Abstract: Objective: To study the effects of miR-99b-5p (non-coding RNA) in alleviating pathological neuropathic pain after paclitaxel chemotherapy by inhibiting NLRP3 inflammatory vesicle activation and the effects on neuronal cells pyrosis and apoptosis. Methods: SD rats were randomly divided into blank group, model group, agomiR-99b-5P treatment group, and agomiR-NC group, 6 rats in each group. The blank group received saline treatment as a control, the model group established a pain model induced by paclitaxel, and the rats in agomiR-99b-5p treatment group and agomiR-NC group were treated with agomiR-99b-5p and agomiR-NC injections, respectively. The expressions of miR-99b-5p in the blank group, model group, and treatment group were detected by RT-qPCR. The mechanical foot retraction threshold (MWT) of the blank group, model group, and treatment group were detected. TUNEL was used to detect the apoptosis of spinal dorsal horn cells. The levels of ROS, MDA, and SOD were detected by ELISA kits. The protein expressions of NLRP3, caspase-1, and IL-1β were detected by immunofluorescence staining. Results: Compared with the model group, the expression level of miR-99b-5p and the MWT were increased significantly in agomiR-99b-5p treatment group (P＜0.05), the apoptosis of dorsal horn cells was inhibited (P＜0.05), the level of antioxidant stress was increased in rats, the levels of ROS and MDA were decreased (P＜0.05), while the level of SOD was increased (P＜0.05). Immunofluorescence showed that the expressions of NLRP3, caspase-1, and IL-1β were inhibited by miR-99b-5p. Conclusion: miR-99b-5p can alleviate the apoptosis and pyroptosis of neurons after paclitaxel chemotherapy by inhibiting the activation of NLRP3 and improving oxidative stress in vivo.

Key words: dorsal root ganglion, miR-99b-5p, oxidative stress, NLRP3