Fig. 3

Representative photomicrograph showing cytoskeletal rearrangement of RASFC (a) and ex vivo synovial explant culture matrigel assays (b) in response to Pam3CSK4 (1 μg/ml). Pam3CSK4 induces cytoskeletal rearrangement in RASFC (iv–vi) compared to basal control (i–iii) as evidenced by loss of F-actin fibres (green) and formation of filopodial and lamellopodial protrusions (red arrows) (n = 3). Original magnification x60 (i, ii, iv, v) or x40 (iii, vi). (b) Pam3CSK4 (1 μg/ml) also induces synovial outgrowths from ex vivo RA explants as indicated by black arrow (right panel) compared to basal (left panel) (n = 3). c Bar graph quantifying beta integrin increased expression of β1-integrin on the cell surface of RASFC treated with Pam3CSK4 (1 μg/ml) (n = 5). d Bar graph representing β1-integrin mRNA in RASFC under basal conditions or stimulated with Pam3CSK4 (1 μg/ml) (n = 5). e Representative Western blot for activated Rac1, total Rac1 and β-actin control in RASFC following 24 h stimulation with Pam3CSK4 (1 μg/ml). f Densitometry quantification of active Rac1 in RASFC (n = 3). Data is represented as mean ± SEM, ^* p <0.05, significantly different to control. RA rheumatoid arthritis, RASFC rheumatoid arthritis synovial fibroblast cells