Postgestational effects of macrophage migration inhibitory factor on embryonic implantation in mice

ObjectiveTo investigate in vivo the effects of macrophage migration inhibitory factor (MIF) on endometrial receptivity and embryonic implantation.DesignA murine experimental model.SettingAnimal facilities at Research Center of Saint-François d'Assise Hospital.Animal(s)Ten-week-old B6C3F-1 female mice.Intervention(s)Intraperitoneal injections of recombinant mouse MIF or saline (control) the day after successful mating and during the peri-implantation period.Main Outcome Measure(s)Markers of uterine receptivity, including integrins and vascular endothelial growth factor (VEGF) were assessed using real-time polymerase chain reaction (PCR) and immunohistochemistry.Result(s)Quantitative real-time PCR and immunohistochemical analyses indicated that MIF induced a marked increase in alpha(v) (αv), beta3 (β3) integrin subunits and VEGF mRNA, and protein expression in the endometrium. The MIF (10 μg/mL) significantly increased the number of von Willebrand factor-stained microvessels, and a significant correlation between VEGF expression and the number of von Willebrand factor-stained vessels was observed. Moreover, a tendency for an enhanced pregnancy rate (PR) in MIF-treated mice was seen compared with controls.Conclusion(s)These findings reveal that after gestation, MIF may play an important role in endometrial receptivity and embryonic implantation.