LPS Administration during Fertilization Affects Epigenetic Inheritance during Embryonic Development

SIMPLE SUMMARY: The long-term effect of exposure to lipopolysaccharide (LPS) endotoxins during fertilization in mammals has not been clarified. In this study, we examined the influence of LPS on early embryonic development and fetal development in mice. The uteruses of mice were examined for the expression of genes related to the inflammatory response. The expression of Il-1β and Il-6 increased following the administration of 200 and 1000 µg/kg LPS. Exposure to LPS during in vitro fertilization (IVF) significantly decreased the embryonic developmental rate. A concentration of 100 µg/kg LPS significantly increased the placental weight and fetal crown–rump length (CRL), whereas a concentration of 200 µg/kg LPS significantly decreased the placenta weight and fetal weight in vivo at 18.5 days post-coitus (dpc). In summary, this study demonstrated that LPS exposure during fertilization causes abnormal embryonic phenotypes and fetal development in mice. Maternal endotoxins may affect epigenetic inheritance in embryonic development from the early to late stages of pregnancy. ABSTRACT: Intrauterine inflammation can cause infertility by disrupting reproductive function. The pathogenesis underlying this process may primarily involve endotoxins from lipopolysaccharides (LPS), which are produced by Gram-negative bacteria. However, the long-term effects of endotoxins in mammalian pregnancy following LPS exposure during fertilization have not been clarified. In this study, we performed experiments to analyze the influence of LPS on early embryonic development and fetal development in mice. Mice uteruses were examined for the expression of genes related to the inflammatory response. The expression of Il-1β and Il-6 increased following the administration of 200 and 1000 µg/kg LPS. Exposure to LPS using in vitro fertilization (IVF) significantly decreased the embryonic developmental rate. A concentration of 100 µg/kg LPS significantly increased the placental weight and fetal crown –rump length (CRL), whereas a concentration of 200 µg/kg LPS significantly decreased the placenta weight and fetal weight in vivo. These findings indicate that maternal LPS during fertilization affects fetal development until the late stage of pregnancy. Thus, maternal endotoxins may affect epigenetic inheritance during embryonic development from the early to late stages of pregnancy.