Elevated maternal linoleic acid alters placental fatty acids, nutrient transporters and inflammatory proteins

Abstract

Linoleic acid (LA) is the major omega‐6 fatty acid which is obtained from our diet. During pregnancy, LA is required for adequate fetal growth and development. For the growing fetus LA can only be obtained from the maternal diet, and is transferred from the maternal to fetal circulations by the placenta. At this time, in Western societies, we are overconsuming LA during pregnancy. Omega‐6 is metabolised by FADS1 and FADS2, which also metabiolise omega‐3. The ratio of omega‐6 to omega‐3 is important for human health, as they are proinflammatory and anti‐inflammatory, respectively. Therefore, the aim of this study is to determine if elevated maternal LA during pregnancy is alters placental fatty acids, nutrient transporter gene expression and inflammatory proteins.

Female Wistar Kyoto rats were fed a diet low in LA (LLA‐1.44% of energy) or diet high in LA (HLA‐6.21% of energy) for 10 weeks before and during gestation. Following mating with a male consuming normal chow, offspring and maternal rats were sacrificed at embryonic day (E)20, and placenta were collected for analysis of placental fatty acids, nutrient transporters and inflammatory markers.

In isolated placenta from pregnancies where mothers consumed an elevated LA diet, the concentration of LA was increased and the concentration of the omega‐3 fatty acid a‐linoleinic acid was decreased. Of interest, the downstream metabolite of LA, arachidonic acid was not altered in placenta from mothers consuming an elevated LA diet. mRNA expression of slc27a1 (fatty acid trasnport protein 1) was significantly downregulated in the male placenta from the dams fed with HLA, but not females. The mRNA expression of slc2a1 (glucose trasnporter 1) was significantly decreased in both male and female placenta from mothers fed the HLA diet. Further, the protein concentration of interleukin‐7 (IL‐7) was significantly decreased in both male and female placenta (labyrinth) from the dams fed with HLA, however there were no changes in protein expression of IL‐6 and TNF‐α in the labyrinth.

In conclusion, a maternal diet high in LA alters fatty acid concentrations, nutrient transporters and inflammatory cytokines in the placenta. The consequences of this on offspring development, and therefore long term health require further investigation.