(A) Actinomycin D substantially inhibited GW4064-mediated upregulation of decorin mRNA. RASMCs were treated with actinomycin D (5µg/mL) for 30 min prior to GW4064 treatment. Twenty-four hours later, Dcn mRNA expression in RASMCs was similarly examined by real-time RT–PCR. In a separate experiment, a series of human Dcn promoter luciferase reporter constructs (shown in panel B) were transiently transfected in CV-1 cells. After 12h, the transfected cells were treated for 24h with different concentrations of GW4064 or vehicle DMSO. The luciferase activity was normalized against the β-gal activity, and the data are reported as fold induction observed with GW treatment relative to DMSO control. Shown in panels C, D, and E are data from transfection with a reporter driven by a Dcn promoter of 3275bp, 2620 bp, and 1261 bp, respectively.