Abstract:Objective: To investigate the relationship and possible molecular mechanism of circular RNA (circRNA) derived from the gene of sodium voltage-gated channel α subunit 9 (SCN9A) with diabetic peripheral neuropathic pain (DPNP). Methods: Firstly, the expression profile of SCN9A-derived circRNAs in serum of DPNP patients was detected. Then, the cytological localization of screened differential circRNAs was studied. The microRNA (miRNA) spong capacity of the circRNAs was detected by luciferase (LUC) reporter assay, and the diagnostic value of circRNAs in DPNP was evaluated by receiver operator characteristic curve (ROC curve) model. Bioinformatics analysis was used to construct the functional pathway of circRNAs in DPNP and the molecular biological mechanism was also verified. Results: SCN9A derived hsa_circ_0117953 (circ_SCN9A) is significantly highly expressed in DPNP serum, and mainly located in the cytoplasm within the cell, regulating the expression of multiple miRNAs (miR-661, miR-1324, miR-877-3p, miR-1256, miR-153-3p, miR-1264) through the miRNA sponge mechanism. Circ_SCN9A had good diagnostic value in DPNP and is related to the levels of pain. Molecular mechanism study revealed multiple miRNAs that circ_SCN9A regulated mainly play a role by Serotonergic synapse pathway. Among them, circ_SCN9A can regulate the potassium inwardly rectifying channel subfamily J member 6 (KCNJ6) gene expression by sponging the miR-1256. Conclusion: SCN9A derived circ_SCN9A involved in DPNP development by Serotonergic synapse pathways and can be used as potential biological indicator in clinical diagnosis of DPNP.