Mechanism of lidocaine-induced ROS generation triggering DNA double-strand breaks and promoting intervertebral disc cell senescence via the MYC-DUSP1-P53 axis.

Discogenic lower back pain (DLBP) is a prevalent lumbar disorder. Functional Anesthetic Discography (FAD) is the primary diagnostic method for DLBP, with a high positivity rate. However, the mechanism by which lidocaine, a local anesthetic commonly used in FAD, induces damage to intervertebral disc cells remains unclear. This study aimed to investigate how lidocaine causes intervertebral disc cell damage and exacerbates the process of intervertebral disc degeneration (IVDD). We conducted primary nucleus pulposus cell (NPC) isolation and culture, and divided the cells into groups by lidocaine concentration (2.0 %, 1.0 %, 0.5 %, and 0 %). The cytotoxic effect of lidocaine on NPCs was evaluated using the CCK-8 colorimetric assay. We then created a mouse IVDD model, and conducted X-ray, magnetic resonance imaging (MRI), and mRNA-seq analysis. Assays, immunofluorescence detection, and real-time quantitative polymerase chain reaction (RT-qPCR) analyses were also performed. Lidocaine-induced oxidative stress damage in NPCs, leading to DNA double-strand breaks and triggering the transition of NPCs into a senescent state. Furthermore, treatment with an ROS inhibitor significantly alleviated both DNA damage and senescence. RNA-seq analysis revealed a marked upregulation in the MYC-DUSP1 axis expression. By employing si-RNA to inhibit the MYC-DUSP1 axis, the expression of senescence-related phenotypes was effectively reduced. Additionally, dasatinib (DASA) administration effectively mitigated the lidocaine-induced senescence of NPCs and alleviated the detrimental effects of lidocaine on IVDD. This study demonstrated that lidocaine exacerbates oxidative stress reactions within NPCs, leading to DNA double-strand breaks and promoting cellular senescence, thereby further aggravating IVDD progression. Moreover, an effective anti-senescence drug was identified, suggesting that DASA could be utilized as an intervention during FAD to reduce further pharmacological damage to NPCs. These findings provide an experimental foundation for optimizing the diagnostic approaches for DLBP.