Expression and regulation of HER1 in St-T1b cells and hESCs.

(A) Effect of decidualization on HER1 expression. Whole cell extracts from two individual hESC preparations or from St-T1b cells, non-decidualized (−) or decidualized (+), were immunoblotted for HER1 (antibody from New England Biolabs), and for GAPDH as a loading control. In addition, the levels of Nur77, α-SMA, MLC2 and phospho-MLC2 were analyzed. (B, C, D) Time-dependent downregulation of HER1 in response to HB-EGF or TCM. Non-decidualized (ND) or decidualized (D) St-T1b cells, maintained in Opti-MEM, were incubated with PDGF-BB, HB-EGF or TCM (20 or 100%) for 5 min (B) or 5, 30 and 60 min (C) and subjected to Western Blot analysis for HER1 (antibody from Santa Cruz). Decidualized St-T1b cells were stimulated with HB-EGF or TCM (100%) for 5, 30 and 60 min or 24 h (D) and analyzed for HER1 by Western blotting (antibody from Santa Cruz), followed by immunoblotting for phospho-ERK1/2 and phosphorylated (Ser473) and total Akt.