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Chemical corrector treatment ameliorates increased seizure susceptibility in a mouse model of familial epilepsy

Abstract

Epilepsy is one of the most common and intractable brain disorders. Mutations in the human gene LGI1, encoding a neuronal secreted protein, cause autosomal dominant lateral temporal lobe epilepsy (ADLTE). However, the pathogenic mechanisms of LGI1 mutations remain unclear. We classified 22 reported LGI1 missense mutations as either secretion defective or secretion competent, and we generated and analyzed two mouse models of ADLTE encoding mutant proteins representative of the two groups. The secretion-defective LGI1E383A protein was recognized by the ER quality-control machinery and prematurely degraded, whereas the secretable LGI1S473L protein abnormally dimerized and was selectively defective in binding to one of its receptors, ADAM22. Both mutations caused a loss of function, compromising intracellular trafficking or ligand activity of LGI1 and converging on reduced synaptic LGI1-ADAM22 interaction. A chemical corrector, 4-phenylbutyrate (4PBA), restored LGI1E383A folding and binding to ADAM22 and ameliorated the increased seizure susceptibility of the LGI1E383A model mice. This study establishes LGI1-related epilepsy as a conformational disease and suggests new therapeutic options for human epilepsy.

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Figure 1: Classification of human epilepsy-related LGI1 missense mutations and generation of two ADLTE mouse models.
Figure 2: LGI1E383A protein is unstable and mislocalized in the brain.
Figure 3: Different properties of two types of LGI1 mutations: defective intracellular trafficking and ligand activity.
Figure 4: Interdependent synaptic localization of LGI1 and ADAM22.
Figure 5: The chemical correctors 4PBA and SAHA improve the secretion of LGI1 mutant proteins.
Figure 6: 4PBA ameliorates the seizure phenotype of the ADLTE mouse model.

References

  1. Gu, W., Brodtkorb, E. & Steinlein, O.K. LGI1 is mutated in familial temporal lobe epilepsy characterized by aphasic seizures. Ann. Neurol. 52, 364–367 (2002).

    CAS  PubMed  Article  Google Scholar 

  2. Kalachikov, S. et al. Mutations in LGI1 cause autosomal-dominant partial epilepsy with auditory features. Nat. Genet. 30, 335–341 (2002).

    PubMed  PubMed Central  Article  Google Scholar 

  3. Morante-Redolat, J.M. et al. Mutations in the LGI1/Epitempin gene on 10q24 cause autosomal dominant lateral temporal epilepsy. Hum. Mol. Genet. 11, 1119–1128 (2002).

    CAS  PubMed  Article  Google Scholar 

  4. Irani, S.R. et al. Antibodies to Kv1 potassium channel-complex proteins leucine-rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan's syndrome and acquired neuromyotonia. Brain 133, 2734–2748 (2010).

    PubMed  PubMed Central  Article  Google Scholar 

  5. Lai, M. et al. Investigation of LGI1 as the antigen in limbic encephalitis previously attributed to potassium channels: a case series. Lancet Neurol. 9, 776–785 (2010).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  6. Ohkawa, T. et al. Autoantibodies to epilepsy-related LGI1 in limbic encephalitis neutralize LGI1-ADAM22 interaction and reduce synaptic AMPA receptors. J. Neurosci. 33, 18161–18174 (2013).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  7. Chabrol, E. et al. Electroclinical characterization of epileptic seizures in leucine-rich, glioma-inactivated 1-deficient mice. Brain 133, 2749–2762 (2010).

    PubMed  PubMed Central  Article  Google Scholar 

  8. Fukata, Y. et al. Disruption of LGI1-linked synaptic complex causes abnormal synaptic transmission and epilepsy. Proc. Natl. Acad. Sci. USA 107, 3799–3804 (2010).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  9. Yu, Y.E. et al. Lgi1 null mutant mice exhibit myoclonic seizures and CA1 neuronal hyperexcitability. Hum. Mol. Genet. 19, 1702–1711 (2010).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  10. Schulte, U. et al. The epilepsy-linked Lgi1 protein assembles into presynaptic Kv1 channels and inhibits inactivation by Kvbeta1. Neuron 49, 697–706 (2006).

    CAS  PubMed  Article  Google Scholar 

  11. Fukata, Y. et al. Epilepsy-related ligand/receptor complex LGI1 and ADAM22 regulate synaptic transmission. Science 313, 1792–1795 (2006).

    CAS  PubMed  Article  Google Scholar 

  12. Sagane, K. et al. Ataxia and peripheral nerve hypomyelination in ADAM22-deficient mice. BMC Neurosci. 6, 33 (2005).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  13. Owuor, K. et al. LGI1-associated epilepsy through altered ADAM23-dependent neuronal morphology. Mol. Cell. Neurosci. 42, 448–457 (2009).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  14. Zhou, Y.D. et al. Arrested maturation of excitatory synapses in autosomal dominant lateral temporal lobe epilepsy. Nat. Med. 15, 1208–1214 (2009).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  15. Nobile, C. et al. LGI1 mutations in autosomal dominant and sporadic lateral temporal epilepsy. Hum. Mutat. 30, 530–536 (2009).

    CAS  PubMed  Article  Google Scholar 

  16. Senechal, K.R., Thaller, C. & Noebels, J.L. ADPEAF mutations reduce levels of secreted LGI1, a putative tumor suppressor protein linked to epilepsy. Hum. Mol. Genet. 14, 1613–1620 (2005).

    CAS  PubMed  Article  Google Scholar 

  17. Striano, P. et al. Familial temporal lobe epilepsy with psychic auras associated with a novel LGI1 mutation. Neurology 76, 1173–1176 (2011).

    CAS  PubMed  Article  Google Scholar 

  18. Ho, Y.Y., Ionita-Laza, I. & Ottman, R. Domain-dependent clustering and genotype-phenotype analysis of LGI1 mutations in ADPEAF. Neurology 78, 563–568 (2012).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  19. Soldà, T., Galli, C., Kaufman, R.J. & Molinari, M. Substrate-specific requirements for UGT1-dependent release from calnexin. Mol. Cell 27, 238–249 (2007).

    PubMed  Article  CAS  Google Scholar 

  20. Honoré, B. The rapidly expanding CREC protein family: members, localization, function, and role in disease. BioEssays 31, 262–277 (2009).

    PubMed  Article  CAS  Google Scholar 

  21. Sirerol-Piquer, M.S. et al. The epilepsy gene LGI1 encodes a secreted glycoprotein that binds to the cell surface. Hum. Mol. Genet. 15, 3436–3445 (2006).

    CAS  PubMed  Article  Google Scholar 

  22. Ozkaynak, E. et al. Adam22 is a major neuronal receptor for Lgi4-mediated Schwann cell signaling. J. Neurosci. 30, 3857–3864 (2010).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  23. Kegel, L. et al. Functional phylogenetic analysis of LGI proteins identifies an interaction motif crucial for myelination. Development 141, 1749–1756 (2014).

    CAS  PubMed  Article  Google Scholar 

  24. Okiyoneda, T. & Lukacs, G.L. Fixing cystic fibrosis by correcting CFTR domain assembly. J. Cell Biol. 199, 199–204 (2012).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  25. Ward, C.L., Omura, S. & Kopito, R.R. Degradation of CFTR by the ubiquitin-proteasome pathway. Cell 83, 121–127 (1995).

    CAS  PubMed  Article  Google Scholar 

  26. Rubenstein, R.C., Egan, M.E. & Zeitlin, P.L. In vitro pharmacologic restoration of CFTR-mediated chloride transport with sodium 4-phenylbutyrate in cystic fibrosis epithelial cells containing delta F508-CFTR. J. Clin. Invest. 100, 2457–2465 (1997).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  27. Hutt, D.M. et al. Reduced histone deacetylase 7 activity restores function to misfolded CFTR in cystic fibrosis. Nat. Chem. Biol. 6, 25–33 (2010).

    CAS  PubMed  Article  Google Scholar 

  28. Mu, T.W. et al. Chemical and biological approaches synergize to ameliorate protein-folding diseases. Cell 134, 769–781 (2008).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  29. Ozcan, U. et al. Chemical chaperones reduce ER stress and restore glucose homeostasis in a mouse model of type 2 diabetes. Science 313, 1137–1140 (2006).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  30. Kopito, R.R. & Ron, D. Conformational disease. Nat. Cell Biol. 2, E207–E209 (2000).

    CAS  PubMed  Article  Google Scholar 

  31. Zode, G.S. et al. Reduction of ER stress via a chemical chaperone prevents disease phenotypes in a mouse model of primary open angle glaucoma. J. Clin. Invest. 121, 3542–3553 (2011).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  32. Lu, J. et al. Histone deacetylase inhibitors prevent the degradation and restore the activity of glucocerebrosidase in Gaucher disease. Proc. Natl. Acad. Sci. USA 108, 21200–21205 (2011).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  33. Yang, C., Huntoon, K., Ksendzovsky, A., Zhuang, Z. & Lonser, R.R. Proteostasis modulators prolong missense VHL protein activity and halt tumor progression. Cell Reports 3, 52–59 (2013).

    CAS  PubMed  Article  Google Scholar 

  34. Gallagher, M.J., Ding, L., Maheshwari, A. & Macdonald, R.L. The GABAA receptor alpha1 subunit epilepsy mutation A322D inhibits transmembrane helix formation and causes proteasomal degradation. Proc. Natl. Acad. Sci. USA 104, 12999–13004 (2007).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  35. Iannitti, T. & Palmieri, B. Clinical and experimental applications of sodium phenylbutyrate. Drugs R D. 11, 227–249 (2011).

    PubMed  Article  Google Scholar 

  36. Pedemonte, N. et al. Phenylglycine and sulfonamide correctors of defective F508 and G551D cystic fibrosis transmembrane conductance regulator chloride-channel gating. Mol. Pharmacol. 67, 1797–1807 (2005).

    CAS  PubMed  Article  Google Scholar 

  37. Van Goor, F. et al. Rescue of CF airway epithelial cell function in vitro by a CFTR potentiator, VX-770. Proc. Natl. Acad. Sci. USA 106, 18825–18830 (2009).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  38. Rosanoff, M.J. & Ottman, R. Penetrance of LGI1 mutations in autosomal dominant partial epilepsy with auditory features. Neurology 71, 567–571 (2008).

    PubMed  PubMed Central  Article  Google Scholar 

  39. Yamazaki, M. et al. TARPs gamma-2 and gamma-7 are essential for AMPA receptor expression in the cerebellum. Eur. J. Neurosci. 31, 2204–2220 (2010).

    PubMed  Article  Google Scholar 

  40. Masuda, K. et al. A combinatorial G protein-coupled receptor reconstitution system on budded baculovirus. Evidence for G alpha(i) and G alpha(o) coupling to a human leukotriene B4 receptor. J. Biol. Chem. 278, 24552–24562 (2003).

    CAS  PubMed  Article  Google Scholar 

  41. Saitoh, R. et al. Viral envelope protein gp64 transgenic mouse facilitates the generation of monoclonal antibodies against exogenous membrane proteins displayed on baculovirus. J. Immunol. Methods 322, 104–117 (2007).

    CAS  PubMed  Article  Google Scholar 

  42. Lüthi, A. et al. Endogenous serine protease inhibitor modulates epileptic activity and hippocampal long-term potentiation. J. Neurosci. 17, 4688–4699 (1997).

    PubMed  Article  PubMed Central  Google Scholar 

  43. Watanabe, M. et al. Selective scarcity of NMDA receptor channel subunits in the stratum lucidum (mossy fibre-recipient layer) of the mouse hippocampal CA3 subfield. Eur. J. Neurosci. 10, 478–487 (1998).

    CAS  PubMed  Article  Google Scholar 

  44. Noritake, J. et al. Mobile DHHC palmitoylating enzyme mediates activity-sensitive synaptic targeting of PSD-95. J. Cell Biol. 186, 147–160 (2009).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  45. Faul, F., Erdfelder, E., Lang, A.G. & Buchner, A. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav. Res. Methods 39, 175–191 (2007).

    PubMed  Article  Google Scholar 

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Acknowledgements

We thank J.L. Noebels and Y. Takahashi for helpful discussion. We thank A. Maas for kind assistance with Adam22 and Adam23 KO mice, S. Okamoto for technical guidance, M. Ohashi for sharing laboratory equipment, and Y. Kawabe and the members of the Fukata laboratory for their technical assistance. We also thank D. Monard (Friedrich Miescher Institute for Biomedical Research, Switzerland) for the kind gift of a Thy1 expression cassette. N.Y. was supported by the Japan Society for the Promotion of Science (22-2876) and Ministry of Education, Culture, Sports, Science and Technology (MEXT) (25890021). Y.F. is supported by grants from MEXT (25110733) and Ministry of Health, Labour and Welfare (MHLW) (Intramural Research Grant (24-12) for Neurological and Psychiatric Disorder of Japan National Center of Neurology and Psychiatry). D.M. and M.J. are supported by grants from the Dutch government to the Netherlands Institute for Regenerative Medicine (FES0908), the VICI (918.66.616) and the European Union (Neuron-Glia Interactions in Nerve Development and Disease, FP7 HEALTH-F2-2008-201535). M.W. is supported by a grant from MEXT (Comprehensive Brain Science Network). M.F. was supported by a grant from the Funding Program for Next Generation World-Leading Researchers (LS123).

Author information

Authors and Affiliations

Authors

Contributions

N.Y. designed and performed most of experiments and analyzed data. Y.F. conceived and supervised the project, performed experiments and analyzed data. D.K. performed experiments on characterization of mutant mice. T.M. performed experiments, analyzed data and wrote the parts of the manuscript on electron microscopic analysis. M.J. produced Adam22 and Adam23 KO mice. T.O. produced reagents. N.T. performed experiments on mouse breeding, genotyping and measurement of seizure frequency. H.I., Y.M. and T.H. produced the LGI1 monoclonal antibody. K.I. provided expert advice on LGI1 seizure phenotypes. D.M. produced the Adam22 and Adam23 KO mice and provided advice and wrote the part of the manuscript on these mice. M.W. produced guinea pig antibody to LGI1 and rabbit antibody to ADAM23, performed immunohistochemical experiments to compare KO mice and wrote the part of the manuscript on immunohistochemical analysis. M.F. conceived and supervised the project, performed experiments and analyzed data. N.Y., Y.F. and M.F. wrote the manuscript.

Corresponding authors

Correspondence to Yuko Fukata or Masaki Fukata.

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Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–5, Supplementary Tables 1–5 and Supplementary Discussion (PDF 6712 kb)

Supplementary Video 1

Epileptic phenotype of Lgi1−/− mice. A P17 Lgi1−/− mouse shows a spontaneous generalized seizure with a sudden onset of limb jerks and/or wild running/jumping, followed by limb clonus and full tonic limb extension. This epileptic phenotype of Lgi1−/− mice was already reported (Fukata, Y. et al., Proc. Natl. Acad. Sci. USA 107, 3799–3804, 2010), and is shown as a control of the epileptic phenotype of Lgi1−/−;Lgi1-TgE383A3 or Lgi1−/−;Lgi1-TgS473L mice (Supplementary Videos 2 and 3). (MOV 2713 kb)

Supplementary Video 2

Epileptic phenotype of Lgi1−/−;Lgi1-TgE383A3 mice. A P21 Lgi1−/−;Lgi1-TgE383A3 mouse shows a spontaneous generalized seizure as the Lgi1−/− mouse does (Supplementary Video 1). (MOV 2726 kb)

Supplementary Video 3

Epileptic phenotype of Lgi1−/−;Lgi1-TgS473L mice. A P17 Lgi1−/−;Lgi1-TgS473L mouse shows a spontaneous generalized seizure as the Lgi1−/− mouse does (Supplementary Video 1). (MOV 2228 kb)

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Yokoi, N., Fukata, Y., Kase, D. et al. Chemical corrector treatment ameliorates increased seizure susceptibility in a mouse model of familial epilepsy. Nat Med 21, 19–26 (2015). https://doi.org/10.1038/nm.3759

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