Tetramethylpyrazine exerts a neuroprotective effect in acute spinal cord injury by mitigating oxidative stress through PKD1: multi-omics analysis and experimental validation.

Abstract

Background: Spinal cord injury (SCI) leads to permanent paralysis, with no current treatments capable of enhancing neurological recovery. Tetramethylpyrazine (TMP) has recently emerged as a potential therapeutic agent for SCI, although further investigation is required to clarify its mechanisms of action.

Methods: To evaluate the therapeutic effects of TMP on SCI, SCI models were established in rats, followed by assessment of therapeutic efficacy. Motor function recovery was quantified using the Beattie, Bresnahan and Basso (BBB) score, electrophysiological measurements, footprint analysis, and Catwalk gait analysis. Spinal cord tissues were examined through HE, Nissl, dihydroethidium (DHE), transmission electron microscopy, and immunofluorescence. Key molecular targets and functional pathways were analyzed via transcriptomic and proteomic sequencing. Additionally, PC12 cells were cultured to validate the molecular mechanisms of TMP, employing cell counting kit-8 (CCK-8) assays, live/dead staining, 2, 7-dichlorodihydrofluorescein diacetic acid fluorescent probe (DCFH-DA), western blotting (WB), and immunofluorescence staining.

Results: TMP treatment significantly enhanced neuronal survival and improved motor function in rats. Sequencing analysis revealed a considerable number of differentially expressed genes following SCI and TMP administration, predominantly associated with stress response, external stimuli, and defense mechanisms. Venn analysis identified PKD1 as a key target, showing reduced expression after SCI and upregulation following TMP treatment. Further validation in spinal cord tissues and cells confirmed these findings. The reduction in PKD1 expression post-SCI was correlated with a marked oxidative stress response, which TMP effectively reversed.

Conclusions: TMP may promote functional recovery by upregulating PKD1 and alleviating oxidative stress-related damage.