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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Life Science / Faculty of Advanced Life Science >
Peer-reviewed Journal Articles, etc >
Vitamin K-dependent carboxylation of osteocalcin affects the efficacy of teriparatide (PTH1-34) for skeletal repair
| Title: | Vitamin K-dependent carboxylation of osteocalcin affects the efficacy of teriparatide (PTH1-34) for skeletal repair |
| Authors: | Shimizu, Tomohiro Browse this author | | Takahata, Masahiko Browse this author →KAKEN DB | | Kameda, Yusuke Browse this author | | Hamano, Hiroki Browse this author | | Ito, Teppei Browse this author | | Kimura-Suda, Hiromi Browse this author | | Todoh, Masahiro Browse this author →KAKEN DB | | Tadano, Shigeru Browse this author →KAKEN DB | | Iwasaki, Norimasa Browse this author →KAKEN DB |
| Keywords: | Vitamin K | | Teriparatide | | Fracture | | Gla-osteocalcin | | Mineralization | | Parathyroid hormone (1-34) |
| Issue Date: | Jul-2014 |
| Publisher: | Elsevier |
| Journal Title: | Bone |
| Volume: | 64 |
| Start Page: | 95 |
| End Page: | 101 |
| Publisher DOI: | 10.1016/j.bone.2014.04.005 |
| PMID: | 24731926 |
| Abstract: | Teriparatide (PTH1-34) promotes skeletal repair and increases bone mass. Vitamin K is involved in bone mineralization as a coenzyme of gamma-carboxylase for Gla proteins, and therefore vitamin K insufficiency caused by malnutrition or therapeutic intake of the vitamin K antagonist warfarin could affect the efficacy of PTH1-34 therapy for bone repair. In the present study, we investigated whether vitamin K influences the efficacy of PTH1-34 therapy for bone repair in a rat osteotomy model. Female 12-week-old Sprague-Dawley rats were subjected to a closed midshaft osteotomy of the femur and randomized into four groups (n = 10 per group): vehicle, PTH1-34 (daily 30 mu g/kg/day subcutaneous injection) + solvent (orally, three times a week), PTh1-34 + warfarin (0.4 mg/kg/day orally, three times a week), and PTH1-34 + vitamin K-2 (menatetrenone, 30 mg/kg/day orally, three times a week). Serum gamma-carboxylated and uncarboxylated osteocalcin (Gla-OC and Glu-OC) levels and radiographic healing were monitored every 2 weeks. Skeletal repair was assessed by micro-computed tomography, mechanical testing, and histology at 8 weeks after surgery. PTH1-34 amplified the osteotomy-induced increase in Gla-OC and improved the mechanical properties as well as the volumetric bone mineral tissue density of the fracture callus. Concurrent use of warfarin decreased the response to PTH1-34 therapy in terms of mechanical recovery, probably by impairing mineralization due to the lack of Gla-OC. Although the effects of combination therapy with PTH1-34 and vitamin K-2 on bone repair did not significantly exceed those of PTH1-34 monotherapy in rats fed sufficient dietary vitamin K, postoperative Gla-OC levels were correlated with the mechanical properties of the osteotomized femur in PTH1-34-treated rats regardless of the use of warfarin or vitamin K-2. These findings suggest the importance of vitamin K dependent gamma-carboxylation of DC for realizing the full effects of PTH1-34 on skeletal repair. (C) 2014 Elsevier Inc. All rights reserved. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/56613 |
| Appears in Collections: | 生命科学院・先端生命科学研究院 (Graduate School of Life Science / Faculty of Advanced Life Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 清水 智弘
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