Figure 7. Effect of nicotine on actin organization.
RAW264.7 cells were plated onto 12-mm coverslips. The cells were cultured with 0 (control) or 10−3 M nicotine in differentiation medium for 7 days and then fixed. Filamentous actin was labeled with fluorescently tagged phalloidin (red), nuclei were labeled with 4′,6-diamidino-2-phenylindole (DAPI, Vector Laboratories) (blue), and osteoclasts were observed by fluorescence microscopy. Representative micrograph of osteoclasts on a coverslip (original objective, ×40) (a). The percentage of osteoclasts exhibiting actin belts under each condition was quantified (b). Data are expressed as the mean±S.D., n = 3 independent experiments, each performed using triplicate coverslips with five randomly selected osteoclasts analyzed per coverslip. **p<0.01 nicotine treatment vs. control.