TGase-mediated induction of matrix degradation is modulated by TGF-β in FLSs. (A-C) C-FLSs were transfected with TG2 or empty vector. (A) Immunoblot analysis using anti-LAP antibody in cell lysates. Densitometric measurements of LAP-to-actin ratios are shown (n = 11). (B) Cells were deposited on a gelatin matrix and incubated with control (Ctl)-IgG or anti-TGF-β antibodies. After 24 hours, the percentage of invadopodia-forming cells was counted (n = 4). (C) Cells were deposited on a gelatin matrix and incubated for 24 hours with LY-364947 (50 nM to 500 nM), and the percentage of invadopodia-forming cells was counted (n = 4). (D, E) Arthritic FLSs were transfected with control- or TG2-shRNA-expressing lentivirus. (D) Total TGF-β was measured with ELISA (n = 4). (E) shRNA-expressing cells were transiently transfected with p3TP-LuX, and luciferase assays were performed (n = 4). Values are expressed as the mean ± SEM (*P < 0.05; ***P < 0.001).
Lauzier et al. Arthritis Research & Therapy 2012 14:R159 doi:10.1186/ar3899