1
|
Cerchiara AG, Imbrici P, Quarta R, Cristiano E, Boccanegra B, Caputo E, Wells DJ, Cappellari O, De Luca A. Ion channels as biomarkers of altered myogenesis in myofiber precursors of Duchenne muscular dystrophy. Ann N Y Acad Sci 2024; 1534:130-144. [PMID: 38517756 DOI: 10.1111/nyas.15124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/20/2024] [Accepted: 02/15/2024] [Indexed: 03/24/2024]
Abstract
Myogenesis is essential for skeletal muscle formation, growth, and regeneration and can be altered in Duchenne muscular dystrophy (DMD), an X-linked disorder due to the absence of the cytoskeletal protein dystrophin. Ion channels play a pivotal role in muscle differentiation and interact with the dystrophin complex. To investigate ion channel involvement in myogenesis in dystrophic settings, we performed electrophysiological characterization of two immortalized mouse cell lines, wild-type (WT) H2K-2B4 and the dystrophic (DYS) H2K-SF1, and measured gene expression of differentiation markers and ion channels. Inward and outward currents/density increased as differentiation progressed in both WT and DYS cells. However, day-11 DYS cells showed higher (27%) inward current density with an increased expression ratio of Scn5a/Scn4a and decreased (48%) barium-sensitive outward current compared to WT. Furthermore, day-11 DYS cells showed more positive resting membrane potential (+10 mV) and lower membrane capacitance (50%) compared to WT. DYS cells also had reduced Myog and Myf5 expression at days 6 and 11. Overall, ion channel profile and myogenesis appeared altered in DYS cells. These results are a first step in validating ion channels as potential drug targets to ameliorate muscle degeneration in DMD settings and as differentiation biomarkers in innovative platforms.
Collapse
Affiliation(s)
| | - Paola Imbrici
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Raffaella Quarta
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Enrica Cristiano
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Brigida Boccanegra
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Erika Caputo
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Dominic J Wells
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
| | - Ornella Cappellari
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Annamaria De Luca
- Department of Pharmacy - Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| |
Collapse
|
2
|
Fernandes CAH, Zuniga D, Fagnen C, Kugler V, Scala R, Péhau-Arnaudet G, Wagner R, Perahia D, Bendahhou S, Vénien-Bryan C. Cryo-electron microscopy unveils unique structural features of the human Kir2.1 channel. SCIENCE ADVANCES 2022; 8:eabq8489. [PMID: 36149965 PMCID: PMC9506730 DOI: 10.1126/sciadv.abq8489] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/04/2022] [Indexed: 06/16/2023]
Abstract
We present the first structure of the human Kir2.1 channel containing both transmembrane domain (TMD) and cytoplasmic domain (CTD). Kir2.1 channels are strongly inward-rectifying potassium channels that play a key role in maintaining resting membrane potential. Their gating is modulated by phosphatidylinositol 4,5-bisphosphate (PIP2). Genetically inherited defects in Kir2.1 channels are responsible for several rare human diseases, including Andersen's syndrome. The structural analysis (cryo-electron microscopy), surface plasmon resonance, and electrophysiological experiments revealed a well-connected network of interactions between the PIP2-binding site and the G-loop through residues R312 and H221. In addition, molecular dynamics simulations and normal mode analysis showed the intrinsic tendency of the CTD to tether to the TMD and a movement of the secondary anionic binding site to the membrane even without PIP2. Our results revealed structural features unique to human Kir2.1 and provided insights into the connection between G-loop and gating and the pathological mechanisms associated with this channel.
Collapse
Affiliation(s)
- Carlos A. H. Fernandes
- UMR 7590, CNRS, Muséum National d’Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie, IMPMC, Sorbonne Université, 75005 Paris, France
| | - Dania Zuniga
- UMR 7590, CNRS, Muséum National d’Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie, IMPMC, Sorbonne Université, 75005 Paris, France
| | - Charline Fagnen
- UMR 7590, CNRS, Muséum National d’Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie, IMPMC, Sorbonne Université, 75005 Paris, France
| | - Valérie Kugler
- IMPReSs Facility, Biotechnology and Cell Signaling UMR 7242, CNRS–University of Strasbourg, Illkirch, Cedex, France
| | - Rosa Scala
- CNRS UMR7370, LP2M, Labex ICST, Faculté de Médecine, Université Côte d’Azur, Nice, France
| | - Gérard Péhau-Arnaudet
- Ultrastructural BioImaging Core Facility/UMR 3528, Institut Pasteur, 75724 Paris Cedex 15, France
| | - Renaud Wagner
- IMPReSs Facility, Biotechnology and Cell Signaling UMR 7242, CNRS–University of Strasbourg, Illkirch, Cedex, France
| | - David Perahia
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure Paris-Saclay, 4 Ave. des Sciences, 91190 Gif-sur-Yvette, France
| | - Saïd Bendahhou
- CNRS UMR7370, LP2M, Labex ICST, Faculté de Médecine, Université Côte d’Azur, Nice, France
| | - Catherine Vénien-Bryan
- UMR 7590, CNRS, Muséum National d’Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie, IMPMC, Sorbonne Université, 75005 Paris, France
| |
Collapse
|
3
|
Déri S, Borbás J, Hartai T, Hategan L, Csányi B, Visnyovszki Á, Madácsy T, Maléth J, Hegedűs Z, Nagy I, Arora R, Labro AJ, Környei L, Varró A, Sepp R, Ördög B. Impaired cytoplasmic domain interactions cause co-assembly defect and loss of function in the p.Glu293Lys KNCJ2 variant isolated from an Andersen-Tawil syndrome patient. Cardiovasc Res 2021; 117:1923-1934. [PMID: 32810216 DOI: 10.1093/cvr/cvaa249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/16/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023] Open
Abstract
AIMS Subunit interactions at the cytoplasmic domain interface (CD-I) have recently been shown to control gating in inward rectifier potassium channels. Here we report the novel KCNJ2 variant p.Glu293Lys that has been found in a patient with Andersen-Tawil syndrome type 1 (ATS1), causing amino acid substitution at the CD-I of the inward rectifier potassium channel subunit Kir2.1. Neither has the role of Glu293 in gating control been investigated nor has a pathogenic variant been described at this position. This study aimed to assess the involvement of Glu293 in CD-I subunit interactions and to establish the pathogenic role of the p.Glu293Lys variant in ATS1. METHODS AND RESULTS The p.Glu293Lys variant produced no current in homomeric form and showed dominant-negative effect over wild-type (WT) subunits. Immunocytochemical labelling showed the p.Glu293Lys subunits to distribute in the subsarcolemmal space. Salt bridge prediction indicated the presence of an intersubunit salt bridge network at the CD-I of Kir2.1, with the involvement of Glu293. Subunit interactions were studied by the NanoLuc® Binary Technology (NanoBiT) split reporter assay. Reporter constructs carrying NanoBiT tags on the intracellular termini produced no bioluminescent signal above background with the p.Glu293Lys variant in homomeric configuration and significantly reduced signals in cells co-expressing WT and p.Glu293Lys subunits simultaneously. Extracellularly presented reporter tags, however, generated comparable bioluminescent signals with heteromeric WT and p.Glu293Lys subunits and with homomeric WT channels. CONCLUSIONS Loss of function and dominant-negative effect confirm the causative role of p.Glu293Lys in ATS1. Co-assembly of Kir2.1 subunits is impaired in homomeric channels consisting of p.Glu293Lys subunits and is partially rescued in heteromeric complexes of WT and p.Glu293Lys Kir2.1 variants. These data point to an important role of Glu293 in mediating subunit assembly, as well as in gating of Kir2.1 channels.
Collapse
Affiliation(s)
- Szilvia Déri
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 12, 6720 Szeged, Hungary
| | - János Borbás
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Teodóra Hartai
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
| | - Lidia Hategan
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Beáta Csányi
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Ádám Visnyovszki
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
| | - Tamara Madácsy
- 1st Department of Internal Medicine, University of Szeged, Korányi fasor 8-10, 6720 Szeged, Hungary, Hungary
| | - József Maléth
- 1st Department of Internal Medicine, University of Szeged, Korányi fasor 8-10, 6720 Szeged, Hungary, Hungary
| | - Zoltán Hegedűs
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Temesvári krt. 62, 6726 Szeged, Hungary
- Department of Biochemistry and Medical Chemistry, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
| | - István Nagy
- Institute of Biochemistry, Biological Research Centre the Hungarian Academy of Sciences, Temesvári krt. 62, 6726 Szeged, Hungary
- Seqomics Biotechnology Ltd, Vállalkozók útja 7, 6782 Mórahalom, Hungary
| | - Rohit Arora
- Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - Alain J Labro
- Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
- Department of Basic Medical Sciences, University of Ghent, C. Heymanslaan 10, 9000 Ghent, Belgium
| | - László Környei
- Gottsegen György National Institute of Cardiology, Haller u. 9, 1096 Budapest, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 12, 6720 Szeged, Hungary
- MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Dóm tér 12, 6720 Szeged, Hungary
| | - Róbert Sepp
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Balázs Ördög
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
| |
Collapse
|
4
|
Dolci C, Sansone VA, Gibelli D, Cappella A, Sforza C. Distinctive facial features in Andersen-Tawil syndrome: A three-dimensional stereophotogrammetric analysis. Am J Med Genet A 2020; 185:781-789. [PMID: 33369085 DOI: 10.1002/ajmg.a.62040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/19/2020] [Accepted: 12/14/2020] [Indexed: 01/28/2023]
Abstract
Andersen-Tawil syndrome (ATS) is a rare potassium channelopathy causing periodic paralysis, cardiac arrhythmias, and dysmorphic features. A detailed analysis of the face could facilitate diagnosis of ATS, as approximately 30% of patients do not show variants in KCNJ2 gene, and diagnosis is established by clinical findings. We aimed to characterize the face in ATS through a quantitative approach, as facial anomalies may be unnoticed on visual inspection. Facial images of 12 subjects with genetically confirmed ATS (six males, six females, age 5-67 years) were acquired through stereophotogrammetry. Using 38 soft-tissue landmarks, linear distances, angles, and ratios were calculated and expressed as z-score values, with reference to 477 healthy subjects matched for sex and age. All patients showed decreased lower facial height with shortening of philtrum (mean z-score ± SD: -1.5 ± 0.9), smaller mid and lower facial depths (-1.9 ± 0.7; -2.3 ± 0.9), short palpebral fissures (right -1.2 ± 0.4; left -1.6 ± 0.6), smaller mandibular ramus length (-2.1 ± 0.4), and increased nasal width/length ratio (1.4 ± 0.5) with smaller nostril axis length (right -1.8 ± 0.8, left -1.6 ± 0.7). Hypertelorism and low-set ears were detected in two-thirds of patients. The study quantified facial dysmorphysm in ATS, extending information about known features, and detecting unrecorded philtrum and nostril characteristics, which may be distinctive traits of the disorder.
Collapse
Affiliation(s)
- Claudia Dolci
- Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| | - Valeria A Sansone
- NEuroMuscularOmnicenter, NEMO Clinical Center, Neurorehabilitation Unit, Università degli Studi di Milano, Milan, Italy
| | - Daniele Gibelli
- Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| | - Annalisa Cappella
- Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| | - Chiarella Sforza
- Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
5
|
Mazzanti A, Guz D, Trancuccio A, Pagan E, Kukavica D, Chargeishvili T, Olivetti N, Biernacka EK, Sacilotto L, Sarquella-Brugada G, Campuzano O, Nof E, Anastasakis A, Sansone VA, Jimenez-Jaimez J, Cruz F, Sánchez-Quiñones J, Hernandez-Afonso J, Fuentes ME, Średniawa B, Garoufi A, Andršová I, Izquierdo M, Marinov R, Danon A, Expósito-García V, Garcia-Fernandez A, Muñoz-Esparza C, Ortíz M, Zienciuk-Krajka A, Tavazzani E, Monteforte N, Bloise R, Marino M, Memmi M, Napolitano C, Zorio E, Monserrat L, Bagnardi V, Priori SG. Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1. J Am Coll Cardiol 2020; 75:1772-1784. [PMID: 32299589 DOI: 10.1016/j.jacc.2020.02.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 01/25/2020] [Accepted: 02/11/2020] [Indexed: 11/25/2022]
|
6
|
Pini J, Giuliano S, Matonti J, Gannoun L, Simkin D, Rouleau M, Bendahhou S. Osteogenic and Chondrogenic Master Genes Expression Is Dependent on the Kir2.1 Potassium Channel Through the Bone Morphogenetic Protein Pathway. J Bone Miner Res 2018; 33:1826-1841. [PMID: 29813186 DOI: 10.1002/jbmr.3474] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/04/2018] [Accepted: 05/20/2018] [Indexed: 11/07/2022]
Abstract
Andersen's syndrome is a rare disorder affecting muscle, heart, and bone that is associated with mutations leading to a loss of function of the inwardly rectifying K+ channel Kir2.1. Although the Kir2.1 function can be anticipated in excitable cells by controlling the electrical activity, its role in non-excitable cells remains to be investigated. Using Andersen's syndrome-induced pluripotent stem cells, we investigated the cellular and molecular events during the osteoblastic and chondrogenic differentiation that are affected by the loss of the Ik1 current. We show that loss of Kir2.1 channel function impairs both osteoblastic and chondrogenic processes through the downregulation of master gene expression. This downregulation is the result of an impairment of the bone morphogenetic proteins signaling pathway through dephosphorylation of the Smad proteins. Restoring Kir2.1 channel function in Andersen's syndrome cells rescued master genes expression and restored normal osteoblast and chondrocyte behavior. Our results show that Kir2.1-mediated activity controls endochondral and intramembranous ossification signaling pathways. © 2018 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Jonathan Pini
- Centre for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA, USA
| | - Serena Giuliano
- UMR7370 CNRS, LP2M, Labex ICST, University Nice Côte d'Azur, Faculté de Médecine, Nice, France
| | - Julia Matonti
- UMR7370 CNRS, LP2M, Labex ICST, University Nice Côte d'Azur, Faculté de Médecine, Nice, France
| | - Lila Gannoun
- UMR7370 CNRS, LP2M, Labex ICST, University Nice Côte d'Azur, Faculté de Médecine, Nice, France
| | - Dina Simkin
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Matthieu Rouleau
- UMR7370 CNRS, LP2M, Labex ICST, University Nice Côte d'Azur, Faculté de Médecine, Nice, France
| | - Saïd Bendahhou
- UMR7370 CNRS, LP2M, Labex ICST, University Nice Côte d'Azur, Faculté de Médecine, Nice, France
| |
Collapse
|
7
|
Simkin D, Robin G, Giuliano S, Vukolic A, Moceri P, Guy N, Wagner KD, Lacampagne A, Allard B, Bendahhou S. Andersen's syndrome mutants produce a knockdown of inwardly rectifying K + channel in mouse skeletal muscle in vivo. Cell Tissue Res 2017; 371:309-323. [PMID: 29018970 DOI: 10.1007/s00441-017-2696-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/05/2017] [Indexed: 11/30/2022]
Abstract
Andersen's syndrome (AS) is a rare autosomal disorder that has been defined by the triad of periodic paralysis, cardiac arrhythmia, and developmental anomalies. AS has been directly linked to over 40 different autosomal dominant negative loss-of-function mutations in the KCNJ2 gene, encoding for the tetrameric strong inward rectifying K+ channel KIR2.1. While KIR2.1 channels have been suggested to contribute to setting the resting membrane potential (RMP) and to control the duration of the action potential (AP) in skeletal and cardiac muscle, the mechanism by which AS mutations produce such complex pathophysiological symptoms is poorly understood. Thus, we use an adenoviral transduction strategy to study in vivo subcellular distribution of wild-type (WT) and AS-associated mutant KIR2.1 channels in mouse skeletal muscle. We determined that WT and D71V AS mutant KIR2.1 channels are localized to the sarcolemma and the transverse tubules (T-tubules) of skeletal muscle fibers, while the ∆314-315 AS KIR2.1 mutation prevents proper trafficking of the homo- or hetero-meric channel complexes. Whole-cell voltage-clamp recordings in individual skeletal muscle fibers confirmed the reduction of inwardly rectifying K+ current (IK1) after transduction with ∆314-315 KIR2.1 as compared to WT channels. Analysis of skeletal muscle function revealed reduced force generation during isometric contraction as well as reduced resistance to muscle fatigue in extensor digitorum longus muscles transduced with AS mutant KIR2.1. Together, these results suggest that KIR2.1 channels may be involved in the excitation-contraction coupling process required for proper skeletal muscle function. Our findings provide clues to mechanisms associated with periodic paralysis in AS.
Collapse
Affiliation(s)
- Dina Simkin
- UMR 7370 CNRS, LP2M, Laboratoire d'Excellence - ICST, Université Côte d'Azur, Faculté de Médecine, 06107, Nice, France.,Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Gaëlle Robin
- UMR CNRS 5534, Université Claude Bernard Lyon 1, 69622, Lyon, France
| | - Serena Giuliano
- UMR 7370 CNRS, LP2M, Laboratoire d'Excellence - ICST, Université Côte d'Azur, Faculté de Médecine, 06107, Nice, France
| | - Ana Vukolic
- Institute for Molecular Health Science, ETH Zurich, 8093, Zurich, Switzerland
| | - Pamela Moceri
- UMR 7370 CNRS, LP2M, Laboratoire d'Excellence - ICST, Université Côte d'Azur, Faculté de Médecine, 06107, Nice, France.,Service de Cardiologie, Pasteur Hospital, CHU de Nice, 06107, Nice, France
| | - Nicolas Guy
- UMR 7275 CNRS, IPMC, Université Côte d'Azur, 06560, Valbonne, France
| | - Kay-Dietrich Wagner
- UMR 7284 CNRS, INSERM, IBV, Université Côte d'Azur, Faculté de Médecine, 06107, Nice, France
| | - Alain Lacampagne
- INSERM U1046, UMR CNRS 9214, Université de Montpellier, CHRU de Montpellier, 34295, Montpellier, France
| | - Bruno Allard
- UMR CNRS 5534, Université Claude Bernard Lyon 1, 69622, Lyon, France
| | - Saïd Bendahhou
- UMR 7370 CNRS, LP2M, Laboratoire d'Excellence - ICST, Université Côte d'Azur, Faculté de Médecine, 06107, Nice, France.
| |
Collapse
|
8
|
Abstract
Familial disorders of skeletal muscle excitability were initially described early in the last century and are now known to be caused by mutations of voltage-gated ion channels. The clinical manifestations are often striking, with an inability to relax after voluntary contraction (myotonia) or transient attacks of severe weakness (periodic paralysis). An essential feature of these disorders is fluctuation of symptoms that are strongly impacted by environmental triggers such as exercise, temperature, or serum K(+) levels. These phenomena have intrigued physiologists for decades, and in the past 25 years the molecular lesions underlying these disorders have been identified and mechanistic studies are providing insights for therapeutic strategies of disease modification. These familial disorders of muscle fiber excitability are "channelopathies" caused by mutations of a chloride channel (ClC-1), sodium channel (NaV1.4), calcium channel (CaV1.1), and several potassium channels (Kir2.1, Kir2.6, and Kir3.4). This review provides a synthesis of the mechanistic connections between functional defects of mutant ion channels, their impact on muscle excitability, how these changes cause clinical phenotypes, and approaches toward therapeutics.
Collapse
Affiliation(s)
- Stephen C Cannon
- Department of Physiology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| |
Collapse
|
9
|
Pini J, Rouleau M, Desnuelle C, Sacconi S, Bendahhou S. Modeling Andersen's Syndrome in Human Induced Pluripotent Stem Cells. Stem Cells Dev 2015; 25:151-9. [PMID: 26573604 DOI: 10.1089/scd.2015.0258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Andersen's syndrome (AS) is a rare disorder characterized by a triad of symptoms: periodic paralysis, cardiac arrhythmia, and bone developmental defects. Most of the patients carry mutations on the inward rectifier potassium channel Kir2.1 encoded by the KCNJ2 gene. kcnj2 knockout mice are lethal at birth preventing, hence, thorough investigations of the physiological and pathophysiological events. We have generated induced pluripotent stem (iPS) cells from healthy as well as from AS patient muscular biopsies using the four-gene cassette required for cellular reprogramming (Oct4, Sox2, Klf4, and c-Myc). The generated AS-iPS cells exhibited the gold standard requirement for iPS cells: expression of genetics and surface pluripotent markers, strong alkaline phosphatase activity, self-renewal, and could be differentiated by the formation of embryoid bodies (EBs) into the three germ layers. Sequencing of the entire coding sequence of the KCNJ2 gene, in AS-iPS cells, revealed that the reprogramming process did not revert the Andersen's syndrome-associated mutation. Moreover, no difference was observed between control and AS-iPS cells in terms of pluripotent markers' expression, self-renewal, and three germ layer differentiation. Interestingly, expression of osteogenic markers are lower in EB-differentiated AS-iPS compared to control iPS cells. Our results showed that the Kir2.1 channel is not important for the reprogramming process and the early step of the development in vitro. However, the osteogenic machinery appears to be hastened in AS-iPS cells, strongly indicating that the generated AS-iPS cells could be a good model to better understand the AS pathophysiology.
Collapse
Affiliation(s)
- Jonathan Pini
- 1 UMR7370 CNRS, LP2M, Labex ICST, Faculté de Médecine, University Nice Sophia Antipolis , Nice, France
| | - Matthieu Rouleau
- 1 UMR7370 CNRS, LP2M, Labex ICST, Faculté de Médecine, University Nice Sophia Antipolis , Nice, France
| | - Claude Desnuelle
- 2 INSERM, U1081, Institute for Research on Cancer and Aging of Nice (IRCAN) , Nice, France .,3 CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice (IRCAN) , Nice, France .,4 Faculty of Medicine, Neuromuscular Diseases and ALS Specialized Center, University of Nice-Sophia-Antipolis , Nice, France
| | - Sabrina Sacconi
- 2 INSERM, U1081, Institute for Research on Cancer and Aging of Nice (IRCAN) , Nice, France .,3 CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice (IRCAN) , Nice, France .,4 Faculty of Medicine, Neuromuscular Diseases and ALS Specialized Center, University of Nice-Sophia-Antipolis , Nice, France
| | - Saïd Bendahhou
- 1 UMR7370 CNRS, LP2M, Labex ICST, Faculté de Médecine, University Nice Sophia Antipolis , Nice, France
| |
Collapse
|
10
|
|
11
|
Tan SV, Z'Graggen WJ, BoËrio D, Rayan DLR, Howard R, Hanna MG, Bostock H. Membrane dysfunction in Andersen-Tawil syndrome assessed by velocity recovery cycles. Muscle Nerve 2012; 46:193-203. [DOI: 10.1002/mus.23293] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
12
|
Raghunandan D, Ravishankar B, Sharanbasava G, Mahesh DB, Harsoor V, Yalagatti MS, Bhagawanraju M, Venkataraman A. Anti-cancer studies of noble metal nanoparticles synthesized using different plant extracts. Cancer Nanotechnol 2011; 2:57-65. [PMID: 26069485 PMCID: PMC4451508 DOI: 10.1007/s12645-011-0014-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 04/26/2011] [Indexed: 01/13/2023] Open
Abstract
Biofunctionalized gold and silver nanoparticles synthesized using different plant extracts of guava and clove in vitro anti-cancer efficacy against four different cancer cell lines human colorectal adenocarcinoma, human kidney, human chronic myelogenous, leukemia, bone marrow, and human cervix have been studied and reported. The present experimental study suggests that flavonoids functionalized gold nanoparticles synthesized using aqueous clove buds extract are more potential than guava leaf extract towards anti-cancer activities. The microscopic and 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay infer that the functionalized irregular shaped gold nanoparticles synthesized with aqueous clove bud extract showed a satisfactory anti-cancer effect on all the cell lines. The silver nanoparticles synthesized using same extracts are devoid of anti-cancer activity. The XTT assay revealed dose-dependent cytotoxicity to cancer cell lines. The study revealed that the free radicals generated by gold nanoparticles are responsible for anti-cancer effect. To confirm the free-radical scavenging efficacy of gold nanoparticle, nitric oxide assay is followed. We observed that the gold nanoparticles swabbed the free radicals in dose-dependent manner. With continued improvements, these nanoparticles may prove to be potential anti-cancer agents.
Collapse
Affiliation(s)
- Deshpande Raghunandan
- HKES Matoshree Taradevi Rampure Institute of Pharmaceutical Sciences, Sedam Road, Gulbarga-585105, Karnataka, India
| | - Bhat Ravishankar
- Materials Chemistry Laboratory, Department of Material Science, Gulbarga University, Gulbarga, 585106 Karnataka, India
| | - Ganachari Sharanbasava
- Materials Chemistry Laboratory, Department of Material Science, Gulbarga University, Gulbarga, 585106 Karnataka, India
| | - D Bedre Mahesh
- Materials Chemistry Laboratory, Department of Material Science, Gulbarga University, Gulbarga, 585106 Karnataka, India
| | - Vasanth Harsoor
- Periferal Cancer Institute, Sedam Road, Gulbarga-585105, Karnataka, India
| | - Manjunath S Yalagatti
- Sri Krupa institute of Pharmaceutical Sciences, Village Velkatta, Siddipet-502277, Medak, Andhra Pradesh India
| | - M Bhagawanraju
- CM College of Pharmacy, Maisammaguda, Dulapally, Hyderabad-500014, Andhra Pradesh India
| | - A Venkataraman
- Materials Chemistry Laboratory, Department of Material Science, Gulbarga University, Gulbarga, 585106 Karnataka, India
| |
Collapse
|
13
|
Dassau L, Conti LR, Radeke CM, Ptáček LJ, Vandenberg CA. Kir2.6 regulates the surface expression of Kir2.x inward rectifier potassium channels. J Biol Chem 2011; 286:9526-41. [PMID: 21209095 DOI: 10.1074/jbc.m110.170597] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Precise trafficking, localization, and activity of inward rectifier potassium Kir2 channels are important for shaping the electrical response of skeletal muscle. However, how coordinated trafficking occurs to target sites remains unclear. Kir2 channels are tetrameric assemblies of Kir2.x subunits. By immunocytochemistry we show that endogenous Kir2.1 and Kir2.2 are localized at the plasma membrane and T-tubules in rodent skeletal muscle. Recently, a new subunit, Kir2.6, present in human skeletal muscle, was identified as a gene in which mutations confer susceptibility to thyrotoxic hypokalemic periodic paralysis. Here we characterize the trafficking and interaction of wild type Kir2.6 with other Kir2.x in COS-1 cells and skeletal muscle in vivo. Immunocytochemical and electrophysiological data demonstrate that Kir2.6 is largely retained in the endoplasmic reticulum, despite high sequence identity with Kir2.2 and conserved endoplasmic reticulum and Golgi trafficking motifs shared with Kir2.1 and Kir2.2. We identify amino acids responsible for the trafficking differences of Kir2.6. Significantly, we show that Kir2.6 subunits can coassemble with Kir2.1 and Kir2.2 in vitro and in vivo. Notably, this interaction limits the surface expression of both Kir2.1 and Kir2.2. We provide evidence that Kir2.6 functions as a dominant negative, in which incorporation of Kir2.6 as a subunit in a Kir2 channel heterotetramer reduces the abundance of Kir2 channels on the plasma membrane.
Collapse
Affiliation(s)
- Lior Dassau
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, California 93106, USA
| | | | | | | | | |
Collapse
|
14
|
|