Fig. 9
From: The amyloid plaque proteome in early onset Alzheimer’s disease and Down syndrome
Validation of ARL8B as a plaque enriched protein in human brain tissue by immunohistochemistry. A Enrichment of ARL8B in amyloid plaques was observed in DS, EOAD and LOAD cases. B Plot shows percentage of ARL8B immunoreactive plaques in the hippocampus of DS, EOAD and LOAD cases (n = 3/group). Results generated by an analysis of 309 ± 41 hippocampal plaques (average ± SEM) in each case. The ratio of ARL8B positive plaques (immunoreactive for both Aβ and ARL8B) over the total number of amyloid plaques was calculated for each case in DS, EOAD and LOAD. C Representative images showing ARL8B distribution in amyloid plaques. Bright puncta of ARL8B were diffusely present throughout both diffuse and neuritic plaques. Basal ARL8B staining was observed in controls in neuron soma. D Intense ARL8B immunoreactivity was observed in plaque-associated cells (i; arrows). Double-fluorescent immunohistochemistry showed that these plaque-associated cells with intense ARL8B immunoreactivity were a subset of plaque-associated reactive astrocytes (ii; GFAP, red arrows), and not plaque associated reactive microglia (iii; IBA1, white arrows) or neurons (iv; MAP2, white arrows). Insert in ii shows a higher magnification image of the colocalization of ARL8B and GFAP in plaque associated astrocytes