12 research outputs found
Vanadate-induced nitric oxide production: role in osteoblast growth and differentiation
Nitric oxide NO. has been shown to act as a mediator of cytokines in bone tissue. We have previously demonstrated that vanadium compounds are insulin- and growth factor-mimetic compounds in osteoblasts in culture, although high doses are toxic to these cells. In this study, we measured NO production in two osteoblast-like cells UMR106 and MC3T3E1. incubated with different concentrations 2.5–100 mM. of vanadate. Vanadate induced NO release in a biphasic manner, with levels being significantly increased at concentrations over 50 mM. The NO donor, sodium nitroprusside, mimicked the vanadate effect: it inhibited cell growth and alkaline phosphatase activity in a dose-dependent manner. Vanadate enhanced the NO synthases, the endothelial and inducible eNOS and iNOS. isoforms, in a dose-dependent manner. Experiments performed with the ionophore A23187 and EGTA suggested that vanadate-induced NO production involves Ca2q-dependent and -independent mechanisms. Altogether, our results suggest that NO may play a critical role in the bioactivity of vanadium in osteoblast-like cells. q2000 Elsevier Science B.V. All rights reserved
Vanadate-induced nitric oxide production: role in osteoblast growth and differentiation
Nitric oxide NO. has been shown to act as a mediator of cytokines in bone tissue. We have previously demonstrated that vanadium compounds are insulin- and growth factor-mimetic compounds in osteoblasts in culture, although high doses are toxic to these cells. In this study, we measured NO production in two osteoblast-like cells UMR106 and MC3T3E1. incubated with different concentrations 2.5–100 mM. of vanadate. Vanadate induced NO release in a biphasic manner, with levels being significantly increased at concentrations over 50 mM. The NO donor, sodium nitroprusside, mimicked the vanadate effect: it inhibited cell growth and alkaline phosphatase activity in a dose-dependent manner. Vanadate enhanced the NO synthases, the endothelial and inducible eNOS and iNOS. isoforms, in a dose-dependent manner. Experiments performed with the ionophore A23187 and EGTA suggested that vanadate-induced NO production involves Ca2q-dependent and -independent mechanisms. Altogether, our results suggest that NO may play a critical role in the bioactivity of vanadium in osteoblast-like cells.Facultad de Ciencias Exacta
Non-enzymatic glycosylation of a type I collagen matrix: effects on osteoblastic development and oxidative stress
BACKGROUND: The tissue accumulation of protein-bound advanced glycation endproducts (AGE) may be involved in the etiology of diabetic chronic complications, including osteopenia. The aim of this study was to investigate the effect of an AGE-modified type I collagen substratum on the adhesion, spreading, proliferation and differentiation of rat osteosarcoma UMR106 and mouse non-transformed MC3T3E1 osteoblastic cells. We also studied the role of reactive oxygen species (ROS) and nitric oxide synthase (NOS) expression on these AGE-collagen mediated effects. RESULTS: AGE-collagen decreased the adhesion of UMR106 cells, but had no effect on the attachment of MC3T3E1 cells. In the UMR106 cell line, AGE-collagen also inhibited cellular proliferation, spreading and alkaline phosphatase (ALP) activity. In preosteoblastic MC3T3E1 cells (24-hour culture), proliferation and spreading were significantly increased by AGE-collagen. After one week of culture (differentiated MC3T3E1 osteoblasts) AGE-collagen inhibited ALP activity, but had no effect on cell number. In mineralizing MC3T3E1 cells (3-week culture) AGE-collagen induced a decrease in the number of surviving cells and of extracellular nodules of mineralization, without modifying their ALP activity. Intracellular ROS production, measured after a 48-hour culture, was decreased by AGE-collagen in MC3T3E1 cells, but was increased by AGE-collagen in UMR106 cells. After a 24-hour culture, AGE-collagen increased the expression of endothelial and inducible NOS, in both osteoblastic cell lines. CONCLUSIONS: These results suggest that the accumulation of AGE on bone extracellular matrix could regulate the proliferation and differentiation of osteoblastic cells. These effects appear to depend on the stage of osteoblastic development, and possibly involve the modulation of NOS expression and intracellular ROS pathways
Non-enzymatic glycosylation of a type 1 collagen matrix: effects on osteoblastic development and oxidative stress
Background : The tissue accumulation of protein-bound advanced glycation endproducts (AGE) may be involved in the etiology of diabetic chronic complications, including osteopenia. The aim of this study was to investigate the effect of an AGE-modified type I collagen substratum on the adhesion, spreading, proliferation and differentiation of rat osteosarcoma UMR106 and mouse nontransformed MC3T3E1 osteoblastic cells. We also studied the role of reactive oxygen species (ROS) and nitric oxide synthase (NOS) expression on these AGE-collagen mediated effects. Results: AGE-collagen decreased the adhesion of UMR106 cells, but had no effect on the attachment of MC3T3E1 cells. In the UMR106 cell line, AGE-collagen also inhibited cellular proliferation, spreading and alkaline phosphatase (ALP) activity. In preosteoblastic MC3T3E1 cells (24-hour culture), proliferation and spreading were significantly increased by AGE-collagen. After one week of culture (differentiated MC3T3E1 osteoblasts) AGE-collagen inhibited ALP activity, but had no effect on cell number. In mineralizing MC3T3E1 cells (3-week culture) AGE-collagen induced a decrease in the number of surviving cells and of extracellular nodules of mineralization, without modifying their ALP activity. Intracellular ROS production, measured after a 48-hour culture, was decreased by AGE-collagen in MC3T3E1 cells, but was increased by AGE-collagen in UMR106 cells. After a 24-hour culture, AGE-collagen increased the expression of endothelial and inducible NOS, in both osteoblastic cell lines. Conclusions: These results suggest that the accumulation of AGE on bone extracellular matrix could regulate the proliferation and differentiation of osteoblastic cells. These effects appear to depend on the stage of osteoblastic development, and possibly involve the modulation of NOS expression and intracellular ROS pathways.Facultad de Ciencias Exacta
Vanadate-induced nitric oxide production: role in osteoblast growth and differentiation
Nitric oxide NO. has been shown to act as a mediator of cytokines in bone tissue. We have previously demonstrated that vanadium compounds are insulin- and growth factor-mimetic compounds in osteoblasts in culture, although high doses are toxic to these cells. In this study, we measured NO production in two osteoblast-like cells UMR106 and MC3T3E1. incubated with different concentrations 2.5–100 mM. of vanadate. Vanadate induced NO release in a biphasic manner, with levels being significantly increased at concentrations over 50 mM. The NO donor, sodium nitroprusside, mimicked the vanadate effect: it inhibited cell growth and alkaline phosphatase activity in a dose-dependent manner. Vanadate enhanced the NO synthases, the endothelial and inducible eNOS and iNOS. isoforms, in a dose-dependent manner. Experiments performed with the ionophore A23187 and EGTA suggested that vanadate-induced NO production involves Ca2q-dependent and -independent mechanisms. Altogether, our results suggest that NO may play a critical role in the bioactivity of vanadium in osteoblast-like cells.Facultad de Ciencias Exacta
Non-enzymatic glycosylation of a type 1 collagen matrix: effects on osteoblastic development and oxidative stress
Background : The tissue accumulation of protein-bound advanced glycation endproducts (AGE) may be involved in the etiology of diabetic chronic complications, including osteopenia. The aim of this study was to investigate the effect of an AGE-modified type I collagen substratum on the adhesion, spreading, proliferation and differentiation of rat osteosarcoma UMR106 and mouse nontransformed MC3T3E1 osteoblastic cells. We also studied the role of reactive oxygen species (ROS) and nitric oxide synthase (NOS) expression on these AGE-collagen mediated effects. Results: AGE-collagen decreased the adhesion of UMR106 cells, but had no effect on the attachment of MC3T3E1 cells. In the UMR106 cell line, AGE-collagen also inhibited cellular proliferation, spreading and alkaline phosphatase (ALP) activity. In preosteoblastic MC3T3E1 cells (24-hour culture), proliferation and spreading were significantly increased by AGE-collagen. After one week of culture (differentiated MC3T3E1 osteoblasts) AGE-collagen inhibited ALP activity, but had no effect on cell number. In mineralizing MC3T3E1 cells (3-week culture) AGE-collagen induced a decrease in the number of surviving cells and of extracellular nodules of mineralization, without modifying their ALP activity. Intracellular ROS production, measured after a 48-hour culture, was decreased by AGE-collagen in MC3T3E1 cells, but was increased by AGE-collagen in UMR106 cells. After a 24-hour culture, AGE-collagen increased the expression of endothelial and inducible NOS, in both osteoblastic cell lines. Conclusions: These results suggest that the accumulation of AGE on bone extracellular matrix could regulate the proliferation and differentiation of osteoblastic cells. These effects appear to depend on the stage of osteoblastic development, and possibly involve the modulation of NOS expression and intracellular ROS pathways.Facultad de Ciencias Exacta
Advanced glycation end-products (AGEs) induce concerted changes in the osteoblastic expression of their receptor RAGE and in the activation of extracellular signal-regulated kinases (ERK)
An increase in the interaction between advanced glycation end-products (AGEs) and their receptor RAGE is believed to contribute to the pathogenesis of chronic complications of Diabetes mellitus, which can include bone alterations such as osteopenia. We have recently found that extracellular AGEs can directly regulate the growth and development of rat osteosarcoma UMR106 cells, and of mouse calvaria-derived MC3T3E1 osteoblasts throughout their successive developmental stages (proliferation, differentiation and mineralisation), possibly by the recognition of AGEs moieties by specific osteoblastic receptors which are present in both cell lines. In the present study we examined the possible expression of RAGE by UMR106 and MC3T3E1 osteoblastic cells, by immunoblot analysis. We also investigated whether short-, medium- or long-term exposure of osteoblasts to extracellular AGEs, could modify their affinity constant and maximal binding for AGEs (by 125I-AGE-BSA binding experiments), their expression of RAGE (by immunoblot analysis) and the activation status of the osteoblastic ERK 1/2 signal transduction mechanism (by immunoblot analysis for ERK and P-ERK). Our results show that both osteoblastic cell lines express readily detectable levels of RAGE. Short-term exposure of phenotypically mature osteoblastic UMR106 cells to AGEs decrease the cellular density of AGE-binding sites while increasing the affinity of these sites for AGEs. This culture condition also dose-dependently increased the expression of RAGE and the activation of ERK. In proliferating MC3T3E1 pre-osteoblasts, 24-72 h exposure to AGEs did not modify expression of RAGE, ERK activation or the cellular density of AGE-binding sites. However, it did change the affinity of these binding sites forAGEs, with both higher- and lower-affinity sites now being apparent. Medium-term ( 1 week) incubation of differentiated MC3T3E1 osteoblasts with AGEs, induced a simultaneous increase in RAGE expression and in the relative amount of P-ERK. Mineralising MC3T3E1 cultures grown for 3 weeks in the presence of extracellular AGEs showed a decrease both in RAGE and P-ERK expression. These results indicate that, in phenotypically mature osteoblastic cells, changes in ERK activation closely follow the AGEs-induced regulation of RAGE expression. Thus, the AGEs-induced biological effects that we have observed previously in osteoblasts, could be mediated by RAGE in the later stages of development, and mediated by other AGE receptors in the earlier pre-osteoblastic stage.Facultad de Ciencias Exacta
Fifteen-Year Surveillance of LTR Receiving Pre-Emptive Therapy for CMV Infection: Prevention of CMV Disease and Incidence of CLAD
The efficacy of pre-emptive therapy in the prevention of cytomegalovirus (CMV) disease and the potential association of CMV infection with the occurrence of chronic lung allograft dysfunction (CLAD) was evaluated in 129 lung transplant recipients receiving pre-emptive therapy based on pp65-antigenemia or CMV-DNA in the blood and in the bronchoalveolar lavage. Seventy-one (55%) patients received pre-emptive ganciclovir/valganciclovir (GCV/VGCV) for CMV infection for a median of 28 (9–191) days. Possible CMV disease occurred in six (5%) patients and was healed after the GCV/VGCV therapy. The cumulative incidence of CLAD was 38% and 54% at 5 and 10 years. Acute rejection and CMV load in the blood (but not in the lung) were independent predictors of the occurrence of CLAD. Pre-emptive therapy is highly effective in preventing CMV disease in lung recipients and does not induce a superior incidence of CLAD compared to what reported for other cohorts of patients who received an extended antiviral prophylaxis
Encuesta Nacional Migrante de Argentina
La Encuesta Nacional Migrante de Argentina (ENMA) surge como proyecto del Eje Migración y Asilo de la Red Orientada a la Resolución de Problemas en Derechos Humanos de CONICET (RIOSP DDHH) y un amplio conjunto de organizaciones de migrantes y de derechos humanos en el año 2020. Se propone como una respuesta, desde la academia y las organizaciones de la sociedad civil, a la ausencia de información actualizada, nacional y confiable sobre la situación de las personas migrantes residentes en la Argentina (cuyo número, según proyecciones recientes, asciende a 2.3 millones y representa cerca del 5% de la población del paÃs). En nuestro paÃs, la ausencia de información cuantitativa sobre la población migrante no solo afecta la representatividad y exhaustividad de los estudios que buscan caracterizar y comprender este fenómeno histórico y contemporáneo en un plano académico e investigativo, sino también las estrategias de incidencia destinadas a garantizar los derechos de este colectivo por parte de las organizaciones de la sociedad y el diseño de polÃticas públicas basadas en evidencia. El Censo Nacional es la única fuente estadÃstica que permite obtener información poblacional completa y su última edición fue en el año 2010, no pudiéndose captar las transformaciones ocurridas en la última década. Por su parte, la Encuesta Permanente de Hogares se realiza solo a nivel de los núcleos urbanos más densamente poblados del paÃs, no permitiendo conocer las dinámicas de espacios rurales y de menor escala demográfica, excluyendo muestralmente los colectivos migratorios más recientes y menos numerosos. La única ocasión en que se realizó una Encuesta Complementaria de Migraciones Internacionales (ECMI) fue como parte del Censo Nacional de Población, Hogares y Viviendas en el año 2001. Por otro lado, los registros administrativos contemplan escasamente las variables vinculadas a la nacionalidad y/o paÃs de origen, además de presentar graves problemas de calidad estadÃstica (RIBOTTA ET AL., 2019). Finalmente, la caracterÃstica federal de nuestro paÃs dificulta aún más obtener información nacional representativa; sumado a que en ningún caso las fuentes citadas permiten conocer las dificultades o no de acceso a derechos de las personas migrantes en nuestro paÃs. La profunda crisis económica en la que se encontraba el paÃs antes de la llegada de la pandemia, aunada a las polÃticas restrictivas y xenófobas implementadas los años previos, llevaron a un grave deterioro de la situación económica, social y documentaria de la población migrante (Debandi y Penchaszadeh, 2020; Gavazzo y Penchaszadeh, 2020; Penchaszadeh, 2021; Debandi, Nicolao y Penchaszadeh, 2021). Las restricciones de movilidad y el estricto cierre de fronteras impuesto, desde marzo de 2020 hasta mediados de 2021, asà como la imposibilidad de gran parte de la población migrante de acceder a las polÃticas y planes de ayuda social implementados, recrudecieron aún más la situación de vulnerabilidad de este colectivo. En ese contexto, la necesidad de contar con datos que permitieran producir información confiable y facilitar la incidencia en la arena polÃtica, se volvió imprescindible. Asà surgió el proyecto de la Encuesta Nacional Migrante de Argentina, desarrollado de manera autónoma e independiente por un conjunto de más de 30 investigadores/as de todo el paÃs agrupados en el eje migración y asilo de la RIOSP-DDHH y con la participación de un extenso número de referentes migrantes y activistas en derechos humanos. El proceso tomó casi un año de trabajo (julio 2020 a mayo 2021) y contó con un Ãnfimo financiamiento ad hoc (del CONICET y la Plataforma Interagencial de respuesta para personas migrantes y refugiadas venezolanas, R4V, de OIM y ACNUR), utilizado principalmente para la difusión, la adquisición del software de encuestas, la limpieza de la base de datos y la divulgación de resultados . La ENMA tiene un alcance nacional con representatividad a nivel de origen nacional, género y edad. Se basa en un diseño muestral por cuotas basado en los datos del Censo 2010 con ajustes a partir de la Encuesta Permanente de Hogares (2019). La primera edición, llevada a cabo en el primer año de la pandemia, se aplicó por medio de un cuestionario digital autoadministrado traducido a tres idiomas (creole haitiano, wolof y chino). El número total de respuestas válidas obtenido, después de la limpieza de la base de datos, fue de 3.114. Los datos se encuentran disponibles en formato abierto desde mayo de 2021 y ya han sido solicitados por más de 30 personas, entre activistas, investigadores y funcionarios de organismos estatales. Después de la limpieza y el procesamiento estadÃstico, se elaboró el Anuario EstadÃstico Migratorio de la Argentina 2020, el cual condensa los principales resultados derivados de la encuesta. Este documento, desarrollado también de manera articulada entre academia y organizaciones de migrantes, presenta una primera mirada informada, objetiva y representativa de la situación de la población migrante residente en el paÃs desde una perspectiva de derechos humanos. El objetivo es incidir en el diseño integral de las polÃticas públicas dirigidas a esta población y contribuir a combatir la xenofobia y la discriminación a partir de evidencia empÃrica. En rigor, uno de los aspectos centrales de la propuesta metodológica, es su elaboración y concepción desde un enfoque práctico de derechos humanos. Sin entrar en detalles que ameritarÃan un extenso desarrollo, el enfoque de derechos plantea en primer lugar, colocar a los destinatarios de las polÃticas públicas como sujetos de derechos, es decir, como actores que pueden exigir determinadas prestaciones y conductas por parte del Estado y la sociedad (Abramovich y Pautassi, 2009; Abramovich, 2006). Entre los principios transversales que fundan el enfoque se encuentran la participación social y la producción de información, ambos estructurales en avanzar en la exigibilidad de los derechos, alejándose de la mirada asistencialista y paternalista de las necesidades del sujeto migrante. Se partió asà de considerar que las personas migrantes no son partÃcipes circunstanciales o secundarios de la ENMA, sino promotores y autores de la investigación en su conjunto. En la primera edición de la encuesta, las personas migrantes fueron impulsoras imprescindibles del proyecto y participaron – en igualdad de condiciones que la academia – en el diseño, difusión, implementación y análisis de los resultados obtenidos colectivamente. Este enfoque práctico de derechos humanos se evidencia en el propio cuestionario, que receptó los principales intereses de las comunidades migrantes, modificó el orden de algunas preguntas sociodemográficas clásicas y definió la forma en que se consultaban o no ciertas cuestiones. Fueron asimismo las organizaciones migrantes quienes permitieron llegar a los territorios y personas a encuestar, logrando alcanzar y superar las cuotas previstas originalmente. Finalmente, cabe destacar que la ENMA se propone como una fuente de periodicidad trianual, complementaria y alternativa a la que producen los organismos oficiales. Para su próxima edición, en 2023 se busca posicionar y consolidar a la ENMA como un instrumento de recolección de información sobre migración internacional desde un enfoque de derechos, desarrollado desde la academia y las organizaciones de migrantes. El desafÃo por delante – en un contexto de postpandemia – es contar con la estructura institucional y presupuestaria que permita potenciar las capacidades de esta conjunción virtuosa entre academia y activismo, datos y conocimiento.Fil: Penchaszadeh, Ana Paula. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Gavazzo, Natalia. Universidad Nacional de San MartÃn. Instituto de Altos Estudios Sociales; ArgentinaFil: Gonzalez, Anahi Patricia. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Gottero, Laura Angélica. Universidad Nacional de Lanús. Rectorado. Secretaria de Ciencia y Técnica. Instituto de Justicia y Derechos Humanos "Eduardo Luis Duhalde".; ArgentinaFil: Hendel, Verónica. Universidad Nacional de Luján. Departamento de Educación; ArgentinaFil: Acosta, Diego. University of Bristol; Reino UnidoFil: Condori Maman, Sandra. Universidad Nacional de Tres de Febrero; ArgentinaFil: Figari Costa, Nicolás. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Lettieri , Martin. Organización de Las Naciones Unidas; ArgentinaFil: Guerreño, Marta. Unión de Colectividades de Córdoba; ArgentinaFil: Courtis, Corina. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras; ArgentinaFil: del Rosario Chavez, Elena. Andhes; ArgentinaFil: Costanzo, Gabriela AnahÃ. Universidad de Buenos Aires. Facultad de Ciencias Sociales; ArgentinaFil: Castiglione, MarÃa Celeste. Universidad Nacional de Jose Clemente Paz. Instituto de Estudios Sociales En Contextos de Desigualdades.; ArgentinaFil: Morzilli, Melina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; ArgentinaFil: Trpin, Verónica. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Kleidermacher, Gisele Paola. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Sander, Joanna Cecilia. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras. Departamento de Ciencias Antropológicas; ArgentinaFil: Debandi, Natalia. Universidad Nacional de RÃo Negro. Sede Atlántica. Instituto de Investigación en PolÃticas Públicas y Gobierno; ArgentinaFil: Cerrutti, Marcela Sandra. Centro de Estudios de Población; ArgentinaFil: Moro, AgustÃn. Universidad de Buenos Aires. Facultad de Ciencias Sociales; ArgentinaFil: Ataide, Soraya. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Investigaciones en Ciencias Sociales y Humanidades. Universidad Nacional de Salta. Facultad de Humanidades. Instituto de Investigaciones en Ciencias Sociales y Humanidades; ArgentinaFil: Baeza, Brigida Norma. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Humanidades y Ciencias Sociales - Sede Comodoro. Instituto de Estudios Sociales y PolÃticos de la Patagonia; ArgentinaFil: González, Mariana Alejandra. Universidad Nacional del Comahue. Instituto Patagónico de Estudios de Humanidades y Ciencias Sociales. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto Patagónico de Estudios de Humanidades y Ciencias Sociales; ArgentinaFil: RodrÃguez Rocha, Eduardo. Universidad Nacional de Córdoba; ArgentinaFil: Nicolao, Julieta. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas; Argentin