Matrix metalloproteinase-8 (MMP-8) regulates the activation of hepatic stellate cells (HSCs) through the ERK-mediated pathway.

ABSTRACT

Hepatic stellate cells (HSCs) are known to play a key role in the progression of liver fibrosis by producing excessive extracellular matrix (ECM). Matrix metalloproteinases (MMPs) belong to a family of endopeptidases, which have a well-established role in the degradation of ECM. Our study suggests that, besides the degradation of the extracellular matrix, matrix metalloproteinase-8 (MMP-8) has a non-canonical role in activating the quiescent HSCs to myofibroblasts by regulating the expression of Col1A1 and αSMA. We have identified that MMP-8 secreted from macrophages as a response to LPS stimulation activates HSCs via ERK1/2-dependent pathway. In addition to this, we determined that MMP-8 may regulate the homodimerization of c-Jun in LX-2 cells, during the trans-differentiation process from quiescent HSC to activate myofibroblasts. Macrophage-released MMP-8 plays a master role in activating the dormant HSCs to activate myofibroblasts through the Erk-mediated pathway and Jun cellular translocation leading to liver fibrosis. Significance MMP-8 can be used as a therapeutic target against liver fibrosis.