Human Bone Marrow Mesenchymal Stem Cells-derived Exosomal miRNA-21-5p Inhibits Lidocaine-induced Apoptosis in SH-SY5Y Neuroblastoma Cells

Background: Local anesthetic lidocaine is one of the most common pain therapies, but high concentration of lidocaine induced neurotoxicity and its mechanism is unclear. Exosomal microRNAs (miRNAs) is implicated in neuronal diseases, but its role in lidocaine induced neurotoxicity remains to be elucidated. Methods: All the experiments were performed at Huzhou Key Laboratory of Molecular Medicine, Huzhou City, Jiangsu Province, China in 2022. Lidocaine was used to induce apoptosis of SH-SY5Y cells. Exosomes isolated from bone marrow mesenchymal stem cells (BMSC-exos) were used to co-treat SH-SY5Y cells with lidocaine. Cell apoptosis was measured using a flow cytometer. PKH-67 Dye was used for exosome uptake assay. miR-21-5p mimics/inhibitors, or negative controls were transfected with Lipo2000 to study its effect on lid-induced injury. Interactions between miR-21-5p and PDCD4 was analyzed by luciferase reporter assay. Results: Administration of BMSC-exo protected SH-SY5Y cells against lidocaine induced apoptosis. Suppressing miR-21-5p dramatically enhanced PDCD4, but miR-21-5p overexpression sharply down-regulated PDCD4. Mechanism study showed that miR-21-5p bound to 3’-UTR of PDCD4 to inhibit it. Suppressing miR-21-5p reversed the effect of BMSC-exo on Lid-induced injury. Results also indicate that miR-21-5p regulated lidocaine-induced injury through targeting PDCD4. Conclusion: BMSC-exos protected SH-SY5Y cells against lidocaine induced apoptosis through miR-21-5p by targeting PDCD4, which may develop new strategy in the management of lidocaine-induced neurotoxicity.