FIGURE 7.

Notch3^ECD deposition in brain vessels is unaffected by genetic reduction of Timp3 or vitronectin. Notch3^ECD deposits were quantified in brain arteries and capillaries from mice with the indicated genotypes at 6 months of age (A–H) and 12 months of age (I–P). Representative images show brain arteries coimmunostained with anti-Notch3^ECD antibody (red) and fluorescein isothiocyanate–conjugated anti–smooth muscle a-actin antibody (green; A–C, I–K) and brain capillaries coimmunostained with anti-Notch3^ECD antibody (red) and antiperlecan antibody (green; E–G, M–0). Quantification of Notch3^ECD deposit numbers per 1,000 μm² in brain arteries (D, L) and brain capillaries (H, P) shows a significantly higher number of deposits in transgenic mice compared to nontransgenic (nonTg) mice, but a comparable number of deposits in TgN3^R169C mice with normal or reduced expression of Timp3 (D, H) and normal, reduced, or no expression of vitronectin (L, P; n = 4–5 mice per genotype). Significance was determined by 1-way analysis of variance followed by Bonferroni post hoc test (***p < 0.001). Scale bars = 10 μm (A–C, I–K) and 15 μm (E–G, M–0). ns = nonsignificant.