Figure 3

Effect of FRα-binding peptide on the expression of Yamanaka factor Sox2 in dentate gyrus and specifically in neurons. (a,b) Representative stitched confocal images of Sox2 expression (in red) in the dentate gyrus (DG) of mice treated with vehicle or FRα-binding peptide. The nuclear marker DAPI is shown in blue. (c) Single-dose treatment with FRα-binding peptide resulted in statistically significant changes in Sox2 immunoreactivity expression in the hilus region, subgranular zone (SGZ) and granular cell layer (GCL), of the DG (t = 3.142, df = 9; t = 3.715, df = 9 and t = 4.673, df = 9, respectively in each layer). (d,e) Representative stitched confocal images of Sox2 (in green), NeuN (in red) and GFAP (in blue) co-expression in the dentate gyrus (DG). Higher magnifications of the dentate gyrus of (d,e) (segmented squares) are shown in f and g respectively. Immunoreactive cells for Sox2 and NeuN (neurons expressing Yamanaka factor Sox2) are marked by a white arrowhead. (h) Single-dose treatment with FRα-binding peptide resulted in statistically significant changes in Sox2 immunoreactivity expression in neurons from the hilus region, granular cell layer (GCL) and in the whole DG (t = 2.497, df = 10; t = 2.645, df = 10 and t = 4.220, df = 10, respectively in each layer). (i) Single-dose treatment with FRα-binding peptide resulted in statistically significant changes in Sox2 immunoreactivity expression in astrocytes from the hilus region, the granular cell layer and in the whole DG (t = 2.855, df = 10; t = 1.857, df = 10; t = 2.513, df = 10, respectively in each layer). (j) Single-dose treatment with FRα-binding peptide did not lead to statistically significant changes in the area occupied by astrocytes (GFAP immunoreactivity) in the hilus region, granular cell layer, and the entire DG (t = 0.3513, df = 10; t = 0.6755, df = 10; t = 0.4631, df = 10, respectively in each layer) (mean ± SEM; *p < 0.05, **p < 0.01, ***p < 0.001; Student’s t-test). Scale bar, 100 µm (a,b,d,e) and 25 µm [higher magnifications in (f,g)].