1 6918 125 [WNT3A SIGNALING PATHWAY PLAYS A ROLE IN NEUROPATHIC PAIN THROUGH EPIGENETIC MODIFICATION OF JMJD6]. TO EXPLORE WHETHER WNT3A EXERTS A ROLE IN NEUROPATHIC PAIN THROUGH JUMONJI C DOMAIN 6 (JMJD6)-ASSOCIATED EPIGENETIC MODIFICATION. METHODS: SD RATS WERE DIVIDED INTO 4 GROUPS: A SHAM GROUP, A CHRONIC CONSTRICTION INJURY (CCI) GROUP, A CCI+NEGATIVE LENTIVIRAL EXPRESSION VECTOR (LV-NC) GROUP AND A CCI+LENTIVIRAL OVEREXPRESSION VECTOR (LV-JMJD6) GROUP. THE SCIATIC NERVE CCI MODEL OF SD RAT AND JMJD6 LENTIVIRAL EXPRESSION VECTOR WERE CONSTRUCTED. ON THE THIRD DAY AFTER CCI, THE INTRATHECAL CATHETER WAS PREPARED, AND 20 MUL OF NORMAL SALINE AND LENTIVIRUS-CONTAINING REAGENT (VIRUS TITER 1X108 TU/ML) WERE ADMINISTERED. THE RATS' PAW WITHDRAWAL MECHANICAL THRESHOLD (PWMT) AND PAW WITHDRAWAL THERMAL LATENCY (PWTL) WERE MONITORED, AND WESTERN BLOTTING WAS USED TO DETECT THE EXPRESSION OF WNT3A AND NR2B PROTEIN IN THE SPINAL CORD. CO-IMMUNOPRECIPITATION WAS APPLIED TO DETECT THE INTERACTION BETWEEN JMJD6 AND WNT3A. RESULTS: COMPARED WITH THE SHAM GROUP, THE PWMT OF THE RATS IN EACH GROUP AFTER CCI WAS SIGNIFICANTLY DECREASED AND THE PWTL WAS SIGNIFICANTLY SHORTENED (P<0.05). COMPARED WITH THE CCI GROUP AND THE CCI+LV-NC GROUP, PWMT IN THE CCI+LV-JMJD6 GROUP WAS INCREASED SIGNIFICANTLY ON THE 10TH DAY AND THE 14TH DAY AFTER CCI, AND THE PWTL WAS SIGNIFICANTLY PROLONGED ON THE 14TH DAY AFTER CCI (P<0.05). ON THE 14TH DAY AFTER CCI, THE EXPRESSION LEVELS OF WNT3A AND NR2B IN THE CCI GROUP AND THE CCI+LV-NC GROUP WERE SIGNIFICANTLY HIGHER THAN THOSE IN THE SHAM GROUP. AFTER INTRATHECAL INJECTION OF LENTIVIRAL VECTOR, WNT3A AND NR2B PROTEIN EXPRESSION LEVELS IN THE CCI+LV-JMJD6 GROUP WERE LOWER COMPARED WITH THE CCI+LV-NC GROUP (P<0.05). THE RESULTS OF CO-IMMUNOPRECIPITATION SHOWED NO DIRECT INTERACTION BETWEEN WNT3A AND JMJD6. CONCLUSION: WNT3A IS INVOLVED IN MEDIATING NEUROPATHIC PAIN, AND ITS EFFECT MAY BE RELATED TO THE EPIGENETIC MODIFICATION OF JMJD6, WHICH IS LIKELY REGULATED THROUGH INDIRECT INTERACTION. 2019 2 6148 31 THE EXPRESSION OF TRANSCRIPTION FACTORS MECP2 AND CREB IS MODULATED IN INFLAMMATORY PELVIC PAIN. EARLY ACTIVATION OF TRANSCRIPTION FACTORS IS ONE OF THE EPIGENETIC MECHANISMS CONTRIBUTING TO THE INDUCTION AND MAINTENANCE OF CHRONIC PAIN STATES. PREVIOUS STUDIES IDENTIFIED THE CHANGES IN A NUMBER OF NOCICEPTION-RELATED GENES, SUCH AS CALCITONIN GENE-RELATED PEPTIDE (CGRP), SUBSTANCE P (SP), AND BRAIN-DERIVED NEUROTROPIC FACTOR (BDNF) IN THE PELVIC ORGANS AFTER TRANSIENT COLONIC INFLAMMATION. THE GENE AND PROTEIN EXPRESSION OF THESE NEUROPEPTIDES COULD BE MODULATED BY TRANSCRIPTION FACTORS METHYL-CPG-BINDING PROTEIN 2 (MECP2) AND CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB). IN THIS STUDY, WE AIMED TO EVALUATE TIME-DEPENDENT CHANGES IN THE EXPRESSION LEVELS OF MECP2 AND CREB IN THE LUMBOSACRAL (LS) SPINAL CORD AND SENSORY GANGLIA AFTER INFLAMMATION-INDUCED PELVIC PAIN IN RAT. ADULT SPRAGUE-DAWLEY RATS WERE TREATED WITH 2,4,6-TRINITROBENZENESULFONIC ACID (TNBS) TO INDUCE TRANSIENT COLONIC INFLAMMATION. LS (L6-S2) SPINAL CORD SEGMENTS AND RESPECTIVE DORSAL ROOT GANGLIAS (DRGS) WERE ISOLATED FROM CONTROL AND EXPERIMENTAL ANIMALS AT 1, 2, 6, 24 H AND 3 DAYS POST-TNBS TREATMENT. IMMUNOHISTOCHEMICAL (IHC) LABELING AND WESTERN BLOTTING EXPERIMENTS WERE PERFORMED TO ASSESS THE EXPRESSION OF MECP2, CREB AND THEIR PHOSPHORYLATED FORMS. TOTAL MECP2 EXPRESSION, BUT NOT PHOSPHORYLATED P-MECP2 (PS421MECP2) EXPRESSION WAS DETECTED IN THE CELLS OF THE SPINAL DORSAL HORN UNDER CONTROL CONDITIONS. COLONIC INFLAMMATION TRIGGERED A SIGNIFICANT DECREASE IN THE NUMBER OF MECP2-EXPRESSING NEURONS IN PARALLEL WITH ELEVATED NUMBERS OF PS421MECP2-EXPRESSING CELLS AT 2 H AND 6 H POST-TNBS. THE MAJORITY OF MECP2-POSITIVE CELLS (80 +/- 6%) CO-EXPRESSED CREB. TNBS TREATMENT CAUSED A TRANSIENT UP-REGULATION OF CREB-EXPRESSING CELLS AT 1 H POST-TNBS ONLY. THE NUMBER OF CELLS EXPRESSING PHOSPHORYLATED CREB (PS133CREB) DID NOT CHANGE AT 1 H AND 2 H POST-TNBS, BUT WAS DOWN-REGULATED BY THREE FOLDS AT 6 H POST-TNBS. ANALYSIS OF DRG SECTIONS REVEALED THAT THE NUMBER OF MECP2-POSITIVE NEURONS WAS UP-REGULATED BY TNBS TREATMENT, REACHING THREE-FOLD INCREASE AT 2 H POST-TNBS, AND EIGHT-FOLD INCREASE AT 6 H POST-TNBS (P