Table 1.
Examined human cases.
Figure 1.
In vivo imaging of fibrillar tau aggregates in the retina of P301S mice.
A SLO examination of the mouse retina using a custom made mouse holder. B, C Pre-examination revealing spots of increased autofluorescence in the retinas of 5-month-old P301S and C57Bl/6 mice. D 24–48 hours after the injection of FSB, fluorescent cells were detected in the retinas of P301S mice but not of C57Bl/6 mice at 450 nm excitation (E). F, G No FSB-positive signals could be detected in the same imaging session when excited at 488 nm. H, I Example for the spectral discrimination of FSB-positive cells from spots of increased autofluorescence in the retina of a P301S mouse. H In vivo image obtained at 488 nm excitation showing dots of increased autofluorescence (AF, red arrows). I FSB-positive cells can only be excited at 450 nm (green arrows).
Figure 2.
FSB labels cells containing hyperphosphorylated tau in the GCL of P301S mice.
A, B In vivo SLO-examination of a P301S mouse crossed with Thy1-YFPH. A Scanning at 488 nm excitation revealed only YFP-positive cells in a unique pattern (Striking cells are numbered 1–4). B In the same retinal area, FSB-positive cells (arrows) adjacent to YFP-positive cells became apparent when excited at 450 nm. C Whole mount preparation of the in vivo examined retina (A, B). D Magnification of the boxed area in B and C. The in vivo observed FSB-positive cells (B) could be counterstained with AT8 (arrows). Axons from RGCs containing hyperphosphorylated tau appear as red background. red, AT8; white, FSB; green, YFP. Scale bars: 50 µm.
Figure 3.
A 10 minutes after the systemic administration, no fluorescence of FSB was observed in SLO images obtained with 450 nm excitation. B Within retinal blood vessels, bright fluorescence appeared 60 min post-injection and was still present 12 hours post-injection (C). D 24 hours post-injection most of the fluorophore was cleared from the blood stream and distinct FSB-positive cells could be observed. E–G These FSB-positive cells were still present 48, 72 hours and even 1 month after the first injection of FSB. H New FSB-positive cells did not appear until a second FSB injection (arrow). p.i. post-injection.
Figure 4.
In vivo long term imaging of FSB-positive cells displays the disease progression in P301S mice.
A–D Representative retina imaged between 2 and 5 months of age in an interval of 1 month. F–I Second retina imaged between 5 and 6.5 months of age in an interval of 2 weeks. A'–I' Enlarged images of the boxed areas in A and F demonstrating the appearance of new FSB-positive cells over the time (arrows). FSB was administrated systemically before each imaging session and images were acquired at 450 nm excitation. E, J Quantification of the increasing number of FSB-positive cells in the age from 2 to 5 months and 5 to 6.5 months. The curve displays the mean from 10 different retinas (n = 5 mice). Error bars show SD. **P<0.01; ***P<0.001.
Figure 5.
Ex vivo analysis of FSB-positive cells.
A, B FSB-positive cells were counted in retinal whole mounts of P301S mice (red, AT8; white, FSB; green, YFP). C Quantification of FSB-positive cells of homozygous and heterozygous P301S mice in cohorts of different ages (n = 5–6). Each data point represents the number of FSB-positive cells in one retina normalized to the area. Shown are mean values ± SD. **P<0.01; ***P<0.001. D, E AT8-staining in the cortex of homozygous P301S mice at the age of 2 and 5 months. Scale bars: 1 mm (A), 100 µm (B, D, E).
Figure 6.
Pathological alterations of tau and Aβ in the retinas of human AD and PSP patients.
A–C Post mortem retinas of AD and PSP patients showing AT8-positive cells in the INL (arrows) and stainings of the plexiform layers and GCL. B, B' Higher magnification image of individual AT8-positive cells in the INL. D Control retinas were not immunopositive for AT8. E–E'' AT8-positive cells could not be co-stained with FSB in AD and PSP retinas. F No 4G8-positive staining against Aβ was found in the retinas of AD patients. G In comparison, control brain slices of AD patients showed severe 4G8-positive Aβ-plaques. ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer. AD, Alzheimer's disease; PSP, progressive supranuclear palsy. Scale bars: 10 µm.