Inovio Pharmaceuticals Inc (INO)

[KR_redondo]

Geoffrey O. Ouma...SVM scientific session June 13-15, 2013

Young inVeStigator
aWard finaliStS

basic Science—angiogenesis/Vasculogenesis
Yia 1 In Vivo electroporation of
Constitutively expressed Hif-1 Plasmid dna
enhances neovascularization in a Mouse
Model of Hindlimb ischemia

Background: Hypoxia-inducible factor-
1alpha (HIF-1a) is a transcription factor that stimulates
angiogenesis during tissue ischemia. Electroporation
(EP) enhances tissue DNA transfer. We evaluated the
neovascularization efficacy of EP of a constitutively
expressed HIF-1a DNA compared to intramuscular (IM)
injection in a mouse model of limb ischemia.
Methods: Mice with ligated left femoral artery were
assigned to one of the three groups: (1) HIF-EP (n=13,
EP of 20 µl HIF-1a plasmid DNA); (2) HIF-IM (n=14, IM
injection of 20 µl HIF-1a plasmid DNA); (3) pVAX-EP
(n=12, EP of 20 µl empty plasmid DNA). Limb perfusion
recovery by Laser Doppler Perfusion Imager, limb function
and limb necrosis were measured. Muscle tissues were
stained for necrosis (H&E); capillary density (anti-CD31);
and collateral vessels and size (anti-a-SMA).

Results: EP of HIF-1a DNA significantly boosted limb
perfusion (HIF-EP: 41.03 ± 0.15 vs. HIF-IM: 0.78 ± 0.064;
P < .05, vs. pVAX-EP: 0.41 ± 0.019; P < .001), limb
function recovery (HIF-EP: 3.5 ± 0.58 vs. HIF-IM, 2.4 ±
1.14; p < 0.05, vs. pVAX-EP: 2.4 ± 1.14; P < .001), and
reduced limb auto-amputation (HIF-EP: 77% ± 12% vs.
HIF-IM: 43% ± 14%; P <.05 vs. pVAX-EP: 17% ± 11%; P
< .01). Muscle necrosis declined (HIF-EP: 20.7% ± 1.75%
vs. HIF-IM: 44% ± 3.73; P < .001, vs. pVAX-EP: 60.05%
± 2.17%; P < .0001), capillary growth improved (HIFEP: 96.83 ± 5.72 vessels/hpf vs. HIF-IM: 62.87 ± 2.0
vessels/hpf; P < .001, vs. pVAX-EP: 39.37 ± 2.76 vessels/
hpf; P < .0001), collateral vessels increased (HI-EP: 76.33
± 1.94 vessels/hpf vs. HIF-IM: 37.5 ± 1.56 vessels/hpf;
P < .0001, vs. pVAX-EP: 18.5 ± 1.34 vessels/hpf; P <
.00001), and the collaterals were larger (HIF-EP: 15,521.67
± 1,298.16 µm² vs. HIF-IM: 7,788.87 ± 392.04 µm²; P <
.001 vs. pVAX-EP: 4,640.25 ± 614.01 µm²; P < .0001).

Conclusions: In vivo EP-mediated delivery of HIF-1a DNA
is more effective in enhancing neovascularization than
IM injection in a mouse model of limb ischemia. This
modality warrants further studies in the treatment of
critical limb ischemia.

http://www.vascularmed.org/annual_meeting/2013-SVM-Meeting-Program.pdf