Fig. 5

Decreased CLDN5 immunostaining in AD affected CPE. In the healthy CP (a), choroid plexus epithelial (CPE) cells stained positive for CLDN5 (red color). In the AD tissue (b) the strings of CPE cells stain much less intensely for CLDN5. Note that in the same AD tissue, CLDN5 is clearly present in the blood vessel wall (arrow). Immunohistochemistry for CLDN5 on (6 μm thick) cryo-sections of CP from a healthy donor (A, Br0) and a donor diagnosed with AD (Br6). CLDN5 was visualized with Cy3 coupled secondary antibodies after labelling with anti-claudin 5 antibody ab53765 (Abcam). Cy3 fluorescence is shown in red. Nuclei are stained with DAPI (blue). The green color shows the autofluorescence that is detected in the FITC channel. This channel was added to reveal autofluorescence possibly overlapping with the Cy3 fluorescence marking the presence of CLDN5. Bar is 20 μm