title: Alpha- and beta-synuclein expression in Parkinson disease with and without dementia.
abstract: Parkinson disease (PD) is the most important movement disorder and about 50% of patients develop dementia over the time. PD belongs to the group of Lewy body disorders. Alpha-synuclein (AS) is the main component of Lewy bodies and its aggregation is a key event in the pathogenesis of PD. Beta-synuclein (BS) inhibits AS aggregation in vitro and in vivo and has been shown to interact directly with AS regulating its functionality and preventing its oligomerization. Recently, we have described a molecular subgroup of DLB characterized by the drastic BS reduction in cortical areas. In this study we have analyzed the expression of two BS transcripts and the main AS transcript SNCA140, in frozen samples of three brain areas, temporal cortex, caudate nucleus and pons, from patients with PD and PDD in comparison with controls. Relative mRNA expression was determined by real-time PCR with SybrGreen, neuron-specific-enolase as housekeeping gene and the deltadeltaCt method. The most important difference in BS and AS mRNA expression between PD and PDD was found in the caudate nucleus, where BS mRNA was overexpressed in PD and AS mRNA diminished in PDD. Our findings provide new insights into the pathogenesis of dementia in PD, indicating that differential BS and AS expression in the caudate nucleus may represent one of the molecular mechanisms involved in these complex diseases.
authors.affiliation: Servicio de Anatomía Patológica, Hospital Universitario Germans Trias i Pujol, Universidad Autonoma de Barcelona, Spain. katrinbeyer@hotmail.com
authors.forename: Katrin
authors.initials: K
authors.lastname: Beyer
authors.forename: Lourdes
authors.initials: L
authors.lastname: Ispierto
authors.forename: Pilar
authors.initials: P
authors.lastname: Latorre
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
authors.forename: Aurelio
authors.initials: A
authors.lastname: Ariza
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D003704:Dementia / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D016631:Lewy Bodies / Q000473:pathology; D008297:Male; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology*; D011180:Postmortem Changes; D011569:Psychiatric Status Rating Scales; D013223:Statistics as Topic; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*; D051846:beta-Synuclein / Q000235:genetics / Q000378:metabolism*
chemical_list: D051844:alpha-Synuclein; D051846:beta-Synuclein