Recapitulating Parkinson's disease pathology in a three-dimensional human neural cell culture model.

Teresa R Taylor-Whiteley,James A Duce,Caroline F Dalton,David P Smith,Christine L Le Maitre

doi:10.1242/dmm.038042

Abstract

ABSTRACTExtensive loss of dopaminergic neurons and aggregation of the protein α-synuclein into ubiquitin-positive Lewy bodies represents a major neuropathological hallmark of Parkinson's disease (PD). At present, the generation of large nuclear-associated Lewy bodies from endogenous wild-type α-synuclein, translationally regulated under its own promoter in human cell culture models, requires costly and time-consuming protocols. Here, we demonstrate that fully differentiated human SH-SY5Y neuroblastoma cells grown in three-dimensional cell culture develop Lewy-body-like pathology upon exposure to exogenous α-synuclein species. In contrast to most cell- and rodent-based PD models, which exhibit multiple diffuse α-synuclein aggregates throughout the cytoplasm, a single large nuclear inclusion that is immunopositive for α-synuclein and ubiquitin is rapidly obtained in our model. This was achieved without the need for overexpression of α-synuclein or genetic modification of the cell line. However, phosphorylation of α-synuclein within these inclusions was not observed. The system described here provides an ideal tool to screen compounds to therapeutically intervene in Lewy body formation, and to investigate the mechanisms involved in disease progression in synucleinopathies.

Highlights

The presence of large cell-associated protein aggregates is the key pathological hallmark commonly associated with many neurodegenerative disorders (Poewe et al, 2017)
Longer neurite length was observed in both retinoic acid (RA) and RA+brain-derived neurotrophic factor (BDNF) groups compared to undifferentiated cells, with increased network complexity in the RA+BDNF group (Fig. 1A)
Findings presented here describe a human 3D cell culture model that recapitulates Lewy bodies (LBs)-like formation

Summary

Introduction

The presence of large cell-associated protein aggregates is the key pathological hallmark commonly associated with many neurodegenerative disorders (Poewe et al, 2017). In Parkinson’s disease (PD) and other synucleinopathies, the intrinsically disordered protein α-synuclein (α-syn) undergoes misfolding into amyloid fibrils (Poewe et al, 2017). These fibrils form the major protein component of intracellular deposits associated with Lewy bodies (LBs) in the cell soma, and Lewy neurites (LNs) in axons of surviving neurons (Theillet et al, 2016; Spillantini et al, 1997; Langston et al, 2015). Insights from in vitro and in vivo models suggest that α-syn acts as a ‘prionlike’ protein, with a propensity to misfold and form aggregates that promote cell-to-cell propagation, which assists in the spread of pathology (Braak et al, 2003; Li et al, 2008; Kordower et al, 2008; Danzer et al, 2009; Aulić et al, 2014; Hawkes et al, 2007)

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Conclusion