Nanoscopic Characterisation of Individual Endogenous Protein Aggregates in Human Neuronal Cells.

Daniel R Whiten,Patrick Flagmeier,Steven F Lee,Mathew H Horrocks,Suman De,Sonia Gandhi,Rohan T Ranasinghe,Santiago E Sanchez,Minee-Liane Choi,David C Wirthensohn,Yukun Zuo,Laura Calo,Maria-Grazia Spillantini,Franziska Kundel,Christopher M Dobson,David Klenerman,Dilan Athauda

doi:10.1002/cbic.201800209

Abstract

The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson's and Alzheimer's diseases. These aggregates are highly heterogeneous in structure, generally of low abundance and typically smaller than the diffraction limit of light (≈250 nm). To overcome the challenges these characteristics pose to the study of endogenous aggregates formed in cells, we have developed a method to characterise them at the nanometre scale without the need for a conjugated fluorophore. Using a combination of DNA PAINT and an amyloid‐specific aptamer, we demonstrate that this technique is able to detect and super‐resolve a range of aggregated species, including those formed by α‐synuclein and amyloid‐β. Additionally, this method enables endogenous protein aggregates within cells to be characterised. We found that neuronal cells derived from patients with Parkinson's disease contain a larger number of protein aggregates than those from healthy controls.

Highlights

The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson’s and Alzheimer’s diseases
In Alzheimer’s disease (AD), the protein tau is deposited in intracellular inclusions,[2] while the amyloid beta (Ab) peptide is in extracellular plaques
Soluble nanometre-sized protein oligomers have been identified as the major cytotoxic species in AD and Parkinson’s disease (PD),[7,8,9,10] but the study of such species has remained challenging, as they tend to be low in abundance and adopt a wide range of heterogeneous structures

Summary

Introduction

The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson’s and Alzheimer’s diseases. Communications important to define the morphology and location of aggre- the Supporting Information) to generate SR images of protein gates in the cellular milieu in order to understand the interplay aggregates (Figure 1 D); we refer to this method as aptamer between protein aggregation and the loss of cellular homeo- DNA PAINT (ADPAINT).

Results

Conclusion