Comparative Studies in the A30P and A53T α-Synuclein C. elegans Strains to Investigate the Molecular Origins of Parkinson's Disease.

Michele Perni,Ryan Limbocker,Michele Vendruscolo,Janet R Kumita,Tessa Sinnige,Giuliana Fusco,Romain F Laine,Julius B Kirkegaard,Gabriele S Kaminski Schierle,Serene W Chen,Denise Barbut,Clemens F Kaminski,Catherine K Xu,Francesco A Aprile,Patrick Flagmeier,Pietro Sormanni,Michael Zasloff,Tjakko J Van Ham,Christopher M Dobson,Alfonso De Simone,Tuomas P J Knowles,Ellen A A Nollen,Annemieke Van Der Goot,Kai Yu ,Karen L Thijssen ,Samuel I Cohen ,M Müller ,Renée I Seinstra ,Pavan Kumar Challa

doi:10.3389/fcell.2021.552549

Abstract

The aggregation of α-synuclein is a hallmark of Parkinson's disease (PD) and a variety of related neurological disorders. A number of mutations in this protein, including A30P and A53T, are associated with familial forms of the disease. Patients carrying the A30P mutation typically exhibit a similar age of onset and symptoms as sporadic PD, while those carrying the A53T mutation generally have an earlier age of onset and an accelerated progression. We report two C. elegans models of PD (PDA30P and PDA53T), which express these mutational variants in the muscle cells, and probed their behavior relative to animals expressing the wild-type protein (PDWT). PDA30P worms showed a reduced speed of movement and an increased paralysis rate, control worms, but no change in the frequency of body bends. By contrast, in PDA53T worms both speed and frequency of body bends were significantly decreased, and paralysis rate was increased. α-Synuclein was also observed to be less well localized into aggregates in PDA30P worms compared to PDA53T and PDWT worms, and amyloid-like features were evident later in the life of the animals, despite comparable levels of expression of α-synuclein. Furthermore, squalamine, a natural product currently in clinical trials for treating symptomatic aspects of PD, was found to reduce significantly the aggregation of α-synuclein and its associated toxicity in PDA53T and PDWT worms, but had less marked effects in PDA30P. In addition, using an antibody that targets the N-terminal region of α-synuclein, we observed a suppression of toxicity in PDA30P, PDA53T and PDWT worms. These results illustrate the use of these two C. elegans models in fundamental and applied PD research.

Highlights

Building on this evidence, we aimed to create a worm transgenic model expressing A30P and A53T variants that could be applied in high-throughput drug screening studies
We first characterized the behavior of the PDA30P and PDA53T worms in combination with the definition of the aggregation profile of α-syn in these two strains, and compared the results with the corresponding data for PDWT worms
We observed that well-established behavioral characteristics, such as body bends per minute (BPMs) (Van Ham et al, 2008; Gidalevitz et al, 2009; Van der Goot et al, 2012; Habchi et al, 2016, 2017; Aprile et al, 2017; Perni et al, 2017a,b), speed of movement (Morley et al, 2002; Van Ham et al, 2008; Gidalevitz et al, 2009) and paralysis rate (Link, 1995; Lublin and Link, 2013; Perni et al, 2017b), were all affected to different extents by the overexpression of the A30P and A53T variants (Figure 1)

Summary

Introduction

We aimed to create a worm transgenic model expressing A30P and A53T variants that could be applied in high-throughput drug screening studies. In order to explore the value of these worm models in the context of familial forms of PD, we used our recently developed high-throughput screening strategy (Perni et al, 2017b, 2018a,b) to investigate the effects of squalamine on the A30P and A53T worm variants developed in this study We complemented these studies by administering to our worm models an antibody that binds to a region of α-syn that has previously been identified to play a key structural role in its membrane-associated aggregation (Fusco et al, 2016) and to mitigate the toxicity of α-syn oligomers (Fusco et al, 2017)

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Conclusion