Fig. 3
Klotho deletion promotes periapical lesion in alveolar bone. a μCT images of the mandibular first molar from OsxCre;KLfl/fl and control mice in apical periodontitis and sham groups. Red arrow depicts the periapical lesion. b Quantitative analysis of periapical lesion area including periapical area (mm3) and periapical diameter (μm), n = 5; and cancellous bone parameters including BV/TV (%), Tb.Th (μm), trabecular pattern factor (Tb.Pf, 1/μm), and Tb.Sp (μm), n = 6 in OsxCre Sham and AP group, n = 7 in OsxCre;KLfl/fl Sham group, and n = 8 in OsxCre;KLfl/fl AP group. c H&E staining of mandibles depict the periapical lesion induced by apical periodontitis. Dash line shows range of periapical lesion. n = 5. d Transcription expression of Tnf-α and Il-6 in periapical bone. n = 5. e, f TRAP staining and quantification of TRAP-positive cells/bone surface. Higher magnifications of boxed areas show more TRAP-positive cells in lesion region of OsxCre;KLfl/fl mice. n = 3. g Immunofluorescence staining for RANKL in the periapical region. Boxed areas show higher expression of RANKL in OsxCre;KLfl/fl AP group. Yellow dash lines depict interface of 1st molar distal root. h Gene expression of Rankl, Opg, and Rankl/Opg ratio in periapical bone of mandibular 1st molar. n = 4 in OsxCre Sham and OsxCre;KLfl/fl AP group, n = 5 in OsxCre-AP group, and n = 3 in OsxCre;KLfl/fl Sham group. i Immunofluorescence double staining of OSX:GFP and tdTomato in periapical bone surrounding the distal root of the mandibular 1st molar. Boxed areas show higher magnifications of OSX:GFP and tdTomato double-positive cells in periapical bone. White arrowhead indicates double-positive cells. j Quantification of OSX:GFP and tdTomato double-positive cells. n = 4 in OsxCre-sham group, n = 13 in OsxCre-AP group, n = 8 in OsxCre;KLfl/fl-sham group, and n = 12 in OsxCre;KLfl/fl-AP group. *, $, #p < 0.05, **, ##p < 0.01, ***, ###p < 0.001, ****, ####p < 0.0001, * indicates AP versus sham, $ indicates OsxCre Sham versus OsxCre;KLfl/fl Sham, # indicates OsxCre AP versus OsxCre;KLfl/fl AP. All data are shown as the mean ± SEM. Scale bar, 200 μm (a, c), 100 μm (e), and 50 μm (g, i)
