文摘
We analyzed embryo鈥搈aternal interactions in the bovine uterus on day 8 of development. Proteomic profiles were obtained by two-dimensional difference gel electrophoresis from 8 paired samples of uterine fluid (UF) from the same animal with and without embryos in the uterus. Results were contrasted with UF obtained after artificial insemination. We detected 50 differential protein spots (t test, p < 0.05). Subsequent protein characterization by nano-LC鈥揈SI鈥揗S/MS enabled us to identify 38 proteins, obtaining for first time the earliest evidence of involvement of the down-regulated NFkB system in cattle as a pregnancy signature pathway. Embryos enhanced the embryotrophic ability of UF and decreased uterine protein, while blood progesterone was unaltered. Twinfilin, hepatoma-derived growth factor, and synaptotagmin-binding cytoplasmic RNA interacting protein have not previously been identified in the mammalian uterus. TNF伪 and IL-1B were localized to embryos by immunocytochemistry, and other proteins were validated by Western blot in UF. Glycosylated-TNF伪, IL-1B, insulin, lactotransferrin, nonphosphorylated-peroxiredoxin, albumin, purine nucleoside phosphorylase, HSPA5, and NFkB were down-regulated, while phosphorylated-peroxiredoxin, annexin A4, and nonglycosylated-TNF伪 were up-regulated. The embryonic signaling agents involved could be TNF伪 and IL-1B, either alone or in a collective dialogue with other proteins. Such molecules might explain the immune privilege during early bovine development.
Keywords:
bovine; embryo; uterus; development; NFkB; TNF; Interleukin-1Beta