RESUMEN
Resumen La política internacional de protección del patrimonio mundial de la UNESCO se integró en las agendas de desarrollo nacional y local de los países de América Latina, gestionando proyectos de mejoramiento social y urbano en barrios históricos de las ciudades. Los efectos sociales, ambientales y económicos de estos procesos de patrimonialización de los lugares no han sido suficientemente analizados. En este sentido, y asumiendo una perspectiva psicoambiental, esta investigación describe y compara los índices de Apego al Lugar e Identidad de Lugar en habitantes de tres barrios de la ciudad de Valparaíso (n=544) (Chile) y dos en la ciudad de Quito (n=209) (Ecuador), que se encuentran ubicados en zonas catalogadas como Patrimonio de la Humanidad. A través de la aplicación de pruebas t de Student de comparación de medias y d de Cohen de valoración del tamaño del efecto, se observó que las personas que cuentan con mayor tiempo de residencia, que habitan barrios patrimoniales consolidados (donde las dimensiones socio-urbanas del entorno se encuentran mayormente intervenidas y desarrolladas) y que son propietarias de sus viviendas presentan puntajes más altos de Apego al Lugar e Identidad de Lugar. Se observó un nivel moderado de Apego de Lugar e Identidad de Lugar en los habitantes de los barrios patrimoniales de las ciudades de Valparaíso y Quito.
Abstract UNESCO's international policy for the protection of world heritage was integrated into the national and local development agendas of Latin American countries, managing social and urban improvement projects in historic city districts. The social, environmental and economic effects of these processes of heritage sites have not been sufficiently analyzed. In this sense and assuming a psycho-environmental perspective, this research describes and compares the indices of place attachment and place identity in 3 neighborhoods in the city of Valparaiso (n=544) and 2 in the city of Quito (n=209), which are located in areas classified as World Heritage. Through the application of Student t tests for comparing means and Cohen d tests for assessing the size of the effect, it was observed that people who have resided for longer periods of time, who live in consolidated heritage neighborhoods and who own their own homes, show higher scores in terms of place attachment and place identity. A moderate level of Place Attachment and Place Identity was observed in Valparaíso and Quito.
RESUMEN
Despite unprecedented global efforts to rapidly develop SARS-CoV-2 treatments, in order to reduce the burden placed on health systems, the situation remains critical. Effective diagnosis, treatment, and prophylactic measures are urgently required to meet global demand: recombinant antibodies fulfill these requirements and have marked clinical potential. Here, we describe the fast-tracked development of an alpaca Nanobody specific for the receptor-binding-domain (RBD) of the SARS-CoV-2 Spike protein with potential therapeutic applicability. We present a rapid method for nanobody isolation that includes an optimized immunization regimen coupled with VHH library E. coli surface display, which allows single-step selection of Nanobodies using a simple density gradient centrifugation of the bacterial library. The selected single and monomeric Nanobody, W25, binds to the SARS-CoV-2 S RBD with sub-nanomolar affinity and efficiently competes with ACE-2 receptor binding. Furthermore, W25 potently neutralizes SARS-CoV-2 wild type and the D614G variant with IC50 values in the nanomolar range, demonstrating its potential as antiviral agent.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Afinidad de Anticuerpos/genética , COVID-19/inmunología , SARS-CoV-2/inmunología , Anticuerpos de Dominio Único/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2/inmunología , Animales , COVID-19/virología , Camélidos del Nuevo Mundo/inmunología , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fluorescentes Verdes/genética , Células HeLa , Humanos , Inmunización , Masculino , Pruebas de Neutralización , Biblioteca de Péptidos , Unión Proteica/genética , SARS-CoV-2/química , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/genética , TransfecciónRESUMEN
Sertoli cell metabolism actively maintains the nutritional needs of germ cells. It has been described that after glucose incorporation in Sertoli cells, less than 1% is converted to glycogen suggesting low levels of glycogen synthase activity. Phosphorylation of muscle glycogen synthase (MGS) at serine 640 (pS640MGS) decreases its activity, and this form of the enzyme was discovered as a non-ribosomal protein that modulates the translation of a subset of transcripts in HeLa cells. The aim of our study was to functionally characterize MGS in cultured Sertoli cells, as well as to explore this new feature related to RNA molecules. We detected MGS in the cytoplasm of Sertoli cells as well as in the nuclei. The activity rates of the enzyme were extremely low indicating that MGS is expressed but almost inactive. Protein targeting to glycogen (PTG) overexpression was performed to activate MGS by dephosphorylation. PTG induced glycogen synthesis massively, confirming that this enzyme is present but inactive. This finding correlates with high levels of pS640MGS, which were assayed by phosphatase treatment. To explore a putative new function for MGS in Sertoli cells, we performed RNA immunoprecipitation coupled to microarray studies. The results revealed that MGS co-immunoprecipitated with the several mRNAs and also rRNAs. These findings indicate that MGS is expressed Sertoli cells but in an inactive form, and also support a possibly novel feature of this metabolic enzyme associated with RNA-related molecules. J. Cell. Biochem. 117: 2597-2607, 2016. © 2016 Wiley Periodicals, Inc.
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Glucógeno Sintasa/metabolismo , Glucógeno/biosíntesis , Músculo Esquelético/enzimología , ARN/metabolismo , Células de Sertoli/enzimología , Animales , Western Blotting , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Glucosa/metabolismo , Inmunoprecipitación , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
The development and survival of male germ cells depend on the antioxidant capacity of the seminiferous tubule. Glutathione (GSH) plays an important role in the antioxidant defenses of the spermatogenic epithelium. Autophagy can act as a pro-survival response during oxidative stress or nutrient deficiency. In this work, we evaluated whether autophagy is involved in spermatogonia-type germ cell survival during severe GSH deficiency. We showed that the disruption of GSH metabolism with l-buthionine-(S,R)-sulfoximine (BSO) decreased reduced (GSH), oxidized (GSSG) glutathione content, and GSH/GSSG ratio in germ cells, without altering reactive oxygen species production and cell viability, evaluated by 2',7'-dichlorodihydrofluorescein (DCF) fluorescence and exclusion of propidium iodide assays, respectively. Autophagy was assessed by processing the endogenous protein LC3I and observing its sub-cellular distribution. Immunoblot and immunofluorescence analysis showed a consistent increase in LC3II and accumulation of autophagic vesicles under GSH-depletion conditions. This condition did not show changes in the level of phosphorylation of AMP-activated protein kinase (AMPK) or the ATP content. A loss in S-glutathionylated protein pattern was also observed. However, inhibition of autophagy resulted in decreased ATP content and increased caspase-3/7 activity in GSH-depleted germ cells. These findings suggest that GSH deficiency triggers an AMPK-independent induction of autophagy in germ cells as an adaptive stress response.
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Proteínas Quinasas Activadas por AMP/metabolismo , Glutatión/metabolismo , Estrés Oxidativo/genética , Espermatogonias/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Adenosina Trifosfato/biosíntesis , Animales , Antioxidantes/metabolismo , Autofagia/genética , Caspasas/metabolismo , Supervivencia Celular/efectos de los fármacos , Glutatión/deficiencia , Disulfuro de Glutatión/metabolismo , Masculino , Ratones , Propidio/administración & dosificación , Especies Reactivas de Oxígeno/metabolismo , Túbulos Seminíferos/crecimiento & desarrollo , Túbulos Seminíferos/metabolismo , Espermatogonias/crecimiento & desarrolloRESUMEN
Glycogen is the main source of glucose for many biological events. However, this molecule may have other functions, including those that have deleterious effects on cells. The rate-limiting enzyme in glycogen synthesis is glycogen synthase (GS). It is encoded by two genes, GYS1, expressed in muscle (muscle glycogen synthase, MGS) and other tissues, and GYS2, primarily expressed in liver (liver glycogen synthase, LGS). Expression of GS and its activity have been widely studied in many tissues. To date, it is not clear which GS isoform is responsible for glycogen synthesis and the role of glycogen in testis. Using RT-PCR, Western blot and immunofluorescence, we have detected expression of MGS but not LGS in mice testis during development. We have also evaluated GS activity and glycogen storage at different days after birth and we show that both GS activity and levels of glycogen are higher during the first days of development. Using RT-PCR, we have also shown that malin and laforin are expressed in testis, key enzymes for regulation of GS activity. These proteins form an active complex that regulates MGS by poly-ubiquitination in both Sertoli cell and male germ cell lines. In addition, PTG overexpression in male germ cell line triggered apoptosis by caspase3 activation, proposing a proapoptotic role of glycogen in testis. These findings suggest that GS activity and glycogen synthesis in testis could be regulated and a disruption of this process may be responsible for the apoptosis and degeneration of seminiferous tubules and possible cause of infertility.
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Células Germinativas/citología , Células Germinativas/metabolismo , Glucógeno Sintasa/metabolismo , Glucógeno/metabolismo , Isoformas de Proteínas/metabolismo , Testículo/citología , Testículo/metabolismo , Animales , Apoptosis/genética , Apoptosis/fisiología , Glucógeno Sintasa/genética , Immunoblotting , Masculino , Ratones , Ratones Transgénicos , Isoformas de Proteínas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Túbulos Seminíferos/citología , Túbulos Seminíferos/metabolismo , Testículo/enzimologíaRESUMEN
In this article, we focus on the fundamental role of vitamin C transporters for the normal delivery of vitamin C to germ cells in the adluminal compartment of seminiferous tubules. We argue that the redox status within spermatozoa or in semen is partly responsible for the etiology of infertility. In this context, antioxidant defence plays a critical role in male fertility. Vitamin C, a micronutrient required for a wide variety of metabolic functions, has long been associated with male reproduction. Two systems for vitamin C transport have been described in mammals. Facilitative hexose transporters (GLUTs), with 14 known isoforms to date, GLUT1-GLUT14, transport the oxidized form of vitamin C (dehydroascorbic acid) into the cells. Sodium ascorbic acid co-transporters (SVCTs), SVCT1 and SVCT2 transport the reduced form of vitamin C (ascorbic acid). Sertoli cells control germ cell proliferation and differentiation through cell-cell communication and form the blood-testis barrier. Because the blood-testis barrier limits direct access of molecules from the plasma into the adluminal compartment of the seminiferous tubule, one important question is the method by which germ cells obtain vitamin C. Some interesting results have thrown light on this matter. Expression of SVCT2 and some isoforms of GLUT transporters in the testis have previously been described. Our group has demonstrated that Sertoli cells express functionally active vitamin C transporters. Kinetic characteristics were described for both transport systems (SVCT and GLUT systems). Sertoli cells are able to transport both forms of vitamin C. These findings are extremely relevant, because Sertoli cells may control the amount of vitamin C in the adluminal compartment, as well as regulating the availability of this metabolite throughout spermatogenesis.
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Ácido Ascórbico/metabolismo , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Estrés Oxidativo/fisiología , Epitelio Seminífero/citología , Epitelio Seminífero/metabolismo , Células de Sertoli/metabolismo , Transportadores de Sodio Acoplados a la Vitamina C/metabolismo , Animales , Transporte Biológico , Humanos , Infertilidad Masculina/metabolismo , Masculino , Mamíferos , Ratones , RatasRESUMEN
In this article, we focus on the fundamental role of vitamin C transporters for the normal delivery of vitamin C to germ cells in the adluminal compartment of seminiferous tubules. We argue that the redox status within spermatozoa or in semen is partly responsible for the etiology of infertility. In this context, antioxidant defence plays a critical role in male fertility. Vitamin C, a micronutrient required for a wide variety of metabolic functions, has long been associated with male reproduction. Two systems for vitamin C transport have been described in mammals. Facilitative hexose transporters (GLUTs), with 14 known isoforms to date, GLUT1-GLUT14, transport the oxidized form of vitamin C (dehydroascorbic acid) into the cells. Sodium ascorbic acid co-transporters (SVCTs), SVCT1 and SVCT2 transport the reduced form of vitamin C (ascorbic acid). Sertoli cells control germ cell proliferation and differentiation through cell-cell communication and form the blood-testis barrier. Because the blood-testis barrier limits direct access of molecules from the plasma into the adluminal compartment of the seminiferous tubule, one important question is the method by which germ cells obtain vitamin C. Some interesting results have thrown light on this matter. Expression of SVCT2 and some isoforms of GLUT transporters in the testis have previously been described. Our group has demonstrated that Sertoli cells express functionally active vitamin C transporters. Kinetic characteristics were described for both transport systems (SVCT and GLUT systems). Sertoli cells are able to transport both forms of vitamin C. These findings are extremely relevant, because Sertoli cells may control the amount of vitamin C in the adluminal compartment, as well as regulating the availability of this metabolite throughout spermatogenesis.
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Animales , Humanos , Masculino , Ratones , Ratas , Ácido Ascórbico/metabolismo , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Estrés Oxidativo/fisiología , Epitelio Seminífero/citología , Epitelio Seminífero/metabolismo , Células de Sertoli/metabolismo , Transportadores de Sodio Acoplados a la Vitamina C/metabolismo , Transporte Biológico , Infertilidad Masculina/metabolismo , MamíferosRESUMEN
Rapid and reliable methods for documenting soil erosion associated with forest harvest operations are needed to support the development of best management practices for soil and water conservation. To address this need, the potential for using 7Be measurements to estimate patterns and amounts of soil redistribution associated with individual post-harvest events was explored. The 7Be technique, which was originally developed for use on agricultural land, was employed to estimate soil redistribution associated with a period of heavy rainfall within a harvested forest area located in the Lake Region of Chile (39 degrees 44'7'' S, 73 degrees 10'39'' W; 22% slope; and mean annual rainfall 2300 mm yr(-1)). The results provided by the 7Be technique were validated against direct measurements of soil gain or loss during the same period obtained using erosion pins. The information produced by the two approaches was similar. The results of this study demonstrate the potential for using 7Be measurements to document event-based erosion in recently harvested forest areas.