@article{UeceylerTopuzoğluSchiesseretal.2011, author = {{\"U}{\c{c}}eyler, Nurcan and Topuzoğlu, Teng{\"u} and Schießer, Peter and Hahnenkamp, Saskia and Sommer, Claudia}, title = {IL-4 Deficiency Is Associated with Mechanical Hypersensitivity in Mice}, series = {PLoS One}, volume = {6}, journal = {PLoS One}, number = {12}, doi = {10.1371/journal.pone.0028205}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137924}, pages = {e28205}, year = {2011}, abstract = {Interleukin-4 (IL-4) is an anti-inflammatory and analgesic cytokine that induces opioid receptor transcription. We investigated IL-4 knockout (ko) mice to characterize their pain behavior before and after chronic constriction injury (CCI) of the sciatic nerve as a model for neuropathic pain. We investigated opioid responsivity and measured cytokine and opioid receptor gene expression in the peripheral and central nervous system (PNS, CNS) of IL-4 ko mice in comparison with wildtype (wt) mice. Na{\"i}ve IL-4 ko mice displayed tactile allodynia (wt: 0.45 g; ko: 0.18 g; p<0.001), while responses to heat and cold stimuli and to muscle pressure were not different. No compensatory changes in the gene expression of tumor necrosis factor-alpha (TNF), IL-1β, IL-10, and IL-13 were found in the PNS and CNS of na{\"i}ve IL-4 ko mice. However, IL-1β gene expression was stronger in the sciatic nerve of IL-4 ko mice (p<0.001) 28 days after CCI and only IL-4 ko mice had elevated IL-10 gene expression (p = 0.014). Remarkably, CCI induced TNF (p<0.01), IL-1β (p<0.05), IL-10 (p<0.05), and IL-13 (p<0.001) gene expression exclusively in the ipsilateral spinal cord of IL-4 ko mice. The compensatory overexpression of the anti-inflammatory and analgesic cytokines IL-10 and IL-13 in the spinal cord of IL-4 ko mice may explain the lack of genotype differences for pain behavior after CCI. Additionally, CCI induced gene expression of μ, κ, and δ opioid receptors in the contralateral cortex and thalamus of IL-4 ko mice, paralleled by fast onset of morphine analgesia, but not in wt mice. We conclude that a lack of IL-4 leads to mechanical sensitivity; the compensatory hyperexpression of analgesic cytokines and opioid receptors after CCI, in turn, protects IL-4 ko mice from enhanced pain behavior after nerve lesion.}, language = {en} } @article{WinterAndelovicKampfetal.2021, author = {Winter, Patrick M. and Andelovic, Kristina and Kampf, Thomas and Hansmann, Jan and Jakob, Peter Michael and Bauer, Wolfgang Rudolf and Zernecke, Alma and Herold, Volker}, title = {Simultaneous measurements of 3D wall shear stress and pulse wave velocity in the murine aortic arch}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {23}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, doi = {10.1186/s12968-021-00725-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259152}, pages = {34}, year = {2021}, abstract = {Purpose Wall shear stress (WSS) and pulse wave velocity (PWV) are important parameters to characterize blood flow in the vessel wall. Their quantification with flow-sensitive phase-contrast (PC) cardiovascular magnetic resonance (CMR), however, is time-consuming. Furthermore, the measurement of WSS requires high spatial resolution, whereas high temporal resolution is necessary for PWV measurements. For these reasons, PWV and WSS are challenging to measure in one CMR session, making it difficult to directly compare these parameters. By using a retrospective approach with a flexible reconstruction framework, we here aimed to simultaneously assess both PWV and WSS in the murine aortic arch from the same 4D flow measurement. Methods Flow was measured in the aortic arch of 18-week-old wildtype (n = 5) and ApoE\(^{-/-}\) mice (n = 5) with a self-navigated radial 4D-PC-CMR sequence. Retrospective data analysis was used to reconstruct the same dataset either at low spatial and high temporal resolution (PWV analysis) or high spatial and low temporal resolution (WSS analysis). To assess WSS, the aortic lumen was labeled by semi-automatically segmenting the reconstruction with high spatial resolution. WSS was determined from the spatial velocity gradients at the lumen surface. For calculation of the PWV, segmentation data was interpolated along the temporal dimension. Subsequently, PWV was quantified from the through-plane flow data using the multiple-points transit-time method. Reconstructions with varying frame rates and spatial resolutions were performed to investigate the influence of spatiotemporal resolution on the PWV and WSS quantification. Results 4D flow measurements were conducted in an acquisition time of only 35 min. Increased peak flow and peak WSS values and lower errors in PWV estimation were observed in the reconstructions with high temporal resolution. Aortic PWV was significantly increased in ApoE\(^{-/-}\) mice compared to the control group (1.7 ± 0.2 versus 2.6 ± 0.2 m/s, p < 0.001). Mean WSS magnitude values averaged over the aortic arch were (1.17 ± 0.07) N/m\(^2\) in wildtype mice and (1.27 ± 0.10) N/m\(^2\) in ApoE\(^{-/-}\) mice. Conclusion The post processing algorithm using the flexible reconstruction framework developed in this study permitted quantification of global PWV and 3D-WSS in a single acquisition. The possibility to assess both parameters in only 35 min will markedly improve the analyses and information content of in vivo measurements.}, language = {en} } @article{WaiderPoppLangeetal.2017, author = {Waider, J and Popp, S and Lange, MD and Kern, R and Kolter, JF and Kobler, J and Donner, NC and Lowe, KR and Malzbender, JH and Brazell, CJ and Arnold, MR and Aboagye, B and Schmitt-B{\"o}hrer, A and Lowry, CA and Pape, HC and Lesch, KP}, title = {Genetically driven brain serotonin deficiency facilitates panic-like escape behavior in mice}, series = {Translational Psychiatry}, volume = {7}, journal = {Translational Psychiatry}, number = {e1246}, doi = {10.1038/tp.2017.209}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170239}, year = {2017}, abstract = {Multiple lines of evidence implicate brain serotonin (5-hydroxytryptamine; 5-HT) system dysfunction in the pathophysiology of stressor-related and anxiety disorders. Here we investigate the influence of constitutively deficient 5-HT synthesis on stressor-related anxiety-like behaviors using Tryptophan hydroxylase 2 (Tph2) mutant mice. Functional assessment of c-Fos after associated foot shock, electrophysiological recordings of GABAergic synaptic transmission, differential expression of the Slc6a4 gene in serotonergic neurons were combined with locomotor and anxiety-like measurements in different contextual settings. Our findings indicate that constitutive Tph2 inactivation and consequential lack of 5-HT synthesis in Tph2 null mutant mice (Tph2\(^{-/-}\)) results in increased freezing to associated foot shock and a differential c-Fos activity pattern in the basolateral complex of the amygdala. This is accompanied by altered GABAergic transmission as observed by recordings of inhibitory postsynaptic currents on principal neurons in the basolateral nucleus, which may explain increased fear associated with hyperlocomotion and escape-like responses in aversive inescapable contexts. In contrast, lifelong 5-HT deficiency as observed in Tph2 heterozygous mice (Tph\(^{+/-}\)) is able to be compensated through reduced GABAergic transmission in the basolateral nucleus of the amygdala based on Slc6a4 mRNA upregulation in subdivisions of dorsal raphe neurons. This results in increased activity of the basolateral nucleus of the amygdala due to associated foot shock. In conclusion, our results reflect characteristic syndromal dimensions of panic disorder and agoraphobia. Thus, constitutive lack of 5-HT synthesis influence the risk for anxiety- and stressor-related disorders including panic disorder and comorbid agoraphobia through the absence of GABAergic-dependent compensatory mechanisms in the basolateral nucleus of the amygdala.}, language = {en} } @article{VeniaminovaCespuglioCheungetal.2017, author = {Veniaminova, Ekaterina and Cespuglio, Raymond and Cheung, Chi Wai and Umriukhin, Alexei and Markova, Nataliia and Shevtsova, Elena and Lesch, Klaus-Peter and Anthony, Daniel C. and Strekalova, Tatyana}, title = {Autism-like behaviours and memory deficits result from a Western Diet in mice}, series = {Neural Plasticity}, journal = {Neural Plasticity}, doi = {10.1155/2017/9498247}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158211}, pages = {9498247}, year = {2017}, abstract = {Nonalcoholic fatty liver disease, induced by a Western diet (WD), evokes central and peripheral inflammation that is accompanied by altered emotionality. These changes can be associated with abnormalities in social behaviour, hippocampus-dependent cognitive functions, and metabolism. Female C57BL/6J mice were fed with a regular chow or with a WD containing 0.2\% of cholesterol and 21\% of saturated fat for three weeks. WD-treated mice exhibited increased social avoidance, crawl-over and digging behaviours, decreased body-body contacts, and hyperlocomotion. The WD-fed group also displayed deficits in hippocampal-dependent performance such as contextual memory in a fear conditioning and pellet displacement paradigms. A reduction in glucose tolerance and elevated levels of serum cholesterol and leptin were also associated with the WD. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1a) mRNA, a marker of mitochondrial activity, was decreased in the prefrontal cortex, hippocampus, hypothalamus, and dorsal raphe, suggesting suppressed brain mitochondrial functions, but not in the liver. This is the first report to show that a WD can profoundly suppress social interactions and induce dominant-like behaviours in na{\"i}ve adult mice. The spectrum of behaviours that were found to be induced are reminiscent of symptoms associated with autism, and, if paralleled in humans, suggest that a WD might exacerbate autism spectrum disorder.}, language = {en} } @article{TuChenLimetal.2012, author = {Tu, Xiaolin and Chen, Jianquan and Lim, Joohyun and Karner, Courtney M. and Lee, Seung-Yon and Heisig, Julia and Wiese, Cornelia and Surendran, Kameswaran and Kopan, Raphael and Gessler, Manfred and Long, Fanxin}, title = {Physiological Notch Signaling Maintains Bone Homeostasis via RBPjk and Hey Upstream of NFATc1}, series = {PLoS Genetics}, volume = {8}, journal = {PLoS Genetics}, number = {3}, doi = {10.1371/journal.pgen.1002577}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133490}, pages = {e1002577}, year = {2012}, abstract = {Notch signaling between neighboring cells controls many cell fate decisions in metazoans both during embryogenesis and in postnatal life. Previously, we uncovered a critical role for physiological Notch signaling in suppressing osteoblast differentiation in vivo. However, the contribution of individual Notch receptors and the downstream signaling mechanism have not been elucidated. Here we report that removal of Notch2, but not Notch1, from the embryonic limb mesenchyme markedly increased trabecular bone mass in adolescent mice. Deletion of the transcription factor RBPjk, a mediator of all canonical Notch signaling, in the mesenchymal progenitors but not the more mature osteoblast-lineage cells, caused a dramatic high-bone-mass phenotype characterized by increased osteoblast numbers, diminished bone marrow mesenchymal progenitor pool, and rapid age-dependent bone loss. Moreover, mice deficient in Hey1 and HeyL, two target genes of Notch-RBPjk signaling, exhibited high bone mass. Interestingly, Hey1 bound to and suppressed the NFATc1 promoter, and RBPjk deletion increased NFATc1 expression in bone. Finally, pharmacological inhibition of NFAT alleviated the high-bone-mass phenotype caused by RBPjk deletion. Thus, Notch-RBPjk signaling functions in part through Hey1-mediated inhibition of NFATc1 to suppress osteoblastogenesis, contributing to bone homeostasis in vivo.}, language = {en} } @phdthesis{TrujilloVargas2005, author = {Trujillo Vargas, Claudia Milena}, title = {Development of vaccines against allergic asthma using products derived from intracellular bacteria or helminths}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-12992}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {Die „Hygiene Hypothese" postuliert, dass der Kontakt mit Infektionserregern in der fr{\"u}hen Kindheit die Entwicklung von Th2-abh{\"a}ngigen allergischen Immunreaktionen verhindern kann, indem dadurch entweder eine vorrangig Th1-gerichtete Immunit{\"a}t etabliert wird oder alternativ die Bildung von regulatorischen T Zellen induziert wird. Basierend auf dieser Theorie zielte die vorliegende Arbeit darauf ab, Produkte von Mikroorganismen oder W{\"u}rmern als m{\"o}gliche Komponenten von Impfstoffen gegen Allergien zu testen. Im ersten Teil dieser Arbeit wurden lebende BCG, Hitze abget{\"o}tete BCG (hk-BCG), CpG und PPD, die alle als Th1 Adjuvantien bekannt sind, auf ihre Effektivit{\"a}t getestet, allergisches Asthma in der Maus zu unterdr{\"u}cken. Alle Adjuvantien konnten die durch Allergie induzierte Lungeneosinophilie, die Schleimproduktion in der Lunge und mit Ausnahme von PPD, die Lungen{\"u}berempfindlichkeit (AHR) unterdr{\"u}cken, wenn sie zusammen mit OVA/alum verabreicht wurden. Die Lungeneosinophilie konnte jedoch nicht in IL-12 oder IFN-gamma defizienten M{\"a}usen durch die Applikation von hk-BCG, CpG oder PPD verhindert werden. Interessanterweise waren jedoch lebende BCG in der Lage, die allergische Th2 Immunreaktion zu unterdr{\"u}cken. Ebenso war die Wirkung von lebendem BCG unabh{\"a}ngig vom IL-10, TLR-2, TLR-4 oder MyD88 vermittelten Signalweg. Wurden M{\"a}use, die mit den verschiedenen Adjuvantien zusammen mit OVA/alum geimpft wurden, einer zweiten Runde OVA/alum Sensibilisierung unterzogen, so konnten nur lebende und hk-BCG die Entwicklung der Entz{\"u}ndung in der Lunge effektiv unterdr{\"u}cken. Diese Wirkung konnte durch den adoptiven Transfer von CD4+ T Zellen auf naive M{\"a}use {\"u}bertragen werden. Zusammenfassend zeigen diese Daten, daß lebende BCG am effektivsten, gefolgt von hk-BCG, CpG und schließlich PPD allergische Th2 Immunreaktionen unterdr{\"u}cken konnten. Als n{\"a}chstes wurde untersucht, ob eine Impfung mit dendritischen Zellen (DC) die Entwicklung von Th2 Zellen durch die Induktion von allergenspezifischen Th1 Zellen verhindern kann. Die Applikation von OVA-gepulsten aus dem Knochenmark stammenden-dendritischen Zellen (BM-DC), die mit CpG in vitro stimuliert wurden, konnten die Lungeneosinophilie und Entz{\"u}ndung in den Atemwegen in OVA-immunisierten M{\"a}usen nicht reduzieren. OVA-spezifische IgG1 und IgE Antik{\"o}rpermengen im Serum waren ebenfalls nicht vermindert. Versuche mit OVA-gepulsten Langerhans-zellen (LC) f{\"u}hrten zu {\"a}hnlichen Ergebnissen wie mit BM-DC. Jedoch waren in M{\"a}usen, die mit CpG/OVA gepulsten BM-DC behandelt wurden, deutlich erh{\"o}hte Werte an OVA-spezifischen IgG2a Antik{\"o}rper im Serum nachzuweisen, was auf die Induktion einer allergenspezifischen Th1 Immunreaktion in vivo schließen l{\"a}ßt. Insgesamt zeigen die Ergebnisse aber, dass weder die Impfung mit OVA-gepulsten und CpG-stimulierten BM-DC noch mit OVA-gepulsten LC eine Verringerung der allergischen Th2 Immunreaktion in einem Mausmodell mit schwerem atopischem Asthma bewirkt. Im dritten Teil der Arbeit wurde NES, ein exkretorisches/sekretorisches Produkt des Helminthen Nippostrongylus brasiliensis, als ein neues m{\"o}gliches Adjuvant zur Unterdr{\"u}ckung allergischer Reaktionen untersucht. Die Applikation von NES zusammen mit OVA/alum inhibierte deutlich die Entwicklung der Lungeneosinophilie, Becherzellmetaplasie und Schleimproduktion in der Lunge sowie die Entwicklung der AHR. Das verwendete NES enthielt geringe Mengen an LPS, die diese Wirkung erkl{\"a}ren k{\"o}nnte. Allerdings war die Unterdr{\"u}ckung der Th2 Immunreaktion durch NES unabh{\"a}ngig von TLR-4 und konnte immer noch nachgewiesen werden, wenn LPS-depletiertes NES verwendet wurde. Schließlich konnte NES die OVA-induzierte Th2 Immunreaktion unabh{\"a}ngig von IL-10 und IFN-gamma reduzieren. Außerdem konnte der Verdau von NES mit Proteinase K oder eine Hitzebehandlung (kochen) den Th2-unterdr{\"u}ckenden Effekt nicht aufheben. Interessanterweise inhibierte NES in vivo eine OVA-spezifische Th2 Immunreaktion in Anwesenheit einer starken NES-spezifischen Th2 Reaktion. Zusammenfassend f{\"u}hren diese Ergebnisse zu dem Schluß, daß der Helminth N. brasiliensis Substanzen produziert, die die Entwicklung von allergischen Th2 Immunreaktionen beeinflussen. Diese Produkte und ihre Wirkmechanismen genauer zu charakterisieren, k{\"o}nnte zu sehr effektiven Adjuvantien f{\"u}hren, welche allergische Reaktionen unterdr{\"u}cken k{\"o}nnten. Die Ergebnisse dieser Arbeit k{\"o}nnten zuk{\"u}nftig dazu beitragen, effiziente Impfungen zu entwickeln, die Menschen vor der Entwicklung von allergischen Immunreaktionen sch{\"u}tzen.}, subject = {Bronchialasthma}, language = {en} } @phdthesis{Topuzoglu2012, author = {Topuzoglu, Teng{\"u} G{\"u}ls{\"u}m}, title = {Charakterisierung von IL-4 Knockout-M{\"a}usen und ihrer Zytokin- und Opioidrezeptor-Expression im peripheren und zentralen Nervensystem}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72372}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {In der vorliegenden Arbeit wurde der Einfluss eines Mangels des antiinflammatorischen Zytokins Interleukin(IL)-4 am Tiermodell einer experimentellen Mononeuropathie (engl. chronic constriction injury, CCI) untersucht. Zentrale Fragestellung der Studie war, ob IL-4 knockout(ko)-M{\"a}use im Vergleich zu Wildtyp(wt)-M{\"a}usen mit einem gesteigerten Schmerzverhalten sowie einer ver{\"a}nderten Zytokinantwort und Opioidrezeptor-Expression nach Anwendung eines neuropathischen Schmerzmodells (CCI) reagieren. In mehreren Tierstudien war zuvor eine antiinflammatorische und analgetische Wirkung von IL-4 belegt worden (Vale et al. 2003; Hao et al. 2006) und in klinischen Studien war ein verminderter IL-4-Spiegel bei Patienten mit verschiedenen neuropathischen Schmerzsyndromen mit einer gesteigerten Schmerzempfindung verbunden ({\"U}{\c{c}}eyler et al. 2006; {\"U}{\c{c}}eyler et al. 2007b). Da IL-4 die Transkription von Opioidrezeptoren induziert (Kraus et al. 2001; B{\"o}rner et al. 2004), wurde zudem das Ansprechen von IL-4 ko-M{\"a}usen auf Morphin und die Genexpression zentraler Opioidrezeptoren untersucht. Vor sowie bis vier Wochen nach Durchf{\"u}hrung einer CCI wurden IL-4 ko- sowie wt- M{\"a}use hinsichtlich ihrer Empfindlichkeit auf mechanische und thermische Stimuli analysiert. Zum Zeitpunkt des Schmerzmaximums nach CCI (Tag 7 bis 9) wurde zudem das Ansprechen beider Genotypen auf Morphin untersucht. Die Genexpression pro- (IL-1 beta, TNF) und antiinflammatorischer Zytokine (IL-10, IL- 13) im peripheren (N. ischiadicus) und zentralen Nervensystem (lumbales und zervikales R{\"u}ckenmark, Pons, Thalamus, Hypothalamus, Striatum, Kortex) sowie die Genexpression zentraler Opioidrezeptoren (m{\"u}-OR, delta-OR, kappa-OR) wurde bei beiden Genotypen vor sowie vier Wochen nach CCI mittels Real-Time-PCR bestimmt. Unbehandelte IL-4 ko-M{\"a}use zeigten im Vergleich zu wt-M{\"a}usen bereits vor Durchf{\"u}hrung einer CCI eine mechanische {\"U}berempfindlichkeit (Hyperalgesie), was m{\"o}glicherweise durch die bei IL-4-Mangel fehlenden zentralen inhibitorischen Mechanismen bedingt ist. Nach CCI entwickelten sowohl IL-4 ko- als auch wt-M{\"a}use eine gleich ausgepr{\"a}gte mechanische und thermische Hyperalgesie. Die Tatsache, dass die mechanische {\"U}berempfindlichkeit bei IL-4 ko-M{\"a}usen nach Nervenl{\"a}sion nicht {\"u}berproportional steigt, kann Ausdruck der nachgewiesenen kompensatorisch st{\"a}rker ausgepr{\"a}gten Genexpression proinflammatorischer, aber insbesondere auch antiinflammatorischer Zytokine in diesem Genotyp sein. Nur bei IL-4 ko-M{\"a}usen war vier Wochen nach CCI die Genexpression der anti- inflammatorischen Zytokine im N. ischiadicus (IL-10) und ipsilateralen R{\"u}ckenmark (IL-10, IL-13), jedoch auch die der proinflammatorischen Zytokine im ipsilateralen R{\"u}ckenmark (TNF, IL-1 beta) erh{\"o}ht. Nach CCI sprachen IL-4 ko-M{\"a}use schneller auf Morphingabe an als wt-M{\"a}use, was durch den bei diesem Genotyp st{\"a}rker ausgepr{\"a}gten Anstieg der Genexpression der Opioidrezeptortypen delta-OR und kappa-OR im kontralateralen Thalamus bedingt sein kann.}, subject = {Neuralgie}, language = {de} } @article{TimofeevSchlerethWanzeletal.2013, author = {Timofeev, Oleg and Schlereth, Katharina and Wanzel, Michael and Braun, Attila and Nieswandt, Bernhard and Pagenstecher, Axel and Rosenwald, Andreas and Els{\"a}sser, Hans-Peter and Stiewe, Thorsten}, title = {p53 DNA Binding Cooperativity Is Essential for Apoptosis and Tumor Suppression In Vivo}, series = {Cell Reports}, volume = {3}, journal = {Cell Reports}, doi = {10.1016/j.celrep.2013.04.008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122168}, pages = {1512-1525}, year = {2013}, abstract = {Four molecules of the tumor suppressor p53 assemble to cooperatively bind proapoptotic target genes. The structural basis for cooperativity consists of interactions between adjacent DNA binding domains. Mutations at the interaction interface that compromise cooperativity were identified in cancer patients, suggesting a requirement of cooperativity for tumor suppression. We report on an analysis of cooperativity mutant p53(E177R) mice. Apoptotic functions of p53 triggered by DNA damage and oncogenes were abolished in these mice, whereas functions in cell-cycle control, senescence, metabolism, and antioxidant defense were retained and were sufficient to suppress development of spontaneous T cell lymphoma. Cooperativity mutant mice are nevertheless highly cancer prone and susceptible to different oncogene-induced tumors. Our data underscore the relevance of DNA binding cooperativity for p53-dependent apoptosis and tumor suppression and highlight cooperativity mutations as a class of p53 mutations that result in a selective loss of apoptotic functions due to an altered quaternary structure of the p53 tetramer.}, language = {en} } @article{StrekalovaVeniaminovaSvirinetal.2021, author = {Strekalova, Tatyana and Veniaminova, Ekaterina and Svirin, Evgeniy and Kopeikina, Ekaterina and Veremeyko, Tatyana and Yung, Amanda W. Y. and Proshin, Andrey and Tan, Shawn Zheng Kai and Khairuddin, Sharafuddin and Lim, Lee Wei and Lesch, Klaus-Peter and Walitza, Susanne and Anthony, Daniel C. and Ponomarev, Eugene D.}, title = {Sex-specific ADHD-like behaviour, altered metabolic functions, and altered EEG activity in sialyltransferase ST3GAL5-deficient mice}, series = {Biomolecules}, volume = {11}, journal = {Biomolecules}, number = {12}, issn = {2218-273X}, doi = {10.3390/biom11121759}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250071}, year = {2021}, abstract = {A deficiency in GM3-derived gangliosides, resulting from a lack of lactosylceramide-alpha-2,3-sialyltransferase (ST3GAL5), leads to severe neuropathology, including epilepsy and metabolic abnormalities. Disruption of ganglioside production by this enzyme may also have a role in the development of neuropsychiatric disorders. ST3Gal5 knock-out (St3gal5\(^{-/-}\)) mice lack a-, b-, and c-series gangliosides, but exhibit no overt neuropathology, possibly owing to the production of compensatory 0-series glycosphingolipids. Here, we sought to investigate the possibility that St3gal5\(^{-/-}\) mice might exhibit attention-deficit/hyperactivity disorder (ADHD)-like behaviours. In addition, we evaluated potential metabolic and electroencephalogram (EEG) abnormalities. St3gal5\(^{-/-}\) mice were subjected to behavioural testing, glucose tolerance tests, and the levels of expression of brain and peripheral A and B isoforms of the insulin receptor (IR) were measured. We found that St3gal5\(^{-/-}\) mice exhibit locomotor hyperactivity, impulsivity, neophobia, and anxiety-like behavior. The genotype also altered blood glucose levels and glucose tolerance. A sex bias was consistently found in relation to body mass and peripheral IR expression. Analysis of the EEG revealed an increase in amplitude in St3gal5\(^{-/-}\) mice. Together, St3gal5\(^{-/-}\) mice exhibit ADHD-like behaviours, altered metabolic and EEG measures providing a useful platform for better understanding of the contribution of brain gangliosides to ADHD and associated comorbidities.}, language = {en} } @article{StrekalovaMarkovaShevtsovaetal.2016, author = {Strekalova, Tatyana and Markova, Nataliia and Shevtsova, Elena and Zubareva, Olga and Bakhmet, Anastassia and Steinbusch, Harry M. and Bachurin, Sergey and Lesch, Klaus-Peter}, title = {Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test}, series = {Neural Plasticity}, volume = {2016}, journal = {Neural Plasticity}, doi = {10.1155/2016/5098591}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147379}, pages = {5098591}, year = {2016}, abstract = {While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.}, language = {en} } @article{SinghKingstonGuptaetal.2015, author = {Singh, Amit K. and Kingston, Joseph J. and Gupta, Shishir K. and Batra, Harsh V.}, title = {Recombinant Bivalent Fusion Protein rVE Induces CD4+ and CD8+ T-Cell Mediated Memory Immune Response for Protection Against Yersinia enterocolitica Infection}, series = {Frontiers in Microbiology}, volume = {6}, journal = {Frontiers in Microbiology}, number = {1407}, doi = {10.3389/fmicb.2015.01407}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136114}, year = {2015}, abstract = {Studies investigating the correlates of immune protection against Yersinia infection have established that both humoral and cell mediated immune responses are required for the comprehensive protection. In our previous study, we established that the bivalent fusion protein (rVE) comprising immunologically active regions of Y pestis LcrV (100-270 aa) and YopE (50-213 aa) proteins conferred complete passive and active protection against lethal Y enterocolitica 8081 challenge. In the present study, cohort of BALB/c mice immunized with rVE or its component proteins rV, rE were assessed for cell mediated immune responses and memory immune protection against Y enterocolitica 8081 rVE immunization resulted in extensive proliferation of both CD4 and CD8 T cell subsets; significantly high antibody titer with balanced IgG1: IgG2a/IgG2b isotypes (1:1 ratio) and up regulation of both Th1 (INF-\(\alpha\), IFN-\(\gamma\), IL 2, and IL 12) and Th2 (IL 4) cytokines. On the other hand, rV immunization resulted in Th2 biased IgG response (11:1 ratio) and proliferation of CD4+ T-cell; rE group of mice exhibited considerably lower serum antibody titer with predominant Th1 response (1:3 ratio) and CD8+ T-cell proliferation. Comprehensive protection with superior survival (100\%) was observed among rVE immunized mice when compared to the significantly lower survival rates among rE (37.5\%) and rV (25\%) groups when IP challenged with Y enterocolitica 8081 after 120 days of immunization. Findings in this and our earlier studies define the bivalent fusion protein rVE as a potent candidate vaccine molecule with the capability to concurrently stimulate humoral and cell mediated immune responses and a proof of concept for developing efficient subunit vaccines against Gram negative facultative intracellular bacterial pathogens.}, language = {en} } @article{SimsekyilmazLiehnWeinandyetal.2016, author = {Simsekyilmaz, Sakine and Liehn, Elisa A. and Weinandy, Stefan and Schreiber, Fabian and Megens, Remco T. A. and Theelen, Wendy and Smeets, Ralf and Jockenh{\"o}vel, Stefan and Gries, Thomas and M{\"o}ller, Martin and Klee, Doris and Weber, Christian and Zernecke, Alma}, title = {Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {5}, doi = {10.1371/journal.pone.0155829}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179745}, year = {2016}, abstract = {Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE\(^{-/-}\) carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.}, language = {en} } @article{ShityakovSalvadorPastorinetal.2015, author = {Shityakov, Sergey and Salvador, Ellaine and Pastorin, Giorgia and F{\"o}rster, Carola}, title = {Blood-brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate}, series = {International Journal of Nanomedicine}, volume = {10}, journal = {International Journal of Nanomedicine}, doi = {10.2147/IJN.S68429}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149233}, pages = {1703-1713}, year = {2015}, abstract = {In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell® system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCN-TFITC rapid dissociation as an intermediate phase.}, language = {en} } @article{SchaeferWeibelDonatetal.2012, author = {Sch{\"a}fer, Simon and Weibel, Stephanie and Donat, Ulrike and Zhang, Quian and Aguilar, Richard J. and Chen, Nanhai G. and Szalay, Aladar A.}, title = {Vaccinia virus-mediated intra-tumoral expression of matrix metalloproteinase 9 enhances oncolysis of PC-3 xenograft tumors}, series = {BMC Cancer}, volume = {12}, journal = {BMC Cancer}, number = {366}, doi = {10.1186/1471-2407-12-366}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140800}, year = {2012}, abstract = {Background Oncolytic viruses, including vaccinia virus (VACV), are a promising alternative to classical mono-cancer treatment methods such as surgery, chemo- or radiotherapy. However, combined therapeutic modalities may be more effective than mono-therapies. In this study, we enhanced the effectiveness of oncolytic virotherapy by matrix metalloproteinase (MMP-9)-mediated degradation of proteins of the tumoral extracellular matrix (ECM), leading to increased viral distribution within the tumors. Methods For this study, the oncolytic vaccinia virus GLV-1h255, containing the mmp-9 gene, was constructed and used to treat PC-3 tumor-bearing mice, achieving an intra-tumoral over-expression of MMP-9. The intra-tumoral MMP-9 content was quantified by immunohistochemistry in tumor sections. Therapeutic efficacy of GLV-1h255 was evaluated by monitoring tumor growth kinetics and intra-tumoral virus titers. Microenvironmental changes mediated by the intra-tumoral MMP-9 over-expression were investigated by microscopic quantification of the collagen IV content, the blood vessel density (BVD) and the analysis of lymph node metastasis formation. Results GLV-1h255-treatment of PC-3 tumors led to a significant over-expression of intra-tumoral MMP-9, accompanied by a marked decrease in collagen IV content in infected tumor areas, when compared to GLV-1h68-infected tumor areas. This led to considerably elevated virus titers in GLV-1h255 infected tumors, and to enhanced tumor regression. The analysis of the BVD, as well as the lumbar and renal lymph node volumes, revealed lower BVD and significantly smaller lymph nodes in both GLV-1h68- and GLV-1h255- injected mice compared to those injected with PBS, indicating that MMP-9 over-expression does not alter the metastasis-reducing effect of oncolytic VACV. Conclusions Taken together, these results indicate that a GLV-1h255-mediated intra-tumoral over-expression of MMP-9 leads to a degradation of collagen IV, facilitating intra-tumoral viral dissemination, and resulting in accelerated tumor regression. We propose that approaches which enhance the oncolytic effect by increasing the intra-tumoral viral load, may be an effective way to improve therapeutic outcome.}, language = {en} } @phdthesis{Schuh2001, author = {Schuh, Kai}, title = {Erzeugung und Analyse NF-ATp-defizienter M{\"a}use}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2001}, abstract = {Ziel dieser Arbeit war es, NF-AT1-Gen-defiziente Mauslinien zu erzeugen und die Folgen dieser genetischen Manipulation in vivo zu untersuchen. Die Untersuchung sollte die durch die Gendefizienz erwarteten M{\"a}ngel w{\"a}hrend der Entwicklung (Embryogenese) und, im Besonderen, die Auswirkungen auf das Immunsytem und die Entwicklung und Differenzierung der T-Zellen aufzeigen. Zur Untersuchung der genomischen Organisation des Maus-NF-AT1-Gens wurde eine genomische l-Phagen-DNA-Bibliothek "gescreent" (durchgef{\"u}hrt von Dr. E. Jankevics, Universit{\"a}t von Riga, Lettland), die entsprechenden l-Phagen, die das NF-AT1-Gen enthielten, isoliert und die DNA pr{\"a}pariert. Nach Analyse der klonierten Phagen (Subklonierung und Sequenzierung) wurde eine Restriktionskarte der entsprechenden Bereiche erstellt und der "targeting-vector" erstellt. Der "targeting-vector" wurde durch Elektroporation in embryonale Stammzellen (ES-Zellen) eingebracht und die Integration in das Genom ("Homologe Rekombination") durch Southern Blotting- bzw. PCR-Analyse untersucht. Manipulierte ES-Zellklone wurden in C57Bl/6-Blastozysten injiziert, diese in scheinschwangere Ammentiere transferiert und die Nachkommen nach Geburt anhand der Fellfarben klassifiziert. Nachkommen mit einem hohen Anteil hellen Fells wurden mit C57 Bl/6-Tieren verpaart und die Integration des manipulierten Zellklons in die Keimbahn wurde anhand der wildtypischen Fellfarbe und Genotypisierung nachgewiesen. Bez{\"u}glich des manipulierten NF-ATp-Gens heterozygote F1-Tiere wurden miteinander verpaart, um eine homozygote NF-ATp-defiziente M{\"a}use zu erhalten. Die Deletion des NF-ATp-Proteins wurde durch in Western-Blotting-Experimenten und EMSAs ("electrophoretic mobility shift assays") nachgewiesen. Die NF-ATp-/--Tiere zeigten keine augenscheinlichen Ver{\"a}nderungen w{\"a}hrend der Entwicklung und, bei jungen Tieren, keine offensichtlichen Ver{\"a}nderungen bei der Entwicklung des Immunsystems. In {\"a}lteren Tieren (> 6 Wochen) war eine Hyperproliferation der Zellen des Immunsystems zu beobachten, was mit einer Splenomegalie, einer verst{\"a}rkten Bildung von Keimzentren in lymphatischen Organen, vergr{\"o}ßerten Lymphknoten und einer verlangsamten Involution des Thymus einherging. Weitergehende Untersuchungen der Ursache dieser hyperproliferativen Erkrankung offenbarten eine verminderte klonale Deletion nach Aktivierung. Die Ursachen dieses {\"u}berraschenden Effekts sind wahrscheinlich vielf{\"a}ltig, da NF-AT-Faktoren an der Regulation der Expression vieler Gene beteiligt sind, u.a. des Apoptose-assoziierten CD95-Liganden. Da sich bez{\"u}glich der IL-2-Expression keine Unterschiede zwischen NF-ATp-defizienten Tieren und Kontrollen zeigten, jedoch eine erh{\"o}hte IL-2-Konzentration im Medium kultivierter NF-ATp-defizienter T-Zellen beobachtet wurde, wurde die Bindung von NF-ATp an putative NF-AT-Bindungssequenzen des CD25-Promotors, die transkriptionelle Aktivierung des Promotors mittels Luciferase-Assays und die Expression der IL-2R-alpha-Kette (CD25) untersucht. Es konnte gezeigt werden, daß (1.) NF-ATp an zwei Regionen des CD25-Promotors bindet, (2.) der CD25-Promotor durch NF-ATp transkriptionell stark stimuliert wird und (3.) T-Zellen NF-ATp-defizienter Tiere nach Stimulation eine verminderte CD25-Expression zeigen. In NF-ATp-defizienten Tieren war die Expression von CD25 moderat reduziert, was eine Erkl{\"a}rung f{\"u}r den abgeschw{\"a}chten Ph{\"a}notyp dieser Tiere - im Vergleich zu IL-2- oder CD25-defizienten Tieren - sein kann. Die hyperproliferativen Erkrankungen dieser verschiedenen Mauslinien weisen auf eine Beteiligung der NF-AT-/IL-2-/IL-2R-Signalwege nicht nur w{\"a}hrend der T-Zell-Aktivierung hin, sondern auch auf eine Beteiligung an Signalwegen, die zur anschließenden Inaktivierung und Apoptose der T-Lymphozyten n{\"o}tig sind.}, subject = {Maus}, language = {de} } @article{SchrautJakobWeidneretal.2014, author = {Schraut, K. G. and Jakob, S. B. and Weidner, M. T. and Schmitt, A. G. and Scholz, C. J. and Strekalova, T. and El Hajj, N. and Eijssen, L. M. T. and Domschke, K. and Reif, A. and Haaf, T. and Ortega, G. and Steinbusch, H. W. M. and Lesch, K. P. and Van den Hove, D. L.}, title = {Prenatal stress-induced programming of genome-wide promoter DNA methylation in 5-HTT-deficient mice}, series = {Translational Psychiatry}, volume = {4}, journal = {Translational Psychiatry}, doi = {10.1038/tp.2014.107}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119199}, pages = {e473}, year = {2014}, abstract = {The serotonin transporter gene (5-HTT/SLC6A4)-linked polymorphic region has been suggested to have a modulatory role in mediating effects of early-life stress exposure on psychopathology rendering carriers of the low-expression short (s)-variant more vulnerable to environmental adversity in later life. The underlying molecular mechanisms of this gene-by-environment interaction are not well understood, but epigenetic regulation including differential DNA methylation has been postulated to have a critical role. Recently, we used a maternal restraint stress paradigm of prenatal stress (PS) in 5-HTT-deficient mice and showed that the effects on behavior and gene expression were particularly marked in the hippocampus of female 5-Htt+/- offspring. Here, we examined to which extent these effects are mediated by differential methylation of DNA. For this purpose, we performed a genome-wide hippocampal DNA methylation screening using methylated-DNA immunoprecipitation (MeDIP) on Affymetrix GeneChip Mouse Promoter 1.0 R arrays. Using hippocampal DNA from the same mice as assessed before enabled us to correlate gene-specific DNA methylation, mRNA expression and behavior. We found that 5-Htt genotype, PS and their interaction differentially affected the DNA methylation signature of numerous genes, a subset of which showed overlap with the expression profiles of the corresponding transcripts. For example, a differentially methylated region in the gene encoding myelin basic protein (Mbp) was associated with its expression in a 5-Htt-, PS- and 5-Htt × PS-dependent manner. Subsequent fine-mapping of this Mbp locus linked the methylation status of two specific CpG sites to Mbp expression and anxiety-related behavior. In conclusion, hippocampal DNA methylation patterns and expression profiles of female prenatally stressed 5-Htt+/- mice suggest that distinct molecular mechanisms, some of which are promoter methylation-dependent, contribute to the behavioral effects of the 5-Htt genotype, PS exposure and their interaction.}, language = {en} } @article{SchapovalovaGorlovadeMunteretal.2022, author = {Schapovalova, Olesia and Gorlova, Anna and de Munter, Johannes and Sheveleva, Elisaveta and Eropkin, Mikhail and Gorbunov, Nikita and Sicker, Michail and Umriukhin, Aleksei and Lyubchyk, Sergiy and Lesch, Klaus-Peter and Strekalova, Tatyana and Schroeter, Careen A.}, title = {Immunomodulatory effects of new phytotherapy on human macrophages and TLR4- and TLR7/8-mediated viral-like inflammation in mice}, series = {Frontiers in Medicine}, volume = {9}, journal = {Frontiers in Medicine}, issn = {2296-858X}, doi = {10.3389/fmed.2022.952977}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286301}, year = {2022}, abstract = {Background While all efforts have been undertaken to propagate the vaccination and develop remedies against SARS-CoV-2, no satisfactory management of this infection is available yet. Moreover, poor availability of any preventive and treatment measures of SARS-CoV-2 in economically disadvantageous communities aggravates the course of the pandemic. Here, we studied a new immunomodulatory phytotherapy (IP), an extract of blackberry, chamomile, garlic, cloves, and elderberry as a potential low-cost solution for these problems given the reported efficacy of herbal medicine during the previous SARS virus outbreak. Methods The key feature of SARS-CoV-2 infection, excessive inflammation, was studied in in vitro and in vivo assays under the application of the IP. First, changes in tumor-necrosis factor (TNF) and lnteurleukin-1 beta (IL-1β) concentrations were measured in a culture of human macrophages following the lipopolysaccharide (LPS) challenge and treatment with IP or prednisolone. Second, chronically IP-pre-treated CD-1 mice received an agonist of Toll-like receptors (TLR)-7/8 resiquimod and were examined for lung and spleen expression of pro-inflammatory cytokines and blood formula. Finally, chronically IP-pre-treated mice challenged with LPS injection were studied for "sickness" behavior. Additionally, the IP was analyzed using high-potency-liquid chromatography (HPLC)-high-resolution-mass-spectrometry (HRMS). Results LPS-induced in vitro release of TNF and IL-1β was reduced by both treatments. The IP-treated mice displayed blunted over-expression of SAA-2, ACE-2, CXCL1, and CXCL10 and decreased changes in blood formula in response to an injection with resiquimod. The IP-treated mice injected with LPS showed normalized locomotion, anxiety, and exploration behaviors but not abnormal forced swimming. Isoquercitrin, choline, leucine, chlorogenic acid, and other constituents were identified by HPLC-HRMS and likely underlie the IP immunomodulatory effects. Conclusions Herbal IP-therapy decreases inflammation and, partly, "sickness behavior," suggesting its potency to combat SARS-CoV-2 infection first of all via its preventive effects.}, language = {en} } @article{SagivMichaeliAssietal.2015, author = {Sagiv, Jitka Y. and Michaeli, Janna and Assi, Simaan and Mishalian, Inbal and Kisos, Hen and Levy, Liran and Damti, Pazzit and Lumbroso, Delphine and Polyansky, Lola and Sionov, Ronit V. and Ariel, Amiram and Hovav, Avi-Hai and Henke, Erik and Fridlender, Zvi G. and Granot, Zvi}, title = {Phenotypic diversity and plasticity in circulating neutrophil subpopulations in cancer}, series = {Cell Reports}, volume = {10}, journal = {Cell Reports}, number = {4}, doi = {10.1016/j.celrep.2014.12.039}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144102}, pages = {562-573}, year = {2015}, abstract = {Controversy surrounds neutrophil function in cancer because neutrophils were shown to provide both pro-and antitumor functions. We identified a heterogeneous subset of low-density neutrophils (LDNs) that appear transiently in self-resolving inflammation but accumulate continuously with cancer progression. LDNs display impaired neutrophil function and immunosuppressive properties, characteristics that are in stark contrast to those of mature, high-density neutrophils (HDNs). LDNs consist of both immature myeloid-derived suppressor cells (MDSCs) and mature cells that are derived from HDNs in a TGF-beta-dependent mechanism. Our findings identify three distinct populations of circulating neutrophils and challenge the concept that mature neutrophils have limited plasticity. Furthermore, our findings provide a mechanistic explanation to mitigate the controversy surrounding neutrophil function in cancer.}, language = {en} } @article{RoederGeillingerZieteketal.2014, author = {R{\"o}der, Pia V. and Geillinger, Kerstin E. and Zietek, Tamara S. and Thorens, Bernard and Koepsell, Hermann and Daniel, Hannelore}, title = {The Role of SGLT1 and GLUT2 in Intestinal Glucose Transport and Sensing}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0089977}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117262}, pages = {e89977}, year = {2014}, abstract = {Intestinal glucose absorption is mediated by SGLT1 whereas GLUT2 is considered to provide basolateral exit. Recently, it was proposed that GLUT2 can be recruited into the apical membrane after a high luminal glucose bolus allowing bulk absorption of glucose by facilitated diffusion. Moreover, SGLT1 and GLUT2 are suggested to play an important role in intestinal glucose sensing and incretin secretion. In mice that lack either SGLT1 or GLUT2 we re-assessed the role of these transporters in intestinal glucose uptake after radiotracer glucose gavage and performed Western blot analysis for transporter abundance in apical membrane fractions in a comparative approach. Moreover, we examined the contribution of these transporters to glucose-induced changes in plasma GIP, GLP-1 and insulin levels. In mice lacking SGLT1, tissue retention of tracer glucose was drastically reduced throughout the entire small intestine whereas GLUT2-deficient animals exhibited higher tracer contents in tissue samples than wild type animals. Deletion of SGLT1 resulted also in reduced blood glucose elevations and abolished GIP and GLP-1 secretion in response to glucose. In mice lacking GLUT2, glucose-induced insulin but not incretin secretion was impaired. Western blot analysis revealed unchanged protein levels of SGLT1 after glucose gavage. GLUT2 detected in apical membrane fractions mainly resulted from contamination with basolateral membranes but did not change in density after glucose administration. SGLT1 is unequivocally the prime intestinal glucose transporter even at high luminal glucose concentrations. Moreover, SGLT1 mediates glucose-induced incretin secretion. Our studies do not provide evidence for GLUT2 playing any role in either apical glucose influx or incretin secretion.}, language = {en} } @article{RiedlKampfHeroldetal.2020, author = {Riedl, Katharina A. and Kampf, Thomas and Herold, Volker and Behr, Volker C. and Bauer, Wolfgang R.}, title = {Wall shear stress analysis using 17.6 Tesla MRI: A longitudinal study in ApoE\(^{-/-}\)mice with histological analysis}, series = {PLoS One}, volume = {15}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0238112}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229318}, year = {2020}, abstract = {This longitudinal study was performed to evaluate the feasibility of detecting the interaction between wall shear stress (WSS) and plaque development. 20 ApoE\(^{-/-}\)mice were separated in 12 mice with Western Diet and 8 mice with Chow Diet. Magnetic resonance (MR) scans at 17.6 Tesla and histological analysis were performed after one week, eight and twelve weeks. Allin vivoMR measurements were acquired using a flow sensitive phase contrast method for determining vectorial flow. Histological sections were stained with Hematoxylin and Eosin, Elastica van Gieson and CD68 staining. Data analysis was performed using Ensight and a Matlab-based "Flow Tool". The body weight of ApoE\(^{-/-}\)mice increased significantly over 12 weeks. WSS values increased in the Western Diet group over the time period; in contrast, in the Chow Diet group the values decreased from the first to the second measurement point. Western Diet mice showed small plaque formations with elastin fragmentations after 8 weeks and big plaque formations after 12 weeks; Chow Diet mice showed a few elastin fragmentations after 8 weeks and small plaque formations after 12 weeks. Favored by high-fat diet, plaque formation results in higher values of WSS. With wall shear stress being a known predictor for atherosclerotic plaque development, ultra highfield MRI can serve as a tool for studying the causes and beginnings of atherosclerosis.}, language = {en} }