Analysis of novel embryonic factors of cattle and effects on endometrial cells in vitro.

Interferon tau (IFNT) is thought to have essential functions in maternal recognition and establishment of pregnancy in ruminants. There, however, is a lack of research on embryonic factors that affect pregnancy other than IFNT. The present study was conducted to determine what are other embryo-derived factors involved in pregnancy recognition and to identify effects on endometrial cells using an in vitro culture system. With use of LC-MS/MS procedures to evaluate the supernatant of elongating embryos of cattle in culture, there was detection of 78 secretary proteins including five cytokines and two growth factors. Then there was analysis for up-regulated genes using ingenuity pathway procedure, IFNT and MIF were identified as upstream regulators of 37 and five genes, respectively. The mRNA transcript of MIF receptors was identified in endometrial cells, however, not in embryos. Among genes induced by MIF, CCL2, IL7 and IL23A transcripts were identified in endometrial cells. When endometrial cells were treated with interferon alpha (IFNA) and MIF, the CCL2 transcript was in a larger abundance of endometrial epithelial and polymorphonuclear neutrophil cells, and there was a larger abundance of there mRNA transcripts as a result of MIF treatment of peripheral blood mononuclear cells. In conclusion, MIF secreted by elongating embryos of cattle synergistically regulates relative abundances of specific mRNA transcripts of endometrial cells when there is treatment with IFNA, indicating further there are several factors other than IFNT that have effects on gene expression in the endometrium during early stages of gestation in cattle.