Angiogenin activates human umbilical artery smooth muscle cells

Angiogenin stimulates proliferation of human umbilical artery smooth muscle cells. This activity of angiogenin depends on the cell density and require s nuclear translocation of the ligand as well as activation of SAPK/JNK MAP kinase. Angiogenin binds to a 170-kDa putative receptor on the cell surfac e and induces phosphorylation of SAPK/JNK. It also undergoes nuclear transl ocation in a time and concentration dependent manner. Neomycin inhibits nuc lear translocation of angiogenin and abolishes angiogenin-induced cell prol iferation but does not inhibit SAPK/JNK phosphorylation. The data demonstra te that smooth muscle cells are targets for angiogenin and that both SAPK/J NK phosphorylation and nuclear translocation of the ligand are required for angiogenin to activate smooth muscle cells. (C) 2001 Academic Press.