Energy and Protein Intake After Return Home in Colorectal Surgery Patients With an Enhanced Recovery Program: A Prospective Observational Study.

[en] BACKGROUND: In patients scheduled for colorectal surgery with an enhanced recovery program (ERP), feeding after returning home has been insufficiently investigated. The aim of this study was to measure energy and protein intake during the first month at home. METHODS: Seventy adult patients scheduled for colorectal surgery with ERP were included. Calorie and protein intakes were calculated, and body weight was measured preoperatively and 3, 7, 15, and 30 days after discharge home. Data are mean ± SD or median (interquartile range). RESULTS: Patient characteristics were age 60.0 ± 15.0 years, BMI = 25.9 ± 5.5 kg/m2 , and colon/rectum of 56/14. The duration of hospitalization was 3 (2-5) days. Calorie and protein intakes (21.9 [17.7-28.6] kilocalorie per kilogram of ideal body weight [kcal/kg IBW] and 0.81 [0.61-1.14] g/kg IBW) were significantly reduced (P < .01) by 15% on day 3, compared with preoperative values, and then increased gradually to reach preoperative values after 1 month. Almost 50% of the patients failed to reach the calorie intake target of 25 kcal/kg IBW, and almost no patient reached the protein intake target of 1.5 g/kg IBW 30 days after discharge home. Weight loss after 30 days at home remained at -1.8 ± 2.7 kg. CONCLUSIONS: Colorectal surgery, even in an ERP, is associated with energy and protein intake below the targets recommended for the rehabilitation phase and results in weight loss. Whether nutrition counseling and prolonged administration of protein-enriched oral supplements could accelerate weight gain needs to be explored

Homology modeling and in vivo functional characterization of the zinc permeation pathway in a heavy metal P-type ATPase

The P1B ATPase Heavy Metal ATPase 4 (HMA4) is responsible for zinc and cadmium translocation from roots to shoots in the plant Arabidopsis thaliana. It couples ATP hydrolysis to cytosolic domain movements enabling metal transport across the membrane. Thanks to high conservation level within the P-type ATPase family, the role of the HMA4 cytoplasmic catalytic domains can be inferred from well characterized pumps. In contrast, the function of its terminal cytosolic extensions as well as the metal permeation mechanism through the membrane remains elusive. Here, homology modeling of the HMA4 transmembrane region was conducted based on the crystal structure of a ZntA bacterial homolog. The analysis highlighted amino acids forming a metal permeation pathway, whose importance was subsequently investigated functionally through mutagenesis and complementation experiments in plants. Although the zinc pathway displayed overall conservation among the two proteins, significant differences were observed, especially in the entrance area with altered electronegativity and the presence of a salt bridge/H-bond network. The analysis also newly identified amino acids whose mutation results in total or partial loss of the protein function. In addition, comparison of zinc and cadmium accumulation in shoots of A. thaliana complemented lines revealed a number of HMA4 mutants exhibiting different abilities in zinc and cadmium translocation. These observations could be instrumental to design low cadmium accumulating crops, hence decreasing human cadmium exposure

Functional study of Ser/Arg-rich splicing factors during zebrafish embryonic development.

Ser/Arg-rich (SR) proteins constitute a phylogenetically conserved family of RNA binding proteins characterized by one or two RNA-recognition motifs (RRMs) at the N-terminus and a C-terminal domain enriched in Ser/Arg dipeptides. They are important regulators of constitutive and alternative splicing. Moreover, SR proteins are involved in many other aspects of RNA metabolism, including transcription, non-sense mediated decay, mRNA export, translational control as well as maintenance of genome stability. While the roles of SR splicing factors have been widely studied at a molecular level, their functions during animal cell differentiation and development are still largely undetermined. In this study, we decided to take advantage of the vertebrate model organism Danio rerio (zebrafish) to investigate SR protein functions by using molecular and genetic approaches. Fifteen zebrafish SR genes were identified belonging to the three subfamilies of SR proteins [SRSF1 (1RRM and 1 pseudo-RRM), SRSF2 (1RRM) and SRSF7 (1RRM +1ZnK)] initially described in humans. The current PhD thesis aimed to study of four of them, Srsfs5a, Srsf9, Srsfs7 and Srsf2b. We first determined the expression pattern of all SR genes by in situ hybridization at 24, 48 and 72 hours post-fertilization. This analysis revealed an ubiquitous expression pattern for SR genes, however pointing a higher expression in the brain and in the eyes. We next performed “knock-down” experiments using morpholinos (MOs) microinjection to determine SR gene functions. One splicing MO, designed to target srsf5a (sMOsrsf5a) showed an interesting phenotype that coincides with the expression pattern of the gene in the eyes. As none of the four other MOs used to target srsf5a could confirm the phenotype, we generated stable knockout mutant lines using TALEN and CRISPR/Cas9. Interestingly, the corresponding homozygous mutants did not display any phenotypic traits. These inconsistencies were attributed to a possible genetic compensation mechanism in mutants, but also to an underestimated large number of inadvertent morpholino RNA targets. Indeed, we uncovered that only 11 consecutive bases complementary to the 25 MO bases are sufficient for binding and subsequent blocking of splice sites, suggesting that the sMOsrsf5a induced phenotype was not due to the inactivation of this unique, specific gene. In addition, we observed that sMOsrsf5a secondary targets can be slightly reduced by increasing embryos growth temperature after microinjection. Our study contributes to the debate concerning MO specificity, efficacy and the number of unknown targeted sequences.  étude fonctionnelle des facteurs d’épissage SR (Ser/Arg-rich) au cours du développement embryonnaire de Danio rerio

Etude fonctionnelle du facteur d'épissage SR SRSF5a au cours du développement embryonnaire du zebrafish

Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the spliceosome, which consist of five small nuclear ribonucleoproteins (snRNPs) and numerous non snRNPs proteins (1). Amongst these non snRNPs proteins, the SR proteins family constituted an important group of splicing factors that are involved in constitutive and alternative splicing (2,3). SR proteins are structurally related as they are characterized by one or two RNA-recognition motifs (RRMs) in N-ter and a C-terminal domain enriched in dipeptide Ser/Arg. Phylogenetic inference using the RRM domain allowed us to identify 13 encoding genes for SR proteins in the vertebrate model organism, Danio rerio. The Zebrafish is increasingly recognized as a powerful model for the study of vertebrate embryonic development in a physiological context. The roles of SR splicing factors during animal cell differentiation and development are largely unknown. The aim of the present research is to investigate SR proteins functions during zebrafish development by using molecular and genetic approaches. In this study, we investigated the role of the SR splicing factor SRSF5a. The expression profile was determined by in situ hybridization at 24, 48 and 72 hours post-fertilization and showed SRSF5a expression mainly in brain, retina and pharyngeal arches at these stages. Furthermore, SRSF5a knock-down by morpholinos microinjection strongly suggests an important role of this specific splicing factor during eyes and brain development. In order to gain insight into the molecular function of SRSF5a, we analysed control and morphant transcriptomes using high throughput RNA sequencing. Finally, we use a complementary approach to morpholinos and generate SRSF5a mutant fishes using TALENs (Tal effector nucleases)(4,5). 1. Wahl MC, Will CL, & Luhrmann R (2009) The spliceosome: design principles of a dynamic RNP machine. Cell 136(4):701-718. 2. Long JC & Caceres JF (2009) The SR protein family of splicing factors: master regulators of gene expression. Biochem J 417(1):15-27. 3. Graveley BR (2000) Sorting out the complexity of SR protein functions. RNA 6(9):1197-1211. 4. Moore et al. (2012) Improved Somatic Mutagenesis in Zebrafish Using Transcription Activator-Like Effector Nucleases (TALENs). Plos One 120(1):1-12. 5. Cade et al (2012) Highly efficient generation of heritable zebrafish gene mutations using homo- and heterodimeric TALENs. Nucleic acid research Vol 40, No 16:8001-8010.Functional stud

Etude fonctionelle du facteur d'épissage SR, SRSF5a, durant le développement embryonnaire du zebrafish

To investigate the role of the splicing factor SRSF5a during zebrafish embryonic development, we performed SRSF5a knockdown by morpholino microinjection and we analysed control and morphant transcriptomes using RNA sequencing.Functional study of SR splicing factors during zebrafish embryonic development using molecular and genetic approache

Recurrent Evolutionary Innovations in Rodent and Primate Schlafen Genes

Posted January 13, 2024 on bioRxiv.International audienceSCHLAFEN proteins are a large family of RNase-related enzymes carrying essential immune and developmental functions. Despite these important roles, Schlafen genes display varying degrees of evolutionary conservation in mammals. While this appears to influence their molecular activities, a detailed understanding of these evolutionary innovations is still lacking. Here, we used in depth phylogenomic approaches to characterize the evolutionary trajectories and selective forces shaping mammalian Schlafen genes. We traced lineage-specific Schlafen amplifications and found that recent duplicates evolved under distinct selective forces, supporting repeated sub-functionalization cycles. Codon-level natural selection analyses in primates and rodents, identified recurrent positive selection over Schlafen protein domains engaged in viral interactions. Combining crystal structures with machine learning predictions, we discovered a novel class of rapidly evolving residues enriched at the contact interface of SCHLAFEN protein dimers. Our results suggest that inter Schlafen compatibilities are under strong selective pressures and are likely to impact their molecular functions. We posit that cycles of genetic conflicts with pathogens and between paralogs drove Schlafens’ recurrent evolutionary innovations in mammals

Zebrafish larvae model to screen for the risk of Acer pseudoplatanus intoxication in grazing animals

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