54 research outputs found

    Diffractive optics for spectral control of the supercontinuum generated in sapphire with femtosecond pulses

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    We propose the use of kinoform diffractive lenses to focus near infrared femtosecond pulses in sapphire crystals for supercontinuum generation. It is shown that a strongly peaked structure appears in the blue region of the supercontinuum spectra. The central wavelength of this peak can be easily controlled by simply changing the lens-crystal distance. Moreover, when compared with the supercontinuum generated with a refractive lens in analogous conditions, the spectral extension of the so-generated continuum is larger. Our results were corroborated for sapphire plates with different thicknesses as well as in other transparent dielectrics such as fused silica.Support from Spanish Ministerio de Ciencia e Innovación (MICINN) through the Consolider Program SAUUL CSD2007-00013, research projects FIS2009-09522 and FIS2010-15746, and from Junta de Castilla y León through the Program for Groups of Excellence (GR27). CR and RBV acknowledge MICINN for support through grants BES-2007-17415 and AP2007-00202, respectively. GMV and OMY gratefully acknowledge partial financial support from Convenio UJI-Bancaixa under the project P1-1B2010-26.We also acknowledge support from the Centro de Láseres Pulsados (CLPU) (Salamanca, Spain

    New insights into cancer: MDM2 binds to the citrullinating enzyme PADI4

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    PADI4 is one of the human isoforms of a family of enzymes implicated in the conversion of arginine to citrulline. MDM2 is an E3 ubiquitin ligase which is crucial for down-regulation of degradation of the tumor suppressor gene p53. Given the relationship between both PADI4 and MDM2 with p53-signaling pathways, we hypothesized they may interact directly, and this interaction could be relevant in the context of cancer. Here, we showed their association in the nucleus and cytosol in several cancer cell lines. Furthermore, binding was hampered in the presence of GSK484, an enzymatic PADI4 inhibitor, suggesting that MDM2 could bind to the active site of PADI4, as confirmed by in silico experiments. In vitro and in silico studies showed that the isolated N-terminal region of MDM2, N-MDM2, interacted with PADI4, and residues Thr26, Val28, Phe91 and Lys98 were more affected by the presence of the enzyme. Moreover, the dissociation constant between N-MDM2 and PADI4 was comparable to the IC50 of GSK484 from in cellulo experiments. The interaction between MDM2 and PADI4 might imply MDM2 citrullination, with potential therapeutic relevance for improving cancer treatment, due to the generation of new antigens

    A Retino-retinal Projection Guided by Unc5c Emerged in Species with Retinal Waves

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    We thank D Baeza and M Herrera for mouse breeding, genotyping and help in in utero electroporation experiments and E Llorens and J Mullet for technical help in experiments involving ferrets. We also thank A Barco for discussion and comments on the manuscript. The laboratory of EH is funded with the following grants: (BFU2016-77605 from the National Grant Research Program, PROMETEO Program (2016/026) from Generalitat Valenciana, (PCIN2015-192-C02-02 from ERA-Net Program) and (ERC282329 from the European Research Council). Work in the laboratory of LMM and SS was supported by the National Grant Research Program (Grant BFU2014-58776-r), cofinanced by the European Regional Development Fund (ERDF). VMB holds a postdoctoral contract from the Regional Government. AJV is the recipient of a FPI fellowship from the National Grant Research Program. We also acknowledge the financial support received from the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2013-0317). AK was supported by the Canadian Institutes for Health Research Operating Grants MOP-77556 and MOP-97758, as well as Brain Canada, Canadian Foundation for Innovation, and the W. Garfield Weston Foundation.Peer reviewedPublisher PD

    Brain-Derived Neurotrophic Factor Levels in Cord Blood from Growth Restricted Fetuses with Doppler Alteration Compared to Adequate for Gestational Age Fetuses

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    Background and Objectives: Fetal growth restriction (FGR) is a severe obstetric disease characterized by a low fetal size entailing a set of undesired consequences. For instance, previous studies have noticed a worrisome association between FGR with an abnormal neurodevelopment. However, the precise link between FGR and neurodevelopmental alterations are not yet fully understood yet. Brain-derived neurotrophic factor (BDNF) is a critical neurotrophin strongly implicated in neurodevelopmental and other neurological processes. In addition, serum levels of BDNF appears to be an interesting indicator of pathological pregnancies, being correlated with the neonatal brain levels. Therefore, the aim of this study is to analyze the blood levels of BDNF in the cord blood from fetuses with FGR in comparison to those with weight appropriate for gestational age (AGA). Materials and Methods: In this study, 130 subjects were recruited: 91 in group A (AGA fetuses); 39 in group B (16 FGR fetuses with exclusively middle cerebral artery (MCA) pulsatility index (PI) 95th percentile). Serum levels of BDNF were determined through ELISA reactions in these groups. Results: Our results show a significant decrease in cord blood levels of BDNF in FGR and more prominently in those with UA PI >95th percentile in comparison to AGA. FGR fetuses with exclusively decreased MCA PI below the 5th percentile also show reduced levels of BDNF than AGA, although this difference was not statistically significant. Conclusions: Overall, our study reports a potential pathophysiological link between reduced levels of BDNF and neurodevelopmental alterations in fetuses with FGR. However, further studies should be conducted in those FGR subjects with MCA PI < 5th percentile in order to understand the possible implications of BDNF in this group.Depto. de Salud Pública y Materno - InfantilFac. de MedicinaTRUEUnión EuropeaComunidad de MadridInstituto de Salud Carlos IIIHalekulani S.LFundación Santiago Dexeus Fontpu

    Aerosol characterization at the Saharan AERONET site Tamanrasset

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    More than 2 years of columnar atmospheric aerosol measurements (2006–2009) at the Tamanrasset site (22.79° N, 5.53° E, 1377 m a.s.l.), in the heart of the Sahara, are analysed. Aerosol Robotic Network (AERONET) level 2.0 data were used. The KCICLO (K is the name of a constant and ciclo means cycle in Spanish) method was applied to a part of the level 1.5 data series to improve the quality of the results. The annual variability of aerosol optical depth (AOD) and Ångström exponent (AE) has been found to be strongly linked to the convective boundary layer (CBL) thermodynamic features. The dry-cool season (autumn and winter) is characterized by a shallow CBL and very low mean turbidity (AOD ~ 0.09 at 440 nm, AE ~ 0.62). The wet-hot season (spring and summer) is dominated by high turbidity of coarse dust particles (AE ~ 0.28, AOD ~ 0.39 at 440 nm) and a deep CBL. The aerosol-type characterization shows desert mineral dust as the prevailing aerosol. Both pure Saharan dust and very clear sky conditions are observed depending on the season. However, several case studies indicate an anthropogenic fine mode contribution from the industrial areas in Libya and Algeria. The concentration weighted trajectory (CWT) source apportionment method was used to identify potential sources of air masses arriving at Tamanrasset at several heights for each season. Microphysical and optical properties and precipitable water vapour were also investigated.The AERONET sun photometer at Tamanrasset has been calibrated within AERONET-EUROPE TNA supported by the PHOTONS and RIMA networks and partially financed by the European Community – Research Infrastructure Action under the Seventh Framework Programme (FP7/2007-2013) “Capacities” specific programme for Integrating Activities, ACTRIS grant agreement no. 262254. Financial support from the Spanish MINECO (projects CGL2011-23413, CGL2012-33576 and CGL2012-37505) is also gratefully acknowledged. J. M. Baldasano and S. Basart acknowledge the Supercomputación y eCiencia project (CSD2007-0050) from the Consolider-Ingenio 2010 and Severo Ochoa (SEV-2011-00067) programs of the Spanish Government

    Influence of Cerebral Vasodilation on Blood Reelin Levels in Growth Restricted Fetuses

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    Fetal growth restriction (FGR) is one of the most important obstetric pathologies. It is frequently caused by placental insufficiency. Previous studies have shown a relationship between FGR and impaired new-born neurodevelopment, although the molecular mechanisms involved in this association have not yet been completely clarified. Reelin is an extracellular matrix glycoprotein involved in development of neocortex, hippocampus, cerebellum and spinal cord. Reelin has been demonstrated to play a key role in regulating perinatal neurodevelopment and to contribute to the emergence and development of various psychiatric pathologies, and its levels are highly influenced by pathological conditions of hypoxia. The purpose of this article is to study whether reelin levels in new-borns vary as a function of severity of fetal growth restriction by gestational age and sex. We sub-grouped fetuses in: normal weight group (Group 1, n = 17), FGR group with normal umbilical artery Doppler and cerebral redistribution at middle cerebral artery Doppler (Group 2, n = 9), and FGR with abnormal umbilical artery Doppler (Group 3, n = 8). Our results show a significant association of elevated Reelin levels in FGR fetuses with cerebral blood redistribution compared to the normal weight group and the FGR with abnormal umbilical artery group. Future research should focus on further expanding the knowledge of the relationship of reelin and its regulated products with neurodevelopment impairment in new-borns with FGR and should include larger and more homogeneous samples and the combined use of different in vivo techniques in neonates with impaired growth during their different adaptive phases

    The intrinsically disordered, epigenetic factor RYBP binds to the citrullinating enzyme PADI4 in cancer cells

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    14 p.-6 fig.-1 tab.RYBP (Ring1 and YY 1 binding protein) is a multifunctional, intrinsically disordered protein (IDP), best described as a transcriptional regulator. It exhibits a ubiquitin-binding functionality, binds to other transcription factors, and has a key role during embryonic development. RYBP, which folds upon binding to DNA, has a Zn-finger domain at its N-terminal region. By contrast, PADI4 is a well-folded protein and it is one the human isoforms of a family of enzymes implicated in the conversion of arginine to citrulline. As both proteins intervene in signaling pathways related to cancer development and are found in the same localizations within the cell, we hypothesized they may interact. We observed their association in the nucleus and cytosol in several cancer cell lines, by using immunofluorescence (IF) and proximity ligation assays (PLAs). Binding also occurred in vitro, as measured by isothermal titration calorimetry (ITC) and fluorescence, with a low micromolar affinity (~1 μM). AlphaFold2-multimer (AF2) results indicate that PADI4's catalytic domain interacts with the Arg53 of RYBP docking into its active site. As RYBP sensitizes cells to PARP (Poly (ADP-ribose) polymerase) inhibitors, we applied them in combination with an enzymatic inhibitor of PADI4 observing a change in cell proliferation, and the hampering of the interaction of both proteins. This study unveils for the first time the possible citrullination of an IDP, and suggests that this new interaction, whether it involves or not citrullination of RYBP, might have implications in cancer development and progression.This research was funded by Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033/ and “ERDF A way of Making Europe” [PID2021-127296OB-I00 to AVC; and PDC2022-133952-I00 to EF]; by Instituto de Salud Carlos III co-funded by European Social Fund “Investing in your future” [CP19/00095 to CdJ] [PI22/00824 to MS and CdJ] [PI18/00394 to OA]; by Diputación General de Aragón [“Protein targets and Bioactive Compounds group” E45-20R to AVC, and “Digestive Pathology Group” B25-20R to OA], and by Consellería de Innovación, Universidades, Ciencia y Sociedad Digital (Generalitat Valenciana) [CAICO 2021/0135 to CdJ and JLN].Peer reviewe

    Structural basis of envelope and phase intrinsic coupling modes in the cerebral cortex

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    Intrinsic coupling modes (ICMs) can be observed in ongoing brain activity at multiple spatial and temporal scales. Two families of ICMs can be distinguished: phase and envelope ICMs. The principles that shape these ICMs remain partly elusive, in particular their relation to the underlying brain structure. Here we explored structure-function relationships in the ferret brain between ICMs quantified from ongoing brain activity recorded with chronically implanted micro-ECoG arrays and structural connectivity (SC) obtained from high-resolution diffusion MRI tractography. Large-scale computational models were used to explore the ability to predict both types of ICMs. Importantly, all investigations were conducted with ICM measures that are sensitive or insensitive to volume conduction effects. The results show that both types of ICMs are significantly related to SC, except for phase ICMs when using measures removing zero-lag coupling. The correlation between SC and ICMs increases with increasing frequency which is accompanied by reduced delays. Computational models produced results that were highly dependent on the specific parameter settings. The most consistent predictions were derived from measures solely based on SC. Overall, the results demonstrate that patterns of cortical functional coupling as reflected in both phase and envelope ICMs are both related, albeit to different degrees, to the underlying structural connectivity in the cerebral cortex.This work was supported by funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - SFB 936 - 178316478 - A1 (C.C.H.), A2 (A.K.E.), and Z3 (C.C.H. and A.M.), SPP1665 - 220176618 - EN533/13-1 (A.K.E.), SPP2041 - 313856816 - HI1286/6-1 (C.C.H.) and EN533/15-1 (A.K.E.), from the European Unions Horizon 2020 Framework Programme for Research and Innovation under Specific Grant Agreements 785907 and 945539 (Human Brain Project SGA2 and SGA3, C.C.H.), and from the 2015 FLAG-ERA Joint Transnational Call for project FIIND - ANR-15-HBPR-0005 (R.T.).Peer reviewe

    Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human.

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    Neuronal migration disorders such as lissencephaly and subcortical band heterotopia are associated with epilepsy and intellectual disability. DCX, PAFAH1B1 and TUBA1A are mutated in these disorders; however, corresponding mouse mutants do not show heterotopic neurons in the neocortex. In contrast, spontaneously arisen HeCo mice display this phenotype, and our study revealed that misplaced apical progenitors contribute to heterotopia formation. While HeCo neurons migrated at the same speed as wild type, abnormally distributed dividing progenitors were found throughout the cortical wall from embryonic day 13. We identified Eml1, encoding a microtubule-associated protein, as the gene mutated in HeCo mice. Full-length transcripts were lacking as a result of a retrotransposon insertion in an intron. Eml1 knockdown mimicked the HeCo progenitor phenotype and reexpression rescued it. We further found EML1 to be mutated in ribbon-like heterotopia in humans. Our data link abnormal spindle orientations, ectopic progenitors and severe heterotopia in mouse and human
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