Formation of α-synuclein Lewy neurite–like aggregates in axons impedes the transport of distinct endosomes

Abstract

Aggregates of α-synuclein (α-syn) accumulate in neurons in Parkinson's disease and other synucleinopathies. These inclusions predominantly localize to axons even in the early stages of the disease, but their affect on axon function has remained unknown. Previously we established a model in which the addition of preformed α-syn fibrils to primary neurons seeds formation of insoluble α-syn inclusions built from endogenously expressed α-syn that closely recapitulate the neuropathological phenotypes of Lewy neurites found in human diseased brains. Here we show, using live-cell imaging, that immobile α-syn inclusions accumulate in axons from the recruitment of α-syn located on mobile α-syn-positive vesicles. Ultrastructural analyses and live imaging demonstrate that α-syn accumulations do not cause a generalized defect in axonal transport; the inclusions do not fill the axonal cytoplasm, disrupt the microtubule cytoskeleton, or affect the transport of synaptophysin or mitochondria. However, the α-syn aggregates impair the transport of Rab7 and TrkB receptor-containing endosomes, as well as autophagosomes. In addition, the TrkB receptor-associated signaling molecule pERK5 accumulates in α-syn aggregate-bearing neurons. Thus α-syn pathology impairs axonal transport of signaling and degradative organelles. These early effects of α-syn accumulations may predict points of intervention in the neurodegenerative process.

DOI: 10.1091/mbc.E14-02-0741

Extracted Key Phrases

010002000201520162017
Citations per Year

2,107 Citations

Semantic Scholar estimates that this publication has 2,107 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@inproceedings{VolpicelliDaley2014FormationO, title={Formation of α-synuclein Lewy neurite–like aggregates in axons impedes the transport of distinct endosomes}, author={Laura A Volpicelli-Daley and Karen L Gamble and Christine E. Schultheiss and Dawn M. Riddle and Andrew B. West and Virginia M.-Y. Lee}, booktitle={Molecular biology of the cell}, year={2014} }