TY  - JOUR
A1  - Archelos, JJ
A1  - Roggenbuck, K.
A1  - Schneider-Schaulies, Jürgen
A1  - Linington, C.
A1  - Toyka, KV
A1  - Hartung, H.-P.
T1  - Production and characterization of monoclonal antibodies to the extracellular domain of PO
N2  - Seven monoclonal antibodies were raised against the immunoglobulin-like extracellular domain of PO (POED), the major protein of peripheral nervous system myelin. Mice were immunized with purified recombinant rat PO-ED. After fusion, 7 clones (POI-P07) recognizing either recombinant, rat, mouse, or human PO-ED were selected by ELlS A and were characterized by Western blot, immunohistochemistry, and a competition assay. Antibodies belonged to the IgG or IgM class, and P04-P07, reacted with PO in fresh-frozen and paraffin-embedded sections of human or rat peripheral nerve, but not with myelin proteins of the central nervous system of either species. Epitope specificity of the antibodies was determined by a competition enzyme-linked immunosorbent assay (ELISA) and a direct ELlS A using short synthetic peptides spanning the entire extracellular domain of PO. These assays showed that POl and P02 exhibiting the same reaction pattern in Western blot and immunohistochemistry reacted with different distant epitopes of PO. Furthermore, the monoclonal antibodies P05 and P06 recognized 2 different epitopes in close proximity within the neuritogenic extracellular sequence of PO. This panel of monoclonal antibodies, each binding to a different epitope of the extracellular domain of PO, will be useful for in vitro and in vivo studies designed to explore the role of PO during myelination and in demyelinating diseases of the peripheral nervous system.
KW  - Immunologie
KW  - peripheral nervous system
KW  - myelin
KW  - epitope specificity
KW  - demyelination
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54889
ER  - 
TY  - JOUR
A1  - Beyer, Felix
A1  - Jadasz, Janusz
A1  - Samper Agrelo, Iria
A1  - Schira‐Heinen, Jessica
A1  - Groh, Janos
A1  - Manousi, Anastasia
A1  - Bütermann, Christine
A1  - Estrada, Veronica
A1  - Reiche, Laura
A1  - Cantone, Martina
A1  - Vera, Julio
A1  - Viganò, Francesca
A1  - Dimou, Leda
A1  - Müller, Hans Werner
A1  - Hartung, Hans‐Peter
A1  - Küry, Patrick
T1  - Heterogeneous fate choice of genetically modulated adult neural stem cells in gray and white matter of the central nervous system
JF  - Glia
N2  - Apart from dedicated oligodendroglial progenitor cells, adult neural stem cells (aNSCs) can also give rise to new oligodendrocytes in the adult central nervous system (CNS). This process mainly confers myelinating glial cell replacement in pathological situations and can hence contribute to glial heterogeneity. Our previous studies demonstrated that the p57kip2 gene encodes an intrinsic regulator of glial fate acquisition and we here investigated to what degree its modulation can affect stem cell‐dependent oligodendrogenesis in different CNS environments. We therefore transplanted p57kip2 knockdown aNSCs into white and gray matter (WM and GM) regions of the mouse brain, into uninjured spinal cords as well as in the vicinity of spinal cord injuries and evaluated integration and differentiation in vivo. Our experiments revealed that under healthy conditions intrinsic suppression of p57kip2 as well as WM localization promote differentiation toward myelinating oligodendrocytes at the expense of astrocyte generation. Moreover, p57kip2 knockdown conferred a strong benefit on cell survival augmenting net oligodendrocyte generation. In the vicinity of hemisectioned spinal cords, the gene knockdown led to a similar induction of oligodendroglial features; however, newly generated oligodendrocytes appeared to suffer more from the hostile environment. This study contributes to our understanding of mechanisms of adult oligodendrogenesis and glial heterogeneity and further reveals critical factors when considering aNSC mediated cell replacement in injury and disease.
KW  - glial fate modulation
KW  - myelin
KW  - neural stem cell
KW  - p57kip2
KW  - regional heterogeneity
KW  - spinal cord injury
KW  - transplantation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218566
VL  - 68
IS  - 2
SP  - 393
EP  - 406
ER  - 
TY  - JOUR
A1  - Ip, Chi Wang
A1  - Kroner, Antje
A1  - Groh, Janos
A1  - Huber, Marianne
A1  - Klein, Dennis
A1  - Spahn, Irene
A1  - Diem, Ricarda
A1  - Williams, Sarah K.
A1  - Nave, Klaus-Armin
A1  - Edgar, Julia M.
A1  - Martini, Rudolf
T1  - Neuroinflammation by Cytotoxic T-Lymphocytes Impairs Retrograde Axonal Transport in an Oligodendrocyte Mutant Mouse
JF  - PLoS One
N2  - Mice overexpressing proteolipid protein (PLP) develop a leukodystrophy-like disease involving cytotoxic, CD8+ T-lymphocytes. Here we show that these cytotoxic T-lymphocytes perturb retrograde axonal transport. Using fluorogold stereotactically injected into the colliculus superior, we found that PLP overexpression in oligodendrocytes led to significantly reduced retrograde axonal transport in retina ganglion cell axons. We also observed an accumulation of mitochondria in the juxtaparanodal axonal swellings, indicative for a disturbed axonal transport. PLP overexpression in the absence of T-lymphocytes rescued retrograde axonal transport defects and abolished axonal swellings. Bone marrow transfer from wildtype mice, but not from perforin- or granzyme B-deficient mutants, into lymphocyte-deficient PLP mutant mice led again to impaired axonal transport and the formation of axonal swellings, which are predominantly located at the juxtaparanodal region. This demonstrates that the adaptive immune system, including cytotoxic T-lymphocytes which release perforin and granzyme B, are necessary to perturb axonal integrity in the PLP-transgenic disease model. Based on our observations, so far not attended molecular and cellular players belonging to the immune system should be considered to understand pathogenesis in inherited myelin disorders with progressive axonal damage.
KW  - myelin
KW  - experimental autoimmune encephalomyelitis
KW  - degeneration
KW  - axonopathic changes
KW  - neural apoptosis
KW  - nervous system
KW  - motor function
KW  - proteolipid protein gene
KW  - retinal ganglion cells
KW  - granzyme B
KW  - multiple sclerosis
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134982
VL  - 7
IS  - 8
ER  - 
TY  - JOUR
A1  - Lüningschrör, Patrick
A1  - Slotta, Carsten
A1  - Heimann, Peter
A1  - Briese, Michael
A1  - Weikert, Ulrich M.
A1  - Massih, Bita
A1  - Appenzeller, Silke
A1  - Sendtner, Michael
A1  - Kaltschmidt, Christian
A1  - Kaltschmidt, Barbara
T1  - Absence of Plekhg5 Results in Myelin Infoldings Corresponding to an Impaired Schwann Cell Autophagy, and a Reduced T-Cell Infiltration Into Peripheral Nerves
JF  - Frontiers in Cellular Neuroscience
N2  - Inflammation and dysregulation of the immune system are hallmarks of several neurodegenerative diseases. An activated immune response is considered to be the cause of myelin breakdown in demyelinating disorders. In the peripheral nervous system (PNS), myelin can be degraded in an autophagy-dependent manner directly by Schwann cells or by macrophages, which are modulated by T-lymphocytes. Here, we show that the NF-κB activator Pleckstrin homology containing family member 5 (Plekhg5) is involved in the regulation of both Schwann cell autophagy and recruitment of T-lymphocytes in peripheral nerves during motoneuron disease. Plekhg5-deficient mice show defective axon/Schwann cell units characterized by myelin infoldings in peripheral nerves. Even at late stages, Plekhg5-deficient mice do not show any signs of demyelination and inflammation. Using RNAseq, we identified a transcriptional signature for an impaired immune response in sciatic nerves, which manifested in a reduced number of CD4\(^+\) and CD8\(^+\) T-cells. These findings identify Plekhg5 as a promising target to impede myelin breakdown in demyelinating PNS disorders.
KW  - Schwann cells
KW  - autophagy
KW  - immune response
KW  - myelin
KW  - PLEKHG5
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207538
SN  - 1662-5102
VL  - 14
ER  - 
TY  - THES
A1  - Patzkó, Ágnes
T1  - CSF-1 receptor as a target for the treatment of Charcot-Marie-Tooth disease 1
T1  - CSF-1 Rezeptor als Target für die Behandlung der Charcot-Marie-Tooth Krankheit Typ 1
N2  - Previous studies by our group revealed that chronic low grade inflammation implicating phagocytosing macrophages is a highly relevant mechanism in the pathogenesis of Charcot-Marie-Tooth disease. The lack of CSF-1, the primary regulator of macrophage function and survival, led to a robust and persistent amelioration of the phenotype in two authentic mouse models of CMT. Moreover, a close contact between CSF-1 producing fibroblasts and endoneurial macrophages carrying CSF-1R has been confirmed in nerve biopsies of CMT patients, further supporting the clinical significance of this pathway. In the current study we treated 3 distinct mouse models of CMT1:  the PMP22tg mice as a model for CMT1A, the P0+/- mice as a model for CMT1B and the Cx32def mice as a model for CMT1X, with a CSF-1R specific kinase (c-FMS) inhibitor (800-1200 mg PLX5622/ kg chow) according to different treatment regimes mimicking an ideal early onset treatment, a late onset treatment and the withdrawal of the drug. Using the above mentioned doses of PLX5622, we documented a dramatic decrease in macrophage numbers in the PNS of all 3 myelin mutants, except for the quadriceps nerve of Cx32def mice. Fibroblast numbers remained unchanged in treated animals. Surprisingly, in spite of the decrease in the number of detrimental macrophages we could not detect an unequivocal phenotypic improvement. CMAP amplitudes were reduced in both wild type and myelin mutant mice treated with CSF-1R inhibitor in comparison to untreated littermates. Corresponding to the electrophysiological findings, the axon number and the percentage of large diameter axons were reduced in the quadriceps nerve of treated P0+/- and Cx32def mice. By contrast we observed a higher number of fully myelinated axons, in parallel with a decrease in the percentage of demyelinated (and hypermyelinated in PMP22tg mice) fibers in the ventral roots of P0+/- mice treated with CSF-1R inhibitor from 3 months up to 6 months of age and PMP22tg animals treated from 9 months up to 15 months of age. Our results indicate that CSF-1R inhibitor has the potential to improve the demyelinating phenotype of at least two models of CMT1. Nevertheless, further studies are necessary (for example with lower doses of the inhibitor) to minimize or even eliminate the putative neurotoxic effect we observed with high dose treatment conditions.
N2  - Vorhergehende Studien unserer Gruppe haben gezeigt, dass eine niedriggradige Entzündung, die von phagozytierenden Makrophagen ausgeht, von ausserordentlicher Bedeutung für die Pathogenese der Charcot-Marie-Tooth Krankheit ist. In Abwesenheit von CSF-1, des primären Regulators für Funktion und Überleben von Makrophagen, trat eine stabile und dauerhafte Verbesserung des Phänotyps in den zwei etablierten CMT Mausmodellen auf. Darüber hinaus konnte ein enger Kontakt zwischen CSF-1-produzierenden Fibroblasten und Makrophagen, die den zugehörigen Rezeptor CSF-1Rexprimieren, in Nervbiopsien von CMT Patienten bestätigt werden, was die klinische Relevanz dieses Mechanismus weiter verdeutlicht. In der aktuellen Studie wurden drei verschiedene CMT1 Mausmodelle, PMP22tg Mäuse als Modell für CMT1A, P0+/- Mäuse als Modell für CMT1B und Cx32-defiziente Mäuse als Modell für CMT1X, mit einem Inhibitor der CSF-1R spezifischen Kinase (c-FMS) (800-1200 mg PLX5622/kg Futter) behandelt. Der Inhibitor wurde gemäß den verschiedenen Behandlungsmethoden eingesetzt, um den Verlauf eineridealerweise frühzeitigen und einer spät-beginnenden Behandlung und des Entzug des Medikaments zu imitieren. Nach der Behandlung mit  PLX5622 konnten wir im PNS aller drei Myelin-Mutanten, mit Ausnahme des N. quadriceps von Cx32-defizienten Mäusen, einen drastischen Rückgang der Makrophagenanzahl feststellen. Die Anzahl der Fibroblasten blieb in den behandelten Tieren unverändert. Überraschenderweise konnten wir, trotz des Rückgangs der Anzahl an schädlichen Makrophagen, keine einheitliche Verbesserung des Phänotyps dokumentieren. CMAP Amplituden waren nach CSF-1R Inhibitor Behandlung sowohl in Wild-Typ Mäusenals auch in den Myelin-Mutanten geringer als in unbehandelten Kontrolltieren. Passend zu den elektrophysiologischen Ergebnissen war die Anzahl an Axonen und die Prozentzahl an großkalibrigen Axonen im N. quadriceps von behandelten P0+/-  und Cx32-defizienten Mäusen reduziert.Im Gegensatz dazu war eine erhöhte Menge an normalmyelinisierten Axonen, mit einer gleichzeitigen Reduktiondemyelinisierter Fasern (und hypermyelinisierten in PMP22tg Mäusen) in den ventralen Spinalwurzeln von P0+/- Mäusen zu beobachten, die mit dem CSF-1R Inhibitor im Alter von 3 bis 6 Monaten behandelt worden waren sowie bei PMP22tg Mäusen, die im Alter von 9 bis 15 Monaten den Inhibitor erhalten hatten. Unsere Ergebnisse deuten an, dass der CSF-1R Inhibitor das Potential besitzt, zumindest in zwei Modellen von CMT1 den demyelinisierenden Phänotyp zu verbessern. Dennoch müssen weitere Studien durchgeführt werden (z.B. die Verwendung einer niedrigeren Dosis des Inhibitors), um den möglichen neurotoxischen Effekt, der bei oben genannten Behandlungsbedingungen zu beobachten war, zu minimieren oder ganz zu beheben.
KW  - Makrophage
KW  - Charcot-Marie-Tooth
KW  - Charcot-Marie-Tooth disease
KW  - Myelin
KW  - CSF-1 Rezeptor
KW  - Neuropathie
KW  - macrophage
KW  - CSF-1 receptor
KW  - neuropathy
KW  - myelin
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85325
ER  - 
TY  - JOUR
A1  - Rajendran, Ranjithkumar
A1  - Böttiger, Gregor
A1  - Dentzien, Niklas
A1  - Rajendran, Vinothkumar
A1  - Sharifi, Bischand
A1  - Ergün, Süleyman
A1  - Stadelmann, Christine
A1  - Karnati, Srikanth
A1  - Berghoff, Martin
T1  - Effects of FGFR tyrosine kinase inhibition in OLN-93 oligodendrocytes
JF  - Cells
N2  - Fibroblast growth factor (FGF) signaling is involved in the pathogenesis of multiple sclerosis (MS). Data from neuropathology studies suggest that FGF signaling contributes to the failure of remyelination in MS. In MOG\(_{35–55}\)-induced EAE, oligodendrocyte-specific deletion of FGFR1 and FGFR2 resulted in a less severe disease course, reduced inflammation, myelin and axon degeneration and changed FGF/FGFR and BDNF/TrkB signaling. Since signaling cascades in oligodendrocytes could not be investigated in the EAE studies, we here aimed to characterize FGFR-dependent oligodendrocyte-specific signaling in vitro. FGFR inhibition was achieved by application of the multi-kinase-inhibitor dovitinib and the FGFR1/2/3-inhibitor AZD4547. Both substances are potent inhibitors of FGF signaling; they are effective in experimental tumor models and patients with malignancies. Effects of FGFR inhibition in oligodendrocytes were studied by immunofluorescence microscopy, protein and gene analyses. Application of the tyrosine kinase inhibitors reduced FGFR1, phosphorylated ERK and Akt expression, and it enhanced BDNF and TrkB expression. Furthermore, the myelin proteins CNPase and PLP were upregulated by FGFR inhibition. In summary, inhibition of FGFR signaling in oligodendrocytes can be achieved by application of tyrosine kinase inhibitors. Decreased phosphorylation of ERK and Akt is associated with an upregulation of BDNF/TrkB signaling, which may be responsible for the increased production of myelin proteins. Furthermore, these data suggest that application of FGFR inhibitors may have the potential to promote remyelination in the CNS.
KW  - multiple sclerosis
KW  - oligodendrocytes
KW  - dovitinib
KW  - AZD4547
KW  - FGFR signaling
KW  - myelin
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239600
SN  - 2073-4409
VL  - 10
IS  - 6
ER  - 
TY  - JOUR
A1  - Samper Agrelo, Iria
A1  - Schira-Heinen, Jessica
A1  - Beyer, Felix
A1  - Groh, Janos
A1  - Bütermann, Christine
A1  - Estrada, Veronica
A1  - Poschmann, Gereon
A1  - Bribian, Ana
A1  - Jadasz, Janusz J.
A1  - Lopez-Mascaraque, Laura
A1  - Kremer, David
A1  - Martini, Rudolf
A1  - Müller, Hans Werner
A1  - Hartung, Hans Peter
A1  - Adjaye, James
A1  - Stühler, Kai
A1  - Küry, Patrick
T1  - Secretome analysis of mesenchymal stem cell factors fostering oligodendroglial differentiation of neural stem cells in vivo
JF  - International Journal of Molecular Sciences
N2  - Mesenchymal stem cell (MSC)-secreted factors have been shown to significantly promote oligodendrogenesis from cultured primary adult neural stem cells (aNSCs) and oligodendroglial precursor cells (OPCs). Revealing underlying mechanisms of how aNSCs can be fostered to differentiate into a specific cell lineage could provide important insights for the establishment of novel neuroregenerative treatment approaches aiming at myelin repair. However, the nature of MSC-derived differentiation and maturation factors acting on the oligodendroglial lineage has not been identified thus far. In addition to missing information on active ingredients, the degree to which MSC-dependent lineage instruction is functional in vivo also remains to be established. We here demonstrate that MSC-derived factors can indeed stimulate oligodendrogenesis and myelin sheath generation of aNSCs transplanted into different rodent central nervous system (CNS) regions, and furthermore, we provide insights into the underlying mechanism on the basis of a comparative mass spectrometry secretome analysis. We identified a number of secreted proteins known to act on oligodendroglia lineage differentiation. Among them, the tissue inhibitor of metalloproteinase type 1 (TIMP-1) was revealed to be an active component of the MSC-conditioned medium, thus validating our chosen secretome approach.
KW  - neural stem cells
KW  - mesenchymal stem cells
KW  - transplantation
KW  - oligodendroglia
KW  - glial fate modulation
KW  - myelin
KW  - spinal cord
KW  - secretome
KW  - TIMP-1
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285465
SN  - 1422-0067
VL  - 21
IS  - 12
ER  -