Deposition of interstitial type 1 collagen following liver injury activates hepatic stellate cells and perpetuates the damage to hepatic tissue through mechanisms that have been unclear. In November 1 Journal of Clinical Investigation, Elvira Olaso and colleagues from Mount Sinai School of Medicine, New York show that discoidin domain tyrosine kinase receptor 2 (DDR2), which signals in response to type I collagen, is induced in stellate cells during liver injury and mediates key features of stellate cell activation.
Olaso et al. developed stellate cell lines overexpressing either wild-type DDR2, a constitutively active chimeric DDR2 receptor (Fc-DDR2), a truncated receptor expressing the extracellular domain or a kinase-dead DDR2. They found that cells overexpressing DDR2 showed enhanced proliferation and invasion through a basement membrane–like matrix (Matrigel). These activities were mediated by increased expression of active matrix metalloproteinase 2 (J Clin Invest 2001, 108:1369-1378).
These results suggest that blocking DDR2 function may stop ...