1 4757 105 NOVEL TREATMENT OPPORTUNITIES FOR SULFUR MUSTARD-RELATED CANCERS: GENETIC AND EPIGENETIC PERSPECTIVES. SULFUR MUSTARD (SM), ALSO KNOWN AS MUSTARD GAS, IS A CHEMICAL WEAPON WHICH BY NOW HAS BEEN USED IN MANY WARS. THE MOST CONCERNING SM TOXIC EFFECT IS PROBABLE CARCINOGENICITY. IN THIS STUDY, THE GENETIC AND EPIGENETIC MECHANISMS OF SM CARCINOGENICITY, BY FOCUSING ON TREATMENT OF SM-ASSOCIATED MALIGNANCIES, PARTICULARLY GENE THERAPEUTICS, CANCER VACCINES, AND EPIGENETIC MEDICATIONS, HAVE BEEN CRITICIZED. THE REQUIRED DATA WERE COLLECTED THROUGH AN ORGANIZED SEARCH ON VALID SCIENTIFIC DATABASES. FOR SM CARCINOGENICITY DUE TO ACUTE OR CHRONIC EXPOSURE, THE ENTIRE ORIGINAL AND REVIEW ARTICLES WERE EVALUATED. IN ADDITION, STUDIES ON THE THERAPEUTIC EFFECTS OF AVAILABLE GENETIC AND EPIGENETIC MEDICATIONS WERE INCLUDED. CURRENTLY, FOUR GENE THERAPEUTICS, TWO CANCER VACCINES WITH GENETIC BASES, AND SEVEN EPIGENETIC MEDICATIONS ARE AVAILABLE FOR CANCER TREATMENT. GENETIC AND EPIGENETIC CANCER TREATMENTS INCLUDING GENDICINE, IMLYGIC, PROVENGE, CIMAVAX-EGF, AZACITIDINE, VORINOSTAT, ROMIDEPSIN, AND BELINOSTAT WILL YIELD OUTSTANDING BENEFITS FOR SM-EXPOSED PATIENTS WHO SUFFER FROM CANCER. 2017 2 2487 27 EPIGENETIC: A MISSING PARADIGM IN CELLULAR AND MOLECULAR PATHWAYS OF SULFUR MUSTARD LUNG: A PROSPECTIVE AND COMPARATIVE STUDY. SULFUR MUSTARD (SM, BIS- (2-CHLOROETHYL) SULPHIDE) IS A CHEMICAL WARFARE AGENT THAT CAUSES DNA ALKYLATION, PROTEIN MODIFICATION AND MEMBRANE DAMAGE. SM CAN TRIGGER SEVERAL MOLECULAR PATHWAYS INVOLVED IN INFLAMMATION AND OXIDATIVE STRESS, WHICH CAUSE CELL NECROSIS AND APOPTOSIS, AND LOSS OF CELLS INTEGRITY AND FUNCTION. EPIGENETIC REGULATION OF GENE EXPRESSION IS A GROWING RESEARCH TOPIC AND IS ADDRESSED BY DNA METHYLATION, HISTONE MODIFICATION, CHROMATIN REMODELING, AND NONCODING RNAS EXPRESSION. IT SEEMS SM CAN INDUCE THE EPIGENETIC MODIFICATIONS THAT ARE TRANSLATED INTO CHANGE IN GENE EXPRESSION. CLASSIFICATION OF EPIGENETIC MODIFICATIONS LONG AFTER EXPOSURE TO SM WOULD CLARIFY ITS MECHANISM AND PAVES A BETTER STRATEGY FOR THE TREATMENT OF SM-AFFECTED PATIENTS. IN THIS STUDY, WE REVIEW THE KEY ABERRANT EPIGENETIC MODIFICATIONS THAT HAVE IMPORTANT ROLES IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND COMPARED WITH MUSTARD LUNG. 2015 3 1294 36 DECREASED EXPRESSION OF MIR-20A AND MIR-92A IN THE SERUM FROM SULFUR MUSTARD-EXPOSED PATIENTS DURING THE CHRONIC PHASE OF RESULTING ILLNESS. CONTEXT: SULFUR MUSTARD (SM), WITH EXTENSIVE NUCLEOPHILIC AND ALKYLATING PROPERTIES, WAS EMPLOYED DURING THE IRAN-IRAQ WAR BY IRAQI FORCES. THE MOST CRITICAL COMPLICATIONS ATTRIBUTED TO SM ARE RELATED TO DANGEROUS PULMONARY DISORDERS COLLECTIVELY KNOWN AS "MUSTARD LUNG". THE SYMPTOMS GRADUALLY EMERGE OVER A LONG PERIOD, BECOMING CHRONIC, AND ARE DEPENDENT ON TIME AND THE AMOUNT OF EXPOSED SM. BECAUSE OF THE UNKNOWN AND COMPLEX NATURE OF THE DISEASE, NO DIFFERENTIAL DIAGNOSTIC METHOD OR ABSOLUTE TREATMENT STRATEGY HAS BEEN FORMALLY DEVELOPED. OBJECTIVE: THE AIM OF OUR STUDY WAS TO DETERMINE THE EXPRESSION PATTERN OF THE MICRORNAS (MIRNAS) MIR-92A AND MIR-20A IN THE SERUM OF PATIENTS WITH MUSTARD LUNG ALONG WITH THAT OF NORMAL INDIVIDUALS. MIRNAS HAVE BEEN SHOWN TO POSSESS STABLE PERSISTENCE IN BIOFLUIDS LIKE PLASMA AND SERUM AND ARE CONSIDERED NON-AGGRESSIVE BIOMARKERS HELPFUL FOR DIAGNOSIS AND TREATMENT OF MANY DISEASES. MATERIALS AND METHODS: A HIGHLY SENSITIVE APPROACH CALLED STEM-LOOP REAL-TIME QUANTITATIVE POLYMERASE CHAIN REACTION WAS EMPLOYED TO STUDY THE EXPRESSION OF MIRNAS. RESULTS: THE EXPRESSION OF MIR-92A AND MIR-20A WAS SIGNIFICANTLY DOWN-REGULATED IN THE SERUM OF PATIENTS WITH MUSTARD LUNG COMPARED TO THE CONTROL GROUP. DISCUSSION: DOWN-REGULATION OF MIR-92A AND MIR-20A MAY BE DUE TO CHRONIC EPIGENETIC ALTERATIONS AFTER SM EXPOSURE, WHICH FINALLY LEADS TO CHANGES IN VITAL CELLULAR PROCESSES SUCH AS DIFFERENTIATION, PROLIFERATION AND SO FORTH. CONCLUSION: OUR FINDINGS MAY PROVIDE A DIFFERENTIAL DIAGNOSTIC METHOD THAT IS EFFECTIVE FOR DIAGNOSING LUNG DISEASES CAUSED BY SM EXPOSURE. ADDITIONALLY, THESE MIRNAS MAY BE REGARDED AS PROBABLE TARGETS FOR TREATMENT OF LUNG INJURIES. 2015 4 2255 27 EPIGENETIC MODULATIONS IN EARLY ENDOTHELIAL CELLS AND DNA HYPERMETHYLATION IN HUMAN SKIN AFTER SULFUR MUSTARD EXPOSURE. VICTIMS THAT WERE EXPOSED TO THE CHEMICAL WARFARE AGENT SULFUR MUSTARD (SM) SUFFER FROM CHRONIC DERMAL AND OCULAR LESIONS, SEVERE PULMONARY PROBLEMS AND CANCER DEVELOPMENT. IT HAS BEEN PROPOSED THAT EPIGENETIC PERTURBATIONS MIGHT BE INVOLVED IN THAT PROCESS BUT THIS HAS NOT BEEN INVESTIGATED SO FAR. IN THIS STUDY, WE INVESTIGATED EPIGENETIC MODULATIONS IN VITRO USING EARLY ENDOTHELIAL CELLS (EEC) THAT WERE EXPOSED TO DIFFERENT SM CONCENTRATIONS (0.5, 1.0, 23.5 AND 50MUM). A COMPREHENSIVE ANALYSIS OF 78 GENES RELATED TO EPIGENETIC PATHWAYS (I.E., DNA-METHYLATION AND POST-TRANSLATIONAL HISTONE MODIFICATIONS) WAS PERFORMED. MOREOVER, WE ANALYZED GLOBAL DNA METHYLATION IN VITRO IN EEC AFTER SM EXPOSURE AS A MAKER FOR EPIGENETIC MODULATIONS AND IN VIVO USING HUMAN SKIN SAMPLES THAT WERE OBTAINED FROM A PATIENT 1 YEAR AFTER AN ACCIDENTLY EXPOSURE TO PURE SM. SM EXPOSURE RESULTED IN A COMPLEX REGULATION PATTERN OF EPIGENETIC MODULATORS WHICH WAS ACCOMPANIED BY A GLOBAL INCREASE OF DNA METHYLATION IN VITRO. EXAMINATION OF THE SM EXPOSED HUMAN SKIN SAMPLES ALSO REVEALED A SIGNIFICANT INCREASE OF GLOBAL DNA METHYLATION IN VIVO, UNDERLINING THE BIOLOGICAL RELEVANCE OF OUR FINDINGS. THUS, WE DEMONSTRATED FOR THE FIRST TIME THAT SM AFFECTS EPIGENETIC PATHWAYS AND CAUSES EPIGENETIC MODULATIONS BOTH IN VIVO AND IN VITRO. 2016 5 3869 21 JNK1 REGULATES HISTONE ACETYLATION IN TRIGEMINAL NEURONS FOLLOWING CHEMICAL STIMULATION. TRIGEMINAL NERVE FIBERS IN NASAL AND ORAL CAVITIES ARE SENSITIVE TO VARIOUS ENVIRONMENTAL HAZARDOUS STIMULI, WHICH TRIGGER MANY NEUROTOXIC PROBLEMS SUCH AS CHRONIC MIGRAINE HEADACHE AND TRIGEMINAL IRRITATED DISORDERS. HOWEVER, THE ROLE OF JNK KINASE CASCADE AND ITS EPIGENETIC MODULATION OF HISTONE REMODELING IN TRIGEMINAL GANGLION (TG) NEURONS ACTIVATED BY ENVIRONMENTAL NEUROTOXINS REMAINS UNKNOWN. HERE WE INVESTIGATED THE ROLE OF JNK/C-JUN CASCADE IN THE REGULATION OF ACETYLATION OF H3 HISTONE IN TG NEURONS FOLLOWING IN VITRO STIMULATION BY A NEURO-INFLAMMATORY AGENT, MUSTARD OIL (MO). WE FOUND THAT MO STIMULATION ELICITED JNK/C-JUN PATHWAY SIGNIFICANTLY BY ENHANCING PHOSPHO-JNK1, PHOSPHO-C-JUN EXPRESSION, AND C-JUN ACTIVITY, WHICH WERE CORRELATED WITH AN ELEVATED ACETYLATED H3 HISTONE IN TG NEURONS. HOWEVER, INCREASES IN PHOSPHO-C-JUN AND C-JUN ACTIVITY WERE SIGNIFICANTLY BLOCKED BY A JNK INHIBITOR, SP600125. WE ALSO FOUND THAT ALTERED H3 HISTONE REMODELING, ASSESSED BY H3 ACETYLATION IN TRIGGERED TG NEURONS, WAS REDUCED BY SP600125. THE STUDY SUGGESTS THAT THE ACTIVATED JNK SIGNALING IN REGULATION OF HISTONE REMODELING MAY CONTRIBUTE TO NEURO-EPIGENTIC CHANGES IN PERIPHERAL SENSORY NEURONS FOLLOWING ENVIRONMENTAL NEUROTOXIC EXPOSURE. 2008 6 5616 25 SAMUL-TANG AMELIORATES OOCYTE DAMAGE DUE TO CYCLOPHOSPHAMIDE-INDUCED CHRONIC OVARIAN DYSFUNCTION IN MICE. SAMUL-TANG (SM), A TRADITIONAL HERBAL MEDICINE, HAS BEEN USED TO TREAT MENSTRUAL IRREGULARITIES AND INFERTILITY IN WOMEN. HOWEVER, THE CELLULAR AND MOLECULAR MECHANISMS UNDERLYING THE EFFECTS OF SM REMAIN ELUSIVE. WE INVESTIGATED THE POTENTIAL PROTECTIVE EFFECT OF SM AGAINST CHRONIC OVARIAN DYSFUNCTION AND USED BIOINFORMATICS ANALYSIS TO IDENTIFY ITS UNDERLYING MECHANISM IN A MOUSE MODEL OF CYCLOPHOSPHAMIDE (CP)-INDUCED DIMINISHED OVARIAN RESERVE. FEMALE C57BL/6 MICE WERE INTRAPERITONEALLY INJECTED WITH CP THREE TIMES A WEEK, FOLLOWED BY ORAL ADMINISTRATION OF DISTILLED WATER (CP GROUP) OR SM (CP + SM GROUP) FOR 4 WEEKS. FOUR WEEKS LATER, THE EFFECT OF SM WAS ASSESSED BY OVARIAN TISSUE HISTOLOGICAL ANALYSIS, STEROID HORMONE MEASUREMENT, OOCYTE QUALITY, AND MRNA AND MICRORNA MICROARRAY ANALYSIS IN THE OVARIES. ALTHOUGH SM ADMINISTRATION DID NOT PREVENT CP-INDUCED FOLLICLE LOSS IN MICE, THE QUALITY OF OOCYTES WAS BETTER IN CP + SM MICE THAN IN CP MICE. GENE EXPRESSION ANALYSIS REVEALED THAT THE EXPRESSION OF FERTILISATION- AND OVARIAN FOLLICLE DEVELOPMENT-RELATED GENES WAS ALTERED BY CP TREATMENT BUT NORMALIZED AFTER SM ADMINISTRATION. FURTHER BIOINFORMATICS ANALYSIS SHOWED POSSIBLE INTERACTIONS BETWEEN DIFFERENTIALLY EXPRESSED MRNAS AND MICRORNAS. THEREFORE, WE DEMONSTRATED THE PROTECTIVE EFFECTS OF SM ON OVARIAN FUNCTION AND OOCYTE MATURATION AGAINST CP-INDUCED DAMAGE VIA MULTIPLE EPIGENETIC MECHANISMS. 2020 7 481 27 ARSENIC-INDUCED SUMOYLATION OF MUS81 IS INVOLVED IN REGULATING GENOMIC STABILITY. CHRONIC ENVIRONMENTAL EXPOSURE TO METAL TOXICANTS SUCH AS CHROMIUM AND ARSENIC IS CLOSELY RELATED TO THE DEVELOPMENT OF SEVERAL TYPES OF COMMON CANCERS. GENETIC AND EPIGENETIC STUDIES IN THE PAST DECADE REVEAL THAT POST-TRANSLATIONAL MODIFICATIONS OF HISTONES PLAY A ROLE IN METAL CARCINOGENESIS. HOWEVER, EXACT MOLECULAR MECHANISMS OF METAL CARCINOGENESIS REMAIN TO BE ELUCIDATED. IN THIS STUDY WE FOUND THAT AS(2)O(3), AN ENVIRONMENTAL METAL TOXICANT, UPREGULATED OVERALL MODIFICATIONS OF MANY CELLULAR PROTEINS BY SUMO2/3. SUMOYLATED PROTEINS FROM ARSENIC-TREATED CELLS CONSTITUTIVELY EXPRESSING HIS(6)-SUMO2 WERE PULLED DOWN BY NI-IDA RESIN UNDER DENATURING CONDITIONS. MASS SPECTROMETRIC ANALYSIS REVEALED OVER 100 PROTEINS THAT WERE POTENTIALLY MODIFIED BY SUMOYLATION. MUS81, A DNA ENDONUCLEASE INVOLVED IN HOMOLOGOUS RECOMBINATION REPAIR, WAS AMONG THE IDENTIFIED PROTEINS WHOSE SUMOYLATION WAS INCREASED AFTER TREATMENT WITH AS(2)O(3.) WE FURTHER SHOWED THAT K10 AND K524 WERE 2 LYSINE RESIDUES ESSENTIAL FOR MUS81 SUMOYLATION. MOREOVER, WE DEMONSTRATED THAT MUS81 SUMOYLATION IS IMPORTANT FOR NORMAL MITOTIC CHROMOSOME CONGRESSION AND THAT CELLS EXPRESSING SUMO-RESISTANT MUS81 MUTANTS DISPLAYED COMPROMISED DNA DAMAGE RESPONSES AFTER EXPOSURE TO METAL TOXINS SUCH AS CR(VI) AND ARSENIC. 2017 8 1130 29 COMPREHENSIVE ANALYSIS OF TRANSCRIPTOME-WIDE M(6)A METHYLOME IN THE LUNG TISSUES OF MICE WITH ACUTE PARTICULATE MATTER EXPOSURE. PARTICULATE MATTER (PM) EXPOSURE IS IDENTIFIED AS A CRITICAL RISK FACTOR FOR CHRONIC AIRWAY DISEASES, BUT THE BIOLOGICAL MECHANISM OF PM-INDUCED LUNG DAMAGE WAS NOT FULLY ELUCIDATED. THE M(6)A METHYLATION, AS THE MAIN MEMBER OF EPIGENETIC MODIFICATIONS, HAS BEEN FOUND TO PLAY AN IMPORTANT ROLE IN DIFFERENT PULMONARY DISEASES, BUT ITS REGULATORY EFFECT ON PM-INDUCED LUNG DAMAGE REMAINS UNKNOWN. THIS STUDY FIRSTLY USED THE METHYLATED RNA IMMUNOPRECIPITATION SEQUENCING (MERIP-SEQ) TO REVEAL THE M(6)A METHYLOME PROFILES IN THE LUNG TISSUES OF MICE WITH ACUTE PM EXPOSURE. COMPARED WITH THE NORMAL CONTROL, A TOTAL OF 2210 DIFFERENTIALLY HYPERMETHYLATED M(6)A PEAKS WITHIN 1879 GENES AND 1278 DIFFERENTIALLY HYPOMETHYLATED M(6)A PEAKS WITHIN 1153 GENES WERE IDENTIFIED IN THE PM-EXPOSED GROUP. CONJOINT ANALYSIS OF MERIP-SEQ AND HIGH-THROUGHPUT SEQUENCING FOR RNA (RNA-SEQ) DATA PREDICATED SEVERAL POTENTIAL PATHWAYS INCLUDING MAPK SIGNALING PATHWAY, CELL SENESCENCE, AND CELL CYCLE. FOUR M(6)A-MODIFIED DIFFERENTIALLY EXPRESSED GENES (IL-1A, IL-1B, ADAM-8, AND HMOX-1) WERE SELECTED FOR VALIDATION USING MERIP-QPCR. FURTHERMORE, THE M(6)A-MODIFIED IL-1A PROMOTED PM-INDUCED INFLAMMATION VIA REGULATING MAPK SIGNALING PATHWAY. THESE RESULTS PROVIDE A NEW INSIGHT INTO THE BIOLOGICAL MECHANISM OF PM-INDUCED LUNG DAMAGE, AND HELP US TO DEVELOP NEW METHODS TO PREVENT AND TREAT PM-INDUCED ADVERSE HEALTH EFFECTS. 2022 9 6664 22 UPREGULATION OF LNCRNA71132 IN THE SPINAL CORD REGULATES HYPERSENSITIVITY IN A RAT MODEL OF BONE CANCER PAIN. BONE CANCER PAIN (BCP) IS A PERVASIVE CLINICAL SYMPTOM WHICH IMPAIRS THE QUALITY LIFE. LONG NONCODING RNAS (LNCRNAS) ARE ENRICHED IN THE CENTRAL NERVOUS SYSTEM AND PLAY INDISPENSABLE ROLES IN NUMEROUS BIOLOGICAL PROCESSES, WHILE ITS REGULATORY FUNCTION IN NOCICEPTIVE INFORMATION PROCESSING REMAINS ELUSIVE. HERE, WE REPORTED THAT FUNCTIONAL MODULATORY ROLE OF ENSRNOT00000071132 (LNCRNA71132) IN THE BCP PROCESS AND SPONGING WITH MIR-143 AND ITS DOWNSTREAM GPR85-DEPENDENT SIGNALING CASCADE. SPINAL LNCRNA71132 WAS REMARKABLY INCREASED IN THE RAT MODEL OF BONE CANCER PAIN. THE KNOCKDOWN OF SPINAL LNCRNA71132 REVERTED BCP BEHAVIORS AND SPINAL C-FOS NEURONAL SENSITIZATION. OVEREXPRESSION OF SPINAL LNCRNA71132 IN NAIVE RAT GENERATED PAIN BEHAVIORS, WHICH WERE ACCOMPANIED BY INCREASED SPINAL C-FOS NEURONAL SENSITIZATION. FURTHERMORE, IT WAS FOUND THAT LNCRNA71132 PARTICIPATES IN THE MODULATION OF BCP BY INVERSELY REGULATING THE PROCESSING OF MIR-143-5P. IN ADDITION, AN INCREASE IN EXPRESSION OF SPINAL LNCRNA71132 RESULTED IN THE DECREASE IN EXPRESSION OF MIR-143 UNDER THE BCP STATE. FINALLY, IT WAS FOUND THAT MIR-143-5P REGULATES PAIN BEHAVIORS BY TARGETING GPR85. OVEREXPRESSION OF MIR-143-5P IN THE SPINAL CORD REVERTED THE NOCICEPTIVE BEHAVIORS TRIGGERED BY BCP, ACCOMPANIED BY A DECREASE IN EXPRESSION OF SPINAL GPR85 PROTEIN, BUT NO INFLUENCE ON EXPRESSION OF GPR85 MRNA. THE FINDINGS OF THIS STUDY INDICATE THAT LNCRNA71132 WORKS AS A MIRNA SPONGE IN MIR-143-5P-MEDIATED POSTTRANSCRIPTIONAL MODULATION OF GPR85 EXPRESSION IN BCP. THEREFORE, EPIGENETIC INTERVENTIONS AGAINST LNCRNA71132 MAY POTENTIALLY WORK AS NOVEL TREATMENT AVENUES IN TREATING NOCICEPTIVE HYPERSENSITIVITY TRIGGERED BY BONE CANCER. 2023 10 1843 28 EFFECTS OF TELOMERASE INHIBITOR ON EPIGENETIC CHROMATIN MODIFICATION ENZYMES IN MALIGNANCIES. TELOMERASE HAS A CRITICAL ROLE IN CELL PROLIFERATION, TUMOR MAINTAINING, AND THERAPY RESISTANCE, WHICH ACT BY MODIFYING MANY SIGNALING PATHWAYS. 2-[(E)-3-NAPHTALEN-2-YL-BUT-2-ENOYLAMINO]-BENZOIC ACID (BIBR1532) IS ONE OF THE MOST STUDIED TELOMERASE INHIBITORS, AND IT TARGETS TELOMERASE COMPONENTS TERC AND TERT. IN THIS NOVEL STUDY, WE AIMED TO INVESTIGATE THE EPIGENETIC EFFECTS OF BIBR1532 ON BOTH HEMATOLOGIC MALIGNANCIES AND SOLID TUMORS. K-562 HUMAN CHRONIC MYELOID LEUKEMIA CELL LINE AND U87MG GLIOBLASTOMA CELL LINE WERE COMPARED WITH CONTROL GROUPS WITHOUT BIBR1532 TREATMENT. CYTOTOXIC EFFECTS OF BIBR1532 WERE DETERMINED BY USING WST-1 ASSAY. APOPTOTIC EFFECTS OF BIBR1532 WERE DETECTED BY USING ANNEXIN V METHOD. TO ASSESS EXPRESSION CHANGES IN THE HUMAN EPIGENETIC CHROMATIN MODIFICATION ENZYME GENES, TOTAL RNA WAS ISOLATED FROM K-562 AND U87MG CELLS TREATED WITH BIBR1532 AND UNTREATED CONTROL CELLS. BIBR1532 INDUCED 2.41-FOLD APOPTOTIC CELL DEATH IN U87MG CELL LINES COMPARED WITH CONTROL GROUPS. APOPTOSIS WAS SLIGHTLY INDUCED IN K-562 CELLS WITH BIBR1532 TREATMENT COMPARED WITH CONTROL CELLS. WE OBSERVED THAT BIBR1532 ALSO REGULATES SIMILAR GENES IN BOTH CELL LINES, AND IT IS USEFUL ON EPIGENETIC MECHANISMS. AS A RESULT, TELOMERASE INHIBITOR BIBR1532 HAS A SIGNIFICANT EFFECT ON BOTH HEMATOLOGICAL MALIGNANCIES AND SOLID TUMORS. 2018 11 4919 20 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 12 6256 18 THE MITOGEN AND STRESS-ACTIVATED PROTEIN KINASE 1 REGULATES THE RAPID EPIGENETIC TAGGING OF DORSAL HORN NEURONS AND NOCIFENSIVE BEHAVIOUR. PHOSPHORYLATION OF HISTONE H3 AT SERINE 10 (P-H3S10) IS A MARKER OF ACTIVE GENE TRANSCRIPTION. USING COGNITIVE MODELS OF NEURAL PLASTICITY, P-H3S10 WAS SHOWN TO BE DOWNSTREAM OF EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK) SIGNALLING IN THE HIPPOCAMPUS. IN THIS STUDY, WE SHOW THAT NOCICEPTIVE SIGNALLING AFTER PERIPHERAL FORMALIN INJECTION INCREASED P-H3S10 EXPRESSION IN THE IPSILATERAL DORSAL HORN. THIS INCREASE WAS MAXIMAL 30 MINUTES AFTER FORMALIN INJECTION AND OCCURRED MAINLY WITHIN P-ERK-POSITIVE NEURONS. SPINAL P-H3S10-ENHANCED EXPRESSION WAS ALSO OBSERVED IN NEUROKININ 1 RECEPTOR (NK1R), C-FOS, AND ZIF268 POSITIVE NEURONS AND WAS INHIBITED BY ABLATION OF SEROTONERGIC DESCENDING CONTROLS. THE MITOGEN AND STRESS-ACTIVATED PROTEIN KINASE 1 (MSK1) IS DOWNSTREAM OF ERK AND CAN INDUCE P-H3S10. WE FOUND THAT, AFTER FORMALIN INJECTION, MOST PHOSPHO-MSK1 (P-MSK1)-POSITIVE CELLS (87% +/- 3%) EXPRESSED P-ERK AND THE MAJORITY OF P-H3S10-POSITIVE CELLS (85% +/- 5%) EXPRESSED P-MSK1. INHIBITION OF ERK ACTIVITY WITH THE MEK INHIBITOR SL327 REDUCED FORMALIN-INDUCED P-ERK, P-MSK1, AND P-H3S10, DEMONSTRATING THAT SPINAL P-MSK1 AND P-H3S10 WERE AT LEAST PARTLY DOWNSTREAM OF ERK SIGNALLING. CRUCIALLY, PHARMACOLOGICAL BLOCKADE OF SPINAL MSK1 ACTIVITY WITH THE NOVEL MSK1 INHIBITOR SB727651A INHIBITED FORMALIN-INDUCED SPINAL P-H3S10 AND NOCIFENSIVE BEHAVIOUR. THESE FINDINGS ARE THE FIRST TO ESTABLISH THE INVOLVEMENT OF P-H3S10 AND ITS MAIN KINASE, MSK1, IN ERK REGULATION OF NOCICEPTION. GIVEN THE GENERAL IMPORTANCE OF ERK SIGNALLING IN PAIN PROCESSING, OUR RESULTS SUGGEST THAT P-H3S10 COULD PLAY A ROLE IN THE RESPONSE TO INJURY. 2016 13 154 21 ABERRANT METHYLATION OF NUCLEOTIDE EXCISION REPAIR GENES IS ASSOCIATED WITH CHRONIC ARSENIC POISONING. OBJECTIVE: TO DEFINE WHETHER ABERRANT METHYLATION OF DNA REPAIR GENES IS ASSOCIATED WITH CHRONIC ARSENIC POISONING. METHODS: HUNDRED AND TWO ENDEMIC ARSENICOSIS PATIENTS AND 36 HEALTHY SUBJECTS WERE RECRUITED. METHYLIGHT AND BISULFITE SEQUENCING (BSP) ASSAYS WERE USED TO EXAMINE THE METHYLATION STATUS OF ERCC1, ERCC2 AND XPC GENES IN PERIPHERAL BLOOD LYMPHOCYTES (PBLS) AND SKIN LESIONS OF ARSENICOSIS PATIENTS AND NAASO(2)-TREATED HACAT CELLS. RESULTS: HYPERMETHYLATION OF ERCC1 AND ERCC2 AND SUPPRESSED GENE EXPRESSION WERE FOUND IN PBLS AND SKIN LESIONS OF ARSENICOSIS PATIENTS AND WAS CORRELATED WITH THE LEVEL OF ARSENIC EXPOSURE. PARTICULARLY, THE EXPRESSION OF ERCC1 AND ERCC2 WAS ASSOCIATED WITH THE SEVERITY OF SKIN LESIONS. IN VITRO STUDIES REVEALED AN INDUCTION OF ERCC2 HYPERMETHYLATION AND DECREASED MRNA EXPRESSION IN RESPONSE TO NAASO(2) TREATMENT. CONCLUSION: HYPERMETHYLATION OF ERCC1 AND ERCC2 AND CONCOMITANT SUPPRESSION OF GENE EXPRESSION MIGHT BE SERVED AS THE EPIGENETIC MARKS ASSOCIATED WITH ARSENIC EXPOSURE AND ADVERSE HEALTH EFFECTS. 2017 14 5692 20 SILENCING OF LNCRNA PKIA-AS1 ATTENUATES SPINAL NERVE LIGATION-INDUCED NEUROPATHIC PAIN THROUGH EPIGENETIC DOWNREGULATION OF CDK6 EXPRESSION. NEUROPATHIC PAIN (NP) IS AMONG THE MOST INTRACTABLE COMORBIDITIES OF SPINAL CORD INJURY. DYSREGULATION OF NON-CODING RNAS HAS ALSO BEEN IMPLICATED IN THE DEVELOPMENT OF NEUROPATHIC PAIN. HERE, WE IDENTIFIED A NOVEL LNCRNA, PKIA-AS1, BY USING LNCRNA ARRAY ANALYSIS IN SPINAL CORD TISSUE OF SPINAL NERVE LIGATION (SNL) MODEL RATS, AND INVESTIGATED THE ROLE OF PKIA-AS1 IN SNL-MEDIATED NEUROPATHIC PAIN. WE OBSERVED THAT PKIA-AS1 WAS SIGNIFICANTLY UPREGULATED IN SNL MODEL RATS AND THAT PKIA-AS1 KNOCKDOWN ATTENUATED NEUROPATHIC PAIN PROGRESSION. ALTERNATIVELY, OVEREXPRESSION OF PKIA-AS1 WAS SUFFICIENT TO INDUCE NEUROPATHIC PAIN-LIKE SYMPTOMS IN UNINJURED RATS. WE ALSO FOUND THAT PKIA-AS1 MEDIATED SNL-INDUCED NEUROPATHIC PAIN BY DIRECTLY REGULATING THE EXPRESSION AND FUNCTION OF CDK6, WHICH IS ESSENTIAL FOR THE INITIATION AND MAINTENANCE OF NEUROINFLAMMATION AND NEUROPATHIC PAIN. THEREFORE, OUR STUDY IDENTIFIES PKIA-AS1 AS A NOVEL THERAPEUTIC TARGET FOR NEUROINFLAMMATION RELATED NEUROPATHIC PAIN. 2019 15 1622 22 DNA METHYLTRANSFERASES IN MALAR MELASMA AND THEIR MODIFICATION BY SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. BACKGROUND: MALAR MELASMA HAS A CHRONIC AND RECURRENT CHARACTER THAT MAY BE RELATED TO EPIGENETIC CHANGES. OBJECTIVE: TO RECOGNIZE THE EXPRESSION AND DNA METHYLATION OF DNA METHYLTRANSFERASES (DNMTS) IN MALAR MELASMA AND PERILESIONAL SKIN, AS WELL AS THE CHANGES IN DNMTS AFTER THEIR TREATMENT WITH SUNSCREEN IN COMBINATION WITH 4% NIACINAMIDE, 0.05% RETINOIC ACID, OR PLACEBO. METHODS: THIRTY FEMALE PATIENTS WERE CLINICALLY EVALUATED FOR THE EXPRESSION OF DNMT1 AND DNMT3B USING REAL-TIME PCR AND IMMUNOFLUORESCENCE. THESE INITIAL RESULTS WERE COMPARED TO RESULTS AFTER EIGHT WEEKS OF TREATMENT WITH SUNSCREEN IN COMBINATION WITH NIACINAMIDE, RETINOIC ACID, OR PLACEBO. RESULTS: THE RELATIVE EXPRESSION OF DNMT1 WAS SIGNIFICANTLY ELEVATED IN MELASMA COMPARED WITH UNAFFECTED SKIN IN ALL SUBJECTS, INDICATING DNA HYPERMETHYLATION. AFTER TREATMENT, IT WAS DECREASED IN ALL GROUPS: NIACINAMIDE (7 VERSUS 1; P<0.01), RETINOIC ACID (7 VERSUS 2; P<0.05), AND PLACEBO (7 VERSUS 3; P<0.05), WHICH CORRELATES WITH CLINICAL IMPROVEMENT. DNMT3B WAS NOT OVEREXPRESSED IN LESIONAL SKIN BUT REDUCED IN ALL GROUPS. CONCLUSIONS: WE FOUND DNA HYPERMETHYLATION IN MELASMA LESIONS. ENVIRONMENTAL FACTORS SUCH AS SOLAR RADIATION MAY INDUCE CELLULAR CHANGES THAT TRIGGER HYPERPIGMENTATION THROUGH THE ACTIVATION OF PATHWAYS REGULATED BY EPIGENETIC MODIFICATIONS. HOWEVER, LIMITING OR DECREASING DNA METHYLATION THROUGH SUNSCREEN, NIACINAMIDE, AND RETINOIC ACID TREATMENTS THAT PROVIDE PHOTOPROTECTION AND GENETIC TRANSCRIPTION CAN COUNTERACT THIS. 2019 16 1016 27 CIITA EXPRESSION IS REGULATED BY HISTONE DEACETYLASE ENZYMES AND HAS A ROLE IN ALPHA-SYNUCLEIN PRE-FORMED FIBRIL-INDUCED ANTIGEN PRESENTATION IN MURINE MICROGLIAL CELL LINE. AIM: PARKINSON'S DISEASE (PD) IS A CHRONIC NEURODEGENERATIVE DISORDER RELATED WITH SEVERAL GENETIC AND EPIGENETIC FACTORS. IN THE CONTEXT OF EPIGENETIC FACTORS, HISTONE ACETYLATION IS ONE OF THE MOST ASSOCIATED MECHANISMS WITH PARKINSON'S DISEASE PROGRESSION. THIS STUDY INVESTIGATES THE EFFECTS OF THE INCREASED HISTONE ACETYLATION ON ANTIGEN PRESENTATION IN MICROGLIAL CELLS WHICH WERE INDUCED BY PRE-FORMED FIBRILS OF ALPHA-SYNUCLEIN (PFF ALPHA-SYNUCLEIN). METHODS: PARKINSON'S DISEASE MODEL WAS CREATED WITH PFF ALPHA-SYNUCLEIN ADMINISTRATION TO THE BV-2 MICROGLIAL CELLS. BV-2 CELLS WERE CO-TREATED WITH CUDC-907 AND TMP-195 TO INCREASE HISTONE ACETYLATION IN THE PRESENCE OF ALPHA-SYNUCLEIN. ANTIGEN REPRESENTATION WAS EVALUATED BY DETERMINING EXPRESSION LEVELS OF MAJOR HISTOCOMPATIBILITY COMPLEX-II (MHC-II) AND CLASS-II MAJOR HISTOCOMPATIBILITY COMPLEX (CIITA). RESULTS: OUR RESULTS SHOWED THAT PFF ALPHA-SYNUCLEIN SIGNIFICANTLY INCREASED MHC-II EXPRESSION, AND THAT EFFECT WAS MOST SEVERE AT 6 H OF ADMINISTRATION OF ALPHA-SYNUCLEIN. INCREASING HISTONE ACETYLATION VIA CUDC-907 AND TMP-195 ENHANCED MHC-II LEVELS EXPRESSION, WHICH WAS MORE SEVERE IN CUDC-907. ADDITIONALLY, CIITA EXPRESSION LEVELS WERE SIGNIFICANTLY INCREASED WITH PFF ALPHA-SYNUCLEIN ADMINISTRATION AND INTENSIFIED WITH THE CO-TREATMENT OF CUDC-907 AND TMP-195. FURTHERMORE, PFF ALPHA-SYNUCLEIN CAUSED A TIME-DEPENDENT INCREASE IN THE IFN-GAMMA (IFN-?) AND INTERLEUKIN-16(IL-16) LEVELS, AND THAT INCREASE WAS POTENTIATED WITH CUDC-907 AND TMP-195. CONCLUSION: CHANGES IN MHC-II AND CIITA EXPRESSION INDICATE THAT HISTONE ACETYLATION INCREASES THE ANTIGEN PRESENTATION PROPERTIES OF MICROGLIAL CELLS AFTER PFF ALPHA-SYNUCLEIN OR HISTONE DEACETYLASE INHIBITOR (HDACI) ADMINISTRATION. OUR RESULTS SHOW THAT MICROGLIAL ANTIGEN PRESENTATION MIGHT HAVE AN ESSENTIAL ROLE IN THE PATHOLOGY OF PARKINSON'S DISEASE, AND ALPHA-SYNUCLEIN LIKELY TO PLAY A PRIMARY ROLE IN THIS MECHANISM. 2022 17 1421 20 DIFFERENTIAL BRAIN ADRA2A AND ADRA2C GENE EXPRESSION AND EPIGENETIC REGULATION IN SCHIZOPHRENIA. EFFECT OF ANTIPSYCHOTIC DRUG TREATMENT. POSTSYNAPTIC ALPHA(2A)-ADRENOCEPTOR DENSITY IS ENHANCED IN THE DORSOLATERAL PREFRONTAL CORTEX (DLPFC) OF ANTIPSYCHOTIC-TREATED SCHIZOPHRENIA SUBJECTS. THIS ALTERATION MIGHT BE DUE TO TRANSCRIPTIONAL ACTIVATION, AND COULD BE REGULATED BY EPIGENETIC MECHANISMS SUCH AS HISTONE POSTTRANSLATIONAL MODIFICATIONS (PTMS). THE AIM OF THIS STUDY WAS TO EVALUATE ADRA2A AND ADRA2C GENE EXPRESSION (CODIFYING FOR ALPHA(2)-ADRENOCEPTOR SUBTYPES), AND PERMISSIVE AND REPRESSIVE HISTONE PTMS AT GENE PROMOTER REGIONS IN THE DLPFC OF SUBJECTS WITH SCHIZOPHRENIA AND MATCHED CONTROLS (N = 24 PAIRS). WE STUDIED THE EFFECT OF ANTIPSYCHOTIC (AP) TREATMENT IN AP-FREE (N = 12) AND AP-TREATED (N = 12) SUBGROUPS OF SCHIZOPHRENIA SUBJECTS AND IN RATS ACUTELY AND CHRONICALLY TREATED WITH TYPICAL AND ATYPICAL ANTIPSYCHOTICS. ADRA2A MRNA EXPRESSION WAS SELECTIVELY UPREGULATED IN AP-TREATED SCHIZOPHRENIA SUBJECTS (+93%) WHEREAS ADRA2C MRNA EXPRESSION WAS UPREGULATED IN ALL SCHIZOPHRENIA SUBJECTS (+53%) REGARDLESS OF ANTIPSYCHOTIC TREATMENT. ACUTE AND CHRONIC CLOZAPINE TREATMENT IN RATS DID NOT ALTER BRAIN CORTEX ADRA2A MRNA EXPRESSION BUT INCREASED ADRA2C MRNA EXPRESSION. BOTH ADRA2A AND ADRA2C PROMOTER REGIONS SHOWED EPIGENETIC MODIFICATION BY HISTONE METHYLATION AND ACETYLATION IN HUMAN DLPFC. THE UPREGULATION OF ADRA2A EXPRESSION IN AP-TREATED SCHIZOPHRENIA SUBJECTS MIGHT BE RELATED TO OBSERVED BIVALENT CHROMATIN AT ADRA2A PROMOTER REGION IN SCHIZOPHRENIA (DEPICTED BY INCREASED PERMISSIVE H3K4ME3 AND REPRESSIVE H3K27ME3) AND COULD BE TRIGGERED BY THE ENHANCED H4K16AC AT ADRA2A PROMOTER. IN CONCLUSION, EPIGENETIC PREDISPOSITION DIFFERENTIALLY MODULATED ADRA2A AND ADRA2C MRNA EXPRESSION IN DLPFC OF SCHIZOPHRENIA SUBJECTS. 2021 18 5625 17 SELECTIVE CLASS I HISTONE DEACETYLASE INHIBITORS SUPPRESS PERSISTENT SPONTANEOUS NOCICEPTION AND THERMAL HYPERSENSITIVITY IN A RAT MODEL OF BEE VENOM-INDUCED INFLAMMATORY PAIN. TO CONFIRM WHETHER CLASS I HISTONE DEACETYLASE INHIBITORS (HDACIS) ARE EFFECTIVE IN RELIEF OF PERIPHERAL INFLAMMATORY PAIN, THE EFFECTS OF TWO SELECTIVE INHIBITORS, MS-275 AND MGCD0103, WERE STUDIED IN RATS INFLAMED BY SUBCUTANEOUS (S.C.) INJECTION OF BEE VENOM (BV). THE BV TEST IS CHARACTERIZED BY DISPLAYING BOTH PERSISTENT SPONTANEOUS NOCICEPTION (PSN) AND PRIMARY HYPERSENSITIVITY. INTRATHECAL (I.T.) PRE-TREATMENT OF EITHER MS-275 OR MGCD0103 WITH A SINGLE DOSE OF 60 NMOL/20 MUL RESULTED IN PROFOUND SUPPRESSION OF BOTH PSN AND PRIMARY THERMAL HYPERSENSITIVITY BUT WITHOUT SIGNIFICANT INFLUENCE UPON THE PRIMARY MECHANICAL HYPERSENSITIVITY AND MIRROR-IMAGE THERMAL HYPERSENSITIVITY. MOREOVER, THE UP-REGULATION OF BOTH HDAC1 AND HDAC2 INDUCED BY S.C. BV INJECTION WAS COMPLETELY SUPPRESSED BY I.T. PRE-TREATMENT OF MS-275. THE PRESENT RESULTS PROVIDE WITH ANOTHER NEW LINE OF EVIDENCE SHOWING INVOLVEMENT OF EPIGENETIC REGULATION OF CHROMATIN STRUCTURE BY HDAC1/2-MEDIATED HISTONE HYPOACETYLATION IN THE BV-INDUCED PSN AND THERMAL HYPERSENSITIVITY AND DEMONSTRATE THE BENEFICIAL EFFECTS OF CLASS I HDACIS IN PREVENTION OF PERIPHERAL INFLAMMATORY PAIN FROM OCCURRING. 2015 19 3236 24 HEN EGG LYSOZYME ALLEVIATES STATIC MECHANICAL PAIN VIA NRF1-PARKIN-TACAN SIGNALING AXIS IN SENSORY NEURONS. MECHANICAL ALLODYNIA IMPINGES ON THE LIFE QUALITY OF PATIENTS. HEN EGG LYSOZYME (HEL) IS A SUBSTANCE EXTRACTED FROM EGGS THAT IS COMMONLY USED TO INHIBIT BACTERIAL ACTIVITY. THE ROLE OF HEL IN REGULATING AND TREATING PAIN IS UNCLEAR. HERE, WE FIND THAT HEL SELECTIVELY ATTENUATES STATIC MECHANICAL ALLODYNIA OF MICE INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA), SPINAL NERVE LIGATION (SNL) AND CHEMOTHERAPEUTIC AGENT. RNA-SEQ SCREENING REVEALS THAT CFA SIGNIFICANTLY REDUCES THE EXPRESSION OF PARKIN IN DORSAL ROOT GANGLION (DRG) NEURONS OF MICE, WHILE PRE-ADMINISTRATION OF HEL INCREASES THE EXPRESSION OF PARKIN AND REMITS THE STATIC MECHANICAL ALLODYNIA INDUCED BY PARKIN-SIRNA. MOREOVER, HEL INCREASES THE INTERACTION BETWEEN NUCLEAR RESPIRATORY FACTOR 1 (NRF1) AND HISTONE ACETYLTRANSFERASE P300 AND THEN ENHANCES THE NRF1 MEDIATED HISTONE ACETYLATION IN PRKN PROMOTER REGION IN DRGS OF MICE. FURTHER, PARKIN INTERACTS WITH MECHANOTRANSDUCING ION CHANNEL TACAN (TMEM120A) AND KNOCKDOWN OF PARKIN SIGNIFICANTLY INCREASES THE MEMBRANE TRAFFICKING OF TACAN IN SENSORY NEURONS OF MICE. WHILE PRE-ADMINISTRATION OF HEL INHIBITS THE INCREASED MEMBRANE TRAFFICKING OF TACAN IN SENSORY NEURONS OF MICE INDUCED BY PARKIN-SIRNA. IN ADDITION, PRE-GIVEN OF HEL ALSO SIGNIFICANTLY ATTENUATES THE STATIC MECHANICAL ALLODYNIA INDUCED BY OVEREXPRESSION OF TACAN IN MICE, AND THE EFFECT OF HEL CAN BE BLOCKED BY PARKIN-SIRNA. THIS INDICATES THAT HEL INCREASES THE EXPRESSION OF PARKIN THROUGH EPIGENETIC MECHANISMS AND THEN DECREASES TACAN MEMBRANE TRAFFICKING IN SENSORY NEURONS TO RELIEVE STATIC MECHANICAL HYPERSENSITIVITY. THEREFORE, WE REVEAL A NOVEL FUNCTION OF HEL, WHICH IS A POTENTIAL SUBSTANCE FOR THE TREATMENT OF STATIC MECHANICAL PAIN. 2022 20 6243 23 THE MECHANISM OF APOLIPROTEIN A1 DOWN-REGULATED BY HEPATITIS B VIRUS. BACKGROUND: HEPATITIS B VIRUS (HBV) INFECTION CORRELATED WITH THE DEVELOPMENT OF CIRRHOSIS, LIVER FAILURE AND HEPATOCELLULAR CARCINOMA (HCC), POSES A HUGE HEALTH BURDEN ON THE GLOBAL COMMUNITY. HOWEVER, THE PATHOGENESIS OF CHRONIC HEPATITIS B (CHB) REMAINS UNCLEAR. APOLIPOPROTEIN A1 (APOA1) MAINLY SECRETED BY HEPATOCYTES, REPRESENTS THE MAJOR PROTEIN COMPONENT OF HIGH-DENSITY LIPOPROTEIN. APOA1 SECRETION MAY BE DISRUPTED BY HBV INFECTION. IN THIS STUDY, WE MAINLY INVESTIGATED THE MOLECULAR MECHANISM OF APOA1 DOWN REGULATED BY HBV FOR REVEALING THE PATHOGENESIS OF CHB. METHODS: APOA1 EXPRESSION IN LIVERS OF CHB PATIENTS AS WELL AS HEALTHY CONTROLS WERE PERFORMED BY REAL-TIME PCR (RT-PCR) AND WESTERN BLOT. THE SERUM APOA1 LEVELS WERE MEASURED BY ENZYMED-LINKED IMMUNOSORBENT ASSAY (ELISA). EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE PERFORMED BY RT-PCR AND WESTERN BLOT IN HUMAN HEPATOMA HEPG2 CELLS AND SUBLINE HEPG2.2.15 CELLS. HBV EXPRESSION CONSTRUCT, PHBV1.3 WERE TRANSFECTED INTO HEPG2, THE CHANGES OF APOA1 MRNA AND PROTEIN EXPRESSION WERE DETECTED BY RT-PCR AND WESTERN BLOT. TO FURTHER STUDY THE MECHANISM OF APOA1 DOWN REGULATION BY HBV, 11 CPG ISLANDS IN APOA1 PROMOTOR WERE TESTED FOR DNA METHYLATION STATUS BY MSP. HEPG2.2.15 CELL LINES WERE TREATED WITH DNA METHYLTRANSFERASE INHIBITOR 5-AZA-DEOXYCYTIDINE (5-AZA-DC), THEN, EXPRESSION OF APOA1 MRNA AND HBV PARTICLES IN THE SUPERNATANT, AS WELL AS APOA1 PROTEIN LEVELS WERE DETECTED BY RT-PCR AND WESTERN BLOT. SECRETION OF HBSAG AND HBEAG IN HEPG2 CELLS COTRANSFECTED WITH PAPOA1 AND PHBV1.3 CONSTRUCTS WAS TESTED BY ELISA. MEANWHILE, SECRETION OF HBSAG AND HBEAG IN THE SUPERNATANT WERE QUANTIFIED BY ELISA IN THE HEPG2.2.15 CELLS TREATED WITH 5-AZA-DC PLUS APOA1 SIRNA. RESULTS: EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS, AS WELL AS SERUM APOA1 LEVELS IN CHB PATIENTS WERE DECREASED CORRESPONDING HEALTHY CONTROLS IN VIVO. IN ADDITION, THE EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE DOWN REGULATED IN HEPG2.2.15 CELLS CORREPONDING HEPG2 CELLS, 11 CPG ISLANDS IN APOA1 PROMOTER WERE TESTED FOR METHYLATION STATUS BY MSP IN HEPG2.2.15 CELLS COMPARED TO HEPG2 CELLS, WHILE TWO CPG ISLANDS WERE FOUND HYPERMETHYLATED. EXPRESSION OF APOA1 MRNA AND PROTEIN LEVELS WERE INCREASED IN HEPG2.2.15 CELLS TREATED WITH DNA METHYLTRANSFERASE INHIBITOR 5-AZA-DC. FURTHERMORE, OVEREXPRESSION OF APOA1 CAN ENHANCE HBV EXPRESSION IN HEPG2 CELLS WHILE THE INHIBITORY EFFECT OF 5-AZA-DC ON HBV EXPRESSION WAS COMPLETELY ABOLISHED BY BLOCKING 5-AZA-DC-INDUCED UP-REGULATION OF APOA1 USING RNAI. CONCLUSIONS: EPIGENETIC SILENCING OF APOA1 GENE EXPRESSION BY CPG ISLAND DNA HYPERMETHYLATION INDUCED BY HBV MAY CONTRIBUTE TO THE PATHOGENESIS OF CHB. 2016