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12. Carnitine deficiency induces a short QT syndrome

Author

Roussel, Julien, Labarthe, François, Thireau, Jerome, Ferro, Fabio, Farah, Charlotte, Roy, Jerome, Horiuchi, Masahisa, Tardieu, Martine, Lefort, Bruno, François Benoist, Jean, Lacampagne, Alain, Richard, Sylvain, Fauconnier, Jeremy, Babuty, Dominique, and Le Guennec, Jean Yves

Published
2016
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14. Transfer of Cardiac Mitochondria Improves the Therapeutic Efficacy of Mesenchymal Stem Cells in a Preclinical Model of Ischemic Heart Disease

Author

Vignais, Marie-Luce, primary, Levoux, Jennyfer, additional, Sicard, Pierre, additional, Khattar, Khattar, additional, Lozza, Catherine, additional, Gervais, Marianne, additional, Mezhoud, Safia, additional, Nakhle, Jean, additional, Relaix, Frederic, additional, Agbulut, Onnik, additional, Fauconnier, Jeremy, additional, and Rodriguez, Anne-Marie, additional

Published
2023
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15. Atomic force and electron microscopic-based study of sarcolemmal surface of living cardiomyocytes unveils unexpected mitochondrial shift in heart failure

Author

Dague, Etienne, Genet, Gaël, Lachaize, Véronique, Guilbeau-Frugier, Céline, Fauconnier, Jérémy, Mias, Céline, Payré, Bruno, Chopinet, Louise, Alsteens, David, Kasas, Sandor, Severac, Childerick, Thireau, Jérôme, Heymes, Christophe, Honton, Benjamin, Lacampagne, Alain, Pathak, Atul, Sénard, Jean-Michel, and Galés, Céline

Published
2014
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16. Disruption of calcium transfer from ER to mitochondria links alterations of mitochondria-associated ER membrane integrity to hepatic insulin resistance

Author

Rieusset, Jennifer, Fauconnier, Jeremy, Paillard, Melanie, Belaidi, Elise, Tubbs, Emily, Chauvin, Marie-Agnès, Durand, Annie, Bravard, Amélie, Teixeira, Geoffrey, Bartosch, Birke, Michelet, Maud, Theurey, Pierre, Vial, Guillaume, Demion, Marie, Blond, Emilie, Zoulim, Fabien, Gomez, Ludovic, Vidal, Hubert, Lacampagne, Alain, and Ovize, Michel

Published
2016
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20. Dendronized oligoethylene glycols with phosphonate tweezers for cell-repellent coating of oxide surfaces: Coarse-scale and nanoscopic interfacial forces

Author

Lanot, Nicolas, Vincenti, Marie, Abassi, Hamouda, Bredy, Charlene, Agullo, Audrey, Gamon, Lucie, Mura, Thibault, Lavastre, Kathleen, De La Villeon, Gregoire, Barrea, Catherine, Meyer, Pierre, Rivier, François, Meli, Albano, Fauconnier, Jeremy, Cazorla, Olivier, Lacampagne, Alain, Amedro, Pascal, MORNET, Dominique, Heidelberg University, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Tokyo Institute of Technology [Tokyo] (TITECH), European Synchrotron Radiation Facility (ESRF), PRESTO [JST, Japan Science and Technology Agency, Kyoto University, Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-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 de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-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)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)

Subjects
Materials science, animal structures, General Chemical Engineering, Oxide, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Coating, Dendrimer, Tweezers, Nanoscopic scale, [CHIM.MATE] Chemical Sciences/Material chemistry, Surface force, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Adhesion, 021001 nanoscience & nanotechnology, Interfacial Force, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0104 chemical sciences, 3. Good health, chemistry, Chemical engineering, [CHIM.OTHE] Chemical Sciences/Other, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, [CHIM.OTHE]Chemical Sciences/Other, 0210 nano-technology
Abstract

Dendronized oligoethylene glycols (dendron OEGs) with two phosphonate groups (phosphonate tweezers) have been drawing significant attention as a new class of coating materials for superparamagnetic iron oxide surfaces. However, despite dendron OEGs showing outstanding stability in physiological fluids in previous studies, little is understood about their structure and mechanical properties. Herein we report the surface and internal structures and mechanical properties of dendron OEGs, and quantitatively determine their ability to avoid non-specific adhesion of blood platelets. To gain insight into the interfacial force interactions, we measured the coarse-scale surface force acting on cell-sized particles and mapped the nanoscopic pinning centers by fast force mapping.

Published
2021
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25. Assessment of left ventricular dyssynchrony by speckle tracking echocardiography in children with duchenne muscular dystrophy.

Author

UCL - SSS/IREC/PEDI - Pôle de Pédiatrie, UCL - (SLuc) Service de cardiologie pédiatrique, Lanot, Nicolas, Vincenti, Marie, Abassi, Hamouda, Bredy, Charlene, Agullo, Audrey, Gamon, Lucie, Mura, Thibault, Lavastre, Kathleen, De La Villeon, Gregoire, Barrea, Catherine, Meyer, Pierre, Rivier, François, Meli, Albano C, Fauconnier, Jeremy, Cazorla, Olivier, Lacampagne, Alain, Amedro, Pascal, UCL - SSS/IREC/PEDI - Pôle de Pédiatrie, UCL - (SLuc) Service de cardiologie pédiatrique, Lanot, Nicolas, Vincenti, Marie, Abassi, Hamouda, Bredy, Charlene, Agullo, Audrey, Gamon, Lucie, Mura, Thibault, Lavastre, Kathleen, De La Villeon, Gregoire, Barrea, Catherine, Meyer, Pierre, Rivier, François, Meli, Albano C, Fauconnier, Jeremy, Cazorla, Olivier, Lacampagne, Alain, and Amedro, Pascal

Abstract

Prognosis of Duchenne muscular dystrophy (DMD) is related to cardiac dysfunction. Two dimensional-speckle tracking echocardiography (2D-STE) has recently emerged as a non-invasive functional biomarker for early detection of DMD-related cardiomyopathy. This study aimed to determine, in DMD children, the existence of left ventricle (LV) dyssynchrony using 2D-STE analysis. This prospective controlled study enrolled 25 boys with DMD (mean age 11.0 ± 3.5 years) with normal LV ejection fraction and 50 age-matched controls. Three measures were performed to assess LV mechanical dyssynchrony: the opposing-wall delays (longitudinal and radial analyses), the modified Yu index, and the time-to-peak delays of each segment. Feasibility and reproducibility of 2D-STE dyssynchrony were evaluated. All three mechanical dyssynchrony criteria were significantly higher in the DMD group than in healthy subjects: (1) opposing-wall delays in basal inferoseptal to basal anterolateral segments (61.4 ± 45.3 ms vs. 18.3 ± 50.4 ms, P < 0.001, respectively) and in mid inferoseptal to mid anterolateral segments (58.6 ± 35.3 ms vs. 42.4 ± 36.4 ms, P < 0.05, respectively), (2) modified Yu index (33.3 ± 10.1 ms vs. 28.5 ± 8.1 ms, P < 0.05, respectively), and (3) most of time-to-peak values, especially in basal and mid anterolateral segments. Feasibility was excellent and reliability was moderate to excellent, with ICC values ranging from 0.49 to 0.97. Detection of LV mechanical dyssynchrony using 2D-STE analysis is an easily and reproducible method in paediatric DMD. The existence of an early LV mechanical dyssynchrony visualized using 2D-STE analysis in children with DMD before the onset of cardiomyopathy represents a perspective for future paediatric drug trials in the DMD-related cardiomyopathy prevention.Clinical Trial Registration Clinicaltrials.gov NCT02418338. Post-hoc study, registered on April 16, 2015.

Published
2022

30. LIX1 controls digestive mesenchyme-derived cell fate decision by regulating cristae organization in mitochondria

Author

Guerin, Amandine, primary, Angebault, Claire, additional, Kinet, Sandrina, additional, Cazevieille, Chantal, additional, Rojo, Manuel, additional, Fauconnier, Jeremy, additional, Lacampagne, Alain, additional, Mourier, Arnaud, additional, Taylor, Naomi, additional, de Santa Barbara, Pascal, additional, and Faure, Sandrine, additional

Published
2022
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31. Assessment of left ventricular dyssynchrony by speckle tracking echocardiography in children with duchenne muscular dystrophy

Author

Lanot, Nicolas, primary, Vincenti, Marie, additional, Abassi, Hamouda, additional, Bredy, Charlene, additional, Agullo, Audrey, additional, Gamon, Lucie, additional, Mura, Thibault, additional, Lavastre, Kathleen, additional, De La Villeon, Gregoire, additional, Barrea, Catherine, additional, Meyer, Pierre, additional, Rivier, François, additional, Meli, Albano C., additional, Fauconnier, Jeremy, additional, Cazorla, Olivier, additional, Lacampagne, Alain, additional, and Amedro, Pascal, additional

Published
2021
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33. ATP/UTP activate cation-permeable channels with TRPC3/7 properties in rat cardiomyocytes

Author

Alvarez, Julio, Coulombe, Alain, Cazorla, Olivier, Ugur, Mehmet, Rauzier, Jean-Michel, Magyar, Janos, Mathieu, Eve-Lyne, Boulay, Guylain, Souto, Rafael, Bideaux, Patrice, Salazar, Guillermo, Rassendren, Francois, Lacampagne, Alain, Fauconnier, Jeremy, and Vassort, Guy

Subjects
Arrhythmia -- Risk factors, Arrhythmia -- Research, Heart cells -- Physiological aspects, Ion channels -- Physiological aspects, Biological sciences
Abstract

Extracellular purines and pyrimidines have major effects on cardiac rhythm and contraction. ATP/UTP are released during various physiopathological conditions, such as ischemia, and despite degradation by ectonucleotidases, their interstitial concentrations can markedly increase, a fact that is clearly associated with arrhythmia. In the present whole cell patch-clamp analysis on ventricular cardiomyocytes isolated from various mammalian species, ATP and UTP elicited a sustained, nonselective cationic current, [I.sub.ATP]. UDP was ineffective, whereas 2'(3')-O-(4-benzoylbenzoyl)-ATP was active, suggesting that P2[Y.sub.2] receptors are involved. [I.sub.ATP] resulted from the binding of AT[P.sup.4-] to P2[Y.sub.2] purinoceptors. [I.sub.ATP] was maintained after ATP removal in the presence of guanosine 5'-[[gamma]-thio]triphosphate and was inhibited by U-73122, a PLC inhibitor. Single-channel openings are rather infrequent under basal conditions. ATP markedly increased opening probability, an effect prevented by U-73122. Two main conductance levels of 14 and 23 pS were easily distinguished. Similarly, in fura-2-1oaded cardiomyocytes, [Mn.sup.2+] quenching and [Ba.sup.2+] influx were significant only in the presence of ATP or UTP. Adult rat ventricular cardiomyocytes expressed transient receptor potential channel TRPC1, -3, -4, and -7 mRNA and the TRPC3 and TRPC7 proteins that coimmunoprecipitated. Finally, the anti-TRPC3 antibody added to the patch pipette solution inhibited [I.sub.ATP]. In conclusion, activation of P2[Y.sub.2] receptors, via a G protein and stimulation of PLC[beta], induces the opening of heteromeric TRPC3/7 channels, leading to a sustained, nonspecific cationic current. Such a depolarizing current could induce cell automaticity and trigger the arrhythmic events during an early infarct when ATP/UTP release occurs. These results emphasize a new, potentially deleterious role of TRPC channel activation. purinergic receptor; signal transduction; infarction; arrhythmia

Published
2008

34. Frequency-dependent and proarrhythmogenic effects of FK-506 in rat ventricular cells

Author

Fauconnier, Jeremy, Lacampagne, Alain, Rauzier, Jean-Michel, Fontanaud, Pierre, Frapier, Jean-Marc, Sejersted, Ole M., Vassort, Guy, and Richard, Sylvain

Subjects
Rats -- Research, Rattus -- Research, Ion channels -- Research, Arrhythmia -- Research, Calcium, Dietary, Biological sciences
Abstract

FK-506, a widely used immunosuppressant, has caused a few clinical cases with QT prolongation and torsades de pointe at high blood concentration. The proarrhytmogenic potential of FK-506 was investigated in single rat ventricular cells using the whole cell clamp method to record action potentials (APs) and ionic currents. Fluorescence measurements of [Ca.sub.2+] transients were performed with indo-1 AM using a multiphotonic microscope. FK-506 (25 [micro]mol/l) hyperpolarized the resting membrane potential (RMP; -3 mV) and prolonged APs (AP duration at 90% repolarization increased by 21%) at 0.1 Hz. Prolongation was enhanced by threefold at 3.3 Hz, and early afterdepolarizations (EADs) occurred in 59% of cells. EADs were prevented by stronger intracellular [Ca.sup.2+] buffering (EGTA: 10 vs. 0.5 mmol/l in the patch pipette) or replacement of extracellular [Na.sup.+] by [Li.sup.+], which abolishes [Na.sup.+]/[Ca.sup.2+] exchange [[Na.sup.+]/[Ca.sup.2+] exchanger current (IN,c,)]. In indo-1-loaded cells, FK-506 generated doublets of [Ca.sup.2+] transients associated with increased diastolic [Ca.sup.2+] in one-half of the cells. FK-506 reversibly decreased the L-type [Ca.sup.2+] current ([I.sub.CaL]) by 25%, although high-frequency-dependent facilitation of [I.sub.CaL] persisted, and decreased three distinct [K.sup.+] currents: delayed rectifier [K.sup.+] current ([I.sub.K]; >80%), transient outward [K.sup.+] current (40%). A shift in the reversal potential of [I.sub.K1] (-5 mV) accounted for RMP hyperpolarization. Numerical simulations, reproducing all experimental effects of FK-506, and the use of nifedipine showed that frequency-dependent facilitation of [I.sub.CaL] plays a role in the occurrence of EADs. In conclusion, the effects of FK-506 on the cardiac AP are more complex than previously reported and include inhibitions of [I.sub.K1] and [I.sub.CaL]. Alterations in [Ca.sup.2+] release and [I.sub.NaCa] may contribute to FK-506-induced AP prolongation and EADs in addition to the permissive role of [I.sub.CaL] facilitation at high rates of stimulation. arrhythmias (mechanisms); long QT syndrome; ion channels; calcium (cellular)

Published
2005

35. FKBP12.6 overexpression decreases [Ca.sup.2+] spark amplitude but enhances [[Ca.sup.2+]]i transient in rat cardiac myocytes

Author

Gomez, Ana M., Schuster, Iris, Fauconnier, Jeremy, Prestle, Jurgen, Hasenfuss, Gerd, and Richard, Sylvain

Subjects
Cardiology -- Research, Biological sciences
Abstract

FKBP12.6 overexpression decreases [Ca.sup.2+] spark amplitude but enhances [[Ca.sup.2+]]i transient in rat cardiac myocytes. Am J Physiol Heart Circ Physiol 287: H1987-H1993, 2004. First published July 22, 2004; doi:10.1152/ ajpheart.00409.2004.--Ryanodine receptors/[Ca.sup.2+]-release channels (RyR2) from the sarcoplasmic reticulum (SR) provide the [Ca.sup.2+] required for contraction at each cardiac twitch. RyR2 are regulated by a variety of proteins, including the immunophilin FK506 binding protein (FKBP12.6). FKBP12.6 seems to be important for coupled gating of RyR2 and its deficit and alteration may be involved in heart failure. The role of FKBP12.6 on [Ca.sup.2+] release has not been analyzed directly, but rather it was inferred from the effects of immunophilins, such us FK506 and rapamycin, which, among other effects, dissociates FKBP12.6 from the RyR2. Here, we investigated directly the effects of FKBP12.6 on local ([Ca.sup.2+] sparks) and global {intracellular [Ca.sup.2+] concentration ([[Ca.sup.2+]]i) transients} [Ca.sup.2+] release in single rat cardiac myocytes. The FKBP12.6 gene was transfected in single myocytes using the adenovirus technique with a reporter gene strategy based on green fluorescent protein (GFP) to check out the success of transfections. Control myocytes were transfected with only GFP (Ad-GFP). Rhod-2 was used as the [Ca.sup.2+] indicator, and cells were viewed with a confocal microscope. We found that overexpression of FKBP12.6 decreases the occurrence, amplitude, duration, and width of spontaneous [Ca.sup.2+] sparks. FK506 had diametrically opposed effects. However, overexpression of FKBP12.6 increased the [[Ca.sup.2+]]i transient amplitude and accelerated its decay in field-stimulated cells. The associated cell shortening was increased. SR [Ca.sup.2+] load, estimated by rapid caffeine application, was increased. In conclusion, FKBP12.6 overexpression decreases spontaneous [Ca.sup.2+] sparks but increases [[Ca.sup.2+]]i transients, in relation with enhanced SR [Ca.sup.2+] load, therefore improving excitation-contraction coupling. calcium (cellular); sarcoplasmic reticulum (function); excitation-contraction coupling; heart

Published
2004

37. Absence of triadin, a protein of the calcium release complex, is responsible for cardiac arrhythmia with sudden death in human

Author

Roux-Buisson, Nathalie, Cacheux, Marine, Fourest-Lieuvin, Anne, Fauconnier, Jeremy, Brocard, Julie, Denjoy, Isabelle, Durand, Philippe, Guicheney, Pascale, Kyndt, Florence, Leenhardt, Antoine, Le Marec, Hervé, Lucet, Vincent, Mabo, Philippe, Probst, Vincent, Monnier, Nicole, Ray, Pierre F., Santoni, Elodie, Trémeaux, Pauline, Lacampagne, Alain, Fauré, Julien, Lunardi, Joël, and Marty, Isabelle

Published
2012
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38. Endothelial Cell Indoleamine 2, 3-Dioxygenase 1 Alters Cardiac Function After Myocardial Infarction Through Kynurenine

Author

Melhem, Nada Joe, primary, Chajadine, Mouna, additional, Gomez, Ingrid, additional, Howangyin, Kiave-Yune, additional, Bouvet, Marion, additional, Knosp, Camille, additional, Sun, Yanyi, additional, Rouanet, Marie, additional, Laurans, Ludivine, additional, Cazorla, Olivier, additional, Lemitre, Mathilde, additional, Vilar, José, additional, Mallat, Ziad, additional, Tedgui, Alain, additional, Ait-Oufella, Hafid, additional, Hulot, Jean-Sébastien, additional, Callebert, Jacques, additional, Launay, Jean-Marie, additional, Fauconnier, Jeremy, additional, Silvestre, Jean-Sébastien, additional, and Taleb, Soraya, additional

Published
2021
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40. Effects of palmitate on [Ca.sup.2+] handling in adult control and ob/ob cardiomyocytes: impact of mitochondrial reactive oxygen species

Author

Fauconnier, Jeremy, Andersson, Daniel C., Zhang, Shi-Jin, Lanner, Johanna T., Wibom, Rolf, Katz, Abram, Bruton, Joseph D., and Westerblad, Hakan

Subjects
Heart cells -- Analysis, Type 2 diabetes -- Genetic aspects -- Risk factors, Muscle cells -- Analysis -- Genetic aspects, Health, Analysis, Genetic aspects, Risk factors
Abstract

Obesity and insulin resistance are associated with enhanced fatty acid utilization, which may play a central role in diabetic cardiomyopathy. We now assess the effect of the saturated fatty acid palmitate (1.2 mmol/l) on [Ca.sup.2+] handling, cell shortening, and mitochondrial production of reactive oxygen species (ROS) in freshly isolated ventricular cardiomyocytes from normal (wild-type) and obese, insulin-resistant ob/ob mice. Cardiomyocytes were electrically stimulated at 1 Hz, and the signal of fluorescent indicators was measured with confocal microscopy. Palmitate decreased the amplitude of cytosolic [Ca.sup.2+] transients (measured with fluo-3), the sarcoplasmic reticulum [Ca.sup.2+] load, and cell shortening by ~20% in wild-type cardiomyocytes; these decreases were prevented by the general antioxidant N-acetylcysteine. In contrast, palmitate accelerated [Ca.sup.2+] transients and increased cell shortening in ob/ob cardiomyocytes. Application of palmitate rapidly dissipated the mitochondrial membrane potential (measured with tetra-methyl rhodamine-ethyl ester) and increased the mitochondrial ROS production (measured with MitoSOX Red) in wild-type but not in ob/ob cardiomyocytes. In conclusion, increased saturated fatty acid levels impair cellular [Ca.sup.2+] handling and contraction in a ROS-dependent manner in normal cardiomyocytes. Conversely, high fatty acid levels may be vital to sustain cardiac [Ca.sup.2+] handling and contraction in obesity and insulin-resistant conditions., Cardiac muscle cells generate ATP at a high rate to support the continuous contractile function of the beating heart. Cardiac cells use various substrates to generate ATP, and the extent [...]

Published
2007

42. The role of [Ca.sup.2+] influx for insulin-mediated glucose uptake in skeletal muscle

Author

Lanner, Johanna T., Katz, Abram, Tavi, Pasi, Sandstrom, Marie E., Zhang, Shi-Jin, Wretman, Charlott, James, Stephen, Fauconnier, Jeremy, Laanergren, Jan, Bruton, Joseph D., and Westerblad, Hakan

Subjects
Diabetes -- Diagnosis -- Care and treatment, Insulin -- Health aspects, Muscles -- Health aspects, Health, Diagnosis, Care and treatment, Health aspects
Abstract

The involvement of [Ca.sup.2+] in insulin-mediated glucose uptake is uncertain. We measured [Ca.sup.2+] influx (as [Mn.sup.2+] quenching or [Ba.sup.2+] influx) and 2-deoxyglucose (2-DG) uptake in single muscle fibers isolated from limbs of adult mice; 2-DG uptake was also measured in isolated whole muscles. Exposure to insulin increased the [Ca.sup.2+] influx in single muscle cells. [Ca.sup.2+] influx in the presence of insulin was decreased by 2-aminoethoxydiphenyl borate (2-APB) and increased by the membrane-permeable diacylglycerol analog 1-oleyl-2-acetyl-sn-glycerol (OAG), agents frequently used to block and activate, respectively, nonselective cation channels. Maneuvers that decreased [Ca.sup.2+] influx in the presence of insulin also decreased 2-DG uptake, whereas increased [Ca.sup.2+] influx was associated with increased insulin-mediated glucose uptake in isolated single cells and whole muscles from both normal and insulin-resistant obese ob/ob mice. 2-APB and OAG affected neither basal nor hypoxia- or contraction-mediated 2-DG uptake. 2-APB did not inhibit the insulin-mediated activation of protein kinase B or extracellular signal-related kinase 112 in whole muscles. In conclusion, alterations in [Ca.sup.2+] influx specifically modulate insulin-mediated glucose uptake in both normal and insulin-resistant skeletal muscle. Moreover, the present results indicate that [Ca.sup.2+] acts late in the insulin signaling pathway, for instance, in the GLUT4 translocation to the plasma membrane., Skeletal muscle accounts for up to 50% of body weight and is the major site of insulin-mediated glucose disposal in humans (1). Insulin, via an incompletely understood cascade of reactions, [...]

Published
2006

43. Insulin and inositol 1,4,5-trisphosphate trigger abnormal cytosolic [Ca.sup.2+] transients and reveal mitochondrial [Ca.sup.2+] handling defects in cardiomyocytes of ob/ob mice

Author

Fauconnier, Jeremy, Lanner, Johanna T., Zhang, Shi-Jin, Tavi, Pasi, Bruton, Joseph D., Katz, Abram, and Westerblad, Hakan

Subjects
Coronary heart disease -- Causes of -- Risk factors, Obesity -- Risk factors, Type 2 diabetes -- Risk factors, Heart failure -- Causes of -- Risk factors, Health, Risk factors, Causes of
Abstract

Obesity, insulin resistance, and type 2 diabetes are leading causes of heart failure, and defective cellular [Ca.sup.2+] handling seems to be a fundamental problem in diabetes. Therefore, we studied the effect of insulin on [Ca.sup.2+] homeostasis in normal, freshly isolated mouse ventricular cardiomyocytes and whether [Ca.sup.2+] handling was changed in an animal model of obesity and type 2 diabetes, ob/ob mice. Electrically evoked [Ca.sup.2+] transients were smaller and slower in ob/ob compared with wild-type cardiomyocytes. Application of insulin (6 or 60 nmol/l) increased the amplitude of [Ca.sup.2+] transients in wild-type cells by ~30%, whereas it broadened the transients and triggered extra [Ca.sup.2+] transients in ob/ob cells. The effects of insulin in ob/ob cells could be reproduced by application of a membrane-permeant inositol trisphosphate (I[P.sub.3]) analog and blocked by a frequently used I[P.sub.3] receptor inhibitor, 2-aminoethoxydiphenyl borate. In ob/ob cardiomyocytes, insulin increased the I[P.sub.3] concentration and mitochondrial [Ca.sup.2+] handling was impaired. In conclusion, we propose a model where insulin increases I[P.sub.3] in ob/ob cardiomyocytes, which prolongs the electrically evoked [Ca.sup.2+] release. This, together with an impaired mitochondrial [Ca.sup.2+] handling, results in insulin-mediated extra [Ca.sup.2+] transients in ob/ob cardiomyocytes that may predispose for arrhythmias in vivo., Obesity and type 2 diabetes are leading causes of coronary heart disease and heart failure (1-4), and clinical and experimental studies have shown that diabetes is associated with altered cardiac [...]

Published
2005

44. Speckle-Tracking Echocardiography in Children With Duchenne Muscular Dystrophy: A Prospective Multicenter Controlled Cross-Sectional Study.

Author

UCL - SSS/IREC/PEDI - Pôle de Pédiatrie, UCL - (SLuc) Service de cardiologie pédiatrique, Amedro, Pascal, Vincenti, Marie, De La Villeon, Gregoire, Lavastre, Kathleen, Barréa, Catherine, Guillaumont, Sophie, Bredy, Charlene, Gamon, Lucie, Meli, Albano C, Cazorla, Olivier, Fauconnier, Jeremy, Meyer, Pierre, Rivier, François, Adda, Jerome, Mura, Thibault, Lacampagne, Alain, UCL - SSS/IREC/PEDI - Pôle de Pédiatrie, UCL - (SLuc) Service de cardiologie pédiatrique, Amedro, Pascal, Vincenti, Marie, De La Villeon, Gregoire, Lavastre, Kathleen, Barréa, Catherine, Guillaumont, Sophie, Bredy, Charlene, Gamon, Lucie, Meli, Albano C, Cazorla, Olivier, Fauconnier, Jeremy, Meyer, Pierre, Rivier, François, Adda, Jerome, Mura, Thibault, and Lacampagne, Alain

Abstract

BACKGROUND: Prognosis of Duchenne muscular dystrophy (DMD) is related to cardiac dysfunction. Speckle-tracking echocardiographic (STE) imaging is emerging as a noninvasive functional biomarker to consider in the early detection of DMD-related cardiomyopathy. However, STE analysis has not been assessed in a prospectively controlled study, especially in presymptomatic children with DMD, and no study has used STE analysis in all three displacements (longitudinal, radial, and circumferential) and for both ventricles. METHODS: This prospective controlled study enrolled 108 boys, 36 of whom had DMD (mean age, 11 ± 3.8 years) and 72 of whom were age-matched control subjects in a 1:2 case-control design. Conventional echocardiographic variables were collected for the left and right ventricles. STE analyses were performed in the longitudinal, radial, and circumferential displacements for the left ventricle and in the free wall longitudinal displacement for the right ventricle. The effect of age on the evolution of two-dimensional strain in children with DMD was studied by adding an interaction term, DMD × age, in the models. RESULTS: Conventional echocardiographic measures were normal in both groups. Left ventricular (LV) ejection fraction ranged from 45% to 76% (mean, 63 ± 6%) in the DMD group and from 55% to 76% (mean, 64 ± 5%) in the control group. Global LV strain mean measures were significantly worse in the DMD group for the longitudinal (-16.8 ± 3.9% vs -20.6 ± 2.6%, P < .0001), radial (22.7 ± 11.3% vs 31.7 ± 14%, P = .002), and circumferential (-16.5 ± 3.8% vs -20.3 ± 3.1%, P < .0001) displacements. The decrease of global LV longitudinal strain with age in children with DMD was 0.34% per year more marked than that in control subjects. The LV inferolateral and anterolateral segments were specifically impaired, especially in the basal area. Right ventricular function evaluated using conventional echocardiography and STE analysis was normal and not different between chi

Published
2019

45. The energy disruptor metformin targets mitochondrial integrity via modification of calcium flux in cancer cells

Author

Loubiere, Camille, Clavel, Stephan, Gilleron, Jerome, Harisseh, Rania, Fauconnier, Jeremy, Ben-Sahra, Issam, Kaminski, Lisa, Laurent, Kathiane, Herkenne, Stephanie, Lacas-Gervais, Sandra, Ambrosetti, Damien, Alcor, Damien, Rocchi, Stephane, Cormont, Mireille, Michiels, Jean-François, Mari, Bernard, Mazure, Nathalie M., Scorrano, Luca, Lacampagne, Alain, Gharib, Abdallah, Tanti, Jean-François, Bost, Frederic, Centre méditerranéen de médecine moléculaire (C3M), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), 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), 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), Northwestern University Chicago, Universita degli Studi di Padova, Dulbecco Telethon Institute, Telethon Foundation, Centre Commun de Microscopie Appliquée (CCMA), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Hôpital Pasteur [Nice] (CHU), Institut de pharmacologie moléculaire et cellulaire (IPMC), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de signalisation, biologie du développement et cancer (ISBDC), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Côte d'Azur (UCA), 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 des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Northwestern University [Chicago, Ill. USA], COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), ITMO-Cancer, foundation ARC, French Ministry of Research, Conseil General Alpes-Maritimes (Appel a projets santé), Region PACA (Appel a projets plateforme), and French Government (National Research Agency, ANR) through the 'Investments for the Future' LABEX SIGNALIFE [ANR-11-LABX-0028-01]

Subjects
endocrine system diseases, Science, [SDV]Life Sciences [q-bio], Endoplasmic Reticulum, biogenèse mitochondriale, Mitochondrial Membrane Transport Proteins, Models, Biological, Article, Mice, stress, membrane mitochondriale, Cell Line, Tumor, Animals, Humans, réticulum endoplasmique, cellule cancereuse, Cancer, apoptose, Organelle Biogenesis, Multidisciplinary, Mitochondrial Permeability Transition Pore, digestive, oral, and skin physiology, nutritional and metabolic diseases, flux de calcium, Endoplasmic Reticulum Stress, Metformin, metformine, Mitochondria, Medicine, Calcium, Energy Metabolism, Mitochondrial Swelling
Abstract

International audience; Mitochondrial integrity is critical for the regulation of cellular energy and apoptosis. Metformin is an energy disruptor targeting complex I of the respiratory chain. We demonstrate that metformin induces endoplasmic reticulum (ER) stress, calcium release from the ER and subsequent uptake of calcium into the mitochondria, thus leading to mitochondrial swelling. Metformin triggers the disorganization of the cristae and inner mitochondrial membrane in several cancer cells and tumors. Mechanistically, these alterations were found to be due to calcium entry into the mitochondria, because the swelling induced by metformin was reversed by the inhibition of mitochondrial calcium uniporter (MCU). We also demonstrated that metformin inhibits the opening of mPTP and induces mitochondrial biogenesis. Altogether, the inhibition of mPTP and the increase in mitochondrial biogenesis may account for the poor pro-apoptotic effect of metformin in cancer cells. Maintaining mitochondrial structural integrity is essential for cells to produce energy, overcome environmental stresses such as nutrient deprivation and hypoxia and respond to genotoxic agents, including chemotherapy. Consequently, the disruption of mitochondrial metabolism sensitizes cells to apoptosis and opens new therapeutic avenues in cancer treatment. Metformin is a biguanide and a widely prescribed anti-diabetic agent, but it is also a metabolic disruptor that specifically targets the metabolism of cancer cells 1. Several reports have shown that this drug inhibits cancer cell growth and has antitumoral effects 2, 3. Biguanides inhibit the activity of the mito-chondrial respiratory chain complex I, thus leading to energetic stress due to the decrease in ATP synthesis 4-6. Decreased intracellular ATP leads to the activation of the energy sensitive kinase AMP-activated protein kinase (AMPK) and the inhibition of mechanistic target of rapamycin (mTORC1), which regulates cell growth and cell proliferation and is frequently hyperactivated in tumors. Despite the well-characterized effects of biguanides on the respiratory chain, their effects on the mitochondrial ultrastructure are poorly understood.

Published
2017
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46. Speckle tracking echocardiography in children with Duchenne muscular dystrophy: A multicenter controlled cross-sectional study

Author

Amedro, Pascal, primary, Vincenti, Marie, additional, De La Villeon, Grégoire, additional, Lavastre, Kathleen, additional, Barrea, Catherine, additional, Guillaumont, Sophie, additional, Bredy, Charlene, additional, Gamon, Lucie, additional, Meli, Albano C., additional, Cazorla, Olivier, additional, Fauconnier, Jeremy, additional, Meyer, Pierre, additional, Rivier, François, additional, Adda, Jerome, additional, Mura, Thibault, additional, and Lacampagne, Alain, additional

Published
2018
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