1
|
Younger DS. Critical illness-associated weakness and related motor disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:707-777. [PMID: 37562893 DOI: 10.1016/b978-0-323-98818-6.00031-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Weakness of limb and respiratory muscles that occurs in the course of critical illness has become an increasingly common and serious complication of adult and pediatric intensive care unit patients and a cause of prolonged ventilatory support, morbidity, and prolonged hospitalization. Two motor disorders that occur singly or together, namely critical illness polyneuropathy and critical illness myopathy, cause weakness of limb and of breathing muscles, making it difficult to be weaned from ventilatory support, commencing rehabilitation, and extending the length of stay in the intensive care unit, with higher rates of morbidity and mortality. Recovery can take weeks or months and in severe cases, and may be incomplete or absent. Recent findings suggest an improved prognosis of critical illness myopathy compared to polyneuropathy. Prevention and treatment are therefore very important. Its management requires an integrated team approach commencing with neurologic consultation, creatine kinase (CK) measurement, detailed electrodiagnostic, respiratory and neuroimaging studies, and potentially muscle biopsy to elucidate the etiopathogenesis of the weakness in the peripheral and/or central nervous system, for which there may be a variety of causes. These tenets of care are being applied to new cases and survivors of the coronavirus-2 disease pandemic of 2019. This chapter provides an update to the understanding and approach to critical illness motor disorders.
Collapse
Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
| |
Collapse
|
2
|
Ganti AKP, Loo BW, Bassetti M, Blakely C, Chiang A, D'Amico TA, D'Avella C, Dowlati A, Downey RJ, Edelman M, Florsheim C, Gold KA, Goldman JW, Grecula JC, Hann C, Iams W, Iyengar P, Kelly K, Khalil M, Koczywas M, Merritt RE, Mohindra N, Molina J, Moran C, Pokharel S, Puri S, Qin A, Rusthoven C, Sands J, Santana-Davila R, Shafique M, Waqar SN, Gregory KM, Hughes M. Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw 2021; 19:1441-1464. [PMID: 34902832 DOI: 10.6004/jnccn.2021.0058] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Afshin Dowlati
- Case Comprehensive Cancer Center/University Hospitals Seidman Cancer Center and Cleveland Clinic Taussig Cancer Institute
| | | | | | | | | | | | - John C Grecula
- The Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute
| | - Christine Hann
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
| | | | | | | | | | | | - Robert E Merritt
- The Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute
| | - Nisha Mohindra
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University
| | | | - Cesar Moran
- The University of Texas MD Anderson Cancer Center
| | | | - Sonam Puri
- Huntsman Cancer Institute at the University of Utah
| | - Angel Qin
- University of Michigan Rogel Cancer Center
| | | | - Jacob Sands
- Dana Farber/Brigham and Women's Cancer Center
| | | | | | - Saiama N Waqar
- Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine
| | | | | |
Collapse
|
3
|
Presynaptic Paraneoplastic Disorders of the Neuromuscular Junction: An Update. Brain Sci 2021; 11:brainsci11081035. [PMID: 34439654 PMCID: PMC8392118 DOI: 10.3390/brainsci11081035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/26/2021] [Accepted: 08/02/2021] [Indexed: 01/17/2023] Open
Abstract
The neuromuscular junction (NMJ) is the target of a variety of immune-mediated disorders, usually classified as presynaptic and postsynaptic, according to the site of the antigenic target and consequently of the neuromuscular transmission alteration. Although less common than the classical autoimmune postsynaptic myasthenia gravis, presynaptic disorders are important to recognize due to the frequent association with cancer. Lambert Eaton myasthenic syndrome is due to a presynaptic failure to release acetylcholine, caused by antibodies to the presynaptic voltage-gated calcium channels. Acquired neuromyotonia is a condition characterized by nerve hyperexcitability often due to the presence of antibodies against proteins associated with voltage-gated potassium channels. This review will focus on the recent developments in the autoimmune presynaptic disorders of the NMJ.
Collapse
|
4
|
Ojala KS, Ginebaugh SP, Wu M, Miller EW, Ortiz G, Covarrubias M, Meriney SD. A high-affinity, partial antagonist effect of 3,4-diaminopyridine mediates action potential broadening and enhancement of transmitter release at NMJs. J Biol Chem 2021; 296:100302. [PMID: 33465376 PMCID: PMC7949096 DOI: 10.1016/j.jbc.2021.100302] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 12/03/2022] Open
Abstract
3,4-Diaminopyridine (3,4-DAP) increases transmitter release from neuromuscular junctions (NMJs), and low doses of 3,4-DAP (estimated to reach ∼1 μM in serum) are the Food and Drug Administration (FDA)-approved treatment for neuromuscular weakness caused by Lambert–Eaton myasthenic syndrome. Canonically, 3,4-DAP is thought to block voltage-gated potassium (Kv) channels, resulting in prolongation of the presynaptic action potential (AP). However, recent reports have shown that low millimolar concentrations of 3,4-DAP have an off-target agonist effect on the Cav1 subtype (“L-type”) of voltage-gated calcium (Cav) channels and have speculated that this agonist effect might contribute to 3,4-DAP effects on transmitter release at the NMJ. To address 3,4-DAP’s mechanism(s) of action, we first used the patch-clamp electrophysiology to characterize the concentration-dependent block of 3,4-DAP on the predominant presynaptic Kv channel subtypes found at the mammalian NMJ (Kv3.3 and Kv3.4). We identified a previously unreported high-affinity (1–10 μM) partial antagonist effect of 3,4-DAP in addition to the well-known low-affinity (0.1–1 mM) antagonist activity. We also showed that 1.5-μM DAP had no effects on Cav1.2 or Cav2.1 current. Next, we used voltage imaging to show that 1.5- or 100-μM 3,4-DAP broadened the AP waveform in a dose-dependent manner, independent of Cav1 calcium channels. Finally, we demonstrated that 1.5- or 100-μM 3,4-DAP augmented transmitter release in a dose-dependent manner and this effect was also independent of Cav1 channels. From these results, we conclude that low micromolar concentrations of 3,4-DAP act solely on Kv channels to mediate AP broadening and enhance transmitter release at the NMJ.
Collapse
Affiliation(s)
- Kristine S Ojala
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Scott P Ginebaugh
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Man Wu
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Evan W Miller
- Departments of Chemistry and Molecular & Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Gloria Ortiz
- Departments of Chemistry and Molecular & Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Manuel Covarrubias
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Stephen D Meriney
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| |
Collapse
|
5
|
Abstract
Lambert-Eaton myasthenic syndrome is a paraneoplastic or primary autoimmune neuromuscular junction disorder characterized by proximal weakness, autonomic dysfunction and ariflexia. The characteristic symptoms are thought to be caused by antibodies generated against the P/Q-type voltage-gated calcium channels present on presynaptic nerve terminals and by diminished release of acetylcholine. More than half of Lambert-Eaton myasthenic syndrome cases are associated with small cell lung carcinoma. Diagnosis is confirmed by serologic testing and electrophysiologic studies. 3,4-diaminopyridine is effective symptomatic treatment of LEMS.
Collapse
Affiliation(s)
- Vita G Kesner
- Neurology Department, 12 Executive Park Drive NE, Atlanta, GA 30329, USA.
| | - Shin J Oh
- University of Alabama at Birmingham, Department of Neurology, SC 350, 1720 2nd Ave South, Birmingham, AL 35294, USA
| | - Mazen M Dimachkie
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA
| |
Collapse
|
6
|
Wang S, Zimmermann S, Parikh K, Mansfield AS, Adjei AA. Current Diagnosis and Management of Small-Cell Lung Cancer. Mayo Clin Proc 2019; 94:1599-1622. [PMID: 31378235 DOI: 10.1016/j.mayocp.2019.01.034] [Citation(s) in RCA: 151] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/05/2019] [Accepted: 01/31/2019] [Indexed: 12/25/2022]
Abstract
Small-cell lung cancer (SCLC) is an aggressive disease with distinct pathological, clinical, and molecular characteristics from non-small-cell lung cancer. SCLC has high metastatic potential, resulting in a clinically poor prognosis. Early concurrent chemo-radiation is the standard of care for limited-stage SCLC (LS-SCLC). Prophylactic cranial irradiation (PCI) is recommended for patients with LS-SCLC without progression of disease after initial therapy. A combination of etoposide and cisplatin or carboplatin remains the mainstay of first-line treatment for ES-SCLC, with the addition of atezolizumab, now becoming standard. Most SCLCs initially respond to therapy but almost invariably recur. Topotecan and amrubicin (in Japan) remain the primary chemotherapy options for relapsed SCLC. Immunotherapy, including nivolumab with or without ipilimumab, is now available for refractory disease. In general, the poor prognosis of SCLC has not improved significantly for more than 3 decades. Recently, next-generation molecular profiling studies have identified new therapeutic targets for SCLC. A variety of proapoptotic agents, compounds capitalizing on DNA-repair defects, immunotherapy agents, and antibody-drug conjugates are being evaluated in SCLC, with a number of them showing early promise.
Collapse
Affiliation(s)
- Shuhang Wang
- Peking University Cancer Hospital, Beijing, China
| | - Stefan Zimmermann
- Département d'Oncologie, service d'Immuno-Oncologie, CHUV, Lausanne, Switzerland
| | | | | | | |
Collapse
|
7
|
Naides SJ. The role of the laboratory in the expanding field of neuroimmunology: Autoantibodies to neural targets. J Immunol Methods 2018; 463:1-20. [PMID: 30300607 DOI: 10.1016/j.jim.2018.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/12/2018] [Indexed: 12/15/2022]
Abstract
Accelerated identification of autoantibodies associated with previously idiopathic neurological disease has provided insights into disease mechanisms, enhanced understanding of neurological function, and opportunities for improved therapeutic interventions. The role of the laboratory in the expanding field of neuroimmunology is critical as specific autoantibody identification provides guidance to clinicians in diagnosis, prognosis, tumor search strategies, and therapeutic interventions. The number of specific autoantibodies identified continues to increase and newer testing strategies increase efficiencies in the laboratory and availability to clinicians. The need for broadly targeted efficient testing is underscored by the variability in clinical presentation and tumor associations attributable to a specific autoantibody, and conversely the various autoantibody specificities that can be the cause of a given clinical presentation. While many of the antineural antibodies were first recognized in the setting of neoplastic disease, idiopathic autoimmune neurological disease in the absence of underlying tumor is increasingly recognized. Appropriation of therapeutic modalities used to treat autoimmune disease to treat these autoantibody mediated neurological diseases has improved patient outcomes. Interaction between clinicians and laboratorians is critical to our understanding of these diseases and optimization of the clinical benefits of our increasing knowledge in neuroimmunology.
Collapse
Affiliation(s)
- Stanley J Naides
- Immunology R&D, Quest Diagnostics Nichols Institute, 33608 Ortega Highway, San Juan Capistrano, CA 92675, USA.
| |
Collapse
|
8
|
Wu M, White HV, Boehm BA, Meriney CJ, Kerrigan K, Frasso M, Liang M, Gotway EM, Wilcox MR, Johnson JW, Wipf P, Meriney SD. New Cav2 calcium channel gating modifiers with agonist activity and therapeutic potential to treat neuromuscular disease. Neuropharmacology 2017; 131:176-189. [PMID: 29246857 DOI: 10.1016/j.neuropharm.2017.12.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 11/28/2017] [Accepted: 12/10/2017] [Indexed: 12/13/2022]
Abstract
Voltage-gated calcium channels (VGCCs) are critical regulators of many cellular functions, including the activity-dependent release of chemical neurotransmitter from nerve terminals. At nerve terminals, the Cav2 family of VGCCs are closely positioned with neurotransmitter-containing synaptic vesicles. The relationship between calcium ions and transmitter release is such that even subtle changes in calcium flux through VGCCs have a strong influence on the magnitude of transmitter released. Therefore, modulators of the calcium influx at nerve terminals have the potential to strongly affect transmitter release at synapses. We have previously developed novel Cav2-selective VGCC gating modifiers (notably GV-58) that slow the deactivation of VGCC current, increasing total calcium ion flux. Here, we describe ten new gating modifiers based on the GV-58 structure that extend our understanding of the structure-activity relationship for this class of molecules and extend the range of modulation of channel activities. In particular, we show that one of these new compounds (MF-06) was more efficacious than GV-58, another (KK-75) acts more quickly on VGCCs than GV-58, and a third (KK-20) has a mix of increased speed and efficacy. A subset of these new VGCC agonist gating modifiers can increase transmitter release during action potentials at neuromuscular synapses, and as such, show potential as therapeutics for diseases with a presynaptic deficit that results in neuromuscular weakness. Further, several of these new compounds can be useful tool compounds for the study of VGCC gating and function.
Collapse
Affiliation(s)
- Man Wu
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Hayley V White
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Blake A Boehm
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Christopher J Meriney
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Kaylan Kerrigan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Michael Frasso
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Mary Liang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Erika M Gotway
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Madeleine R Wilcox
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Jon W Johnson
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Stephen D Meriney
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, United States.
| |
Collapse
|
9
|
Meriney SD, Tarr TB, Ojala KS, Wu M, Li Y, Lacomis D, Garcia-Ocaña A, Liang M, Valdomir G, Wipf P. Lambert-Eaton myasthenic syndrome: mouse passive-transfer model illuminates disease pathology and facilitates testing therapeutic leads. Ann N Y Acad Sci 2017; 1412:73-81. [PMID: 29125190 DOI: 10.1111/nyas.13512] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/31/2017] [Accepted: 09/09/2017] [Indexed: 11/29/2022]
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder caused by antibodies directed against the voltage-gated calcium channels that provide the calcium ion flux that triggers acetylcholine release at the neuromuscular junction. To study the pathophysiology of LEMS and test candidate therapeutic strategies, a passive-transfer animal model has been developed in mice, which can be created by daily intraperitoneal injections of LEMS patient serum or IgG into mice for 2-4 weeks. Results from studies of the mouse neuromuscular junction have revealed that each synapse has hundreds of transmitter release sites but that the probability for release at each one is likely to be low. LEMS further reduces this low probability such that transmission is no longer effective at triggering a muscle contraction. The LEMS-mediated attack reduces the number of presynaptic calcium channels, disorganizes transmitter release sites, and results in the homeostatic upregulation of other calcium channel types. Symptomatic treatment is focused on increasing the probability of release from dysfunctional release sites. Current treatment uses the potassium channel blocker 3,4-diaminopyridine (DAP) to broaden the presynaptic action potential, providing more time for calcium channels to open. Current research is focused on testing new calcium channel gating modifiers that work synergistically with DAP.
Collapse
Affiliation(s)
- Stephen D Meriney
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tyler B Tarr
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kristine S Ojala
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Man Wu
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Yizhi Li
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - David Lacomis
- Division of Neuromuscular Diseases, Departments of Neurology and Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mary Liang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Guillermo Valdomir
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
| |
Collapse
|
10
|
Abstract
Autoantibodies targeting proteins at the neuromuscular junction are known to cause several distinct myasthenic syndromes. Recently, autoantibodies targeting neurotransmitter receptors and associated proteins have also emerged as a cause of severe, but potentially treatable, diseases of the CNS. Here, we review the clinical evidence as well as in vitro and in vivo experimental evidence that autoantibodies account for myasthenic syndromes and autoimmune disorders of the CNS by disrupting the functional or structural integrity of synapses. Studying neurological and psychiatric diseases of autoimmune origin may provide new insights into the cellular and circuit mechanisms underlying a broad range of CNS disorders.
Collapse
Affiliation(s)
- Sarah J Crisp
- UCL Institute of Neurology, University College London, Queen Square House, Queen Square, London WC1N 3BG, UK
| | - Dimitri M Kullmann
- UCL Institute of Neurology, University College London, Queen Square House, Queen Square, London WC1N 3BG, UK
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK
| |
Collapse
|
11
|
Chefdeville A, Honnorat J, Hampe CS, Desestret V. Neuronal central nervous system syndromes probably mediated by autoantibodies. Eur J Neurosci 2016; 43:1535-52. [PMID: 26918657 DOI: 10.1111/ejn.13212] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/09/2016] [Accepted: 02/15/2016] [Indexed: 01/17/2023]
Abstract
In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients' antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies.
Collapse
Affiliation(s)
- Aude Chefdeville
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France
| | - Jérôme Honnorat
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
| | | | - Virginie Desestret
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
| |
Collapse
|
12
|
Sun H, Luo L, Lal B, Ma X, Chen L, Hann CL, Fulton AM, Leahy DJ, Laterra J, Li M. A monoclonal antibody against KCNK9 K(+) channel extracellular domain inhibits tumour growth and metastasis. Nat Commun 2016; 7:10339. [PMID: 26842342 PMCID: PMC4742836 DOI: 10.1038/ncomms10339] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/30/2015] [Indexed: 12/25/2022] Open
Abstract
Two-pore domain potassium (K2P) channels act to maintain cell resting membrane potential--a prerequisite for many biological processes. KCNK9, a member of K2P family, is implicated in cancer, owing to its overexpression in human tumours and its ability to promote neoplastic cell survival and growth. However, KCNK9's underlying contributions to malignancy remain elusive due to the absence of specific modulators. Here we describe the development of monoclonal antibodies against the KCNK9 extracellular domain and their functional effects. We show that one antibody (Y4) with the highest affinity binding induces channel internalization. The addition of Y4 to KCNK9-expressing carcinoma cells reduces cell viability and increases cell death. Systemic administration of Y4 effectively inhibits growth of human lung cancer xenografts and murine breast cancer metastasis in mice. Evidence for Y4-mediated carcinoma cell autonomous and immune-dependent cytotoxicity is presented. Our study reveals that antibody-based KCNK9 targeting is a promising therapeutic strategy in KCNK9-expressing malignancies.
Collapse
Affiliation(s)
- Han Sun
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.,Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland 21205, USA
| | - Liqun Luo
- Immunotherapy Institute, Fujian Medical University, Fujian 350108, China
| | - Bachchu Lal
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland 21205, USA
| | - Xinrong Ma
- Department of Pathology, University of Maryland, Baltimore, Maryland 21201, USA
| | - Lieping Chen
- Department of Immunobiology and Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Christine L Hann
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Amy M Fulton
- Department of Pathology, University of Maryland, Baltimore, Maryland 21201, USA.,Baltimore Veterans Administration Medical Center, Baltimore, Maryland 21201, USA
| | - Daniel J Leahy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - John Laterra
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.,Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland 21205, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Min Li
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| |
Collapse
|
13
|
Spillane J, Ermolyuk Y, Cano-Jaimez M, Lang B, Vincent A, Volynski KE, Kullmann DM. Lambert-Eaton syndrome IgG inhibits transmitter release via P/Q Ca2+ channels. Neurology 2015; 84:575-9. [PMID: 25589670 PMCID: PMC4335987 DOI: 10.1212/wnl.0000000000001225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: To determine whether immunoglobulin G (IgG) from patients with Lambert-Eaton myasthenic syndrome (LEMS) decreases action potential–evoked synaptic vesicle exocytosis, and whether the effect is mediated by P/Q-type voltage-gated calcium channels (VGCCs). Methods: IgG was obtained from 4 patients with LEMS (3 males, 1 female), including 2 patients with lung malignancy. Antibodies against P/Q-type VGCCs were detected in all 4 patients, and against N-type VGCCs in 2. We incubated neuronal cultures with LEMS IgG and determined the size of the total recycling pool of synaptic vesicles and the rate of action potential–evoked exocytosis using fluorescence imaging of the amphiphilic dye SynaptoRed C1. Pooled IgG from healthy volunteers was used as a control. We repeated the experiments on synapses lacking P/Q-type calcium channels from a Cacna1a knockout mouse to determine whether these channels account for the pathogenic effect of LEMS IgG. Results: LEMS IgG had no effect on the total recycling pool size but significantly reduced the rate of action potential–evoked synaptic exocytosis in wild-type neurons when compared with neurons treated with control IgG. In contrast, LEMS IgG had no effect on the rate of synaptic vesicle exocytosis in neurons lacking P/Q-type channels. Conclusions: These data provide direct evidence that LEMS IgG inhibits neurotransmitter release by acting on P/Q-type VGCCs.
Collapse
|
14
|
Joubert B, Honnorat J. Autoimmune channelopathies in paraneoplastic neurological syndromes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2665-76. [PMID: 25883091 DOI: 10.1016/j.bbamem.2015.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/10/2015] [Accepted: 04/03/2015] [Indexed: 01/17/2023]
Abstract
Paraneoplastic neurological syndromes and autoimmune encephalitides are immune neurological disorders occurring or not in association with a cancer. They are thought to be due to an autoimmune reaction against neuronal antigens ectopically expressed by the underlying tumour or by cross-reaction with an unknown infectious agent. In some instances, paraneoplastic neurological syndromes and autoimmune encephalitides are related to an antibody-induced dysfunction of ion channels, a situation that can be labelled as autoimmune channelopathies. Such functional alterations of ion channels are caused by the specific fixation of an autoantibody upon its target, implying that autoimmune channelopathies are usually highly responsive to immuno-modulatory treatments. Over the recent years, numerous autoantibodies corresponding to various neurological syndromes have been discovered and their mechanisms of action partially deciphered. Autoantibodies in neurological autoimmune channelopathies may target either directly ion channels or proteins associated to ion channels and induce channel dysfunction by various mechanisms generally leading to the reduction of synaptic expression of the considered channel. The discovery of those mechanisms of action has provided insights on the regulation of the synaptic expression of the altered channels as well as the putative roles of some of their functional subdomains. Interestingly, patients' autoantibodies themselves can be used as specific tools in order to study the functions of ion channels. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
Collapse
Affiliation(s)
- Bastien Joubert
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372 Lyon Cedex 08, France; INSERM, UMR-S1028, CNRS, UMR-5292, Lyon Neuroscience Research Center, Neuro-Oncology and Neuro-Inflammation Team, 7, Rue Guillaume Paradin, Lyon Cedex 08F-69372, France
| | - Jérôme Honnorat
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372 Lyon Cedex 08, France; INSERM, UMR-S1028, CNRS, UMR-5292, Lyon Neuroscience Research Center, Neuro-Oncology and Neuro-Inflammation Team, 7, Rue Guillaume Paradin, Lyon Cedex 08F-69372, France; National Reference Centre for Paraneoplastic Neurological Diseases, hospices civils de Lyon, hôpital neurologique, 69677 Bron, France; Hospices Civils de Lyon, Neuro-oncology, Hôpital Neurologique, F-69677 Bron, France.
| |
Collapse
|
15
|
Wilkinson TCI, Gardener MJ, Williams WA. Discovery of Functional Antibodies Targeting Ion Channels. ACTA ACUST UNITED AC 2014; 20:454-67. [DOI: 10.1177/1087057114560698] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ion channels play critical roles in physiology and disease by modulation of cellular functions such as electrical excitability, secretion, cell migration, and gene transcription. Ion channels represent an important target class for drug discovery that has been largely addressed, to date, using small-molecule approaches. A significant opportunity exists to target these channels with antibodies and alternative formats of biologics. Antibodies display high specificity and affinity for their target antigen, and they have the potential to target ion channels very selectively. Nevertheless, isolating antibodies to this target class is challenging due to the difficulties in expression and purification of ion channels in a format suitable for antibody drug discovery in addition to the complexity of screening for function. In this article, we will review the current state of ion channel biologics discovery and the progress that has been made. We will also highlight the challenges in isolating functional antibodies to these targets and how these challenges may be addressed. Finally, we also illustrate successful approaches to isolating functional monoclonal antibodies targeting ion channels by way of a number of case studies drawn from recent publications.
Collapse
Affiliation(s)
| | | | - Wendy A. Williams
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
| |
Collapse
|
16
|
Tarr TB, Wipf P, Meriney SD. Synaptic Pathophysiology and Treatment of Lambert-Eaton Myasthenic Syndrome. Mol Neurobiol 2014; 52:456-63. [PMID: 25195700 DOI: 10.1007/s12035-014-8887-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 08/29/2014] [Indexed: 12/12/2022]
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that disrupts the normally reliable neurotransmission at the neuromuscular junction (NMJ). This disruption is thought to result from an autoantibody-mediated removal of a subset of the P/Q-type Ca(2+) channels involved with neurotransmitter release. With less neurotransmitter release at the NMJ, LEMS patients experience debilitating muscle weakness. The underlying cause of LEMS in slightly more than half of all patients is small cell lung cancer, and cancer therapy is the priority for these patients. In the remaining cases, the cause of LEMS is unknown, and these patients often rely on symptomatic treatment options, as there is no cure. However, current symptomatic treatment options, such as 3,4-diaminopyridine (3,4-DAP), can have significant dose-limiting side effects; thus, additional treatment approaches would benefit LEMS patients. Recent studies introduced a novel Ca(2+) channel agonist (GV-58) as a potential therapeutic alternative for LEMS. Additionally, this work has shown that GV-58 and 3,4-DAP interact in a supra-additive manner to completely restore the magnitude of neurotransmitter release at the NMJs of a LEMS mouse model. In this review, we discuss synaptic mechanisms for reliability at the NMJ and how these mechanisms are disrupted in LEMS. We then discuss the current treatment options for LEMS patients, while also considering recent work demonstrating the therapeutic potential of GV-58 alone and in combination with 3,4-DAP.
Collapse
Affiliation(s)
- Tyler B Tarr
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | | | | |
Collapse
|
17
|
Tarr TB, Lacomis D, Reddel SW, Liang M, Valdomir G, Frasso M, Wipf P, Meriney SD. Complete reversal of Lambert-Eaton myasthenic syndrome synaptic impairment by the combined use of a K+ channel blocker and a Ca2+ channel agonist. J Physiol 2014; 592:3687-96. [PMID: 25015919 DOI: 10.1113/jphysiol.2014.276493] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder in which a significant fraction of the presynaptic P/Q-type Ca(2+) channels critical to the triggering of neurotransmitter release at the neuromuscular junction (NMJ) are thought to be removed. There is no cure for LEMS, and the current most commonly used symptomatic treatment option is a potassium channel blocker [3,4-diaminopyridine (3,4-DAP)] that does not completely reverse symptoms and can have dose-limiting side-effects. We previously reported the development of a novel Ca(2+) channel agonist, GV-58, as a possible alternative treatment strategy for LEMS. In this study, we tested the hypothesis that the combination of GV-58 and 3,4-DAP will elicit a supra-additive increase in neurotransmitter release at LEMS model NMJs. First, we tested GV-58 in a cell survival assay to assess potential effects on cyclin-dependent kinases (Cdks) and showed that GV-58 did not affect cell survival at the relevant concentrations for Ca(2+) channel effects. Then, we examined the voltage dependence of GV-58 effects on Ca(2+) channels using patch clamp techniques; this showed the effects of GV-58 to be dependent upon Ca(2+) channel opening. Based on this mechanism, we predicted an interaction between 3,4-DAP and GV-58. We tested this hypothesis using a mouse passive transfer model of LEMS. Using intracellular electrophysiological ex vivo recordings, we demonstrated that a combined application of 3,4-DAP plus GV-58 had a supra-additive effect that completely reversed the deficit in neurotransmitter release magnitude at LEMS model NMJs. This reversal contrasts with the less significant improvement observed with either compound alone. Our data indicate that a combination of 3,4-DAP and GV-58 represents a promising treatment option for LEMS and potentially for other disorders of the NMJ.
Collapse
Affiliation(s)
- Tyler B Tarr
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - David Lacomis
- Division of Neuromuscular Diseases, Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen W Reddel
- Department of Clinical Neurology, Concord Hospital, Sydney, NSW, Australia
| | - Mary Liang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, PA, USA
| | - Guillermo Valdomir
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael Frasso
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen D Meriney
- Department of Neuroscience, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
18
|
Kalemkerian GP, Akerley W, Bogner P, Borghaei H, Chow LQ, Downey RJ, Gandhi L, Ganti AKP, Govindan R, Grecula JC, Hayman J, Heist RS, Horn L, Jahan T, Koczywas M, Loo BW, Merritt RE, Moran CA, Niell HB, O'Malley J, Patel JD, Ready N, Rudin CM, Williams CC, Gregory K, Hughes M. Small cell lung cancer. J Natl Compr Canc Netw 2013; 11:78-98. [PMID: 23307984 DOI: 10.6004/jnccn.2013.0011] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neuroendocrine tumors account for approximately 20% of lung cancers; most (≈15%) are small cell lung cancer (SCLC). These NCCN Clinical Practice Guidelines in Oncology for SCLC focus on extensive-stage SCLC because it occurs more frequently than limited-stage disease. SCLC is highly sensitive to initial therapy; however, most patients eventually die of recurrent disease. In patients with extensive-stage disease, chemotherapy alone can palliate symptoms and prolong survival in most patients; however, long-term survival is rare. Most cases of SCLC are attributable to cigarette smoking; therefore, smoking cessation should be strongly promoted.
Collapse
|
19
|
Briggs SE, Gozzard P, Talbot DC. The association between Lambert-Eaton myasthenic syndrome and small cell lung carcinoma. Immunotargets Ther 2013; 2:31-7. [PMID: 27471686 PMCID: PMC4928366 DOI: 10.2147/itt.s31971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder mediated by autoantibodies to voltage-gated calcium channels. The disorder is diagnosed clinically on the basis of a triad of symptoms (proximal muscle weakness, hyporeflexia, and autonomic disturbance), supported by electrophysiological findings and the presence of autoantibodies. Between 40% and 62% of patients diagnosed with LEMS are found to have small-cell lung cancer (SCLC), almost all of whom develop neurological symptoms before their cancer is diagnosed. Prompt identification of LEMS and appropriate screening for SCLC is key to improving the outcome of both conditions. Here we review the pathophysiology and clinical management of LEMS, focusing particularly on the relationship with SCLC.
Collapse
Affiliation(s)
- Sarah Ew Briggs
- Department of Oncology, Oxford University Hospitals Trust, Churchill Hospital, Oxford, UK
| | - Paul Gozzard
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford UK
| | - Denis C Talbot
- Department of Oncology, Oxford University Hospitals Trust, Churchill Hospital, Oxford, UK
| |
Collapse
|
20
|
Tarr TB, Valdomir G, Liang M, Wipf P, Meriney SD. New calcium channel agonists as potential therapeutics in Lambert-Eaton myasthenic syndrome and other neuromuscular diseases. Ann N Y Acad Sci 2012; 1275:85-91. [DOI: 10.1111/nyas.12001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
21
|
Kazarian M, Laird-Offringa IA. Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy. Mol Cancer 2011; 10:33. [PMID: 21450098 PMCID: PMC3080347 DOI: 10.1186/1476-4598-10-33] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 03/30/2011] [Indexed: 12/26/2022] Open
Abstract
Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.
Collapse
Affiliation(s)
- Meleeneh Kazarian
- Department of Surgery, Norris Cancer Center, Keck School of Medicine, University of Southern California, 1441 Eastlake Ave, NOR 6420, Los Angeles, CA 90089-9176, USA
| | | |
Collapse
|
22
|
Tsou JA, Kazarian M, Patel A, Galler JS, Laird-Offringa IA, Carpenter CL, London SJ. Low level anti-Hu reactivity: A risk marker for small cell lung cancer? ACTA ACUST UNITED AC 2008; 32:292-9. [PMID: 19070439 DOI: 10.1016/j.cdp.2008.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Previous experimental and laboratory studies have implicated antibodies against Hu proteins (anti-Hu) as a potential marker for small cell lung cancer (SCLC); there are no estimates of the association between anti-Hu and SCLC using a population-based design. METHODS We used stored plasma specimens to evaluate anti-Hu reactivity in relationship to small cell lung cancer in a population-based case-control study. Using Western Blot analysis, we measured anti-Hu reactivity against recombinant Hu family member, HuD, in plasma samples from 41 SCLC cases and 79 controls individually matched for age, race, sex, and smoking status (never, past, current). We analyzed the association between anti-Hu reactivity and SCLC using conditional logistic regression. RESULTS Anti-Hu reactivity was associated with SCLC, both before and after adjustment for amount of smoking. We observed a smoking-adjusted odds ratio of 3.2 (95% confidence interval from 0.98 to 13.4) comparing subjects above 1800 units (the lower limit of the second tertile of the distribution among antibody positive controls) to subjects with lower reactivity. We also found suggestive evidence in follow-up of our cases that anti-Hu above 1800 units was related to longer-term survival from SCLC. The present research is the first report of anti-Hu reactivity and SCLC in a population-based study. CONCLUSIONS Given the suggestive evidence in this study, prospective analyses to examine whether anti-Hu reactivity might predict risk of developing SCLC, or whether anti-Hu reactivity could serve as an early marker for SCLC, may be warranted.
Collapse
Affiliation(s)
- Jeffrey A Tsou
- Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9176, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Anti-Ca2+ channel antibody attenuates Ca2+ currents and mimics cerebellar ataxia in vivo. Proc Natl Acad Sci U S A 2008; 105:2705-10. [PMID: 18272482 DOI: 10.1073/pnas.0710771105] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Voltage-gated Ca(2+) channels (VGCCs) are membrane proteins that determine the activity and survival of neurons, and mutations in the P/Q-type VGCCs are known to cause cerebellar ataxia. VGCC dysfunction may also underlie acquired peripheral and central nervous system diseases associated with small-cell lung cancer, including Lambert-Eaton myasthenic syndrome (LEMS) and paraneoplastic cerebellar ataxia (PCA). The pathogenic role of anti-VGCC antibody in LEMS is well established. Although anti-VGCC antibody is also found in a significant fraction of PCA patients, its contribution to PCA is unclear. Using a polyclonal peptide antibody against a major immunogenic region in P/Q-type VGCCs (the extracellular Domain-III S5-S6 loop), we demonstrated that such antibody was sufficient to inhibit VGCC function in neuronal and recombinant VGCCs, alter cerebellar synaptic transmission, and confer the phenotype of cerebellar ataxia. Our data support the hypothesis that anti-VGCC antibody may play a significant role in the pathogenesis of cerebellar dysfunction in PCA.
Collapse
|
24
|
Vincent A. Autoantibodies in different forms of myasthenia gravis and in the Lambert-Eaton syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2008; 91:213-227. [PMID: 18631844 DOI: 10.1016/s0072-9752(07)01506-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Angela Vincent
- Department of Clinical Neurology, University of Oxford, Oxford, UK.
| |
Collapse
|
25
|
Wirtz PW, Bradshaw J, Wintzen AR, Verschuuren JJ. Associated autoimmune diseases in patients with the Lambert-Eaton myasthenic syndrome and their families. J Neurol 2005; 251:1255-9. [PMID: 15503107 DOI: 10.1007/s00415-004-0528-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 04/27/2004] [Accepted: 05/03/2004] [Indexed: 11/25/2022]
Abstract
In view of the clustering of autoimmune diseases (AIDs), we studied the frequency and nature of additional AIDs in patients with the Lambert-Eaton myasthenic syndrome (LEMS) and their family members, in both small cell lung carcinoma (SCLC) related and non-tumour (NT) related cases. Additional AIDs in patients with LEMS were assessed by interviewing the patient and studying the medical record. Family histories up to second-degree family members were established by interviewing patients, controls and family members. Forty-four patients with LEMS were assessed, of whom eighteen (41%) had SCLC. In the NT group seven patients (27%) had an additional AID, in the SCLC group two (11 %) (p=0.20). Thyroid disorder (five patients) and insulin dependent diabetes mellitus (two patients) were the most common AIDs. AIDs were significantly more frequent in families of patients with NT-LEMS (64%) than in control families (27%) (p=0.002), which was not found in SCLC-LEMS (36%, p=0.53). Affected family members were linked to the NT-LEMS patient through the maternal line in all cases. In conclusion, AIDs were more frequently found in LEMS patients without a tumour and their families, which could not be shown for SCLC-LEMS. This suggests that NT-LEMS shares immunogenetic factors with other AIDs. In families of NT-LEMS, a remarkable preponderance of maternal inheritance was seen, as has been reported previously in myasthenia gravis.
Collapse
Affiliation(s)
- Paul W Wirtz
- Department of Neurology, J3R-166 Leiden University Medical Centre, P. O. Box 9600, 2300, RC Leiden, The Netherlands.
| | | | | | | |
Collapse
|
26
|
Lang B, Pinto A, Giovannini F, Newsom-Davis J, Vincent A. Pathogenic Autoantibodies in the Lambert-Eaton Myasthenic Syndrome. Ann N Y Acad Sci 2003; 998:187-95. [PMID: 14592874 DOI: 10.1196/annals.1254.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of neuromuscular transmission in which antibodies are directed against voltage-gated calcium channels (VGCCs). We studied the action of LEMS immunoglobulin G (IgG) on cloned human VGCCs stably transfected into human embryonic kidney cells (HEK293). All LEMS IgGs tested bound to the surface of the P/Q-type VGCC cell line and caused a significant reduction in whole-cell calcium currents in these cells. By contrast, only 2 out of 6 IgGs bound extracellularly to the N-type VGCC cell line, and none of the LEMS IgGs tested was able to reduce whole-cell calcium currents in these cells. We used this apparent specificity of LEMS IgG for the P/Q-type VGCC to investigate the action of these IgGs on model systems where a number of different VGCC populations exist in equilibrium. LEMS IgG caused a significant downregulation in the omega-agatoxin IVA-sensitive P/Q-type VGCCs of cultured rat cerebellar neurons, but this was accompanied by a concomitant rise in the "resistant" R-type VGCCs. By using the passive transfer model of LEMS, similar results were observed at the mouse neuromuscular junction, where a significant reduction in P/Q-type VGCCs was paralleled by an increase in L- and R-type VGCCs. These results demonstrate an unexpected plasticity in the expression of VGCCs in mammalian neurons and may represent a mechanism by which the pathogenic effects of LEMS IgG are reduced.
Collapse
Affiliation(s)
- Bethan Lang
- Neurosciences Group and Department of Clinical Neurology, Oxford University, Oxford, United Kingdom.
| | | | | | | | | |
Collapse
|
27
|
Pinto A, Iwasa K, Newland C, Newsom-Davis J, Lang B. The action of Lambert-Eaton myasthenic syndrome immunoglobulin G on cloned human voltage-gated calcium channels. Muscle Nerve 2002; 25:715-724. [PMID: 11994966 DOI: 10.1002/mus.10087] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the Lambert-Eaton myasthenic syndrome (LEMS), immunoglobulin G (IgG) autoantibodies to presynaptic voltage-gated calcium channels (VGCCs) at the neuromuscular junction lead to a reduction in nerve-evoked release of neurotransmitter and muscle weakness. We have examined the action of LEMS IgGs on cloned human VGCCs stably expressed in transfected human embryonic kidney (HEK293) cell lines: 10-13 (alpha(1A-2), alpha(2b)delta, beta(4a)) and C2D7 (alpha(1B-1), alpha(2b)delta, beta(1b)). All LEMS IgGs studied showed surface binding to [(125)I]-omega-CTx-MVIIC-labeled VGCCs in the alpha(1A) cell line and two of six IgGs showed surface binding to [(125)I]-omega-CTx-GVIA-labeled VGCCs in the alpha(1B) cell line. We next studied the effect of LEMS IgGs (2 mg/ml) on whole-cell calcium currents in the alpha(1A) and alpha(1B) cell lines. Overnight treatment of alpha(1A) (10-13) cells with LEMS IgGs led to a significant reduction in peak current density without alteration of the current-voltage relationship or the voltage dependence of steady-state inactivation. In contrast, LEMS IgGs did not reduce peak current density in the alpha(1B) cell line. Overall these data demonstrate the specificity of LEMS IgGs for the alpha(1A) cell line and suggest that LEMS IgGs bind to and downregulate VGCCs in this cell line. Although several LEMS IgGs can be shown to bind to the alpha(1B) (C2D7) cell line, no functional effects were seen on this channel.
Collapse
Affiliation(s)
- Ashwin Pinto
- Neurosciences Group, Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Kazuo Iwasa
- Neurosciences Group, Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
- Department of Neurology, Kanazawa University School of Medicine, Kanazawa, Japan
| | - Claire Newland
- Neurosciences Group, Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - John Newsom-Davis
- Neurosciences Group, Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Bethan Lang
- Neurosciences Group, Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| |
Collapse
|
28
|
Abstract
Small cell lung carcinoma typically presents as a central endobronchial lesion in chronic cigarette smokers with hilar enlargement and disseminated disease. The diagnostic pathology should be reviewed by a pathologist accomplished in reading pulmonary pathology, and, if any doubt exists in the diagnosis, additional special stains or diagnostic material should be obtained. Patients with extensive stage disease should be managed by combination chemotherapy, whereas patients with limited stage disease should be treated with etoposide/cisplatin plus concurrent chest irradiation. The chemotherapy should be administered for 4 to 6 months and then should be discontinued. Prophylactic cranial irradiation should be given to patients who achieve a complete remission. Patients should be retreated with chemotherapy if they develop a relapse of their small cell lung cancer. The patients who are followed in complete remission should be observed carefully for second cancers, and appropriate therapy should be administered if the cancer reappears.
Collapse
Affiliation(s)
- Bruce E Johnson
- Lowe Center for Thoracic Oncology, Department of Adult Oncology, Dana Farber Cancer Institute, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
| |
Collapse
|
29
|
Abstract
Paraneoplastic disorders may affect any part of the central or peripheral nervous systems. Although relatively uncommon, these disorders are a significant cause of neurologic morbidity for cancer patients. At least some paraneoplastic syndromes are believed to be caused by an autoimmune reaction against shared tumor-neural antigens. This article summarizes the clinical features of paraneoplastic disorders, the current evidence for autoimmunity, and guidelines for diagnosis and treatment.
Collapse
Affiliation(s)
- Edward J Dropcho
- Department of Neurology, Indiana University Medical Center, The Richard Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana 46202, USA.
| |
Collapse
|
30
|
Affiliation(s)
- A F Carpentier
- Fédération de neurologie Mazarin, Hopital de la Salpêtrière, 75013 Paris, France
| | | |
Collapse
|
31
|
Antoine JC. Immunological mechanisms in paraneoplastic peripheral neuropathy. Clin Rev Allergy Immunol 2000; 19:61-72. [PMID: 11064827 DOI: 10.1385/criai:19:1:61] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- J C Antoine
- Service de Neurologie, Hôpital de Bellevue, Saint-Etienne, France
| |
Collapse
|
32
|
|
33
|
Takamori M, Komai K, Iwasa K. Antibodies to calcium channel and synaptotagmin in Lambert-Eaton myasthenic syndrome. Am J Med Sci 2000; 319:204-8. [PMID: 10768604 DOI: 10.1097/00000441-200004000-00002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In the Lambert-Eaton myasthenic syndrome (LEMS), an autoimmune disease that is often associated with lung cancer and characterized by reduced quantal release of acetylcholine from the motor nerve terminal, our studies to search for the target of LEMS antibodies have brought the voltage-gated calcium channel (VGCC) into relief. Among multiple types of VGCCs, the P/Q-type was highly recognized by LEMS antibodies. Using synthetic peptides or recombinant proteins as antigens, the study specified the S5-S6 linker regions in 3 of 4 domains as immunodominant sites in the molecular structure of P/Q-type VGCC alpha1 subunit. Synaptotagmin, one of the functionally VGCC-associated synaptic proteins, was also found to be an immunogen in the pathogenesis of LEMS.
Collapse
Affiliation(s)
- M Takamori
- Neurological Center, Kanazawa-Nishi Hospital, Kanazawa, Japan
| | | | | |
Collapse
|
34
|
Takamori M, Maruta T, Komai K. Lambert-Eaton myasthenic syndrome as an autoimmune calcium-channelopathy. Neurosci Res 2000; 36:183-91. [PMID: 10683522 DOI: 10.1016/s0168-0102(99)00135-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lambert-Eaton myasthenic syndrome (LEMS), often associated with small cell lung carcinoma (SCLC), is a disease of neuromuscular transmission in which antibodies directed against voltage-gated calcium channel (VGCC) in the motor nerve terminal play a crucial role in causing a deficient quantal release of acetylcholine. We focused attention on the P/Q-type VGCC, against which a majority of LEMS patients carry the specific antibody. Since the P/Q-type VGCC expresses in SCLC, the motor nerve terminal and SCLC may share a common VGCC antigen. In search for antigenic sites at the molecular level, We employed peptides or recombinant protein corresponding to the S5-S6 linker of each of four domains forming the alpha 1A subunit and tested their antigenicity. As the result, we specified the domain II, III and IV as immunodominant sites by the induction of an immune-mediated animal model of LEMS and the assay for antibodies in LEMS patients. Also, by use of peptides or recombinant protein corresponding to the synaptotagmin I, we found that in this VGCC-associated protein, the segment which exposes extracellularly during exocytosis can be antigenic for LEMS.
Collapse
Affiliation(s)
- M Takamori
- Neurological Center, Kanazawa-Nishi Hospital, 77, Ko, Kita-machi, Kanazawa, Japan
| | | | | |
Collapse
|
35
|
Nagado T, Arimura K, Sonoda Y, Kurono A, Horikiri Y, Kameyama A, Kameyama M, Pongs O, Osame M. Potassium current suppression in patients with peripheral nerve hyperexcitability. Brain 1999; 122 ( Pt 11):2057-66. [PMID: 10545391 DOI: 10.1093/brain/122.11.2057] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Acquired neuromyotonia (Isaac's syndrome) is considered to be an autoimmune disease, and the pathomechanism of nerve hyperexcitability in this syndrome is correlated with anti-voltage-gated K(+) channel (VGKC) antibodies. The patch-clamp technique was used to investigate the effects of immunoglobulins from acquired neuromyotonia patients on VGKCs and voltage-gated Na(+) channels in a human neuroblastoma cell line (NB-1). K(+) currents were suppressed in cells that had been co-cultured with acquired neuromyotonia patients' immunoglobulin for 3 days but not for 1 day. The activation and inactivation kinetics of the outward K(+) currents were not altered by these immunoglobulins, nor did the immunoglobulins significantly affect the Na(+) currents. Myokymia or myokymic discharges, with peripheral nerve hyperexcitability, also occur in various neurological disorders such as Guillain-Barré syndrome and idiopathic generalized myokymia without pseudomyotonia. Immuno-globulins from patients with these diseases suppressed K(+) but not Na(+) currents. In addition, in hKv 1.1- and 1.6-transfected CHO (Chinese hamster ovary)-K1 cells, the expressed VGKCs were suppressed by sera from acquired neuromyotonia patients without a change in gating kinetics. Our findings indicate that nerve hyperexcitability is mainly associated with the suppression of voltage-gated K(+) currents with no change in gating kinetics, and that this suppression occurs not only in acquired neuromyotonia but also in Guillain-Barré syndrome and idiopathic generalized myokymia without pseudomyotonia.
Collapse
Affiliation(s)
- T Nagado
- Third Department of Internal Medicine, Kagoshima University School of Medicine, Kagoshima, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
|
37
|
Abstract
Calcium channels that are regulated by voltage have an important role in linking cellular stimulation to physiological responses in the nervous system. In addition, a number of autoimmune or genetic disorders that affect calcium channels (channelopathies) have been identified, including several that affect neuromuscular function. These include the Lambert-Eaton myasthenic syndrome, which is associated with autoantibodies directed against neuronal calcium channels, as well as at least two inherited neuromuscular diseases-hypokalemic periodic paralysis and some varieties of malignant hyperthermia-that affect calcium channels in skeletal muscle. Preliminary progress has been achieved in understanding the relationship between these immunological or genetic abnormalities and the alterations in channel function that they produce. A major challenge that remains is to determine how calcium channelopathies lead to the curious assortment of paroxysmal and progressive disorders that are observed clinically.
Collapse
Affiliation(s)
- D A Greenberg
- Buck Center for Research in Aging, Novato, California, USA
| |
Collapse
|
38
|
Abstract
The Lambert-Eaton myasthenic syndrome is a neuromuscular disorder characterised by defective neurotransmitter release at autonomic neurones and presynaptic terminals of the neuromuscular junction. It is caused by an IgG autoantibody formed against especially the P/Q type of voltage-gated calcium channels (VGCC) which is an essential component of the mechanism of neurotransmitter release. Many patients have an associated small cell carcinoma of the lung which appears to provide the antigenic stimulus for antibody production, although there is another group with no underlying malignancy. Both groups show an association with immunological disorders. Assay of VGCC antibody titres and electrophysiological tests help to differentiate Lambert-Eaton myasthenic syndrome from other disorders of the neuromuscular junction. Several drugs and therapeutic interventions capable of producing significant clinical improvement are currently available. Patients should also be investigated for underlying tumours, the specific treatment of which can result in remission or amelioration of symptoms.
Collapse
Affiliation(s)
- U Seneviratne
- Department of Neurology, Southern General Hospital, Glasgow, UK
| | | |
Collapse
|
39
|
Lambert-Eaton antibodies inhibit Ca2+ currents but paradoxically increase exocytosis during stimulus trains in bovine adrenal chromaffin cells. J Neurosci 1999. [PMID: 10212298 DOI: 10.1523/jneurosci.19-09-03384.1999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that affects neurotransmitter release at peripheral synapses. LEMS antibodies inhibit Ca2+ currents in excitable cells, but it is not known whether there are additional effects on stimulus-secretion coupling. The effect of LEMS antibodies on Ca2+ currents and exocytosis was studied in bovine adrenal chromaffin cells using whole-cell voltage clamp in perforated-patch recordings. Purified LEMS IgGs from five patients inhibited N- and P/Q-type Ca2+ current components to different extents. The reduction in Ca2+ current resulted in smaller exocytotic responses to single depolarizing pulses, but the normal relationship between integrated Ca2+ entry and exocytosis (Enisch and Nowycky, 1996) was preserved. The hallmark of LEMS is a large potentiation of neuromuscular transmission after high-frequency stimulation. In chromaffin cells, stimulus trains can induce activity-dependent enhancement of the Ca2+-exocytosis relationship. Enhancement during trains occurs most frequently when pulses are brief and evoke very small amounts of Ca2+ entry (Engisch et al., 1997). LEMS antibody treatment increased the percentage of trains eliciting enhancement through two mechanisms: (1) by reducing Ca2+ entry and (2) through a Ca2+-independent effect on the process of enhancement. This leads to a paradoxical increase in the amount of exocytosis during stimulus trains, despite inhibition of Ca2+ currents.
Collapse
|
40
|
Voltz R, Carpentier AF, Rosenfeld MR, Posner JB, Dalmau J. P/Q-type voltage-gated calcium channel antibodies in paraneoplastic disorders of the central nervous system. Muscle Nerve 1999; 22:119-22. [PMID: 9883867 DOI: 10.1002/(sici)1097-4598(199901)22:1<119::aid-mus19>3.0.co;2-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Whether P/Q-type voltage-gated calcium channel (VGCC) antibodies are present in the serum of patients with paraneoplastic syndromes other than the Lambert-Eaton myasthenic syndrome (LEMS) and tumors other than small-cell lung cancer (SCLC) is controversial. Using a commercially available radioimmunoprecipitation assay kit, we examined the sera of 93 patients with paraneoplastic syndromes of the central nervous system (CNS), including 27 patients with paraneoplastic cerebellar degeneration (PCD) associated with tumors other than SCLC and 66 SCLC patients with paraneoplastic encephalomyelitis and sensory neuronopathy (PEM/SN). All PCD sera from patients with tumors other than SCLC were negative for P/Q-type VGCC antibodies. Eight of 66 (12%) SCLC patients with PEM/SN had P/Q-type VGCC antibodies; 4 had LEMS and the other 4 had no symptoms of LEMS or they were overlooked and, therefore, not examined electrophysiologically. In patients with paraneoplastic syndromes of the CNS, the detection of P/Q-type VGCC antibodies supports the diagnosis of LEMS; in our series, only 6% of patients with SCLC and PEM/SN may have had a false positive antibody result, or undiagnosed LEMS.
Collapse
Affiliation(s)
- R Voltz
- Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
| | | | | | | | | |
Collapse
|
41
|
Pinto A, Gillard S, Moss F, Whyte K, Brust P, Williams M, Stauderman K, Harpold M, Lang B, Newsom-Davis J, Bleakman D, Lodge D, Boot J. Human autoantibodies specific for the alpha1A calcium channel subunit reduce both P-type and Q-type calcium currents in cerebellar neurons. Proc Natl Acad Sci U S A 1998; 95:8328-33. [PMID: 9653186 PMCID: PMC20975 DOI: 10.1073/pnas.95.14.8328] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The pharmacological properties of voltage-dependent calcium channel (VDCC) subtypes appear mainly to be determined by the alpha1 pore-forming subunit but, whether P-and Q-type VDCCs are encoded by the same alpha1 gene presently is unresolved. To investigate this, we used IgG antibodies to presynaptic VDCCs at motor nerve terminals that underlie muscle weakness in the autoimmune Lambert-Eaton myasthenic syndrome (LEMS). We first studied their action on changes in intracellular free Ca2+ concentration [Ca2+]i in human embryonic kidney (HEK293) cell lines expressing different combinations of human recombinant VDCC subunits. Incubation for 18 h with LEMS IgG (2 mg/ml) caused a significant dose-dependent reduction in the K+-stimulated [Ca2+]i increase in the alpha1A cell line but not in the alpha1B, alpha1C, alpha1D, and alpha1E cell lines, establishing the alpha1A subunit as the target for these autoantibodies. Exploiting this specificity, we incubated cultured rat cerebellar neurones with LEMS IgG and observed a reduction in P-type current in Purkinje cells and both P- and Q-type currents in granule cells. These data are consistent with the hypothesis that the alpha1A gene encodes for the pore-forming subunit of both P-type and Q-type VDCCs.
Collapse
Affiliation(s)
- A Pinto
- Neurosciences Group, Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, OX3 9DS, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Sher E, Codignola A, Passafaro M, Tarroni P, Magnelli V, Carbone E, Clementi F. Nicotinic receptors and calcium channels in small cell lung carcinoma. Functional role, modulation, and autoimmunity. Ann N Y Acad Sci 1998; 841:606-24. [PMID: 9668305 DOI: 10.1111/j.1749-6632.1998.tb10993.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E Sher
- CNR Cellular and Molecular Pharmacology Center, Department of Medical Pharmacology, University of Milan, Italy
| | | | | | | | | | | | | |
Collapse
|
43
|
Black JL, Griesmann GE, Erickson J, Kryzer TJ, Lamke GT, Lennon VA. Lambert-Eaton myasthenic syndrome. Antigenicity of recombinant human P/Q-type calcium channel alpha 1 subunit putative ion pore region (domain IV, S5-S6). Ann N Y Acad Sci 1998; 841:691-5. [PMID: 9668316 DOI: 10.1111/j.1749-6632.1998.tb11004.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J L Black
- Department of Psychiatry, Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | | | | | | | | | | |
Collapse
|
44
|
Kim YI, Nam TS, Kim SH, Viglione MP, Kim J. Specificity of the Lambert-Eaton syndrome antibodies. Downregulation of P/Q-type calcium channels in bovine adrenal chromaffin cells. Ann N Y Acad Sci 1998; 841:677-83. [PMID: 9668313 DOI: 10.1111/j.1749-6632.1998.tb11001.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Y I Kim
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville 22908, USA
| | | | | | | | | |
Collapse
|
45
|
Satoh Y, Hirashima N, Tokumaru H, Takahashi MP, Kang J, Viglione MP, Kim YI, Kirino Y. Lambert-Eaton syndrome antibodies inhibit acetylcholine release and P/Q-type Ca2+ channels in electric ray nerve endings. J Physiol 1998; 508 ( Pt 2):427-38. [PMID: 9508807 PMCID: PMC2230882 DOI: 10.1111/j.1469-7793.1998.427bq.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
1. The types of voltage-dependent calcium channels (VDCCs) present in the cholinergic terminals isolated from the electric organ of the ray, Narke japonica, were characterized on the basis of their pharmacological sensitivity to specific antagonists. Inhibition of these channel types by autoantibodies from patients with the Lambert-Eaton syndrome (LES) was then studied to determine the specificity of the pathogenic IgG. 2. In normal untreated synaptosomal preparations, maximal doses of N- and P and/or Q-type Ca2+ channel antagonists, omega-conotoxin GVIA and omega-agatoxin IVA, inhibited depolarization-evoked ACh release by 47 % and 43 %, respectively. Calciseptine, an L-type VDCC antagonist, caused a 20 % reduction in the release. This indicates that the exocytotic release process is predominantly mediated by N- and P/Q-type VDCCs. 3. LES IgG or sera caused an inhibition of ACh release by 39-45 % in comparison with the control antibody-treated preparations. The ionomycin-induced ACh release, however, was not altered by the antibodies. Additionally, the same LES antibodies inhibited whole-cell calcium currents (ICa) in bovine adrenal chromaffin cells. Thus, the pathogenic antibodies exert their action on VDCCs present in the synaptosomes. 4. The efficacy of three Ca2+ channel antagonists in blocking ACh release was determined in preparations pretreated with LES IgG. omega-Agatoxin IVA produced only an additional 3-5 % reduction in release beyond that obtained with LES antibodies. Despite the pretreatment with LES IgG, omega-conotoxin GVIA and calciseptine inhibited the release to nearly their control levels. 5. These results indicate that LES antibodies mainly downregulate P/Q-type Ca2+ channels which contribute to presynaptic transmitter release from the cholinergic nerve terminals of electric organ. 6. The present findings are consistent with the hypothesis that P/Q-type VDCCs at the neuromuscular junction are the target of LES antibodies and that their inhibition by the antibodies produces the characteristic neuromuscular defect in this disease.
Collapse
Affiliation(s)
- Y Satoh
- School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
| | | | | | | | | | | | | | | |
Collapse
|
46
|
|
47
|
Abstract
Peripheral nerve diseases are among the most prevalent disorders of the nervous system. Because of the accessibility of the peripheral nervous system (PNS) to direct physiological and pathological study, neuropathies have traditionally played a unique role in developing our understanding of basic mechanism of nervous system injury and repair. At present they are providing new insight into the mechanisms of immune injury to the nervous system. A rapidly growing catalogue of PNS disorders are now suspected to be immune-mediated, and in the best understood of these disorders, the molecular and cellular targets of immune attack are known, and the pathophysiology follows directly from the specific immune injury. This review summarizes the immunologically relevant features of the PNS, then considers selected immune-mediated neuropathies, focusing on pathogenetic mechanisms. Finally, the PNS is providing a testing ground for new immunotherapies and approaches to protection and regeneration, including the use of trophic factors. The current status of treatment and implications for future approaches is reviewed.
Collapse
Affiliation(s)
- T W Ho
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | | | | |
Collapse
|
48
|
Abstract
Several neurologic paraneoplastic disorders are believed to be caused by an autoimmune reaction against antigen(s) co-expressed by tumour cells and neurons. Of the paraneoplastic syndromes, the evidence for an autoimmune etiology is strongest for the Lambert-Eaton myasthenic syndrome, in which autoantibodies downregulate voltage-gated calcium channels at the presynaptic nerve terminal. For other syndromes, including cerebellar degeneration, multifocal encephalomyelitis, sensory neuronopathy, limbic encephalitis, opsoclonus-myoclonus, stiff person syndrome, and retinal degeneration, the autoimmune theory is supported by the presence of specific antineuronal antibodies. These antibodies serve as a useful diagnostic tool, but their actual role in causing neuronal injury and clinical disease remains unclear. Further understanding of immunopathogenesis awaits successful experimental models. Among different syndromes, a varied proportion of patients shows neurologic improvement with immunosuppressive treatments; it is likely that many patients have already suffered irreversible neuronal injury at the time of diagnosis.
Collapse
Affiliation(s)
- E J Dropcho
- Department of Neurology, Indiana University Medical Center, Indianapolis 46202, USA.
| |
Collapse
|
49
|
Abstract
Channels involved in the influx and intracellular mobilization of calcium have been implicated as targets of diverse genetic and immune-mediated neurological diseases. These include the L-type voltage-gated calcium channel of skeletal muscle (hypokalemic periodic paralysis), the neuronal P/Q-type voltage-gated calcium channel (familial hemiplegic migraine, episodic ataxia type 2, spinocerebellar ataxia 6, and Lambert-Eaton myasthenic syndrome), and the skeletal muscle ryanodine receptor (malignant hyperthermia and central core disease). The discovery of these and other calcium channelopathies should help to clarify how different mutations affect channel function and how altered channel function produces disease, and may lead to new treatments for these conditions.
Collapse
Affiliation(s)
- D A Greenberg
- Department of Neurology, University of Pittsburgh School of Medicine, PA 15213, USA
| |
Collapse
|