1. Neuroscience

Antisense, but not sense, repeat expanded RNAs activate PKR/eIF2α-dependent ISR in C9ORF72 FTD/ALS

  1. Janani Parameswaran
  2. Nancy Zhang
  3. Elke Braems
  4. Kedamawit Tilahun
  5. Devesh C Pant
  6. Keena Yin
  7. Seneshaw Asress
  8. Kara Heeren
  9. Anwesha Banerjee
  10. Emma Davis
  11. Samantha L Schwartz
  12. Graeme L Conn
  13. Gary J Bassell
  14. Ludo Van Den Bosch
  15. Jie Jiang  Is a corresponding author
  1. Emory University, United States
  2. KU Leuven, Belgium
https://doi.org/10.7554/eLife.85902
Share this article
Cite this article
  1. Janani Parameswaran
  2. Nancy Zhang
  3. Elke Braems
  4. Kedamawit Tilahun
  5. Devesh C Pant
  6. Keena Yin
  7. Seneshaw Asress
  8. Kara Heeren
  9. Anwesha Banerjee
  10. Emma Davis
  11. Samantha L Schwartz
  12. Graeme L Conn
  13. Gary J Bassell
  14. Ludo Van Den Bosch
  15. Jie Jiang
(2023)
Antisense, but not sense, repeat expanded RNAs activate PKR/eIF2α-dependent ISR in C9ORF72 FTD/ALS
eLife 12:e85902.
https://doi.org/10.7554/eLife.85902
  2. Download BibTeX
  3. Download .RIS

Abstract

GGGGCC (G4C2) hexanucleotide repeat expansion in the C9ORF72 gene is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). The repeat is bidirectionally transcribed and confers gain of toxicity. However, the underlying toxic species is debated, and it is not clear whether antisense CCCCGG (C4G2) repeat expanded RNAs contribute to disease pathogenesis. Our study shows that C9ORF72 antisense C4G2 repeat expanded RNAs trigger the activation of the PKR/eIF2α-dependent integrated stress response independent of dipeptide repeat proteins that are produced through repeat-associated non-AUG initiated translation, leading to global translation inhibition and stress granule formation. Reducing PKR levels with either siRNA or morpholinos mitigates integrated stress response and toxicity caused by the antisense C4G2 RNAs in cell lines, primary neurons, and zebrafish. Increased phosphorylation of PKR/eIF2α is also observed in the frontal cortex of C9ORF72 FTD/ALS patients. Finally, only antisense C4G2, but not sense G4C2, repeat expanded RNAs robustly activate the PKR/eIF2α pathway and induce aberrant stress granule formation. These results provide a mechanism by which antisense C4G2 repeat expanded RNAs elicit neuronal toxicity in FTD/ALS caused by C9ORF72 repeat expansions.

Data availability

All data generated or analysed during this study are included in the manuscript.

Article and author information

Author details

  1. Janani Parameswaran

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9030-4953

  2. Nancy Zhang

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Elke Braems

    Department of Neurosciences, KU Leuven, Leuven, Belgium
    Competing interests
    The authors declare that no competing interests exist.

  4. Kedamawit Tilahun

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2107-1580

  5. Devesh C Pant

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4046-4195

  6. Keena Yin

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Seneshaw Asress

    Department of Neurology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  8. Kara Heeren

    Department of Neurosciences, KU Leuven, Leuven, Belgium
    Competing interests
    The authors declare that no competing interests exist.

  9. Anwesha Banerjee

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  10. Emma Davis

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  11. Samantha L Schwartz

    Department of Biochemistry, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  12. Graeme L Conn

    Department of Biochemistry, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  13. Gary J Bassell

    Department of Cell Biology, Emory University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.

  14. Ludo Van Den Bosch

    Department of Neurosciences, KU Leuven, Leuven, Belgium
    Competing interests
    The authors declare that no competing interests exist.

  15. Jie Jiang

    Department of Cell Biology, Emory University, Atlanta, United States
    For correspondence
    jie.jiang@emory.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9519-4992

Funding

National Institute of Neurological Disorders and Stroke (R01NS114253)

  • Anwesha Banerjee
  • Gary J Bassell

National Institutes of Health (R01AG068247)

  • Jie Jiang

ALS Association (21-PDF-585)

  • Janani Parameswaran

Fonds Wetenschappelijk Onderzoek (G0C1620N)

  • Ludo Van Den Bosch

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

Copyright

© 2023, Parameswaran 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.

Metrics

  • 2,370
    views
  • 434
    downloads
  • 11
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Janani Parameswaran
  2. Nancy Zhang
  3. Elke Braems
  4. Kedamawit Tilahun
  5. Devesh C Pant
  6. Keena Yin
  7. Seneshaw Asress
  8. Kara Heeren
  9. Anwesha Banerjee
  10. Emma Davis
  11. Samantha L Schwartz
  12. Graeme L Conn
  13. Gary J Bassell
  14. Ludo Van Den Bosch
  15. Jie Jiang
(2023)
Antisense, but not sense, repeat expanded RNAs activate PKR/eIF2α-dependent ISR in C9ORF72 FTD/ALS
eLife 12:e85902.
https://doi.org/10.7554/eLife.85902

Share this article

https://doi.org/10.7554/eLife.85902

Categories and tags

Research organism

Further reading

    1. Neuroscience

    Rhythmic circuit function is more robust to changes in synaptic than intrinsic conductances

    Zachary Fournier, Leandro M Alonso, Eve Marder
    Research Article

    Circuit function results from both intrinsic conductances of network neurons and the synaptic conductances that connect them. In models of neural circuits, different combinations of maximal conductances can give rise to similar activity. We compared the robustness of a neural circuit to changes in their intrinsic versus synaptic conductances. To address this, we performed a sensitivity analysis on a population of conductance-based models of the pyloric network from the crustacean stomatogastric ganglion (STG). The model network consists of three neurons with nine currents: a sodium current (Na), three potassium currents (Kd, KCa, KA), two calcium currents (CaS and CaT), a hyperpolarization-activated current (H), a non-voltage-gated leak current (leak), and a neuromodulatory current (MI). The model cells are connected by seven synapses of two types, glutamatergic and cholinergic. We produced one hundred models of the pyloric network that displayed similar activities with values of maximal conductances distributed over wide ranges. We evaluated the robustness of each model to changes in their maximal conductances. We found that individual models have different sensitivities to changes in their maximal conductances, both in their intrinsic and synaptic conductances. As expected, the models become less robust as the extent of the changes increases. Despite quantitative differences in their robustness, we found that in all cases, the model networks are more sensitive to the perturbation of their intrinsic conductances than their synaptic conductances.

    1. Neuroscience

    Cognition: When working memory works for our goals

    Jacob A Miller
    Insight

    When navigating environments with changing rules, human brain circuits flexibly adapt how and where we retain information to help us achieve our immediate goals.

    1. Neuroscience

    Cerebellar Purkinje cells control posture in larval zebrafish (Danio rerio)

    Franziska Auer, Katherine Nardone ... David Schoppik
    Research Article

    Cerebellar dysfunction leads to postural instability. Recent work in freely moving rodents has transformed investigations of cerebellar contributions to posture. However, the combined complexity of terrestrial locomotion and the rodent cerebellum motivate new approaches to perturb cerebellar function in simpler vertebrates. Here, we adapted a validated chemogenetic tool (TRPV1/capsaicin) to describe the role of Purkinje cells — the output neurons of the cerebellar cortex — as larval zebrafish swam freely in depth. We achieved both bidirectional control (activation and ablation) of Purkinje cells while performing quantitative high-throughput assessment of posture and locomotion. Activation modified postural control in the pitch (nose-up/nose-down) axis. Similarly, ablations disrupted pitch-axis posture and fin-body coordination responsible for climbs. Postural disruption was more widespread in older larvae, offering a window into emergent roles for the developing cerebellum in the control of posture. Finally, we found that activity in Purkinje cells could individually and collectively encode tilt direction, a key feature of postural control neurons. Our findings delineate an expected role for the cerebellum in postural control and vestibular sensation in larval zebrafish, establishing the validity of TRPV1/capsaicin-mediated perturbations in a simple, genetically tractable vertebrate. Moreover, by comparing the contributions of Purkinje cell ablations to posture in time, we uncover signatures of emerging cerebellar control of posture across early development. This work takes a major step towards understanding an ancestral role of the cerebellum in regulating postural maturation.