Serial analysis of gene expression (sage) to study the endothelial cell response to an atherogenic stimulus

Activation of the endothelium in the arterial vessel wall is thought to be an early event in the pathogenesis of atherosclerosis To identify the repertoire of endothelial cell genes that are differentially expressed after activation we have analyzed over 12.000 transcripts derived from resting human umbilical vein endothelial cells (HUVEC) and from HUVEC activated for six hours with the supernatant of oxidized-LDL stimulated monocytes using SAGE Over 7% of the total amount of analyzed transcripts is derived from genes that are differentially expressed (at least five fold up- or down regulated). These transcripts are derived from only 69 genes, less than 13% of the total number of analyzed genes Among these 69 differentially expressed genes were 48 known genes, including hallmark endothelial cell activation markers like ELAM-1, VCAM-1, Interleukin 8 and MCP-1 The remaining 21 genes were either novel or matched Expressed Sequence Tags in the database of the National Center for Biotechnology Information (NCBIdbEST) Our results support a major immediate early phenotypic change of the endothelium upon activation This is exemplified by an increase in the expression of genes involved in cell adhesion, chemotaxis/cell activation cellular remodelling, vesicular transport and metabolism Furthermore, our analysis shows a significant increase in the majority of the mitochondria! transcripts indicating an elevation of the ATP producing capacity of the activated cell. Our data demonstrate that, with the SAGE technique, a moderate number of analyzed transcripts can reveal a significant difference in transcript repertoires of eukaryotic cells.