Figure 7.

PS2 affects neither EGFR expression nor EGF-dependent neuroprotection. A) (Top) PCNC from WT (+/+) and PS2 heterozygous (+/−) and homozygous (−/−) KO embryonic mouse brains were cultured in 6-well plates. At 9 DIV, lysates were collected and probed on WBs for the indicated proteins. (Bottom) Densitometric analysis of the relative amounts of EGFR shown above expressed as EGFR-to-actin ratio. B) WT, PS2^+/−, and PS2^−/− mouse PCNC were grown in 24-well plates. At 9 DIV, cultures were treated overnight with 20 ng/ml of either Hb-EGF or EGF. Next day, the medium was switched to HBSS containing Hb-EGF or EGF for 30 min, followed by 50 μM glutamate incubation for 3 h (Fig. 2A). Cell viability was evaluated by MTT assay and normalized to nontreated cells. Treatment with growth factors alone had no effect on neuronal viability compared to untreated cultures. Bars represent mean and error bars sem. Data were respectively obtained from at least 4 separate experiments. *P < 0.05 [unpaired Student’s t test for (A), paired Student’s t test for (B)].