Fig. 2: MFG-E8 is highly enriched in the human brain vasculature, increases with CAA and is associated with cognitive dysfunction in patients with Alzheimer’s disease.
From: Medin co-aggregates with vascular amyloid-β in Alzheimer’s disease
a–c, Analysis of human brain sections from patients with Alzheimer’s disease (n = 16 patients analysed), stained for medin (1H4 antibody; green), amyloid-β (red) and the amyloid dye Methoxy-X04 (cyan). Blood vessels show substantial medin staining (a,b) (quantification for 5 female and 5 male patients, with a total of n = 478 vessels analysed), while staining is absent on amyloid plaques (c). d, Confocal z-stack of an isolated human cerebral blood vessel and western blotting of the vascular marker α-SMA and MFG-E8. e, Quantification of MFG-E8 by ELISA (controls: 4 women and 5 men; Alzheimer’s disease with low CAA: 5 women and 5 men; Alzheimer’s disease with high CAA: 4 women and 5 men). AD, Alzheimer’s disease; ctrl, control. f, Quantification of total amyloid-β from the individuals in e by ELISA. g, Western blot analysis of different fractions using an anti-human medin antibody (6B3) (3 female and 3 male age-matched individuals per group). Note the very low protein levels in formic acid-extracted, RIPA-insoluble fractions, evident from the lack of β-actin signal. h, MFGE8 expression in 566 individuals from the ROSMAP cohort23 (control: 123 women and 78 men; mild cognitive impairment (MCI): 94 women and 49 men; Alzheimer’s disease: 152 women and 68 men). Linear regression analysis was used to examine the effect of MFGE8 expression levels, plaque load (CERAD score) and tau pathology (Braak score; numbers in brackets indicate a change between two particular scores) on cognitive ability (mmse30 score), indicating an independent contribution of MFGE8 levels to cognitive dysfunction. The heat map shows WGCNA module 3 of the RNA-seq data set, which contains the MFGE8 gene (green) and is associated with Alzheimer’s disease. Expression-weighted cell-type enrichment demonstrates that the increased MFGE8 expression in patients with Alzheimer’s disease is attributable to smooth muscle cells (Padj < 0.05; see Methods). Data are mean ± s.e.m. FPKM, fragments per kilobase million. e, Two-way ANOVA with Tukey’s post hoc test. f,g, Kruskal–Wallis test with Dunn’s post hoc test, h, with Benjamini–Hochberg correction. Scale bars: 20 µm. Uncropped western blots are shown in Supplementary Fig. 2.
