Fig. 6
The mobility of astrocytes is plectin dependent. (A) Time-lapse images of Plec+/+p53−/− (Ai) and Plec−/−p53−/− (Aii) astrocytes, and of U-251 MG GBM cells (Aiii) at 0, 12, and 24 h after the initiation of a wound-healing assay. The cell-free (gap) area is depicted in white. The percentages indicate the area of the gap area versus the initial gap in the representative images. Scale bars: 200 µm. B The closure of the gap over time is shown for Plec+/+p53−/− (Bi), Plec−/−p53−/− (Bii), and U-251 MG (Biii) cells. The complete closure of the gap was achieved in 25.2 ± 0.9 h for Plec+/+p53−/−, 29 ± 0.9 h for Plec−/−p53−/−, and 94.7 ± 0.9 h for U-251 MG cells. Solid lines represent the linear regression of the first four time points (0–12 h). Dotted lines indicate confidence limits (α = 0.05). Biv,v The collective migration of Plec+/+p53−/− astrocytes was faster in comparison with Plec−/−p53−/− astrocytes (**P < 0.01; Mann–Whitney U test), which was reflected in the shorter time needed for Plec+/+p53−/− cells to repopulate 50% of the gap (t1/2; *P < 0.05; Mann–Whitney U test). Bvi,vii The median speed of the collective migration of U-251 MG cells was 3.5 ± 0.1 µm/h, and the median t1/2 = 45.7 ± 1.1 h. The data were obtained from astrocytes isolated from two Plec+/+p53−/− and two Plec−/− p53−/− mice, and from U-251 MG cells. C Graphs depict enhanced mobility of Plec−/−p53−/− astrocytes after forced expression of isoform P1c. Note that the average speed of Plec−/−p53−/− cells transfected with P1c was higher than that of Plec+/+p53−/− cells in each time period measured; the speed of non-transfected Plec−/−p53−/− cells (NTC) was the lowest (Ci). In line with the velocity measurements, Plec−/−p53−/− NTC migrated over the shortest distance (Cii) (*P < 0.05; one-way ANOVA followed by Dunn’s method). The data were obtained from astrocytes isolated from two Plec+/+p53−/− and two Plec−/−p53−/− mice, and from U-251 MG cells. Numbers above the boxplots in B denote the number of replicates; C n denotes the number of cells analyzed