Figure 1.

Sema4D antagonizes integrin-mediated cell migration. (A) PC12 cells were tested in the transwell assay either in the presence or absence of Sema4D. Transwell chambers were coated on the lower side with varying concentrations of collagen I. Migrated cells were visualized by the staining of crystal violet. (C and E) PC12 cells were pretreated with 5 μg/ml of functional blocking monoclonal antibodies against α₁ and β₁ integrin subunits (3A3 and P5D2, respectively) or control mouse IgG1 and subjected to the transwell assay. Migrated cells were visualized by the staining of crystal violet. (B, D, and F) Relative cell migration was determined by the number of the migrated cells normalized to the total number of cells. Results are the means ± SEM of three independent experiments. Bars, 1 mm.