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Polyunsaturated fatty acids (PUFA), such as omega-6 (n-6) and omega-3 (n-3), play a vital role in nutrient metabolism, inflammatory response, and gene regulation. microRNAs (miRNA), which can potentially degrade targeted messenger RNAs (mRNA) and/or inhibit their translation, might play a relevant role in PUFA-related changes in gene expression. Although differential expression analyses can provide a comprehensive picture of gene expression variation, they are unable to disentangle when in the mRNA life cycle the regulation of expression is taking place, including any putative functional miRNA-driven repression. To capture this, we used an exon–intron split analysis (EISA) approach to account for posttranscriptional changes in response to extreme values of n-6/n-3 PUFA ratio. Longissimus dorsi muscle samples of male and female piglets from sows fed with n-6/n-3 PUFA ratio of 13:1 (SOY) or 4:1 (LIN), were analyzed in a bidirectional contrast (LIN vs. SOY, SOY vs. LIN). Our results allowed the identification of genes showing strong posttranscriptional downregulation signals putatively targeted by significantly upregulated miRNA. Moreover, we identified genes primarily involved in the regulation of lipid-related metabolism and immune response, which may be associated with the pro- and anti-inflammatory functions of the n-6 and n-3 PUFA, respectively. EISA allowed us to uncover regulatory networks complementing canonical differential expression analyses, thus providing a more comprehensive view of muscle metabolic changes in response to PUFA concentration.

Polyunsaturated fatty acids (PUFA), such as omega-6 (n-6) and omega-3 (n-3), play a vital role in nutrient metabolism, inflammatory response, and gene regulation. microRNAs (miRNA), which can potentially degrade targeted messenger RNAs (mRNA) and/or inhibit their translation, might play a relevant role in PUFA-related changes in gene expression. Although differential expression analyses can provide a comprehensive picture of gene expression variation, they are unable to disentangle when in the mRNA life cycle the regulation of expression is taking place, including any putative functional miRNA-driven repression. To capture this, we used an exon-intron split analysis (EISA) approach to account for posttranscriptional changes in response to extreme values of n-6/n-3 PUFA ratio. Longissimus dorsi muscle samples of male and female piglets from sows fed with n-6/n-3 PUFA ratio of 13:1 (SOY) or 4:1 (LIN), were analyzed in a bidirectional contrast (LIN vs. SOY, SOY vs. LIN). Our results allowed the identification of genes showing strong posttranscriptional downregulation signals putatively targeted by significantly upregulated miRNA. Moreover, we identified genes primarily involved in the regulation of lipid-related metabolism and immune response, which may be associated with the pro- and anti-inflammatory functions of the n-6 and n-3 PUFA, respectively. EISA allowed us to uncover regulatory networks complementing canonical differential expression analyses, thus providing a more comprehensive view of muscle metabolic changes in response to PUFA concentration.

Elevated omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) ratios in swine diets can potentially impose a higher risk of inflammatory and metabolic diseases in swine. A low ratio between the two omega PUFAs has beneficial effects on sows’ and piglets’ production performance and immunity status. At present, there are few studies on how sow nutrition directly affects the protein and fat deposition in suckling piglets. Two groups of sows were fed diets with high or low n-6/n-3 polyunsaturated ratios of 13:1 (SOY) and 4:1 (LIN), respectively, during gestation and lactation. Longissimus dorsi muscle and adipose tissue from newborn piglets, nourished only with sow’s milk, were subjected to fatty acid profiling by gas chromatography–mass spectrometry (GC-MS) and to proteomics assays based on nano-liquid chromatography coupled to high-resolution tandem mass spectrometry (nLC-HRMS). Fatty acid profiles on both muscle and adipose tissues resembled the magnitude of the differences between fatty acid across diets. Proteomic analysis revealed overabundance of 4 muscle and 11 adipose tissue proteins in SOY compared to LIN in both piglet tissues. The detected overabundance of haptoglobin, an acute-phase protein, and the stimulation of protein-coding genes and proteins related to the innate immune response and acute inflammatory response could be associated with the pro-inflammatory role of n-6 PUFAs.

The aim of this study was to assess the effect of nucleotides administration on growth performance and immune response in post-weaning piglets. Twenty-eight male weaned piglets, homogeneous for age and weight were randomly allocated to two experimental treatments. Treated group (T) was daily orally administered 0.8 g/head of a mixture of nucleotides suspended in 2.1 mL water solution; while control group (C) received 2.1 mL saline solution. Body weight (BW) and average daily gain (ADG) were individually recorded weekly, while feed intake (FI), and gain:feed (G:F) were recorded and calculated on pen basis. Faecal score was evaluated every seven days. On day 0, 9, 18 and 27 blood samples were collected to determine IgA, IgG and haptoglobin concentration. At day 28 all piglets were sacrificed, and tissue samples of ileal Peyer’s patches were collected for the evaluation of IL1α, IL1β, IL6, IL10, TNFα, TLR2, TLR4 and PPARγ gene expression. Nucleotides supplementation significantly increased BW (17.37 vs. 19.00 kg/pig; p = <.01), ADG (.351 vs.400 kg/d; p <.01), and FI (3.96 vs. 4.39 kg/d; p <.01), but not G:F (.61 vs.64; p =.29). Faecal consistency was not different between the experimental groups and no occurrence of diarrhoea was reported. IgA and IgG content in blood was not influenced by the treatment, as well as gene expression of inflammatory cytokines in Peyer’s patches. The present trial shows that nucleotide administration is able to improve growth performance of post-weaning piglets, with no effects on inflammatory response and the expression of immune-related genes. Highlights Nucleotides administration increased BW, ADG and FI. Nucleotides did not affect inflammatory and immune response.