Fig. 3

M2-Exos attenuate alveolar bone resorption in periodontitis mice. a Schematic diagram showing the process of construction of the periodontitis animal model and exosomes injection into mice. b 3D-reconstructed images produced by micro-CT were performed on maxillae of PBS, 50 μg/ml M2-Exos, or 100 μg/ml M2-Exos treated groups. The average distance from alveolar bone crest (ABC) to cement-enamel junction (CEJ) on (e) three palatal sides (mesial, central, and distal sites) and (f) three buccal sides (mesial, central, and distal sites) of left maxillary second molar was measured. Data are shown as means ± SEM. c H&E staining images showing the alveolar bone resorption of the periodontium from each group. d Confocal analysis showing TRAP-stained osteoclasts (arrows) in the sections of periodontium from each group. Blue, nuclei; red, osteoclasts. g The number of TRAP-stained osteoclasts was counted via microscope in each group. Data are mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001. 2nd M, second molar; CEJ, cementum-enamel junction; B, bone