Abstract
Matrix metalloproteineases are associated with extracellular remodeling that occurs in injury and repair processes in the central nervous system (CNS). We examined the role of MMP-2 in a model of olfactory nerve injury and found that MMP-2 levels increased several hours following injury, peaked at day 7 and then decreased rapidly. We previously reported a rapid increase in MMP-9, within 5 h after nerve injury, corresponding to neuronal degeneration and increased glial activity. In this study, we show that MMP-2 peaks later than MMP-9, at the onset of neuronal regeneration and repair. Using MMP-9 knockout mice, we determined that the MMP-2 increase is independent of MMP-9. Our data suggest that MMP-2 and MMP-9 may play different roles in the injury and repair processes.