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A progressive dopaminergic phenotype associated with neurotoxic conversion of α-synuclein in BAC-transgenic rats

2013; Oxford University Press; Volume: 136; Issue: 2 Linguagem: Inglês

10.1093/brain/aws358

1460-2156

Silke Nuber, Florian Harmuth, Zacharias Kohl, Anthony Adame, Margaritha Trejo, Kai Schönig, Frank Zimmermann, Claudia Bauer, Nicolas Casadei, Christiane Giel, Carsten Calaminus, Bernd J. Pichler, Poul Henning Jensen, Christian P. Müller, Davide Amato, Johannes Kornhuber, Peter Teismann, Hodaka Yamakado, Ryōsuke Takahashi, Jürgen Winkler, Eliezer Masliah, Olaf Rieß,

Neurological disorders and treatments

Conversion of soluble α-synuclein into insoluble and fibrillar inclusions is a hallmark of Parkinson's disease and other synucleinopathies. Accumulating evidence points towards a relationship between its generation at nerve terminals and structural synaptic pathology. Little is known about the pathogenic impact of α-synuclein conversion and deposition at nigrostriatal dopaminergic synapses in transgenic mice, mainly owing to expression limitations of the α-synuclein construct. Here, we explore whether both the rat as a model and expression of the bacterial artificial chromosome construct consisting of human full-length wild-type α-synuclein could exert dopaminergic neuropathological effects. We found that the human promoter induced a pan-neuronal expression, matching the rodent α-synuclein expression pattern, however, with prominent C-terminally truncated fragments. Ageing promoted conversion of both full-length and C-terminally truncated α-synuclein species into insolube and proteinase K-resistant fibres, with strongest accumulation in the striatum, resembling biochemical changes seen in human Parkinson's disease. Transgenic rats develop early changes in novelty-seeking, avoidance and smell before the progressive motor deficit. Importantly, the observed pathological changes were associated with severe loss of the dopaminergic integrity, thus resembling more closely the human pathology.