@phdthesis{Greeske2008,
  author    = {Greeske, Juliane},
  title     = {Mechanismen der Makrophagen-Aktivierung in Connexin32-defizienten M{\"a}usen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-27491},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Connexin32- defiziente M{\"a}use stellen ein Mausmodell f{\"u}r eine Form der heredit{\"a}ren peripheren Neuropahtie dar. Es konnte gezeigt werden, dass Makrophagen, m{\"o}glicherweise aktiviert durch MCP-1, die Demyelinisierung in Connexin32-defizienten M{\"a}usen vermitteln. Diese Arbeit untersucht m{\"o}gliche Signaltransduktionswege, die in den peripheren Nerven Connexin32- defizienter M{\"a}use aktiviert sein k{\"o}nnten und damit in Zusammenhang mit der Genexpression von MCP-1 und/oder Makrophagen-Aktivierung stehen k{\"o}nnten.},
  subject      = {Makrophage},
  language  = {de}
}
@phdthesis{Fischer2008,
  author    = {Fischer, Stefan Martin},
  title     = {Regulation and functional consequences of MCP-1 expression in a model of Charcot-Marie-Tooth 1B disease},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29189},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Charcot-Marie-Tooth 1B (CMT1B) is a progressive inherited demyelinating disease of human peripheral nervous system leading to sensory and/or motor function disability and is caused by mutations in the P0 gene. Mice heterozygously deficient for P0 (P0+/-) are an adequate model of this human disorder showing myelin degeneration, formation of onion bulbs, remyelination and a reduced motor conduction velocity of around 30m/s similar to patients. Previously, it had been shown that T-lymphocytes and macrophages play a crucial role during pathogenesis in peripheral nerves of P0+/- mice. Both, T-lymphocytes and macrophages increase in number in the endoneurium and deletion of T-lymphocytes or deletion of a macrophage-directed cytokine ameliorates the disease. In this study the monocyte chemoattractant protein-1 (MCP-1) was identified as an early regulated cytokine before onset of disease is visible at the age of six months. MCP-1 mRNA and protein expression could be detected in femoral quadriceps and sciatic nerves of P0+/- mice already at the age of one month but not in cutaneous saphenous nerves which are never affected by the disease. MCP-1 was shown to be expressed by Schwann cells and to mediate the immigration of immune cells into peripheral nerves. Deletion of MCP-1 in P0+/- mice accomplished by crossbreeding P0 and MCP-1 deficient mice revealed a substantial reduction of immune cells in peripheral nerves of P0+/-/MCP-1+/- and P0+/-/MCP-1-/- mice at the age of six months. In twelve months old mice reduction of immune cells in peripheral nerves is accompanied by amelioration of demyelinating disease in P0+/-/MCP-1+/- and aggravation of demyelinating disease in lumbar ventral roots of P0+/ /MCP-1-/- mice in comparison to P0+/ /MCP 1+/+ mice. Furthermore, activation of the MEK1/2-ERK1/2 signalling cascade could be demonstrated to take place in Schwann cells of affected peripheral nerves of P0+/- mice overlapping temporarily and spatially with MCP-1 expression. An animal experiment using a MEK1/2-inhibitor in vivo, CI-1040, revealed that upon reduction of ERK1/2 phosphorylation MCP-1 mRNA expression is diminished suggesting that the activation of the MEK1/2-ERK1/2 signalling cascade is necessary for MCP-1 expression. Additionally, peripheral nerves of P0+/- mice showing reduced ERK1/2 phosphorylation and MCP-1 mRNA expression also show reduced numbers of macrophages in the endoneurium. This study shows a molecular link between a Schwann cell based mutation and immune cell function. Inhibition of the identified signalling cascade might be a putative target for therapeutic approaches.},
  subject      = {Schwann-Zelle},
  language  = {en}
}
@phdthesis{Kohl2009,
  author    = {Kohl, Bianca Dorothea},
  title     = {PMP22-overexpressing mice as a model for Charcot-Marie-Tooth 1A neuropathy implicate a role of immune-related cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43066},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2009},
  abstract  = {Charcot-Marie-Tooth disease (CMT) is a cohort of human hereditary disorders of the peripheral nervous system (PNS) which exhibit symptoms like sensory dysfunction, muscle weakness and gait disturbances. Different mutations are described as causation for this neuropathy, such as a duplication of chromosome 17 comprising the gene for the peripheral myelin protein-22 (PMP22). Based on different animal models former studies identified immune cells, i.e. macrophages and T-lymphocytes, as crucial mediators of pathology in these neuropathies. In this study, PMP22-overexpressing mice (PMP22tg, C61), serving as a model for a specific type of CMT - CMT1A - were crossbred with immune-deficient mutant mice to examine the impact of the immune system on nerve pathology. Crossbreeding of PMP22tg mice with recombination activating gene-1 (RAG-1) deficient mice, lacking mature T- and B-lymphocytes, caused no striking alterations of pathogenesis in peripheral nerves of mutant mice. In contrast, crossbreeding of PMP22tg myelin mutants with mice deficient in the chemokine monocyte chemoattractant protein-1 (MCP-1, CCL2) caused an amelioration of the demyelinating phenotype of peripheral nerves when MCP-1 was either reduced or completely absent. Furthermore, functional investigations, i.e. neurographic recordings and examinations of the grip strength of the extremities, revealed an amelioration in PMP22tg/MCP-1-/- mice in regard to a symptomatic improvement in the compound action muscle potential (CMAP) and stronger grip strength of the hindlimbs. Interestingly, peripheral nerves of PMP22tg mice showed an irregular distribution of potassium channels in presence of MCP-1, whereas the absence of MCP-1 in the myelin mutants rescued the ion channel distribution and resulted in a more wild type-like phenotype. Having shown the impact of MCP-1 as an important mediator of nerve pathology in PMP22/MCP-1 double mutants, the regulation of this chemokine became an important target for potential treatment strategies. We found that the signaling cascade MEK1/2/ERK1/2 was more strongly activated in peripheral nerves of PMP22tg mice compared to nerves of wild type mice. This activation corresponded to an increase in MCP-1 mRNA expression in peripheral nerves at the same age. Furthermore, a MEK1/2-inhibitor was used in vivo to confirm the regulation of MCP-1 by the MEK1/2/ERK1/2 pathway. After a treatment period of three weeks, a clear reduction of ERK1/2-phosphorylation as well as a reduction of MCP-1 mRNA expression was observed, accompanied by a decline in macrophage number in peripheral nerves of PMP22tg mice. These observations suggest that the expression of MCP-1 is crucial for the neuropathological progression in a mouse model for CMT1A. Therefore, this chemokine could provide a basis for a putative treatment strategy of inherited neuropathies.},
  subject      = {Myelin},
  language  = {en}
}
@phdthesis{Patzko2012,
  author    = {Patzk{\´o}, {\´A}gnes},
  title     = {CSF-1 receptor as a target for the treatment of Charcot-Marie-Tooth disease 1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85325},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {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.},
  subject      = {Makrophage},
  language  = {en}
}
@phdthesis{Schreiber2019,
  author    = {Schreiber, David Lukas},
  title     = {CSF-1-Rezeptor Inhibitor als Therapieansatz in Mausmodellen f{\"u}r Charcot-Marie-Tooth Neuropathien Typ 1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174931},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Charcot-Marie-Tooth Neuropathien sind die h{\"a}ufigsten heredit{\"a}ren Erkrankungen des peripheren Nervensystems und dennoch bis heute nicht therapierbar. Die Lebensqualit{\"a}t der Patienten ist durch motorische und sensorische Defizite der Extremit{\"a}ten h{\"a}ufig stark eingeschr{\"a}nkt. Ursache k{\"o}nnen unter anderem Mutationen in Schwann-Zellen sein, die zu dem typischen Bild von Demyelinisierung und axonalem Schaden f{\"u}hren. In den letzten Jahren konnte in Mausmodellen das Immunsystem als wichtiger Mediator in der Pathogenese der CMT 1 Subtypen A, B und X identifiziert werden. Insbesondere Makrophagen spielen eine tragende Rolle bei dem Verlust der axonalen Integrit{\"a}t, bei der Sch{\"a}digung der Myelinscheiden, sowie bei der Dedifferenzierung von Schwann-Zellen. Entscheidender Faktor f{\"u}r Proliferation und Aktivierung der Makrophagen ist hierbei das Zytokin CSF-1, dessen korrespondierender Rezeptor auf Makrophagen exprimiert wird. Der CSF-1/CSF1R Signalweg bietet somit einen vielversprechenden Angriffspunkt. In der vorliegenden Arbeit wurden Mausmodelle der CMT 1 Subtypen A, B und X mit einem niedermolekularen CSF-1-Rezeptor Inhibitor behandelt. Anschließend erfolgte eine funktionelle und strukturelle Auswertung der peripheren Nerven. Das beste Ansprechen auf die Therapie zeigten Cx32def Mutanten. Strukturell fielen ein verringerter axonaler Schaden und eine verbesserte axonale Regenerationsf{\"a}higkeit sowie erhaltene neuromuskul{\"a}re Synapsen auf. Funktionell {\"a}ußerte sich dies in verbesserten elektrophysiologischen Parametern und einem Krafterhalt, welcher als klinischer Parameter die gr{\"o}ßte Relevanz f{\"u}r betroffene Patienten hat und somit besonders hervorzuheben ist. Auch P0het Mutanten zeigten Verbesserungen nach der CSF1RI Behandlung. Anders als bei Cx32def Tieren zeigte sich hier jedoch vor allem ein Erhalt der Myelinintegrit{\"a}t. Weiterhin wirkte sich die Therapie positiv auf elektrophysiologische Parameter und Krafttests aus. Vor allem besonders stark betroffene Individuen schienen hierbei von der CSF1RI Behandlung zu profitieren. Bei PMP22tg Mutanten hingegen konnten keine positiven Effekte der CSF1RI Behandlung nachgewiesen werden. Strukturelle und funktionelle Parameter behandelter Tiere unterschieden sich nicht von unbehandelten. Diese Ergebnisse unterstreichen die Relevanz der sekund{\"a}ren Entz{\"u}ndungsreaktion in CMT 1 Neuropathien als wichtigen Mediator in der Pathogenese. Weiterhin konnte gezeigt werden, dass eine Intervention im CSF-1/CSF1R Signalweg einen vielversprechenden m{\"o}glichen Ansatz f{\"u}r die Therapie der bisher nicht behandelbaren CMT 1 Subypen X und B darstellt. Unausweichlich ist hierbei ein m{\"o}glichst fr{\"u}her Therapiestart vor Auspr{\"a}gung der ersten molekularen und histologischen Ver{\"a}nderungen. Im Hinblick auf die nicht die Lebenserwartung reduzierende Erkrankung muss ferner eine Minimierung der Nebenwirkungen der Therapie gew{\"a}hrleistet sein. Besonders hervorzuheben ist hier die Verwendung eines Inhibitors, welcher nicht in das zentrale Nervensystem vordringen kann und somit die Funktion der Mikroglia nicht beeintr{\"a}chtigt.},
  subject      = {CSF-1},
  language  = {de}
}