Figure 4

PS1 complexes are present in human and mouse CSF and plasma. (A) Plasma samples from NDC subjects were blotted with an anti-NTF-PS1 antibody (from Calbiochem) with and without depletion of plasma abundant proteins by immunoaffinity-based protein subtraction chromatography with IgY microbeads (Seppro™). (B) CSF and plasma samples from control wild-type (WT) and PS1 conditional knockout mice (cKO) were blotted with an anti-NTF-PS1 antibody. In general, immunoreactivities of the bands corresponding to PS1 complexes were weak in mouse (or rat, not shown) than in human samples. PS1 levels are reduced in CSF from PS1 cKO mice, and unchanged in plasma. PS1 immunoreactivity detected in CSF from PS1 cKO mice may be due to PS1 expressed in glia and interneurons. However, it is also highly likely that some nonspecific binding may occur at 50 kDa (*).