Protective effect of troxerutin against spinal cord injury in rats: a transcriptomic study

Abstract

Objective To investigate the protective effect of troxerutin against spinal cord injury (SCI) in rats and explore the underlying mechanisms. Methods Sixty 8-week-old male SD rats were randomly divided into sham operation group, SCI group and troxerutin treatment group. In the sham group, the rats were subjected to laminectomy without SCI; rat models of SCI were established in SCI group and troxerutin treatment group, and in the latter group, the rats received daily intravenous injection of troxerutin after SCI for 4 consecutive weeks. Neurological recovery of the rats was assessed based on the Basso-Beattie-Bresnehan (BBB) score, and HE staining was used to observe the changes in the vacuoles and blood vessels at the injury site of the spinal cord. RNA sequencing was used to examine the differential gene expressions in the injured spinal cord tissue between SCI group and troxerutin group, and Western blotting was performed to verify the differential expression of caspase-6 protein. Results Two weeks of troxerutin treatment significantly increased the BBB score of the rats as compared with the rats in SCI group (P < 0.05), though the BBB scores in both groups were still lower than that in the sham operation group. At 4 weeks of treatment, the rats in troxerutin group showed decreased vacuoles with increased angiogenesis in the injured spinal cord tissues in comparison with the rats in SCI group. RNA sequencing showed that 261 genes were differentially expressed in the injured spinal cord tissue between troxerutin group and SCI group, including 217 up-regulated and 44 down-regulated genes. GO and KEGG enrichment analysis suggested that troxerutin was capable of activating several signaling pathways including the Wnt, Hippo, TGF-β and Apoptosis pathways, which were functionally related to apoptosis, angiogenesis, neuronal formation, and vasculature. The expression of caspase-6 protein in the semi-dark zone of the injured spinal cord tissues was significantly higher in SCI group than in troxerutin group (P < 0.05). Conclusion Troxerutin shows obvious protective effect against spinal cord injury in rats, possibly by inhibiting cell apoptosis and promoting angiogenesis in the injured spinal cord.

Keywords

• troxerutin
• spinal cord injury
• angiogenesis
• apoptosis
• rna sequencing