Expression of Serpine2 mRNA and protein in the mouse uterus during pregnancy. (A) A real-time PCR analysis was conducted to quantitate the Serpine2 gene's expression levels at various pregnancy stages. The relative levels of mRNA were normalized to Hprt mRNA levels. Data are presented as the mean ± standard deviation (SD) from four independent experiments. a Significant difference compared to other Serpin mRNA levels (p < 0.05). (B) SERPINE2 protein expression in the uterus was examined at various pregnancy stages. Forty-five micrograms of total protein prepared from various days of a pregnant uterus was analyzed by Western blotting. The arrowhead indicates a possible protein complex of SERPINE2 and a certain protease. Arrows indicate the isoform proteins of SERPINE2. The α-tubulin protein level is shown as the loading control.