G2C4 targeting antisense oligonucleotides potently mitigate TDP-43 dysfunction in human C9orf72 ALS/FTD induced pluripotent stem cell derived neurons

Jeffrey D Rothstein; Victoria Baskerville; Sampath Rapuri; Emma Mehlhop; Paymaan Jafar-Nejad; Frank Rigo; Frank Bennett; Sarah Mizielinska; Adrian Isaacs; Alyssa N Coyne

doi:10.1007/s00401-023-02652-3

G₂C₄ targeting antisense oligonucleotides potently mitigate TDP-43 dysfunction in human C9orf72 ALS/FTD induced pluripotent stem cell derived neurons

Acta Neuropathol. 2023 Nov 29;147(1):1. doi: 10.1007/s00401-023-02652-3.

Authors

Jeffrey D Rothstein^{1

2}, Victoria Baskerville^{3

4}, Sampath Rapuri^{3

4}, Emma Mehlhop^{3

4}, Paymaan Jafar-Nejad⁵, Frank Rigo⁵, Frank Bennett⁵, Sarah Mizielinska^{6

7}, Adrian Isaacs^{8

9

10}, Alyssa N Coyne^{11

12}

Affiliations

¹ Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. jrothstein@jhmi.edu.
² Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. jrothstein@jhmi.edu.
³ Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
⁴ Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
⁵ Ionis Pharmaceuticals, Carlsbad, CA, 92010, USA.
⁶ UK Dementia Research Institute at King's College London, London, UK.
⁷ Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK.
⁸ UK Dementia Research Institute at UCL, London, UK.
⁹ Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.
¹⁰ UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, UK.
¹¹ Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. acoyne3@jhmi.edu.
¹² Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. acoyne3@jhmi.edu.

Abstract

The G₄C₂ repeat expansion in the C9orf72 gene is the most common genetic cause of Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Many studies suggest that dipeptide repeat proteins produced from this repeat are toxic, yet, the contribution of repeat RNA toxicity is under investigated and even less is known regarding the pathogenicity of antisense repeat RNA. Recently, two clinical trials targeting G₄C₂ (sense) repeat RNA via antisense oligonucleotide failed despite a robust decrease in sense-encoded dipeptide repeat proteins demonstrating target engagement. Here, in this brief report, we show that G₂C₄ antisense, but not G₄C₂ sense, repeat RNA is sufficient to induce TDP-43 dysfunction in induced pluripotent stem cell (iPSC) derived neurons (iPSNs). Unexpectedly, only G₂C₄, but not G₄C₂ sense strand targeting, ASOs mitigate deficits in TDP-43 function in authentic C9orf72 ALS/FTD patient iPSNs. Collectively, our data suggest that the G₂C₄ antisense repeat RNA may be an important therapeutic target and provide insights into a possible explanation for the recent G₄C₂ ASO clinical trial failure.

Keywords: ALS; Antisense oligonucleotides; C9orf72; Induced pluripotent stem cell derived neurons; Repeat RNA; TDP-43.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Amyotrophic Lateral Sclerosis* / genetics
C9orf72 Protein / genetics
DNA-Binding Proteins / genetics
Dipeptides
Frontotemporal Dementia* / genetics
Humans
Induced Pluripotent Stem Cells*
Neurons
Oligonucleotides, Antisense / pharmacology
RNA, Antisense

Substances

Oligonucleotides, Antisense
C9orf72 Protein
DNA-Binding Proteins
RNA, Antisense
Dipeptides
C9orf72 protein, human

Abstract

Publication types

MeSH terms

Substances

Grants and funding