Figure 3. 5-HT_4d receptor-stimulated APP shedding requires Src and phospholipase C, but not PKC or calcium.

(A), (B) and (C) SH-SY5Y cells, transfected with pEAK12-AP-APP and pcDNA3.1-5-HT_4d, were treated with 1 µM prucalopride or 5-HT (5-HT₄ receptor agonists) and PMA in the absence or presence of 50 µM Bosutinib (Src inhibitor) (A), 30 µM D609 (PLC inhibitor) (B) or 2 µM GF109203X (PKC inhibitor) (C) and secretion of sAPPα was analyzed via measuring SEAP. Values shown are mean ± SEM of 6 individual wells and were normalized towards vehicle control. (D) SH-SY5Y cells, transfected with pEAK12-AP-APP and pcDNA3.1-5-HT_4d, were loaded with Fluo-4 NW mix and fluorescence of the calcium-sensitive dye in each well was recorded at the baseline (F₀) and after stimulation with 1 µM prucalopride, 30 µM ATP (purinergic ionotropic receptors agonist), 20 µM Ionomycin (calcium ionophore) or DMSO (F). Calcium response shown is a ratio of maximum fluorescence intensity at 40 sec to baseline fluorescence (F/F₀). Values shown are mean ± SEM of 2 individual wells and were normalized to vehicle control. * P<0.05, ** P<0.01, *** P<0.001, one-way ANOVA with Tukey-Kramer's post-hoc test.