Fig. 2

ALK4 and ALK5 are involved in the GDF-11-induced downregulation of CGB expression. A and B BeWo (A) and JEG-3 (B) cells were pretreated with vehicle control (DMSO) or 10 µM SB431542 for 1 h, and then treated with 10 ng/mL GDF-11 (G11) every 24 h for 48 h. The protein levels of CGB were examined by western blot. C and D BeWo cells were transfected with 50 nM control siRNA (si-Ctrl), ALK4 siRNA (si-ALK4), or ALK5 siRNA (si-ALK5) for 48 h, and then treated with 10 ng/mL GDF-11 (G11) every 24 h for 48 h. The mRNA (C) levels of ALK4, ALK5, and CGB were examined by RT-qPCR. The protein (D) levels of CGB were examined by western blot. The results are expressed as the mean ± SEM of at least three independent experiments. The values without a common letter are significantly different (p < 0.05)