Figure 7.

DNA damage induces de-phosphorylation of nuclear Tau. (a) The effect of Etoposide and Vinblastine treatment on mouse C17.2 cells is shown by confocal microscopy upon immune staining of PFA-fixed cells with antibodies against the microtubule marker β-tubulin (in cyan) or the DNA damage marker γH2A-X (in red). (b) Confocal microscopic quantification of the activated kinases in the nucleus (DAPI mask). Mean percent ± sem relative to the respective controls. 2-tailed unpaired Mann-Whitney test, ****p < 0.0001. (c) Confocal microscopy images of C17.2 cells with induced Tau₄₄₁ expression treated in the absence or presence of 60 µM Etoposide for 5 hr and stained for with the human Tau antibody (Tau13). Quantification of immune fluorescent detection of human Tau in DAPI-stained nuclei. Mean percent ± sem relative to the control. 2-tailed unpaired Mann-Whitney test, ****p < 0.0001. (d) Cytosolic and nuclear fractions obtained from biological replicates of C17.2 cells with induced Tau expression and treated as indicated are analysed by western blot with antibodies for the two phosphosites pT₁₈₁ and pS₄₀₄ and for the dephosphorylated Tau1 epitope are quantified upon normalization for total Tau. Data represent mean percent ± SD relative to the untreated controls. Non-parametric Kruskal-Wallis test, *p < 0.05, **p < 0.01.