2,589 research outputs found

    Ucma/GRP inhibits phosphate-induced vascular smooth muscle cell calcification via SMAD-dependent BMP signalling

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    Vascular calcification (VC) is the process of deposition of calcium phosphate crystals in the blood vessel wall, with a central role for vascular smooth muscle cells (VSMCs). VC is highly prevalent in chronic kidney disease (CKD) patients and thought, in part, to be induced by phosphate imbalance. The molecular mechanisms that regulate VC are not fully known. Here we propose a novel role for the mineralisation regulator Ucma/GRP (Upper zone of growth plate and Cartilage Matrix Associated protein/Gla Rich Protein) in phosphate-induced VSMC calcification. We show that Ucma/GRP is present in calcified atherosclerotic plaques and highly expressed in calcifying VSMCs in vitro. VSMCs from Ucma/GRP(-/-) mice showed increased mineralisation and expression of osteo/chondrogenic markers (BMP-2, Runx2, beta-catenin, p-SMAD1/5/8, ALP, OCN), and decreased expression of mineralisation inhibitor MGP, suggesting that Ucma/GRP is an inhibitor of mineralisation. Using BMP signalling inhibitor noggin and SMAD1/5/8 signalling inhibitor dorsomorphin we showed that Ucma/GRP is involved in inhibiting the BMP-2-SMAD1/5/8 osteo/chondrogenic signalling pathway in VSMCs treated with elevated phosphate concentrations. Additionally, we showed for the first time evidence of a direct interaction between Ucma/GRP and BMP-2. These results demonstrate an important role of Ucma/GRP in regulating osteo/chondrogenic differentiation and phosphate-induced mineralisation of VSMCs.NWO ZonMw [MKMD 40-42600-98-13007]; FCT [SFRH/BPD/70277/2010]info:eu-repo/semantics/publishedVersio

    Comparison of the Simple Patient-Centric Atopic Dermatitis Scoring System PEST with SCORAD in Young Children Using a Ceramide Dominant Therapeutic Moisturizer.

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    INTRODUCTION: Patient eczema severity time (PEST) is a new atopic dermatitis (AD) scoring system based on patients' own perception of their disease. Conventional scales such as SCORing of atopic dermatitis (SCORAD) reflect the clinician's observations during the clinic visit. Instead, the PEST score captures eczema severity, relapse and recovery as experienced by the patient or caregiver on a daily basis, promoting patient engagement, compliance with treatment and improved outcomes. This study aims to determine the correlation between carer-assessed PEST and clinician-assessed SCORAD in paediatric AD patients after 12 weeks of treatment using a ceramide-dominant therapeutic moisturizer. METHODS: Prospective, open-label, observational, multi-centre study in which children with AD aged 6 months to 6 years were treated with a ceramide dominant therapeutic moisturizer twice daily for 12 weeks; 58 children with mild-to-moderate AD were included. Correlation between the 7-day averaged PEST and SCORAD scores for assessment of AD severity was measured within a general linear model. PEST and SCORAD were compared in week 4 and week 12. RESULTS: At week 12, a moderate correlation was found between the SCORAD and PEST scores (r = 0.51). The mean change in SCORAD and PEST scores from baseline to week 12 was -11.46 [95% confidence interval (CI) -14.99 to -7.92, p < 0.0001] and -1.33 (95% CI -0.71 to -0.10, p < 0.0001) respectively. PEST demonstrated greater responsiveness to change (33.3% of scale) compared to SCORAD (13.8% of scale). CONCLUSION: The PEST score correlates well with the SCORAD score and may have improved sensitivity when detecting changes in the severity of AD. The ceramide-dominant therapeutic moisturizer used was safe and effective in the management of AD in young children

    Impaired perceptual learning in a mouse model of Fragile X syndrome is mediated by parvalbumin neuron dysfunction and is reversible.

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    To uncover the circuit-level alterations that underlie atypical sensory processing associated with autism, we adopted a symptom-to-circuit approach in the Fmr1-knockout (Fmr1-/-) mouse model of Fragile X syndrome. Using a go/no-go task and in vivo two-photon calcium imaging, we find that impaired visual discrimination in Fmr1-/- mice correlates with marked deficits in orientation tuning of principal neurons and with a decrease in the activity of parvalbumin interneurons in primary visual cortex. Restoring visually evoked activity in parvalbumin cells in Fmr1-/- mice with a chemogenetic strategy using designer receptors exclusively activated by designer drugs was sufficient to rescue their behavioral performance. Strikingly, human subjects with Fragile X syndrome exhibit impairments in visual discrimination similar to those in Fmr1-/- mice. These results suggest that manipulating inhibition may help sensory processing in Fragile X syndrome

    Effects of Attractiveness and Social Status on Dating Desire in Heterosexual Adolescents: An Experimental Study

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    The present study examined to what extent adolescent dating desire is based on attractiveness and social status of a potential short-term partner. Further, we tested whether self-perceived mate value moderated the relationship between dating desire and attractiveness of a potential partner. Data were used from a sample of 1,913 adolescents aged 13–18. Participants rated the importance of various characteristics of a potential partner and also participated in an experimental vignette study in which dating desire was measured with either low or high attractive potential partners having either a high or low social status. The results showed that boys rated attractiveness as more important than girls, while social status was rated as relatively unimportant by both sexes. In addition, in the experimental vignette study, it was found that attractiveness was the primary factor for boys’ dating desire. Only when a potential partner was attractive, social status became important for boys’ dating desire. For girls, on the other hand, it appeared that both attractiveness and social status of a potential partner were important for their dating desire. Finally, boys and girls who perceived themselves as having a high mate value showed more dating desire toward an attractive potential partner compared to adolescents who perceived themselves as having a low mate value. The present results extend previous research by showing that attractiveness of a potential partner is important to both adolescent boys and girls, but social status does not strongly affect dating desire during this particular age period

    X-Ray Spectroscopy of Stars

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    (abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag

    HLA-DM Mediates Epitope Selection by a “Compare-Exchange” Mechanism when a Potential Peptide Pool Is Available

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    BACKGROUND: HLA-DM (DM) mediates exchange of peptides bound to MHC class II (MHCII) during the epitope selection process. Although DM has been shown to have two activities, peptide release and MHC class II refolding, a clear characterization of the mechanism by which DM facilitates peptide exchange has remained elusive. METHODOLOGY/PRINCIPAL FINDINGS: We have previously demonstrated that peptide binding to and dissociation from MHCII in the absence of DM are cooperative processes, likely related to conformational changes in the peptide-MHCII complex. Here we show that DM promotes peptide release by a non-cooperative process, whereas it enhances cooperative folding of the exchange peptide. Through electron paramagnetic resonance (EPR) and fluorescence polarization (FP) we show that DM releases prebound peptide very poorly in the absence of a candidate peptide for the exchange process. The affinity and concentration of the candidate peptide are also important for the release of the prebound peptide. Increased fluorescence energy transfer between the prebound and exchange peptides in the presence of DM is evidence for a tetramolecular complex which resolves in favor of the peptide that has superior folding properties. CONCLUSION/SIGNIFICANCE: This study shows that both the peptide releasing activity on loaded MHCII and the facilitating of MHCII binding by a candidate exchange peptide are integral to DM mediated epitope selection. The exchange process is initiated only in the presence of candidate peptides, avoiding possible release of a prebound peptide and loss of a potential epitope. In a tetramolecular transitional complex, the candidate peptides are checked for their ability to replace the pre-bound peptide with a geometry that allows the rebinding of the original peptide. Thus, DM promotes a "compare-exchange" sorting algorithm on an available peptide pool. Such a "third party"-mediated mechanism may be generally applicable for diverse ligand recognition in other biological systems

    Limit on the Radiative Neutrinoless Double Electron Capture of 36^{36}Ar from GERDA Phase I

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    Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of 36^{36}Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of 36^{36}Ar was established: T1/2>T_{1/2} > 3.6 ×\times 1021^{21} yr at 90 % C.I.Comment: 7 pages, 3 figure

    The HSP70 modulator MAL3-101 inhibits Merkel cell carcinoma

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    Merkel Cell Carcinoma (MCC) is a rare and highly aggressive neuroendocrine skin cancer for which no effective treatment is available. MCC represents a human cancer with the best experimental evidence for a causal role of a polyoma virus. Large T antigens (LTA) encoded by polyoma viruses are oncoproteins, which are thought to require support of cellular heat shock protein 70 (HSP70) to exert their transforming activity. Here we evaluated the capability of MAL3-101, a synthetic HSP70 inhibitor, to limit proliferation and survival of various MCC cell lines. Remarkably, MAL3-101 treatment resulted in considerable apoptosis in 5 out of 7 MCC cell lines. While this effect was not associated with the viral status of the MCC cells, quantitative mRNA expression analysis of the known HSP70 isoforms revealed a significant correlation between MAL3-101 sensitivity and HSC70 expression, the most prominent isoform in all cell lines. Moreover, MAL3-101 also exhibited in vivo antitumor activity in an MCC xenograft model suggesting that this substance or related compounds are potential therapeutics for the treatment of MCC in the future. © 2014 Adam et al
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