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)

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

Retinoic acid is synthesized from retinaldehyde by several different dehydrogenases, which are arranged in conserved spatial and developmentally regulated patterns. Here we show for the mouse that a class-1 aldehyde dehydrogenase, characterized by oxidation and disulfiram sensitivity, is found in the brain at high levels only in the basal forebrain. It is present in axons and terminals of a subpopulation of dopaminergic neurons of the mesostriatal and mesolimbic system, forming a retinoic acid-generating projection from the ventral tegmentum to the corpus striatum and the shell of the nucleus accumbens. In the striatum the projection is heaviest to dorsal and rostral regions, declining gradually toward ventral. The enzyme is expressed early in development, shortly after appearance of tyrosine hydroxylase. Other dopaminergic neurons in the brain, as well as the chromaffin cells of the adrenal medulla, do not contain this dehydrogenase. The presence of this enzyme may be a factor in the long-term success of transplants of dopaminergic cells to the corpus striatum in Parkinson disease, and it may play a role in parkinsonism and catatonia due to disulfiram (Antabuse) neurotoxicity.
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PMID:High levels of a retinoic acid-generating dehydrogenase in the meso-telencephalic dopamine system. 805 59

The retinoic acid-generating enzyme, aldehyde dehydrogenase (AHD), is expressed in a subpopulation of dopaminergic neurons found in the substantia nigra. Using AHD and tyrosine hydroxylase (TH) as immunohistochemical markers, we determined whether differential dissection of the embryonic (E16) ventral mesencephalon (VM) into its lateral and medial portions contributed equally to the number of TH cells surviving transplantation, if grafted AHD/TH neurons reinnervate the host striatum according to their normal projection patterns, and examined the functional recovery caused by the implanted cells as assessed by amphetamine-induced rotation in a 6-OHDA-lesioned model of Parkinson's disease. The embryonic tissue was transplanted as solid pieces injected via a 20-gauge lumbar puncture needle into the center of the deafferented striatum. Groups received either one complete ventral mesencephalic piece (VM), two medial pieces of ventral mesencephalic tissue (MVM), or two lateral pieces of ventral mesencephalic tissue (LVM). Both VM and MVM groups showed a significant decrease in amphetamine-induced rotation over time and, there was no difference in the degree of reduction observed between the two groups. Histological evaluation of the transplants revealed a much larger total number of surviving TH cells in grafts from the VM and MVM groups compared to the LVM group. Surviving AHD/TH neurons were found in all groups. Whereas TH staining of the transplanted striatum displayed a halo of graft-derived fibers all around the transplant and integration of these fibers into the host neuropil, AHD staining showed a preferential reinnervation of the dorsolateral striatum corresponding to the normal projection pattern of AHD/TH neurons. In summary, selective dissection of the embryonic ventral mesencephalon is possible, functional recovery as assessed by amphetamine-induced rotation in animals transplanted with MVM is similar to that seen in animals grafted with VM, and AHD/TH neurons have a selective reinnervation pattern in the PD transplantation paradigm. These findings may have implications for the grafting of fetal mesencephalic tissue in PD patients.
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PMID:Differential dissection of the rat E16 ventral mesencephalon and survival and reinnervation of the 6-OHDA-lesioned striatum by a subset of aldehyde dehydrogenase-positive TH neurons. 917 Nov 57

In retinoic acid-differentiated SH-SY5Y cells an endogenous neurotoxin N-methyl(R)salsolinol induced apoptotic cell death. Using a single cell gel electrophoresis (comet) assay, DNA damage was quantitatively measured, and it was found to depend on the concentration of N-methyl(R)salsolinol and the incubation time up to 6 h. The differentiated cells were more sensitive to N-methyl(R)salsolinol than the undifferentiated cells. Radical scavengers protected the cells from DNA damage, indicating oxidative stress is involved in the apoptotic cell process. These results suggest that apoptosis induced by endogenous neurotoxins might be the mechanism of the cell death of dopamine neurons in Parkinson's disease.
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PMID:A neurotoxin N-methyl(R)salsolinol induces apoptotic cell death in differentiated human dopaminergic neuroblastoma SH-SY5Y cells. 931 Mar 1

In the adult mouse, single and compound null mutations in the genes for retinoic acid receptor beta and retinoid X receptors beta and gamma resulted in locomotor defects related to dysfunction of the mesolimbic dopamine signaling pathway. Expression of the D1 and D2 receptors for dopamine was reduced in the ventral striatum of mutant mice, and the response of double null mutant mice to cocaine, which affects dopamine signaling in the mesolimbic system, was blunted. Thus, retinoid receptors are involved in the regulation of brain functions, and retinoic acid signaling defects may contribute to pathologies such as Parkinson's disease and schizophrenia.
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PMID:Impaired locomotion and dopamine signaling in retinoid receptor mutant mice. 945 86

Retinoic acids, bound to their receptors, function in the brain and pituitary gland by regulating the expression of the dopamine receptor D2R, which is a component of the dopaminergic system. The liganded retinoic acid receptors are specific transcription factors that are essential for full expression of D2R. D2R-knockout mice lack these retinoic acid receptors and exhibit a defect in locomotor ability similar to that seen in Parkinson's disease.
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PMID:Vitamin A functions in the regulation of the dopaminergic system in the brain and pituitary gland. 988 83

Programmed cell death (apoptosis) is an important mechanism shaping the size of different cell populations within the developing nervous system. In our study we used the NT2/D1 clone originally established from the Ntera 2 cell line to investigate the baseline levels of apoptosis in cultured postmitotic hNT (NT2-N) neurons previously treated for 3, 4 or 5 weeks with retinoic acid (RA) and compared it with apoptosis in NT2 precursors unexposed to RA. First, we examined whether different lengths of exposure to RA might affect baseline apoptotic rate in differentiating hNT neurons. Second, we investigated whether cultured hNT neurons, previously shown to possess dopaminergic characteristics, would be preferentially affected by apoptosis. Using the terminal deoxynucleotidyl transferase (tdt)-labeling technique we found that the postmitotic hNT neuronal cells exposed to RA demonstrated significantly higher numbers of apoptotic cells (12.5-15.8%) in comparison to rapidly dividing NT2 precursor cell line (3.6-4.4%) at both studied (1 and 5 days in vitro, DIV) time points. Similar apoptotic nuclear morphology, including a variable extent of nuclear fragmentation was observed in all examined hNT cultures. On the other hand, the incidence of apoptotic nuclei was rare in cultures of NT2 precursors not subjected to RA treatment. Combined immunocytochemistry for tyrosine hydroxylase (TH) and Hoechst staining revealed dopaminergic hNT neurons destined to die. Our double-labeling studies have demonstrated that only a subset of TH-positive hNT cells had condensed chromatin after 1 (approx. 15%) and 5 (approx. 20%) DIV. NT2 precursors were not TH-positive. Collectively, our results demonstrated that exposure to differentiating agent RA triggers an apoptotic commitment in a subset of postmitotic hNT neurons. These results suggest that this cell line may serve as a model of neuronal development to test various pathogenic factors implicated in the etiology of Parkinson's disease (PD), as well as to screen numerous pharmacological treatments that may slow or prevent dopaminergic deterioration.
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PMID:Apoptosis in cultured hNT neurons. 1128 65

Dysfunction of the ubiquitin-dependent proteolytic pathway contributes to progressive accumulation of ubiquitinated protein inclusions in neurodegenerative disorders, such as Parkinson's disease (PD). Ubiquitin C-terminal hydrolase-L1 (UCH-L1), alternatively designated protein gene product 9.5 (PGP9.5), is a neural deubiquitinating enzyme which is identified as a principal constituent of Lewy bodies. To clarify the regulatory mechanism of UCH-L1 expression in human neural cells, we studied the constitutive, cytokine/neurotrophic factor-regulated, and heat stress-induced expression of UCH-L1 in cultured human neural cell lines by Western blot analysis. The constitutive expression of UCH-L1 was identified in SK-N-SH neuroblastoma cells, IMR-32 neuroblastoma cells, U-373MG astrocytoma cells, and NTera2 teratocarcinoma-derived differentiated neurones (NTera2-N). The levels of UCH-L1 expression were unaltered in these cell lines following treatment with TNF-alpha, IL-1beta, BDNF, GDNF, dibutyryl cyclic AMP, or phorbol 12-myristate 13-acetate, and remained unchanged by exposure to heat stress. In contrast, its levels were elevated substantially in NTera2 teratocarcinoma cells following retinoic acid-induced neuronal differentiation, accompanied with an increased expression of alpha-synuclein and synaptophysin. These results indicate that UCH-L1 is expressed constitutively in human neual cell lines, where it is upregulated following induction of neuronal differentiation, but unaffected by exposure to heat stress, cytokines, or growth/differentiation factors which are supposed to be invloved in the nigral neuronal death and survival in PD.
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PMID:Ubiquitin C-terminal hydrolase-L1 (PGP9.5) expression in human neural cell lines following induction of neuronal differentiation and exposure to cytokines, neurotrophic factors or heat stress. 1143 90

Increasing evidence has indicated that proinflammatory cytokines such as TNF-alpha and IL-1beta, produced by activated microglia and astrocytes, play a key role in progressive degeneration of the nigrostriatal dopaminergic neurons in Parkinson's disease (PD). Since alpha-synuclein is a major component of Lewy bodies in PD brains, we studied the constitutive and cytokine/neurotrophic factor-regulated expression of alpha-synuclein in cultured human neurons by Northern blot and Western blot analyses. The constitutive expression of alpha-synuclein mRNA was identified in a variety of human neural and non-neural cell lines. The levels of alpha-synuclein expression were elevated markedly in NTera2 teratocarcinoma cells following retinoic acid-induced neuronal differentiation, accompanied with an increased expression of synphilin-1, while they were unaltered in NTera2-derived differentiated neurons by exposure to TNF-alpha, IL-1beta, BDNF or GDNF. These results indicate that alpha-synuclein expression in human neurons is up-regulated during differentiation, but is unaffected by a panel of cytokines and neurotrophic factors which are supposed to be involved in the nigral neuronal death and survival.
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PMID:Alpha-synuclein expression is up-regulated in NTera2 cells during neuronal differentiation but unaffected by exposure to cytokines and neurotrophic factors. 1147 75

Neuronal transplantation is considered to be a promising therapeutic approach to neurodegenerative diseases. In addition to fetal tissues and neural stem cells, embryonic stem cells are good candidates for the creation of neurons. We have recently identified a stromal cell-derived inducing activity that promotes neural differentiation of mouse embryoric stem cells. This activity accumulated on the surface of PA6 stromal cells and induced efficient neuronal differentiation of co-cultured embryonic stem cells under serum-free conditions without the use of either retinoic acid or embryoid bodies. A high proportion of tyrosine hydroxylase-positive neurons producing dopamine are obtained. Induction of neurons with stromal cell-derived inducing activity may be a useful new method for basic neuroscience research and therapeutic applications, including cell transplantation therapy for Parkinson's disease.
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PMID:Generation of dopaminergic neurons from embryonic stem cells. 1237 63


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