Internalisation and toxic effects resulting from the addition of extracellular hyperphosphorylated monomeric Tau
-
1
University of Mons, Belgium
As stated in our previous studies (Wauters et al., 2016), monomeric Tau protein (1-441) from a prokaryotic system was able to enter inside neurons when added in the extracellular space and more readily when it was hyperphosphorylated suggesting a role in the early transmission of pathological species. On second thoughts, we aimed to reproduce our manipulations by applying a more physiological Tau protein comprising post-translational modifications. As a result, we produced two recombinant Tau proteins with a C-terminal HaloTag in mammalian cells (HEK293T): a physiological phosphorylated form and an hyperphosphorylated form thanks to the overexpression of GSK3β. Following some adjustments, we succeeded to purify them using the HaloTag Protein Purification System (Promega). We are currently identifying their phosphorylation sites by western blotting and mass spectrometry. Moreover, we are in the process of testing the internalisation of proteins trough different concentrations and times of incubation. Besides the transmission part of the study, we planned to determine the adverse effects of proteins by immunocytochemistry (Synaptotagmin, AMPA subunits) and calcium imaging. While studies mostly focused on the transmission of aggregates into the brain, no direct proof of toxicity was demonstrated for now. In conclusion, if the hyperphosphorylated soluble Tau turned out to be toxic, it would be of interest to pay more attention to its implication in the propagation of Tau pathology before aggregation occurs.
La protéine Tau joue un rôle déterminant dans un ensemble de pathologies dénommées Tauopathies, dont fait partie la maladie d’Alzheimer. Normalement, la protéine participe au maintien du « squelette » des neurones jusqu’à la survenue d’une modification anormale (hyperphosphorylation) aboutissant à l’accumulation de celle-ci et à son agrégation. Ces agrégats, connus sous le terme de dégénérescences neurofibrillaires, sont considérés comme responsables de la propagation des lésions cérébrales au cours de la maladie d’Alzheimer. Cependant, de nouvelles pistes suggèrent que, lors des premières étapes de la maladie, la protéine seule, non-agrégée, pourrait être toxique pour les neurones. C’est cette potentielle toxicité que nous étudions dans un modèle in vitro de culture cellulaire.
Acknowledgements
M.W. is a recipient of a FRIA fellowship (F.R.S. – FNRS).
References
Wauters Mathilde, Wattiez Ruddy, Ris Laurence, "Internalization of the extracellular full-length Tau inside Neuro2A and cortical cells is enhanced by phosphorylation" in Biomolecules, 6(3), 36, 1-13, doi:10.3390/biom6030036 (2016)
Keywords:
Monomeric,
tau,
Phosphorylation,
Toxicicity,
Internalisation
Conference:
Belgian Brain Congress 2018 — Belgian Brain Council, LIEGE, Belgium, 19 Oct - 19 Oct, 2018.
Presentation Type:
e-posters
Topic:
NOVEL STRATEGIES FOR NEUROLOGICAL AND MENTAL DISORDERS: SCIENTIFIC BASIS AND VALUE FOR PATIENT-CENTERED CARE
Citation:
Wauters
M,
Leroy
B,
Coppée
F and
Ris
L
(2019). Internalisation and toxic effects resulting from the addition of extracellular hyperphosphorylated monomeric Tau.
Front. Neurosci.
Conference Abstract:
Belgian Brain Congress 2018 — Belgian Brain Council.
doi: 10.3389/conf.fnins.2018.95.00026
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
10 Aug 2018;
Published Online:
17 Jan 2019.
*
Correspondence:
Mrs. Mathilde Wauters, University of Mons, Mons, Belgium, mathilde.wauters@umons.ac.be