TY - JOUR A1 - Reschke, Moritz A1 - Salvador, Ellaine A1 - Schlegel, Nicolas A1 - Burek, Malgorzata A1 - Karnati, Srikanth A1 - Wunder, Christian A1 - Förster, Carola Y. T1 - Isosteviol sodium (STVNA) reduces pro-inflammatory cytokine IL-6 and GM-CSF in an in vitro murine stroke model of the blood–brain barrier (BBB) JF - Pharmaceutics N2 - Early treatment with glucocorticoids could help reduce both cytotoxic and vasogenic edema, leading to improved clinical outcome after stroke. In our previous study, isosteviol sodium (STVNA) demonstrated neuroprotective effects in an in vitro stroke model, which utilizes oxygen-glucose deprivation (OGD). Herein, we tested the hypothesis that STVNA can activate glucocorticoid receptor (GR) transcriptional activity in brain microvascular endothelial cells (BMECs) as previously published for T cells. STVNA exhibited no effects on transcriptional activation of the glucocorticoid receptor, contrary to previous reports in Jurkat cells. However, similar to dexamethasone, STVNA inhibited inflammatory marker IL-6 as well as granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. Based on these results, STVNA proves to be beneficial as a possible prevention and treatment modality for brain ischemia-reperfusion injury-induced blood–brain barrier (BBB) dysfunction. KW - IL-6 KW - ischemia KW - isosteviol sodium (STVNA) KW - dexamethasone KW - glucocorticoid receptor KW - cerebEND Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286275 SN - 1999-4923 VL - 14 IS - 9 ER - TY - THES A1 - Arndt, Petra T1 - Klonierung und funktionelle Charakterisierung von organischen Kationentransportern aus der Rattenniere T1 - Cloning and functional characterization of organic cation transporters from rat kidney N2 - Der organische Kationentransport im proximalen Tubulus der Niere spielt eine wichtige Rolle bei der Aufrechterhaltung der Homöostase der Körperflüssigkeiten und der Ausschleusung von toxischen organischen Kationen. Der Transport von organischen Kationen wird an der Bürstensaummembran durch den H+/organische Kationen-Austauscher vermittelt, während bei dem Transport von organischen Kationen an der basolateralen Membran das nach innen gerichtete negative Membranpotential eine treibende Kraft darstellt. Durch Expressionsklonierung wurde der erste organische Kationentransporter, rOCT1, aus der Rattenniere isoliert. Kurz darauf wurde im Rahmen dieser Arbeit ein zweiter organischer Kationentransporter ebenfalls aus der Ratenniere kloniert. rOCT2 besteht aus 593 Aminosäuren und besitzt 12 putative Transmembrandomänen. Zum funktionellen Vergleich zwischen rOCT1 und rOCT2 wurde das Oozytenexpressionssystem verwendet. In der vorliegenden Arbeit wurde ein pharmakologisches Profil von rOCT2 erstellt. Das Substratsprektrum von rOCT2 ist dem von rOCT1 sehr ähnlich. Die Affinitäten von rOCT2 gegenüber verschiedenen Substanzen wurden direkt mit denen von rOCT1 verglichen. Einerseits fanden wir bei einigen Substraten Unterschiede in den Km- und Vmax-Werten, aber andererseits auch viele Ähnlichkeiten zwischen beiden Transportern. Anionen (z. B. p-Aminohippurat) wurden als neue Gruppe von Inhibitoren für den durch rOCT1- und rOCT2-vermittelten Transport identifiziert. Die Potentialdifferenz ist die treibende Kraft des rOCT1- und rOCT2-vermittelten Transportes. Wir konnten potentialabhängige Veränderungen der Km-Werte von Cholin-induzierten Einwärtsströmen zeigen. Bei dem Austausch von Na+-Ionen gegen K+-Ionen im Reaktionspuffer wurde die Aufnahme von Cholin und MPP durch rOCT2 erniedrigt. Der bidirektionale Transport von MPP wurde gezeigt und trans-Stimulationsexperimente für MPP-Influx und MPP-Efflux durchgeführt, um die Asymmetrie des Transporters zu studieren. Darüberhinaus wurde in der vorliegenden Arbeit die Interaktion von verschiedenen Substraten mit rOCT1 und rOCT2 untersucht und ein kompetitver und nicht-kompetitiver Hemmtyp bei der TEA-Aufnahme gefunden. N2 - Organic cation transport in the renal tubule is an important physiological function for the maintenance of body fluid homeostasis and detoxification of harmful organic cations. In general, transport of organic cations in brush-border membranes is mediated by the H+/organic cation antiporter, whereas transport of organic cations in basolateral membranes is stimulated by the inside-negative membrane potential. By the expression cloning method, the organic cation transporter rOCT1, which is expressed in rat liver and kidney, was isolated. In 1996 another organic cation transporter from rat kidney, rOCT2, was isolated by homology cloning. rOCT2 was deduced to be a glycoprotein comprised of 593 amino acid residues with 12 putative transmembrane domains. To analyse the functional characteristics of rOCT2 in comparison with rOCT1 we utilized the Xenopus expression system. During this dissertation a pharmacological profile was made for rOCT2. The apparent substrate spectrum of rOCT2 was similar to that of rOCT1. Affinities of rOCT2 against several compounds were directly compared with those of rOCT1. We found differences in Km- and IC50-values for distinct substrates but also a lot of similarities between both transporters. Anions like p-aminohippuric acid were identified as a new group of inhibitors for rOCT1- and rOCT2-mediated transport. The potential difference is the driving force of transport mediated by rOCT1 and rOCT2. We showed the potential-dependent changes of Km-values of choline induced inward currents. Further when extracellular Na+ ions were replaced with K+ ions, the uptake of MPP and choline by rOCT2 was decreased. The bidirectional transport of MPP was shown and trans-sitmulation experiments for MPP influx and efflux were performed to study asymmetry of the transporter. The mechanism of interaction of several substrates with rOCT1 and rOCT2 were investigated and we found competitive and non-competitive inhibition of TEA uptake. KW - Ratte KW - Niere KW - Kation KW - Stofftransport KW - Molekularbiologie KW - rOCT1 KW - rOCT2 KW - proximaler Tubulus KW - Niere KW - Sekretion KW - Xenopus laevis KW - Oozyte KW - Transport KW - Inhibition KW - Homologieklonierung KW - rOCT1 KW - rOCT2 KW - proximal tubule KW - kidney KW - secretion KW - Xenopus laevis KW - oocyte KW - transport KW - inhibition KW - homology cloning Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-793 ER - TY - THES A1 - Groth, Sofie Claire T1 - Korrelation der Elastizität von Rückenmarksgewebe und histologischen Veränderungen in einem Tiermodell der Multiplen Sklerose T1 - Correlation of elasticity of spinal cord tissues and histological changes in an animal model of multiple sclerosis N2 - Multiple Sklerose ist eine der häufigsten und bedeutsamsten entzündlichen Autoimmunerkrankungen bei jungen Erwachsenen. Obwohl die klassischen Kennzeichen der Krankheit wie Infiltration von Immunzellen, Demyelinisierung, Astrogliose und axonale Schädigung bekannt sind, sind die genauen Ursachen und die zugrundeliegende Pathophysiologie noch nicht geklärt. In der Fachliteratur wurden bereits biomechanische Veränderungen mit histologischen Veränderungen im ZNS in Verbindung gebracht. Der genaue Zusammenhang und das Ausmaß zwischen den mechanischen Gewebeeigenschaften und den zugrundeliegenden histologischen Veränderungen wurde bis heute jedoch nur wenig erforscht. Die vorliegende Arbeit untersuchte in ihrem methodischen Rahmen den möglichen Zusammenhang zwischen den mechanischen Veränderungen des Gewebes und den zugrundeliegenden histologischen Gewebeveränderungen in den unterschiedlichen Krankheitsstadien der EAE, dem Tiermodell der MS. Die hier dargestellten Experimente konnten demonstrieren, dass das ZNS-Gewebe durch zunehmende Zelldichte steifer wird, während es bei fortschreitender Demyelinisierung zur Erweichung des Gewebes kommt. Ferner wurden die mechanischen Gewebeeigenschaften in den unterschiedlichen Krankheitsstadien der EAE durch die Astrogliose und die Mikroglia/Makrophageninfiltration beeinflusst. N2 - Multiple sclerosis is one of the most frequent and significant autoimmune inflammatory diseases in young adults. Although the classic hallmarks of the disease, such as immune cell infiltration, demyelination, gliosis and axonal damage, are known, the causes and underlying pathophysiology remain largely elusive. In recent studies biomechanical changes have already been associated with histological changes in the CNS. However, the correlation between tissue stiffness and the underlying structural changes is currently poorly understood. In this thesis I investigated how tissue stiffness is linked to the underlying structural changes during the different stages of an experimental autoimmune encephalomyelitis mouse model of MS. My data indicate that an increase in cell density leads to an increase in the CNS tissue stiffness, while demyelination reduces tissue stiffness. Furthermore, the mechanical properties were influenced by gliosis and microglia / macrophage infiltration. KW - Multiple Sklerose KW - Experimentelle autoimmune Enzepahlomyelitis KW - Biomechanische Eigenschaften KW - Immunhistochemie KW - Multiple sclerosis KW - Experimental autoimmune encephalomyelitis KW - Biomechanical properties KW - immunohistochemistry Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-179370 ER - TY - JOUR A1 - Dunkel, Franz T1 - Lectotypisierung von Ranunculus puberulus W. Koch – eine verkannte Art aus dem Ranunculus auricomus-Komplex N2 - Die Beschreibung von Ranunculus puberulus W. Koch erfolgte bereits 1933. Walo Koch bestimmte in der Folge eine Vielzahl von Belegen zum Teil deutlich verschiedener Taxa als R. puberulus. In Übereinstimmung mit den Arbeiten von Borchers-Kolb 1985 und Brodtbeck 1988 wird unter Hinzuziehung der publizierten Diagnose ein Lectotypus aus der Originalsammlung von Kummer & Koch von Hilzingen, Baden-Württemberg, ausgewählt und abgebildet. Anhand von rezenten Aufsammlungen an der Typuslokalität wird R. puberulus nach inzwischen standardisierten Kriterien charakterisiert und dargestellt. R. puberulus ist durch eine feine unregelmäßige Zähnung der Schlussblätter auffällig und stellt im Gegensatz zur weit verbreiteten Auffassung einen Endemiten des Hegau im südwestlichsten Deutschland dar. Insgesamt sind zur Zeit nur zwei Populationen bekannt, so dass für die Art zumindest eine starke Gefährdung anzunehmen ist. N2 - Ranunculus puberulus was described by Walo Koch as early as 1933. Consequently, he identified a multitude of specimens obviously belonging to different taxa as R. puberulus. In concordance with the opinion of Borchers-Kolb (1985) and Brodtbeck (1988) a lectotype was chosen and depicted from the specimens of Hilzingen, Baden-Württemberg, collected by Kummer & Koch in 1928. Recent collections of the type locality were used to characterise R. puberulus in detail. A fine irregular dentated leaf edge of the final basal leaves is striking. In contrast to the prevailing opinion, R. puberulus is not a widespread species but a local endemic of the Hegau in southwestern Germany. Currently, there are only two populations known and R. puberulus is at least severely endangered. KW - Ranunculus puberulus KW - Lectotypus KW - lectotype KW - taxonomy KW - Taxonomie Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-108834 UR - http://www.forum-geobotanicum.net/articles/vol_6-2012/dunkel_r_puberulus/2015_Dunkel_R_puberulus.pdf SN - 1867-9315 ER - TY - JOUR A1 - Thangaraj Selvaraj, Bhuvaneish A1 - Frank, Nicolas A1 - Bender, Florian L. P. A1 - Asan, Esther A1 - Sendtner, Michael T1 - Local axonal function of STAT3 rescues axon degeneration in the pmn model of motoneuron disease JF - The Journal of Cell Biology N2 - Axonal maintenance, plasticity, and regeneration are influenced by signals from neighboring cells, in particular Schwann cells of the peripheral nervous system. Schwann cells produce neurotrophic factors, but the mechanisms by which ciliary neurotrophic factor (CNTF) and other neurotrophic molecules modify the axonal cytoskeleton are not well understood. In this paper, we show that activated signal transducer and activator of transcription-3 (STAT3), an intracellular mediator of the effects of CNTF and other neurotrophic cytokines, acts locally in axons of motoneurons to modify the tubulin cytoskeleton. Specifically, we show that activated STAT3 interacted with stathmin and inhibited its microtubule-destabilizing activity. Thus, ectopic CNTF-mediated activation of STAT3 restored axon elongation and maintenance in motoneurons from progressive motor neuronopathy mutant mice, a mouse model of motoneuron disease. This mechanism could also be relevant for other neurodegenerative diseases and provide a target for new therapies for axonal degeneration. KW - Schwann cells KW - transcription-3 (STAT3) KW - ciliary neurotrophic factor (CNTF) KW - axonal degeneration Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-154675 VL - 199 IS - 3 SP - 437 EP - 451 ER - TY - THES A1 - Smul, Thorsten T1 - Lokalisation von hochaffinen Glutamattransportern in verschiedenen ZNS-Regionen der Maus T1 - Localization of high-affinity glutamate transporters in different regions of the murine central nervous system N2 - Um das Transmittersignal von Glutamat zu beenden und eine neurotoxische Anreicherung zu verhindern, muss Glutamat aus dem Extrazellularraum des ZNS entfernt werden. Dafür sind die hochaffinen Glutamattransporter in Gliazellen und Neuronen zuständig, die Glutamat aus dem Extrazellularraum aufnehmen. In der vorliegenden Arbeit wurde die regionale und zelluläre Verteilung der Glutamattransporter GLT1, GLAST und EAAC1 in Hippocampus, Kleinhirn und Rückenmark von Maus und Ratte untersucht. Als Nachweismethoden wurden Western Blot-Analysen und immunhistochemische Nachweise an fixierten Kryostatschnitten und Semidünnschnitten von gefriergetrockneten Geweben eingesetzt. N2 - L-glutamate is the major excitatory transmitter in the vertebrate central nervous system (CNS). Glutamate is removed from the extracellular space by high-affinity transporters (e.g. GLT1, GLAST, EAAC1). In this study the regional and cellular distribution of these glutamate transporters has been examined in the CNS of mouse and rat using immunocytochemistry and immunoblotting methods. KW - Glutamattransporter KW - GLT1 KW - GLAST KW - EAAC1 KW - glutamate transporter KW - GLT1 KW - GLAST KW - EAAC1 Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-13971 ER - TY - THES A1 - Meier-Stiegen, Anna Sofia T1 - Lokalisierung und Charakterisierung von Zellkontaktproteinen im olfaktorischen Epithel T1 - localisation and characterisation of cell adhesion proteins in olfactory epithelium N2 - Ziel der vorliegenden Arbeit war die Lokalisierung und Charakterisierung von Zellkontaktproteinen im olfaktorischen Epithel. Hierzu wurde die Riechschleimhaut der Ratte für immunhistochemische, elektronenmikroskopische und biochemische Experimente aufbereitet. Nachdem das Erscheinungsbild der verschiedenen Interzellularkontakte im histologischen Schnitt charakterisiert worden war, wurde durch die Detektion von Transmembranproteinen, zytoplasmatischen Plaqueproteinen und spezifischen Markermolekülen die genaue zelltypspezifische Zusammensetzung der Zellkontakte dargestellt. N2 - localisation and characterisation of cell adhesion proteins in olfactory epithelium KW - Zellkontaktproteine KW - olfaktorisches Epithel KW - Lokalisierung KW - Charakterisierung KW - cell adhesion proteins KW - olfactory epithelium KW - localisation KW - characterisation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-12209 ER - TY - JOUR A1 - Werner, Rudolf A1 - Wakabayashi, Hiroshi A1 - Bauer, Jochen A1 - Schütz, Claudia A1 - Zechmeister, Christina A1 - Hayakawa, Nobuyuki A1 - Javadi, Mehrbod S. A1 - Lapa, Constantin A1 - Jahns, Roland A1 - Ergün, Süleyman A1 - Jahns, Valerie A1 - Higuchi, Takahiro T1 - Longitudinal \(^{18}\)F-FDG PET imaging in a Rat Model of Autoimmune Myocarditis JF - European Heart Journal Cardiovascular Imaging N2 - Aims: Although mortality rate is very high, diagnosis of acute myocarditis remains challenging with conventional tests. We aimed to elucidate the potential role of longitudinal 2-Deoxy-2-\(^{18}\)F-fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography (PET) inflammation monitoring in a rat model of experimental autoimmune myocarditis. Methods and results: Autoimmune myocarditis was induced in Lewis rats by immunizing with porcine cardiac myosin emulsified in complete Freund’s adjuvant. Time course of disease was assessed by longitudinal \(^{18}\)F-FDG PET imaging. A correlative analysis between in- and ex vivo \(^{18}\)F-FDG signalling and macrophage infiltration using CD68 staining was conducted. Finally, immunohistochemistry analysis of the cell-adhesion markers CD34 and CD44 was performed at different disease stages determined by longitudinal \(^{18}\)F-FDG PET imaging. After immunization, myocarditis rats revealed a temporal increase in 18F-FDG uptake (peaked at week 3), which was followed by a rapid decline thereafter. Localization of CD68 positive cells was well correlated with in vivo \(^{18}\)F-FDG PET signalling (R\(^2\) = 0.92) as well as with ex vivo 18F-FDG autoradiography (R\(^2\) = 0.9, P < 0.001, respectively). CD44 positivity was primarily observed at tissue samples obtained at acute phase (i.e. at peak 18F-FDG uptake), while CD34-positive staining areas were predominantly identified in samples harvested at both sub-acute and chronic phases (i.e. at \(^{18}\)F-FDG decrease). Conclusion: \(^{18}\)F-FDG PET imaging can provide non-invasive serial monitoring of cardiac inflammation in a rat model of acute myocarditis. KW - positron emission tomography KW - Myokarditis KW - myocarditis KW - inflammation KW - 18F-FDG KW - PET KW - personalized treatment Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165601 SN - 2047-2404 ER - TY - JOUR A1 - Rossow, Leonie A1 - Veitl, Simona A1 - Vorlová, Sandra A1 - Wax, Jacqueline K. A1 - Kuhn, Anja E. A1 - Maltzahn, Verena A1 - Upcin, Berin A1 - Karl, Franziska A1 - Hoffmann, Helene A1 - Gätzner, Sabine A1 - Kallius, Matthias A1 - Nandigama, Rajender A1 - Scheld, Daniela A1 - Irmak, Ster A1 - Herterich, Sabine A1 - Zernecke, Alma A1 - Ergün, Süleyman A1 - Henke, Erik T1 - LOX-catalyzed collagen stabilization is a proximal cause for intrinsic resistance to chemotherapy JF - Oncogene N2 - The potential of altering the tumor ECM to improve drug response remains fairly unexplored. To identify targets for modification of the ECM aiming to improve drug response and overcome resistance, we analyzed expression data sets from pre-treatment patient cohorts. Cross-evaluation identified a subset of chemoresistant tumors characterized by increased expression of collagens and collagen-stabilizing enzymes. We demonstrate that strong collagen expression and stabilization sets off a vicious circle of self-propagating hypoxia, malignant signaling, and aberrant angiogenesis that can be broken by an appropriate auxiliary intervention: Interfering with collagen stabilization by inhibition of lysyl oxidases significantly enhanced response to chemotherapy in various tumor models, even in metastatic disease. Inhibition of collagen stabilization by itself can reduce or enhance tumor growth depending on the tumor type. The mechanistical basis for this behavior is the dependence of the individual tumor on nutritional supply on one hand and on high tissue stiffness for FAK signaling on the other. KW - Cancer models KW - Cancer therapeutic resistance KW - Targeted therapies KW - Tumour angiogenesis Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227008 VL - 37 ER - TY - THES A1 - Filatova, Alina T1 - Mechanism and Control of Nuclear-Cytoplasmic Translocation of the Transporter Regulator RS1 T1 - Mechanismus und Kontrolle der Translokation der Transporterregulator RS1 zwischen Kern und Zytoplasma N2 - Das RS1 Protein (Gen RSC1A1) beteiligt sich an der Regulation des Na+-D-Glukose-kotransporters SGLT1 und einiger anderer Transporter. In subkonfluenten LLC-PK1 Zellen hemmt RS1 die Freisetzung von SGLT1 aus dem trans-Golgi-Netzwerk und die Transkription von SGLT1. Während es sich in konfluenten Zellen hauptsächlich im Zytoplasma befindet, ist RS1 in subkonfluenten Zellen im Kern und im Zytoplasma lokalisiert. In der vorliegenden Arbeit wurden Mechanismus und Regulation der konfluenzabhängigen Kernlokalisation von RS1 untersucht. Dabel konnte gezeigt werden, dass die von Konfluenz abhängige Kernlokalisation von RS1 durch den Zellzyklus reguliert wird. In RS1 aus Sus scrofa (pRS1) wurde eine Sequenz identifiziert („nuclear shuttling signal“, NS), die für die konfluenzabhängige Verteilung von RS1 verantwortlich ist und sowohl das Signal für die Kernlokalisation (NLS) als auch das Signal für den Export aus dem Kern (NES) beinhaltet. Die NLS und NES Signale von RS1 vermitteln die Translokation des Proteins in den Kern und aus dem Kern mit Hilfe von Importin β1 bzw. CRM1, wobei die Verteilung von RS1 zwischen Kern und Zytoplasma durch die Aktivität des Exportsystems bestimmt wird. Es wurde gezeigt, dass die benachbarte Proteinkinase C (PKC) Phosphorylierungsstelle an Serin 370 von pRS1 die NS-gesteuerte Kernlokalisierung kontrolliert und für die vom Zellzyklus abhängige Kernlokalisation notwendig ist. Aufgrund der Ergebnisse der ortsgerichteten Mutagenese, PKC-Aktivierungsexperimenten und Massenspektrometrie-Analyse des Phosphorylierungsmusters von RS1 wurde ein Modell vorgeschlagen, das die Regulation der Kernlokalisation des RS1 Proteins in LLC-PK1 Zellen beschreibt. Dem Modell zufolge wird RS1 in subkonfluenten Zellen stark in den Kern befördert, während der Export von RS1 aus dem Kern nicht stattfindet. Das führt zur Anreicherung von RS1 im Kern. Nach Konfluenz wird Serin 370 durch PKC phosphoryliert, was die Steigerung des RS1-Exports aus dem Kern begünstigt und die überwiegend zytoplasmatische Lokalisation des Proteins in konfluenten Zellen hervorruft. Die konfluenzabhängige Regulation der Lokalisation von RS1 kann die Expression von SGLT1 während der Regeneration von Enterozyten im Dünndarm und der Regeneration von Zellen der Nierentubuli nach hypoxämischem Stress kontrollieren. Außerdem deutet die Analyse der Genexpression in embryonalen Fibroblasten der RS-/- Mäuse deutet darauf hin, dass die transkriptionale Regulation durch RS1 im Zellzyklus und bei der Zellteilung eine wichtige Rolle spielen kann. Da die Lokalisation von RS1 zellzyklusabhängig ist, kann RS1 für die Regulation der Transporter in spezifischen Phasen des Zellzyklus wichtig sein. N2 - The RS1 protein (gene RSC1A1) participates in regulation of Na+-D-glucose cotransporter SGLT1 and some other solute carriers. In subconfluent LLC-PK1 cells, RS1 inhibits release of SGLT1 from the trans-Golgi network and transcription of SGLT1. In subconfluent cells, RS1 is localized in the nucleus and the cytoplasm whereas confluent cells contain predominantly cytoplasmic RS1. In the present study, the mechanism and regulation of confluence-dependent nuclear location of RS1 was investigated. Confluence dependent nuclear location of RS1 was shown to be regulated by the cell cycle. A nuclear shuttling signal (NS) in pRS1 was identified that ensures confluence-dependent distribution of pRS1 and comprises nuclear localization signal (NLS) and nuclear export signal (NES). The NLS and NES of RS1 mediate translocation into and out of the nucleus via importin ß1 and CRM1, respectively, and the nuclear/cytoplasmic distribution of the RS1 protein is determined by the nuclear export activity. The adjacent protein kinase C (PKC) phosphorylation site at serine 370 of pRS1 was shown to control nuclear localization driven by NS and is necessary for the differential localization of RS1 in quiescent versus proliferating cells. Basing on the data of site-directed mutagenesis, PKC activation experiments and mass spectrometry analysis of RS1 phosphorylation, the following model of the regulation of RS1 nuclear location in LLC-PK1 cells was proposed. In subconfluent cells, RS1 is actively imported into the nucleus whereas nuclear export of RS1 is not active leading to accumulation of RS1 in the nucleus. After confluence, phosphorylation of serine 370 of pRS1 by PKC takes place leading to enhancement of RS1 nuclear export and predominantly cytoplasmic distribution of the protein in the confluent cells. The confluence-dependent regulation of RS1 localization may control SGLT1 expression during regeneration of enterocytes in small intestine and during regeneration of renal tubular cells after hypoxemic stress. Moreover, the gene expression profiling of mouse embryonic fibroblasts with RS1-/- genotype suggests that transcriptional regulation by RS1 might be important for the cell cycle and cell division. Since RS1 localization depends on the cell cycle, RS1 might play a role in the regulation of the solute carriers during specific phases of the cell cycle. KW - RS1 KW - NES KW - NLS KW - Kern KW - Regulation KW - SGLT1 KW - Zellzyklus KW - Glukose KW - RS1 KW - NES KW - NLS KW - nucleus KW - transporter regulator KW - SGLT1 KW - glucose KW - nuclear export signal KW - nuclear localization signal KW - cell cycle KW - glucose Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-38512 ER - TY - JOUR A1 - Scholz, Nicole A1 - Guan, Chonglin A1 - Nieberler, Matthias A1 - Grotmeyer, Alexander A1 - Maiellaro, Isabella A1 - Gao, Shiqiang A1 - Beck, Sebastian A1 - Pawlak, Matthias A1 - Sauer, Markus A1 - Asan, Esther A1 - Rothemund, Sven A1 - Winkler, Jana A1 - Prömel, Simone A1 - Nagel, Georg A1 - Langenhan, Tobias A1 - Kittel, Robert J T1 - Mechano-dependent signaling by Latrophilin/CIRL quenches cAMP in proprioceptive neurons JF - eLife N2 - Adhesion-type G protein-coupled receptors (aGPCRs), a large molecule family with over 30 members in humans, operate in organ development, brain function and govern immunological responses. Correspondingly, this receptor family is linked to a multitude of diverse human diseases. aGPCRs have been suggested to possess mechanosensory properties, though their mechanism of action is fully unknown. Here we show that the Drosophila aGPCR Latrophilin/dCIRL acts in mechanosensory neurons by modulating ionotropic receptor currents, the initiating step of cellular mechanosensation. This process depends on the length of the extended ectodomain and the tethered agonist of the receptor, but not on its autoproteolysis, a characteristic biochemical feature of the aGPCR family. Intracellularly, dCIRL quenches cAMP levels upon mechanical activation thereby specifically increasing the mechanosensitivity of neurons. These results provide direct evidence that the aGPCR dCIRL acts as a molecular sensor and signal transducer that detects and converts mechanical stimuli into a metabotropic response. KW - Latrophilin KW - adhesion GPCR KW - dCIRL KW - sensory physiology KW - metabotropic signalling KW - mechanotransduction Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170520 VL - 6 IS - e28360 ER - TY - THES A1 - Dziewior, Frank T1 - Messung der intrazellulären Ca2+-Konzentration in Gefäßendothelzellen unter rheologischer Beanspruchung T1 - Measurement of intracellular Ca2+-concentration in vessel endothelial cells subjected to rheological demand N2 - Die den Zellstoffwechsel und das Zytoskelett betreffenden Adaptationsvorgänge in Endothelzellen unter rheologischer Beanspruchung sind von besonderem klinischen Interesse, da Gefäßwandschäden eine entscheidende pathogenetische Relevanz bei der Entstehung vaskulärer Erkrankungen wie z.B. der Arteriosklerose zukommt. Der intrazelluläre Signalweg, über den die Zelle einen rheologischen Reiz in eine entsprechende Zellantwort umsetzt, ist bisher weitgehend ungeklärt geblieben, wobei eine Erhöhung der zytosolischen Calciumkonzentration als Signalgeber diskutiert wurde. Im Rahmen der vorliegenden Arbeit ist es gelungen, einen Messplatz zu etablieren, der es gestattet, Veränderungen in der zytosolischen Calciumkonzentration in kultivierten Endothelzellen nach Applikation von Ca2+-erhöhenden Agonisten, Calciumionophoren sowie während rheologischer Beanspruchung in Echtzeit zu dokumentieren. Die Eignung des verwendeten rheologischen Systems für Scherstressexperimente konnte durch die Beobachtung der für Endothelzellen unter rheologischer Beanspruchung typischen zytoskelettalen Umbauvorgänge im Sinne einer Neuordnung der Aktinfilamente mit der Ausbildung von Stressfasern gezeigt werden. Erstmalig konnte dabei auch die Reaktion mikrovaskulärer Endothelzellen der MyEnd-Zelllinie der Maus auf Scherstressbeanspruchung gesehen werden. Bei diesen Zellen konnte eine Vermehrung des F-Aktin-Gehaltes beobachtet werden, im Gegensatz zu kultivierten Endothelzellen des Truncus pulmonalis des Hausschweins blieb aber eine signifikante Bildung von Stressfasern aus. Diese unterschiedliche Verhalten ist wahrscheinlich der andersartigen Zellmorphologie der MyEnd-Zellen zuzuschreiben. Es konnte in zwei verschiedenen Endothelzellsystemen gezeigt werden, daß Gefäßendothelzellen den Kontakt mit verschiedenen endogenen Stimuli bzw. Calciumionophoren mit einer zytosolischen Calciumerhöhung unterschiedlichen Ausmaßes beantworten. Bei einsetzendem oder sich verstärkenden Flüssigkeitsscherstress konnte von uns hingegen keine Calciumantwort beobachtet werden. An der Induktion zytoskelettaler Umbauvorgänge scheint Calcium als Botenstoff in den hier untersuchten Zellsystemen also nicht primär beteiligt zu sein N2 - The adjustment processes in endothelial cells under rheological demand induced by changes in cell metabolism are of particularly clinical interest, as vessel wall damage has a decisive influence on formation of vascular deseases as e.g. atherosclerosis. The intracellular signal pathway the cell uses to transmit a rheological stimulus into a corresponding cell answer has previously remaind unclarified. In this publication we were able to establish a measuring technique that allows to document changes in cytosolic free calcium in the presence of Ca2+-increasing agonist, calcium ionophores as well as during rheological demand. The suitability of the used rheological system could be proved by observation of the cytoskeleton reorganization processes, that are typical for endothelial cells under rheological demand. A reorientation of actin filaments and formation of shear stress fibers could be observed. For the first time we could see in this context the reaction of microvacular endothelial cells of the mice MyEnd-population on rheological demand. In these cells we could notice an increase of F-actin, but in contrast to cultivated pulmonary endothelial cells of the pig we could not observe a significant formation of shear stress fibers. This different behaviour is probably due to the different cell morphology of MyEnd cells. In two different endothelial cell systems could be shown that vessel endothelial cells answer on stimulation with varying endogeneous agonists and calcium ionophores with an elevation of cytosolic free calcium. No increase in cytosolic free calcium could be shown subsequently to starting or increasing rheological demand. In the investigated cell populations calcium seems not to be involved as a messenger for cytoskeletal reorganization. KW - Endothel KW - Calcium KW - Scherstress KW - Stressfasern KW - Aktin KW - Arteriosklerose KW - endothelium KW - calcium KW - shear stress KW - shear stress fibers KW - actin KW - atherosclerosis Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-1181128 ER - TY - JOUR A1 - Nose, Naoko A1 - Werner, Rudolf A. A1 - Ueda, Yuichiro A1 - Günther, Katharina A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. A1 - Fukushima, Kazuhito A1 - Edenhofer, Frank A1 - Higuchi, Takahiro T1 - Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay JF - International Journal of Cardiology N2 - BACKGROUND: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. MATERIAL AND METHODS: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F‑2‑fluoro‑2‑deoxy‑d‑glucose (\(^{18}\)F-FDG) and \(^{125}\)I‑β‑methyl‑iodophenyl‑pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. RESULTS: After cardiac differentiation of hiPSCs, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. CONCLUSIONS: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications. KW - tracer KW - Stammzelle KW - induced pluripotent stem cells KW - cardiomyocytes KW - fatty acid KW - stem cell therapy KW - hiPSC-CM Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170699 VL - 269 ER - TY - INPR A1 - Nose, Naoko A1 - Werner, Rudolf A. A1 - Ueda, Yuichiro A1 - Günther, Katharina A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. A1 - Fukushima, Kazuhito A1 - Edenhofer, Frank A1 - Higuchi, Takahiro T1 - Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay T2 - International Journal of Cardiology N2 - Background: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. Material and Methods: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F-2-fluoro-2-deoxy-D-glucose (\(^{18}\)F-FDG) and \(^{125}\)I-β-methyl-iodophenyl-pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. Results: After cardiac differentiation of hiPSC, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. Conclusions: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications. KW - tracer KW - Stammzelle KW - induced pluripotent stem cells KW - cardiomyocytes KW - fatty acid KW - stem cell therapy KW - hiPSC-CM Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-163320 SN - 0167-5273 ER - TY - CHAP A1 - Viviani, A. A1 - Lutz, Werner K. T1 - Modulation of the in vivo covalent binding of the carcinogen benzo(a)pyrene to rat liver DNA by selective induction of microsomal and nuclear aryl hydrocarbon hydroxylase activity N2 - The influence of microsomal (mAHH) and nuclear (nAHH) aryl hydrocarbon hydroxylase activity on the covalent binding of t:titiated benzo(a)pyrene to rat liver DNA was evaluated in vivo. Induction ofmAHH was obtained after phenobarbitone treatment (180% of control), which increased DNA binding to 210%, but left the nAHH unchanged. mAHH and nAHH were slightly indilced with dieldrin (130% and 120%), but the binding remairred unchanged. The increasing effect of mAHlt as weil as the possibly decreasing effect of nAHH induction on the binding became obvious when the data of 11 individual rats were used to solve the equation Binding = aX(mAHH) + bX(nAHH) + c. Multiple linear regression analysis resulted in positive values for a and c, a negative value for b, and a multiple correlation coefficient R = 0.82. An influence of other enzymes involved in the metabolism of benzo(a)pyrene cannot be excluded. The Study shows clearly that the binding of a foreign compound to DNA in vivo is not only dependent on microsomal enzyme activities but also on nuclear activities even if the latter are considerably lower than those of mic'rosomes. KW - DNA KW - Benzo(a)pyrene KW - DNA-Binding KW - Carcinogen KW - Enzyme KW - Induction KW - Aryl Hydrocarbon Hydroxylase KW - Rats KW - Phenobarbitone KW - Dieldrin Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80132 ER - TY - JOUR A1 - Gorboulev, Valentin A1 - Büchner, Hubert A1 - Akhundova, Aida A1 - Fahrenholz, Falk T1 - Molecular cloning and functional characterization of V2 [8-Iysine] vasopressin and oxytocin receptors from a pig kidney cell line (LLC-PK1) N2 - No abstract available KW - Biologie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59311 ER - TY - JOUR A1 - Gorboulev, Valentin A1 - Akhundova, Aida A1 - Büchner, Hubert A1 - Fahrenholz, Falk T1 - Molecular cloning of a new bombesin receptor subtype expressed in uterus during pregnancy N2 - The homology screening approach has been used to clone a new member of the guanine-nucleotidebinding-protein-coupled receptor superfamily from guinea pig uterus. The cloned cDNA encodes a 399-amino-acid protein and shows the highest amino acid similarity to members of the bombesin receptor family; 52% and 47% similarity to the gastrin-releasing-peptide (GRP) receptor and the neuromedin-B receptor, respectively. Bindingexperiments with the stably transfected LLC-PK1 cell line expressing the new receptor protein confmned the bombesin-like nature of the cloned receptor. The relative order ofligand affinity, GRP = neuromedin C >> neuromedin B, suggests that the cloned cDNA represents the GRP subtype rather than the neuromedin-B subtype of bombesin receptors. Northern-blot analysis of mRNA species from several guinea-pig tissues showed that the mRNA for the new bombesin receptor subtype is expressed mainly in uteri of pregnant animals. KW - Biologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59304 ER - TY - JOUR A1 - Gorboulev, Valentin A1 - Akhundova, Aida A1 - Luzius, Heike A1 - Fahrenholz, Falk T1 - Molecular cloning of substance P receptor cDNA from guinea-pig uterus N2 - A cDNA encoding guinea-pig uterine substance P (SP) receptor has been isolated using the homology screening approach. Northern blot analysis reveals that the corresponding mRNA, of approx. 4.8 kb, is expressed in all tissues tested, but predominantly in the uteri of non-pregnant animals; during pregnancy its expression is reduced. The guinea-pig SP receptor was expressed in COS-7 cells and demonstrated relative Iigand affinity in the order: SP >> neurokinin A > neurokinin B. KW - Biologie KW - Substance P receptor KW - G-protein-coupled receptor KW - Guinea-pig uterus KW - COS cell expression Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59293 ER - TY - THES A1 - Blecharz, Kinga Grażyna T1 - Molekulare Ziele der Glukokortikoidbehandlung unter verschiedenen pathophysiologischen Bedingungen in einem in vitro Modell der Blut-Hirn-Schranke T1 - Molecular targets of glucocorticoid-treatment under different pathophysiological conditions in an in vitro model of the blood brain barrier N2 - Die Integrität der Blut-Hirn-Schranke (BHS) ist bei vielen Erkrankungen des humanen zentralen Nervensystems (ZNS) beeinträchtigt. Unter verschiedenen neuroinflammatorischen Bedingungen, wie bei zerebralen Ischämien, Traumata, Hirntumoren oder der Multiplen Sklerose (MS), kommt es zum Verlust der protektiven Schrankenfunktion. Zu den ersten Anzeichen des BHS-Zusammenbruchs zählt der Verlust der Zell-Zell-Adhäsion: der Adhärens- und Occludenskontakte. Therapeutische Maßnahmen dieser Krankheiten beinhalten Behandlungen mit Glukokortikoiden (GCs), wobei der Mechanismus und die Wirkungsweise dieser Substanzen bis heute nicht vollkommen aufgeklärt sind. In der zerebralen Hirnendothelzelllinie cEND [Forster C, Silwedel C, Golenhofen N, Burek M, Kietz S, Mankertz J & Drenckhahn D. (2005). Occludin as direct target for glucocorticoid-induced improvement of blood-brain barrier properties in a murine in vitro system. J Physiol 565, 475-486] wurde eine Funktionsverbesserung der Endothelbarriere durch die Expressionerhöhung von Occludin nach GC-Behandlung bereits analysiert. Daraufhin wurden andere Kandidaten des apikalen Junktionssystems gesucht, die positiv auf GC-Gabe ansprechen. Der erste Teil der Arbeit präsentiert den positiven Einfluss der Dexamethason-Behandlung auf die Expression des Adhärenskontakt-Proteins VE- (Vascular-Endothelial) Cadherin in cEND-Zellen. Dabei wurde eine Reorganisation des Zytoskeletts, eine verstärkte Verankerung des VE-Cadherins an das Zytoskelett, sowie eine einhergehende Morphologieänderung der behandelten Zellen beobachtet. Untersuchungen der Transkriptionsaktivierung des VE-Cadherin-Promoters nach Dexamethason-Behandlung, wiesen auf einen indirekten Steroid-Effekt hin, der zu einer Erhöhung der VE-Cadherin-Proteinsynthese führte. Somit sind GCs wichtig für die Proteinsynthese und -organisation beider Kontaktproteinarten: der Adhärens- und Occludenskontakte in mikrovaskulären Hirnendothelzellen. Die Beeinträchtigung der BHS-Integrität mit Veränderungen der Occludenskontaktexpression zählt zu den frühen Ereignissen bei der Entstehung einer Inflammation des ZNS, wie beispielsweise bei der MS. Im zweiten Teil der Dissertation wurde die Herunterregulation von Occludenskontaktproteinen in der cEND-Zelllinie untersucht. Dabei wurden cEND-Zellen mit Seren von Patienten, die sich in zwei verschiedenen Stadien der MS befanden, behandelt: in der akuten Exazerbationsphase oder der Remissionsphase, und auf die Protein- und Genexpression mit und ohne Dexamethasons-Behandlung untersucht. Es konnte ein negativer Effekt auf den Barrierewiderstand und die Occludenskontaktexpression, sowie eine erhöhte MMP-9-Genexpression nach Krankheitssereninkubation gezeigt werden. Die Dexamethason-Behandlung ergab eine geringe, aber keine vollständige Rekonstitution der Barrierefunktion. Anhand dieser Studie konnte jedoch erstmals eine Erniedrigung der Protein- und mRNA-Synthese von Claudin-5 und Occludin in Remissionspatientenseren inkubierten cEND-Zellen demonstriert werden. Somit könnten diese Erkenntnisse zur Prädiagnose einer bevorstehenden Exazerbationsphase der MS eingesetzt werden. Eine Langzeit-GC-Behandlung führt zu zahlreichen Nebenwirkungen, u. a. zum Bluthochdruck, welcher aufgrund einer eingeschränkten Produktion des vasodilatativen Faktors Stickstoffmonoxid, NO, im myokardialen Endothel hervorgerufen wird. Veränderungen in der NO-Produktion, wie auch anderer Faktoren der NO-Signalkaskade in der myokardialen Endothelzelllinie MyEND unter Einfluss von Dexamethason standen im Zentrum des dritten Teils dieser Arbeit. Während keine Veränderungen in der Expression der endothelialen NO-Synthase, eNOS, nach GC-Behandlung gezeigt werden konnten, wurden repressive Einflüsse von Dexamethason auf die Enzymaktivität der eNOS in MyEND-Zellen untersucht. GC-Gabe führte zur einer herabgesetzten Synthese des essenziellen Co-Faktors der eNOS, des Tetrahydrobiopterins, BH4, sowie zu einer Herunterregulation der GTP-Cyclohydrolase-1 (GTPCH-1), des geschwindigkeitsbestimmenden Enzyms der BH4-Produktion. Im Gegensatz zu bisherigen Ergebnissen anderer Arbeitsgruppen, konnte in der vorliegenden Studie belegt werden, dass die Herunterregulation der GTPCH-1 mRNA-Level auf den Liganden-abhängigen proteasomalen Abbau des Glukokortikoid-Rezeptors (GR) zurückzuführen ist. Das 26S-Proteasom moduliert die GR-abhängige Genexpression durch Kontrolle des Umsatzes und des Recyclings des Rezeptors selbst, wodurch eine regulierte Hormonresponsivität gewährleistet wird. Die Aufhebung des Liganden-abhängigen Abbaus des GR-Proteins durch gezielte Proteasominhibition, sowie durch eine Überexpression des ubiquitinylierungsdefekten GR-Konstruktes, K426A-GR, in Dexamethason-behandelten MyEND-Zellen resultierte in einer Erhöhung der GTPCH-1-Expression, sowie einer gesteigerten eNOS-Aktivität. Die hier beschriebenen Ergebnisse erlauben einen innovativen Einblick in die Erkenntnisse zur GC-vemittelten Hypertonie. Zusammenfassend kann festgestellt werden, dass GC-Behandlungen von mikrovaskulären Hirnendothelzellen zu einer Stabilisierung der Endothelbarriere führen. Unter pathologischen Bedingungen, wie der MS, wird der protektive GC-Effekt durch andere Faktoren beeinträchtigt N2 - The integrity of the blood-brain barrier (BBB) is compromised in many disorders of the human central nervous system. A breakdown of the blood-brain barrier under conditions of neuroinflammation and cerebral ischemia, but also traumas, brain tumours and multiple Sclerosis (MS), leads to loss of the protective function of the barrier. In its breakdown one of the first observable changes is the loss of intercellular adhesion and concomitant an increase of permeability. Although therapeutic strategies for diseases with impaired BBB function include the treatment with glucocorticoids (GCs) but the mechanism explaining GC action still remains unclear. Recent studies showed the influence of GCs on the expression of the tight junction protein occludin in the brain capillary endothelial cell line cEND, contributing to improvement in endothelial barrier functions. In this study, we investigated GC effects on the expression of the adherens junction proteins VE- (vascular-endothelial) cadherin. It was possible to show a positive influence of dexamethasone administration on VE-cadherin protein levels as well as a rearrangement and the anchorage of VE-cadherin protein to the cytoskeleton. Investigation of transcriptional activation of the VE-cadherin promoter by dexamethasone, however, did not point to direct glucocorticoid-mediated VE-cadherin gene induction. But it rather suggested indirect steroid effects leading to increased VE-cadherin protein synthesis. We thus propose that glucocorticoid effects on VE-cadherin protein synthesis and organization are important for the formation of both adherens and tight junctions, and for improved barrier properties in microvascular brain endothelial cells. Abnormalities in the expression profile of tight junctions in cerebral endothelium constituting barrier functions occur early during neuroinflammation, as Multiple Sclerosis (MS). In the second part of this study, the disruption of tight junction proteins in the cEND cell line was analysed. cEND cells were incubated with sera from patients, which were in two different states of MS: in the acute exacerbation or the remission phase of the disease, and protein levels and gene expression of claudin-5, occludin and VE-cadherin with and without dexamethasone treatment were investigated. There arised a downregulation of claudin-5 and occludin on protein and mRNA levels and an accompanying upregulation of MMP-9 activity revealed. A minor reconstitution of barrier functions related to dexamethasone treatment could be shown. However, no reconstitution could be detected to the control level. Especially, observations in downregulation of claudin-5 and occludin in cEND cells incubated with sera from patients in remission phase of MS could not be demonstrated before. Thus, this finding is proposed to be a new useful prediagnostic tool for an early detection of upcoming exacerbation phase. One of the numerous side effects of GC therapy is hypertension arising from reduced release of the endothelium-derived vasodilator nitric oxide, NO, being in the centre of the third part of this study. While effects of dexamethasone on endothelial NO synthase, eNOS, expression itself could not be demonstrated, repressive effects of dexamethasone on eNOS enzyme activity were shown in the myocardial endothelial cell line MyEND. Following GC-treatment we observed decreased levels of the essential cofactor of eNOS, tetrahydrobiopterin, BH4. We also determined a downregulation of GTP cyclohydrolase-1, GTPCH-1, the key enzyme of BH4 synthesis. In contrast to recent data from other groups, we postulate that this downregulation of GTPCH-1 mRNA levels is not a direct downregulation effect of GC action. But it is rather a consequence of the ligand-dependent proteasomal degradation of the GC receptor, GR. The 26S-proteasome modulates GR-dependent gene transcription by regulation of its turnover and the recycling of receptor/transcriptional DNA complexes, thereby ensuring continued regulation of hormone responsivity. In this work, the inhibition of proteasome-mediated proteolysis of GR by using inhibitors of the 26S-proteasome, or overexpression of a point-mutated, ubiquitination-defective GR construct, K426A-GR, which attenuates endothelial GC responsivity, was demonstrated. The abrogation of ligand-dependent degradation of GR protein resulted in increased levels of GTPCH-1 hence expression, leading to an increased eNOS-activity. These results provide a new insight into the research of GC-induced hypertension. Taken together, these data demonstrate, that GC treatment in microvascular brain endothelial cells leads to barrier stabilisation, but under conditions of MS there are many other factors like cytokines and chemokines, which abrogate this positive action. KW - Blut-Hirn-Schranke KW - Endothel KW - Tight junction KW - Dexamethason KW - Zellskelett KW - Proteasom KW - Hypertonie KW - Glukokortikoide KW - Endothelzelllinie KW - Adherens-Junction KW - blood brain barrier KW - brain endothelial cell line KW - tight junction KW - adherens junction KW - multiple sclerosis KW - proteasome Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-57256 ER - TY - JOUR A1 - Drenckhahn, Detlev T1 - Morphologie und Jahreszyklus von Ficaria calthifolia Rchb. – eine neu etablierte Sippe in Deutschland T1 - Morphology and annual cycle of Ficaria calthifolia Rchb. – a recently established species for Germany JF - Forum Geobotanicum N2 - Ficaria calthifolia (diploide Form, Typ1) wurde kürzlich nord-westlich des geschlossenen südosteuropäischen Verbreitungsgebiet auch in Deutschland gefunden, nämlich in Würzburg (2006) und an Elbedeichen in Brandenburg (2014) und Sachsen (2015). Ficaria calthifolia ist durch das Fehlen von verlängerten mehrgliedrigen Stängeln und die Abwesenheit von Brutknollen in den Blattachseln gekennzeichnet. Die 1–2 (3) Stängel von Ficaria calthifolia verbleiben überwiegend im Boden (hypogäisch), können aber im Laufe der Anthese aus dem Boden hervorwachsen. Die gestielten Laubblätter setzen sich aus Grundblättern und einer Rosette von bis zu 8 Stängelblättern pro Stängel zusammen. Letztere entspringen aus dem terminalen Stängelknoten (Stängelblatt-rosette). In Würzburg kommen zwei Populationen von Ficaria calthifolia vor, diploide Typ1-Pflanzen und triploide Typ2-Pflanzen. Letztere sind robuster, besitzen größere Blüten (bis 4 cm) und entwickeln nur vereinzelte reife Nüsschen. Pflanzen mit höherem Ploidiegrad (wahrscheinlich pentaploid, Typ3) wurden auch gefunden. Etwa 60% der 3 bis 8 Blütenstiele von Typ1-Pflanzen besitzt kein Stängelblatt, der Rest einen Knoten mit 1 bis 2 (3) Hochblättern. Die Zahl der Kronblätter beträgt 8 (vereinzelt 9), die durchschnittliche Zahl reifer, eiförmiger Nüsschen pro Fruchtstand beträgt 7 (Würzburg) / 14 (Elbe) (maximal 26). Aus vom Rhizom abgebrochenen und im Mai gepflanzten Speicherknollen keimten im Spätherbst desselben Jahrs neue Pflanzen. Der Jahreszyklus des Wurzelsystems wird beschrieben. Durch spontane Ablösungen einzelner Speicherknollen findet eine vegetative Vermehrung statt. Neben Nüsschen wären abgebrochene Speicherknollen für die Fernansiedlung der Sippe an Elbe (u.a. Verschleppung durch Hochwasser) und Main (Verschleppung durch Schiffe und andere Vektoren) ausreichend. N2 - Ficaria calthifolia (typical diploid form, type1) has recently been discovered to grow outside its southeastern European distribution area also in Germany, namely in Northern Bavaria (Würzburg) and at dikes of the river Elbe in Brandenburg and Saxony. Ficaria calthifolia is distinguished from Ficaria verna by the absence of both elongated multisegmental stems and axillary tubers (bulbils). The 1–2 (3) short stems of Ficaria calthifolia remain mostly underground and may extend during anthesis few cm above ground. Leaves form a rosette-like cluster consisting of ground leaves (directly arising from the rhizome) and a rosette of up to 8 stem-leaves that emanate from the single (terminal) node of the short stems. The majority of flower stalks are leafless (true pedicles) but about 40% contain a single, a pair or rarely a triplet of petiolate leaves. The number of petals is 8 (9). Diploid Ficaria calthifolia is fertile with average 7 (Würzburg) to 14 nutlets (Elbe population) per head (maximum 26). In Würzburg also triploid plants (type2) were encountered being more robust than diploid plants with larger flowers, larger blades and largely abortive nutlets. A small population of plants (type3) with higher numbers of chromosomes (probably pentaploid) was also found. Plants intermediate between Ficaria calthifolia and Ficaria verna are readily distinguished by axillary tubers at stem leaves. Tubers removed from rhizome of Ficaria calthifolia and planted in soil in May gave rise to new plants sprouting in late autumn. Annual cycle of the root system is described. Spontaneous shedding of tubers from rhizome appears to be a regular mechanism of vegetative proliferation of Ficaria calthifolia. Thus, accidental displacement not only of nutlets but also of tubers via rivers (i.e. river Elbe) or by other (anthropogenic) vectors could be sufficient for north-westward expansion of the distribution area. KW - Ficaria calthifolia KW - Morphotype KW - Ficaria verna KW - Karyotyp KW - morphotypes KW - karyotypes Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136225 UR - http://www.forum-geobotanicum.net/articles/vol_7-2016/drenckhahn_ficaria/drenckhahn_ficaria_calthifolia.pdf SN - 1867-9315 VL - 7 ER - TY - THES A1 - Dippacher, Sonja T1 - Morphologische und molekularbiologische Untersuchungen zur Bedeutung der Serin-Threonin-Proteinkinase SRPK79D in Drosophila melanogaster T1 - Morphological and molecular biological investigations on the role of serine threonine kinase SRPK779D in Drosophila melanogaster N2 - Die intakte Signalübertragung im animalischen Nervensystem erfordert eine an richtiger Stelle ausgebildete funktionsfähige Synapse zwischen zwei Nervenzellen bzw. zwischen Nerv und Muskel. In der vorliegenden Arbeit wurde eine Mutante von Drosophila melanogaster untersucht, bei der es zu Veränderungen der Verteilung eines wichtigen Organisationsproteins der synaptischen aktiven Zone kommt. Ein wichtiges Ergebnis der Untersuchungen ist die Beobachtung, dass es in der Mutante zu einer ektopen Ausbildung von Elementen aktiver Zonen in Axonen kommt. In den Arbeitsgruppen von E. Buchner und S. Sigrist ist bereits das Protein Bruchpilot (BRP) charakterisiert worden, das Bestandteil der präsynaptischen Ribbons, bei Drosophila als T-bars bezeichnet, ist. Bei der Suche nach Interaktionspartnern von BRP, ist eine Serin-Arginin-Protein spezifische Kinase SRPK79D entdeckt worden, die offenbar an der Regulation des Aufbaus der Tbars beteiligt ist (Nieratschker et al., 2009). Es gibt vier verschiedene Isoformen der Kinase. Werden nur zwei Isoformen der Kinase (SRPK79D-RB und -RE) exprimiert bzw. das Gen der Kinase komplett ausgeschaltet, findet man Ansammlungen von BRP als immunreaktive Aggregate in der Immunfluoreszenz- Färbung von larvalen Motoneuron-Axonen (Nieratschker, 2008). Es ist unser übergeordnetes Ziel, die Funktion und den molekularen Signalweg der Kinase SRPK79D zu entschlüsseln. Ein Ziel der vorliegenden Arbeit war es, PB-Protein in Reinform für eine Affinitätsreinigung eines PB-Antikörpers zu gewinnen, um in nachfolgenden Untersuchungen die Lokalisation dieser Kinase-Isoform zu untersuchen. Die Proteinreinigung war erfolgreich, aber es gelang nicht, eine für eine Affinitätsreinigung ausreichende Menge des Proteins zu isolieren. Ein weiterer Versuch, Lokalisationsuntersuchungen zur Expression der Kinase in Drosophila- Embryonen durchzuführen, war ebenfalls nicht erfolgreich. Obwohl die Herstellung einer für die SRPK79D mRNA spezifischen RNA Sonde für die in-Situ-Hybridisierung gelang, war die Sensitivität dieser Sonde nicht hoch genug, um die Lokalisation vornehmen zu können. Eindeutige und aufschlussreiche Ergebnisse dagegen ergab die Untersuchung der Ultrastruktur der BRP-Ansammlungen in den larvalen Motornerven. Als deren Korrelat fanden sich elektronenmikroskopisch charakteristische Ansammlungen elektronendichter intraaxonaler Strukturen, deren Form Ähnlichkeiten zu T-bars aufwies und die von Vesikeln umgeben waren. Die elektronendichten Strukturen zeigten zahlreiche Formvariationen, die wie Ansammlungen von T-bars nebeneinander bzw. „miteinander verklebte“ T-bars oder wie zerstörte T-bars aussahen. In einer nachfolgenden Studie wurde durch eine immun-elektronenmikroskopische Untersuchung gezeigt, dass diese Strukturen in der Tat BRP enthalten (Nieratschker et al., 2009). Ergebnis der Untersuchungen der vorliegenden Arbeit war der Nachweis, dass prinzipiell ähnliche Aggregate auch im Wildtyp gelegentlich gefunden werden, dass sie aber in Mutanten signifikant häufiger vorkommen und auch einen signifikant höheren Durchmesser aufweisen. Doppelimmunreaktionen mit Antikörpern, die den C- bzw. N-terminalen Bereich von BRP erkennen, belegten darüber hinaus, dass in den Aggregaten das vollständige BRP-Protein vorliegt. Angeregt durch die Ultrastrukturbefunde von mit den elektronendichten Strukturen in den Aggregaten assoziierten Vesikeln wurde in weiteren Doppelimmunreaktionen untersucht, ob ein typisches Protein synaptischer Vesikel neuromuskulärer Synapsen in Drosophila, der vesikuläre Glutamattransporter (DVGlut), in den BRP-Ansammlungen nachweisbar ist. Während Kolokalisation von BRP und DVGlut in aktiven Zonen präsynaptischer Boutons nachgewiesen werden konnte, war der Vesikelmarker in BRP-Aggregaten nicht kolokalisiert. Die Ergebnisse belegen, dass die Kinase SRPK79D für die Vermeidung einer ektopen Bildung von BRP-enthaltenden, elektronenmikroskopisch atypischen aktiven Zonen ähnelnden Strukturen in larvalen Motoneuronaxonen notwendig ist. Die in diesen Aggregaten regelmäßig zu beobachtenden Vesikel ähneln morphologisch synaptischen Vesikeln, besitzen aber keine dafür typischen Vesikelmarker. N2 - Intact signal transmission in an animal’s nervous system requires a properly localized and functional synapse between two neurons or between neuron and muscle. This dissertation is part of the investigation of a Drosophila melanogaster mutant which displays alterations in the distribution of a synaptic active zone protein. An important result of the present study is the documentation of an ectopic formation of active zone structural elements in this mutant. Analyses carried out in the laboratories of E. Buchner and S. Sigrist contributed to the characterization of the protein Bruchpilot (BRP), a constituent of the T-bar, the characteristic presynaptic ribbon in Drosophila. Searching for interaction partners of BRP, a serine-arginine-protein specific kinase was identified that apparently regulates T-bar assembly (Nieratschker et al., 2009). There are four kinase isoforms. Knocking out two of these isoforms (SRPK79D-RB and -RE) results in accumulations of BRP-immunoreactive aggregates in the larval ventral nerves (Nieratschker, 2008). Further studies were designed to identify the function and molecular signalling pathways of the kinase SRPK79D. One objective of the present experiments was to produce purified PB-protein in order to enable affinity-purification of an antibody against this isoform of the kinase for subsequent specific immunohistochemical localization analyses. Although production of the antigen was successful, the amount of protein produced was too low to allow efficient affinity purification. An attempt to show the expression pattern of the kinase in Drosophila embryos with in-situ hybridization resulted in production of a SRPK79D specific RNAprobe, however, the probe sensitivity was not high enough to yield conclusive results for mRNA localization. Ultrastructural analyses of the BRP-ir aggregates in the larval ventral nerves, on the other hand, yielded definite and conclusive results. These aggregates corresponded to extensive intraaxonal electron-dense, ribbon-like structures surrounded by vesicles. These electron-dense structures were differently shaped and resembled accumulations of regularly shaped, clotted or dysmorphic T-bars, which in subsequent immuno-electronmicroscopic analyses carried out by another investigator were proven to contain BRP (Nieratschker et al., 2009). An important result of the present study was the observation that similar intraaxonal aggregates were occasionally also present in wild type nerves, however, the aggregates found in the mutants were significantly more frequent and of significantly larger size than those observed in wild-type larvae. Moreover, double-immunostaining using BRP-antibodies recognizing specifically the C- and the N-terminal part of the protein, respectively, provided evidence that the complete BRP protein is localized in the aggregates. Since electron microscopy had showed that numerous vesicles were associated with the electron dense aggregates, we tested whether the vesicular glutamate transporter (DVGlut), a marker protein for synaptic vesicles of motoneurons in Drosophila, could be localized in BRP-ir aggregates. While colocalization of BRP and DVGlut was observed at the presynaptic active zones, no colocalization of the synaptic vesicle marker was observed in the BRP-ir aggregates in the larval nerves. In conclusion, the results provide evidence that the kinase SRPK79D is required for the prevention of ectopic formation of BRP-containing ribbon-like structures in larval ventral nerves. These structures include vesicles resembling synaptic vesicles, which however do not display immunoreactivity for a typical synaptic vesicle marker protein. KW - Bruchpilot KW - BRP KW - Serin-Threonin-Kinase KW - SR-Protein Kinase KW - aktive Zone KW - Cytomatrix der aktiven Zone KW - Elektronenmikroskopie KW - Ultrastruktur KW - Bruchpilot KW - SR-Protein Kinase KW - aktive Zone KW - Cytomatrix der aktiven Zone KW - Ultrastruktur KW - Bruchpilot KW - synaptic active zone cytomatrix KW - SR protein kinase KW - ultrastructure KW - electron microscopy Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70937 ER - TY - JOUR A1 - Hübner, Stefanie A1 - Wissemann, Volker T1 - Morphometrische Analysen zur Variabilität von Prunus spinosa L. - Populationen(Prunoideae, Rosaceae) im mittleren Saaletal, Thüringen T1 - Morphometric analysis on the variability of Prunus spinosa L. - populations(Prunoideae, Rosaceae) in the central valley of the river Saale, Thuringia N2 - Prunus spinosa L. (Rosaceae) is one of the most widespread members of the genus Prunus in middle europe. Its morphological plasticity resulted in a number of described taxa at subspecific level. Since the early neolithic times, drupes of the plum family are recorded and exhibit already a remarkable diversity in size and form. Here we present a short historical account to the use of P. spinosa and an overview of the different taxonomic treatments. We examined distribution patterns in general and in particular in the central valley of the river Saale (Thuringia) with respect to ecological, edaphic and climatic factors. We assessed within 16 populations the variability of 22 metric and 10 qualitative morphological characters at 7 different locations. Population sites included forest-, way- and fieldsides, as well as lightish pine forests. Pollen fertility did not increase during the flowering period, all flowers were directly fully fertile from the beginning. In contrast, glucose content varied significantly depending of the status of fertilization. Epicuticular wax structure was without variation amongst the populations. P. spinosa leaves are covered with a smooth layer of slightly striated wax. Morphological characters were scored on 270 branches and 506 fruits. Most of the characters showed enormous variability among and within populations such as metrics of leaves, thorns and character states of flower morphology. The lowest variability among populations and therefore not dependend of modificatory factors was found in fruit characters. Since kernel morphology seems to be genetically rather than modificatory controlled, we applied the 3 taxonomical concepts of Werneck, Kühn and Scholz u. Scholz to identify evolutionary units at subspecific levels. However, population variability was still so high, that from our study here we can not support an infraspecific classification of Prunus spinosa L. KW - Prunus KW - Rosengewächse KW - Systematik KW - Rosaceae KW - Prunus KW - Evolution KW - Morphology KW - Systematics Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-35207 ER - TY - JOUR A1 - Elsner, Clara A1 - Kunz, Andreas Steven A1 - Wagner, Nicole A1 - Huflage, Henner A1 - Hübner, Stefan A1 - Luetkens, Karsten Sebastian A1 - Bley, Thorsten Alexander A1 - Schmitt, Rainer A1 - Ergün, Süleyman A1 - Grunz, Jan-Peter T1 - MRI-based evaluation of the flexor digitorum superficialis anatomy: investigating the prevalence and morphometry of the “chiasma antebrachii” JF - Diagnostics N2 - Recent dissection studies resulted in the introduction of the term “chiasma antebrachii”, which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.3 ± 21.3 years), MRI examinations of the forearm (2010–2021) were reviewed by two radiologists, who evaluated all studies for the presence and length of the chiasma as well as its distance from the distal radioulnar and elbow joint. The chiasma antebrachii was identified in the distal third of the forearm in 88 patients (98.9%), while one intersection was located more proximally in the middle part. The chiasma had a median length of 28 mm (interquartile range: 24–35 mm). Its distances to the distal radioulnar and elbow joint were 16 mm (8–25 mm) and 215 mm (187–227 mm), respectively. T1-weighted post-contrast sequences were found to be superior to T2- or proton-density-weighted sequences in 71 cases (79.8%). To conclude, the chiasma antebrachii is part of the standard FDS anatomy. Knowledge of its morphology is important, e.g., in targeted injections of therapeutics or reconstructive surgery. KW - flexor digitorum superficialis KW - flexor tendon KW - chiasma antebrachii KW - magnetic resonance imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362631 SN - 2075-4418 VL - 13 IS - 14 ER - TY - JOUR A1 - Madrahimov, Nodir A1 - Mutsenko, Vitalii A1 - Natanov, Ruslan A1 - Radaković, Dejan A1 - Klapproth, André A1 - Hassan, Mohamed A1 - Rosenfeldt, Mathias A1 - Kleefeldt, Florian A1 - Aleksic, Ivan A1 - Ergün, Süleyman A1 - Otto, Christoph A1 - Leyh, Rainer G. A1 - Bening, Constanze T1 - Multiorgan recovery in a cadaver body using mild hypothermic ECMO treatment in a murine model JF - Intensive Care Medicine Experimental N2 - Background Transplant candidates on the waiting list are increasingly challenged by the lack of organs. Most of the organs can only be kept viable within very limited timeframes (e.g., mere 4–6 h for heart and lungs exposed to refrigeration temperatures ex vivo). Donation after circulatory death (DCD) using extracorporeal membrane oxygenation (ECMO) can significantly enlarge the donor pool, organ yield per donor, and shelf life. Nevertheless, clinical attempts to recover organs for transplantation after uncontrolled DCD are extremely complex and hardly reproducible. Therefore, as a preliminary strategy to fulfill this task, experimental protocols using feasible animal models are highly warranted. The primary aim of the study was to develop a model of ECMO-based cadaver organ recovery in mice. Our model mimics uncontrolled organ donation after an “out-of-hospital” sudden unexpected death with subsequent “in-hospital” cadaver management post-mortem. The secondary aim was to assess blood gas parameters, cardiac activity as well as overall organ state. The study protocol included post-mortem heparin–streptokinase administration 10 min after confirmed death induced by cervical dislocation under full anesthesia. After cannulation, veno-arterial ECMO (V–A ECMO) was started 1 h after death and continued for 2 h under mild hypothermic conditions followed by organ harvest. Pressure- and flow-controlled oxygenated blood-based reperfusion of a cadaver body was accompanied by blood gas analysis (BGA), electrocardiography, and histological evaluation of ischemia–reperfusion injury. For the first time, we designed and implemented, a not yet reported, miniaturized murine hemodialysis circuit for the treatment of severe hyperkalemia and metabolic acidosis post-mortem. Results BGA parameters confirmed profound ischemia typical for cadavers and incompatible with normal physiology, including extremely low blood pH, profound negative base excess, and enormously high levels of lactate. Two hours after ECMO implantation, blood pH values of a cadaver body restored from < 6.5 to 7.3 ± 0.05, pCO2 was lowered from > 130 to 41.7 ± 10.5 mmHg, sO2, base excess, and HCO3 were all elevated from below detection thresholds to 99.5 ± 0.6%, − 4 ± 6.2 and 22.0 ± 6.0 mmol/L, respectively (Student T test, p < 0.05). A substantial decrease in hyperlactatemia (from > 20 to 10.5 ± 1.7 mmol/L) and hyperkalemia (from > 9 to 6.9 ± 1.0 mmol/L) was observed when hemodialysis was implemented. On balance, the first signs of regained heart activity appeared on average 10 min after ECMO initiation without cardioplegia or any inotropic and vasopressor support. This was followed by restoration of myocardial contractility with a heart rate of up to 200 beats per minute (bpm) as detected by an electrocardiogram (ECG). Histological examinations revealed no evidence of heart injury 3 h post-mortem, whereas shock-specific morphological changes relevant to acute death and consequent cardiac/circulatory arrest were observed in the lungs, liver, and kidney of both control and ECMO-treated cadaver mice. Conclusions Thus, our model represents a promising approach to facilitate studying perspectives of cadaveric multiorgan recovery for transplantation. Moreover, it opens new possibilities for cadaver organ treatment to extend and potentiate donation and, hence, contribute to solving the organ shortage dilemma. KW - extracorporeal membrane oxygenation KW - cadaver multiorgan preservation KW - mild hypothermia KW - post-mortem heart recovery Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357381 VL - 11 ER - TY - JOUR A1 - Janz, Anna A1 - Walz, Katharina A1 - Cirnu, Alexandra A1 - Surjanto, Jessica A1 - Urlaub, Daniela A1 - Leskien, Miriam A1 - Kohlhaas, Michael A1 - Nickel, Alexander A1 - Brand, Theresa A1 - Nose, Naoko A1 - Wörsdörfer, Philipp A1 - Wagner, Nicole A1 - Higuchi, Takahiro A1 - Maack, Christoph A1 - Dudek, Jan A1 - Lorenz, Kristina A1 - Klopocki, Eva A1 - Ergün, Süleyman A1 - Duff, Henry J. A1 - Gerull, Brenda T1 - Mutations in DNAJC19 cause altered mitochondrial structure and increased mitochondrial respiration in human iPSC-derived cardiomyocytes JF - Molecular Metabolism N2 - Highlights • Loss of DNAJC19's DnaJ domain disrupts cardiac mitochondrial structure, leading to abnormal cristae formation in iPSC-CMs. • Impaired mitochondrial structures lead to an increased mitochondrial respiration, ROS and an elevated membrane potential. • Mutant iPSC-CMs show sarcomere dysfunction and a trend to more arrhythmias, resembling DCMA-associated cardiomyopathy. Background Dilated cardiomyopathy with ataxia (DCMA) is an autosomal recessive disorder arising from truncating mutations in DNAJC19, which encodes an inner mitochondrial membrane protein. Clinical features include an early onset, often life-threatening, cardiomyopathy associated with other metabolic features. Here, we aim to understand the metabolic and pathophysiological mechanisms of mutant DNAJC19 for the development of cardiomyopathy. Methods We generated induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) of two affected siblings with DCMA and a gene-edited truncation variant (tv) of DNAJC19 which all lack the conserved DnaJ interaction domain. The mutant iPSC-CMs and their respective control cells were subjected to various analyses, including assessments of morphology, metabolic function, and physiological consequences such as Ca\(^{2+}\) kinetics, contractility, and arrhythmic potential. Validation of respiration analysis was done in a gene-edited HeLa cell line (DNAJC19tv\(_{HeLa}\)). Results Structural analyses revealed mitochondrial fragmentation and abnormal cristae formation associated with an overall reduced mitochondrial protein expression in mutant iPSC-CMs. Morphological alterations were associated with higher oxygen consumption rates (OCRs) in all three mutant iPSC-CMs, indicating higher electron transport chain activity to meet cellular ATP demands. Additionally, increased extracellular acidification rates suggested an increase in overall metabolic flux, while radioactive tracer uptake studies revealed decreased fatty acid uptake and utilization of glucose. Mutant iPSC-CMs also showed increased reactive oxygen species (ROS) and an elevated mitochondrial membrane potential. Increased mitochondrial respiration with pyruvate and malate as substrates was observed in mutant DNAJC19tv HeLa cells in addition to an upregulation of respiratory chain complexes, while cellular ATP-levels remain the same. Moreover, mitochondrial alterations were associated with increased beating frequencies, elevated diastolic Ca\(^{2+}\) concentrations, reduced sarcomere shortening and an increased beat-to-beat rate variability in mutant cell lines in response to β-adrenergic stimulation. Conclusions Loss of the DnaJ domain disturbs cardiac mitochondrial structure with abnormal cristae formation and leads to mitochondrial dysfunction, suggesting that DNAJC19 plays an essential role in mitochondrial morphogenesis and biogenesis. Moreover, increased mitochondrial respiration, altered substrate utilization, increased ROS production and abnormal Ca\(^{2+}\) kinetics provide insights into the pathogenesis of DCMA-related cardiomyopathy. KW - cell biology KW - molecular biology KW - dilated cardiomyopathy with ataxia KW - genetics KW - metabolism KW - mitochondria KW - OXPHOS KW - ROS KW - contractility Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350393 SN - 2212-8778 VL - 79 ER - TY - JOUR A1 - Scognamiglio, Roberta A1 - Cabezas-Wallscheid, Nina A1 - Thier, Marc Christian A1 - Altamura, Sandro A1 - Reyes, Alejandro A1 - Prendergast, Áine M. A1 - Baumgärtner, Daniel A1 - Carnevalli, Larissa S. A1 - Atzberger, Ann A1 - Haas, Simon A1 - von Paleske, Lisa A1 - Boroviak, Thorsten A1 - Wörsdörfer, Philipp A1 - Essers, Marieke A. G. A1 - Kloz, Ulrich A1 - Eisenman, Robert N. A1 - Edenhofer, Frank A1 - Bertone, Paul A1 - Huber, Wolfgang A1 - van der Hoeven, Franciscus A1 - Smith, Austin A1 - Trumpp, Andreas T1 - Myc depletion induces a pluripotent dormant state mimicking diapause JF - Cell N2 - Mouse embryonic stem cells (ESCs) are maintained in a naive ground state of pluripotency in the presence of MEK and GSK3 inhibitors. Here, we show that ground-state ESCs express low Myc levels. Deletion of both c-myc and N-myc (dKO) or pharmacological inhibition of Myc activity strongly decreases transcription, splicing, and protein synthesis, leading to proliferation arrest. This process is reversible and occurs without affecting pluripotency, suggesting that Myc-depleted stem cells enter a state of dormancy similar to embryonic diapause. Indeed, c-Myc is depleted in diapaused blastocysts, and the differential expression signatures of dKO ESCs and diapaused epiblasts are remarkably similar. Following Myc inhibition, pre-implantation blastocysts enter biosynthetic dormancy but can progress through their normal developmental program after transfer into pseudo-pregnant recipients. Our study shows that Myc controls the biosynthetic machinery of stem cells without affecting their potency, thus regulating their entry and exit from the dormant state. KW - hematopoietic stem cells KW - leukemia inhibitory factor KW - c-Myc KW - N-Myc KW - gene expression KW - embryonic stem cells KW - self-renewal KW - protein synthesis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190868 VL - 164 IS - 4 ER - TY - JOUR A1 - Behera, Ananyaashree A1 - Jain, Preeti A1 - Ganguli, Geetanjali A1 - Biswas, Mainak A1 - Padhi, Avinash A1 - Pattanaik, Kali Prasad A1 - Nayak, Barsa A1 - Ergün, Süleyman A1 - Hagens, Kristine A1 - Redinger, Natalja A1 - Saqib, Mohd A1 - Mishra, Bibhuti B. A1 - Schaible, Ulrich E. A1 - Karnati, Srikanth A1 - Sonawane, Avinash T1 - Mycobacterium tuberculosis acetyltransferase suppresses oxidative stress by inducing peroxisome formation in macrophages JF - International Journal of Molecular Sciences N2 - Mycobacterium tuberculosis (Mtb) inhibits host oxidative stress responses facilitating its survival in macrophages; however, the underlying molecular mechanisms are poorly understood. Here, we identified a Mtb acetyltransferase (Rv3034c) as a novel counter actor of macrophage oxidative stress responses by inducing peroxisome formation. An inducible Rv3034c deletion mutant of Mtb failed to induce peroxisome biogenesis, expression of the peroxisomal β-oxidation pathway intermediates (ACOX1, ACAA1, MFP2) in macrophages, resulting in reduced intracellular survival compared to the parental strain. This reduced virulence phenotype was rescued by repletion of Rv3034c. Peroxisome induction depended on the interaction between Rv3034c and the macrophage mannose receptor (MR). Interaction between Rv3034c and MR induced expression of the peroxisomal biogenesis proteins PEX5p, PEX13p, PEX14p, PEX11β, PEX19p, the peroxisomal membrane lipid transporter ABCD3, and catalase. Expression of PEX14p and ABCD3 was also enhanced in lungs from Mtb aerosol-infected mice. This is the first report that peroxisome-mediated control of ROS balance is essential for innate immune responses to Mtb but can be counteracted by the mycobacterial acetyltransferase Rv3034c. Thus, peroxisomes represent interesting targets for host-directed therapeutics to tuberculosis. KW - peroxisome KW - Rv3034c KW - acetyltransferase KW - macrophages KW - oxidative stress KW - Mycobacterium tuberculosis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284080 SN - 1422-0067 VL - 23 IS - 5 ER - TY - JOUR A1 - Münst, Bernhard A1 - Thier, Marc Christian A1 - Winnemöller, Dirk A1 - Helfen, Martina A1 - Thummer, Rajkumar P. A1 - Edenhofer, Frank T1 - Nanog induces suppression of senescence through downregulation of p27\(^{KIP1}\) expression JF - Journal of Cell Science N2 - A comprehensive analysis of the molecular network of cellular factors establishing and maintaining pluripotency as well as self renewal of pluripotent stem cells is key for further progress in understanding basic stem cell biology. Nanog is necessary for the natural induction of pluripotency in early mammalian development but dispensable for both its maintenance and its artificial induction. To gain further insight into the molecular activity of Nanog, we analyzed the outcomes of Nanog gain-of-function in various cell models employing a recently developed biologically active recombinant cell-permeant protein, Nanog-TAT. We found that Nanog enhances the proliferation of both NIH 3T3 and primary fibroblast cells. Nanog transduction into primary fibroblasts results in suppression of senescence-associated beta-galactosidase activity. Investigation of cell cycle factors revealed that transient activation of Nanog correlates with consistent downregulation of the cell cycle inhibitor p27\(^{KIP1}\) (also known as CDKN1B). By performing chromatin immunoprecipitation analysis, we confirmed bona fide Nanog-binding sites upstream of the p27\(^{KIP1}\) gene, establishing a direct link between physical occupancy and functional regulation. Our data demonstrates that Nanog enhances proliferation of fibroblasts through transcriptional regulation of cell cycle inhibitor p27 gene. KW - Embryonic stem cell KW - Protein transduction KW - Pluripotency KW - Senescence KW - Cell reprogramming KW - p27(KIP1) Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190761 VL - 129 IS - 5 ER - TY - JOUR A1 - Klein, Diana A1 - Meissner, Nicole A1 - Kleff, Veronika A1 - Jastrow, Holger A1 - Yamaguchi, Masahiro A1 - Ergün, Süleyman A1 - Jendrossek, Verena T1 - Nestin(+) Tissue-Resident Multipotent Stem Cells Contribute to Tumor Progression by Differentiating into Pericytes and Smooth Muscle Cells Resulting in Blood Vessel Remodeling JF - Frontiers in Oncology N2 - Tumor vessels with resistance to anti-angiogenic therapy are characterized by the normalization of the vascular structures through integration of mature pericytes and smooth muscle cells (SMC) into the vessel wall, a process termed vessel stabilization. Unfortunately, stabilization-associated vascular remodeling can result in reduced sensitivity to subsequent anti-angiogenic therapy. We show here that blockade of VEGF by bevacizumab induces stabilization of angiogenic tumor blood vessels in human tumor specimen by recruiting Nestin-positive cells, whereas mature vessels down-regulated Nestin-expression. Using xenograft tumors growing on bone-marrow (BM) chimera of C57Bl/6 wildtype and Nestin-GFP transgenic mice, we show for first time that Nestin(+) cells inducing the maturation of tumor vessels do not originate from the BM but presumably reside within the adventitia of adult blood vessels. Complementary ex vivo experiments using explants of murine aortas revealed that Nestin(+) multipotent stem cells (MPSCs) are mobilized from their niche and differentiated into pericytes and SMC through the influence of tumor-cell-secreted factors. We conclude that tissue-resident Nestin(+) cells are more relevant than BM-derived cells for vessel stabilization and therefore have to be considered in future strategies for anti-angiogenic therapy. The identification of proteins mediating recruitment or differentiation of local Nestin(+) cells with potential stem cell character to angiogenic blood vessels may allow the definition of new therapeutic targets to reduce tumor resistance against anti-angiogenic drugs. Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120973 SN - 2234-943X VL - 4 IS - 169 ER - TY - JOUR A1 - Drenckhahn, Detlev A1 - Gottschlich, Günter A1 - Zonneveld, Ben T1 - Neubeschreibungen und 2C-Werte von Pilosella macranthela subsp. silvae-pici (Spessart-Mausohrhabichtskraut) und Pilosella ottonis (Otto-Mausohrhabichtskraut) mit einer Übersicht über das Vorkommen von P. macranthela-Taxa in Bayern. T1 - New descriptions and 2C-values of Pilosella macranthela subsp. silvae-pici (Spessart mouse-ear hawkweed) and Pilosella ottonis (Otto mouse-ear hawkweed) with an overview of the occurrence of P. macranthela taxa in Bavaria. JF - Forum Geobotanicum N2 - A pentaploid taxon from the Pilosella macranthela group was discovered in Lower Franconia/Bavaria which is newly described here as P. macranthela subsp. sylvae-pici. It grows mainly in the Bavarian Bunter Spessart and occurs with three small, isolated stands also in the limestone area of the Main valley and Tauber area. Its habit of growth is intermediate between the furcata and laxicephala types of Pilosellae with epigeal and partly hypogeal stolons and a tendency to form clusters. The upper and lower surfaces of the rosette leaves have stellate hairs. The peduncles and the phyllaries are densely covered with dark glandular hairs with yellowish glandular heads. The lateral teeth of the ligules often are separated by incisions. A tetra- und pentaploid transitional taxon between P. macranthela subsp. sylvae-pici and P. officinarum is described as P. ottonis. P. ottonis is tetra- and pentaploid with up to 7 capitula. It is densely covered with dark stalk glands on phyllaries and resembles forms of P. acutifolia in habit. The phyllaries of P. ottonis are covered with numerous epidermal papillae with a diameter of about 10–20 μm and in this aspect resemble P. macranthela subsp. sylvae-pici and P. glomerata. However, in P. officinarum epidermal papillae are absent. Plants of genetically heterogeneous tetra- and heptaploid P. macranthela have been found outside the Spessart as spontaneous hybrids between P. glomerata and P. officinarum and also occur sporadically without P. glomerata in the vicinity. N2 - Eine pentaploide Sippe aus der Pilosella macranthela-Verwandtschaft wurde in Unterfranken/Bayern entdeckt, die hier als P. macranthela subsp. sylvae-pici neu beschrieben wird. Sie wächst hauptsächlich im bayerischen Buntsandstein-Spessart und kommt mit drei kleinen, isolierten Wuchsorten auch in den Kalkgebieten des Maintals und Tauberbereichs vor. Die Wuchsform steht zwischen dem Furcata- und Laxicephala-Typus von Pilosellinen mit ober- und teils unterirdischen Ausläufern und zeigt Neigung, Horste zu bilden. Die Ober- und Unterseiten der Rosettenblätter besitzen Sternhaare. Die Korbstiele und Hüllblätter sind dicht mit dunkel gestielten Drüsenhaaren mit gelblichen Drüsenköpfen besetzt. Die seitlichen Zähne der Blütenzungen sind oft durch Einschnitte abgetrennt. Tetra- und pentaploide Zwischenarten zwischen P. macranthela subsp. sylvae-pici und P. officinarum werden als P. ottonis neu beschrieben. P. ottonis ist tetra- und pentaploid mit bis zu 7 Körben, ist an den Hüllblättern mit dunklen Stieldrüsen besetzt und ähnelt vom Habitus Formen von P. acutlifolia. Die Hüllen von P. ottonis besitzen wie die von P. macranthela subsp. sylvae-pici und P. glomerata zahlreiche, ca. 10–20 μm dicke Epidermispapillen, die stets bei P. officinarum fehlen. Heterogene P. marcanthela-Sippen (tetra- und heptaploid) kommen als Spontanhybride zwischen P. glomerata und P. officinarum auch außerhalb des Spessartgebiets vor und wurden auch ohne benachbarte P. glomerata gefunden. KW - Asteraceae KW - Pilosella macranthela KW - cytotopes KW - 2C-values KW - Bavaria KW - Habichtskraut KW - Pilosella ottonis KW - Germany Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-344797 UR - http://forum-geobotanicum.net/articles/vol_11-2023/DD-GG-BZ_Neubeschreibungen_pp21-34/FG---DD-GG-BZ_Neubeschreibungen-P_macranthela-P_ottonis.pdf SN - 1867-9315 VL - 11 ER - TY - JOUR A1 - Drenckhahn, Detlev T1 - Neue und wieder entdeckte Hieracien auf Rügen T1 - New taxa and rediscovered hawkweeds on the island of Rügen, Germany N2 - The island of Rügen (Rugia), located in the Baltic sea, is the most northeastern (NE) part of Germany. Due to its particular geographic position at the border between scandinavian, middle european and continental european floral elements, Rügen harbours several hawkweed species (Hieracia) of the scandinavian area such as Hieracium fuscocinererum, H. subramosum, H. subrigidum and H. diaphanoides subsp. neoornatum and, at the same time, is the most northwestern location of H. echioides. Two endemic Hieracium species have been identified recently, i. e. H. muorum subsp. rugianum and H. caesium subsp. zabelianum (Gottschlich et al. 1998, Bot. Rundbr. Mecklenburg-Vorpommern 31:1-94). In the present communication, two further novel endemic Hieracium taxa will be described, which are restricted to the chalk cliffs of Cape Arkona and Jasmund, i. e. H. swantevitii and H. lachenalii subsp. litocretaceum. H. swantevitii (Swantevit’s hawkweed) is intermediate between H. caesium/H. bifidum and H. lachenalii with hairy, modestly glandular involucre and slightly serrated elongated leaves . This view of an intermediate position of H. swantevitii between these species was further supported by the ultrastructure of epidermal papillae of the outer bracts of the involucre visualized by scanning electron microscopy. H. lachenalii subsp. litocretaceum (chalk cliff hawkweed) is characterized by its narrow anguste to almost linear denticulate leaves in combination with mode rately glandular heads. In addition to the description of these two new hawkweed taxa , the rediscovery of three further species will be reported for Rügen, i. e. H. echioides (W. Gager in SE Rügen), H. cymosum subsp. cymosum (close to Göhren in SE Rügen) and H. subrigidum E Glowe in N Rügen. The locality of H. echioides appears to be most north-western site in middle Europe, the locality of H. cymosum is one of the last growth sites in the northern German lowlands and H. subrigidum (so far only known as a single herbarium specimen, collected 1858 in Rügen) has so far not been recorded in other localities of middle Europe. KW - Habichtskraut KW - Hieracium swantevitii KW - Hieracium lachenalii subsp. litocretaceum KW - Hieracium subrigidum KW - Hieracium cymosum KW - Hieracium echioides KW - Scanning electron microscopy KW - Epidermal papillae Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34843 ER - TY - JOUR A1 - Rockel, Anna F. A1 - Wagner, Nicole A1 - Spenger, Peter A1 - Ergün, Süleyman A1 - Wörsdörfer, Philipp T1 - Neuro-mesodermal assembloids recapitulate aspects of peripheral nervous system development \(in\) \(vitro\) JF - Stem Cell Reports N2 - Summary Here we describe a novel neuro-mesodermal assembloid model that recapitulates aspects of peripheral nervous system (PNS) development such as neural crest cell (NCC) induction, migration, and sensory as well as sympathetic ganglion formation. The ganglia send projections to the mesodermal as well as neural compartment. Axons in the mesodermal part are associated with Schwann cells. In addition, peripheral ganglia and nerve fibers interact with a co-developing vascular plexus, forming a neurovascular niche. Finally, developing sensory ganglia show response to capsaicin indicating their functionality. The presented assembloid model could help to uncover mechanisms of human NCC induction, delamination, migration, and PNS development. Moreover, the model could be used for toxicity screenings or drug testing. The co-development of mesodermal and neuroectodermal tissues and a vascular plexus along with a PNS allows us to investigate the crosstalk between neuroectoderm and mesoderm and between peripheral neurons/neuroblasts and endothelial cells. Highlights •Novel neuro-mesodermal assembloid model of peripheral nervous system development •Model covers neural crest cell induction, migration, and ganglion formation •Ganglia send projections to the mesodermal as well as neural compartment •Peripheral ganglia and nerve fibers interact with a co-developing vascular plexus KW - peripheral nervous system KW - neural crest KW - sensory ganglia KW - sensory neuron KW - vasculature KW - blood vessel KW - neural organoid KW - mesodermal organoid KW - assembloid KW - human induced pluripotent stem cells Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349925 SN - 2213-6711 VL - 18 IS - 5 ER - TY - JOUR A1 - Yadav, Preeti A1 - Selvaraj, Bhuvaneish T. A1 - Bender, Florian L. P. A1 - Behringer, Marcus A1 - Moradi, Mehri A1 - Sivadasan, Rajeeve A1 - Dombert, Benjamin A1 - Blum, Robert A1 - Asan, Esther A1 - Sauer, Markus A1 - Julien, Jean-Pierre A1 - Sendtner, Michael T1 - Neurofilament depletion improves microtubule dynamics via modulation of Stat3/stathmin signaling JF - Acta Neuropathologica N2 - In neurons, microtubules form a dense array within axons, and the stability and function of this microtubule network is modulated by neurofilaments. Accumulation of neurofilaments has been observed in several forms of neurodegenerative diseases, but the mechanisms how elevated neurofilament levels destabilize axons are unknown so far. Here, we show that increased neurofilament expression in motor nerves of pmn mutant mice, a model of motoneuron disease, causes disturbed microtubule dynamics. The disease is caused by a point mutation in the tubulin-specific chaperone E (Tbce) gene, leading to an exchange of the most C-terminal amino acid tryptophan to glycine. As a consequence, the TBCE protein becomes instable which then results in destabilization of axonal microtubules and defects in axonal transport, in particular in motoneurons. Depletion of neurofilament increases the number and regrowth of microtubules in pmn mutant motoneurons and restores axon elongation. This effect is mediated by interaction of neurofilament with the stathmin complex. Accumulating neurofilaments associate with stathmin in axons of pmn mutant motoneurons. Depletion of neurofilament by Nefl knockout increases Stat3-stathmin interaction and stabilizes the microtubules in pmn mutant motoneurons. Consequently, counteracting enhanced neurofilament expression improves axonal maintenance and prolongs survival of pmn mutant mice. We propose that this mechanism could also be relevant for other neurodegenerative diseases in which neurofilament accumulation and loss of microtubules are prominent features. KW - Amyotrophic-lateral-sclerosis KW - Transgenic mice KW - Mouse model KW - Alzheimers disease KW - Neurofilament KW - Progressive motor neuronopathy KW - Axonal transport KW - Intermediate filaments KW - Motoneuron disease KW - Lacking neurofilaments KW - Missense mutation KW - Axon degeneration KW - Microtubules KW - Stathmin KW - Stat3 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188234 VL - 132 IS - 1 ER - TY - JOUR A1 - Kutateladze, T. V. A1 - Axelrod, V. D. A1 - Gorboulev, Valentin G. A1 - Belzhelarskaya, S. N. A1 - Vartikyan, R. V. T1 - New procedure of high-voltage electrophoresis in polyacrylamide gel and its application to the sequencing of nucleic acids N2 - Fractionation of nucleic acids and their fragments with polyacrylamide gel has been widely applied in sequencing of nucleic acids. Although the conditions of electrophoresis for this purpose have previously been suggested. we have found that polyacrylamide gel electrophoresis at 5000 V (100 V/cm) is possible and effective. An apparatus consisting of a horizontal thermostated plate is used to remove the heat which was formed during the electrophoretic process. The techniques for loading samples on the horizontal thin gel and the procedure for high-voltage gel electrophoresis are described and illustrated by the fractionation of the spleen phosphodiesterase partial digest of tRNA¥~1 as well as by the RNA synthesis by RNA polymerase from E. coli with poly[d(A- T)j as template in the presence of "terminator," 3'-O-methyluridine 5'-triphosphate. This same technique was used for electrophoresis of oligonucleotides on acetylcellulose and was incorporated into a two-dimensional system which was demonstrated by fingerprinting of the guanylo-RNase digest of tRNAT'P from baker's yeast. In the third part of the article a simple technique for the electric trapping of nucleic acids or their fragments from a slab gel on a DEAE-paper sheet is presented. Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46927 ER - TY - JOUR A1 - Gallo, Lorenzo T1 - Nomenclatural adjustments and typifications in the genus Phedimus (Crassulaceae) JF - Forum Geobotanicum N2 - This paper deals with the taxonomical position and the nomenclature of two taxa belonging to the genus Sedum (Crassulaceae), today treated as Phedimus, namely Sedum middendorffianum Maxim var. diffusum Praeger and Sedum oppositifolium Sims. The correct taxonomical application of names is based on the nomenclatural types designated here. KW - lectotype KW - neotype KW - Phedimus middendorffianus, var. diffusus KW - Phedimus spurius subsp. oppositifolius KW - Sedum oppositifolium Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206347 UR - http://www.forum-geobotanicum.net/articles/vol_9-2020/gallo-phedimus/gallo-phedimus.pdf SN - 1867-9315 VL - 9 ER - TY - JOUR A1 - Weber, Heinrich E. T1 - Nomenklatorische Korrektur in der Gattung Rubus T1 - Nomenclatural correction in the genus Rubus JF - Forum Geobotanicum N2 - Wegen des älteren Homonyms Rubus tilioides Gand. 1884 wird für Rubus tilioides W. Jansen & H. E. Weber 2010 der neue Name Rubus tiliifrons W. Jansen & H. E. Weber veröffentlicht. N2 - Because of the older homonym Rubus tilioides Gand. 1884 the name Rubus tiliifrons W. Jansen & H. E. Weber is established as new name for Rubus tilioides W. Jansen & H. E. Weber 2010. KW - Rubus L. sectio Corylifolii KW - Botanische Nomenklatur KW - Nomen novum KW - new name Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174587 UR - http://www.forum-geobotanicum.net/articles/vol_8-2018/weber_rubus/weber_rubus-tiliifrons.pdf SN - 1867-9315 VL - 8 ER - TY - JOUR A1 - Rajendran, Ranjithkumar A1 - Rajendran, Vinothkumar A1 - Giraldo-Velasquez, Mario A1 - Megalofonou, Fevronia-Foivi A1 - Gurski, Fynn A1 - Stadelmann, Christine A1 - Karnati, Srikanth A1 - Berghoff, Martin T1 - Oligodendrocyte-specific deletion of FGFR1 reduces cerebellar inflammation and neurodegeneration in MOG\(_{35-55}\)-induced EAE JF - International Journal of Molecular Sciences N2 - Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of the central nervous system (CNS). MS commonly affects the cerebellum causing acute and chronic symptoms. Cerebellar signs significantly contribute to clinical disability, and symptoms such as tremor, ataxia, and dysarthria are difficult to treat. Fibroblast growth factors (FGFs) and their receptors (FGFRs) are involved in demyelinating pathologies such as MS. In autopsy tissue from patients with MS, increased expression of FGF1, FGF2, FGF9, and FGFR1 was found in lesion areas. Recent research using mouse models has focused on regions such as the spinal cord, and data on the expression of FGF/FGFR in the cerebellum are not available. In recent EAE studies, we detected that oligodendrocyte-specific deletion of FGFRs results in a milder disease course, less cellular infiltrates, and reduced neurodegeneration in the spinal cord. The objective of this study was to characterize the role of FGFR1 in oligodendrocytes in the cerebellum. Conditional deletion of FGFR1 in oligodendrocytes (Fgfr1\(^{ind−/−}\) was achieved by tamoxifen application, EAE was induced using the MOG\(_{35-55}\) peptide. The cerebellum was analyzed by histology, immunohistochemistry, and western blot. At day 62 p.i., Fgfr1\(^{ind−/−}\) mice showed less myelin and axonal degeneration compared to FGFR1-competent mice. Infiltration of CD3(+) T cells, Mac3(+) cells, B220(+) B cells and IgG(+) plasma cells in cerebellar white matter lesions (WML) was less in Fgfr1\(^{ind−/−}\)mice. There were no effects on the number of OPC or mature oligodendrocytes in white matter lesion (WML). Expression of FGF2 and FGF9 associated with less myelin and axonal degeneration, and of the pro-inflammatory cytokines IL-1β, IL-6, and CD200 was downregulated in Fgfr1\(^{ind−/−}\) mice. The FGF/FGFR signaling protein pAkt, BDNF, and TrkB were increased in Fgfr1\(^{ind−/−}\) mice. These data suggest that cell-specific deletion of FGFR1 in oligodendrocytes has anti-inflammatory and neuroprotective effects in the cerebellum in the EAE disease model of MS. KW - FGFR1 KW - oligodendrocytes KW - demyelination KW - inflammation KW - cerebellum KW - EAE KW - MS Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284296 SN - 1422-0067 VL - 22 IS - 17 ER - TY - JOUR A1 - Kamali, Salar A1 - Rajendran, Ranjithkumar A1 - Stadelmann, Christine A1 - Karnati, Srikanth A1 - Rajendran, Vinothkumar A1 - Giraldo‐Velasquez, Mario A1 - Berghoff, Martin T1 - Oligodendrocyte‐specific deletion of FGFR2 ameliorates MOG\(_{35-55}\)‐induced EAE through ERK and Akt signalling JF - Brain Pathology N2 - Fibroblast growth factors (FGFs) and their receptors (FGFRs) are involved in demyelinating pathologies including multiple sclerosis (MS). In our recent study, oligodendrocyte‐specific deletion of FGFR1 resulted in a milder disease course, less inflammation, reduced myelin and axon damage in EAE. The objective of this study was to elucidate the role of oligodendroglial FGFR2 in MOG\(_{35-55}\)‐induced EAE. Oligodendrocyte‐specific knockout of FGFR2 (Fgfr2\(^{ind-/-}\)) was achieved by application of tamoxifen; EAE was induced using the MOG\(_{35-55}\) peptide. EAE symptoms were monitored over 62 days. Spinal cord tissue was analysed by histology, immunohistochemistry and western blot. Fgfr2\(^{ind-/-}\) mice revealed a milder disease course, less myelin damage and enhanced axonal density. The number of oligodendrocytes was not affected in demyelinated areas. However, protein expression of FGFR2, FGF2 and FGF9 was downregulated in Fgfr2\(^{ind-/-}\) mice. FGF/FGFR dependent signalling proteins were differentially regulated; pAkt was upregulated and pERK was downregulated in Fgfr2\(^{ind-/-}\) mice. The number of CD3(+) T cells, Mac3(+) cells and B220(+) B cells was less in demyelinated lesions of Fgfr2\(^{ind-/-}\) mice. Furthermore, expression of IL‐1β, TNF‐α and CD200 was less in Fgfr2\(^{ind-/-}\) mice than controls. Fgfr2ind−/− mice showed an upregulation of PLP and downregulation of the remyelination inhibitors SEMA3A and TGF‐β expression. These data suggest that cell‐specific deletion of FGFR2 in oligodendrocytes has anti‐inflammatory and neuroprotective effects accompanied by changes in FGF/FGFR dependent signalling, inflammatory cytokines and expression of remyelination inhibitors. Thus, FGFRs in oligodendrocytes may represent potential targets for the treatment of inflammatory and demyelinating diseases including MS. KW - experimental autoimmune encephalomyelitis KW - FGF/FGFR signalling KW - multiple sclerosis KW - oligodendrocytes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224354 VL - 31 SP - 297 EP - 311 ER - TY - JOUR A1 - Kozlov, J. V. A1 - Gorboulev, Valentin G. A1 - Kurmanova, A. G. A1 - Bayev, Alexander A. A1 - Shilov, A. A. A1 - Zhdanov, V. M. T1 - On the origin of the H1N1 (A/USSR/90/77) influenza virus N2 - The influenza virus H1N1 (the A/USSR/90/77 strain) that reappeared in 1977 after the H1N1 influenza viruses had disappeared from the human population, is compared with the A/FM/1/47 and the A/FW/1/50 influenza viruses by the method of oligonucleotide mapping of individual segments of the viral RNAs. Seven genes of the A/USSR/90/77 virus appear to be very similar to the corresponding genes of the A/FW/1/50 virus, whereas the gene coding for the M protein displays considerable homology to the corresponding gene of the A/FM/1/47 virus. The data demonstrate that the A/USSR/90/77 strain is a recombinant virus. KW - influenza virus ; virion RNA segments ; oligonucleotide mapping ; gene reassortment Y1 - 1981 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32556 ER - TY - JOUR A1 - Gorboulev, Valentin G. A1 - Akhundova, Aida A1 - Grzeschik, K.-H. A1 - Fahrenholz, Falk T1 - Organization and chromosomal localization of the gene for the human bombesin receptor subtype expressed in pregnant uterus N2 - The gene encoding the human homologue of the guinea pig uterine bombesm receptor [( 1992) Eur. J. Biochem. 208,405] was isolated from a genomic lambda library by the PCR/homology screening approach. The gene spans more than 4 kb and consists of 3 exons and 2 introns. The deduced amino acid sequence shows about 86% identity to that of guinea pig bombesin receptor. This subtype of bombesin receptor is expressed in the pregnant uterus and in two human tumour cell lines, T47D (ductal breast carcinoma) and A431 (epidermal carcinoma). PCR analysis of genomic DNA from human-mouse cell hybrids allows the cloned gene to be localized to the region q26q28 on chromosome X. KW - Bombesin ; Bombesin receptor ; Chromosomal localization Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32572 ER - TY - JOUR A1 - Ergün, Süleyman A1 - Wörsdörfer, Philipp T1 - Organoids, assembloids and embryoids: New avenues for developmental biology, disease modeling, drug testing and toxicity assessment without animal experimentation JF - Organoids N2 - No abstract available KW - developmental biology KW - organoids Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284101 SN - 2674-1172 VL - 1 IS - 1 SP - 37 EP - 40 ER - TY - THES A1 - Chintalapati, Chakravarthi T1 - Ornithine decarboxylase is the receptor of regulatory protein RS1 (RSC1A1) mediating RS1 dependent shortterm regulation of glucose transporter SGLT1 T1 - Ornithindecarboxylase ist der Rezeptor des regulatorischen Proteins RS1 (RSC1A1) vermittelnde RS1 abhängig kurzfristige Regulierung der Glucose-Transporter SGLT1 N2 - RS1 is the intron less singel copy gene involved in regulation of plasme membrane transporters. Ornithine decarboxylase is identified as the receptor of RS1 specific for the release of vesicles containing SGLT1 specifically at the trans-golgi network. RS1 decreases the activity of ODC there by inhibiting the release of vesicles containing specifically SGLT1. N2 - Das Protein RS1 welches spezifisch in Säugetieren vorkommt hat ein Molekulargewicht von 67 kDa und wird von einem intronfreien „ single copy gene“ kodiert. Es ist an der Regulation verschiedener in der Plasmamembran enthaltenen Transportern beteilig. Der am besten untersuchte Zieltransporter für RS1 ist der Na+-Glukose-Kotransporter SGLT1, welcher sowohl auf transkripioneller, wie auch auf posttranskripioneller Ebene reguliert wird. RS1 ist am Transgolgi-Netzwerk (TGN) lokalisiert und blockiert hier die Abschnürung von Transporter-enthaltenen Vesikeln. Es enthält N-Terminal ein 83 Aminosäure langes Fragment (RS1-Reg) welches für die glukoseabhängige posttranskripionelle Regulation von SGLT1 verantwortlich ist. Die Komplexität dieser Regulation wird dadurch ersichtlich, dass RS1-Reg 20 Serine in Konsensussequenzen für verschiedenste Kinasen sowie zweimal das Tripeptid QSP und einmal das Oktapeptid SDSDRIEP enthält. Diese Peptide können SGLT1 wie RS1- reg glukoseabhängig regulieren. In der vorliegenden Studie wurde das Protein Ornithin- Decarboxylase (ODC) als Rezeptor für die von RS1 vermittelte spezifische Regulation von SGLT1 identifiziert. Die Identifizierung erfolgte zunächst durch „yeast two hybrid screening“ und dann durch Immunkopräzipitation. Zunächst wurde die Interaktion von ODC mit den ersten 312 Aminosäuren von RS1 gefunden. In weiterführenden Experimenten zeigte sich, dass bereits RS1-Reg für die Interaktion ausreicht. Nach Koexpression von ODC mit SGLT1 in Xenopus laevis-Oocyten konnte eine erhörte Aktivität des SGLT1 gezeigt werden. Durch Hemmung der endogenen ODC Aktivität in Oozyten durch den spezifischen ODC-Blocker Difluoromethylornithin (DFMO) wurde die durch SGLT1 vermittelte Aufnahme von Glukose gehemmt. Da DFMO keinen additiven Effekt gegenüber dem Exocytoseblocker Brefeldin A zeigte, scheint diese Aktivierung auf einer Regulation der Abschnürung Transporter- enthaltender Vesikel zu beruhen. Es wurde außerdem gezeigt, dass Putrescin, ein Produkt von ODC, in der Lage ist die Regulation von SGLT1 durch RS1-Reg zu blockieren. Dies legt den Schluss nahe, dass die Regulation von SGLT1 durch RS1-Reg auf einer Inhibition von ODC durch RS1-Reg beruht. In gleicher Weise konnte der inhibitorische Effekt des Tripeptids QEP durch Putrescin blockiert werden. QEP ähnelt der phosphorylierten Form QSP in RS1- reg. Die Tatsache, dass QEP die enzymatische Aktivität von ODC hemmte war ein Nachweis für die Interaktion eines aktivierten Peptidmotifs aus RS1-Reg. Die erzielten Ergebnisse sind für die Entwicklung neuer pharmakologischer Therapien, bei denen die Regulation der Glukoseabsorption durch RS1 beeinflußt wird, von Bedeutung. KW - RS1 KW - ODC KW - exocytosis KW - polyamines KW - Ornithindecarboxylase Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85622 ER - TY - JOUR A1 - Watermann, Christoph A1 - Meyer, Malin Tordis A1 - Wagner, Steffen A1 - Wittekindt, Claus A1 - Klussmann, Jens Peter A1 - Erguen, Sueleyman A1 - Baumgart-Vogt, Eveline A1 - Karnati, Srikanth T1 - Peroxisomes are highly abundant and heterogeneous in human parotid glands JF - International Journal of Molecular Sciences N2 - The parotid gland is one of the major salivary glands producing a serous secretion, and it plays an essential role in the digestive and immune systems. Knowledge of peroxisomes in the human parotid gland is minimal; furthermore, the peroxisomal compartment and its enzyme composition in the different cell types of the human parotid gland have never been subjected to a detailed investigation. Therefore, we performed a comprehensive analysis of peroxisomes in the human parotid gland’s striated duct and acinar cells. We combined biochemical techniques with various light and electron microscopy techniques to determine the localization of parotid secretory proteins and different peroxisomal marker proteins in parotid gland tissue. Moreover, we analyzed the mRNA of numerous gene encoding proteins localized in peroxisomes using real-time quantitative PCR. The results confirm the presence of peroxisomes in all striated duct and acinar cells of the human parotid gland. Immunofluorescence analyses for various peroxisomal proteins showed a higher abundance and more intense staining in striated duct cells compared to acinar cells. Moreover, human parotid glands comprise high quantities of catalase and other antioxidative enzymes in discrete subcellular regions, suggesting their role in protection against oxidative stress. This study provides the first thorough description of parotid peroxisomes in different parotid cell types of healthy human tissue. KW - peroxisomes KW - parotid gland KW - human KW - catalase KW - differential expression KW - PSP KW - mRNA KW - immunofluorescence Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311079 SN - 1422-0067 VL - 24 IS - 5 ER - TY - CHAP A1 - Werner, Rudolf A1 - Wakabayashi, Hiroshi A1 - Jahns, Roland A1 - Ergün, Süleyman A1 - Jahns, Valerie A1 - Higuchi, Takahiro T1 - PET-Guided Histological Characterization of Myocardial Infiltrating Cells in a Rat Model of Myocarditis T2 - European Heart Journal - Cardiovascular Imaging N2 - No abstract available. KW - Myokarditis KW - positron emission tomography KW - myocarditis KW - PET KW - 18F-FDG Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161127 SN - 2047-2404 N1 - This is a pre-copyedited, author-produced version of an article accepted for publication in European Heart Journal Cardiovascular Imaging following peer review. The version of record . Eur Heart J Cardiovasc Imaging. ISSN: 2047-2404. Supplement, vol. 18, i1-i3, May 2017 is available online at: 10.1093/ehjci/jex071. VL - 18 IS - Supplement PB - Oxford University Press ER - TY - JOUR A1 - Sagiv, Jitka Y. A1 - Michaeli, Janna A1 - Assi, Simaan A1 - Mishalian, Inbal A1 - Kisos, Hen A1 - Levy, Liran A1 - Damti, Pazzit A1 - Lumbroso, Delphine A1 - Polyansky, Lola A1 - Sionov, Ronit V. A1 - Ariel, Amiram A1 - Hovav, Avi-Hai A1 - Henke, Erik A1 - Fridlender, Zvi G. A1 - Granot, Zvi T1 - Phenotypic diversity and plasticity in circulating neutrophil subpopulations in cancer JF - Cell Reports N2 - Controversy surrounds neutrophil function in cancer because neutrophils were shown to provide both pro-and antitumor functions. We identified a heterogeneous subset of low-density neutrophils (LDNs) that appear transiently in self-resolving inflammation but accumulate continuously with cancer progression. LDNs display impaired neutrophil function and immunosuppressive properties, characteristics that are in stark contrast to those of mature, high-density neutrophils (HDNs). LDNs consist of both immature myeloid-derived suppressor cells (MDSCs) and mature cells that are derived from HDNs in a TGF-beta-dependent mechanism. Our findings identify three distinct populations of circulating neutrophils and challenge the concept that mature neutrophils have limited plasticity. Furthermore, our findings provide a mechanistic explanation to mitigate the controversy surrounding neutrophil function in cancer. KW - tumorigenic properties KW - innate immunity KW - adenocarcinoma KW - inhibition KW - model KW - suppressor cells KW - tumor KW - TGF-beta KW - mice KW - lung Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144102 VL - 10 IS - 4 ER - TY - JOUR A1 - Richter, K. A1 - Mathes, V. A1 - Fronius, M. A1 - Althaus, M. A1 - Hecker, A. A1 - Krasteva-Christ, G. A1 - Padberg, W. A1 - Hone, A. J. A1 - McIntosh, J. M. A1 - Zakrzewicz, A. A1 - Grau, V. T1 - Phosphocholine - an agonist of metabotropic but not of ionotropic functions of α9-containing nicotinic acetylcholine receptors JF - Scientific Reports N2 - We demonstrated previously that phosphocholine and phosphocholine-modified macromolecules efficiently inhibit ATP-dependent release of interleukin-1β from human and murine monocytes by a mechanism involving nicotinic acetylcholine receptors (nAChR). Interleukin-1β is a potent pro-inflammatory cytokine of innate immunity that plays pivotal roles in host defence. Control of interleukin-1β release is vital as excessively high systemic levels cause life threatening inflammatory diseases. In spite of its structural similarity to acetylcholine, there are no other reports on interactions of phosphocholine with nAChR. In this study, we demonstrate that phosphocholine inhibits ion-channel function of ATP receptor P2X7 in monocytic cells via nAChR containing α9 and α10 subunits. In stark contrast to choline, phosphocholine does not evoke ion current responses in Xenopus laevis oocytes, which heterologously express functional homomeric nAChR composed of α9 subunits or heteromeric receptors containing α9 and α10 subunits. Preincubation of these oocytes with phosphocholine, however, attenuated choline-induced ion current changes, suggesting that phosphocholine may act as a silent agonist. We conclude that phophocholine activates immuno-modulatory nAChR expressed by monocytes but does not stimulate canonical ionotropic receptor functions. KW - phosphocholine KW - interleukin-1β KW - nicotinic acetylcholine receptors Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167655 VL - 6 IS - 28660 ER - TY - JOUR A1 - Haveman, Rense T1 - Phytosociological notes on hedges in South Ayrshire, Scotland JF - Forum Geobotanicum N2 - On the basis of four relevées of hedges around Straiton en Dailly in South Ayrshire, Scotland, some features of hedges are discussed. On the basis of the brambles, the vegetation of these hedges can be assigned to the Pruno-Rubion sprengelii, which comprises the bramble scrubs of circumneutral and nutrient rich soils in West Europe (Haveman et al. 2017, Haveman & de Ronde 2019). Until now, this alliance was thought to be restricted to the northwestern edge of the European continent, but based on these relevées and the known distribution area of Rubus nemoralis and Rubus polyanthemus, both characteristic for the Pruno-Rubion sprengelii, large parts of North England and Scotland have to be included in the distribution area of the alliance. The Pruno-Rubion sprengelii is optimally developed in rather narrow structures, like hedges, which are pruned every year. Here, brambles and herbs alike can grow with and under the shrubs, facilitated by the light that reaches large parts of the ground. Where the economic base of hedges perishes, they are not longer maintained, and the shrubs can grow out to their natural proportions. This changes the amount of light reaching the surface in the inner parts of the thicket, changing the competition between the species. The brambles as well as the herbs are displaced to the outer edges of the scrub, and the vegetation "dissociates" in a high-growing scrub, a fore-mantle ("cuff") with brambles, and a fringe with perennial herbs. These elements can hardly ever be assigned to the Pruno-Rubion anymore. The Pruno-Rubion sprengelii in optima forma is a scrub in which the three elements (shrubs, brambles, and herbs) grow closely intertwined. This is rarely found in natural landscapes, and thus the alliance is a typical element of the old farmer landscape. What is more: the typical species of the alliance, like Rubus nemoralis and R. polyanthemus, could only evolve after the landscape was opened by farmers in the last six millennia (Matzke-Hajek 1997), giving way to Rubus ulmifolius to expand its distribution area. This caused an explosion of hybrids which stabilised through apomixis into the wealth of Rubus species inhibiting the West European landscape nowadays (Sochor et al. 2015). Many of these species have their original home in a man-made landscape. Therefore, the Pruno-Rubion sprengelii can be characterised as a "farmers alliance" pur sang. KW - agricultural landscape KW - management KW - Pruno-Rubion sprengelii KW - Rhamno-Prunetea KW - vegetation KW - Brombeere Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312634 UR - http://forum-geobotanicum.net/articles/vol_11-2023/haveman_hedges_pp1-7/FG---haveman-hedges.pdf SN - 1867-9315 VL - 11 ER - TY - THES A1 - Öllinger, Rupert T1 - Polymerisationseigenschaften des Synaptonemalkomplexproteins SYCP1 und Charakterisierung von Bindungspartnern : Architektur meiotischer Chromosomen T1 - Polymerization Properties of the Synaptonemal Complex Protein SYCP1 and Characterization of Binding Partners N2 - Das Synaptonemalkomplexprotein SYCP1 ist eine Strukturkomponente des Synaptonemalkomplexes (SC) von Saeugern, einer meiosespezifischen Struktur, die wesentlich fuer die Synapse, Rekombination und Segregation homologer Chromosomen ist. Der SC besteht aus zwei lateralen Elementen (LEs) und einer zentralen Region (CR), in deren Mitte das zentrale Element (CE) liegt. Dabei sind die LEs den Achsen der homologen Chromosomen aufgelagert und werden in der CR durch Transversalfilamente (TFs) mit dem CE verbunden. Im Protein SYCP1 (125 kDa) flankieren zwei nicht-helikale terminale Domaenen eine ausgedehnte zentrale „Coiled-Coil“-Domaene. Fuer diese Domaene wird angenommen, dass sie die die Kluft zwischen LEs und CE ueberbrueckt, wobei die C-Termini in den LEs verankert sind und die N-Termini im CE lokalisiert wurden. Um die molekulare Architektur des SC besser zu verstehen und die Bedeutung von SYCP1 für die Zusammenlagerung des SC aufzudecken, wurden die Polymerisationseigenschaften von SYCP1 erforscht. Dazu wurde das Protein in somatischen Zellen exprimiert. In diesem experimentellem Ansatz polymerisierte SYCP1 autonom zu filamentoesen Strukturen, welche sich auf ultrastruktureller Ebene als alternierende elektronendichte Balken offenbarten, die ueber TFs verbunden waren. Dieser Aufbau glich parallel aneinander gereihten Stapeln von SCs, so genannten Polykomplexen (PCs). Die Analyse der Orientierung der SYCP1 Molekuele innerhalb der PCs erwies, dass diese hochorganisiert vorliegen und die Organisation von SYCP1 innerhalb von PCs und SCs identisch ist. Folglich kann sich SYCP1 sogar in Abwesenheit anderer SC-Proteine zu Strukturen zusammenlagern, die der CR entsprechen und muss dementsprechend beim Aufbau der CR des SC den grundlegenden Faktor darstellen. Für eine genauere Analyse wurden ausgewaehlte Mutanten von SYCP1 exprimiert. Moleküle mit modifizierter Laenge der zentralen alpha-helikalen Domaene resultierten in der Bildung von PCs mit veränderter Weite der CR. Dies beweist, dass die „Coiled-Coil“-Domaene den Abstand der CR eines PC bestimmt und impliziert dieselbe Funktion in der SC-Bildung. Darueber hinaus wurde gezeigt, dass SYCP1 Molekuele mit Deletion des nicht-helikalen N-Terminus immer noch in der Lage sind, PCs zu bilden, diese Eigenschaft aber stark eingeschraenkt ist. Das bezeugt die Bedeutung des N-Terminus sowohl in der PC-Bildung als auch im Aufbau des CE von SCs, weist aber dabei auch dem vorderen Teil der „Coiled-Coil“-Domaene eine wichtige Rolle zu. Im Gegensatz dazu war bei Mutanten mit Deletion des nicht-helikalen C-Terminus die PC-Bildung vollstaendig blockiert, was auf eine große Bedeutung dieser Domaene fuer die Polymerisation hinweist. Ein weiterer Hauptgegenstand der Arbeit war die Charakterisierung von Bindungspartnern von SYCP1. Über Immungoldlokalisation auf Maushoden konnten die Proteine Syce1 und Cesc1 als erste ausschliessliche Komponenten des CE des SC bestimmt werden. Zusaetzlich wurde die Interaktion dieser Proteine mit dem N-Terminus von SYCP1 verifiziert. SYCP1 bildet also die Grundstruktur des CE aus und rekrutiert Syce1 und Cesc1. N2 - The synaptonemal complex protein 1 (SYCP1) is a structural component of the mammalian synaptonemal complex (SC), a meiosis-specific nuclear structure essential for synapsis, recombination and segregation of homologous chromosomes. The SC is a tripartite structure consisting of two lateral elements (LEs) and the central region (CR) with a central element (CE) in its middle. The LEs are attached to the axes of homologous chromosomes and are connected with the CE by transversal filaments (TFs). The protein SYCP1 (125 kDa) contains a long central á-helical domain, which is predicted to mediate dimerization in a parallel coiled-coil structure, flanked by two non-helical ends. The coiled-coil is thought to cross the gap between the LEs and the CE, the C-termini are anchored in the LEs and the N-termini have been localized to the CE. In order to better understand the molecular architecture of the SC and the role of SYCP1 in SC-assembly the polymerization properties of SYCP1 were investigated. To this end the protein was expressed in somatic cells. In this approach SYCP1 is able to form stable filamentous structures autonomously, which on the ultrastructural level represent alternating lines connected by TFs. This composition resembles multimeric SC-like complexes arranged in parallel, so called polycomplexes (PCs). By determining the orientation of SYCP1 molecules it was proven that PCs are highly ordered structures with the same arrangement of SYCP1 molecules as in SCs. These results demonstrate that SYCP1 is able to assemble into structures closely resembling the CR of SCs even in the absence of other SC-proteins, which signifies that SYCP1 is the primary determinant of SC assembly which in turn plays a key role in synapsis of homologous chromosomes. For a more detailed analysis, selected mutated constructs of SYCP1 were expressed. Mutations that modified the length of the central alpha-helical domain resulted in the formation of PCs consisting of repeat units of altered width, verifying that the coiled-coil domain determines the distance between the lines of the PC. This result implies the same function of this domain in SC assembly. Moreover, it was observed that SYCP1 molecules lacking the non-helical N-terminus are still able to form PCs, albeit at a strongly reduced level. This shows the importance of the N-terminus both in SYCP1 autoassembly and in the formation of the CE of SCs, but also implies a significant role of the N-terminal part of the coiled-coil domain. In contrast, when the non-helical C-terminus was deleted, filament formation was eliminated indicating a major role of the C-terminus in SYCP1 autoassembly. Another major topic of this work was the characterization of SYCP1 binding partners. By immunogold localization on mouse testis the proteins Syce1 and Cesc1 could be identified as the first exclusive components of the CE of SCs. Furthermore, the interaction of these proteins with the N-terminal region of SYCP1 was validated. Hence, SYCP1 forms the basic structure of the CE and recruits Syce1 and Cesc1. KW - Synaptinemal-Komplex KW - Coiled coil KW - Skleroproteine KW - Synaptonemalkomplex KW - Meiose KW - Keimzellentwicklung KW - Sturkturprotein KW - Coiled-Coile KW - synaptonemal complex KW - meiosis KW - germ cell development KW - structural protein KW - coiled-coil Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-15456 ER - TY - JOUR A1 - Huflage, Henner A1 - Grunz, Jan-Peter A1 - Patzer, Theresa Sophie A1 - Pannenbecker, Pauline A1 - Feldle, Philipp A1 - Sauer, Stephanie Tina A1 - Petritsch, Bernhard A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Kunz, Andreas Steven T1 - Potential of unenhanced ultra-low-dose abdominal photon-counting CT with tin filtration: a cadaveric study JF - Diagnostics N2 - Objectives: This study investigated the feasibility and image quality of ultra-low-dose unenhanced abdominal CT using photon-counting detector technology and tin prefiltration. Materials and Methods: Employing a first-generation photon-counting CT scanner, eight cadaveric specimens were examined both with tin prefiltration (Sn 100 kVp) and polychromatic (120 kVp) scan protocols matched for radiation dose at three different levels: standard-dose (3 mGy), low-dose (1 mGy) and ultra-low-dose (0.5 mGy). Image quality was evaluated quantitatively by means of contrast-to-noise-ratios (CNR) with regions of interest placed in the renal cortex and subcutaneous fat. Additionally, three independent radiologists performed subjective evaluation of image quality. The intraclass correlation coefficient was calculated as a measure of interrater reliability. Results: Irrespective of scan mode, CNR in the renal cortex decreased with lower radiation dose. Despite similar mean energy of the applied x-ray spectrum, CNR was superior for Sn 100 kVp over 120 kVp at standard-dose (17.75 ± 3.51 vs. 14.13 ± 4.02), low-dose (13.99 ± 2.6 vs. 10.68 ± 2.17) and ultra-low-dose levels (8.88 ± 2.01 vs. 11.06 ± 1.74) (all p ≤ 0.05). Subjective image quality was highest for both standard-dose protocols (score 5; interquartile range 5–5). While no difference was ascertained between Sn 100 kVp and 120 kVp examinations at standard and low-dose levels, the subjective image quality of tin-filtered scans was superior to 120 kVp with ultra-low radiation dose (p < 0.05). An intraclass correlation coefficient of 0.844 (95% confidence interval 0.763–0.906; p < 0.001) indicated good interrater reliability. Conclusions: Photon-counting detector CT permits excellent image quality in unenhanced abdominal CT with very low radiation dose. Employment of tin prefiltration at 100 kVp instead of polychromatic imaging at 120 kVp increases the image quality even further in the ultra-low-dose range of 0.5 mGy. KW - spectral shaping KW - tin prefiltration KW - abdominal imaging KW - ultra-low-dose CT KW - urinary calculi KW - photon-counting Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304122 SN - 2075-4418 VL - 13 IS - 4 ER - TY - JOUR A1 - Parker, H. E. A1 - Adriaenssens, A. A1 - Rogers, G. A1 - Richards, P. A1 - Koepsell, H. A1 - Reimann, F. A1 - Gribble, F. M. T1 - Predominant role of active versus facilitative glucose transport for glucagon-like peptide-1 secretion JF - Diabetologia N2 - Aims/hypothesis Several glucose-sensing pathways have been implicated in glucose-triggered secretion of glucagon-like peptide-1 (GLP-1) from intestinal L cells. One involves glucose metabolism and closure of ATP-sensitive K\(^+\) channels, and another exploits the electrogenic nature of Na\(^+\)-coupled glucose transporters (SGLTs). This study aimed to elucidate the role of these distinct mechanisms in glucose-stimulated GLP-1 secretion. Methods Glucose uptake into L cells (either GLUTag cells or cells in primary cultures, using a new transgenic mouse model combining proglucagon promoter-driven Cre recombinase with a ROSA26tdRFP reporter) was monitored with the FLII\(_{12}\)Pglu-700μδ6 glucose sensor. Effects of pharmacological and genetic interference with SGLT1 or facilitative glucose transport (GLUT) on intracellular glucose accumulation and metabolism (measured by NAD(P)H autofluorescence), cytosolic Ca\(^{2+}\) (monitored with Fura2) and GLP-1 secretion (assayed by ELISA) were assessed. Results L cell glucose uptake was dominated by GLUT-mediated transport, being abolished by phloretin but not phloridzin. NAD(P)H autofluorescence was glucose dependent and enhanced by a glucokinase activator. In GLUTag cells, but not primary L cells, phloretin partially impaired glucose-dependent secretion, and suppressed an amplifying effect of glucose under depolarising high K\(^+\) conditions. The key importance of SGLT1 in GLUTag and primary cells was evident from the impairment of secretion by phloridzin or Sglt1 knockdown and failure of glucose to trigger cytosolic Ca\(^{2+}\) elevation in primary L cells from Sglt1 knockout mice. Conclusions/interpretation SGLT1 acts as the luminal glucose sensor in L cells, but intracellular glucose concentrations are largely determined by GLUT activity. Although L cell glucose metabolism depends partially on glucokinase activity, this plays only a minor role in glucose-stimulated GLP-1 secretion. KW - KATP channel KW - glucokinase KW - glucagon-like peptide-1 (GLP-1) KW - SGLT1 KW - L cells Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125927 VL - 55 IS - 9 ER -