Published ahead of print on November 7, 2003, doi:10.1165/rcmb.2003-0314OC
© 2004 American Thoracic Society DOI: 10.1165/rcmb.2003-0314OC Expression and Function of the Vascular Endothelial Growth Factor Receptor FLT-1 in Human EosinophilsDivision of General Internal Medicine, Department of Internal Medicine, University of Innsbruck, Innsbruck, Austria Address correspondence to: Prof. Dr. Christian J. Wiedermann, Department of Internal Medicine, University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria. E-mail: christian.wiedermann{at}uibk.ac.at Vascular endothelial growth factor (VEGF) is highly expressed in the airway of patients with asthma. Whether VEGF affects eosinophil function in vitro and if VEGF receptors are involved was tested. Eosinophils were from venous blood of healthy donors. Cell migration was studied by micropore filter assays. Signaling mechanisms required for VEGF-dependent migration were tested using signaling enzyme blockers. Expression of flt-1 and KDR/flk-1 mRNA in eosinophils was demonstrated in reverse transcriptase–polymerase chain reaction, and receptor expression was investigated by fluorescence-activated cell sorting analysis. Eosinophil cationic protein release was measured in eosinophil supernatants by enzyme-linked immunosorbent assay. VEGF significantly stimulated eosinophil chemotaxis via activation of protein kinase C and phosphatidylinositol 3'-kinase. The effect on migration was reversed by an antibody against VEGF receptor flt-1, but not by an antibody against KDR/flk-1. Expression of VEGF receptor flt-1 mRNA was shown and synthesis of VEGF receptor in eosinophils is suggested by detection of VEGF receptor immunoreactivity on the cell surface. Data suggest that VEGF receptor flt-1 is expressed by eosinophils whose activation with VEGF stimulates directed migration and release of eosinophil cationic protein. Thus, VEGF may play an important role in the modulation of eosinophilic inflammation.
Abbreviations: bovine serum albumin, BSA • bisindolylmaleimide I GF 109203X, GFX • chemotaxis index, CI • eosinophil cationic protein, ECP • ethylenediamietetraacetic acid, EDTA • fluorescence-activated cell sorting, FACS • granulocyte/macrophage colony-stimulating factor, GM-CSF • Hanks' balanced salt solution, HBSS • human umbilical vein endothelial cells, HUVEC • isobutylmethylxanthine, IBMX • magnetic-activated cell sorting, MACS • phosphate-buffered saline, PBS • phosphatidylinositol 3'-kinase, PI3K • protein kinase C, PKC • regulated upon activation, normal T-lymphocytes expressed and secreted, RANTES • recombinant human vascular endothelial growth factor, rhVEGF • reverse transcriptase–polymerase chain reaction, RT-PCR • vascular endothelial growth factor, VEGF This article has been cited by other articles:
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