1
|
Delafenêtre A, Chapotte-Baldacci CA, Dorémus L, Massouridès E, Bernard M, Régnacq M, Piquereau J, Chatelier A, Cognard C, Pinset C, Sebille S. Duchenne muscular dystrophy skeletal muscle cells derived from human induced pluripotent stem cells recapitulate various calcium dysregulation pathways. Cell Calcium 2024; 123:102943. [PMID: 39154623 DOI: 10.1016/j.ceca.2024.102943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/23/2024] [Accepted: 08/11/2024] [Indexed: 08/20/2024]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked progressive muscle degenerative disease, caused by mutations in the dystrophin gene and resulting in premature death. As a major secondary event, an abnormal elevation of the intracellular calcium concentration in the dystrophin-deficient muscle contributes to disease progression in DMD. In this study, we investigated the specific functional features of induced pluripotent stem cell-derived muscle cells (hiPSC-skMCs) generated from DMD patients to regulate intracellular calcium concentration. As compared to healthy hiPSC-skMCs, DMD hiPSC-skMCs displayed specific spontaneous calcium signatures with high levels of intracellular calcium concentration. Furthermore, stimulations with electrical field or with acetylcholine perfusion induced higher calcium response in DMD hiPSC-skMCs as compared to healthy cells. Finally, Mn2+ quenching experiments demonstrated high levels of constitutive calcium entries in DMD hiPSC-skMCs as compared to healthy cells. Our findings converge on the fact that DMD hiPSC-skMCs display intracellular calcium dysregulation as demonstrated in several other models. Observed calcium disorders associated with RNAseq analysis on these DMD cells highlighted some mechanisms, such as spontaneous and activated sarcoplasmic reticulum (SR) releases or constitutive calcium entries, known to be disturbed in other dystrophin-deficient models. However, store operated calcium entries (SOCEs) were not found to be dysregulated in our DMD hiPSC-skMCs model. These results suggest that all the mechanisms of calcium impairment observed in other animal models may not be as pronounced in humans and could point to a preference for certain mechanisms that could correspond to major molecular targets for DMD therapies.
Collapse
Affiliation(s)
| | | | - Léa Dorémus
- PRETI laboratory, University of Poitiers, France
| | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Mareedu S, Million ED, Duan D, Babu GJ. Abnormal Calcium Handling in Duchenne Muscular Dystrophy: Mechanisms and Potential Therapies. Front Physiol 2021; 12:647010. [PMID: 33897454 PMCID: PMC8063049 DOI: 10.3389/fphys.2021.647010] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/02/2021] [Indexed: 12/18/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked muscle-wasting disease caused by the loss of dystrophin. DMD is associated with muscle degeneration, necrosis, inflammation, fatty replacement, and fibrosis, resulting in muscle weakness, respiratory and cardiac failure, and premature death. There is no curative treatment. Investigations on disease-causing mechanisms offer an opportunity to identify new therapeutic targets to treat DMD. An abnormal elevation of the intracellular calcium (Cai2+) concentration in the dystrophin-deficient muscle is a major secondary event, which contributes to disease progression in DMD. Emerging studies have suggested that targeting Ca2+-handling proteins and/or mechanisms could be a promising therapeutic strategy for DMD. Here, we provide an updated overview of the mechanistic roles the sarcolemma, sarcoplasmic/endoplasmic reticulum, and mitochondria play in the abnormal and sustained elevation of Cai2+ levels and their involvement in DMD pathogenesis. We also discuss current approaches aimed at restoring Ca2+ homeostasis as potential therapies for DMD.
Collapse
Affiliation(s)
- Satvik Mareedu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Emily D Million
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, MO, United States
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, The University of Missouri, Columbia, MO, United States.,Department of Biomedical, Biological & Chemical Engineering, The University of Missouri, Columbia, MO, United States
| | - Gopal J Babu
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| |
Collapse
|
3
|
|
4
|
Dubinin MV, Talanov EY, Tenkov KS, Starinets VS, Mikheeva IB, Sharapov MG, Belosludtsev KN. Duchenne muscular dystrophy is associated with the inhibition of calcium uniport in mitochondria and an increased sensitivity of the organelles to the calcium-induced permeability transition. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165674. [PMID: 31926263 DOI: 10.1016/j.bbadis.2020.165674] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is characterized by a pronounced and progressive degradation of the structure of skeletal muscles, which decreases their strength and lowers endurance of the organism. At muscular dystrophy, mitochondria are known to undergo significant functional changes, which is manifested in a decreased efficiency of oxidative phosphorylation and impaired energy metabolism of the cell. It is believed that the DMD-induced functional changes of mitochondria are mainly associated with the dysregulation of Ca2+ homeostasis. This work examines the kinetic parameters of Ca2+ transport and the opening of the Ca2+-dependent MPT pore in the skeletal-muscle mitochondria of the dystrophin-deficient C57BL/10ScSn-mdx mice. As compared to the organelles of wild-type animals, skeletal-muscle mitochondria of mdx mice have been found to be much less efficient in respect to Ca2+ uniport, with the kinetics of Na+-dependent Ca2+ efflux not changing. The data obtained indicate that the decreased rate of Ca2+ uniport in the mitochondria of mdx mice may be associated with the increased level of the dominant negative subunit of Ca2+ uniporter (MCUb). The experiments have also shown that in mdx mice, skeletal-muscle mitochondria have low resistance to the induction of MPT, which may be related to a significantly increased expression of adenylate translocator (ANT2), a possible structural element of the MPT pore. The paper discusses how changes in the expression of calcium uniporter and putative components of the MPT pore caused by the development of DMD can affect Ca2+ homeostasis of skeletal-muscle mitochondria.
Collapse
Affiliation(s)
- Mikhail V Dubinin
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia.
| | - Eugeny Yu Talanov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Kirill S Tenkov
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Vlada S Starinets
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Irina B Mikheeva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Mars G Sharapov
- Institute of Cell Biophysics, Russian Academy of Sciences, PSCBR RAS, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Konstantin N Belosludtsev
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| |
Collapse
|
5
|
Valladares D, Utreras-Mendoza Y, Campos C, Morales C, Diaz-Vegas A, Contreras-Ferrat A, Westermeier F, Jaimovich E, Marchi S, Pinton P, Lavandero S. IP 3 receptor blockade restores autophagy and mitochondrial function in skeletal muscle fibers of dystrophic mice. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3685-3695. [PMID: 30251688 DOI: 10.1016/j.bbadis.2018.08.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 08/06/2018] [Accepted: 08/30/2018] [Indexed: 12/14/2022]
Abstract
Duchenne muscular dystrophy (DMD) is characterized by a severe and progressive destruction of muscle fibers associated with altered Ca2+ homeostasis. We have previously shown that the IP3 receptor (IP3R) plays a role in elevating basal cytoplasmic Ca2+ and that pharmacological blockade of IP3R restores muscle function. Moreover, we have shown that the IP3R pathway negatively regulates autophagy by controlling mitochondrial Ca2+ levels. Nevertheless, it remains unclear whether IP3R is involved in abnormal mitochondrial Ca2+ levels, mitochondrial dynamics, or autophagy and mitophagy observed in adult DMD skeletal muscle. Here, we show that the elevated basal autophagy and autophagic flux levels were normalized when IP3R was downregulated in mdx fibers. Pharmacological blockade of IP3R in mdx fibers restored both increased mitochondrial Ca2+ levels and mitochondrial membrane potential under resting conditions. Interestingly, mdx mitochondria changed from a fission to an elongated state after IP3R knockdown, and the elevated mitophagy levels in mdx fibers were normalized. To our knowledge, this is the first study associating IP3R1 activity with changes in autophagy, mitochondrial Ca2+ levels, mitochondrial membrane potential, mitochondrial dynamics, and mitophagy in adult mouse skeletal muscle. Moreover, these results suggest that increased IP3R activity in mdx fibers plays an important role in the pathophysiology of DMD. Overall, these results lead us to propose the use of specific IP3R blockers as a new pharmacological treatment for DMD, given their ability to restore both autophagy/mitophagy and mitochondrial function.
Collapse
Affiliation(s)
- Denisse Valladares
- Advanced Center for Chronic Diseases (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Escuela de Kinesiologia, Facultad de Medicina, Universidad Finis Terrae, Santiago, Chile.
| | - Yildy Utreras-Mendoza
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Cristian Campos
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Camilo Morales
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Alexis Diaz-Vegas
- Advanced Center for Chronic Diseases (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Ariel Contreras-Ferrat
- Advanced Center for Chronic Diseases (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Francisco Westermeier
- Advanced Center for Chronic Diseases (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Enrique Jaimovich
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Chile
| | - Saverio Marchi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Center for Studies of Exercise, Metabolism and Cancer (CEMC), Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile; Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
6
|
Optogenetic approach for targeted activation of global calcium transients in differentiated C2C12 myotubes. Sci Rep 2017; 7:11108. [PMID: 28894267 PMCID: PMC5593883 DOI: 10.1038/s41598-017-11551-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/14/2017] [Indexed: 12/22/2022] Open
Abstract
Excitation-contraction coupling in muscle cells is initiated by a restricted membrane depolarization delimited within the neuromuscular junction. This targeted depolarization triggers an action potential that propagates and induces a global cellular calcium response and a consequent contraction. To date, numerous studies have investigated this excitation-calcium response coupling by using different techniques to depolarize muscle cells. However, none of these techniques mimic the temporal and spatial resolution of membrane depolarization observed in the neuromuscular junction. By using optogenetics in C2C12 muscle cells, we developed a technique to study the calcium response following membrane depolarization induced by photostimulations of membrane surface similar or narrower than the neuromuscular junction area. These stimulations coupled to confocal calcium imaging generate a global cellular calcium response that is the consequence of a membrane depolarization propagation. In this context, this technique provides an interesting, contactless and relatively easy way of investigation of calcium increase/release as well as calcium decrease/re-uptake triggered by a propagated membrane depolarization.
Collapse
|
7
|
Berridge MJ. The Inositol Trisphosphate/Calcium Signaling Pathway in Health and Disease. Physiol Rev 2016; 96:1261-96. [DOI: 10.1152/physrev.00006.2016] [Citation(s) in RCA: 377] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many cellular functions are regulated by calcium (Ca2+) signals that are generated by different signaling pathways. One of these is the inositol 1,4,5-trisphosphate/calcium (InsP3/Ca2+) signaling pathway that operates through either primary or modulatory mechanisms. In its primary role, it generates the Ca2+ that acts directly to control processes such as metabolism, secretion, fertilization, proliferation, and smooth muscle contraction. Its modulatory role occurs in excitable cells where it modulates the primary Ca2+ signal generated by the entry of Ca2+ through voltage-operated channels that releases Ca2+ from ryanodine receptors (RYRs) on the internal stores. In carrying out this modulatory role, the InsP3/Ca2+ signaling pathway induces subtle changes in the generation and function of the voltage-dependent primary Ca2+ signal. Changes in the nature of both the primary and modulatory roles of InsP3/Ca2+ signaling are a contributory factor responsible for the onset of a large number human diseases.
Collapse
Affiliation(s)
- Michael J. Berridge
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom
| |
Collapse
|
8
|
Aguettaz E, Lopez J, Krzesiak A, Constantin B, Cognard C, Sebille S. Data on calcium increases depending on stretch in dystrophic cardiomyocytes. Data Brief 2016; 8:1443-7. [PMID: 27617280 PMCID: PMC5007543 DOI: 10.1016/j.dib.2016.08.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 11/30/2022] Open
Abstract
In this data article, intracellular Ca2+ concentration ([Ca2+]i) was measured in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch. Using a carbon microfibers technique, axial stretch was applied to mimic effects of physiological conditions of ventricular filling. A study of cation entry with the same experimental model and the manganese quenching method reported (i) a constitutive cation entry in mdx cardiomyocytes and (ii) the involvement of TRPV2 channels in axial-stretch dependant cation entry, “Axial stretch-dependent cation entry in dystrophic cardiomyopathy: involvement of several TRPs channels” (Aguettaz et al., 2016) [1]. Here, the Ca2+ dye fluo-8 was used for [Ca2+]i measurement, in both resting and stretching conditions, using a perfusion protocol starting initially with a calcium free Tyrode solution followed by the perfusion of 1.8 mM Ca2+ Tyrode solution. The variation of [Ca2+]i was found higher in mdx cardiomyocytes.
Collapse
Affiliation(s)
- E. Aguettaz
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - J.J. Lopez
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Calcium et Microenvironnement des Cellules Souches (CMCS), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - A. Krzesiak
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - B. Constantin
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Calcium et Microenvironnement des Cellules Souches (CMCS), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - C. Cognard
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
| | - S. Sebille
- Laboratoire de Signalisation et Transports Ioniques Membranaires (STIM), Equipe Transferts Ioniques et Rythmicité Cardiaque (TIRC), Université de Poitiers, 86073 Poitiers Cedex 9, France
- Corresponding author.
| |
Collapse
|
9
|
Wei W, Huang W, Yue J. Requirement of IP3 receptor 3 (IP3R3) in nitric oxide induced cardiomyocyte differentiation of mouse embryonic stem cells. Exp Cell Res 2016; 346:9-16. [PMID: 27349290 DOI: 10.1016/j.yexcr.2016.06.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 01/29/2023]
Abstract
Nitric oxide (NO) markedly induces cardiomyocyte (CM) differentiation of embryonic stem (ES) cells. Here we examined the role of the Ca(2+) signaling in the NO-induced CM differentiation of mouse ES cells. We found that NO induced intracellular Ca(2+) increases in ES cells in a dose-dependent manner, and application of IP3 pathway antagonists not only significantly inhibited this induced Ca(2+) increase but also abolished NO-induced CM differentiation of ES cells. Subsequently, all 3 types of inositol 1, 4, 5-trisphosphate (IP3) receptors (IP3Rs) in mouse ES cells were individually or triply knocked down. Interestingly, only knockdown of type 3 IP3R (IP3R3) or triple-knockdown of three types of IP3Rs significantly inhibited the NO-induced Ca(2+) increases. Consistently, IP3R3 knockdown blocked the NO-induced CM differentiation of ES cells. CMs derived from IP3R3 knockdown ES cells also showed both structural and functional defects. In summary, our results indicate that the IP3R3-Ca(2+) pathway is required for NO-induced CM differentiation of ES cells.
Collapse
Affiliation(s)
- Wenjie Wei
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China; Department of Biology, South University of Science and Technology of China, Shenzhen 518052, China
| | - Wei Huang
- Department of Biology, South University of Science and Technology of China, Shenzhen 518052, China
| | - Jianbo Yue
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.
| |
Collapse
|
10
|
Farini A, Sitzia C, Cassinelli L, Colleoni F, Parolini D, Giovanella U, Maciotta S, Colombo A, Meregalli M, Torrente Y. Inositol 1,4,5-trisphosphate (IP3)-dependent Ca2+ signaling mediates delayed myogenesis in Duchenne muscular dystrophy fetal muscle. Development 2016; 143:658-69. [DOI: 10.1242/dev.126193] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disorder characterized by muscle wasting and premature death. The defective gene is dystrophin, a structural protein, absence of which causes membrane fragility and myofiber necrosis. Several lines of evidence showed that in adult DMD patients dystrophin is involved in signaling pathways that regulate calcium homeostasis and differentiation programs. However, secondary aspects of the disease, such as inflammation and fibrosis development, might represent a bias in the analysis. Because fetal muscle is not influenced by gravity and does not suffer from mechanical load and/or inflammation, we investigated 12-week-old fetal DMD skeletal muscles, highlighting for the first time early alterations in signaling pathways mediated by the absence of dystrophin itself. We found that PLC/IP3/IP3R/Ryr1/Ca2+ signaling is widely active in fetal DMD skeletal muscles and, through the calcium-dependent PKCα protein, exerts a fundamental regulatory role in delaying myogenesis and in myofiber commitment. These data provide new insights into the origin of DMD pathology during muscle development.
Collapse
Affiliation(s)
- Andrea Farini
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Clementina Sitzia
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Letizia Cassinelli
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Federica Colleoni
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Daniele Parolini
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Umberto Giovanella
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio delle Macromolecole (CNR-ISMAC), via Bassini 15, Milano 20133, Italy
| | - Simona Maciotta
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Augusto Colombo
- Servizio ‘Legge 194’ Dipartimento BDN-Fondazione IRCCS, Policlinico Mangiagalli-Regina Elena, Via Francesco Sforza 35, Milan 20122, Italy
| | - Mirella Meregalli
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| | - Yvan Torrente
- Laboratorio di Cellule Staminali, Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milano, Centro Dino Ferrari, Via Francesco Sforza 35, Milan 20122, Centro Dino Ferrari, Italy
| |
Collapse
|
11
|
Burr AR, Molkentin JD. Genetic evidence in the mouse solidifies the calcium hypothesis of myofiber death in muscular dystrophy. Cell Death Differ 2015; 22:1402-12. [PMID: 26088163 PMCID: PMC4532779 DOI: 10.1038/cdd.2015.65] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 04/03/2015] [Accepted: 04/17/2015] [Indexed: 01/19/2023] Open
Abstract
Muscular dystrophy (MD) refers to a clinically and genetically heterogeneous group of degenerative muscle disorders characterized by progressive muscle wasting and often premature death. Although the primary defect underlying most forms of MD typically results from a loss of sarcolemmal integrity, the secondary molecular mechanisms leading to muscle degeneration and myofiber necrosis is debated. One hypothesis suggests that elevated or dysregulated cytosolic calcium is the common transducing event, resulting in myofiber necrosis in MD. Previous measurements of resting calcium levels in myofibers from dystrophic animal models or humans produced equivocal results. However, recent studies in genetically altered mouse models have largely solidified the calcium hypothesis of MD, such that models with artificially elevated calcium in skeletal muscle manifest fulminant dystrophic-like disease, whereas models with enhanced calcium clearance or inhibited calcium influx are resistant to myofiber death and MD. Here, we will review the field and the recent cadre of data from genetically altered mouse models, which we propose have collectively mostly proven the hypothesis that calcium is the primary effector of myofiber necrosis in MD. This new consensus on calcium should guide future selection of drugs to be evaluated in clinical trials as well as gene therapy-based approaches.
Collapse
Affiliation(s)
- A R Burr
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, 240 Albert Sabin Way, Cincinnati, OH, USA
| | - J D Molkentin
- 1] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, 240 Albert Sabin Way, Cincinnati, OH, USA [2] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Howard Hughes Medical Institute, Molecular Cardiovascular Biology, 240 Albert Sabin Way, Cincinnati, OH, USA
| |
Collapse
|
12
|
Brown SA, Loew LM. Integration of modeling with experimental and clinical findings synthesizes and refines the central role of inositol 1,4,5-trisphosphate receptor 1 in spinocerebellar ataxia. Front Neurosci 2015; 8:453. [PMID: 25653583 PMCID: PMC4300941 DOI: 10.3389/fnins.2014.00453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 12/22/2014] [Indexed: 12/22/2022] Open
Abstract
A suite of models was developed to study the role of inositol 1,4,5-trisphosphate receptor 1 (IP3R1) in spinocerebellar ataxias (SCAs). Several SCAs are linked to reduced abundance of IP3R1 or to supranormal sensitivity of the receptor to activation by its ligand inositol 1,4,5-trisphosphate (IP3). Detailed multidimensional models have been created to simulate biochemical calcium signaling and membrane electrophysiology in cerebellar Purkinje neurons. In these models, IP3R1-mediated calcium release is allowed to interact with ion channel response on the cell membrane. Experimental findings in mice and clinical observations in humans provide data input for the models. The SCA modeling suite helps interpret experimental results and provides suggestions to guide experiments. The models predict IP3R1 supersensitivity in SCA1 and compensatory mechanisms in SCA1, SCA2, and SCA3. Simulations explain the impact of calcium buffer proteins. Results show that IP3R1-mediated calcium release activates voltage-gated calcium-activated potassium channels in the plasma membrane. The SCA modeling suite unifies observations from experiments in a number of SCAs. The cadre of simulations demonstrates the central role of IP3R1.
Collapse
Affiliation(s)
| | - Leslie M Loew
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center Farmington, CT, USA
| |
Collapse
|
13
|
Antigny F, Konig S, Bernheim L, Frieden M. Inositol 1,4,5 trisphosphate receptor 1 is a key player of human myoblast differentiation. Cell Calcium 2014; 56:513-21. [PMID: 25468730 DOI: 10.1016/j.ceca.2014.10.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/17/2014] [Accepted: 10/27/2014] [Indexed: 11/18/2022]
Abstract
Cytosolic Ca(2+) signals are fundamental for the early and late steps of myoblast differentiation and are, as in many cells, generated by Ca(2+) release from internal stores as well as by plasma membrane Ca(2+) entry. Our recent studies identified the store-operated Ca(2+) channels, Orai1 and TRPC1&C4, as crucial for the early steps of human myogenesis and for the late fusion events. In the present work, we assessed the role of the inositol-1,4,5 tris-phosphate receptor (IP3R) type 1 during human myoblast differentiation. We demonstrated, using siRNA strategy that IP3R1 is required for the expression of muscle-specific transcription factors such as myogenin and MEF2 (myocyte enhancer factor 2), and for the formation of myotubes. The knockdown of IP3R1 strongly reduced endogenous spontaneous Ca(2+) transients, and attenuated store-operated Ca(2+) entry. As well, two Ca(2+)-dependent key enzymes of muscle differentiation, NFAT and CamKII are down-regulated upon siIP3R1 treatment. On the contrary, the overexpression of IP3R1 accelerated myoblasts differentiation. These findings identify Ca(2+) release mediated by IP3R1 as an essential mechanism during the early steps of myoblast differentiation.
Collapse
MESH Headings
- Calcium/physiology
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/physiology
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cells, Cultured
- Humans
- Inositol 1,4,5-Trisphosphate Receptors/drug effects
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- MEF2 Transcription Factors/physiology
- Myoblasts, Skeletal/cytology
- Myoblasts, Skeletal/physiology
- Myogenin/physiology
- NFATC Transcription Factors/physiology
- RNA, Small Interfering/pharmacology
Collapse
Affiliation(s)
- Fabrice Antigny
- Department of Basic Neurosciences, Geneva Medical Center, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Stéphane Konig
- Department of Basic Neurosciences, Geneva Medical Center, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Laurent Bernheim
- Department of Basic Neurosciences, Geneva Medical Center, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Maud Frieden
- Department of Basic Neurosciences, Geneva Medical Center, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland; Department of Cell Physiology and Metabolism, Geneva Medical Center, 1, Rue Michel Servet, 1211 Geneva 4, Switzerland.
| |
Collapse
|
14
|
Ho HT, Liu B, Snyder JS, Lou Q, Brundage EA, Velez-Cortes F, Wang H, Ziolo MT, Anderson ME, Sen CK, Wehrens XHT, Fedorov VV, Biesiadecki BJ, Hund TJ, Györke S. Ryanodine receptor phosphorylation by oxidized CaMKII contributes to the cardiotoxic effects of cardiac glycosides. Cardiovasc Res 2013; 101:165-74. [PMID: 24104877 DOI: 10.1093/cvr/cvt233] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS Recent studies suggest that proarrhythmic effects of cardiac glycosides (CGs) on cardiomyocyte Ca(2+) handling involve generation of reactive oxygen species (ROS). However, the specific pathway(s) of ROS production and the subsequent downstream molecular events that mediate CG-dependent arrhythmogenesis remain to be defined. METHODS AND RESULTS We examined the effects of digitoxin (DGT) on Ca(2+) handling and ROS production in cardiomyocytes using a combination of pharmacological approaches and genetic mouse models. Myocytes isolated from mice deficient in NADPH oxidase type 2 (NOX2KO) and mice transgenically overexpressing mitochondrial superoxide dismutase displayed markedly increased tolerance to the proarrhythmic action of DGT as manifested by the inhibition of DGT-dependent ROS and spontaneous Ca(2+) waves (SCW). Additionally, DGT-induced mitochondrial membrane potential depolarization was abolished in NOX2KO cells. DGT-dependent ROS was suppressed by the inhibition of PI3K, PKC, and the mitochondrial KATP channel, suggesting roles for these proteins, respectively, in activation of NOX2 and in mitochondrial ROS generation. Western blot analysis revealed increased levels of oxidized CaMKII in WT but not in NOX2KO hearts treated with DGT. The DGT-induced increase in SCW frequency was abolished in myocytes isolated from mice in which the Ser 2814 CaMKII phosphorylation site on RyR2 is constitutively inactivated. CONCLUSION These results suggest that the arrhythmogenic adverse effects of CGs on Ca(2+) handling involve PI3K- and PKC-mediated stimulation of NOX2 and subsequent NOX2-dependent ROS release from the mitochondria; mitochondria-derived ROS then activate CaMKII with consequent phosphorylation of RyR2 at Ser 2814.
Collapse
Affiliation(s)
- Hsiang-Ting Ho
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Tjondrokoesoemo A, Li N, Lin PH, Pan Z, Ferrante CJ, Shirokova N, Brotto M, Weisleder N, Ma J. Type 1 inositol (1,4,5)-trisphosphate receptor activates ryanodine receptor 1 to mediate calcium spark signaling in adult mammalian skeletal muscle. J Biol Chem 2012; 288:2103-9. [PMID: 23223241 DOI: 10.1074/jbc.m112.425975] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Functional coupling between inositol (1,4,5)-trisphosphate receptor (IP(3)R) and ryanodine receptor (RyR) represents a critical component of intracellular Ca(2+) signaling in many excitable cells; however, the role of this mechanism in skeletal muscle remains elusive. In skeletal muscle, RyR-mediated Ca(2+) sparks are suppressed in resting conditions, whereas application of transient osmotic stress can trigger activation of Ca(2+) sparks that are restricted to the periphery of the fiber. Here we show that onset of these spatially confined Ca(2+) sparks involves interaction between activation of IP(3)R and RyR near the sarcolemmal membrane. Pharmacological prevention of IP(3) production or inhibition of IP(3)R channel activity abolishes stress-induced Ca(2+) sparks in skeletal muscle. Although genetic ablation of the type 2 IP(3)R does not appear to affect Ca(2+) sparks in skeletal muscle, specific silencing of the type 1 IP(3)R leads to ablation of stress-induced Ca(2+) sparks. Our data indicate that membrane-delimited signaling involving cross-talk between IP(3)R1 and RyR1 contributes to Ca(2+) spark activation in skeletal muscle.
Collapse
Affiliation(s)
- Andoria Tjondrokoesoemo
- Department of Physiology and Biophysics, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Dystrophin/α1-syntrophin scaffold regulated PLC/PKC-dependent store-operated calcium entry in myotubes. Cell Calcium 2012; 52:445-56. [DOI: 10.1016/j.ceca.2012.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 07/16/2012] [Accepted: 08/06/2012] [Indexed: 11/17/2022]
|
17
|
Mills SJ, Luyten T, Erneux C, Parys JB, Potter BVL. Multivalent benzene polyphosphate derivatives are non-Ca 2+-mobilizing Ins(1,4,5)P 3 receptor antagonists. MESSENGER (LOS ANGELES, CALIF. : PRINT) 2012; 1:167-181. [PMID: 24749014 PMCID: PMC3988618 DOI: 10.1166/msr.2012.1016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Inositol 1,4,5-trisphosphate [Ins(1,4,5)P31] mobilizes intracellular Ca2+ through the Ins(1,4,5)P3 receptor [InsP3R]. Although some progress has been made in the design of synthetic InsP3R partial agonists and antagonists, there are still few examples of useful small molecule competitive antagonists. A "multivalent" approach is explored and new dimeric polyphosphorylated aromatic derivatives were designed, synthesized and biologically evaluated. The established weak InsP3R ligand benzene 1,2,4-trisphosphate [Bz(1,2,4)P32] is dimerized through its 5-position in two different ways, first directly as the biphenyl derivative biphenyl 2,2',4,4',5,5'-hexakisphosphate, [BiPh(2,2',4,4',5,5')P68] and with its regioisomeric biphenyl 3,3',4,4',5,5'-hexakisphosphate [BiPh(3,3',4,4',5,5')P611]. Secondly, a linker motif is introduced in a flexible ethylene-bridged dimer (9) with its corresponding 1,2-bisphosphate dimer (10), both loosely analogous to the very weak antagonist 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA 7). In permeabilized L15 fibroblasts overexpressing type 1 InsP3R, BiPh(2,2',4,4',5,5')P6 (8) inhibits Ins(1,4,5)P3-induced Ca2+ release in a apparently competitive fashion [IC50 187 nM] and the Bz(1,2,4)P3 dimer (9) is only slightly weaker [IC50 380 nM]. Compounds were also evaluated against type I Ins(1,4,5)P3 5-phosphatase. All compounds are resistant to dephosphorylation, with BiPh(2,2',4,4',5,5')P6 (8), being the most effective inhibitor of any biphenyl derivative synthesized to date [IC50 480 nM] and the Bz(1,2,4)P3 ethylene dimer (9) weaker [IC50 3.55 μM]. BiPh(3,3',4,4',5,5')P6 (11) also inhibits 5-phosphatase [IC50 730 nM] and exhibits unexpected Ca2+ releasing activity [EC50 800 nM]. Thus, relocation of only a single mirrored phenyl phosphate group in (11) from that of antagonist (8) does not markedly change enzyme inhibitory activity, but elicits a dramatic switch in Ca2+-releasing activity. Such new agents demonstrate the power of the multivalent approach and may be useful to investigate the chemical biology of signaling through InsP3R and as templates for further design.
Collapse
Affiliation(s)
- Stephen J Mills
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Tomas Luyten
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1, Herestraat 49, Bus 802, 3000 Leuven, Belgium
| | - Christophe Erneux
- Institut de Recherche Interdisciplinaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Brussels, Belgium
| | - Jan B. Parys
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1, Herestraat 49, Bus 802, 3000 Leuven, Belgium
| | - Barry V. L. Potter
- Professor B. V. L. Potter, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK. University of Bath, Claverton Down, Bath, BA2 7AY, Tel: +44 1225 386639; Fax: +44 1225 386114;
| |
Collapse
|
18
|
Naranjo JR, Mellström B. Ca2+-dependent transcriptional control of Ca2+ homeostasis. J Biol Chem 2012; 287:31674-80. [PMID: 22822058 DOI: 10.1074/jbc.r112.384982] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Intracellular free Ca(2+) ions regulate many cellular functions, and in turn, the cell devotes many genes/proteins to keep tight control of the level of intracellular free Ca(2+). Here, we review recent work on Ca(2+)-dependent mechanisms and effectors that regulate the transcription of genes encoding proteins involved in the maintenance of the homeostasis of Ca(2+) in the cell.
Collapse
Affiliation(s)
- Jose R Naranjo
- National Center of Biotechnology, Consejo Superior de Investigaciones Científicas (CSIC) and the Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28049 Madrid, Spain.
| | | |
Collapse
|
19
|
Zhu H, Bhattacharyya BJ, Lin H, Gomez CM. Skeletal muscle IP3R1 receptors amplify physiological and pathological synaptic calcium signals. J Neurosci 2011; 31:15269-83. [PMID: 22031873 PMCID: PMC3237715 DOI: 10.1523/jneurosci.3766-11.2011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/24/2011] [Accepted: 09/01/2011] [Indexed: 01/11/2023] Open
Abstract
Ca(2+) release from internal stores is critical for mediating both normal and pathological intracellular Ca(2+) signaling. Recent studies suggest that the inositol 1,4,5-triphosphate (IP(3)) receptor mediates Ca(2+) release from internal stores upon cholinergic activation of the neuromuscular junction (NMJ) in both physiological and pathological conditions. Here, we report that the type I IP(3) receptor (IP(3)R(1))-mediated Ca(2+) release plays a crucial role in synaptic gene expression, development, and neuromuscular transmission, as well as mediating degeneration during excessive cholinergic activation. We found that IP(3)R(1)-mediated Ca(2+) release plays a key role in early development of the NMJ, homeostatic regulation of neuromuscular transmission, and synaptic gene expression. Reducing IP(3)R(1)-mediated Ca(2+) release via siRNA knockdown or IP(3)R blockers in C2C12 cells decreased calpain activity and prevented agonist-induced acetylcholine receptor (AChR) cluster dispersal. In fully developed NMJ in adult muscle, IP(3)R(1) knockdown or blockade effectively increased synaptic strength at presynaptic and postsynaptic sites by increasing both quantal release and expression of AChR subunits and other NMJ-specific genes in a pattern resembling muscle denervation. Moreover, in two mouse models of cholinergic overactivity and NMJ Ca(2+) overload, anti-cholinesterase toxicity and the slow-channel myasthenic syndrome (SCS), IP(3)R(1) knockdown eliminated NMJ Ca(2+) overload, pathological activation of calpain and caspase proteases, and markers of DNA damage at subsynaptic nuclei, and improved both neuromuscular transmission and clinical measures of motor function. Thus, blockade or genetic silencing of muscle IP(3)R(1) may be an effective and well tolerated therapeutic strategy in SCS and other conditions of excitotoxicity or Ca(2+) overload.
Collapse
MESH Headings
- Action Potentials/drug effects
- Action Potentials/genetics
- Animals
- Boron Compounds/pharmacology
- Calcium/metabolism
- Calcium Signaling/genetics
- Calcium Signaling/physiology
- Calpain/metabolism
- Carbachol/pharmacology
- Caspase 3/metabolism
- Caspase 9/metabolism
- Cell Line, Transformed
- Cholinergic Agonists/pharmacology
- Cholinesterase Inhibitors/toxicity
- Disease Models, Animal
- Electromyography
- Electroporation/methods
- Exercise Test
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Green Fluorescent Proteins/genetics
- Histone Deacetylases/metabolism
- Histones/genetics
- Histones/metabolism
- In Vitro Techniques
- Inositol 1,4,5-Trisphosphate Receptors/deficiency
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- Male
- Membrane Potentials/drug effects
- Membrane Potentials/genetics
- Mice
- Mice, Transgenic
- Muscle, Skeletal/metabolism
- Myasthenic Syndromes, Congenital/genetics
- Myasthenic Syndromes, Congenital/pathology
- Myasthenic Syndromes, Congenital/therapy
- Neostigmine/toxicity
- Nerve Tissue Proteins/metabolism
- Neuromuscular Junction/metabolism
- Neuromuscular Junction/physiology
- Neurotoxicity Syndromes/etiology
- Neurotoxicity Syndromes/pathology
- Neurotoxicity Syndromes/therapy
- Patch-Clamp Techniques
- RNA, Small Interfering/pharmacology
- Receptors, Cholinergic/classification
- Receptors, Cholinergic/genetics
- Receptors, Cholinergic/metabolism
- Sciatic Nerve/physiopathology
- Time Factors
Collapse
Affiliation(s)
- Haipeng Zhu
- Department of Neurology, University of Chicago Medical Center, Chicago, Illinois 60637
| | - Bula J. Bhattacharyya
- Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, and
| | - Hong Lin
- Departments of Neurology and Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104-4318
| | - Christopher M. Gomez
- Department of Neurology, University of Chicago Medical Center, Chicago, Illinois 60637
| |
Collapse
|