Stimulation of astrocyte-enriched culture with arachidonic acid increases proenkephalin mRNA: involvement of proto-oncoprotein and mitogen activated protein kinases.
Brain Res Mol Brain Res
; 76(2): 396-406, 2000 Mar 29.
Article
em En
| MEDLINE
| ID: mdl-10762717
ABSTRACT
In astrocyte-enriched cultures, arachidonic acid (AA, 100 microM) significantly increased the proenkephalin (proENK) mRNA level (4. 9-fold at 8 h). In addition, AA also increased several AP-1 proteins, such as c-Fos, Fra-1, Fra-2, JunB, JunD, and c-Jun, or AP-1 and ENKCRE-2 DNA-binding activity. As well as AP-1 proteins and their DNA-binding activities, proENK mRNA level induced by AA was reduced by the pretreatment with 15 microM of cycloheximide (CHX; 1.6-fold). AA-dependent increase of proENK mRNA is not mediated by cyclooxygenase- or lipoxygenase-dependent metabolites, or free radicals, because the AA-induced increase of proENK mRNA levels was not affected by indomethacin (10 microM), nordihydroguaiaretic acid (10 microM), or N-acetylcysteine. However, as well as proto-oncoprotein levels, such as Fra-1, Fra-2, c-Jun, JunB, but not JunD, AA-induced increase of proENK mRNA was significantly reduced by the pretreatment with 10 microM of PD98059 (1.3-fold) or 10 microM of SB203580 (1.8-fold). These results strongly suggest that AA rather than one of its metabolites is involved in the increase of proENK mRNA. In addition, the activation of both the p38 and ERK pathways appears to be involved in the AA-induced increase of proENK mRNA via activating the expression of proto-oncoprotein, such as Fra-1, Fra-2, c-Jun, and JunB.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Precursores de Proteínas
/
Transcrição Gênica
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Encefalinas
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Córtex Cerebral
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Regulação da Expressão Gênica
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Astrócitos
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Proteínas Proto-Oncogênicas
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Ácido Araquidônico
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Proteínas Quinases Ativadas por Mitógeno
Limite:
Animals
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article