Co-cultures of spleen cells and BMSCs treated with TNYL-RAW (50 µM) or controls. These cultures were further treated by vehicle or IGF-I 10 ng/ml 24 hrs before analyses. A–D: Number of osteoclasts (arrows) formed in the cultures was counted and shown under the corresponding pictures. mRNA levels of ephrin B1 and ephrin B2 receptors EphB2, EphB3, EphA4 (E) and RANKL, RANK, OPG, AP and NFATc1 (F) in the co-cultures were determined by Q-PCR. Results are expressed as mean ± SD. a: P < 0.05 vs. vehicle treated control. n = 4 wells in each group.