Figure 7
Both sc-tPA and tc-tPA at 10 nM promote EGFR signaling and are neuroprotective. (a) Representative immunoblots for phospho-EGFR (tyrosine 1173) and total EGFR on neurons after treatments with sc-tPA and tc-tPA (10 nM) during 15 min. (b and c) Quantification of phosphorylated EGFRs and total EGFRs compared with the control condition (n=3 experiments; *P<0.05). (d) After two NMDA stimulations used as baseline, neurons were incubated for 45 min in the presence of buffer (control, n=75 cells), AG1478 at 5 μM (n=77 cells), sc-tPA (10 nM) alone or in combination with AG1478 (sc-tPA, n=78 cells; sc-tPA+AG1478, n=83 cells) or tc-tPA (10 nM) alone or in combination with AG1478 (tc-tPA, n=92 cells; tc-tPA+AG1478, n=92 cells) prior to a second set of NMDA stimulations. Percentages of potentiation or inhibition after incubation are calculated for each cell. (e) Percentages of responsiveness for each group (mean±S.E.M.; *P<0.0001 Kruskal–Wallis test followed by Mann–Whitney test; #P<0.0001 Wilcoxon test comparison of preincubation and postincubation responses). (f) Percentages of cells either potentiated, inhbited or without effect for each group. (g) Cortical neurons were subjected to 24-h exposure to NMDA (10 μM) in the presence of either sc-tPA or tc-tPA (10 nM) alone or in combination with AG1478 (5 μM; n=3 experiments; 4 wells per condition; *P<0.05, NS: not significant; Kruskal–Wallis test followed by Mann–Whitney test). (h) Neuronal death measured after a 24-h exposure to either serum deprivation (SD) alone or in the presence of either sc-tPA or tc-tPA at 300 or 10 nM (n=3 experiments; 4 wells per condition experiments; *P<0.05, NS: not significant; Kruskal–Wallis test followed by Mann–Whitney test, mean±S.E.M.)
