Figure 3.

Calcitriol prevents cytoskeleton and morphological changes required for FLS invasion. DA (A–C) and RA (G–I) FLSs treated with DMSO have an elongated shape, with thick and longitudinal actin filaments, polarized formation of lamellipodia and p-FAK colocalization with lamellipodia. Calcitriol-treated DA (D–F) and RA (J–L) FLSs have a round, nonfusiform shape, with disorganized actin fibers and with either no lamellipodia formation or a nonpolarized formation of lamellipodia-like structures around the cell rim. These lamellipodia-like structures do not colocalize with p-FAK, which in calcitriol-treated cells tends to have a diffuse distribution (red = p-FAK; green = phalloidin-FITC-actin staining; images are representative of four different DA and five different RA FLS cell lines; bar in the picture = 10 μm) (magnification 630×).