62 research outputs found
The Interplay between NF-kappaB and E2F1 Coordinately Regulates Inflammation and Metabolism in Human Cardiac Cells
Pyruvate dehydrogenase kinase 4 (PDK4) inhibition by nuclear factor-κB (NF-κB) is related to a shift towards increased glycolysis during cardiac pathological processes such as cardiac hypertrophy and heart failure. The transcription factors estrogen-related receptor-α (ERRα) and peroxisome proliferator-activated receptor (PPAR) regulate PDK4 expression through the potent transcriptional coactivator PPARγ coactivator-1α (PGC-1α). NF-κB activation in AC16 cardiac cells inhibit ERRα and PPARβ/δ transcriptional activity, resulting in reduced PGC-1α and PDK4 expression, and an enhanced glucose oxidation rate. However, addition of the NF-κB inhibitor parthenolide to these cells prevents the downregulation of PDK4 expression but not ERRα and PPARβ/δ DNA binding activity, thus suggesting that additional transcription factors are regulating PDK4. Interestingly, a recent study has demonstrated that the transcription factor E2F1, which is crucial for cell cycle control, may regulate PDK4 expression. Given that NF-κB may antagonize the transcriptional activity of E2F1 in cardiac myocytes, we sought to study whether inflammatory processes driven by NF-κB can downregulate PDK4 expression in human cardiac AC16 cells through E2F1 inhibition. Protein coimmunoprecipitation indicated that PDK4 downregulation entailed enhanced physical interaction between the p65 subunit of NF-κB and E2F1. Chromatin immunoprecipitation analyses demonstrated that p65 translocation into the nucleus prevented the recruitment of E2F1 to the PDK4 promoter and its subsequent E2F1-dependent gene transcription. Interestingly, the NF-κB inhibitor parthenolide prevented the inhibition of E2F1, while E2F1 overexpression reduced interleukin expression in stimulated cardiac cells. Based on these findings, we propose that NF-κB acts as a molecular switch that regulates E2F1-dependent PDK4 gene transcription
A Slc38a8 Mouse Model of FHONDA Syndrome Faithfully Recapitulates the Visual Deficits of Albinism Without Pigmentation Defects
Purpose: We aimed to generate and phenotype a mouse model of foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA), a rare disease associated with mutations in Slc38a8 that causes severe visual alterations similar to albinism without affecting pigmentation. Methods: The FHONDA mouse model was generated with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology using an RNA guide targeting the Scl38a8 murine locus. The resulting mice were backcrossed to C57BL/6J. Melanin content was measured using spectrophotometry. Retinal cell architecture was analyzed through light and electron microscopy. Retinal projections to the brain were evaluated with anterograde labelling in embryos and adults. Visual function was assessed by electroretinography (ERG) and the optomotor test (OT). Results: From numerous Slc38a8 mouse mutant alleles generated, we selected one that encodes a truncated protein (p.196Pro*, equivalent to p.199Pro* in the human protein) closely resembling a mutant allele described in patients (p.200Gln*). Slc38a8 mutant mice exhibit wild-type eye and coat pigmentation with comparable melanin content. Subcellular abnormalities were observed in retinal pigment epithelium cells of Slc38a8 mutant mice. Anterograde labeling experiments of retinal projections in embryos and adults showed a reduction of ipsilateral fibers. Functional visual analyses revealed a decreased ERG response in scotopic conditions and a reduction of visual acuity in mutant mice measured by OT. Conclusions: Slc38a8 mutant mice recapitulate the phenotype of patients with FHONDA concerning their normal pigmentation and their abnormal visual system, in the latter being a hallmark of all types of albinism. These mice will be helpful in better understanding the pathophysiology of this genetic condition.Funded by the Spanish Ministry of Economy and Competitiveness under BIO2015-70978-R, the Spanish Ministry of Science and Innovation under RTI2018-101223-B-I00, CIBERER and Fundación Ramón Areces to L.M. Additionally, Spanish Ministry of Science and Innovation (FEDER-PID2019-106230RB-I00, 2019) and Generalitat Valenciana IDIFEDER/2017/064, 2017, PROMETEO/2021/024, 2021 supported the work of N.C. Funds from INSERM, Sorbonne Université, Retina France and Genespoir supported the work of A.R., as well as LabEx LIFESENSES (ANR-10-LABX-65) and IHU FOReSIGHT (ANR-18-IAHU-01) for the Institut de la Vision, a doctoral fellowship from the French Ministry of Education and Research to V.C
Role for arabidopsis PLC7 in stomatal movement, seed mucilage attachment, and leaf serration
Phospholipase C (PLC) has been suggested to play important roles in plant stress and development. To increase our understanding of PLC signaling in plants, we have started to analyze knock-out (KO), knock-down (KD) and overexpression mutants of Arabidopsis thaliana, which contains nine PLCs. Earlier, we characterized PLC2, PLC3 and PLC5. Here, the role of PLC7 is functionally addressed. Promoter-GUS analyses revealed that PLC7 is specifically expressed in the phloem of roots, leaves and flowers, and is also present in trichomes and hydathodes. Two T-DNA insertion mutants were obtained, i.e., plc7-3 being a KO- and plc7-4 a KD line. In contrast to earlier characterized phloem-expressed PLC mutants, i.e., plc3 and plc5, no defects in primary- or lateral root development were found for plc7 mutants. Like plc3 mutants, they were less sensitive to ABA during stomatal closure. Double-knockout plc3 plc7 lines were lethal, but plc5 plc7 (plc5/7) double mutants were viable, and revealed several new phenotypes, not observed earlier in the single mutants. These include a defect in seed mucilage, enhanced leaf serration, and an increased tolerance to drought. Overexpression of PLC7 enhanced drought tolerance too, similar to what was earlier found for PLC3-and PLC5 overexpression. In vivo 32Pi-labeling of seedlings and treatment with sorbitol to mimic drought stress, revealed stronger PIP2 responses in both drought-tolerant plc5/7 and PLC7-OE mutants. Together, these results show novel functions for PLC in plant stress and development. Potential molecular mechanisms are discussed.Fil: van Wijk, Ringo. University of Amsterdam; Países BajosFil: Zhang, Qianqian. University of Amsterdam; Países BajosFil: Zarza, Xavier. University of Amsterdam; Países BajosFil: Lamers, Mart. University of Amsterdam; Países BajosFil: Reyes Marquez, Francisca. Wageningen University and Research, Wageningen; Países BajosFil: Guardia, Aisha Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Scuffi, Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Garcia-Mata, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Ligterink, Wilco. Wageningen University and Research, Wageningen; Países BajosFil: Haring, Michel A.. University of Amsterdam; Países BajosFil: Laxalt, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Munnik, Teun. University of Amsterdam; Países Bajo
Magnetic nanoparticles with bulk-like properties
The magnetic behavior of nanoparticles synthesized either by
high-temperature decomposition of an organic iron precursor or low-temperature
co-precipitation in aqueous conditions, is compared. Transmission electron
microscopy, X-ray absorption spectroscopy, X-ray magnetic circular dichroism
and magnetization measurements show that nanoparticles synthesized by thermal
decomposition display high crystal quality and bulk-like magnetic and
electronic properties, while nanoparticles synthesized by co-precipitation show
much poorer crystallinity and particle-like phenomenology, including reduced
magnetization, high closure fields and shifted hysteresis loops. The key role
of the crystal quality is thus suggested since particle-like behavior for
particles larger than about 5 nm is only observed when they are structurally
defective. These conclusions are supported by Monte Carlo simulations. It is
also shown that thermal decomposition is capable of producing nanoparticles
that, after further stabilization in physiological conditions, are suitable for
biomedical applications such as magnetic resonance imaging or bio-distribution
studies.Comment: Review article. 20 pages, 7 figures. Invited contribution to 55th MMM
Conference 2010 (Atlanta), Session HG-01. To be published in J. Appl. Phy
Las causas del absentismo de los estudiantes de Derecho según su propia opinión
El absentismo en las aulas de los estudiantes de Derecho se ha convertido recientemente en un lugar común de las preocupaciones del profesorado y de la administración universitaria. El objetivo del presente estudio, que cuenta con precedentes en los cursos 2007-2008 y 2009-2010, es identificar los motivos esgrimidos por los estudiantes del grado de Derecho de la UB para explicar las causas del fenómeno absentista. El trabajo, más allá de su vertiente científica, pretende convertirse en un instrumento para poder diseñar políticas, sobre todo docentes y académicas, para reducir el absentismo en aquellos ámbitos en que sea posible. El estudio se ha realizado a partir de la opinión recogida a una muestra de 577 estudiantes del grado durante la primavera del 2017, mediante un muestreo aleatorio simple y a través de un cuestionario con 18 preguntas cerradas sobre los motivos que llevan a los estudiantes a no asistir a clase, 5 variables sociodemográficas y una pregunta abierta final. Se ha realizado un análisis estadístico cuantitativo, un análisis factorial y un análisis cualitativo de las respuestas abiertas. Los resultados indican que los posibles factores vinculados con el absentismo tienen que ver, en un sentido amplio, con la metodología docente –en muchos casos todavía únicamente de tipo magistral– utilizada por los profesores; no son irrelevantes las causas debidas a la organización logística del estudiante, pero en todo caso son causas secundarias. Que los profesores dispongan de otros recursos metodológicos además de la clase magistral y saber otorgar valor añadido a las clases –desarrollando por tanto políticas docentes y formación del profesorado– se antojan como algunas de las soluciones a un fenómeno complejo y multicausal
Expression of TILs and Patterns of Gene Expression from Paired Samples of Malignant Pleural Mesothelioma (MPM) Patients
Gene expression; Immunotherapy; Malignant pleural mesotheliomaExpresión génica; Inmunoterapia; Mesotelioma pleural malignoExpressió gènica; Immunoteràpia; Mesotelioma pleural maligneMPM is an aggressive disease with an immunosuppressive tumor microenvironment, and interest in exploring immunotherapy in this disease has been increasing. In the first line of treatment, the combination of nivolumab and ipilimumab demonstrated an improvement in survival over chemotherapy. The presence of TILs has been recognized as a marker of antitumor immune response to chemotherapy in solid tumors. The aim of our study is to identify the effect of treatment on immune cells and the immune gene profile in MPM. We investigated the changes in expression of TILs in 10 human MPM paired tumor tissues using immunohistochemistry and gene expression analysis from paired untreated and treated samples. In this small series, we demonstrated that during the evolution of disease without any treatment there was an increase in the inflammatory component in tumor samples. After systemic treatment there was a decrease in the number of TILs. We observed that after systemic treatment or disease progression immune gene signatures were suppressed. Our integrated analysis of paired samples with immune profile and genomic changes on MPM suggested that during the evolution of the disease the immune system tends to switch, turning off with treatment.The study was partially funded by Project PREDICT-Meso (GEACC19003CED), funded by Fundación AECC
The Interplay between NF-kappaB and E2F1 Coordinately Regulates Inflammation and Metabolism in Human Cardiac Cells
Pyruvate dehydrogenase kinase 4 (PDK4) inhibition by nuclear factor-κB (NF-κB) is related to a shift towards increased glycolysis during cardiac pathological processes such as cardiac hypertrophy and heart failure. The transcription factors estrogen-related receptor-α (ERRα) and peroxisome proliferator-activated receptor (PPAR) regulate PDK4 expression through the potent transcriptional coactivator PPARγ coactivator-1α (PGC-1α). NF-κB activation in AC16 cardiac cells inhibit ERRα and PPARβ/δ transcriptional activity, resulting in reduced PGC-1α and PDK4 expression, and an enhanced glucose oxidation rate. However, addition of the NF-κB inhibitor parthenolide to these cells prevents the downregulation of PDK4 expression but not ERRα and PPARβ/δ DNA binding activity, thus suggesting that additional transcription factors are regulating PDK4. Interestingly, a recent study has demonstrated that the transcription factor E2F1, which is crucial for cell cycle control, may regulate PDK4 expression. Given that NF-κB may antagonize the transcriptional activity of E2F1 in cardiac myocytes, we sought to study whether inflammatory processes driven by NF-κB can downregulate PDK4 expression in human cardiac AC16 cells through E2F1 inhibition. Protein coimmunoprecipitation indicated that PDK4 downregulation entailed enhanced physical interaction between the p65 subunit of NF-κB and E2F1. Chromatin immunoprecipitation analyses demonstrated that p65 translocation into the nucleus prevented the recruitment of E2F1 to the PDK4 promoter and its subsequent E2F1-dependent gene transcription. Interestingly, the NF-κB inhibitor parthenolide prevented the inhibition of E2F1, while E2F1 overexpression reduced interleukin expression in stimulated cardiac cells. Based on these findings, we propose that NF-κB acts as a molecular switch that regulates E2F1-dependent PDK4 gene transcription
Role for Arabidopsis PLC7 in Stomatal Movement, Seed Mucilage Attachment, and Leaf Serration
Phospholipase C (PLC) has been suggested to play important roles in plant stress and development. To increase our understanding of PLC signaling in plants, we have started to analyze knock-out (KO), knock-down (KD) and overexpression mutants of Arabidopsis thaliana, which contains nine PLCs. Earlier, we characterized PLC2, PLC3 and PLC5. Here, the role of PLC7 is functionally addressed. Promoter-GUS analyses revealed that PLC7 is specifically expressed in the phloem of roots, leaves and flowers, and is also present in trichomes and hydathodes. Two T-DNA insertion mutants were obtained, i.e., plc7-3 being a KO- and plc7-4 a KD line. In contrast to earlier characterized phloem-expressed PLC mutants, i.e., plc3 and plc5, no defects in primary- or lateral root development were found for plc7 mutants. Like plc3 mutants, they were less sensitive to ABA during stomatal closure. Double-knockout plc3 plc7 lines were lethal, but plc5 plc7 (plc5/7) double mutants were viable, and revealed several new phenotypes, not observed earlier in the single mutants. These include a defect in seed mucilage, enhanced leaf serration, and an increased tolerance to drought. Overexpression of PLC7 enhanced drought tolerance too, similar to what was earlier found for PLC3-and PLC5 overexpression. In vivo32Pi-labeling of seedlings and treatment with sorbitol to mimic drought stress, revealed stronger PIP2 responses in both drought-tolerant plc5/7 and PLC7-OE mutants. Together, these results show novel functions for PLC in plant stress and development. Potential molecular mechanisms are discussed
High-resolution hepatitis C virus subtyping using NS5B deep sequencing and phylogeny, an alternative to current methods
HepatitisCvirus(HCV)is classified into seven major genotypesand67 subtypes. Recent studies haveshownthat inHCVgenotype 1-infected
patients, response rates to regimens containingdirect-acting antivirals(DAAs)are subtype dependent. Currently available genotypingmethods
have limited subtyping accuracy.Wehave evaluated theperformanceof adeep-sequencing-basedHCVsubtyping assay, developed for the
454/GS-Junior platform, in comparisonwith thoseof two commercial assays (VersantHCVgenotype 2.0andAbbott Real-timeHCVGenotype
II)andusingdirectNS5Bsequencing as a gold standard (direct sequencing), in 114 clinical specimenspreviously tested by first-generation
hybridization assay (82 genotype 1and32 with uninterpretable results). Phylogenetic analysis of deep-sequencing reads matched subtype
1 callingbypopulation Sanger sequencing(69%1b,31%1a) in 81 specimensandidentified amixed-subtype infection (1b/3a/1a) in one sample.
Similarly,amongthe 32previously indeterminate specimens, identical genotypeandsubtype results were obtained by directanddeep
sequencing in all but four samples with dual infection. In contrast, both VersantHCVGenotype 2.0andAbbott Real-timeHCVGenotype II
failed subtype 1 calling in 13 (16%) samples eachandwere unable to identify theHCVgenotype and/or subtype inmore than half of the nongenotype
1 samples.Weconcluded that deep sequencing ismore efficient forHCVsubtyping than currently available methodsandallows
qualitative identificationofmixed infectionsandmay bemorehelpfulwith respect to informing treatment strategies withnewDAA-containing
regimens across allHCVsubtypesThis study has been supported by CDTI (Centro para el Desarrollo Tecnológico
Industrial), Spanish Ministry of Economics and Competitiveness
(MINECO), IDI-20110115; MINECO projects SAF 2009-10403; and
also by the Spanish Ministry of Health, Instituto de Salud Carlos III (FIS)
projects PI10/01505, PI12/01893, and PI13/00456. CIBERehd is funded
by the Instituto de Salud Carlos III, Madrid, Spain. Work at CBMSO was
supported by grant MINECO-BFU2011-23604, FIPSE, and Fundación
Ramón Areces.
X. Forns received unrestricted grant support from Roche and has
acted as advisor for MSD, Gilead, and Abbvie. M. Alvarez-Tejado, J. Gregori,
and J. M. Muñoz work in Roche Diagnostic
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