40 research outputs found

    Desarrollo de un servicio experimental de teledetección en los riegos del Porma (León) para el cálculo ajustado de necesidades hídricas y mejora en la gestión del regadío

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    El proyecto de innovación tecnológica OPTIREG Eficiencia Hídrica, impulsado por el Grupo Tragsa, tiene entre sus objetivos principales introducir el uso de la teledetección, como tecnología de apoyo a la gestión hídrica. Para ello se está desarrollando un servicio web gis experimental que servirá de repositorio único de imágenes y de sus productos derivados y que facilitará, tanto a los regantes, como a los gestores del riego, el seguimiento de los cultivos y de sus necesidades hídricas. Diversos estudios científicos han demostrado la buena relación lineal existente entre el índice de vegetación normalizado (NDVI), derivado de las imágenes de satélite, y el coeficiente de cultivo, Kc (Torres, 2010), utilizado en el cálculo de la evapotranspiración y las necesidades hídricas. Una primera evaluación de los resultados obtenidos en la campaña 2015 para los principales cultivos en regadío en la zona de estudio del Porma (León), indica que el Kc calculado a partir del NDVI, se ajusta mejor que el de FAO. Por ello, se considera un sistema muy válido como referencia para ajustar no sólo la cantidad de agua, sino también para determinar el momento más adecuado de riego, que redundará en una mayor eficiencia hídrica

    Impact of Liver Inflammation on Bile Acid Side Chain Shortening and Amidation

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    Bile acid (BA) synthesis from cholesterol by hepatocytes is inhibited by inflammatory cytokines. Whether liver inflammation also affects BA side chain shortening and conjugation was investigated. In human liver cell lines (IHH, HepG2, and HepaRG), agonists of nuclear receptors including the farnesoid X receptor (FXR), liver X receptor (LXR), and peroxisome proliferator-activated receptors (PPARs) did not affect the expression of BA-related peroxisomal enzymes. In contrast, hepatocyte nuclear factor 4? (HNF4?) inhibition down-regulated acyl-CoA oxidase 2 (ACOX2). ACOX2 was repressed by fibroblast growth factor 19 (FGF19), which was prevented by extracellular signal-regulated kinase (ERK) pathway inhibition. These changes were paralleled by altered BA synthesis (HPLC-MS/MS). Cytokines able to down-regulate cholesterol-7?-hydroxylase (CYP7A1) had little effect on peroxisomal enzymes involved in BA synthesis except for ACOX2 and bile acid-CoA:amino acid N-acyltransferase (BAAT), which were down-regulated, mainly by oncostatin M (OSM). This effect was prevented by Janus kinase (JAK) inhibition, which restored BA side chain shortening and conjugation. The binding of OSM to the extracellular matrix accounted for a persistent effect after culture medium replacement. In silico analysis of four databases (n = 201) and a validation cohort (n = 90) revealed an inverse relationship between liver inflammation and ACOX2/BAAT expression which was associated with changes in HNF4? levels. In conclusion, BA side chain shortening and conjugation are inhibited by inflammatory effectors. However, other mechanisms involved in BA homeostasis counterbalance any significant impact on the serum BA profile

    Beneficial Effect of Ursodeoxycholic Acid in Patients with ACOX2 Deficiency-Associated Hypertransaminasemia

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    Background: A variant (p.Arg225Trp) of peroxisomal acyl-CoA oxidase 2 (ACOX2), involved in bile acid (BA) side-chain shortening, has been associated with unexplained persistent hypertransaminasemia and accumulation of C27-BAs, mainly trihydroxycholestanoic acid (THCA). Aims: To investigate the prevalence of ACOX2 deficiency-associated hypertransaminasemia (ADAH), its response to ursodeoxycholic acid (UDCA), elucidate its pathophysiological mechanism and identify other inborn errors that could cause this alteration. Methods & results: Among 33 patients with unexplained hypertransaminasemia from 11 hospitals, and 13 of their relatives, 7 individuals with abnormally high C27-BA levels (>50% of total BAs) were identified by HPLC-MS/MS. The p.Arg225Trp variant was found in homozygosity (exon amplification/sequencing) in 2 patients and 3 family members. Two additional non-related patients were heterozygous carriers of different alleles: c.673C>T (p.Arg225Trp) and c.456_459del (p.Thr154fs). In ADAH patients, impaired liver expression of ACOX2, but not ACOX3, was found (immunohistochemistry). Treatment with UDCA normalized transaminases levels. Incubation of HuH-7 liver cells with THCA, which was efficiently taken up, but not through BA transporters, increased ROS production (flow cytometry), ER stress biomarkers (GRP78, CHOP and XBP1-S/XBP1-U ratio), and BAX¿ expression (RT-qPCR and immunoblot), whereas cell viability was decreased (MTT). THCA-induced cell toxicity was higher than that of major C24-BAs and was not prevented by UDCA. Fourteen predicted ACOX2 variants were generated (site-directed mutagenesis) and expressed in HuH-7 cells. Functional tests to determine their ability to metabolize THCA identified six with the potential to cause ADAH. Conclusion: Dysfunctional ACOX2 has been found in several patients with unexplained hypertransaminasemia. This condition can be accurately identified by a non-invasive diagnostic strategy based on plasma BA profiling and ACOX2 sequencing. Moreover, UDCA treatment can efficiently attenuate liver damage in these patients.This study was supported by the following grants: CIBERehd (EHD15PI05/2016); Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain (PI19/00819 and PI20/00189), co-funded by European Regional Development Fund/European Social Fund, “Investing in your future”; “Junta de Castilla y León” (SA074P20); Fundació Marato TV3 (201916–31); AECC Scientific Foundation (2017/2020), Spain; and “Centro Internacional sobre el Envejecimiento” (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. We also acknowledge support from grants PID2019-111669RBI- 100, PID2020-115055RB- I00 from Plan Nacional de I+D funded by the “Agencia Estatal de Investigación” (AEI) and the center grant P50AA011999 Southern California Research Center for ALPD and Cirrhosis funded by NIAAA/NIH, as well as support from AGAUR of the “Generalitat de Catalunya” SGR-2017- 1112, European Cooperation in Science & Technology (COST) ACTION CA17112 Prospective European Drug-Induced Liver Injury Network. Marta Alonso-Peña was the recipient of a predoctoral fellowship from “Ministerio de Educación, Cultura y Deporte” (BOE-A- 2015- 9456; FPU-14/ 00214) and a Mobility Grant for Short Stays from “Ministerio de Ciencia, Innovación y Universidades” (EST17/00186). Ricardo Espinosa-Escudero is the recipient of a predoctoral fellowship from “Junta de Castilla y León” and “Fondo Social Europeo” (EDU/574/2018). The funding sources were not involved in the research design or preparation of the articl

    Beneficial effect of ursodeoxycholic acid in patients with acyl-CoA oxidase 2 (ACOX2) deficiency-associated hypertransaminasemia

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    Background and aims: A variant (p.Arg225Trp) of peroxisomal acyl-CoA oxidase 2 (ACOX2), involved in bile acid (BA) side-chain shortening, has been associated with unexplained persistent hypertransaminasemia and accumulation of C27-BAs, mainly 3?,7?,12?-trihydroxy-5?-cholestanoic acid (THCA). We aimed to investigate the prevalence of ACOX2 deficiency-associated hypertransaminasemia (ADAH), its response to ursodeoxycholic acid (UDCA), elucidate its pathophysiological mechanism and identify other inborn errors that could cause this alteration. Methods and results: Among 33 patients with unexplained hypertransaminasemia from 11 hospitals and 13 of their relatives, seven individuals with abnormally high C27-BA levels (>50% of total BAs) were identified by high-performance liquid chromatography-mass spectrometry. The p.Arg225Trp variant was found in homozygosity (exon amplification/sequencing) in two patients and three family members. Two additional nonrelated patients were heterozygous carriers of different alleles: c.673C>T (p.Arg225Trp) and c.456_459del (p.Thr154fs). In patients with ADAH, impaired liver expression of ACOX2, but not ACOX3, was found (immunohistochemistry). Treatment with UDCA normalized aminotransferase levels. Incubation of HuH-7 hepatoma cells with THCA, which was efficiently taken up, but not through BA transporters, increased reactive oxygen species production (flow cytometry), endoplasmic reticulum stress biomarkers (GRP78, CHOP, and XBP1-S/XBP1-U ratio), and BAX? expression (reverse transcription followed by quantitative polymerase chain reaction and immunoblot), whereas cell viability was decreased (tetrazolium salt-based cell viability test). THCA-induced cell toxicity was higher than that of major C24-BAs and was not prevented by UDCA. Fourteen predicted ACOX2 variants were generated (site-directed mutagenesis) and expressed in HuH-7 cells. Functional tests to determine their ability to metabolize THCA identified six with the potential to cause ADAH. Conclusions: Dysfunctional ACOX2 has been found in several patients with unexplained hypertransaminasemia. This condition can be accurately identified by a noninvasive diagnostic strategy based on plasma BA profiling and ACOX2 sequencing. Moreover, UDCA treatment can efficiently attenuate liver damage in these patients.Funding information: This study was supported by the following grants: CIBERehd (EHD15PI05/2016); Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain (PI19/00819 and PI20/00189), co-funded by European Regional Development Fund/European Social Fund, “Investing in your future”; “Junta de Castilla y León” (SA074P20); Fundació Marato TV3 (201916–31); AECC Scientific Foundation (2017/2020), Spain; and “Centro Internacional sobre el Envejecimiento” (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. We also acknowledge support from grants PID2019-111669RBI-100, PID2020-115055RB-I00 from Plan Nacional de I+D funded by the “Agencia Estatal de Investigación” (AEI) and the center grant P50AA011999 Southern California Research Center for ALPD and Cirrhosis funded by NIAAA/NIH, as well as support from AGAUR of the “Generalitat de Catalunya” SGR-2017-1112, European Cooperation in Science & Technology (COST) ACTION CA17112 Prospective European Drug-Induced Liver Injury Network. Marta Alonso-Peña was the recipient of a predoctoral fellowship from “Ministerio de Educación, Cultura y Deporte” (BOE-A-2015-9456; FPU-14/00214) and a Mobility Grant for Short Stays from “Ministerio de Ciencia, Innovación y Universidades” (EST17/00186). Ricardo Espinosa-Escudero is the recipient of a predoctoral fellowship from “Junta de Castilla y León” and “Fondo Social Europeo” (EDU/574/2018). The funding sources were not involved in the research design or preparation of the article

    Splicing factor SLU7 prevents oxidative stress-mediated hepatocyte nuclear factor 4α degradation, preserving hepatic differentiation and protecting from liver damage

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    Background and Aims: Hepatocellular dedifferentiation is emerging as an important determinant in liver disease progression. Preservation of mature hepatocyte identity relies on a set of key genes, predominantly the transcription factor hepatocyte nuclear factor 4α (HNF4α) but also splicing factors like SLU7. How these factors interact and become dysregulated and the impact of their impairment in driving liver disease are not fully understood. Approach and Results: Expression of SLU7 and that of the adult and oncofetal isoforms of HNF4α, driven by its promoter 1 (P1) and P2, respectively, was studied in diseased human and mouse livers. Hepatic function and damage response were analyzed in wild-type and Slu7-haploinsufficient/heterozygous (Slu7+/−) mice undergoing chronic (CCl4) and acute (acetaminophen) injury. SLU7 expression was restored in CCl4-injured mice using SLU7-expressing adeno-associated viruses (AAV-SLU7). The hepatocellular SLU7 interactome was characterized by mass spectrometry. Reduced SLU7 expression in human and mouse diseased livers correlated with a switch in HNF4α P1 to P2 usage. This response was reproduced in Slu7+/− mice, which displayed increased sensitivity to chronic and acute liver injury, enhanced oxidative stress, and marked impairment of hepatic functions. AAV-SLU7 infection prevented liver injury and hepatocellular dedifferentiation. Mechanistically we demonstrate a unique role for SLU7 in the preservation of HNF4α1 protein stability through its capacity to protect the liver against oxidative stress. SLU7 is herein identified as a key component of the stress granule proteome, an essential part of the cell’s antioxidant machinery. Conclusions: Our results place SLU7 at the highest level of hepatocellular identity control, identifying SLU7 as a link between stress-protective mechanisms and liver differentiation. These findings emphasize the importance of the preservation of hepatic functions in the protection from liver injury.Supported by MINECO/AEI/FEDER (UE SAF2016‐75972‐R, PID2019‐104265RB‐I00/AEI/10.13039/501100011033, and PID2019‐104878RB‐100/AEI/10.13039/501100011033), CIBERehd, Fundación La Caixa (HEPACARE), an AECC postdoctoral fellowship (POSTD18014AREC, to M.A.), a Ministerio de Educación FPU fellowship (FPU18/01461, to M.G.R.), a Ministerio de Educación FPI fellowship (BES‐2017‐079883, to M.R.); a Ramón y Cajal Program contract (RYC2018‐024475‐1, to M.G.F.B.), the Fundación Eugenio Rodríguez Pascual, the Fundación Mario Losantos, the Fundación M. Torres, and a generous donation from Mr. Eduardo Avila

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Anales de Edafología y Agrobiología Tomo 27 Número 3-4

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    Oligoelementos en árboles de bosque (Pinus). IV. Estudio edafológico de las ocho parcelas forestales elegidas, por R. Lagunas-Gil, M. Deán-Guelbenzu, J. M. López de Azcona y A. Santos Ruiz.-- Representación de la curva de p F en papel probabilístieo, por R. Román Alba.-- Medida de los potenciales de raíz, por S. Oliver y T . Mendizábal.-- Deficiencias nutritivas en diversas repoblaciones le coníferas del centro de España por F. Complejos de adsorción de la vermiculita con dimctilsulfóxido, por M. Sánchez Camazano y S. González García .-- Los suelos de la provincia de Cáceres. III. Suelos sobre calizas y rocas ígneas básicas, por J. Forteza Bonnin, A. García Rodríguez, Mª Sánchez Camazano y Mª T. Martín Patino.-- Los suelos, de la provincia de Cáceres. IV. Suelos formados sobre sedimentos terciarios y cuaternarios por J. Forteza Bonnin, A. García Rodríguez, Mª Sánchez Camazano y Mª. T. Martin.-- Algunas observaciones sobre la evolución de las yemas del olivo (Ulea Europea L.), por A. Troncoso de Arce.-- Determinación potenciométrica de cloruros, por S. Oliver.-- Influencia de: césped sobre la estructura de suelo, por J. Benayas Casares y Mª Alonso Checa.-- Notas. Aniversario del fallecimiento del Prof. Albareda.-- Centros.-- Reestructuración del Instituto de Edafología y Biología Vegetal.-- Congresos, Reuniones internacionales y becas.-- Instituto de Orientación y Asistencia Técnica del Sureste.-- Departamento de Economía Agraria.-- Acuerdo del Excmo. Ayuntamiento de Jaca.-- Conferencia del Dr. N. R. Dhar.-- Conferencia sobre «Supresión del barbecho».-- Comisión Científica de Protección de la Naturaleza.-- V Congreso Internacional de la Detergencia.-- Nombramiento de becarios en los Centros del Instituto Nacional de Edafología y Agro Convocatoria del Premio Agrícola Aedos, 1968 biología «José María Albareda».-- BibliografíaPeer reviewe
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