Wnt3a signaling pathway plays a role in neuropathic pain through epigenetic modification of JMJD6

Abstract

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 μL of normal saline and lentivirus-containing reagent (virus titer 1×108 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.