Whole brain delivery of an instability-prone Mecp2 transgene improves behavioral and molecular pathological defects in mouse models of Rett syndrome

  1. Mirko Luoni
  2. Serena Giannelli
  3. Marzia Tina Indrigo
  4. Antonio Niro
  5. Luca Massimino
  6. Angelo Iannielli
  7. Laura Passeri
  8. Fabio Russo
  9. Giuseppe Morabito
  10. Piera Calamita
  11. Silvia Gregori
  12. Benjamin Deverman
  13. Vania Broccoli  Is a corresponding author
  1. San Raffaele Scientific Institute, Italy
  2. National Institute of Molecular Genetics, Italy
  3. Stanley Center for Psychiatric Research at Broad Institute, United States

Abstract

Rett syndrome is an incurable neurodevelopmental disorder caused by mutations in the gene encoding for methyl-CpG binding-protein 2 (MeCP2). Gene therapy for this disease presents inherent hurdles since MECP2 is expressed throughout the brain and its duplication leads to severe neurological conditions as well. Herein, we use the AAV-PHP.eB to deliver an instability-prone Mecp2 (iMecp2) transgene cassette which, increasing RNA destabilization and inefficient protein translation of the viral Mecp2 transgene, limits supraphysiological Mecp2 protein levels. Intravenous injections of the PHP.eB-iMecp2 virus in symptomatic Mecp2 mutant mice significantly improved locomotor activity, lifespan and gene expression normalization. Remarkably, PHP.eB-iMecp2 administration was well tolerated in female Mecp2 mutant or in wild-type animals. In contrast, we observed a strong immune response to the transgene in treated male Mecp2 mutant mice that was overcome by immunosuppression. Overall, PHP.eB-mediated delivery of iMecp2 provided widespread and efficient gene transfer maintaining physiological Mecp2 protein levels in the brain.

Data availability

Sequencing data have been deposited in GEO under accession code GSE125155.

The following data sets were generated

Article and author information

Author details

  1. Mirko Luoni

    Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  2. Serena Giannelli

    Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  3. Marzia Tina Indrigo

    Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  4. Antonio Niro

    Division of Neuroscience, San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  5. Luca Massimino

    Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  6. Angelo Iannielli

    Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  7. Laura Passeri

    Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  8. Fabio Russo

    Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  9. Giuseppe Morabito

    Division of Neuroscience, San Raffaele Scientific Institute, Mialno, Italy
    Competing interests
    The authors declare that no competing interests exist.
  10. Piera Calamita

    National Institute of Molecular Genetics, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9029-9346
  11. Silvia Gregori

    Institute for Gene Therapy (SR-Tiget), San Raffaele Scientific Institute, Milano, Italy
    Competing interests
    The authors declare that no competing interests exist.
  12. Benjamin Deverman

    Stanley Center for Psychiatric Research at Broad Institute, Cambridge, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6223-9303
  13. Vania Broccoli

    Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
    For correspondence
    broccoli.vania@hsr.it
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4050-0926

Funding

Fondazione Telethon (GGP19038)

  • Mirko Luoni

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All procedures were performed according to protocols approved by the internal IACUC and reported to the Italian Ministry of Health according to the European Communities Council Directive 2010/63/EU.

Reviewing Editor

  1. Sonia Garel, Ecole Normale Superieure, France

Publication history

  1. Received: October 10, 2019
  2. Accepted: March 23, 2020
  3. Accepted Manuscript published: March 24, 2020 (version 1)
  4. Version of Record published: April 2, 2020 (version 2)

Copyright

© 2020, Luoni et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Mirko Luoni
  2. Serena Giannelli
  3. Marzia Tina Indrigo
  4. Antonio Niro
  5. Luca Massimino
  6. Angelo Iannielli
  7. Laura Passeri
  8. Fabio Russo
  9. Giuseppe Morabito
  10. Piera Calamita
  11. Silvia Gregori
  12. Benjamin Deverman
  13. Vania Broccoli
(2020)
Whole brain delivery of an instability-prone Mecp2 transgene improves behavioral and molecular pathological defects in mouse models of Rett syndrome
eLife 9:e52629.
https://doi.org/10.7554/eLife.52629

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