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The bacterial amyloids phenol soluble modulins from staphylococcus aureus catalyze alpha-synuclein aggregation

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DOI

  • Caroline Haikal, Sect. of Neurosci. at Lund Univ.
  • ,
  • Lei Ortigosa Pascual, Lund University
  • ,
  • Zahra Najarzadeh
  • ,
  • Katja Bernfur, Lund University
  • ,
  • Alexander Svanbergsson, Sect. of Neurosci. at Lund Univ.
  • ,
  • Daniel E. Otzen
  • Sara Linse, Lund University
  • ,
  • Jia Yi Li, Sect. of Neurosci. at Lund Univ., China Medical University

Aggregated α-synuclein (α-syn) is the main constituent of Lewy bodies, which are a pathological hallmark of Parkinson’s disease (PD). Environmental factors are thought to be potential triggers capable of initiating the aggregation of the otherwise monomeric α-syn. Braak’s seminal work redirected attention to the intestine and recent reports of dysbiosis have highlighted the potential causative role of the microbiome in the initiation of pathology of PD. Staphylococcus aureus is a bacterium carried by 30–70% of the general population. It has been shown to produce functional amy-loids, called phenol soluble modulins (PSMαs). Here, we studied the kinetics of α-syn aggregation under quiescent conditions in the presence or absence of four different PSMα peptides and observed a remarkable shortening of the lag phase in their presence. Whereas pure α-syn monomer did not aggregate up to 450 h after initiation of the experiment in neither neutral nor mildly acidic buffer, the addition of different PSMα peptides resulted in an almost immediate increase in the Thioflavin T (ThT) fluorescence. Despite similar peptide sequences, the different PSMα peptides displayed distinct effects on the kinetics of α-syn aggregation. Kinetic analyses of the data suggest that all four peptides catalyze α-syn aggregation through heterogeneous primary nucleation. The immunogold electron microscopic analyses showed that the aggregates were fibrillar and composed of α-syn. In addition of the co-aggregated materials to a cell model expressing the A53T α-syn variant fused to GFP was found to catalyze α-syn aggregation and phosphorylation in the cells. Our results provide evidence of a potential trigger of synucleinopathies and could have implications for the prevention of the diseases.

Original languageEnglish
Article number11594
JournalInternational Journal of Molecular Sciences
Volume22
Issue21
ISSN1661-6596
DOIs
Publication statusPublished - Nov 2021

Bibliographical note

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.

    Research areas

  • Aggregation, Alpha-synuclein, Bacterial amyloids, Parkinson’s disease, Protein folding

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