Global expression analysis of primary endothelial cells before and after TNFa stimulation

Endothelial cells are a primary site of leukocyte recruitment during inflammation. An increase in tumor necrosis factor-alpha (TNFa) levels as a result of infection or some autoimmune diseases can trigger this process. Several autoimmune diseases are now treated with TNFa inhibitors. However, genomic alterations that occur as a result of TNF-mediated inflammation are not well understood. To investigate molecular targets and networks resulting from increased TNFa, we measured DNA methylation and gene expression in 40 human umbilical vein endothelial cell primary cell lines before and 24 hours after stimulation with TNFa via microarray. After quality control, 39 sample pairs (treated and untreated) remained for analysis, and 18,937 probes were collapsed to 14,019 genes by selecting the probe with the maximum mean intensity value for each gene