Figure 4.

Hemichannel opening and ionomycin-induced intracellular calcium (Ca²⁺) increase are necessary, but not sufficient, to promote Thy-1-induced cell migration. (A) Quantification of Lucifer yellow uptake by primary astrocytes pre-incubated with TNF (10 ng/mL for 48 h), BAPTA-AM (5 µM for 30 min) and then stimulated with Thy-1-Fc or ionomicyn (1 µM) for 10 min. Values in the graph correspond to the mean fluorescence intensity normalized to the non-stimulated condition; (B) Cell migration quantification of primary astrocytes incubated as indicated in (A). Cells were allowed to migrate for 2 h in inserts pre-coated on the lower side with fibronectin (2 μg/mL). Migrating cells were visualized by crystal violet staining of cells on the lower side of the inserts. Data were normalized to non-treated cells and are shown as the average of 7 different fields from each independent experiment, n = 3, ns = non-significant, * p < 0.05, ** p < 0.01, *** p < 0.001. Solid lines indicate comparisons of pairs under the same experimental conditions, i.e., −TNF or +TNF. Dashed lines are comparisons of pairs between experimental conditions, i.e., between −TNF and +TNF.