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8 results on '"Ronan Le Bouffant"'

1. PathogenicVibrio harveyi, in contrast to non-pathogenic strains, intervenes with the p38 MAPK pathway to avoid an abalone haemocyte immune response

Author

Florence Buzin, Bertrand Cougard, Marcel Koken, Ronan Le Bouffant, Carolyn S. Friedman, Marie-Agnès Travers, Christine Paillard, Sylvain Huchette, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Scea France Haliotis, Gametogenèse et génotoxicité (UMR_S_566 ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-IFR13-Institut National de la Santé et de la Recherche Médicale (INSERM), School of Aquatic and Fishery Sciences, University of Washington [Seattle], and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Hemocytes, Abalone, MAP Kinase Signaling System, Phagocytosis, Gastropoda, Virulence, p38 Mitogen-Activated Protein Kinases, Biochemistry, Microbiology, 03 medical and health sciences, Immune system, Animals, Molecular Biology, Pathogen, Vibrio, 030304 developmental biology, 0303 health sciences, biology, Vibrio harveyi, immune escape, Aquatic animal, 04 agricultural and veterinary sciences, Cell Biology, biology.organism_classification, MAPK, 3. Good health, virulence, Vibrio Infections, [SDE]Environmental Sciences, 040102 fisheries, 0401 agriculture, forestry, and fisheries, Reactive Oxygen Species, Haliotis tuberculata, Bacteria
Abstract

International audience; Vibrio harveyi is a marine bacterial pathogen responsible for episodic abalone epidemics associated with massive mortalities in France, Japan, and Australia. The aim of this study was the understanding of a possible role of the p38 MAPK in abalone haemocyte responses towards this bacterium. First, the pathogenicity of different V. harveyi strains was compared in both immersion and injection trials, and clear differences were detected. The three strains, ORM4, 04/092, and 05/053, all isolated from moribund abalone, induced up to 80% mortalities in immersion or injection challenges (LD(50) (ORM4) = 2.5 x 10(2) CFU animal(-1)). The two strains, LMG 4044T and LMG 7890 were non-pathogenic towards abalone in immersion trials, and needed very high numbers for killing by intramuscular injections (LD(50) = 8.9 x 10(4) and 1.6 x 10(5) CFU animal(-1), respectively). To start unraveling the mechanism explaining these differences, the p38-MAPK, a keyplayer in antimicrobial immune response, was studied. The non-pathogenic strain, LMG 7890 can be eliminated by abalone haemocytes and induces haemocyte phagocytosis and high ROS production. With different concentrations of a p38-specific inhibitor, SB203580, p38 implication was shown. This inhibitor reduced phagocytosis and ROS induction leading to LMG 7890 proliferation. In the case of the pathogenic ORM4 which can not be eliminated by abalone haemocytes, no phagocytosis and ROS production was induced, and a retarded p38 activation was observed. Taken together, our results suggest that p38 MAPK modulation may be one of the ways of virulent V. harveyi to attack its host and escape abalone immune response.

Published
2009
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2. Inhibition of translation and modification of translation factors during apoptosis induced by the DNA-damaging agent MMS in sea urchin embryos

Author

Julia Morales, Sandrine Boulben, Ronan Le Bouffant, Robert Bellé, Odile Mulner-Lorillon, Patrick Cormier, Mer et santé (MS), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Ribosomal Proteins, Embryo, Nonmammalian, MESH: Eukaryotic Initiation Factor-2, Protein subunit, Eukaryotic Initiation Factor-2, MESH: Methyl Methanesulfonate, Apoptosis, Biology, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, MESH: Ovum, biology.animal, Protein biosynthesis, Animals, MESH: Animals, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Translation factor, Phosphorylation, Sea urchin, Ovum, 030304 developmental biology, MESH: DNA Damage, 0303 health sciences, MESH: Phosphorylation, EIF4G, MESH: Apoptosis, organic chemicals, fungi, MESH: Embryo, Nonmammalian, Translation (biology), MESH: Eukaryotic Initiation Factor-4G, Cell Biology, Methyl Methanesulfonate, MESH: Ribosomal Proteins, MESH: Sea Urchins, Methyl methanesulfonate, chemistry, Biochemistry, Protein Biosynthesis, Sea Urchins, MESH: Protein Biosynthesis, 030220 oncology & carcinogenesis, embryonic structures, Eukaryotic Initiation Factor-4G, DNA Damage
Abstract

International audience; Translational control was investigated in sea urchin eggs and embryos in response to the DNA-damaging agent methyl methanesulfonate (MMS). We have shown in this report that exposure of sea urchin embryos to MMS induces drastic effects on protein synthesis activity, and on translation factors level, integrity and post-translational modifications. In response to the treatment of embryos by the DNA-damaging agent MMS, protein synthesis is inhibited independently of the translation inhibitor 4E-BP and in correlation with phosphorylation of the translation factor eIF2alpha subunit. Furthermore, a low molecular weight form of translation initiation factor eIF4G is detected correlatively with MMS-induced apoptosis. We propose that modifications of translation factors play an important role in protein synthesis modulation that occurs during DNA-damage induced apoptosis.

Published
2008
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3. An adhesome comprising laminin, dystroglycan and myosin IIA is required during notochord development in Xenopus laevis

Author

Elsa Denker, Thierry Darribère, Nicolas Buisson, Nicole Moreau, Aline Goullancourt, Ronan Le Bouffant, Valérie Bello, Cathy Sirour, Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ARC, AFM, and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Proteomics, Organogenesis, [SDV]Life Sciences [q-bio], Blotting, Western, Notochord, Morpholinos, Xenopus laevis, 03 medical and health sciences, 0302 clinical medicine, Tandem Mass Spectrometry, Laminin, medicine, Dystroglycan, Animals, Immunoprecipitation, Dystroglycans, Cytoskeleton, Molecular Biology, [SDV.BDD]Life Sciences [q-bio]/Development Biology, In Situ Hybridization, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Adhesome, Nonmuscle Myosin Type IIA, Notochord morphogenesis, Cell Polarity, Cortical actin cytoskeleton, Mediolateral intercalation, Cell Biology, Anatomy, Molecular biology, Cell biology, medicine.anatomical_structure, Bromodeoxyuridine, Gene Knockdown Techniques, Vacuoles, biology.protein, Pikachurin, 030217 neurology & neurosurgery, Developmental Biology
Abstract

Dystroglycan (Dg) is a transmembrane receptor for laminin that must be expressed at the right time and place in order to be involved in notochord morphogenesis. The function of Dg was examined in Xenopus laevis embryos by knockdown of Dg and overexpression and replacement of the endogenous Dg with a mutated form of the protein. This analysis revealed that Dg is required for correct laminin assembly, for cell polarization during mediolateral intercalation and for proper differentiation of vacuoles. Using mutations in the cytoplasmic domain, we identified two sites that are involved in cell polarization and are required for mediolateral cell intercalation, and a site that is required for vacuolation. Furthermore, using a proteomic analysis, the cytoskeletal non-muscle myosin IIA has been identified for the first time as a molecular link between the Dg-cytoplasmic domain and cortical actin. The data allowed us to identify the adhesome laminin-Dg-myosin IIA as being required to maintain the cortical actin cytoskeleton network during vacuolation, which is crucial to maintain the shape of notochordal cells.

Published
2014
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4. Retinoic acid-dependent control of MAP kinase phosphatase-3 is necessary for early kidney development in Xenopus

Author

Ronan Le Bouffant, Muriel Umbhauer, Isabelle Buisson, Mélinée Futel, Jean-François Riou, Jian-Hong Wang, Signalisation et morphogenèse = Signalling and morphogenesis (LBD-E12), Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), CNRS, Universite Pierre et Marie Curie, Emergence-UPMC, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, medicine.medical_specialty, Mesoderm, FGFR Inhibition, Xenopus, Retinoic acid, Tretinoin, Xenopus Proteins, Biology, Fibroblast growth factor, Kidney, Xenopus laevis, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Dual Specificity Phosphatase 6, Internal medicine, Phosphoprotein Phosphatases, medicine, Animals, FGF, Protein kinase A, [SDV.BDD]Life Sciences [q-bio]/Development Biology, 030304 developmental biology, 0303 health sciences, Gene Expression Regulation, Developmental, Cell Biology, General Medicine, Receptors, Fibroblast Growth Factor, Cell biology, Pronephros, Fibroblast Growth Factors, Gastrulation, Endocrinology, medicine.anatomical_structure, chemistry, Fibroblast growth factor receptor, Female, MKP3, 030217 neurology & neurosurgery, Signal Transduction
Abstract

International audience; Background information In Xenopus, the functional kidney of the tadpole, the pronephros, forms from the kidney field, which is specified at completion of gastrulation. Specification of the kidney field requires retinoic acid (RA) signalling during gastrulation, while fibroblast growth factor (FGF) signals inhibit should be inhibit this process. Results We have analysed the functional interactions taking place during gastrulation between RA and FGF signals in the lateral marginal zone (LMZ), that is in the environment of unspecified pronephric mesoderm precursors. Inhibition of FGF receptor (FGFR) signalling with SU5402 does not significantly affect expression of genes encoding RA metabolism enzymes and RA receptor-a in LMZ explants. Furthermore, SU5402 has no effect on the expression of hoxa1, a major RA target in the LMZ, showing that FGF is not antagonising RA in the LMZ. Disruption of RA signalling affects FGF ligand production to some extent, especially FGF8b, but the strongest effect is the down-regulation of the mitogen-activated protein kinase phosphatase-3 (MKP3)-encoding gene, mkp3. A strong up-regulation of mkp3 occurs in response to exogenous RA. This effect is reduced in a context of FGFR inhibition, suggesting that RA and FGF signals are co-operating upstream of mkp3. Mkp3 knockdown results in an inhibition of the kidney field markers pax8 and lhx1 and in a defective development of the pronephros. Conclusions FGF is not negatively influencing pronephric specification by antagonising RA signalling. Functional interactions between RA and FGF rather take place at the level of the transcriptional regulation of mkp3, indicating that RA may antagonise FGF signalling at the level of the extracellular signal-regulated kinase (Erk) pathway. A fine tuning of Erk signalling by MKP3 is important for the proper establishment of the kidney field.

Published
2012
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5. The translational repressor 4E-BP mediates the hypoxia-induced defects in myotome cells

Author

Ronan Le Bouffant, Valérie Bello, Michèle Beaudry, Nicolas Buisson, Thierry Darribère, Magdalena Hidalgo, Patrick Cormier, Réponses Cellulaires et Fonctionnelles à l'Hypoxie (LRPH), Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-UFR SMBH, Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie Intégrative des Modèles Marins (LBI2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Station biologique de Roscoff [Roscoff] (SBR), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Muscle Cells, Embryo, Nonmammalian, [SDV]Life Sciences [q-bio], MESH: Cell Hypoxia, MESH: Anoxia, Xenopus, Muscle Proteins, Apoptosis, Cell Count, Xenopus Proteins, MyoD, Xenopus laevis, 0302 clinical medicine, MESH: Animals, Phosphorylation, Hypoxia, MESH: Xenopus Proteins, 0303 health sciences, EIF4E, MESH: Eukaryotic Initiation Factor-4E, Cell Hypoxia, Cell biology, Somites, MESH: Repressor Proteins, MESH: Protein Biosynthesis, 030220 oncology & carcinogenesis, medicine.symptom, MESH: Oxygen, Protein Binding, Mitosis, Biology, Models, Biological, MESH: Somites, MESH: Muscle Proteins, 03 medical and health sciences, MESH: Xenopus laevis, medicine, Animals, MESH: Protein Binding, Transcription factor, PI3K/AKT/mTOR pathway, 030304 developmental biology, Muscle Cells, MESH: Phosphorylation, MESH: Proto-Oncogene Proteins c-akt, MESH: Cell Count, Cell growth, MESH: Apoptosis, MESH: Models, Biological, MESH: Embryo, Nonmammalian, Cell Biology, MESH: Mitosis, Hypoxia (medical), biology.organism_classification, Molecular biology, Oxygen, Repressor Proteins, Eukaryotic Initiation Factor-4E, Protein Biosynthesis, Proto-Oncogene Proteins c-akt
Abstract

International audience; Cell growth, proliferation, differentiation and survival are influenced by the availability of oxygen. The effect of hypoxia on embryonic cells and the underlying molecular mechanisms to maintain cellular viability are still poorly understood. In this study, we show that hypoxia during Xenopus embryogenesis rapidly leads to a significant developmental delay and to cell apoptosis after prolonged exposure. We provide strong evidence that hypoxia does not affect somitogenesis but affects the number of mitotic cells and muscle-specific protein accumulation in somites, without interfering with the expression of MyoD and MRF4 transcription factors. We also demonstrate that hypoxia reversibly decreases Akt phosphorylation and increases the total amount of the translational repressor 4E-BP, in combination with an increase of the 4E-BP associated with eIF4E. Interestingly, the inhibition of PI3-kinase or mTOR, with LY29002 or rapamycin, respectively, triggers the 4E-BP accumulation in Xenopus embryos. Finally, the overexpression of the non-phosphorylatable 4E-BP protein induces, similar to hypoxia, a decrease in mitotic cells and a decrease in muscle-specific protein accumulation in somites. Taken together, our studies suggest that 4E-BP plays a central role under hypoxia in promoting the cap-independent translation at the expense of cap-dependent translation and triggers specific defects in muscle development.

Published
2012
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6. TOPAZ1, a novel germ cell-specific expressed gene conserved during evolution across vertebrates

Author

Ronan Le Bouffant, Gabriel Livera, Corinne Cotinot, Beatrice Mandon-Pepin, Adrienne Baillet, Elodie Poumerol, Alix Luangpraseuth, Eric Pailhoux, Dominique Thépot, Jean Nicolas Volff, Biologie du Développement et Reproduction (BDR), Institut National de la Recherche Agronomique (INRA), DSV/DRR/SEGG/LDRG, Laboratoire de Différenciation et Radiobiologie des Gonades, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Génomique Fonctionnelle - Montpellier GenomiX (IGF MGX), Institut de Génomique Fonctionnelle (IGF), Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), This work was supported in part by PHASE Division, INRA. AB was supported by a doctoral fellowship from the Ministere delegue a l'Enseignement superieur et a la Recherche, France. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., Mandon Pepin, Béatrice, Biologie du développement et reproduction (BDR), École nationale vétérinaire - Alfort (ENVA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ProdInra, Archive Ouverte, and Centre National de la Recherche Scientifique (CNRS)-École nationale vétérinaire d'Alfort (ENVA)-Institut National de la Recherche Agronomique (INRA)

Subjects
Male, multidisciplinary sciences, lcsh:Medicine, Gene Expression, Fluorescent Antibody Technique, gene, mammalian gene, oocyte, TOPAZ1, marqueurs, science and technology, gamétogénèse mâle, souris, Germline, gonade, Mice, Exon, 0302 clinical medicine, ovin, Molecular Cell Biology, Testis, Gene expression, Morphogenesis, évolution, lcsh:Science, [SDV.BDD]Life Sciences [q-bio]/Development Biology, Phylogeny, Expressed Sequence Tags, Genetics, 0303 health sciences, Multidisciplinary, Reverse Transcriptase Polymerase Chain Reaction, Biologie du développement, Gene Expression Regulation, Developmental, Development Biology, Meiosis, medicine.anatomical_structure, Vertebrates, Female, Germ line development, Germ cell, Research Article, méiose, endocrine system, expression génique, Blotting, Western, Molecular Sequence Data, Biology, Real-Time Polymerase Chain Reaction, analyse phylogénétique, gamétogénèse femelle, Evolution, Molecular, 03 medical and health sciences, [SDV.BDD] Life Sciences [q-bio]/Development Biology, medicine, Animals, rt pcr, Amino Acid Sequence, RNA, Messenger, Gene, 030304 developmental biology, Homeodomain Proteins, Evolutionary Biology, Sheep, Sequence Homology, Amino Acid, Evolutionary Developmental Biology, lcsh:R, Ovary, développement ovarien, Oocyte, Mice, Inbred C57BL, Germ Cells, cellule germinale, Suppression subtractive hybridization, lcsh:Q, 030217 neurology & neurosurgery, Developmental Biology
Abstract

BACKGROUND: We had previously reported that the Suppression Subtractive Hybridization (SSH) approach was relevant for the isolation of new mammalian genes involved in oogenesis and early follicle development. Some of these transcripts might be potential new oocyte and granulosa cell markers. We have now characterized one of them, named TOPAZ1 for the Testis and Ovary-specific PAZ domain gene. PRINCIPAL FINDINGS: Sheep and mouse TOPAZ1 mRNA have 4,803 bp and 4,962 bp open reading frames (20 exons), respectively, and encode putative TOPAZ1 proteins containing 1,600 and 1653 amino acids. They possess PAZ and CCCH domains. In sheep, TOPAZ1 mRNA is preferentially expressed in females during fetal life with a peak during prophase I of meiosis, and in males during adulthood. In the mouse, Topaz1 is a germ cell-specific gene. TOPAZ1 protein is highly conserved in vertebrates and specifically expressed in mouse and sheep gonads. It is localized in the cytoplasm of germ cells from the sheep fetal ovary and mouse adult testis. CONCLUSIONS: We have identified a novel PAZ-domain protein that is abundantly expressed in the gonads during germ cell meiosis. The expression pattern of TOPAZ1, and its high degree of conservation, suggests that it may play an important role in germ cell development. Further characterization of TOPAZ1 may elucidate the mechanisms involved in gametogenesis, and particularly in the RNA silencing process in the germ line

Published
2011
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7. Chromium(III) triggers the DNA-damaged checkpoint of the cell cycle and induces a functional increase of 4E-BP

Author

Odile Mulner-Lorillon, Robert Bellé, Julia Morales, Patrick Cormier, Ronan Le Bouffant, Mer et santé (MS), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Cell cycle checkpoint, Embryo, Nonmammalian, Time Factors, MESH: Cell Cycle, Apoptosis, Toxicology, MESH: Dose-Response Relationship, Drug, chemistry.chemical_compound, 0302 clinical medicine, MESH: Ovum, MESH: Chromium Compounds, MESH: Embryonic Development, MESH: Animals, 0303 health sciences, EIF4G, EIF4E, Cell Cycle, Intracellular Signaling Peptides and Proteins, Translation (biology), General Medicine, Cell cycle, MESH: Eukaryotic Initiation Factor-4E, Cell biology, 030220 oncology & carcinogenesis, Protein Binding, Embryonic Development, Biology, Biological pathway, 03 medical and health sciences, Chlorides, MESH: Intracellular Signaling Peptides and Proteins, Chromium Compounds, Initiation factor, MESH: Protein Binding, Animals, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, CHEK1, MESH: Chlorides, 030304 developmental biology, Ovum, MESH: DNA Damage, Dose-Response Relationship, Drug, MESH: Apoptosis, MESH: Time Factors, MESH: Embryo, Nonmammalian, MESH: Sea Urchins, Eukaryotic Initiation Factor-4E, chemistry, Sea Urchins, DNA Damage
Abstract

International audience; Using sea urchin early embryos as a pertinent model, chromium(III) provoked cell cycle arrest and induced apoptosis. The molecular machinery of translation initiation was investigated. Chromium provoked a time- and dose-dependent increase in the level of 4E-BP protein, the natural regulator of the cap-dependent initiation factor 4E (eIF4E). The 4E-BP increase was the result of 4E-BP stabilization and appeared functional for physiological eIF4E binding, removal of eIF4E from the initiation factor eIF4G, and almost full inhibition of cap-dependent translation in vivo. The protein 4E-BP may be involved in the biological pathway of apoptosis associated with the activation of the DNA-damaged checkpoint of the cell cycle.

Published
2008
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8. TRPP2-dependent Ca2+ signaling in dorso-lateral mesoderm is required for kidney field establishment in Xenopus

Author

Muriel Umbhauer, Jean-François Riou, Isabelle Buisson, Marc Moreau, Isabelle Néant, Mélinée Futel, Ronan Le Bouffant, Catherine Leclerc, Signalisation et morphogenèse = Signalling and morphogenesis (LBD-E12), Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), CNRS, Universite Pierre et Marie Curie (UPMC), Emergence-UPMC research program, `Complexite du Vivant' doctoral school, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Embryo, Nonmammalian, TRPP Cation Channels, Field (physics), Xenopus, Retinoic acid, Kidney field specification, Xenopus Proteins, Biology, Kidney, Pronephros, chemistry.chemical_compound, Transient receptor potential channel, PAX8 Transcription Factor, Xenopus laevis, 03 medical and health sciences, 0302 clinical medicine, Downregulation and upregulation, Extracellular, medicine, Animals, Paired Box Transcription Factors, Calcium Signaling, Ca2+ signaling, [SDV.BDD]Life Sciences [q-bio]/Development Biology, Molecular Biology, 030304 developmental biology, 0303 health sciences, urogenital system, Lateral plate mesoderm, Cell Biology, Anatomy, biology.organism_classification, Molecular biology, Pax8, Cell biology, medicine.anatomical_structure, chemistry, 030217 neurology & neurosurgery, Ca2 signaling, TRPP2, Developmental Biology
Abstract

In Xenopus laevis embryos, kidney field specification is dependent on retinoic acid (RA) and coincides with a dramatic increase of Ca 2+ transients, but the role of Ca 2+ signaling in the kidney field is unknown. Here, we identify TRPP2, a member of the transient receptor potential (TRP) superfamily of channel proteins encoded by the pkd2 gene, as a central component of Ca 2+ signaling in the kidney field. TRPP2 is strongly expressed at the plasma membrane where it might regulate extracellular Ca 2+ entry. Knockdown of pkd2 in the kidney field results in the downregulation of pax8 , but not of other kidney field genes ( lhx1 , osr1 and osr2 ). We further show that inhibition of Ca 2+ signaling with an inducible Ca 2+ chelator also causes downregulation of pax8 , and that pkd2 knockdown results in a severe inhibition of Ca 2+ transients in kidney field explants. Finally, we show that disruption of RA results both in an inhibition of intracellular Ca 2+ signaling and of TRPP2 incorporation into the plasma membrane of kidney field cells. We propose that TRPP2-dependent Ca 2+ signaling is a key component of pax8 regulation in the kidney field downstream of RA-mediated non-transcriptional control of TRPP2.

Published
2015
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