Fig. 6

Immunostaining of brain sections from P301S and WT mice demonstrates a significant increase of astrogliosis and reduction of Nrf2 through the progression of tauopathy. a and b : Representative images of GFAP staining from WT mice (upper panel) and P301S (lower panel) from brain stem (a) and hippocampus (b) showing the early accumulation of GFAP reactive astrocytes by 2 month age for P301S mice and shows a progressive increase at 4 and 6 months. GFAP signals from P301S manifest a bold cytoplasmic processes (arrow) while a few resting astrocytes with fine cytoplasmic processes and mild expression are shown from the brain sections of WT mice (arrow heads). Scale bar = 20 μm. c and d: Bar graphs representing the quantitative analysis of mean of GFAP⁺ cell counts per field from all the imaged brain sections for 2, 4 and 6 months P301S and WT mice (c) and GFAP signals mean density (d). e and f: Show the representative figures from Nrf2 staining of brain section of WT mice (upper panel) and P301S (lower panel) from brain stem (e) and hippocampus (f), showing a reduction of Nrf2 expression with the progression of the tauopathy in P301S compared to sections from WT mice at 4 and 6 months. The perinuclear staining of Nrf2 identified in the brain sections from WT or the early stages of P301S (arrow), is significantly reduced at 4 and 6 months P301S. g and h: Bar graphs representing the quantitative analysis of mean of Nrf2 + cell counts per field (c) and Nrf2 signals mean density per examined field from all the imaged brain section (d). Data for all graphs are expressed as mean +/- SEM of brain sections from 5 to 6 mice. P value is tested by using Student’s T test to compare between two strains of the same age group. p values throughout the figure are expressed as follow: * p < 0.05, ** p < 0.01, *** p < 0.001 and **** p < 0.0001