Browsing by Author "Riveras Hernández, Eleodoro Javier"

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    A simple RNA preparation method for SARS-CoV-2 detection by RT-qPCR
    (2020) Wozniak Banchero, Aniela; Cerda Rojas, Ariel Patricio; Lamig Giannini, Liliana Andrea; Solari Gajardo, Sandra; Guzmán Durán, Ana María; Riveras Hernández, Eleodoro Javier; Ferres Garrido, Marcela Viviana; Gutiérrez Ilabaca, Rodrigo Antonio; García Cañete, Patricia; Ibarra Henriquez, C.; Sebastian, V.; Armijo, G.; Lamig, L.; Miranda, C.; Lagos, M.; Quiroga, T.; Hitschfeld, S.
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    La función de calcio en la vía de señalización mediada por nitrato en raíces de Arabidopsis thaliana /
    (2015) Riveras Hernández, Eleodoro Javier; Gutiérrez Ilabaca, Rodrigo Antonio; Pontificia Universidad Católica de Chile. Facultad de Ciencias Biológicas
    Entender como las plantas censan y responden a cambios en la disponibilidad de nitrógeno (N) es el primer paso para desarrollar estrategias para aplicaciones biotecnológicas tales como mejorar la eficiencia del uso del nitrógeno. Sin embargo, los componentes involucrados en las vías de señalización de N son pobremente conocidos. Calcio es un segundo mensajero en vías de transducción de señales en plantas pero su rol en la respuesta a nitrato no ha sido evaluado. Usando una planta reportera que expresa la proteína Aequorina, hemos observado que tratamientos con nitrato incrementan la concentración de calcio citoplasmático ([Ca2+]cyt). Encontramos que nitrato también induce un aumento en los niveles de inositol trifosfato (IP3). El incremento en los niveles de IP3 y [Ca2+]cyt en respuesta a nitrato fue bloqueado por U73122, un inhibidor de la actividad de la fosfolipasa C (PLC), pero no por el análogo no funcional U73343. Además, el incremento en los niveles de IP3 y [Ca2+]cyt en respuesta a nitrato fue inhibido en la mutante del receptor de nitrato NRT1.1/AtNPF6.3. La expresión de genes de respuesta nitrato fue severamente afectada por pre-tratamientos con bloqueadores de canales de calcio e inhibidores de la PLC. Estos resultados indican que el calcio actúa como un segundo mensajero en la vía de señalización de nitrato de Arabidopsis thaliana. Nuestros resultados sugieren un modelo en el que NRT1.1/AtNPF6.3 y la actividad de la PLC median el incremento de calcio en respuesta a nitrato, el cual a su vez produce el cambio en la expresión de genes de respuesta a nitrato.
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    Nitrate in 2020: Thirty years from transport to signaling networks
    (2020) Vidal, Elena A.; Alvarez, José M.; Araus, Viviana; Riveras Hernández, Eleodoro Javier; Brooks, Matthew D.; Krouk, Gabriel; Ruffel, Sandrine; Lejay, Laurence; Crawford, Nigel M.; Coruzzi, Gloria M.; Gutiérrez Ilabaca, Rodrigo Antonio
    Nitrogen (N) is an essential macronutrient for plants and a major limiting factor for plant growth and crop production. Nitrate is the main source of N available to plants in agricultural soils and in many natural environments. Sustaining agricultural productivity is of paramount importance in the current scenario of increasing world population, diversification of crop uses, and climate change. Plant productivity for major crops around the world, however, is still supported by excess application of N-rich fertilizers with detrimental economic and environmental impacts. Thus, understanding how plants regulate nitrate uptake and metabolism is key for developing new crops with enhanced N use efficiency and to cope with future world food demands. The study of plant responses to nitrate has gained considerable interest over the last 30 years. This review provides an overview of key findings in nitrate research, spanning biochemistry, molecular genetics, genomics, and systems biology. We discuss how we have reached our current view of nitrate transport, local and systemic nitrate sensing/signaling, and the regulatory networks underlying nitrate-controlled outputs in plants. We hope this summary will serve not only as a timeline and information repository but also as a baseline to define outstanding questions for future research.
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    SMZ/SNZ and gibberellin signaling are required for nitrate-elicited delay of flowering time in Arabidopsis thaliana
    (2018) Gras, D. E.; Vidal Olate, Elena Alejandra; Undurraga, S. F.; Riveras Hernández, Eleodoro Javier; Moreno, S.; Domínguez Figueroa, J.; Alabadi, D.; Blazquez, M. A.; Medina, J.; Gutiérrez Ilabaca, Rodrigo Antonio
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    Transcriptomic profiles reveal differences in zinc metabolism, inflammation, and tight junction proteins in duodenum from cholesterol gallstone subjects
    (2020) Riveras Hernández, Eleodoro Javier; Azócar, Lorena; Moyano, Tomás C.; Ocares, Marcia; Molina, Héctor; Romero, Diego; Roa Strauch, Juan Carlos Enrique; Valbuena Mora, José Rafael; Gutiérrez, Rodrigo A.; Miquel P., Juan Francisco
    Cholesterol Gallstone Disease (GSD) is a common multifactorial disorder characterized by crystallization and aggregation of biliary cholesterol in the gallbladder. The global prevalence of GSD is similar to 10-20% in the adult population but rises to 28% in Chile (17% among men and 30% among women). The small intestine may play a role in GSD pathogenesis, but the molecular mechanisms have not been clarified. Our aim was to identify the role of the small intestine in GSD pathogenesis. Duodenal biopsy samples were obtained from patients with GSD and healthy volunteers. GSD status was defined by abdominal ultrasonography. We performed a transcriptome study in a discovery cohort using Illumina HiSeq. 2500, and qPCR, immunohistochemistry and immunofluorescence were used to validate differentially expressed genes among additional case-control cohorts. 548 differentially expressed genes between GSD and control subjects were identified. Enriched biological processes related to cellular response to zinc, and immune and antimicrobial responses were observed in GSD patients. We validated lower transcript levels of metallothionein, NPC1L1 and tight junction genes and higher transcript levels of genes involved in immune and antimicrobial pathways in GSD patients. Interestingly, serum zinc and phytosterol to cholesterol precursor ratios were lower in GSD patients. A significant association was observed between serum zinc and phytosterol levels. Our results support a model where proximal small intestine plays a key role in GSD pathogenesis. Zinc supplementation, modulation of proximal microbiota and/or intestinal barrier may be novel targets for strategies to prevent GSD.