Comparative effects of estrogen and antiestrogens on differentiation of osteoblasts in mouse bone marrow culture

• Published in: Journal of cellular biochemistry Vol. 73; no. 4; pp. 500 - 507
• Main Authors: Qu, Qiang, Härkönen, Pirkko L., Väänänen, H. Kalervo
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 15.06.1999
• Subjects: Animals; Bone Marrow Cells - cytology; Bone Marrow Cells - drug effects; Bone Marrow Cells - physiology; Bone Matrix - drug effects; Calcification, Physiologic - drug effects; Cell Differentiation - drug effects; Cell Division - drug effects; Cells, Cultured; Estradiol - pharmacology; estrogen; Estrogen Receptor Modulators - pharmacology; FC1271a; Female; Mice; osteoblast; Osteoblasts - cytology; Osteoblasts - drug effects; Osteoblasts - physiology; raloxifene; Space life sciences; tamoxifen
• ISSN: 0730-2312; 1097-4644
• DOI: 10.1002/(SICI)1097-4644(19990615)73:4<500::AID-JCB8>3.0.CO;2-E

Estrogens as well as some antiestrogens have been shown to prevent bone loss in postmenopausal women. These compounds seem to inhibit bone resorption, but their anabolic effects have been less explored. In this study, bone marrow cultures were used to compare the effect of 17β‐estradiol (E2), and two triphenylethylene derivatives, tamoxifen (TAM), and FC1271a, and a benzothiophene derivative raloxifene (RAL) on differentiation of osteoblasts. All enhanced osteoblastic differentiation of 21‐day cultures as indicated by increased mineralization and bone nodule formation. All, except RAL, stimulated cell proliferation during the first 6 days of the culture. However, in the presence of RAL the content of total protein was increased in 13‐day cultures. SDS‐PAGE and autoradiography of [14C]‐proline labeled proteins revealed elevated level of the newly synthesized collagen type I. The pure antiestrogen ICI 182,780 abolished the increase of the specific activity of alkaline phosphatase by E2, TAM, and FC1271a but not the effect of RAL on protein synthesis. Our results show that E2 as well as TAM, FC1271a, and RAL stimulate bone formation in vitro but the mechanism of the anabolic action of RAL in bone clearly differs from that of E2, TAM, and FC1271a. J. Cell. Biochem. 73:500–507, 1999. © 1999 Wiley‐Liss, Inc.