Alteration of Blood-spinal Cord Barrier and Matrix Metalloproteinases-9 in Mice after Spinal Cord Injury / 中国康复理论与实践

ABSTRACT

Objective To investigate the influence of matrix metalloproteinases-9 (MMP-9) on permeability of blood-spinal cord barrier (BSCB) after spinal cord injury (SCI). Methods 68 male C57BL/6 mice were randomly divided into sham group, 2 days group (S2), 7 days group (S7) and 14 days group (S14) after SCI with 17 mice in each group. All the groups received a moderate impacted spinal cord injury ex-cept the sham group. Evan's Blue (EB) was administered intraperitoneally to detect the permeability of BSCB. Occludin was analyzed by im-munofluorescence, the expressions of occludin and MMP-9 were detected by Western blotting. Results After SCI, BMS score significantly reduced, compared with S2 group, S14 group showed a significant increase (P<0.01). The permeability of BSCB was seriously damaged af-ter SCI. Compared with S2 group, S14 group showed a notable down-regulation in the permeability of injured micro-vessels (P<0.05). The expression of occludin was down-regulated and the expression of MMP-9 was up-regulated 7 days after SCI (P<0.05). Compared with S2 group, S14 group showed a significant up-regulation of occludin and a remarkable down-regulation of MMP-9 (P<0.05). Conclusion After SCI, MMP-9 might mediate the expression of occludin to influence the BSCB permeability.