Figure 5
The functions of osteoblasts and osteocytes on osteoclast fusion. (A–C) In this “live” group, the bottom-level cells (all of them “live”) were directly co-cultured with top-level cells. (D–F) In this group (CM), the topmost cells were separated from the bottom cells by transwell chambers with a 0.4um pore size. This restricted communication of secreted matters. (G–I) In this “dead” group, bottom cells were rendered dead via application of 4%PFA. Under these conditions, only the membrane molecules of the bottom cells were able to interact with the top cells. The results indicate that osteocytes have much stronger ability than osteoblasts with respect to the promotion of osteoclast fusion (A–C). Secreted matters from osteoblasts were more effective in inducing fusion (D–F). However, osteocytes’ membrane-linked molecules produced significantly more fusion (G–I). Scare bar: 100um. 3T3: MC3T3-E1 cells as bottom cells; Y4: MLO-Y4 cells as bottom cells. All error bars shown are the calculated standard deviation (SD) across triplicate experiments. * for p < 0.05; **p < 0.01; ***p < 0.001.
