Spin-label EPR study in thylakoid membranes from a new herbicide-resistant D1 mutant from soybean cell cultures deficient in fatty acid desaturation

El pdf del artículo es la versión post-print.Fatty acid desaturation effect on the lipid fluidity in thylakoid membranes isolated from the STR7 mutant was investigated by electron paramagnetic resonance (EPR) using spin label probes. The spectra of both 5- and 16-n-doxylstearic acid probes were measured as a function of the temperature between 10-305 K and compared to those of the wild type. This complete thermal evolution provides a wider picture of the dynamics. The spectra of the 5-n-doxylstearic acid probe were identical in both STR7 mutant and wild type thylakoids as well as their temperature evolution. However, differences were found with the 16-n-doxylstearic acid probe at temperatures between 230-305 K. The differences in the thermal evolution of the EPR spectra can be interpreted as a 5-10 K shift toward higher temperatures of the probe motional rates in the STR7 mutant as compared with that in the wild type. At temperatures below 230 K no differences were observed. The results indicated that the lipid motion in the outermost region of the thylakoids is the same in the STR7 mutant than in the wild type while the fluidity in the inner region of the STR7 mutant membrane decreases. Our data point out a picture of the STR7 thylakoid membrane in which the lipid motion is slower most probably as a consequence of fatty acid desaturation deficiency.M.A. and I.G.-R. were recipients of a contract and a fellowship, respectively, from the Ministerio de Educación y Cultura of Spain. This work was supported by the Dirección General de Investigación Científica y Técnica (Grant PB98-1632) and by the Diputación General de Aragón (Project P17/98).Peer reviewe

Activation of p53 by nutlin-3a induces apoptosis and cellular senescence in human glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite concerted efforts to improve current therapies and develop novel clinical approaches, patient survival remains poor. As such, increasing attention has focused on developing new therapeutic strategies that specifically target the apoptotic pathway in order to improve treatment responses. Recently, nutlins, small-molecule antagonists of MDM2, have been developed to inhibit p53-MDM2 interaction and activate p53 signaling in cancer cells. Glioma cell lines and primary cultured glioblastoma cells were treated with nutlin-3a. Nutlin-3a induced p53-dependent G1- and G2-M cell cycle arrest and apoptosis in glioma cell lines with normal TP53 status. In addition, nutlin-arrested glioma cells show morphological features of senescence and persistent induction of p21 protein. Furthermore, senescence induced by nutlin-3a might be depending on mTOR pathway activity. In wild-type TP53 primary cultured cells, exposure to nutlin-3a resulted in variable degrees of apoptosis as well as cellular features of senescence. Nutlin-3a-induced apoptosis and senescence were firmly dependent on the presence of functional p53, as revealed by the fact that glioblastoma cells with knockdown p53 with specific siRNA, or cells with mutated or functionally impaired p53 pathway, were completely insensitive to the drug. Finally, we also found that nutlin-3a increased response of glioma cells to radiation therapy. The results provide a basis for the rational use of MDM2 antagonists as a novel treatment option for glioblastoma patients

Asymptotics and zeros of Sobolev orthogonal polynomials on unbounded supports

In this paper we present a survey about analytic properties of polynomials orthogonal with respect to a weighted Sobolev inner product such that the vector of measures has an unbounded support. In particular, we are focused in the study of the asymptotic behaviour of such polynomials as well as in the distribution of their zeros. Some open problems as well as some new directions for a future research are formulated.Comment: Changed content; 34 pages, 41 reference

Rainfall homogenizes while fruiting increases diversity of spore deposition in Mediterranean conditions

There is a lack of knowledge regarding the main factors modulating fungal spore deposition in forest ecosystems. We have described the local spatio-temporal dynamics of fungal spore deposition along a single fruiting season and its relation with fruit body emergence and rainfall events. Passive spore traps were weekly sampled during autumn and analysed by metabarcoding of the ITS2 region in combination with qPCR. There were larger compositional changes of deposited spores across sampling weeks than amongst sampling plots. Spore diversity and abundance correlated with mushroom emergence and weekly rainfall. Spore compositional changes were related to rainfall, with lower spatial compositional heterogeneity across plots during weeks with higher rainfall. Soil saprotrophs, and amongst them, puffball species, showed the strongest positive correlation with rainfall across fungal guilds. We saw high fine-scale temporal changes of deposited spores, and both mushroom emergence and rainfall may be important factors driving airborne spore deposition.This work was partially supported by the Spanish Ministry of Science, Innovation and Universities, grants N° AGL2015-66001-C3, RTI2018-099315-A-I00, the CERCA Programme / Generalitat de Catalunya, and by the European project StarTree (No. 311919). J.G.A. was supported by Juan de la Cierva (Grant number IJCI-2014-21393) and Ramon y Cajal fellowships (RYC-2016-20528), while JO was supported by Ramon y Cajal fellowship (RYC-2015-17459). José Antonio Bonet benefitted from a Serra-Húnter Fellowship provided by the Generalitat of Catalunya. Carles Castaño received the support of the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya through the program of Doctorats Industrials, and benefitted from a STSM grant from COST Action FP1203

TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Is Upregulated in Lymphocytes Stimulated with Concanavalin A

The glycolytic modulator TP53-Inducible Glycolysis and Apoptosis Regulator (TIGAR) is overexpressed in several types of cancer and has a role in metabolic rewiring during tumor development. However, little is known about the role of this enzyme in proliferative tissues under physiological conditions. In the current work, we analysed the role of TIGAR in primary human lymphocytes stimulated with the mitotic agent Concanavalin A (ConA). We found that TIGAR expression was induced in stimulated lymphocytes through the PI3K/AKT pathway, since Akti-1/2 and LY294002 inhibitors prevented the upregulation of TIGAR in response to ConA. In addition, suppression of TIGAR expression by siRNA decreased the levels of the proliferative marker PCNA and increased cellular ROS levels. In this model, TIGAR was found to support the activity of glucose 6-phosphate dehydrogenase (G6PDH), the first enzyme of the pentose phosphate pathway (PPP), since the inhibition of TIGAR reduced G6PDH activity and increased autophagy. In conclusion, we demonstrate here that TIGAR is upregulated in stimulated human lymphocytes through the PI3K/AKT signaling pathway, which contributes to the redirection of the carbon flux to the PPP

Formation of the University Faculty in Methodological Stategies to Incorporation of E-Learning in European Space of Higher Education

El documento que presentamos, es una síntesis de una propuesta que presentamos al Ministerio de Educación español, y se acoge a la línea de trabajo sobre «el proceso de aprendizaje en el marco del EEES: estrategias universitarias», centrándonos más concretamente en el desarrollo de nuevas metodologías docentes y del evaluación del aprendizaje así como en el análisis y creación de estrategias para la docencia universitaria orientadas al desarrollo del aprendizaje electrónico.The document that present, is a synthesis of a proposal that present to Department of Spanish Education, and is received to the line of work on the «process of learning in Europe Space for Higher Education: university strategies», centering us more concretely in the development educational of new methodologies and of the evaluation of the learning as well as in the analysis and creation of strategies for the university teaching oriented toward development of the electronic learning

Persistent antiphospholipid antibodies are not associated with worse clinical outcomes in a prospective cohort of hospitalised patients with SARS-CoV-2 infection.

Objective: Patients with COVID-19 presented with an elevated prevalence of antiphospholipid antibodies (aPL) but the relationship with thrombosis is controversial. We analysed the persistence of aPL and their association with the clinical outcomes during hospitalisation in a cohort of COVID-19 patients. Patients and methods: We conducted a prospective study including consecutive hospitalised patients with COVID-19 from Hospital Clínic of Barcelona between March 28th and April 22nd, 2020. Clinical outcomes during hospitalisation were thrombosis, intensive care unit (ICU) admission, and severe ventilatory failure. We determined both criteria and non-criteria aPL. Of note, in those patients with a positive result in the first determination, a second sample separated by at least 12 weeks was drawn to test the persistence of aPL. Results: One hundred and fifty-eight patients (59.5% men) with a mean age of 61.4 ± 14.9 years old were included. Thrombosis was present in 28 (17.7%) patients, severe respiratory failure in 47 (30.5%), and 30 (18.9%) patients were admitted to ICU. Sixteen (28.6%) patients were positive for the criteria aPL at both determinations and only two (3.6%) of them suffered from thrombosis during hospitalisations (both had aCL IgG). However, they presented with low titers of aCL. Of note, aPL were not related to thrombosis, ICU admission or severe respiratory failure. Conclusion: Although aPL were prevalent in our cohort of hospitalised COVID-19 patients and they were persistent in half of tested patients, most determinations were at low titers and they were not related to worse clinical outcomes