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Reduced C9ORF72 function exacerbates gain of toxicity from ALS/FTD-causing repeat expansion in C9orf72

Abstract

Hexanucleotide expansions in C9orf72, which encodes a predicted guanine exchange factor, are the most frequent genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Although repeat expansion has been established to generate toxic products, mRNAs encoding the C9ORF72 protein are also reduced in affected individuals. In this study, we tested how C9ORF72 protein levels affected repeat-mediated toxicity. In somatic transgenic mice expressing 66 GGGGCC repeats, inactivation of one or both endogenous C9orf72 alleles provoked or accelerated, respectively, early death. In mice expressing a C9orf72 transgene with 450 repeats that did not encode the C9ORF72 protein, inactivation of one or both endogenous C9orf72 alleles exacerbated cognitive deficits, hippocampal neuron loss, glial activation and accumulation of dipeptide-repeat proteins from translation of repeat-containing RNAs. Reduced C9ORF72 was shown to suppress repeat-mediated elevation in autophagy. These efforts support a disease mechanism in ALS/FTD resulting from reduced C9ORF72, which can lead to autophagy deficits, synergizing with repeat-dependent gain of toxicity.

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Fig. 1: Reduction or loss of C9ORF72 in mice expressing 66 GGGGCC repeats induces or accelerates, respectively, premature death and leads to increased dipeptide-repeat protein accumulation.
Fig. 2: No detection of a predicted C9ORF72 short isoform protein in the frontal cortex from human samples or C9450C transgenic mice.
Fig. 3: Reduction or loss of endogenous C9ORF72 exacerbates age-dependent cognitive abnormalities and motor deficits in C9450C mice.
Fig. 4: Loss of C9ORF72 promotes degeneration of hippocampal neurons and glial activation in C9450C transgenic mice.
Fig. 5: Loss of endogenous C9ORF72 inhibits autophagy accompanied by increased accumulation of polydipeptides produced by AUG-independent translation in C9450C transgenic mice.

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Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

References

  1. DeJesus-Hernandez, M. et al. Expanded GGGGCC hexanucleotide repeat in noncoding region of C9ORF72 causes chromosome 9p-linked FTD and ALS. Neuron 72, 245–256 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Renton, A. E. et al. A hexanucleotide repeat expansion in C9ORF72 is the cause of chromosome 9p21-linked ALS-FTD. Neuron 72, 257–268 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Levine, T. P., Daniels, R. D., Gatta, A. T., Wong, L. H. & Hayes, M. J. The product of C9orf72, a gene strongly implicated in neurodegeneration, is structurally related to DENN Rab-GEFs. Bioinformatics 29, 499–503 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Zu, T. et al. Non-ATG-initiated translation directed by microsatellite expansions. Proc. Natl Acad. Sci. USA 108, 260–265 (2011).

    Article  CAS  PubMed  Google Scholar 

  5. Zu, T. et al. RAN proteins and RNA foci from antisense transcripts in C9ORF72 ALS and frontotemporal dementia. Proc. Natl Acad. Sci. USA 110, E4968–E4977 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Mori, K. et al. Bidirectional transcripts of the expanded C9orf72 hexanucleotide repeat are translated into aggregating dipeptide repeat proteins. Acta Neuropathol. 126, 881–893 (2013).

    Article  CAS  PubMed  Google Scholar 

  7. Ash, P. E. et al. Unconventional translation of C9ORF72 GGGGCC expansion generates insoluble polypeptides specific to c9FTD/ALS. Neuron 77, 639–646 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Balendra, R. & Isaacs, A. M. C9orf72-mediated ALS and FTD: multiple pathways to disease. Nat. Rev. Neurol. 14, 544–558 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Mackenzie, I. R. et al. Quantitative analysis and clinico-pathological correlations of different dipeptide repeat protein pathologies in C9ORF72 mutation carriers. Acta Neuropathol. 130, 845–861 (2015).

    Article  CAS  PubMed  Google Scholar 

  10. Li, N. & Lagier-Tourenne, C. Nuclear pores: the gate to neurodegeneration. Nat. Neurosci. 21, 156–158 (2018).

    Article  CAS  PubMed  Google Scholar 

  11. Saberi, S. et al. Sense-encoded poly-GR dipeptide repeat proteins correlate to neurodegeneration and uniquely co-localize with TDP-43 in dendrites of repeat-expanded C9orf72 amyotrophic lateral sclerosis. Acta Neuropathol. 135, 459–474 (2018).

    Article  CAS  PubMed  Google Scholar 

  12. Mackenzie, I. R. et al. Dipeptide repeat protein pathology in C9ORF72 mutation cases: clinico-pathological correlations. Acta Neuropathol. 126, 859–879 (2013).

    Article  CAS  PubMed  Google Scholar 

  13. Lagier-Tourenne, C. et al. Targeted degradation of sense and antisense C9orf72 RNA foci as therapy for ALS and frontotemporal degeneration. Proc. Natl Acad. Sci. USA 110, E4530–E4539 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Wojciechowska, M. & Krzyzosiak, W. J. Cellular toxicity of expanded RNA repeats: focus on RNA foci. Hum. Mol. Genet. 20, 3811–3821 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Haeusler, A. R., Donnelly, C. J. & Rothstein, J. D. The expanding biology of the C9orf72 nucleotide repeat expansion in neurodegenerative disease. Nat. Rev. Neurosci. 17, 383–395 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Burguete, A. S. et al. GGGGCC microsatellite RNA is neuritically localized, induces branching defects, and perturbs transport granule function. eLife 4, e08881 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  17. Jiang, J. et al. Gain of toxicity from ALS/FTD-linked repeat expansions in C9ORF72 is alleviated by antisense oligonucleotides targeting GGGGCC-containing RNAs. Neuron 90, 535–550 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Liu, Y. et al. C9orf72 BAC mouse model with motor deficits and neurodegenerative features of ALS/FTD. Neuron 90, 521–534 (2016).

    Article  CAS  PubMed  Google Scholar 

  19. Chew, J. et al. Neurodegeneration. C9ORF72 repeat expansions in mice cause TDP-43 pathology, neuronal loss, and behavioral deficits. Science 348, 1151–1154 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Belzil, V. V. et al. Reduced C9orf72 gene expression in c9FTD/ALS is caused by histone trimethylation, an epigenetic event detectable in blood. Acta Neuropathol. 126, 895–905 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Donnelly, C. J. et al. RNA toxicity from the ALS/FTD C9ORF72 expansion is mitigated by antisense intervention. Neuron 80, 415–428 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Frick, P. et al. Novel antibodies reveal presynaptic localization of C9orf72 protein and reduced protein levels in C9orf72 mutation carriers. Acta Neuropathol. Commun. 6, 72 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  23. Waite, A. J. et al. Reduced C9orf72 protein levels in frontal cortex of amyotrophic lateral sclerosis and frontotemporal degeneration brain with the C9ORF72 hexanucleotide repeat expansion. Neurobiol. Aging 35, 1779 e1775–1779 e1713 (2014).

    Article  CAS  Google Scholar 

  24. Xi, Z. et al. Hypermethylation of the CpG island near the G4C2 repeat in ALS with a C9orf72 expansion. Am. J. Hum. Genet. 92, 981–989 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Xi, Z. et al. The C9orf72 repeat expansion itself is methylated in ALS and FTLD patients. Acta Neuropathol. 129, 715–727 (2015).

    Article  CAS  PubMed  Google Scholar 

  26. Ciura, S. et al. Loss of function of C9orf72 causes motor deficits in a zebrafish model of amyotrophic lateral sclerosis. Ann. Neurol. 74, 180–187 (2013).

    CAS  PubMed  Google Scholar 

  27. Therrien, M., Rouleau, G. A., Dion, P. A. & Parker, J. A. Deletion of C9ORF72 results in motor neuron degeneration and stress sensitivity in C. elegans. PLoS ONE 8, e83450 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  28. O’Rourke, J. G. et al. C9orf72 is required for proper macrophage and microglial function in mice. Science 351, 1324–1329 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  29. Atanasio, A. et al. C9orf72 ablation causes immune dysregulation characterized by leukocyte expansion, autoantibody production, and glomerulonephropathy in mice. Sci. Rep. 6, 23204 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Ugolino, J. et al. Loss of C9orf72 enhances autophagic activity via deregulated mTOR and TFEB signaling. PLoS Genet. 12, e1006443 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  31. Burberry, A. et al. Loss-of-function mutations in the C9ORF72 mouse ortholog cause fatal autoimmune disease. Sci. Transl. Med. 8, 347ra393 (2016).

    Article  CAS  Google Scholar 

  32. Sullivan, P. M. et al. The ALS/FTLD associated protein C9orf72 associates with SMCR8 and WDR41 to regulate the autophagy-lysosome pathway. Acta Neuropathol. Commun. 4, 51 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  33. Koppers, M. et al. C9orf72 ablation in mice does not cause motor neuron degeneration or motor deficits. Ann. Neurol. 78, 426–438 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Shi, Y. et al. Haploinsufficiency leads to neurodegeneration in C9ORF72 ALS/FTD human induced motor neurons. Nat. Med. 24, 313–325 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Sellier, C. et al. Loss of C9ORF72 impairs autophagy and synergizes with polyQ Ataxin-2 to induce motor neuron dysfunction and cell death. EMBO J. 35, 1276–1297 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Yang, M. et al. A C9ORF72/SMCR8-containing complex regulates ULK1 and plays a dual role in autophagy. Sci. Adv. 2, e1601167 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  37. Webster, C. P. et al. The C9orf72 protein interacts with Rab1a and the ULK1 complex to regulate initiation of autophagy. EMBO J. 35, 1656–1676 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Zhang, Y. et al. The C9orf72-interacting protein Smcr8 is a negative regulator of autoimmunity and lysosomal exocytosis. Genes Dev. 32, 929–943 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Ho, W. Y. et al. The ALS-FTD-linked gene product, C9orf72, regulates neuronal morphogenesis via autophagy. Autophagy 15, 827–842 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Liu, E. Y. et al. C9orf72 hypermethylation protects against repeat expansion-associated pathology in ALS/FTD. Acta Neuropathol. 128, 525–541 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Zhang, D., Iyer, L. M., He, F. & Aravind, L. Discovery of novel DENN proteins: implications for the evolution of eukaryotic intracellular membrane structures and human disease. Front. Genet. 3, 283 (2012).

    PubMed  PubMed Central  Google Scholar 

  42. Scholz, J., Niibori, Y., W Frankland, P. & P Lerch, J. Rotarod training in mice is associated with changes in brain structure observable with multimodal MRI. Neuroimage 107, 182–189 (2015).

    Article  PubMed  Google Scholar 

  43. Nixon, R. A., Yang, D. S. & Lee, J. H. Neurodegenerative lysosomal disorders: a continuum from development to late age. Autophagy 4, 590–599 (2008).

    Article  CAS  PubMed  Google Scholar 

  44. Klionsky, D. J. et al. Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). Autophagy 12, 1–222 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  45. Ciechanover, A. The ubiquitin-proteasome proteolytic pathway. Cell 79, 13–21 (1994).

    Article  CAS  PubMed  Google Scholar 

  46. Chitiprolu, M. et al. A complex of C9ORF72 and p62 uses arginine methylation to eliminate stress granules by autophagy. Nat. Commun. 9, 2794 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  47. Jiang, J. & Ravits, J. Pathogenic mechanisms and therapy development for C9orf72 amyotrophic lateral sclerosis/frontotemporal dementia. Neurotherapeutics 16, 1115–1132 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Nassif, M., Woehlbier, U. & Manque, P. A. The enigmatic role of C9ORF72 in autophagy. Front. Neurosci. 11, 442 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  49. Taylor, J. P., Brown, R. H. Jr. & Cleveland, D. W. Decoding ALS: from genes to mechanism. Nature 539, 197–206 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  50. Roy Sarkar, S. & Banerjee, S. Gut microbiota in neurodegenerative disorders. J. Neuroimmunol. 328, 98–104 (2019).

    Article  CAS  PubMed  Google Scholar 

  51. Kramer, N. J. et al. Spt4 selectively regulates the expression of C9orf72 sense and antisense mutant transcripts. Science 353, 708–712 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Su, Z. et al. Discovery of a biomarker and lead small molecules to target r(GGGGCC)-associated defects in c9FTD/ALS. Neuron 83, 1043–1050 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Gendron, T. F. et al. Cerebellar c9RAN proteins associate with clinical and neuropathological characteristics of C9ORF72 repeat expansion carriers. Acta Neuropathol. 130, 559–573 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Parone, P. A. et al. Enhancing mitochondrial calcium buffering capacity reduces aggregation of misfolded SOD1 and motor neuron cell death without extending survival in mouse models of inherited amyotrophic lateral sclerosis. J. Neurosci. 33, 4657–4671 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Shao, C. et al. Mitotic recombination produces the majority of recessive fibroblast variants in heterozygous mice. Proc. Natl Acad. Sci. USA 96, 9230–9235 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Jiang, L. L. et al. Membralin deficiency dysregulates astrocytic glutamate homeostasis leading to ALS-like impairment. J. Clin. Invest. 129, 3103–3120 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

We thank B. Myers, M. Maldonado, J. Kim, J. Lim, J. Yasis, C.J. Heyser, D. Ditsworth, K. Osborn and J. Chew for their advice and technical assistance. We thank M. Fugere and B. Kaspar at AveXis for providing help in sorting mouse ESC-derived motor neurons. We thank Ionis Pharmaceuticals for providing ASOs. We thank all members of the D.W.C., C.L.-T., J.R., and S.D.C. groups for critical suggestions on this project. This work was supported by grants from NINDS/NIH R01-NS27036 to D.W.C. and S.D.C. and R01-NS087227 to C.L.-T.; from the NIA/NIH-supported UCSD Alzheimer’s Disease Research Center (P50-AG005131) to C.L.-T. and D.W.C.; from Target ALS to C.L.-T. and J.R.; from NINDS/NIH R35-NS097273, P01-NS084974 and R01-NS088689 to L.P.; from P01-NS099114 to T.G. and L.P.; and from Target ALS to T.G., L.P. and Y.Z. C.L.-T. is the recipient of the Healey Family ALS Endowed Chair for Research. Q.Z. was the recipient of a Milton Safenowitz Postdoctoral Fellowship and a STARTER grant from the ALS Association. J.J. was the recipient of a career development grant from the Muscular Dystrophy Association (479769).

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Q.Z., J.J., S.D.C., C.L.-T. and D.W.C. designed the research. Q.Z., J.J., T.F.G., A.R.L.S., H.X., L.P., J.R., S.D.C., C.L.-T. and D.W.C. analyzed the data. Q.Z., J.J., T.F.G., M.M.D., L.J., A.T., S.D.G., S.G.D., M.J.R., P.K. and Y.Z. performed research. Q.Z., J.J., S.D.C., C.L.-T. and D.W.C. wrote the manuscript.

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Correspondence to Clotilde Lagier-Tourenne or Don W. Cleveland.

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D.W.C. is a consultant for Ionis Pharmaceuticals. The other authors report no conflicts of interest.

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Zhu, Q., Jiang, J., Gendron, T.F. et al. Reduced C9ORF72 function exacerbates gain of toxicity from ALS/FTD-causing repeat expansion in C9orf72. Nat Neurosci 23, 615–624 (2020). https://doi.org/10.1038/s41593-020-0619-5

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