Tetramethylpyrazine promotes angiogenesis and nerve regeneration and nerve defect repair in rats with spinal cord injury.

Objective: This study evaluated the regulatory effect of Tetramethylpyrazine (TMP) on the spinal cord injury (SCI) rat model and clarified the neuroprotective mechanism of TMP on SCI. Methods: An SCI rat model was generated and treated with TMP injections for two weeks. miR-497-5p and EGFL7 expression changes were evaluated, motor function recovery after SCI was assessed by BBB score test and footprint analysis, lesions of rat spinal cord were assessed by HE staining and TUNEL staining; angiogenesis was assessed by immunoblotting for CD31; inflammatory factor levels were detected by ELISA. EGFL7 was verified as a target of miR-497-5p by bioinformatics website analysis and luciferase reporter gene assay. H2O2-injured neurons were cultured in vitro to explore the effect of TMP. Results: After SCI, miR-497-5p was upregulated while EGFL7 was downregulated in rats. TMP inhibited apoptosis and promoted angiogenesis, nerve regeneration, and repair of nerve defects by reducing miR-497-5p and increasing EGFL7 expression. miR-497-5p targeted EGFL7. In addition, TMP hindered neuronal inflammation and apoptosis induced by H2O2in vitro. Conclusion: TMP promotes angiogenesis by downregulating miR-497-5p to target EGFL7, and promotes nerve regeneration and repair of nerve defects in rats with SCI.