Maternal Supplementation of Dietary Choline and Docosahexaenoic Acid during Gestational Nutrition Restriction Alters Hepatic mRNA and miRNA Expression Patterns in Full-Term Fetal Pigs.

Background: Supplementing choline and docosahexaenoic acid (DHA) to pregnant gilts modified fetal pig hepatic global DNA methylation induced by gestational malnutrition, suggesting that gene expression and regulation and its associated metabolic pathways are affected in the liver of offspring during growth and development.

Objective: To investigate the effect of maternal supplementation of choline, DHA and their interaction on hepatic mRNA expression, miRNA regulation and metabolic pathways in the fetal pigs born to malnourished mothers.

Methods: The abundance of mRNA and miRNA was profiled in fetal liver from sows with undernutrition supplemented with choline and DHA in a 2 × 2 factorial design. The effects of choline, DHA, and their interaction on mRNA and miRNA expression were evaluated. Identification of the Biological Processes from the Gene Ontology database and miRNA Target Prediction Analysis were performed using the DAVID Functional Annotation Tool and Ingenuity Pathway Analysis. The identified miRNA-mRNA pairings were validated using RT-qPCR.

Results: 144 mRNA and 1 miRNA were altered by supplementation of choline and the alterations were associated with the inhibitions of cardiac hypertrophy signaling, IL-6 signaling, IL-3 signaling, the Th1 pathway, and the acute phase response signaling pathway. 151 mRNAs and 6 miRNAs were altered by maternal supplementation DHA and were associated with inhibition of 5 inositol-related pathways, 5 immune-related pathways, and 7 other pathways and the stimulation of PPAR signaling and RhoGDI signaling pathways. 383 mRNAs and 25 miRNAs displayed choline x DHA interactions including synergistic effects on acute phase response signaling, and antagonistic effects on tRNA splicing, PPARα/RXRα activation, and sirtuin signaling, NAD signaling and RNA polymerase I transcription pathways. 10 of the identified 20 miRNA-mRNA pairings were validated using RT-qPCR.

Conclusions: We identified and confirmed that supplementation of choline, DHA or choline plus DHA to pregnant gilts modifies liver mRNA, miRNA, and pathways in fetal pigs during gestational undernutrition.