As an indirect approach towards glycan structures, qRT-PCR analyses using the Delta Delta C-T method were performed to investigate changes in expression levels of heparan sulfate-synthesising enzymes Of Stimulated and unstimulated HMVECs. We chose NDSTs as early enzymes initiating sulfation and 3OSTs which act late generating specific binding sites. Major changes in expression patterns were found for the NDST3 and 3OST1 isoforms. Both enzymes were down-regulated 7- and 6-fold, respectively, following TNF-alpha Stimulation, and 3.5- and 7.6-fold following LPS-stimulation suggesting a common restructuring process of HS in inflammation leading to a less diverse sulfation pattern. Immunostaining of TNF-alpha-stimulated cells using a phage display-derived antibody specific for 3-O-sulfation and unsulfated regions of HS resulted in significant fluorescence changes between unstimulated and stimulated. (C) 2008 Elsevier Inc. All rights reserved.