Peak in matrix metaloproteinases-2 levels observed during recovery from olfactory nerve injury
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Published on: August 11, 2016
Richard M Costanzo1, Lisa A Perrino
1Department of Physiology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA. rconstanz@vcu.edu
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.
Insights
Matrix metalloproteinase-2 (MMP-2) plays a key role in central nervous system (CNS) repair after olfactory nerve injury. Its delayed peak suggests a distinct function in neuronal regeneration compared to MMP-9.
Area of Science:
- Neuroscience
- Biochemistry
- Extracellular Matrix Remodeling
Background:
- Matrix metalloproteinases (MMPs) are crucial for extracellular remodeling in the central nervous system (CNS) during injury and repair.
- Previous research indicated MMP-9's rapid increase post-injury, correlating with neuronal damage and glial activation.
Purpose of the Study:
- To investigate the specific role of MMP-2 in the context of olfactory nerve injury.
- To compare the temporal expression profile of MMP-2 with MMP-9 following injury.
Main Methods:
- Olfactory nerve injury model in mice.
- Quantification of MMP-2 and MMP-9 levels over time post-injury.
- Utilized MMP-9 knockout mice to assess MMP-2's independence from MMP-9.
Main Results:
- MMP-2 levels increased several hours after injury, peaking at day 7, and then declined.
- MMP-2 expression peaked significantly later than the rapid MMP-9 increase observed within 5 hours post-injury.
- The observed increase in MMP-2 was independent of MMP-9, as confirmed in MMP-9 knockout mice.
Conclusions:
- MMP-2 expression is temporally distinct from MMP-9 following olfactory nerve injury.
- MMP-2's delayed peak coincides with the onset of neuronal regeneration and repair processes.
- MMP-2 and MMP-9 likely have differential roles in the complex cascade of CNS injury and repair.
