Enhanced therapeutic angiogenesis by cotransfection of prostacyclin synthase gene or optimization of intramuscular injection of naked plasmid DNA.
BACKGROUND
Although clinical trials of therapeutic angiogenesis by angiogenic growth factors with intramuscular injection of naked plasmid DNA have been successful, there are still unresolved problems such as low transfection efficiency. From this viewpoint, we performed the following modifications: (1) combination with vasodilation using prostacyclin and (2) changing the agents or volume of naked plasmid DNA in vivo.


RESULTS
First, we examined cotransfection of the VEGF gene with the prostacyclin synthase gene in a mouse hindlimb ischemia model. Cotransfection of the VEGF gene with the prostacyclin synthase gene resulted in a further increase in blood flow and capillary density compared with single VEGF gene. Similar results were obtained with other angiogenic growth factors, such as hepatocyte growth factor (HGF). Alternatively, we changed the injection volume of the solution of plasmid DNA. Luciferase activity was increased in a volume-dependent manner. An increase in injection volume at 1 site rather than separate injections at multiple sites resulted in high transfection efficiency, which suggests that transfection of naked plasmid DNA is mediated by pressure. Interestingly, treatment with hyperbaric oxygen increased the transfection efficiency. Finally, we also examined the effects of different solutions. Saline and PBS, but not water, achieved high transfection efficiency. In addition, sucrose solution but not glucose solution resulted in high luciferase activity.


CONCLUSIONS
Overall, angiogenesis might be enhanced by cotransfection of prostacyclin synthase gene or an increase in injection volume and osmotic pressure. These data provide important information for the clinical application of therapeutic angiogenesis to treat peripheral arterial disease.
Hiraoka
Kazuya
K
Division of Clinical Gene Therapy, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita 565-0871, Japan.
Koike
Hiromi
H
Yamamoto
Seiji
S
Tomita
Naruya
N
Yokoyama
Chieko
C
Tanabe
Tadashi
T
Aikou
Takashi
T
Ogihara
Toshio
T
Kaneda
Yasufumi
Y
Morishita
Ryuichi
R
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D004247:DNA / Q000008:administration & dosage*; D004195:Disease Models, Animal; D015316:Genetic Therapy / Q000379:methods; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D007273:Injections, Intramuscular; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D007511:Ischemia / Q000473:pathology / Q000628:therapy*; D051379:Mice; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D010957:Plasmids / Q000008:administration & dosage* / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology
D042461:Vascular Endothelial Growth Factor A; D017228:Hepatocyte Growth Factor; D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase