| First Author | Suzuki T | Year | 2007 |
| Journal | Biochem Biophys Res Commun | Volume | 362 |
| Issue | 4 | Pages | 1019-25 |
| PubMed ID | 17825261 | Mgi Jnum | J:125186 |
| Mgi Id | MGI:3757812 | Doi | 10.1016/j.bbrc.2007.08.099 |
| Citation | Suzuki T, et al. (2007) Osteoblast-specific Angiopoietin 1 overexpression increases bone mass. Biochem Biophys Res Commun 362(4):1019-1025 |
| abstractText | Although osteoblasts express the angiogenic protein Angiopoietin 1 (Ang1), the role of Ang1 in bone formation remains largely unknown. Here we report that Ang1 overexpression in osteoblasts driven by the osteoblast-specific 2.3kb alpha 1 type 1 collagen promoter results in increased bone mass in vivo. In Ang1-transgenic mice (Ang1-Tg), bone volume and bone parameters increased significantly compared with wild-type littermates, although the Ang1 receptor, Tie2 was not expressed in osteoblasts. Tie2 is primarily expressed in vascular endothelial cells, and Ang1-Tie2 signaling is reportedly crucial for angiogenesis. We found that the number of vascular endothelial cells was significantly elevated in Ang1-Tg mice compared with that of wild-type littermates, an increase accompanied by increased alkaline-phosphatase activity, a marker of osteoblast activation. The number of osteoclasts in the bone of Ang1-Tg mice did not differ from wild-type littermates. These results indicate that angiogenesis induced by Ang1 expressed in osteoblasts is coupled with osteogenesis. |
