Abstract: Objective The aim of our study was to investigate the influence of pericytes on microvascular angiogenesis after spinal cord injury (SCI). Methods C57BL/6 mice were randomly divided into four groups: sham group, 2 days (S2), 7 days (S7) and 14 days after SCI group (S14) (n=9 per group). The injury group received a moderate impacted spinal cord injury. Perfused blood vessels were detected by FITC-LEA intravenous injection; microvessel area density (MVA) and microvessel density (MVD) were analyzed by immunofluorescence and immunohistochemistry, respectively; pericyte coverage was further calculated by immunofluorescence. Hypoxic condition (95% N2 and 5% CO2) was applied to mimic the phathological situation of SCI, endothelial tubular formation was detected by matrigel system. Results The area of perfused blood vessels, MVA and MVD at S2 were significantly decreased compared with that at sham (P < 0.001). MVA and MVD at S7 was notably increased compared with that at S2 (P < 0.05). The area of perfused blood vessels, MVA and MVD at S14 showed a markedly increase compared with that at S2 (P < 0.05, P < 0.01), which were still lower than that at sham. Pericyte coverage was decreased at S2 and S7 in mice compared with sham control. Co-culture of pericytes and endothelial cells (ECs) could markedly increase endothelia tube length compared with ECs alone under hypoxia (P < 0.01). Conclusion Pericytes might promote angiogenesis in spinal cord injury C57BL/6 mice.

Key words: pericyte, spinal cord injury, angiogenesis