Transcription factor EB overexpression prevents neurodegeneration in experimental synucleinopathies
Marie-Laure Arotcarena, … , Erwan Bezard, Benjamin Dehay
Marie-Laure Arotcarena, … , Erwan Bezard, Benjamin Dehay
Published August 22, 2019
Citation Information: JCI Insight. 2019;4(16):e129719. https://doi.org/10.1172/jci.insight.129719.
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Research Article Neuroscience Therapeutics

Transcription factor EB overexpression prevents neurodegeneration in experimental synucleinopathies

Abstract

The synucleinopathies Parkinson’s disease (PD) and Multiple system atrophy (MSA) — characterized by α-synuclein intracytoplasmic inclusions into, respectively, neurons and oligodendrocytes — are associated with impairment of the autophagy-lysosomal pathways (ALP). Increased expression of the master regulator of ALP, transcription factor EB (TFEB), is hypothesized to promote the clearance of WT α-synuclein and survival of dopaminergic neurons. Here, we explore the efficacy of targeted TFEB overexpression either in neurons or oligodendrocytes to reduce the pathological burden of α-synuclein in a PD rat model and a MSA mouse model. While TFEB neuronal expression was sufficient to prevent neurodegeneration in the PD model, we show that only TFEB oligodendroglial overexpression leads to neuroprotective effects in the MSA model. These beneficial effects were associated with a decreased accumulation of α-synuclein into oligodendrocytes through recovery of the ALP machinery. Our study demonstrates that the cell type where α-synuclein aggregates dictates the target of TFEB overexpression in order to be protective, paving the way for adapted therapies.

Authors

Marie-Laure Arotcarena, Mathieu Bourdenx, Nathalie Dutheil, Marie-Laure Thiolat, Evelyne Doudnikoff, Sandra Dovero, Andrea Ballabio, Pierre-Olivier Fernagut, Wassilios G. Meissner, Erwan Bezard, Benjamin Dehay

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Figure 3

Sustainable TFEB transgene expression in vitro and in vivo.

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Sustainable TFEB transgene expression in vitro and in vivo. (A) Represen...
(A) Representative images (top) and quantification (bottom) of TFEB and HA tag immunoblotting in HEK293T cells transfected for 48 hours with the mTFEB-expressed plasmid under the neuronal CMVie/Synapsin promoter (CMVie/Synapsin-mTFEB-HA-WPRE). (B) Representative images (top) and quantification (bottom) of TFEB and Flag tag immunoblotting in HEK293T cells transfected for 48 hours with the mTFEB-expressed plasmid under the oligodendroglial promoter MBP (MBP-mTFEB-3×Flag-WPRE). Data represent mean ± SEM. Comparisons were made using nonparametric t test. *P < 0.05 compared with nontransfected cells. (C) Confocal images using HA tag and tyrosine hydroxylase (TH) antibodies in the ipsilateral SN of mice injected with the CMVie/Synpasin-mTFEB-HA virus 5 months after the injection. The white arrows indicate the presence of HA-tagged mTFEB signal into the nucleus of TH-positive neurons. Scale bar: 10 μm. (D) Representative images (top) and quantification (bottom) of HA tag immunoblotting in the ipsilateral SN of CMVie/Synapsin-mTFEB-HA–injected WT and PLP mice 5 months after the injection. n = 5 per group. Data represent mean ± SEM. Comparisons were made using 1-way ANOVA and Tukey’s correction for multiple comparisons. White bars, control; blue bars, CMVie/Synapsin-mTFEB-HA. (E) Confocal images using Flag tag and CNPase antibodies in the ipsilateral SN of mice injected with the MBP-mTFEB-3×Flag virus 5 months after the injection. The white arrow indicates the presence of Flag tag signals into the nucleus of CNPase-positive oligodendrocytes. Scale bar: 10 μm. (F) Representative images (top) and quantification (bottom) of Flag tag immunoblotting in the ipsilateral SN of MBP-mTFEB–injected WT and PLP mice 5 months after the injection. Data represent mean ± SEM. Comparisons were made using 1-way ANOVA and Tukey’s correction for multiple comparisons. White bars, control; green bars, MBP-mTFEB-3×Flag. In A, B, D, and F, lanes were run on the same gel but were noncontiguous.