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Calcified Tissue International

, Volume 94, Issue 1, pp 25–34 | Cite as

Osteocyte-Driven Bone Remodeling

  • Teresita Bellido
Review

Abstract

Osteocytes, the most abundant cells in bone, have been long postulated to detect and respond to mechanical and hormonal stimuli and to coordinate the function of osteoblasts and osteoclasts. The discovery that the inhibitor of bone formation sclerostin is primarily expressed in osteocytes in bone and downregulated by anabolic stimuli provided a mechanism by which osteocytes influence the activity of osteoblasts. Advances of the last few years provided experimental evidence demonstrating that osteocytes also participate in the recruitment of osteoclasts and the initiation of bone remodeling. Apoptotic osteocytes trigger yet-to-be-identified signals that attract osteoclast precursors to specific areas of bone, which in turn differentiate to mature, bone-resorbing osteoclasts. Osteocytes are also the source of molecules that regulate the generation and activity of osteoclasts, such as OPG and RANKL; and genetic manipulations of the mouse genome leading to loss or gain of function or to altered expression of either molecule in osteocytes markedly affect bone resorption. This review highlights these investigations and discusses how the novel concept of osteocyte-driven bone resorption and formation impacts our understanding of the mechanisms by which current therapies control bone remodeling.

Keywords

Osteocyte Osteoclast Osteoblast Bone remodeling RANKL OPG Sost 

Notes

Acknowledgments

This research was supported by the National Institutes of Health (R01-AR053643, KO2-AR02127, R03 TW006919, R01-DK076007, and P01-AG13918).

Disclosures

None.

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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of Anatomy and Cell BiologyIndiana University School of MedicineIndianapolisUSA
  2. 2.Division of Endocrinology, Department of MedicineIndiana University School of MedicineIndianapolisUSA
  3. 3.Roudebush Veterans Administration Medical CenterIndianapolisUSA

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