Figure 5.

Tau deletion induces γ-H2AX accumulation under hyperthermia. H2AX phosphorylation was detected using an anti-γ-H2AX antibody in hippocampal sections from 7 m WT and KO-Tau mice. (A) Representative images of sagittal DG and CA1 sections from WT and KO-Tau mice under control (C) or HS conditions labeled for γ-H2AX and analyzed using confocal microscopy are shown. DAPI stained the nuclear chromatin. HS induced a strong increase in γ-H2AX specifically in the KO-Tau hippocampus. The scale bars indicate 50 µm. (B) Nuclear extracts of the hippocampus from WT and KO-Tau mice in the C or HS condition were analyzed using immunoblotting for γ-H2AX. Lamin B was used as a specific nuclear loading protein. (C) Sagittal DG sections from WT and KO-Tau mice were subjected to a TUNEL assay, labeled with γ-H2AX and analyzed using confocal microscopy. Comparisons of TUNEL-γ-H2AX, TUNEL-DAPI and Υ-H2AX-DAPI overlays highlighted the occurrence of double-strand breaks (DBS) only in some nuclei (arrows). Scale bars indicate 10 µm. (D) Representative images of sagittal DG sections from 7-month-old KO-Tau mice 24 h after HS labeled for γ-H2AX and analyzed using laser scanning confocal microscopy. The nuclei were detected using DAPI staining. Nuclear γ-H2AX labeling returned to control levels in DG neurons, but discrete γ-H2AX foci persisted in the nuclei of CA1 neurons. The scale bars indicate 50 µm.