Maternal supplementation with uridine influences fatty acid and amino acid constituents of offspring in a sow-piglet model

To investigate the cumulative effects of maternal supplementation with nucleotides in the form of uridine (UR) on fatty acid and amino acid constituents of neonatal piglets, fifty-two sows in late gestation were assigned randomly into the control (CON) group (fed a basal diet) or UR group (fed a basal diet with 150 g/t UR). Samples of neonates were collected during farrowing. Results showed that supplementing with UR in sows' diet significantly decreased the birth mortality of pigs (P = 0.05), and increased serum total cholesterol, HDL and LDL of neonatal piglets (P < 0.05). Moreover, the amino acid profile of serum and liver of neonatal piglets was affected by the addition of UR in sows' diets (P < 0.05). Furthermore, an up-regulation of mRNA expression of energy metabolism-related genes, including fatty acid elongase 5, fatty acid desaturase 1, hormone-sensitive lipase and cholesterol-7a-hydroxylase, was observed in the liver of neonates from the UR group. Additionally, a decrease in placental gene expression of excitatory amino acid transporters 2, excitatory amino acid transporter 3 and neutral AA transporter 1 in the UR group was concurrently observed (P < 0.05), and higher protein expression of phosphorylated protein kinase B, raptor, PPAR alpha and PPAR gamma in placenta from the UR group was also observed (P < 0.05). Together, these results showed that maternal UR supplementation could regulate placental nutrient transport, largely in response to an alteration of mTORC1-PPAR signalling, thus regulating the nutrition metabolism of neonatal piglets and improving reproductive performance.