To extend our previous finding in a larger sample and further determine the role of SNCA in the development of PD, we screened a sample of 194 familial PD (FPD), 327 sporadic PD (SPD), and 215 controls with the Rep1 marker and 2 single nucleotide polymorphisms (SNPs) (770 and int4) in the SNCA gene.
Small molecules targeting αSyn reverted the degenerative phenotype under both basal and induced stress conditions, indicating a treatment strategy for PD and other synucleinopathies.
Brain regions with and without a Parkinson's disease-related increase in α-synuclein levels were assessed in autopsy samples from subjects with sporadic Parkinson's disease (n = 19) and age- and post-mortem delay-matched controls (n = 10).
We hypothesize dysregulated expression of wild-type alpha-synuclein results in parkinsonism and may explain the recent association of common SNCA variants in sporadic Parkinson's disease.
Patients with the alpha-synuclein mutation were significantly younger (mean 7.6 years), showed the first sign of the disease significantly earlier in life (mean 10.8 years), and had significantly longer duration of the disease compared with patients with sPD.
The protein alpha-synuclein accumulates in the brain of patients with sporadic Parkinson's disease (PD), and increased gene dosage causes a severe, dominantly inherited form of PD, but we know little about the effects of synuclein that precede degeneration. alpha-Synuclein localizes to the nerve terminal, but the knockout has little if any effect on synaptic transmission.
These data indicate that overexpression of alpha-synuclein is sufficient to cause olfactory deficits in mice similar to that observed in patients with PD.
Post mortem studies on familial and sporadic Parkinson's disease patient striatal tissue have shown that nearly 90% of α-synuclein deposited in Lewy-bodies is phosphorylated at serine-129 (pSyn-129) as opposed to only 4% in normal human brain.
We provide evidence for functional consequences of PD-associated SNCA gene variants at the 3' region, suggesting that genetic regulation of SNCA splicing plays an important role in the development of the disease.
In this review, we focus on the recent advances on the role of Rab GTPases in the biology of two main proteins involved in Parkinson's disease: LRRK2 and α-synuclein, given that mutations in their genes (LRRK2 and SNCA) cause familial and sporadic Parkinson's disease.
Genetic mouse models based on alpha-synuclein overexpression are particularly compelling because abnormal accumulation of alpha-synuclein occurs in sporadic Parkinson's disease (PD).
These findings reveal a significant additional mechanism by which alpha-synuclein is regulated and point toward new therapeutic regimes for lowering endogenous alpha-synuclein levels in patients with familial or sporadic Parkinson disease.