Fig. 3

Increased STAT5B expression and phosphorylation during syncytialization of human trophoblasts. A The putative STAT5B binding sites at the ADAM12 promoter revealed by in silico analysis. TSS, transcription start site. B–E Immunohistochemical staining showed that total STAT5B and phosphorylated STAT5B were mainly localized in the syncytiotrophoblast (STB) but not the cytotrophoblast (CTB) of human placental villi at both early and term pregnancies. Total STAT5B was localized in both cytoplasm and nucleus, while phosphorylated STAT5B was localized mainly in the nucleus of syncytiotrophoblast. Non-immune serum served as negative control (NC). Scale bars, 20 μm. F Increased STAT5B mRNA (n = 6) and protein (n = 7) abundance during syncytialization of cultured human trophoblasts. (G) Increased STAT5B phosphorylation during syncytialization of cultured human trophoblasts (n = 4). Top panels of F and G are representative immunoblots. Data are means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 vs 3 hrs