Repository logo

SRSF1-dependent inhibition of C9ORF72 -repeat RNA nuclear export: genome-wide mechanisms for neuroprotection in amyotrophic lateral sclerosis

Published version

Change log


Castelli, Lydia M. 
Cutillo, Luisa 
Souza, Cleide Dos Santos 
Sanchez-Martinez, Alvaro 
Granata, Ilaria 


Abstract: Background: Loss of motor neurons in amyotrophic lateral sclerosis (ALS) leads to progressive paralysis and death. Dysregulation of thousands of RNA molecules with roles in multiple cellular pathways hinders the identification of ALS-causing alterations over downstream changes secondary to the neurodegenerative process. How many and which of these pathological gene expression changes require therapeutic normalisation remains a fundamental question. Methods: Here, we investigated genome-wide RNA changes in C9ORF72-ALS patient-derived neurons and Drosophila, as well as upon neuroprotection taking advantage of our gene therapy approach which specifically inhibits the SRSF1-dependent nuclear export of pathological C9ORF72-repeat transcripts. This is a critical study to evaluate (i) the overall safety and efficacy of the partial depletion of SRSF1, a member of a protein family involved itself in gene expression, and (ii) a unique opportunity to identify neuroprotective RNA changes. Results: Our study shows that manipulation of 362 transcripts out of 2257 pathological changes, in addition to inhibiting the nuclear export of repeat transcripts, is sufficient to confer neuroprotection in C9ORF72-ALS patient-derived neurons. In particular, expression of 90 disease-altered transcripts is fully reverted upon neuroprotection leading to the characterisation of a human C9ORF72-ALS disease-modifying gene expression signature. These findings were further investigated in vivo in diseased and neuroprotected Drosophila transcriptomes, highlighting a list of 21 neuroprotective changes conserved with 16 human orthologues in patient-derived neurons. We also functionally validated the high neuroprotective potential of one of these disease-modifying transcripts, demonstrating that inhibition of ALS-upregulated human KCNN1–3 (Drosophila SK) voltage-gated potassium channel orthologs mitigates degeneration of human motor neurons and Drosophila motor deficits. Conclusions: Strikingly, the partial depletion of SRSF1 leads to expression changes in only a small proportion of disease-altered transcripts, indicating that not all RNA alterations need normalization and that the gene therapeutic approach is safe in the above preclinical models as it does not disrupt globally gene expression. The efficacy of this intervention is also validated at genome-wide level with transcripts modulated in the vast majority of biological processes affected in C9ORF72-ALS. Finally, the identification of a characteristic signature with key RNA changes modified in both the disease state and upon neuroprotection also provides potential new therapeutic targets and biomarkers.


Funder: Academy of Medical Sciences Springboard Award


Research Article, Amyotrophic lateral sclerosis, C9ORF72-repeat expansions, Pre-clinical models, Transcriptome, Genome-wide mechanisms of neuroprotection, SRSF1-dependent RNA nuclear export, Disease-modifying gene expression signature, Voltage-gated potassium ion channel

Journal Title

Molecular Neurodegeneration

Conference Name

Journal ISSN


Volume Title



BioMed Central
Motor Neurone Disease Association (Hautbergue/Apr16/846-791, Apr16/848-791, AMBRoSIA 972-797)
Biotechnology and Biological Sciences Research Council (BB/S005277/1)
Medical Research Council (MR/R024162/1, MR/M010864/1, MC_UU_00015/6, MRC DPFS 129016, MR/S004920/1)
Royal Society International Research and Exchanges grant (IEC\R3\17010)
Fondation Thierry Latran (FTLAAP2016/ Astrocyte secretome)
H2020 European Research Council (DYNAMITO)
Alzheimer's Research UK (ARUK-PG2018B-005)
NIHR Sheffield Biomedical Research Centre (IS-BRC-1215-20017)