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

Molecular Neurodegeneration

Marta Milo¹  Alvaro Sanchez-Martinez²  Alexander J. Whitworth²  Mario R. Guarracino³  Ilaria Granata³  Luisa Cutillo⁴  Lydia M. Castelli⁵  Cleide Dos Santos Souza⁵  Ya-Hui Lin⁵  Paul R. Heath⁵  Monika A. Myszczynska⁵  Ke Ning⁶  Matthew R. Livesey⁶  Laura Ferraiuolo⁶  Mimoun Azzouz⁶  Guillaume M. Hautbergue⁶  Pamela J. Shaw⁶ 

[1] Department of Biomedical Science, University of Sheffield, Western Bank, S10 2TN, Sheffield, UK;Present Address: AstraZeneca, Academy House, 136 Hills Road, CB2 8PA, Cambridge, UK;MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Hills Road, CB2 0XY, Cambridge, UK;National Research Council of Italy, High Performance Computing and Networking Institute (ICAR-CNR), 111 Via Pietro Castellino, 80131, Naples, Italy;School of Mathematics, University of Leeds, LS2 9JT, Leeds, UK;Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, S10 2HQ, Sheffield, UK;Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, S10 2HQ, Sheffield, UK;Neuroscience Institute, University of Sheffield, Western Bank, S10 2TN, Sheffield, UK;

关键词: Amyotrophic lateral sclerosis;    C9ORF72;    Pre-clinical models;    Transcriptome;    Genome-wide mechanisms of neuroprotection;    SRSF1-dependent RNA nuclear export;    Disease-modifying gene expression signature;    Voltage-gated potassium ion channel;   

DOI  :  10.1186/s13024-021-00475-y

来源: Springer

【 摘 要 】

BackgroundLoss 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.MethodsHere, 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.ResultsOur 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.ConclusionsStrikingly, 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.

【 授权许可】

CC BY