Altered activation of HIF-1α in fibroblasts harboring the M146V PSEN1 FAD mutation. Fibroblast cell lines harboring human wild type Psen1 (HuPS1Wt) or the M146V FAD mutant both on the mouse Psen1-/- background were treated with cobalt chloride (A) or insulin (C) as in Figure 1 for the indicated times (hours). Representative blots are shown from experiments that were performed multiple times. The experiment in panel A is quantitated in panel B. In panel D, the insulin induction time course in panel C was quantitated. Asterisks (*) indicate p = 0.04 at 3 hours and p = 0.02 at 6 hours (unpaired t-tests).