Fig.5.

a) SPARC is colocalized to amyloid plaques. SPARC expression (green) is increased around pathological protein deposits (ThioS positive structures) (A–D). To differentiate between true ThioS signal and lipofuscin autofluorescence, the SPARC channel (appearing in green) has been overlaid with the red channel (unstained, but lipofuscin autofluorescence). Image B shows dying neurons covered in plaques and surrounded by SPARC. Image D depicts immune cells accumulating in the plaques area. b) SPARC is expressed by microglia found in close proximity to pathological protein aggregates. A: Positive SPARC staining, shown in green and auto-fluorescent lipofuscin in red. B: White-light image of Iba-1 positive microglia, immunoperoxidase stain. C: Thioflavin S staining against amyloid plaques. D: Merged image of A and C at the exact same location as in B, allowing for the conclusion that microglia express SPARC and that there is an association between SPARC expression and the pathological hallmarks of Alzheimer’s disease.