TY  - JOUR
A1  - Hassouna, I.
A1  - Ott, C.
A1  - Wüstefeld, L.
A1  - Offen, N.
A1  - Neher, R. A.
A1  - Mitkovski, M.
A1  - Winkler, D.
A1  - Sperling, S.
A1  - Fries, L.
A1  - Goebbels, S.
A1  - Vreja, I. C.
A1  - Hagemeyer, N.
A1  - Dittrich, M.
A1  - Rossetti, M. F.
A1  - Kröhnert, K.
A1  - Hannke, K.
A1  - Boretius, S.
A1  - Zeug, A.
A1  - Höschen, C.
A1  - Dandekar, T.
A1  - Dere, E.
A1  - Neher, E.
A1  - Rizzoli, S. O.
A1  - Nave, K.-A.
A1  - Sirén, A.-L.
A1  - Ehrenreich, H.
T1  - Revisiting adult neurogenesis and the role of erythropoietin for neuronal and oligodendroglial differentiation in the hippocampus
JF  - Molecular Psychiatry
N2  - Recombinant human erythropoietin (EPO) improves cognitive performance in neuropsychiatric diseases ranging from schizophrenia and multiple sclerosis to major depression and bipolar disease. This consistent EPO effect on cognition is independent of its role in hematopoiesis. The cellular mechanisms of action in brain, however, have remained unclear. Here we studied healthy young mice and observed that 3-week EPO administration was associated with an increased number of pyramidal neurons and oligodendrocytes in the hippocampus of similar to 20%. Under constant cognitive challenge, neuron numbers remained elevated until >6 months of age. Surprisingly, this increase occurred in absence of altered cell proliferation or apoptosis. After feeding a \(^{15}\)N-leucine diet, we used nanoscopic secondary ion mass spectrometry, and found that in EPO-treated mice, an equivalent number of neurons was defined by elevated \(^{15}\)N-leucine incorporation. In EPO-treated NG2-Cre-ERT2 mice, we confirmed enhanced differentiation of preexisting oligodendrocyte precursors in the absence of elevated DNA synthesis. A corresponding analysis of the neuronal lineage awaits the identification of suitable neuronal markers. In cultured neurospheres, EPO reduced Sox9 and stimulated miR124, associated with advanced neuronal differentiation. We are discussing a resulting working model in which EPO drives the differentiation of non-dividing precursors in both (NG2+) oligodendroglial and neuronal lineages. As endogenous EPO expression is induced by brain injury, such a mechanism of adult neurogenesis may be relevant for central nervous system regeneration.
KW  - neural stem-cells
KW  - recombinat-human-erythropoietin
KW  - cognitive functions
KW  - pyramidal neurons
KW  - nervous-sytem
KW  - brain-injury
KW  - mouse-brain
KW  - progenitors
KW  - mice
KW  - memory
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186669
VL  - 21
IS  - 12
ER  - 
TY  - JOUR
A1  - Singh, Amit K.
A1  - Kingston, Joseph J.
A1  - Gupta, Shishir K.
A1  - Batra, Harsh V.
T1  - Recombinant Bivalent Fusion Protein rVE Induces CD4+ and CD8+ T-Cell Mediated Memory Immune Response for Protection Against Yersinia enterocolitica Infection
JF  - Frontiers in Microbiology
N2  - 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.
KW  - I-tasser
KW  - Yersinia enterocolitica
KW  - memory immune responses
KW  - cytokine profiling
KW  - CD8+T cells
KW  - CD4+T cells
KW  - recombinant protein rVE
KW  - resistance
KW  - pneumonic plague
KW  - pestis infection
KW  - nonhuman-primates
KW  - III secretion
KW  - V-antigen
KW  - mice
KW  - vaccine
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136114
VL  - 6
IS  - 1407
ER  - 
TY  - JOUR
A1  - Tu, Xiaolin
A1  - Chen, Jianquan
A1  - Lim, Joohyun
A1  - Karner, Courtney M.
A1  - Lee, Seung-Yon
A1  - Heisig, Julia
A1  - Wiese, Cornelia
A1  - Surendran, Kameswaran
A1  - Kopan, Raphael
A1  - Gessler, Manfred
A1  - Long, Fanxin
T1  - Physiological Notch Signaling Maintains Bone Homeostasis via RBPjk and Hey Upstream of NFATc1
JF  - PLoS Genetics
N2  - 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.
KW  - expression
KW  - axial skeletal defects
KW  - transcription factor
KW  - alagille syndrome
KW  - osteoblast differentiation
KW  - human jagged1
KW  - aortic-valve
KW  - T cells
KW  - mutations
KW  - mice
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133490
VL  - 8
IS  - 3
ER  - 
TY  - JOUR
A1  - Hepbasli, Denis
A1  - Gredy, Sina
A1  - Ullrich, Melanie
A1  - Reigl, Amelie
A1  - Abeßer, Marco
A1  - Raabe, Thomas
A1  - Schuh, Kai
T1  - Genotype- and Age-Dependent Differences in Ultrasound Vocalizations of SPRED2 Mutant Mice Revealed by Machine Deep Learning
JF  - Brain Sciences
N2  - Vocalization is an important part of social communication, not only for humans but also for mice. Here, we show in a mouse model that functional deficiency of Sprouty-related EVH1 domain-containing 2 (SPRED2), a protein ubiquitously expressed in the brain, causes differences in social ultrasound vocalizations (USVs), using an uncomplicated and reliable experimental setting of a short meeting of two individuals. SPRED2 mutant mice show an OCD-like behaviour, accompanied by an increased release of stress hormones from the hypothalamic–pituitary–adrenal axis, both factors probably influencing USV usage. To determine genotype-related differences in USV usage, we analyzed call rate, subtype profile, and acoustic parameters (i.e., duration, bandwidth, and mean peak frequency) in young and old SPRED2-KO mice. We recorded USVs of interacting male and female mice, and analyzed the calls with the deep-learning DeepSqueak software, which was trained to recognize and categorize the emitted USVs. Our findings provide the first classification of SPRED2-KO vs. wild-type mouse USVs using neural networks and reveal significant differences in their development and use of calls. Our results show, first, that simple experimental settings in combination with deep learning are successful at identifying genotype-dependent USV usage and, second, that SPRED2 deficiency negatively affects the vocalization usage and social communication of mice.
KW  - SPRED
KW  - SPRED2
KW  - mice
KW  - neural networks
KW  - ultrasound vocalizations
KW  - DeepSqueak
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-248525
SN  - 2076-3425
VL  - 11
IS  - 10
ER  - 
TY  - THES
A1  - Schuh, Kai
T1  - Erzeugung und Analyse NF-ATp-defizienter Mäuse
T1  - Generation and Analysis of NF-ATp-deficient Mice
N2  - 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 Mängel während 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" (durchgeführt von Dr. E. Jankevics, Universität von Riga, Lettland), die entsprechenden l-Phagen, die das NF-AT1-Gen enthielten, isoliert und die DNA präpariert. 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. Bezüglich des manipulierten NF-ATp-Gens heterozygote F1-Tiere wurden miteinander verpaart, um eine homozygote NF-ATp-defiziente Mäuse 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 Veränderungen während der Entwicklung und, bei jungen Tieren, keine offensichtlichen Veränderungen bei der Entwicklung des Immunsystems. In älteren Tieren (> 6 Wochen) war eine Hyperproliferation der Zellen des Immunsystems zu beobachten, was mit einer Splenomegalie, einer verstärkten Bildung von Keimzentren in lymphatischen Organen, vergrößerten 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 überraschenden Effekts sind wahrscheinlich vielfältig, da NF-AT-Faktoren an der Regulation der Expression vieler Gene beteiligt sind, u.a. des Apoptose-assoziierten CD95-Liganden. Da sich bezüglich der IL-2-Expression keine Unterschiede zwischen NF-ATp-defizienten Tieren und Kontrollen zeigten, jedoch eine erhöhte 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 Erklärung für den abgeschwächten Phänotyp 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 während der T-Zell-Aktivierung hin, sondern auch auf eine Beteiligung an Signalwegen, die zur anschließenden Inaktivierung und Apoptose der T-Lymphozyten nötig sind.
N2  - Aim of this work was the generation of NF-ATp-deficient mice and to investigate the effects of this genetic manipulation in vivo. The investigation included observation of defects during embryogenesis and, in particular, effects on development and differentiation of T cells of the immune system. To characterize the genomic organisation of the NF-ATp gene, a genomic DNA library was screened (done by E. Jankevics, PhD, University of Riga, Latvia), the NF-ATp gene containing phages isolated and analyzed (subcloning and sequencing). A restriction map was made, necessary for construction of the targeting vector. The targeting vector was brought into E14.1 embryonic stem cells by electroporation and integration through "homologous recombination" was confirmed by Southern blotting and PCR analysis. Successfully manipulated ES cell clones were injected in C57 Bl/6 blastocystes, injected blastocystes transferred into pseudo-pregnant foster mice, and the offsprings classified according to coat colour. Offsprings showing a high level of fair coat colour were mated to C57Bl/6 inbreed animals, integration of the manipulated cell clone into germline was verified by wild-type coat colour and genotyping. Heterozygous animals were crossbred to obtain homozygous NF-ATp-deficient animals. Loss of NF-ATp protein was confirmed in Western blotting assays and EMSAs. NF-ATp-deficient mice showed no obvious changes in embryogenesis and no differences in the development of the immune system. Older Animals (> 6 weeks) developed a hyperproliverative disorder of lymphatic cells going along with splenomegalie, enlarged lymph nodes and retarted involution of the thymus. Further investigations revealed a normal activation but reduced clonal deletion of T cells after activation. This may be due to different causes, since NF-AT factors are involved in the regulation of many genes, e.g. the apoptosis-associated CD95 ligand. Phenotypical similarities with interleukin 2- (IL-2) or IL-2 receptor- (IL-2R) deficient mice and, in contrast, the observation of elevated IL-2 levels in supernatants of cultivated NF-ATp-deficient T cells, suggested a role of NF-ATp in the regulation of the IL-2/IL-2R system. Since no difference in IL-2 expression between NF-ATp-/--mice and controls was observed, binding of NF-ATp to putative NF-AT concensus sequences of the CD25 (IL-2R alpha chain) promoter, transcriptional activation by NF-ATp, and expression of CD25 were investigated. It was demonstrated that (1) NF-ATp binds to two regions of the CD25 promoter, (2) that NF-ATp is a stimulator of the CD25 promoter, and (3) T cells of NF-ATp-deficient mice display a decreased expression of CD25 after stimulation, compared to wild-type controls. The expression of CD25 is moderately decreased in NF-ATp-deficient mice, proposing an explanation for the "weak phenotype" of NF-ATp-/--mice, compared to IL-2- or IL2R-deficient mice. The hyperprolifertive disorders of these different mouse lines are pointing towards a participation of NF-AT-/IL-2-/IL-2R signaling not only in activation of T cells, but also in pathways necessary for subsequent inactivation.
KW  - Maus
KW  - Induzierte Mutation
KW  - T-Lymphozyt
KW  - T-Zellen
KW  - NF-AT
KW  - knock-out
KW  - Mäuse
KW  - T cells
KW  - NF-AT
KW  - knock-out
KW  - mice
Y1  - 2001
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117
ER  -