The aggregation of NFTs, the abnormal hyperphosphorylation of tau protein, and the interaction between tau and alpha-synuclein may all contribute to the cell death and poor axonal transport observed in PD and Parkinsonism.
Here, we describe a novel missense mutation in exon 4 of SNCA encoding a H50Q substitution in a patient with dopa-responsive Parkinson's disease with a family history of parkinsonism and dementia.
Leucine-rich repeat kinase 2 (LRRK2) mutation is the most common cause of genetic-related parkinsonism and is usually associated with Lewy body pathology; however, tau, α-synuclein, and ubiquitin pathologies have also been reported.
However, MnCl(2) resulted in a significantly stronger decreased viability of cells overexpressing alpha-synuclein after 72 h. These findings suggest that manganese may co-operate with alpha-synuclein in triggering neuronal cell death such as seen in manganese parkinsonism.
The fact that Lewy bodies stain strongly with antibodies to asynuclein and that mutations in the alpha-synuclein gene lead to syndromes in which parkinsonism and dementia occur gives us important clues regarding the biologic processes leading to disease.
We also detected strong associations at SNCA on 4q22 (P = 7.35 x 10(-17)) and LRRK2 on 12q12 (P = 2.72 x 10(-8)), both of which are implicated in autosomal dominant forms of parkinsonism.
We included studies that reported data on CSF total, oligomeric and phosphorylated α-synuclein in patients with PD and healthy participants, neurological controls, or other parkinsonisms.
We briefly discuss some of the lessons we have learned from research into the physiological role of α-synuclein and its pathological links to neurodegeneration and parkinsonism.
Here, we investigated the kinase involved and show that the Tau-specific kinase, glycogen synthase kinase 3beta (GSK-3beta), is robustly activated in various MPP(+)/MPTP models of Parkinsonism (SH-SY5Y cotransfected cells, mesencephalic neurons, transgenic mice overexpressing alpha-Syn, and postmortem striatum of PD patients).
Mutations in five causative genes combined [alpha-Synuclein (SNCA), Parkin, PTEN-induced kinase 1 (PINK1), DJ-1, Leucine-rich repeat kinase 2 (LRRK2)] account for 2-3% of all cases with classical parkinsonism, often clinically indistinguishable from idiopathic Parkinson's disease.
There appears to be four common processes linking the two disorders, as mutations in genes associated with Parkinsonism initiate similar adverse biological reactions acknowledged to stimulate Mn-induced dopaminergic cell death including; (1) disruption of mitochondrial function leading to oxidative stress, (2) abnormalities in vesicle processing, (3) altered proteasomal and lysosomal protein degradation, and (4) α-synuclein aggregation The mutual neurotoxic processes provoked by mutations in these genes in concert with the biological disturbances produced by Mn, most likely, act in synchrony to contribute to the severity, characteristics and onset of both disorders.
<b>Results:</b> Plasma α-synuclein level was significantly increased in patients with PD and APS when compared with controls and FTD without parkinsonism (<i>p</i> < 0.01).
The identification of SNCA as the first gene implicated in monogenic parkinsonism led to the recognition of α-synuclein as a key protein in the pathogenesis and a major component of pathological hallmark lesions.
Synucleinopathies are a spectrum of neurodegenerative diseases characterized by the intracellular deposition of the protein α-synuclein leading to multiple outcomes, including dementia and Parkinsonism.
We examined 7 patients from a family harboring a novel mutation in the alpha-synuclein gene (E46K) that segregated with a phenotype of parkinsonism and dementia with Lewy bodies.