Plasmid-mediated VEGF gene transfer induces cardiomyogenesis and reduces myocardial infarct size in sheep

We have recently reported that in pigs with chronic myocardial ischemia heart transfection with a plasmid encoding the 165 isoform of human vascular endothelial growth factor (pVEGF165) induces an increase in the mitotic index of adult cardiomyocytes and cardiomyocyte hyperplasia. On these bases we hypothesized that VEGF gene transfer could also modify the evolution of experimental myocardial infarct. In adult sheep pVEGF165 (3.8 mg, n=7) or empty plasmid (n=7) was injected intramyocardially 1 h after coronary artery ligation. After 15 days infarct area was 11.3±1.3% of the left ventricle in the VEGF group and 18.2±2.1% in the empty plasmid group (P<0.02). The mechanisms involved in infarct size reduction (assessed in additional sheep at 7 and 10 days after infarction) included an increase in early angiogenesis and arteriogenesis, a decrease in peri-infarct fibrosis, a decrease in myofibroblast proliferation, enhanced cardiomyoblast proliferation and mitosis of adult cardiomyocytes with occasional cytokinesis. Resting myocardial perfusion (99mTc-sestamibi SPECT) was higher in VEGF-treated group than in empty plasmid group 15 days after myocardial infarction. We conclude that plasmid-mediated VEGF gene transfer reduces myocardial infarct size by a combination of effects including neovascular proliferation, modification of fibrosis and cardiomyocyte regeneration.Fil: Vera Janavel, G.. Universidad Favaloro; ArgentinaFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Cabeza Meckert, Patricia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Favaloro; ArgentinaFil: Cuniberti, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Mele, A.. Fundación Favaloro; ArgentinaFil: Papouchado, Mariana. Biosidus S. A.; ArgentinaFil: Fernández, N.. Biosidus S. A.; ArgentinaFil: Bercovich, A.. Biosidus S. A.; ArgentinaFil: Criscuolo, M.. Biosidus S. A.; ArgentinaFil: Melo, C.. Biosidus S. A.; ArgentinaFil: Laguens, Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; Argentin

Repeated, but not single, VEGF gene transfer affords protection against ischemic muscle lesions in rabbits with hindlimb ischemia

Vascular endothelial growth factor (VEGF) gene transfer-mediated angiogenesis has been proposed for peripheral artery disease. However, protocols using single administration have shown little benefit. Given that the transient nature of VEGF gene expression provokes instability of neovasculature, we hypothesized that repeated administration would provide efficient tissue protection. We thus compared single vs repeated transfection in a rabbit model of hindlimb ischemia by injecting a plasmid encoding human VEGF165 (pVEGF165) at 7 (GI, n=10) or 7 and 21 (GII, n=10) days after surgery. Placebo animals (GIII, n=10) received empty plasmid. Fifty days after surgery, single and repeated administration similarly increased saphenous peak flow velocity and quantity of angiographically visible collaterals. However, microvasculature increased only with repeated transfection: capillary density was 49.4±15.4 capillaries per 100 myocytes in GI, 84.6±14.7 in GII (P<0.01 vs GI and GIII) and 49.3±13.6 in GIII, and arteriolar density was 1.9±0.6 arterioles per mm2 in GI, 3.0±0.9 in GII (P<0.01 vs GI and GIII) and 1.5±0.6 in GIII. Muscle lesions were reduced only within repeated transfection. With single administration, gene expression peaked at 7 days and declined rapidly, but with repeated administration, it remained positive at 50 days. At 90 days of repeated transfection (additional animals), gene expression decreased significantly, but neovessel densities did not. Thus, repeated, but not single, VEGF gene transfection resulted in increased microvasculature, which, in turn, afforded effective protection against ischemic muscle damage.Fil: Olea, Fernanda Daniela. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera Janavel, G.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Cuniberti, Luis Alberto. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Yannarelli, Gustavo Gabriel. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabeza Meckert, Patricia. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Cors, J.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Valdivieso, L.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Lev, G.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Mendiz, O.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Bercovich, A.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Criscuolo, M.. Biosidus S. A.; ArgentinaFil: Melo, C.. Biosidus S. A.; ArgentinaFil: Laguens, R.. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Crottogini, Alberto José. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin