Fig. 3: Notch and APP processing in cultured aOPCs.

a Effects of FGF2 on the levels of Notch1 and NICDs in cultured aOPCs (15 μg/lane). The expression levels were also compared with those in postnatal rat brains (100 μg/lane) at day 10 and 21 and the adult rat cortex (co) and hippocampus (hip) (3-month old, 100 μg/lane). GAPDH: glyceraldehyde-3- phosphate dehydrogenase. For quantification, see Supplementary Fig. 5A, B. b Effects of FGF2 on the levels of APP and β- and γ-secretases (20 μg/lane). BACE1 β-site amyloid precursor cleaving enzyme 1 (β-secretase), PS1 presenilin 1, PS1 FL PS1 full length, PS1 NTF PS1 N-terminal fragment, PS1 CTF PS1 C-terminal fragment, APH-1 anterior pharynx-defective 1. For quantification, see Supplementary Fig. 5C–I. c Effects of FGF2 on the levels of secreted Aβs. Western blot analysis of immunoprecipitated (i.p.) Aβs (x-40, x-42). M3.2 monoclonal antibody against rat Aβs (Aβ10-15), E.I. enhanced image, Arrowheads indicate the position of molecular weight marker, 10 kDa. d ELISA for rodent Aβx-40 and Aβx-42, and the Aβ42/total Aβ ratio. Secreted Aβx-40 and x-42 levels from cultured fetal rat hippocampal neurons (3 weeks in vitro) are also analyzed (n = 4/group; ****P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.05; one-way ANOVA, Tukey’s multiple comparisons test [Aβx-40: F_{6, 21} = 123.2, P < 0.0001; Aβx-42: F_{6, 21} = 233.9, P < 0.0001; Aβx-42/Total Aβ ratio: F_{6, 21} = 65.3, P < 0.0001]). e Immunocytochemical analysis of a typical cored-SP-like plexin-B3⁺ aOPC cultured in 0 ng/ml FGF2 for 5 days. Note that plexin-B3⁺ aOPC is also M3.2 positive. Scale bar: 15 μm. f Quantitative analysis of plexin-B3 and M3.2 immunoreactive areas. An example of region of interest for a single cell is shown in the left panels. Note that as plexin-B3 immunoreactivities increased, M3.2 immunoreactivities increased (right graph). Mean intensity: the integrated total value of signal intensities adjusted by single cell area. Pearson’s correlation coefficient: r = 0.908, P < 0.0001, n = 148.