Premium
Beta‐amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes
Author(s) -
Tokay Tursonjan,
Masmoudi Olfa,
Gandolfo Pierrick,
Leprince Jérôme,
Pelletier Georges,
Vaudry Hubert,
To MarieChristine
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03102.x
Subject(s) - cycloheximide , astrocyte , gene expression , biosynthesis , biology , peptide , amyloid precursor protein , alzheimer's disease , protein biosynthesis , microbiology and biotechnology , chemistry , biochemistry , endocrinology , medicine , gene , central nervous system , disease
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 Aβ 25−35 , 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 Aβ 25−35 was prevented by Congo red. Measurement of the number of living cells revealed that Aβ 25−35 induced a trophic rather than a toxic effect on astrocytes. Administration of cycloheximide blocked Aβ 25−35 ‐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.