Effects of maternal dietary omega-3 polyunsaturated fatty acids and methionine during late gestation on fetal growth, DNA methylation, and mRNA relative expression of genes associated with the inflammatory response, lipid metabolism and DNA methylation in placenta and offspring’s liver in sheep

Abstract

Background Omega-3 PUFA or methionine (Met) supply during gestation alters offspring physiology. However, the effect of both nutrients on fetal development has not been explored. Our objective was to determine the effects of supplementation of these two nutrients during late gestation on fetal growth, DNA methylation, and mRNA expression of genes associated with the inflammatory response, and DNA methylation. Ewes (n = 5/treatment) were fed from day 100 to 145 of gestation one of the following treatments: 1) basal diet (NS) without fatty acids (FS) or methionine (MS) supplementation; 2) FS (10 g/kg Ca salts, source omega-3 PUFA); 3) MS (1 g/kg rumen protected methionine); and 4) FS and MS (FS-MS). On day 145, ewes were euthanized, and data from dams and fetus was recorded. Placenta (cotyledon), fetal liver, and blood samples were collected. Results A treatments interaction on fetal liver weight, ewe body weight and body condition score (BCS) was observed; FS-MS were heavier (P < 0.01) than FS and MS, and FS-MS ewes had a better (P = 0.02) BCS than NS. Methionine increased (P = 0.03) ewe plasma glucose concentration. Fetal liver global DNA methylation increased (P < 0.01) in FS and MS. Dietary treatments modify the mRNA relative expression on some of the genes evaluated. In the fetal liver, FS increased (P = 0.04) the mRNA relative expression of arachidonate-5-lipoxygenase-activating-protein and tended to decrease (P = 0.06) methionine-adenosyltransferase-1A. Moreover, MS decreased (P = 0.04) DNA-methyltransferase-1 and tended to decrease (P = 0.08) free-fatty-acid-receptor-1 mRNA relative expression. Furthermore, FS-MS decreased mRNA relative expression of tumor-necrosis-factor-alpha (P = 0.05), peroxisome-proliferator-activated-receptor-delta (P = 0.03) and gamma (P = 0.04), tended to decrease (P ≤ 0.09) interleukin-6, fatty-acid-transport-protein-1, and delta-5-desaturase, and increased adenosylhomocysteinase (P = 0.04) mRNA relative expression. In cotyledon, FS tended to decrease fatty acid binding protein 4 (P = 0.09) mRNA relative expression. Conclusion Omega-3 PUFA and Met supplementation improves dam’s performance in late gestation, which was positively correlated with an increase in offspring’s liver development. Moreover, FS-MS decreased mRNA relative expression of proinflammatory cytokines, and lipogenic genes, and increased the expression on an enzyme that has an important role in methylation.

Role of Long Chain Fatty Acids in Developmental Programming in Ruminants

“…The last third of gestation is when the increase of LC-PUFA in the fetal circulation occurs; thus, an increase in maternal dietary supply during late gestation might have a direct effect in intrauterine growth and fetal development affecting offspring subsequent development and welfare [ 68 ]. Previous research has demonstrated the beneficial effects of supplementing a source of LC-PUFA during the last third of gestation in fetal development, energy metabolism, mRNA expression, global DNA methylation, and inflammatory response, as well as in offspring growth [ 69 ], energy metabolism [ 8 , 10 , 11 , 65 , 70 ], carcass characteristics [ 70 , 71 ], and in the long-term effects in the performance of the offspring [ 69 ] ( Table 1 ). Therefore, in utero changes with subsequent possible lasting effects in metabolism and performance of the offspring, by altering maternal diet in late gestation, can be a management practice to enhance animal health and productivity of food producing animals.…”

“…Regarding the effects of the addition of PUFA in the diet of the dam during the last third of gestation on the development of the progeny, an increase in growth has been reported in the postnatal period in different ruminant models [ 8 , 69 , 70 ]. Rosa-Velázquez et al [ 10 ] did not report differences in fetal weight when ewes were supplemented with a source of n-3 PUFA during late gestation. In sheep, lambs born to ewes fed n-3 PUFA during the last third of gestation showed an increase in body weight at birth [ 7 ] and during the finishing period [ 7 , 8 , 10 ] ( Table 1 ).…”

“…Rosa-Velázquez et al [ 10 ] did not report differences in fetal weight when ewes were supplemented with a source of n-3 PUFA during late gestation. In sheep, lambs born to ewes fed n-3 PUFA during the last third of gestation showed an increase in body weight at birth [ 7 ] and during the finishing period [ 7 , 8 , 10 ] ( Table 1 ). Supplementation during late gestation and early lactation with a source of n-3 PUFA has also affected lamb growth during the preweaning period [ 72 , 73 ] ( Table 1 ).…”

“…Brandão et al [ 76 ] noted that the reason for the treatment by sex interaction on average daily gain reported in their study was unclear, since steers and heifers were equally managed as a single group in the feed yard. In sheep, a study conducted in our lab [ 10 ] also reported a dam treatment by offspring sex. Ewe lambs born to MUFA supplemented dams were heavier than wethers born to MUFA dams, while wethers born to n-3 PUFA supplemented dams were heavier than ewe lambs born to n-3 PUFA supplemented dams at 60 days of age.…”

“…Fatty acids have multiple functions in the body, but, in this review, we will focus on the developmental programming effect of FA in ruminants, considering the effect of FA supplementation on imprinting during gametogenesis, embryo, fetal, and postnatal development. Current research has demonstrated beneficial effects of polyunsaturated FA supplementation, especially n-3 FA, during pregnancy in ruminants [5][6][7][8][9][10][11][12].…”