Fig. 4

Activation of the ERK1/2 signaling pathway is required for TGF-β1-induced kisspeptin expression in human EVT cells. A HTR-8/SVneo cells were treated with 5 ng/mL TGF-β1 or 100 ng/mL EGF for 10 min. The levels of phosphorylated and total forms of ERK1/2 and AKT were determined by western blot. B and C HTR-8/SVneo cells were pretreated with vehicle control (DMSO), 5 μM U0126 or 5 μM LY294002 for 1 h, and then treated with 5 ng/mL TGF-β1 (T) for 24 h. The kisspeptin mRNA levels (B) and protein levels (C) were examined by RT-qPCR and western blot, respectively. D Primary cultures of human EVT cells were pretreated with vehicle control (DMSO), 10 μM SB431542 or 5 μM U0126 for 1 h, and then treated with 5 ng/mL TGF-β1 (T) for 24 h. The kisspeptin protein levels were examined by western blot. The results are expressed as the mean ± SEM of at least three independent experiments. Values that are statistically different from one another (p < 0.05) are indicated by different letters