@article{MammadovaBachBraun2019, author = {Mammadova-Bach, Elmina and Braun, Attila}, title = {Zinc homeostasis in platelet-related diseases}, series = {International Journal of Molecular Sciences}, volume = {20}, journal = {International Journal of Molecular Sciences}, number = {21}, issn = {1422-0067}, doi = {10.3390/ijms20215258}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285554}, year = {2019}, abstract = {Zn\(^{2+}\) deficiency in the human population is frequent in underdeveloped countries. Worldwide, approximatively 2 billion people consume Zn\(^{2+}\)-deficient diets, accounting for 1-4\% of deaths each year, mainly in infants with a compromised immune system. Depending on the severity of Zn\(^{2+}\) deficiency, clinical symptoms are associated with impaired wound healing, alopecia, diarrhea, poor growth, dysfunction of the immune and nervous system with congenital abnormalities and bleeding disorders. Poor nutritional Zn\(^{2+}\) status in patients with metastatic squamous cell carcinoma or with advanced non-Hodgkin lymphoma, was accompanied by cutaneous bleeding and platelet dysfunction. Forcing Zn\(^{2+}\) uptake in the gut using different nutritional supplementation of Zn\(^{2+}\) could ameliorate many of these pathological symptoms in humans. Feeding adult rodents with a low Zn\(^{2+}\) diet caused poor platelet aggregation and increased bleeding tendency, thereby attracting great scientific interest in investigating the role of Zn\(^{2+}\) in hemostasis. Storage protein metallothionein maintains or releases Zn\(^{2+}\) in the cytoplasm, and the dynamic change of this cytoplasmic Zn\(^{2+}\) pool is regulated by the redox status of the cell. An increase of labile Zn\(^{2+}\) pool can be toxic for the cells, and therefore cytoplasmic Zn\(^{2+}\) levels are tightly regulated by several Zn\(^{2+}\) transporters located on the cell surface and also on the intracellular membrane of Zn\(^{2+}\) storage organelles, such as secretory vesicles, endoplasmic reticulum or Golgi apparatus. Although Zn\(^{2+}\) is a critical cofactor for more than 2000 transcription factors and 300 enzymes, regulating cell differentiation, proliferation, and basic metabolic functions of the cells, the molecular mechanisms of Zn\(^{2+}\) transport and the physiological role of Zn\(^{2+}\) store in megakaryocyte and platelet function remain elusive. In this review, we summarize the contribution of extracellular or intracellular Zn\(^{2+}\) to megakaryocyte and platelet function and discuss the consequences of dysregulated Zn\(^{2+}\) homeostasis in platelet-related diseases by focusing on thrombosis, ischemic stroke and storage pool diseases.}, language = {en} } @article{KraftDrechslerGunrebenetal.2014, author = {Kraft, Peter and Drechsler, Christiane and Gunreben, Ignaz and Nieswandt, Bernhard and Stoll, Guido and Heuschmann, Peter Ulrich and Kleinschnitz, Christoph}, title = {Von Willebrand Factor Regulation in Patients with Acute and Chronic Cerebrovascular Disease: A Pilot, Case-Control Study}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {6}, issn = {1932-6203}, doi = {10.1371/journal.pone.0099851}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119588}, pages = {e99851}, year = {2014}, abstract = {Background and Purpose In animal models, von Willebrand factor (VWF) is involved in thrombus formation and propagation of ischemic stroke. However, the pathophysiological relevance of this molecule in humans, and its potential use as a biomarker for the risk and severity of ischemic stroke remains unclear. This study had two aims: to identify predictors of altered VWF levels and to examine whether VWF levels differ between acute cerebrovascular events and chronic cerebrovascular disease (CCD). Methods A case-control study was undertaken between 2010 and 2013 at our University clinic. In total, 116 patients with acute ischemic stroke (AIS) or transitory ischemic attack (TIA), 117 patients with CCD, and 104 healthy volunteers (HV) were included. Blood was taken at days 0, 1, and 3 in patients with AIS or TIA, and once in CCD patients and HV. VWF serum levels were measured and correlated with demographic and clinical parameters by multivariate linear regression and ANOVA. Results Patients with CCD (158±46\%) had significantly higher VWF levels than HV (113±36\%, P<0.001), but lower levels than AIS/TIA patients (200±95\%, P<0.001). Age, sex, and stroke severity influenced VWF levels (P<0.05). Conclusions VWF levels differed across disease subtypes and patient characteristics. Our study confirms increased VWF levels as a risk factor for cerebrovascular disease and, moreover, suggests that it may represent a potential biomarker for stroke severity, warranting further investigation.}, language = {en} } @phdthesis{Gromova2007, author = {Gromova, Kira V.}, title = {Visualization of the Smad direct signaling response to Bone Morphogenetic Protein 4 activation with FRET-based biosensors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-25855}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2007}, abstract = {The Transforming Growth Factor (TGF) superfamily of cytokines and their serine/threonine kinase receptors play an important role in the regulation of cell division, differentiation, adhesion, migration, organization, and death. Smad proteins are the major intracellular signal transducers for the TGF receptor superfamily that mediate the signal from the membrane into the nucleus. Bone Morphogenetic Protein-4 (BMP-4) is a representative of the TGF superfamily, which regulates the formation of teeth, limbs and bone, and also plays a role in fracture repair. Binding of BMP-4 to its receptor stimulates phosphorylation of Smad1, which subsequently recruits Smad4. A hetero-oligomeric complex consisting of Smad1 and Smad4 then translocates into the nucleus and regulates transcription of target genes by interacting with transcription factors. Although the individual steps of the signaling cascade from the receptor to the nucleus have been identified, the exact kinetics and the rate limiting step(s) have remained elusive. Standard biochemical techniques are not suitable for resolving these issues, as they do not offer sufficiently high sensitivity and temporal resolution. In this study, advanced optical techniques were used for direct visualization of Smad signaling in live mammalian cells. Novel fluorescent biosensors were developed by fusing cyan and yellow fluorescent proteins to the signaling molecules Smad1 and Smad4. By measuring Fluorescence Resonance Energy Transfer (FRET) between the two fluorescent proteins, the kinetics of BMP/Smad signaling was unraveled. A rate-limiting delay of 2 - 5 minutes occurred between BMP receptor stimulation and Smad1 activation. A similar delay was observed in the complex formation between Smad1 and Smad4. Further experimentation indicated that the delay is dependent on the Mad homology 1 (MH1) domain of Smad1. These results give new insights into the dynamics of the BMP receptor - Smad1/4 signaling process and provide a new tool for studying Smads and for testing inhibitory drugs.}, subject = {FRET}, language = {en} } @phdthesis{Blachutzik2012, author = {Blachutzik, J{\"o}rg O.}, title = {Visualisierung von Plasmamembran-Dom{\"a}nen in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71925}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Unter Verwendung fluoreszenzmarkierter Remorine der taxonomischen Gruppe 1b wurden Nanodom{\"a}nen in Arabidopsis Plasmamembranen (PM) unter Verwendung hoch aufl{\"o}sender Laser Scanning-Systeme sichtbar gemacht. In diesen kompartimentierten Membranbereichen lagerten sich Sterol-abh{\"a}ngige Remorine aus verschiedenen Pflanzen-familien zusammen und zeigten dort Kolokalisation. Dies wurde statistisch belegt durch hohe Pearson und Spearman Korrelationskoeffizienten. Remorine konnten schließlich als pflanzliche Markerproteine f{\"u}r kompartimentierte Membranbereiche etabliert werden. Die Nanodom{\"a}nen zeigten zu keinem Zeitpunkt laterale Bewegungen in der PM und scheinen sowohl von zytoskelett{\"a}ren Strukturen als auch von Komponenten der Zellwand stabilisiert zu werden. M{\"o}glicherweise spielen transmembrane Tetraspanine sowie GPI-verankerte SKU5-Proteine eine Rolle bei der stabilen Verankerung. F{\"u}r zwei native Arabidopsis Remorine wurden posttranslationale Modifikationsstellen aufgedeckt, die der Anheftung dieser hydrophilen Proteine an die PM dienen. Weiterhin scheinen gleichartige Remorine miteinander zu interagieren. Beispielsweise waren im Zytosol lokalisierte Remorin-Mutanten bei einer gleichzeitigen Expression der entsprechenden Voll{\"a}ngenproteine erneut an der PM zu finden. F{\"u}r die Remorine wurde postuliert, dass sie mit anderen Proteinen interagieren und dabei makromolekulare Strukturen ausbilden. Den Remorinen k{\"o}nnte daher eine Aufgabe bei der molekularen Organisation pflanzlicher Membrandom{\"a}nen zukommen, indem sie ein filamentartiges Netzwerk innerhalb distinkter Dom{\"a}nen ausbilden, das m{\"o}glicherweise zur Stabilit{\"a}t und Aufrechterhaltung dieser spezialisierten Bereiche beitr{\"a}gt. Unter Einbeziehung der STED-Mikroskopie wurde eine empirische Gr{\"o}ßenverteilung von 97±4nm Durchmesser f{\"u}r PM-st{\"a}ndige Dom{\"a}nen in Arabidopsis ermittelt. Hinsichtlich der physiologischen Relevanz konnte gezeigt werden, dass die Dom{\"a}nen eine Rolle bei der ABA-vermittelten, kalziumabh{\"a}ngigen Regulation des Anionenkanals SLAH3 einnehmen. SLAH3 wird durch kalziumabh{\"a}ngige Kinasen aus der CDPK-Familie aktiviert, im Speziellen durch CPK21 und CPK23. Beide Kinasen werden durch die ABA-sensitiven Phosphatasen ABI1 und ABI2 reguliert. Die spezifisch stattfindenden Interaktionen zwischen SLAH3 und CPK21, sowie zwischen CPK21 und ABI1 waren auf Nanodom{\"a}nen beschr{\"a}nkt und wurden durch die Methodik der bimolekularen Fluoreszenzkomplementation erstmals in planta nachgewiesen, mit Remorinen der taxonomischen Gruppe 1b als etablierte Markerproteine f{\"u}r Membrandom{\"a}nen.}, subject = {Plasmamembran}, language = {de} } @article{KoenigWolfHeisenberg2016, author = {Koenig, Sebastian and Wolf, Reinhard and Heisenberg, Martin}, title = {Visual Attention in Flies-Dopamine in the Mushroom Bodies Mediates the After-Effect of Cueing}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0161412}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179564}, year = {2016}, abstract = {Visual environments may simultaneously comprise stimuli of different significance. Often such stimuli require incompatible responses. Selective visual attention allows an animal to respond exclusively to the stimuli at a certain location in the visual field. In the process of establishing its focus of attention the animal can be influenced by external cues. Here we characterize the behavioral properties and neural mechanism of cueing in the fly Drosophila melanogaster. A cue can be attractive, repulsive or ineffective depending upon (e.g.) its visual properties and location in the visual field. Dopamine signaling in the brain is required to maintain the effect of cueing once the cue has disappeared. Raising or lowering dopamine at the synapse abolishes this after-effect. Specifically, dopamine is necessary and sufficient in the αβ-lobes of the mushroom bodies. Evidence is provided for an involvement of the αβ\(_{posterior}\) Kenyon cells.}, language = {en} } @phdthesis{Sareen2011, author = {Sareen, Preeti}, title = {Visual attention in Drosophila melanogaster}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69616}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {There is such vast amount of visual information in our surroundings at any time that filtering out the important information for further processing is a basic requirement for any visual system. This is accomplished by deploying attention to focus on one source of sensory inputs to the exclusion of others (Luck and Mangun 2009). Attention has been studied extensively in humans and non human primates (NHPs). In Drosophila, visual attention was first demonstrated in 1980 (Wolf and Heisenberg 1980) but this field remained largely unexplored until recently. Lately, however, studies have emerged that hypothesize the role of attention in several behaviors but do not specify the characteristic properties of attention. So, the aim of this research was to characterize the phenomenon of visual attention in wild-type Drosophila, including both externally cued and covert attention using tethered flight at a torque meter. Development of systematic quantifiable behavioral tests was a key aspect for this which was not only important for analyzing the behavior of a population of wild-type flies but also for comparing the wild-type flies with mutant flies. The latter would help understand the molecular, genetic, and neuronal bases of attention. Since Drosophila provides handy genetic tools, a model of attention in Drosophila will serve to the greater questions about the neuronal circuitry and mechanisms involved which might be analogous to those in primates. Such a model might later be used in research involving disorders of attention. Attention can be guided to a certain location in the visual field by the use of external cues. Here, using visual cues the attention of the fly was directed to one or the other of the two visual half-fields. A simple yet robust paradigm was designed with which the results were easily quantifiable. This paradigm helped discover several interesting properties of the cued attention, the most substantial one being that this kind of external guidance of attention is restricted to the lower part of the fly's visual field. The guiding cue had an after-effect, i.e. it could occur at least up to 2 seconds before the test and still bias it. The cue could also be spatially separated from the test by at least 20° and yet attract the attention although the extent of the focus of attention (FoA) was smaller than one lower visual half-field. These observations excluded the possibility of any kind of interference between the test and the cue stimuli. Another interesting observation was the essentiality of continuous visibility of the test stimulus but not the cue for effective cuing. When the contrast of the visual scene was inverted, differences in response frequencies and cuing effects were observed. Syndirectional yaw torque responses became more frequent than the antidirectional responses and cuing was no longer effective in the lower visual field with inverted contrast. Interestingly, the test stimulus with simultaneous displacement of two stripes not only effectuated a phasic yaw torque response but also a landing response. A 50 landing response was produced in more than half of the cases whenever a yaw torque response was produced. Elucidation of the neuronal correlates of the cued attention was commenced. Pilot experiments with hydroxyurea (HU) treated flies showed that mushroom bodies were not required for the kind of guidance of attention tested in this study. Dopamine mutants were also tested for the guidance of attention in the lower visual field. Surprisingly, TH-Gal4/UAS-shits1 flies flew like wild-type flies and also showed normal optomotor response during the initial calibration phase of the experiment but did not show any phasic yaw torque or landing response at 18 °C, 25 °C or 30 °C. dumb2 flies that have almost no D1 dopamine receptor dDA1 expression in the mushroom bodies and the central complex (Kim et al. 2007) were also tested and like THGal4/ UAS-shits1 flies did not show any phasic yaw torque or landing response. Since the dopamine mutants did not show the basic yaw torque response for the test the role of dopamine in attention could not be deduced. A different paradigm would be needed to test these mutants. Not only can attention be guided through external cues, it can also be shifted endogenously (covert attention). Experiments with the windows having oscillating stripes nicely demonstrated the phenomenon of covert attention due to the production of a characteristic yaw torque pattern by the flies. However, the results were not easily quantifiable and reproducible thereby calling for a more systematic approach. Experiments with simultaneous opposing displacements of two stripes provide a promising avenue as the results from these experiments showed that the flies had a higher tendency to deliver one type of response than when the responses would be produced stochastically suggesting that attention increased this tendency. Further experiments and analysis of such experiments could shed more light on the mechanisms of covert attention in flies.}, subject = {Visuelle Aufmerksamkeit}, language = {en} } @article{KoenigWolfHeisenberg2016, author = {Koenig, Sebastian and Wolf, Reinhard and Heisenberg, Martin}, title = {Vision in Flies: Measuring the Attention Span}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {2}, doi = {10.1371/journal.pone.0148208}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179947}, year = {2016}, abstract = {A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.}, language = {en} } @article{PatilGentschevAdelfingeretal.2012, author = {Patil, Sandeep S. and Gentschev, Ivaylo and Adelfinger, Marion and Donat, Ulrike and Hess, Michael and Weibel, Stephanie and Nolte, Ingo and Frentzen, Alexa and Szalay, Aladar A.}, title = {Virotherapy of Canine Tumors with Oncolytic Vaccinia Virus GLV-1h109 Expressing an Anti-VEGF Single-Chain Antibody}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047472}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130039}, pages = {e47472}, year = {2012}, abstract = {Virotherapy using oncolytic vaccinia virus (VACV) strains is one promising new strategy for cancer therapy. We have previously reported that oncolytic vaccinia virus strains expressing an anti-VEGF (Vascular Endothelial Growth Factor) single-chain antibody (scAb) GLAF-1 exhibited significant therapeutic efficacy for treatment of human tumor xenografts. Here, we describe the use of oncolytic vaccinia virus GLV-1h109 encoding GLAF-1 for canine cancer therapy. In this study we analyzed the virus-mediated delivery and production of scAb GLAF-1 and the oncolytic and immunological effects of the GLV-1h109 vaccinia virus strain against canine soft tissue sarcoma and canine prostate carcinoma in xenograft models. Cell culture data demonstrated that the GLV-1h109 virus efficiently infect, replicate in and destroy both tested canine cancer cell lines. In addition, successful expression of GLAF-1 was demonstrated in virus-infected canine cancer cells and the antibody specifically recognized canine VEGF. In two different xenograft models, the systemic administration of the GLV-1h109 virus was found to be safe and led to anti-tumor and immunological effects resulting in the significant reduction of tumor growth in comparison to untreated control mice. Furthermore, tumor-specific virus infection led to a continued production of functional scAb GLAF-1, resulting in inhibition of angiogenesis. Overall, the GLV-1h109-mediated cancer therapy and production of immunotherapeutic anti-VEGF scAb may open the way for combination therapy concept i.e. vaccinia virus mediated oncolysis and intratumoral production of therapeutic drugs in canine cancer patients.}, language = {en} } @article{GholamiChenBelinetal.2013, author = {Gholami, Sepideh and Chen, Chun-Hao and Belin, Laurence J. and Lou, Emil and Fujisawa, Sho and Antonacci, Caroline and Carew, Amanda and Chen, Nanhai G. and De Brot, Marina and Zanzonico, Pat B. and Szalay, Aladar A. and Fong, Yuman}, title = {Vaccinia virus GLV-1h153 is a novel agent for detection and effective local control of positive surgical margins for breast cancer}, series = {Breast Cancer Research}, volume = {15}, journal = {Breast Cancer Research}, number = {R26}, doi = {10.1186/bcr3404}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122140}, year = {2013}, abstract = {Introduction: Surgery is currently the definitive treatment for early-stage breast cancer. However, the rate of positive surgical margins remains unacceptably high. The human sodium iodide symporter (hNIS) is a naturally occurring protein in human thyroid tissue, which enables cells to concentrate radionuclides. The hNIS has been exploited to image and treat thyroid cancer. We therefore investigated the potential of a novel oncolytic vaccinia virus GLV1h-153 engineered to express the hNIS gene for identifying positive surgical margins after tumor resection via positron emission tomography (PET). Furthermore, we studied its role as an adjuvant therapeutic agent in achieving local control of remaining tumors in an orthotopic breast cancer model. Methods: GLV-1h153, a replication-competent vaccinia virus, was tested against breast cancer cell lines at various multiplicities of infection (MOIs). Cytotoxicity and viral replication were determined. Mammary fat pad tumors were generated in athymic nude mice. To determine the utility of GLV-1h153 in identifying positive surgical margins, 90\% of the mammary fat pad tumors were surgically resected and subsequently injected with GLV-1h153 or phosphate buffered saline (PBS) in the surgical wound. Serial Focus 120 microPET images were obtained six hours post-tail vein injection of approximately 600 mu Ci of I-124-iodide. Results: Viral infectivity, measured by green fluorescent protein (GFP) expression, was time-and concentrationdependent. All cell lines showed less than 10\% of cell survival five days after treatment at an MOI of 5. GLV-1h153 replicated efficiently in all cell lines with a peak titer of 27 million viral plaque forming units (PFU) ( < 10,000-fold increase from the initial viral dose) by Day 4. Administration of GLV-1h153 into the surgical wound allowed positive surgical margins to be identified via PET scanning. In vivo, mean volume of infected surgically resected residual tumors four weeks after treatment was 14 mm(3) versus 168 mm(3) in untreated controls (P < 0.05). Conclusions: This is the first study to our knowledge to demonstrate a novel vaccinia virus carrying hNIS as an imaging tool in identifying positive surgical margins of breast cancers in an orthotopic murine model. Moreover, our results suggest that GLV-1h153 is a promising therapeutic agent in achieving local control for positive surgical margins in resected breast tumors.}, language = {en} } @article{BarcenaUribarriTheinMaieretal.2013, author = {B{\´a}rcena-Uribarri, Iv{\´a}n and Thein, Marcus and Maier, Elke and Bonde, Mari and Bergstr{\"o}m, Sven and Benz, Roland}, title = {Use of Nonelectrolytes Reveals the Channel Size and Oligomeric Constitution of the Borrelia burgdorferi P66 Porin}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0078272}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129965}, pages = {e78272}, year = {2013}, abstract = {In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. We studied the diameter of the P66 channel by analyzing its single-channel conductance in black lipid bilayers in the presence of different nonelectrolytes with known hydrodynamic radii. We calculated the filling of the channel with these nonelectrolytes and the results suggested that nonelectrolytes (NEs) with hydrodynamic radii of 0.34 nm or smaller pass through the pore, whereas neutral molecules with greater radii only partially filled the channel or were not able to enter it at all. The diameter of the entrance of the P66 channel was determined to be \(\leq\)1.9 nm and the channel has a central constriction of about 0.8 nm. The size of the channel appeared to be symmetrical as judged from one-sidedness of addition of NEs. Furthermore, the P66-induced membrane conductance could be blocked by 80-90\% by the addition of the nonelectrolytes PEG 400, PEG 600 and maltohexaose to the aqueous phase in the low millimolar range. The analysis of the power density spectra of ion current through P66 after blockage with these NEs revealed no chemical reaction responsible for channel block. Interestingly, the blockage of the single-channel conductance of P66 by these NEs occurred in about eight subconductance states, indicating that the P66 channel could be an oligomer of about eight individual channels. The organization of P66 as a possible octamer was confirmed by Blue Native PAGE and immunoblot analysis, which both demonstrated that P66 forms a complex with a mass of approximately 460 kDa. Two dimension SDS PAGE revealed that P66 is the only polypeptide in the complex.}, language = {en} }