Lipoxin A4: The double-edge sword in mice pregnancy.

PROBLEM: To evaluate the role for LXA4 in the pregnancy. METHOD OF STUDY: We detected the changes of LXA4 and LXA4 biosynthetic enzymes in the mice's pregnancy, blocked LXA4 signaling pathway, managed LXA4 level, and treated LPS-induced mouse abortion model to systematically determine how LXA4 impact pregnancy. RESULTS: The concentrations of LXA4 in serum and uterus were lowest on Days 4.5 of pregnancy and in labor as compared to Day 12.5 of pregnancy (270.2 ± 33.2, 277.5 ± 23.7 versus 457.1 ± 40.9 pg/mL). Inhibition of the LXA4 signaling pathway did not affect pregnancy during the peri-implantation period of pregnancy, but induced abortion when administered after implantation of blastocysts. High levels of LXA4 interfered with implantation, but protected mice from aborting in response to LPS. CONCLUSION: LXA4 might be involved in the process of pregnancy, and LXA4 might act as the double-edge sword in pregnancy: the anti-implantation effect in the stage of peri-implantation and the anti-abortion affect after blastocyst implantation.