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

Doença Covid-19. Relatório do primeiro caso confirmado em Córdoba (Argentina) e revisão da literature

La enfermedad COVID-19 es una infección respiratoria producida por un virus denominado coronavirus 2 del síndrome respiratorio agudo severo (SARS-CoV-2), el cual se transmite principalmente a través de gotas respiratorias eliminadas por un paciente infectado cuando tose, estornuda o habla. En el siguiente texto se describen los síntomas, signos y resultados de laboratorio y tomografía solicitados al primer paciente confirmado de enfermedad COVID-19 en Córdoba, Argentina. Además se comenta el manejo del paciente de forma domiciliaria mediante telemedicina y su evolución hasta el alta con posterior resolución de la enfermedad.publishedVersionFil: Milanesio, Martín. Hospital Privado Universitario de Córdoba. Clínica Médica; Argentina.Fil: Escudero, Daiana. Hospital Privado Universitario de Córdoba. Servicio de Infectología; Argentina.Fil: Caeiro, Juan Pablo. Hospital Privado Universitario de Córdoba. Servicio de Infectología; Argentina

Epidermal growth factor receptor silencing blunts the slow force response to myocardial stretch

Background-Myocardial stretch increases force biphasically: the Frank-Starling mechanism followed by the slow force response (SFR). Based on pharmacological strategies, we proposed that epidermal growth factor (EGF) receptor (EGFR or ErbB1) activation is crucial for SFR development. Pharmacological inhibitors could block ErbB4, a member of the ErbB family present in the adult heart. We aimed to specifically test the role of EGFR activation after stretch, with an interference RNA incorporated into a lentiviral vector (small hairpin RNA [shRNA]-EGFR). Methods and Results-Silencing capability of p-shEGFR was assessed in EGFR-GFP transiently transfected HEK293T cells. Four weeks after lentivirus injection into the left ventricular wall of Wistar rats, shRNA-EGFR-injected hearts showed -60% reduction of EGFR protein expression compared with shRNA-SCR-injected hearts. ErbB2 and ErbB4 expression did not change. The SFR to stretch evaluated in isolated papillary muscles was ≈130% of initial rapid phase in the shRNA-SCR group, while it was blunted in shRNA-EGFR-expressing muscles. Angiotensin II (Ang II)-dependent Na+/H+ exchanger 1 activation was indirectly evaluated by intracellular pH measurements in bicarbonate-free medium, demonstrating an increase in shRNA-SCR-injected myocardium, an effect not observed in the silenced group. Ang II- or EGF-triggered reactive oxygen species production was significantly reduced in shRNA-EGFR-injected hearts compared with that in the shRNA-SCR group. Chronic lentivirus treatment affected neither the myocardial basal redox state (thiobarbituric acid reactive substances) nor NADPH oxidase activity or expression. Finally, Ang II or EGF triggered a redox-sensitive pathway, leading to p90RSK activation in shRNA-SCR-injected myocardium, an effect that was absent in the shRNA-EGFR group. Conclusions-Our results provide evidence that specific EGFR activation after myocardial stretch is a key factor in promoting the redox-sensitive kinase activation pathway, leading to SFR development.Centro de Investigaciones CardiovascularesFacultad de Ciencias Veterinaria

Influence of a tutorial system based on the use of ICT in the decrease of dropout and academic failure of first-year students of the Veterinary career of the Juan Agustín Maza University (Argentina)

El trabajo aborda el uso de TIC en los Sistemas de Tutorías Universitarias como estrategia para disminuir la deserción de estudiantes. Se pretende describir y aplicar un modelo de orientación particular, el Modelo Tecnológico, y su impacto en la deserción universitaria. Se trabaja con una metodología cuantitativa, desde una perspectiva empírica-analítica. Se pretende mostrar un nuevo escenario para el Sistema de Tutorías implementado en la Universidad Maza desde el año 1997. Se procurará incorporar un proceso de orientación integral basado en el uso de TIC, que permita la inclusión de todos los alumnos, no importa qué estadio de la carrera se encuentren transitando, de manera de favorecer la retención con calidad y la efectividad terminal. El resultado esperado es un programa de orientación y tutoría diseñado para ser útil a tutores y estudiantes universitarios, implementado en una plataforma virtual personalizada.The work addresses the use of ICT in the University Tutorials System as a strategy to reduce student dropouts. The aim is to describe and apply a particular orientation model, the Technological Model and analyze its impact on university dropout. We work with a quantitative methodology, from an empirical-analytical perspective. It is intended to show a new scenario for the Tutorial System implemented at the Maza University since 1997. It will seek to incorporate a comprehensive orientation process based on the use of ICT, which allows the inclusion of all students, no matter what stage of the university career they are transiting, in way to favor the retention with quality, and the terminal effectiveness. The expected result is an orientation and tutoring program designed to be useful to tutors and university students, implemented in a personalized virtual platform.Ponencias.Facultad de Ciencias Veterinaria

Influence of a tutorial system based on the use of ICT in the decrease of dropout and academic failure of first-year students of the Veterinary career of the Juan Agustín Maza University (Argentina)

El trabajo aborda el uso de TIC en los Sistemas de Tutorías Universitarias como estrategia para disminuir la deserción de estudiantes. Se pretende describir y aplicar un modelo de orientación particular, el Modelo Tecnológico, y su impacto en la deserción universitaria. Se trabaja con una metodología cuantitativa, desde una perspectiva empírica-analítica. Se pretende mostrar un nuevo escenario para el Sistema de Tutorías implementado en la Universidad Maza desde el año 1997. Se procurará incorporar un proceso de orientación integral basado en el uso de TIC, que permita la inclusión de todos los alumnos, no importa qué estadio de la carrera se encuentren transitando, de manera de favorecer la retención con calidad y la efectividad terminal. El resultado esperado es un programa de orientación y tutoría diseñado para ser útil a tutores y estudiantes universitarios, implementado en una plataforma virtual personalizada.The work addresses the use of ICT in the University Tutorials System as a strategy to reduce student dropouts. The aim is to describe and apply a particular orientation model, the Technological Model and analyze its impact on university dropout. We work with a quantitative methodology, from an empirical-analytical perspective. It is intended to show a new scenario for the Tutorial System implemented at the Maza University since 1997. It will seek to incorporate a comprehensive orientation process based on the use of ICT, which allows the inclusion of all students, no matter what stage of the university career they are transiting, in way to favor the retention with quality, and the terminal effectiveness. The expected result is an orientation and tutoring program designed to be useful to tutors and university students, implemented in a personalized virtual platform.Ponencias.Facultad de Ciencias Veterinaria

Epidermal growth factor receptor silencing blunts the slow force response to myocardial stretch

Background-Myocardial stretch increases force biphasically: the Frank-Starling mechanism followed by the slow force response (SFR). Based on pharmacological strategies, we proposed that epidermal growth factor (EGF) receptor (EGFR or ErbB1) activation is crucial for SFR development. Pharmacological inhibitors could block ErbB4, a member of the ErbB family present in the adult heart. We aimed to specifically test the role of EGFR activation after stretch, with an interference RNA incorporated into a lentiviral vector (small hairpin RNA [shRNA]-EGFR). Methods and Results-Silencing capability of p-shEGFR was assessed in EGFR-GFP transiently transfected HEK293T cells. Four weeks after lentivirus injection into the left ventricular wall of Wistar rats, shRNA-EGFR-injected hearts showed -60% reduction of EGFR protein expression compared with shRNA-SCR-injected hearts. ErbB2 and ErbB4 expression did not change. The SFR to stretch evaluated in isolated papillary muscles was ≈130% of initial rapid phase in the shRNA-SCR group, while it was blunted in shRNA-EGFR-expressing muscles. Angiotensin II (Ang II)-dependent Na+/H+ exchanger 1 activation was indirectly evaluated by intracellular pH measurements in bicarbonate-free medium, demonstrating an increase in shRNA-SCR-injected myocardium, an effect not observed in the silenced group. Ang II- or EGF-triggered reactive oxygen species production was significantly reduced in shRNA-EGFR-injected hearts compared with that in the shRNA-SCR group. Chronic lentivirus treatment affected neither the myocardial basal redox state (thiobarbituric acid reactive substances) nor NADPH oxidase activity or expression. Finally, Ang II or EGF triggered a redox-sensitive pathway, leading to p90RSK activation in shRNA-SCR-injected myocardium, an effect that was absent in the shRNA-EGFR group. Conclusions-Our results provide evidence that specific EGFR activation after myocardial stretch is a key factor in promoting the redox-sensitive kinase activation pathway, leading to SFR development.Centro de Investigaciones CardiovascularesFacultad de Ciencias Veterinaria

p38-MAP Kinase Negatively Regulates the Slow Force Response to Stretch in Rat Myocardium through the Up-Regulation of Dual Specificity Phosphatase 6 (DUSP6)

Background/aims: Myocardial stretch increases cardiac force in two consecutive phases: The first one due to Frank-Starling mechanism, followed by the gradually developed slow force response (SFR). The latter is the mechanical counterpart of an autocrine/paracrine mechanism involving the release of angiotensin II (Ang II) and endothelin (ET) leading to Na⁺/H⁺ exchanger 1 (NHE-1) phosphorylation and activation. Since previous evidence indicates that p38-MAP kinase (p38-MAPK) negatively regulates the Ang II-induced NHE1 activation in vascular smooth muscle and the positive inotropic effect of ET in the heart, we hypothesized that this kinase might modulate the magnitude of the SFR to stretch. Methods: Experiments were performed in isolated rat papillary muscles subjected to sudden stretch from 92 to 98% of its maximal length, in the absence or presence of the p38-MAPK inhibitor SB202190, or its inactive analogous SB202474. Western blot technique was used to determine phosphorylation level of p38-MAPK, ERK1/2, p90RSK and NHE-1 (previously immunoprecipitated with NHE-1 polyclonal antibody). Dual specificity phosphatase 6 (DUSP6) expression was evaluated by RT-PCR and western blot. Additionally, the Na⁺-dependent intracellular pH recovery from an ammonium prepulse-induced acid load was used to asses NHE-1 activity. Results: The SFR was larger under p38-MAPK inhibition (SB202190), effect that was not observed in the presence of an inactive analogous (SB202474). Myocardial stretch activated p38-MAPK, while pre-treatment with SB202190 precluded this effect. Inhibition of p38-MAPK increased stretched-induced NHE-1 phosphorylation and activity, key event in the SFR development. Consistently, p38-MAPK inhibition promoted a greater increase in ERK1/2-p90RSK phosphorylation/activation after myocardial stretch, effect that may certainly be responsible for the observed increase in NHE-1 phosphorylation under this condition. Myocardial stretch induced up-regulation of the DUSP6, which specifically dephosphorylates ERK1/2, effect that was blunted by SB202190. Conclusion: Taken together, our data support the notion that p38-MAPK activation after myocardial stretch restricts the SFR by limiting ERK1/2-p90RSK phosphorylation, and consequently NHE-1 phosphorylation/activity, through a mechanism that involves DUSP6 up-regulation.Facultad de Ciencias MédicasCentro de Investigaciones Cardiovasculare

Dynamics of soluble immune mediators in COVID-19 patients from an Argentinean cohort with moderate and severe symptoms

The cytokine storm, a form of systemic inflammatory response syndrome, is one of the most dreadful complications that can occur during COVID-19. The severity of infection is associated at different levels of these immune mediators and many molecules are considered marker of COVID mortality. Because of its central role in the pathogenesis of SARS-CoV-2 infection, the cytokine storm have become a therapeutic target in the treatment of COVID-19 patients.In this work, we aimed at studying the concentration of different pro- and anti-inflammatory cytokines in a cohort of COVID-19 patients from Córdoba (Argentine). The immunological reaction triggered by infection with SARS-CoV-2 mobilizes numerous cytokines, mainly of proinflammatory character. Changes in their levels are associated with the presence of the disease and with a more severe prognosis. Although our data have similarities with those in international reports, the complete profiling of different parameters (cytokine/chemokines, risk factors, epidemiological and clinical characteristics) in the local cases add value by identifying particularities that may be relevant for the management and prognosis during SARS-CoV2 infection in Argentine.Fil: Almada, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Angiolin, Sofia C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Dho, Nicolás. Universidad Nacional de Córdoba; ArgentinaFil: Dutto, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Gazzon, Yamila. Universidad Nacional de Córdoba; ArgentinaFil: Manzone, Clarisa. Universidad Nacional de Córdoba; ArgentinaFil: Marin, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Ponce, Nicolás Eric. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Iribarren, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Cerban, Fabio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Morón, Gabriel. Universidad Nacional de Córdoba; ArgentinaFil: Amezcua Vesely, Carolina. Universidad Nacional de Córdoba; ArgentinaFil: Ana, Yamile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Cervi, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Chiapello, Laura Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Fozzatt, Laura. Universidad Nacional de Córdoba; ArgentinaFil: Icely, Paula Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Maccioni, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Mena, Cristian Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Montes, Carolina Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Motrán, Cristina. Universidad Nacional de Córdoba; ArgentinaFil: Rodríguez Galán, Cecilia. Universidad Nacional de Córdoba; ArgentinaFil: Stempin, Cinthia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Viano, María Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Bertone, M.. Hospital Privado Universitario de Córdoba; ArgentinaFil: Abiega, Claudio Daniel. Hospital Privado Universitario de Córdoba; ArgentinaFil: Escudero, Daiana Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Hospital Privado Universitario de Córdoba; ArgentinaFil: Kahn, Adrian Mario. Hospital Privado Universitario de Córdoba; ArgentinaFil: Caeiro, Juan Pablo. Hospital Privado Universitario de Córdoba; ArgentinaFil: Arroyo, Daniela Soledad. Hospital Privado Universitario de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Maletto, Belkys Angélica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Acosta Rodriguez, Eva Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Gruppi, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Sotomayor, Claudia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaLXVI reunión anual de la sociedad argentina de investigación clínica (saic), LXIX reunión anual de la sociedad argentina de inmunología (sai), LIII reunión anual de la asociación argentina de farmacología experimental (aafe), XI reunión anual de la asociación argentina de nanomedicinas (nanomed-ar)Buenos AiresArgentinaSociedad Argentina de Inmunologí

COVID-19 patients display changes in lymphocyte subsets with a higher frequency of dysfunctional CD8lo T cells associated with disease severity

This work examines cellular immunity against SARS-CoV-2 in patients from Córdoba, Argentina, during two major waves characterized by different circulating viral variants and different social behavior. Using flow cytometry, we evaluated the main lymphocyte populations of peripheral blood from hospitalized patients with moderate and severe COVID-19 disease. Our results show disturbances in the cellular immune compartment, as previously reported in different cohorts worldwide. We observed an increased frequency of B cells and a significant decrease in the frequency of CD3+ T cells in COVID-19 patients compared to healthy donors (HD). We also found a reduction in Tregs, which was more pronounced in severe patients. During the first wave, the frequency of GZMB, CD107a, CD39, and PD-1-expressing conventional CD4+ T (T conv) cells was significantly higher in moderate and severe patients than in HD. During the second wave, only the GZMB+ T conv cells of moderate and severe patients increased significantly. In addition, these patients showed a decreased frequency in IL-2-producing T conv cells. Interestingly, we identified two subsets of circulating CD8+ T cells with low and high CD8 surface expression in both HD and COVID-19 patients. While the percentages of CD8hi and CD8lo T cells within the CD8+ population in HD are similar, a significant increase was observed in CD8lo T cell frequency in COVID-19 patients. CD8lo T cell populations from HD as well as from SARS-CoV-2 infected patients exhibited lower frequencies of the effector cytokine-producing cells, TNF, IL-2, and IFN-γ, than CD8hi T cells. Interestingly, the frequency of CD8lo T cells increased with disease severity, suggesting that this parameter could be a potential marker for disease progression. Indeed, the CD8hi/CD8lo index helped to significantly improve the patient’s clinical stratification and disease outcome prediction. Our data support the addition of, at least, a CD8hi/CD8lo index into the panel of biomarkers commonly used in clinical labs, since its determination may be a useful tool with impact on the therapeutic management of the patients

Regulación de la actividad del intercambiador Na<SUP>+</SUP>/H<SUP>+</SUP> miocárdico por proteína quinasa G : Posibles implicancias terapéuticas

Objetivo general: El presente trabajo de Tesis Doctoral tiene como objetivo general la caracterización funcional y molecular de la regulación del NHE1 por fosforilación en el miocardio, poniendo especial énfasis en el análisis de la participación de la ruta GMPc/PKG en condiciones normales (miocardio normotrófico) y patológicas (miocardio hipertrófico). Objetivos específicos: - Caracterizar la activación de la ruta GMPc/PKG inducida por inhibición de la FDE5A con SIL sobre la actividad del NHE1 en cardiomiocitos de ratas normotensas Wistar y espontáneamente hipertensas SHR. - Evaluar el posible efecto anti-hipertrofiante de la administración crónica de SIL en un modelo in vitro de crecimiento celular disparado por Ang II en células H9C2 (línea celular proveniente de mioblastos de miocardio de rata). - Evaluar el posible efecto anti-hipertrofiante de la administración crónica de SIL in vivo en un modelo de hipertrofia miocárdica por hipertensión (ratas SHR), caracterizando los posibles mecanismos intracelulares involucrados.Facultad de Ciencias Exacta