@phdthesis{Rajab2021, author = {Rajab, Suhaila}, title = {Untersuchung von Sub-Millisekunden Dynamiken und allosterischer Kommunikation in Ligandenbindedom{\"a}nen ionotroper Glutamatrezeptoren}, doi = {10.25972/OPUS-24494}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244946}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Ionotrope Glutamatrezeptoren (iGluRs) sind ligandengesteuerte Ionenkan{\"a}le und vermitteln den Großteil der exzitatorischen Signalweiterleitung im gesamten zentralen Nervensystem. Dar{\"u}ber hinaus spielen iGluRs eine entscheidende Rolle bei der neuronalen Entwicklung und Funktion, einschließlich Lernprozessen und Ged{\"a}chtnisbildung. Da eine Fehlfunktion dieser Rezeptoren mit zahlreichen neurodegenerativen Erkrankungen verbunden ist, stellen iGluRs zudem wichtige Zielproteine f{\"u}r die pharmakologische Wirkstoffentwicklung dar. Im Allgemeinen wird zwischen drei Untergruppen ionotroper Glutamatrezeptoren unterschieden, welche aufgrund ihrer Selektivit{\"a}t f{\"u}r einen bestimmten Liganden benannt sind: AMPA-, Kainate-, und NMDA-Rezeptoren. Die iGluRs jeder dieser Untergruppen bestehen in der Regel aus vier Untereinheiten, welche wiederum aus vier semiautonomen Dom{\"a}nen aufgebaut sind: (i) die aminoterminale Dom{\"a}ne (ATD), (ii) die Ligandenbindedom{\"a}ne (LBD), (iii) die Transmembrandom{\"a}ne (TMD) und (iv) die carboxyterminale Dom{\"a}ne (CTD). Die Ligandenbindedom{\"a}ne, welche wiederum aus zwei Lobes (D1 und D2) besteht und in ihrer Struktur einer Muschelschale {\"a}hnelt, vollzieht bei Bindung eines Neurotransmitters eine Konformations{\"a}nderung, wobei sie sich um den gebundenen Agonisten herumschließt. Diese Konformations{\"a}nderung der LBD wird auf die Transmembrandom{\"a}ne, welche den membran{\"u}berspannenden Ionenkanal ausbildet, {\"u}bertragen, was in einer Umlagerung der Transmembranhelices und infolgedessen der {\"O}ffnung des Ionenkanals resultiert. Die Konformations{\"a}nderung der LBD ist demnach die treibende Kraft, welche dem {\"O}ffnen und Schließen des Ionenkanals zugrunde liegt. Aus diesem Grund stellt die isolierte Ligandenbindedom{\"a}ne, welche als l{\"o}sliches Protein hergestellt werden kann, ein etabliertes Modellsystem zur Untersuchung der strukturellen und funktionellen Zusammenh{\"a}nge innerhalb des Funktionsmechanismus ionotroper Glutamatrezeptoren dar. Im Rahmen dieser Arbeit wurden die Konformationsdynamiken der in Escherichia coli-Bakterien exprimierten isolierten Ligandenbindedom{\"a}nen der drei homologen Untergruppen - AMPA-, Kainate- und NMDA-Rezeptoren - sowohl als Monomer als auch als Dimer untersucht. Hierbei wurden im ungebundenen Apo-Zustand der Proteine signifikante Kinetiken im Bereich von Nanosekunden bis Mikrosekunden festgestellt, welche bei Bindung eines Agonisten sowie bei Dimerisierung erheblichen Ver{\"a}nderungen zeigen. Dar{\"u}ber hinaus wurde allosterische Kommunikation zwischen den LBDs der NMDA-Untergruppe untersucht, wobei in der Tat ein deutlicher allosterischer Effekt in Bezug auf die Konformationsdynamiken der Proteine gemessen werden konnte. Weiterhin wurde ein PET-FCS-basiertes Verfahren zur Messung der Dissoziationskonstante der Bindung eines Liganden an die LBD eines AMPA-Rezeptors entwickelt. Zuletzt wurde außerdem ermittelt, ob ein Unterschied zwischen vollen und partiellen Agonisten hinsichtlich ihres Einflusses auf die Konformationsdynamiken einer AMPA-Rezeptor LBD besteht, was nachgewiesenermaßen nicht der Fall ist. Alle Messungen wurden auf Einzelmolek{\"u}lebene auf Zeitskalen von Nanosekunden bis Millisekunden basierend auf Fluoreszenzfluktuationen unter Verwendung des photoinduzierten Elektronentransfers (PET) in Kombination mit Korrelationsspektroskopie (PET-FCS) durchgef{\"u}hrt. Zu diesem Zweck wurden PET-basierte Fluoreszenzsonden entwickelt, um Konformations{\"a}nderungen auf einer r{\"a}umlichen Skala von einem Nanometer zu detektieren. Durch die Experimente innerhalb dieser Arbeit konnte gezeigt werden, dass die PET-FCS-Methode eine vielversprechende Erg{\"a}nzung zu allen bisher bestehenden Methoden zur Untersuchung der Konformationsdynamiken der Ligandenbindedom{\"a}ne ionotroper Glutamatrezeptoren darstellt und daher eine aussichtsreiche M{\"o}glichkeit zur Erweiterung des zuk{\"u}nftigen Verst{\"a}ndnisses der Funktionsweise von iGluRs bietet.}, subject = {Fluoreszenzkorrelationsspektroskopie}, language = {de} } @phdthesis{Schubert2021, author = {Schubert, Jonathan}, title = {Bildgebende Zweifarben-Einzelmolek{\"u}l-PET-Fluoreszenzspektroskopie am molekularen Chaperon Hsp90}, doi = {10.25972/OPUS-24493}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244938}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Im Forschungsfeld der Proteindynamik h{\"a}ufen sich in den letzten Jahren Untersuchungen an einzelnen Molek{\"u}len. Damit k{\"o}nnen molekulare Ereignisse, die in konventioneller Spektroskopie durch stochastische Prozesse unentdeckt bleiben, durch direkte Beobachtung identifiziert und analysiert werden, was zu tieferem mechanistischem Verst{\"a}ndnis des untersuchten Systems beitragen kann. Die Implikation des molekularen Chaperons Hsp90 in die korrekte Faltung und Aktivierung einer Vielzahl davon abh{\"a}ngiger Klientenproteine machen es zu einem zentralen Knotenpunkt der zellul{\"a}ren Proteinhom{\"o}ostase, allerdings ist der Mechanismus seiner breiten Klientenerkennung und -prozessierung bisher nur l{\"u}ckenhaft untersucht. Mit der Erkenntnis, dass Hsp90 ATP abh{\"a}ngig große, ratenlimitierende Umstrukturierungen erf{\"a}hrt, wurden Reportersysteme entwickelt, die auf dem F{\"o}rster-Resonanzenergietransfer mit einer r{\"a}umlichen Aufl{\"o}sung von ca. 2-10 nm basieren. Diese dokumentieren einen Klammerschluss des Chaperons und prognostizieren einen intermediatbbasierten Konformations-Zyklus. Details {\"u}ber den Mechanismus der Umstrukturierungen wurden mit der Entwicklung von Reportersystemen ermittelt, die auf dem photoinduzierten Elektronentransfer zwischen der Aminos{\"a}ure Tryptophan und einem organischen Farbstoff basieren. Die Technik beruht auf kontaktinduzierter Fluoreszenzl{\"o}schung und damit verbundenen digitalen Intensit{\"a}ts{\"u}berg{\"a}ngen, dabei erm{\"o}glicht die r{\"a}umliche Sensitivit{\"a}t von < 1 nm die Beobachtung von lokalen Umstrukturierungen. In Hsp90 wurden damit mittels konventioneller Spektroskopie drei kritische lokale Umlagerungen untersucht und daraus ein Modell mit heterogenen apo-Konformationen sowie ein kooperativer Konformationszyklus abgeleitet, der dem intermediatbasierten Modell gegen{\"u}bersteht. Im Rahmen dieser Dissertation wurde anhand des Hsp90-Chaperons eine Methode entwickelt, die eine bildgebende PET Fluoreszenzspektroskopie von mehreren Umstrukturierungen gleichzeitig an einzelnen Molek{\"u}len erlaubt. Ein umfangreiches Farbstoffscreening f{\"u}hrte zur Identifizierung eines Farbstoffpaars, das die PET-basierte simultane Aufzeichnung zweier Konformations-Koordinaten erm{\"o}glicht. {\"U}ber verschiedene Modifikationen des Chaperons konnten einzelmolek{\"u}ltaugliche Oberfl{\"a}chen hergestellt werden, auf denen zweifach markierte Hsp90-Proteine immobilisiert sind. Fluoreszenzintensit{\"a}tszeitspuren einzelner Chaperone und entsprechende Kontrollkonstrukte best{\"a}tigen qualitativ den Erfolg der Methode, f{\"u}r die quantitative Analyse wurde eine Routine in der Programmiersprache Python entwickelt, mit welcher kinetische Informationen ermittelt werden konnten. Diese legen eine enge wechselseitige Abh{\"a}ngigkeit der drei lokalen Elemente nahe, wobei der Großteil der Konformations{\"u}berg{\"a}nge zweier simultan aufgezeichneter Umstrukturierungen Synchronit{\"a}t innerhalb von zwei Sekunden zeigt. Im Vergleich zur Hydrolyse von einem ATP in mehreren Minuten deutet das auf eine enge Kopplung hin. Weiter konnte eine Beschleunigung der Dynamiken durch aromatische Modifikation des N-Terminus von Hsp90 beobachtet werden, zudem erlaubt der Einzelmolek{\"u}lansatz die Verwendung des nativen Nukleotids ATP, wodurch auch die lokalen {\"O}ffnungsdynamiken zug{\"a}nglich werden. Die zur Bestimmung der Zeitkonstanten durchgef{\"u}hrte Analyse unterst{\"u}tzt die Ansicht heterogener apo-Zust{\"a}nde und einer einheitlich geschlossenen Konformation. Die bildgebende Zweifarben-Einzelmolek{\"u}l-PET-Spektroskopie konnte insgesamt zu einem Komplement der Einzelmolek{\"u}l-FRET-Spektroskopie entwickelt werden, um damit lokale Konformationsdynamiken zu untersuchen. Der bildgebende Ansatz erlaubt eine einfache Implementierung in einen experimentellen Einzelmolek{\"u}l-FRET Aufbau bei gleichzeitiger Erweiterung der beobachteten Koordinaten und wird so zu einem breit anwendbaren Werkzeug multidimensionaler Dynamikuntersuchungen einzelner Proteine.}, subject = {Fluoreszenzspektroskopie}, language = {de} } @phdthesis{Staus2021, author = {Staus, Madlen}, title = {Glutathione-dependent reprogramming in melanoma}, doi = {10.25972/OPUS-16842}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168424}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {These days, treatment of melanoma patients relies on targeted therapy with BRAF/MEK inhibitors and on immunotherapy. About half of all patients initially respond to existing therapies. Nevertheless, the identification of alternative therapies for melanoma patients with intrinsic or acquired resistance is of great importance. In melanoma, antioxidants play an essential role in the maintenance of the redox homeostasis. Therefore, disruption of the redox homeostasis is regarded as highly therapeutically relevant and is the focus of the present work. An adequate supply of cysteine is essential for the production of the most important intracellular antioxidants, such as glutathione. In the present work, it was investigated whether the depletion of cysteine and glutathione is therapeutically useful. Depletion of glutathione in melanoma cells could be achieved by blocking cysteine supply, glutathione synthesis, and NADPH regeneration. As expected, this led to an increased level of reactive oxygen species (ROS). Surprisingly, however, these changes did not impair the proliferation and survival of the melanoma cells. In contrast, glutathione depletion led to cellular reprogramming which was characterized by the induction of mesenchymal genes and the repression of differentiation markers (phenotypic switch). This was accompanied by an increased migration and invasion potential which was favored by the induction of the transcription factor FOSL1. To study in vivo reprogramming, Gclc, the first and rate-limiting enzyme in glutathione synthesis, was knocked out by CRISPR/Cas9 in murine melanoma cells. The cells were devoid of glutathione, but were fully viable and showed a phenotypic switch, the latter only in MITF-expressing B16F1 cells and not in MITF-deficient D4M3A.781 cells. Following subcutaneous injection into immunocompetent C57BL/6 mice, Gclc knockout B16F1 cells grew more aggressively and resulted in an earlier tumor onset than B16F1 control cells. In summary, this work demonstrates that inhibition of cysteine supply and thus, glutathione synthesis leads to cellular reprogramming in melanoma. In this context, melanoma cells show metastatic capabilities, promoting a more aggressive form of the disease.}, subject = {Melanom}, language = {en} } @article{YeWilhelmGentschevetal.2021, author = {Ye, Mingyu and Wilhelm, Martina and Gentschev, Ivaylo and Szalay, Alad{\´a}r}, title = {A modified limiting dilution method for monoclonal stable cell line selection using a real-time fluorescence imaging system: A practical workflow and advanced applications}, series = {Methods and Protocols}, volume = {4}, journal = {Methods and Protocols}, number = {1}, doi = {10.3390/mps4010016}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228896}, year = {2021}, abstract = {Stable cell lines are widely used in laboratory research and pharmaceutical industry. They are mainly applied in recombinant protein and antibody productions, gene function studies, drug screens, toxicity assessments, and for cancer therapy investigation. There are two types of cell lines, polyclonal and monoclonal origin, that differ regarding their homogeneity and heterogeneity. Generating a high-quality stable cell line, which can grow continuously and carry a stable genetic modification without alteration is very important for most studies, because polyclonal cell lines of multicellular origin can be highly variable and unstable and lead to inconclusive experimental results. The most commonly used technologies of single cell originate monoclonal stable cell isolation in laboratory are fluorescence-activated cell sorting (FACS) sorting and limiting dilution cloning. Here, we describe a modified limiting dilution method of monoclonal stable cell line selection using the real-time fluorescence imaging system IncuCyte\(^®\)S3.}, language = {en} } @article{BoetzlSchueleKraussetal.2020, author = {Boetzl, Fabian A. and Schuele, Maren and Krauss, Jochen and Steffan-Dewenter, Ingolf}, title = {Pest control potential of adjacent agri-environment schemes varies with crop type and is shaped by landscape context and within-field position}, series = {Journal of Applied Ecology}, volume = {57}, journal = {Journal of Applied Ecology}, number = {8}, doi = {10.1111/1365-2664.13653}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218265}, pages = {1482 -- 1493}, year = {2020}, abstract = {Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri-environmental schemes (AES) on natural pest control and within-field distance functions of natural pest control agents have rarely been addressed but might affect the distribution of biocontrol providers. Importantly, it is currently unknown whether ecosystem services provided by adjacent AES are consistent for different crop types during crop rotation. In this study, we assessed whether crop rotation from oilseed rape to cereals altered within-field distance functions of ground-dwelling predators from adjacent agri-environmental fields along a gradient in landscape context. Additionally, we recorded crop pests, predation rates, parasitoids as well as crop yields on a total of 30 study sites. Distance functions varied between trophic levels: Carabid richness decreased while densities of carabid beetles, staphylinid beetles as well as crop yields increased towards the field centres. Distance functions of parasitoids and pests were modulated by the amount of semi-natural habitat in the surrounding landscape, while the effects of adjacent AES were limited. Distance decay functions found for ground-dwelling predators in oilseed rape in the previous year were not always present in cereals. Increasing distance to the field edge also increased effects of crop rotation on carabid beetle assemblages, indicating a source habitat function of field edges. Synthesis and applications. Distance functions of natural pest control are not universal and the effects of agri-environmental schemes (AES) in different adjacent crops during crop rotation vary and depend on ecological contrasts. A network of semi-natural habitats and spatially optimized AES habitats can benefit pest control in agricultural landscapes, but constraints as a result of crop type need to be addressed by annually targeted, spatially shifting agri-environment schemes for different crops.}, language = {en} } @article{LamatschTrifonovSchoriesetal.2011, author = {Lamatsch, D. K. and Trifonov, V. and Schories, S. and Epplen, J. T. and Schmid, M. and Schartl, M.}, title = {Isolation of a Cancer-Associated Microchromosome in the Sperm-Dependent Parthenogen Poecilia formosa}, series = {Cytogenetic and Genome Research}, volume = {135}, journal = {Cytogenetic and Genome Research}, number = {2}, issn = {1424-8581}, doi = {10.1159/000331271}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196785}, pages = {135-142}, year = {2011}, abstract = {In the asexual all-female fish species Poecilia formosa, the Amazon molly, supernumerary chromosomes have frequently been found in both laboratory-reared and wild-caught individuals. While wild-caught individuals with B chromosomes are phenotypically indifferent from conspecifics, individuals carrying B chromosomes from recent introgression events in the laboratory show phenotypic changes. Former analyses showed that the expression of a pigment cell locus is associated with the presence of these B chromosomes. In addition, they contain a so far unidentified locus that confers a higher susceptibility to tumor formation in the presence of pigmentation pattern. Isolation by microdissection and hybridization to metaphase chromosomes revealed that they contain one or several sequences with similarity to a highly repetitive pericentromeric and subtelomeric sequence in A chromosomes. Isolation of one particular sequence by AFLP showed that the B chromosomes contain at least 1 copy of an A-chromosomal region which is highly conserved in the whole genus Poecilia, i.e. more than 5 million years old. We propose it to be a single copy sequence.}, language = {en} } @article{HabensteinAminiGruebeletal.2020, author = {Habenstein, Jens and Amini, Emad and Gr{\"u}bel, Kornelia and el Jundi, Basil and R{\"o}ssler, Wolfgang}, title = {The brain of Cataglyphis ants: Neuronal organization and visual projections}, series = {Journal of Comparative Neurology}, volume = {528}, journal = {Journal of Comparative Neurology}, number = {18}, doi = {10.1002/cne.24934}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218212}, pages = {3479 -- 3506}, year = {2020}, abstract = {Cataglyphis ants are known for their outstanding navigational abilities. They return to their inconspicuous nest after far-reaching foraging trips using path integration, and whenever available, learn and memorize visual features of panoramic sceneries. To achieve this, the ants combine directional visual information from celestial cues and panoramic scenes with distance information from an intrinsic odometer. The largely vision-based navigation in Cataglyphis requires sophisticated neuronal networks to process the broad repertoire of visual stimuli. Although Cataglyphis ants have been subjected to many neuroethological studies, little is known about the general neuronal organization of their central brain and the visual pathways beyond major circuits. Here, we provide a comprehensive, three-dimensional neuronal map of synapse-rich neuropils in the brain of Cataglyphis nodus including major connecting fiber systems. In addition, we examined neuronal tracts underlying the processing of visual information in more detail. This study revealed a total of 33 brain neuropils and 30 neuronal fiber tracts including six distinct tracts between the optic lobes and the cerebrum. We also discuss the importance of comparative studies on insect brain architecture for a profound understanding of neuronal networks and their function.}, language = {en} } @article{StiebKelberWehneretal.2011, author = {Stieb, Sara Mae and Kelber, Christina and Wehner, R{\"u}diger and R{\"o}ssler, Wolfgang}, title = {Antennal-Lobe Organization in Desert Ants of the Genus Cataglyphis}, series = {Brain, Behavior and Evolution}, volume = {77}, journal = {Brain, Behavior and Evolution}, number = {3}, issn = {0006-8977}, doi = {10.1159/000326211}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196815}, pages = {136-146}, year = {2011}, abstract = {Desert ants of the genus Cataglyphis possess remarkable visual navigation capabilities. Although Cataglyphis species lack a trail pheromone system, Cataglyphis fortis employs olfactory cues for detecting nest and food sites. To investigate potential adaptations in primary olfactory centers of the brain of C. fortis, we analyzed olfactory glomeruli (odor processing units) in their antennal lobes and compared them to glomeruli in different Cataglyphis species. Using confocal imaging and 3D reconstruction, we analyzed the number, size and spatial arrangement of olfactory glomeruli in C. fortis, C.albicans, C.bicolor, C.rubra, and C.noda. Workers of all Cataglyphis species have smaller numbers of glomeruli (198-249) compared to those previously found in olfactory-guided ants. Analyses in 2 species of Formica - a genus closely related to Cataglyphis - revealed substantially higher numbers of olfactory glomeruli (c. 370), which is likely to reflect the importance of olfaction in these wood ant species. Comparisons between Cataglyphis species revealed 2 special features in C. fortis. First, with c. 198 C. fortis has the lowest number of glomeruli compared to all other species. Second, a conspicuously enlarged glomerulus is located close to the antennal nerve entrance. Males of C. fortis possess a significantly smaller number of glomeruli (c. 150) compared to female workers and queens. A prominent male-specific macroglomerulus likely to be involved in sex pheromone communication occupies a position different from that of the enlarged glomerulus in females. The behavioral significance of the enlarged glomerulus in female workers remains elusive. The fact that C. fortis inhabits microhabitats (salt pans) that are avoided by all other Cataglyphis species suggests that extreme ecological conditions may not only have resulted in adaptations of visual capabilities, but also in specializations of the olfactory system.}, language = {en} } @article{StieglervonHoermannMuelleretal.2020, author = {Stiegler, Jonas and von Hoermann, Christian and M{\"u}ller, J{\"o}rg and Benbow, M. Eric and Heurich, Marco}, title = {Carcass provisioning for scavenger conservation in a temperate forest ecosystem}, series = {Ecosphere}, volume = {11}, journal = {Ecosphere}, number = {4}, doi = {10.1002/ecs2.3063}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218054}, year = {2020}, abstract = {Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far-reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species.}, language = {en} } @article{DoerflerCadotteWeisseretal.2020, author = {Doerfler, Inken and Cadotte, Marc W. and Weisser, Wolfgang W. and M{\"u}ller, J{\"o}rg and Gossner, Martin M. and Heibl, Christoph and B{\"a}ssler, Claus and Thorn, Simon and Seibold, Sebastian}, title = {Restoration-oriented forest management affects community assembly patterns of deadwood-dependent organisms}, series = {Journal of Applied Ecology}, volume = {57}, journal = {Journal of Applied Ecology}, number = {12}, doi = {10.1111/1365-2664.13741}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217918}, pages = {2429 -- 2440}, year = {2020}, abstract = {Land-use intensification leads to loss and degradation of habitats and is thus a major driver of biodiversity loss. Restoration strategies typically focus on promoting biodiversity but often neglect that land-use intensification could have changed the underlying mechanisms of community assembly. Since assembly mechanisms determine the diversity and composition of communities, we propose that evaluation of restoration strategies should consider effects of restoration on biodiversity and community assembly. Using a multi-taxon approach, we tested whether a strategy that promotes forest biodiversity by restoring deadwood habitats also affects assembly patterns. We assessed saproxylic (i.e. deadwood-dependent) beetles and fungi, as well as non-saproxylic plants and birds in 68 beech forest plots in southern Germany, 8 years after the commencement of a restoration project. To assess changes in community assembly, we analysed the patterns of functional-phylogenetic diversity, community-weighted mean (CWM) traits and their diversity. We hypothesized that restoration increases habitat amount and heterogeneity of deadwood and reduces canopy cover and thereby decreases the strength of environmental filters imposed by past silvicultural intensification, such as a low amount in deadwood. With the restoration of deadwood habitats, saproxylic beetle communities became less functionally-phylogenetically similar, whereas the assembly patterns of saproxylic fungi and non-saproxylic taxa remained unaffected by deadwood restoration. Among the traits analysed, deadwood diameter niche position of species was most strongly affected indicating that the enrichment of large deadwood objects led to lower functional-phylogenetical similarity of saproxylic beetles. Community assembly and traits of plants were mainly influenced by microclimate associated with changes in canopy cover. Synthesis and applications. Our results indicate that the positive effects of deadwood restoration on saproxylic beetle richness are associated with an increase in deadwood amount. This might be linked to an increase in deadwood heterogeneity, and therefore decreasing management-induced environmental filters. Deadwood enrichment can thus be considered an effective restoration strategy which reduces the negative effects of intense forest management on saproxylic taxa by not only promoting biodiversity but also by decreasing the environmental filters shaping saproxylic beetle communities, thus allowing the possibly for more interactions between species and a higher functional diversity.}, language = {en} } @phdthesis{Georgiev2021, author = {Georgiev, Kostadin}, title = {Sustainable management of naturally disturbed forests}, doi = {10.25972/OPUS-24285}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242854}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Owing to climate change, natural forest disturbances and consecutive salvage logging are drastically increasing worldwide, consequently increasing the importance of understanding how these disturbances would affect biodiversity conservation and provision of ecosystem services. In chapter II, I used long-term water monitoring data and mid-term data on α-diversity of twelve species groups to quantify the effects of natural disturbances (windthrow and bark beetle) and salvage logging on concentrations of nitrate and dissolved organic carbon (DOC) in streamwater and α-diversity. I found that natural disturbances led to a temporal increase of nitrate concentrations in streamwater, but these concentrations remained within the health limits recommended by the World Health Organization for drinking water. Salvage logging did not exert any additional impact on nitrate and DOC concentrations, and hence did not affect streamwater quality. Thus, neither natural forest disturbances in watersheds nor associated salvage logging have a harmful effect on the quality of the streamwater used for drinking water. Natural disturbances increased the α-diversity in eight out of twelve species groups. Salvage logging additionally increased the α-diversity of five species groups related to open habitats, but decreased the biodiversity of three deadwood-dependent species groups. In chapter III, I investigated whether salvage logging following natural disturbances (wildfire and windthrow) altered the natural successional trajectories of bird communities. I compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, over a period of 17 years and tested whether bird community dissimilarities changed over time for taxonomic, functional and phylogenetic diversity when rare, common and dominant species were weighted differently. I found that salvage logging led to significantly larger dissimilarities than expected by chance and that these dissimilarities persisted over time for rare, common and dominant species, evolutionary lineages, and for rare functional groups. Dissimilarities were highest for rare, followed by common and dominant species. In chapter IV, I investigated how β-diversity of 13 taxonomic groups would differ in intact, undisturbed forests, disturbed, unlogged forests and salvage-logged forests 11 years after a windthrow and salvage logging. The study suggests that both windthrow and salvage logging drive changes in between-treatment β-diversity, whereas windthrow alone seems to drive changes in within-treatment β-diversity. Over a decade after the windthrow at the studied site, the effect of subsequent salvage logging on within-treatment β-diversity was no longer detectable but the effect on between-treatment β-diversity persisted, with more prominent changes in saproxylic groups and rare species than in non-saproxylic groups or common and dominant species. Based on these results, I suggest that salvage logging needs to be carefully weighed against its long-lasting impact on communities of rare species. Also, setting aside patches of naturally disturbed areas is a valuable management alternative as these patches would enable post-disturbance succession of bird communities in unmanaged patches and would promote the conservation of deadwood-dependent species, without posing health risks to drinking water sources.}, subject = {species richness}, language = {en} } @phdthesis{Roeschert2021, author = {R{\"o}schert, Isabelle}, title = {Aurora-A prevents transcription-replication conflicts in MYCN-amplified neuroblastoma}, doi = {10.25972/OPUS-24303}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-243037}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Neuroblastoma is the most abundant, solid, extracranial tumor in early childhood and the leading cause of cancer-related childhood deaths worldwide. Patients with high-risk neuroblastoma often show MYCN-amplification and elevated levels of Aurora-A. They have a low overall survival and despite multimodal therapy options a poor therapeutic prognosis. MYCN-amplified neuroblastoma cells depend on Aurora-A functionality. Aurora-A stabilizes MYCN and prevents it from proteasomal degradation by competing with the E3 ligase SCFFBXW7. Interaction between Aurora-A and MYCN can be observed only in S phase of the cell cycle and activation of Aurora-A can be induced by MYCN in vitro. These findings suggest the existence of a profound interconnection between Aurora-A and MYCN in S phase. Nevertheless, the details remain elusive and were investigated in this study. Fractionation experiments show that Aurora-A is recruited to chromatin in S phase in a MYCN-dependent manner. Albeit being unphosphorylated on the activating T288 residue, Aurora-A kinase activity was still present in S phase and several putative, novel targets were identified by phosphoproteomic analysis. Particularly, eight phosphosites dependent on MYCN-activated Aurora-A were identified. Additionally, phosphorylation of serine 10 on histone 3 was verified as a target of this complex in S phase. ChIP-sequencing experiments reveal that Aurora-A regulates transcription elongation as well as histone H3.3 variant incorporation in S phase. 4sU-sequencing as well as immunoblotting demonstrated that Aurora-A activity impacts splicing. PLA measurements between the transcription and replication machinery revealed that Aurora-A prevents the formation of transcription-replication conflicts, which activate of kinase ATR. Aurora-A inhibitors are already used to treat neuroblastoma but display dose-limiting toxicity. To further improve Aurora-A based therapies, we investigated whether low doses of Aurora-A inhibitor combined with ATR inhibitor could increase the efficacy of the treatment albeit reducing toxicity. The study shows that the combination of both drugs leads to a reduction in cell growth as well as an increase in apoptosis in MYCN-amplified neuroblastoma cells, which is not observable in MYCN non-amplified neuroblastoma cells. This new approach was also tested by a collaboration partner in vivo resulting in a decrease in tumor burden, an increase in overall survival and a cure of 25\% of TH-MYCN mice. These findings indicate indeed a therapeutic window for targeting MYCN-amplified neuroblastoma.}, subject = {Neuroblastom}, language = {en} } @phdthesis{LopezArboleda2021, author = {L{\´o}pez Arboleda, William Andr{\´e}s}, title = {Global Genetic Heterogeneity in Adaptive Traits}, doi = {10.25972/OPUS-24246}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242468}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Genome Wide Association Studies (GWAS) have revolutionized the way on how genotype-phenotype relations are assessed. In the 20 years long history of GWAS, multiple challenges from a biological, computational, and statistical point of view have been faced. The implementation of this technique using the model plant species Arabidopsis thaliana, has enabled the detection of many association for multiple traits. Despite a lot of studies implementing GWAS have discovered new candidate genes for multiple traits, different samples are used across studies. In many cases, either globally diverse samples or samples composed of accessions from a geographically restricted area are used. With the aim of comparing GWAS outcomes between populations from different geographic areas, this thesis describes the performance of GWAS in different European samples of A. thaliana. Here, association mapping results for flowering time were compared. Chapter 2 describes the analyses of random resampling from this original sample. The aim was to establish reduced subsamples to later carry out GWAS and compare the outcomes between these subsamples. In Chapter 3, the European sample was split into eight equally-sized local samples representing different geographic regions. Next, GWAS was carried out and an attempt was made to clarify the differences in GWAS outcomes. Chapter 4 contains the results of a collaboration with Prof. Dr. Wolfgang Dr{\"o}ge- Laser, in which my mainly task was the analysis of RNAseq data from A. thaliana plants infected by pathogenic fungi. Finally, Appendix A presents a very short description of my participation in the GHP Project on Access to Care for Cardiometabolic Diseases (HPACC) at the university of Heidelberg.}, language = {en} } @phdthesis{Boegelein2021, author = {B{\"o}gelein, Anna}, title = {Einfluss systemischer Therapeutika auf die CXCR4-Expression von Myelomzellen}, doi = {10.25972/OPUS-24174}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241746}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Im Zuge der Bem{\"u}hungen um neue, tumorspezifische Therapieans{\"a}tze f{\"u}r die Myelomerkrankung hat sich der C-X-C-Chemokinrezeptor 4 (CXCR4) aufgrund seiner zentralen Rolle in der Tumorgenese als vielversprechender Angriffspunkt hervorgetan. Im Sinne eines theranostischen Konzepts wird der Rezeptor mithilfe eines radioaktiv markierten Liganden quantifiziert und anschließend von rezeptorspezifischen Radiotherapeutika als Zielstruktur genutzt. Die CXCR4-Expression ist allerdings ein h{\"o}chst dynamischer Prozess mit großer inter- und intraindividueller Heterogenit{\"a}t, der u.a. durch eine begleitende Chemotherapie beeinflusst werden kann. Ob sich therapieinduzierte Ver{\"a}nderungen der Rezeptorexpression gezielt nutzen lassen, um die CXCR4-Expression zu optimieren und so die Effektivit{\"a}t der CXCR4-gerichteten Strategien zu steigern, wurde bislang nicht untersucht. Vor diesem Hintergrund wurden in der vorliegenden Arbeit verschiedene, in der Myelomtherapie etablierte Substanzen sowohl einzeln als auch in Kombination hinsichtlich ihres Einflusses auf die CXCR4-Expression von MM-Zelllinien und prim{\"a}ren MM-Zellen unter in vitro Bedingungen analysiert. In den durchgef{\"u}hrten Experimenten zeigte sich eine hohe Variabilit{\"a}t der CXCR4-Expression der MM-Zellen nach Therapieinduktion, die sich als substanz-, dosis- und zeitabh{\"a}ngig herausstellte. Die Ergebnisse best{\"a}tigten das große Potenzial der therapieinduzierten Modulation der CXCR4-Expression. Im weiteren Verlauf sind translationale Forschungsans{\"a}tze gerechtfertigt, die die {\"U}bertragbarkeit der in vitro gewonnenen Ergebnisse auf die komplexen Vorg{\"a}nge im lebenden Organismus {\"u}berpr{\"u}fen. Langfristiges Ziel ist der Entwurf eines patientenzentrierten, multimodalen Therapiekonzepts, welches das CXCR4-gerichtete theranostische Konzept mit einer individuell angepassten, medikament{\"o}sen MM-Therapie kombiniert.}, subject = {Plasmozytom}, language = {de} } @phdthesis{daCruzGueerisoli2021, author = {da Cruz G{\"u}erisoli, Irene Maria}, title = {Investigating the murine meiotic telomere complex TERB1-TERB2-MAJIN: spatial organization and evolutionary history}, doi = {10.25972/OPUS-21056}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-210562}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Einess der faszinierenden Merkmale der meiotischen Prophase I sind die hochkonservierten kr{\"a}ftigen Bewegungen homologer Chromosomen. Diese Bewegungen sind entscheidend f{\"u}r den Erfolg von Schl{\"u}sselereignissen wie die Ausrichtung, Paarung und Rekombination der homologen Chromosomen. Mehrere bisher untersuchte Organismen, darunter S{\"a}ugetiere, W{\"u}rmer, Hefen und Pflanzen, erreichen diese Bewegungen, indem sie die Chromosomenenden an spezialisierten Stellen in der Kernh{\"u}lle verankern. Diese Verankerung erfordert Telomer-Adapterproteine, die bisher in der Spalthefe und der Maus identifiziert wurden. Die meiosespezifischen Telomer-Adapterproteine der Maus, TERB1, TERB2 und MAJIN, sind an der Verankerung des ubiquit{\"a}ren Telomer-Shelterin-protein an den LINC-Komplex beteiligt, mit einem analogen Mechanismus, wie er die Spalthefe beschrieben wird. Obgleich die meiose-spezifischen TelomerAdapterproteine eine wesentliche Rolle spielen, ist der genaue Mechanismus der Verankerung der Telomere an die Kernh{\"u}lle sowie ihre evolution{\"a}re Geschichte bisher noch wenig verstanden. Das Hauptziel dieser Arbeit ist daher die Untersuchung der Organisation des meiosespezifischen TelomerAdapterkomplexes TERB1-TERB2-MAJIN der Maus und dessen Evolutionsgeschichte. Im ersten Teil dieser Arbeit wurde die Organisation des TERB1-TERB2-MAJIN Komplexes mittels hochaufl{\"o}sender Mikroskopie (SIM), an Mausspermatozyten untersucht, sowie die Lokalisation in Bezug auf TRF1 des Telomer-ShelterinKomplexes und die telomerische DNA analysiert. In den Stadien Zygot{\"a}n und Pachyt{\"a}n zeigten die Fluoreszenzsignale eine starke {\"U}berlappung der Verteilung der meiotischen Telomer-Komplex-Proteine, wobei die Organisation von TERB2 an den Chromosomenenden heterogener war als die von TERB1 und MAJIN. Außerdem konnte die TRF1-Lokalisation an den Enden der Lateralelemente (LEs) mit einer griffartigen Anordnung um die TERB1- und MAJIN-Signale im Zygot{\"a}n- und Pachyt{\"a}n-Stadium gezeigt werden. Interessanterweise erwies sich die telomerische DNA als lateral verteilt und teilweise {\"u}berlappend mit der zentralen Verteilung der meiotischen Telomer-Komplex-Proteine an den Enden der LEs. Die Kombination dieser Ergebnisse erlaubte die Beschreibung eines alternativen Modells der Verankerung der Telomer an die Kernh{\"u}lle w{\"a}hrend der meiotischen Prophase I. Der zweite Teil dieser Arbeit analysiert die Evolutionsgeschichte der Mausproteine von TERB1, TERB2 und MAJIN. Die fehlende {\"U}bereinstimmung zwischen den Meiose-spezifische Telomer-Adapteproteinen der Maus und der Spalthefe hat die Frage nach dem evolutionsbedingten Ursprung dieses spezifischen Komplexes aufgeworfen. Um vermeintliche Orthologen der Mausproteinevon TERB1, TERB2 und MAJIN {\"u}ber Metazoen hinweg zu identifizieren, wurden computergest{\"u}tzte Verfahren und phylogenetische Analysen durchgef{\"u}hrt. Dar{\"u}ber hinaus wurden Expressionsstudien implementiert, um ihre potenzielle Funktion w{\"a}hrend der Meiose zu testen. Die Analysen haben ergeben, dass der Meiose-spezifische Telomer-Komplex der Maus sehr alt ist, da er bereits in den Eumetazoen entstand, was auf einen einzigen Ursprung hindeutet. Das Fehlen jeglicher Homologen des meiosespezifischen Telomerkomplexes in Nematoden und die einigen wenigen in Arthropoden nachgewiesenen Kandidaten, deuten darauf hin, dass die Telomer-Adapterproteine in diesen Abstammungslinien verloren/ersetzt oder stark diversifiziert worden sind. Bemerkenswerterweise zeigten Proteindom{\"a}nen von TERB1, TERB2 und MAJIN, die an der Bildung des Komplexes sowie an der Interaktion mit dem Telomer-Shelterin-Protein und den LINC-Komplexen beteiligt sind, eine hohe Sequenz{\"a}hnlichkeit {\"u}ber alle Kladen hinweg. Abschließend lieferte die Genexpression im Nesseltier Hydra vulgaris den Beweis, dass der TERB1-TERB2-MAJIN-Komplex selektiv in der Keimbahn exprimiert wird, was auf die Konservierung meiotischer Funktionen {\"u}ber die gesamte Metazoen-Evolution hinweg hindeutet. Zusammenfassend bietet diese Arbeit bedeutende neue Erkenntnisse hinsichtlich des Meiose-spezifischen Telomer-Adapterkomplex, seines Mechanismus zur Verankerung der Telomer an die Kernh{\"u}lle und die Entschl{\"u}sselung seines Ursprungs in den Metazoen.}, language = {en} } @article{HardulakMoriniereHausmannetal.2020, author = {Hardulak, Laura A. and Morini{\`e}re, J{\´e}r{\^o}me and Hausmann, Axel and Hendrich, Lars and Schmidt, Stefan and Doczkal, Dieter and M{\"u}ller, J{\"o}rg and Hebert, Paul D. N. and Haszprunar, Gerhard}, title = {DNA metabarcoding for biodiversity monitoring in a national park: Screening for invasive and pest species}, series = {Molecular Ecology Resources}, volume = {20}, journal = {Molecular Ecology Resources}, number = {6}, doi = {10.1111/1755-0998.13212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217812}, pages = {1542 -- 1557}, year = {2020}, abstract = {DNA metabarcoding was utilized for a large-scale, multiyear assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal component analysis of read count-based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of barcode index numbers (BINs) at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger-sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6\% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park.}, language = {en} } @phdthesis{CruzGarcia2021, author = {Cruz Garcia, Yiliam}, title = {Interactome of the β2b subunit of L-type voltage-gated calcium channels in cardiomyocytes}, doi = {10.25972/OPUS-20857}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208579}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {L-type voltage-gated calcium channels (LTCC) are heteromultimeric membrane proteins that allow Ca2+ entry into the cell upon plasma membrane depolarization. The β subunit of voltage-dependent calcium channels (Cavβ) binds to the α-interaction domain in the pore-forming α1 subunit and regulates the trafficking and biophysical properties of these channels. Of the four Cavβ isoforms, Cavβ2 is predominantly expressed in cardiomyocytes. This subunit associates with diverse proteins besides LTCC, but the molecular composition of the Cavβ2 nanoenvironments in cardiomyocytes is yet unresolved. Here, we used a protein-labeling technique in living cells based on an engineered ascorbate peroxidase 2 (APEX2). In this strategy, Cavβ2b was fused to APEX2 and expressed in adult rat cardiomyocytes using an adenovirus system. Nearby proteins covalently labeled with biotin-phenol were purified using streptavidin-coated beads and identified by mass spectrometry (MS). Analysis of the in situ APEX2-based biotin labeling by MS revealed 61 proteins located in the nanoenvironments of Cavβ2b, with a high specificity and consistency in all the replicates. These proteins are involved in diverse cellular functions such as cellular trafficking, sarcomere organization and excitation-contraction coupling. Among these proteins, we demonstrated an interaction between the ryanodine receptor 2 (RyR2) and Cavβ2b, probably coupling LTCC and the RyR2 into a supramolecular complex at the dyads. This interaction is mediated by the Src homology 3 (SH3) domain of Cavβ2b and is necessary for an effective pacing frequency-dependent increase in Ca2+-induced Ca2+ release in cardiomyocytes.}, subject = {Calciumkanal}, language = {en} } @article{VogelBusslerFinnbergetal.2021, author = {Vogel, Sebastian and Bussler, Heinz and Finnberg, Sven and M{\"u}ller, J{\"o}rg and Stengel, Elisa and Thorn, Simon}, title = {Diversity and conservation of saproxylic beetles in 42 European tree species: an experimental approach using early successional stages of branches}, series = {Insect Conservation and Diversity}, volume = {14}, journal = {Insect Conservation and Diversity}, number = {1}, doi = {10.1111/icad.12442}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218401}, pages = {132 -- 143}, year = {2021}, abstract = {Tree species diversity is important to maintain saproxylic beetle diversity in managed forests. Yet, knowledge about the conservational importance of single tree species and implications for forest management and conservation practices are lacking. We exposed freshly cut branch-bundles of 42 tree species, representing tree species native and non-native to Europe, under sun-exposed and shaded conditions for 1 year. Afterwards, communities of saproxylic beetles were reared ex situ for 2 years. We tested for the impact of tree species and sun exposure on alpha-, beta-, and gamma-diversity as well as composition of saproxylic beetle communities. Furthermore, the number of colonised tree species by each saproxylic beetle species was determined. Tree species had a lower impact on saproxylic beetle communities compared to sun exposure. The diversity of saproxylic beetles varied strongly among tree species, with highest alpha- and gamma-diversity found in Quercus petraea. Red-listed saproxylic beetle species occurred ubiquitously among tree species. We found distinct differences in the community composition of broadleaved and coniferous tree species, native and non-native tree species as well as sun-exposed and shaded deadwood. Our study enhances the understanding of the importance of previously understudied and non-native tree species for the diversity of saproxylic beetles. To improve conservation practices for saproxylic beetles and especially red-listed species, we suggest a stronger incorporation of tree species diversity and sun exposure of into forest management strategies, including the enrichment of deadwood from native and with a specific focus on locally rare or silviculturally less important tree species.}, language = {en} } @article{LeverkusGustafssonLindenmayeretal.2020, author = {Leverkus, Alexandro B and Gustafsson, Lena and Lindenmayer, David B and Castro, Jorge and Rey Benayas, Jos{\´e} Mar{\´i}a and Ranius, Thomas and Thorn, Simon}, title = {Salvage logging effects on regulating ecosystem services and fuel loads}, series = {Frontiers in Ecology and the Environment}, volume = {18}, journal = {Frontiers in Ecology and the Environment}, number = {7}, doi = {10.1002/fee.2219}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216111}, pages = {391 -- 400}, year = {2020}, abstract = {Salvage logging, or logging after natural disturbances such as wildfires, insect outbreaks, and windstorms, is carried out to recover some of a forest's natural and/or economic capital. However, trade-offs between management objectives and a lack of consensus on the ecological consequences of salvage logging impair science-based decision making on the management of forests after natural disturbances. We conducted a global meta-analysis of the impacts of salvage logging on regulating ecosystem services and on fuel loads, as a frequent post-disturbance objective is preventing subsequent wildfires that could be fueled by the accumulation of dead trunks and branches. Salvage logging affected ecosystem services in a moderately negative way, regardless of disturbance type and severity, time elapsed since salvage logging, intensity of salvage logging, and the group of regulating ecosystem services being considered. However, prolonging the time between natural disturbance and salvage logging mitigated negative effects on regulating ecosystem services. Salvage logging had no overall effect on surface fuels; rather, different fuel types responded differently depending on the time elapsed since salvage logging. Delaying salvage logging by ~2-4 years may reduce negative ecological impacts without affecting surface fuel loads.}, language = {en} } @article{KouhestaniGeisAlsourietal.2021, author = {Kouhestani, Dina and Geis, Maria and Alsouri, Saed and Bumm, Thomas G. P. and Einsele, Hermann and Sauer, Markus and Stuhler, Gernot}, title = {Variant signaling topology at the cancer cell-T-cell interface induced by a two-component T-cell engager}, series = {Cellular \& Molecular Immunology}, volume = {18}, journal = {Cellular \& Molecular Immunology}, doi = {10.1038/s41423-020-0507-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241189}, pages = {1568-1570}, year = {2021}, abstract = {No abstract available.}, language = {en} } @article{HensgenEnglandHombergetal.2021, author = {Hensgen, Ronja and England, Laura and Homberg, Uwe and Pfeiffer, Keram}, title = {Neuroarchitecture of the central complex in the brain of the honeybee: Neuronal cell types}, series = {Journal of Comparative Neurology}, volume = {529}, journal = {Journal of Comparative Neurology}, doi = {10.1002/cne.24941}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215566}, pages = {159-186}, year = {2021}, abstract = {The central complex (CX) in the insect brain is a higher order integration center that controls a number of behaviors, most prominently goal directed locomotion. The CX comprises the protocerebral bridge (PB), the upper division of the central body (CBU), the lower division of the central body (CBL), and the paired noduli (NO). Although spatial orientation has been extensively studied in honeybees at the behavioral level, most electrophysiological and anatomical analyses have been carried out in other insect species, leaving the morphology and physiology of neurons that constitute the CX in the honeybee mostly enigmatic. The goal of this study was to morphologically identify neuronal cell types of the CX in the honeybee Apis mellifera. By performing iontophoretic dye injections into the CX, we traced 16 subtypes of neuron that connect a subdivision of the CX with other regions in the bee's central brain, and eight subtypes that mainly interconnect different subdivisions of the CX. They establish extensive connections between the CX and the lateral complex, the superior protocerebrum and the posterior protocerebrum. Characterized neuron classes and subtypes are morphologically similar to those described in other insects, suggesting considerable conservation in the neural network relevant for orientation.}, language = {en} } @article{AntonRoessler2021, author = {Anton, Sylvia and R{\"o}ssler, Wolfgang}, title = {Plasticity and modulation of olfactory circuits in insects}, series = {Cell and Tissue Research}, volume = {383}, journal = {Cell and Tissue Research}, issn = {0302-766X}, doi = {10.1007/s00441-020-03329-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235820}, pages = {149-164}, year = {2021}, abstract = {Olfactory circuits change structurally and physiologically during development and adult life. This allows insects to respond to olfactory cues in an appropriate and adaptive way according to their physiological and behavioral state, and to adapt to their specific abiotic and biotic natural environment. We highlight here findings on olfactory plasticity and modulation in various model and non-model insects with an emphasis on moths and social Hymenoptera. Different categories of plasticity occur in the olfactory systems of insects. One type relates to the reproductive or feeding state, as well as to adult age. Another type of plasticity is context-dependent and includes influences of the immediate sensory and abiotic environment, but also environmental conditions during postembryonic development, periods of adult behavioral maturation, and short- and long-term sensory experience. Finally, plasticity in olfactory circuits is linked to associative learning and memory formation. The vast majority of the available literature summarized here deals with plasticity in primary and secondary olfactory brain centers, but also peripheral modulation is treated. The described molecular, physiological, and structural neuronal changes occur under the influence of neuromodulators such as biogenic amines, neuropeptides, and hormones, but the mechanisms through which they act are only beginning to be analyzed.}, language = {en} } @article{BohnertReinertTrellaetal.2021, author = {Bohnert, Simone and Reinert, Christoph and Trella, Stefanie and Schmitz, Werner and Ondruschka, Benjamin and Bohnert, Michael}, title = {Metabolomics in postmortem cerebrospinal fluid diagnostics: a state-of-the-art method to interpret central nervous system-related pathological processes}, series = {International Journal of Legal Medicine}, volume = {135}, journal = {International Journal of Legal Medicine}, issn = {0937-9827}, doi = {10.1007/s00414-020-02462-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235724}, pages = {183-191}, year = {2021}, abstract = {In the last few years, quantitative analysis of metabolites in body fluids using LC/MS has become an established method in laboratory medicine and toxicology. By preparing metabolite profiles in biological specimens, we are able to understand pathophysiological mechanisms at the biochemical and thus the functional level. An innovative investigative method, which has not yet been used widely in the forensic context, is to use the clinical application of metabolomics. In a metabolomic analysis of 41 samples of postmortem cerebrospinal fluid (CSF) samples divided into cohorts of four different causes of death, namely, cardiovascular fatalities, isoIated torso trauma, traumatic brain injury, and multi-organ failure, we were able to identify relevant differences in the metabolite profile between these individual groups. According to this preliminary assessment, we assume that information on biochemical processes is not gained by differences in the concentration of individual metabolites in CSF, but by a combination of differently distributed metabolites forming the perspective of a new generation of biomarkers for diagnosing (fatal) TBI and associated neuropathological changes in the CNS using CSF samples.}, language = {en} } @article{BoffHenriqueFriedeletal.2020, author = {Boff, Samuel and Henrique, Jessica Amaral and Friedel, Anna and Raizer, Josu{\´e}}, title = {Disentangling the path of pollinator attraction in temporarily colored flowers}, series = {International Journal of Tropical Insect Science}, volume = {41}, journal = {International Journal of Tropical Insect Science}, doi = {10.1007/s42690-020-00323-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235402}, pages = {1305-1311}, year = {2020}, abstract = {Plants may use different strategies to attract pollinators in long distance (e.g. floral display) and in short distance (e.g. ratio between differentially colored flowers) scales. The Verbenaceae Lantana canescens Kunth is a wide spread species in open sites of the Brazilian Pantanal wetland. Individuals of this generalist species can produce a variable number of open inflorescences with yellow and white flowers that are organized in whorls. In this study we tested the hypothesis that increased floral display (long distance attraction) and the ratio between yellow and white flowers (short distance attraction) enhances the number of pollinator species and individuals. We observed flower visitors and calculated floral parameters in 38 plots of 1 m2 each, that contained a varying number of flowering L. canescens individuals. Non-metric multidimensional scaling and Bray-Curtis distances were used to account for flower visitor composition and the relative visitation rate, respectively. We used a structural equation model to test the power of each predictor variable on the visitation rate and a covariance analysis to disentangle the effect of each independent variable on the frequency of plant-pollinator interactions. We found that the number of flower visitors and the visitation rate increased with increasing number of inflorescences. Disentangling long and short distance attraction indicated that the number of inflorescences (per plot) and the number of yellow flowers (yellowing effect) contributed most to flower visitation at long and short distance, respectively.}, language = {en} } @article{JessenKressBaluapurietal.2020, author = {Jessen, Christina and Kreß, Julia K. C. and Baluapuri, Apoorva and Hufnagel, Anita and Schmitz, Werner and Kneitz, Susanne and Roth, Sabine and Marquardt, Andr{\´e} and Appenzeller, Silke and Ade, Casten P. and Glutsch, Valerie and Wobser, Marion and Friedmann-Angeli, Jos{\´e} Pedro and Mosteo, Laura and Goding, Colin R. and Schilling, Bastian and Geissinger, Eva and Wolf, Elmar and Meierjohann, Svenja}, title = {The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression}, series = {Oncogene}, volume = {39}, journal = {Oncogene}, issn = {0950-9232}, doi = {10.1038/s41388-020-01477-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235064}, pages = {6841-6855}, year = {2020}, abstract = {The transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H\(_2\)O\(_2\) or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma.}, language = {en} } @unpublished{Dandekar2021, author = {Dandekar, Thomas}, title = {Our universe may have started by Qubit decoherence}, doi = {10.25972/OPUS-23918}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239181}, pages = {54}, year = {2021}, abstract = {Our universe may have started by Qubit decoherence: In quantum computers, qubits have all their states undefined during calculation and become defined as output ("decoherence"). We study the transition from an uncontrolled, chaotic quantum vacuum ("before") to a clearly interacting "real world". In such a cosmology, the Big Bang singularity is replaced by a condensation event of interacting strings. This triggers a crystallization process. This avoids inflation, not fitting current observations: increasing long-range interactions limit growth and crystal symmetries ensure the same laws of nature and basic symmetries over the whole crystal. Tiny mis-arrangements provide nuclei of superclusters and galaxies and crystal structure allows arrangement of dark (halo regions) and normal matter (galaxy nuclei) for galaxy formation. Crystals come and go: an evolutionary cosmology is explored: entropic forces from the quantum soup "outside" of the crystal try to dissolve it. This corresponds to dark energy and leads to a "big rip" in 70 Gigayears. Selection for best growth and condensation events over generations of crystals favors multiple self-organizing processes within the crystal including life or even conscious observers in our universe. Philosophically this theory shows harmony with nature and replaces absurd perspectives of current cosmology. Independent of cosmology, we suggest that a "real world" (so our everyday macroscopic world) happens only inside a crystal. "Outside" there is wild quantum foam and superposition of all possibilities. In our crystallized world the vacuum no longer boils but is cooled down by the crystallization event, space-time exists and general relativity holds. Vacuum energy becomes 10**20 smaller, exactly as observed in our everyday world. We live in a "solid" state, within a crystal, the n quanta which build our world have all their different m states nicely separated. There are only nm states available for this local "multiverse". The arrow of entropy for each edge of the crystal forms one fate, one world-line or clear development of our world, while layers of the crystal are different system states. Mathematical leads from loop quantum gravity (LQG) point to required interactions and potentials. Interaction potentials for strings or loop quanta of any dimension allow a solid, decoherent state of quanta challenging to calculate. However, if we introduce here the heuristic that any type of physical interaction of strings corresponds just to a type of calculation, there is already since 1898 the Hurwitz theorem showing that then only 1D, 2D, 4D and 8D (octonions) allow complex or hypercomplex number calculations. No other hypercomplex numbers and hence dimensions or symmetries are possible to allow calculations without yielding divisions by zero. However, the richest solution allowed by the Hurwitz theorem, octonions, is actually the observed symmetry of our universe, E8. Standard physics such as condensation, crystallization and magnetization but also solid-state physics and quantum computing allow us to show an initial mathematical treatment of our new theory by LQG to describe the cosmological state transformations by equations, and, most importantly, point out routes to parametrization of free parameters looking at testable phenomena, experiments and formulas that describe processes of crystallization, protein folding, magnetization, solid-state physics and quantum computing. This is presented here for LQG, for string theory it would be more elegant but was too demanding to be shown here. Note: While my previous Opus server preprint "A new cosmology of a crystallization process (decoherence) from the surrounding quantum soup provides heuristics to unify general relativity and quantum physics by solid state physics" (https://doi.org/10.25972/OPUS-23076) deals with the same topics and basic formulas, this new version is improved: clearer in title, better introduction, more stringent in its mathematics and improved discussion of the implications including quantum computing, hints for parametrization and connections to LQG and other current cosmological efforts. This 5th of June 2021 version is again an OPUS preprint, but this will next be edited for Archives https://arxiv.org.}, language = {en} } @phdthesis{Mayr2021, author = {Mayr, Antonia Veronika}, title = {Following Bees and Wasps up Mt. Kilimanjaro: From Diversity and Traits to hidden Interactions of Species}, doi = {10.25972/OPUS-18292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-182922}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Chapter 1 - General Introduction One of the greatest challenges of ecological research is to predict the response of ecosystems to global change; that is to changes in climate and land use. A complex question in this context is how changing environmental conditions affect ecosystem processes at different levels of communities. To shed light on this issue, I investigate drivers of biodiversity on the level of species richness, functional traits and species interactions in cavity-nesting Hymenoptera. For this purpose, I take advantage of the steep elevational gradient of Mt. Kilimanjaro that shows strong environmental changes on a relatively small spatial scale and thus, provides a good environmental scenario for investigating drivers of diversity. In this thesis, I focus on 1) drivers of species richness at different trophic levels (Chapter 2); 2) seasonal patterns in nest-building activity, life-history traits and ecological rates in three different functional groups and at different elevations (Chapter 3) and 3) changes in cuticular hydrocarbons, pollen composition and microbiomes in Lasioglossum bees caused by climatic variables (Chapter 4). Chapter 2 - Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera Drivers of species richness have been subject to research for centuries. Temperature, resource availability and top-down regulation as well as the impact of land use are considered to be important factors in determining insect diversity. Yet, the relative importance of each of these factors is unknown. Using trap nests along the elevational gradient of Mt. Kilimanjaro, we tried to disentangle drivers of species richness at different trophic levels. Temperature was the major driver of species richness across trophic levels, with increasing importance of food resources at higher trophic levels in natural antagonists. Parasitism rate was both related to temperature and trophic level, indicating that the relative importance of bottom-up and top-down forces might shift with climate change. Chapter 3 - Seasonal variation in the ecology of tropical cavity-nesting Hymenoptera Natural populations fluctuate with the availability of resources, presence of natural enemies and climatic variations. But tropical mountain seasonality is not yet well investigated. We investigated seasonal patterns in nest-building activity, functional traits and ecological rates in three different insect groups at lower and higher elevations separately. Insects were caught with trap nests which were checked monthly during a 17 months period that included three dry and three rainy seasons. Insects were grouped according to their functional guilds. All groups showed strong seasonality in nest-building activity which was higher and more synchronised among groups at lower elevations. Seasonality in nest building activity of caterpillar-hunting and spider-hunting wasps was linked to climate seasonality while in bees it was strongly linked to the availability of flowers, as well as for the survival rate and sex ratio of bees. Finding adaptations to environmental seasonality might imply that further changes in climatic seasonality by climate change could have an influence on life-history traits of tropical mountain species. Chapter 4 - Cryptic species and hidden ecological interactions of halictine bees along an elevational Gradient Strong environmental gradients such as those occurring along mountain slopes are challenging for species. In this context, hidden adaptations or interactions have rarely been considered. We used bees of the genus Lasioglossum as model organisms because Lasioglossum is the only bee genus occurring with a distribution across the entire elevational gradient at Mt. Kilimanjaro. We asked if and how (a) cuticular hydrocarbons (CHC), which act as a desiccation barrier, change in composition and chain length along with changes in temperature and humidity (b), Lasioglossum bees change their pollen diet with changing resource availability, (c) gut microbiota change with pollen diet and climatic conditions, and surface microbiota change with CHC and climatic conditions, respectively, and if changes are rather influenced by turnover in Lasioglossum species along the elevational gradient. We found physiological adaptations with climate in CHC as well as changes in communities with regard to pollen diet and microbiota, which also correlated with each other. These results suggest that complex interactions and feedbacks among abiotic and biotic conditions determine the species composition in a community. Chapter 5 - General Discussion Abiotic and biotic factors drove species diversity, traits and interactions and they worked differently depending on the functional group that has been studied, and whether spatial or temporal units were considered. It is therefore likely, that in the light of global change, different species, traits and interactions will be affected differently. Furthermore, increasing land use intensity could have additional or interacting effects with climate change on biodiversity, even though the potential land-use effects at Mt. Kilimanjaro are still low and not impairing cavity-nesting Hymenoptera so far. Further studies should address species networks which might reveal more sensitive changes. For that purpose, trap nests provide a good model system to investigate effects of global change on multiple trophic levels and may also reveal direct effects of climate change on entire life-history traits when established under different microclimatic conditions. The non-uniform effects of abiotic and biotic conditions on multiple aspects of biodiversity revealed with this study also highlight that evaluating different aspects of biodiversity can give a more comprehensive picture than single observations.}, subject = {land use}, language = {en} } @phdthesis{Krimmer2021, author = {Krimmer, Elena}, title = {Agri-environment schemes and ecosystem services: The influence of different sown flower field characteristics on pollination, natural pest control and crop yield}, doi = {10.25972/OPUS-20657}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206577}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Insects are responsible for the major part of the ecosystem services pollination and natural pest control. If insects decline, these ecosystem services can not longer be reliably delivered. Agricultural intensification and the subsequent loss and fragmentation of habitats has among others been identified to cause insect decline. Ecological intensification aims to promote alternative and sustainable management practices in agricultural farming, for example to decrease the use of external inputs such as pesticides. Agri-environment schemes make amends for farmers if they integrate ecologically beneficial measures into their farming regime and can therefore promote ecological intensification. There is a wide variety of agri-environment schemes, but the implementation of sown flower fields on crop fields is often included. Flower fields offer foraging resources as well as nesting sites for many different insect species and should be able to support insect populations as well as to increase ecosystem services to adjacent fields. However, the potential of flower fields to exhibit these effects is depending on many factors. Among others, the age and size of the flower field can influence if and how different insects profit from the measure. Additionally, the complexity of the surrounding landscape and therefore the existing biodiversity is influencing the potential of flower fields to increase ecosystem services locally. The goal of this study is to disentangle to which degree these factors influence the ecosystem services pollination and natural pest control and if these factors interact with each other. Furthermore, it will be examined if and how flower fields and ecosystem services influence crop yield. Additional factors examined in this study are distance decay and pesticide use. The abundance of beneficial insects can decrease strongly with increasing distance to suitable habitats. Pesticide use in turn could abrogate positive effects of flower fields on beneficial insects. To examine these different aspects and to be able to make recommendations for flower field implementation, field experiments were conducted on differently composed sown flower fields and adjacent oilseed rape fields. Flower fields differed in their age and continuity as well as in their size. Additionally, flower and oilseed rape fields were chosen in landscapes with different amounts of semi-natural habitat. Oilseed rape fields adjacent to calcareous grasslands and conventional crop fields served as controls. Pollinator observations and pollen beetle and parasitism surveys were conducted in the oilseed rape fields. Additionally, different yield parameters of the oilseed rape plants were recorded. Observations were conducted and samples taken in increasing distance to the flower fields to examine distance decay functions. Spray windows were established to inspect the influence of pesticides on ecosystem services and crop yields. Linear mixed models were used for statistical analysis. The results show, that newly established flower fields with high amounts of flower cover are very attractive for pollinators. If the flower fields reached a certain size (> 1.5ha), the pollinators tended to stay in these fields and did not distribute into the surroundings. High amounts of semi-natural habitat in the surrounding landscape increased the value of small flower fields as starting points for pollinators and their subsequent spillover into crop fields. Additionally, high amounts of semi-natural habitat decreased the decay of pollinators with increasing distance to the flower fields. Based on these results, it can be recommended to establish many small flower fields in landscapes with high amounts of semi-natural habitat and large flower fields in landscapes with low amounts of semi-natural habitat. However, it is mentionable that flower fields are no substitute for perennial semi-natural habitats. These still must be actively conserved to increase pollination to crop fields. Furthermore, the lowest amount of pollen beetle infestation was found on oilseed rape fields adjacent to continuous flower fields aged older than 6 years. Flower fields and calcareous grasslands in general increased pollen beetle parasitism in adjacent oilseed rape fields compared to conventional crop fields. The threshold for effective natural pest control could only be reached in the pesticide free areas in the oilseed rape fields adjacent to continuous flower fields and calcareous grasslands. Parasitism and superparasitism declined with increasing distance to the adjacent fields in pesticide treated areas of the oilseed rape fields. However, they remained on a similar level in spray windows without pesticides. Large flower fields increased parasitism and superparasitism more than small flower fields. Flower fields generally have the potential to increase pollen beetle parasitism rates, but pesticides can abrogate these positive effects of flower fields on natural pest control. Last but not least, effects of flower fields and ecosystem services on oilseed rape yield were examined. No positive effects of pollination on oilseed rape yield could be found. Old and continuous flower fields increased natural pest control in oilseed rape fields, which in turn increased seed set and total seed weight of oilseed rape plants. The pesticide treatment had negative effects on natural pest control, but positive effects on crop yield. Pollination and natural pest control decreased with increasing distance to the field edge, but fruit set slightly increased. The quality of the field in terms of soil and climatic conditions did not influence the yield parameters examined in this study. Yield formation in oilseed rape plants is a complex process with many factors involved, and it is difficult to disentangle indirect effects of flower fields on yield. However, perennial flower fields can promote ecological intensification by increasing crop yield via natural pest control. This study contributes to a better understanding of the effects of differently composed flower fields on pollination, natural pest control and oilseed rape yield.}, subject = {{\"O}kologie}, language = {en} } @article{WuPonsGoudetetal.2017, author = {Wu, Yu and Pons, Val{\´e}rie and Goudet, Am{\´e}lie and Panigai, Laetitia and Fischer, Annette and Herweg, Jo-Ana and Kali, Sabrina and Davey, Robert A. and Laporte, J{\´e}r{\^o}me and Bouclier, C{\´e}line and Yousfi, Rahima and Aubenque, C{\´e}line and Merer, Goulven and Gobbo, Emilie and Lopez, Roman and Gillet, Cynthia and Cojean, Sandrine and Popoff, Michel R. and Clayette, Pascal and Le Grand, Roger and Boulogne, Claire and Tordo, No{\"e}l and Lemichez, Emmanuel and Loiseau, Philippe M. and Rudel, Thomas and Sauvaire, Didier and Cintrat, Jean-Christophe and Gillet, Daniel and Barbier, Julien}, title = {ABMA, a small molecule that inhibits intracellular toxins and pathogens by interfering with late endosomal compartments}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, doi = {10.1038/s41598-017-15466-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173170}, year = {2017}, abstract = {Intracellular pathogenic microorganisms and toxins exploit host cell mechanisms to enter, exert their deleterious effects as well as hijack host nutrition for their development. A potential approach to treat multiple pathogen infections and that should not induce drug resistance is the use of small molecules that target host components. We identifed the compound 1-adamantyl (5-bromo-2-methoxybenzyl) amine (ABMA) from a cell-based high throughput screening for its capacity to protect human cells and mice against ricin toxin without toxicity. This compound efciently protects cells against various toxins and pathogens including viruses, intracellular bacteria and parasite. ABMA provokes Rab7-positive late endosomal compartment accumulation in mammalian cells without affecting other organelles (early endosomes, lysosomes, the Golgi apparatus, the endoplasmic reticulum or the nucleus). As the mechanism of action of ABMA is restricted to host-endosomal compartments, it reduces cell infection by pathogens that depend on this pathway to invade cells. ABMA may represent a novel class of broad-spectrum compounds with therapeutic potential against diverse severe infectious diseases.}, language = {en} } @article{LukešGlatzovaKvičalovaetal.2017, author = {Lukeš, Tom{\´a}š and Glatzov{\´a}, Daniela and Kv{\´i}čalov{\´a}, Zuzana and Levet, Florian and Benda, Aleš and Letschert, Sebastian and Sauer, Markus and Brdička, Tom{\´a}š and Lasser, Theo and Cebecauer, Marek}, title = {Quantifying protein densities on cell membranes using super-resolution optical fluctuation imaging}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, doi = {10.1038/s41467-017-01857-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172993}, year = {2017}, abstract = {Quantitative approaches for characterizing molecular organization of cell membrane molecules under physiological and pathological conditions profit from recently developed super-resolution imaging techniques. Current tools employ statistical algorithms to determine clusters of molecules based on single-molecule localization microscopy (SMLM) data. These approaches are limited by the ability of SMLM techniques to identify and localize molecules in densely populated areas and experimental conditions of sample preparation and image acquisition. We have developed a robust, model-free, quantitative clustering analysis to determine the distribution of membrane molecules that excels in densely labeled areas and is tolerant to various experimental conditions, i.e. multiple-blinking or high blinking rates. The method is based on a TIRF microscope followed by a super-resolution optical fluctuation imaging (SOFI) analysis. The effectiveness and robustness of the method is validated using simulated and experimental data investigating nanoscale distribution of CD4 glycoprotein mutants in the plasma membrane of T cells.}, language = {en} } @article{KasaragodMidekessaSridharetal.2017, author = {Kasaragod, Prasad and Midekessa, Getnet B. and Sridhar, Shruthi and Schmitz, Werner and Kiema, Tiila-Riikka and Hiltunen, Jukka K. and Wierenga, Rik K.}, title = {Structural enzymology comparisons of multifunctional enzyme, type-1 (MFE1): the flexibility of its dehydrogenase part}, series = {FEBS Open Bio}, volume = {7}, journal = {FEBS Open Bio}, number = {12}, doi = {10.1002/2211-5463.12337}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172732}, pages = {1830-1842}, year = {2017}, abstract = {Multifunctional enzyme, type-1 (MFE1) is a monomeric enzyme with a 2E-enoyl-CoA hydratase and a 3S-hydroxyacyl-CoA dehydrogenase (HAD) active site. Enzyme kinetic data of rat peroxisomal MFE1 show that the catalytic efficiencies for converting the short-chain substrate 2E-butenoyl-CoA into acetoacetyl-CoA are much lower when compared with those of the homologous monofunctional enzymes. The mode of binding of acetoacetyl-CoA (to the hydratase active site) and the very similar mode of binding of NAD\(^+\) and NADH (to the HAD part) are described and compared with those of their monofunctional counterparts. Structural comparisons suggest that the conformational flexibility of the HAD and hydratase parts of MFE1 are correlated. The possible importance of the conformational flexibility of MFE1 for its biocatalytic properties is discussed.}, language = {en} } @article{TemmeFriebeSchmidtetal.2017, author = {Temme, Sebastian and Friebe, Daniela and Schmidt, Timo and Poschmann, Gereon and Hesse, Julia and Steckel, Bodo and St{\"u}hler, Kai and Kunz, Meik and Dandekar, Thomas and Ding, Zhaoping and Akhyari, Payam and Lichtenberg, Artur and Schrader, J{\"u}rgen}, title = {Genetic profiling and surface proteome analysis of human atrial stromal cells and rat ventricular epicardium-derived cells reveals novel insights into their cardiogenic potential}, series = {Stem Cell Research}, volume = {25}, journal = {Stem Cell Research}, doi = {10.1016/j.scr.2017.11.006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172716}, pages = {183-190}, year = {2017}, abstract = {Epicardium-derived cells (EPDC) and atrial stromal cells (ASC) display cardio-regenerative potential, but the molecular details are still unexplored. Signals which induce activation, migration and differentiation of these cells are largely unknown. Here we have isolated rat ventricular EPDC and rat/human ASC and performed genetic and proteomic profiling. EPDC and ASC expressed epicardial/mesenchymal markers (WT-1, Tbx18, CD73,CD90, CD44, CD105), cardiac markers (Gata4, Tbx5, troponin T) and also contained phosphocreatine. We used cell surface biotinylation to isolate plasma membrane proteins of rEPDC and hASC, Nano-liquid chromatography with subsequent mass spectrometry and bioinformatics analysis identified 396 rat and 239 human plasma membrane proteins with 149 overlapping proteins. Functional GO-term analysis revealed several significantly enriched categories related to extracellular matrix (ECM), cell migration/differentiation, immunology or angiogenesis. We identified receptors for ephrin and growth factors (IGF, PDGF, EGF, anthrax toxin) known to be involved in cardiac repair and regeneration. Functional category enrichment identified clusters around integrins, PI3K/Akt-signaling and various cardiomyopathies. Our study indicates that EPDC and ASC have a similar molecular phenotype related to cardiac healing/regeneration. The cell surface proteome repository will help to further unravel the molecular details of their cardio-regenerative potential and their role in cardiac diseases.}, language = {en} } @article{CosteaCoelhoSunagawaetal.2017, author = {Costea, Paul I. and Coelho, Louis Pedro and Sunagawa, Shinichi and Munch, Robin and Huerta-Cepas, Jaime and Forslund, Kristoffer and Hildebrand, Falk and Kushugulova, Almagul and Zeller, Georg and Bork, Peer}, title = {Subspecies in the global human gut microbiome}, series = {Molecular Systems Biology}, volume = {13}, journal = {Molecular Systems Biology}, number = {12}, doi = {10.15252/msb.20177589}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172674}, year = {2017}, abstract = {Population genomics of prokaryotes has been studied in depth in only a small number of primarily pathogenic bacteria, as genome sequences of isolates of diverse origin are lacking for most species. Here, we conducted a large-scale survey of population structure in prevalent human gut microbial species, sampled from their natural environment, with a culture-independent metagenomic approach. We examined the variation landscape of 71 species in 2,144 human fecal metagenomes and found that in 44 of these, accounting for 72\% of the total assigned microbial abundance, single-nucleotide variation clearly indicates the existence of sub-populations (here termed subspecies). A single subspecies (per species) usually dominates within each host, as expected from ecological theory. At the global scale, geographic distributions of subspecies differ between phyla, with Firmicutes subspecies being significantly more geographically restricted. To investigate the functional significance of the delineated subspecies, we identified genes that consistently distinguish them in a manner that is independent of reference genomes. We further associated these subspecies-specific genes with properties of the microbial community and the host. For example, two of the three Eubacterium rectale subspecies consistently harbor an accessory pro-inflammatory flagellum operon that is associated with lower gut community diversity, higher host BMI, and higher blood fasting insulin levels. Using an additional 676 human oral samples, we further demonstrate the existence of niche specialized subspecies in the different parts of the oral cavity. Taken together, we provide evidence for subspecies in the majority of abundant gut prokaryotes, leading to a better functional and ecological understanding of the human gut microbiome in conjunction with its host.}, language = {en} } @article{LapuenteArandjelovicKuehletal.2020, author = {Lapuente, Juan and Arandjelovic, Mimi and K{\"u}hl, Hjalmar and Dieguez, Paula and Boesch, Christophe and Linsenmair, K. Eduard}, title = {Sustainable Peeling of Kapok Tree (Ceiba pentandra) Bark by the Chimpanzees (Pan troglodytes verus) of Como{\´e} National Park, Ivory Coast}, series = {International Journal of Primatology}, volume = {41}, journal = {International Journal of Primatology}, issn = {0164-0291}, doi = {10.1007/s10764-020-00152-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232581}, pages = {962-988}, year = {2020}, abstract = {Primates often consume either bark or cambium (inner bark) as a fallback food tocomplete their diet during periods of food scarcity. Wild chimpanzees exhibit greatbehavioral diversity across Africa, as studies of new populations frequently reveal.Since 2014, we have been using a combination of camera traps and indirect signs tostudy the ecology and behavior of wild chimpanzees (Pan troglodytes verus) in Como{\´e}National Park, Ivory Coast, to document and understand the behavioral adaptations thathelp them to survive in a savanna-forest mosaic landscape. We found that Como{\´e}chimpanzees peel the bark of the buttresses of kapok tree (Ceiba pentandra) trees to eatthe cambium underneath. Individuals of all sex/age classes across at least six neigh-boring communities peeled the bark, but only during the late rainy season andbeginning of the dry season, when cambium may represent an important fallback food.Baboons (Papio anubis) also target the same trees but mainly eat the bark itself. Mostof the bark-peeling wounds onCeibatrees healed completely within 2 years, seeminglywithout any permanent damage. We recorded chimpanzees visiting trees in early stagesof wound recovery but leaving them unpeeled. Only 6\% of peeled trees (N= 53) werereexploited after a year, suggesting that chimpanzees waited for the rest of the trees toregrow the bark fully before peeling them again, thus using them sustainably. Manyhuman groups of hunter-gatherers and herders exploited cambium sustainably in thepast. The observation that similar sustainable bark-peeling behavior evolved in bothchimpanzees and humans suggests that it has an important adaptive value in harshenvironments when other food sources become seasonally scarce, by avoiding thedepletion of the resource and keeping it available for periods of scarcity.}, language = {en} } @article{PetersClassenMuelleretal.2020, author = {Peters, Marcell K. and Classen, Alice and M{\"u}ller, J{\"o}rg and Steffan‑Dewenter, Ingolf}, title = {Increasing the phylogenetic coverage for understanding broad-scale diversity gradients}, series = {Oecologia}, volume = {192}, journal = {Oecologia}, issn = {0029-8549}, doi = {10.1007/s00442-020-04615-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232519}, pages = {629-639}, year = {2020}, abstract = {Despite decades of scientific effort, there is still no consensus on the determinants of broad-scale gradients of animal diver-sity. We argue that general drivers of diversity are unlikely to be found among the narrowly defined taxa which are typically analyzed in studies of broad-scale diversity gradients because ecological niches evolve largely conservatively. This causes constraints in the use of available niche space leading to systematic differences in diversity gradients among taxa. We instead advocate studies of phylogenetically diverse animal communities along broad environmental gradients. Such multi-taxa communities are less constrained in resource use and diversification and may be better targets for testing major classical hypotheses on diversity gradients. Besides increasing the spatial scale in analyses, expanding the phylogenetic coverage may be a second way to achieve higher levels of generality in studies of broad-scale diversity gradients}, language = {en} } @article{KablauBergRutschmannetal.2020, author = {Kablau, Arne and Berg, Stefan and Rutschmann, Benjamin and Scheiner, Ricarda}, title = {Short-term hyperthermia at larval age reduces sucrose responsiveness of adult honeybees and can increase life span}, series = {Apidologie}, volume = {51}, journal = {Apidologie}, issn = {0044-8435}, doi = {10.1007/s13592-020-00743-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232462}, pages = {570-582}, year = {2020}, abstract = {Honeybees are very sensitive to their breeding temperature. Even slightly lower temperatures during larval development can significantly affect adult behavior. Several devices which are employed for killing the honeybee ectoparasite Varroa destructor rely on short-term hyperthermia in the honeybee hive. The device used here applies 43.7 °C for 2 h, which is highly effective in killing the mites. We study how short-term hyperthermia affects worker brood and behavior of emerging adult bees. Sucrose responsiveness was strongly reduced after treatment of larvae early or late of larval development. Hyperthermia significantly enhanced life span, particularly in bees receiving treated early in larval development. To ask whether increased life span correlated with foraging performance, we used radio frequency identification (RFID). Onset and offset of foraging behavior as well as foraging trip duration and lifetime foraging effort were unaffected by hyperthermia treatment as prepupa.}, language = {en} } @article{SchaeblerAmatobiHornetal.2020, author = {Sch{\"a}bler, Stefan and Amatobi, Kelechi M. and Horn, Melanie and Rieger, Dirk and Helfrich‑F{\"o}rster, Charlotte and Mueller, Martin J. and Wegener, Christian and Fekete, Agnes}, title = {Loss of function in the Drosophila clock gene period results in altered intermediary lipid metabolism and increased susceptibility to starvation}, series = {Cellular and Molecular Life Sciences}, volume = {77}, journal = {Cellular and Molecular Life Sciences}, issn = {1420-682X}, doi = {10.1007/s00018-019-03441-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232432}, pages = {4939-4956}, year = {2020}, abstract = {The fruit fly Drosophila is a prime model in circadian research, but still little is known about its circadian regulation of metabolism. Daily rhythmicity in levels of several metabolites has been found, but knowledge about hydrophobic metabolites is limited. We here compared metabolite levels including lipids between period\(^{01}\) (per\(^{01}\)) clock mutants and Canton-S wildtype (WT\(_{CS}\)) flies in an isogenic and non-isogenic background using LC-MS. In the non-isogenic background, metabo-lites with differing levels comprised essential amino acids, kynurenines, pterinates, glycero(phospho)lipids, and fatty acid esters. Notably, detectable diacylglycerols (DAG) and acylcarnitines (AC), involved in lipid metabolism, showed lower levels in per\(^{01}\) mutants. Most of these differences disappeared in the isogenic background, yet the level differences for AC as well as DAG were consistent for fly bodies. AC levels were dependent on the time of day in WTCS in phase with food consumption under LD conditions, while DAGs showed weak daily oscillations. Two short-chain ACs continued to cycle even in constant darkness. per\(^{01}\) mutants in LD showed no or very weak diel AC oscillations out of phase with feeding activity. The low levels of DAGs and ACs in per\(^{01}\) did not correlate with lower total food consumption, body mass or weight. Clock mutant flies showed higher sensitivity to starvation independent of their background-dependent activity level. Our results suggest that neither feeding, energy storage nor mobilisation is significantly affected in per\(^{01}\) mutants, but point towards impaired mitochondrial activity, supported by upregulation of the mitochondrial stress marker 4EBP in the clock mutants}, language = {en} } @article{SchlegelSauer2020, author = {Schlegel, Jan and Sauer, Markus}, title = {Hochaufgel{\"o}ste Visualisierung einzelner Molek{\"u}le auf ganzen Zellen}, series = {BIOspektrum}, volume = {7}, journal = {BIOspektrum}, issn = {0947-0867}, doi = {10.1007/s12268-020-1501-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232365}, pages = {736-738}, year = {2020}, abstract = {Biological systems are dynamic and three-dimensional but many techniques allow only static and two-dimensional observation of cells. We used three-dimensional (3D) lattice light-sheet single-molecule localization microscopy (dSTORM) to investigate the complex interactions and distribution of single molecules in the plasma membrane of whole cells. Different receptor densities of the adhesion receptor CD56 at different parts of the cell highlight the importance and need of three-dimensional observation and analysis techniques.}, language = {de} } @article{LamazeOeztuerkColakFischeretal.2017, author = {Lamaze, Angelique and {\"O}zt{\"u}rk-{\c{C}}olak, Arzu and Fischer, Robin and Peschel, Nicolai and Koh, Kyunghee and Jepson, James E. C.}, title = {Regulation of sleep plasticity by a thermo-sensitive circuit in Drosophila}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, doi = {10.1038/srep40304}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181146}, pages = {12}, year = {2017}, abstract = {Sleep is a highly conserved and essential behaviour in many species, including the fruit fly Drosophila melanogaster. In the wild, sensory signalling encoding environmental information must be integrated with sleep drive to ensure that sleep is not initiated during detrimental conditions. However, the molecular and circuit mechanisms by which sleep timing is modulated by the environment are unclear. Here we introduce a novel behavioural paradigm to study this issue. We show that in male fruit flies, onset of the daytime siesta is delayed by ambient temperatures above 29°C. We term this effect Prolonged Morning Wakefulness (PMW). We show that signalling through the TrpA1 thermo-sensor is required for PMW, and that TrpA1 specifically impacts siesta onset, but not night sleep onset, in response to elevated temperatures. We identify two critical TrpA1-expressing circuits and show that both contact DN1p clock neurons, the output of which is also required for PMW. Finally, we identify the circadian blue-light photoreceptor CRYPTOCHROME as a molecular regulator of PMW, and propose a model in which the Drosophila nervous system integrates information encoding temperature, light, and time to dynamically control when sleep is initiated. Our results provide a platform to investigate how environmental inputs co-ordinately regulate sleep plasticity.}, language = {en} } @article{EwaldBartlDandekaretal.2017, author = {Ewald, Jan and Bartl, Martin and Dandekar, Thomas and Kaleta, Christoph}, title = {Optimality principles reveal a complex interplay of intermediate toxicity and kinetic efficiency in the regulation of prokaryotic metabolism}, series = {PLOS Computational Biology}, volume = {13}, journal = {PLOS Computational Biology}, number = {2}, doi = {10.1371/journal.pcbi.1005371}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-180870}, pages = {19}, year = {2017}, abstract = {A precise and rapid adjustment of fluxes through metabolic pathways is crucial for organisms to prevail in changing environmental conditions. Based on this reasoning, many guiding principles that govern the evolution of metabolic networks and their regulation have been uncovered. To this end, methods from dynamic optimization are ideally suited since they allow to uncover optimality principles behind the regulation of metabolic networks. We used dynamic optimization to investigate the influence of toxic intermediates in connection with the efficiency of enzymes on the regulation of a linear metabolic pathway. Our results predict that transcriptional regulation favors the control of highly efficient enzymes with less toxic upstream intermediates to reduce accumulation of toxic downstream intermediates. We show that the derived optimality principles hold by the analysis of the interplay between intermediate toxicity and pathway regulation in the metabolic pathways of over 5000 sequenced prokaryotes. Moreover, using the lipopolysaccharide biosynthesis in Escherichia coli as an example, we show how knowledge about the relation of regulation, kinetic efficiency and intermediate toxicity can be used to identify drug targets, which control endogenous toxic metabolites and prevent microbial growth. Beyond prokaryotes, we discuss the potential of our findings for the development of antifungal drugs.}, language = {en} } @article{FlemmingHankirErnestusetal.2020, author = {Flemming, S. and Hankir, M. and Ernestus, R.-I. and Seyfried, F. and Germer, C.-T. and Meybohm, P. and Wurmb, T. and Vogel, U. and Wiegering, A.}, title = {Surgery in times of COVID-19 — recommendations for hospital and patient management}, series = {Langenbeck's Archives of Surgery}, volume = {405}, journal = {Langenbeck's Archives of Surgery}, issn = {1435-2443}, doi = {10.1007/s00423-020-01888-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231766}, pages = {359-364}, year = {2020}, abstract = {Background The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has escalated rapidly to a global pandemic stretching healthcare systems worldwide to their limits. Surgeonshave had to immediately react to this unprecedented clinical challenge by systematically repurposing surgical wards. Purpose To provide a detailed set of guidelines developed in a surgical ward at University Hospital Wuerzburg to safelyaccommodate the exponentially rising cases of SARS-CoV-2 infected patients without compromising the care of emergencysurgery and oncological patients or jeopardizing the well-being of hospital staff. Conclusions The dynamic prioritization of SARS-CoV-2 infected and surgical patient groups is key to preserving life whilemaintaining high surgical standards. Strictly segregating patient groups in emergency rooms, non-intensive care wards andoperating areas prevents viral spread while adequately training and carefully selecting hospital staff allow them to confidentlyand successfully undertake their respective clinical duties.}, language = {en} } @article{BaeHeidrichLevicketal.2020, author = {Bae, Soyeon and Heidrich, Lea and Levick, Shaun R. and Gossner, Martin M. and Seibold, Sebastian and Weisser, Wolfgang W. and Magdon, Paul and Serebryanyk, Alla and B{\"a}ssler, Claus and Sch{\"a}fer, Deborah and Schulze, Ernst-Detlef and Doerfler, Inken and M{\"u}ller, J{\"o}rg and Jung, Kirsten and Heurich, Marco and Fischer, Markus and Roth, Nicolas and Schall, Peter and Boch, Steffen and W{\"o}llauer, Stephan and Renner, Swen C. and M{\"u}ller, J{\"o}rg}, title = {Dispersal ability, trophic position and body size mediate species turnover processes: Insights from a multi-taxa and multi-scale approach}, series = {Diversity and Distribution}, volume = {27}, journal = {Diversity and Distribution}, number = {3}, doi = {10.1111/ddi.13204}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236117}, pages = {439-453}, year = {2020}, abstract = {Aim: Despite increasing interest in β-diversity, that is the spatial and temporal turnover of species, the mechanisms underlying species turnover at different spatial scales are not fully understood, although they likely differ among different functional groups. We investigated the relative importance of dispersal limitations and the environmental filtering caused by vegetation for local, multi-taxa forest communities differing in their dispersal ability, trophic position and body size. Location: Temperate forests in five regions across Germany. Methods: In the inter-region analysis, the independent and shared effects of the regional spatial structure (regional species pool), landscape spatial structure (dispersal limitation) and environmental factors on species turnover were quantified with a 1-ha grain across 11 functional groups in up to 495 plots by variation partitioning. In the intra-region analysis, the relative importance of three environmental factors related to vegetation (herb and tree layer composition and forest physiognomy) and spatial structure for species turnover was determined. Results: In the inter-region analysis, over half of the explained variation in community composition (23\% of the total explained 35\%) was explained by the shared effects of several factors, indicative of spatially structured environmental filtering. Among the independent effects, environmental factors were the strongest on average over 11 groups, but the importance of landscape spatial structure increased for less dispersive functional groups. In the intra-region analysis, the independent effect of plant species composition had a stronger influence on species turnover than forest physiognomy, but the relative importance of the latter increased with increasing trophic position and body size. Main conclusions: Our study revealed that the mechanisms structuring assemblage composition are associated with the traits of functional groups. Hence, conservation frameworks targeting biodiversity of multiple groups should cover both environmental and biogeographical gradients. Within regions, forest management can enhance β-diversity particularly by diversifying tree species composition and forest physiognomy.}, language = {en} } @article{PetrovGentschevVyalkovaetal.2020, author = {Petrov, Ivan and Gentschev, Ivaylo and Vyalkova, Anna and Elashry, Mohamed I. and Klymiuk, Michele C. and Arnhold, Stefan and Szalay, Aladar A.}, title = {Canine Adipose-Derived Mesenchymal Stem Cells (cAdMSCs) as a "Trojan Horse" in Vaccinia Virus Mediated Oncolytic Therapy against Canine Soft Tissue Sarcomas}, series = {Viruses}, volume = {12}, journal = {Viruses}, number = {7}, doi = {10.3390/v12070750}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236007}, year = {2020}, abstract = {Several oncolytic viruses (OVs) including various human and canine adenoviruses, canine distemper virus, herpes-simplex virus, reovirus, and members of the poxvirus family, such as vaccinia virus and myxoma virus, have been successfully tested for canine cancer therapy in preclinical and clinical settings. The success of the cancer virotherapy is dependent on the ability of oncolytic viruses to overcome the attacks of the host immune system, to preferentially infect and lyse cancer cells, and to initiate tumor-specific immunity. To date, several different strategies have been developed to overcome the antiviral host defense barriers. In our study, we used canine adipose-derived mesenchymal stem cells (cAdMSCs) as a "Trojan horse" for the delivery of oncolytic vaccinia virus Copenhagen strain to achieve maximum oncolysis against canine soft tissue sarcoma (CSTS) tumors. A single systemic administration of vaccinia virus-loaded cAdMSCs was found to be safe and led to the significant reduction and substantial inhibition of tumor growth in a CSTS xenograft mouse model. This is the first example that vaccinia virus-loaded cAdMSCs could serve as a therapeutic agent against CSTS tumors.}, language = {en} } @article{BoschertKlenkAbtetal.2020, author = {Boschert, Verena and Klenk, Nicola and Abt, Alexander and Raman, Sudha Janaki and Fischer, Markus and Brands, Roman C. and Seher, Axel and Linz, Christian and M{\"u}ller-Richter, Urs D. A. and Bischler, Thorsten and Hartmann, Stefan}, title = {The influence of Met receptor level on HGF-induced glycolytic reprogramming in head and neck squamous cell carcinoma}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {2}, issn = {1422-0067}, doi = {10.3390/ijms21020471}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235995}, year = {2020}, abstract = {Head and neck squamous cell carcinoma (HNSCC) is known to overexpress a variety of receptor tyrosine kinases, such as the HGF receptor Met. Like other malignancies, HNSCC involves a mutual interaction between the tumor cells and surrounding tissues and cells. We hypothesized that activation of HGF/Met signaling in HNSCC influences glucose metabolism and therefore substantially changes the tumor microenvironment. To determine the effect of HGF, we submitted three established HNSCC cell lines to mRNA sequencing. Dynamic changes in glucose metabolism were measured in real time by an extracellular flux analyzer. As expected, the cell lines exhibited different levels of Met and responded differently to HGF stimulation. As confirmed by mRNA sequencing, the level of Met expression was associated with the number of upregulated HGF-dependent genes. Overall, Met stimulation by HGF leads to increased glycolysis, presumably mediated by higher expression of three key enzymes of glycolysis. These effects appear to be stronger in Met\(^{high}\)-expressing HNSCC cells. Collectively, our data support the hypothesized role of HGF/Met signaling in metabolic reprogramming of HNSCC.}, language = {en} } @phdthesis{Vollmuth2021, author = {Vollmuth, Nadine}, title = {Role of the proto-oncogene c-Myc in the development of Chlamydia trachomatis}, doi = {10.25972/OPUS-20365}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203655}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Chlamydia trachomatis, an obligate intracellular human pathogen, is the world's leading cause of infection related blindness and the most common, bacterial sexually transmitted disease. In order to establish an optimal replicative niche, the pathogen extensively interferes with the physiology of the host cell. Chlamydia switches in its complex developmental cycle between the infectious non-replicative elementary bodies (EBs) and the non-infectious replicative reticulate bodies (RBs). The transformation to RBs, shortly after entering a host cell, is a crucial process in infection to start chlamydial replication. Currently it is unknown how the transition from EBs to RBs is initiated. In this thesis, we could show that, in an axenic media approach, L glutamine uptake by the pathogen is crucial to initiate the EB to RB transition. L-glutamine is converted to amino acids which are used by the bacteria to synthesize peptidoglycan. Peptidoglycan inturn is believed to function in separating dividing Chlamydia. The glutamine metabolism is reprogrammed in infected cells in a c-Myc-dependent manner, in order to accomplish the increased requirement for L-glutamine. Upon a chlamydial infection, the proto-oncogene c-Myc gets upregulated to promote host cell glutaminolysis via glutaminase GLS1 and the L-glutamine transporter SLC1A5/ASCT2. Interference with this metabolic reprogramming leads to limited growth of C. trachomatis. Besides the active infection, Chlamydia can persist over a long period of time within the host cell whereby chronic and recurrent infections establish. C. trachomatis acquire a persistent state during an immune attack in response to elevated interferon-γ (IFN-γ) levels. It has been shown that IFN-γ activates the catabolic depletion of L-tryptophan via indoleamine 2,3-dioxygenase (IDO), resulting in the formation of non-infectious atypical chlamydial forms. In this thesis, we could show that IFN-γ depletes the key metabolic regulator c-Myc, which has been demonstrated to be a prerequisite for chlamydial development and growth, in a STAT1-dependent manner. Moreover, metabolic analyses revealed that the pathogen de routs the host cell TCA cycle to enrich pyrimidine biosynthesis. Supplementing pyrimidines or a-ketoglutarate helps the bacteria to partially overcome the persistent state. Together, the results indicate a central role of c-Myc induced host glutamine metabolism reprogramming and L-glutamine for the development of C. trachomatis, which may provide a basis for anti-infectious strategies. Furthermore, they challenge the longstanding hypothesis of L-tryptophan shortage as the sole reason for IFN-γ induced persistence and suggest a pivotal role of c-Myc in the control of the C. trachomatis dormancy.}, language = {en} } @article{ClassenEardleyHempetal.2020, author = {Classen, Alice and Eardley, Connal D. and Hemp, Andreas and Peters, Marcell K. and Peters, Ralph S. and Ssymank, Axel and Steffan-Dewenter, Ingolf}, title = {Specialization of plant-pollinator interactions increases with temperature at Mt. Kilimanjaro}, series = {Ecology and Evolution}, volume = {10}, journal = {Ecology and Evolution}, number = {4}, doi = {10.1002/ece3.6056}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235959}, pages = {2182-2195}, year = {2020}, abstract = {Aim: Species differ in their degree of specialization when interacting with other species, with significant consequences for the function and robustness of ecosystems. In order to better estimate such consequences, we need to improve our understanding of the spatial patterns and drivers of specialization in interaction networks. Methods: Here, we used the extensive environmental gradient of Mt. Kilimanjaro (Tanzania, East Africa) to study patterns and drivers of specialization, and robustness of plant-pollinator interactions against simulated species extinction with standardized sampling methods. We studied specialization, network robustness and other network indices of 67 quantitative plant-pollinator networks consisting of 268 observational hours and 4,380 plant-pollinator interactions along a 3.4 km elevational gradient. Using path analysis, we tested whether resource availability, pollinator richness, visitation rates, temperature, and/or area explain average specialization in pollinator communities. We further linked pollinator specialization to different pollinator taxa, and species traits, that is, proboscis length, body size, and species elevational ranges. Results: We found that specialization decreased with increasing elevation at different levels of biological organization. Among all variables, mean annual temperature was the best predictor of average specialization in pollinator communities. Specialization differed between pollinator taxa, but was not related to pollinator traits. Network robustness against simulated species extinctions of both plants and pollinators was lowest in the most specialized interaction networks, that is, in the lowlands. Conclusions: Our study uncovers patterns in plant-pollinator specialization along elevational gradients. Mean annual temperature was closely linked to pollinator specialization. Energetic constraints, caused by short activity timeframes in cold highlands, may force ectothermic species to broaden their dietary spectrum. Alternatively or in addition, accelerated evolutionary rates might facilitate the establishment of specialization under warm climates. Despite the mechanisms behind the patterns have yet to be fully resolved, our data suggest that temperature shifts in the course of climate change may destabilize pollination networks by affecting network architecture.}, language = {en} } @phdthesis{Roth2021, author = {Roth, Nicolas M{\´e}riadec Max Andr{\´e}}, title = {Temporal development of communities with a focus on insects, in time series of one to four decades}, doi = {10.25972/OPUS-23549}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235499}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Changes and development are fundamental principles in biocenoses and can affect a multitude of ecological processes. In insect communities phenological and density changes, changes in species richness and community composition, as well as interactions between those changes, are the most important macro processes. However, climate change and other factors like habitat degradation and loss alter these processes leading to shifts and general biodiversity declines. Even though knowledge about insect decline in central Europe increased during the last decades, there are significant knowledge gaps about the development of insect communities in certain habitats and taxa. For example, insect communities in small lentic as well as in forested habitats are under-sampled and reported to be less endangered than communities in other habitats. Furthermore, the changes within habitats and taxa are additionally influenced by certain traits, like host or feeding specialization. To disentangle these influences and to increase the knowledge about the general long-term development of insect communities, comprehensive long-term monitoring studies are needed. In addition, long-term effects of conservation strategies should also be evaluated on large time scales in order to be able to decide on a scientific base which strategies are effective in promoting possibly declining taxa. Hence, this thesis also tackles the effects of an integrative conservation strategy on wood dependent beetle and fungi, beside the development of water beetle and macro moth communities over multiple decades. In Chapter 2 I present a study on the development of water beetle communities (Dytiscidae, Haliplidae, Noteridae) in 33 water bodies in Southern Germany from 1991 to 2018. Time-standardized capture per waterbody was used during three periods: between 1991 and 1995, 2007 and 2008, and 2017 and 2018. Results showed annual declines in both species number (ca. -1\%) and abundance (ca. -2\%). In addition, community composition shifted over time in part due to changing pH values. Hence, the recorded changes during the 28-year study period partly reflect natural succession processes. However, since also moor-related beetle species decreased significantly, it is likely that water beetles in southern Germany are also threatened by non-successional factors, including desiccation, increased nitrogen input and/or mineralization, as well as the loss of specific habitats. The results suggest, that in small to midsize lentic waterbodies, current development should aim for constant creation of new water bodies and protection of moor waterbodies in order to protect water beetle communities on a landscape scale. In Chapter 3 I present an analysis of the development of nocturnal macro moth species richness, abundance and biomass over four decades in forests of southern Germany. Two local scale data sets featuring a coppiced oak forest as well as an oak high forest were analysed separately from a regional data set representing all forest types in the temperate zone of Central Europe. At the regional scale species richness, abundance and biomass showed annual declines of ca. 1 \%, 1.3 \% and 1.4 \%, respectively. These declines were more pronounced in plant host specialists and in dark coloured species. In contrast, species richness increased by ca. 1.5 \% annually in the coppiced forest, while no significant trends were found in the high forest. In contrast to past assumptions, insect decline apparently affects also hyper diverse insect groups in forests. Since host specialists and dark coloured species were affected more heavily by the decline than other groups, habitat loss and climate change seem to be potential drivers of the observed trends. However, the positive development of species richness in the coppiced oak forest indicates that maintaining complex and diverse forest ecosystems through active management might compensate for negative trends in biodiversity. Chapter 4 features a study specifically aiming to investigate the long-term effect of deadwood enrichment as an integrative conservation strategy on saproxylic beetles and fungi in a central European beech forest at a landscape scale. A before-after control-impact design, was used to compare assemblages and gamma diversities of saproxylic organisms (beetles and fungi) in strictly protected old-growth forest areas (reserves) and previously moderately and intensively managed forest areas. Forests were sampled one year before and a decade after starting a landscape-wide strategy of dead-wood enrichment. Ten years after the start of the dead-wood enrichment, neither gamma diversities of saproxylic organisms nor species composition of beetles did reflect the previous management types anymore. However, fungal species composition still mirrored the previous management gradient. The results demonstrated that intentional enrichment of dead wood at the landscape scale can effectively restore communities of saproxylic organisms and may thus be a suitable strategy in addition to permanent strict reserves in order to protect wood dependent organisms in Europe. In this thesis I showed, that in contrast to what was assumed and partly reported so far, also water beetles in lentic water bodies and macro moths in forests decreased in species richness, abundance and biomass during the last three to four decades. In line with earlier studies, especially dark coloured species and specialists decreased more than light-coloured species and generalists. The reasons for these declines could partly be attributed to natural processes and pollution and possibly to climate change. However, further studies, especially experimental ones, will be needed to achieve a better understanding of the reasons for insect decline. Furthermore, analyses of time series data should be interpreted cautiously especially if the number of sampling years is smaller than ten years. In addition, validation techniques such as left- and right- censoring and cross validation should be used in order to proof the robustness of the analyses. However, the lack of knowledge, we are still facing today, should not prevent scientists and practitioners from applying conservation measures. In order to prove the effectiveness of such measures, long-term monitoring is crucial. Such control of success is essential for evidence based and thus adapted conservation strategies of threatened organisms.}, subject = {climate change}, language = {en} } @article{DeLiraRamanSchulzeetal.2020, author = {De Lira, Maria Nathalia and Raman, Sudha Janaki and Schulze, Almut and Schneider-Schaulies, Sibylle and Avota, Elita}, title = {Neutral Sphingomyelinase-2 (NSM 2) Controls T Cell Metabolic Homeostasis and Reprogramming During Activation}, series = {Frontiers in Molecular Biosciences}, volume = {7}, journal = {Frontiers in Molecular Biosciences}, issn = {2296-889X}, doi = {10.3389/fmolb.2020.00217}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211311}, year = {2020}, abstract = {Neutral sphingomyelinase-2 (NSM2) is a member of a superfamily of enzymes responsible for conversion of sphingomyelin into phosphocholine and ceramide at the cytosolic leaflet of the plasma membrane. Upon specific ablation of NSM2, T cells proved to be hyper-responsive to CD3/CD28 co-stimulation, indicating that the enzyme acts to dampen early overshooting activation of these cells. It remained unclear whether hyper-reactivity of NSM2-deficient T cells is supported by a deregulated metabolic activity in these cells. Here, we demonstrate that ablation of NSM2 activity affects metabolism of the quiescent CD4\(^+\) T cells which accumulate ATP in mitochondria and increase basal glycolytic activity. This supports enhanced production of total ATP and metabolic switch early after TCR/CD28 stimulation. Most interestingly, increased metabolic activity in resting NSM2-deficient T cells does not support sustained response upon stimulation. While elevated under steady-state conditions in NSM2-deficient CD4\(^+\) T cells, the mTORC1 pathway regulating mitochondria size, oxidative phosphorylation, and ATP production is impaired after 24 h of stimulation. Taken together, the absence of NSM2 promotes a hyperactive metabolic state in unstimulated CD4\(^+\) T cells yet fails to support sustained T cell responses upon antigenic stimulation.}, language = {en} } @article{YangHeydarianKozjakPavlovicetal.2020, author = {Yang, Tao and Heydarian, Motaharehsadat and Kozjak-Pavlovic, Vera and Urban, Manuela and Harbottle, Richard P. and Rudel, Thomas}, title = {Folliculin Controls the Intracellular Survival and Trans-Epithelial Passage of Neisseria gonorrhoeae}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {10}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {422}, issn = {2235-2988}, doi = {10.3389/fcimb.2020.00422}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211372}, year = {2020}, abstract = {Neisseria gonorrhoeae, a Gram-negative obligate human pathogenic bacterium, infects human epithelial cells and causes sexually transmitted diseases. Emerging multi-antibiotic resistant gonococci and increasing numbers of infections complicate the treatment of infected patients. Here, we used an shRNA library screen and next-generation sequencing to identify factors involved in epithelial cell infection. Folliculin (FLCN), a 64 kDa protein with a tumor repressor function was identified as a novel host factor important for N. gonorrhoeae survival after uptake. We further determined that FLCN did not affect N. gonorrhoeae adherence and invasion but was essential for its survival in the cells by modulating autophagy. In addition, FLCN was also required to maintain cell to cell contacts in the epithelial layer. In an infection model with polarized cells, FLCN inhibited the polarized localization of E-cadherin and the transcytosis of gonococci across polarized epithelial cells. In conclusion, we demonstrate here the connection between FLCN and bacterial infection and in particular the role of FLCN in the intracellular survival and transcytosis of gonococci across polarized epithelial cell layers.}, language = {en} } @article{BalkenholKaltdorfMammadovaBachetal.2020, author = {Balkenhol, Johannes and Kaltdorf, Kristin V. and Mammadova-Bach, Elmina and Braun, Attila and Nieswandt, Bernhard and Dittrich, Marcus and Dandekar, Thomas}, title = {Comparison of the central human and mouse platelet signaling cascade by systems biological analysis}, series = {BMC Genomics}, volume = {21}, journal = {BMC Genomics}, doi = {10.1186/s12864-020-07215-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230377}, year = {2020}, abstract = {Background Understanding the molecular mechanisms of platelet activation and aggregation is of high interest for basic and clinical hemostasis and thrombosis research. The central platelet protein interaction network is involved in major responses to exogenous factors. This is defined by systemsbiological pathway analysis as the central regulating signaling cascade of platelets (CC). Results The CC is systematically compared here between mouse and human and major differences were found. Genetic differences were analysed comparing orthologous human and mouse genes. We next analyzed different expression levels of mRNAs. Considering 4 mouse and 7 human high-quality proteome data sets, we identified then those major mRNA expression differences (81\%) which were supported by proteome data. CC is conserved regarding genetic completeness, but we observed major differences in mRNA and protein levels between both species. Looking at central interactors, human PLCB2, MMP9, BDNF, ITPR3 and SLC25A6 (always Entrez notation) show absence in all murine datasets. CC interactors GNG12, PRKCE and ADCY9 occur only in mice. Looking at the common proteins, TLN1, CALM3, PRKCB, APP, SOD2 and TIMP1 are higher abundant in human, whereas RASGRP2, ITGB2, MYL9, EIF4EBP1, ADAM17, ARRB2, CD9 and ZYX are higher abundant in mouse. Pivotal kinase SRC shows different regulation on mRNA and protein level as well as ADP receptor P2RY12. Conclusions Our results highlight species-specific differences in platelet signaling and points of specific fine-tuning in human platelets as well as murine-specific signaling differences.}, language = {en} }