@article{GresleAlexandrouWuetal.2012, author = {Gresle, Melissa M. and Alexandrou, Estella and Wu, Qizhu and Egan, Gary and Jokubaitis, Vilija and Ayers, Margaret and Jonas, Anna and Doherty, William and Friedhuber, Anna and Shaw, Gerry and Sendtner, Michael and Emery, Ben and Kilpatrick, Trevor and Butzkueven, Helmut}, title = {Leukemia Inhibitory Factor Protects Axons in Experimental Autoimmune Encephalomyelitis via an Oligodendrocyte-Independent Mechanism}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047379}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134617}, pages = {e47379}, year = {2012}, abstract = {Leukemia inhibitory factor (LIF) and Ciliary Neurotrophic factor (CNTF) are members of the interleukin-6 family of cytokines, defined by use of the gp130 molecule as an obligate receptor. In the murine experimental autoimmune encephalomyelitis (EAE) model, antagonism of LIF and genetic deletion of CNTF worsen disease. The potential mechanism of action of these cytokines in EAE is complex, as gp130 is expressed by all neural cells, and could involve immuno-modulation, reduction of oligodendrocyte injury, neuronal protection, or a combination of these actions. In this study we aim to investigate whether the beneficial effects of CNTF/LIF signalling in EAE are associated with axonal protection; and whether this requires signalling through oligodendrocytes. We induced MOG\(_{35-55}\) EAE in CNTF, LIF and double knockout mice. On a CNTF null background, LIF knockout was associated with increased EAE severity (EAE grade 2.1\(\pm\)0.14 vs 2.6\(\pm\)0.19; P<0.05). These mice also showed increased axonal damage relative to LIF heterozygous mice, as indicated by decreased optic nerve parallel diffusivity on MRI (1540\(\pm\)207 \(\mu\)m\(^2\)-/s vs 1310\(\pm\)175 \(\mu\)m\(^2\)-/s; P<0.05), and optic nerve (-12.5\%) and spinal cord (-16\%) axon densities; and increased serum neurofilament-H levels (2.5 fold increase). No differences in inflammatory cell numbers or peripheral auto-immune T-cell priming were evident. Oligodendrocyte-targeted gp130 knockout mice showed that disruption of CNTF/LIF signalling in these cells has no effect on acute EAE severity. These studies demonstrate that endogenous CNTF and LIF act centrally to protect axons from acute inflammatory destruction via an oligodendrocyte-independent mechanism.}, language = {en} } @article{PfeifferGoetzXiangetal.2013, author = {Pfeiffer, Verena and G{\"o}tz, Rudolf and Xiang, Chaomei and Camarero, Guadelupe and Braun, Attila and Zhang, Yina and Blum, Robert and Heinsen, Helmut and Nieswandt, Bernhard and Rapp, Ulf R.}, title = {Ablation of BRaf Impairs Neuronal Differentiation in the Postnatal Hippocampus and Cerebellum}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0058259}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130304}, pages = {e58259}, year = {2013}, abstract = {This study focuses on the role of the kinase BRaf in postnatal brain development. Mice expressing truncated, non-functional BRaf in neural stem cell-derived brain tissue demonstrate alterations in the cerebellum, with decreased sizes and fuzzy borders of the glomeruli in the granule cell layer. In addition we observed reduced numbers and misplaced ectopic Purkinje cells that showed an altered structure of their dendritic arborizations in the hippocampus, while the overall cornus ammonis architecture appeared to be unchanged. In male mice lacking BRaf in the hippocampus the size of the granule cell layer was normal at postnatal day 12 (P12) but diminished at P21, as compared to control littermates. This defect was caused by a reduced ability of dentate gyrus progenitor cells to differentiate into NeuN positive granule cell neurons. In vitro cell culture of P0/P1 hippocampal cells revealed that BRaf deficient cells were impaired in their ability to form microtubule-associated protein 2 positive neurons. Together with the alterations in behaviour, such as autoaggression and loss of balance fitness, these observations indicate that in the absence of BRaf all neuronal cellular structures develop, but neuronal circuits in the cerebellum and hippocampus are partially disturbed besides impaired neuronal generation in both structures.}, language = {en} } @article{ReddyAlbanitoDeMarcoetal.2013, author = {Reddy, C. E. and Albanito, L. and De Marco, P. and Aiello, D. and Maggiolini, M. and Napoli, A. and Musti, A. M.}, title = {Multisite phosphorylation of c-Jun at threonine 91/93/95 triggers the onset of c-Jun pro-apoptotic activity in cerebellar granule neurons}, series = {Cell Death \& Disease}, volume = {4}, journal = {Cell Death \& Disease}, number = {e852}, doi = {10.1038/cddis.2013.381}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128793}, year = {2013}, abstract = {Cerebellar granule cell (CGC) apoptosis by trophic/potassium (TK) deprivation is a model of election to study the interplay of pro-apoptotic and pro-survival signaling pathways in neuronal cell death. In this model, the c-Jun N-terminal kinase (JNK) induces pro-apoptotic genes through the c-Jun/activator protein 1 (AP-1) transcription factor. On the other side, a survival pathway initiated by lithium leads to repression of pro-apoptotic c-Jun/AP-1 target genes without interfering with JNK activity. Yet, the mechanism by which lithium inhibits c-Jun activity remains to be elucidated. Here, we used this model system to study the regulation and function of site-specific c-Jun phosphorylation at the S63 and T91/T93 JNK sites in neuronal cell death. We found that TK-deprivation led to c-Jun multiphosphorylation at all three JNK sites. However, immunofluorescence analysis of c-Jun phosphorylation at single cell level revealed that the S63 site was phosphorylated in all c-Jun-expressing cells, whereas the response of T91/T93 phosphorylation was more sensitive, mirroring the switch-like apoptotic response of CGCs. Conversely, lithium prevented T91T93 phosphorylation and cell death without affecting the S63 site, suggesting that T91T93 phosphorylation triggers c-Jun pro-apoptotic activity. Accordingly, a c-Jun mutant lacking the T95 priming site for T91/93 phosphorylation protected CGCs from apoptosis, whereas it was able to induce neurite outgrowth in PC12 cells. Vice versa, a c-Jun mutant bearing aspartate substitution of T95 overwhelmed lithium-mediate protection of CGCs from TK-deprivation, validating that inhibition of T91/T93/T95 phosphorylation underlies the effect of lithium on cell death. Mass spectrometry analysis confirmed multiphosphorylation of c-Jun at T91/T93/T95 in cells. Moreover, JNK phosphorylated recombinant c-Jun at T91/T93 in a T95-dependent manner. On the basis of our results, we propose that T91/T93/T95 multiphosphorylation of c-Jun functions as a sensitivity amplifier of the JNK cascade, setting the threshold for c-Jun pro-apoptotic activity in neuronal cells.}, language = {en} } @article{GoetzSendtner2014, author = {G{\"o}tz, Rudolf and Sendtner, Michael}, title = {Cooperation of Tyrosine Kinase Receptor TrkB and Epidermal Growth Factor Receptor Signaling Enhances Migration and Dispersal of Lung Tumor Cells}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {6}, issn = {1932-6203}, doi = {10.1371/journal.pone.0100944}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119578}, pages = {e100944}, year = {2014}, abstract = {TrkB mediates the effects of brain-derived neurotrophic factor (BDNF) in neuronal and nonnneuronal cells. Based on recent reports that TrkB can also be transactivated through epidermal growth-factor receptor (EGFR) signaling and thus regulates migration of early neurons, we investigated the role of TrkB in migration of lung tumor cells. Early metastasis remains a major challenge in the clinical management of non-small cell lung cancer (NSCLC). TrkB receptor signaling is associated with metastasis and poor patient prognosis in NSCLC. Expression of this receptor in A549 cells and in another adenocarcinoma cell line, NCI-H441, promoted enhanced migratory capacity in wound healing assays in the presence of the TrkB ligand BDNF. Furthermore, TrkB expression in A549 cells potentiated the stimulatory effect of EGF in wound healing and in Boyden chamber migration experiments. Consistent with a potential loss of cell polarity upon TrkB expression, cell dispersal and de-clustering was induced in A549 cells independently of exogeneous BDNF. Morphological transformation involved extensive cytoskeletal changes, reduced E-cadherin expression and suppression of E-cadherin expression on the cell surface in TrkB expressing tumor cells. This function depended on MEK and Akt kinase activity but was independent of Src. These data indicate that TrkB expression in lung adenoma cells is an early step in tumor cell dissemination, and thus could represent a target for therapy development.}, language = {en} } @article{BuchnerBlancoRedondoBunzetal.2013, author = {Buchner, Erich and Blanco Redondo, Beatriz and Bunz, Melanie and Halder, Partho and Sadanandappa, Madhumala K. and M{\"u}hlbauer, Barbara and Erwin, Felix and Hofbauer, Alois and Rodrigues, Veronica and VijayRaghavan, K. and Ramaswami, Mani and Rieger, Dirk and Wegener, Christian and F{\"o}rster, Charlotte}, title = {Identification and Structural Characterization of Interneurons of the Drosophila Brain by Monoclonal Antibodies of the W{\"u}rzburg Hybridoma Library}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97109}, year = {2013}, abstract = {Several novel synaptic proteins have been identified by monoclonal antibodies (mAbs) of the W{\"u}rzburg hybridoma library generated against homogenized Drosophila brains, e.g. cysteine string protein, synapse-associated protein of 47 kDa, and Bruchpilot. However, at present no routine technique exists to identify the antigens of mAbs of our library that label only a small number of cells in the brain. Yet these antibodies can be used to reproducibly label and thereby identify these cells by immunohistochemical staining. Here we describe the staining patterns in the Drosophila brain for ten mAbs of the W{\"u}rzburg hybridoma library. Besides revealing the neuroanatomical structure and distribution of ten different sets of cells we compare the staining patterns with those of antibodies against known antigens and GFP expression patterns driven by selected Gal4 lines employing regulatory sequences of neuronal genes. We present examples where our antibodies apparently stain the same cells in different Gal4 lines suggesting that the corresponding regulatory sequences can be exploited by the split-Gal4 technique for transgene expression exclusively in these cells. The detection of Gal4 expression in cells labeled by mAbs may also help in the identification of the antigens recognized by the antibodies which then in addition to their value for neuroanatomy will represent important tools for the characterization of the antigens. Implications and future strategies for the identification of the antigens are discussed.}, language = {en} }