Figure 2.

TGF-β1 stimulates dendritic cells to secrete biologically active VEGF. (A) DC2.4 cells (5 × 10⁵/well) were transfected with Smad3/4 or DN-Smad3 (1 µg each). Cells were cultured with TGF-β1 (1 ng/ml) and CoCl₂ (50 µM). After 2 days of culture, supernatants were collected and VEGF production was measured by ELISA. Data are means of triplicate samples ± SEM. ^*P < 0.05. (B) Wound-healing assay in which conditioned media 1 (CM1) was prepared from cultured DC2.4 cells transfected with pcDNA3 and CM2 was prepared from DC2.4 cells transfected with Smad3/4 treated with TGF-β1 (1 ng/ml) and CoCl₂ (50 µM). Confluent B16-F1 cells were scraped by using P200 tips and cultured with various stimuli as indicated. To neutralize VEGF and TGF-β1, conditioned media (CM2) was pre-incubated with the corresponding neutralizing Abs. Wound healing was determined with a light microscope (×100) after 2 days incubation.