Fig. 7.
Effects of OPN on C6 astroglia (A) and normal human astrocyte (B) cell migration. The migration assay was performed in the Transwell cell culture chamber, as described in Materials and Methods. The indicated concentration of OPN was coated on the lower surface of the membrane. The cell suspension (containing 6 × 105 C6 cells or 4 × 104 human astrocytes in a vol of 0.2 μl) was added in the upper compartment and incubated for 24 hr. The relative number of migrated cells (on the lower surface of the filters) was measured by optical density at 640 nm for C6 cells or determined microscopically by counting four high-power fields per filter for human astrocytes. In the concentration range of 0–0.24 μm OPN, ∼0.5–4% of C6 cells or 0.7–3% of human astrocytes were migrated. The data are the mean ± SE of three experiments performed in triplicate. *p < 0.05; **p < 0.01; ***p < 0.001, as compared with the control.