Anvers: In a collaboration with CNRS and the University of Antwerp, KU Leuven
neurobiologists have discovered that the shape of aggregates –
'cylinders' or 'ribbons' – determines whether a patient develops
Parkinson's disease or Multiple System Atrophy, respectively.
Several neurodegenerative disorders are caused by aggregates of a single protein known as alpha-synuclein. Typical of neurodegenerative disorders is the disrupted communication
between brain cells together with a loss of cells in specific brain
regions. For some brain diseases this phenomenon is linked to a protein
known as alpha-synuclein. The exact function of this protein remains
unclear, but it may play a role in the communication between brain
cells. However, in the case of specific diseases, including Parkinson’s
disease, Multiple System Atrophy (MSA), and dementia with Lewy bodies
(DLB), this protein forms aggregates that cause neurodegeneration.
“When alpha-synuclein aggregates accumulate within a brain cell, they
interfere with the normal functioning of the cell. The protein
aggregates disrupt the communication between brain cells, resulting in
cell death. Up to now, nobody understood how aggregates of this single
protein could induce different pathologies,” says Professor Veerle
Baekelandt from the Research Group for Neurobiology and Gene Therapy.
“You could compare it to the construction of a house,” doctoral
researcher Wouter Peelaerts explains. “With the same building blocks –
in this case the alpha-synuclein protein – you can create many different
structures. In 2013, Professor Ronald Melki and his colleagues from
CNRS isolated several forms of fibres called ‘strains’. The two most
important strains were cylinder-shaped fibres reminiscent of spaghetti
and broad ribbons that resemble linguini. We injected these fibres
separately into the brain and blood stream of rats. We noticed that the
rats developed different symptoms: while the ‘cylinders’ induced
Parkinson’s disease, the ‘ribbons’ caused MSA symptoms.” This clearly
demonstrates that distinct diseases result from alpha-synuclein fibres
that are structurally different.
“We are gaining more insight into the differences between the
diseases. But we suspect that more fibres with different shapes and
effects are waiting to be discovered, apart from the two that we
examined in this study. In any case, our findings open up possibilities
for the development of new treatments. A drug that counteracts the
development of aggregates could be used to treat a whole range of brain
diseases.”