Alteration of the glycocalyx of two blood-brain barrier mimicking cell lines is inducible by glioma conditioned media

Recent studies showed that glioma conditioned medium is able to induce blood-brain barrier properties in in vitro models. In this regard, it was investigated whether glioma conditioned medium can also influence the lectin-binding capacity of blood-brain barrier in vitro models. For the presented study cell lines PBMEC/C1-2 and ECV304 were chosen because it was previously shown that glioma conditioned medium was able to induce specific blood-brain barrier properties in these cell lines. Six different plant lectins (WGA, STL, LCA, UEA-I, DBA, PNA) with distinct sugar specificities were applied in order to elucidate the glycosylation patterns of cell line PBMEC/C1-2 and ECV304. Lectin-binding studies were carried out with monolayers as well as with single cells. In the case of PBMEC/C1-2 monolayers, results showed a significant increase of the binding of lectins WGA, STL, UEA-I, DBA and PNA after application of 25 pmol lectin when cultured in media containing soluble factors derived from glioma cell line C6, whereas the binding capacity for LCA remained similar. For ECV304 monolayers, a significant decrease of WGA, STL and LCA was observable, whereas UEA-I binding increased in comparison to cells grown in the corresponding basal growth medium without soluble C6 factors. Single cell studies showed less significant, but similar changes in the lectin-interactions with the cell surfaces. In conclusion, it was shown that soluble factors derived from glioma cell line C6 can modulate the "glycocalyx" of blood-brain barrier mimicking cell lines. (C) 2009 Elsevier B.V. All rights reserved.