2. Academic Validation
  3. A multimodal screening platform for endogenous dipeptide repeat proteins in C9orf72 patient iPSC neurons

A multimodal screening platform for endogenous dipeptide repeat proteins in C9orf72 patient iPSC neurons

  • Cell Rep. 2025 May 27;44(5):115695. doi: 10.1016/j.celrep.2025.115695.
Benedikt V Hölbling 1,  Yashica Gupta 1,  Paolo M Marchi 1,  Magda L Atilano 2,  Michael Flower 1,  Enric Ureña 2,  Rajkumar A Goulden 2,  Hannah K Dobbs 1,  Eszter Katona 1,  Alla Mikheenko 3,  Ashling Giblin 4,  Ali Raza Awan 5,  Chloe L Fisher-Ward 6,  Niamh O'Brien 7,  Deniz Vaizoglu 1,  Liam Kempthorne 1,  Katherine M Wilson 1,  Lauren M Gittings 1,  Mireia Carcolé 1,  Marc-David Ruepp 7,  Sarah Mizielinska 7,  Linda Partridge 2,  Pietro Fratta 8,  Sarah J Tabrizi 1,  Bhuvaneish T Selvaraj 9,  Siddharthan Chandran 9,  Emma Armstrong 10,  Paul Whiting 11,  Adrian M Isaacs 12
Affiliations

Affiliations

  • 1 Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK.
  • 2 Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, UCL, London, UK.
  • 3 UK Dementia Research Institute at UCL, London, UK; Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK.
  • 4 Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK; Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, UCL, London, UK.
  • 5 Genomics Innovation Unit, Guy's and St Thomas' NHS Trust, London, UK; Comprehensive Cancer Centre, King's College London, London, UK.
  • 6 Genomics Innovation Unit, Guy's and St Thomas' NHS Trust, London, UK.
  • 7 UK Dementia Research Institute at King's College London, London, UK; Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
  • 8 Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK; The Francis Crick Institute, London, UK.
  • 9 UK Dementia Research Institute at University of Edinburgh, Edinburgh, UK; Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.
  • 10 Alzheimer's Research UK Drug Discovery Institute, UCL, London, UK.
  • 11 UK Dementia Research Institute at UCL, London, UK; Alzheimer's Research UK Drug Discovery Institute, UCL, London, UK.
  • 12 Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK. Electronic address: a.isaacs@ucl.ac.uk.
PMID: 40349338 DOI: 10.1016/j.celrep.2025.115695
Abstract

Repeat expansions in C9orf72 are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia. Repeat-associated non-AUG (RAN) translation generates neurotoxic dipeptide repeat proteins (DPRs). To study endogenous DPRs, we inserted the minimal HiBiT luciferase reporter downstream of sense repeat derived DPRs polyGA or polyGP in C9orf72 patient iPSCs. We show these "DPReporter" lines sensitively and rapidly report DPR levels in lysed and live cells and optimize screening in iPSC neurons. Small-molecule screening showed the ERK1/2 activator periplocin dose dependently increases DPR levels. Consistent with this, ERK1/2 inhibition reduced DPR levels and prolonged survival in C9orf72 repeat expansion flies. CRISPR knockout screening of all human helicases revealed telomere-associated helicases modulate DPR expression, suggesting common regulation of telomeric and C9orf72 repeats. These DPReporter lines allow investigation of DPRs in their endogenous context and provide a template for studying endogenous RAN-translated proteins, at scale, in Other repeat expansion disorders.

Keywords

C9orf72; CP: Neuroscience; RAN translation; amyotrophic lateral sclerosis; frontotemporal dementia; repeat expansion.

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