Fig. 1

Down-regulated BMP9 expression in the knee synovial tissue from patients with RA. The levels of BMP9 in the synovial tissue from patients with either OA or RA were determined by immunohistochemistry, Western blot, and RT-PCR. Data are representative images or expressed as the mean ± SD of each group from three separate experiments (n = 3 per group). A Representative images of immunohistochemistry (magnification ×100) show more inflammatory hyperplasia in RA synovial tissue, with a lower expression of BMP9 compared to OA. B, C Western blot. D RT-PCR. *p < 0.05 vs. the OA group. **p < 0.01 vs. the OA group