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Retinoids and activation of PKC induce tissue-type plasminogen activator expression and storage in human astrocytes |
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Published in | Journal of thrombosis and haemostasis. 2008, vol. 6, no. 10, p. 1796-803 | |
Abstract | BACKGROUND: Emerging data demonstrate important roles for tissue-type plasminogen activator (t-PA) in the central nervous system (CNS). In contrast to endothelial cells, little is known about the regulation of t-PA gene expression and secretion in astrocytes. OBJECTIVES: The aims of the present study were to investigate whether t-PA gene expression is regulated by retinoids and the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) in human astrocytes, and to study whether t-PA is stored and subject to regulated release from these cells, as with endothelial cells. METHODS: Native human astrocytes were treated with RA and/or PMA. mRNA was quantified by real-time RT-PCR and protein secretion determined by ELISA. Intracellular t-PA immunoreactivity in astrocytes was examined by immunocyto- and histochemistry. RESULTS: RA and/or PMA induced a time-dependent increase in t-PA mRNA and protein levels in astrocytes, reaching 10-fold after combined treatment. This was associated with increased amounts of t-PA storage in intracellular granular structures. Both forskolin and histamine induced regulated release of t-PA. The presence of t-PA in reactive astrocytes was confirmed in human brain tissue. CONCLUSIONS: These data show that RA and PKC activation induce a strong up-regulation of t-PA expression in astrocytes, and increased intracellular storage pools. Moreover, a regulated release of t-PA can be induced from these cells. This raises the possibility that astrocytes contribute to the regulation of extracellular t-PA levels in the CNS. | |
Keywords | Astrocytes/metabolism — Brain Chemistry — Enzyme Activation/drug effects — Gene Expression Regulation — Humans — Kinetics — Protein Kinase C/metabolism — RNA, Messenger/analysis — Retinoids/pharmacology — Tetradecanoylphorbol Acetate/pharmacology — Tissue Plasminogen Activator/genetics/metabolism/secretion | |
Identifiers | PMID: 18647223 | |
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Research groups | Endothélium vasculaire (11) Recherche translationnelle : anomalies de l'hémostase et thromboses (504) | |
Citation (ISO format) | HULTMAN, K. et al. Retinoids and activation of PKC induce tissue-type plasminogen activator expression and storage in human astrocytes. In: Journal of thrombosis and haemostasis, 2008, vol. 6, n° 10, p. 1796-803. doi: 10.1111/j.1538-7836.2008.03084.x https://archive-ouverte.unige.ch/unige:2534 |