Evaluation of angiogenesis and side effects in ischemic rabbit hindlimbs after intramuscular injection of adenoviral vectors encoding VEGF and LacZ.
BACKGROUND
Recent studies have suggested the therapeutic potential of vascular endothelial growth factor (VEGF) gene therapy in ischemic skeletal muscle. However, only limited information is available about the effects of VEGF gene therapy in different regions of ischemic limbs, effects of control adenoviruses, and biodistribution of the transgenes after intramuscular (i.m.) administration. Here we studied angiogenesis and side effects of adenovirus-mediated VEGF and beta-galactosidase (LacZ) gene transfers in ischemic rabbit hindlimbs.


RESULTS
Ten days after induction of ischemia, rabbits were treated with i.m. injections of saline, LacZ adenovirus (AdLacZ; 2x10(10) pfu) or adenovirus encoding mouse VEGF(164) (AdVEGF; 2x10(10) pfu). In rabbits treated with AdVEGF an increase in serum VEGF(164) levels was detected by ELISA three and seven days after the gene transfer. 30 days after the gene transfer a positive effect on capillary density was observed in the thigh region both in rabbits treated with AdVEGF and AdLacZ compared with animals that received saline. On the other hand, AdVEGF and AdLacZ gene transfers had no effect on the capillary density in the calf region on day 30. A positive correlation between the capillary density and the number of collateral arteries was observed in the thigh. Hindlimb and testis edema and excess non-physiological growth of capillaries were detected as adverse effects of the AdVEGF gene therapy. Biodistribution analysis showed that the transgene was present not only in the target muscle, but also in ectopic tissues seven days after i.m. gene transfer.


CONCLUSIONS
The results suggest that a high dose of adenoviral vector encoding either AdVEGF or AdLacZ induces angiogenesis in the rabbit hindlimb ischemia model; i.m. injection of adenovirus leads to the transfection of ectopic organs; and AdVEGF gene transfer induces edema in ischemic skeletal muscle.
A.I. Virtanen Institute, Kuopio University, Finland.
Ismo
I
Vajanto
Tuomas T
TT
Rissanen
Juha
J
Rutanen
Mikko O
MO
Hiltunen
Tiina T
TT
Tuomisto
Katja
K
Arve
Outi
O
Närvänen
Hannu
H
Manninen
Heikki
H
Räsänen
Mikko
M
Hippeläinen
Esko
E
Alhava
Seppo
S
Ylä-Herttuala
D000256:Adenoviridae; D000818:Animals; D016228:Endothelial Growth Factors / Q000235:genetics / Q000627:therapeutic use*; D005121:Extremities / Q000098:blood supply; D015316:Genetic Therapy / Q000009:adverse effects* / Q000379:methods; D005822:Genetic Vectors; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000627:therapeutic use*; D007511:Ischemia / Q000628:therapy; D007763:Lac Operon; D008222:Lymphokines / Q000235:genetics / Q000627:therapeutic use*; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000628:therapy*; D011817:Rabbits; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors