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Ritzau-Jost A, Gsell F, Sell J, Sachs S, Montanaro J, Kirmann T, Maaß S, Irani SR, Werner C, Geis C, Sauer M, Shigemoto R, Hallermann S. LGI1 Autoantibodies Enhance Synaptic Transmission by Presynaptic K v1 Loss and Increased Action Potential Broadening. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2024; 11:e200284. [PMID: 39141878 DOI: 10.1212/nxi.0000000000200284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
BACKGROUND AND OBJECTIVES Autoantibodies against the protein leucine-rich glioma inactivated 1 (LGI1) cause the most common subtype of autoimmune encephalitis with predominant involvement of the limbic system, associated with seizures and memory deficits. LGI1 and its receptor ADAM22 are part of a transsynaptic protein complex that includes several proteins involved in presynaptic neurotransmitter release and postsynaptic glutamate sensing. Autoantibodies against LGI1 increase excitatory synaptic strength, but studies that genetically disrupt the LGI1-ADAM22 complex report a reduction in postsynaptic glutamate receptor-mediated responses. Thus, the mechanisms underlying the increased synaptic strength induced by LGI1 autoantibodies remain elusive, and the contributions of presynaptic molecules to the LGI1-transsynaptic complex remain unclear. We therefore investigated the presynaptic mechanisms that mediate autoantibody-induced synaptic strengthening. METHODS We studied the effects of patient-derived purified polyclonal LGI1 autoantibodies on synaptic structure and function by combining direct patch-clamp recordings from presynaptic boutons and somata of hippocampal neurons with super-resolution light and electron microscopy of hippocampal cultures and brain slices. We also identified the protein domain mediating the presynaptic effect using domain-specific patient-derived monoclonal antibodies. RESULTS LGI1 autoantibodies dose-dependently increased short-term depression during high-frequency transmission, consistent with increased release probability. The increased neurotransmission was not related to presynaptic calcium channels because presynaptic Cav2.1 channel density, calcium current amplitude, and calcium channel gating were unaffected by LGI1 autoantibodies. By contrast, application of LGI1 autoantibodies homogeneously reduced Kv1.1 and Kv1.2 channel density on the surface of presynaptic boutons. Direct presynaptic patch-clamp recordings revealed that LGI1 autoantibodies cause a pronounced broadening of the presynaptic action potential. Domain-specific effects of LGI1 autoantibodies were analyzed at the neuronal soma. Somatic action potential broadening was induced by polyclonal LGI1 autoantibodies and patient-derived monoclonal autoantibodies targeting the epitempin domain, but not the leucin-rich repeat domain. DISCUSSION Our results indicate that LGI1 autoantibodies reduce the density of both Kv1.1 and Kv1.2 on presynaptic boutons, without actions on calcium channel density or function, thereby broadening the presynaptic action potential and increasing neurotransmitter release. This study provides a molecular explanation for the neuronal hyperactivity observed in patients with LGI1 autoantibodies.
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Affiliation(s)
- Andreas Ritzau-Jost
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Felix Gsell
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Josefine Sell
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Stefan Sachs
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Jacqueline Montanaro
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Toni Kirmann
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Sebastian Maaß
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Sarosh R Irani
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Christian Werner
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Christian Geis
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Markus Sauer
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Ryuichi Shigemoto
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
| | - Stefan Hallermann
- From the Carl-Ludwig-Institute of Physiology (A.R.-J., F.G., T.K., S.M., S.H.), Faculty of Medicine, Leipzig University; Section Translational Neuroimmunology (J.S., C.G.), Department of Neurology, Jena University Hospital; Department of Biotechnology and Biophysics (S.S., C.W., M.S.), University of Würzburg, Biocenter, Germany; Institute of Science and Technology Austria (ISTA) (J.M., R.S.), Klosterneuburg, Austria; Oxford Autoimmune Neurology Group (S.R.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, ; Department of Neurology (S.R.I.), John Radcliffe Hospital, Oxford University Hospitals, United Kingdom; and Departments of Neurology and Neurosciences (S.R.I.), Mayo Clinic Jacksonville, FL
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Ramirez-Franco J, Debreux K, Sangiardi M, Belghazi M, Kim Y, Lee SH, Lévêque C, Seagar M, El Far O. The downregulation of Kv 1 channels in Lgi1 -/-mice is accompanied by a profound modification of its interactome and a parallel decrease in Kv 2 channels. Neurobiol Dis 2024; 196:106513. [PMID: 38663634 DOI: 10.1016/j.nbd.2024.106513] [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: 11/08/2023] [Revised: 03/12/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024] Open
Abstract
In animal models of LGI1-dependent autosomal dominant lateral temporal lobe epilepsy, Kv1 channels are downregulated, suggesting their crucial involvement in epileptogenesis. The molecular basis of Kv1 channel-downregulation in LGI1 knock-out mice has not been elucidated and how the absence of this extracellular protein induces an important modification in the expression of Kv1 remains unknown. In this study we analyse by immunofluorescence the modifications in neuronal Kv1.1 and Kv1.2 distribution throughout the hippocampal formation of LGI1 knock-out mice. We show that Kv1 downregulation is not restricted to the axonal compartment, but also takes place in the somatodendritic region and is accompanied by a drastic decrease in Kv2 expression levels. Moreover, we find that the downregulation of these Kv channels is associated with a marked increase in bursting patterns. Finally, mass spectrometry uncovered key modifications in the Kv1 interactome that highlight the epileptogenic implication of Kv1 downregulation in LGI1 knock-out animals.
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Affiliation(s)
- Jorge Ramirez-Franco
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
| | - Kévin Debreux
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Marion Sangiardi
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Maya Belghazi
- Marseille Protéomique (MaP), Plateforme Protéomique IMM, CNRS FR3479, Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13009 Marseille, France
| | - Yujin Kim
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Suk-Ho Lee
- Department of Physiology, Cell Physiology Lab, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 03080, South Korea
| | - Christian Lévêque
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Michael Seagar
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France
| | - Oussama El Far
- INSERM UMR_S 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, Aix-Marseille Université, 13015 Marseille, France.
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Cuhadar U, Calzado-Reyes L, Pascual-Caro C, Aberra AS, Ritzau-Jost A, Aggarwal A, Ibata K, Podgorski K, Yuzaki M, Geis C, Hallerman S, Hoppa MB, de Juan-Sanz J. Activity-driven synaptic translocation of LGI1 controls excitatory neurotransmission. Cell Rep 2024; 43:114186. [PMID: 38700985 PMCID: PMC11156761 DOI: 10.1016/j.celrep.2024.114186] [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: 06/28/2022] [Revised: 12/14/2023] [Accepted: 04/17/2024] [Indexed: 05/05/2024] Open
Abstract
The fine control of synaptic function requires robust trans-synaptic molecular interactions. However, it remains poorly understood how trans-synaptic bridges change to reflect the functional states of the synapse. Here, we develop optical tools to visualize in firing synapses the molecular behavior of two trans-synaptic proteins, LGI1 and ADAM23, and find that neuronal activity acutely rearranges their abundance at the synaptic cleft. Surprisingly, synaptic LGI1 is primarily not secreted, as described elsewhere, but exo- and endocytosed through its interaction with ADAM23. Activity-driven translocation of LGI1 facilitates the formation of trans-synaptic connections proportionally to the history of activity of the synapse, adjusting excitatory transmission to synaptic firing rates. Accordingly, we find that patient-derived autoantibodies against LGI1 reduce its surface fraction and cause increased glutamate release. Our findings suggest that LGI1 abundance at the synaptic cleft can be acutely remodeled and serves as a critical control point for synaptic function.
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Affiliation(s)
- Ulku Cuhadar
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Lorenzo Calzado-Reyes
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Carlos Pascual-Caro
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Aman S Aberra
- Department of Biology, Dartmouth College, Hanover, NH 03755, USA
| | - Andreas Ritzau-Jost
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, 04317 Leipzig, Germany
| | - Abhi Aggarwal
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Keiji Ibata
- Department of Neurophysiology, Keio University, Tokyo 160-8582, Japan
| | | | - Michisuke Yuzaki
- Department of Neurophysiology, Keio University, Tokyo 160-8582, Japan
| | - Christian Geis
- Department of Neurology, Section Translational Neuroimmunology, Jena University Hospital, 07747 Jena, Germany
| | - Stefan Hallerman
- Carl-Ludwig-Institute of Physiology, Faculty of Medicine, Leipzig University, 04317 Leipzig, Germany
| | - Michael B Hoppa
- Department of Biology, Dartmouth College, Hanover, NH 03755, USA
| | - Jaime de Juan-Sanz
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France.
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Extrémet J, Ramirez-Franco J, Fronzaroli-Molinieres L, Boumedine-Guignon N, Ankri N, El Far O, Garrido JJ, Debanne D, Russier M. Rescue of Normal Excitability in LGI1-Deficient Epileptic Neurons. J Neurosci 2023; 43:8596-8606. [PMID: 37863654 PMCID: PMC10727174 DOI: 10.1523/jneurosci.0701-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/08/2023] [Accepted: 10/14/2023] [Indexed: 10/22/2023] Open
Abstract
Leucine-rich glioma inactivated 1 (LGI1) is a glycoprotein secreted by neurons, the deletion of which leads to autosomal dominant lateral temporal lobe epilepsy. We previously showed that LGI1 deficiency in a mouse model (i.e., knock-out for LGI1 or KO-Lgi1) decreased Kv1.1 channel density at the axon initial segment (AIS) and at presynaptic terminals, thus enhancing both intrinsic excitability and glutamate release. However, it is not known whether normal excitability can be restored in epileptic neurons. Here, we show that the selective expression of LGI1 in KO-Lgi1 neurons from mice of both sexes, using single-cell electroporation, reduces intrinsic excitability and restores both the Kv1.1-mediated D-type current and Kv1.1 channels at the AIS. In addition, we show that the homeostatic-like shortening of the AIS length observed in KO-Lgi1 neurons is prevented in neurons electroporated with the Lgi1 gene. Furthermore, we reveal a spatial gradient of intrinsic excitability that is centered on the electroporated neuron. We conclude that expression of LGI1 restores normal excitability through functional Kv1 channels at the AIS.SIGNIFICANCE STATEMENT The lack of leucine-rich glioma inactivated 1 (LGI1) protein induces severe epileptic seizures that leads to death. Enhanced intrinsic and synaptic excitation in KO-Lgi1 mice is because of the decrease in Kv1.1 channels in CA3 neurons. However, the conditions to restore normal excitability profile in epileptic neurons remain to be defined. We show here that the expression of LGI1 in KO-Lgi1 neurons in single neurons reduces intrinsic excitability, and restores both the Kv1.1-mediated D-type current and Kv1.1 channels at the axon initial segment (AIS). Furthermore, the homeostatic shortening of the AIS length observed in KO-Lgi1 neurons is prevented in neurons in which the Lgi1 gene has been rescued. We conclude that LGI1 constitutes a critical factor to restore normal excitability in epileptic neurons.
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Affiliation(s)
- Johanna Extrémet
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Jorge Ramirez-Franco
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Laure Fronzaroli-Molinieres
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Norah Boumedine-Guignon
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Norbert Ankri
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Oussama El Far
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Juan José Garrido
- Cajal Institute, Consejo Superior de Investigaciones Cientificas, Madrid, 28002, Spain
| | - Dominique Debanne
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
| | - Michaël Russier
- Unité de Neurobiologie des canaux Ioniques et de la Synapse, Unité Mixte de Recherche 1072, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille Université, Marseille, 13015, France
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Pişkin ŞA, Korkmaz HY, Ulusoy CA, Şanlı E, Küçükali CI, Onat F, Tüzün E, Çarçak N. Antibody induced seizure susceptibility and impaired cognitive performance in a passive transfer rat model of autoimmune encephalitis. Front Immunol 2023; 14:1268986. [PMID: 38035091 PMCID: PMC10684964 DOI: 10.3389/fimmu.2023.1268986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Objective Autoimmune encephalitis (AE) is a distinct neuro-immunological disorder associated with the production of autoantibodies against neuronal proteins responsible for pharmacoresistant seizures, cognitive decline and behavioral problems. To establish the causal link between leucine-rich glioma inactivated 1 (LGI1) antibody and seizures, we developed an in-vivo antibody-mediated AE rat model in which serum antibodies (IgG) obtained from blood samples of leucine-rich glioma inactivated 1 (LGI1) protein antibody (IgG) positive encephalitis patients were passively transferred into non-epileptic Wistar rats. Serum IgG of N-methyl-d-aspartate receptor (NMDAR) antibody positive patients were used as positive control since the pathogenicity of this antibody has been previously shown in animal models. Methods Total IgG obtained from the pooled sera of NMDAR and LGI1-IgG positive patients with epileptic seizures and healthy subjects was applied chronically every other day for 11 days into the cerebral lateral ventricle. Spontaneous seizure development was followed by electroencephalography. Behavioral tests for memory and locomotor activity were applied before and after the antibody infusions. Then, pentylenetetrazol (PTZ) was administered intraperitoneally to evaluate seizure susceptibility. Immunohistochemistry processed for assessment of hippocampal astrocyte proliferation and expression intensity of target NMDAR and LGI1 antigens. Results No spontaneous activity was observed during the antibody infusions. PTZ-induced seizure stage was significantly higher in the NMDAR-IgG and LGI1-IgG groups compared to control. Besides, memory deficits were observed in the NMDAR and LGI1-IgG groups. We observed enhanced astrocyte proliferation in NMDAR- and LGI1-IgG groups and reduced hippocampal NMDAR expression in NMDAR-IgG group. Significance These findings suggest that neuronal surface auto-antibody administration induces seizure susceptibility and disturbed cognitive performance in the passive transfer rat model of LGI1 AE, which could be a potential in-vivo model for understanding immune-mediated mechanisms underlying epileptogenesis and highlight the potential targets for immune-mediated seizures in AE patients.
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Affiliation(s)
- Şura Akat Pişkin
- Department of Pharmacology, Faculty of Pharmacy, Institute of Health Sciences, Istanbul University, Istanbul, Türkiye
| | - Hande Yüceer Korkmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Institute of Health Sciences, Istanbul University, Istanbul, Türkiye
| | - Canan Aysel Ulusoy
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istabul University, Istanbul, Türkiye
| | - Elif Şanlı
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Institute of Health Sciences, Istanbul University, Istanbul, Türkiye
| | - Cem Ismail Küçükali
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istabul University, Istanbul, Türkiye
| | - Filiz Onat
- Department of Medical Pharmacology, Acibadem Mehmet Ali Aydinlar University Faculty of Medicine, Istanbul, Türkiye
- Deparment of Neuroscience, Acibadem Mehmet Ali Aydinlar University Health Sciences Institute, Istanbul, Türkiye
| | - Erdem Tüzün
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istabul University, Istanbul, Türkiye
| | - Nihan Çarçak
- Deparment of Neuroscience, Acibadem Mehmet Ali Aydinlar University Health Sciences Institute, Istanbul, Türkiye
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Istanbul, Türkiye
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Ramirez-Franco J, Debreux K, Extremet J, Maulet Y, Belghazi M, Villard C, Sangiardi M, Youssouf F, El Far L, Lévêque C, Debarnot C, Marchot P, Paneva S, Debanne D, Russier M, Seagar M, Irani SR, El Far O. Patient-derived antibodies reveal the subcellular distribution and heterogeneous interactome of LGI1. Brain 2022; 145:3843-3858. [PMID: 35727946 DOI: 10.1093/brain/awac218] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/14/2022] Open
Abstract
Autoantibodies against leucine-rich glioma-inactivated 1 (LGI1) occur in patients with encephalitis who present with frequent focal seizures and a pattern of amnesia consistent with focal hippocampal damage. To investigate whether the cellular and subcellular distribution of LGI1 may explain the localization of these features, and hence gain broader insights into LGI1's neurobiology, we analysed the detailed localization of LGI1 and the diversity of its protein interactome, in mouse brains using patient-derived recombinant monoclonal LGI1 antibodies. Combined immunofluorescence and mass spectrometry analyses showed that LGI1 is enriched in excitatory and inhibitory synaptic contact sites, most densely within CA3 regions of the hippocampus. LGI1 is secreted in both neuronal somatodendritic and axonal compartments, and occurs in oligodendrocytic, neuro-oligodendrocytic and astro-microglial protein complexes. Proteomic data support the presence of LGI1-Kv1-MAGUK complexes, but did not reveal LGI1 complexes with postsynaptic glutamate receptors. Our results extend our understanding of regional, cellular and subcellular LGI1 expression profiles and reveal novel LGI1-associated complexes, thus providing insights into the complex biology of LGI1 and its relationship to seizures and memory loss.
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Affiliation(s)
- Jorge Ramirez-Franco
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Kévin Debreux
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Johanna Extremet
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Yves Maulet
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Maya Belghazi
- Aix-Marseille University, CNRS, Institute of Neurophysiopathology (INP), PINT, PFNT, 13385 cedex 5 Marseille, France
| | - Claude Villard
- Aix-Marseille University, CNRS, Institute of Neurophysiopathology (INP), PINT, PFNT, 13385 cedex 5 Marseille, France
| | - Marion Sangiardi
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Fahamoe Youssouf
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Lara El Far
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Christian Lévêque
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Claire Debarnot
- Laboratoire 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', CNRS, Aix-Marseille Université, 13288 cedex 09 Marseille, France
| | - Pascale Marchot
- Laboratoire 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', CNRS, Aix-Marseille Université, 13288 cedex 09 Marseille, France
| | - Sofija Paneva
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Dominique Debanne
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Michael Russier
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Michael Seagar
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Department of Neurology, Oxford University Hospitals, Oxford, UK
| | - Oussama El Far
- INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015 Marseille, France
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7
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Seery N, Butzkueven H, O'Brien TJ, Monif M. Contemporary advances in antibody-mediated encephalitis: anti-LGI1 and anti-Caspr2 antibody (Ab)-mediated encephalitides. Autoimmun Rev 2022; 21:103074. [PMID: 35247644 DOI: 10.1016/j.autrev.2022.103074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 02/27/2022] [Indexed: 01/17/2023]
Abstract
Encephalitides with antibodies directed against leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (Caspr2) represent two increasingly well characterised forms of autoimmune encephalitis. Both share overlapping and distinct clinical features, are mediated by autoantibodies directed against differing proteins complexed with voltage-gated potassium channels, with unique genetic predisposition identified to date. Herein we summarise disease mechanisms, clinical features, treatment considerations, prognostic factors and clinical outcomes regarding these disorders.
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Affiliation(s)
- Nabil Seery
- Department of Neuroscience, Central Clinical School, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia; Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
| | - Helmut Butzkueven
- Department of Neuroscience, Central Clinical School, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia; Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia; Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
| | - Mastura Monif
- Department of Neuroscience, Central Clinical School, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia; Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia; Department of Neurology, Royal Melbourne Hospital, Melbourne, Victoria, Australia.
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8
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Furia A, Licchetta L, Muccioli L, Ferri L, Mostacci B, Mazzoni S, Menghi V, Minardi R, Tinuper P, Bisulli F. Epilepsy With Auditory Features: From Etiology to Treatment. Front Neurol 2022; 12:807939. [PMID: 35153984 PMCID: PMC8829259 DOI: 10.3389/fneur.2021.807939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/31/2021] [Indexed: 01/22/2023] Open
Abstract
Epilepsy with auditory features (EAF) is a focal epilepsy belonging to the focal epileptic syndromes with onset at variable age according to the new ILAE Classification. It is characterized by seizures with auditory aura or receptive aphasia suggesting a lateral temporal lobe involvement of the epileptic discharge. Etiological factors underlying EAF are largely unknown. In the familial cases with an autosomal dominant pattern of inheritance several genes have been involved, among which the first discovered, LGI1, was thought to be predominant. However, increasing evidence now points to a multifactorial etiology, as familial and sporadic EAF share a virtually identical electro-clinical characterization and only a few have a documented genetic etiology. Patients with EAF usually have an unremarkable neurological examination and a good response to antiseizure medications. However, it must be underscored that total remission might be lower than expected and that treatment withdrawal might lead to relapses. Thus, a proper understanding of this condition is in order for better patient treatment and counseling. Further studies are still required to further characterize the many facets of EAF.
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Affiliation(s)
- Alessandro Furia
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Laura Licchetta
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Lorenzo Muccioli
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Lorenzo Ferri
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Barbara Mostacci
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Stefania Mazzoni
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Veronica Menghi
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Raffaella Minardi
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Paolo Tinuper
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
| | - Francesca Bisulli
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Reference Center for Rare and Complex Epilepsies, Bologna, Italy
- *Correspondence: Francesca Bisulli
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9
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Tocco C, Bertacchi M, Studer M. Structural and Functional Aspects of the Neurodevelopmental Gene NR2F1: From Animal Models to Human Pathology. Front Mol Neurosci 2022; 14:767965. [PMID: 34975398 PMCID: PMC8715095 DOI: 10.3389/fnmol.2021.767965] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 01/28/2023] Open
Abstract
The assembly and maturation of the mammalian brain result from an intricate cascade of highly coordinated developmental events, such as cell proliferation, migration, and differentiation. Any impairment of this delicate multi-factorial process can lead to complex neurodevelopmental diseases, sharing common pathogenic mechanisms and molecular pathways resulting in multiple clinical signs. A recently described monogenic neurodevelopmental syndrome named Bosch-Boonstra-Schaaf Optic Atrophy Syndrome (BBSOAS) is caused by NR2F1 haploinsufficiency. The NR2F1 gene, coding for a transcriptional regulator belonging to the steroid/thyroid hormone receptor superfamily, is known to play key roles in several brain developmental processes, from proliferation and differentiation of neural progenitors to migration and identity acquisition of neocortical neurons. In a clinical context, the disruption of these cellular processes could underlie the pathogenesis of several symptoms affecting BBSOAS patients, such as intellectual disability, visual impairment, epilepsy, and autistic traits. In this review, we will introduce NR2F1 protein structure, molecular functioning, and expression profile in the developing mouse brain. Then, we will focus on Nr2f1 several functions during cortical development, from neocortical area and cell-type specification to maturation of network activity, hippocampal development governing learning behaviors, assembly of the visual system, and finally establishment of cortico-spinal descending tracts regulating motor execution. Whenever possible, we will link experimental findings in animal or cellular models to corresponding features of the human pathology. Finally, we will highlight some of the unresolved questions on the diverse functions played by Nr2f1 during brain development, in order to propose future research directions. All in all, we believe that understanding BBSOAS mechanisms will contribute to further unveiling pathophysiological mechanisms shared by several neurodevelopmental disorders and eventually lead to effective treatments.
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Affiliation(s)
- Chiara Tocco
- Université Côte d'Azur, CNRS, Inserm, iBV, Nice, France
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10
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Baudin P, Cousyn L, Navarro V. The LGI1 protein: molecular structure, physiological functions and disruption-related seizures. Cell Mol Life Sci 2021; 79:16. [PMID: 34967933 PMCID: PMC11072701 DOI: 10.1007/s00018-021-04088-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 01/16/2023]
Abstract
Leucine-rich, glioma inactivated 1 (LGI1) is a secreted glycoprotein, mainly expressed in the brain, and involved in central nervous system development and physiology. Mutations of LGI1 have been linked to autosomal dominant lateral temporal lobe epilepsy (ADLTE). Recently auto-antibodies against LGI1 have been described as the basis for an autoimmune encephalitis, associated with specific motor and limbic epileptic seizures. It is the second most common cause of autoimmune encephalitis. This review presents details on the molecular structure, expression and physiological functions of LGI1, and examines how their disruption underlies human pathologies. Knock-down of LGI1 in rodents reveals that this protein is necessary for normal brain development. In mature brains, LGI1 is associated with Kv1 channels and AMPA receptors, via domain-specific interaction with membrane anchoring proteins and contributes to regulation of the expression and function of these channels. Loss of function, due to mutations or autoantibodies, of this key protein in the control of neuronal activity is a common feature in the genesis of epileptic seizures in ADLTE and anti-LGI1 autoimmune encephalitis.
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Affiliation(s)
- Paul Baudin
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Louis Cousyn
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
- AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Vincent Navarro
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, AP-HP, Pitié-Salpêtrière Hospital, Paris, France.
- AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France.
- AP-HP, Center of Reference for Rare Epilepsies, Pitié-Salpêtrière Hospital, 47-83 Boulevard de l'Hôpital, 75013, Paris, France.
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11
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Fels E, Muñiz-Castrillo S, Vogrig A, Joubert B, Honnorat J, Pascual O. Role of LGI1 protein in synaptic transmission: From physiology to pathology. Neurobiol Dis 2021; 160:105537. [PMID: 34695575 DOI: 10.1016/j.nbd.2021.105537] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/17/2023] Open
Abstract
Leucine-Rich Glioma Inactivated protein 1 (LGI1) is a secreted neuronal protein highly expressed in the central nervous system and high amount are found in the hippocampus. An alteration of its function has been described in few families of patients with autosomal dominant temporal lobe epilepsy (ADLTE) or with autoimmune limbic encephalitis (LE), both characterized by epileptic seizures. Studies have shown that LGI1 plays an essential role during development, but also in neuronal excitability through an action on voltage-gated potassium Kv1.1 channels, and in synaptic transmission by regulating the surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-R). Over the last decade, a growing number of studies investigating LGI1 functions have been published. They aimed to improve the understanding of LGI1 function in the regulation of neuronal networks using different animal and cellular models. LGI1 appears to be a major actor of synaptic regulation by modulating trans-synaptically pre- and post-synaptic proteins. In this review, we will focus on LGI1 binding partners, "A Disintegrin And Metalloprotease (ADAM) 22 and 23", the complex they form at the synapse, and will discuss the effects of LGI1 on neuronal excitability and synaptic transmission in physiological and pathological conditions. Finally, we will highlight new insights regarding N-terminal Leucine-Rich Repeat (LRR) domain and C-terminal Epitempin repeat (EPTP) domain and their potentially distinct role in LGI1 function.
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Affiliation(s)
- Elodie Fels
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France
| | - Sergio Muñiz-Castrillo
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Alberto Vogrig
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Bastien Joubert
- Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France
| | - Jérôme Honnorat
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France; French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677 Bron Cedex, France.
| | - Olivier Pascual
- Synaptopathies and Auto-antibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Universités de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Université Claude Bernard Lyon 1, Universités de Lyon, Lyon, France.
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12
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LGI1 governs neuritin-mediated resilience to chronic stress. Neurobiol Stress 2021; 15:100373. [PMID: 34401409 PMCID: PMC8350063 DOI: 10.1016/j.ynstr.2021.100373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/23/2022] Open
Abstract
Depression is accompanied by neuronal atrophy and decreased neuroplasticity. Leucine-rich glioma-inactivated protein 1 (LGI1), a metastasis suppressor, plays an important role in the development of CNS synapses. We found that LGI1 expression was reduced in the hippocampi of mice that underwent chronic unpredictable stress (CUS), and could be rescued by the antidepressant, fluoxetine. Recombinant soluble neuritin, an endogenous protein previously implicated in antidepressant-like behaviors, elevated hippocampal LGI1 expression in a manner dependent on histone deacetylase 5 (HDAC5) phosphorylation. Accordingly, Nrn1 flox/flox ;Pomc-cre (Nrn1 cOE) mice, which conditionally overexpress neuritin, displayed increases in hippocampal LGI1 level under CUS and exhibited resilience to CUS that were blocked by hippocampal depletion of LGI1. Interestingly, neuritin-mediated LGI1 expression was inhibited by HNMPA-(AM)3, an insulin receptor inhibitor, as was neuritin-mediated HDAC5 phosphorylation. We thus establish hippocampal LGI1 as an effector of neurite outgrowth and stress resilience, and suggest that HDAC5-LGI1 plays a critical role in ameliorating pathological depression.
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13
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Fukata Y, Hirano Y, Miyazaki Y, Yokoi N, Fukata M. Trans-synaptic LGI1–ADAM22–MAGUK in AMPA and NMDA receptor regulation. Neuropharmacology 2021; 194:108628. [DOI: 10.1016/j.neuropharm.2021.108628] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 02/06/2023]
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14
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Matthews PM, Pinggera A, Kampjut D, Greger IH. Biology of AMPA receptor interacting proteins - From biogenesis to synaptic plasticity. Neuropharmacology 2021; 197:108709. [PMID: 34271020 DOI: 10.1016/j.neuropharm.2021.108709] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/19/2021] [Accepted: 07/08/2021] [Indexed: 12/19/2022]
Abstract
AMPA-type glutamate receptors mediate the majority of excitatory synaptic transmission in the central nervous system. Their signaling properties and abundance at synapses are both crucial determinants of synapse efficacy and plasticity, and are therefore under sophisticated control. Unique to this ionotropic glutamate receptor (iGluR) is the abundance of interacting proteins that contribute to its complex regulation. These include transient interactions with the receptor cytoplasmic tail as well as the N-terminal domain locating to the synaptic cleft, both of which are involved in AMPAR trafficking and receptor stabilization at the synapse. Moreover, an array of transmembrane proteins operate as auxiliary subunits that in addition to receptor trafficking and stabilization also substantially impact AMPAR gating and pharmacology. Here, we provide an overview of the catalogue of AMPAR interacting proteins, and how they contribute to the complex biology of this central glutamate receptor.
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Affiliation(s)
- Peter M Matthews
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Alexandra Pinggera
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Domen Kampjut
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.
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15
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Kirch C, Gollo LL. Spatially resolved dendritic integration: towards a functional classification of neurons. PeerJ 2020; 8:e10250. [PMID: 33282551 PMCID: PMC7694565 DOI: 10.7717/peerj.10250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 10/06/2020] [Indexed: 01/19/2023] Open
Abstract
The vast tree-like dendritic structure of neurons allows them to receive and integrate input from many neurons. A wide variety of neuronal morphologies exist, however, their role in dendritic integration, and how it shapes the response of the neuron, is not yet fully understood. Here, we study the evolution and interactions of dendritic spikes in excitable neurons with complex real branch structures. We focus on dozens of digitally reconstructed illustrative neurons from the online repository NeuroMorpho.org, which contains over 130,000 neurons. Yet, our methods can be promptly extended to any other neuron. This approach allows us to estimate and map specific and heterogeneous patterns of activity observed across extensive dendritic trees with thousands of compartments. We propose a classification of neurons based on the location of the soma (centrality) and the number of branches connected to the soma. These are key topological factors in determining the neuron's energy consumption, firing rate, and the dynamic range, which quantifies the range in synaptic input rate that can be reliably encoded by the neuron's firing rate. Moreover, we find that bifurcations, the structural building blocks of complex dendrites, play a major role in increasing the dynamic range of neurons. Our results provide a better understanding of the effects of neuronal morphology in the diversity of neuronal dynamics and function.
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Affiliation(s)
- Christoph Kirch
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- Queensland University of Technology, Brisbane, QLD, Australia
| | - Leonardo L. Gollo
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- Queensland University of Technology, Brisbane, QLD, Australia
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, VIC, Australia
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16
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Lugarà E, Kaushik R, Leite M, Chabrol E, Dityatev A, Lignani G, Walker MC. LGI1 downregulation increases neuronal circuit excitability. Epilepsia 2020; 61:2836-2846. [DOI: 10.1111/epi.16736] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/29/2020] [Accepted: 09/29/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Eleonora Lugarà
- Department of Clinical and Experimental Epilepsy UCL Queen Square Institute of Neurology London UK
| | - Rahul Kaushik
- German Center for Neurodegenerative Diseases Magdeburg Germany
- Center for Behavioral Brain Sciences Magdeburg Germany
| | - Marco Leite
- Department of Clinical and Experimental Epilepsy UCL Queen Square Institute of Neurology London UK
| | - Elodie Chabrol
- Department of Clinical and Experimental Epilepsy UCL Queen Square Institute of Neurology London UK
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases Magdeburg Germany
- Center for Behavioral Brain Sciences Magdeburg Germany
- Medical Faculty Otto von Guericke University Magdeburg Germany
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy UCL Queen Square Institute of Neurology London UK
| | - Matthew C. Walker
- Department of Clinical and Experimental Epilepsy UCL Queen Square Institute of Neurology London UK
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17
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Del Pino I, Tocco C, Magrinelli E, Marcantoni A, Ferraguto C, Tomagra G, Bertacchi M, Alfano C, Leinekugel X, Frick A, Studer M. COUP-TFI/Nr2f1 Orchestrates Intrinsic Neuronal Activity during Development of the Somatosensory Cortex. Cereb Cortex 2020; 30:5667-5685. [DOI: 10.1093/cercor/bhaa137] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/17/2020] [Accepted: 04/29/2020] [Indexed: 01/19/2023] Open
Abstract
Abstract
The formation of functional cortical maps in the cerebral cortex results from a timely regulated interaction between intrinsic genetic mechanisms and electrical activity. To understand how transcriptional regulation influences network activity and neuronal excitability within the neocortex, we used mice deficient for Nr2f1 (also known as COUP-TFI), a key determinant of primary somatosensory (S1) area specification during development. We found that the cortical loss of Nr2f1 impacts on spontaneous network activity and synchronization of S1 cortex at perinatal stages. In addition, we observed alterations in the intrinsic excitability and morphological features of layer V pyramidal neurons. Accordingly, we identified distinct voltage-gated ion channels regulated by Nr2f1 that might directly influence intrinsic bioelectrical properties during critical time windows of S1 cortex specification. Altogether, our data suggest a tight link between Nr2f1 and neuronal excitability in the developmental sequence that ultimately sculpts the emergence of cortical network activity within the immature neocortex.
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Affiliation(s)
- Isabel Del Pino
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
- Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
| | - Chiara Tocco
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
| | - Elia Magrinelli
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
- Département des Neurosciences Fondamentales, Université de Lausanne, CH-1005 Lausanne, Switzerland
| | - Andrea Marcantoni
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | - Giulia Tomagra
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | | | - Xavier Leinekugel
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Andreas Frick
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Michèle Studer
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
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18
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Kornau HC, Kreye J, Stumpf A, Fukata Y, Parthier D, Sammons RP, Imbrosci B, Kurpjuweit S, Kowski AB, Fukata M, Prüss H, Schmitz D. Human Cerebrospinal Fluid Monoclonal LGI1 Autoantibodies Increase Neuronal Excitability. Ann Neurol 2020; 87:405-418. [PMID: 31900946 DOI: 10.1002/ana.25666] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 12/30/2019] [Accepted: 12/30/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Leucine-rich glioma-inactivated 1 (LGI1) encephalitis is the second most common antibody-mediated encephalopathy, but insight into the intrathecal B-cell autoimmune response, including clonal relationships, isotype distribution, frequency, and pathogenic effects of single LGI1 antibodies, has remained limited. METHODS We cloned, expressed, and tested antibodies from 90 antibody-secreting cells (ASCs) and B cells from the cerebrospinal fluid (CSF) of several patients with LGI1 encephalitis. RESULTS Eighty-four percent of the ASCs and 21% of the memory B cells encoded LGI1-reactive antibodies, whereas reactivities to other brain epitopes were rare. All LGI1 antibodies were of IgG1, IgG2, or IgG4 isotype and had undergone affinity maturation. Seven of the overall 26 LGI1 antibodies efficiently blocked the interaction of LGI1 with its receptor ADAM22 in vitro, and their mean LGI1 signal on mouse brain sections was weak compared to the remaining, non-ADAM22-competing antibodies. Nevertheless, both types of LGI1 antibodies increased the intrinsic cellular excitability and glutamatergic synaptic transmission of hippocampal CA3 neurons in slice cultures. INTERPRETATION Our data show that the patients' intrathecal B-cell autoimmune response is dominated by LGI1 antibodies and that LGI1 antibodies alone are sufficient to promote neuronal excitability, a basis of seizure generation. Fundamental differences in target specificity and antibody hypermutations compared to the CSF autoantibody repertoire in N-methyl-D-aspartate receptor encephalitis underline the clinical concept that autoimmune encephalitides are very distinct entities. Ann Neurol 2020;87:405-418.
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Affiliation(s)
- Hans-Christian Kornau
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jakob Kreye
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Alexander Stumpf
- Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Graduate University for Advanced Studies, Okazaki, Japan
| | - Daniel Parthier
- Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Rosanna P Sammons
- Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Barbara Imbrosci
- Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sarah Kurpjuweit
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Alexander B Kowski
- Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Graduate University for Advanced Studies, Okazaki, Japan
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Dietmar Schmitz
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.,Neuroscience Research Center, Cluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Einstein Center for Neurosciences, Berlin, Germany
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19
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Du J, Vegh V, Reutens DC. Persistent sodium current blockers can suppress seizures caused by loss of low-threshold D-type potassium currents: Predictions from an in silico study of K v1 channel disorders. Epilepsia Open 2020; 5:86-96. [PMID: 32140647 PMCID: PMC7049813 DOI: 10.1002/epi4.12379] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/04/2019] [Accepted: 12/24/2019] [Indexed: 11/17/2022] Open
Abstract
Objective Ion channels belonging to subfamily A of voltage‐gated potassium channels (Kv1) are highly expressed on axons, where they play a key role in determining resting membrane potential, in shaping action potentials, and in modulating action potential frequency during repetitive neuronal firing. We aimed to study the genesis of seizures caused by mutations affecting Kv1 channels and searched for potential therapeutic targets. Methods We used a novel in silico model, the laminar cortex model (LCM), to examine changes in neuronal excitability and network dynamics associated with loss‐of‐function mutations in Kv1 channels. The LCM simulates the activities of a network of tens of thousands of interconnected neurons and incorporates the kinetics of 11 types of ion channel and three classes of neurotransmitter receptor. Changes in two types of potassium currents conducted by Kv1 channels were examined: slowly inactivating D‐type currents and rapidly inactivating A‐type currents. Effects on neuronal firing rate, action potential shape, and neuronal oscillation state were evaluated. A systematic parameter scan was performed to identify parameter changes that can reverse the effects of the changes. Results Reduced axonal D‐type currents led to lower firing threshold and widened action potentials, both lowering the seizure threshold. Two potential therapeutic targets for treating seizures caused by loss‐of‐function changes in Kv1 channels were identified: persistent sodium channels and NMDA receptors. Blocking persistent sodium channels restored the firing threshold and reduced action potential width. NMDA receptor antagonists reduced excitatory postsynaptic currents from excessive glutamate release related to widened action potentials. Significance Riluzole reduces persistent sodium currents and excitatory postsynaptic currents from NMDA receptor activation. Our results suggest that this FDA‐approved drug can be repurposed to treat epilepsies caused by mutations affecting axonal Kv1 channels.
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Affiliation(s)
- Jiaxin Du
- Centre for Advanced Imaging The University of Queensland St Lucia Qld Australia
| | - Viktor Vegh
- Centre for Advanced Imaging The University of Queensland St Lucia Qld Australia
| | - David C Reutens
- Centre for Advanced Imaging The University of Queensland St Lucia Qld Australia
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20
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Farhoodi R, Lansdell BJ, Kording KP. Quantifying How Staining Methods Bias Measurements of Neuron Morphologies. Front Neuroinform 2019; 13:36. [PMID: 31191283 PMCID: PMC6541099 DOI: 10.3389/fninf.2019.00036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 04/25/2019] [Indexed: 12/20/2022] Open
Abstract
The process through which neurons are labeled is a key methodological choice in measuring neuron morphology. However, little is known about how this choice may bias measurements. To quantify this bias we compare the extracted morphology of neurons collected from the same rodent species, experimental condition, gender distribution, age distribution, brain region and putative cell type, but obtained with 19 distinct staining methods. We found strong biases on measured features of morphology. These were largest in features related to the coverage of the dendritic tree (e.g., the total dendritic tree length). Understanding measurement biases is crucial for interpreting morphological data.
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Affiliation(s)
- Roozbeh Farhoodi
- Department of Mathematics, Sharif University of Technology, Tehran, Iran
| | | | - Konrad Paul Kording
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States.,Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, United States
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21
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Antagonizing Increased miR-135a Levels at the Chronic Stage of Experimental TLE Reduces Spontaneous Recurrent Seizures. J Neurosci 2019; 39:5064-5079. [PMID: 31015341 DOI: 10.1523/jneurosci.3014-18.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/31/2019] [Accepted: 04/16/2019] [Indexed: 01/01/2023] Open
Abstract
Mesial temporal lobe epilepsy (mTLE) is a chronic neurological disease characterized by recurrent seizures. The antiepileptic drugs currently available to treat mTLE are ineffective in one-third of patients and lack disease-modifying effects. miRNAs, a class of small noncoding RNAs which control gene expression at the post-transcriptional level, play a key role in the pathogenesis of mTLE and other epilepsies. Although manipulation of miRNAs at acute stages has been reported to reduce subsequent spontaneous seizures, it is uncertain whether targeting miRNAs at chronic stages of mTLE can also reduce seizures. Furthermore, the functional role and downstream targets of most epilepsy-associated miRNAs remain poorly understood. Here, we show that miR-135a is selectively upregulated within neurons in epileptic brain and report that targeting miR-135a in vivo using antagomirs after onset of spontaneous recurrent seizures can reduce seizure activity at the chronic stage of experimental mTLE in male mice. Further, by using an unbiased approach combining immunoprecipitation and RNA sequencing, we identify several novel neuronal targets of miR-135a, including Mef2a Mef2 proteins are key regulators of excitatory synapse density. Mef2a and miR-135a show reciprocal expression regulation in human (of both sexes) and experimental TLE, and miR-135a regulates dendritic spine number and type through Mef2. Together, our data show that miR-135a is target for reducing seizure activity in chronic epilepsy, and that deregulation of miR-135a in epilepsy may alter Mef2a expression and thereby affect synaptic function and plasticity.SIGNIFICANCE STATEMENT miRNAs are post-transcriptional regulators of gene expression with roles in the pathogenesis of epilepsy. However, the precise mechanism of action and therapeutic potential of most epilepsy-associated miRNAs remain poorly understood. Our study reveals dramatic upregulation of the key neuronal miRNA miR-135a in both experimental and human mesial temporal lobe epilepsy. Silencing miR-135a in experimental temporal lobe epilepsy reduces seizure activity at the spontaneous recurrent seizure stage. These data support the exciting possibility that miRNAs can be targeted to combat seizures after spontaneous seizure activity has been established. Further, by using unbiased approaches novel neuronal targets of miR-135a, including members of the Mef2 protein family, are identified that begin to explain how deregulation of miR-135a may contribute to epilepsy.
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22
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Lancaster E, Burnor E, Zhang J, Lancaster E. ADAM23 is a negative regulator of K v1.1/K v1.4 potassium currents. Neurosci Lett 2019; 704:159-163. [PMID: 30965109 DOI: 10.1016/j.neulet.2019.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/12/2019] [Accepted: 04/05/2019] [Indexed: 01/15/2023]
Abstract
Background ADAM22 and ADAM23 are transmembrane proteins that bind the secreted synaptic protein LGI1 and associate with Kv1.1/Kv1.4 potassium channels. However, the roles of these proteins in regulated voltage-gated potassium currents are poorly understood. Methods Cultured cells were transfected to express ADAM22, ADAM23, and Kv1.1/Kv1.4. Voltage-gated potassium currents were measured by whole-cell patch-clamp. Immunostaining Kv1.1 with fluorescent antibodies and fluorescently tagged Kv1.1 subunits was used to measure the effects of ADAM proteins on cell-surface and total expression of Kv1.1 channels. LGI1-conditioned media was added to assess the effect on LGI1 on Kv1.1 currents. Results Cells transfected with Kv1.1/Kv1.4 showed voltage-gated potassium currents (Kv1.1 currents). ADAM23 was a powerful negative regulator of Kv1.1 currents and caused decreased surface expression of Kv1.1 subunits. This decrease in current was not mediated by clathrin-dependent endocytosis. LGI1-conditioned media did not affect the negative regulation of Kv1.1 currents by ADAM23. ADAM22 had no significant effect on Kv1.1 currents by itself, but in the presence of LGI1-conditioned media markedly potentiated Kv1.1 currents without changing channel activation kinetics. Conclusions ADAM22 and ADAM23 have opposite effects on Kv1.1 currents. The relative expression of these proteins, and the availability of LGI1 may shape the expression of Kv1.1 currents in different neuronal membrane domains.
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Affiliation(s)
- Eunjoo Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Elisabeth Burnor
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Junxian Zhang
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Eric Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
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23
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Down-Regulation of Astrocytic Kir4.1 Channels during the Audiogenic Epileptogenesis in Leucine-Rich Glioma-Inactivated 1 ( Lgi1) Mutant Rats. Int J Mol Sci 2019; 20:ijms20051013. [PMID: 30813600 PMCID: PMC6429235 DOI: 10.3390/ijms20051013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 02/07/2023] Open
Abstract
The dysfunction of astrocytic inwardly rectifying potassium (Kir) 4.1 channels, which mediate the spatial potassium-buffering function of astrocytes, is known to be involved in the development of epilepsy. Here, we analyzed the Kir4.1 expressional changes in Leucine-Rich Glioma-Inactivated 1 (Lgi1) mutant rats, which is a model of autosomal dominant lateral temporal lobe epilepsy in humans, to clarify the role of astrocytic Kir4.1 channels in Lgi1-related epileptogenesis. Priming acoustic stimulation (at postnatal day 16) conferred seizure susceptibility on Lgi1 mutant rats, which evoked audiogenic seizures with test stimulation at eight weeks. In the seizure-susceptible Lgi1 mutant rats (before test stimulation), astrocytic Kir4.1 expression was down-regulated region-specifically in the cerebral cortex, hippocampus, and amygdala. In addition, prophylactic treatments of Lgi1 mutant rats with valproic acid (VPA, 30 mg/kg and 200 mg/kg) for two weeks prevented both the development of seizure susceptibility and the down-regulation of Kir4.1 expression in astrocytes. The present study demonstrated for the first time that the astrocytic Kir4.1 expression was reduced in the Lgi1-related seizure model, suggesting that the down-regulation of Kir4.1 channels in astrocytes is involved in audiogenic epileptogenesis caused by Lgi1 mutation. In addition, VPA seemed to have a prophylactic effect on Lgi1-related seizures.
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24
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Geis C, Planagumà J, Carreño M, Graus F, Dalmau J. Autoimmune seizures and epilepsy. J Clin Invest 2019; 129:926-940. [PMID: 30714986 DOI: 10.1172/jci125178] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The rapid expansion in the number of encephalitis disorders associated with autoantibodies against neuronal proteins has led to an incremental increase in use of the term "autoimmune epilepsy," yet has occurred with limited attention to the physiopathology of each disease and genuine propensity to develop epilepsy. Indeed, most autoimmune encephalitides present with seizures, but the probability of evolving to epilepsy is relatively small. The risk of epilepsy is higher for disorders in which the antigens are intracellular (often T cell-mediated) compared with disorders in which the antigens are on the cell surface (antibody-mediated). Most autoantibodies against neuronal surface antigens show robust effects on the target proteins, resulting in hyperexcitability and impairment of synaptic function and plasticity. Here, we trace the evolution of the concept of autoimmune epilepsy and examine common inflammatory pathways that might lead to epilepsy. Then, we focus on several antibody-mediated encephalitis disorders that associate with seizures and review the synaptic alterations caused by patients' antibodies, with emphasis on those that have been modeled in animals (e.g., antibodies against NMDA, AMPA receptors, LGI1 protein) or in cultured neurons (e.g., antibodies against the GABAb receptor).
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Affiliation(s)
- Christian Geis
- Department of Neurology, Jena University Hospital, Jena, Germany
| | - Jesus Planagumà
- Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and
| | - Mar Carreño
- Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Francesc Graus
- Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and.,Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Josep Dalmau
- Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and.,Hospital Clinic, University of Barcelona, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.,Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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25
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Silva J, Qin H, Cowell JK. Selective inactivation of LGI1 in neuronal precursor cells leads to cortical dysplasia in mice. Genesis 2018; 57:e23268. [DOI: 10.1002/dvg.23268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/30/2018] [Accepted: 11/26/2018] [Indexed: 01/23/2023]
Affiliation(s)
- Jeane Silva
- Department of Pathology, Georgia Cancer Center; Augusta University; Augusta Georgia
| | - Haiyan Qin
- Department of Pathology, Georgia Cancer Center; Augusta University; Augusta Georgia
| | - John K Cowell
- Department of Pathology, Georgia Cancer Center; Augusta University; Augusta Georgia
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26
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Petit-Pedrol M, Sell J, Planagumà J, Mannara F, Radosevic M, Haselmann H, Ceanga M, Sabater L, Spatola M, Soto D, Gasull X, Dalmau J, Geis C. LGI1 antibodies alter Kv1.1 and AMPA receptors changing synaptic excitability, plasticity and memory. Brain 2018; 141:3144-3159. [PMID: 30346486 PMCID: PMC6202570 DOI: 10.1093/brain/awy253] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/23/2018] [Accepted: 08/28/2018] [Indexed: 12/23/2022] Open
Abstract
Leucine-rich glioma-inactivated 1 (LGI1) is a secreted neuronal protein that forms a trans-synaptic complex that includes the presynaptic disintegrin and metalloproteinase domain-containing protein 23 (ADAM23), which interacts with voltage-gated potassium channels Kv1.1, and the postsynaptic ADAM22, which interacts with AMPA receptors. Human autoantibodies against LGI1 associate with a form of autoimmune limbic encephalitis characterized by severe but treatable memory impairment and frequent faciobrachial dystonic seizures. Although there is evidence that this disease is immune-mediated, the underlying LGI1 antibody-mediated mechanisms are unknown. Here, we used patient-derived immunoglobulin G (IgG) antibodies to determine the main epitope regions of LGI1 and whether the antibodies disrupt the interaction of LGI1 with ADAM23 and ADAM22. In addition, we assessed the effects of patient-derived antibodies on Kv1.1, AMPA receptors, and memory in a mouse model based on cerebroventricular transfer of patient-derived IgG. We found that IgG from all patients (n = 25), but not from healthy participants (n = 20), prevented the binding of LGI1 to ADAM23 and ADAM22. Using full-length LGI1, LGI3, and LGI1 constructs containing the LRR1 domain (EPTP1-deleted) or EPTP1 domain (LRR3-EPTP1), IgG from all patients reacted with epitope regions contained in the LRR1 and EPTP1 domains. Confocal analysis of hippocampal slices of mice infused with pooled IgG from eight patients, but not pooled IgG from controls, showed a decrease of total and synaptic levels of Kv1.1 and AMPA receptors. The effects on Kv1.1 preceded those involving the AMPA receptors. In acute slice preparations of hippocampus, patch-clamp analysis from dentate gyrus granule cells and CA1 pyramidal neurons showed neuronal hyperexcitability with increased glutamatergic transmission, higher presynaptic release probability, and reduced synaptic failure rate upon minimal stimulation, all likely caused by the decreased expression of Kv1.1. Analysis of synaptic plasticity by recording field potentials in the CA1 region of the hippocampus showed a severe impairment of long-term potentiation. This defect in synaptic plasticity was independent from Kv1 blockade and was possibly mediated by ineffective recruitment of postsynaptic AMPA receptors. In parallel with these findings, mice infused with patient-derived IgG showed severe memory deficits in the novel object recognition test that progressively improved after stopping the infusion of patient-derived IgG. Different from genetic models of LGI1 deficiency, we did not observe aberrant dendritic sprouting or defective synaptic pruning as potential cause of the symptoms. Overall, these findings demonstrate that patient-derived IgG disrupt presynaptic and postsynaptic LGI1 signalling, causing neuronal hyperexcitability, decreased plasticity, and reversible memory deficits.
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Affiliation(s)
- Mar Petit-Pedrol
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Josefine Sell
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Jesús Planagumà
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Francesco Mannara
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Marija Radosevic
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Holger Haselmann
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Mihai Ceanga
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Lidia Sabater
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Marianna Spatola
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- University of Lausanne (UNIL), Lausanne, Switzerland
| | - David Soto
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Xavier Gasull
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Josep Dalmau
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
- Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER), Valencia, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Christian Geis
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
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The Nogo Receptor Ligand LGI1 Regulates Synapse Number and Synaptic Activity in Hippocampal and Cortical Neurons. eNeuro 2018; 5:eN-NWR-0185-18. [PMID: 30225353 PMCID: PMC6140115 DOI: 10.1523/eneuro.0185-18.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/31/2018] [Accepted: 08/14/2018] [Indexed: 12/20/2022] Open
Abstract
Leucine-rich glioma-inactivated protein 1 (LGI1) is a secreted neuronal protein and a Nogo receptor 1 (NgR1) ligand. Mutations in LGI1 in humans causes autosomal dominant lateral temporal lobe epilepsy and homozygous deletion of LGI1 in mice results in severe epileptic seizures that cause early postnatal death. NgR1 plays an important role in the development of CNS synapses and circuitry by limiting plasticity in the adult cortex via the activation of RhoA. These relationships and functions prompted us to examine the effect of LGI1 on synapse formation in vitro and in vivo. We report that application of LGI1 increases synaptic density in neuronal culture and that LGI1 null hippocampus has fewer dendritic mushroom spines than in wild-type (WT) littermates. Further, our electrophysiological investigations demonstrate that LGI1 null hippocampal neurons possess fewer and weaker synapses. RhoA activity is significantly increased in cortical cultures derived from LGI1 null mice and using a reconstituted system; we show directly that LGI1 antagonizes NgR1-tumor necrosis factor receptor orphan Y (TROY) signaling. Our data suggests that LGI1 enhances synapse formation in cortical and hippocampal neurons by reducing NgR1 signaling.
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28
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Hivert B, Marien L, Agbam KN, Faivre-Sarrailh C. ADAM22 and ADAM23 modulate the targeting of the Kv1 channel-associated protein LGI1 to the axon initial segment. J Cell Sci 2018; 132:jcs.219774. [DOI: 10.1242/jcs.219774] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 12/19/2018] [Indexed: 01/30/2023] Open
Abstract
The distribution of voltage-gated potassium channels Kv1 at the axon initial segment (AIS) influences neuronal intrinsic excitability. Kv1.1/1.2 subunits are associated with cell adhesion molecules (CAMs), including Caspr2 and LGI1 that are implicated in autoimmune and genetic neurological diseases with seizures. In particular, mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy (ADLTE). Here, using rat hippocampal neurons in culture, we showed that LGI1 is recruited at the AIS and colocalized with ADAM22 and Kv1 channels. Strikingly, the missense mutations S473L and R474Q of LGI1 identified in ADLTE prevent its association with ADAM22 and enrichment at the AIS. Moreover, we observed that ADAM22 or ADAM23 modulates the trafficking of LGI1, and promotes its ER export and expression at the overall neuronal cell surface. Live-cell imaging indicated that LGI1 is co-transported in axonal vesicles with ADAM22 or ADAM23. Finally, we showed that ADAM22 and ADAM23 also associate with Caspr2 and TAG-1 to be selectively targeted within different axonal sub-regions. So, the combinatorial expression of Kv1-associated CAMs may be critical to tune intrinsic excitability in physiological or epileptogenic context.
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Affiliation(s)
- Bruno Hivert
- Aix Marseille Université, INSERM UMR1249, F-13273 Marseille, France
- Present address: Aix Marseille Université, CNRS UMR7289, Institut de Neurosciences de la Timone, F-13385 Marseille, France
| | - Laurène Marien
- Aix Marseille Université, INSERM UMR1249, F-13273 Marseille, France
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LGI1 tunes intrinsic excitability by regulating the density of axonal Kv1 channels. Proc Natl Acad Sci U S A 2017; 114:7719-7724. [PMID: 28673977 DOI: 10.1073/pnas.1618656114] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Autosomal dominant epilepsy with auditory features results from mutations in leucine-rich glioma-inactivated 1 (LGI1), a soluble glycoprotein secreted by neurons. Animal models of LGI1 depletion display spontaneous seizures, however, the function of LGI1 and the mechanisms by which deficiency leads to epilepsy are unknown. We investigated the effects of pure recombinant LGI1 and genetic depletion on intrinsic excitability, in the absence of synaptic input, in hippocampal CA3 neurons, a classical focus for epileptogenesis. Our data indicate that LGI1 is expressed at the axonal initial segment and regulates action potential firing by setting the density of the axonal Kv1.1 channels that underlie dendrotoxin-sensitive D-type potassium current. LGI1 deficiency incurs a >50% down-regulation of the expression of Kv1.1 and Kv1.2 via a posttranscriptional mechanism, resulting in a reduction in the capacity of axonal D-type current to limit glutamate release, thus contributing to epileptogenesis.
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Fukata Y, Yokoi N, Miyazaki Y, Fukata M. The LGI1–ADAM22 protein complex in synaptic transmission and synaptic disorders. Neurosci Res 2017; 116:39-45. [DOI: 10.1016/j.neures.2016.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/18/2016] [Accepted: 09/22/2016] [Indexed: 12/21/2022]
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Lascano AM, Korff CM, Picard F. Seizures and Epilepsies due to Channelopathies and Neurotransmitter Receptor Dysfunction: A Parallel between Genetic and Immune Aspects. Mol Syndromol 2016; 7:197-209. [PMID: 27781030 DOI: 10.1159/000447707] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Despite intensive research activity leading to many important discoveries, the pathophysiological mechanisms underlying seizures and epilepsy remain poorly understood. An important number of specific gene defects have been related to various forms of epilepsies, and autoimmunity and epilepsy have been associated for a long time. Certain central nervous system proteins have been involved in epilepsy or acute neurological diseases with seizures either due to underlying gene defects or immune dysfunction. Here, we focus on 2 of them that have been the object of particular attention and in-depth research over the past years: the N-methyl-D-aspartate receptor and the leucin-rich glioma-inactivated protein 1 (LGI1). We also describe illustrative examples of situations in which genetics and immunology meet in the complex pathways that underlie seizures and epilepsy.
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Affiliation(s)
- Agustina M Lascano
- EEG and Epilepsy Exploration Unit, University Hospitals Geneva, Geneva, Switzerland
| | - Christian M Korff
- Pediatric Neurology Unit, Child and Adolescent Department, University Hospitals Geneva, Geneva, Switzerland
| | - Fabienne Picard
- EEG and Epilepsy Exploration Unit, University Hospitals Geneva, Geneva, Switzerland
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