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National audience; Introduction et but de l’étude : La qualité nutritionnelle de la viande de lapin est modifiée en fonction de la qualité et la quantité des acides gras (AG) ingérés (Benatmane et al, 2011). L’apport de C18 :3 n-3 (ALA) dans l’aliment permet d’augmenter notablement le dépôt de cet AG dans sa viande. Mais ce précurseur est peu transformé en dérivés à longues chaînes comme le C22:6 n-3 (DHA). Ainsi, pour compléter la démarche de produits animaux à valeur santé ajoutée déjà obtenue avec des graines de lin extrudées (source de ALA), l’incorporation de micro-algues riches en DHA est testée afin d’en étudier le dépôt dans la viande. L’étude est complétée par des sources d’AG n-6 afin de pouvoir, par la suite, modéliser les compétitions qui existent entre les dépôts des AG n-6 et n-3. Ce résumé rapporte les valeurs d’AG déposés dans différents tissus. Matériel et méthodes : 42 lapins (7 par lot) de 50 jours d’âge ont reçu pendant 21 jours des régimes isolipidiques (4%) et isoénergétiques. La source lipidique variait entre les 6 régimes : tournesol (TOUR-source de n-6), graines de lin extrudées (GLE- source de ALA), micro-algues (MALG- riche en DHA)), mélanges (1/1) TOUR-GLE ou TOUR-MALG ou GLE-MALG. A l’abattage, des échantillons de tissu adipeux abdominal (TAB), de muscle longissimus dorsi (LD) et la cuisse ont été prélevés. Les lipides ont été extraits et analysés en chromatographie en phase gazeuse afin de déterminer le profil en AG. Les résultats ont été comparés par analyse de variance avec le régime comme facteur principal. Résultats et Analyse statistique : Dans le LD et la cuisse, la teneur en DHA est fortement augmentée (pConclusion : Cette étude montre que le précurseur C18:3 n-3 et/ou le dérivé à longue chaîne C22:6 n-3 peuvent être introduits dans l’aliment du lapin afin de les retrouver dans la viande destinée au consommateur. L’apport en n-3 est mieux équilibré par rapport aux recommandations chez l’homme en utilisant un régime avec un mélange lipidique GLE et MALG. Cependant cette stratégie, bonne pour la santé humaine, pourrait entrainer une peroxydation des acides gras polyinsaturés. La supplémentation en antioxydants végétaux conjointement à l’apport d’AG n-3 dans le régime du lapin sera à étudier.

Made available in DSpace on 2013-08-12T19:14:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-01 Made available in DSpace on 2013-09-30T19:21:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:33:28Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T15:33:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-01 There is a molecular crosstalk between the trophoblast and maternal immune cells of bovine endometrium. The uterine cells are able to secrete cytokine/chemokines to either induce a suppressive environment for establishment of the pregnancy or to recruit immune cells to the endometrium to fight infections. Despite morphological differences between women and cows, mechanisms for immune tolerance during pregnancy seem to be conserved. Mechanisms for uterine immunesuppression in the cow include: reduced expression of major histocompatability proteins by the trophoblast; recruitment of macrophages to the pregnant endometrium; and modulation of immune-related genes in response to the presence of the conceptus. Recently, an eGFP transgenic cloned embryo model developed by our group showed that there is modulation of foetal proteins expressed at the site of syncytium formation, suggesting that foetal cell can regulate not only by the secretion of specific factors such as interferon-tau, but also by regulating their own protein expression to avoid excessive maternal recognition by the local immune system. Furthermore, foetal DNA can be detected in the maternal circulation; this may reflect the occurrence of an invasion of trophoblast cells and/or their fragment beyond the uterine basement membrane in the cow. In fact, the newly description of exosome release by the trophoblast cell suggests that could be a new fashion of maternal-foetal communication at the placental barrier. Additionally, recent global transcriptome studies on bovine endometrium suggested that the immune system is aware, from an immunological point of view, of the presence of the foetus in the cow during early pregnancy. Univ São Paulo, Dept Basic Sci, Fac Zootecnia & Engn Alimentos, Pirassununga, SP, Brazil Baylor Coll Med, Dept Pathol & Immunol, Houston, TX 77030 USA Univ Estadual Paulista, Fac Zootecnia, Dracena, SP, Brazil Univ Estadual Paulista, Fac Zootecnia, Dracena, SP, Brazil

Consumption of trans fatty acids (TFA) increases cardiovascular risk more than do saturated FA but the mechanisms explaining their atherogenicity are still unclear. We investigated the impact of membrane TFA incorporation on the cholesterol efflux by exposing J774 mouse macrophages or human monocyte derived macrophages (HMDM) to media enriched or not (standard medium) with industrially produced elaidic (trans-9 18:1) acid, naturally produced vaccenic (trans-11 18:1) acid or palmitic acid (34 h, 70 µM). In J774 macrophages, elaidic and palmitic acids, but not vaccenic acid, reduced ABCA1-mediated efflux by ~ 23% without affecting aqueous diffusion, SR-BI or ABCG1-mediated pathways and this effect was maintained in cholesterol-loaded cells. The impact of elaidic acid on ABCA1 pathway was weaker on cholesterol-normal HMDM, but elaidic acid induced a strong reduction of ABCA1-efflux in cholesterol- loaded cells (-36%). In J774 cells, the FA supplementations had no impact on cellular free cholesterol or cholesteryl esters masses, the abundance of ABCA1 mRNA or the total and plasma membrane ABCA1 protein contents. Conversely, TFA or palmitic acid incorporation induced strong modifications of the membrane FA composition with a decrease in the ratio (cis-monounsatured FA+polyunsaturated FA) / (saturated FA+TFA), with elaidic and vaccenic acids representing each 20% and 13% of the total FA composition, respectively. Moreover, we demonstrated that cellular ATP was required for the effect of elaidic, suggesting that it contributes to atherogenesis by impairing the ABCA1 cholesterol efflux in macrophages, likely by decreasing the membrane fluidity, which could thereby reduce ATPase activity and the function of the transporter.

This study sought to determine the earliest response of the bovine uterine endometrium to the presence of the conceptus at key developmental stages of early pregnancy. There were no detectable differences in gene expression in endometria from pregnant and cyclic heifers on Days 5, 7, and 13 postestrus, but the expression of 764 genes was altered due to the presence of the conceptus at maternal recognition of pregnancy (Day 16). Of these 514 genes, MX2, BST2, RSAD2, ISG15, OAS1, USP18, IFI44, ISG20, SAMD9, EIF4E, and IFIT2 increased to the greatest extent in pregnant endometria (>8-fold log2 fold change increase). The expression of OXTR, Bt.643 (unofficial symbol), and KCNMA1 was reduced the most, but short-term treatment with recombinant ovine interferon tau (IFNT) in vitro or in vivo did not alter their expression. In vivo intrauterine infusion of IFNT induced the expression of EIF4E, IFIT2, IFI44, ISG20, MX2, RSAD2, SAMD9, and USP18. These results revealed for the first time that changes that occur in the endometrial transcriptome are independent of the presence of a conceptus until pregnancy recognition. The differentially expressed genes (including MX2, BST2, RSAD2, ISG15, OAS1, USP18, IFI44, ISG20, SAMD, and EIF4E) are a consequence of IFNT production by the conceptus. The identified genes represent known and novel early markers of conceptus development and/or return to cyclicity and may be useful to identify the earliest stage at which the endometrial response to the conceptus is detectable.

This study sought to determine the earliest response of the bovine uterine endometrium to the presence of the conceptus at key developmental stages of early pregnancy. There were no detectable differences in gene expression in endometria from pregnant and cyclic heifers on Days 5, 7, and 13 postestrus, but the expression of 764 genes was altered due to the presence of the conceptus at maternal recognition of pregnancy (Day 16). Of these 514 genes, MX2, BST2, RSAD2, ISG15, OAS1, USP18, IFI44, ISG20, SAMD9, EIF4E, and IFIT2 increased to the greatest extent in pregnant endometria (>8-fold log2 fold change increase). The expression of OXTR, Bt.643 (unofficial symbol), and KCNMA1 was reduced the most, but short-term treatment with recombinant ovine interferon tau (IFNT) in vitro or in vivo did not alter their expression. In vivo intrauterine infusion of IFNT induced the expression of EIF4E, IFIT2, IFI44, ISG20, MX2, RSAD2, SAMD9, and USP18. These results revealed for the first time that changes that occur in the endometrial transcriptome are independent of the presence of a conceptus until pregnancy recognition. The differentially expressed genes (including MX2, BST2, RSAD2, ISG15, OAS1, USP18, IFI44, ISG20, SAMD, and EIF4E) are a consequence of IFNT production by the conceptus. The identified genes represent known and novel early markers of conceptus development and/or return to cyclicity and may be useful to identify the earliest stage at which the endometrial response to the conceptus is detectable.

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