Control of autophagosome axonal retrograde flux by presynaptic activity unveiled using botulinum neurotoxin type a.
J. Neurosci.. 2015-04-15; 35(15): 6179-6194
DOI: 10.1523/jneurosci.3757-14.2015
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1. J Neurosci. 2015 Apr 15;35(15):6179-94. doi: 10.1523/JNEUROSCI.3757-14.2015.
Control of autophagosome axonal retrograde flux by presynaptic activity unveiled
using botulinum neurotoxin type a.
Wang T(1), Martin S(1), Papadopulos A(1), Harper CB(1), Mavlyutov TA(2), Niranjan
D(3), Glass NR(4), Cooper-White JJ(5), Sibarita JB(6), Choquet D(7), Davletov
B(8), Meunier FA(9).
Author information:
(1)Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute.
(2)University of Wisconsin Medical School, Madison, Wisconsin 53706.
(3)Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH,
United Kingdom.
(4)Australian Institute for Bioengineering and Nanotechnology, and.
(5)Australian Institute for Bioengineering and Nanotechnology, and School of
Chemical Engineering, University of Queensland, Brisbane, Queensland 4072,
Australia, Materials Science and Engineering Division, Commonwealth Scientific
and Industrial Research Organization, Clayton, Victoria 3169, Australia.
(6)University of Bordeaux, Interdisciplinary Institute for Neuroscience, Centre
National de la Recherche Scientifique, Unité Mixte de Recherche 5297, Bordeaux,
France.
(7)University of Bordeaux, Interdisciplinary Institute for Neuroscience, Centre
National de la Recherche Scientifique, Unité Mixte de Recherche 5297, Bordeaux,
France, Bordeaux Imaging Center, Unité Mixte de Service 3420, Centre National de
la Recherche Scientifique, US4 INSERM, University of Bordeaux, France, and.
(8)Department of Biomedical Science, The University of Sheffield, Sheffield, S10
2TN, United Kingdom.
(9)Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute,
.
Botulinum neurotoxin type A (BoNT/A) is a highly potent neurotoxin that elicits
flaccid paralysis by enzymatic cleavage of the exocytic machinery component
SNAP25 in motor nerve terminals. However, recent evidence suggests that the
neurotoxic activity of BoNT/A is not restricted to the periphery, but also
reaches the CNS after retrograde axonal transport. Because BoNT/A is internalized
in recycling synaptic vesicles, it is unclear which compartment facilitates this
transport. Using live-cell confocal and single-molecule imaging of rat
hippocampal neurons cultured in microfluidic devices, we show that the
activity-dependent uptake of the binding domain of the BoNT/A heavy chain
(BoNT/A-Hc) is followed by a delayed increase in retrograde axonal transport of
BoNT/A-Hc carriers. Consistent with a role of presynaptic activity in initiating
transport of the active toxin, activity-dependent uptake of BoNT/A in the
terminal led to a significant increase in SNAP25 cleavage detected in the soma
chamber compared with nonstimulated neurons. Surprisingly, most endocytosed
BoNT/A-Hc was incorporated into LC3-positive autophagosomes generated in the
nerve terminals, which then underwent retrograde transport to the cell soma,
where they fused with lysosomes both in vitro and in vivo. Blocking autophagosome
formation or acidification with wortmannin or bafilomycin A1, respectively,
inhibited the activity-dependent retrograde trafficking of BoNT/A-Hc. Our data
demonstrate that both the presynaptic formation of autophagosomes and the
initiation of their retrograde trafficking are tightly regulated by presynaptic
activity.
Copyright © 2015 the authors 0270-6474/15/356179-16$15.00/0.
DOI: 10.1523/JNEUROSCI.3757-14.2015
PMCID: PMC4787026
PMID: 25878289 [Indexed for MEDLINE]