Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alpha-synuclein, a presynaptic protein, was found to be the major component in the Lewy bodies (LB) in both inherited and sporadic Parkinson's disease (PD). Furthermore, rare mutations of alpha-synuclein cause autosomal-dominant PD. However, it is unknown how alpha-synuclein is involved in the pathogenesis of nigral degeneration in PD. In this study, we examine the protein-protein interactions of wild-type and mutant (A53T) a-synuclein with adult human brain cDNA expression library using the yeast two-hybrid technique. We found that both normal and mutant alpha-synuclein specifically interact with the mitochondrial complex IV enzyme, cytochrome C oxidase (COX). Wild-type and mutant alpha-synuclein genes were further fused with c-Myc tag and translated in rabbit reticulocyte lysate. Using anti-c-Myc antibody, we demonstrated that both wild-type and mutant alpha-synuclein, coimmunoprecipitated with COX. We also showed that potassium cyanide, a selective COX inhibitor, synergistically enhanced the sensitivity of SH-SY5Y neuroblastoma cells to dopamine-induced cell death. In conclusion, we found specific protein-protein interactions of alpha-synuclein, a major LB protein, to COX, a key enzyme of the mithochondrial respiratory system. This interaction suggests that alpha-synuclein aggregation may contribute to enhance the mitochondrial dysfunction, which might be a key factor in the pathogenesis of PD.
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PMID:Mutant and wild-type alpha-synuclein interact with mitochondrial cytochrome C oxidase. 1205 41

Alpha-synuclein is a brain presynaptic protein that is linked to familiar early onset Parkinson's disease and it is also a major component of Lewy bodies in sporadic Parkinson's disease and other neurodegenerative disorders. Alpha-synuclein expression increases in substantia nigra of both MPTP-treated rodents and non-human primates, used as animal models of parkinsonism. Here we describe an increase in alpha-synuclein expression in a human neuroblastoma cell line, SH-SY5Y, caused by 5-100 microM MPP+, the active metabolite of MPTP, which induces apoptosis in SH-SY5Y cells after a 4-day treatment. We also analysed the activation of the MAPK family, which is involved in several cellular responses to toxins and stressing conditions. Parallel to the increase in alpha-synuclein expression we observed activation of MEK1,2 and ERK/MAPK but not of SAPK/JNK or p38 kinase. The inhibition of the ERK/MAPK pathway with U0126, however, did not affect the increase in alpha-synuclein. The highest increase in alpha-synuclein (more than threefold) in 4-day cultures was found in adherent cells treated with low concentrations of MPP+ (5 microM). Inhibition of ERK/MAPK reduced the damage caused by MPP+. We suggest that alpha-synuclein increase and ERK/MAPK activation have a prominent role in the cell mechanisms of rescue and damage, respectively, after MPP+ -treatment.
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PMID:MPP+ increases alpha-synuclein expression and ERK/MAP-kinase phosphorylation in human neuroblastoma SH-SY5Y cells. 1206 70

Chronic systemic complex I inhibition caused by rotenone exposure induces features of Parkinson's disease (PD) in rats, including selective nigrostriatal dopaminergic degeneration and formation of ubiquitin- and alpha-synuclein-positive inclusions (Betarbet et al., 2000). To determine underlying mechanisms of rotenone-induced cell death, we developed a chronic in vitro model based on treating human neuroblastoma cells with 5 nm rotenone for 1-4 weeks. For up to 4 weeks, cells grown in the presence of rotenone had normal morphology and growth kinetics, but at this time point, approximately 5% of cells began to undergo apoptosis. Short-term rotenone treatment (1 week) elevated soluble alpha-synuclein protein levels without changing message levels, suggesting that alpha-synuclein degradation was retarded. Chronic rotenone exposure (4 weeks) increased levels of SDS-insoluble alpha-synuclein and ubiquitin. After a latency of >2 weeks, rotenone-treated cells showed evidence of oxidative stress, including loss of glutathione and increased oxidative DNA and protein damage. Chronic rotenone treatment (4 weeks) caused a slight elevation in basal apoptosis and markedly sensitized cells to further oxidative challenge. In response to H2O2, there was cytochrome c release from mitochondria, caspase-3 activation, and apoptosis, all of which occurred earlier and to a much greater extent in rotenone-treated cells; caspase inhibition provided substantial protection. These studies indicate that chronic low-grade complex I inhibition caused by rotenone exposure induces accumulation and aggregation of alpha-synuclein and ubiquitin, progressive oxidative damage, and caspase-dependent death, mechanisms that may be central to PD pathogenesis.
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PMID:An in vitro model of Parkinson's disease: linking mitochondrial impairment to altered alpha-synuclein metabolism and oxidative damage. 1217 98

Nur-related factor 1 (Nurr1), nerve growth factor-induced gene B (NGFI-B) and neuron-derived orphan receptor-1 (NOR-1) constitute the orphan nuclear receptor subfamily of transcription factors. Previous studies showed that midbrain dopaminergic neuronal precursor cells failed to differentiate in Nurr1-deficient mice. To investigate a role of Nurr1 in human neuronal function, Nurr1 mRNA expression was studied in human neural cell lines by RT-PCR and northern blot analysis. Nurr1, NGFI-B and NOR-1 mRNA were coexpressed in all human neural and nonneural cell lines under the serum-containing culture condition, except for SK-N-SH neuroblastoma, in which Nurr1 mRNA was undetectable. The levels of Nurr1, NGFI-B and NOR-1 mRNA were elevated markedly in NTera2 teratocarcinoma-derived neurons (NTera2-N), a model of differentiated human neurons, following a 1.5 or 3 h-exposure to 1 mM dibutyryl cyclic AMP or 100 nm phorbol 12-myristate 13-acetate. NGFI-B mRNA levels were also elevated in NTera2-N cells by exposure to 100 ng/mL brain-derived neurotrophic factor (BDNF). To identify Nurr1-target genes, the mRNA expression of 27 genes potentially involved in dopaminergic neuronal differentiation and survival, including BDNF, glia-derived neurotrophic factor, their receptors, tyrosine hydroxylase and alpha-synuclein, were studied in HEK293 cells following overexpression of Nurr1. None of these genes examined, however, showed significant changes. These results indicate that Nurr1, NGFI-B and NOR-1 mRNA are expressed constitutively in various human neural and non-neural cell lines under the serum-containing culture condition, and their levels are up-regulated in human neurons by activation of protein kinase A or protein kinase C pathway, although putative coactivators expressed in dopaminergic neuronal precursor cells might be required for efficient transcriptional activation of Nurr1-target genes.
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PMID:The constitutive and inducible expression of Nurr1, a key regulator of dopaminergic neuronal differentiation, in human neural and non-neural cell lines. 1256 61

Total gene expression analysis (TOGA) was used to identify genes that are differentially expressed in brain regions between the alcohol-naive, inbred alcohol-preferring (iP), and -nonpreferring (iNP) rats. alpha-Synuclein, expressed at >2-fold higher levels in the hippocampus of the iP than the iNP rat, was prioritized for further study. In situ hybridization was used to determine specific brain regions and cells expressing alpha-synuclein in the iP and iNP rats. Similar to alpha-synuclein mRNA levels, protein levels in the hippocampus were higher in iP rats than iNP rats. Higher protein levels were also observed in the caudate putamen of iP rats compared with iNP rats. Sequence analysis identified two single nucleotide polymorphisms in the 3' UTR of the cDNA. The polymorphism was used to map the gene, by using recombination-based methods, to chromosome 4, within a quantitative trait locus for alcohol consumption that was identified in the iP and iNP rats. A nucleotide exchange in the iNP 3' UTR reduced expression of the luciferase reporter gene in SK-N-SH neuroblastoma cells. These results suggest that differential expression of the alpha-synuclein gene may contribute to alcohol preference in the iP rats.
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PMID:alpha-Synuclein maps to a quantitative trait locus for alcohol preference and is differentially expressed in alcohol-preferring and -nonpreferring rats. 1266 21

Abnormal accumulation of alpha-synuclein in Lewy bodies is a neuropathological hallmark of both sporadic and familial Parkinson's disease (PD). Although mutations in alpha-synuclein have been identified in autosomal dominant PD, the mechanism by which dopaminergic cell death occurs remains unknown. We investigated transcriptional changes in neuroblastoma cell lines transfected with either normal or mutant (A30P or A53T) alpha-synuclein using microarrays, with confirmation of selected genes by quantitative RT-PCR. Gene products whose expression was found to be significantly altered included members of diverse functional groups such as stress response, transcription regulators, apoptosis-inducing molecules, transcription factors and membrane-bound proteins. We also found evidence of altered expression of dihydropteridine reductase, which indirectly regulates the synthesis of dopamine. Because of the importance of dopamine in PD, we investigated the expression of all the known genes in dopamine synthesis. We found co-ordinated downregulation of mRNA for GTP cyclohydrolase, sepiapterin reductase (SR), tyrosine hydroxylase (TH) and aromatic acid decarboxylase by wild-type but not mutant alpha-synuclein. These were confirmed at the protein level for SR and TH. Reduced expression of the orphan nuclear receptor Nurr1 was also noted, suggesting that the co-ordinate regulation of dopamine synthesis is regulated through this transcription factor.
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PMID:Co-ordinate transcriptional regulation of dopamine synthesis genes by alpha-synuclein in human neuroblastoma cell lines. 1271 27

alpha-Synuclein accumulates in Lewy bodies and two missense mutations, A30P and A53T, have been linked to familial Parkinson's disease. Neither the normal function of alpha-synuclein nor the pathomechanism of alpha-synuclein-induced neuropathy are known. SK-N-MC neuroblastoma cells were transiently transfected with either wt alpha-synuclein, or its mutants, and their abilities to protect against oxidative stress were assessed. At low expression levels (1 microg cDNA/10(5) cells), all three synuclein variants were devoid of any effect on dopamine-induced cytotoxicity and nitrite production, whereas at higher expression (5 microg cDNA/10(5) cells), the variants enhanced dopamine-mediated effects. Low levels of wt alpha-synuclein blocked H(2)O(2)-induced cytotoxicity and nitrite production, a protective effect that was partly decreased upon higher expression. Both A30P and A53T increased in a dose-dependent manner H(2)O(2)-induced nitrite production and cell death. These results show an absence of protective effects for the A30P/A53T mutants, and a differential cytoprotective role of alpha-synuclein against oxidants, which varies according to expression levels.
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PMID:Differential cytotoxicity of dopamine and H2O2 in a human neuroblastoma divided cell line transfected with alpha-synuclein and its familial Parkinson's disease-linked mutants. 1272 33

alpha-Synuclein accumulation plays an important role in the pathogenesis of Lewy body disease (LBD) and Parkinson's disease (PD). Although the mechanisms are not yet clear, it is possible that dysregulation of the extracellular signal-regulated kinase (ERK) might play a role. As caveolins form scaffolds onto which signaling molecules such as ERK can assemble, we propose that signaling alterations associated with alpha-synuclein accumulation and neurodegeneration, might be mediated via caveolae. Therefore, the objective of the present study was to investigate the potential contribution of alterations in the caveolar system in mediating alpha-synuclein effects on the ERK signaling pathway. For this, synuclein-transfected B103 neuroblastoma cells were used as a model system. In this cell line, caveolin-1 expression was up-regulated, whereas, ERK was down-regulated. ERK was weakly but consistently co-immunoprecipitated with alpha-synuclein but caveolin-1 did not co-immunoprecipitate with alpha-synuclein. Moreover, treatment of alpha-synuclein- overexpressing cells with caveolin-1 antisense oligonucleotides resulted in stimulation of ERK activity, with amelioration of the neuritic alterations. Transduction of alpha-synuclein-overexpressing cells, with an adenoviral vector directing the expression of ERK, resulted in suppression of caveolin-1 expression and re-establishment of the normal patterns of neurite outgrowth. These results suggest that alpha-synuclein may also interfere with ERK signaling by dysregulating caveolin-1 expression. Thus, the caveolin-1/ERK pathway could be a therapeutic target for the alpha-synuclein-related neurodegenerative disorders.
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PMID:Alpha-synuclein up-regulates expression of caveolin-1 and down-regulates extracellular signal-regulated kinase activity in B103 neuroblastoma cells: role in the pathogenesis of Parkinson's disease. 1278 66

Free cytoplasmic dopamine may be involved in the genesis of neuronal degeneration in Parkinson's disease and other such diseases. We used SH-SY5Y human neuroblastoma cells to study the effect of dopamine on cell death, activation of stress-induced pathways, and expression of alpha-synuclein, the characteristic protein accumulated in Lewy bodies. We show that 100 and 500 microM dopamine causes a 40% and 60% decrease of viability, respectively, and triggers autophagy after 24 hr of exposure, characterized by the presence of numerous cytoplasmic vacuoles with inclusions. Dopamine causes mitochondrial aggregation in adherent cells prior to the loss of functionality. Plasma membrane and nucleus also maintain their integrity. Cell viability is protected by the dopamine transporter blocker nomifensine and the antioxidants N-acetylcysteine and ascorbic acid. Dopamine activates the stress-response kinases, SAPK/JNK and p38, but not ERK/MAPK or MEK, and increases alpha-synuclein expression. Both cell viability and the increase in alpha-synuclein expression are prevented by antioxidants; by the specific inhibitors of p38 and SAPK/JNK, SB203580 and SP600125, respectively; and by the inhibitor of autophagy 3-methyladenine. This indicates that oxidative stress, stress-activated kinases, and factors involved in autophagy up-regulate alpha-synuclein content. The results show that nonapoptotic death pathways are triggered by dopamine, leading to autophagy. These findings should be taken into account in the search for strategies to protect dopaminergic neurons from degeneration.
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PMID:Dopamine induces autophagic cell death and alpha-synuclein increase in human neuroblastoma SH-SY5Y cells. 1286 68

NACP-Rep1, a polymorphic microsatellite upstream of the alpha-synuclein gene ( SNCA), consisting of the nucleotides (TC)(x)(T)(2)(TC)(y)(TA)(z)(CA)(w), has five alleles originally defined by 2-bp differences in (CA)(w). Different NACP-Rep1 alleles have been associated with sporadic Parkinson's disease in some, but not all, studies and can effect expression driven by the SNCA promoter over a three-fold range in the neuroblastoma cell line, SH-SY5Y. By analyzing children in CEPH families in which parents appeared to be homozygous for a NACP-Rep1 allele, we found that there are sequence differences within same-sized NACP-Rep1 alleles, contributed mainly by variation of the (TC)(y)(TA)(z) portion of the microsatellite repeat. To test whether these sequence differences might impact on promoter function we determined the effect of two sequence variant alleles, both of size "1", using the luciferase reporter system. There was only a very small expression difference between these two variant alleles. This finding implies that the overall length of the NACP-Rep1 allele plays the main role in the transcription regulation by the NACP-Rep1 element and suggests that functional differences due to sequence heterogeneity within NACP-Rep1 alleles of the same length are probably not confounding factors in association studies based on alleles defined by length.
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PMID:Functional analysis of intra-allelic variation at NACP-Rep1 in the alpha-synuclein gene. 1292 82


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