Gene transfer-based strategies for heart regeneration

Ischemic heart disease is the leading cause of mortality worldwide. Its most frequent and serious complication is acute myocardial infarction, after which the remaining contractile tissue undergoes a process characterized by myocyte hypertrophy and death of the remaining myocardium, and its progressive replacement by fibrosis (Sutton and Sharpe 2000). This process, termed remodeling, eventually leads to left ventricular dilation and heart failure. The extent of remodeling is largely dependent upon infarct size (Lenderink et al. 1995). Small infarcts do not induce significant remodeling. Large ones, contrarily, provoke substantial remodeling and therefore evolve towards contractile failure. This explains why regenerating the contractile tissue, a process named cardiomyogenesis, has become a major objective in biomedical research.Sociedad Argentina de Fisiologí

Lights and shadows in cardiac regeneration

Given that the adult human heart has an extremely limited regenerative capacity, diseases characterized by contractile cell loss, as myocardial infarction and cardiomyopathies, lead to ventricular remodeling and heart failure. Hence, diverse strategies to promote myocardial regeneration have been proposed and assessed in animals and humans with ischemic heart disease. Of these, gene transfer and especially stem cell therapy have been used. So far, the overall main outcome is a gross disparity between the promising results obtained in mammalian models and the poor, if any, benefit observed in randomized, controlled clinical trials. Many reasons may account for this disappointing scenario. Some, including flawed trial design and methodology, differences in cell type and dosing as well as in route of administration, erroneous end points selection and heterogeneous patient populations have been extensively discussed in comprehensive reviews. Others, more recently addressed, signal the use of inadequate or non-precise laboratory techniques in cell identification and fate, this leading to precarious or misleading conclusions. We hereby summarize part of the work done and quote some new approaches, like the use of induced pluripotent stem cells and the promotion of selfregeneration by targeting the adult cardiomyocyte cell cycle, that may cast some light in the otherwise shadowy field of cardiac regeneration.Dada la limitadísima capacidad regenerativa del corazón humano adulto, las enfermedades caracterizadas por pérdida de tejido contráctil, como el infarto de miocardio y las miocardiopatías, conducen al remodelamiento ventricular y la insuficiencia cardíaca. Por ello, diversas estrategias cardiorregenerativas han sido propuestas y evaluadas en modelos animales y pacientes con cardiopatía isquémica. De ellas, las más usadas han sido la transferencia génica y, especialmente, la terapia con células madre. Hasta aquí, el resultado global es una gran disparidad entre los prometedores resultados obtenidos en modelos animales y los pobres o nulos beneficios observados en los ensayos clínicos. Muchas razones explican este decepcionante escenario. Algunas, tales como imperfecciones de diseño y metodología, diferencias en el tipo y dosis de células así como en la vía de administración, puntos finales erróneamente elegidos, y heterogeneidad en las poblaciones de pacientes, han sido ampliamente discutidos en muy completas revisiones. Otros, más recientemente abordados, señalan el uso de inadecuadas o imprecisas técnicas de laboratorio para identificar el tipo de célula y su destino, conducentes a conclusiones precarias o engañosas. En este artículo resumimos parte del trabajo realizado y citamos algunos nuevos abordajes, tales como el uso de células pluripotentes inducidas y la auto- regeneración por manipulación del ciclo celular del miocardiocito adulto, que podrían arrojar algo de luz al sombrío campo de la regeneración cardíaca.Sociedad Argentina de Fisiologí

Allogeneic mesenchymal stromal cells overexpressing mutant human Hypoxia-inducible factor 1-α (HIF1-α) in an ovine model of acute myocardial infarction

Background-Bone marrow mesenchymal stromal cells (BMMSCs) are cardioprotective in acute myocardial infarction (AMI) because of release of paracrine angiogenic and prosurvival factors. Hypoxia-inducible factor 1-α (HIF1-α), rapidly degraded during normoxia, is stabilized during ischemia and upregulates various cardioprotective genes. We hypothesized that BMMSCs engineered to overexpress mutant, oxygen-resistant HIF1-α would confer greater cardioprotection than nontransfected BMMSCs in sheep with AMI. Methods and Results-Allogeneic BMMSCs transfected with a minicircle vector encoding mutant HIF1-α (BMMSC-HIF) were injected in the peri-infarct of sheep (n=6) undergoing coronary occlusion. Over 2 months, infarct volume measured by cardiac magnetic resonance (CMR) imaging decreased by 71.7±1.3% (P < 0.001), and left ventricular (LV) percent ejection fraction (%EF) increased near 2-fold (P < 0.001) in the presence of markedly decreased end-systolic volume. Sheep receiving nontransfected BMMSCs (BMMSC; n=6) displayed less infarct size limitation and percent LVEF improvement, whereas in placebo-treated animals (n=6), neither parameters changed over time. HIF1-α-transfected BMMSCs (BMMSC-HIF) induced angio-/arteriogenesis and decreased apoptosis by HIF1-mediated overexpression of erythropoietin, inducible nitrous oxide synthase, vascular endothelial growth factor, and angiopoietin-1. Cell tracking using paramagnetic iron nanoparticles in 12 additional sheep revealed enhanced long-term retention of BMMSC-HIF. Conclusions-Intramyocardial delivery of BMMSC-HIF reduced infarct size and improved LV systolic performance compared to BMMSC, attributed to increased neovascularization and cardioprotective effects induced by HIF1-mediated overexpression of paracrine factors and enhanced retention of injected cells. Given the safety of the minicircle vector and the feasibility of BMMSCs for allogeneic application, this treatment may be potentially useful in the clinic.Fil: Hnatiuk, Anna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Ong, Sang-Ging. Stanford University School of Medicine; Estados UnidosFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Riegler, Johannes. Stanford University School of Medicine; Estados UnidosFil: Lee, Won Hee. Stanford University School of Medicine; Estados UnidosFil: Jen, Cheng Hao. University of London; Reino UnidoFil: De Lorenzi, Andrea. Fundación Favaloro; ArgentinaFil: Giménez, Carlos Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Laguens, Rubén. Universidad Favaloro; ArgentinaFil: Wu, Joseph C.. Stanford University School of Medicine; Estados UnidosFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentin

Activated macrophages as a feeder layer for growth of resident cardiac progenitor cells

The adult heart contains a population of cardiac progenitor cells (CPCs). Growing and collecting an adequate number of CPCs demands complex culture media containing growth factors. Since activated macrophages secrete many growth factors, we investigated if activated isolated heart cells seeded on a feeder layer of activated peritoneal macrophages (PM) could result in CPCs and if these, in turn, could exert cardioprotection in rats with myocardial infarction (MI). Heart cells of inbred Wistar rats were isolated by collagenase digestion and cultured on PM obtained 72 h after intraperitoneal injection of 12 ml thioglycollate. Cells (1 × 106) exhibiting CPC phenotype (immunohistochemistry) were injected in the periphery of rat MI 10 min after coronary artery occlusion. Control rats received vehicle. Three weeks later, left ventricular (LV) function (echocardiogram) was assessed, animals were euthanized and the hearts removed for histological studies. Five to six days after seeding heart cells on PM, spherical clusters composed of small bright and spherical cells expressing mostly c-Kit and Sca-1 antigens were apparent. After explant, those clusters developed cobblestone-like monolayers that expressed smooth muscle actin and sarcomeric actin and were successfully transferred for more than ten passages. When injected in the MI periphery, many of them survived at 21 days after coronary ligature, improved LV ejection fraction and decreased scar size as compared with control rats. CPC-derived cells with cardiocyte and smooth muscle phenotypes can be successfully grown on a feeder layer of activated syngeneic PM. These cells decreased scar size and improved heart function in rats with MI.Facultad de Ciencias MédicasCentro de Investigaciones Cardiovasculare

Targeting the cardiomyocyte cell cycle for heart regeneration

Adult mammalian cardiomyocytes (CMs) exhibit limited proliferative capacity, as cell cycle activity leads to an increase in DNA content, but mitosis and cytokinesis are infrequent. This makes the heart highly inefficient in replacing with neoformed cardiomyocytes lost contractile cells as occurs in diseases such as myocardial infarction and dilated cardiomyopathy. Regenerative therapies based on the implant of stem cells of diverse origin do not warrant engraftment and electromechanical connection of the new cells with the resident ones, a fundamental condition to restore the physiology of the cardiac syncytium. Consequently, there is a growing interest in identifying factors playing relevant roles in the regulation of the CM cell cycle to be targeted in order to induce the resident cardiomyocytes to divide into daughter cells and thus achieve myocardial regeneration with preservation of physiologic syncytial performance. Despite the scientific progress achieved over the last decades, many questions remain unanswered, including how cardiomyocyte proliferation is regulated during heart development in gestation and neonatal life. This can reveal unknown cell cycle regulation mechanisms and molecules that may be manipulated to achieve cardiac self-regeneration. We hereby revise updated data on CM cell cycle regulation, participating molecules and pathways recently linked with the cell cycle, as well as experimental therapies involving them.Fil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentina. Universidad Favaloro; ArgentinaFil: Giménez, Carlos Sebastián. Universidad Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Uranga Vega, Martin. Universidad Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentina. Universidad Favaloro; ArgentinaFil: Belaich, Mariano Nicolas. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

High-dose intramyocardial HMGB1 induces long-term cardioprotection in sheep with myocardial infarction

In rodents with acute myocardial infarction (AMI), high mobility group box 1 (HMGB1) injection has produced controversial results. Given the lack of data in large mammals, we searched the dose that would promote angiogenesis and expression of specific regenerative genes in sheep with AMI (protocol 1) and, subsequently, use this dose to study long-term effects on infarct size and left ventricular (LV) function (protocol 2). Protocol 1: Sheep with AMI received 250 μg (high-dose, n = 7), 25 μg (low-dose, n = 7) HMGB1, or PBS (placebo, n = 7) in 10 intramyocardial injections (0.2 ml each) in the peri-infarct area. Seven days later, only the high-HMGB1-dose group exhibited higher microvascular densities, Ki67-positive cardiomyocytes, and overexpression of VEGF, Ckit, Tbx20, Nkx2.5, and Gata4. Protocol 2: Sheep with AMI received HMGB1 250 μg (n = 6) or PBS (n = 6). At 60 days, HMGB1-treated sheep showed smaller infarcts (8.5 ± 2.11 vs. 12.2 ± 1.97% LV area, P < 0.05, ANOVA-Bonferroni) and higher microvascular density (capillaries, 1798 ± 252 vs. 1266 ± 250/mm2; arterioles, 18.3 ± 3.9 vs. 11.7 ± 2.2/mm2; both P < 0.01). Echocardiographic LV ejection fraction, circumferential shortening, and wall thickening increased from day 3 to 60 with HMGB1 (all P < 0.05). Conclusion: in ovine AMI, high-dose HMGB1 induces angio-arteriogenesis, reduces infarct size, and improves LV function at 2 months post-treatment.Fil: Bauza, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Giménez, Carlos Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: De Lorenzi, Andrea. Fundación Favaloro; ArgentinaFil: Hnatiuk, Anna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Capogrossi, Maurizio C.. Johns Hopkins Bayview Medical Center; Estados UnidosFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Cuniberti, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentin

Vascular endothelial growth factor overexpression does not enhance adipose stromal cell-induced protection on muscle damage in critical limb ischemia

Objectives: Critical limb ischemia complicates peripheral artery disease leading to tissue damage and amputation. We hypothesized that modifying adipose stromal cells (ASCs) to overexpress human vascular endothelial growth factor 165 (VEGF) would limit ischemic muscle damage to a larger extent than nonmodified ASCs. Approach and Results: Rabbits with critical hindlimb ischemia were injected with allogeneic abdominal fat-derived ASCs transfected with plasmid-VEGF165 (ASCs-VEGF; n=10). Additional rabbits received nontransfected ASCs (ASCs; n=10) or vehicle (placebo; n=10). One month later, ASCs-VEGF rabbits exhibited significantly higher density of angiographically visible collaterals and capillaries versus placebo (both P<0.05) but not versus ASCs (both P=NS). Arteriolar density, however, was increased in both ASCs and ASCs-VEGF groups (both P<0.05 versus placebo). ASCs-VEGF and ASCs showed comparable post-treatment improvements in Doppler-assessed peak systolic velocity, blood pressure ratio, and resistance index. Ischemic lesions were found in 40% of the muscle samples in the placebo group, 19% in the ASCs-VEGF group, and 17% in the ASCs groups (both P<0.05 versus placebo, Fisher test). Conclusions: In a rabbit model of critical limb ischemia, intramuscular injection of ASCs genetically modified to overexpress VEGF increase angiographically visible collaterals and capillary density. However, both modified and nonmodified ASCs increase arteriolar density to a similar extent and afford equal protection against ischemia-induced muscle lesions. These results indicate that modifying ASCs to overexpress VEGF does not enhance the protective effect of ASCs, and that arteriolar proliferation plays a pivotal role in limiting the irreversible tissue damage of critical limb ischemia.Fil: Olea, Fernanda Daniela. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Hnatiuk, Anna. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: De Lorenzi, Andrea. Fundación Favaloro; ArgentinaFil: Valdivieso, León. Fundación Favaloro; ArgentinaFil: Rocha, Estefanía. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Ramirez, Rodrigo Julio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Área de Investigación y Desarrollo; ArgentinaFil: Laguens, Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. 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

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

Mesenchymal stromal cells overexpressing vascular endothelial growth factor in ovine myocardial infarction

Mesenchymal stromal cells (MSCs) are cardioprotective in acute myocardial infarction (AMI). Besides, we have shown that intramyocardial injection of plasmid-VEGF165 (pVEGF) in ovine AMI reduces infarct size and improves left ventricular (LV) function. We thus hypothesized that MSCs overexpressing VEGF165 (MSCs-pVEGF) would afford greater cardioprotection than non-modified MSCs or pVEGF alone. Sheep underwent an anteroapical AMI and, 1 week later, received intramyocardial MSCs-pVEGF in the infarct border. One month post treatment, infarct size (magnetic resonance) decreased by 31% vs pre-treatment. Of note, myocardial salvage occurred predominantly at the subendocardium, the myocardial region displaying the largest contribution to systolic performance. Consistently, LV ejection fraction recovered to almost its baseline value because of marked decrease in end-systolic volume. None of these effects were observed in sheep receiving non-transfected MSCs or pVEGF. Although myocardial retention of MSCs decreased steeply over time, the treatment induced significant capillary and arteriolar proliferation, which reduced subendocardial fibrosis. We conclude that in ovine AMI, allogeneic VEGF-overexpressing MSCs induce subendocardial myocardium salvage through microvascular proliferation, reducing infarct size and improving LV function more than non-transfected MSCs or the naked plasmid. Importantly, the use of a plasmid rather than a virus allows for repeated treatments, likely needed in ischemic heart disease.Fil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Instituto de Investigación en Ciencias Básicas. Departamento de Ciencias Fisiológicas, Farmacológicas y Bioquímicas; ArgentinaFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Instituto de Investigación en Ciencias Básicas. Departamento de Ciencias Fisiológicas, Farmacológicas y Bioquímicas; ArgentinaFil: Hnatiuk, Anna. Universidad Favaloro. Instituto de Investigación en Ciencias Básicas. Departamento de Ciencias Fisiológicas, Farmacológicas y Bioquímicas; ArgentinaFil: De Lorenzi, Andrea. Universidad Favaloro; Argentina. Fundación Favaloro; ArgentinaFil: Cerda, Martín E.. Universidad Favaloro; Argentina. Fundación Favaloro; ArgentinaFil: Giménez, Carlos Sebastián. Fundación Favaloro; Argentina. Universidad Favaloro. Instituto de Investigación en Ciencias Básicas. Departamento de Ciencias Fisiológicas, Farmacológicas y Bioquímicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sepúlveda, Diana Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; ArgentinaFil: Laguens, Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; ArgentinaFil: Crottogini, Alberto José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro. Instituto de Investigación en Ciencias Básicas. Departamento de Ciencias Fisiológicas, Farmacológicas y Bioquímicas; Argentin

Combined VEGF gene transfer and erythropoietin in ovine reperfused myocardial infarction

BACKGROUND: In reperfused acute myocardial infarction (RAMI), cardioprotective treatments may enhance myocardial salvage and hence reduce the area of necrosis. Based on studies showing that plasmid-mediated vascular endothelial growth factor (pVEGF) gene transfer reduces infarct size by combining angio-arteriogenic and cardiomyogenic effects and that erythropoietin (EPO) exerts anti-apoptotic actions in animal models of AMI, we aimed to assess if their association would reduce infarct size to a larger extent than any of them individually in a large mammalian model of RAMI. METHODS: Adult sheep subjected to 90-minute coronary artery occlusion received upon reperfusion intramyocardial pVEGF 3.8 mg plus intravenous EPO 1000 IU/kg (n=8), pVEGF (n=8), EPO (n=8) or placebo (n=8). RESULTS: Fifteen days after treatment, infarct size was smaller in the 3 treatment groups (pVEGF+EPO: 8 ± 1 %; pVEGF: 16 ± 5 %; EPO: 13 ± 4 %) compared to placebo (25 ± 7 %, p<0.001). However, in the EPO+VEGF group infarct size was significantly smaller than in the groups receiving EPO or VEGF individually (p<0.05). DNA fragmentation, a hallmark of late apoptosis, was significantly lower in sheep receiving EPO. The combined treatment, while not affecting global left ventricular performance, improved regional peri-infarct function and prevented over-time expansion of the post-infarct perfusion defect. CONCLUSIONS: Combined pVEGF and EPO treatment might be clinically useful to enhance the benefits of early revascularization in patients with acute myocardial infarction.Fil: Olea, Fernanda Daniela. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: De Lorenzi, Andrea. Fundación Favaloro; ArgentinaFil: Cortés, Claudia. Fundación Favaloro; ArgentinaFil: Cuniberti, Luis Alberto. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fazzi, Lucía. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Flamenco, María del Pilar. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; ArgentinaFil: Locatelli, Paola. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabeza Meckert, Patricia. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; ArgentinaFil: Bercovich, Andrés. Bio Sidus; ArgentinaFil: Laguens, Rubén. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Crottogini, Alberto José. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin