title: Transcriptomic Changes in Liver of Young Bulls Caused by Diets Low in Mineral and Protein Contents and Supplemented with n-3 Fatty Acids and Conjugated Linoleic Acid.
abstract: The aim of the present study was to identify transcriptional modifications and regulatory networks accounting for physiological and metabolic responses to specific nutrients in the liver of young Belgian Blue × Holstein bulls using RNA-sequencing. A larger trial has been carried out in which animals were fed with different diets: 1] a conventional diet; 2] a low-protein/low-mineral diet (low-impact diet) and 3] a diet enriched in n-3 fatty acids (FAs), conjugated linoleic acid (CLA) and vitamin E (nutraceutical diet). The initial hypothesis was that the administration of low-impact and nutraceutical diets might influence the transcriptional profiles in bovine liver and the resultant nutrient fluxes, which are essential for optimal liver function and nutrient interconversion. Results showed that the nutraceutical diet significantly reduced subcutaneous fat covering in vivo and liver pH. Dietary treatments did not affect overall liver fat content, but significantly modified the liver profile of 33 FA traits (out of the total 89 identified by gas-chromatography). In bulls fed nutraceutical diet, the percentage of n-3 and CLA FAs increased around 2.5-fold compared with the other diets, whereas the ratio of n6/n3 decreased 2.5-fold. Liver transcriptomic analyses revealed a total of 198 differentially expressed genes (DEGs) when comparing low-impact, nutraceutical and conventional diets, with the nutraceutical diet showing the greatest effects on liver transcriptome. Functional analyses using ClueGo and Ingenuity Pathway Analysis evidenced that DEGs in bovine liver were variously involved in energy reserve metabolic process, glutathione metabolism, and carbohydrate and lipid metabolism. Modifications in feeding strategies affected key transcription factors regulating the expression of several genes involved in fatty acid metabolism, e.g. insulin-induced gene 1, insulin receptor substrate 2, and RAR-related orphan receptor C. This study provides noteworthy insights into the molecular changes occurring as a result of nutrient variation in diets (aimed at reducing the environmental impact and improving human health) and broadens our understanding of the relationship between nutrients variation and phenotypic effects.
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Padova, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Pegolo
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Padova, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Cecchinato
authors.affiliation: Animal Genetics and Integrative Biology unit (GABI), INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.
authors.forename: Núria
authors.initials: N
authors.lastname: Mach
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Padova, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Babbucci
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Padova, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Pauletto
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bargelloni
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Padova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Schiavon
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Padova, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bittante
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D002417:Cattle; D004044:Dietary Proteins / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D015870:Gene Expression; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage*; D008099:Liver / Q000378:metabolism*; D008297:Male; D008903:Minerals / Q000008:administration & dosage* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D004044:Dietary Proteins; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D044243:Linoleic Acids, Conjugated; D008903:Minerals