The role and mechanism of the up-regulation of fibrinolytic activity in painful peripheral nerve injury.

Peripheral nerve injury is followed by Wallerians degeneration (WD) and degradation and regeneration of the extracellular matrix (ECM) are very important events in these processes. We tested fibrinolytic activities and the expression level of tPA and uPA levels in chronic constriction injury (CCI) model. The presented data demonstrates that in the injury nerve of CCI model, the fibrinolytic activities is upregulated and main caused by the upregulation of tPA expression. We also find that the activities of tPA and MMP-9 are co-upregulated post-CCI, both at CCI site and proximal site. These results indicate that tPA activity may regulate the MMP-9 activity in injury nerve post-CCI.