tailieunhanh - Báo cáo khoa học: Gene transcription of fgl2 in endothelial cells is controlled by Ets-1 and Oct-1 and requires the presence of both Sp1 and Sp3

The immune coagulant fgl2/fibroleukin has been previously shown to play a pivotal role in the pathogenesis of murine and human fulminant hepatitis and fetal loss syndrome. Constitutive expression of fgl2 transcripts at low levels are seen in cytotoxic T cells, endothelial, intestinal and tropho-blast cells, while specific factors (such as virus and cytokines) are required to induce high levels of fgl2 expression in other cell types including monocytes/macrophages. To address the transcriptional mechanisms that regulate constitutive expressionof fgl2,murinegenomic cloneswere characterized and the transcription start site was defined by 5¢-RACE and primer extension. . | Eur. J. Biochem. 270 2274-2286 2003 FEBS 2003 doi Gene transcription of fgl2 in endothelial cells is controlled by Ets-1 and Oct-1 and requires the presence of both Sp1 and Sp3 Mingfeng Liu1 Julian L. Leibowitz2 David A. Clark1 4 Michael Mendicino1 Qin Ning1 Jin Wen Ding1 Cheryl D Abreo3 Laisum Fung1 Philip A. Marsden3 and Gary A. Levy1 1 Multi Organ Transplant Program Toronto General Hospital and The University of Toronto Canada department of Pathology and Laboratory Medicine Texas A M University System College of Medicine USA 3Renal Division and Department of Medicine St. Michael s Hospital and University of Toronto Canada 4McMaster University Ontario Canada The immune coagulant fgl2 fibroleukin has been previously shown to play a pivotal role in the pathogenesis of murine and human fulminant hepatitis and fetal loss syndrome. Constitutive expression of fgl2 transcripts at low levels are seen in cytotoxic T cells endothelial intestinal and trophoblast cells while specific factors such as virus and cytokines are required to induce high levels of fgl2 expression in other cell types including monocytes macrophages. To address the transcriptional mechanisms that regulate constitutive expression of fgl2 murine genomic clones were characterized and the transcription start site was defined by 5 -RACE and primer extension. A comprehensive assessment of basal fgl2 promoter activity in murine vascular endothelial cells defined a minimal 119 bp region responsible for constitutive fgl2 transcription. A complexpositive regulatory domain PRD spanning a 39-bp sequence from -87 to -49 relative to the transcription start site was identified. Electrophoretic mobility shift assay studies in vascular endothelial cells revealed that the nucleoprotein complexes that form on this positive regulatory domain PRD contain Sp1 Sp3 family members Oct-1 and Ets-1. Heterologous expression studies in Drosophila Schneider cells confirmed that the constitutive .