Enteric alpha-synuclein expression is increased in Parkinson's disease but not Alzheimer's disease.
OBJECTIVE
Alpha-synuclein (α-Syn) is immunohistochemically detectable in enteric neurons in some subjects. We determined its age distribution in the general autopsy population and in an age-matched subset investigated differences with Parkinson's (PD) and Alzheimer's diseases (AD).


METHODS
Archival autopsy samples of colon from 95 cases (77 general population, 10 PD, and 8 AD) were immunostained with monoclonal antibody KM51. α-Syn detectability was semiquantitatively graded 1 to 3.


RESULTS
α-Syn was detectable in 52% of the general population, and its level of expression did not change between ages 40 and 91. All PD subjects were α-Syn positive, with higher prevalence (P = 0.001) and grade (P = 0.003) than age-matched controls. AD subjects were no more likely to be α-Syn positive or have a higher grade than controls.


CONCLUSIONS
Either PD develops selectively in the enterically α-Syn-positive population subset or PD induces this expression. Absence of increased α-Syn expression in AD points to differences in pathogenesis.
Laboratory Medicine, St. Michael's Hospital, University of Toronto & Li Ka Shing Knowledge Institute, Toronto, Ontario, Canada.
Andrea
A
Gold
Zorbey T
ZT
Turkalp
David G
DG
Munoz
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D001344:Autopsy; D001921:Brain / Q000473:pathology; D017615:Enteric Nervous System / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016631:Lewy Bodies / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009197:Myenteric Plexus / Q000473:pathology; D010300:Parkinson Disease / Q000378:metabolism* / Q000473:pathology; D013368:Submucous Plexus / Q000473:pathology; D055815:Young Adult; D051844:alpha-Synuclein / Q000096:biosynthesis*
D051844:alpha-Synuclein