Hsp104 antagonizes α-synuclein aggregation and reduces dopaminergic degeneration in a rat model of Parkinson disease
Christophe Lo Bianco, … , Susan Lindquist, Patrick Aebischer
Christophe Lo Bianco, … , Susan Lindquist, Patrick Aebischer
Published August 14, 2008
Citation Information: J Clin Invest. 2008;118(9):3087-3097. https://doi.org/10.1172/JCI35781.
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Research Article Neuroscience

Hsp104 antagonizes α-synuclein aggregation and reduces dopaminergic degeneration in a rat model of Parkinson disease

Abstract

Parkinson disease (PD) is characterized by dopaminergic neurodegeneration and intracellular inclusions of α-synuclein amyloid fibers, which are stable and difficult to dissolve. Whether inclusions are neuroprotective or pathological remains controversial, because prefibrillar oligomers may be more toxic than amyloid inclusions. Thus, whether therapies should target inclusions, preamyloid oligomers, or both is a critically important issue. In yeast, the protein-remodeling factor Hsp104 cooperates with Hsp70 and Hsp40 to dissolve and reactivate aggregated proteins. Metazoans, however, have no Hsp104 ortholog. Here we introduced Hsp104 into a rat PD model. Remarkably, Hsp104 reduced formation of phosphorylated α-synuclein inclusions and prevented nigrostriatal dopaminergic neurodegeneration induced by PD-linked α-synuclein (A30P). An in vitro assay employing pure proteins revealed that Hsp104 prevented fibrillization of α-synuclein and PD-linked variants (A30P, A53T, E46K). Hsp104 coupled ATP hydrolysis to the disassembly of preamyloid oligomers and amyloid fibers composed of α-synuclein. Furthermore, the mammalian Hsp70 and Hsp40 chaperones, Hsc70 and Hdj2, enhanced α-synuclein fiber disassembly by Hsp104. Hsp104 likely protects dopaminergic neurons by antagonizing toxic α-synuclein assemblies and might have therapeutic potential for PD and other neurodegenerative amyloidoses.

Authors

Christophe Lo Bianco, James Shorter, Etienne Régulier, Hilal Lashuel, Takeshi Iwatsubo, Susan Lindquist, Patrick Aebischer

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Figure 5

Hsp104 inhibits α-syn fibrillization.

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Hsp104 inhibits α-syn fibrillization. (A and B) Kinetics of rotated (80 ...
(A and B) Kinetics of rotated (80 rpm) α-syn (80 μM) fibrillization at 37°C without or with either Hsp104 (0.2–1.6 μM) plus ATP and regeneration system (20 mM creatine phosphate and 0.1 mg/ml creatine kinase), Hsp104 (0.2 μM) with no nucleotide, Hsp104 (0.2 μM) plus nonhydrolyzable ATP analogue (AMP-PNP), or Hsp104K218T:K620T (0.2 μM) plus ATP and regeneration system. Fibrillization was measured by ThT fluorescence (A) or sedimentation analysis (B). Values represent mean ± SD; n = 3. (C) EM of α-syn (80 μM) fibrillization at 37°C for 48 hours without or with Hsp104 (1.6 μM) plus ATP and regeneration system. Scale bar: 200 nm. (D) α-syn (80 μM) was incubated for 96 hours with rotation at 37°C in the presence or absence of Hsp104 (1.6 μM) plus ATP and regeneration system. After 72 hours, reactions were either supplemented with buffer or fresh Hsp104 (1.6 μM). Fibrillization was measured by ThT fluorescence. Values represent mean ± SD; n = 3. (E) Fibrillization kinetics of wild-type, A53T, A30P, E46K, S129A, and S129E α-syn (80 μM) in the presence or absence of Hsp104 (2 μM) plus ATP and regeneration system. Another reaction contained A53T (80 μM) plus Hsp104 (4 μM) with ATP and regeneration system. Reactions were rotated (80 rpm) at 37°C. Fibrillization was measured by ThT fluorescence. Values represent mean ± SD; n = 4.