Fig. 1
Diabetes mellitus (DM) aggravates periodontitis and alveolar bone loss by m6A methylation. A Scheme of the establishment of periodontitis with diabetes in mice. B Glucose levels of overnight-fasting and corresponding time points of the oral glucose tolerance test (OGTT) test one week after streptozotocin (STZ) administration (n = 6). C, E Representative micro–computed tomography (CT) 3-dimensional reconstruction shows the experimental periodontitis in normal and DM mice. Alveolar bone crests (ABC) are shown in red dotted lines, cemento-enamel junctions (CEJ) are shown in blue dotted lines. Scale bar = 500 μm. Quantification of alveolar bone loss, represented by distance of CEJ-ABC on buccal root surfaces of the maxillary first molar (Black arrow) (n = 6). Con, control; DM, diabetes mellitus; EP, experimental periodontitis; DP, diabetes-associated periodontitis. D Original micro-CT images of 2-dimensional slices on sagittal direction. The red arrow indicates the region of interest (ROI) with alveolar bone loss. Scale bar = 500 μm. F Quantitative analysis of bone volume/tissue volume (BV/TV), trabecular thickness (Tb·Th), and trabecular number (Tb.N) of alveolar bone in normal and DM mice with or without periodontitis (n = 6). G Representative images of hematoxylin and eosin (H&E) staining of periodontal tissue between maxillary first molar and second molar. Inflammatory infiltration (blue arrows), alveolar bone resorption (red arrows) are shown. Scale bar = 600 μm. PDL, periodontal ligament; AB, alveolar bone; M1, first molar; M2, second molar. H Representative immunofluorescence images of FTO at 200 × magnification (scale bar = 200 µm). Data are expressed as the mean ± SEM. ns, not significant. *P < 0.05. **P < 0.01. ***P < 0.001. ****P < 0.0001