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Ketoconazole and phorbol myristate acetate regulate osteoclast precursor fusion in primary murine marrow culture
Author(s) -
Fan Xian,
Biskobing Diane M.,
Bain Steven,
Rubin Janet
Publication year - 1996
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.5650110912
Subject(s) - ketoconazole , staurosporine , multinucleate , phorbol , osteoclast , cell fusion , microbiology and biotechnology , cell culture , tartrate resistant acid phosphatase , chemistry , biology , protein kinase c , in vitro , endocrinology , biochemistry , cell , kinase , antifungal , genetics
Osteoclast formation requires both precursor proliferation and then fusion into a multinuclear cell. These processes can be separated in primary murine marrow culture where osteoclastogenesis is stimulated by 1,25‐dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ). Here we investigate the regulation of precursor fusion. Ketoconazole, an agent known to inhibit cell fusion, added during the fusion period (days 5–6), dose‐dependently inhibited formation of tartrate‐resistant acid phosphatase + (TRAP + ) multinucleated cells (TRAP + MNCs), maximally at 62 ± 4% ( n = 10). TRAP + MNCs in cultures exposed to 48 h of ketoconazole (1 μM) during fusion had fewer nuclei compared with control (11.7 ± 0.6 vs. 15.1 ± 0.9). This inhibitory effect was completely reversed 24 h after removal of ketoconazole from culture. Phorbol myristate acetate (PMA) stimulated TRAP + MNC formation when given during the last 12 h of culture (2.3 ± 0.2 fold compared with control). This increased formation was unaffected by the addition of hydroxyurea and accompanied by an increase in nuclei per TRAP + MNC (15.5 ± 0.9 vs. 13.1 ± 0.6). Finally, staurosporine decreased TRAP + MNC formation in the presence or absence of PMA, implying that protein kinase C is involved in fusogenic processes. Regulation of fusion appears to be another mechanism by which bone remodeling can be modulated in vivo.