Gli1⁺ Cells Residing in Bone Sutures Respond to Mechanical Force via IP₃R to Mediate Osteogenesis

Figure 2

Pharmacological inhibition of Gli1⁺ cells suppresses mechanical force-induced maxillofacial bone remodeling. (a) Experimental procedure: Gli1-LacZ mice were treated with GANT61 every second day before they were sacrificed, and RME was induced on day 3 (RME+GANT61). Mice in the RME group were treated with vehicle. (b) HE and Masson’s staining showed decreased midpalatal suture remodeling in GANT61-treated mice. The midpalatal suture is shown between the two dotted lines. Scale bar: 100 μm; . (c) Calcein labelling shows that new bone formation is less in the RME+GANT61 group. Scale bar: 20 μm; . (d) New bone deposition rate decreased in the RME+GANT61 group, ; . (e) Micro-CT shows the horizontal plane views of maxillae of both groups. Scale bar: 2 mm. The left panel shows magnified sutures (in boxes), and GANT61-treated mice show narrow midpalatal sutures. Scale bar: 0.5 mm. (f) The distance between two first molars decreased in GANT61 application mice. ; . (g) Gli1 (green) and RUNX2 (red) expression in the midpalatal suture areas of both groups visualized by immunofluorescence staining. Scale bar: 100 μm. Regions in boxes are magnified in the right panel: “N” indicates the nasal side of the midpalatal suture and “O” indicates the oral side. Scale bar: 50 μm. (h) Proportions of Gli1⁺ cells decreased in the nasal and oral sides and in the midpalatal suture in GANT61-treated mice. ; . (i) The proportions of RUNX2⁺ cells in the midpalatal suture decrease in the RME+GANT61 group. ; . (j) Gli1⁺ and RUNX2⁺ cells decreased in the sutures of the RME+GANT61 group. ; .

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