Transcriptome Analysis of Intestinal Dysfunction in Newborn Piglets with Intrauterine Growth Restriction and Improve their Performance by Dimethylglycine Sodium Salt Supplementation after Weaning

Abstract Background Few studies are available on the mechanism of intestinal dysfunction in newborn piglets with intrauterine growth restriction (IUGR). This work aimed to study the mechanism of jejunum dysfunction in IUGR newborn piglets through RNA-seq and improve their performance by dimethylglycine sodium salt (DMG-Na) supplementation after weaning. Methods In total, 13 normal birth weight (NBW) newborn piglets and 23 IUGR newborn piglets were obtained. Among them, 3 NBW and 3 IUGR newborn piglets were selected and stunned by electric shock after birth without suckling and collected the jejunum samples for RNA-sEq. After weaning at 21 days, they were randomly assigned to 3 groups (n = 10): NBW weaned piglets fed with common basal diets (N); IUGR weaned piglets fed with common basal diets (I); IUGR weaned piglets fed with common basal diets plus 0.1% DMG-Na (ID). All piglets are slaughtered at 49 days of age to collect serum and jejunum samples. Results The hub genes, including ATP8, C11orf86, CDKN1C, DDX58. HPX, INHBB, LECT2, ND1, NFIX, PRDM5, PSD3, SCD, and ZNF770, were found from the data analyzed by RNA-seq and WGCNA. Interestingly, we found ATP8 was the most significantly changed gene, which was crucial in maintaining mitochondrial function. After weaning, the growth performance of ID group was improved (P < 0.05) compared to that in I group. Jejunum histological morphology and its sub-organelle ultrastructure, serum immunoglobulin, jejunum sIgA level, and jejunum digestive enzyme activity were improved (P < 0.05) in ID group compared to those in I group. The redox status of serum, jejunum and its mitochondrial, as well as jejunum redox status-related and mitochondrial function-related gene expression level and protein content were improved (P < 0.05) in ID group in comparison to those in I group. Conclusion The activity of the SIRT1/PGC1α pathway was inhibited in the IUGR weaned piglets, which in turn leads to damage to their redox status and jejunum structure and function, and finally lowers their performance. The IUGR weaned piglets activate the SIRT1/PGC1α pathway by taking in the antioxidant substance like DMG-Na, thereby improving their unfavorable body state.