title: AAV1/2-induced overexpression of A53T-α-synuclein in the substantia nigra results in degeneration of the nigrostriatal system with Lewy-like pathology and motor impairment: a new mouse model for Parkinson's disease.
abstract: α-Synuclein is a protein implicated in the etiopathogenesis of Parkinson's disease (PD). AAV1/2-driven overexpression of human mutated A53T-α-synuclein in rat and monkey substantia nigra (SN) induces degeneration of nigral dopaminergic neurons and decreases striatal dopamine and tyrosine hydroxylase (TH). Given certain advantages of the mouse, especially it being amendable to genetic manipulation, translating the AAV1/2-A53T α-synuclein model to mice would be of significant value. AAV1/2-A53T α-synuclein or AAV1/2 empty vector (EV) at a concentration of 5.16 x 1012gp/ml were unilaterally injected into the right SN of male adult C57BL/6 mice. Post-mortem examinations included immunohistochemistry to analyze nigral α-synuclein, Ser129 phosphorylated α-synuclein and TH expression, striatal dopamine transporter (DAT) levels by autoradiography and dopamine levels by high performance liquid chromatography. At 10 weeks, in AAV1/2-A53T α-synuclein mice there was a 33% reduction in TH+ dopaminergic nigral neurons (P < 0.001), 29% deficit in striatal DAT binding (P < 0.05), 38% and 33% reductions in dopamine (P < 0.001) and DOPAC (P < 0.01) levels and a 60% increase in dopamine turnover (homovanilic acid/dopamine ratio; P < 0.001). Immunofluorescence showed that the AAV1/2-A53T α-synuclein injected mice had widespread nigral and striatal expression of vector-delivered A53T-α-synuclein. Concurrent staining with human PD SN samples using gold standard histological methodology for Lewy pathology detection by proteinase K digestion and application of specific antibody raised against human Lewy body α-synuclein (LB509) and Ser129 phosphorylated α-synuclein (81A) revealed insoluble α-synuclein aggregates in AAV1/2-A53T α-synuclein mice resembling Lewy-like neurites and bodies. In the cylinder test, we observed significant paw use asymmetry in the AAV1/2-A53T α-synuclein group when compared to EV controls at 5 and 9 weeks post injection (P < 0.001; P < 0.05). These data show that unilateral injection of AAV1/2-A53T α-synuclein into the mouse SN leads to persistent motor deficits, neurodegeneration of the nigrostriatal dopaminergic system and development of Lewy-like pathology, thereby reflecting clinical and pathological hallmarks of human PD.
authors.affiliation: Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany. ip_c@ukw.de.
authors.forename: Chi Wang
authors.identifier: http://orcid.org/0000-0003-0484-385X
authors.initials: CW
authors.lastname: Ip
authors.affiliation: Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
authors.forename: Laura-Christin
authors.initials: LC
authors.lastname: Klaus
authors.affiliation: Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
authors.forename: Akua A
authors.initials: AA
authors.lastname: Karikari
authors.affiliation: Morton and Gloria Shulman Movement Disorders Centre & Edmund J. Saffra Program in Parkinson's Disease, Toronto Western Hospital, Toronto Western Hospital, 399 Bathurst Street, 9MC 422, Toronto, ON, M5T 2S8, Canada.
authors.forename: Naomi P
authors.initials: NP
authors.lastname: Visanji
authors.affiliation: Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, 8KD402, Toronto, ON, M5T 2S8, Canada.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Brotchie
authors.affiliation: Morton and Gloria Shulman Movement Disorders Centre & Edmund J. Saffra Program in Parkinson's Disease, Toronto Western Hospital, Toronto Western Hospital, 399 Bathurst Street, 9MC 422, Toronto, ON, M5T 2S8, Canada.|Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, 8KD402, Toronto, ON, M5T 2S8, Canada.|Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.|Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.affiliation: Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Volkmann
authors.affiliation: Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, 8KD402, Toronto, ON, M5T 2S8, Canada.
authors.forename: James B
authors.initials: JB
authors.lastname: Koprich
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism / Q000473:pathology; D000229:Dependovirus / Q000235:genetics; D004298:Dopamine / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005822:Genetic Vectors; D006719:Homovanillic Acid / Q000378:metabolism; D006801:Humans; D008297:Male; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology*; D009154:Mutation; D009410:Nerve Degeneration / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D020734:Parkinsonian Disorders / Q000378:metabolism* / Q000473:pathology; D013378:Substantia Nigra / Q000378:metabolism* / Q000473:pathology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; C497604:SNCA protein, human; D051844:alpha-Synuclein; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine; D006719:Homovanillic Acid
keywords: A53T mutation; Lewy-like pathology; Mouse model; Parkinson’s disease; α-synuclein