Prefibrillar Tau oligomers alter the nucleic acid protective function of Tau in hippocampal neurons in vivo

Marie Violet, Alban Chauderlier, Lucie Delattre, Meryem Tardivel, Meliza Sendid Chouala, Audrey Sultan, Elodie Marciniak, Sandrine Humez, Lester Binder, Rakez Kayed, Bruno Lefebvre, Eliette Bonnefoy, Luc Buée, Marie Christine Galas

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

The accumulation of DNA and RNA oxidative damage is observed in cortical and hippocampal neurons from Alzheimer's disease (AD) brains at early stages of pathology. We recently reported that Tau is a key nuclear player in the protection of neuronal nucleic acid integrity in vivo under physiological conditions and hyperthermia, a strong inducer of oxidative stress. In a mouse model of tauopathy (THY-Tau22), we demonstrate that hyperthermia selectively induces nucleic acid oxidative damage and nucleic acid strand breaks in the nucleus and cytoplasm of hippocampal neurons that display early Tau phosphorylation but no Tau fibrils. Nucleic acid-damaged neurons were exclusively immunoreactive for prefibrillar Tau oligomers. A similar association between prefibrillar Tau oligomers and nucleic acid oxidative damage was observed in AD brains. Pretreatment with Methylene Blue (MB), a Tau aggregation inhibitor and a redox cycler, reduced hyperthermia-induced Tau oligomerization as well as nucleic acid damage. This study clearly highlights the existence of an early and critical time frame for hyperthermia-induced Tau oligomerization, which most likely occurs through increased oxidative stress, and nucleic acid vulnerability during the progression of Tau pathology. These results suggest that at early stages of AD, Tau oligomerization triggers the loss of the nucleic acid protective function of monomeric Tau. This study highlights the existence of a short therapeutic window in which to prevent the formation of pathological forms of Tau and their harmful consequences on nucleic acid integrity during the progression of Tau pathology.

Original languageEnglish (US)
Pages (from-to)540-551
Number of pages12
JournalNeurobiology of Disease
Volume82
DOIs
StatePublished - Oct 1 2015

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Keywords

  • Alzheimer
  • DNA damage
  • Hyperthermia
  • Methylene Blue
  • Oxidative stress
  • RNA damage
  • Tau
  • Tau oligomers

ASJC Scopus subject areas

  • Neurology

Cite this

Violet, M., Chauderlier, A., Delattre, L., Tardivel, M., Chouala, M. S., Sultan, A., Marciniak, E., Humez, S., Binder, L., Kayed, R., Lefebvre, B., Bonnefoy, E., Buée, L., & Galas, M. C. (2015). Prefibrillar Tau oligomers alter the nucleic acid protective function of Tau in hippocampal neurons in vivo. Neurobiology of Disease, 82, 540-551. https://doi.org/10.1016/j.nbd.2015.09.003