Beta-amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes
Article first published online: 15 JUN 2005
Journal of Neurochemistry
Volume 94, Issue 3, pages 607–616, August 2005
How to Cite
Tokay, T., Masmoudi, O., Gandolfo, P., Leprince, J., Pelletier, G., Vaudry, H. and Tonon, M.-C. (2005), Beta-amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes. Journal of Neurochemistry, 94: 607–616. doi: 10.1111/j.1471-4159.2005.03102.x
- Issue published online: 22 JUN 2005
- Article first published online: 15 JUN 2005
- Received September 16, 2004; revised manuscript received November 25, 2004; accepted November 25, 2004.
- β-amyloid protein;
- diazepam-binding inhibitor;
Accumulation of β-amyloid peptide (Aβ), which is a landmark of Alzheimer's disease, may alter astrocyte functions before any visible symptoms of the disease occur. Here, we examined the effects of Aβ on biosynthesis and release of diazepam-binding inhibitor (DBI), a polypeptide primarily expressed by astroglial cells in the CNS. Quantitative RT–PCR and specific radioimmunoassay demonstrated that aggregated Aβ25−35, at concentrations up to 10−4 m, induced a dose-dependent increase in DBI mRNA expression and DBI-related peptide release from cultured rat astrocytes. These effects were totally suppressed when aggregation of Aβ25−35 was prevented by Congo red. Measurement of the number of living cells revealed that Aβ25−35 induced a trophic rather than a toxic effect on astrocytes. Administration of cycloheximide blocked Aβ25−35-induced increase of DBI gene expression and endozepine accumulation in astrocytes, indicating that protein synthesis is required for DBI gene expression. Altogether, the present data suggest that Aβ-induced activation of endozepine biosynthesis and release may contribute to astrocyte proliferation associated with Alzheimer's disease.