TY - JOUR A1 - Münch, Miriam A1 - Hsin, Chih-Hsuan A1 - Ferber, Elena A1 - Berger, Susanne A1 - Müller, Martin J. T1 - Reactive electrophilic oxylipins trigger a heat stress-like response through HSFA1 transcription factors JF - Journal of Experimental Botany N2 - Electrophilic oxylipins trigger a heat-shock-like response in the absence of heat through the canonical heat-shock transcription factor A1, thereby helping to cope with stresses associated with protein damage.Abiotic and biotic stresses are often characterized by an induction of reactive electrophile species (RES) such as the jasmonate 12-oxo-phytodienoic acid (OPDA) or the structurally related phytoprostanes. Previously, RES oxylipins have been shown massively to induce heat-shock-response (HSR) genes including HSP101 chaperones. Moreover, jasmonates have been reported to play a role in basal thermotolerance. We show that representative HSR marker genes are strongly induced by RES oxylipins through the four master regulator transcription factors HSFA1a, b, d, and e essential for short-term adaptation to heat stress in Arabidopsis. When compared with Arabidopsis seedlings treated at the optimal acclimation temperature of 37 A degrees C, the exogenous application of RES oxylipins at 20 A degrees C induced a much weaker induction of HSP101 at both the gene and protein expression levels which, however, was not sufficient to confer short-term acquired thermotolerance. Moreover, jasmonate-deficient mutant lines displayed a wild-type-like HSR and were not compromised in acquiring thermotolerance. Hence, the OPDA- and RES oxylipin-induced HSR is not sufficient to protect seedlings from severe heat stress but may help plants to cope better with stresses associated with protein unfolding by inducing a battery of chaperones in the absence of heat. KW - arabidopsis-thaliana KW - shock response KW - gene-expression KW - model KW - acquired thermotolerance KW - 12-oxo-phytodienoic acid KW - thermotolerance KW - plants KW - detoxification KW - acquisition KW - activation KW - heat stress KW - jasmonates KW - phytoprostanes KW - reactive electrophilic species KW - unfolded protein response Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186766 VL - 67 IS - 21 ER - TY - JOUR A1 - Avota, Elita A1 - de Lira, Maria Nathalia A1 - Schneider-Schaulies, Sibylle T1 - Sphingomyelin breakdown in T cells: role of membrane compartmentalization in T cell signaling and interference by a pathogen JF - Frontiers in Cell and Developmental Biology N2 - Sphingolipids are major components of cellular membranes, and at steady-state level, their metabolic fluxes are tightly controlled. On challenge by external signals, they undergo rapid turnover, which substantially affects the biophysical properties of membrane lipid and protein compartments and, consequently, signaling and morphodynamics. In T cells, external cues translate into formation of membrane microdomains where proximal signaling platforms essential for metabolic reprograming and cytoskeletal reorganization are organized. This review will focus on sphingomyelinases, which mediate sphingomyelin breakdown and ensuing ceramide release that have been implicated in T-cell viability and function. Acting at the sphingomyelin pool at the extrafacial or cytosolic leaflet of cellular membranes, acid and neutral sphingomyelinases organize ceramide-enriched membrane microdomains that regulate T-cell homeostatic activity and, upon stimulation, compartmentalize receptors, membrane proximal signaling complexes, and cytoskeletal dynamics as essential for initiating T-cell motility and interaction with endothelia and antigen-presenting cells. Prominent examples to be discussed in this review include death receptor family members, integrins, CD3, and CD28 and their associated signalosomes. Progress made with regard to experimental tools has greatly aided our understanding of the role of bioactive sphingolipids in T-cell biology at a molecular level and of targets explored by a model pathogen (measles virus) to specifically interfere with their physiological activity. KW - T cell KW - sphingomyelinase KW - activation KW - motility KW - measles virus Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199168 SN - 2296-634X VL - 7 IS - 152 ER - TY - JOUR A1 - Bernt, Alexander A1 - Rangrez, Ashraf Y. A1 - Eden, Matthias A1 - Jungmann, Andreas A1 - Katz, Sylvia A1 - Rohr, Claudia A1 - Müller, Oliver J. A1 - Katus, Hugo A. A1 - Sossalla, Samuel T. A1 - Williams, Tatjana A1 - Ritter, Oliver A1 - Frank, Derk A1 - Frey, Norbert T1 - Sumoylation-independent activation of Calcineurin-NFAT-signaling via SUMO2 mediates cardiomyocyte hypertrophy JF - Scientific Reports N2 - The objective of this study was to identify unknown modulators of Calcineurin (Cn)-NFAT signaling. Measurement of NFAT reporter driven luciferase activity was therefore utilized to screen a human cardiac cDNA-library (~10\(^{7}\) primary clones) in C2C12 cells through serial dilutions until single clones could be identified. This extensive screening strategy culminated in the identification of SUMO2 as a most efficient Cn-NFAT activator. SUMO2-mediated activation of Cn-NFAT signaling in cardiomyocytes translated into a hypertrophic phenotype. Prohypertrophic effects were also observed in mice expressing SUMO2 in the heart using AAV9 (Adeno-associated virus), complementing the in vitro findings. In addition, increased SUMO2-mediated sumoylation in human cardiomyopathy patients and in mouse models of cardiomyopathy were observed. To decipher the underlying mechanism, we generated a sumoylation-deficient SUMO2 mutant (ΔGG). Surprisingly, ΔGG replicated Cn-NFAT-activation and the prohypertrophic effects of native SUMO2, both in vitro and in vivo, suggesting a sumoylation-independent mechanism. Finally, we discerned a direct interaction between SUMO2 and CnA, which promotes CnA nuclear localization. In conclusion, we identified SUMO2 as a novel activator of Cn-NFAT signaling in cardiomyocytes. In broader terms, these findings reveal an unexpected role for SUMO2 in cardiac hypertrophy and cardiomyopathy, which may open the possibility for therapeutic manipulation of this pathway. KW - Calcineurin-NFATsignaling KW - activation KW - SUMO2 KW - cardiac hypertrophy Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167525 VL - 6 IS - 35758 ER - TY - JOUR A1 - Hausmann, Stefan A1 - Brandt, Evelyn A1 - Köchel, Carolin A1 - Einsele, Hermann A1 - Bargou, Ralf C. A1 - Seggewiss-Bernhardt, Ruth A1 - Stühmer, Thorsten T1 - Loss of serum and glucocorticoid-regulated kinase 3 (SGK3) does not affect proliferation and survival of multiple myeloma cell lines JF - PLoS ONE N2 - Multiple myeloma (MM) is a generally fatal plasma cell cancer that often shows activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway. Targeted pharmacologic therapies, however, have not yet progressed beyond the clinical trial stage, and given the complexity of the PI3K/Akt signalling system (e.g. multiple protein isoforms, diverse feedback regulation mechanisms, strong variability between patients) it is mandatory to characterise its ramifications in order to better guide informed decisions about the best therapeutic approaches. Here we explore whether serum and glucocorticoid-regulated kinase 3 (SGK3), a potential downstream effector of PI3K, plays a role in oncogenic signalling in MM cells-either in concert with or independent of Akt. SGK3 was expressed in all MM cell lines and in all primary MM samples tested. Four MM cell lines representing a broad range of intrinsic Akt activation (very strong: MM. 1s, moderate: L 363 and JJN-3, absent: AMO-1) were chosen to test the effects of transient SGK3 knockdown alone and in combination with pharmacological inhibition of Akt, PI3K-p110\(\alpha\), or in the context of serum starvation. Although the electroporation protocol led to strong SGK3 depletion for at least 5 days its absence had no substantial effect on the activation status of potential downstream substrates, or on the survival, viability or proliferation of MM cells in all experimental contexts tested. We conclude that it is unlikely that SGK3 plays a significant role for oncogenic signalling in multiple myeloma. KW - Akt KW - phosphorylation KW - downstream KW - mechanism KW - pathway KW - isoforms KW - activation KW - cancer KW - inhibition KW - phosphatidylinositol 3-kinase/Akt Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148708 VL - 10 IS - 4 ER - TY - JOUR A1 - Firdessa, Rebuma A1 - Good, Liam A1 - Amstalden, Maria Cecilia A1 - Chindera, Kantaraja A1 - Kamaruzzaman, Nor Fadhilah A1 - Schultheis, Martina A1 - Röger, Bianca A1 - Hecht, Nina A1 - Oelschlaeger, Tobias A. A1 - Meinel, Lorenz A1 - Lühmann, Tessa A1 - Moll, Heidrun T1 - Pathogen- and host-directed antileishmanial effects mediated by polyhexanide (PHMB) JF - PLoS Neglected Tropical Diseases N2 - Background Cutaneous leishmaniasis (CL) is a neglected tropical disease caused by protozoan parasites of the genus Leishmania. CL causes enormous suffering in many countries worldwide. There is no licensed vaccine against CL, and the chemotherapy options show limited efficacy and high toxicity. Localization of the parasites inside host cells is a barrier to most standard chemo- and immune-based interventions. Hence, novel drugs, which are safe, effective and readily accessible to third-world countries and/or drug delivery technologies for effective CL treatments are desperately needed. Methodology/Principal Findings Here we evaluated the antileishmanial properties and delivery potential of polyhexamethylene biguanide (PHMB; polyhexanide), a widely used antimicrobial and wound antiseptic, in the Leishmania model. PHMB showed an inherent antileishmanial activity at submicromolar concentrations. Our data revealed that PHMB kills Leishmania major (L. major) via a dual mechanism involving disruption of membrane integrity and selective chromosome condensation and damage. PHMB's DNA binding and host cell entry properties were further exploited to improve the delivery and immunomodulatory activities of unmethylated cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODN). PHMB spontaneously bound CpG ODN, forming stable nanopolyplexes that enhanced uptake of CpG ODN, potentiated antimicrobial killing and reduced host cell toxicity of PHMB. Conclusions Given its low cost and long history of safe topical use, PHMB holds promise as a drug for CL therapy and delivery vehicle for nucleic acid immunomodulators. KW - resistance KW - activation KW - dendritic cells KW - Cutaneous leishmaniasis KW - topical treatment KW - biocide polyhexamethylene biguanide KW - experimental visceral leishmaniasis KW - drug-delivery systems KW - therapy KW - paromomycin Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148162 VL - 9 IS - 10 ER - TY - JOUR A1 - Hoffmann, Linda S A1 - Schmidt, Peter M A1 - Keim, Yvonne A1 - Hoffmann, Carsten A1 - Schmidt, Harald H H W A1 - Stasch, Johannes-Peter T1 - Fluorescence Dequenching Makes Haem-Free Soluble Guanylate Cyclase Detectable in Living Cells JF - PLOS ONE N2 - In cardiovascular disease, the protective NO/sGC/cGMP signalling-pathway is impaired due to a decreased pool of NO-sensitive haem-containing sGC accompanied by a reciprocal increase in NO-insensitive haem-free sGC. However, no direct method to detect cellular haem-free sGC other than its activation by the new therapeutic class of haem mimetics, such as BAY 58-2667, is available. Here we show that fluorescence dequenching, based on the interaction of the optical active prosthetic haem group and the attached biarsenical fluorophor FlAsH can be used to detect changes in cellular sGC haem status. The partly overlap of the emission spectrum of haem and FlAsH allows energy transfer from the fluorophore to the haem which reduces the intensity of FlAsH fluorescence. Loss of the prosthetic group, e. g. by oxidative stress or by replacement with the haem mimetic BAY 58-2667, prevented the energy transfer resulting in increased fluorescence. Haem loss was corroborated by an observed decrease in NO-induced sGC activity, reduced sGC protein levels, and an increased effect of BAY 58-2667. The use of a haem-free sGC mutant and a biarsenical dye that was not quenched by haem as controls further validated that the increase in fluorescence was due to the loss of the prosthetic haem group. The present approach is based on the cellular expression of an engineered sGC variant limiting is applicability to recombinant expression systems. Nevertheless, it allows to monitor sGC's redox regulation in living cells and future enhancements might be able to extend this approach to in vivo conditions. KW - spontaneously hypersensitive-rats KW - nitric-oxide KW - down-regulation KW - energy-transfer KW - cyclic-gmp KW - protein KW - activation KW - identification KW - in-vivo KW - no Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-139631 VL - 6 IS - 8 ER - TY - JOUR A1 - Zanucco, Emanuele A1 - Götz, Rudolf A1 - Potapenko, Tamara A1 - Carraretto, Irene A1 - Ceteci, Semra A1 - Ceteci, Fatih A1 - Seeger, Werner A1 - Savai, Rajkumar A1 - Rapp, Ulf R. T1 - Expression of B-RAF V600E in Type II Pneumocytes Causes Abnormalities in Alveolar Formation, Airspace Enlargement and Tumor Formation in Mice JF - PLOS ONE N2 - Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation. KW - obstructive pulmonary-disease KW - lung-cancer KW - somatic mutations KW - epithelial-cells KW - mouse models KW - protein KW - kinase KW - inflammation KW - activation KW - pathway Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137061 VL - 6 IS - 12 ER - TY - JOUR A1 - Atak, Sinem A1 - Langlhofer, Georg A1 - Schaefer, Natascha A1 - Kessler, Denise A1 - Meiselbach, Heike A1 - Delto, Carolyn A1 - Schindelin, Hermann A1 - Villmann, Carmen T1 - Disturbances of ligand potency and enhanced degradation of the human glycine receptor at affected positions G160 and T162 originally identified in patients suffering from hyperekplexia JF - Frontiers in Molecular Neuroscience N2 - Ligand-binding of Cys-loop receptors is determined by N-terminal extracellular loop structures from the plus as well as from the minus side of two adjacent subunits in the pentameric receptor complex. An aromatic residue in loop B of the glycine receptor (GIyR) undergoes direct interaction with the incoming ligand via a cation-π interaction. Recently, we showed that mutated residues in loop B identified from human patients suffering from hyperekplexia disturb ligand-binding. Here, we exchanged the affected human residues by amino acids found in related members of the Cys-loop receptor family to determine the effects of side chain volume for ion channel properties. GIyR variants were characterized in vitro following transfection into cell lines in order to analyze protein expression, trafficking, degradation and ion channel function. GIyR α1 G160 mutations significantly decrease glycine potency arguing for a positional effect on neighboring aromatic residues and consequently glycine-binding within the ligand-binding pocket. Disturbed glycinergic inhibition due to T162 α1 mutations is an additive effect of affected biogenesis and structural changes within the ligand-binding site. Protein trafficking from the ER toward the ER-Golgi intermediate compartment, the secretory Golgi pathways and finally the cell surface is largely diminished, but still sufficient to deliver ion channels that are functional at least at high glycine concentrations. The majority of T162 mutant protein accumulates in the ER and is delivered to ER-associated proteasomal degradation. Hence, G160 is an important determinant during glycine binding. In contrast, 1162 affects primarily receptor biogenesis whereas exchanges in functionality are secondary effects thereof. KW - mutations KW - trafficking KW - domain KW - hyperekplexia KW - loop B KW - side chain properties KW - ligand potencies KW - Cys-loop receptor KW - glycine receptor KW - site KW - activation KW - binding KW - channel KW - mechanisms KW - dominant KW - startle Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144818 VL - 8 IS - 79 ER - TY - JOUR A1 - Meziane, Hadj Boumediene A1 - Moisello, Clara A1 - Perfetti, Bernardo A1 - Kvint, Svetlana A1 - Isaias, Ioannis Ugo A1 - Quartarone, Angelo A1 - Di Rocco, Alessandro A1 - Ghilardi, Maria Felice T1 - Movement preparation and bilateral modulation of beta activity in aging and Parkinson's disease JF - PLoS ONE N2 - In previous studies of young subjects performing a reaction-time reaching task, we found that faster reaction times are associated with increased suppression of beta power over primary sensorimotor areas just before target presentation. Here we ascertain whether such beta decrease similarly occurs in normally aging subjects and also in patients with Parkinson's disease (PD), where deficits in movement execution and abnormalities of beta power are usually present. We found that in both groups, beta power decreased during the motor task in the electrodes over the two primary sensorimotor areas. However, before target presentation, beta decreases in PD were significantly smaller over the right than over the left areas, while they were symmetrical in controls. In both groups, functional connectivity between the two regions, measured with imaginary coherence, increased before the target appearance; however, in PD, it decreased immediately after, while in controls, it remained elevated throughout motor planning. As in previous studies with young subjects, the degree of beta power before target appearance correlated with reaction time. The values of coherence during motor planning, instead, correlated with movement time, peak velocity and acceleration. We conclude that planning of prompt and fast movements partially depends on coordinated beta activity of both sensorimotor areas, already at the time of target presentation. The delayed onset of beta decreases over the right region observed in PD is possibly related to a decreased functional connectivity between the two areas, and this might account for deficits in force programming, movement duration and velocity modulation. KW - event-related desynchronization KW - reaction-time tasks KW - brain dynamics KW - coherence KW - bradykinesia KW - activation KW - cortical oscillatory activity KW - voluntary movement KW - EEG data KW - L-DOPA Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144147 VL - 10 IS - 1 ER - TY - JOUR A1 - Rodriguez, Héctor A1 - Rico, Sergio A1 - Yepes, Ana A1 - Franco-Echevarría, Elsa A1 - Antoraz, Sergio A1 - Santamaría, Ramón I. A1 - Díaz, Margerita T1 - The two kinases, AbrC1 and AbrC2, of the atypical two-component system AbrC are needed to regulate antibiotic production and differentiation in Streptomyces coelicolor JF - Frontiers in Microbiology N2 - Two-component systems (TCSs) are the most important sensing mechanisms in bacteria. In Streptomyces, TCSs-mediated responses to environmental stimuli are involved in the regulation of antibiotic production. This study examines the individual role of two histidine kinases (HKs), AbrC1 and AbrC2, which form part of an atypical TCS in Streptomyces coelicolor. gRT-PCR analysis of the expression of both kinases demonstrated that both are expressed at similar levels in NB and NMMP media. Single deletion of abrC1 elicited a significant increase in antibiotic production, while deletion of abrC2 did not have any clear effect. The origin of this phenotype, probably related to the differential phosphorylation ability of the two kinases, was also explored indirectly, analyzing the toxic phenotypes associated with high levels of phosphorylated RR. The higher the AbrC3 regulator phosphorylation rate, the greater the cell toxicity. For the first time, the present work shows in Streptomyces the combined involvement of two different HKs in the response of a regulator to environmental signals. Regarding the possible applications of this research, the fact that an abrC1 deletion mutant overproduces three of the S. coelicolor antibiotics makes this strain an excellent candidate as a host for the heterologous production of secondary metabolites. KW - halstedii JM8 KW - biosynthesis KW - expression mutants KW - domain genes A3(2) KW - two-component systems KW - Streptomyces KW - antibiotic production KW - histidine kinases KW - heterologous production KW - activation KW - response regulator KW - PCR Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143048 VL - 6 IS - 450 ER -