Figure 2.

MLO-A5 bone cells express primary cilia. MLO-A5s were stained with anti-acetylated α-tubulin to visualize primary cilia (indicated by white arrowheads) and DAPI to indicate nuclei (blue; A, C, D) or biotinylated HA-binding protein (red; B). The primary cilium was seen to protrude from the apical cell surface of MLO-A5 cells cultured in vitro (A, B). The microtubule network within the cell was also visualized (green; A). The HA component of the glycocalyx was evident over the entire cell membrane, including around the primary cilium (B). Exposure to CH for 24 h caused structural defects in primary cilia of MLO-A5 cells, indicated by orange arrows (C), and disorganization of the cell microtubule network, but this recovered after 24 h. As the exposure time of MLO-A5 cells to CH increased from 0 to 72 h, a greater number of primary cilia were damaged or removed (D), and the cilia of cells subjected to longer CH exposure also took longer to grow back to normal size when recovering in fresh medium (white arrowheads are representative of relative number of primary cilia present).