Fig. 1.
Notch ligand-specific induction of regulatory contractile gene expression. A: wild-type primary mouse aortic smooth muscle cells (SMCs) induced by Jagged1 (Fc-J1) or delta-like protein-4 (Dll4; Fc-Dll4). Relative myosin light chain kinase (MLCK) and myosin phosphatase-targeting subunit 1 (MYPT1) transcript levels are shown. Real-time quantitative PCR data were normalized to control (Fc) treatment and represent means ± SE (n = 7 for MLCK; n = 5 for MYPT1). Data were analyzed using a t-test, *P < 0.001. B: immunoblots showing Jagged1 induction of MLCK, phosphorylated myosin light chain (p-MLC), and p-Thr696/853 MYPT1 in contrast to Dll4 induction of MYPT1. T-MLC, total myosin light chain. C: densitometric quantitation of representative immunoblots in B. Data were normalized to Fc treatment and represent means ± SE (n = 5). Data were analyzed using a one-way ANOVA with Tukey’s post hoc test, *P < 0.001 and **P < 0.01 (Dll4 vs. J1). p-MLC/T-MLC, p-MLC-to-total MLC ratio. D: Hairy/enhancer-of-split related with YRPW motif protein (HEY) target gene expression in Jagged1- and Dll4-stimulated wild-type primary aortic SMCs. Relative to unstimulating control ligand (Fc), both Jagged1 (Fc-J1) and Dll4 (Fc-Dll4) induced HEY1 and HEY2 transcripts. Real-time quantitative PCR data were normalized to control treatment and represent means ± SE (n = 3 for HEY1; n = 4 for HEY2). Data were analyzed using a t-test, P = not significant (HEY1 vs. HEY2 per ligand stimulation).