Consequences of Exchanging Carbohydrates for Proteins in the Cholesterol Metabolism of Mice Fed a High-fat Diet

Consumption of low-carbohydrate, high-protein, high-fat diets lead to rapid weight loss but the cardioprotective effects of these diets have been questioned. We examined the impact of high-protein and high-fat diets on cholesterol metabolism by comparing the plasma cholesterol and the expression of cholesterol biosynthesis genes in the liver of mice fed a high-fat (HF) diet that has a high (H) or a low (L) protein-to-carbohydrate (P/C) ratio. H-P/C-HF feeding, compared with L-P/C-HF feeding, decreased plasma total cholesterol and increased HDL cholesterol concentrations at 4-wk. Interestingly, the expression of genes involved in hepatic steroid biosynthesis responded to an increased dietary P/C ratio by first down-regulation (2-d) followed by later up-regulation at 4-wk, and the temporal gene expression patterns were connected to the putative activity of SREBF1 and 2. In contrast, Cyp7a1, the gene responsible for the conversion of cholesterol to bile acids, was consistently up-regulated in the H-P/C-HF liver regardless of feeding duration. Over expression of Cyp7a1 after 2-d and 4-wk H-P/C-HF feeding was connected to two unique sets of transcription regulators. At both time points, up-regulation of the Cyp7a1 gene could be explained by enhanced activations and reduced suppressions of multiple transcription regulators. In conclusion, we demonstrated that the hypocholesterolemic effect of H-P/C-HF feeding coincided with orchestrated changes of gene expressions in lipid metabolic pathways in the liver of mice. Based on these results, we hypothesize that the cholesterol lowering effect of high-protein feeding is associated with enhanced bile acid production but clinical validation is warranted. (246 words

The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

Caractérisation phénotypique et fonctionnelle de la protéine PA3731 de Pseudomonas aeruginosa

Dans le cadre d une recherche de nouvelles cibles contre les biofilms à P. aeruginosa, nous avons identifié une protéine impliquée dans l adhésion bactérienne. Nous avons alors caractérisé le phénotype du mutant pA3731 correspondant. Ce mutant est profondément altéré dans : sa capacité à adhérer, son swarming, sa production de rhamnolipides, sa virulence et sa résistance à la tobramycine. Une analyse du génome a montré que ce gène appartient à un cluster (pA3729-pA3732) codant pour des protéines hypothétiques. Par sa structure secondaire la protéine PA3731 est proche de PspA d E. coli. Néanmoins, des différences avec le cluster psp nous ont conduits à baptiser le cluster bac pour Biofilm Associated Cluster. Pour déterminer la fonction du système bac, nous avons analysé l incidence d un inhibiteur de systèmes d efflux, les sécrétomes et réalisé des études des complexomes. Ces travaux préliminaires n ont pas encore apporté d éléments probants au niveau de la fonction du système bac.Biofilms are prevalent in diseases caused by P. aeruginosa. We previously identified a hypothetical protein of this bacterium that was accumulated by biofilm cells. We showed here that a pA3731 mutant is profoundly impaired in its ability to adhere, in swarming, in the rhamnolipides production, in virulence and in resistance to tobramycin. The protein PA3731 has a predicted secondary structure similar to that of the PspA of E. coli and belonged to a cluster of 4 genes (pA3729-pA3732) not previously described. However, some differences led us to named this locus bac for biofilm-associated cluster. In the aim to provide preliminary hypotheses to bac function, we compared the effect of an inhibitor of efflux systems, on the wild-type and mutant strains. We also initiated analyses of the strain secretomes and performed complexome studies by electrophoresis blue-native. These preliminary investigations have yet to provide evidence in the function of the bac system.ROUEN-BU Sciences (764512102) / SudocSudocFranceF

The zinc fingers and homeoboxes 2 protein ZHX2 and its interacting proteins regulate upstream pathways in podocyte diseases

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Impact of a centre and home-based cardiac rehabilitation program on the quality of life of teenagers and young adults with congenital heart disease: The QUALI-REHAB study rationale, design and methods

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