Meat quality has a close relationship with fat and connective tissue; therefore, screening and identifying functional genes related to lipid metabolism is essential for the production of high-grade beef. The transcriptomes of the Longissimus dorsi muscle in Wagyu and Chinese Red Steppe cattle, breeds with significant differences in meat quality and intramuscular fat deposition, were analyzed using RNA-seq to screen for candidate genes associated with beef quality traits. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the 388 differentially expressed genes (DEGs) were involved in biological processes such as short-chain fatty acid metabolism, regulation of fatty acid transport and the peroxisome proliferator-activated receptor (PPAR) signaling pathway. In addition, crystallin alpha B (CRYAB), ankyrin repeat domain 2 (ANKRD2), aldehyde dehydrogenase 9 family member A1 (ALDH9A1) and enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH) were investigated for their effects on intracellular triglyceride and fatty acid content and their regulatory effects on genes in lipogenesis and fatty acid metabolism pathways. This study generated a dataset from transcriptome profiling of two cattle breeds, with differing capacities for fat-deposition in the muscle, and revealed molecular evidence that CRYAB, ANKRD2, ALDH9A1 and EHHADH are related to fat metabolism in bovine fetal fibroblasts (BFFs). The results provide potential functional genes for maker-assisted selection and molecular breeding to improve meat quality traits in beef cattle.

Delta-like non-canonical Notch ligand 1 (DLK1), which inhibits the differentiation of precursor adipocytes, is a recognized marker gene for precursor adipocytes. Lipids play a crucial role in energy storage and metabolism as a vital determinant of beef quality. In this study, we investigated the mechanism of the DLK1 gene in lipid metabolism by constructing adipose tissue-specific knockout mice. We examined some phenotypic traits, including body weight, liver coefficient, fat index, the content of triglyceride (TG) and cholesterol (CHOL) in abdominal white adipose tissue (WAT) and blood. Subsequently, the fatty acid content and genes related to lipid metabolism expression were detected in DLK1^−/− and wild-type mice via GC-MS/MS analysis and quantitative real-time PCR (qRT-PCR), respectively. The results illustrated that DLK1^−/− mice exhibited significant abdominal fat deposition compared to wild-type mice. HE staining and immunohistochemistry (IHC) results showed that the white adipocytes of DLK1^−/− mice were larger, and the protein expression level of DLK1^−/− was significantly lower. Regarding the blood biochemical parameters of female mice, DLK1^−/− mice had a strikingly higher triglyceride content (p < 0.001). The fatty acid content in DLK1^−/− mice was generally reduced. There was a significant reduction in the expression levels of the majority of genes that play a crucial role in lipid metabolism. This study reveals the molecular regulatory mechanism of fat metabolism in mice and provides a molecular basis and reference for the future application of the DLK1 gene in the breeding of beef cattle with an excellent meat quality traits. It also provides a molecular basis for unravelling the complex and subtle relationship between adipose tissue and health.

Ulcerative colitis (UC) leads to systemic complications with excessive oxidative stress, colonic barrier damage, and inflammation. Deuterohemin-AlaHisThrValGluLys (DhHP-6) is the biomimetic nanozyme rationally designed to mimic the peroxidase activity of Microperoxidase-11. It exhibits potent antioxidant properties, which might emerge as a promising therapeutic candidate compound for UC. In this paper, we aimed to probe the therapeutic effects of DhHP-6 on UC and clarify the underlying molecular mechanisms. We employed dextran sulfate sodium-induced C57BL/6 J male mice for in vivo studies. Lipopolysaccharides-induced intestinal epithelial (Caco-2) and macrophage (RAW264.7) cells were established for in vitro studies. Immunofluorescence, reactive oxygen species (ROS) assays were utilized to evaluate the therapeutic effects on UC. Mitochondrial function assessment, Western blotting analysis, luciferase reporter assays, and AlphaFold 3 studies, the mechanism by which DhHP-6 affected UC via NRF2 was explored. DhHP-6 ameliorated UC by eliminating ROS to protect the colonic barrier and immune homeostasis. It upregulated NRF2 expression, validated by the enhanced NRF2/ARE luciferase activity (p < 0.001) and NRF2 immunofluorescence. AlphaFold 3 analysis revealed the stable binding of DhHP-6 to the KEAP1 Kelch domain, which might interfere with the KEAP1-NRF2 interaction. The activation of NRF2 restored mitochondrial function, inhibited apoptosis, and attenuated inflammation. In summary, DhHP-6 exerted multi-dimensional therapeutic effects on UC, which were underpinned by the activation of the KEAP1-NRF2-ARE pathway as demonstrated through in vivo, in vitro, and in silico analyses. Therefore, DhHP-6 might be a highly promising candidate compound for the management of UC.

Lutein is a dietary xanthophyll carotenoid with recognized antioxidant and immunomodulatory potential, yet the molecular basis underlying its nutritional effects in laying hens remains insufficiently understood. Here, liver transcriptomic profiling and 16S rRNA sequencing were combined to investigate the response of laying hens to dietary lutein supplementation. A total of 951 differentially expressed genes were identified in the liver, indicating marked transcriptional remodeling after lutein supplementation. Functional enrichment, gene set enrichment, and weighted gene co-expression network analyses consistently showed that these changes were mainly associated with metabolic regulation, redox/stress adaptation, and immune-related communication. In parallel, lutein supplementation changed cecal microbial community structure and shifted specific microbial biomarkers. Integrated correlation analyses further identified candidate host–microbiota association patterns, including a KLF2/FOXO3/Faecalibacterium axis and a KLF2/IL8L2/Prevotellaceae_Ga6A1_group axis. Overall, dietary lutein was associated with coordinated changes in the hepatic transcriptional profile and cecal microbial community structure, which converged on these two functional directions. These findings provide new insight into the nutritional effects of lutein in laying hens and identify candidate pathways and microbial nodes for future functional validation in poultry feeding systems.

Skeletal muscle development is a key determinant of meat production and meat-quality traits in sheep, but the coordinated long non-coding RNA (lncRNA) and messenger RNA (mRNA) co-expression landscape underlying postnatal muscle development in Hanper sheep remains unclear. In this study, RNA sequencing was performed on Longissimus Dorsi muscle samples from Hanper sheep at 1 month (M1), 7 months (M7), and 13 months (M13) of age to characterize lncRNA and mRNA expression profiles during postnatal growth. A total of 13,940 candidate lncRNAs were identified, and these lncRNAs exhibited typical structural features, including shorter transcript lengths, fewer exons, and shorter open reading frames than mRNAs. Differential expression analysis identified 39, 11, and 174 differentially expressed lncRNAs in M7_vs_M1, M13_vs_M7, and M13_vs_M1, respectively, while 357, 160, and 446 differentially expressed mRNAs were detected in the corresponding comparisons. Functional enrichment analyses showed that differentially expressed mRNAs and co-expressed mRNAs associated with differentially expressed lncRNAs were mainly involved in RNA metabolism, translation, ribosome biogenesis, amino acid biosynthesis, energy and lipid metabolism, extracellular matrix remodeling, and cell adhesion. Several muscle-development-related signaling pathways, including AMPK, insulin, PI3K-Akt, PPAR, mTOR, FoxO, ECM–receptor interaction, and focal adhesion pathways, were also enriched. Integrated lncRNA–mRNA analysis further identified candidate lncRNA-associated differentially expressed genes, including IGF2, FOS, ACTC1, ADIPOQ, SPP1, PECAM1, and SLC16A7. These findings provide a comprehensive lncRNA and mRNA transcriptomic resource and reveal candidate regulatory molecules potentially involved in postnatal Longissimus Dorsi muscle development in Hanper sheep.