Fig. 5

The upregulation of VDR signaling rescues bone loss and decreases osteogenic activity induced by a high-fat diet. a Representative 3D-reconstructed μCT images of trabecular bone in the distal femur metaphysis, jaw bone from the first mandibular molar root furcation region, cortical bone at the femur mid-diaphysis and cortical bone from the first mandibular molar root furcation region of the Veh group and 1,25VD group (scale bars = 1 mm). b µCT analyses of the trabecular bone volume/total volume (Tb. BV/TV) and BMD in the distal femur trabecular bone or in the first mandibular molar root furcation regions as well as the cortical bone volume/total volume (Ct. BV/TV) at the femoral diaphysis or in the first mandibular molar root furcation regions. c Representative sections subjected to NCAD immunofluorescence staining, histological TRAP-stained sections, and Goldner’s trichrome-stained sections of the femoral bone marrow cavity from each group (scale bars = 50 μm). NCAD⁺ osteoblasts in the paraffin sections were stained green (white arrows). Osteoclasts in the TRAP-stained sections were stained red (black arrow). In Goldner’s trichrome-stained sections, the trabecular surface was covered with intratrabecular osteoid (black arrows). d Representative histological TRAP-stained sections of the alveolar bone of each group (scale bars = 50 μm). e Quantification of osteoclastogenic activity and osteogenic activity in the femoral bone marrow cavity or in the alveolar bone of each group (N.Ob/B.Pm osteoblast number per bone perimeter, N.Oc/B.Pm osteoclast number per bone perimeter, Oc.S/bs osteoclast surface per bone surface, OA/BA osteoid area per bone area). The data were shown as the mean ± SEM. N = 5, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.000 1