FoxD1 expression identifies a distinct subset of hepatic stellate cells involved in liver fibrosis.

Hepatic stellate cells (HSCs) are pericytes of the liver responsible for liver fibrosis and cirrhosis, which are the end stages of chronic liver diseases. TGF-β activates HSCs, leading to the differentiation of myofibroblasts in the process of liver fibrosis. While the heterogeneity of HSCs is appreciated in the fibrotic liver, it remains elusive which HSC subsets mainly contribute to fibrosis. Here, we show that the expression of the pericyte marker FoxD1 specifically marks a subset of HSCs in FoxD1-fate tracer mice. HSCs fate-mapped by FoxD1 were preferentially localized in the portal and peripheral areas of both the homeostatic and fibrotic liver induced by carbon tetrachloride. Furthermore, the deletion of Cbfβ, which is necessary for TGF-β signaling, in FoxD1-expressing cells ameliorated liver fibrosis. Thus, we identified an HSC subset that preferentially responds to liver injuries.