Fli-1 transcription factor is implicated in the pathogenesis of human and murine lupus. A two-fold overexpression of Fli-1 protein in transgenic mice results in the development of a lupus-like disease. Expression of Fli-1 in lupus patients is higher compared to normal controls. Endothelial cells play a role in a number of biological processes ranging from inflammation to the regulation of blood flow. We have reported that Fli-1 directly regulates the expression of MCP-1 in endothelial cells. In this study we investigated if Fli-1 also regulates other inflammatory chemokines. We transfected an endothelial cell line with Fli-1 specific siRNA and negative control oligo siRNA. There was more than an 80% decrease in Fli-1 expression in cells transfected with Fli-1 siRNA when compared to those transfected with control siRNA. Next, we stimulated these cells with TLR4 ligand lipopolysaccharide and extracted mRNA. An mRNA array was used to screen the levels of 26 chemokines. A number of message levels were decreased, including MCP-1, in the cells transfected with Fli-1 specific siRNA when compared to the control. Expression of MIF was higher in the cells when Fli-1 was silenced. We further confirmed MIF mRNA expression levels by real-time PCR. Our data indicates that Fli-1 is likely involved in regulating the production of several chemokines in endothelial cells.
- Copyright © 2013 by The American Association of Immunologists, Inc.