title: Noninvasive bioluminescence imaging of α-synuclein oligomerization in mouse brain using split firefly luciferase reporters.
abstract: Alpha-synuclein (αSYN) aggregation plays a pivotal role in the pathogenesis of Parkinson's disease and other synucleinopathies. In this multistep process, oligomerization of αSYN monomers is the first step in the formation of fibrils and intracytoplasmic inclusions. Although αSYN oligomers are generally considered to be the culprit of these diseases, the methodology currently available to follow-up oligomerization in cells and in brain is inadequate. We developed a split firefly luciferase complementation system to visualize oligomerization of viral vector-encoded αSYN fusion proteins. αSYN oligomerization resulted in successful luciferase complementation in cell culture and in mouse brain. Oligomerization of αSYN was monitored noninvasively with bioluminescence imaging in the mouse striatum and substantia nigra up to 8 months after injection. Moreover, the visualized αSYN oligomers retained their toxic and aggregation properties in both model systems. Next, the effect of two small molecules, FK506 and (-)-epigallocatechin-3-gallate (EGCG), known to inhibit αSYN fibril formation, was investigated. FK506 inhibited the observed αSYN oligomerization both in cell culture and in mouse brain. In conclusion, the split firefly luciferase-αSYN complementation assay will increase our insight in the role of αSYN oligomers in synucleinopathies and opens new opportunities to evaluate potential αSYN-based neuroprotective therapies.
authors.affiliation: KU Leuven, Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, 3000 Leuven, Flanders, Belgium.
authors.forename: Sarah-Ann
authors.initials: SA
authors.lastname: Aelvoet
authors.affiliation: KU Leuven, Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, 3000 Leuven, Flanders, Belgium, and.
authors.forename: Abdelilah
authors.initials: A
authors.lastname: Ibrahimi
authors.affiliation: KU Leuven, Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, 3000 Leuven, Flanders, Belgium.
authors.forename: Francesca
authors.initials: F
authors.lastname: Macchi
authors.affiliation: KU Leuven, Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, 3000 Leuven, Flanders, Belgium, and KU Leuven, Leuven Viral Vector Core, 3000 Leuven, Flanders, Belgium.
authors.forename: Rik
authors.initials: R
authors.lastname: Gijsbers
authors.affiliation: KU Leuven, Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, 3000 Leuven, Flanders, Belgium, KU Leuven, Leuven Viral Vector Core, 3000 Leuven, Flanders, Belgium.
authors.forename: Chris
authors.initials: C
authors.lastname: Van den Haute
authors.affiliation: KU Leuven, Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, 3000 Leuven, Flanders, Belgium, and.
authors.forename: Zeger
authors.initials: Z
authors.lastname: Debyser
authors.affiliation: KU Leuven, Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences, 3000 Leuven, Flanders, Belgium, veerle.baekelandt@med.kuleuven.be.
authors.forename: Veerle
authors.identifier: http://orcid.org/0000-0001-8966-2921
authors.initials: V
authors.lastname: Baekelandt
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D059290:Dopaminergic Neurons / Q000187:drug effects; D006801:Humans; D049409:Luciferases, Firefly / Q000235:genetics* / Q000378:metabolism; D008163:Luminescent Measurements / Q000379:methods*; D051379:Mice; D059906:Neuroimaging / Q000379:methods*; D018696:Neuroprotective Agents / Q000494:pharmacology; D066329:Protein Aggregates / Q000187:drug effects*; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism*; D016559:Tacrolimus / Q000494:pharmacology; D051844:alpha-Synuclein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018696:Neuroprotective Agents; D066329:Protein Aggregates; C497605:Snca protein, mouse; D051844:alpha-Synuclein; D002392:Catechin; C045651:epigallocatechin gallate; D049409:Luciferases, Firefly; D016559:Tacrolimus
keywords: alpha-synuclein; imaging; mice; noninvasive; oligomerization; split-Fluc