MicroRNA-212-3p Attenuates Neuropathic Pain via Targeting Sodium Voltage-gated Channel Alpha Subunit 3 (Nav 1.3)

Purpose: To explore the role and potential mechanism of m R-212-3p in neuropathic pain regulation. Methods: Adult male rats were used to establish chronic constriction injury (CCI) model to mimic the neuropathic pain. Then, paw withdrawal threshold (PWT) and paw withdrawal thermal latency (PWL) were determined. The concentrations of interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were measured with enzyme-linked immune sorbent assay (ELISA) kit and the expression of miR-212-3p was measured by real time quantitative PCR (RT-qPCR). Besides, miR-212-3p agomir was intrathecally injected into CCI rats and the expression of key apoptotic proteins was determined by western blot. Furthermore, dual-luciferase reporter assay was used to determine the binding of miR-212-3p and 3' untranslated regions (3'UTR) of Na(v)1.3 and the expression levels of Na(v)1.3 were measured by western blot and RT-qPCR. Results: In the CCI group, the PWT and PWL were significantly decreased and IL-1 beta, IL 6 and TNF-alpha were increased. miR-212-3p was decreased in response to CCI. The intrathecal injection of miR-212-3p agomir into CCI rats improved the PWT and PWL, decreased the IL-1 beta, IL-6 and INF-alpha, decreased the expression levels of BCL2 associated X, apoptosis regulator (Bax), cleaved caspase-3 and increased the expression levels of BCL2 apoptosis regulator (Bc1-2). The results of dual--luciferase reporter assay showed that miR-212-3p could directly bind with 3'UTR of Na(v)1.3. The expression of Na(v)1.3 was up-regulated in CCI rats who were intrathecally injected with miRctrl, whereas it decreased in CCI rats intrathecally injected with miR-212-3p agomir. Conclusion: The expression of miR-212a-3p attenuates neuropathic pain by targeting Na(v)1.3.