Effect of syndecan-1 on multinucleate (> 3 nuclei) TRAP-positive and ALP-positive cell formation in murine bone marrow cultures. Bone marrow cells (106 cells/well) were cultured in α-MEM containing media in multiwell dishes for a total of 8 days. (A) Syndecan-1 inhibits osteoclastogenesis: Either 10−8mol/L 1,25(OH)2D3 alone or 10−8mol/L 1,25(OH)2D3 with 0.65 to 65 pmol/L syndecan-1 purified by immunoaffinity chromatography was added during the last 4 days in the culture period and cells were stained for TRAP. One of three representative experiments is shown. (B) Syndecan-1 promotes osteoblastogenesis: 0.65 to 65 pmol/L syndecan-1 was added during the last 4 days in the culture period and cells were stained for ALP. One of three representative experiments is shown. (C) Inhibition of osteoclast development by syndecan-1 does not require the intact syndecan ectodomain. Purified intact syndecan-1 ectodomain (45 pmol/L), syndecan-1 pretreated with heparitinase (Hase), purified syndecan-1 GAGs, or heparin (1 μg/mL) was added for the last 4 days in the culture period and cells were stained for TRAP. (D) Promotion of osteoblast development by syndecan-1 does not require the intact syndecan ectodomain. Purified intact syndecan-1 ectodomain (45 pmol/L), syndecan-1 pretreated with heparitinase (Hase), GAGs purified from syndecan-1, or heparin (1 μg/mL) was added for the last 4 days in the culture period and cells were stained for ALP (*P < .05; **P < .01).
