Stat1 activation in VSMCs depends on uPA/uPAR signaling.(A) VSMCs were treated with anti-uPA and anti-uPAR antibodies separately, before coculture with monocytes, and were analyzed for Stat1 by immunofluorescence. Total cell number and the number of cells with translocated Stat1 were counted for each view field. Nine to 10 view fields have been evaluated in each experiment. The result is a representative of 3 experiments (mean ± SD [n = 3]). (B) VSMCs were treated with anti-uPA antibody before the addition of monocytes; VSMCs in monoculture is control. GAS/ISRE binding activity of nuclear extracts prepared from the above anti-uPA antibody-treated VSMC was analyzed using EMSA. (C) Immunofluorescence staining for Stat1 in mouse VSMCs in coculture with monocytes from uPA^-/- and in VSMCs from uPAR^-/- mice cocultured with wild-type monocytes using anti-Stat1 rabbit polyclonal antibody. As controls, wild-type cells and VSMCs from uPA^-/- mice are included.