Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a method for the assay of urinary 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid), based on its separation on a microparticulate reversed-phase column and direct electrochemical detection. Patients with neuroblastoma, pheochromocytoma, and Parkinson's disease have increased amounts of this compound in their urine.
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PMID:Assay of 4-hydroxy-3-methoxyphenylacetic (homovanillic) acid by liquid chromatography with electrochemical detection. 50 5

Cultured human catecholaminergic and non-catecholaminergic donor cells were used in neural transplantation experiments in a rat model of Parkinson's disease. Using two different human catecholaminergic neuroblastoma cell lines, one control non-catecholaminergic neuroblastoma cell line, and one sham control (tissue culture medium), transplants were made into the striatum using a modified Ungerstedt hemiparkinsonian rat model. Significant decreases in apomorphine-induced rotational behavior were produced by two of three catecholaminergic cell lines. Grafted cells staining positively for tyrosine hydroxylase (TH) and catecholamine fluorescence indicated viable catecholamine activity in the two cell lines which produced reductions in rotational behavior. Catecholamine fluorescence was not detected in either of the two controls. These data suggest a link between catecholamine secretion by transplanted cells and motor improvement using a rat rotational behavior model.
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PMID:Transplantation of human neuroblastoma cells, catecholaminergic and non-catecholaminergic: effects on rotational behavior in Parkinson's rat model. 135 66

Brain-derived neurotrophic factor (BDNF) has recently been shown to enhance the survival of dopamine neurons in cultures derived from the embryonic rat mesencephalon. We now extend this study by demonstrating that, in addition to the effect of sustaining survival of dopaminergic neurons, BDNF also confers protection against the neurotoxic effects of 6-hydroxydopamine (6-OHDA) and N-methyl-4-phenylpyridinium ion (MPP+). Exposure of mesencephalic cultures to either 6-OHDA or MPP+ resulted in a loss of 70-80% of dopaminergic neurons, as determined by tyrosine hydroxylase (TH) immunocytochemistry. In BDNF-treated cultures, loss of TH-positive cells after exposure to either toxin was reduced to only 30%. To facilitate biochemical measurements, we studied SH-SY5Y dopaminergic neuroblastoma cells. BDNF was found to protect these cells from the dopaminergic neurotoxins, 6-OHDA and MPP+. Indicative of oxidative stress, treatment of SH-SY5Y cells with 10 microM 6-OHDA for 24 h caused a fivefold increase in the levels of oxidized glutathione (GSSG). Pretreatment with BDNF for 24 h completely prevented the rise in GSSG. Further examination revealed that BDNF increased the activity of the protective enzyme, glutathione reductase, by 100%. In contrast, BDNF had no effect on the activity of catalase. These results add further impetus to exploring the therapeutic potential of BDNF in animal models of Parkinson's disease.
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PMID:Brain-derived neurotrophic factor protects dopamine neurons against 6-hydroxydopamine and N-methyl-4-phenylpyridinium ion toxicity: involvement of the glutathione system. 845 44

The biochemical, pharmacological and immunological characterization of cells derived from human neuroblastoma tumors recently acquired great interest, since these cells may be a putative donor source for transplantation in animal models of neurological disorders. We measured monoamine levels, tyrosine hydroxylase (TH) immunostaining, and the expression of major histocompatibility cell surface antigens (MHC) in 7 human neuroblastoma cell lines. Three cell lines (LAN5, NB69 and CHP126) had high levels of monoamines. TH immunostaining was strongly positive in CHP126 and LAN5, and NB69. MHC were not detected in any of the cells with high catecholamine levels. Treatment with neuroleptics increased the metabolism of dopamine in LAN5 but not in NB69. The implantation of LAN5 cells in immunocompetent, unilaterally 6-hydroxydopamine-lesioned rats decreased the apomorphine-induced contralateral rotation. The effect of the implant was greatest in animals in which LAN5 neuroblastoma cells, pretreated with dibutyryl cyclic adenosine monophosphate (DBcAMP) and prostaglandin E1 (PGE1, were implanted into the cerebral ventricle ipsilateral to the lesion, and then irrigated with DBcAMP administered through a totally implanted drug delivery system. The effect of the implant decreased after the second week. Neuroblastoma cells were found in approximately 50% of the implanted animals. TH immunostaining was weak or absent in the grafted animals. Inflammatory changes were present in the majority of the brains examined. Extensive tumor growth was present in one animal implanted with untreated cells. Grafting of cells treated with DBcAMP and PGE1 plus with mitomycin C and bromodeoxyuridine in animals immunosuppressed with cyclosporin A reduced the apomorphine-induced rotation to 40-60% of baseline levels and this reduction persisted beyond the period of infusion with DBcAMP. Intraventricular infusion of DBcAMP in animals injected with cell culture medium produced a transient reduction of rotation to 70% of baseline. The amphetamine-induced rotation was not significantly reduced during the 4 weeks follow up. Atypical cells, consistent with surviving neuroblastoma cells, were observed in the brain of all transplanted animals. TH immunostaining was weak or negative in most cases. Human neuroblastoma cells may be an alternative donor tissue for the study of the effects of transplantation in animal models of Parkinson's disease.
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PMID:Biochemical properties of monoamine-rich human neuroblastoma cells. 256 96

Little is known about the molecular events mediating neurotransmitter release, a crucial step in synaptic transmission. In this paper, the biosynthesis and release of L-beta-3,4-dihydroxyphenylalanine (L-DOPA) and dopamine were analyzed in three heterologous cell lines after retroviral-mediated gene transfer of tyrosine hydroxylase (EC 1.14.16.2), the rate-limiting enzyme in catecholamine synthesis. A recombinant retrovirus encoding human tyrosine hydroxylase type I as well as neomycin-resistance gene was used to infect a fibroblast (NIH 3T3), a neuroblastoma (NS20 Y), and a neuroendocrine (AtT-20) cell line. After selection in the presence of neomycin and in tyrosine-free medium, high levels of exogenous tyrosine hydroxylase activity were detected in extracts of the three cell lines. High-performance liquid chromatography of cell extracts and culture supernatants confirmed that the three cell lines hydroxylated tyrosine to form L-DOPA and released this metabolite into the culture medium. Interestingly, the neuroendocrine cell line AtT-20 synthesized not only L-DOPA but also dopamine. Evoked secretion studies established that AtT-20 cells released the transmitter upon depolarization in a regulated, calcium-dependent way. We discuss the implication of this approach for the analyses of neurotransmitter release as well as in the context of degenerative disorders such as Parkinson disease.
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PMID:Retroviral transfer of a human tyrosine hydroxylase cDNA in various cell lines: regulated release of dopamine in mouse anterior pituitary AtT-20 cells. 257 Nov 52

We have isolated a heme protein from canine midbrains that possesses potent peroxidase activity. This enzyme catalyzes the oxidation of dopamine to neuromelanin in the presence of H2O2. We have further shown that the isolated peroxidase possesses potent cytotoxic activity in the presence of superoxide or H2O2 and Cl-. The enzyme possesses an endogenous NAD(P)H oxidase activity that can promote the cytotoxic activity by virtue of its production of superoxide. Other enzymes such as dihydroorotate dehydrogenase and galactose oxidase, which produce O2- and H2O2, respectively, are also effective in promoting the cytotoxic activity of the brainstem peroxidase. Although rat erythrocytes were routinely used as the target cell, other cell types, including rat hepatoma and mouse neuroblastoma cells, are also susceptible to the toxic action of the peroxidase. The cytotoxic action of the brainstem peroxidase is dramatically enhanced by kainic acid and is significantly enhanced by Mn2+, whereas dopamine was found to be a potent inhibitor of the cytotoxic activity. Based on these findings, we postulate a central role for the brainstem peroxidase in dopamine metabolism as well as in the biochemical and anatomical changes associated with Parkinson's disease.
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PMID:Neuromelanogenic and cytotoxic properties of canine brainstem peroxidase. 302 61

The influence of memantine on several properties of a neuronal cell line was tested. The aim was to get some insight into possible mechanisms of action of this drug which is therapeutically applicable in treatment of spasticity, Parkinson's disease, and cerebral coma. In neuroblastoma X glioma hybrid cells, memantine, at micromolar concentrations, blocked the depolarization induced by iontophoretically applied serotonin (5-hydroxytryptamine, 5-HT). In the hybrid cells, receptors of the 5-HT3 type mediated the depolarization, which was frequently accompanied by a series of action potentials. The inhibition by memantine of the serotonin response occurred fast and was completely reversible, irrespective of whether the cell showed a stable membrane potential or spontaneous action potentials. However, memantine did not alter spontaneous or electrically evoked action potential activity in the hybrid cells, and apparently did not block the underlying ionic conductances. Furthermore memantine did not affect either the cation permeability activated by substance P in the hybrid cells or the K+ channel triggered by bradykinin in a glioma cell line. Thus, memantine appears specifically to suppress the ion channel opened by serotonin in the hybrid cells. The interaction of memantine with serotonin receptors and the associated ion channels reported here, might give an important clue, as to a site of action of memantine in the nervous system.
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PMID:Memantine (1-amino-3,5-dimethyladamantane) blocks the serotonin-induced depolarization response in a neuronal cell line. 335 74

Immature neurons, including fetal and tumoral cells, are used for investigating neuronal differentiation in vitro. The human neuroblastoma cell line NB69 could be induced to differentiate to dopamine or acetylcholine neurons by different compounds, including neurotrophins and activators of the protein kinases. In these NB69 cells dibutyryl cyclic AMP (dbcAMP) at 2 mM reduced the division rate and increased the levels of catecholamines, tyrosine hydroxylase (TH) activity, and monoamine oxidase activity. The dbcAMP also increased cell size, dendritic arborization, density of the sites for high-affinity dopamine uptake, and activity of choline acetyltransferase. In fetal rat midbrain neurons treatment with dbcAMP increased the levels of dopamine and the number of TH-immunoreactive neurons in the culture. When embryonic day 14 fetal midbrain neurons, previously exposed to 1 microM retinoic acid (a compound that severely reduces the number of fetal midbrain dopamine neurons), were treated with dbcAMP, the levels of dopamine and the number of TH-immunoreactive cells returned to normal levels. This suggests that dbcAMP induces the differentiation to dopamine neurons of quiescent progenitor or facilitates expression of the dopamine phenotype in immature neurons. Therefore, dbcAMP not only differentiates uncommitted immature dopamine neurons, but also reverses the antidopaminergic effects of retinoic acid. These properties of dbcAMP could be of therapeutic value in Parkinson's disease.
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PMID:Effects of dibutyryl cyclic AMP and retinoic acid on the differentiation of dopamine neurons: prevention of cell death by dibutyryl cyclic AMP. 759 58

Cells from a human neuroblastoma cell line (SH-SY5Y) have been used to examine their potential suitability as donor cells for neural transplantation. Grafts of SH-SY5Y cells were placed in the basal ganglia of the rat brain 7 days after kainic acid lesions of the striatum. The animals were killed 4 or 8 weeks following grafting, and light and electron microscopic studies showed that the graft formed a well-vascularized compact mass of cells in the host brain. At both time points grafted cells showed evidence of cellular differentiation with process formation, especially at the graft-host interface where there was intermingling of graft and host neuronal process. Electron microscopic studies showed that graft cell processes containing irregularly-shaped, clear vesicles or membrane-bound dense core vesicles, established regions of specialized contact with other graft cells and formed close associations with host neuronal processes. There was little difference between the grafts of different ages, except that in the older grafts there were early signs of neurodegeneration. Since the SH-SY5Y cells used in these grafts express the enzyme tyrosine hydroxylase and synthesize dopamine in vitro, these cells were used in the hope that they may potentially be useful for repairing lesions in the dopamine pathway, such as that seen in Parkinson's disease. Our behavioural studies show that grafting SH-SY5Y cells into the striatum of rats with 6-hydroxydopamine lesions of the median forebrain bundle result in a reduction of amphetamine-induced rotation. However, this was unlikely to be due to dopamine release since there was no tyrosine hydroxylase immunoreactivity seen in the region of the grafts. Thus grafted human neuroblastoma cells survive, establish specialized morphological associations with graft and host processes and improve behavioural deficits resulting from 6-hydroxydopamine lesions. We suggest that grafted differentiated human neuroblastoma cells can interact with cells in the host brain with beneficial effects, and that in the medium-term, neuroblastoma grafts will make useful models for examining graft-host interactions. However, the presence of early degenerative changes in the older grafts suggests that neuroblastoma cells may not be suitable for long-term neural transplantation therapy for neurodegenerative diseases.
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PMID:The morphology of human neuroblastoma cell grafts in the kainic acid-lesioned basal ganglia of the rat. 759 66

Oxidative stress, resulting either from excess generation or reduced scavenging of free radicals, has been proposed to play a role in damaging striatal neurons in Parkinson's disease. Since metallothionein is able to regulate the intracellular redox potential, we have undertaken a group of experiments to see whether or not 6-hydroxydopamine, which generates free radicals and is toxic to dopaminergic neurons, could alter the level of zinc and metallothionein. 6-Hydroxydopamine (8 micrograms in 4 microliters 0.02% ascorbic acid) reduced the level of zinc and metallothionein in the striatum but not other brain regions tested. Dopamine plus selegiline increased the synthesis of metallothionein in Chang cells as judged by enhanced incorporation of [35S]cysteine into metallothionein. The effect of dopamine was selective, in that dopamine could not stimulate the synthesis of metallothionein in neuroblastoma IMR-32 cells, which are devoid of dopaminergic receptors. The effect of dopamine in stimulating the synthesis of metallothionein was similar to that of zinc, known to generate the synthesis of metallothionein, and to that of H2O2 and FeS04, known to generate free radicals. The results of these experiments provide additional evidence that zinc or zinc metallothionein are altered in conditions where oxidative stress has taken place.
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PMID:The effects of 6-hydroxydopamine and oxidative stress on the level of brain metallothionein. 828 Nov 25


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