JCI - Insulin receptor substrate-1 in osteoblast is indispensable for maintaining bone turnover

Insulin receptor substrate-1 in osteoblast is indispensable for maintaining bone turnover

Naoshi Ogata, Daichi Chikazu, Naoto Kubota, Yasuo Terauchi, Kazuyuki Tobe, Yoshiaki Azuma, Tomohiro Ohta, Takashi Kadowaki, Kozo Nakamura, Hiroshi Kawaguchi

Published in Volume 105, Issue 7

J Clin Invest. 2000; 105(7):935–943 doi:10.1172/JCI9017

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Figure 5

Osteoclastogenesis in the coculture of bone marrow cells and osteoblasts. (a) The number of TRAP-positive multinucleated osteoclasts formed in the coculture of marrow cells and osteoblasts both from WT or IRS-1^–/– littermates for 8 days in the presence or absence of 1,25(OH)₂D₃ (VD₃, 10 nM), IGF-I (10 nM), PGE₂ (100 nM), PTH (10 nM), and IL-11 (10 ng/mL) was counted. Data are expressed as mean (bars) ± SEM (error bars) for 8 wells/group. Significantly different from WT cultures, ^AP < 0.05, ^BP < 0.01. Steady-state mRNA levels of RANKL/ODF in cultured osteoblasts from neonatal WT and IRS-1^–/– littermates were determined by Northern blot analysis after 24 hours of culture with or without the factors above. (b) The number of osteoclasts formed in the coculture of marrow cells and osteoblasts from WT and IRS-1^–/– littermates in the presence of 1,25(OH)₂D₃ (10 nM) (top) and the pit area resorbed by osteoclasts for an additional 48 hours of coculture on a dentine slice (bottom). Data are expressed as mean (bars) ± SEM (error bars) for 12 wells/group. Significantly different from WT:WT culture, ^AP < 0.01.