Endothelial Precursor Cells (EPC) contribute to physiological and pathological neovascularization. Previous data have indicated that CYP4A/F-20-HETE system may be involved in regulation of neovascularization. Therefore, we studied whether angiogenic effects of the CYP4A/F-20-HETE system involves regulation of EPC function. We isolated EPC from human umbilical cord blood. These cells expressed AC133+ CD34+, and KDR surface markers. We detected the presence of mRNA and protein for CYP4A11 and CYPA22 enzymes in these cells. In contrast, mesenchymal stem cells expressed negligible amounts of CYP4A11/22. EPC produced 20-HETE when incubated with arachidonic acid (AA). Additionally, we found that EPC responded to 20-HETE with increases in cell proliferation and migration. VEGF also induced EPC proliferation and migration. Incubation with HET0016 (1µM), a selective inhibitor of the synthesis of 20-HETE, reduced the proliferative and migrative effects of VEGF. HET0016 also significantly abolished SDF-1 mediated EPC migration. In addition,(6,15)20-hydroxyeicosatetraeonic acid (20-HEDE) markedly inhibited the SDF-1 mediated EPC migration. Furthermore, Co-culturing of EC and EPC on the Matrigel matrix leads to tube formation. This response was inhibited by both HET0016 and 20-HEDE. We concluded that the CYP4A11-20-HETE system is expressed in EPC and can act as a regulatory autocrine/paracrine factor.
- Received January 11, 2011.
- Revision received April 26, 2011.
- Accepted April 27, 2011.
- The American Society for Pharmacology and Experimental Therapeutics