CXCL1/macrophage inflammatory protein-2-induced angiogenesis in vivo is mediated by neutrophil-derived vascular endothelial growth factor-A.
The angiogenic activity of CXC-ELR(+) chemokines, including CXCL8/IL-8, CXCL1/macrophage inflammatory protein-2 (MIP-2), and CXCL1/growth-related oncogene-alpha in the Matrigel sponge angiogenesis assay in vivo, is strictly neutrophil dependent, as neutrophil depletion of the animals completely abrogates the angiogenic response. In this study, we demonstrate that mice deficient in the src family kinases, Hck and Fgr (hck(-/-)fgr(-/-)), are unable to develop an angiogenic response to CXCL1/MIP-2, although they respond normally to vascular endothelial growth factor-A (VEGF-A). Histological examination of the CXCL1/MIP-2-containing Matrigel implants isolated from wild-type or hck(-/-)fgr(-/-) mice showed the presence of an extensive neutrophil infiltrate, excluding a defective neutrophil recruitment into the Matrigel sponges. Accordingly, neutrophils from hck(-/-)fgr(-/-) mice normally migrated and released gelatinase B in response to CXCL1/MIP-2 in vitro, similarly to wild-type neutrophils. However, unlike wild-type neutrophils, those from hck(-/-)fgr(-/-) mice were completely unable to release VEGF-A upon stimulation with CXCL1/MIP-2. Furthermore, neutralizing anti-VEGF-A Abs abrogated the angiogenic response to CXCL1/MIP-2 in wild-type mice and CXCL1/MIP-2 induced angiogenesis in the chick embryo chorioallantoic membrane assay, indicating that neutrophil-derived VEGF-A is a major mediator of CXCL1/MIP-2-induced angiogenesis. Finally, in vitro kinase assays confirmed that CXCL1/MIP-2 activates Hck and Fgr in murine neutrophils. Taken together, these data demonstrate that CXCL1/MIP-2 leads to recruitment of neutrophils that, in turn, release biologically active VEGF-A, resulting in angiogenesis in vivo. Our observations delineate a novel mechanism by which CXCL1/MIP-2 induces neutrophil-dependent angiogenesis in vivo.
Scapini
Patrizia
P
Department of Pathology, Section of General Pathology, University of Verona, Verona, Italy.
Morini
Monica
M
Tecchio
Cristina
C
Minghelli
Simona
S
Di Carlo
Emma
E
Tanghetti
Elena
E
Albini
Adriana
A
Lowell
Clifford
C
Berton
Giorgio
G
Noonan
Douglas M
DM
Cassatella
Marco A
MA
D043925:Angiogenesis Inducing Agents / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D000818:Animals; D019138:Antibodies, Blocking / Q000008:administration & dosage; D002469:Cell Separation; D002478:Cells, Cultured; D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; D018925:Chemokines / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D019743:Chemokines, CXC / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D006801:Humans; D007279:Injections, Subcutaneous; D036341:Intercellular Signaling Peptides and Proteins / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018919:Neovascularization, Physiologic / Q000276:immunology / Q000502:physiology*; D020556:Neutrophil Infiltration / Q000502:physiology; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D051572:Proto-Oncogene Proteins c-hck; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology / Q000502:physiology*; D019061:src-Family Kinases
D043925:Angiogenesis Inducing Agents; D020533:Angiogenesis Inhibitors; D019138:Antibodies, Blocking; D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; D018925:Chemokines; D019743:Chemokines, CXC; C475895:Cxcl1 protein, mouse; C404915:Cxcl2 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D011518:Proto-Oncogene Proteins; D042461:Vascular Endothelial Growth Factor A; D011505:Protein-Tyrosine Kinases; C496631:HCK protein, human; C496632:Hck protein, mouse; D051572:Proto-Oncogene Proteins c-hck; C053102:proto-oncogene proteins c-fgr; D019061:src-Family Kinases