Vascular endothelial growth factor-angiopoietin chimera with improved properties for therapeutic angiogenesis.
BACKGROUND
There is an unmet need for proangiogenic therapeutic molecules for the treatment of tissue ischemia in cardiovascular diseases. However, major inducers of angiogenesis such as vascular endothelial growth factor (VEGF/VEGF-A) have side effects that limit their therapeutic utility in vivo, especially at high concentrations. Angiopoietin-1 has been considered to be a blood vessel stabilization factor that can inhibit the intrinsic property of VEGF to promote vessel leakiness. In this study, we have designed and tested the angiogenic properties of chimeric molecules consisting of receptor-binding parts of VEGF and angiopoietin-1. We aimed at combining the activities of both factors into 1 molecule for easy delivery and expression in target tissues.


RESULTS
The VEGF-angiopoietin-1 (VA1) chimeric protein bound to both VEGF receptor-2 and Tie2 and induced the activation of both receptors. Detailed analysis of VA1 versus VEGF revealed differences in the kinetics of VEGF receptor-2 activation and endocytosis, downstream kinase activation, and VE-cadherin internalization. The delivery of a VA1 transgene into mouse skeletal muscle led to increased blood flow and enhanced angiogenesis. VA1 was also very efficient in rescuing ischemic limb perfusion. However, VA1 induced less plasma protein leakage and myeloid inflammatory cell recruitment than VEGF. Furthermore, angioma-like structures associated with VEGF expression were not observed with VA1.


CONCLUSIONS
The VEGF-angiopoietin-1 chimera is a potent angiogenic factor that triggers a novel mode of VEGF receptor-2 activation, promoting less vessel leakiness, less tissue inflammation, and better perfusion in ischemic muscle than VEGF. These properties of VA1 make it an attractive therapeutic tool.
Wihuri Research Institute, Biomedicum Helsinki, PO Box 63 (Haartmaninkatu 8), University of Helsinki, Helsinki, 00014 Finland.
Andrey
A
Anisimov
Denis
D
Tvorogov
Annamari
A
Alitalo
Veli-Matti
VM
Leppänen
Yuri
Y
An
Eun Chun
EC
Han
Fabrizio
F
Orsenigo
Emília Ilona
EI
Gaál
Tanja
T
Holopainen
Young Jun
YJ
Koh
Tuomas
T
Tammela
Petra
P
Korpisalo
Salla
S
Keskitalo
Michael
M
Jeltsch
Seppo
S
Ylä-Herttuala
Elisabetta
E
Dejana
Gou Young
GY
Koh
Chulhee
C
Choi
Pipsa
P
Saharinen
Kari
K
Alitalo
D000256:Adenoviridae / Q000235:genetics; D042683:Angiopoietin-1 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002199:Capillary Permeability / Q000502:physiology; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D057809:HEK293 Cells; D006614:Hindlimb / Q000098:blood supply; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007511:Ischemia / Q000188:drug therapy* / Q000235:genetics; D007951:Leukemia, Myeloid; D051379:Mice; D008815:Mice, Inbred Strains; D018482:Muscle, Skeletal / Q000098:blood supply; D018919:Neovascularization, Physiologic / Q000502:physiology*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D042787:Receptor, TIE-2; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D015398:Signal Transduction / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D042683:Angiopoietin-1; C467628:Angpt1 protein, mouse; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D020794:Receptor Protein-Tyrosine Kinases; D042787:Receptor, TIE-2; C079086:Tek protein, mouse; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2