TIMP1 a key marker of hepatic stellate cell activation and fibrogenic response
TIMP1, also known as TIMP-1 (Tissue Inhibitor of Metallo Proteinases 1), is an endogenous extracellular inhibitor of MMPs (matrix metalloproteinases) belonging to the TIMP family, of which four isoforms are known (TIMP1 to TIMP4).
TIMP1 plays a crucial role in Extracellular Matrix (ECM) composition, and is a key modulator of extracellular matrix degradation. It regulates matrix metalloproteinases (MMPs) by forming 1:1 complexes with MMPs (such as MMP-2 and MMP-9), and irreversibly inactivates them.
In culture supernatants and biological fluids, TIMP1 exists either as the free form TIMP1 (uncomplexed), or as tight TIMP1-MMP complexes.
TIMPs maintain the balance between matrix destruction and formation. A MMPs/TIMPs imbalance leads to excessive ECM deposition and to fibrogenic processes.