Florence Roux-Dalvai

Publications (3)18.89 Total impact

• Source

  Available from: Bertrand Perret

  Article: Mitochondrial inhibitory factor 1 (IF1) is present in human serum and is positively correlated with HDL-cholesterol.

  Annelise Genoux, Véronique Pons, Claudia Radojkovic, Florence Roux-Dalvai, Guillaume Combes, Corinne Rolland, Nicole Malet, Bernard Monsarrat, Frédéric Lopez, Jean-Bernard Ruidavets, Bertrand Perret, Laurent O Martinez
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  ABSTRACT: Mitochondrial ATP synthase is expressed as a plasma membrane receptor for apolipoprotein A-I (apoA-I), the major protein component in High Density Lipoproteins (HDL). On hepatocytes, apoA-I binds to cell surface ATP synthase (namely ecto-F(1)-ATPase) and stimulates its ATPase activity, generating extracellular ADP. This production of extracellular ADP activates a P2Y(13)-mediated HDL endocytosis pathway. Conversely, exogenous IF1, classically known as a natural mitochondrial specific inhibitor of F(1)-ATPase activity, inhibits ecto-F(1)-ATPase activity and decreases HDL endocytosis by both human hepatocytes and perfused rat liver. Since recent reports also described the presence of IF1 at the plasma membrane of different cell types, we investigated whether IF1 is present in the systemic circulation in humans. We first unambiguously detected IF1 in human serum by immunoprecipitation and mass spectrometry. We then set up a competitive ELISA assay in order to quantify its level in human serum. Analyses of IF1 levels in 100 normolipemic male subjects evidenced a normal distribution, with a median value of 0.49 µg/mL and a 95% confidence interval of 0.22-0.82 µg/mL. Correlations between IF1 levels and serum lipid levels demonstrated that serum IF1 levels are positively correlated with HDL-cholesterol and negatively with triglycerides (TG). Altogether, these data support the view that, in humans, circulating IF1 might affect HDL levels by inhibiting hepatic HDL uptake and also impact TG metabolism.
  PLoS ONE 01/2011; 6(9):e23949. · 4.09 Impact Factor
• Article: In-depth exploration of cerebrospinal fluid by combining peptide ligand library treatment and label-free protein quantification.

  Emmanuelle Mouton-Barbosa, Florence Roux-Dalvai, David Bouyssié, François Berger, Eric Schmidt, Pier Giorgio Righetti, Luc Guerrier, Egisto Boschetti, Odile Burlet-Schiltz, Bernard Monsarrat, Anne Gonzalez de Peredo
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  ABSTRACT: Cerebrospinal fluid (CSF) is the biological fluid in closest contact with the brain and thus contains proteins of neural cell origin. Hence, CSF is a biochemical window into the brain and is particularly attractive for the search for biomarkers of neurological diseases. However, as in the case of other biological fluids, one of the main analytical challenges in proteomic characterization of the CSF is the very wide concentration range of proteins, largely exceeding the dynamic range of current analytical approaches. Here, we used the combinatorial peptide ligand library technology (ProteoMiner) to reduce the dynamic range of protein concentration in CSF and unmask previously undetected proteins by nano-LC-MS/MS analysis on an LTQ-Orbitrap mass spectrometer. This method was first applied on a large pool of CSF from different sources with the aim to better characterize the protein content of this fluid, especially for the low abundance components. We were able to identify 1212 proteins in CSF, and among these, 745 were only detected after peptide library treatment. However, additional difficulties for clinical studies of CSF are the low protein concentration of this fluid and the low volumes typically obtained after lumbar puncture, precluding the conventional use of ProteoMiner with large volume columns for treatment of patient samples. The method has thus been optimized to be compatible with low volume samples. We could show that the treatment is still efficient with this miniaturized protocol and that the dynamic range of protein concentration is actually reduced even with small amounts of beads, leading to an increase of more than 100% of the number of identified proteins in one LC-MS/MS run. Moreover, using a dedicated bioinformatics analytical work flow, we found that the method is reproducible and applicable for label-free quantification of series of samples processed in parallel.
  Molecular &amp Cellular Proteomics 05/2010; 9(5):1006-21. · 7.40 Impact Factor
• Article: Extensive analysis of the cytoplasmic proteome of human erythrocytes using the peptide ligand library technology and advanced mass spectrometry.

  Florence Roux-Dalvai, Anne Gonzalez de Peredo, Carolina Simó, Luc Guerrier, David Bouyssié, Alberto Zanella, Attilio Citterio, Odile Burlet-Schiltz, Egisto Boschetti, Pier Giorgio Righetti, Bernard Monsarrat
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  ABSTRACT: The erythrocyte cytoplasmic proteome is composed of 98% hemoglobin; the remaining 2% is largely unexplored. Here we used a combinatorial library of hexameric peptides as a capturing agent to lower the signal of hemoglobin and amplify the signal of low to very low abundance proteins in the cytoplasm of human red blood cells (RBCs). Two types of hexapeptide library beads have been adopted: amino-terminal hexapeptide beads and beads in which the peptides have been further derivatized by carboxylation. The amplification of the signal of low abundance and suppression of the signal of high abundance species were fully demonstrated by two-dimensional gel maps and nano-LC-MSMS analysis. The effect of this new methodology on quantitative information also was explored. Moreover using this approach on an LTQ-Orbitrap mass spectrometer, we could identify with high confidence as many as 1578 proteins in the cytoplasmic fraction of a highly purified preparation of RBCs, allowing a deep exploration of the classical RBC pathways as well as the identification of unexpected minor proteins. In addition, we were able to detect the presence of eight different hemoglobin chains including embryonic and newly discovered globin chains. Thus, this extensive study provides a huge data set of proteins that are present in the RBC cytoplasm that may help to better understand the biology of this simplified cell and may open the way to further studies on blood pathologies using targeted approaches.
  Molecular &amp Cellular Proteomics 08/2008; 7(11):2254-69. · 7.40 Impact Factor