RT Journal
A1 McCourt M, Wang J, Sookhai S, Redmond H
T1 PRoinflammatory mediators stimulate neutrophil-directed angiogenesis
JF Archives of Surgery
JO Archives of Surgery
YR 1999
FD December 1
VO 134
IS 12
SP 1325
OP 1331
DO 10.1001/archsurg.134.12.1325
UL http://dx.doi.org/10.1001/archsurg.134.12.1325
AB Background 
    Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF.Hypothesis 
    The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis.Methods 
    Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-α–stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis.Results 
    Lipopolysaccharide and TNF-α stimulation resulted in significantly increased release of PMN VEGF (532 ± 49 and 484 ± 80 pg/mL, respectively; for all, presented as mean ± SEM) compared with control experiments (32 ± 4 pg/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-α–stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti–human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store.Conclusion 
    Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome, wound healing, and tumor growth.