201. Investigation of the intercellular transmission of α-synuclein, amyloid-β and TDP-43
- Author
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Sackmann, Christopher and Sackmann, Christopher
- Abstract
Neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), frontotemporal lobar dementia (FTLD) and amyotrophic lateral sclerosis (ALS) are disorders characterized by the progressive deposition of proteinaceous inclusions throughout the brain in a predictable manner. Each disease is described by the involvement of different misfolded and aggregated proteins (AD, amyloid-β and tau; PD, α-synuclein; ALS and FTLD, TDP-43) that spread between anatomically connected brain regions, causing cell death in previously healthy regions. Disease progresses as these aggregated proteins spread throughout the brain in a prion-like fashion. Oligomeric forms of these proteins (aggregates comprising of ≈3-30 individual proteins) are thought to be the most relevant to disease, as they are capable of prion-like propagation and can cause cellular toxicity. The work in this thesis aims to elucidate the mechanisms by which different neurodegenerative disease related proteins (amyloid-β, α-synuclein and TDP-43) are taken up and transferred between cells, and the effects exerted by these proteins on downstream cells. Paper I examined the uptake and cell to cell transmission of oligomeric α-synuclein (α-syn). Using a 3D co-culture model, we determined that α-syn (monomeric, oligomeric and fibrillar assemblies) were readily taken up and transferred between neuron-like cells, and that this transfer was mediated by an endosomal/lysosomal mechanism. It was also determined that larger α-syn assemblies (oligomers and fibrils) were found in donor and acceptor cells more frequently than monomeric α-syn, which we speculate is a due to the larger aggregates’ resistance to cellular proteases. In Paper II, we identified a novel mechanism for the uptake of oligomeric proteins, in the discovery that the gap junction channel protein connexin 32 mediates the uptake of α-syn oligomers in a preferential manner. Gap junction proteins act as a means of communication between adjacent c
- Published
- 2019
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