Fig. 1

Schematic diagram showing seeding of the two cell types in the co-culture system. a “Cell Contact” model: MC3T3-E1 osteoblasts were seeded on the basal surface of the membrane andMLO-Y4 osteocytes were then seeded on the apical surface of the membrane. The two cell types were permitted to come into direct contact. b “No Cell Contact” model: MC3T3-E1 osteoblasts were seeded on the bottom of the wells, and MLO-Y4 osteocytes were seeded on the apical surface of the membrane. The two cell types could not come into direct contact