TY  - JOUR
A1  - Pütz, Stephanie M.
A1  - Kram, Jette
A1  - Rauh, Elisa
A1  - Kaiser, Sophie
A1  - Toews, Romy
A1  - Lueningschroer-Wang, Yi
A1  - Rieger, Dirk
A1  - Raabe, Thomas
T1  - Loss of p21-activated kinase Mbt/PAK4 causes Parkinson-like symptoms in Drosophila
JF  - Disease Models & Mechanisms
N2  - Parkinson's disease (PD) provokes bradykinesia, resting tremor, rigidity and postural instability, and also non-motor symptoms such as depression, anxiety, sleep and cognitive impairments. Similar phenotypes can be induced in Drosophila melanogaster through modification of PD-relevant genes or the administration of PD inducing toxins. Recent studies correlated deregulation of human p21-activated kinase 4 (PAK4) with PD, leaving open the question of a causative relationship of mutations in this gene for manifestation of PD symptoms. To determine whether flies lacking the PAK4 homolog Mushroom bodies tiny (Mbt) show PD-like phenotypes, we tested for a variety of PD criteria. Here, we demonstrate that mbt mutant flies show PD-like phenotypes including age-dependent movement deficits, reduced life expectancy and fragmented sleep. They also react to a stressful situation with higher immobility, indicating an influence of Mbt on emotional behavior. Loss of Mbt function has a negative effect on the number of dopaminergic protocerebral anterior medial (PAM) neurons, most likely caused by a proliferation defect of neural progenitors. The age-dependent movement deficits are not accompanied by a corresponding further loss of PAM neurons. Previous studies highlighted the importance of a small PAM subgroup for age-dependent PD motor impairments. We show that impaired motor skills are caused by a lack of Mbt in this PAM subgroup. In addition, a broader re-expression of Mbt in PAM neurons improves life expectancy. Conversely, selective Mbt knockout in the same cells shortens lifespan. We conclude that mutations in Mbt/PAK4 can play a causative role in the development of PD phenotypes.
KW  - Sleep fragmentation
KW  - Life expectancy
KW  - Emotional behavior
KW  - Dopaminergic PAM cluster neurons
KW  - Drosophila
KW  - Parkinson's disease
KW  - Mbt
KW  - PAK4
KW  - Negative geotaxis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259222
VL  - 14
IS  - 6
ER  - 
TY  - JOUR
A1  - Schmitz, Werner
A1  - Koderer, Corinna
A1  - El-Mesery, Mohamed
A1  - Gobik, Sebastian
A1  - Sampers, Rene
A1  - Straub, Anton
A1  - Kübler, Alexander Christian
A1  - Seher, Axel
T1  - Metabolic fingerprinting of murine L929 fibroblasts as a cell-based tumour suppressor model system for methionine restriction
JF  - International Journal of Molecular Sciences
N2  - Since Otto Warburg reported in 1924 that cancer cells address their increased energy requirement through a massive intake of glucose, the cellular energy level has offered a therapeutic anticancer strategy. Methionine restriction (MetR) is one of the most effective approaches for inducing low-energy metabolism (LEM) due to the central position in metabolism of this amino acid. However, no simple in vitro system for the rapid analysis of MetR is currently available, and this study establishes the murine cell line L929 as such a model system. L929 cells react rapidly and efficiently to MetR, and the analysis of more than 150 different metabolites belonging to different classes (amino acids, urea and tricarboxylic acid cycle (TCA) cycles, carbohydrates, etc.) by liquid chromatography/mass spectrometry (LC/MS) defines a metabolic fingerprint and enables the identification of specific metabolites representing normal or MetR conditions. The system facilitates the rapid and efficient testing of potential cancer therapeutic metabolic targets. To date, MS studies of MetR have been performed using organisms and yeast, and the current LC/MS analysis of the intra- and extracellular metabolites in the murine cell line L929 over a period of 5 days thus provides new insights into the effects of MetR at the cellular metabolic level.
KW  - methionine restriction
KW  - caloric restriction
KW  - mass spectrometry
KW  - LC/MS
KW  - liquid chromatography/mass spectrometry
KW  - metabolism
KW  - L929
KW  - amino acid
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259198
SN  - 1422-0067
VL  - 22
IS  - 6
ER  - 
TY  - JOUR
A1  - Peters, Simon
A1  - Kaiser, Lena
A1  - Fink, Julian
A1  - Schumacher, Fabian
A1  - Perschin, Veronika
A1  - Schlegel, Jan
A1  - Sauer, Markus
A1  - Stigloher, Christian
A1  - Kleuser, Burkhard
A1  - Seibel, Juergen
A1  - Schubert-Unkmeir, Alexandra
T1  - Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria
JF  - Scientific Reports
N2  - Sphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce 'click-AT-CLEM', a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.
KW  - antimicrobials
KW  - biological techniques
KW  - imaging
KW  - microbiology
KW  - microbiology techniques
KW  - microscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259147
VL  - 11
IS  - 1
ER  - 
TY  - JOUR
A1  - Heydarian, Motaharehsadat
A1  - Schweinlin, Matthias
A1  - Schwarz, Thomas
A1  - Rawal, Ravisha
A1  - Walles, Heike
A1  - Metzger, Marco
A1  - Rudel, Thomas
A1  - Kozjak-Pavlovic, Vera
T1  - Triple co-culture and perfusion bioreactor for studying the interaction between Neisseria gonorrhoeae and neutrophils: A novel 3D tissue model for bacterial infection and immunity
JF  - Journal of Tissue Engineering
N2  - Gonorrhea, a sexually transmitted disease caused by the bacteria Neisseria gonorrhoeae, is characterized by a large number of neutrophils recruited to the site of infection. Therefore, proper modeling of the N. gonorrhoeae interaction with neutrophils is very important for investigating and understanding the mechanisms that gonococci use to evade the immune response. We have used a combination of a unique human 3D tissue model together with a dynamic culture system to study neutrophil transmigration to the site of N. gonorrhoeae infection. The triple co-culture model consisted of epithelial cells (T84 human colorectal carcinoma cells), human primary dermal fibroblasts, and human umbilical vein endothelial cells on a biological scaffold (SIS). After the infection of the tissue model with N. gonorrhoeae, we introduced primary human neutrophils to the endothelial side of the model using a perfusion-based bioreactor system. By this approach, we were able to demonstrate the activation and transmigration of neutrophils across the 3D tissue model and their recruitment to the site of infection. In summary, the triple co-culture model supplemented by neutrophils represents a promising tool for investigating N. gonorrhoeae and other bacterial infections and interactions with the innate immunity cells under conditions closely resembling the native tissue environment.
KW  - Triple co-culture
KW  - biomimetic 3D tissue model
KW  - Neisseria gonorrhoeae
KW  - perfusion-based bioreactor system
KW  - neutrophil transmigration
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259032
VL  - 12
ER  - 
TY  - JOUR
A1  - Liang, Chunguang
A1  - Bencurova, Elena
A1  - Psota, Eric
A1  - Neurgaonkar, Priya
A1  - Prelog, Martina
A1  - Scheller, Carsten
A1  - Dandekar, Thomas
T1  - Population-predicted MHC class II epitope presentation of SARS-CoV-2 structural proteins correlates to the case fatality rates of COVID-19 in different countries
JF  - International Journal of Molecular Sciences
N2  - We observed substantial differences in predicted Major Histocompatibility Complex II (MHCII) epitope presentation of SARS-CoV-2 proteins for different populations but only minor differences in predicted MHCI epitope presentation. A comparison of this predicted epitope MHC-coverage revealed for the early phase of infection spread (till day 15 after reaching 128 observed infection cases) highly significant negative correlations with the case fatality rate. Specifically, this was observed in different populations for MHC class II presentation of the viral spike protein (p-value: 0.0733 for linear regression), the envelope protein (p-value: 0.023), and the membrane protein (p-value: 0.00053), indicating that the high case fatality rates of COVID-19 observed in some countries seem to be related with poor MHC class II presentation and hence weak adaptive immune response against these viral envelope proteins. Our results highlight the general importance of the SARS-CoV-2 structural proteins in immunological control in early infection spread looking at a global census in various countries and taking case fatality rate into account. Other factors such as health system and control measures become more important after the early spread. Our study should encourage further studies on MHCII alleles as potential risk factors in COVID-19 including assessment of local populations and specific allele distributions.
KW  - COVID-19
KW  - population coverage
KW  - MHC II
KW  - MHC I
KW  - B-cell
KW  - T-cell
KW  - epitope mapping
KW  - lethality rate
KW  - infection spread
KW  - SARS-CoV-2
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258936
SN  - 1422-0067
VL  - 22
IS  - 5
ER  - 
TY  - JOUR
A1  - Meir, Michael
A1  - Kannapin, Felix
A1  - Diefenbacher, Markus
A1  - Ghoreishi, Yalda
A1  - Kollmann, Catherine
A1  - Flemming, Sven
A1  - Germer, Christoph-Thomas
A1  - Waschke, Jens
A1  - Leven, Patrick
A1  - Schneider, Reiner
A1  - Wehner, Sven
A1  - Burkard, Natalie
A1  - Schlegel, Nicolas
T1  - Intestinal epithelial barrier maturation by enteric glial cells is GDNF-dependent
JF  - International Journal of Molecular Sciences
N2  - Enteric glial cells (EGCs) of the enteric nervous system are critically involved in the maintenance of intestinal epithelial barrier function (IEB). The underlying mechanisms remain undefined. Glial cell line-derived neurotrophic factor (GDNF) contributes to IEB maturation and may therefore be the predominant mediator of this process by EGCs. Using GFAP\(^{cre}\) x Ai14\(^{floxed}\) mice to isolate EGCs by Fluorescence-activated cell sorting (FACS), we confirmed that they synthesize GDNF in vivo as well as in primary cultures demonstrating that EGCs are a rich source of GDNF in vivo and in vitro. Co-culture of EGCs with Caco2 cells resulted in IEB maturation which was abrogated when GDNF was either depleted from EGC supernatants, or knocked down in EGCs or when the GDNF receptor RET was blocked. Further, TNFα-induced loss of IEB function in Caco2 cells and in organoids was attenuated by EGC supernatants or by recombinant GDNF. These barrier-protective effects were blunted when using supernatants from GDNF-deficient EGCs or by RET receptor blockade. Together, our data show that EGCs produce GDNF to maintain IEB function in vitro through the RET receptor.
KW  - enteric glial cells
KW  - neurotrophic factors
KW  - intestinal epithelial barrier
KW  - GDNF5
KW  - RET6
KW  - inflammatory bowel disease
KW  - enteric nervous system
KW  - gut barrier
KW  - intercellular junctions
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258913
SN  - 1422-0067
VL  - 22
IS  - 4
ER  - 
TY  - JOUR
A1  - Grob, Robin
A1  - Heinig, Niklas
A1  - Grübel, Kornelia
A1  - Rössler, Wolfgang
A1  - Fleischmann, Pauline N.
T1  - Sex-specific and caste-specific brain adaptations related to spatial orientation in Cataglyphis ants
JF  - Journal of Comparative Neurology
N2  - Cataglyphis desert ants are charismatic central place foragers. After long-ranging foraging trips, individual workers navigate back to their nest relying mostly on visual cues. The reproductive caste faces other orientation challenges, i.e. mate finding and colony foundation. Here we compare brain structures involved in spatial orientation of Cataglyphis nodus males, gynes, and foragers by quantifying relative neuropil volumes associated with two visual pathways, and numbers and volumes of antennal lobe (AL) olfactory glomeruli. Furthermore, we determined absolute numbers of synaptic complexes in visual and olfactory regions of the mushroom bodies (MB) and a major relay station of the sky-compass pathway to the central complex (CX). Both female castes possess enlarged brain centers for sensory integration, learning, and memory, reflected in voluminous MBs containing about twice the numbers of synaptic complexes compared with males. Overall, male brains are smaller compared with both female castes, but the relative volumes of the optic lobes and CX are enlarged indicating the importance of visual guidance during innate behaviors. Male ALs contain greatly enlarged glomeruli, presumably involved in sex-pheromone detection. Adaptations at both the neuropil and synaptic levels clearly reflect differences in sex-specific and caste-specific demands for sensory processing and behavioral plasticity underlying spatial orientation.
KW  - antennal lobe
KW  - synaptic plasticity
KW  - polymorphism
KW  - optic lobes
KW  - mushroom bodies
KW  - learning and memory
KW  - central complex
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257299
VL  - 529
IS  - 18
ER  - 
TY  - JOUR
A1  - Villagomez, Gemma N.
A1  - Nürnberger, Fabian
A1  - Requier, Fabrice
A1  - Schiele, Susanne
A1  - Steffan-Dewenter, Ingo
T1  - Effects of temperature and photoperiod on the seasonal timing of Western honey bee colonies and an early spring flowering plant
JF  - Ecology and Evolution
N2  - Temperature and photoperiod are important Zeitgebers for plants and pollinators to synchronize growth and reproduction with suitable environmental conditions and their mutualistic interaction partners. Global warming can disturb this temporal synchronization since interacting species may respond differently to new combinations of photoperiod and temperature under future climates, but experimental studies on the potential phenological responses of plants and pollinators are lacking. We simulated current and future combinations of temperature and photoperiod to assess effects on the overwintering and spring phenology of an early flowering plant species (Crocus sieberi) and the Western honey bee (Apis mellifera). We could show that increased mean temperatures in winter and early spring advanced the flowering phenology of C. sieberi and intensified brood rearing activity of A. mellifera but did not advance their brood rearing activity. Flowering phenology of C. sieberi also relied on photoperiod, while brood rearing activity of A. mellifera did not. The results confirm that increases in temperature can induce changes in phenological responses and suggest that photoperiod can also play a critical role in these responses, with currently unknown consequences for real-world ecosystems in a warming climate.
KW  - Apis mellifera
KW  - climate change
KW  - rocus sieberi
KW  - phenology
KW  - plant–pollinator interaction
KW  - temporal mismatch
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258770
VL  - 11
IS  - 12
ER  - 
TY  - JOUR
A1  - Roth, Nicolas
A1  - Hacker, Herrmann Heinrich
A1  - Heidrich, Lea
A1  - Friess, Nicolas
A1  - García-Barroas, Enrique
A1  - Habel, Jan Christian
A1  - Thorn, Simon
A1  - Müler, Jörg
T1  - Host specificity and species colouration mediate the regional decline of nocturnal moths in central European forests
JF  - Ecography
N2  - The high diversity of insects has limited the volume of long-term community data with a high taxonomic resolution and considerable geographic replications, especially in forests. Therefore, trends and causes of changes are poorly understood. Here we analyse trends in species richness, abundance and biomass of nocturnal macro moths in three quantitative data sets collected over four decades in forests in southern Germany. Two local data sets, one from coppiced oak forests and one from high oak forests included 125K and 48K specimens from 559 and 532 species, respectively. A third regional data set, representing all forest types in the temperate zone of central Europe comprised 735K specimens from 848 species. Generalized additive mixed models revealed temporal declines in species richness (−38%), abundance (−53%) and biomass (−57%) at the regional scale. These were more pronounced in plant host specialists and in dark coloured species. In contrast, the local coppiced oak forests showed an increase, in species richness (+62%), while the high oak forests showed no clear trends. Left and right censoring as well as cross validation confirmed the robustness of the analyses, which led to four conclusions. First, the decline in insects appears in hyper diverse insect groups in forests and affects species richness, abundance and biomass. Second, the pronounced decline in host specialists suggests habitat loss as an important driver of the observed decline. Third, the more severe decline in dark species might be an indication of global warming as a potential driver. Fourth, the trends in coppiced oak forests indicate that maintaining complex and diverse forest ecosystems through active management may be a promising conservation strategy in order to counteract negative trends in biodiversity, alongside rewilding approaches.
KW  - climate change
KW  - colour patterns
KW  - global change
KW  - Lepidoptera
KW  - macro moths
KW  - specialists
KW  - time series
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258731
VL  - 44
IS  - 6
ER  - 
TY  - JOUR
A1  - Sivarajan, Rinu
A1  - Kessie, David Komla
A1  - Oberwinkler, Heike
A1  - Pallmann, Niklas
A1  - Walles, Thorsten
A1  - Scherzad, Agmal
A1  - Hackenberg, Stephan
A1  - Steinke, Maria
T1  - Susceptibility of Human Airway Tissue Models Derived From Different Anatomical Sites to Bordetella pertussis and Its Virulence Factor Adenylate Cyclase Toxin
JF  - Frontiers in Cellular and Infection Microbiology
N2  - To study the interaction of human pathogens with their host target structures, human tissue models based on primary cells are considered suitable. Complex tissue models of the human airways have been used as infection models for various viral and bacterial pathogens. The Gram-negative bacterium Bordetella pertussis is of relevant clinical interest since whooping cough has developed into a resurgent infectious disease. In the present study, we created three-dimensional tissue models of the human ciliated nasal and tracheo-bronchial mucosa. We compared the innate immune response of these models towards the B. pertussis virulence factor adenylate cyclase toxin (CyaA) and its enzymatically inactive but fully pore-forming toxoid CyaA-AC\(^-\). Applying molecular biological, histological, and microbiological assays, we found that 1 µg/ml CyaA elevated the intracellular cAMP level but did not disturb the epithelial barrier integrity of nasal and tracheo-bronchial airway mucosa tissue models. Interestingly, CyaA significantly increased interleukin 6, interleukin 8, and human beta defensin 2 secretion in nasal tissue models, whereas tracheo-bronchial tissue models were not significantly affected compared to the controls. Subsequently, we investigated the interaction of B. pertussis with both differentiated primary nasal and tracheo-bronchial tissue models and demonstrated bacterial adherence and invasion without observing host cell type-specific significant differences. Even though the nasal and the tracheo-bronchial mucosa appear similar from a histological perspective, they are differentially susceptible to B. pertussis CyaA in vitro. Our finding that nasal tissue models showed an increased innate immune response towards the B. pertussis virulence factor CyaA compared to tracheo-bronchial tissue models may reflect the key role of the nasal airway mucosa as the first line of defense against airborne pathogens.
KW  - human nasal epithelial cells
KW  - human tracheo-bronchial epithelial cells
KW  - human airway mucosa tissue models
KW  - adenylate cyclase toxin
KW  - Bordetella pertussis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-253302
SN  - 2235-2988
VL  - 11
ER  -