Gamma-secretase inhibitor Compound E affects BK-dependent p38 activation in PS-1 (M146L) AD fibroblasts but not ERK activation in Trisomy 21 fibroblasts.

<p>Trisomy 21 and PS-1 (M146L) AD fibroblasts plus normal control human skin fibroblasts were treated with Gamma secretase inhibitor Compound E (10 nM) or DMSO vehicle control for 24 hr and then stimulated with 250 nM BK for 0–30 min. Cell lysates were immunoblotted and analyzed as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004655#pone-0004655-g006" target="_blank">Figures 6</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004655#pone-0004655-g007" target="_blank">7</a>, by Odyssey for ERK (A,B) and by chemiluminesence for p38 (C,D). Activity levels were normalized to tubulin as a loading control. ERK activation was quantified as a percentage of basal activation in buffer-treated cells (0 min) pre-treated with DMSO or Compound E (panel B). In panel D p38 activation was quantified as O.D. values as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004655#s4" target="_blank">Materials and Methods</a>. ERK activity phenotypes are graphically represented in control fibroblasts compared with AD pre-disposed Trisomy 21 fibroblasts (B), and p38 activity phenotypes are graphically represented in control and PS-1 (M146L) AD fibroblasts (D). All graphs show mean±S.E. Statistical analysis was performed via t-test with **p-value<0.005; n = 3.