Fig. 2.

ALK4 and ALK5 mediate the stimulatory effect of GDF-11 on MMP2 expression in human EVT cells. A and B, HTR-8/SVneo and primary EVT cells were pretreated with vehicle control (DMSO) or 10 µM SB431542 for 1 h, and then treated with 30 ng/mL GDF-11 (G11) for 24 h. The mRNA (A) and protein (B) levels of MMP2 were examined by RT-qPCR and western blot, respectively. C and D, HTR-8/SVneo 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 30 ng/mL GDF-11 (G11) for 24 h. The ALK4, ALK5, MMP2 mRNA (C), and MMP2 protein (D) levels were examined by RT-qPCR and western blot, respectively. The results are expressed as the mean ± SEM of at least three independent experiments. Multiple comparisons were analyzed using one-way ANOVA followed by Tukey’s multiple comparison test. Values that are statistically different from one another (p < 0.05) are indicated by different letters. The values with any common letter are not significantly different