Mitochondrial DNA double-strand breaks in oligodendrocytes cause demyelination, axonal injury, and CNS inflammation

Pernille M. Madsen, Milena Pinto, Shreyans Patel, Stephanie McCarthy, Han Gao, Mehran Taherian, Shaffiat Karmally, Claudia V. Pereira, Galina Dvoriantchikova, Dmitry Ivanov, Kenji F. Tanaka, Carlos T. Moraes, Roberta Brambilla

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8 Citations (Scopus)

Abstract

Mitochondrial dysfunction has been implicated in the pathophysiology of neurodegenerative disorders, including multiple sclerosis (MS). To date, the investigation of mitochondrial dysfunction in MS has focused exclusively on neurons, with no studies exploring whether dysregulation of mitochondrial bioenergetics and/or genetics in oligodendrocytes might be associated with the etiopathogenesis of MS and other demyelinating syndromes. To address this question, we established a mouse model where mitochondrial DNA (mtDNA) double-strand breaks (DSBs) were specifically induced in myelinating oligodendrocytes (PLP:mtPstI mice) by expressing a mitochondrial-targeted endonuclease, mtPstI, starting at 3 weeks of age. In both female and male mice, DSBs of oligodendroglial mtDNA caused impairment of locomotor function, chronic demyelination, glial activation, and axonal degeneration, which became more severe with time of induction. In addition, after short transient induction of mtDNA DSBs, PLP:mtPstI mice showed an exacerbated response to experimental autoimmune encephalomyelitis. Together, our data demonstrate that mtDNA damage can cause primary oligodendropathy, which in turn triggers demyelination, proving PLP:mtPstI mice to be a useful tool to study the pathological consequences of mitochondrial dysfunction in oligodendrocytes. In addition, the demyelination and axonal loss displayed by PLP:mtPstI mice recapitulate some of the key features of chronic demyelinating syndromes, including progressive MS forms, which are not accurately reproduced in the models currently available. For this reason, the PLP: mtPstI mouse represents a unique and much needed platform for testing remyelinating therapies.

Original languageEnglish
Pages (from-to)10185-10199
Number of pages15
JournalJournal of Neuroscience
Volume37
Issue number42
DOIs
Publication statusPublished - 2017 Oct 18

Keywords

  • Animal model
  • Demyelination
  • Mitochondria
  • Multiple sclerosis
  • Oxidative phosphorylation
  • Remyelination

ASJC Scopus subject areas

  • Neuroscience(all)

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  • Cite this

    Madsen, P. M., Pinto, M., Patel, S., McCarthy, S., Gao, H., Taherian, M., Karmally, S., Pereira, C. V., Dvoriantchikova, G., Ivanov, D., Tanaka, K. F., Moraes, C. T., & Brambilla, R. (2017). Mitochondrial DNA double-strand breaks in oligodendrocytes cause demyelination, axonal injury, and CNS inflammation. Journal of Neuroscience, 37(42), 10185-10199. https://doi.org/10.1523/JNEUROSCI.1378-17.2017