Shh mediates PDGF-BB chemotactic effect on SMCs. (A) PDGF-BB–stimulated (10 ng/mL) and nonstimulated (Ctrl) SMC migration was assessed in the presence of the Smo inhibitor cyclopamine (Cyclop; 1 µmol/L), the Hh blocking antibody 5E1 (1.5 µg/mL), an siRNA directed against Shh RNA (siShh) (30 nmol/L), or their respective controls (IgG1, ethanol 0.005% [EtOH], and siCtrl). (B) SMC migration in response to various concentrations of Shh (1 ng/mL to 1000 ng/mL), Ihh (1000 ng/mL), Dhh (1000 ng/mL), and PDGF-BB (10 ng/mL). (C) SMC motility was tested for 72 hours in wound-healing assays and 15 hours in random motility assays with or without stimulation by recombinant Shh (1 µg/mL). Data represent means ± SD of relative values vs Ctrl from 3 independent experiments performed in triplicate. P > .05 (NS); **P < .005; ***P < .0005. NS, nonsignificant.