Shifts in full length APP patterns induced by acLDL, polystyrene beads, and LPS. Human mononuclear phagocytes were isolated and cultivated as indicated and left unstimulated (CON) or stimulated with 4*107/ml polystyrene beads (PB), 10 μg/ml acLDL (acLDL), 10 ng/ml LPS (LPS) or a combination of polystyrene beads and LPS (PB+LPS). (A) shows a representative SDS-PAGE/immunoblot of whole cell lysates from human mononuclear phagocytes after 72 h in vitro immunoreacted with the 1E8 antibody. Staining of the same western blots with a polyclonal antibody specific for β-actin served as a loading control. (B) Semiquantitative assessment of the changes in expression of total APP (APP1+ APP2+APP3+APP4) compared to control. (C) Shifts in the ratio APP1:APP2+3 after application of the different stimulation paradigms. Values are expressed as mean ± SD. *P < .05, **P < .01, ***P < .001 compared with CON (one-way ANOVA followed by Dunnett's multiple comparison test). Note the increase in total APP expression under all conditions as well as the increased proportion of APP1 (mature APP) after stimulation with polysterene beads or acLDL.