Effects of flaxseed supplementation on endometrial expression of ISG17 and intrauterine prostaglandin concentrations in primiparous dairy cows submitted to GnRH-based synchronized ovulation

Effects of differentn-6:n-3 fatty acid ratios and of enterolactone on gene expression and PG secretion in bovine endometrial cells

Feeding flaxseed to dairy cows can modulate gene expression and PG synthesis in the uterus at the time of peri-implantation. The objectives of the present study were to determine which flaxseed components are responsible for these effects and how different endometrial cell types are affected. We evaluated the effects of six different linoleic acid (n-6):α-linolenic acid (n-3) ratios and three concentrations of the lignan enterolactone (ENL) on endometrial stromal cells (SC) and epithelial cells (EC). The mRNA abundance of genes with known or suspected roles in embryo survival or PG synthesis was evaluated, along with PGE2and PGF2αconcentrations in culture media. The mRNA abundance of several genes was modulated by different fatty acid (FA) ratios and/or ENL, and this modulation differed between cell types. The FA4 (FA at ann-6:n-3 ratio of 4) treatment (rich inn-3 FA) increased the mRNA abundance of genes that have positive effects on uterine receptivity and implantation when compared with the FA25 (FA at ann-6:n-3 ratio of 25) treatment (rich inn-6 FA). ENL decreased PGE2and PGF2αconcentrations in both cell types, and this reduction was associated with lower mRNA abundance of the PG synthase genesAKR1B1andPTGESin SC. The combination of ENL with FA (FA4 treatment) resulted in the greatest reduction in PGF2αconcentrations when compared with the addition of FA (FA4) or ENL alone. Because of the known luteolytic properties of PGF2α, a reduction in endometrial PGF2αsecretion would favour the establishment and maintenance of pregnancy.