Vascular endothelial growth factor-C (VEGF-C/VEGF-2) promotes angiogenesis in the setting of tissue ischemia.
Recently, vascular endothelial growth factor-C (VEGF-C or VEGF-2) was described as a specific ligand for the endothelial receptor tyrosine kinases VEGFR-2 and VEGFR-3. In vivo data, limited to constitutive overexpression in transgenic mice, have been interpreted as evidence that the growth-promoting effects of VEGF-C are restricted to development of the lymphatic vasculature. The current studies were designed to test the hypothesis that constitutive expression of VEGF-C in adult animals promotes angiogenesis. In vitro, VEGF-C exhibited a dose-dependent mitogenic and chemotactic effect on endothelial cells, particularly for microvascular endothelial cells (72% and 95% potency, respectively, compared with VEGF-A/VEGF-1). VEGF-C stimulated release of nitric oxide from endothelial cells and increased vascular permeability in the Miles assay; the latter effect was attenuated by pretreatment with the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester. Both VEGFR-2 and VEGFR-3 receptors were shown to be expressed in human saphenous vein and internal mammary artery. The potential for VEGF-C to promote angiogenesis in vivo was then tested in a rabbit ischemic hindlimb model. Ten days after ligation of the external iliac artery, VEGF-C was administered as naked plasmid DNA (pcVEGF-C; 500 microg) from the polymer coating of an angioplasty balloon (n = 8 each) or as recombinant human protein (rhVEGF-C; 500 microg) by direct intra-arterial infusion. Physiological and anatomical assessments of angiogenesis 30 days later showed evidence of therapeutic angiogenesis for both pcVEGF-C and rhVEGF-C. Hindlimb blood pressure ratio (ischemic/normal) after pcVEGF-C increased to 0.83 +/- 0.03 after pcVEGF-C versus 0.59 +/- 0.04 (P < 0.005) in pGSVLacZ controls and to 0.76 +/- 0.04 after rhVEGF-C versus 0.58 +/- 0.03 (P < 0.01) in control rabbits receiving rabbit serum albumin. Doppler-derived iliac flow reserve was 2.7 +/- 0.1 versus 2.0 +/- 0.2 (P < 0.05) for pcVEGF-C versus LacZ controls and 2.9 +/- 0.3 versus 2.1 +/- 0.2 (P < 0.05) for rhVEGF-C versus albumin controls. Neovascularity was documented by angiography in vivo (angiographic scores: 0.85 +/- 0.05 versus 0.51 +/- 0.02 (P < 0.001) for plasmid DNA and 0.74 +/- 0.08 versus 0.53 +/- 0.03 (P < 0.05) for protein), and capillary density (per mm2) was measured at necropsy (252 +/- 12 versus 183 +/- 10 (P < 0.005) for plasmid DNA and 229 +/- 20 versus 164 +/- 20 (P < 0.05) for protein). In contrast to the results of gene targeting experiments, constitutive expression of VEGF-C in adult animals promotes angiogenesis in the setting of limb ischemia. VEGF-C and its receptors thus constitute an apparently redundant pathway for postnatal angiogenesis and may represent an alternative to VEGF-A for strategies of therapeutic angiogenesis in patients with limb and/or myocardial ischemia.
Department of Medicine, St. Elizabeth's Medical Center of Boston, Tufts University School of Medicine, Massachusetts 02135, USA.
B
B
Witzenbichler
T
T
Asahara
T
T
Murohara
M
M
Silver
I
I
Spyridopoulos
M
M
Magner
N
N
Principe
M
M
Kearney
J S
JS
Hu
J M
JM
Isner
D000792:Angiography; D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016228:Endothelial Growth Factors / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018014:Gene Transfer Techniques; D006168:Guinea Pigs; D006614:Hindlimb / Q000098:blood supply; D006651:Histocytochemistry; D006801:Humans; D007269:Injections, Intra-Arterial; D007511:Ischemia; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D017978:Receptors, Growth Factor / Q000235:genetics; D040262:Receptors, Vascular Endothelial Growth Factor; D011994:Recombinant Proteins / Q000494:pharmacology; D042582:Vascular Endothelial Growth Factor C
D016228:Endothelial Growth Factors; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D011994:Recombinant Proteins; D042582:Vascular Endothelial Growth Factor C; D009569:Nitric Oxide; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; D019331:NG-Nitroarginine Methyl Ester