Figure 1. PDGF signaling induces VSMCs to release chemokines.

(a) Strategy for activating a conditional PDGFRβ^D849V allele in VSMCs. The conditional PDGFRβ^D849V allele consists of a loxP-flanked stop cassette preceding a full-length mouse PDGFRβ cDNA with a single amino acid substitution (D849V), which was targeted to the Pdgfrβ gene. When the conditional allele is present in Sm22α-Cre transgenic mice, the stop is removed in VSMCs and PDGFRβ^D849V is expressed. SA = splice acceptor. (b) Fold change in chemokine mRNA levels in cultured VSMCs from PDGFRβ^Sm22D849V (β-D849V) mutant mice and Sm22α-Cre (Wt) control mice was determined by quantitative RT-PCR. Results are shown as fold increase in mutant over control, n=3 different VSMC isolates per genotype. (c) Quantification of chemokines secreted into the media of cultured VSMCs as determined by ELISA, n=3 different VSMC isolates per genotype. (d) Quantification of chemokines in plasma from mutant mice and control mice as determined by ELISA, n=3 mice per genotype. (e) Fold change in chemokine mRNA levels in cultured Wt VSMCs treated with 10ng ml⁻¹ PDGF-BB ligand for the indicated times was determined by quantitative RT-PCR. Results are shown as fold increase in treated cells over untreated controls, n=3 different VSMC isolates. All data were assessed using Student’s t-test and are present as mean ± s.e.m. *P<0.05; **P<0.01.