Fig. 5

Accumulation of lysosomal markers and diffuse cytoplasmic Cat D immunoreactivity in tauopathies. a Western blot analysis of LAMP1 in human post-mortem brain (frontal cortex) extracts from control individuals (Ctrl, n = 3), early onset familial AD (FAD, n = 3) and CBD (n = 2). b LAMP1 levels quantified by densitometry and normalized to GAPDH in Ctrl, FAD and CBD. Results are shown as the mean value of arbitrary unit ± S.D (mean of three independent experiments). c-t Double immunohistochemistry against hyperphosphorylated tau (Tau/pS422, red, c-f) and Cat D (HPA003001, Sigma-Aldrich) (green, g-j) are shown by confocal analysis. k-n Merged pictures with nuclear staining (DAPI, blue). In FAD, CBD and PSP cases, strong Cat D-immunoreactivity is present in the soma of the cells in frontal cortex compared to the control. k-m (and high magnification q-s) Distinct vesicle-like structures (asterisks) and diffuse immunoreactivity (arrows) of Cat D throughout the cell bodies are shown in the pictures. In addition, in FAD and PSP, arrowheads in k and m and high magnification pictures (o-p) of boxed areas show hyperphosphorylated tau-positive structures close to Cat D-positive structures. t Brain tissues from control individuals show few Cat D-positive vesicle structures (asterisks). Scale bars: 50 μm (5 μm high magnification)