Fig. 2: HFD-induced appearance of FGF23-expressing mucus-like cells in gastric lesions.

Epithelial lesions visualized by TFF1 staining in CD-fed mice (A) and mice on HFD (B). Coimmunolabeling of FGF23 (green) and TFF1 (red) in patchy disorganized glands in the stomach of a CD-fed mouse (C) and of a mouse on HFD (D). Insets: PAS staining verifies the presence of mucin in gastric lesions. Extensive purple color indicates pronounced mucus production, most prominently in elongated foveolae and some dilated glands in the midportion of the mucosa. E-G Higher magnification of the stomach from a mouse on HFD. (CD: n = 3; HFD: n = 4). H Arithmetic means ± SEM of FGF23-/TFF1-positive areas expressed as proportion of total mucosal thickness (CD: n = 3; HFD: n = 4; student’s t-test). I Arithmetic means ± SEM of the number of cells positive for the indicated markers counted in mucosal lesions (CD: n = 3; HFD: n = 4; cells positive for FGF23/TFF1 and TFF1: student’s t-test, cells positive for FGF23: Welch’s t-test). A dashed line encircles epithelial lesions. Sections were counterstained with DAPI. Scale bars: 100 µm (A, B), 50 μm (C, D), 10 μm (E–G). *p < 0.05; **p <0.01. CD control diet, FGF23 fibroblast growth factor 23, HFD high fat diet, PAS periodic acid-Schiff, TFF1, trefoil factor 1.