BMP6 upregulates the expression of CTGF in hGL cells. A and B, SVOG cells were treated with a vehicle control or increasing concentrations (5, 20, or 100 ng/ml) of BMP6 for 3 h (A) or 6 h (B), and the mRNA (A) and protein (B) levels of CTGF were examined using RT-qPCR and western blotting, respectively. C and D, SVOG cells were treated with vehicle control or 30 ng/ml of BMP6 for 1, 3, 6, 12, or 24 h, and the mRNA (C) and protein (D) levels of CTGF were examined using RT-qPCR and western blotting, respectively. E and F, Primary hGL cells were treated with a vehicle control or increasing concentrations (5, 20, or 100 ng/ml) of BMP6 for 3 h (E) or 6 h (F), and the mRNA (E) and protein (F) levels of CTGF were examined using RT-qPCR and Western blot, respectively. The results are expressed as the mean ± SEM of at least three independent experiments. Values marked by different letters are significantly different (P < 0.05). B6, BMP6; Ctrl, control; hGL, primary human granulosa lutein.