Matrix metalloproteinase-8 and Matrix metalloproteinase-9 (MMP-8 and MMP-9)

Matrix metalloproteinase-8 (MMP-8), also known as neutrophil collagenase, and Matrix metalloproteinase-9 (MMP-9), or gelatinase B, are zinc-dependent endopeptidases that belong to the larger matrix metalloproteinase family (UniProt P22894, P14780). These enzymes are primarily responsible for the degradation and remodeling of extracellular matrix (ECM) components, such as collagen and gelatin, which is essential for physiological processes like wound healing, bone remodeling, and leukocyte migration (NIH, 2022). However, their overactivity is strongly linked to pathological tissue destruction in diseases such as periodontitis, rheumatoid arthritis, and various cancers, where they facilitate tumor invasion and metastasis (ResearchGate, 2024). In the cardiovascular system, they contribute to plaque instability and aneurysm formation (MDPI, 2025). Pharmacological targeting of these enzymes has primarily involved small-molecule inhibitors that bind to the catalytic zinc ion, such as the tetracycline derivative doxycycline, which is FDA-approved at sub-antimicrobial doses for periodontitis (ACS, 2024). A major challenge in developing drugs for these targets is achieving sufficient selectivity to avoid the musculoskeletal syndrome associated with broad-spectrum MMP inhibition and to preserve the beneficial roles some MMPs play in tissue repair.

Other names

Neutrophil collagenase (MMP-8)Gelatinase B (MMP-9)Collagenase-2PMNL collagenaseCLG1HNC92 kDa type IV collagenase

Inhibition of the catalytic zinc-dependent endopeptidase activity through direct binding to the active site or indirect modulation of enzyme expression and activation.