Omics & gene networks

Gene Co-Expression Networks Reveal Diet-Dependent Cytokine Interactions in Pig Brain Tissue

---

Abstract

Pigs share important anatomical and physiological similarities with humans and represent a relevant translational model for investigating the effects of dietary lipids and inflammation on brain molecular pathways. This study aimed to evaluate brain gene co-expression networks and their associations with circulating cytokines in pigs fed diets differing in lipid source. Fifty-four pigs derived from three genetically distant purebred Large White sires and 32 dams were used, with inbreeding maintained below 14%. Animals were fed corn-soybean meal-based diets supplemented with 3% soybean oil (SO), 3% canola oil (CO), or 3% fish oil (FO) for 98 days. At the end of the trial, frontal lobe samples were collected, immediately frozen in liquid nitrogen, and stored at −80 °C. Total RNA was extracted, and mRNA sequencing was performed following standard protocols. Sequencing quality was assessed using FastQC, adapter trimming was conducted with TrimGalore, and reads were aligned and quantified using Bowtie2 and RSEM against the Sus scrofa 11.1 reference genome. Gene expression data from all animals were used to construct weighted gene co-expression networks using weighted gene co-expression network analysis (WGCNA). Circulating cytokines (IL-10, IFN-γ, IL-1β, IL-6, IL-18, and TNF-α) were quantified in serum by multiplex ELISA. Cytokine concentrations were adjusted for sire as a fixed effect and correlated with gene co-expression modules within each dietary treatment. Although no statistically significant differences were observed in serum cytokine concentrations among diets, significant module-trait associations were identified (|r| ≥ 0.50; p < 0.05). In pigs fed the CO diet, the Darkolivegreen module (176 genes) showed a strong positive correlation with TNF-α (r = 0.79). The hub gene of this module was VIPR2 (vasoactive intestinal peptide receptor 2), and functional enrichment analysis revealed overrepresentation of pathways related to cell surface receptor signaling (FDR < 0.05). In contrast, under the FO diet, the Darkorange module (194 genes) was negatively correlated with TNF-α (r = −0.61), with RPLP0 (ribosomal protein lateral stalk subunit P0) identified as the hub gene. This module was enriched for Gene Ontology terms associated with translation, gene expression, and ribosomal structure (FDR < 0.05). The positive co-expression between VIPR2 and TNF-α observed in the CO diet suggests a potential interaction between dietary lipid composition, inflammatory signaling, and receptor-mediated pathways in the brain. Given previous associations of VIPR2 alterations with neuropsychiatric disorders, these findings merit further investigation. Conversely, the negative association between RPLP0 and TNF-α under the FO diet may reflect a stable, housekeeping-related expression pattern rather than an inflammatory response. Overall, the results indicate that dietary fat sources can modulate brain gene co-expression patterns linked to inflammatory signaling, even in the absence of detectable differences in circulating cytokine levels, highlighting diet-dependent molecular responses in nervous tissue.

Keywords: 2026

How to Cite:

Ciconello, F., da Silva, B., Gomes, J., Fanalli, S. & Cesar, A., (2026) “Gene Co-Expression Networks Reveal Diet-Dependent Cytokine Interactions in Pig Brain Tissue”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286069. doi: https://doi.org/10.31274/wcgalp.23845

Rights: 1