A prolyl oligopeptidase inhibitor, KYP-2047, reduces α-synuclein protein levels and aggregates in cellular and animal models of Parkinson's disease.
OBJECTIVE
The aggregation of α-synuclein is connected to the pathology of Parkinson's disease and prolyl oligopeptidase (PREP) accelerates the aggregation of α-synuclein in vitro. The aim of this study was to investigate the effects of a PREP inhibitor, KYP-2047, on α-synuclein aggregation in cell lines overexpressing wild-type or A30P/A53T mutant human α-syn and in the brains of two A30P α-synuclein transgenic mouse strains.


METHODS
Cells were exposed to oxidative stress and then incubated with the PREP inhibitor during or after the stress. Wild-type or transgenic mice were treated for 5 days with KYP-2047 (2 × 3 mg·kg(-1) a day). Besides immunohistochemistry and thioflavin S staining, soluble and insoluble α-synuclein protein levels were measured by Western blot. α-synuclein mRNA levels were quantified by PCR. The colocalization of PREP and α-synuclein,and the effect of KYP-2047 on cell viability were also investigated.


RESULTS
In cell lines, oxidative stress induced a robust aggregation of α-synuclein,and low concentrations of KYP-2047 significantly reduced the number of cells with α-synuclein inclusions while abolishing the colocalization of α-synuclein and PREP. KYP-2047 significantly reduced the amount of aggregated α-synuclein,and it had beneficial effects on cell viability. In the transgenic mice, a 5-day treatment with the PREP inhibitor reduced the amount of α-synuclein immunoreactivity and soluble α-synuclein protein in the brain.


CONCLUSIONS
The results suggest that the PREP may play a role in brain accumulation and aggregation of α-synuclein, while KYP-2047 seems to effectively prevent these processes.
Division of Pharmacology and Toxicology, University of Helsinki, Finland. timo.myöhänen@helsinki.fi
T T
TT
Myöhänen
M J
MJ
Hannula
R
R
Van Elzen
M
M
Gerard
P
P
Van Der Veken
J A
JA
García-Horsman
V
V
Baekelandt
P T
PT
Männistö
A M
AM
Lambeir
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D009043:Motor Activity / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D020734:Parkinsonian Disorders / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D000085822:Prolyl Oligopeptidases; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D014162:Transfection; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*
C551540:4-phenylbutanoyl-prolylcyanopyrrolidine; D015842:Serine Proteinase Inhibitors; D051844:alpha-Synuclein; D011392:Proline; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases