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Lewy bodies (LBs) are the pathologic hallmark of Parkinson’s disease. Recent studies revealed that LBs exhibit several morphologic and molecular similarities to aggresomes. Aggresomes are perinuclear aggregates representing intracellular deposits of misfolded proteins. Recently, valosin-containing protein (VCP) was one of the components of LBs, suggesting its involvement in LB formation. Here, we showed the localization of VCP in aggresomes induced by a proteasome inhibitor in cultured cells. Cells overexpressing mutant VCP (K524M: D2) showed reduced aggresome formation relative to those overexpressing wild-type and mutant (K251M: D1) VCPs. Our findings suggest that the D2 domain is involved in aggresome formation.

Objective Recently, genomic multiplications of α-synuclein gene (SNCA) have been reported to cause hereditary early-onset parkinsonism. The objective of this study was to assess the frequency of SNCA multiplications among autosomal dominant hereditary Parkinson's disease (ADPD). Methods We screened 113 ADPD probands and 200 sporadic PD cases by quantitative polymerase chain reaction and confirmed SNCA multiplications by flurorescence in situ hybridization (FISH) and comparative genomic hybridization array. Results Two families (two patients from Family A and one from Family B) with SNCA duplication were identified among ADPD patients. Even though they had the same SNCA duplication, one patient had dementia. Because there was exactly the same difference between the regions originated from each patient, the finding suggests that the phenotype of SNCA multiplication may be also influenced by the range of duplication region. We also detected asymptomatic carriers in the families of both patients. Interestingly, the penetrance ratio was 33.3% (2/6) in one kindred, indicating that the ratio was very much lower than expected. Interpretation These two newly identified Japanese patients with SNCA duplication and the five previously identified American and European families with SNCA triplication or duplication mutations indicate that the incidence of SNCA multiplication may be more frequent than previously estimated. Ann Neurol 2006

In this report, we evaluated the allele frequency of the D/N394 single nucleotide polymorphism (SNP) in exon 11 of the parkin gene in 200 Japanese patients with sporadic Parkinson's disease (PD) and 200 normal controls. Although the reported allele frequency of G-to-A (D/N394) is 2% in Caucasians, this SNP was not detected in Japanese patients and healthy controls. Evaluation of L/I272 polymorphism, a C-to-A transition in exon 7, showed the polymorphism in only six controls, but not in PD patients. Our results suggest that the frequencies of parkin polymorphisms are different among Asians and Caucasians.

Ubiquitin is one of the major components of Lewy bodies (LB), the pathological hallmark of Parkinson’s disease (PD). Here, we identified that a phosphorylated form of IκBα (pIκBα), an inhibitor of NF-κB, and SCFβ-TrCP, the ubiquitin ligase of pIκBα, are components of LB in brains of PD patients. In vitro studies identified those proteins in the ubiquitin- and α-synuclein (known as the major component of LB)-positive LB-like inclusions generated in dopaminergic SH-SY5Y cells treated with MG132, a proteasome inhibitor. Intriguingly, IκBα migration into such ubiquitinated inclusions in cells treated with MG132 was inhibited by a cell-permeable peptide known to block phosphorylation of IκBα, although this peptide did not influence cell viability under proteasomal inhibition. Our results indicate that phosphorylation of IκBα plays a role in the formation of IκBα-containing inclusions caused by proteasomal dysfunction, and that the generation of such inclusion is independent of cell death caused by impairment of proteasome.

The authors have studied the preparation and the function of intelligent drug release membranes by UV curing. Temperature responsive fragrance release membranes were prepared by UV curing process and the release functions were investigated as the function of thickness and composition of membrane. Microscopic observations were used to prove the postulated release mechanism.

We recently identified a novel gene, parkin, as a pathogenic gene for autosomal recessive juvenile parkinsonism. Parkin encodes a 52-kDa protein with a ubiquitin-like domain and two RING-finger motifs. To provide a insight into the function of parkin, we have examined its intracellular distribution in cultured cells. We found that parkin was localized in the trans-Golgi network and the secretory vesicles in U-373MG or SH-SY5Y cells by immunocytochemical analyses. In the subsequent subcellular fractionation studies of rat brain, we showed that parkin was copurified with the synaptic vesicles (SVs) when we used low ionic conditions throughout the procedure. An immunoelectromicroscopic analysis indicated that parkin was present on the SV membrane. Parkin was readily released from SVs into the soluble phase by increasing ionic strength at neutral pH, but not by a non-ionic detergent. To elucidate its responsible region for membrane association, we transfected with green fluorescent protein-tagged deletion mutants of parkin into COS-1 cells followed by subcellular fractionation. We demonstrated the ability of parkin to bind to the membranes through a broad region except for the ubiquitin-like domain. The significance of SV localization of parkin is discussed.

Considering the involvement of ubiquitin-proteasome system (UPS) in Parkinson's disease (PD), the aim of the present study was to determine the distribution of proteasomes in PD brains. Immunohistochemical studies showed localization of 20S proteasome in the nuclei of neurons of the putamen and substantia nigra of PD. In contrast, no nuclear staining was observed in the same areas of brains of controls. Our results suggest that nuclear localization of 20S proteasome seems to be associated with the pathogenesis of PD.

Mutational dysfunction of PARKIN gene, which encodes a double RING finger protein and has ubiquitin ligase E3 activity, is the major cause of autosomal recessive juvenile Parkinsonism. Although many studies explored the functions of Parkin, its biochemical character is poorly understood. To address this issue, we established an E3 assay system using maltose-binding protein-fused Parkin purified from Escherichia coli. Using this recombinant Parkin, we found that not the front but the rear RING finger motif is responsible for the E3 activity of Parkin, and it catalyzes multiple monoubiquitylation. Intriguingly, for autosomal recessive juvenile Parkinsonism-causing mutations of Parkin, whereas there was loss of E3 activity in the rear RING domain, other pathogenic mutants still exhibited E3 activity equivalent to that of the wild-type Parkin. The evidence presented allows us to reconsider the function of Parkin-catalyzed ubiquitylation and to conclude that autosomal recessive juvenile Parkinsonism is not solely attributable to catalytic impairment of the E3 activity of Parkin.

Ubiquitin is one of the major components of Lewy bodies (LB), the pathological hallmark of Parkinson's disease (PD). Here, we identified that a phosphorylated form of IkappaBalpha (pIkappaBalpha), an inhibitor of NF-kappaB, and SCF(beta-TrCP), the ubiquitin ligase of pIkappaBalpha, are components of LB in brains of PD patients. In vitro studies identified those proteins in the ubiquitin- and alpha-synuclein (known as the major component of LB)-positive LB-like inclusions generated in dopaminergic SH-SY5Y cells treated with MG132, a proteasome inhibitor. Intriguingly, IkappaBalpha migration into such ubiquitinated inclusions in cells treated with MG132 was inhibited by a cell-permeable peptide known to block phosphorylation of IkappaBalpha, although this peptide did not influence cell viability under proteasomal inhibition. Our results indicate that phosphorylation of IkappaBalpha plays a role in the formation of IkappaBalpha-containing inclusions caused by proteasomal dysfunction, and that the generation of such inclusion is independent of cell death caused by impairment of proteasome.

In most patients with Parkinson’s disease (PD), the contribution of genetic and environmental factors remains to be elucidated. The importance of genes in PD was controversial for many years. It has become clear, however, genetic factors contribute to the pathogenesis of PD after identification of the distinct genetic loci for certain forms of familial PD (FPD) 1–6. In addition, the role of genetic factors is supported by the high concordance in twins using positron emission tomography (PET)1,2 and the increased risk among relatives of PD patients in case-control and family studies3,4. These findings indicate that genetic factors contribute to PD susceptibility. It is now clear that clinically defined PD represents a heterogeneous disorders that encompasses a small proportion of individuals with inherited disease and a large population with seemingly sporadic disease.

We administered 400 mg of bezafibrate daily to 27 patients with hyperlipidemia for seven moths. Most biochemical parameters remained unchanged, whereas levels of alkaline phosphatase (Al-P)and gamma-glutamyl transpeptidase (gamma-GTP), which are the hepatobiliary enzymes, were significantly decreased. Blood lipid levels were improved. Al-P levels decreased significantly from the baseline level of 174.5 IU/l to 116.7 IU/l (-26.5%) and gamma-GTP levels also decreased from 64.4 IU/l to 34.4 IU/l (-29.5%) (p < 0.001). When we compared the changes in serum lipid levels with those in Al-P and gamma-GTP levels following bezafibrate therapy, we found a slight degree of correlation between changes in gamma-GTP and triglyceride (T-G) levels, but no correlation at all between the changes of Al-P and total-cholesterol (T-cho), T-G or high density lipoprotein cholesterol (HDL-C). A close correlation was observed between both Al-P and gamma-GTP (r = 0.81, p < 0.001). From these results it was suggested that bezafibrate has not only a lipid lowering effect but has a favorable efficacy on the hepatobiliary enzymes.