Figure 4
Simultaneous inhibition of PI3K or overexpression of GSK-3β abolishes the EphB2 activation-induced tau dephosphorylation.
(a-c) SK-N-SH cells were treated with ephrinB1/Fc alone or ephrinB1/Fc plus wortmannin (an inhibitor of PI3K) for 2 h and then phosphorylation level of GSK-3β at Ser9 and tau at Thr231 was measured by Western blotting. *P < 0.05 versus untreated control; #P < 0.05, ##P < 0.01 versus ephrinB1/Fc. (d, e) HEK293 cells were transfected with pcDNA3.0 (Vector), or with GSK-3β, or with EphB2wt for 24 h and ephrinB1/Fc stimulation for 45 min, or with co-transfection of EphB2wt and GSK-3β□plus ephrinB1/Fc stimulation. The phosphorylation levels of GSK-3β at Ser9 and tau at Thr205, Thr231 and Ser396 were measured by Western blotting. The phosphorylation level of GSK-3β at Ser9 was normalized against total GSK-3β, while the phosphorylation of tau was normalized against total tau probed by R134d or Tau5. Data were representative of at least three independent experiments with cells from 9 ~ 12 culture wells for each group and presented as the mean ± SD. *P < 0.05, **P < 0.01 GSK-3β versus Vector; #P < 0.05, ##P < 0.01 EphB2/ephrinB1/Fc versus GSK-3β; $ <0.05, $$ P < 0.01 GSK-3β/EphB2/ephrinB1/Fc versus EphB2/ephrinB1/Fc.
