title: Biochemical analysis of selenoprotein expression in brain cell lines and in distinct brain regions.
abstract: Selenium is present in various biologically important selenoproteins. The preferential incorporation of selenium into the brain indicates its significance for this organ, but so far knowledge concerning the cerebral selenoproteome is scarce. We therefore investigated the expression of selenoproteins in various regions of the rat brain, various subcellular fractions and several brain cell lines by (75)Se-labelling, gel electrophoretic separation and autoradiography, with the (75)Se tracer as the selenoprotein marker. Quantitative evaluation of the labelled proteins in selenium-deficient rats revealed information regarding preferentially supplied selenoproteins and their distribution; 21 selenoproteins could be distinguished, among them a novel or modified 15-kDa selenoprotein enriched in the cerebellum cytosol. The selenoproteins differed in the degree of their expression among the brain regions and within a region among the subcellular fractions. Some cell-type-specific selenium-containing proteins were found in the cell lines. Differences in the distribution patterns between mono-cultured and co-cultured endothelial cells and astrocytes showed that mediators produced by other cells could affect the selenoprotein expression of a specific cell-type. This effect might play a role in the uptake and distribution of selenium in the brain but could also be of significance in the selenium metabolism of other tissues.
authors.affiliation: Department of Molecular Trace Element Research in the Life Sciences, Hahn-Meitner-Institut, Berlin, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Hoppe
authors.forename: Anja U
authors.initials: AU
authors.lastname: Bräuer
authors.forename: Markus
authors.initials: M
authors.lastname: Kühbacher
authors.forename: Nicolai E
authors.initials: NE
authors.lastname: Savaskan
authors.forename: Dietrich
authors.initials: D
authors.lastname: Behne
authors.forename: Antonios
authors.initials: A
authors.lastname: Kyriakopoulos
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D002460:Cell Line; D018920:Coculture Techniques; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008297:Male; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D051140:Selenoproteins / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D051140:Selenoproteins