TY  - THES
A1  - Kuklovsky [former Finke], Valerie
T1  - Are some bees smarter than others? An examination of consistent individual differences in the cognitive abilities of honey bees
T1  - Sind manche Bienen schlauer als andere? Eine Untersuchung von konsistenten individuellen Unterschieden in den kognitiven Fähigkeiten von Honigbienen
N2  - Cognition refers to the ability to of animals to acquire, process, store and use vital information from the environment. Cognitive processes are necessary to predict the future and reduce the uncertainty of the ever-changing environment. Classically, research on animal cognition focuses on decisive cognitive tests to determine the capacity of a species by the testing the ability of a few individuals. This approach views variability between these tested key individuals as unwanted noise and is thus often neglected. However, inter-individual variability provides important insights to behavioral plasticity, cognitive specialization and brain modularity. Honey bees Apis mellifera are a robust and traditional model for the study of learning, memory and cognition due to their impressive capabilities and rich behavioral repertoire. In this thesis I have applied a novel view on the learning abilities of honey bees by looking explicitly at individual differences in a variety of learning tasks. Are some individual bees consistently smarter than some of her sisters? If so, will a smart individual always perform good independent of the time, the context and the cognitive requirements or do bees show distinct isolated ‘cognitive modules’? 

My thesis presents the first comprehensive investigation of consistent individual differences in the cognitive abilities of honey bees. To speak of an individual as behaving consistently, a crucial step is to test the individual multiple times to examine the repeatability of a behavior. I show that free-flying bees remain consistent in a visual discrimination task for three consecutive days. Successively, I explored individual consistency in cognitive proficiency across tasks involving different sensory modalities, contexts and cognitive requirements. I found that free-flying bees show a cognitive specialization between visual and olfactory learning but remained consistent across a simple discrimination task and a complex concept learning task. I wished to further explore individual consistency with respect to tasks of different cognitive complexity, a question that has never been tackled before in an insect. I thus performed a series of four experiments using either visual or olfactory stimuli and a different training context (free-flying and restrained) and tested bees in a discrimination task, reversal learning and negative patterning. Intriguingly, across all these experiments I evidenced the same results: The bees’ performances were consistent across the discrimination task and reversal learning and negative patterning respectively. No association was evidenced between reversal learning and negative patterning. After establishing the existence of consistent individual differences in the cognitive proficiency of honey bees I wished to determine factors which could underlie these differences. Since genetic components are known to underlie inter-individual variability in learning abilities, I studied the effects of genetics on consistency in cognitive proficiency by contrasting bees originating from either from a hive with a single patriline (low genetic diversity) or with multiple patrilines (high genetic diversity). These two groups of bees showed differences in the patterns of individually correlated performances, indicating a genetic component accounts for consistent cognitive individuality. Another major factor underlying variability in learning performances is the individual responsiveness to sucrose solution and to visual stimuli, as evidenced by many studies on restrained bees showing a positive correlation between responsiveness to task relevant stimuli and learning performances. I thus tested whether these relationships between sucrose/visual responsiveness and learning performances are applicable for free-flying bees. Free-flying bees were again subjected to reversal learning and negative patterning and subsequently tested in the laboratory for their responsiveness to sucrose and to light. There was no evidence of a positive relationship between sucrose/visual responsiveness and neither performances of free-flying bees in an elemental discrimination, reversal learning and negative patterning. These findings indicate that relationships established between responsiveness to task relevant stimuli and learning proficiency established in the laboratory with restrained bees might not hold true for a completely different behavioral context i.e. for free-flying bees in their natural environment.  

These results show that the honey bee is an excellent insect model to study consistency in cognitive proficiency and to identify the underlying factors. I mainly discuss the results with respect to the question of brain modularity in insects and the adaptive significance of individuality in cognitive abilities for honey bee colonies. I also provide a proposition of research questions which tie in this theme of consistent cognitive proficiency and could provide fruitful areas for future research.
N2  - Unter Kognition versteht man die Fähigkeit von Tieren, essenzielle Informationen aus der Umwelt zu erfassen, zu verarbeiten, zu speichern und zu nutzen. Kognitive Prozesse sind notwendig, um die Zukunft vorherzusagen und die Unvorhersehbarkeit der sich ständig verändernden Umwelt zu verringern. Die Forschung der Kognition von Tieren konzentriert sich klassischerweise auf entscheidende kognitive Tests, um die Fähigkeit einer Spezies anhand der Leistungen einiger weniger Individuen zu bestimmen. Bei diesem Ansatz wird die Variabilität zwischen Individuen als unerwünschtes Rauschen betrachtet und daher vernachlässigt. Die interindividuelle Variabilität liefert jedoch wichtige Erkenntnisse über die Plastizität des Verhaltens, die kognitive Spezialisierung und die Modularität des Gehirns. Die Honigbiene Apis mellifera ist aufgrund ihrer eindrucksvollen Fähigkeiten und ihres reichen Verhaltensrepertoires ein robuster und traditioneller Modellorganismus für die Untersuchung von Lernen, Gedächtnis und Kognition. In dieser Arbeit habe ich das Lernverhalten von Honigbienen in einem neuen Blickwinkel betrachtet, indem ich explizit die individuellen Unterschiede bei diversen Lernaufgaben untersucht habe. Zeigen manche Bienen durchweg eine erhöhte Lernleistung im Vergleich zu ihren Schwestern? Wenn ja, erbringt ein Individuum unabhängig von der Zeit, dem Kontext und den kognitiven Anforderungen der Lernaufgaben immer gute Leistungen, oder zeigen Bienen ausgeprägte unabhängige "kognitive Module"? 

Die vorliegende Doktorarbeit stellt die erste umfassende Untersuchung konsistenter individueller Unterschiede in den kognitiven Fähigkeiten von Honigbienen dar. Um von einem konsistenten Verhalten sprechen zu können, ist es entscheidend das Individuum mehrfach zu testen, um die Wiederholbarkeit eines Verhaltens zu untersuchen. Ich konnte zeigen, dass frei fliegende Bienen bei einer visuellen Unterscheidungsaufgabe an drei aufeinanderfolgenden Tagen eine konsistente Lernleistung zeigen. Im Anschluss untersuchte ich die individuelle Konsistenz der kognitiven Fähigkeiten bei Lernaufgaben mit unterschiedlichen sensorischen Modalitäten, Kontexten und kognitiven Anforderungen. Frei fliegende Bienen zeigten eine kognitive Spezialisierung zwischen visuellem und olfaktorischem Lernen, während sie bei einer einfachen Unterscheidungsaufgabe und einer komplexen Konzeptlernaufgabe konsistent im Lernverhalten blieben. Anschließend wollte ich die individuelle Konsistenz im Lernverhalten bei Aufgaben unterschiedlicher kognitiver Komplexität weiter erforschen, eine Frage, die bisher noch nie bei einem Insekt behandelt wurde. Ich führte dazu eine Reihe von vier Experimenten durch, bei denen entweder visuelle oder olfaktorische Stimuli und ein unterschiedlicher Trainingskontext (frei fliegend oder eingespannt) verwendet wurden. Die Bienen wurden in einer Unterscheidungsaufgabe, einer Umlernaufgabe und in Negative Patterning getestet. Erstaunlicherweise wurden bei diesen Experimenten die gleichen Ergebnisse festgestellt: Die Lernleitung der Bienen in der Unterscheidungsaufgabe zeigte eine positive Korrelation mit der Lernleistung im Umlernen und Negative Patterning. Zwischen dem Umkehrlernen und Negative Patterning konnte jedoch kein Zusammenhang festgestellt werden.  

Nachdem ich festgestellt hatte, dass es konsistente individuelle Unterschiede in den kognitiven Fähigkeiten von Bienen gibt, wollte ich die Faktoren ermitteln, die diesen Unterschieden zugrunde liegen könnten. Es war bereits bekannt, dass genetische Komponenten der interindividuellen Variabilität im Lernverhalten zugrunde liegen. Deshalb untersuchte ich den Einfluss von genetischer Vielfalt auf die Beständigkeit von kognitiven Fähigkeiten, indem ich Bienen gegenüberstellte, die entweder aus einem Bienenstock mit einer einzigen Patriline (geringe genetische Vielfalt) oder mit mehreren Patrilinen (hohe genetische Vielfalt) stammten. Diese beiden Gruppen von Bienen wiesen Unterschiede in den Mustern der individuellen korrelierten Lernleistungen auf, was darauf hindeutet, dass eine genetische Komponente für kognitive Individualität verantwortlich ist. Ein weiterer wichtiger Faktor, welcher der Variabilität im Lernverhalten zugrunde liegt, ist die individuelle Reaktionsfähigkeit auf Saccharose Lösungen und auf visuelle Stimuli. Dies wurde durch viele Studien an eingespannten Bienen gezeigt, die eine positive Korrelation zwischen der Reaktionsfähigkeit auf aufgabenrelevante Reize und den Lernfähigkeiten feststellten. Ich habe daher untersucht, ob diese Beziehungen zwischen der Reaktionsfähigkeit auf Saccharose und visuellen Stimuli und den Lernleistungen auch für frei fliegende Bienen zutreffen. Die individuellen Lernleistungen im Umlernen und Negative patterning von frei fliegenden Bienen wurden erneut ermittelt und anschließend wurde im Labor die Reaktionsfähigkeit auf Saccharose und Licht getestet. Es gab keine Hinweise auf eine positive Korrelation zwischen der Reaktionsfähigkeit auf Saccharose und Licht und den Lernleistungen von frei fliegenden Bienen. Diese Ergebnisse deuten darauf hin, dass Beziehungen zwischen der Reaktionsfähigkeit auf aufgabenrelevante Stimuli und der Lernleistung, die im Labor mit eingespannten Bienen festgestellt wurden, möglicherweise nicht für einen anderen Verhaltenskontext gelten, d. h. für frei fliegende Bienen in ihrer natürlichen Umgebung.  

Diese Ergebnisse zeigen, dass die Honigbiene ein hervorragendes Insektenmodell ist, um die Konsistenz kognitiver Fähigkeiten zu untersuchen und die zugrunde liegenden Faktoren zu ermitteln. Ich diskutiere die Ergebnisse vor allem im Hinblick auf die Frage der Modularität des Gehirns bei Insekten und die adaptive Bedeutung von individuellen konsistenten kognitiven Fähigkeiten für Honigbienenvölker. Ich schlage auch Forschungsfragen vor, die mit individuellen konsistenten kognitiven Fähigkeiten zusammenhängen und wertvolle Bereiche für künftige Forschungen darstellen könnten.
KW  - Lernen
KW  - Biene
KW  - Kognition
KW  - Individual differences
KW  - Cognitive consistency
KW  - Cognitive profile
KW  - Learning
KW  - Honeybee
KW  - Cognition
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323012
ER  - 
TY  - JOUR
A1  - Becher, Isabelle
A1  - Andrés-Pons, Amparo
A1  - Romanov, Natalie
A1  - Stein, Frank
A1  - Schramm, Maike
A1  - Baudin, Florence
A1  - Helm, Dominic
A1  - Kurzawa, Nils
A1  - Mateus, André
A1  - Mackmull, Marie-Therese
A1  - Typas, Athanasios
A1  - Müller, Christoph W.
A1  - Bork, Peer
A1  - Beck, Martin
A1  - Savitski, Mikhail M.
T1  - Pervasive Protein Thermal Stability Variation during the Cell Cycle
JF  - Cell
N2  - Quantitative mass spectrometry has established proteome-wide regulation of protein abundance and post-translational modifications in various biological processes. Here, we used quantitative mass spectrometry to systematically analyze the thermal stability and solubility of proteins on a proteome-wide scale during the eukaryotic cell cycle. We demonstrate pervasive variation of these biophysical parameters with most changes occurring in mitosis and G1. Various cellular pathways and components vary in thermal stability, such as cell-cycle factors, polymerases, and chromatin remodelers. We demonstrate that protein thermal stability serves as a proxy for enzyme activity, DNA binding, and complex formation in situ. Strikingly, a large cohort of intrinsically disordered and mitotically phosphorylated proteins is stabilized and solubilized in mitosis, suggesting a fundamental remodeling of the biophysical environment of the mitotic cell. Our data represent a rich resource for cell, structural, and systems biologists interested in proteome regulation during biological transitions.
KW  - thermal proteome profiling
KW  - cell cycle
KW  - proteomics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-221565
VL  - 173
ER  - 
TY  - JOUR
A1  - Mooij, Wolf M
A1  - van Wijk, Dianneke
A1  - Beusen, Arthur HW
A1  - Brederveld, Robert J
A1  - Chang, Manqi
A1  - Cobben, Marleen MP
A1  - DeAngelis, Don L
A1  - Downing, Andrea S
A1  - Green, Pamela
A1  - Gsell, Alena S
A1  - Huttunen, Inese
A1  - Janse, Jan H
A1  - Janssen, Annette BG
A1  - Hengeveld, Geerten M
A1  - Kong, Xiangzhen
A1  - Kramer, Lilith
A1  - Kuiper, Jan J
A1  - Langan, Simon J
A1  - Nolet, Bart A
A1  - Nuijten, Rascha JM
A1  - Strokal, Maryna
A1  - Troost, Tineke A
A1  - van Dam, Anne A
A1  - Teurlincx, Sven
T1  - Modeling water quality in the Anthropocene: directions for the next-generation aquatic ecosystem models
JF  - Current Opinion in Environmental Sustainability
N2  - “Everything changes and nothing stands still” (Heraclitus). Here we review three major improvements to freshwater aquatic ecosystem models — and ecological models in general — as water quality scenario analysis tools towards a sustainable future. To tackle the rapid and deeply connected dynamics characteristic of the Anthropocene, we argue for the inclusion of eco-evolutionary, novel ecosystem and social-ecological dynamics. These dynamics arise from adaptive responses in organisms and ecosystems to global environmental change and act at different integration levels and different time scales. We provide reasons and means to incorporate each improvement into aquatic ecosystem models. Throughout this study we refer to Lake Victoria as a microcosm of the evolving novel social-ecological systems of the Anthropocene. The Lake Victoria case clearly shows how interlinked eco-evolutionary, novel ecosystem and social-ecological dynamics are, and demonstrates the need for transdisciplinary research approaches towards global sustainability.
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224173
VL  - 36
ER  - 
TY  - JOUR
A1  - Flunkert, Julia
A1  - Maierhofer, Anna
A1  - Dittrich, Marcus
A1  - Müller, Tobias
A1  - Horvath, Steve
A1  - Nanda, Indrajit
A1  - Haaf, Thomas
T1  - Genetic and epigenetic changes in clonal descendants of irradiated human fibroblasts
JF  - Experimental Cell Research
N2  - To study delayed genetic and epigenetic radiation effects, which may trigger radiation-induced carcinogenesis, we have established single-cell clones from irradiated and non-irradiated primary human fibroblasts. Stable clones were endowed with the same karyotype in all analyzed metaphases after 20 population doublings (PDs), whereas unstable clones displayed mosaics of normal and abnormal karyotypes. To account for variation in radiation sensitivity, all experiments were performed with two different fibroblast strains. After a single X-ray dose of 2 Gy more than half of the irradiated clones exhibited radiation-induced genome instability (RIGI). Irradiated clones displayed an increased rate of loss of chromosome Y (LOY) and copy number variations (CNVs), compared to controls. CNV breakpoints clustered in specific chromosome regions, in particular 3p14.2 and 7q11.21, coinciding with common fragile sites. CNVs affecting the FHIT gene in FRA3B were observed in independent unstable clones and may drive RIGI. Bisulfite pyrosequencing of control clones and the respective primary culture revealed global hypomethylation of ALU, LINE-1, and alpha-satellite repeats as well as rDNA hypermethylation during in vitro ageing. Irradiated clones showed further reduced ALU and alpha-satellite methylation and increased rDNA methylation, compared to controls. Methylation arrays identified several hundred differentially methylated genes and several enriched pathways associated with in vitro ageing. Methylation changes in 259 genes and the MAP kinase signaling pathway were associated with delayed radiation effects (after 20 PDs). Collectively, our results suggest that both genetic (LOY and CNVs) and epigenetic changes occur in the progeny of exposed cells that were not damaged directly by irradiation, likely contributing to radiation-induced carcinogenesis. We did not observe epigenetic differences between stable and unstable irradiated clones. The fact that the DNA methylation (DNAm) age of clones derived from the same primary culture varied greatly suggests that DNAm age of a single cell (represented by a clone) can be quite different from the DNAm age of a tissue. We propose that DNAm age reflects the emergent property of a large number of individual cells whose respective DNAm ages can be highly variable.
KW  - copy number variation (CNV)
KW  - delayed radiation effects
KW  - DNA methylation (DNAm) age
KW  - global DNA methylation
KW  - loss of chromosome Y (LOY);
KW  - methylation array analysis
KW  - radiation-induced genome instability (RIGI)
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228177
VL  - 370
ER  - 
TY  - JOUR
A1  - Schubert, Frank K.
A1  - Hagedorn, Nicolas
A1  - Yoshii, Taishi
A1  - Helfrich-Förster, Charlotte
A1  - Rieger, Dirk
T1  - Neuroanatomical details of the lateral neurons of Drosophila melanogaster support their functional role in the circadian system
JF  - Journal of Comparative Neurology
N2  - Drosophila melanogaster is a long-standing model organism in the circadian clock research. A major advantage is the relative small number of about 150 neurons, which built the circadian clock in Drosophila. In our recent work, we focused on the neuroanatomical properties of the lateral neurons of the clock network. By applying the multicolor-labeling technique Flybow we were able to identify the anatomical similarity of the previously described E2 subunit of the evening oscillator of the clock, which is built by the 5th small ventrolateral neuron (5th s-LNv) and one ITP positive dorsolateral neuron (LNd). These two clock neurons share the same spatial and functional properties. We found both neurons innervating the same brain areas with similar pre- and postsynaptic sites in the brain. Here the anatomical findings support their shared function as a main evening oscillator in the clock network like also found in previous studies. A second quite surprising finding addresses the large lateral ventral PDF-neurons (l-LNvs). We could show that the four hardly distinguishable l-LNvs consist of two subgroups with different innervation patterns. While three of the neurons reflect the well-known branching pattern reproduced by PDF immunohistochemistry, one neuron per brain hemisphere has a distinguished innervation profile and is restricted only to the proximal part of the medulla-surface. We named this neuron “extra” l-LNv (l-LNvx). We suggest the anatomical findings reflect different functional properties of the two l-LNv subgroups.
KW  - circadian clock neurons
KW  - Drosophila melanogaster
KW  - flybow
KW  - morphology
KW  - RRID: AB_760350
KW  - RRID: AB_2315460
KW  - RRID: AB_2314242
KW  - RRID: AB_2315311
KW  - RRID: AB_2314041
KW  - RRID: AB_300798
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234477
VL  - 526
ER  - 
TY  - THES
A1  - Korte, Pamela
T1  - Die funktionelle Bedeutung des Lipidstoffwechsels für die Stomataöffnung bei Hitzestress in \(Arabidopsis\) \(thaliana\)
T1  - The functional significance of lipid metabolism for stomatal opening during heat stress in \(Arabidopsis\) \(thaliana\)
N2  - Pflanzen sind verschiedenen Umweltbedingungen ausgesetzt, die zu suboptimalen Wachstumsbedingungen führen können. Dies gilt für eine Vielzahl von biotischen und abiotischen Faktoren. In der hier vorgelegten Arbeit wird der Effekt von erhöhten Temperaturen und Hitze genauer analysiert. Hitze ist einer der wichtigsten abiotischen Stressfaktoren, der das Pflanzenwachstum und die Reproduktion beeinflusst. Viele wichtige Kulturpflanzen zeigen immense Ertragseinbußen, die durch Hitze hervorgerufen werden. Durch den fortschreitenden Klimawandel werden jedoch Hitzeperioden immer häufiger und somit die Folgen für die Nahrungsproduktion immer gravierender. Zur Züchtung von Pflanzen die hitzetolerant sind und weniger hohe Ertragseinbußen unter diesem Stress aufweisen, ist es essenziell die grundlegenden molekularen Mechanismen der Hitzetoleranz zu verstehen. Es müssen die verschiedenen physiologischen und biochemischen Prozesse identifiziert werden, die es Pflanzen ermöglichen, sich anzupassen. Es ist bekannt, dass die Anpassungsmechanismen von Pflanzen komplex sind und sowohl Veränderungen auf zellulärer wie auch auf organismischer Ebene beinhalten. Ziel dieser Arbeit war es, weitere Erkenntnisse zu gewinnen, wie diese Anpassung vonstattengeht und welche molekularen Prozesse an ihr beteiligt sind. Ein Hauptaugenmerk lag dabei auf dem Einfluss des Lipidmetabolismus und den daran beteiligten Enzymen. Es konnte bereits gezeigt werden, dass die Akkumulation von Triacylglycerolen bei hohen Temperaturen die basale Thermotoleranz bei Arabidopsis thaliana erhöht. Wie jedoch der genaue Mechanismus dieser durch Triacylglycerole vermittelten Thermotoleranz funktioniert, war bis dato nicht bekannt. Ich konnte zeigen, dass die angesammelten Triacylglycerole genutzt werden können, um die Stomata während des Hitzestress zu öffnen. Dies führt zu einer erhöhten Transpiration und somit einer Kühlung der Blätter. Der Abbau von Triacylglycerolen und Stärke am Morgen ist notwendig, um die Stomata zu öffnen. Zusätzlich dient der Abbau der Aufrechterhaltung des Citratzyklus und somit der Energieversorgung. In weiteren Experimenten konnte ich durch Fütterung mit stabil markierter Laurinsäure zeigen, dass die Triacylglycerole auch dem Aufbau neuer Aminosäuren unter Stressbedingungen dienen. Die hier vorgestellten Arbeiten bieten die Grundlage, um den Mechanismus der Thermotoleranz besser zu verstehen. Das Verständnis der in dieser Arbeit beschriebenen molekularen Signalwege und Enzyme kann langfristig dazu beitragen hitzeresistentere Nutzpflanzen zu züchten.
N2  - Plants are exposed to various environmental conditions that can lead to suboptimal growth 
conditions. This applies to a variety of biotic and abiotic factors. In the work presented here, 
the effect of elevated temperatures and heat is analyzed in more detail. Heat is one of the most 
important abiotic stress factors affecting plant growth and reproduction. Many important crops 
show immense yield losses caused by heat. However, as climate change progresses, periods 
of heat are becoming more frequent and the consequences for food production are becoming 
increasingly serious. Understanding the basic molecular mechanisms of heat tolerance is 
essential to breed plants that are heat tolerant and show less yield loss under this stress. The 
various physiological and biochemical processes that enable plants to adapt need to be 
identified. It is known that the adaptation mechanisms of plants are complex and involve 
changes at both the cellular and organismal level. The aim of this work was to gain further 
insights into how this adaptation takes place and which molecular processes are involved. The 
main focus was on the influence of lipid metabolism and the enzymes involved. It has already 
been shown that the accumulation of triacylglycerols at high temperatures increases basal 
thermotolerance in Arabidopsis thaliana. However, the exact mechanism of this triacylglycerol
mediated thermotolerance was not known until now. I was able to show that the accumulated 
triacylglycerols can be used to open the stomata during heat stress. This leads to increased 
transpiration and thus cooling of the leaves. The degradation of triacylglycerols and starch in 
the morning is necessary to open the stomata. In addition, the degradation serves to maintain 
the citrate cycle and thus the energy supply. In further experiments, I was able to show by 
feeding stably labeled lauric acid that the triacylglycerols also serve to build up new amino 
acids under stress conditions. The work presented here provides the basis for a better 
understanding of the mechanism of thermotolerance. Understanding the molecular signaling 
pathways and enzymes described in this work could - in the long term - contribute to breeding 
of more heat-resistant crops.
KW  - Hitzestress
KW  - Ackerschmalwand
KW  - Arabidopsis thaliana
KW  - Triacylglycerol
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-370461
ER  - 
TY  - JOUR
A1  - Göttlich, Claudia
A1  - Kunz, Meik
A1  - Zapp, Cornelia
A1  - Nietzer, Sarah L.
A1  - Walles, Heike
A1  - Dandekar, Thomas
A1  - Dandekar, Gudrun
T1  - A combined tissue-engineered/in silico signature tool patient stratification in lung cancer
JF  - Molecular Oncology
N2  - Patient-tailored therapy based on tumor drivers is promising for lung cancer treatment. For this, we combined in vitro tissue models with in silico analyses. Using individual cell lines with specific mutations, we demonstrate a generic and rapid stratification pipeline for targeted tumor therapy. We improve in vitro models of tissue conditions by a biological matrix-based three-dimensional (3D) tissue culture that allows in vitro drug testing: It correctly shows a strong drug response upon gefitinib (Gef) treatment in a cell line harboring an EGFR-activating mutation (HCC827), but no clear drug response upon treatment with the HSP90 inhibitor 17AAG in two cell lines with KRAS mutations (H441, A549). In contrast, 2D testing implies wrongly KRAS as a biomarker for HSP90 inhibitor treatment, although this fails in clinical studies. Signaling analysis by phospho-arrays showed similar effects of EGFR inhibition by Gef in HCC827 cells, under both 2D and 3D conditions. Western blot analysis confirmed that for 3D conditions, HSP90 inhibitor treatment implies different p53 regulation and decreased MET inhibition in HCC827 and H441 cells. Using in vitro data (western, phospho-kinase array, proliferation, and apoptosis), we generated cell line-specific in silico topologies and condition-specific (2D, 3D) simulations of signaling correctly mirroring in vitro treatment responses. Networks predict drug targets considering key interactions and individual cell line mutations using the Human Protein Reference Database and the COSMIC database. A signature of potential biomarkers and matching drugs improve stratification and treatment in KRAS-mutated tumors. In silico screening and dynamic simulation of drug actions resulted in individual therapeutic suggestions, that is, targeting HIF1A in H441 and LKB1 in A549 cells. In conclusion, our in vitro tumor tissue model combined with an in silico tool improves drug effect prediction and patient stratification. Our tool is used in our comprehensive cancer center and is made now publicly available for targeted therapy decisions.
KW  - 3D lung tumor model
KW  - Boolean signaling network
KW  - chemoresistance
KW  - HSP90 inhibitor
KW  - insilico drug screening too
KW  - KRAS mutation signature
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233137
VL  - 12
ER  - 
TY  - JOUR
A1  - Grebinyk, Anna
A1  - Grebinyk, Sergii
A1  - Prylutska, Svitlana
A1  - Ritter, Uwe
A1  - Matyshevska, Olga
A1  - Dandekar, Thomas
A1  - Frohme, Marcus
T1  - C60 fullerene accumulation in human leukemic cells and perspectives of LED-mediated photodynamic therapy
JF  - Free Radical Biology and Medicine
N2  - Recent progress in nanobiotechnology has attracted interest to a biomedical application of the carbon nanostructure C60 fullerene since it possesses a unique structure and versatile biological activity. C60 fullerene potential application in the frame of cancer photodynamic therapy (PDT) relies on rapid development of new light sources as well as on better understanding of the fullerene interaction with cells.

The aim of this study was to analyze C60 fullerene effects on human leukemic cells (CCRF-CEM) in combination with high power single chip light-emitting diodes (LEDs) light irradiation of different wavelengths: ultraviolet (UV, 365 nm), violet (405 nm), green (515 nm) and red (632 nm). The time-dependent accumulation of fullerene C60 in CCRF-CEM cells up to 250 ng/106 cells at 24 h with predominant localization within mitochondria was demonstrated with immunocytochemical staining and liquid chromatography mass spectrometry. In a cell viability assay we studied photoexcitation of the accumulated C60 nanostructures with ultraviolet or violet LEDs and could prove that significant phototoxic effects did arise. A less pronounced C60 fullerene phototoxic effect was observed after irradiation with green, and no effect was detected with red light. A C60 fullerene photoactivation with violet light induced substantial ROS generation and apoptotic cell death, confirmed by caspase3/7 activation and plasma membrane phosphatidylserine externalization. Our work proved C60 fullerene ability to induce apoptosis of leukemic cells after photoexcitation with high power single chip 405 nm LED as a light source. This underlined the potential for application of C60 nanostructure as a photosensitizer for anticancer therapy.
KW  - C-60 fullerene
KW  - photodanamic therapy
KW  - LEDs
KW  - leukemic cells
KW  - immunocytochemistry
KW  - HPLC-ESI-MS
KW  - apoptosis
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228245
VL  - 124
ER  -