28 research outputs found

    Sequential inverse dysregulation of the RNA helicases DDX3X and DDX3Y facilitates MYC-driven lymphomagenesis

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    Summary DDX3X is a ubiquitously expressed RNA helicase involved in multiple stages of RNA biogenesis. DDX3X is frequently mutated in Burkitt lymphoma, but the functional basis for this is unknown. Here, we show that loss-of-function DDX3X mutations are also enriched in MYC-translocated diffuse large B cell lymphoma and reveal functional cooperation between mutant DDX3X and MYC. DDX3X promotes the translation of mRNA encoding components of the core translational machinery, thereby driving global protein synthesis. Loss-of-function DDX3X mutations moderate MYC-driven global protein synthesis, thereby buffering MYC-induced proteotoxic stress during early lymphomagenesis. Established lymphoma cells restore full protein synthetic capacity by aberrant expression of DDX3Y, a Y chromosome homolog, the expression of which is normally restricted to the testis. These findings show that DDX3X loss of function can buffer MYC-driven proteotoxic stress and highlight the capacity of male B cell lymphomas to then compensate for this loss by ectopic DDX3Y expression

    Interleukin 15 Levels in Serum May Predict a Severe Disease Course in Patients with Early Arthritis

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    Background: Interleukin-15 (IL-15) is thought to be involved in the physiopathological mechanisms of RA and it can be detected in the serum and the synovial fluid of inflamed joints in patients with RA but not in patients with osteoarthritis or other inflammatory joint diseases. Therefore, the objective of this work is to analyse whether serum IL-15 (sIL-15) levels serve as a biomarker of disease severity in patients with early arthritis (EA). Methodology and Results: Data from 190 patients in an EA register were analysed (77.2% female; median age 53 years; 6-month median disease duration at entry). Clinical and treatment information was recorded systematically, especially the prescription of disease modifying anti-rheumatic drugs. Two multivariate longitudinal analyses were performed with different dependent variables: 1) DAS28 and 2) a variable reflecting intensive treatment. Both included sIL-15 as predictive variable and other variables associated with disease severity, including rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA). Of the 171 patients (638 visits analysed) completing the follow-up, 71% suffered rheumatoid arthritis and 29% were considered as undifferentiated arthritis. Elevated sIL-15 was detected in 29% of this population and this biomarker did not overlap extensively with RF or ACPA. High sIL-15 levels (β Coefficient [95% confidence interval]: 0.12 [0.06-0.18]; p&0.001) or ACPA (0.34 [0.01-0.67]; p = 0.044) were significantly and independently associated with a higher DAS28 during follow-up, after adjusting for confounding variables such as gender, age and treatment. In addition, those patients with elevated sIL-15 had a significantly higher risk of receiving intensive treatment (RR 1.78, 95% confidence interval 1.18-2.7; p = 0.007). Conclusions: Patients with EA displaying high baseline sIL-15 suffered a more severe disease and received more intensive treatment. Thus, sIL-15 may be a biomarker for patients that are candidates for early and more intensive treatmentThe work of Belen Díaz-Sánchez was supported by the RETICS Programme (Programa de Redes Temáticas de Investigación Colaborativa [Colaborative Research Thematic Network Programme]; RD08/0075 - RIER [Red de Inflamación y Enfermedades Reumáticas; Inflammation and Rheumatic Diseases Network]) from the Instituto de Salud Carlos III, Spain (URL: www.isciii.es) within the VI National Plan for I+D+I 2008–2011 (FEDER). The work of Isidoro González-Álvaro was in part supported by a grant for the Intensification of the Research Tasks in the National Health Care System from Instituto de Salud Carlos III, Spain. The consumables for measurements and data analysis were supported by a Fondo de Investigación Sanitaria grant (08/0754) from the Instituto de Salud Carlos II

    High quality reduced graphene oxide flakes by fast kinetically controlled and clean indirect UV-induced radical reduction

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    This work highlights a surprisingly simple and kinetically controlled highly efficient indirect method for the production of high quality reduced graphene oxide (rGO) flakes via UV irradiation of aqueous dispersions of graphene oxide (GO), in which the GO is not excited directly. While the direct photoexcitation of aqueous GO (when GO is the only light-absorbing component) takes several hours of reaction time at ambient temperature (4 h) leading only to a partial GO reduction, the addition of small amounts of isopropanol and acetone (2% and 1%) leads to a dramatically shortened reaction time by more than two orders of magnitude (2 min) and a very efficient and soft reduction of graphene oxide. This method avoids the formation of non-volatile species and in turn contamination of the produced rGO and it is based on the highly efficient generation of reducing carbon centered isopropanol radicals via the reaction of triplet acetone with isopropanol. While the direct photolysis of GO dispersions easily leads to degradation of the carbon lattice of GO and thus to a relatively low electric conductivity of the films of flakes, our indirect photoreduction of GO instead largely avoids the formation of defects, keeping the carbon lattice intact. Mechanisms of the direct and indirect photoreduction of GO have been elucidated and compared. Raman spectroscopy, XPS and conductivity measurements prove the efficiency of the indirect photoreduction in comparison with the state-of-the-art reduction method for GO (hydriodic acid/trifluoroacetic acid). The rapid reduction times and water solvent containing only small amounts of isopropanol and acetone may allow easy process up-scaling for technical applications and low-energy consumption

    Modulation of Cytokine Release in Ex Vivo-Stimulated Blood from Borreliosis Patients

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    In lipopolysaccharide-stimulated blood from 71 late-stage borreliosis patients, the ex vivo cytokine release capacity of tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) was reduced to 28% ± 5% and to 31% ± 5% (P ≤ 0.001), respectively, compared to that of 24 healthy controls. White blood cell counts were normal in both groups. To investigate direct interactions between the pathogen and the immune cells, blood from healthy controls was exposed in vitro to live or heat-killed Borrelia or to Borrelia lysate. Compared to the pattern induced by bacterial endotoxins, a reduced release of TNF-α and IFN-γ and an enhanced secretion of interleukin-10 and granulocyte colony-stimulating factor was found. In blood from 10 borreliosis patients stimulated with Borrelia lysate, TNF-α formation was decreased to 31% ± 14% and IFN-γ formation was decreased to 8% ± 3% (P ≤ 0.001) compared to the cytokine response of blood from healthy controls (n = 24). We propose to consider anti-inflammatory changes in the blood cytokine response capacity elicited by Borrelia as a condition that might favor the persistence of the spirochete
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