@article{FigueiredoKraussSteffanDewenteretal.2019, author = {Figueiredo, Ludmilla and Krauss, Jochen and Steffan-Dewenter, Ingolf and Cabral, Juliano Sarmento}, title = {Understanding extinction debts: spatio-temporal scales, mechanisms and a roadmap for future research}, series = {Ecography}, volume = {42}, journal = {Ecography}, number = {12}, doi = {10.1111/ecog.04740}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204859}, pages = {1973-1990}, year = {2019}, abstract = {Extinction debt refers to delayed species extinctions expected as a consequence of ecosystem perturbation. Quantifying such extinctions and investigating long-term consequences of perturbations has proven challenging, because perturbations are not isolated and occur across various spatial and temporal scales, from local habitat losses to global warming. Additionally, the relative importance of eco-evolutionary processes varies across scales, because levels of ecological organization, i.e. individuals, (meta)populations and (meta)communities, respond hierarchically to perturbations. To summarize our current knowledge of the scales and mechanisms influencing extinction debts, we reviewed recent empirical, theoretical and methodological studies addressing either the spatio-temporal scales of extinction debts or the eco-evolutionary mechanisms delaying extinctions. Extinction debts were detected across a range of ecosystems and taxonomic groups, with estimates ranging from 9 to 90\% of current species richness. The duration over which debts have been sustained varies from 5 to 570 yr, and projections of the total period required to settle a debt can extend to 1000 yr. Reported causes of delayed extinctions are 1) life-history traits that prolong individual survival, and 2) population and metapopulation dynamics that maintain populations under deteriorated conditions. Other potential factors that may extend survival time such as microevolutionary dynamics, or delayed extinctions of interaction partners, have rarely been analyzed. Therefore, we propose a roadmap for future research with three key avenues: 1) the microevolutionary dynamics of extinction processes, 2) the disjunctive loss of interacting species and 3) the impact of multiple regimes of perturbation on the payment of debts. For their ability to integrate processes occurring at different levels of ecological organization, we highlight mechanistic simulation models as tools to address these knowledge gaps and to deepen our understanding of extinction dynamics.}, language = {en} } @article{GrebinykPrylutskaBuchelnikovetal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Buchelnikov, Anatoliy and Tverdokhleb, Nina and Grebinyk, Sergii and Evstigneev, Maxim and Matyshevska, Olga and Cherepanov, Vsevolod and Prylutskyy, Yuriy and Yashchuk, Valeriy and Naumovets, Anton and Ritter, Uwe and Dandekar, Thomas and Frohme, Marcus}, title = {C60 fullerene as an effective nanoplatform of alkaloid Berberine delivery into leukemic cells}, series = {Pharmaceutics}, volume = {11}, journal = {Pharmaceutics}, number = {11}, issn = {1999-4923}, doi = {10.3390/pharmaceutics11110586}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193216}, pages = {586}, year = {2019}, abstract = {A herbal alkaloid Berberine (Ber), used for centuries in Ayurvedic, Chinese, Middle-Eastern, and native American folk medicines, is nowadays proved to function as a safe anticancer agent. Yet, its poor water solubility, stability, and bioavailability hinder clinical application. In this study, we have explored a nanosized carbon nanoparticle—C60 fullerene (C60)—for optimized Ber delivery into leukemic cells. Water dispersions of noncovalent C60-Ber nanocomplexes in the 1:2, 1:1, and 2:1 molar ratios were prepared. UV-Vis spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM) evidenced a complexation of the Ber cation with the negatively charged C60 molecule. The computer simulation showed that π-stacking dominates in Ber and C\(_{60}\) binding in an aqueous solution. Complexation with C\(_{60}\) was found to promote Ber intracellular uptake. By increasing C\(_{60}\) concentration, the C\(_{60}\)-Ber nanocomplexes exhibited higher antiproliferative potential towards CCRF-CEM cells, in accordance with the following order: free Ber < 1:2 < 1:1 < 2:1 (the most toxic). The activation of caspase 3/7 and accumulation in the sub-G1 phase of CCRF-CEM cells treated with C\(_{60}\)-Ber nanocomplexes evidenced apoptosis induction. Thus, this study indicates that the fast and easy noncovalent complexation of alkaloid Ber with C\(_{60}\) improved its in vitro efficiency against cancer cells.}, language = {en} } @article{BeerSchenkHelfrichFoersteretal.2019, author = {Beer, Katharina and Schenk, Mariela and Helfrich-F{\"o}rster, Charlotte and Holzschuh, Andrea}, title = {The circadian clock uses different environmental time cues to synchronize emergence and locomotion of the solitary bee Osmia bicornis}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-54111-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202721}, pages = {17748}, year = {2019}, abstract = {Life on earth adapted to the daily reoccurring changes in environment by evolving an endogenous circadian clock. Although the circadian clock has a crucial impact on survival and behavior of solitary bees, many aspects of solitary bee clock mechanisms remain unknown. Our study is the first to show that the circadian clock governs emergence in Osmia bicornis, a bee species which overwinters as adult inside its cocoon. Therefore, its eclosion from the pupal case is separated by an interjacent diapause from its emergence in spring. We show that this bee species synchronizes its emergence to the morning. The daily rhythms of emergence are triggered by temperature cycles but not by light cycles. In contrast to this, the bee's daily rhythms in locomotion are synchronized by light cycles. Thus, we show that the circadian clock of O. bicornis is set by either temperature or light, depending on what activity is timed. Light is a valuable cue for setting the circadian clock when bees have left the nest. However, for pre-emerged bees, temperature is the most important cue, which may represent an evolutionary adaptation of the circadian system to the cavity-nesting life style of O. bicornis.}, language = {en} } @article{MaierhoferFlunkertOshimaetal.2019, author = {Maierhofer, Anna and Flunkert, Julia and Oshima, Junko and Martin, George M. and Poot, Martin and Nanda, Indrajit and Dittrich, Marcus and M{\"u}ller, Tobias and Haaf, Thomas}, title = {Epigenetic signatures of Werner syndrome occur early in life and are distinct from normal epigenetic aging processes}, series = {Aging Cell}, volume = {18}, journal = {Aging Cell}, doi = {10.1111/acel.12995}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202733}, pages = {e12995}, year = {2019}, abstract = {Werner Syndrome (WS) is an adult-onset segmental progeroid syndrome. Bisulfite pyrosequencing of repetitive DNA families revealed comparable blood DNA methylation levels between classical (18 WRN-mutant) or atypical WS (3 LMNA-mutant and 3 POLD1-mutant) patients and age- and sex-matched controls. WS was not associated with either age-related accelerated global losses of ALU, LINE1, and α-satellite DNA methylations or gains of rDNA methylation. Single CpG methylation was analyzed with Infinium MethylationEPIC arrays. In a correspondence analysis, atypical WS samples clustered together with the controls and were clearly separated from classical WS, consistent with distinct epigenetic pathologies. In classical WS, we identified 659 differentially methylated regions (DMRs) comprising 3,656 CpG sites and 613 RefSeq genes. The top DMR was located in the HOXA4 promoter. Additional DMR genes included LMNA, POLD1, and 132 genes which have been reported to be differentially expressed in WRN-mutant/depleted cells. DMRs were enriched in genes with molecular functions linked to transcription factor activity and sequence-specific DNA binding to promoters transcribed by RNA polymerase II. We propose that transcriptional misregulation of downstream genes by the absence of WRN protein contributes to the variable premature aging phenotypes of WS. There were no CpG sites showing significant differences in DNA methylation changes with age between WS patients and controls. Genes with both WS- and age-related methylation changes exhibited a constant offset of methylation between WRN-mutant patients and controls across the entire analyzed age range. WS-specific epigenetic signatures occur early in life and do not simply reflect an acceleration of normal epigenetic aging processes.}, language = {en} } @article{ThoelkenThammErbacheretal.2019, author = {Th{\"o}lken, Clemens and Thamm, Markus and Erbacher, Christoph and Lechner, Marcus}, title = {Sequence and structural properties of circular RNAs in the brain of nurse and forager honeybees (Apis mellifera)}, series = {BMC Genomics}, volume = {20}, journal = {BMC Genomics}, doi = {10.1186/s12864-018-5402-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241302}, year = {2019}, abstract = {Background The honeybee (Apis mellifera) represents a model organism for social insects displaying behavioral plasticity. This is reflected by an age-dependent task allocation. The most protruding tasks are performed by young nurse bees and older forager bees that take care of the brood inside the hive and collect food from outside the hive, respectively. The molecular mechanism leading to the transition from nurse bees to foragers is currently under intense research. Circular RNAs, however, were not considered in this context so far. As of today, this group of non-coding RNAs was only known to exist in two other insects, Drosophila melanogaster and Bombyx mori. Here we complement the state of circular RNA research with the first characterization in a social insect. Results We identified numerous circular RNAs in the brain of A. mellifera nurse bees and forager bees using RNA-Seq with exonuclease enrichment. Presence and circularity were verified for the most abundant representatives. Back-splicing in honeybee occurs further towards the end of transcripts and in transcripts with a high number of exons. The occurrence of circularized exons is correlated with length and CpG-content of their flanking introns. The latter coincides with increased DNA-methylation in the respective loci. For two prominent circular RNAs the abundance in worker bee brains was quantified in TaqMan assays. In line with previous findings of circular RNAs in Drosophila, circAmrsmep2 accumulates with increasing age of the insect. In contrast, the levels of circAmrad appear age-independent and correlate with the bee's task. Its parental gene is related to amnesia-resistant memory. Conclusions We provide the first characterization of circRNAs in a social insect. Many of the RNAs identified here show homologies to circular RNAs found in Drosophila and Bombyx, indicating that circular RNAs are a common feature among insects. We find that exon circularization is correlated to DNA-methylation at the flanking introns. The levels of circAmrad suggest a task-dependent abundance that is decoupled from age. Moreover, a GO term analysis shows an enrichment of task-related functions. We conclude that circular RNAs could be relevant for task allocation in honeybee and should be investigated further in this context.}, language = {en} } @article{MayerLoefflerLozaValdesetal.2019, author = {Mayer, Alexander E. and L{\"o}ffler, Mona C. and Loza Vald{\´e}s, Angel E. and Schmitz, Werner and El-Merahbi, Rabih and Trujillo-Viera, Jonathan and Erk, Manuela and Zhang, Thianzhou and Braun, Ursula and Heikenwalder, Mathias and Leitges, Michael and Schulze, Almut and Sumara, Grzegorz}, title = {The kinase PKD3 provides negative feedback on cholesterol and triglyceride synthesis by suppressing insulin signaling}, series = {Science Signaling}, journal = {Science Signaling}, edition = {accepted manuscript}, doi = {10.1126/scisignal.aav9150}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250025}, year = {2019}, abstract = {Hepatic activation of protein kinase C (PKC) isoforms by diacylglycerol (DAG) promotes insulin resistance and contributes to the development of type 2 diabetes (T2D). The closely related protein kinase D (PKD) isoforms act as effectors for DAG and PKC. Here, we showed that PKD3 was the predominant PKD isoform expressed in hepatocytes and was activated by lipid overload. PKD3 suppressed the activity of downstream insulin effectors including the kinase AKT and mechanistic target of rapamycin complex 1 and 2 (mTORC1 and mTORC2). Hepatic deletion of PKD3 in mice improved insulin-induced glucose tolerance. However, increased insulin signaling in the absence of PKD3 promoted lipogenesis mediated by SREBP (sterol regulatory element-binding protein) and consequently increased triglyceride and cholesterol content in the livers of PKD3-deficient mice fed a high-fat diet. Conversely, hepatic-specific overexpression of a constitutively active PKD3 mutant suppressed insulin-induced signaling and caused insulin resistance. Our results indicate that PKD3 provides feedback on hepatic lipid production and suppresses insulin signaling. Therefore, manipulation of PKD3 activity could be used to decrease hepatic lipid content or improve hepatic insulin sensitivity.}, language = {en} } @article{DopplerSchusterAppeltshauseretal.2019, author = {Doppler, Kathrin and Schuster, Yasmin and Appeltshauser, Luise and Biko, Lydia and Villmann, Carmen and Weishaupt, Andreas and Werner, Christian and Sommer, Claudia}, title = {Anti-CNTN1 IgG3 induces acute conduction block and motor deficits in a passive transfer rat model}, series = {Journal of Neuroinflammation}, volume = {16}, journal = {Journal of Neuroinflammation}, number = {73}, doi = {10.1186/s12974-019-1462-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200476}, year = {2019}, abstract = {Background: Autoantibodies against the paranodal protein contactin-1 have recently been described in patients with severe acute-onset autoimmune neuropathies and mainly belong to the IgG4 subclass that does not activate complement. IgG3 anti-contactin-1 autoantibodies are rare, but have been detected during the acute onset of disease in some cases. There is evidence that anti-contactin-1 prevents adhesive interaction, and chronic exposure to anti-contactin-1 IgG4 leads to structural changes at the nodes accompanied by neuropathic symptoms. However, the pathomechanism of acute onset of disease and the pathogenic role of IgG3 anti-contactin-1 is largely unknown. Methods: In the present study, we aimed to model acute autoantibody exposure by intraneural injection of IgG of patients with anti-contacin-1 autoantibodies to Lewis rats. Patient IgG obtained during acute onset of disease (IgG3 predominant) and IgG from the chronic phase of disease (IgG4 predominant) were studied in comparison. Results: Conduction blocks were measured in rats injected with the "acute" IgG more often than after injection of "chronic" IgG (83.3\% versus 35\%) and proved to be reversible within a week after injection. Impaired nerve conduction was accompanied by motor deficits in rats after injection of the "acute" IgG but only minor structural changes of the nodes. Paranodal complement deposition was detected after injection of the "acute IgG". We did not detect any inflammatory infiltrates, arguing against an inflammatory cascade as cause of damage to the nerve. We also did not observe dispersion of paranodal proteins or sodium channels to the juxtaparanodes as seen in patients after chronic exposure to anti-contactin-1. Conclusions: Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients. This supports the notion of anti-contactin-1-associated neuropathy as a paranodopathy with the nodes of Ranvier as the site of pathogenesis.}, language = {en} } @article{Voulgari‐KokotaAnkenbrandGrimmeretal.2019, author = {Voulgari-Kokota, Anna and Ankenbrand, Markus J. and Grimmer, Gudrun and Steffan-Dewenter, Ingolf and Keller, Alexander}, title = {Linking pollen foraging of megachilid bees to their nest bacterial microbiota}, series = {Ecology and Evolution}, volume = {2019}, journal = {Ecology and Evolution}, number = {9}, issn = {00}, doi = {10.1002/ece3.5599}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201749}, pages = {10788-10800}, year = {2019}, abstract = {Solitary bees build their nests by modifying the interior of natural cavities, and they provision them with food by importing collected pollen. As a result, the microbiota of the solitary bee nests may be highly dependent on introduced materials. In order to investigate how the collected pollen is associated with the nest microbiota, we used metabarcoding of the ITS2 rDNA and the 16S rDNA to simultaneously characterize the pollen composition and the bacterial communities of 100 solitary bee nest chambers belonging to seven megachilid species. We found a weak correlation between bacterial and pollen alpha diversity and significant associations between the composition of pollen and that of the nest microbiota, contributing to the understanding of the link between foraging and bacteria acquisition for solitary bees. Since solitary bees cannot establish bacterial transmission routes through eusociality, this link could be essential for obtaining bacterial symbionts for this group of valuable pollinators.}, language = {en} } @article{BreitenbachLorenzDandekar2019, author = {Breitenbach, Tim and Lorenz, Kristina and Dandekar, Thomas}, title = {How to steer and control ERK and the ERK signaling cascade exemplified by looking at cardiac insufficiency}, series = {International Journal of Molecular Sciences}, volume = {20}, journal = {International Journal of Molecular Sciences}, number = {9}, issn = {1422-0067}, doi = {10.3390/ijms20092179}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285164}, year = {2019}, abstract = {Mathematical optimization framework allows the identification of certain nodes within a signaling network. In this work, we analyzed the complex extracellular-signal-regulated kinase 1 and 2 (ERK1/2) cascade in cardiomyocytes using the framework to find efficient adjustment screws for this cascade that is important for cardiomyocyte survival and maladaptive heart muscle growth. We modeled optimal pharmacological intervention points that are beneficial for the heart, but avoid the occurrence of a maladaptive ERK1/2 modification, the autophosphorylation of ERK at threonine 188 (ERK\(^{Thr188}\) phosphorylation), which causes cardiac hypertrophy. For this purpose, a network of a cardiomyocyte that was fitted to experimental data was equipped with external stimuli that model the pharmacological intervention points. Specifically, two situations were considered. In the first one, the cardiomyocyte was driven to a desired expression level with different treatment strategies. These strategies were quantified with respect to beneficial effects and maleficent side effects and then which one is the best treatment strategy was evaluated. In the second situation, it was shown how to model constitutively activated pathways and how to identify drug targets to obtain a desired activity level that is associated with a healthy state and in contrast to the maleficent expression pattern caused by the constitutively activated pathway. An implementation of the algorithms used for the calculations is also presented in this paper, which simplifies the application of the presented framework for drug targeting, optimal drug combinations and the systematic and automatic search for pharmacological intervention points. The codes were designed such that they can be combined with any mathematical model given by ordinary differential equations.}, language = {en} } @article{SchlegelPetersDooseetal.2019, author = {Schlegel, Jan and Peters, Simon and Doose, S{\"o}ren and Schubert-Unkmeir, Alexandra and Sauer, Markus}, title = {Super-resolution microscopy reveals local accumulation of plasma membrane gangliosides at Neisseria meningitidis Invasion Sites}, series = {Frontiers in Cell and Developmental Biology}, volume = {7}, journal = {Frontiers in Cell and Developmental Biology}, number = {194}, doi = {10.3389/fcell.2019.00194}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201639}, year = {2019}, abstract = {Neisseria meningitidis (meningococcus) is a Gram-negative bacterium responsible for epidemic meningitis and sepsis worldwide. A critical step in the development of meningitis is the interaction of bacteria with cells forming the blood-cerebrospinal fluid barrier, which requires tight adhesion of the pathogen to highly specialized brain endothelial cells. Two endothelial receptors, CD147 and the β2-adrenergic receptor, have been found to be sequentially recruited by meningococci involving the interaction with type IV pilus. Despite the identification of cellular key players in bacterial adhesion the detailed mechanism of invasion is still poorly understood. Here, we investigated cellular dynamics and mobility of the type IV pilus receptor CD147 upon treatment with pili enriched fractions and specific antibodies directed against two extracellular Ig-like domains in living human brain microvascular endothelial cells. Modulation of CD147 mobility after ligand binding revealed by single-molecule tracking experiments demonstrates receptor activation and indicates plasma membrane rearrangements. Exploiting the binding of Shiga (STxB) and Cholera toxin B (CTxB) subunits to the two native plasma membrane sphingolipids globotriaosylceramide (Gb3) and raft-associated monosialotetrahexosylganglioside GM1, respectively, we investigated their involvement in bacterial invasion by super-resolution microscopy. Structured illumination microscopy (SIM) and direct stochastic optical reconstruction microscopy (dSTORM) unraveled accumulation and coating of meningococci with GM1 upon cellular uptake. Blocking of CTxB binding sites did not impair bacterial adhesion but dramatically reduced bacterial invasion efficiency. In addition, cell cycle arrest in G1 phase induced by serum starvation led to an overall increase of GM1 molecules in the plasma membrane and consequently also in bacterial invasion efficiency. Our results will help to understand downstream signaling events after initial type IV pilus-host cell interactions and thus have general impact on the development of new therapeutics targeting key molecules involved in infection.}, language = {en} } @article{BartelPeinPopperetal.2019, author = {Bartel, Karin and Pein, Helmut and Popper, Bastian and Schmitt, Sabine and Janaki-Raman, Sudha and Schulze, Almut and Lengauer, Florian and Koeberle, Andreas and Werz, Oliver and Zischka, Hans and M{\"u}ller, Rolf and Vollmar, Angelika M. and Schwarzenberg, Karin von}, title = {Connecting lysosomes and mitochondria - a novel role for lipid metabolism in cancer cell death}, series = {Cell Communication and Signaling}, volume = {17}, journal = {Cell Communication and Signaling}, doi = {10.1186/s12964-019-0399-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221524}, year = {2019}, abstract = {Background The understanding of lysosomes has been expanded in recent research way beyond their view as cellular trash can. Lysosomes are pivotal in regulating metabolism, endocytosis and autophagy and are implicated in cancer. Recently it was discovered that the lysosomal V-ATPase, which is known to induce apoptosis, interferes with lipid metabolism in cancer, yet the interplay between these organelles is poorly understood. Methods LC-MS/MS analysis was performed to investigate lipid distribution in cells. Cell survival and signaling pathways were analyzed by means of cell biological methods (qPCR, Western Blot, flow cytometry, CellTiter-Blue). Mitochondrial structure was analyzed by confocal imaging and electron microscopy, their function was determined by flow cytometry and seahorse measurements. Results Our data reveal that interfering with lysosomal function changes composition and subcellular localization of triacylglycerids accompanied by an upregulation of PGC1α and PPARα expression, master regulators of energy and lipid metabolism. Furthermore, cardiolipin content is reduced driving mitochondria into fission, accompanied by a loss of membrane potential and reduction in oxidative capacity, which leads to a deregulation in cellular ROS and induction of mitochondria-driven apoptosis. Additionally, cells undergo a metabolic shift to glutamine dependency, correlated with the fission phenotype and sensitivity to lysosomal inhibition, most prominent in Ras mutated cells. Conclusion This study sheds mechanistic light on a largely uninvestigated triangle between lysosomes, lipid metabolism and mitochondrial function. Insight into this organelle crosstalk increases our understanding of mitochondria-driven cell death. Our findings furthermore provide a first hint on a connection of Ras pathway mutations and sensitivity towards lysosomal inhibitors.}, language = {en} } @article{GrebinykPrylutskaGrebinyketal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Grebinyk, Sergii and Prylutskyy, Yuriy and Ritter, Uwe and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {Complexation with C\(_{60}\) fullerene increases doxorubicin efficiency against leukemic cells in vitro}, series = {Nanoscale Research Letters}, volume = {14}, journal = {Nanoscale Research Letters}, number = {61}, doi = {10.1186/s11671-019-2894-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228257}, year = {2019}, abstract = {Conventional anticancer chemotherapy is limited because of severe side effects as well as a quickly evolving multidrug resistance of the tumor cells. To address this problem, we have explored a C\(_{60}\) fullerene-based nanosized system as a carrier for anticancer drugs for an optimized drug delivery to leukemic cells.Here, we studied the physicochemical properties and anticancer activity of C\(_{60}\) fullerene noncovalent complexes with the commonly used anticancer drug doxorubicin. C\(_{60}\)-Doxorubicin complexes in a ratio 1:1 and 2:1 were characterized with UV/Vis spectrometry, dynamic light scattering, and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The obtained analytical data indicated that the 140-nm complexes were stable and could be used for biological applications. In leukemic cell lines (CCRF-CEM, Jurkat, THP1 and Molt-16), the nanocomplexes revealed 3.5 higher cytotoxic potential in comparison with the free drug in a range of nanomolar concentrations. Also, the intracellular drug's level evidenced C\(_{60}\) fullerene considerable nanocarrier function.The results of this study indicated that C\(_{60}\) fullerene-based delivery nanocomplexes had a potential value for optimization of doxorubicin efficiency against leukemic cells.}, language = {en} } @article{HeydarianYangSchweinlinetal.2019, author = {Heydarian, Motaharehsadat and Yang, Tao and Schweinlin, Matthias and Steinke, Maria and Walles, Heike and Rudel, Thomas and Kozjak-Pavlovic, Vera}, title = {Biomimetic human tissue model for long-term study of Neisseria gonorrhoeae infection}, series = {Frontiers in Microbiology}, volume = {10}, journal = {Frontiers in Microbiology}, number = {1740}, issn = {1664-302X}, doi = {10.3389/fmicb.2019.01740}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197912}, year = {2019}, abstract = {Gonorrhea is the second most common sexually transmitted infection in the world and is caused by Gram-negative diplococcus Neisseria gonorrhoeae. Since N. gonorrhoeae is a human-specific pathogen, animal infection models are only of limited use. Therefore, a suitable in vitro cell culture model for studying the complete infection including adhesion, transmigration and transport to deeper tissue layers is required. In the present study, we generated three independent 3D tissue models based on porcine small intestinal submucosa (SIS) scaffold by co-culturing human dermal fibroblasts with human colorectal carcinoma, endometrial epithelial, and male uroepithelial cells. Functional analyses such as transepithelial electrical resistance (TEER) and FITC-dextran assay indicated the high barrier integrity of the created monolayer. The histological, immunohistochemical, and ultra-structural analyses showed that the 3D SIS scaffold-based models closely mimic the main characteristics of the site of gonococcal infection in human host including the epithelial monolayer, the underlying connective tissue, mucus production, tight junction, and microvilli formation. We infected the established 3D tissue models with different N. gonorrhoeae strains and derivatives presenting various phenotypes regarding adhesion and invasion. The results indicated that the disruption of tight junctions and increase in interleukin production in response to the infection is strain and cell type-dependent. In addition, the models supported bacterial survival and proved to be better suitable for studying infection over the course of several days in comparison to commonly used Transwell® models. This was primarily due to increased resilience of the SIS scaffold models to infection in terms of changes in permeability, cell destruction and bacterial transmigration. In summary, the SIS scaffold-based 3D tissue models of human mucosal tissues represent promising tools for investigating N. gonorrhoeae infections under close-to-natural conditions.}, language = {en} } @article{GrebinykPrylutskaChepurnaetal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Chepurna, Oksana and Grebinyk, Sergii and Prylutskyy, Yuriy and Ritter, Uwe and Ohulchanskyy, Tymish Y. and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {Synergy of chemo- and photodynamic therapies with C\(_{60}\) Fullerene-Doxorubicin nanocomplex}, series = {Nanomaterials}, volume = {9}, journal = {Nanomaterials}, number = {11}, issn = {2079-4991}, doi = {10.3390/nano9111540}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193140}, year = {2019}, abstract = {A nanosized drug complex was explored to improve the efficiency of cancer chemotherapy, complementing it with nanodelivery and photodynamic therapy. For this, nanomolar amounts of a non-covalent nanocomplex of Doxorubicin (Dox) with carbon nanoparticle C\(_{60}\) fullerene (C\(_{60}\)) were applied in 1:1 and 2:1 molar ratio, exploiting C\(_{60}\) both as a drug-carrier and as a photosensitizer. The fluorescence microscopy analysis of human leukemic CCRF-CEM cells, in vitro cancer model, treated with nanocomplexes showed Dox's nuclear and C\(_{60}\)'s extranuclear localization. It gave an opportunity to realize a double hit strategy against cancer cells based on Dox's antiproliferative activity and C\(_{60}\)'s photoinduced pro-oxidant activity. When cells were treated with 2:1 C\(_{60}\)-Dox and irradiated at 405 nm the high cytotoxicity of photo-irradiated C\(_{60}\)-Dox enabled a nanomolar concentration of Dox and C\(_{60}\) to efficiently kill cancer cells in vitro. The high pro-oxidant and pro-apoptotic efficiency decreased IC\(_{50}\) 16, 9 and 7 × 10\(^3\)-fold, if compared with the action of Dox, non-irradiated nanocomplex, and C\(_{60}\)'s photodynamic effect, correspondingly. Hereafter, a strong synergy of therapy arising from the combination of C\(_{60}\)-mediated Dox delivery and C\(_{60}\) photoexcitation was revealed. Our data indicate that a combination of chemo- and photodynamic therapies with C\(_{60}\)-Dox nanoformulation provides a promising synergetic approach for cancer treatment.}, language = {en} } @article{VillalobosWieseImhoffetal.2019, author = {Villalobos, Alvaro S. and Wiese, Jutta and Imhoff, Johannes F. and Dorador, Cristina and Keller, Alexander and Hentschel, Ute}, title = {Systematic affiliation and genome analysis of Subtercola vilae DB165T with particular emphasis on cold adaptation of an isolate from a high-altitude cold volcano lake}, series = {Microorganisms}, volume = {7}, journal = {Microorganisms}, number = {4}, issn = {2076-2607}, doi = {10.3390/microorganisms7040107}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197394}, year = {2019}, abstract = {Among the Microbacteriaceae the species of Subtercola and Agreia form closely associated clusters. Phylogenetic analysis demonstrated three major phylogenetic branches of these species. One of these branches contains the two psychrophilic species Subtercola frigoramans and Subtercola vilae, together with a larger number of isolates from various cold environments. Genomic evidence supports the separation of Agreia and Subtercola species. In order to gain insight into the ability of S. vilae to adapt to life in this extreme environment, we analyzed the genome with a particular focus on properties related to possible adaptation to a cold environment. General properties of the genome are presented, including carbon and energy metabolism, as well as secondary metabolite production. The repertoire of genes in the genome of S. vilae DB165\(^T\) linked to adaptations to the harsh conditions found in Llullaillaco Volcano Lake includes several mechanisms to transcribe proteins under low temperatures, such as a high number of tRNAs and cold shock proteins. In addition, S. vilae DB165\(^T\) is capable of producing a number of proteins to cope with oxidative stress, which is of particular relevance at low temperature environments, in which reactive oxygen species are more abundant. Most important, it obtains capacities to produce cryo-protectants, and to combat against ice crystal formation, it produces ice-binding proteins. Two new ice-binding proteins were identified which are unique to S. vilae DB165\(^T\). These results indicate that S. vilae has the capacity to employ different mechanisms to live under the extreme and cold conditions prevalent in Llullaillaco Volcano Lake.}, language = {en} } @article{LiuKinoshitaAdolfietal.2019, author = {Liu, Ruiqi and Kinoshita, Masato and Adolfi, Mateus C. and Schartl, Manfred}, title = {Analysis of the role of the Mc4r system in development, growth, and puberty of medaka}, series = {Frontiers in Endocrinology}, volume = {10}, journal = {Frontiers in Endocrinology}, doi = {10.3389/fendo.2019.00213}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201472}, pages = {213}, year = {2019}, abstract = {In mammals the melanocortin 4 receptor (Mc4r) signaling system has been mainly associated with the regulation of appetite and energy homeostasis. In fish of the genus Xiphophorus (platyfish and swordtails) puberty onset is genetically determined by a single locus, which encodes the mc4r. Wild populations of Xiphophorus are polymorphic for early and late-maturing individuals. Copy number variation of different mc4r alleles is responsible for the difference in puberty onset. To answer whether this is a special adaptation of the Mc4r signaling system in the lineage of Xiphophorus or a more widely conserved mechanism in teleosts, we studied the role of Mc4r in reproductive biology of medaka (Oryzias latipes), a close relative to Xiphophorus and a well-established model to study gonadal development. To understand the potential role of Mc4r in medaka, we characterized the major features of the Mc4r signaling system (mc4r, mrap2, pomc, agrp1). In medaka, all these genes are expressed before hatching. In adults, they are mainly expressed in the brain. The transcript of the receptor accessory protein mrap2 co-localizes with mc4r in the hypothalamus in adult brains indicating a conserved function of modulating Mc4r signaling. Comparing growth and puberty between wild-type and mc4r knockout medaka revealed that absence of Mc4r does not change puberty timing but significantly delays hatching. Embryonic development of knockout animals is retarded compared to wild-types. In conclusion, the Mc4r system in medaka is involved in regulation of growth rather than puberty.}, language = {en} } @article{KrebsBehrmannKalogirouetal.2019, author = {Krebs, Markus and Behrmann, Christoph and Kalogirou, Charis and Sokolakis, Ioannis and Kneitz, Susanne and Kruithof-de Julio, Marianna and Zoni, Eugenio and Rech, Anne and Schilling, Bastian and K{\"u}bler, Hubert and Spahn, Martin and Kneitz, Burkhard}, title = {miR-221 Augments TRAIL-mediated apoptosis in prostate cancer cells by inducing endogenous TRAIL expression and targeting the functional repressors SOCS3 and PIK3R1}, series = {BioMed Research International}, volume = {2019}, journal = {BioMed Research International}, doi = {10.1155/2019/6392748}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202480}, pages = {6392748}, year = {2019}, abstract = {miR-221 is regarded as an oncogene in many malignancies, and miR-221-mediated resistance towards TRAIL was one of the first oncogenic roles shown for this small noncoding RNA. In contrast, miR-221 is downregulated in prostate cancer (PCa), thereby implying a tumour suppressive function. By using proliferation and apoptosis assays, we show a novel feature of miR-221 in PCa cells: instead of inducing TRAIL resistance, miR-221 sensitized cells towards TRAIL-induced proliferation inhibition and apoptosis induction. Partially responsible for this effect was the interferon-mediated gene signature, which among other things contained an endogenous overexpression of the TRAIL encoding gene TNFSF10. This TRAIL-friendly environment was provoked by downregulation of the established miR-221 target gene SOCS3. Moreover, we introduced PIK3R1 as a target gene of miR-221 in PCa cells. Proliferation assays showed that siRNA-mediated downregulation of SOCS3 and PIK3R1 mimicked the effect of miR-221 on TRAIL sensitivity. Finally, Western blotting experiments confirmed lower amounts of phospho-Akt after siRNA-mediated downregulation of PIK3R1 in PC3 cells. Our results further support the tumour suppressing role of miR-221 in PCa, since it sensitises PCa cells towards TRAIL by regulating the expression of the oncogenes SOCS3 and PIK3R1. Given the TRAIL-inhibiting effect of miR-221 in various cancer entities, our results suggest that the influence of miR-221 on TRAIL-mediated apoptosis is highly context- and entity-dependent.}, language = {en} } @article{MolinasGonzalezCastroGonzalezMegiasetal.2019, author = {Molinas-Gonz{\´a}lez, Carlos R. and Castro, Jorge and Gonz{\´a}lez-Meg{\´i}as, Adela and Leverkus, Alexandro B.}, title = {Effects of post-fire deadwood management on soil macroarthropod communities}, series = {Forests}, volume = {10}, journal = {Forests}, number = {11}, issn = {1999-4907}, doi = {10.3390/f10111046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193079}, year = {2019}, abstract = {Dead wood comprises a vast amount of biological legacies that set the scene for ecological regeneration after wildfires, yet its removal is the most frequent management strategy worldwide. Soil-dwelling organisms are conspicuous, and they provide essential ecosystem functions, but their possible affection by different post-fire management strategies has so far been neglected. We analyzed the abundance, richness, and composition of belowground macroarthropod communities under two contrasting dead-wood management regimes after a large wildfire in the Sierra Nevada Natural and National Park (Southeast Spain). Two plots at different elevation were established, each containing three replicates of two experimental treatments: partial cut, where trees were cut and their branches lopped off and left over the ground, and salvage logging, where all the trees were cut, logs were piled, branches were mechanically masticated, and slash was spread on the ground. Ten years after the application of the treatments, soil cores were extracted from two types of microhabitat created by these treatments: bare-soil (in both treatments) and under-logs (in the partial cut treatment only). Soil macroarthropod assemblages were dominated by Hemiptera and Hymenoptera (mostly ants) and were more abundant and richer in the lowest plot. The differences between dead-wood treatments were most evident at the scale of management interventions: abundance and richness were lowest after salvage logging, even under similar microhabitats (bare-soil). However, there were no significant differences between microhabitat types on abundance and richness within the partial cut treatment. Higher abundance and richness in the partial cut treatment likely resulted from higher resource availability and higher plant diversity after natural regeneration. Our results suggest that belowground macroarthropod communities are sensitive to the manipulation of dead-wood legacies and that management through salvage logging could reduce soil macroarthropod recuperation compared to other treatments with less intense management even a decade after application.}, language = {en} } @article{WagnerEikenHaubitzetal.2019, author = {Wagner, Johanna and Eiken, Barbara and Haubitz, Imme and Lichthardt, Sven and Matthes, Niels and L{\"o}b, Stefan and Klein, Ingo and Germer, Christoph-Thomas and Wiegering, Armin}, title = {Suprapubic bladder drainage and epidural catheters following abdominal surgery—a risk for urinary tract infections?}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0209825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177731}, pages = {e0209825}, year = {2019}, abstract = {Background Epidural catheters are state of the art for postoperative analgesic in abdominal surgery. Due to neurolysis it can lead to postoperative urinary tract retention (POUR), which leads to prolonged bladder catheterization, which has an increased risk for urinary tract infections (UTI). Our aim was to identify the current perioperative management of urinary catheters and, second, to identify the optimal time of suprapubic bladder catheter removal in regard to the removal of the epidural catheter. Methods We sent a questionnaire to 102 German hospitals and analyzed the 83 received answers to evaluate the current handling of bladder drainage and epidural catheters. Then, we conducted a retrospective study including 501 patients, who received an epidural and suprapubic catheter after abdominal surgery at the University Hospital W{\"u}rzburg. We divided the patients into three groups according to the point in time of suprapubic bladder drainage removal in regard to the removal of the epidural catheter and analyzed the onset of a UTI. Results Our survey showed that in almost all hospitals (98.8\%), patients received an epidural catheter and a bladder drainage after abdominal surgery. The point in time of urinary catheter removal was equally distributed between before, simultaneously and after the removal of the epidural catheter (respectively: ~28-29\%). The retrospective study showed a catheter-associated UTI in 6.7\%. Women were affected significantly more often than men (10,7\% versus 2,5\%, p<0.001). There was a non-significant trend to more UTIs when the suprapubic catheter was removed after the epidural catheter (before: 5.7\%, after: 8.4\%). Conclusion The point in time of suprapubic bladder drainage removal in relation to the removal of the epidural catheter does not seem to correlate with the rate of UTIs. The current handling in Germany is inhomogeneous, so further studies to standardize treatment are recommended.}, language = {en} } @article{HovestadtThomasMitesseretal.2019, author = {Hovestadt, Thomas and Thomas, Jeremy A. and Mitesser, Oliver and Sch{\"o}nrogge, Karsten}, title = {Multiple host use and the dynamics of host-switching in host-parasite systems}, series = {Insect Conservation and Diversity}, volume = {12}, journal = {Insect Conservation and Diversity}, number = {6}, doi = {10.1111/icad.12374}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204747}, pages = {511-522}, year = {2019}, abstract = {The link between multi-host use and host switching in host-parasite interactions is a continuing area of debate. Lycaenid butterflies in the genus Maculinea, for example, exploit societies of different Myrmica ant species across their ranges, but there is only rare evidence that they simultaneously utilise multiple hosts at a local site, even where alternative hosts are present. We present a simple population-genetic model accounting for the proportion of two alternative hosts and the fitness of parasite genotypes on each host. In agreement with standard models, we conclude that simultaneous host use is possible whenever fitness of heterozygotes on alternative hosts is not too low. We specifically focus on host-shifting dynamics when the frequency of hosts changes. We find that (i) host shifting may proceed so rapidly that multiple host use is unlikely to be observed, (ii) back and forth transition in host use can exhibit a hysteresis loop, (iii) the parasites' host use may not be proportional to local host frequencies and be restricted to the rarer host under some conditions, and (iv) that a substantial decline in parasite abundance may typically precede a shift in host use. We conclude that focusing not just on possible equilibrium conditions but also considering the dynamics of host shifting in non-equilibrium situations may provide added insights into host-parasite systems.}, language = {en} }