45 research outputs found

    A new class of fatty acid allene oxide formed by the DOX-P450 fusion proteins of human and plant pathogenic fungi, C. immitis and Z. tritic

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    Linoleate dioxygenase-cytochrome P450 (DOX-CYP) fusion enzymes are common in pathogenic fungi. The DOX domains form hydroperoxy metabolites of 18:2n-6, which can be transformed by the CYP domains to 1,2- or 1,4-diols, epoxy alcohols, or to allene oxides. We have characterized two novel allene oxide synthases (AOSs), namely, recombinant 8R-DOX-AOS of Coccidioides immitis (causing valley fever) and 8S-DOX-AOS of Zymoseptoria tritici (causing septoria tritici blotch of wheat). The 8R-DOX-AOS oxidized 18:2n-6 sequentially to 8R-hydroperoxy-9Z,12Z-octadecadienoic acid (8R-HPODE) and to an allene oxide, 8R(9)-epoxy-9,12Z-octadecadienoic acid, as judged from the accumulation of the α-ketol, 8S-hydroxy-9-oxo-12Z-octadecenoic acid. The 8S-DOX-AOS of Z. tritici transformed 18:2n-6 sequentially to 8S-HPODE and to an α-ketol, 8R-hydroxy-9-oxo-12Z-octadecenoic acid, likely formed by hydrolysis of 8S(9)-epoxy-9,12Z-octadecadienoic acid. The 8S-DOX-AOS oxidized [8R-2H]18:2n-6 to 8S-HPODE with retention of the 2H-label, suggesting suprafacial hydrogen abstraction and oxygenation in contrast to 8R-DOX-AOS. Both enzymes oxidized 18:1n-9 and 18:3n-3 to α-ketols, but the catalysis of the 8R- and 8S-AOS domains differed. 8R-DOX-AOS transformed 9R-HPODE to epoxy alcohols, but 8S-DOX-AOS converted 9S-HPODE to an α-ketol (9-hydroxy-10-oxo-12Z-octadecenoic acid) and epoxy alcohols in a ratio of ∼1:2. Whereas all fatty acid allene oxides described so far have a conjugated diene impinging on the epoxide, the allene oxides formed by 8-DOX-AOS are unconjugated

    Aplicación de modelos de procesos puntuales para la caracterización espacio-temporal del régimen de incendios en el este de España

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    Ponència presentada al VI Congreso Forestal Español, celebrat a Vitoria-Gasteiz, els dies 10-14 de juny de 2013Las incidencias de los modelos espacio-temporal de los incendios forestales y sus relaciones con las variables meteorológicas, geográficas y usos del suelo son analizadas en este trabajo. Estas relaciones pueden ser tratadas en un incendio forestal como componentes en los modelos de procesos puntuales es decir como actividades separadas. En este trabajo se muestran algunas técnicas para el análisis de modelos espaciales puntuales que están disponibles gracias a los recientes desarrollos de aplicaciones informáticas en los modelos de procesos puntuales. Estos avances permiten realizar un análisis exploratorio de los datos de forma conveniente, ajuste de los datos a un modelo y evaluación del modelo. La discusión de estas técnicas se realiza conjuntamente dentro del contexto de algunos análisis preliminares de una colección de datos que son de un considerable interés por ellos mismos. Este conjunto de datos consiste en los registros de incendios forestales en la provincia de Castellón (años del 2001 al 2006) y Cataluña (2001 al 2008). Los resultados de estos trabajos apuntan a la posibilidad de zonificar las áreas forestales en zonas de mayor o menor riesgo e intensidad de incendio forestal, con lo que se podría planificar las actuaciones preventivas de una forma mas efectiva y acotada

    Phosphoenolpyruvate from Glycolysis and PEPCK Regulate Cancer Cell Fate by Altering Cytosolic Ca2+

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    Changes in phosphoenolpyruvate (PEP) concentrations secondary to variations in glucose availability can regulate calcium signaling in T cells as this metabolite potently inhibits the sarcoplasmic reticulum Ca2+/ATPase pump (SERCA). This regulation is critical to assert immune activation in the tumor as T cells and cancer cells compete for available nutrients. We examined here whether cytosolic calcium and the activation of downstream effector pathways important for tumor biology are influenced by the presence of glucose and/or cataplerosis through the phosphoenolpyruvate carboxykinase (PEPCK) pathway, as both are hypothesized to feed the PEP pool. Our data demonstrate that cellular PEP parallels extracellular glucose in two human colon carcinoma cell lines, HCT-116 and SW480. PEP correlated with cytosolic calcium and NFAT activity, together with transcriptional up-regulation of canonical targets PTGS2 and IL6 that was fully prevented by CsA pre-treatment. Similarly, loading the metabolite directly into the cell increased cytosolic calcium and NFAT activity. PEP-stirred cytosolic calcium was also responsible for the calmodulin (CaM) dependent phosphorylation of c-Myc at Ser62, resulting in increased activity, probably through enhanced stabilization of the protein. Protein expression of several c-Myc targets also correlated with PEP levels. Finally, the participation of PEPCK in this axis was interrogated as it should directly contribute to PEP through cataplerosis from TCA cycle intermediates, especially in glucose starvation conditions. Inhibition of PEPCK activity showed the expected regulation of PEP and calcium levels and consequential downstream modulation of NFAT and c-Myc activities. Collectively, these results suggest that glucose and PEPCK can regulate NFAT and c-Myc activities through their influence on the PEP/Ca2+ axis, advancing a role for PEP as a second messenger communicating metabolism, calcium cell signaling, and tumor biology

    Dibenzylxanthines as PPEPCK-M inhibitors for cancer therapy

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    Phosphoenolpyruvate carboxykinase (PEPCK) is the key enzyme in gluconeogenesis/glyceroneogenesis, which catalyzes the decarboxylation of oxaloacetate to phosphoenolpyruvate. In eukaryotes, there are two isozymes present either in the cytosol (PEPCKC, PCK1) or the mitochondria (PEPCK-M, PCK2). While PCK1 is found in gluconeogenic tissues and has a very clear metabolic function, PCK2 is expressed in non-gluconeogenic cell types, where its role remains largely unknown. For example, PCK2 is highly expressed in most cancer cells, where it provides a growth advantage to cancer cells in nutrient-poor environments

    Glycosylation defects, offset by PEPCK-M, drive entosis in breast carcinoma cells

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    On glucose restriction, epithelial cells can undergo entosis, a cell-in-cell cannibalistic process, to allow considerable withstanding to this metabolic stress. Thus, we hypothesized that reduced protein glycosylation might participate in the activation of this cell survival pathway. Glucose deprivation promoted entosis in an MCF7 breast carcinoma model, as evaluated by direct inspection under the microscope, or revealed by a shift to apoptosis + necrosis in cells undergoing entosis treated with a Rho-GTPase kinase inhibitor (ROCKi). In this context, curbing protein glycosylation defects with N-acetyl-glucosamine partially rescued entosis, whereas limiting glycosylation in the presence of glucose with tunicamycin or NGI-1, but not with other unrelated ER-stress inducers such as thapsigargin or amino-acid limitation, stimulated entosis. Mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M; PCK2) is upregulated by glucose deprivation, thereby enhancing cell survival. Therefore, we presumed that PEPCK-M could play a role in this process by offsetting key metabolites into glycosyl moieties using alternative substrates. PEPCK-M inhibition using iPEPCK-2 promoted entosis in the absence of glucose, whereas its overexpression inhibited entosis. PEPCK-M inhibition had a direct role on total protein glycosylation as determined by Concanavalin A binding, and the specific ratio of fully glycosylated LAMP1 or E-cadherin. The content of metabolites, and the fluxes from C-13-glutamine label into glycolytic intermediates up to glucose-6-phosphate, and ribose- and ribulose-5-phosphate, was dependent on PEPCK-M content as measured by GC/MS. All in all, we demonstrate for the first time that protein glycosylation defects precede and initiate the entosis process and implicates PEPCK-M in this survival program to dampen the consequences of glucose deprivation. These results have broad implications to our understanding of tumor metabolism and treatment strategies

    Azobioisosteres of Curcumin with Pronounced Activity against Amyloid Aggregation, Intracellular Oxidative Stress, and Neuroinflammation

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    Many (poly‐)phenolic natural products, for example, curcumin and taxifolin, have been studied for their activity against specific hallmarks of neurodegeneration, such as amyloid‐β 42 (Aβ42) aggregation and neuroinflammation. Due to their drawbacks, arising from poor pharmacokinetics, rapid metabolism, and even instability in aqueous medium, the biological activity of azobenzene compounds carrying a pharmacophoric catechol group, which have been designed as bioisoteres of curcumin has been examined. Molecular simulations reveal the ability of these compounds to form a hydrophobic cluster with Aβ42, which adopts different folds, affecting the propensity to populate fibril‐like conformations. Furthermore, the curcumin bioisosteres exceeded the parent compound in activity against Aβ42 aggregation inhibition, glutamate‐induced intracellular oxidative stress in HT22 cells, and neuroinflammation in microglial BV‐2 cells. The most active compound prevented apoptosis of HT22 cells at a concentration of 2.5 μm (83 % cell survival), whereas curcumin only showed very low protection at 10 μm (21 % cell survival)

    CXCR7 expression in diffuse large B-cell lymphoma identifies a subgroup of CXCR4+ patients with good prognosis

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    © 2018 Moreno et al.The CXCR4/CXCL12 axis has been extensively associated with different types of cancer correlating with higher aggressiveness and metastasis. In diffuse large B-cell lymphoma (DLBCL), the expression of the chemokine receptor CXCR4 is involved in the dissemination of malignant B cells and is a marker of poor prognosis. CXCR7 is a chemokine receptor that binds to the same ligand as CXCR4 and regulates de CXCR4-CXCL12 axis. These findings together with the report of CXCR7 prognostic value in several tumor types, led us to evaluate the expression of CXCR7 in diffuse large B-cell lymphoma biopsies. Here, we describe that CXCR7 receptor is an independent prognostic factor that associates with good clinical outcome. Moreover, the expression of CXCR7 associates with increased survival in CXCR4+ but not in CXCR4- DLBCL patients. Thus, the combined immunohistochemical evaluation of both CXCR7 and CXCR4 expression in DLBCL biopsies may improve their prognostic value as single markers. Finally, we show that CXCR7 overexpression in vitro is able to diminish DLBCL cell survival and increase their sensitivity to antitumor drugs. Hence, further studies on the CXCR7 receptor may establish its role in DLBCL and the molecular mechanisms that modulate CXCR4 activity.This work was supported by Instituto de Salud Carlos III (co-founding from FEDER) [ FIS PI11/00872, RD12/0036/0071, FIS PI14/00450 to J.S., FIS PI15/00378 to R.M., PIE15/00028 to R.M. and J.S., RD12/0036/0069, PS09/01382 to M.G.D, PI15/01393 to M.A, CD13/00074 to V.P.]; Centro de Investigación Biomédica en Red (CIBER) [CB06/01/1031 and Nanomets3 to R.M. and CB16/12/00233 to M.G.D.]; Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR) [2014-SGR-1041, 2014PROD0005 to R.M and 2014-SGR-1281 to J.S]; Fundació La Marató TV3 [416/C/2013-2030 to R.M, 100830/31/32 to J.S and M.G.D.]; Josep Carreras Leukaemia Research Institute [P/AG 2014 to R.M.]; the Health Council of Castilla y León (BIO/SA56/13 and BIO/SA78/15 to M.A.); Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR) [2017FI_B00680 to A.F.]

    PEPCK-M recoups tumor cell anabolic potential in a PKC-ζ-dependent manner

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    Background: Mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M; PCK2) is expressed in all cancer types examined and in neuroprogenitor cells. The gene is upregulated by amino acid limitation and ER-stress in an ATF4- dependent manner, and its activity modulates the PEP/Ca2+ signaling axis, providing clear arguments for a functional relationship with metabolic adaptations for cell survival. Despite its potential relevance to cancer metabolism, the mechanisms responsible for its pro-survival activity have not been completely elucidated. Methods: [U-13C]glutamine and [U-13C]glucose labeling of glycolytic and TCA cycle intermediates and their anabolic end-products was evaluated quantitatively using LC/MS and GC/MS in conditions of abundant glucose and glucose limitation in loss-of-function (shRNA) and gain-of-function (lentiviral constitutive overexpression) HeLa cervix carcinoma cell models. Cell viability was assessed in conjunction with various glucose concentrations and in xenografts in vivo. Results: PEPCK-M levels linearly correlated with [U-13C]glutamine label abundance in most glycolytic and TCA cycle intermediate pools under nutritional stress. In particular, serine, glycine, and proline metabolism, and the anabolic potential of the cell, were sensitive to PEPCK-M activity. Therefore, cell viability defects could be rescued by supplementing with an excess of those amino acids. PEPCK-M silenced or inhibited cells in the presence of abundant glucose showed limited growth secondary to TCA cycle blockade and increased ROS. In limiting glucose conditions, downregulation of PKC-ζ tumor suppressor has been shown to enhance survival. Consistently, HeLa cells also sustained a survival advantage when PKC-ζ tumor suppressor was downregulated using shRNA, but this advantage was abolished in the absence of PEPCK-M, as its inhibition restores cell growth to control levels. The relationship between these two pathways is also highlighted by the anti-correlation observed between PEPCK-M and PKC-ζ protein levels in all clones tested, suggesting co-regulation in the absence of glucose. Finally, PEPCK-M loss negatively impacted on anchorage-independent colony formation and xenograft growth in vivo. Conclusions: All in all, our data suggest that PEPCK-M might participate in the mechanisms to regulate proteostasis in the anabolic and stalling phases of tumor growth. We provide molecular clues into the clinical relevance of PEPCK-M as a mechanism of evasion of cancer cells in conditions of nutrient stress

    The Main Indicators of Economic Accounts in the EC, the United States and Japan. 1970-1983

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    [Background] Metabolic alterations play a role in the development of inflammatory myopathies (IMs). Herein, we have investigated through a multiplex assay whether proteins of energy metabolism could provide biomarkers of IMs.[Methods] A cohort of thirty-two muscle biopsies and forty plasma samples comprising polymyositis (PM), dermatomyositis (DM) and sporadic inclusion body myositis (sIBM) and control donors was interrogated with monoclonal antibodies against proteins of energy metabolism using reverse phase protein microarrays (RPPA)[Results] When compared to controls the expression of the proteins is not significantly affected in the muscle of PM patients. However, the expression of β-actin is significantly increased in DM and sIBM in consistence with muscle and fiber regeneration. Concurrently, the expression of some proteins involved in glucose metabolism displayed a significant reduction in muscle of sIBM suggesting a repression of glycolytic metabolism in these patients. In contrasts to these findings, the expression of the glycolytic pyruvate kinase isoform M2 (PKM2) and of the mitochondrial ATPase Inhibitor Factor 1 (IF1) and Hsp60 were significantly augmented in DM when compared to other IMs in accordance with a metabolic shift prone to cancer development. PKM2 alone or in combination with other biomarkers allowed the discrimination of control and IMs with very high (>95%) sensitivity and specificity. Unfortunately, plasma levels of PKM2 were not significantly altered in DM patients to recommend its use as a non-invasive biomarker of the disease.[Conclusions] Expression of proteins of energy metabolism in muscle enabled discrimination of patients with IMs. RPPA identified the glycolysis promoting PKM2 and IF1 proteins as specific biomarkers of dermatomyositis, providing a biochemical link of this IM with oncogenesis.FS was supported by a pre-doctoral fellowship from FPI-UAM Spain. The work was supported by Grants from the Ministerio de Economía y Competitividad (SAF2013-41945-R; SAF2016-75916-R), Fundación Ramón Areces (FRA), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Fundación CELLEX and Comunidad de Madrid (S2011/BMD-2402), Spain. The CBMSO receives an institutional grant from FRA.Peer Reviewe

    Medicaments i lactància materna

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    Treballs d'Educació Farmacèutica als ciutadans. Unitat Docent d'Estades en Pràctiques Tutelades. Facultat de Farmàcia, Universitat de Barcelona. Curs: 2015-2016. Tutors: Dolors Soy Muner, Neus Pagès i Marian March Pujol.En el present treball es desenvolupa un programa integral d’educació farmacèutica orientada a les famílies que es trobin en el període de lactància materna al nadó. Els objectius principals del treball són: 1) conscienciar de la importància i beneficis de la lactància materna, 2) aconsellar sobre els aspectes més rellevants per tal de facilitarla mitjançant informació sobre com afrontar els problemes que puguin originar-se, i 3) informar dels possibles efectes que poden ocasionar en el nadó els medicaments, els preparats de fitoteràpia o altres substàncies bioactives que passen a la llet materna. Per tal d’aconseguir-ho, s’han realitzat diferents activitats educatives, tals com una presentació tipus conferència (activitat 1), un vídeo (activitat 2), un tríptic informatiu (activitat 3) i un joc de preguntes (activitat 4)
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