TIMP1 and liver disorder: Meanwhile, applying a 10% strain at 0.5 Hz for 24 h on LI90 cell lines that mimics mechanical stretch induced by increasing portal blood flow, causes increased MMP-1 and decreased MMP-2 and tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 production, suggesting that HSCs are activated by mechanical stretch at the early phase of portal hypertension and that the matrix stiffness has changed (Goto et al., 2004).