Intramyocardial gene silencing by interfering RNA

RNAi is a widely used methodology for gene silencing. The action mechanism of siRNA molecules has been well studiedin recent years, and the technique has been optimized in terms of safety and effectiveness. Cardiovascular diseases havea high incidence in the current population, and despite of the extensive research, safe and efficient therapeutics have notyet been found, which is reflected by 17.1 million people who die each year for this cause. In this context, siRNAs arebeing considered a therapeutic tool to regulate the expression of genes involved in the generation of these pathologies.The efficacy of siRNAs entry to cardiomyocytes, the safety of the delivery process and the degree of silencing achievedare main aspects before consider it as a cardiovascular disease therapy. Presently, we will give a brief outline of thecurrent understanding of the RNAi mechanism and the delivery system to the heart. We describe the use of lentivirus fora functional silencing of cardiac proteins in the study of a pathophysiological process, the slow force response to cardiacstretch.Fil: Brea, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Morgan, Patricio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; Argentin

Cardiac Mineralocorticoid Receptor and the Na+/H+ Exchanger: Spilling the Beans

Current evidence reveals that cardiac mineralocorticoid receptor (MR) activation following myocardial stretch plays an important physiological role in adapting developed force to sudden changes in hemodynamic conditions. Its underlying mechanism involves a previously unknown nongenomic effect of the MR that triggers redox-mediated Na+/H+ exchanger (NHE1) activation, intracellular Na+ accumulation, and a consequent increase in Ca2+ transient amplitude through reverse Na+/Ca2+ exchange. However, clinical evidence assigns a detrimental role to MR activation in the pathogenesis of severe cardiac diseases such as congestive heart failure. This mini review is meant to present and briefly discuss some recent discoveries about locally triggered cardiac MR signals with the objective of shedding some light on its physiological but potentially pathological consequences in the heart.Fil: Ennis, Irene Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

Cardiac mineralocorticoid receptor and the Na+/H+ exchanger: Spilling the beans.

Current evidence reveals that cardiac mineralocorticoid receptor (MR) activation following myocardial stretch plays an important physiological role in adapting developed force to sudden changes in hemodynamic conditions. Its underlying mechanism involves a previously unknown nongenomic effect of the MR that triggers redox-mediated Na+/H+ exchanger (NHE1) activation, intracellular Na+ accumulation, and a consequent increase in Ca2+ transient amplitude through reverse Na+/Ca2+ exchange. However, clinical evidence assigns a detrimental role to MR activation in the pathogenesis of severe cardiac diseases such as congestive heart failure. This mini review is meant to present and briefly discuss some recent discoveries about locally triggered cardiac MR signals with the objective of shedding some light on its physiological but potentially pathological consequences in the heart.Fil: Ennis, Irene Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

Myocardial Impact of NHE1 Regulation by Sildenafil

The cardiac Na+/H+ exchanger (NHE1) is a membrane glycoprotein fundamental for proper cell functioning due its multiple housekeeping tasks, including regulation of intracellular pH, Na+ concentration, and cell volume. In the heart, hyperactivation of NHE1 has been linked to the development of different pathologies. Several studies in animal models that reproduce the deleterious effects of ischemia/reperfusion injury or cardiac hypertrophy have conclusively demonstrated that NHE1 inhibition provides cardioprotection. Unfortunately, NHE1 inhibitors failed to reproduce these effects in the clinical arena. The reasons for those discrepancies are not apparent yet. However, a reasonable clue to consider would be that drugs that completely abolish the exchanger activity, including that its essential housekeeping function may not be the best therapeutic approach. Therefore, interventions tending to specifically reduce its hyperactive state without affecting its basal activity emerge as a novel potential gold standard. In this regard, a promising goal seems to be the modulation of the phosphorylation state of the cytosolic tail of the exchanger. Recent own experiments demonstrated that Sildenafil, a phosphodiesterase 5A inhibitor drug that has been widely used for the treatment of erectile dysfunction is able to decrease NHE1 phosphorylation, and hence reduce its hyperactivity. In connection, growing evidence demonstrates cardioprotective properties of Sildenafil against different cardiac pathologies, with the distinctive characteristic of directly affecting cardiac tissue without altering blood pressure. This mini-review was aimed to focus on the regulation of NHE1 activity by Sildenafil. For this purpose, experimental data reporting Sildenafil effects in different animal models of heart disease will be discussed.Fil: Escudero, Daiana Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Diaz, Romina Gisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

Oxidative stress and cardiac contractility: a double edge sword?

The stretch of cardiac muscle increases developed force in two phases. The first phase occurs immediately after stretch and is the expression of the Frank–Starling mechanism, while the second one or slow force response (SFR) occurs gradually and is due to an increase in the calcium transient amplitude. Previously, we have shown that the SFR is the mechanical manifestation of an autocrine/paracrine mechanism activated by wall stretch involving growth factors-triggered reactive oxygen species (ROS) formation, and followed by redox-mediated cardiac Na+ /H+ exchanger (NHE1) activation leading to an increase in the Ca2+ "transient" amplitude. Recent own experiments assigned a role to thioredoxin-1 (“TRX1”, an important cellular antioxidant enzymatic system) in the development of the SFR. Interestingly, cardiac hypertrophy and failure, two of the most important health problems in western societies, are both triggered by intracellular signals triggered by myocardial stretch, being oxidative stress a critical step for its progression. Remarkably, experimental evidence has revealed that TRX1 overexpression negatively regulates cardiac hypertrophy. In this scenario, this short review was meant to briefly discuss the physiological, but potentially pathological, role of oxidative stress following myocardial stretch.El estiramiento miocárdico produce una respuesta contráctil en dos fases: un aumento rápido inmediato que es la expresión del mecanismo de Frank-Starling, y uno lento posterior denominado segunda fase de fuerza (SFF). En trabajos anteriores hemos mostrado que la SFF es la manifestación mecánica de un mecanismo autocrino/paracrino disparado por el estiramiento, que involucra liberación de factores de crecimiento seguida de la activación redox-dependiente del intercambiador Na+ /H+ cardíaco (NHE1) que conduce a un aumento Na+ -dependiente del Ca2+ intracelular. Experimentos más recientes de nuestro grupo han demostrado además que la tioredoxina-1 (“TRX1”, importante sistema enzimático antioxidante a nivel celular) es capaz de modular la magnitud de la SFF. Interesantemente, la hipertrofia y la insuficiencia cardíaca, dos de los problemas de salud más importantes en sociedades occidentales, se desencadenan por señales intracelulares que ocurren después del estiramiento miocárdico e incluyen estrés oxidativo como factor clave para su progresión patológica. En conexión, se ha demostrado que la sobreexpresión de TRX1 regula negativamente la hipertrofia cardíaca. En este escenario, esta revisión tiene como objetivo discutir brevemente el papel fisiológico, pero potencialmente patológico, del estrés oxidativo disparado por el estiramiento del miocardio.Fil: Zavala, Maite Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Diaz, Romina Gisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Villa-Abrille, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

Thioredoxin 1 (TRX1) Overexpression Cancels the Slow Force Response (SFR) Development

The stretch of cardiac muscle increases developed force in two phases. The first phase occurs immediately after stretch and is the expression of the Frank–Starling mechanism, while the second one or slow force response (SFR) occurs gradually and is due to an increase in the calcium transient amplitude. An important step in the chain of events leading to the SFR generation is the increased production of reactive oxygen species (ROS) leading to redox sensitive ERK1/2, p90RSK, and NHE1 phosphorylation/activation. Conversely, suppression of ROS production blunts the SFR. The purpose of this study was to explore whether overexpression of the ubiquitously expressed antioxidant molecule thioredoxin-1 (TRX1) affects the SFR development and NHE1 phosphorylation. We did not detect any change in basal phopho-ERK1/2, phopho-p90RSK, and NHE1 expression in mice with TRX1 overexpression compared to wild type (WT). Isolated papillary muscles from WT or TRX1-overexpressing mice were stretched from 92 to 98% of its maximal length. A prominent SFR was observed in WT mice that was completely canceled in TRX1 animals. Interestingly, myocardial stretch induced a significant increase in NHE1 phosphorylation in WT mice that was not detected in TRX1-overexpressing mice. These novel results suggest that magnification of cardiac antioxidant defense power by overexpression of TRX1 precludes NHE1 phosphorylation/activation after stretch, consequently blunting the SFR development.Fil: Zavala, Maite Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Diaz, Romina Gisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Villa-Abrille, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

Prevención de eventos cardiovasculares en la insuficiencia renal crónica factores de riesgo no tradicionales

La principal causa de muerte de los pacientes con insuficiencia renal crónica es el evento cardiovascular. El control de los "factores de riesgo tradicionales" son las estrategias ampliamente utilizadas, a pesar de ello, la mortalidad por eventos cardiovasculares no ha disminuido considerablemente. Otros factores "no tradicionales2 como la anemia, la inflamación crónica, las calcificaciones vasculares, el aumento de la Lp(a) y de homocisteina han demostrado solo asociaciones con la aumentada mortalidad de esto pacientes, pero aun requieren estudios que demuestren causales de esta aumentada incidencia de eventos cardiovasculares durante la insuficiencia renal crónica.Fil: Flores Allende, Gustavo Alberto. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Gobierno de la Provincia de Cordoba. Hospital Misericordia Nuevo Siglo; ArgentinaFil: Perez, Hernan A.. Blossom Dmo; ArgentinaFil: Garcia, Nestor Horacio. Fundacion J Robert Cade; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentin

Endothelin isoforms and the response to myocardial stretch

Myocardial stretch elicits a biphasic increase in developed force with a first rapid force response and a second slow force response (SFR). The rapid phase is due to an increase in myofilament Ca(2+) responsiveness; the SFR, analyzed here, is ascribed to a progressive increase in Ca(2+) transients. Experiments were performed in cat papillary muscles to further elucidate the signaling pathway underlying the SFR. Although the SFR was diminished by BQ-123, a similar endothelin (ET)-1-induced increase in force was not affected: 23 +/- 2 vs. 23 +/- 3% (not significant). Instead, BQ-123 suppressed the contractile effects of ET-2 or ET-3 (21 +/- 2 and 25 +/- 3% vs. -1 +/- 1 and -7 +/- 3% respectively, P < 0.05), suggesting that ET-2 or ET-3, but not ET-1, was involved in the SFR. Each isoform activated the Na(+)/H(+) exchanger (NHE-1), increasing intracellular Na(+) concentration by 2.0 +/- 0.1, 2.3 +/- 0.1, and 2.1 +/- 0.4 mmol/l for ET-1, ET-2, and ET-3, respectively (P < 0.05). The NHE-1 inhibitor HOE-642 prevented the increases in force and intracellular Na(+) concentration induced by all the ET isoforms, but only ET-2 and ET-3 effects were sensitive to BQ-123. Real-time RT-PCR measurements of prepro-ET-1, -ET-2, and -ET-3 were performed before and 5, 15, and 30 min after stretch. No changes in ET-1 or ET-2, but an increase of approximately 60% in ET-3, mRNA after 15 min of stretch were detected. Stretch-induced ET-3 mRNA upregulation and its mechanical counterpart were suppressed by AT(1) receptor blockade with losartan. These data suggest a role for AT(1)-mediated ET-3 released in the early activation of NHE-1 that follows myocardial stretch.Fil: Ennis, Irene Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Garciarena, Carolina Denis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Dulce, Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Camilion, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Cingolani, Horacio Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; Argentin

Carbonic anhydrase inhibitors reduce cardiac dysfunction after sustained coronary artery ligation in rats

Background Two potent carbonic anhydrase (CA) inhibitors with widely differing membrane permeability, poorly diffusible benzolamide (BZ), and highly diffusible ethoxzolamide (ETZ) were assessed to determine whether they can reduce cardiac dysfunction in rats subjected to coronary artery ligation (CAL)-induced myocardial infarction. Methods and results Rats with evidence of heart failure (HF) at 32 weeks following a permanent left anterior coronary artery occlusion were treated with placebo, BZ, or ETZ (4 mg kg�day−1) for 4 weeks at which time left ventricular function and structure were evaluated. Lung weight/body weight (LW/BW) ratio increased in CAL rats by 17�1% vs. control, suggesting pulmonary edema. There was a trend for BZ and ETZ to ameliorate the increase in LW/BW by almost 50% (9�5% and 9�8%, respectively, versus CAL) (P=.16, NS). Echocardiographic assessment showed decreased left ventricular midwall shortening in HF rats, 21�1% vs. control 32�1%, which was improved by BZ to 29�1% and ETZ to 27�1%, and reduced endocardial shortening in HF rats 38�3% vs. control 62�1%, partially restored by BZ and ETZ to ~50%. Expression of the hypoxia-inducible membrane-associated CAIX isoform increased by ~60% in HF rat hearts, and this effect was blocked by ETZ. Conclusions We conclude that CAL-induced myocardial interstitial fibrosis and associated decline in left ventricular function were diminished with BZ or ETZ treatment. The reductions in cardiac remodeling in HF with both ETZ and BZ CA inhibitors suggest that inhibition of a membrane-bound CA appears to be the critical site for this protection.Fil: Vargas, Lorena Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Pinilla, Oscar Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Diaz, Romina Gisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Sepúlveda, Diana Elizabeth. Universidad Favaloro. Facultad de Medicina. Departamento de Ciencias Básicas de la Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Swenson, Erik R.. University of Washington. School of Medicine; Estados UnidosFil: Perez, Nestor Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; ArgentinaFil: Alvarez, Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares ; Argentin

Accounting for pastoralists in Argentina

No official statistics exist on pastoralism in Argentina, so their number is not known. Between 30,000 to 35,000 households practise pastoralism, estimates Red Chaco based on the 2018 National Census. In some areas, pastoralism is alive as a mobile, extensive production system. Despite the uncertainty about the precise numbers, pastoralists play a significant role in Argentinian agriculture and society. Argentina is a large but highly urbanized country, with 92% of the population living in towns and cities. Only 13.2% of the country is agriculturally well endowed; 70% of the land is semi-arid, and much of the rest is mountainous or too cold for growing crops. Livestock-raising is the main form of agriculture in such marginal areas, either as ranching or as pastoralism.Estación Experimental Agropecuaria BarilocheFil: Lanari, Maria Rosa. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche; ArgentinaFil: Perez Centeno, Marcelo. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Preda, Graciela Maria. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Quiroga Mendiola, Mariana. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Ejarque, Mercedes. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Lammel, Sofía Ailén. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Moronta, Martin Nestor. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región Patagonia; ArgentinaFil: Quiroga Rogers, Juan. Instituto Nacional de Tecnologia Agropecuaria (INTA). Área de Investigación para la Agricultura Familiar Región NOA; ArgentinaFil: Losardo, Pablo Gustavo. Ministerio de Agricultura, Ganadería y Pesca de la Nación; ArgentinaFil: Frere, Pablo. Fundación Gran Chaco; Argentin