Table 1.
MMPs and their activities in ALI
| MMP | ALI Model and Species | Activity of the MMP | Mechanism |
|---|---|---|---|
| MMP-3 | IT-MIP2 (mouse) | ↑ PMN accumulation | Not known (21) |
| Immune complex –mediated ALI (mouse) | ↑ Lung injury | ||
| MMP-7 | Bleomycin-mediated ALI (mouse) | ↑Transepithelial efflux of PMNs | MMP7 cleaves syndecan-1 from epithelial cell surfaces to release and activate KC bound to syndecan-1 (13) |
| ↑ Lung fibrotic responses to lung injury | |||
| MMP-8 | High pressure VILI (mouse) | ↑ Lung edema | ↑ Lung levels of CXCL5, MIP-2, and IFN-γ |
| ↑ Lung injury | ↓ Lung levels of IL-4 and IL-10 (2) | ||
| ↓ Gas exchange | |||
| ↑ PMN accumulation | |||
| IT LPS and hyperoxia (mouse) | ↓Lung PMNs and macrophages | Proteolytic inactivation of MIP-1α (18) | |
| ↓Lung injury | |||
| Low-tidal-volume VILI | ↓Lung injury | Not known (8) | |
| MMP-9 | Hyperoxia (mouse) | ↑ Mortality | Not known (14) |
| VILI with MMP9 inhibition (rat) | ↑ PMN accumulation | Not known (12) | |
| ↑ Lung injury | |||
| VILI (MMP9−/− mice) | ↓ Lung PMN accumulation | ↓ Lung levels of IL-1β and IL-4 (3) | |
| ↓ Lung injury | |||
| Immune complex (mouse) | ↑ Lung injury | Not known (21) | |
| MMP-12 | IT instillation of hrMMP-12 (mouse) | ↑ Lung PMN and macrophage counts | ↑ Lung levels of IL-6, TNF-α, MIP1α, MCP-1, KC (16) |
| Immune complex (mouse) | ↑ PMN accumulation | Not known (22) | |
| ↑ Lung injury | |||
| MMP-13 | Hyperoxia (mouse) | ↓ Lung macrophage counts | Proteolytic inactivation of MCP-1 (19) |
ALI, acute lung injury; hrMMP-12, human recombinant matrix metalloproteinase (MMP)12; IFN-γ, interferon-γ; IL, interleukin; IT, intratracheal; KC, keratinocyte-derived chemokine; MCP-1, monocyte chemotactic protein-1; MIP-1α, macrophage inflammatory protein-1α; PMN, polymorphonuclear neutrophil; VILI, ventilator-induced lung injury; ↑, increased; ↓, decreased.