MEMORIES OF ADVERSE EVENTS THAT OCCURRED DURING EARLY LIFE. THEREFORE, WE HYPOTHESIZED THAT EPIGENETIC MECHANISMS ALTER GR AND CRH EXPRESSION IN THE CEA AND UNDERLIE CHRONIC VISCERAL PAIN AFTER ELS. METHODS: NEONATAL RATS WERE EXPOSED TO UNPREDICTABLE, PREDICTABLE ELS, OR ODOR ONLY (NO STRESS CONTROL) FROM POSTNATAL DAYS 8 TO 12. IN ADULTHOOD, VISCERAL SENSITIVITY WAS ASSESSED OR THE CEA WAS ISOLATED FOR WESTERN BLOT OR CHIP-QPCR TO STUDY HISTONE MODIFICATIONS AT THE GR AND CRH PROMOTERS. FEMALE ADULT RATS UNDERWENT STEREOTAXIC IMPLANTATION OF INDWELLING CANNULAS FOR MICROINJECTIONS OF GARCINOL (HAT INHIBITOR) INTO THE CEA. AFTER 7 DAYS OF MICROINJECTIONS, VISCERAL SENSITIVITY WAS ASSESSED OR THE CEA WAS ISOLATED FOR CHIP-QPCR ASSAYS. RESULTS: UNPREDICTABLE ELS INCREASED VISCERAL SENSITIVITY IN ADULT FEMALE RATS, BUT NOT IN MALE COUNTERPARTS. ELS INCREASED HISTONE 3 LYSINE 9 (H3K9) ACETYLATION IN THE CEA AND H3K9 ACETYLATION LEVELS AT THE GR PROMOTER IN THE CEA OF ADULT FEMALE RATS. AFTER UNPREDICTABLE ELS, H3K9 ACETYLATION WAS INCREASED AND GR BINDING WAS DECREASED AT THE CRH PROMOTER. ADMINISTRATION OF GARCINOL IN THE CEA OF ADULT FEMALES, THAT UNDERWENT UNPREDICTABLE ELS, NORMALIZED H3K9 ACETYLATION AND RESTORED GR BINDING AT THE CRH PROMOTER. CONCLUSION: DYSREGULATED HISTONE ACETYLATION AND GR BINDING AT THE CRH PROMOTER IN THE CEA ARE AN IMPORTANT MECHANISM FOR "MEMORIZING" ELS EVENTS MEDIATING VISCERAL PAIN IN ADULTHOOD. 2020 19 3832 26 INVOLVEMENT OF SPINAL SIRT1 IN DEVELOPMENT OF CHRONIC CONSTRICTION INJURY INDUCED NEUROPATHIC PAIN IN RATS. IT IS KNOWN THAT THE EPIGENETIC PROCESS OF HISTONE ACETYLATION IS INVOLVED IN THE NEUROPATHIC PAIN. THE AIM OF THIS STUDY WAS TO DETERMINE WHETHER SIRTUIN TYPE 1 (SIRT1), AN NAD(+) DEPENDENT DEACETYLASE, AFFECTED ALLODYNIA AND HYPERALGESIA IN NEUROPATHIC PAIN. THE NEUROPATHIC PAIN MODEL WAS ESTABLISHED BY LIGATURE OF THE RIGHT SCIATIC NERVE TO INDUCE CHRONIC CONSTRICTION INJURY (CCI) IN RATS. HISTONE ACETYLTRANSFERASE (HAT) ACTIVITY WAS INCREASED AND, AND HISTONE DEACETYLASE (HDAC) ACTIVITY WAS DECLINED IN TISSUE OF THE SPINAL DORSA HORN IN CCI RATES BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA). THE PERSISTENT HYPERALGESIA AND ALLODYNIA CAUSED BY CCI WERE ASSOCIATED WITH DOWNREGULATION OF SIRT1 AND UPREGULATION OF ACETYLATED-H3 (AC-H3) IN TISSUE OF THE SPINAL CORD BY WESTERN BLOT ASSAY, WHICH WAS REVERSED AFTER INTRATHECAL INJECTION OF SIRT1 AGONIST SRT1720. SRT1720 TREATMENT ACHIEVED ANALGESIC THROUGH INHIBITING THE ACETYLATION OF NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND BLOCKING THE RELEASES OF THE INFLAMMATORY FACTORS INCLUDING TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) AND INTERLEUKIN (IL)-6 BY MEANS OF WESTERN BLOT AND REAL-TIME QUANTITATIVE PCR (RT-PCR), RESPECTIVELY. TAKEN TOGETHER, THESE DATA SUGGEST THAT SIRT1 IN THE SPINAL CORD PLAYS AN IMPORTANT ROLE IN THE NEUROPATHIC PAIN IN THE RAT MODEL. 2018 20 2885 24 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