Effect of rs3910105 in the Synuclein Gene on Dopamine Transporter Availability in Healthy Subjects

PURPOSE: The present study investigated associations between dopamine transporter (DAT) availability and α-synuclein levels in cerebrospinal fluid, as well as synuclein gene (SNCA) transcripts, and the effect of single nucleotide polymorphism of SNCA on DAT availability in healthy subjects. MATERIALS AND METHODS: The study population comprised healthy controls who underwent 123I-FP-CIT single-photon emission computed tomography screening. Five SNCA probes were used to target the boundaries of exon 3 and exon 4 (SNCA-E3E4), transcripts with a long 3′UTR region (SNCA-3UTR-1, SNCA-3UTR-2), transcripts that skip exon 5 (SNCA-E4E6), and the rare short transcript isoforms that comprise exons 1–4 (SNCA-007). RESULTS: In total, 123 healthy subjects (male 75, female 48) were included in this study. DAT availability in the caudate nucleus (p=0.0661) and putamen (p=0.0739) tended to differ according to rs3910105 genotype. In post-hoc analysis, DAT availability in the putamen was lower in subjects of TT genotype than those of CC/CT (p=0.0317). DAT availability in the caudate nucleus also showed a trend similar to that in the putamen (p=0.0597). Subjects of CT genotype with rs3910105 showed negative correlations with DAT availability in the putamen with SNCA-E3E4 (p=0.037, rho=−0.277), and SNCA-E4E6 (p=0.042, rho=−0.270), but not those of CC/TT genotypes. CONCLUSION: This is the first study to investigate the association of rs3910105 in SNCA with DAT availability. rs3910105 had an effect on DAT availability, and the correlation between DAT availability and SNCA transcripts were significant in CT genotypes of rs3910105.

MPTP-induced vulnerability of dopamine neurons in A53T α-synuclein overexpressed mice with the potential involvement of DJ-1 downregulation

Familial Parkinson's disease (PD) has been linked to point mutations and duplication of the α-synuclein (α-syn) gene. Mutant α-syn expression increases the vulnerability of neurons to exogenous insults. In this study, we developed a new PD model in the transgenic mice expressing mutant hemizygous (hemi) or homozygous (homo) A53T α-synuclein (α-syn Tg) and their wildtype (WT) littermates by treatment with sub-toxic (10 mg/kg, i.p., daily for 5 days) or toxic (30 mg/kg, i.p., daily for 5 days) dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Tyrosine hydroxylase and Bcl-2 levels were reduced in the α-syn Tg but not WT mice by sub-toxic MPTP injection. In the adhesive removal test, time to remove paper was significantly increased only in the homo α-syn Tg mice. In the challenging beam test, the hemi and homo α-syn Tg mice spent significantly longer time to traverse as compared to that of WT group. In order to find out responsible proteins related with vulnerability of mutant α-syn expressed neurons, DJ-1 and ubiquitin enzyme expressions were examined. In the SN, DJ-1 and ubiquitin conjugating enzyme, UBE2N, levels were significantly decreased in the α-syn Tg mice. Moreover, A53T α-syn overexpression decreased DJ-1 expression in SH-SY5Y cells. These findings suggest that the vulnerability to oxidative injury such as MPTP of A53T α-syn mice can be explained by downregulation of DJ-1.

siRNA-Mediated Suppression of Synuclein gamma Inhibits MDA-MB-231 Cell Migration and Proliferation by Downregulating the Phosphorylation of AKT and ERK / 한국유방암학회지

PURPOSE: Synuclein-gamma (SNCG), which was initially identified as breast cancer specific gene 1, is highly expressed in advanced breast cancers, but not in normal or benign breast tissue. This study aimed to evaluate the effects of SNCG siRNA-treatment on breast cancer cells and elucidate the associated mechanisms. METHODS: Vectors containing SNCG and negative control (NC) siRNAs were transfected into MDA-MB-231 cells; mRNA levels were determined by real-time polymerase chain reaction. Cell proliferation was evaluated using the MTT assay, cell migration was assessed by the Transwell assay, apoptosis and cell cycle analyses were conducted with the flow cytometer, and Western blot analysis was performed to determine the relative levels of AKT, ERK, p-AKT, and p-ERK expression. RESULTS: SNCG mRNA levels were significantly reduced in MDA-MB-231 cells transfected with SNCG siRNA. Our results indicate that in SNCG siRNA-treated cells, cell migration and proliferation decreased significantly, apoptosis was induced, and the cell cycle was arrested. Western blot analysis indicated that the protein levels of p-AKT and p-ERK were much lower in the SNCG siRNA-treated groups, than in the control and NC groups. CONCLUSION: SNCG siRNA could decrease the migration and proliferation of breast cancer cells by downregulating the phosphorylation of AKT and ERK.

The Effects of Recombinant Synucleins and Insulin-like Growth Factor 1 on Cancer Cell Migration

The synuclein family consists of three distinct genes, alpha-synuclein, beta-synuclein, and gamma-synuclein. The alpha-synuclein and beta-synuclein are predominately expressed in brain and especially alpha-synuclein is related with Parkinson's disease, Alzheimer's disease, and dementia with Lewy bodies. The gamma-synuclein was first identified as breast cancer specific gene 1. It is expressed in the peripheral nervous system and also detected in breast and ovarian cancers. The gamma-synuclein is also known to mediate metastasis of breast and ovarian cancer cells. Insulin-like growth factor 1 (IGF-I) is one of the growth factors that plays an important role in cell proliferation and migration in cancer cells, as well as in normal cells. In this study, we investigated the migrations of SKOV-3, MDAMB-231, and HeLa cells by the recombinant synuclein proteins (alpha-, beta-, and gamma-synucleins) and IGF-I and the molecular mechanism. Furthermore, we investigated the membrane ruffle formation of SKOV-3 cells by recombinant synuclein proteins and IGF-I. As a result, synucleins and IGF-I were found to induce cancer cell migrations. Simultaneous synucleins and IGF-I treatment on the cancer cells induced more migrations than the individual synuclein or IGF-I treatments. The synucleins or IGF-I treatments increased the expressions of membrane-type1 matrix metalloproteinase (MT1-MMP) and cluster of differentiation 44 (CD44). Moreover, simultaneous synucleins and IGF-I treatments further increased the expressions of MT1-MMP and CD44. The synucleins and IGF-I promoted the conformational change of actin filaments, and then this led to the membrane ruffle formation.

The gamma-Synuclein Expression in Breast Cancer and its Correlation with the Expression of the HER-2/neu Gene / 한국유방암학회지

PURPOSE: Synuclein has been identified as an important neuroprotein for developing pathologic deposits in Alzheimer's and Parkinson's disease patients. gamma-synuclein is also known as a breast cancer-specific gene 1 thats's not found in normal breast tissues but it has been reported to be overexpressed in breast cancer, ovarian cancer and other tumors. To evaluate the availability of gamma-synuclein expression as a prognostic factor for infiltrative breast cancer, we analyzed its correlation with the clinical parameters and the HER-2/neu gene expression. METHODS: Two hundred fiffty samples of breast cancer tissues embedded in paraffin and that were obtained from the infiltrative breast cancer patients who were operated in our institution from January 1995 to December 2000 were analyzed with employing the tissue microarray technique. The expression of gamma-synuclein was studied with immunohistochemistry and with using gamma-synulcein antibodies. One hundred thirty one cases that showed favorable staining were selected and studied retrospectively. RESULTS: Fiffty five% (71/131) of the patients showed gamma-synuclein overexpression. The histopathological findings that significantly correlated with gamma-synuclein overexpression were the number of metastatic lymph nodes (p<0.01) and the cancer stage (p<0.01). Using the same tissue mircoarray, the HER-2/neu gene expression and gamma-synuclein expression also showed statistically significant correlation (p=0.04). CONCLUSION: gamma-synuclein overexpression showed significant correaltion with lymph node metastasis and cancer stage. It also showed significant relevance with the HER-2/neu gene expression, and that is already known to be a prognostic factor for breast cancer. Therefore gamma-synuclein may be a useful prognostic factor for infiltrative breast cancer and further studies on the its correlation with survival, local recurrence, and distant metastasis should be conducted

Effect of repeated acute hypoxic treatment on the expression of alpha-synuclein in the mouse brain cortex / 生理学报

An anti-alpha-synuclein (alpha-SYN) monoclonal antibody produced in our laboratory was used to investigate the effect of repeated acute hypoxic treatments on the expression of alpha-SYN in the mouse cerebral cortex. Western blot analysis showed that the expression levels of alpha-SYN in the cortex changed accordingly upon hypoxic exposure times, as that the alpha-synuclein level significantly increased after the first hypoxic exposure and then dropped down to the background level after the fourth hypoxic exposure. Immunohistochemical staining revealed that the alpha-SYN-immunopositive substance was localized not only in the nerve endings, but also within the nuclei of some neurons. The cell density of the neurons with alpha-SYN immunopositive nuclei was increased significantly after the first hypoxic exposure but returned back to control levels after the fourth hypoxic exposure. Our results indicate that both of the alpha-SYN expression level in the brain and the number of the neurons with alpha-SYN positive nuclei are affected by the repeated acute hypoxic treatments and that this modification is hypoxic time-dependent. The mechanism and the physiological significance underlying these changes need to be further investigated.

Study on gamma-synuclein gene in patients with idiopathic Parkinson's disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the relationship between idiopathic Parkinson's disease (PD) and two polymorphisms (C243G and A377T) of the gamma-synuclein gene in a Chinese Han population of Shanghai area.</p><p><b>METHODS</b>Polymorphic genotyping was performed with PCR-RPLP technique. Association analysis was carried out in 145 unrelated idiopathic PD patients and 184 age-matched healthy controls.</p><p><b>RESULTS</b>The authors failed to detect any distributional difference of the C243G and A377T polymorphisms of the gamma-synuclein gene between PD cases and control subjects, nor did they find any association.</p><p><b>CONCLUSION</b>These data do not support that gamma-synuclein gene C243G and A377T polymorphisms are involved in idiopathic PD onset in the Han population of Shanghai area.</p>

Study on exons 3 and 4 of alpha-synuclein gene in Chinese familial Parkinson disease patients / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the relationship of Chinese familial Parkinson disease with alpha-synuclein gene.</p><p><b>METHODS</b>Polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and polymerase chain reaction-heteroduplex analysis(PCR-HA) were employed to detect the abnormal mobilization in the familial Parkinson disease and sporadic Parkinson disease patients, then it was verified by gene sequencing.</p><p><b>RESULTS</b>No mutation was found in alpha-synuclein gene exons 3 and 4 by PCR-SSCP together with PCR-HA. An inserted c and an inserted t were found in intron 4, position 23 and position 67 respectively.</p><p><b>CONCLUSION</b>(1) Exons 3 and 4 of alpha-synuclein gene are not the mutational hot spots of Chinese familial Parkinson disease. (2) Two polymorphisms were found in intron 4 of alpha-synuclein gene. They are 23 ins c and 67 ins t.</p>

Alpha-synuclein immunoreactivity and ultrastructural study of glial cytoplasmic inclusions in multiple system atrophy / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To understand the possible pathogenesis of sporadic multiple system atrophy (MSA).</p><p><b>METHODS</b>The immunoreactivity and ultrastructural features of glial cytoplasmic inclusions (GCIs) in 12 autopsy patients with MSA and 4 normal control groups were studied. All regional sections from each subject were evaluated with HE staining, Klüver-Barrera (KB), Holzer's, modified Gallyas-Braak's (GB) methods and immunohistochemical staining with alpha-synuclein and ubiquitin antibodies. Pontine white matter with abundant GCIs from case 1 was examined, using conventional electron microscopy, Gallyas-Braak's electron microscopy and immunoelectron microscopy.</p><p><b>RESULTS</b>The presence of GCIs as constantly demonstrated in all MSA patients. Strong alpha-synuclein immunoreactivity was observed in all of the ubiquitinated GCIs. However, the density of alpha-synuclein positive GCIs differed from case to case, and there was no relationship between the density of GCIs and age, sex, or MSA subtype. Ultrastructural features indicated that argyrophilic granule-associated filaments of about 25 nm in diameter were the predominant constituents of GCIs, and the anti alpha-synuclein antibody selectively labeled in these filaments. No GCIs and alpha-synuclein immunoreaction were found in control brain tissues.</p><p><b>CONCLUSIONS</b>GCI was a pathognomonic change in sporadic MSA patients. Accumulation of alpha-synuclein in GCIs may occur during the early stags of MSA. Seletcive alpha-synuclein positive abnormal microtubules in GCIs therefore play an important role in the pathogenesis of MSA.</p>