Fig. 3

Ultrastructural and molecular remodeling of both apical and basal cellular compartments during aging. A High magnification TEM images showing representative microvilli at 2 and 20 months old (m.o.). Yellow dashed lines indicate the apical cell surface from which microvilli originate. Quantification of microvilli length (B) and surface occupied by microvilli (C) averaged per cell. D Representative images of Ezrin immunofluorescence (red) at 2–3 and 20–24 m.o. E High magnification TEM images showing representative basolateral invaginations at 2 and 20 m.o. F Quantification of the surface of basolateral invaginations. G Distribution in the three age groups of the surface occupied by basolateral invaginations organized by median size. H Representative low-magnification immunofluorescence images of Na⁺/K⁺-ATPase (magenta) and GLUT1 (green) immunoreactivities at 2–3 and 20–24 m.o. I Quantification of fluorescence mean intensity at 2–3, 8–12 and 20–24 m.o. A.U., arbitrary unit. J Western blot of GLUT1, Na⁺/K⁺-ATPase and AQP1. K Western blot quantification. L Representative high magnification immunofluorescence images of Na⁺/K⁺-ATPase (magenta) and GLUT1 (green) at 2–3 and 20–24 m.o. B, C, F n = 30 cells per animal, 3 animals per age; black dashed line: median; Kruskal–Wallis; I, K n = 3 animals per age; Data are mean ± s.e.m.. *p < 0.05, **p < 0.01, ****p < 0.0001. Scale bars: 1 µm (A, E), 6 µm (H), 10 µm (L)