Cathepsin K-deficient osteocytes prevent lactation-induced bone loss and parathyroid hormone suppression
| Autor: | Virginia-Jeni A. Parkman, Yoshihito Ishihara, Vincent T. Carpentier, Noriko Ide, Lynn Neff, Kenichi Nagano, Sutada Lotinun, Dorothy Hu, Roland Baron, Mary L. Bouxsein, Pamela Dann, Riku Kiviranta, Daniel J. Brooks, Francesca Gori, John J. Wysolmerski |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty Bone disease Osteoporosis Cathepsin K Parathyroid hormone Osteocytes Bone resorption 03 medical and health sciences Mice 0302 clinical medicine Osteoclast Osteogenesis Internal medicine medicine Animals Lactation Bone Resorption Cells Cultured Chemistry General Medicine medicine.disease Resorption Mice Inbred C57BL 030104 developmental biology medicine.anatomical_structure Endocrinology Parathyroid Hormone 030220 oncology & carcinogenesis Osteocyte Commentary Calcium Female Bone Remodeling |
| Zdroj: | J Clin Invest |
| ISSN: | 1558-8238 |
| Popis: | Lactation induces bone loss to provide sufficient calcium in the milk, a process that involves osteoclastic bone resorption but also osteocytes and perilacunar resorption. The exact mechanisms by which osteocytes contribute to bone loss remain elusive. Osteocytes express genes required in osteoclasts for bone resorption, including cathepsin K (Ctsk), and lactation elevates their expression. We show that Ctsk deletion in osteocytes prevented the increase in osteocyte lacunar area seen during lactation, as well as the effects of lactation to increase osteoclast numbers and decrease trabecular bone volume, cortical thickness and mechanical properties. In addition, Ctsk deletion in osteocytes increased bone Parathyroid Hormone related Peptide (PTHrP), prevented the decrease in serum Parathyroid Hormone (PTH) induced by lactation, but amplified the increase in serum 1,25(OH)2D. The net result of these changes is to maintain serum and milk calcium levels in the normal range, ensuring normal offspring skeletal development. Our studies confirm the fundamental role of osteocytic perilacunar remodeling in physiological states of lactation and provides genetic evidence that osteocyte-derived Ctsk contributes not only to osteocyte perilacunar remodeling, but also to the regulation of PTH, PTHrP, 1,25-Dyhydroxyvitamin D (1,25(OH)2D), osteoclastogenesis and bone loss in response to the high calcium demand associated with lactation. |
| Databáze: | OpenAIRE |
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