Browsing by Author "Costa, Ana S. H."
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- Carcass fat partitioning and meat quality of Alentejana and Barrosã young bulls fed high or low maize silage dietsPublication . Costa, Ana S. H.; Costa, Paulo; Bessa, Rui J. B.; Lemos, José P. C.; Simões, Jorge A.; Silva, José Santos; Fontes, Carlos M. G. A.; Prates, José A. M.This study assessed the effect of breed and diet on carcass composition, particularly fat partitioning, and meat quality in young bulls. An experiment with forty young bulls from two phylogenetically distant Portuguese bovine breeds, Alentejana and Barrosã, fed two diets with different maize silage to concentrate ratios, but isoenergetic and isonitrogenous, was carried out until the animals reached 18 months of age. In the longissimus lumborum muscle, Barrosã bulls fed the low silage diet had the highest intramuscular fat (IMF) content. Bulls fed the low silage diet also had the highest IMF content in the semitendinosus muscle. Diet determined the proportions of total visceral fat and individual fat depots. Under these experimental conditions, it was shown that the genetic background is a major determinant of carcass composition and meat quality, and that the dietary differences studied had limited effect on carcass composition.
- Content and distribution of conjugated linoleic acid isomers in bovine milk, cheese and butter from AzoresPublication . Pestana, Jose M.; Martins, Susana I. V.; Alfaia, Cristina M. M.; Lopes, Paula A.; Costa, Ana S. H.; Bessa, Rui J. B.; Castro, Matilde L. F.; Prates, Jose A. M.Pasture intake is a major factor affecting the content and the distribution of the conjugated linoleic acid (CLA) isomers in bovine milk fat. The aim of this study was to determine the CLA contents and its isomeric distribution in milk, cheese and butter
- Control of endothelial quiescence by FOXO-regulated metabolitesPublication . Andrade, Jorge; Shi, Chenyue; Costa, Ana S. H.; Choi, Jeongwoon; Kim, Jaeryung; Doddaballapur, Anuradha; Sugino, Toshiya; Ong, Yu Ting; Castro, Marco; Zimmermann, Barbara; Kaulich, Manuel; Guenther, Stefan; Wilhelm, Kerstin; Kubota, Yoshiaki; Braun, Thomas; Koh, Gou Young; Grosso, Ana Rita; Frezza, Christian; Potente, MichaelEndothelial cells (ECs) adapt their metabolism to enable the growth of new blood vessels, but little is known how ECs regulate metabolism to adopt a quiescent state. Here, we show that the metabolite S-2-hydroxyglutarate (S-2HG) plays a crucial role in the regulation of endothelial quiescence. We find that S-2HG is produced in ECs after activation of the transcription factor forkhead box O1 (FOXO1), where it limits cell cycle progression, metabolic activity and vascular expansion. FOXO1 stimulates S-2HG production by inhibiting the mitochondrial enzyme 2-oxoglutarate dehydrogenase. This inhibition relies on branched-chain amino acid catabolites such as 3-methyl-2-oxovalerate, which increase in ECs with activated FOXO1. Treatment of ECs with 3-methyl-2-oxovalerate elicits S-2HG production and suppresses proliferation, causing vascular rarefaction in mice. Our findings identify a metabolic programme that promotes the acquisition of a quiescent endothelial state and highlight the role of metabolites as signalling molecules in the endothelium.
- Genetic background and diet impact beef fatty acid composition and stearoyl-CoA desaturase mRNA expressionPublication . Costa, Ana S. H.; Silva, Marta P.; Alfaia, Cristina P. M.; Pires, Virgínia M. R.; Fontes, Carlos M. G. A.; Bessa, Rui J. B.; Prates, José A. M.The intramuscular fat composition of ruminant meats influences the quality of the final product, which explains the increasing interest in assessing the fatty acid profile of meat from different production systems. In this study, it was hypothesized that there are breed- and diet induced variations on lipid metabolism in the muscle, which may be, at least partially, modulated by the stearoyl-CoA desaturase (SCD) gene expression levels. Forty purebred young bulls from two phylogenetically distant autochthonous cattle breeds, Alentejana and Barrosã(n = 20 for each breed), were assigned to two different diets (low vs. high silage) and slaughtered at 18 months of age. Meat fatty acid composition, including the detailed conjugated linoleic acid (CLA) isomeric profile, was determined along with the SCD mRNA levels. Meat from Barrosã bulls fed the low silage diet was richer in monounsaturated fatty acids, CLA and trans fatty acids, when compared to that from Alentejana bulls. The meat content in polyunsaturated fatty acids was similar across experimental groups. Moderate positive correlations between the SCD mRNA levels and the products of this enzyme activity were found, although they were not reflected on the calculated desaturase indices. Overall, these findings highlight the importance of taking into account the genetic background while devising feeding strategies to manipulate beef fatty acid composition.