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Conditioned Medium of Soybean Treated Osteoblasts Inhibits RANKL Induced Differentiation of Osteoclasts with Selective Expression of Osteoprotegerin
Author(s) -
Park KyungHo,
Ju WonChul,
Cho Yunhi
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.697
Subject(s) - rankl , osteoprotegerin , chemistry , osteoclast , genistein , medicine , endocrinology , bone resorption , paracrine signalling , isoflavones , receptor , activator (genetics) , biochemistry , biology
Soybean is of particular interest as a food supplement of isoflavones for inhibiting bone resorption in postmenopausal woman. These beneficial effects of isoflavones are caused by functioning as partial agonists or antagonists of estrogen, of which anti‐resorptive and anti differentiation effects on osteoclasts effect is mediated indirectly through paracrine factors produced by osteoblasts. In this study, we investigated the indirect effect of soybean on osteoclastic differentiation of RAW264.7 cells. The conditioned medium were collected from MC3T3‐E1 osbeoblasts treated with 0.001 mg/ml – 0.1 mg/ml soybean extracts for 6 days, mixed in 1:1 ratio with osteoclast medium, and then added into RAW264.7 cells with receptor activator of nuclear factor kappa B ligand (RANKL), a differentiation inducer for 3 days. Of paracrine factors in the conditioned medium, the protein expression of osteoprotegerin (OPG) with soybean extract was specifically higher in a dose dependent manner than with 10 −9 M – 10 −6 M of estrogen or isoflavone standards such as genistein and daidzein. In RAW264.7 cells, the conditioned medium with soybean extract inhibited RANKL induced osteoclastic differentiation as total number of multinucleated tartrate‐resistant alkaline phosphatase (TRAP)‐positive osteoclasts and protein expression of matrix metalloproteinase (MMP)‐9 were significantly decreased. Coupled with the low expression of estrogen receptor α and β proteins in RANKL treated RAW264.7 cells, we demonstrate that the conditioned medium of soybean treated osteoblasts inhibits RANKL induced differentiation of osteoclasts with the selective expression of OPG in osteoblasts.