Fig. 4

E2 stimulation induces the expression of myogenic marker in female smooth muscle progenitor cells (pSMCs) (a, b). Expression levels of SMC-specific genes were analyzed by quantitative real-time RT-PCR in male and female pSMCs. E2 promoted the gene expression of myogenic markers, including SM22, smoothelin, and/or α-SMA in female H9-pSMCs and HuF5-pSMCs (*p < 0.05 vs untreated cells), but not in male H1-pSMCs and HuF1-pSMCs. Student’s t test indicates significantly lower smoothelin expression at baseline (no estrogen stimulation) in female compared to male cell lines (^# p < 0.05, ^## p < 0.01). Estrogen stimulation data analyzed by one-way and two-way ANOVA followed by Tukey post-hoc test. Data shown represent the mean ± SD from three independent experiments, each performed in duplicate. F female, M male, SMA smooth muscle actin