The receptor tyrosine kinase KDR/flk-1 is expressed uniquely in vascular endothelial cells. The ligand for KDR/flk-1 is the endothelial cell- specific mitogen and angiogenic peptide vascular endothelial growth factor (VEGF). KDR/flk-1 and VEGF function as the key regulators of physiologic as well as pathological angiogenesis. More importantly, KDR/flk-1 is one of the earliest markers for angioblasts, the precursors of vascular endothelial cells, and KDR/flk-1 is necessary for these precursors to develop into mature endothelial cells. We hypothesize that the restricted expression of KDR/flk-1 in mature vascular endothelial cells, and its expression in angioblasts, is regulated by the interaction of specific DNA sequences (cis-acting elements) and their cognate DNA- binding proteins (trans-acting factors). We have isolated the human KDR/flk-1 gene and characterized its 5'-flanking sequence. The goal of the proposed work is to isolate the cis-acting elements important for endothelial cell-specific expression of KDR/flk-1 and for its induction during angiogenesis in vitro. The cis-acting elements identified in vitro will be tested in vivo in transgenic mice to determine whether they are sufficient to confer developmental and endothelial cell-restricted expression of the reporter gene. With these cis-acting elements, it will be possible to isolate the genes coding for the cognate trans-acting factors and study their expression in the contexts of vasculogenesis and angiogenesis. These experiments will allow us to isolate nodal genes encoding the trans-acting factors that regulate cells of the endothelial lineage, thereby defining potential targets for the regulation of angiogenesis. In addition, the endothelial cell-specific cis-acting elements uncovered by this work may be useful tools in gene therapy aimed at restricting expression of transduced genes to the vessel wall.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL057664-04
Application #
6131248
Study Section
Special Emphasis Panel (ZHL1-CSR-N (S1))
Project Start
1996-09-30
Project End
2000-08-31
Budget Start
1999-09-01
Budget End
2000-08-31
Support Year
4
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Brigham and Women's Hospital
Department
Type
DUNS #
071723621
City
Boston
State
MA
Country
United States
Zip Code
02115