Matrix-degrading enzymes
Matrix metalloproteinases (MMPs)
Also searched as Matrix metalloproteinases (MMPs).
You want them restrained: unchecked matrix proteases thin cartilage and connective tissue faster than either can be rebuilt.
In depth
Matrix metalloproteinases — the extracellular collagenases that cut structural collagen outside the cell, where cathepsin K cuts it inside. Inflammation switches them on.
What drives it
Inflammation signal (TNF-α) increases it.
Inflammatory cytokine induction of matrix proteases. Resorption exceeding formation drives 'a progressive loss of bone mass and impairment of bone microarchitecture'. PMID 23904864
Galectin-3 increases it.
Extracellular matrix turnover is the currency of scarring. In spinal cord injury, inhibiting galectin-3 with TD139 or silencing it with lentiviral shRNA 'effectively mitigated fibrotic scar formation and extracellular matrix deposition within the injured spinal cord, leading to better neurological outcomes and function recovery' (PMC11481377). The route is direct: galectin-3 from infiltrating macrophages is internalized by PDGFR-beta positive fibroblasts, and 'Galectin-3 inhibition result[ed] in reduced PDGFRbeta expression'. This is a mouse crush-injury model with intrathecal dosing; it is not oral supplementation in people. PMC11481377
UV radiation increases it.
UV induces AP-1-driven matrix metalloproteinase expression, the collagen-degrading mechanism of photoaging. PMID 11511297
What it drives
It reduces Joint comfort.
Matrix metalloproteinases are the extracellular collagenase arm, working outside the cell where cathepsin K works inside its lysosomes and resorption lacunae. The cathepsin literature contrasts the two compartments directly. PMID 21718816
It reduces Tissue remodeling.
The shared substrate is structural collagen itself. Verbatim from the cathepsin comparison: 'a protease with intense collagenase activity' (PMC2951121) - MMPs are the metal-dependent collagenases of the same substrate class. PMC2951121
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.