Figure 2.

Analysis of the signaling pathways mediated by rBMP-2/Fc in synovial cells. (A) Analysis of the association between BMP-2 and NF-κB expression in synovial cells as determined by luciferase activity. (B) The viability of synovial cells following incubation with rBMP-2/Fc (10 mg/ml), BMP-2 (2 mg/ml) or PBS for different time periods as determined by the refractive index. (C) The growth rate of synovial cells following treatment with PBS, DEX or rBMP-2/Fc for 24, 48 and 72 has determined by an MTT assay. (D) The effects of rBMP-2/Fc on the apoptosis of synovial cells as determined by flow cytometry. Western blot analysis was performed to determine the protein expression levels of (E) NF-κB, (F) p65, IKK-β and IκBα in synovial cells following treatment with BMP-2R or rBMP-2/Fc. The protein expression of (G) ALP, Runx2, osterix and osteocalcin, and (H) pSmad-1, pSmad-5 and pSmad-8 in Saos-2 cells was determined via western blot analysis.*P<0.05, **P<0.01. BMP-2, bone morphogenetic protein-2; rBMP, recombinant bone morphogenetic protein; Fc, Fc fragment; BMP-2R, bone morphogenetic protein-2 receptor; NF, nuclear factor; IKK-β, inhibitor of NF-κB kinase-β; IκBα, NF-κB inhibitor-α; ALP, alkaline phosphatase; Runx2, runt-related transcription factor 2; p, phosphorylated; DEX, dexamethasone.