BioProject

Activation of the vascular endothelium with cytokines such as TNF is widely used to study the role of the vasculature in proinflammatory disease. More...

Activation of the vascular endothelium with cytokines such as TNF is widely used to study the role of the vasculature in proinflammatory disease. To gain insight into mechanisms of prolonged vascular endothelial activation we compared changes in gene expression induced by continuous activation in stable tmTNFalpha expressing cells with changes due to acute TNFalpha challenge in vitro. Affymetrix Genechip® analysis was performed on RNA from control, acute and continuous TNFalpha-activated endothelial cells. Only 36% of the significant changes in gene expression were convergent between the acute and continuously activated endothelial cells in comparison to the control. From the divergently regulated genes, for example the cytokine ENA-78 was specifically induced in chronically activated cells, while E-Selectin, a cell adhesion molecule, was upregulated only in acutely activated endothelial cells. Antioxidant SOD gene induction was noted in acute activation while NADPH oxidase was selectively upregulated in continuous activated endothelium in accordance with significant ROS induction occurred only in these cells. In addition, the anti-angiogenic genes PAI-1 and thrombospondin were upregulated only in acutely activated endothelium, consistent with reduced angiogenic activity observed in acute versus chronically activated endothelial cells in vitro. These data suggest that continuous activation of endothelial cells leads to specific expression and functional changes, consistent with alterations observed in dysfunctional endothelium exposed to or involved in chronic inflammation. Keywords: Expression profiling Overall design: This experiment compares the response of endothelial cells from newborn mice that were either stably transfected with a non-cleavable transmembrane mutant form of murine TNFalpha, or treated with soluble TNFalpha (20ng/ml) for 4 hours. Each treatment was compared to mock-transfected control cells. Four replicates for each condition were used. Five micrograms of total RNA was assayed per Genechip using standard Affymetrix protocols. Less...