24 research outputs found
Organización y función de las subunidades de ATPasa Translocadora de protones (F1 - ATPasa) de micrococcus lysodeikticus : estudio inmunológico y bioquímico
Tesis-Universidad Complutense, 1.984.Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEProQuestpu
Organización y función de las subunidades de ATPasa Translocadora de protones (F1 - ATPasa) de micrococcus lysodeikticus : estudio inmunológico y bioquímico
Tesis-Universidad Complutense, 1.984.Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEProQuestpu
Arginase activity and CD3ζ expression after major surgery
Letter.-- et al.The studies from our laboratory were supported by grants from Spanish Ministerio de Economia y Competitividad (SAF2011-30518; and RD12/0036/0065 from Red Temática de Investigación Cooperativa en Cáncer, Instituto de Salud Carlos III, cofunded by the Fondo Europeo de Desarrollo Regional of the European Union), the European Community’s Seventh Framework Programme FP7-2007-2013 (grant HEALTH-F2-2011-256986, PANACREAS), and Junta de Castilla y León (CSI052A11-2 and CSI221A12-2).Peer Reviewe
Arginase as a new concern in blood transfusion
Letter to the editor.-- et al.This work was supported in part from the Junta de Castilla y León (Biomedicine project 2011-2012, and CSI221A12-2), Red Temática de Investigación Cooperativa en Cáncer, Instituto de Salud Carlos III, co-funded by the Fondo Europeo de Desarrollo Regional of the European Union (RD06/0020/1037 and RD12/0036/0065), and the Spanish Ministerio de Economia y Competitividad (SAF2011-30518).Peer Reviewe
Substitution at the indole 3 position yields highly potent indolecombretastatins with reduced susceptibility to MDR resistance
[EN]Resistance to combretastatin A-4 is mediated by metabolic modification of the phenolic hydroxyl and ether groups of the 3-hydroxy-4-methoxyphenyl (B ring). Replacement of the B ring of combretastatin A-4 by a N-methyl-5-indolyl reduces tubulin polymerization inhibition (TPI) and cytotoxicity against human cancer cell lines but cyano, methoxycarbonyl, formyl, and hydroxyiminomethyl substitutions at the indole 3-position restores potent TPI and cytotoxicity against sensitive human cancer cell lines. These highly potent substituted derivatives displayed low nanomolar cytotoxicity against several human cancer cell lines due to tubulin inhibition, as shown by cell cycle analysis, confocal microscopy, and tubulin polymerization inhibitory activity studies and promoted cell killing mediated by caspase-3 activation. Binding at the colchicine site was suggested by molecular modeling studies. Substituted combretastatins displayed higher potencies than the isomeric isocombretastatins and the highest potencies were achieved for the hydroxyiminomethyl (21) and cyano (23) groups, with TPI values in the submicromolar range and cytotoxicities in the subnanomolar range. Dose-response and time-course studies showed that drug concentrations as low as 1 nM (23) or 10 nM (21) led to a complete G2/M cell cycle arrest after 15 h treatment followed by a high apoptosis-like cell
§ These authors contributed equally to this work.
3
response after 48-72 h treatment. The P-glycoprotein and calcium antagonist verapamil increased 21 and 23 cytotoxicity to IC50 values of 10-10 M, and highly potentiated the cytotoxic activity in 100-fold of the CHO derivative (17), in A549 human non-small cell lung cancer cells. The differences in cytotoxic potency observed between the highly potent cyano (23) and hydroxyiminomethyl (21) groups and other substituents with similar TPI values (17) were very much reduced upon co-treatment with verapamil. A 3,4,5-trimethoxyphenyl ring always afforded more potent derivatives than a 2,3,4-trimethoxyphenyl ring
Depletion of L-arginine induces autophagy as a cytoprotective response to endoplasmic reticulum stress in human T lymphocytes
PMCID: PMC3494587L-arginine (L-Arg) deficiency results in decreased T-cell proliferation and impaired T-cell function. Here we have found that L-Arg depletion inhibited expression of different membrane antigens, including CD247 (CD3ζ), and led to an ER stress response, as well as cell cycle arrest at G(0)/G(1) in both human Jurkat and peripheral blood mitogen-activated T cells, without undergoing apoptosis. By genetic and biochemical approaches, we found that L-Arg depletion also induced autophagy. Deprivation of L-Arg induced EIF2S1 (eIF2α), MAPK8 (JNK), BCL2 (Bcl-2) phosphorylation, and displacement of BECN1 (Beclin 1) binding to BCL2, leading to autophagosome formation. Silencing of ERN1 (IRE1α) prevented the induction of autophagy as well as MAPK8 activation, BCL2 phosphorylation and XBP1 splicing, whereas led T lymphocytes to apoptosis under L-Arg starvation, suggesting that the ERN1-MAPK8 pathway plays a major role in the activation of autophagy following L-Arg depletion. Autophagy was required for survival of T lymphocytes in the absence of L-Arg, and resulted in a reversible process. Replenishment of L-Arg made T lymphocytes to regain the normal cell cycle profile and proliferate, whereas autophagy was inhibited. Inhibition of autophagy by ERN1, BECN1 and ATG7 silencing, or by pharmacological inhibitors, promoted cell death of T lymphocytes incubated in the absence of L-Arg. Our data indicate for the first time that depletion of L-Arg in T lymphocytes leads to a reversible response that preserves T lymphocytes through ER stress and autophagy, while remaining arrested at G(0)/G(1). Our data also show that the L-Arg depletion-induced ER stress response could lead to apoptosis when autophagy is blocked.This work was supported by the Spanish Ministerio de Ciencia e Innovación (SAF2008-02251, SAF2011-30518, and RD06/0020/1037 from Red Temática de Investigación Cooperativa en Cáncer, Instituto de Salud Carlos III, cofunded by the Fondo Europeo de Desarrollo Regional of the European Union), European Community’s Seventh Framework Programme FP7-2007-2013 (grant HEALTH-F2-2011-256986), Junta de Castilla y León (CSI052A11-2, GR15-Experimental Therapeutics and Translational Oncology Program, Biomedicine Project 2009), and Acciones Integradas Spain-Germany (HA2007-0080).Peer Reviewe
Neutrophils drive endoplasmic reticulum stress-mediated apoptosis in cancer cells through arginase-1 release
Abstract Human neutrophils constitutively express high amounts of arginase-1, which depletes arginine from the surrounding medium and downregulates T-cell activation. Here, we have found that neutrophil arginase-1, released from activated human neutrophils or dead cells, induced apoptosis in cancer cells through an endoplasmic reticulum (ER) stress pathway. Silencing of PERK in cancer cells prevented the induction of ER stress and apoptosis. Arginase inhibitor Nω-hydroxy-nor-arginine inhibited apoptosis and ER stress response induced by conditioned medium from activated neutrophils. A number of tumor cell lines, derived from different tissues, were sensitive to neutrophil arginase-1, with pancreatic, breast, ovarian and lung cancer cells showing the highest sensitivity. Neutrophil-released arginase-1 and arginine deprivation potentiated the antitumor action against pancreatic cancer cells of the ER-targeted antitumor alkylphospholipid analog edelfosine. Our study demonstrates the involvement of neutrophil arginase-1 in cancer cell killing and highlights the importance and complex role of neutrophils in tumor surveillance and biology
Antitumor activity of new hydridotris(pyrazolyl)borate ruthenium(II) complexes containing the phosphanes PTA and 1-CH3–PTA
11 páginas, 4 figuras, 5 tablas.-- et al.The synthesis and full characterization of new half-sandwich ruthenium(II) complexes containing κ3(N,N,N)-hydridotris(pyrazolyl)borate (κ3(N,N,N)-Tp) and the water-soluble phosphanes 1,3,5-triaza-7-phosphatricyclo[3.3.1.13,7]decane (PTA) and 1-methyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.13,7]decane (1-CH3-PTA) has been explored. Single crystal X-ray diffraction analysis for complex [RuCl{κ3(N,N,N)-Tp}(PMe2Ph)(1-CH3-PTA)][CF3SO3]·2NCMe is also reported. DNA binding properties of the ruthenium complexes have been evaluated by mobility shift assay and MALDI-TOF mass spectrometry. The in vitro antitumor activity of these compounds was assessed by examining their ability to inhibit cell proliferation in a number of human cancer cell lines (NCI-H460, SF-268, MCF-7) and non-tumor human umbilical vein endothelial cells (HUVEC). Some of these new compounds show promising cytotoxic activity with IC50 values in the low micromolar range, and display differential effects on cancer and normal cell growth.This work was supported by the Spanish Ministry of Science and
Innovation (CTQ2006-08485, SAF2008-02251), Consolider Ingenio
2010 (CSD2007-00006), and Red Temática de Investigación
Cooperativa en Cáncer, Instituto de Salud Carlos III, cofunded
by the Fondo Europeo de Desarrollo Regional of the European
Union (RD06/0020/1037). A. García-Fernández thanks the
Spanish Ministry of Education and Science for a scholarship.
We also thank Anette Rasmussen, Department of Biochemistry
andMolecular Biology, University of Southern Denmark, for her
assistance with the MALDI-TOF MS experiments.Peer reviewe
The metalloprotease ADAM8 is associated with and regulates the function of the adhesion receptor PSGL-1 through ERM proteins
The P-selectin glycoprotein ligand-1 (PSGL-1) is involved in the initial contact of leukocytes with activated endothelium, and its adhesive function is regulated through its proteolytic processing. We have found that the metalloprotease ADAM8 is both associated with PSGL-1 through the ezrin-radixin-moesin actin-binding proteins and able to cause the proteolytic cleavage of this adhesion receptor. Accordingly, ADAM8 knockdown increases PSGL-1 expression, and functional assays show that ADAM8 is able to reduce leukocyte rolling on P-selectin and hence on activated endothelial cells. We conclude that ADAM8 modulates the expression and function of PSGL-1. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.This work was supported by grants from the Spanish Ministry of Health (Fondo de Investigaciones Sanitarias) to A. Urzainqui (FIS-PI080894) and to F. Díaz González (FIS 09/02209), by grants from Ministerio de Ciencia e Innovación to F. S. M. (SAF2008-02635) and to F. M. (SAF2008-02251) and by the Redes RIER, RTICC (RD06/0020/1037) and RECAVA del Instituto de Salud Carlos III and RTICCR.Peer Reviewe
Transient inhibition of capacitative calcium entry in human neutrophils by a monoclonal antibody directed against a 19-kDa antigen
P1C3 is a monoclonal antibody that binds p19, a novel neutrophil activation antigen that translocates to the cell surface upon neutrophil activation. We find that P1C3 inhibits capacitative Ca2+ entry, induced by emptying the intracellular Ca2+ stores with thapsigarin. The effect is transient, reaching its maximum at 30-60 s, but becomes permanent upon pretreatment of the cells with the protein phosphatase inhibitor calyculin A, suggesting the involvement of protein phosphorylation. The inhibitory action is similar to the one reported previously for the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (fMLP), although the transduction mechanism may be different. Inhibition of Ca2+ entry by fMLP was prevented by pretreatment with pertussis toxin, whereas inhibition by P1C3 was not. Pretreatment with cholera toxin had no effect. This suggests that the effect of P1C3 may not be mediated by a heterotrimeric G protein. Tyrosine kinase inhibitors did not prevent inhibition by either fMLP or P1C3. Phospholipase C activation seems not to be involved as P1C3, contrarily to fMLP, was unable to induce Ca2+ release from the intracellular Ca2+ stores