Sonia Chalbot

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Prominent neuronal and glial tau filamentous inclusions are hallmarks of neurodegenerative tauopathies, among them Alzheimer's disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), Pick's disease (PiD), and argyrophilic grain disease (AgD). AgD is a late onset dementia in which pathologically aggregated tau proteins are found(More)
Dehydroepiandrosterone (DHEA) is 7alpha-hydroxylated by the cytochome P450 7B1 (CYP7B1) in the human brain and liver. This produces 7alpha-hydroxy-DHEA that is a substrate for 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) which exists in the same tissues and carries out the inter-conversion of 7alpha- and 7beta-hydroxy-DHEA through a(More)
Dehydroepiandrosterone (DHEA) and 3beta-hydroxy-5alpha-androstan-17-one (epiandrosterone, EpiA) are both precursors for 7alpha- and 7beta-hydroxylated metabolites in the human brain. These 7-hydroxylated derivatives were shown to exert anti-glucocorticoid and neuroprotective effects. When these steroids are administered per os to humans, the first organ(More)
Dehydroepiandrosterone (DHEA) is 7alpha-hydroxylated by the cytochrome P4507B1 in the liver, skin and brain, which are targets for glucocorticoids. 7alpha-Hydroxy-DHEA produced anti-glucocorticoid effects in vivo but the interference between the glucocorticoid hormone binding with its receptor could not be determined. In the organs mentioned above,(More)
The cytochrome P4507B1 (P4507B1) in the human hippocampus is responsible for the production of 7alpha-hydroxylated derivatives of dehydroepiandrosterone (DHEA) and other 3beta-hydroxylated neurosteroids. Minor quantities of the 7beta-hydroxylated derivatives are also produced. Neuroprotective action of these 7-hydroxysteroids was reported. Recombinant human(More)
The cytochrome P4507B1 (P4507B1) is responsible for the 7alpha-hydroxylation of dehydroepiandrosterone (DHEA) and other 3beta-hydroxysteroids in the brain and other organs. The cDNA of human P4507B1 was used for DNA immunization of mice. The best responding mouse led to the production of monoclonal antibodies (mAbs). The clone D16-37 produced an IgM(More)
The 7 alpha- and 7 beta-hydroxylated derivatives of [4-14C]-dehydroepiandrosterone were prepared with use of the yeast-expressed human cytochrome p4507B1. Epiandrosterone (EPIA), 5 alpha-androstane-3beta,17 beta-diol, and 5 alpha-androstane-3,17-dione were obtained after incubation of [4-14C]-5 alpha-dihydrotestosterone with Escherichia coli-expressed(More)
Abstract Successive action of cytochrome P450-7B1 (CYP7B1) and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) on 3β-hydroxysteroids such as DHEA and epiandrosterone leads to the production of cytoprotective 7β-hydroxylated derivatives. Investigation of the presence of these enzymes in human tissues could be carried out on commercially available human(More)
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