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1. Acute Effects of Brevetoxin-3 Administered via Oral Gavage to Mice

Author: Peggy Barbe, Jordi Molgó, Robert Thai, Apolline Urman, Denis Servent, Nathalie Arnich, and Mathilde Keck
Subjects: brevetoxin-3, oral gavage, mice, males, females, body temperature, Biology (General), QH301-705.5
Abstract: Brevetoxins (BTXs) constitute a family of lipid-soluble toxic cyclic polyethers mainly produced by Karenia brevis, which is the main vector for a foodborne syndrome known as neurotoxic shellfish poisoning (NSP) in humans. To prevent health risks associated with the consumption of contaminated shellfish in France, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) recommended assessing the effects of BTXs via an acute oral toxicity study in rodents. Here, we investigated the effect of a single oral administration in both male and female mice with several doses of BTX-3 (100 to 1,500 µg kg−1 bw) during a 48 h observation period in order to provide toxicity data to be used as a starting point for establishing an acute oral reference dose (ARfD). We monitored biological parameters and observed symptomatology, revealing different effects of this toxin depending on the sex. Females were more sensitive than males to the impact of BTX-3 at the lowest doses on weight loss. For both males and females, BTX-3 induced a rapid, transient and dose-dependent decrease in body temperature, and a transient dose-dependent reduced muscle activity. Males were more sensitive to BTX-3 than females with more frequent observations of failures in the grip test, convulsive jaw movements, and tremors. BTX-3’s impacts on symptomatology were rapid, appearing during the 2 h after administration, and were transient, disappearing 24 h after administration. The highest dose of BTX-3 administered in this study, 1,500 µg kg−1 bw, was more toxic to males, leading to the euthanasia of three out of five males only 4 h after administration. BTX-3 had no effect on water intake, and affected neither the plasma chemistry parameters nor the organs’ weight. We identified potential points of departure that could be used to establish an ARfD (decrease in body weight, body temperature, and muscle activity).
Published: 2023
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2. C910 chemical compound inhibits the traffiking of several bacterial AB toxins with cross-protection against influenza virus

Author: Yu Wu, Nassim Mahtal, Eléa Paillares, Léa Swistak, Sara Sagadiev, Mridu Acharya, Caroline Demeret, Sylvie Van Der Werf, Florence Guivel-Benhassine, Olivier Schwartz, Serena Petracchini, Amel Mettouchi, Lucie Caramelle, Pierre Couvineau, Robert Thai, Peggy Barbe, Mathilde Keck, Priscille Brodin, Arnaud Machelart, Valentin Sencio, François Trottein, Martin Sachse, Gaëtan Chicanne, Bernard Payrastre, Florian Ville, Victor Kreis, Michel-Robert Popoff, Ludger Johannes, Jean-Christophe Cintrat, Julien Barbier, Daniel Gillet, and Emmanuel Lemichez
Subjects: Biological sciences, Microbiology, Science
Abstract: Summary: The development of anti-infectives against a large range of AB-like toxin-producing bacteria includes the identification of compounds disrupting toxin transport through both the endolysosomal and retrograde pathways. Here, we performed a high-throughput screening of compounds blocking Rac1 proteasomal degradation triggered by the Cytotoxic Necrotizing Factor-1 (CNF1) toxin, which was followed by orthogonal screens against two toxins that hijack the endolysosomal (diphtheria toxin) or retrograde (Shiga-like toxin 1) pathways to intoxicate cells. This led to the identification of the molecule C910 that induces the enlargement of EEA1-positive early endosomes associated with sorting defects of CNF1 and Shiga toxins to their trafficking pathways. C910 protects cells against eight bacterial AB toxins and the CNF1-mediated pathogenic Escherichia coli invasion. Interestingly, C910 reduces influenza A H1N1 and SARS-CoV-2 viral infection in vitro. Moreover, parenteral administration of C910 to mice resulted in its accumulation in lung tissues and a reduction in lethal influenza infection.
Published: 2022
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3. A metabolically stable apelin-17 analog decreases AVP-induced antidiuresis and improves hyponatremia

Author: Adrien Flahault, Pierre-Emmanuel Girault-Sotias, Mathilde Keck, Rodrigo Alvear-Perez, Nadia De Mota, Lucie Estéoulle, Sridévi M. Ramanoudjame, Xavier Iturrioz, Dominique Bonnet, and Catherine Llorens-Cortes
Subjects: Science
Abstract: Apelin and AVP have opposing effects water balance in humans and rodents. Here, the authors report that a metabolically stable apelin-17 analog, by acting at the kidney level, reduces AVP-induced antidiuresis and improves hyponatremia in rodents, demonstrating a potential approach for treating water metabolism disorders.
Published: 2021
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4. A variant of ASIC2 mediates sodium retention in nephrotic syndrome

Author: Marc Fila, Ali Sassi, Gaëlle Brideau, Lydie Cheval, Luciana Morla, Pascal Houillier, Christine Walter, Michel Gennaoui, Laure Collignon, Mathilde Keck, Gabrielle Planelles, Naziha Bakouh, Michel Peuchmaur, Georges Deschênes, Ignacio Anegon, Séverine Remy, Bruno Vogt, Gilles Crambert, and Alain Doucet
Subjects: Nephrology, Medicine
Abstract: Idiopathic nephrotic syndrome (INS) is characterized by proteinuria and renal sodium retention leading to edema. This sodium retention is usually attributed to epithelial sodium channel (ENaC) activation after plasma aldosterone increase. However, most nephrotic patients show normal aldosterone levels. Using a corticosteroid-clamped (CC) rat model of INS (CC-PAN), we showed that the observed electrogenic and amiloride-sensitive Na retention could not be attributed to ENaC. We then identified a truncated variant of acid-sensing ion channel 2b (ASIC2b) that induced sustained acid-stimulated sodium currents when coexpressed with ASIC2a. Interestingly, CC-PAN nephrotic ASIC2b-null rats did not develop sodium retention. We finally showed that the expression of the truncated ASIC2b in the kidney was dependent on the presence of albumin in the tubule lumen and activation of ERK in renal cells. Finally, the presence of ASIC2 mRNA was also detected in kidney biopsies from patients with INS but not in any of the patients with other renal diseases. We have therefore identified a variant of ASIC2b responsible for the renal Na retention in the pathological context of INS.
Published: 2021
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5. LIT01-196, a Metabolically Stable Apelin-17 Analog, Normalizes Blood Pressure in Hypertensive DOCA-Salt Rats via a NO Synthase-dependent Mechanism

Author: Adrien Flahault, Mathilde Keck, Pierre-Emmanuel Girault-Sotias, Lucie Esteoulle, Nadia De Mota, Dominique Bonnet, and Catherine Llorens-Cortes
Subjects: apelin, metabolically stable apelin analogs, APJ receptor, hypertension, DOCA-salt hypertensive rats, Therapeutics. Pharmacology, RM1-950
Abstract: Apelin is a neuro-vasoactive peptide that plays a major role in the control of cardiovascular functions and water balance, but has an in-vivo half-life in the minute range, limiting its therapeutic use. We previously developed LIT01-196, a systemically active metabolically stable apelin-17 analog, produced by chemical addition of a fluorocarbon chain to the N-terminal part of apelin-17. LIT01-196 behaves as a potent full agonist for the apelin receptor and has an in vivo half-life in the bloodstream of 28 min after intravenous (i.v.) and 156 min after subcutaneous (s.c.) administrations in conscious normotensive rats. We aimed to investigate the effects of LIT01-196 following systemic administrations on arterial blood pressure, heart rate, fluid balance and electrolytes in conscious normotensive and hypertensive deoxycorticosterone acetate (DOCA)-salt rats. Acute i.v. LIT01-196 administration, in increasing doses, dose-dependently decreases arterial blood pressure with ED50 values of 9.8 and 3.1 nmol/kg in normotensive and hypertensive rats, respectively. This effect occurs for both via a nitric oxide-dependent mechanism. Moreover, acute s.c. LIT01-196 administration (90 nmol/kg) normalizes arterial blood pressure in conscious hypertensive DOCA-salt rats for more than 7 h. The LIT01-196-induced blood pressure decrease remains unchanged after 4 consecutive daily s.c. administrations of 90 nmol/kg, and does not induce any alteration of plasma sodium and potassium levels and kidney function as shown by the lack of change in plasma creatinine and urea nitrogen levels. Activating the apelin receptor with LIT01-196 may constitute a novel approach for the treatment of hypertension.
Published: 2021
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6. From a Cone Snail Toxin to a Competitive MC4R Antagonist

Author: Steve Reynaud, Suli-Anne Laurin, Justyna Ciolek, Peggy Barbe, Anne-Cécile Van Baelen, Michaël Susset, Florian Blondel, Marine Ghazarian, Julia Boeri, Margot Vanden Driessche, Grégory Upert, Gilles Mourier, Pascal Kessler, Laure Konnert, Rémy Beroud, Mathilde Keck, Denis Servent, Michel Bouvier, Nicolas Gilles, Service d'Ingénierie Moléculaire pour la Santé (ex SIMOPRO) (SIMoS), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Montréal (UdeM), and Smartox Biotechnologies
Subjects: [SDV]Life Sciences [q-bio], Snails, Drug Discovery, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [CHIM]Chemical Sciences, Animals, Receptor, Melanocortin, Type 4, Molecular Medicine, Amino Acid Sequence, Conotoxins, Ligands, Melanocortins
Abstract: International audience; The melanocortin 4 receptor (MC4R) plays a role in energy homeostasis and represents a target for treating energy balance disorders. For decades, synthetic ligands have been derived from MC4R endogenous agonists and antagonists, such as setmelanotide used to treat rare forms of genetic obesity. Recently, animal venoms have demonstrated their capacity to provide melanocortin ligands with toxins from a scorpion and a spider. Here, we described a cone snail toxin, N-CTX-Ltg1a, with a nanomolar affinity for hMC4R but unrelated to any known toxins or melanocortin ligands. We then derived from the conotoxin the linear peptide HT1-0, a competitive antagonist of G s , G 15 , and β-arrestin2 pathways with a low nanomolar affinity for hMC4R. Similar to endogenous ligands, HT1-0 needs hydrophobic and basic residues to bind hMC4R. Altogether, it represents the first venom-derived peptide of high affinity on MC4R and paves the way for the development of new MC4R antagonists.
Published: 2022
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7. QGC606: A Best-in-Class Orally Active Centrally Acting Aminopeptidase A Inhibitor Prodrug for Treating Heart Failure Following Myocardial Infarction

Author: Solène E. Boitard, Mathilde Keck, Robin Deloux, Pierre-Emmanuel Girault-Sotias, Yannick Marc, Nadia De Mota, Delphine Compere, Onnik Agbulut, Fabrice Balavoine, Catherine Llorens-Cortes, Neuropeptides centraux et régulations hydrique et cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Labex MemoLife, Université Paris sciences et lettres (PSL)-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), Quantum Genomics [Paris, France] (QG), Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Keck, Mathilde
Subjects: Heart Failure, Male, Ventricular Remodeling, Myocardium, [SDV]Life Sciences [q-bio], Myocardial Infarction, Glutamyl Aminopeptidase, Fibrosis, [SDV] Life Sciences [q-bio], Mice, Ramipril, [SDV.SP.PHARMA] Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Animals, Humans, Prodrugs, RNA, Messenger, Cardiology and Cardiovascular Medicine
Abstract: International audience; Background: Blockade of brain renin-angiotensin system (RAS) overactivity by firibastat, the first centrally acting aminopeptidase A (APA) inhibitor prodrug, has already demonstrated its effectiveness in improving cardiac function after myocardial infarction (MI). We developed QGC606, a more potent and more selective APA inhibitor prodrug and studied its effects after long-term oral administration in mice post-MI.Methods: Two days after MI induced by the left anterior descending artery ligation, adult male mice were randomized into 4 groups to receive oral treatment during 4 weeks with vehicle; QGC606; firibastat; or the angiotensin-I converting enzyme inhibitor ramipril, used as positive control.Results: Four weeks post-MI, brain APA was overactivated in vehicle-treated MI mice. QGC606 treatment normalized brain APA hyperactivity to control values measured in sham-operated mice. Four weeks post-MI, QGC606-treated mice had higher left ventricular (LV) ejection fractions, significantly smaller LV end-systolic diameter and volume, significantly lower HF biomarkers mRNA expression (Myh7 and Anf) and plasma N-terminal pro B-type natriuretic peptide (NT-pro-BNP) and noradrenaline levels than saline-treated mice. QGC606 treatment significantly improved the dP/dt max and min, LV end-diastolic pressure without affecting blood pressure (BP), whereas we observed a decrease in BP in ramipril-treated mice. We observed also a reduction of cardiac fibrosis, highlighted by lower connective tissue growth factor mRNA levels and a reduction of both the fibrotic area and MI size in QGC606-treated mice.Conclusions: Chronic oral QGC606 administration in post-MI mice showed beneficial effects in improving cardiac function and reducing cardiac remodeling and fibrosis but, unlike ramipril, without lowering BP.
Published: 2022
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8. Monitoring In Vivo Performances of Protein–Drug Conjugates Using Site-Selective Dual Radiolabeling and Ex Vivo Digital Imaging

Author: Héloïse Cahuzac, Antoine Sallustrau, Carole Malgorn, Fabrice Beau, Peggy Barbe, Victor Babin, Steven Dubois, Alberto Palazzolo, Robert Thai, Isabelle Correia, Ki Baek Lee, Sébastien Garcia-Argote, Olivier Lequin, Mathilde Keck, Hervé Nozach, Sophie Feuillastre, Xin Ge, Gregory Pieters, Davide Audisio, Laurent Devel, Service d'Ingénierie Moléculaire pour la Santé (ex SIMOPRO) (SIMoS), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Service de Chimie Bio-Organique et de Marquage (SCBM), Laboratoire des biomolécules (LBM UMR 7203), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and The University of Texas Health Science Center at Houston (UTHealth)
Subjects: Immunoconjugates, [SDV]Life Sciences [q-bio], Drug Discovery, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Molecular Medicine, Carbon Radioisotopes, Article
Abstract: International audience; In preclinical models, the development and optimization of protein−drug conjugates require accurate determination of the plasma and tissue profiles of both the protein and its conjugated drug. To this aim, we developed a bioanalytical strategy based on dual radiolabeling and ex vivo digital imaging. By combining enzymatic and chemical reactions, we obtained homogeneous dual-labeled anti-MMP-14 Fabs (antigen-binding fragments) conjugated to monomethyl auristatin E where the protein scaffold was labeled with carbon-14 (14C) and the conjugated drug with tritium (3H). These antibody−drug conjugates with either a noncleavable or a cleavable linker were then evaluated in vivo. By combining liquid scintillation counting and ex vivo dual-isotope radio-imaging, it was possible not only to monitor both components simultaneously during their circulation phase but also to quantify accurately their amount accumulated within the different organs.
Published: 2022
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9. A new Kunitz‐type snake toxin family associated with an original mode of interaction with the vasopressin 2 receptor

Author: Laura Droctové, Justyna Ciolek, Christiane Mendre, Amélia Chorfa, Paola Huerta, Chrystelle Carvalho, Charlotte Gouin, Manon Lancien, Goran Stanajic‐Petrovic, Lorine Braco, Guillaume Blanchet, Gregory Upert, Gregory De Pauw, Peggy Barbe, Mathilde Keck, Gilles Mourier, Bernard Mouillac, Servent Denis, Ricardo C. Rodríguez de la Vega, Loïc Quinton, Nicolas Gilles, Service d'Ingénierie Moléculaire pour la Santé (ex SIMOPRO) (SIMoS), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Génomique Fonctionnelle (IGF), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Laboratory of Mass Spectrometry, GIGA, Université de Liège, Ecologie Systématique et Evolution (ESE), AgroParisTech-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), This work was supported by the French Atomic and Alternative Energies and La Ligue contre le Cancer for financial support and for the Amelia Chorfa PhD programme funding., and Keck, Mathilde
Subjects: Pharmacology, Proteomics, Receptors, Vasopressin, Peptide sequencing, Snake venom, Vasopressins, [SDV]Life Sciences [q-bio], Antagonist, V2R, Kunitz peptide, Rats, [SDV] Life Sciences [q-bio], Peptide synthesis, [SDV.SP.PHARMA] Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [SDV.TOX]Life Sciences [q-bio]/Toxicology, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Animals, Elapidae, Peptides, ComputingMilieux_MISCELLANEOUS, Snake Venoms
Abstract: International audience; Background and Purpose: Venomous animals express numerous Kunitz-type peptides. The mambaquaretin-1 (MQ1) peptide identified from the Dendroaspis angusticeps venom is the most selective antagonist of the arginine-vasopressin V2 receptor (V2R) and the only unique Kunitz-type peptide active on a GPCR. We aimed to exploit other mamba venoms to enlarge the V2R-Kunitz peptide family and gain insight into the MQ1 molecular mode of action.Experimental Approach: We used a bio-guided screening assay to identify novel MQs and placed them phylogenetically. MQs were produced by solid-phase peptide synthesis and characterized in vitro by binding and functional tests and in vivo by diuresis measurement in rats.Key Results: Eight additional MQs were identified with nanomolar affinities for the V2R, all antagonists. MQs form a new subgroup in the Kunitz family, close to the V2R non-active dendrotoxins and to two V2R-active cobra toxins. Sequence comparison between active and non-active V2R Kunitz peptides highlighted five positions, among which four are involved in V2R interaction and belong to the two large MQ1 loops. We finally determined that eight positions, part of these two loops, interact with the V2R. The variant MQ1-K39A showed a higher affinity for the hV2R, but not for the rat V2R.Conclusions and Implications: A new function and mode of action is associated with the Kunitz peptides. The number of MQ1 residues involved in V2R binding is large and may explain its absolute selectivity. MQ1-K39A represents the first step in the improvement of the MQ1 design from a medicinal perspective.
Published: 2022
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10. A screening pipeline identifies a broad-spectrum inhibitor of bacterial AB toxins with cross protection against influenza A virus H1N1 and SARS-CoV-2

Author: Yu Wu, Nassim Mahtal, Léa Swistak, Sara Sagadiev, Mridu Acharya, Caroline Demeret, Sylvie van der Werf, Florence Guivel-Benhassine, Olivier Schwartz, Serena Petracchini, Amel Mettouchi, Eléa Paillares, Lucie Caramelle, Pierre Couvineau, Robert Thai, Peggy Barbe, Mathilde Keck, Priscille Brodin, Arnaud Machelart, Valentin Sencio, François Trottein, Martin Sachse, Gaëtan Chicanne, Bernard Payrastre, Florian Ville, Victor Kreis, Michel-Robert Popoff, Ludger Johannes, Jean-Christophe Cintrat, Julien Barbier, Daniel Gillet, and Emmanuel Lemichez
Subjects: Diphtheria toxin, biology, Toxin, Endosome, Chemistry, Toxin transport, Shiga toxin, medicine.disease_cause, Microbiology, PIKFYVE, AB toxin, biology.protein, Influenza A virus, medicine
Abstract: A challenge for the development of host-targeted anti-infectives against a large spectrum of AB-like toxin-producing bacteria encompasses the identification of chemical compounds corrupting toxin transport through both endolysosomal and retrograde pathways. Here, we performed a high-throughput screening of small chemical compounds blocking active Rac1 proteasomal degradation triggered by the Cytotoxic Necrotizing Factor-1 (CNF1) toxin, followed by orthogonal screens against two AB toxins hijacking defined endolysosomal (Diphtheria toxin) or retrograde (Shiga-like toxin 1) pathways to intoxicate cells. This led to the identification of the molecule N-(3,3-diphenylpropyl)-1-propyl-4-piperidinamine, referred to as C910. This compound induces the swelling of EEA1-positive early endosomes, in absence of PIKfyve kinase inhibition, and disturbs the trafficking of CNF1 and the B-subunit of Shiga toxin along the endolysosomal or retrograde pathways, respectively. Together, we show that C910 protects cells against 8 bacterial AB toxins including large clostridial glucosylating toxins from Clostridium difficile. Of interest, C910 also reduced viral infection in vitro including influenza A virus subtype H1N1 and SARS-CoV-2. Moreover, parenteral administration of C910 to the mice resulted in its accumulation in lung tissues and reduced lethal influenza infection.
Published: 2021
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11. A new Kunitz-type snake toxin family associated with an original mode of interaction with the vasopressin 2 receptor

Author: Gregory Upert, Loïc Quinton, Christiane Mendre, Denis Servent, Edwin De Pauw, Amélia Chorfa, Manon Lancien, Bernard Mouillac, Nicolas Gilles, Justyna Ciolek, Guillaume Blanchet, Laura Droctové, Peggy Barbe, Mathilde Keck, Gilles Mourier, Chrystelle Carvalho, Ricardo Rodriguez-de-la-vega, Charlotte Gouin, and Paola Huerta
Subjects: chemistry.chemical_classification, chemistry.chemical_compound, chemistry, Biochemistry, Arginine vasopressin receptor 2, Peptide synthesis, Venom, Peptide, Mode of action, Receptor, Function (biology), G protein-coupled receptor
Abstract: Background and purpose. Venomous animals express numerous Kunitz-type peptides. The mambaquaretin-1 (MQ1) recently identified from the Dendroaspis angusticeps venom is the most selective antagonist of the arginine-vasopressin V2 receptor (V2R) and the unique Kunitz-type peptide active on a GPCR. We aimed to exploit other mamba venoms to enlarge the V2R-Kunitz peptide family and get insight into the MQ1 molecular mode of action. Experimental approach. We used a bio-guided screening assay to identify novel MQs and placed them phylogenetically. Several newly identified MQs were produced by solid phase peptide synthesis. They were characterized in vitro by binding and functional tests andin vivo by diuresis measurement in rats. Key results. Eight additional MQs were identified with nanomolar affinities for the V2R, all antagonists. MQs form a new subgroup in the Kunitz family, close to the V2R non-active dendrotoxins and to 2 V2R active cobra toxins. Sequence comparison between active and non-active V2R Kunitz peptides highlighted 5 specific V2R positions. Four of them are involved in V2R activity and belong to the 2 large MQ1 loops. We finally determined that 8 positions, part of these 2 loops, interact with the V2R. The variant MQ1-K39A showed specificity for the human versus the rat V2R . Conclusions and implications. A third function and mode of action is now associated with the Kunitz-peptides. The number of MQ1 residues involved in V2R binding is large and may explain its absolute selectivity. MQ1-K39A represents the first step in the improvement of the MQ1 design for medicinal perspective.
Published: 2021
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12. A variant of ASIC2 mediates sodium retention in nephrotic syndrome

Author: Georges Deschênes, Marc Fila, Gabrielle Planelles, Pascal Houillier, Gilles Crambert, Alain Doucet, Michel Gennaoui, Christine Walter, Ignacio Anegon, Laure Collignon, Luciana Morla, Lydie Cheval, Gaëlle Brideau, Michel Peuchmaur, Mathilde Keck, Naziha Bakouh, Bruno Vogt, Séverine Remy, Ali Sassi, and CNRS ERL 8228 - Laboratoire de physiologie rénale et tubulopathies, 75006, Paris, France. (TIR)
Subjects: Nephrology, Epithelial sodium channel, medicine.medical_specialty, Nephrotic Syndrome, MAP Kinase Signaling System, Sodium channels, Kidney, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, chemistry.chemical_compound, Albumins, Internal medicine, Edema, medicine, Homeostasis, Animals, ComputingMilieux_MISCELLANEOUS, Aldosterone, Chemistry, Gene Expression Profiling, Sodium channel, Sodium, General Medicine, medicine.disease, Rats, 3. Good health, Acid Sensing Ion Channels, Disease Models, Animal, Proteinuria, medicine.anatomical_structure, Endocrinology, Ion channels, medicine.symptom, Nephrotic syndrome, Research Article
Abstract: Idiopathic nephrotic syndrome (INS) is characterized by proteinuria and renal sodium retention leading to edema. This sodium retention is usually attributed to epithelial sodium channel (ENaC) activation after plasma aldosterone increase. However, most nephrotic patients show normal aldosterone levels. Using a corticosteroid-clamped (CC) rat model of INS (CC-PAN), we showed that the observed electrogenic and amiloride-sensitive Na retention could not be attributed to ENaC. We then identified a truncated variant of acid-sensing ion channel 2b (ASIC2b) that induced sustained acid-stimulated sodium currents when coexpressed with ASIC2a. Interestingly, CC-PAN nephrotic ASIC2b-null rats did not develop sodium retention. We finally showed that the expression of the truncated ASIC2b in the kidney was dependent on the presence of albumin in the tubule lumen and activation of ERK in renal cells. Finally, the presence of ASIC2 mRNA was also detected in kidney biopsies from patients with INS but not in any of the patients with other renal diseases. We have therefore identified a variant of ASIC2b responsible for the renal Na retention in the pathological context of INS.
Published: 2021
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13. A new variant of ASIC2 mediates sodium retention in nephrotic syndrome

Author: Mathilde Keck, Laure Collignon L, Ignacio Anegon, Lydie Cheval, Gabrielle Planelles, Georges Deschênes, Gilles Crambert, Bruno Vogt, Michel Peuchmaur, Christine Walter, Michel Gennaoui, Pascal Houillier, Alain Doucet, Marc Fila, Luciana Morla, Naziha Bakouh, Séverine Remy, Gaëlle Brideau, Ali Sassi, Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université de Paris (UP), and CNRS ERL 8228 - Laboratoire de physiologie rénale et tubulopathies, 75006, Paris, France. (TIR)
Subjects: Epithelial sodium channel, 0303 health sciences, Kidney, medicine.medical_specialty, Proteinuria, Aldosterone, [SDV]Life Sciences [q-bio], Albumin, Context (language use), medicine.disease, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, 3. Good health, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, medicine.anatomical_structure, Endocrinology, chemistry, Internal medicine, medicine, medicine.symptom, Nephrotic syndrome, 030217 neurology & neurosurgery, Acid-sensing ion channel, 030304 developmental biology
Abstract: Idiopathic nephrotic syndrome (INS) is characterized by proteinuria and renal Na retention leading to oedema. This Na retention is usually attributed to epithelial sodium channel (ENaC) activation following plasma aldosterone increase. However, most nephrotic patients show normal aldosterone levels. Using a corticosteroid-clamped rat model of INS (CC-PAN), we showed that the observed electrogenic and amiloride-sensitive Na retention could not be attributed to ENaC. We, then, identified a truncated variant of acid sensing ion channel 2b (ASIC2b) that induced sustained acid-stimulated sodium currents when co-expressed with ASIC2a. Interestingly, CC-PAN nephrotic ASIC2b-null rats did not develop sodium retention. We finally showed that expression of the truncated ASIC2b in kidney was dependent on the presence of albumin in the tubule lumen and activation of ERK in renal cells. Finally, the presence of ASIC2 mRNA was also detected in kidney biopsies from patients with INS but in any of the patients with other renal diseases. We have, therefore, identified a novel variant of ASIC2b responsible for the renal Na retention in the pathological context of INS.
Published: 2021

14. BRAIN-PENETRATING AMINOPEPTIDASE A INHIBITORS FOR NEW TREATMENT OF HYPERTENSION AND HEART FAILURE

Author: Mathilde Keck, Bernard P. Roques, Fabrice Balavoine, Reda Hmazzou, Catherine Llorens-Cortes, Solène Emmanuelle Boitard, and Yannick Marc
Subjects: medicine.medical_specialty, Aminopeptidase A, Physiology, business.industry, Heart failure, Internal medicine, Internal Medicine, Cardiology, Medicine, Cardiology and Cardiovascular Medicine, business, medicine.disease
Published: 2021
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15. Analysis of CLCNKB mutations at dimer-interface, calcium binding site and pore reveals a variety of functional alterations in ClC-Kb channel leading to Bartter syndrome

Author: Marc Paulais, Imene Sakhi, Mathilde Keck, Yohan Bignon, Olga Andrini, Gabrielle Planelles, Naziha Bakouh, Sara Bitam, Nadia Frachon, Jacques Teulon, Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Métabolisme et physiologie rénales (ERL 8228), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université de Paris (UP)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université de Paris (UP), Institut NeuroMyoGène (INMG), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École pratique des hautes études (EPHE), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Espace et action, Université de Lyon-Université de Lyon-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Neuropeptides centraux et régulations hydrique et cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Paulais, Marc, Centre National de la Recherche Scientifique (CNRS)-Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), and Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: kidney, chloride channel, Xenopus, [SDV]Life Sciences [q-bio], Mutant, [SDV.BBM.BP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, medicine.disease_cause, Bartter syndrome, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, CLCNKB, Cell Line, 03 medical and health sciences, Chloride Channels, Genetics, medicine, Animals, Humans, Genetics (clinical), ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Mutation, Binding Sites, biology, Endoplasmic reticulum, 030305 genetics & heredity, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, medicine.disease, biology.organism_classification, ClC-Kb, 3. Good health, Cell biology, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Protein Transport, Chloride channel, biology.protein, Oocytes, Calcium, Protein Multimerization, mutation, Intracellular, Protein Binding
Abstract: International audience; Pathological missense mutations in CLCNKB gene give a wide spectrum of clinical phenotypes in Bartter syndrome type III patients. Molecular analysis of the mutated ClC-Kb channels can be helpful to classify the mutations according to their functional alteration. We investigated the functional consequences of nine mutations in the CLCNKB gene causing Bartter syndrome. We first established that all tested mutations lead to decreased ClC-Kb currents. Combining electrophysiological and biochemical methods in Xenopus laevis oocytes and in MDCKII cells, we identified three classes of mutations. One class is characterized by altered channel trafficking. p.A210V, p.P216L, p.G424R, and p.G437R are totally or partially retained in the endoplasmic reticulum. p.S218N is characterized by reduced channel insertion at the plasma membrane and altered pH-sensitivity; thus, it falls in the second class of mutations. Finally, we found a novel class of functionally inactivated mutants normally present at the plasma membrane. Indeed, we found that p.A204T alters the pH-sensitivity, p.A254V abolishes the calcium-sensitivity. p.G219C and p.G465R are probably partially inactive at the plasma membrane. In conclusion, most pathogenic mutants accumulate partly or totally in intracellular compartments, but some mutants are normally present at the membrane surface and simultaneously show a large range of altered channel gating properties.
Published: 2019
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16. P4481NI956/QGC006, a potent orally active, brain-penetrating aminopeptidase A inhibitor prodrug for treating hypertension

Author: Delphine Compere, Mathilde Keck, Fabrice Balavoine, Bernard P. Roques, Catherine Llorens-Cortes, Adrien Flahault, Nicolas Inguimbert, and H De Almeida
Subjects: Aminopeptidase A, Orally active, business.industry, Medicine, Pharmacology, Prodrug, Cardiology and Cardiovascular Medicine, business
Abstract: Background Brain renin-angiotensin system hyperactivity has been implicated in the development and maintenance of hypertension. We previously showed that aminopeptidase A (APA) generates in the brain, angiotensin III, which exerts a tonic stimulatory control over blood pressure in hypertensive rats. Thus, the central injection of the specific and selective APA inhibitor, EC33 ((3S)-3-amino-4-sulfanyl-butane-1-sulfonic acid), by blocking the formation of brain angiotensin III, normalizes blood pressure in experimental models of hypertension. Therefore, brain APA appears as a potential new therapeutic target for the treatment of hypertension. We then developed RB150/firibastat, a prodrug of EC33, able of inhibiting brain APA activity and decreasing blood pressure in hypertensive rats after oral administration. Purpose However, considering the high dose of orally active RB150/firibastat required to decrease BP in spontaneously hypertensive rats (SHR) (150 mg/kg) and deoxycorticosterone acetate-salt (DOCA-salt) (50 mg/kg) rats, the aim of our work was to develop new more potent APA inhibitor prodrugs with greater bioavailability for inhibiting brain APA activity. Methods We used a salt- and volume-dependent model of hypertension, the DOCA-salt rat. For in vivo assessments of brain APA activity, brains were collected 4 hours after the oral administration. A catheter was inserted into the right femoral artery to monitor mean arterial blood pressure in alert rats. We evaluated plasma arginine-vasopressin (AVP) levels by radioimmunoassay. Rats were individually housed in metabolic cages for urine and electrolyte output measurements. Results We report here the development of a new APA inhibitor prodrug, NI956/QGC006, obtained by the disulfide bridge-mediated dimerization of NI929 ((3S,4S)-3-amino-4-mercapto-6-phenyl-hexane-1-sulfonic acid). NI929 is 10 more efficient than EC33 at inhibiting recombinant mouse APA activity in vitro. Following oral administration at a dose of 4 mg/kg in conscious DOCA-salt rats, NI956/QGC006 normalized brain APA activity and induced a marked decrease in blood pressure of −44±13 mmHg four hours after treatment (p Conclusions This study shows that NI956/QGC006 is a “best-in-class” central-acting APA inhibitor prodrug, belonging to the same drug class as RB150/firibastat, supporting the strategy of brain APA inhibition for hypertension treatment. Acknowledgement/Funding ANR (Agence Nationale de la Recherche) grant to Catherine Llorens-Cortes (LabCom CARDIOBAPAI) and Quantum Genomics financial support.
Published: 2019
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17. P4473Brain renin-angiotensin system blockade with firibastat, an orally active, central acting aminopeptidase A inhibitor prodrug prevents cardiac dysfunction after myocardial infarction in mice

Author: Mathilde Keck, Fabrice Balavoine, N Mougenot, S Boitard-Joanne, Onnik Agbulut, Yannick Marc, and Catherine Llorens-Cortes
Subjects: Renin angiotensin system blockade, Aminopeptidase A, Orally active, business.industry, medicine, Myocardial infarction, Pharmacology, Prodrug, Cardiology and Cardiovascular Medicine, medicine.disease, business, Cardiac dysfunction
Abstract: Introduction Brain renin-angiotensin system (RAS) hyperactivity has been implicated in sympathetic hyperactivity and progressive left ventricular (LV) dysfunction after myocardial infarction (MI). Brain angiotensin III, generated by aminopeptidase A (APA), is one of the main effector peptides of the brain RAS in the control of cardiac function. Purpose We hypothesized that orally administered firibastat (previously named RB150), an orally central acting APA inhibitor prodrug, would attenuate heart failure (HF) development after MI in mice, by blocking brain RAS hyperactivity. Methods Two days after MI induced by the left anterior descending artery ligation, adult male CD1 mice were randomized to three groups, for four to eight weeks of oral treatment with vehicle (MI+vehicle), firibastat (150 mg/kg; MI+firibastat) or the angiotensin I converting enzyme inhibitor enalapril (1 mg/kg; MI+enalapril) as a positive control. Results From one to four weeks post-MI, brain APA hyperactivity occurred, contributing to brain RAS hyperactivity. Firibastat treatment during four weeks after MI normalized brain APA hyperactivity, with a return to the control values measured in the sham group. Four and six weeks after MI, MI+firibastat mice had a significant lower LV end-diastolic pressure, LV end-systolic diameter and volume, and a higher LV ejection fraction than MI+vehicle mice. Moreover, the mRNA levels of biomarkers of HF (Myh7, Bnp and Anf) were significantly lower following firibastat treatment. For a similar infarct size, the peri-infarct area of MI+firibastat mice displayed lower levels of mRNA for markers of fibrosis such Ctgf and collagen types I and III than MI+vehicle mice. Conclusions Chronic oral firibastat administration after MI in mice normalizes brain APA hyperactivity, thereby normalizing brain RAS hyperactivity, whilst preventing cardiac dysfunction and attenuating cardiac hypertrophy and fibrosis. Acknowledgement/Funding INSERM, College de France, ANR LabCom, and Quantum Genomics
Published: 2019
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18. P4554Central-acting aminopeptidase a inhibitors for new treatment of hypertension: from discovery to clinical trial

Author: Yannick Marc, Catherine Llorens-Cortes, Fabrice Balavoine, Michel Azizi, Mathilde Keck, Bernard P. Roques, Adrien Flahault, and Reda Hmazzou
Subjects: Clinical trial, Aminopeptidase A, business.industry, Medicine, Pharmacology, Cardiology and Cardiovascular Medicine, business
Abstract: The hyperactivity of the brain renin–angiotensin system (RAS) has been implicated in the development and maintenance of arterial hypertension (HTA). Our aim was to demonstrate that normalizing brain RAS hyperactivity could constitute a new therapeutic approach for HTA treatment We first demonstrated in the brain that aminopeptidase A (APA) is the enzyme generating angiotensin III (AngIII) from AngII. Then, using the specific and selective APA inhibitor, EC33 ((3S)-3-amino-4-sulfanyl-butane-1-sulfonic acid), we showed that AngIII is one of the main effector peptides of the brain RAS, exerting a tonic stimulatory control over blood pressure (BP) in hypertensive rats. This suggests that brain APA may be a potential therapeutic target for HTA treatment. We then designed RB150 {4,4-dithio[bis(3-aminobutyl sulfonic acid)]}, an orally active prodrug of EC33. RB150, given orally in conscious deoxycorticosterone acetate-salt (DOCA-salt) rats or spontaneously hypertensive rats, crosses the intestinal, hepatic and blood-brain barriers, enters the brain, where it is cleaved by brain reductases, generating two active molecules of EC33 which inhibit brain APA activity, block the formation of brain AngIII and induce a marked and sustained decrease in BP. The RB150-induced BP decrease is due to a reduced vasopressin release, which increases diuresis, reducing extracellular volume, a decrease in sympathetic tone, leading to a reduction of vascular resistances and the improvement of the baroreflex function (Figure below). RB150 was renamed firibastat by OMS. Phase Ia/Ib clinical trials showed that firibastat is clinically and biologically well-tolerated in healthy volunteers. Firibastat could constitute the first drug candidate of a new class of antihypertensive agents targeting the brain RAS, the clinical efficacy of which (Phase IIa and Phase IIb) in hypertensive patients was achieved. Acknowledgement/Funding INSERM, College de France, ANR LabCom, Quantum Genomics
Published: 2019
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19. NI956/QGC006, a Potent Orally Active, Brain-Penetrating Aminopeptidase A Inhibitor for Treating Hypertension

Author: Catherine Llorens-Cortes, Mathilde Keck, Adrien Flahault, Fabrice Balavoine, Nicolas Inguimbert, Bernard P. Roques, Hugo De Almeida, Delphine Compere, Neuropeptides centraux et régulations hydrique et cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Labex MemoLife, Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Quantum Genomics, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Université des Antilles (UA)-Institut d'écologie et environnement-Université de la Nouvelle-Calédonie (UNC)-Université de la Polynésie Française (UPF)-Université de La Réunion (UR)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Université des Antilles et de la Guyane (UAG)-Institut de Recherche pour le Développement (IRD), UFR des Sciences Pharmaceutiques et Biologiques, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS - UM 4 (UMR 8258 / U1022)), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), USR 3278, PSL EPHE-CNRS-UPVD, USR 3278, CRIOBE, Labex Corail, University of Perpignan, France, and Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5)-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)
Subjects: Male, [SDV]Life Sciences [q-bio], Angiotensin III, Blood Pressure, 030204 cardiovascular system & hematology, Pharmacology, Glutamyl Aminopeptidase, Rats, Inbred WKY, Natriuresis, Renin-Angiotensin System, 03 medical and health sciences, 0302 clinical medicine, Aminopeptidase A, Rats, Inbred SHR, Renin–angiotensin system, Internal Medicine, Animals, Medicine, Disulfides, 030212 general & internal medicine, ComputingMilieux_MISCELLANEOUS, business.industry, Brain, Prodrug, Rats, 3. Good health, Disease Models, Animal, Blood pressure, Orally active, Hypertension, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Sulfonic Acids, business
Abstract: Brain renin-angiotensin system hyperactivity has been implicated in the development and maintenance of hypertension. We have shown that aminopeptidase A is involved in the formation of brain angiotensin III, which exerts tonic stimulatory control over blood pressure in hypertensive deoxycorticosterone acetate-salt rats and spontaneously hypertensive rats. We have also shown that injection of the specific and selective aminopeptidase A inhibitor, (3S)-3-amino-4-sulfanyl-butane-1-sulfonic acid (EC33), by central route or its prodrug, RB150/firibastat, by oral route inhibited brain aminopeptidase A activity and blocked the formation of brain angiotensin III, normalizing blood pressure in hypertensive rats. These findings identified brain aminopeptidase A as a potential new therapeutic target for hypertension. We report here the development of a new aminopeptidase A inhibitor prodrug, NI956/QGC006, obtained by the disulfide bridge-mediated dimerization of NI929. NI929 is 10× more efficient than EC33 at inhibiting recombinant mouse aminopeptidase A activity in vitro. After oral administration at a dose of 4 mg/kg in conscious deoxycorticosterone acetate-salt rats, NI956/QGC006 normalized brain aminopeptidase A activity and induced a marked decrease in blood pressure of −44±13 mm Hg 4 hours after treatment ( P< 0.001), sustained over 10 hours (−21±12 mm Hg; P< 0.05). Moreover, NI956/QGC006 decreased plasma arginine-vasopressin levels, and increased diuresis and natriuresis, that may participate to the blood pressure decrease. Finally, NI956/QGC006 did not affect plasma sodium and potassium concentrations. This study shows that NI956/QGC006 is a best-in-class central-acting aminopeptidase A inhibitor prodrug. Our results support the development of hypertension treatments targeting brain aminopeptidase A.
Published: 2019
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20. Brain renin-angiotensin system blockade with orally active aminopeptidase A inhibitor prevents cardiac dysfunction after myocardial infarction in mice

Author: Fabrice Balavoine, Onnik Agbulut, Solène Emmanuelle Boitard, Catherine Llorens-Cortes, Nathalie Mougenot, Mathilde Keck, Yannick Marc, Neuropeptides centraux et régulations hydrique et cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Labex MemoLife, Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Quantum Genomics, Coeur, Muscle et Vaisseaux, Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Adaptation Biologique et Vieillissement = Biological Adaptation and Ageing (B2A), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Sorbonne Université (SU)-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), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-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), CCSD, Accord Elsevier, Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre interdisciplinaire de recherche en biologie (CIRB), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Labex MemoLife, Université Paris sciences et lettres (PSL)-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), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Male, 0301 basic medicine, Cardiac function curve, medicine.medical_specialty, [SDV]Life Sciences [q-bio], Angiotensin III, Myocardial Infarction, Administration, Oral, Cardiomegaly, 030204 cardiovascular system & hematology, Glutamyl Aminopeptidase, Renin-Angiotensin System, Mice, 03 medical and health sciences, 0302 clinical medicine, Enalapril, Fibrosis, Internal medicine, medicine, Animals, [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Myocardial infarction, Enzyme Inhibitors, Molecular Biology, ComputingMilieux_MISCELLANEOUS, Heart Failure, Ejection fraction, business.industry, Brain, Heart, Stroke Volume, medicine.disease, [SDV] Life Sciences [q-bio], CTGF, Disease Models, Animal, 030104 developmental biology, Endocrinology, [SDV.SP.PHARMA] Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Heart failure, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Inflammation Mediators, Cardiology and Cardiovascular Medicine, business, Biomarkers, medicine.drug
Abstract: Brain renin-angiotensin system (RAS) hyperactivity has been implicated in sympathetic hyperactivity and progressive left ventricular (LV) dysfunction after myocardial infarction (MI). Angiotensin III, generated by aminopeptidase A (APA), is one of the main effector peptides of the brain RAS in the control of cardiac function. We hypothesized that orally administered firibastat (previously named RB150), an APA inhibitor prodrug, would attenuate heart failure (HF) development after MI in mice, by blocking brain RAS hyperactivity. Two days after MI, adult male CD1 mice were randomized to three groups, for four to eight weeks of oral treatment with vehicle (MI + vehicle), firibastat (150 mg/kg; MI + firibastat) or the angiotensin I converting enzyme inhibitor enalapril (1 mg/kg; MI + enalapril) as a positive control. From one to four weeks post-MI, brain APA hyperactivity occurred, contributing to brain RAS hyperactivity. Firibastat treatment normalized brain APA hyperactivity, with a return to the control values measured in sham group two weeks after MI. Four and six weeks after MI, MI + firibastat mice had a significant lower LV end-diastolic pressure, LV end-systolic diameter and volume, and a higher LV ejection fraction than MI + vehicle mice. Moreover, the mRNA levels of biomarkers of HF (Myh7, Bnp and Anf) were significantly lower following firibastat treatment. For a similar infarct size, the peri-infarct area of MI + firibastat mice displayed lower levels of mRNA for Ctgf and collagen types I and III (markers of fibrosis) than MI + vehicle mice. Thus, chronic oral firibastat administration after MI in mice prevents cardiac dysfunction by normalizing brain APA hyperactivity, and attenuates cardiac hypertrophy and fibrosis.
Published: 2019
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21. Cardiac inflammatory CD11b/c cells exert a protective role in hypertrophied cardiomyocyte by promoting TNFR2- and Orai3- dependent signaling

Author: Camille Barbier, Sophie Favier, Jean-Sébastien Hulot, Mathilde Keck, Nathalie Mougenot, Anne-Marie Lompré, Sophie Nadaud, Mathilde Flamant, Catherine Pavoine, Fabrice Atassi, Azevedo, Chloe, Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière] (IHU ICAN), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Phénotypage du petit animal (UMS28), Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Institute of cardiometabolism and nutrition (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), and Gestionnaire, Hal Sorbonne Université
Subjects: 0301 basic medicine, Lipopolysaccharide, [SDV]Life Sciences [q-bio], Cell, lcsh:Medicine, Inflammation, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, medicine.disease_cause, Muscle hypertrophy, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, In vivo, medicine, lcsh:Science, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, Multidisciplinary, Chemistry, lcsh:R, [SDV.MHEP.CSC] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Cell biology, [SDV] Life Sciences [q-bio], 030104 developmental biology, medicine.anatomical_structure, lcsh:Q, Tumor necrosis factor alpha, medicine.symptom, Signal transduction, 030217 neurology & neurosurgery, Oxidative stress
Abstract: Early adaptive cardiac hypertrophy (EACH) is initially a compensatory process to optimize pump function. We reported the emergence of Orai3 activity during EACH. This study aimed to characterize how inflammation regulates store-independent activation of Orai3-calcium influx and to evaluate the functional role of this influx. Isoproterenol infusion or abdominal aortic banding triggered EACH. TNFα or conditioned medium from cardiac CD11b/c cells activated either in vivo [isolated from rats displaying EACH], or in vitro [isolated from normal rats and activated with lipopolysaccharide], were added to adult cardiomyocytes before measuring calcium entry, cell hypertrophy and cell injury. Using intramyocardial injection of siRNA, Orai3 was in vivo knockdown during EACH to evaluate its protective activity in heart failure. Inflammatory CD11b/c cells trigger a store-independent calcium influx in hypertrophied cardiomyocytes, that is mimicked by TNFα. Pharmacological or molecular (siRNA) approaches demonstrate that this calcium influx, depends on TNFR2, is Orai3-driven, and elicits cardiomyocyte hypertrophy and resistance to oxidative stress. Neutralization of Orai3 inhibits protective GSK3β phosphorylation, impairs EACH and accelerates heart failure. Orai3 exerts a pathophysiological protective impact in EACH promoting hypertrophy and resistance to oxidative stress. We highlight inflammation arising from CD11b/c cells as a potential trigger of TNFR2- and Orai3-dependent signaling pathways.
Published: 2019
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22. Cardiac inflammatory CD11b/c cells exert a protective role in hypertrophied cardiomyocyte by promoting TNFR

Author: Mathilde, Keck, Mathilde, Flamant, Nathalie, Mougenot, Sophie, Favier, Fabrice, Atassi, Camille, Barbier, Sophie, Nadaud, Anne-Marie, Lompré, Jean-Sébastien, Hulot, and Catherine, Pavoine
Subjects: Heart Failure, Male, CD11b Antigen, Glycogen Synthase Kinase 3 beta, Tumor Necrosis Factor-alpha, Isoproterenol, Cardiomegaly, Article, CD11c Antigen, Rats, Disease Models, Animal, Oxidative Stress, Culture Media, Conditioned, Gene Knockdown Techniques, Disease Progression, Animals, Humans, Receptors, Tumor Necrosis Factor, Type II, Calcium, Myocytes, Cardiac, Calcium Channels, Phosphorylation, RNA, Small Interfering, Signal Transduction
Abstract: Early adaptive cardiac hypertrophy (EACH) is initially a compensatory process to optimize pump function. We reported the emergence of Orai3 activity during EACH. This study aimed to characterize how inflammation regulates store-independent activation of Orai3-calcium influx and to evaluate the functional role of this influx. Isoproterenol infusion or abdominal aortic banding triggered EACH. TNFα or conditioned medium from cardiac CD11b/c cells activated either in vivo [isolated from rats displaying EACH], or in vitro [isolated from normal rats and activated with lipopolysaccharide], were added to adult cardiomyocytes before measuring calcium entry, cell hypertrophy and cell injury. Using intramyocardial injection of siRNA, Orai3 was in vivo knockdown during EACH to evaluate its protective activity in heart failure. Inflammatory CD11b/c cells trigger a store-independent calcium influx in hypertrophied cardiomyocytes, that is mimicked by TNFα. Pharmacological or molecular (siRNA) approaches demonstrate that this calcium influx, depends on TNFR2, is Orai3-driven, and elicits cardiomyocyte hypertrophy and resistance to oxidative stress. Neutralization of Orai3 inhibits protective GSK3β phosphorylation, impairs EACH and accelerates heart failure. Orai3 exerts a pathophysiological protective impact in EACH promoting hypertrophy and resistance to oxidative stress. We highlight inflammation arising from CD11b/c cells as a potential trigger of TNFR2- and Orai3-dependent signaling pathways.
Published: 2018

23. ClC-K chloride channels: emerging pathophysiology of Bartter syndrome type 3

Author: Mathilde Keck, Jacques Teulon, Stéphane Lourdel, Olga Andrini, Rodolfo Briones, Rosa Vargas-Poussou, Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Max Planck Institute for Biophysical Chemistry (MPI-BPC), Max-Planck-Gesellschaft, Service de Génétique [CHU HEGP], Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Service de Génétique [AP-HP Hôpital Européen Georges Pompidou, Paris], and Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)
Subjects: chloride channel, Physiology, [SDV]Life Sciences [q-bio], Anion Transport Proteins, DNA Mutational Analysis, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, Bartter syndrome, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, Chloride, Type (biology), Chloride Channels, medicine, Animals, Humans, Genetic Predisposition to Disease, ComputingMilieux_MISCELLANEOUS, Genetics, CLCNKB gene, medicine.disease, Pathophysiology, 3. Good health, Mutation, Chloride channel, CLC family of chloride transporters and channels, medicine.drug
Abstract: International audience; The mutations in the CLCNKB gene encoding the ClC-Kb chloride channel are responsible for Bartter syndrome type 3, one of the four variants of Bartter syndrome in the genetically based nomenclature. All forms of Bartter syndrome are characterized by hypokalemia, metabolic alkalosis, and secondary hyperaldosteronism, but Bartter syndrome type 3 has the most heterogeneous presentation, extending from severe to very mild. A relatively large number of CLCNKB mutations have been reported, including gene deletions and nonsense or missense mutations. However, only 20 CLCNKB mutations have been functionally analyzed, due to technical difficulties regarding ClC-Kb functional expression in heterologous systems. This review provides an overview of recent progress in the functional consequences of CLCNKB mutations on ClC-Kb chloride channel activity. It has been observed that 1) all ClC-Kb mutants have an impaired expression at the membrane; and 2) a minority of the mutants combines reduced membrane expression with altered pH-dependent channel gating. Although further investigation is needed to fully characterize disease pathogenesis, Bartter syndrome type 3 probably belongs to the large family of conformational diseases, in which the mutations destabilize channel structure, inducing ClC-Kb retention in the endoplasmic reticulum and accelerated channel degradation.
Published: 2015
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24. Clinical and Genetic Spectrum of Bartter Syndrome Type 3

Author: Maria Mileva, Sandrine Lemoine, Christiane Mousson, Elsa Seys, Rosa Vargas-Poussou, Mathilde Cailliez, Gwenaëlle Roussey-Kesler, Aurélia Bertholet-Thomas, Paul Cozette, Theresa Kwon, Anne Blanchard, Guylhène Bourdat-Michel, Pauline Krug, Jean Sébastien Borde, Jacques Teulon, Christophe Simian, Laurence Dubourg, Robert Novo, Isabelle Vrillon, Bertrand Knebelmann, Brigitte Llanas, Djamal Djeddi, Dominique Chaveau, Stephen B. Walsh, Olga Andrini, François Nobili, Jean Daniel Delbet, Marc Fila, Georges Deschênes, Mathilde Keck, Ferielle Louillet, Lamisse Mansour-Hendili, Elodie Merieau, Stéphane Decramer, Noémie Jourde-Chiche, Marie-Pierre Lavocat, Pierre-Yves Courand, Luisa Mota-Vieira, Guillaume Bobrie, Pediatric Nephrology Unit, American Memorial Hospital, Reims University Hospital, Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Paris Descartes - Paris 5 (UPD5)-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), Université Paris Descartes - Faculté de Médecine (UPD5 Médecine), Université Paris Descartes - Paris 5 (UPD5), Service de Génétique [CHU HEGP], Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Centre d'Investigation Clinique - Epidemiologie Clinique/essais Cliniques [CHU HEGP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de Cardiologie [Hôpital Croix- Rousse, HCL] (Centre d'excellence de la Société européenne d'hypertension artérielle), Hospices Civils de Lyon (HCL)-Hôpital de la Croix-Rousse [CHU - HCL], Hospices Civils de Lyon (HCL), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service Génétique, Union nationale des coopératives d’élevage et d’insémination animale (UNCEIA), Unité de Néphrologie Pédiatrique, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Robert Debré, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre de Référence des Maladies Rénales Rares Néphrogones, Hôpital Femme Mère Enfant [CHU - HCL] (HFME), Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Nephrology Unit, Clinique du Vert Galant, Tremblay-en-France, Nephrology Unit, Centre hospitalier de Saintonge, Saintes, Centre Hospitalo-Universitaire de Grenoble (CHU de Grenoble), CHU Grenoble, Service de pédiatrie multidisciplinaire [Hôpital de la Timone Enfants - APHM], Hôpital de la Timone [CHU - APHM] (TIMONE), Assistance Publique - Hôpitaux de Marseille (APHM), Pediatric Nephrology Unit, Centre Hospitalier du Pays d'Aix, Nephrology Unit, Centre Hospitalier du Pays d'Aix, CHU Trousseau [APHP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Métabolomique et maladies métaboliques, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Référence du Sud Ouest des Maladies Rénales Rares, CHU Toulouse [Toulouse]-Hôpital des Enfants, CHU Toulouse [Toulouse], Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Vascular research center of Marseille (VRCM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Service de néphrologie pédiatrique [CHU Necker], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre Hospitalier Universitaire de Saint-Etienne (CHU de Saint-Etienne), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Pédiatrie médicale et médecine de l'adolescent [Amiens], CHU Amiens-Picardie, Service de pédiatrie néonatale et réanimation - neuropédiatrie [CHU Rouen], CHU Rouen, Normandie Université (NU)-Normandie Université (NU)-Hôpital Charles Nicolle [Rouen]-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Centre Hospitalier Régional Universitaire de Tours (CHRU Tours), Department of Pediatrics, Centre Hospitalier Pierre Oudot de Bourgoin-Jallieu, Bourgoin-Jallieu, Molecular Genetics and Pathology Unit, Hospital of Divino Espirito Santo of Ponta Delgada, Service de néphrologie (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Service de néphrologie pédiatrique [CHRU Besançon], Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), Hôpital Jeanne de Flandres, Université de Lille, Droit et Santé-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Centre hospitalier universitaire de Nantes (CHU Nantes), Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Department of Aeronautical and Automotive Engineering, Loughborough University, Paris-Centre de Recherche Cardiovasculaire (PARCC - UMR-S U970), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Santé Lyon Est - Louis Léopold Ollier, Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Union Nationale des Coopératives Agricoles d'Elevage et d'Insémination Animale, Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Robert Debré, Unité d'hypertension artérielle, Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), CHU Necker - Enfants Malades [AP-HP]-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Service de nephrologie pédiatrique, Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université de Paris (UP), Université de Paris - Faculté de Médecine Paris Centre (UP Médecine Paris Centre), Université de Paris (UP), Service de Génétique [AP-HP Hôpital Européen Georges Pompidou, Paris], Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre hospitalier universitaire de Grenoble (CHU de Grenoble), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université, Centre de néphrologie et transplantation rénale [Hôpital de la Conception - APHM], Assistance Publique - Hôpitaux de Marseille (APHM)-Hôpital de la Conception [CHU - APHM] (LA CONCEPTION), Service de pédiatrie néonatale et réanimation - neuropédiatrie [Rouen], Hôpital Charles Nicolle [Rouen]-CHU Rouen, Normandie Université (NU)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Centre Hospitalier Régional Universitaire de Tours (CHRU TOURS), Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP), Université de Lyon, Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte [CHU-Necker] (MARHEA), Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Centre Hospitalier Universitaire de Saint-Etienne [CHU Saint-Etienne] (CHU ST-E), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hôpital Charles Nicolle [Rouen], and Normandie Université (NU)-Normandie Université (NU)-CHU Rouen
Subjects: 0301 basic medicine, Adult, Male, medicine.medical_specialty, Adolescent, [SDV]Life Sciences [q-bio], Nonsense mutation, 030232 urology & nephrology, Bartter syndrome, urologic and male genital diseases, Hypocalciuria, 03 medical and health sciences, Young Adult, 0302 clinical medicine, Tubulopathy, Clinical Research, Internal medicine, Genotype, medicine, Humans, Child, Genetic Association Studies, ComputingMilieux_MISCELLANEOUS, Retrospective Studies, CLCNKB, biology, business.industry, Bartter Syndrome, Infant, General Medicine, Gitelman syndrome, medicine.disease, 3. Good health, Bartter's syndrome, 030104 developmental biology, Endocrinology, Nephrology, Child, Preschool, Mutation, biology.protein, Female, medicine.symptom, business
Abstract: Bartter syndrome type 3 is a clinically heterogeneous hereditary salt-losing tubulopathy caused by mutations of the chloride voltage-gated channel Kb gene (CLCNKB), which encodes the ClC-Kb chloride channel involved in NaCl reabsorption in the renal tubule. To study phenotype/genotype correlations, we performed genetic analyses by direct sequencing and multiplex ligation-dependent probe amplification and retrospectively analyzed medical charts for 115 patients with CLCNKB mutations. Functional analyses were performed in Xenopus laevis oocytes for eight missense and two nonsense mutations. We detected 60 mutations, including 27 previously unreported mutations. Among patients, 29.5% had a phenotype of ante/neonatal Bartter syndrome (polyhydramnios or diagnosis in the first month of life), 44.5% had classic Bartter syndrome (diagnosis during childhood, hypercalciuria, and/or polyuria), and 26.0% had Gitelman-like syndrome (fortuitous discovery of hypokalemia with hypomagnesemia and/or hypocalciuria in childhood or adulthood). Nine of the ten mutations expressed in vitro decreased or abolished chloride conductance. Severe (large deletions, frameshift, nonsense, and essential splicing) and missense mutations resulting in poor residual conductance were associated with younger age at diagnosis. Electrolyte supplements and indomethacin were used frequently to induce catch-up growth, with few adverse effects. After a median follow-up of 8 (range, 1-41) years in 77 patients, chronic renal failure was detected in 19 patients (25%): one required hemodialysis and four underwent renal transplant. In summary, we report a genotype/phenotype correlation for Bartter syndrome type 3: complete loss-of-function mutations associated with younger age at diagnosis, and CKD was observed in all phenotypes.
Published: 2017
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25. The ClC-K2 Chloride Channel Is Critical for Salt Handling in the Distal Nephron

Author: Yohan Bignon, Nicolas Picard, Régine Chambrey, Antje K. Huebner, J. Christopher Hennings, Olga Andrini, Mathilde Keck, Marc Paulais, Thomas J. Jentsch, Dominique Eladari, Nicolas Cornière, Christian A. Hübner, Jacques Teulon, Irma Karen Lopez Cayuqueo, Friedrich-Schiller-Universität Jena, Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Paris-Centre de Recherche Cardiovasculaire (PARCC - UMR-S U970), Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centro de Estudios Científicos (CECs), Centre Hospitalier Universitaire de La Réunion (CHU La Réunion), Leibniz Forschungsinstitut für Molekulare Pharmakolgie = Leibniz Institute for Molecular Pharmacology [Berlin, Allemagne] (FMP), Leibniz Association, Leibniz-Institut für Molekulare Pharmakologie, Zentrum fuer Molekulare Neurobiologie, Universität Hamburg (UHH)-Institut für Molekulare Neuropathobiologie, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Keck, Mathilde, Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany, Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité), Centro de Estudios Científicos, Valdivia, Centre hospitalier Félix-Guyon [Saint-Denis, La Réunion], Université Paris Cité - UFR Médecine [Santé] (UPCité UFR Médecine), Université Paris Cité (UPCité), Centre National de la Recherche Scientifique (CNRS), Physiologie et pharmacologie vasculaire et rénale, IFR58-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université de Paris (UP), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Université de Paris - UFR Médecine Paris Centre [Santé] (UP Médecine Paris Centre), and Université de Paris (UP)
Subjects: 0301 basic medicine, medicine.medical_specialty, Sodium Chloride Symporter Inhibitors, [SDV]Life Sciences [q-bio], Anion Transport Proteins, 030232 urology & nephrology, Metabolic alkalosis, Sodium Chloride, Bartter syndrome, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, Mice, 03 medical and health sciences, 0302 clinical medicine, Chloride Channels, Furosemide, Internal medicine, medicine, [SDV.MHEP.PHY]Life Sciences [q-bio]/Human health and pathology/Tissues and Organs [q-bio.TO], Bartter-s syndrome, chloride channels, ion transport, transgenic mouse, Animals, Distal convoluted tubule, Diuretics, ComputingMilieux_MISCELLANEOUS, Mice, Knockout, business.industry, urogenital system, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Nephrons, General Medicine, medicine.disease, [SDV] Life Sciences [q-bio], [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Bartter's syndrome, Basic Research, 030104 developmental biology, Endocrinology, medicine.anatomical_structure, Nephrology, Chloride channel, business, Cotransporter, Homeostasis, medicine.drug
Abstract: International audience; Chloride transport by the renal tubule is critical for blood pressure (BP), acid-base, and potassium homeostasis. Chloride uptake from the urinary fluid is mediated by various apical transporters, whereas basolateral chloride exit is thought to be mediated by ClC-Ka/K1 and ClC-Kb/K2, two chloride channels from the ClC family, or by KCl cotransporters from the SLC12 gene family. Nevertheless, the localization and role of ClC-K channels is not fully resolved. Because inactivating mutations in ClC-Kb/K2 cause Bartter syndrome, a disease that mimics the effects of the loop diuretic furosemide, ClC-Kb/K2 is assumed to have a critical role in salt handling by the thick ascending limb. To dissect the role of this channel in detail, we generated a mouse model with a targeted disruption of the murine ortholog ClC-K2. Mutant mice developed a Bartter syndrome phenotype, characterized by renal salt loss, marked hypokalemia, and metabolic alkalosis. Patch-clamp analysis of tubules isolated from knockout (KO) mice suggested that ClC-K2 is the main basolateral chloride channel in the thick ascending limb and in the aldosterone-sensitive distal nephron. Accordingly, ClC-K2 KO mice did not exhibit the natriuretic response to furosemide and exhibited a severely blunted response to thiazide. We conclude that ClC-Kb/K2 is critical for salt absorption not only by the thick ascending limb, but also by the distal convoluted tubule.
Published: 2017
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26. Characterization of the mouse ClC-K1/Barttin chloride channel

Author: Alexei Diakov, Stéphane Lourdel, Jacques Teulon, Teddy Grand, Olga Andrini, Mathilde Keck, Sébastien L'Hoste, Christoph Korbmacher, Laurent Beck, Laurent Pinelli, Marc Paulais, Mathieu Genete, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Université de Nantes - UFR Odontologie, Université de Nantes (UN), Université Paris Descartes - Paris 5 (UPD5)-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), ERL 7226, Centre National de la Recherche Scientifique (CNRS), Institut für Zelluläre und Molekulare Physiologie [Erlanger], Lourdel, Stéphane, Laboratoire de physiologie, physiopathologie et génomique rénales, Centre National de la Recherche Scientifique (CNRS)-Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité)-École Pratique des Hautes Études (EPHE), and Université de Nantes - UFR Odontologie (UFR Odonto)
Subjects: Patch-Clamp Techniques, [SDV]Life Sciences [q-bio], Xenopus, Biophysics, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Kidney, Biochemistry, Xenopus laevis, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Chloride Channels, ClC, medicine, Animals, Humans, Patch clamp, Distal convoluted tubule, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, ClC-K1, 0303 health sciences, biology, urogenital system, Depolarization, Cell Biology, biology.organism_classification, Recombinant Proteins, Connecting tubule, [SDV] Life Sciences [q-bio], Electrophysiology, HEK293 Cells, Kidney Tubules, medicine.anatomical_structure, chemistry, DIDS, Chloride channel, Patch-clamp, 030217 neurology & neurosurgery
Abstract: International audience; Several Cl(-) channels have been described in the native renal tubule, but their correspondence with ClC-K1 and ClC-K2 channels (orthologs of human ClC-Ka and ClC-Kb), which play a major role in transcellular Cl(-) absorption in the kidney, has yet to be established. This is partly because investigation of heterologous expression has involved rat or human ClC-K models, whereas characterization of the native renal tubule has been done in mice. Here, we investigate the electrophysiological properties of mouse ClC-K1 channels heterologously expressed in Xenopus laevis oocytes and in HEK293 cells with or without their accessory Barttin subunit. Current amplitudes and plasma membrane insertion of mouse ClC-K1 were enhanced by Barttin. External basic pH or elevated calcium stimulated currents followed the anion permeability sequence Cl(-)>Br(-)>NO3(-)>I(-). Single-channel recordings revealed a unit conductance of ~40pS. Channel activity in cell-attached patches increased with membrane depolarization (voltage for half-maximal activation: ~-65mV). Insertion of the V166E mutation, which introduces a glutamate in mouse ClC-K1, which is crucial for channel gating, reduced the unit conductance to ~20pS. This mutation shifted the depolarizing voltage for half-maximal channel activation to ~+25mV. The unit conductance and voltage dependence of wild-type and V166E ClC-K1 were not affected by Barttin. Owing to their strikingly similar properties, we propose that the ClC-K1/Barttin complex is the molecular substrate of a chloride channel previously detected in the mouse thick ascending limb (Paulais et al., J Membr. Biol, 1990, 113:253-260).
Published: 2013
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27. Emergence of Orai3 activity during cardiac hypertrophy

Author: Youakim Saliba, Olivier Cazorla, Jean-Sébastien Hulot, Alain Lacampagne, Nassim Fares, Mathilde Keck, Anne Marie Lompré, Aude Ouillé, Mohamed Trebak, Fabrice Atassi, Jérémy Fauconnier, Alexandre Marchand, Catherine Pavoine, MORNET, Dominique, Laboratoire de Recherche en Physiologie et Physiopathologie, Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière] (IHU ICAN), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Center for Cardiovascular Sciences, Albany Medical College, Icahn School of Medicine at Mount Sinai [New York] (MSSM), Université Saint-Joseph de Beyrouth (USJ), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Institute of cardiometabolism and nutrition (ICAN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [APHP], Université Pierre et Marie Curie - Paris 6 (UPMC), Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Signalisation et physiopathologie des cellules épithéliales, Université Paris-Sud - Paris 11 (UP11)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Mondor de recherche biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Physiopathologie, génétique et pharmacologie du remodelage cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-IFR14-Institut National de la Santé et de la Recherche Médicale (INSERM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), and Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Male, inorganic chemicals, medicine.medical_specialty, Small interfering RNA, Time Factors, ORAI1 Protein, Fura-2, Physiology, [SDV]Life Sciences [q-bio], Biology, Transfection, Membrane Potentials, Muscle hypertrophy, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Physiology (medical), Internal medicine, medicine, Animals, Myocytes, Cardiac, Calcium Signaling, Stromal Interaction Molecule 1, Rats, Wistar, Cells, Cultured, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Calcium signaling, 0303 health sciences, Arachidonic Acid, Membrane Glycoproteins, Voltage-dependent calcium channel, ORAI1, Cardiac myocyte, STIM1, [SDV] Life Sciences [q-bio], Calcium Channel Agonists, Disease Models, Animal, Endocrinology, chemistry, Hypertrophy, Left Ventricular, RNA Interference, Calcium Channels, Cardiology and Cardiovascular Medicine, 030217 neurology & neurosurgery, Protein Binding
Abstract: Aims Stromal interaction molecule 1 (STIM1) has been shown to control a calcium (Ca2+) influx pathway that emerges during the hypertrophic remodeling of cardiomyocytes. Our aim was to determine the interaction of Orai1 and Orai3 with STIM1 and their role in the constitutive store-independent and the store-operated, STIM1-dependent, Ca2+ influx in cardiomyocytes. Methods and Results We characterized the expression profile of Orai proteins and their interaction with STIM1 in both normal and hypertrophied adult rat ventricular cardiomyocytes. Orai1 and 3 protein levels were unaltered during the hypertrophic process and both proteins co-immunoprecipitated with STIM1. The main partner of STIM1 in control cardiomyocytes was Orai1, but the abundance of Orai3 in the STIM1/Orai1/Orai3 macromolecular complex was markedly enhanced in hypertrophied cardiomyocytes. We then used a non-viral method to deliver Cy3-tagged siRNAs in vivo to adult ventricular cardiomyocytes and silence Orai channel candidates. Cardiomyocytes were subsequently isolated then the voltage-independent i.e. store-independent and store-operated Ca2+ entries were measured on Fura-2 AM loaded Cy3-labelled and control isolated cardiomyocytes. The whole cell patch-clamp technique was used to measure Orai-mediated currents. Specific Orai1 and Orai3 knockdown established Orai3, but not Orai1, as the critical partner of STIM1 carrying these voltage-independent Ca2+ entries in the adult hypertrophied cardiomyocytes. Orai3 also drove an arachidonic acid-activated inward current. Conclusion Cardiac Orai3 is the essential partner of STIM1 and drives voltage-independent Ca2+ entries in adult cardiomyocytes. Arachidonic acid-activated currents, which are supported by Orai3, are present in adult cardiomyocytes and increased during hypertrophy.
Published: 2015
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28. Mutations in SLC2A2 Gene Reveal hGLUT2 Function in Pancreatic β Cell Development

Author: Patricia Serradas, Armelle Leturque, Raphael Scharfmann, Sébastien L'Hoste, Jacques Teulon, Maude Le Gall, Aurélien Michau, Mathilde Keck, A. Grosfeld, E. Brot-Laroche, Ghislaine Guillemain, Pascale de Lonlay, Danielle Chateau, Sandrine Vuillaumier-Barrot, Teddy Grand, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), U845 Department of Physiology, CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Service de biochimie hormonale, métabolique et génétique, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris Diderot - Paris 7 (UPD7), Centre de référence pour les maladies métaboliques héréditaires [CHU Necker Enfants Malades - AP-HP], Université Paris Descartes - Paris 5 (UPD5)-CHU Necker - Enfants Malades [AP-HP], Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Institut de Cardiométabolisme et Nutrition = Institute of Cardiometabolism and Nutrition [CHU Pitié Salpêtrière] (IHU ICAN), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Institute of cardiometabolism and nutrition (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), 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), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Nutrition, métabolisme, obésité: aspect cellulaire et moléculaire, Institut National de la Santé et de la Recherche Médicale (INSERM), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris]-Université Paris Diderot - Paris 7 (UPD7), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Imagine - Institut des maladies génétiques (IMAGINE - U1163), Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Pancréas endocrine et diabète de l'enfant, Centre de recherche sur l'Inflammation (CRI (UMR_S_1149 / ERL_8252 / U1149)), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: medicine.medical_treatment, Cellular differentiation, [SDV]Life Sciences [q-bio], Mutant, Mutation, Missense, Biological Transport, Active, Biology, medicine.disease_cause, Biochemistry, Polymorphism, Single Nucleotide, 03 medical and health sciences, Mice, Xenopus laevis, 0302 clinical medicine, Cell Line, Tumor, Insulin-Secreting Cells, Insulin Secretion, medicine, Animals, Humans, Insulin, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Glucose Transporter Type 2, 0303 health sciences, Mutation, Cell growth, Glucose transporter, Cell Differentiation, Cell Biology, Rats, Glucose, Metabolism, Amino Acid Substitution, biology.protein, GLUT2, Signal transduction, 030217 neurology & neurosurgery, Signal Transduction
Abstract: The structure-function relationships of sugar transporter-receptor hGLUT2 coded by SLC2A2 and their impact on insulin secretion and β cell differentiation were investigated through the detailed characterization of a panel of mutations along the protein. We studied naturally occurring SLC2A2 variants or mutants: two single-nucleotide polymorphisms and four proposed inactivating mutations associated to Fanconi-Bickel syndrome. We also engineered mutations based on sequence alignment and conserved amino acids in selected domains. The single-nucleotide polymorphisms P68L and T110I did not impact on sugar transport as assayed in Xenopus oocytes. All the Fanconi-Bickel syndrome-associated mutations invalidated glucose transport by hGLUT2 either through absence of protein at the plasma membrane (G20D and S242R) or through loss of transport capacity despite membrane targeting (P417L and W444R), pointing out crucial amino acids for hGLUT2 transport function. In contrast, engineered mutants were located at the plasma membrane and able to transport sugar, albeit with modified kinetic parameters. Notably, these mutations resulted in gain of function. G20S and L368P mutations increased insulin secretion in the absence of glucose. In addition, these mutants increased insulin-positive cell differentiation when expressed in cultured rat embryonic pancreas. F295Y mutation induced β cell differentiation even in the absence of glucose, suggesting that mutated GLUT2, as a sugar receptor, triggers a signaling pathway independently of glucose transport and metabolism. Our results describe the first gain of function mutations for hGLUT2, revealing the importance of its receptor versus transporter function in pancreatic β cell development and insulin secretion.
Published: 2013
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29. Novel CLCNKB Mutations Causing Bartter Syndrome Affect Channel Surface Expression

Author: Sébastien L‘Hoste, L. Pablo Cid, Jacques Teulon, Olivier Lahuna, Francisco V. Sepúlveda, Johanna Burgos, Olga Andrini, Anne Blanchard, Mathilde Keck, Rosa Vargas-Poussou, Stéphane Lourdel, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Paris Descartes - Paris 5 (UPD5)-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), Centro de Estudios Científicos (CECs), Centre d'Investigation Clinique - Epidemiologie Clinique/essais Cliniques [CHU HEGP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Paris - UFR Médecine Paris Centre [Santé] (UP Médecine Paris Centre), Université de Paris (UP), Service de génétique [CHU HEGP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Descartes - Faculté de Médecine (UPD5 Médecine), Université Paris Descartes - Paris 5 (UPD5), Service de Génétique [AP-HP Hôpital Européen Georges Pompidou, Paris], Hôpital Européen Georges Pompidou [APHP] (HEGP), Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), UFR Médecine [Santé] - Université Paris Cité (UFR Médecine UPCité), and Université Paris Cité (UPCité)
Subjects: Adult, Male, Adolescent, [SDV]Life Sciences [q-bio], Mutant, Anion Transport Proteins, Xenopus, Bartter syndrome, 03 medical and health sciences, Xenopus laevis, Young Adult, 0302 clinical medicine, Western blot, Tubulopathy, Chloride Channels, Genetics, medicine, Animals, Humans, Point Mutation, Genetics (clinical), ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, CLCNKB, medicine.diagnostic_test, biology, urogenital system, HEK 293 cells, Bartter Syndrome, Infant, medicine.disease, biology.organism_classification, Molecular biology, HEK293 Cells, Biochemistry, Chloride channel, biology.protein, Oocytes, Female, 030217 neurology & neurosurgery
Abstract: Mutations in the CLCNKB gene encoding the ClC-Kb Cl(-) channel cause Bartter syndrome, which is a salt-losing renal tubulopathy. Here, we investigate the functional consequences of seven mutations. When expressed in Xenopus laevis oocytes, four mutants carried no current (c.736G>C, p.Gly246Arg; c.1271G>A, p.Gly424Glu; c.1313G>A, p.Arg438His; c.1316T>C, p.Leu439Pro), whereas others displayed a 30%-60% reduction in conductance as compared with wild-type ClC-Kb (c.242T>C, p.Leu81Pro; c.274C>T, p.Arg92Trp; c.1052G>C, p.Arg351Pro). Anion selectivity and sensitivity to external Ca(2+) and H(+), typical of the ClC-Kb channel, were not modified in the partially active mutants. In oocytes, we found that all the mutations reduced surface expression with a profile similar to that observed for currents. In HEK293 cells, the currents in the mutants had similar profiles to those obtained in oocytes, except for p.Leu81Pro, which produced no current. Furthermore, p.Arg92Trp and p.Arg351Pro mutations did not modify the unit-conductance of closely related ClC-K1. Western blot analysis in HEK293 cells showed that ClC-Kb protein abundance was lower for the nonconducting mutants but similar to wild-type for other mutants. Overall, two classes of mutants can be distinguished: nonconducting mutants associated with low total protein expression, and partially conducting mutants with unaltered channel properties and ClC-Kb protein abundance.
Published: 2013
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30. Abstract 313: STIM1 Silencing Reverses Pressure-overload Induced Cardiac Hypertrophy In Mice

Author: Ludovic Benard, Mathilde Keck, Daniel S Matasic, Roger J. Hajjar, Jean-Sébastien Hulot, and Anne-Marie Lompré
Subjects: Pressure overload, medicine.medical_specialty, Pathology, Physiology, Hemodynamics, STIM1, Biology, medicine.disease, Left ventricular hypertrophy, Muscle hypertrophy, Endocrinology, Fibrosis, Internal medicine, Heart failure, medicine, Myocyte, Cardiology and Cardiovascular Medicine
Abstract: STromal Interaction Molecule 1 (STIM1), a membrane protein of the sarcoplasmic reticulum, has recently been proposed as a positive regulator of cardiomyocyte growth by promoting Ca2+ entry through the plasma membrane and the activation of Ca2+-mediated signaling pathways. We demonstrated that STIM1 silencing prevented the development of left ventricular hypertrophy (LVH) in rats after abdominal aortic banding. Our aim was to study the role of STIM1 during the transition from LVH to heart failure (HF). For experimental timeline, see figure. Transverse Aortic Constriction (TAC) was performed in C57Bl/6 mice. In vivo gene silencing was performed using recombinant Associated AdenoVirus 9 (AAV9). Mice were injected with saline or with AAV9 expressing shRNA control or against STIM1 (shSTIM1) (dose: 1e+11 viral genome), which decreased STIM1 cardiac expression by 70% compared to control. While cardiac parameters were similar between the TAC groups at weeks 3 and 6, shSTIM1 animals displayed a progressive and total reversion of LVH with LV walls thickness returning to values observed in sham mice at week 8. This reversion was associated with the development of significant LV dilation and severe contractile dysfunction, as assessed by echography. Hemodynamic analysis confirmed the altered contractile function and dilation of shSTIM1 animals. Immunohistochemistry showed a trend to more fibrosis. Despite hypertrophic stimuli, there was a significant reduction in cardiac myocytes cross-section area in shSTIM1-treated animals as compared to other TAC mice. This study showed that STIM1 is essential to maintain compensatory LVH and that its silencing accelerates the transition to HF.
Published: 2013
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31. Abstract 312: STIM1 And The Development Of Pressure-overload Induced Cardiac Hypertrophy In Rodents

Author: Ludovic O Bénard, Daniel S Matasic, Mathilde Keck, Anne-Marie Lompré, Roger J Hajjar, and Jean-Sébastien Hulot
Subjects: Physiology, Cardiology and Cardiovascular Medicine
Abstract: STromal Interaction Molecule 1 (STIM1), a membrane protein of the sarcoplasmic reticulum, has recently been proposed as a positive regulator of cardiomyocyte growth by promoting Ca2+ entry through the plasma membrane and the activation of Ca2+-mediated signaling pathways. We studied the role of STIM1 in a pressure-overload induced cardiac hypertrophy model in mice. We observed that STIM1 cardiac expression is increased during left ventricular hypertrophy (LVH) induced by Transverse Aortic Constriction (TAC). We then used recombinant Associated Adenovirus 9 (AAV9) to perform cardiac-targeted gene silencing in vivo. C57Bl/6 mice were injected with saline (noAAV) or with AAV9 expressing shRNA against STIM1 (shSTIM1) at the dose of 1e+11 viral genome which resulted in 70% decrease of STIM1 cardiac expression compared to control mice. Three weeks later, TAC was performed and mice were studied three other weeks later. We found that TAC-shSTIM1 treated mice did not develop LVH compared to noAAV despite the same increase in aortic pressure. Echocardiographic and hemodynamic measurements (see table) showed that TAC-shSTIM1-treated mice had LV dilation and a decreased left ventricular contractile function in line with the absence of compensatory LVH in these mice. Immunohistochemistry demonstrated that LVH prevention was observed at the cellular level with cardiac myocytes cross-section area comparable to sham littermates however with a trend towards more interstitial fibrosis. This study reveals the essential role of STIM1 in the development of compensatory LVH in mice.
Published: 2013
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32. Abstract 198: Stim/orai Channel Complex In Normal And Hypertrophied Adult Cardiac Myocytes

Author: Youakim Saliba, Jérémy Fauconnier, Ludovic Benard, Mathilde Keck, Nassim Fares, Jean-Sébastien Hulot, Alexandre Marchand, and Anne-Marie Lompré
Subjects: medicine.medical_specialty, Channel complex, Physiology, Chemistry, chemistry.chemical_element, Calcium, Muscle hypertrophy, Coupling (electronics), Endocrinology, Internal medicine, medicine, Biophysics, Myocyte, Cardiology and Cardiovascular Medicine
Abstract: Cardiac myocytes use Ca2+ not only in excitation-contraction coupling but also as a signaling molecule for cardiac growth. It is however unclear how Ca2+ triggers signaling in cardiac myocytes in the presence of the rapid and large Ca2+ fluctuations that occur during excitation-contraction coupling. We have recently reported that stromal interaction molecule 1 (STIM1), a calcium sensor in the sarcoplasmic reticulum, is a critical element in promoting cardiomyocyte growth through the control of a previously unrecognized sarcolemmal voltage-independent current. Our goal was to characterize the plasma membrane partners that contribute to STIM1-dependent currents in normal and hypertrophied adult cardiac myocytes. We firstly characterized the expression profile of TRPCs and ORAIs proteins in both normal and hypertrophied ventricular myocytes from abdominal aortic banded rats. The expression of TRPC1, 3, 4, 5 and 6 and of ORAI1 - 3 was identified with an up-regulation of TRPC1 in hypertrophied cells. We then used a non-viral method to deliver cy3-tagged siRNAs to ventricular myocytes to knock-down the candidate channels. The cardiac myocytes were isolated and whole cell patch-clamp technique as well as Fura-2 imaging were performed to measure the currents in cy3-labelled and in control cardiac myocytes. Our data demonstrated that the drug-inducible STIM1-dependent store-operated calcium entry was marginal in normal myocytes but was enhanced in hypertrophied myocytes. In addition, a basal inwardly rectifying current was observed in hypertrophied but not in control myocytes. This spontaneous current was recorded in the absence of calcium store depletion, required STIM1 expression and meets the characteristics of Arachidonate-Regulated Calcium selective (ARC) channels. ORAI silencing completely inhibited both store-dependent and store-independent currents suggesting the critical implication of ORAIs whereas TRPCs were only marginally involved. In conclusion, ORAI channels are involved in STIM1-dependent currents observed in hypertrophied adult cardiac myocytes. In addition to store-operated calcium entry, the STIM1/ORAI complex provides an alternative, store-independent pathway for agonist-activated Ca2+ entry.
Published: 2013
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33. Genotype‐phenotype relationship in patients affected by novel CLCNKB mutations

Author: Mathilde Keck, Jacques Teulon, Stéphane Lourdel, Olga Andrini, Anne Blanchard, and Rosa Vargas-Poussou
Subjects: Genetics, CLCNKB, biology, biology.protein, In patient, Molecular Biology, Biochemistry, Biotechnology, Genotype phenotype
Published: 2013
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34. Renal phenotype in mice lacking the Kir5.1 (Kcnj16) K+ channel subunit contrasts with that observed in SeSAME/EAST syndrome

Author: May Bloch-Faure, Marc Paulais, Stéphane Lourdel, Mathilde Keck, Suresh Krishna Ramakrishnan, Pascal Houillier, Jacques Teulon, Dominique Eladari, Thibaut Jacques, Nicolas Picard, Fabien Sohet, Stephen J. Tucker, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Clarendon Laboratory, Department of Physics, University of Oxford [Oxford], Laboratoire de physiologie, physiopathologie et génomique rénales, Centre National de la Recherche Scientifique (CNRS)-Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité), Université Paris Descartes - Faculté de Médecine (UPD5 Médecine), Université Paris Descartes - Paris 5 (UPD5), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Clarendon Laboratory [Oxford], University of Oxford, This work was supported by Agence Nationale de la Recherche (ANR) Grant Physio 2007-RPVO7084. M.K. holds a PhD fellowship from the French Ministère de la Recherche. S.K.R. holds a PhD fellowship from the Erasmus Mundus External Cooperation Window Lot 15 India European scholarship program. M.P. is an Institut National de la Santé et de la Recherche Médicale researcher. S.J.T. was supported by the Royal Society., Paulais, Marc, Laboratoire de physiologie génomique et de physiopathologie rénale (CNRS ERL 7226), Centre National de la Recherche Scientifique (CNRS)-Centre de Recherche des Cordeliers, École Pratique des Hautes Études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité)-École Pratique des Hautes Études (EPHE)
Subjects: medicine.medical_specialty, Patch-Clamp Techniques, Intracellular pH, [SDV]Life Sciences [q-bio], 030232 urology & nephrology, Hypokalemia, KCNJ10, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, Amiloride, Mice, 03 medical and health sciences, 0302 clinical medicine, Sodium Potassium Chloride Symporter Inhibitors, Tubulopathy, Furosemide, Internal medicine, EAST syndrome, medicine, Animals, Humans, Hypercalciuria, Distal convoluted tubule, Potassium Channels, Inwardly Rectifying, Diuretics, Ion transporter, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Mice, Knockout, 0303 health sciences, Multidisciplinary, biology, Chemistry, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Syndrome, Biological Sciences, medicine.disease, [SDV.MHEP.UN] Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, Hydrochlorothiazide, Kidney Tubules, Phenotype, Endocrinology, medicine.anatomical_structure, biology.protein, medicine.symptom, Acidosis, Sodium Channel Blockers
Abstract: The heteromeric inwardly rectifying Kir4.1/Kir5.1 K + channel underlies the basolateral K + conductance in the distal nephron and is extremely sensitive to inhibition by intracellular pH. The functional importance of Kir4.1/Kir5.1 in renal ion transport has recently been highlighted by mutations in the human Kir4.1 gene ( KCNJ10 ) that result in seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance (SeSAME)/epilepsy, ataxia, sensorineural deafness, and renal tubulopathy (EAST) syndrome, a complex disorder that includes salt wasting and hypokalemic alkalosis. Here, we investigated the role of the Kir5.1 subunit in mice with a targeted disruption of the Kir5.1 gene ( Kcnj16 ). The Kir5.1 −/− mice displayed hypokalemic, hyperchloremic metabolic acidosis with hypercalciuria. The short-term responses to hydrochlorothiazide, an inhibitor of ion transport in the distal convoluted tubule (DCT), were also exaggerated, indicating excessive renal Na + absorption in this segment. Furthermore, chronic treatment with hydrochlorothiazide normalized urinary excretion of Na + and Ca 2+ , and abolished acidosis in Kir5.1 −/− mice. Finally, in contrast to WT mice, electrophysiological recording of K + channels in the DCT basolateral membrane of Kir5.1 −/− mice revealed that, even though Kir5.1 is absent, there is an increased K + conductance caused by the decreased pH sensitivity of the remaining homomeric Kir4.1 channels. In conclusion, disruption of Kcnj16 induces a severe renal phenotype that, apart from hypokalemia, is the opposite of the phenotype seen in SeSAME/EAST syndrome. These results highlight the important role that Kir5.1 plays as a pH-sensitive regulator of salt transport in the DCT, and the implication of these results for the correct genetic diagnosis of renal tubulopathies is discussed.
Published: 2011
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35. Functional analysis of novel CLCNKB mutations in patients with Bartter syndrome

Author: Mathilde Keck, Anne Blanchard, Mathieu Genete, Teddy Grand, Jacques Teulon, Rosa Vargas-Poussou, Sébastien L'Hoste, and Stéphane Lourdel
Subjects: Genetics, CLCNKB, Functional analysis, biology, urogenital system, business.industry, Metabolic alkalosis, food and beverages, urologic and male genital diseases, medicine.disease, Bartter syndrome, Biochemistry, Tubulopathy, biology.protein, Medicine, In patient, business, Molecular Biology, Biotechnology
Abstract: Bartter’s syndrome is a hereditary renal tubulopathy characterized by salt-wasting and hypokalaemic metabolic alkalosis, which can be due to loss-of-function mutations in genes encoding ClC-Kb / Ba...
Published: 2011
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36. Heterogeneity in the processing of ClC-5 mutants related to Dent disease

Author: Nadia Defontaine, Mathieu Genete, Mathilde Keck, David Mordasini, Kamel Laghmani, Jacques Teulon, Teddy Grand, Sébastien L'Hoste, Thomas Pennaforte, Stéphane Lourdel, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ERL 7226, Centre National de la Recherche Scientifique (CNRS), Laboratoire de physiologie, physiopathologie et génomique rénales, Centre National de la Recherche Scientifique (CNRS)-Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Université Paris Cité (UPCité), Centre de Recherche des Cordeliers ( CRC (UMR_S 872) ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris Descartes - Paris 5 ( UPD5 ) -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 Paris Descartes - Paris 5 (UPD5)-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), and Sorbonne Université (SU)
Subjects: [SDV]Life Sciences [q-bio], Mutant, Xenopus, Dent Disease, ClC-5, Kidney Tubules, Proximal, Xenopus laevis, 0302 clinical medicine, Jacques, Genetics (clinical), ComputingMilieux_MISCELLANEOUS, Cells, Cultured, INSERM, 0303 health sciences, biology, Life Sciences, Cell biology, Complete List of Authors: Grand, David, Biochemistry, ERL 7226 Key Words: Dent's disease, ERL 7226 Mordasini, ERL 7226 Keck, Endosome, CNRS, Protein subunit, Nadia, Molecular Sequence Data, ERL 7226 Lourdel, Chloride/proton exchanger, Kamel, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Processing, ERL 7226 L'Hoste, Mathilde, 03 medical and health sciences, Chloride Channels, Genetics, Stéphane, Animals, Humans, Amino Acid Sequence, Sébastien, 030304 developmental biology, UPMC Univ Paris 06, ERL 7226 Pennaforte, Teddy, Mathieu, urogenital system, CLCN5, Endoplasmic reticulum, HEK 293 cells, ERL 7226 Teulon, biology.organism_classification, Thomas, HEK293 Cells, Mutation, biology.protein, Oocytes, ERL 7226 Defontaine, UMR_S 872, Sequence Alignment, 030217 neurology & neurosurgery, ERL 7226 Laghmani, ERL 7226 Genete
Abstract: International audience; Mutations in the electrogenic Cl-/H+ exchanger ClC-5 gene CLCN5 are frequently associated with Dent disease, an X-linked recessive disorder affecting the proximal tubules. Here, we investigate the consequences in X. laevis oocytes and in HEK293 cells of 9 previously reported, pathogenic, missense mutations of ClC-5, most of them which are located in regions forming the subunit interface. Two mutants trafficked normally to the cell surface and to early endosomes, and displayed complex glycosylation at the cell surface like wild-type ClC 5, but exhibited reduced currents. Three mutants displayed improper N-glycosylation, and were non-functional due to being retained and degraded at the endoplasmic reticulum. Functional characterization of four mutants allowed us to identify a novel mechanism leading to ClC-5 dysfunction in Dent disease. We report that these mutant proteins were delayed in their processing and that the stability of their complex glycosylated form was reduced, causing lower cell surface expression. The early endosome distribution of these mutants was normal. Half of these mutants displayed reduced currents, whereas the other half showed abolished currents. Our study revealed distinct cellular mechanisms accounting for ClC-5 loss-of-function in Dent disease.
Published: 2011
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