Smoothelin, a new marker to determine the origin of liver fibrogenic cells

Figure 2 α-smooth muscle actin and smoothelin expression in normal, fibrotic and cirrhotic livers. A and B: In the normal liver, α-smooth muscle actin (A) and smoothelin (B) show similar expression in tunica media smooth muscle cells of the portal arteries and veins and in the centrilobular veins; C and D: In severe fibrosis, myofibroblasts express high amounts of α-smooth muscle actin (C), while smoothelin is only expressed at low levels (D) (α-smooth muscle actin and smoothelin are coexpressed in vascular smooth muscle cells); E and F: In the cirrhotic liver, myofibroblasts express α-smooth muscle actin in fibrotic septae (E) and numerous myofibroblasts also express smoothelin (F); however, smoothelin expression is lower compared with α-smooth muscle actin expression (insert). α-smooth muscle actin and smoothelin are co-expressed in vascular tunica media smooth muscle cells (F).