@article{DotterweichTowerBrandletal.2016, author = {Dotterweich, Julia and Tower, Robert J. and Brandl, Andreas and M{\"u}ller, Marc and Hofbauer, Lorenz C. and Beilhack, Andreas and Ebert, Regina and Gl{\"u}er, Claus C. and Tiwari, Sanjay and Sch{\"u}tze, Norbert and Jakob, Franz}, title = {The KISS1 Receptor as an In Vivo Microenvironment Imaging Biomarker of Multiple Myeloma Bone Disease}, series = {PLoS One}, volume = {11}, journal = {PLoS One}, number = {5}, doi = {10.1371/journal.pone.0155087}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146960}, pages = {e0155087}, year = {2016}, abstract = {Multiple myeloma is one of the most common hematological diseases and is characterized by an aberrant proliferation of plasma cells within the bone marrow. As a result of crosstalk between cancer cells and the bone microenvironment, bone homeostasis is disrupted leading to osteolytic lesions and poor prognosis. Current diagnostic strategies for myeloma typically rely on detection of excess monoclonal immunoglobulins or light chains in the urine or serum. However, these strategies fail to localize the sites of malignancies. In this study we sought to identify novel biomarkers of myeloma bone disease which could target the malignant cells and/or the surrounding cells of the tumor microenvironment. From these studies, the KISS1 receptor (KISS1R), a G-protein-coupled receptor known to play a role in the regulation of endocrine functions, was identified as a target gene that was upregulated on mesenchymal stem cells (MSCs) and osteoprogenitor cells (OPCs) when co-cultured with myeloma cells. To determine the potential of this receptor as a biomarker, in vitro and in vivo studies were performed with the KISS1R ligand, kisspeptin, conjugated with a fluorescent dye. In vitro microscopy showed binding of fluorescently-labeled kisspeptin to both myeloma cells as well as MSCs under direct co-culture conditions. Next, conjugated kisspeptin was injected into immune-competent mice containing myeloma bone lesions. Tumor-burdened limbs showed increased peak fluorescence compared to contralateral controls. These data suggest the utility of the KISS1R as a novel biomarker for multiple myeloma, capable of targeting both tumor cells and host cells of the tumor microenvironment.}, language = {en} } @article{SimsekyilmazLiehnWeinandyetal.2016, author = {Simsekyilmaz, Sakine and Liehn, Elisa A. and Weinandy, Stefan and Schreiber, Fabian and Megens, Remco T. A. and Theelen, Wendy and Smeets, Ralf and Jockenh{\"o}vel, Stefan and Gries, Thomas and M{\"o}ller, Martin and Klee, Doris and Weber, Christian and Zernecke, Alma}, title = {Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {5}, doi = {10.1371/journal.pone.0155829}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179745}, year = {2016}, abstract = {Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE\(^{-/-}\) carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.}, language = {en} } @article{LaineAlbeckavandeLindeetal.2015, author = {Laine, Romain F. and Albecka, Anna and van de Linde, Sebastian and Rees, Eric J. and Crump, Colin M. and Kaminski, Clemens F.}, title = {Structural analysis of herpes simplex virus by optical super-resolution imaging}, series = {Nature Communications}, volume = {6}, journal = {Nature Communications}, number = {5980}, doi = {10.1038/ncomms6980}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144623}, year = {2015}, abstract = {Herpes simplex virus type-1 (HSV-1) is one of the most widespread pathogens among humans. Although the structure of HSV-1 has been extensively investigated, the precise organization of tegument and envelope proteins remains elusive. Here we use super-resolution imaging by direct stochastic optical reconstruction microscopy (dSTORM) in combination with a model-based analysis of single-molecule localization data, to determine the position of protein layers within virus particles. We resolve different protein layers within individual HSV-1 particles using multi-colour dSTORM imaging and discriminate envelope-anchored glycoproteins from tegument proteins, both in purified virions and in virions present in infected cells. Precise characterization of HSV-1 structure was achieved by particle averaging of purified viruses and model-based analysis of the radial distribution of the tegument proteins VP16, VP1/2 and pUL37, and envelope protein gD. From this data, we propose a model of the protein organization inside the tegument.}, language = {en} } @article{SchneiderKleinMielichSuessetal.2015, author = {Schneider, Johannes and Klein, Teresa and Mielich-S{\"u}ss, Benjamin and Koch, Gudrun and Franke, Christian and Kuipers, Oskar P. and Kov{\´a}cs, {\´A}kos T. and Sauer, Markus and Lopez, Daniel}, title = {Spatio-temporal Remodeling of Functional Membrane Microdomains Organizes the Signaling Networks of a Bacterium}, series = {PLoS Genetics}, volume = {11}, journal = {PLoS Genetics}, number = {4}, doi = {10.1371/journal.pgen.1005140}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125577}, pages = {e1005140}, year = {2015}, abstract = {Lipid rafts are membrane microdomains specialized in the regulation of numerous cellular processes related to membrane organization, as diverse as signal transduction, protein sorting, membrane trafficking or pathogen invasion. It has been proposed that this functional diversity would require a heterogeneous population of raft domains with varying compositions. However, a mechanism for such diversification is not known. We recently discovered that bacterial membranes organize their signal transduction pathways in functional membrane microdomains (FMMs) that are structurally and functionally similar to the eukaryotic lipid rafts. In this report, we took advantage of the tractability of the prokaryotic model Bacillus subtilis to provide evidence for the coexistence of two distinct families of FMMs in bacterial membranes, displaying a distinctive distribution of proteins specialized in different biological processes. One family of microdomains harbors the scaffolding flotillin protein FloA that selectively tethers proteins specialized in regulating cell envelope turnover and primary metabolism. A second population of microdomains containing the two scaffolding flotillins, FloA and FloT, arises exclusively at later stages of cell growth and specializes in adaptation of cells to stationary phase. Importantly, the diversification of membrane microdomains does not occur arbitrarily. We discovered that bacterial cells control the spatio-temporal remodeling of microdomains by restricting the activation of FloT expression to stationary phase. This regulation ensures a sequential assembly of functionally specialized membrane microdomains to strategically organize signaling networks at the right time during the lifespan of a bacterium.}, language = {en} } @article{WeibelBasseLuesebrinkHessetal.2013, author = {Weibel, Stephanie and Basse-Luesebrink, Thomas Christian and Hess, Michael and Hofmann, Elisabeth and Seubert, Carolin and Langbein-Laugwitz, Johanna and Gentschev, Ivaylo and Sturm, Volker J{\"o}rg Friedrich and Ye, Yuxiang and Kampf, Thomas and Jakob, Peter Michael and Szalay, Aladar A.}, title = {Imaging of Intratumoral Inflammation during Oncolytic Virotherapy of Tumors by \(^{19}\)F-Magnetic Resonance Imaging (MRI)}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0056317}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130311}, pages = {e56317}, year = {2013}, abstract = {Background Oncolytic virotherapy of tumors is an up-coming, promising therapeutic modality of cancer therapy. Unfortunately, non-invasive techniques to evaluate the inflammatory host response to treatment are rare. Here, we evaluate \(^{19}\)F magnetic resonance imaging (MRI) which enables the non-invasive visualization of inflammatory processes in pathological conditions by the use of perfluorocarbon nanoemulsions (PFC) for monitoring of oncolytic virotherapy. Methodology/Principal Findings The Vaccinia virus strain GLV-1h68 was used as an oncolytic agent for the treatment of different tumor models. Systemic application of PFC emulsions followed by \(^1H\)/\(^{19}\)F MRI of mock-infected and GLV-1h68-infected tumor-bearing mice revealed a significant accumulation of the \(^{19}\)F signal in the tumor rim of virus-treated mice. Histological examination of tumors confirmed a similar spatial distribution of the \(^{19}\)F signal hot spots and \(CD68^+\)-macrophages. Thereby, the \(CD68^+\)-macrophages encapsulate the GFP-positive viral infection foci. In multiple tumor models, we specifically visualized early inflammatory cell recruitment in Vaccinia virus colonized tumors. Furthermore, we documented that the \(^{19}\)F signal correlated with the extent of viral spreading within tumors. Conclusions/Significance These results suggest \(^{19}\)F MRI as a non-invasive methodology to document the tumor-associated host immune response as well as the extent of intratumoral viral replication. Thus, \(^{19}\)F MRI represents a new platform to non-invasively investigate the role of the host immune response for therapeutic outcome of oncolytic virotherapy and individual patient response.}, language = {en} } @article{GoetzPanzerTrinksetal.2020, author = {G{\"o}tz, Ralph and Panzer, Sabine and Trinks, Nora and Eilts, Janna and Wagener, Johannes and Turr{\`a}, David and Di Pietro, Antonio and Sauer, Markus and Terpitz, Ulrich}, title = {Expansion Microscopy for Cell Biology Analysis in Fungi}, series = {Frontiers in Microbiology}, volume = {11}, journal = {Frontiers in Microbiology}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.00574}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202569}, year = {2020}, abstract = {Super-resolution microscopy has evolved as a powerful method for subdiffraction-resolution fluorescence imaging of cells and cellular organelles, but requires sophisticated and expensive installations. Expansion microscopy (ExM), which is based on the physical expansion of the cellular structure of interest, provides a cheap alternative to bypass the diffraction limit and enable super-resolution imaging on a conventional fluorescence microscope. While ExM has shown impressive results for the magnified visualization of proteins and RNAs in cells and tissues, it has not yet been applied in fungi, mainly due to their complex cell wall. Here we developed a method that enables reliable isotropic expansion of ascomycetes and basidiomycetes upon treatment with cell wall degrading enzymes. Confocal laser scanning microscopy (CLSM) and structured illumination microscopy (SIM) images of 4.5-fold expanded sporidia of Ustilago maydis expressing fluorescent fungal rhodopsins and hyphae of Fusarium oxysporum or Aspergillus fumigatus expressing either histone H1-mCherry together with Lifeact-sGFP or mRFP targeted to mitochondria, revealed details of subcellular structures with an estimated spatial resolution of around 30 nm. ExM is thus well suited for cell biology studies in fungi on conventional fluorescence microscopes.}, language = {en} } @article{ProppertWolterHolmetal.2014, author = {Proppert, Sven and Wolter, Steve and Holm, Thorge and Klein, Theresa and van de Linde, Sebastian and Sauer, Markus}, title = {Cubic B-spline calibration for 3D super-resolution measurements using astigmatic imaging}, series = {Optics Express}, volume = {22}, journal = {Optics Express}, number = {9}, issn = {1094-4087}, doi = {10.1364/OE.22.010304}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119730}, pages = {10304-16}, year = {2014}, abstract = {In recent years three-dimensional (3D) super-resolution fluorescence imaging by single-molecule localization (localization microscopy) has gained considerable interest because of its simple implementation and high optical resolution. Astigmatic and biplane imaging are experimentally simple methods to engineer a 3D-specific point spread function (PSF), but existing evaluation methods have proven problematic in practical application. Here we introduce the use of cubic B-splines to model the relationship of axial position and PSF width in the above mentioned approaches and compare the performance with existing methods. We show that cubic B-splines are the first method that can combine precision, accuracy and simplicity.}, language = {en} } @article{ShityakovSalvadorPastorinetal.2015, author = {Shityakov, Sergey and Salvador, Ellaine and Pastorin, Giorgia and F{\"o}rster, Carola}, title = {Blood-brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate}, series = {International Journal of Nanomedicine}, volume = {10}, journal = {International Journal of Nanomedicine}, doi = {10.2147/IJN.S68429}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149233}, pages = {1703-1713}, year = {2015}, abstract = {In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell® system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCN-TFITC rapid dissociation as an intermediate phase.}, language = {en} }