L-DOPA and glia-conditioned medium have additive effects on tyrosine hydroxylase expression in human catecholamine-rich neuroblastoma NB69 cells
| Autor: | E, Rodríguez-Martín, S, Canals, M J, Casarejos, S, de Bernardo, A, Handler, M A, Mena |
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| Rok vydání: | 2001 |
| Předmět: |
Time Factors
Tyrosine 3-Monooxygenase Dopamine Dopamine Agents Immunoblotting bcl-X Protein Apoptosis Ascorbic Acid Antioxidants Culture Media Serum-Free Levodopa Neuroblastoma In Situ Nick-End Labeling Tumor Cells Cultured Humans Enzyme Inhibitors Buthionine Sulfoximine Neurons Dose-Response Relationship Drug Carbidopa Cell Differentiation Glutathione Immunohistochemistry Proto-Oncogene Proteins c-bcl-2 Culture Media Conditioned Neuroglia |
| Zdroj: | Journal of neurochemistry. 78(3) |
| ISSN: | 0022-3042 |
| Popis: | The aim of this study was to investigate the effect of L-DOPA and glia-conditioned medium (GCM) on cell viability, tyrosine hydroxylase (TH) expression, dopamine (DA) metabolism and glutathione (GSH) levels of NB69 cells. L-DOPA (200 microM) induced differentiation of NB69 cells of more than 4 weeks in vitro, as shown by phase-contrast microscopy and TH immunocytochemistry, and decreased replication, as shown by 5-bromodeoxyuridine immunostaining. L-DOPA did not increase the number of necrotic or apoptotic cells, as shown by morphological features, Trypan Blue, lactate dehydrogenase activity, bis-benzimide staining and TUNEL assay. Furthermore, L-DOPA (200 microM) increased Bcl-xL protein expression. Incubation of cells with L-DOPA (50, 100, 200 microM) for 24 h resulted in an increase in TH protein levels (174, 196 and 212% versus control). Neither carbidopa, an inhibitor of L-aromatic amino acid decarboxylase enzyme, nor L-buthionine sulfoximine, which inhibits GSH synthesis, or ascorbic acid, an antioxidant, blocked the L-DOPA-induced effect on TH protein expression. L-DOPA (0, 50, 100 and 200 microM) plus GCM further increased the amount of TH protein (346, 446, 472 and 424%). L-DOPA (200 microM) increased TH protein levels to 132, 191 and 245% of controls after incubation for 24, 48 and 72 h. DA metabolism in NB69 cells was increased in cultures treated with either L-DOPA (200-300 microM) or GCM and these two agents had a synergistic effect on DA metabolism. In addition, L-DOPA (200 microM) or/and GCM-treated cells increased their GSH extracellular levels (223, 257, 300% of controls) after 48 h of treatment. The L-DOPA-induced increase of TH protein expression in NB69 cells was independent of DA production, free radicals and GSH up-regulation. |
| Databáze: | OpenAIRE |
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