Biological or Clinical Significance:
Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade extracellular matrix proteins. They are secreted as zymogens (pro-MMPs) that are activated by a variety of proteinases. They are inhibited by specific tissue inhibitors of metalloproteinases (TIMPs) and by non-specific proteinase inhibitor, α2-macroglobulin. The regulation of MMP activity is important in tissue remodeling, inflammation, tumor growth and metastasis.
MMP-3 (also referred to as stromelysin-1) may be expressed in fibroblasts, chondrocytes, endothelial cells, macrophages, vascular smooth muscle cells, osteoblasts, and keratinocytes in response to appropriate stimuli. Various agents regulate its biosynthesis. Inflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-β), epidermal growth factor, platelet-derived growth factor, phorbol, and oncogenic cellular transformation are the inductive agents. In comparison, retinoic acid, glucocorticoids, estrogen, progesterone and transforming growth factor-beta (TGF-β) suppress MMP-3 synthesis.
MMP-3 is secreted from the cells as a proenzyme. Activation of the proenzyme results in the removal of the pro-domain. The active MMP-3 is capable of cleaving types III, IV, IX and X collagen, aggrecan, fibronectin, laminin, insulin-like growth factor binding protein-3 (IGFBP-3), serpins, and IL-1β. The active enzyme also activates pro MMP-1, -8, -9, and -13. Therefore, it is suggested that MMP-3 may participate in physiological matrix turnover and pathological destruction of the tissue.
Principle of Test Method:
The MMP-3 assay is a solid-phase ELISA that employs the quantitative sandwich enzyme immunoassay principle.