Fig. 3

Quantification of numbers and areas of progranulin-positive plaques. (a-c). Low magnification of representative images of low plaque (a), high plaque (b) and Alzheimer’s disease (c) cases stained for PGRN (purple) and Aβ (6E10) brown. Series of sections were used for quantification using image analysis software. Examples of PGRN-positive (top) and PGRN-negative plaques (lower) are shown as insets. Scale bars represent 200 μm. (d). Higher magnification images of PGRN-negative (arrowhead) and PGRN-positive (arrows) amyloid plaques identified with antibodies to PGRN (purple) and 6E10 (brown). PGRN-positive plaques tended to have a more aggregated morphology while PGRN-negative were more diffuse. Scale bar represents 30 μm. (e). PGRN, Aβ and thioflavin-S confocal microscope image. Colocalization of PGRN (red) associated with thioS-positive (green)-Aβ plaques (blue)(arrows) with thioS-negative Aβ plaque with minimal amount of PGRN (arrowhead) in an AD section. Scale bar represents 20 μm. Images were acquired with Leica SP8 microscope. (F). Bar chart showing total number of Aβ plaques in all cases studies. LP (n = 16), HP (n = 15) and AD (n = 14). Results represent mean ± standard error of mean (S.E.M.). Significant increase in numbers of plaques in HP and AD compared to LP **** (p < 0.0001), between LP and HP **** (p < 0.0001) and between HP and AD (** p < 0.01). (G). Bar chart showing number of Aβ plaques with associated PGRN in all cases studies. LP (n = 16), HP (n = 15) and AD (n = 14). Results represent mean± standard error of mean (S.E.M.). Significant increase in numbers of plaques in HP and AD compared to LP **** (p < 0.0001) and between HP and AD (**** p < 0.0001). (h). Bar chart showing total area (percentage) occupied by PGRN-associated Aβ plaques in all cases studies. LP (n = 16), HP (n = 15) and AD (n = 14). Results represent mean ± S.E.M. Significant increase in numbers of plaque occupied area in HP and AD compared to LP **** (p < 0.0001) and between HP and AD (**** p < 0.0001). (i). Bar chart showing average plaque size (pixels) of PGRN-associated plaques in all cases studies. Numbers derived from total area occupied divided by number of plaques for each case. Results represent mean ±S.E.M. LP (n = 16), HP (n = 15) and AD (n = 14). Significant increase in average plaque size in LP and AD compared to LP ****p < 0.001) and between HP and LP (*** p < 0.001). NS - Not significantly different.