TY - JOUR A1 - Groh, Janos A1 - Hörner, Michaela A1 - Martini, Rudolf T1 - Teriflunomide attenuates neuroinflammation-related neural damage in mice carrying human PLP1 mutations JF - Journal of Neuroinflammation N2 - Background: Genetically caused neurological disorders of the central nervous system (CNS) are mostly characterized by poor or even fatal clinical outcome and few or no causative treatments are available. Often, these disorders are associated with low-grade, disease-promoting inflammation, another feature shared by progressive forms of multiple sclerosis (PMS). We previously generated two mouse lines carrying distinct mutations in the oligodendrocytic PLP1 gene that have initially been identified in patients diagnosed with MS. These mutations cause a loss of PLP function leading to a histopathological and clinical phenotype common to both PMS and genetic CNS disorders, like hereditary spastic paraplegias. Importantly, neuroinflammation promotes disease progression in these models, suggesting that pharmacological modulation of inflammation might ameliorate disease outcome. Methods: We applied teriflunomide, an approved medication for relapsing-remitting MS targeting activated T-lymphocytes, in the drinking water (10 mg/kg body weight/day). Experimental long-term treatment of PLP mutant mice was non-invasively monitored by longitudinal optical coherence tomography and by rotarod analysis. Immunomodulatory effects were subsequently analyzed by flow cytometry and immunohistochemistry and treatment effects regarding neural damage, and neurodegeneration were assessed by histology and immunohistochemistry. Results: Preventive treatment with teriflunomide attenuated the increase in number of CD8+ cytotoxic effector T cells and fostered the proliferation of CD8+ CD122+ PD-1+ regulatory T cells in the CNS. This led to an amelioration of axonopathic features and neuron loss in the retinotectal system, also reflected by reduced thinning of the innermost retinal composite layer in longitudinal studies and ameliorated clinical outcome upon preventive long-term treatment. Treatment of immune-incompetent PLP mutants did not provide evidence for a direct, neuroprotective effect of the medication. When treatment was terminated, no rebound of neuroinflammation occurred and histopathological improvement was preserved for at least 75 days without treatment. After disease onset, teriflunomide halted ongoing axonal perturbation and enabled a recovery of dendritic arborization by surviving ganglion cells. However, neither neuron loss nor clinical features were ameliorated, likely due to already advanced neurodegeneration before treatment onset. Conclusions: We identify teriflunomide as a possible medication not only for PMS but also for inflammation-related genetic diseases of the nervous system for which causal treatment options are presently lacking. KW - axonal degeneration KW - inflammation KW - proteolipid protein KW - T-lymphocytes KW - teriflunomide Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176524 VL - 15 IS - 194 ER - TY - JOUR A1 - Groh, Janos A1 - Abdelwahab, Tassnim A1 - Kattimani, Yogita A1 - Hörner, Michaela A1 - Loserth, Silke A1 - Gudi, Viktoria A1 - Adalbert, Robert A1 - Imdahl, Fabian A1 - Saliba, Antoine-Emmanuel A1 - Coleman, Michael A1 - Stangel, Martin A1 - Simons, Mikael A1 - Martini, Rudolf T1 - Microglia-mediated demyelination protects against CD8\(^+\) T cell-driven axon degeneration in mice carrying PLP defects JF - Nature Communications N2 - Axon degeneration and functional decline in myelin diseases are often attributed to loss of myelin but their relation is not fully understood. Perturbed myelinating glia can instigate chronic neuroinflammation and contribute to demyelination and axonal damage. Here we study mice with distinct defects in the proteolipid protein 1 gene that develop axonal damage which is driven by cytotoxic T cells targeting myelinating oligodendrocytes. We show that persistent ensheathment with perturbed myelin poses a risk for axon degeneration, neuron loss, and behavioral decline. We demonstrate that CD8\(^+\) T cell-driven axonal damage is less likely to progress towards degeneration when axons are efficiently demyelinated by activated microglia. Mechanistically, we show that cytotoxic T cell effector molecules induce cytoskeletal alterations within myelinating glia and aberrant actomyosin constriction of axons at paranodal domains. Our study identifies detrimental axon-glia-immune interactions which promote neurodegeneration and possible therapeutic targets for disorders associated with myelin defects and neuroinflammation. KW - diseases of the nervous system KW - myelin biology and repair KW - neuroimmunology Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357641 VL - 14 ER - TY - THES A1 - Hörner, Michaela T1 - The role of inflammation in hereditary spastic paraplegia type 11 T1 - Die Rolle von Entzündungsreaktionen bei hereditärer spastischer Paraplegie Typ 11 N2 - Hereditary spastic paraplegias (HSPs) are genetically-determined, neurodegenerative disorders characterized by progressive weakness and spasticity of the lower limbs. Spastic paraplegia type 11 (SPG11) is a complicated form of HSP, which is caused by mutations in the SPG11 gene encoding spatacsin, a protein possibly involved in lysosomal reformation. Based on our previous studies demonstrating that secondary neuroinflammation can be a robust amplifier of various genetically-mediated diseases of both the central and peripheral nervous system, we here test the possibility that neuroinflammation may modify the disease outcome also in a mouse model for SPG11. Spg11-knockout (Spg11-/-) mice develop early walking pattern and behavioral abnormalities, at least partially reflecting motor, and behavioral changes typical for patients. Furthermore, we detected a progressive increase in axonal damage and axonal spheroid formation in the white and grey matter compartments of the central nervous system of Spg11-/- mice. This was accompanied by a concomitant substantial increase of secondary inflammation by cytotoxic CD8+ and CD4+ T-lymphocytes. We here provide evidence that disease-related changes can be ameliorated/delayed by the genetic deletion of the adaptive immune system. Accordingly, we provide evidence that repurposing clinically approved immunomodulators (fingolimod/FTY720 or teriflunomide), that are in use for treatment of multiple sclerosis (MS), also improve disease symptoms in mice, when administered in an early (before neural damage) or late (after/during neural damage) treatment regime. This work provides strong evidence that immunomodulation can be a therapeutic option for the still untreatable SPG11, including its typical neuropsychological features. This poses the question if inflammation is not only a disease amplifier in SPG11 but can act as a unifying factor also for other genetically mediated disorders of the CNS. If true, this may pave the way to therapeutic options in a wide range of still untreatable, primarily genetic, neurological disorders by repurposing approved immunomodulators. N2 - Hereditäre spastische Paraplegien (HSPs) sind genetisch-determinierte, neurodegenerative Erkrankungen, die durch eine progressive Schwäche und Spastizität der unteren Extremitäten charakterisiert sind. Die spastische Paraplegie Typ 11 (SPG11) ist eine komplizierte Form der HSP, die durch eine Mutation des SPG11 Gens hervorgerufen wird. Dieses Gen kodiert Spatacsin, ein Protein, das wahrscheinlich in der lysosomalen Reformation eine Rolle spielt. Frühere Studien unserer Arbeitsgruppe konnten zeigen, dass sekundäre Entzündungsreaktionen verschiedene genetisch-determinierte Krankheiten des zentralen und peripheren Nervensystems verstärken können. Daher haben wir hier untersucht, ob neuroinflammatorische Reaktionen auch in einem Mausmodell für SPG11 den Krankheitsverlauf beeinflussen. Spg11-knockout (Spg11-/-) Mäuse entwickeln frühzeitige Gangveränderungen und Verhaltensauffälligkeiten, welche die Veränderungen der Patienten, zumindest teilweise, abbilden. Außerdem konnten wir eine progressive Zunahme von axonalem Schaden und die Bildung von axonalen Schwellungen in der weißen und grauen Substanz des zentralen Nervensystems von Spg11-/- Mäusen feststellen. Dies wurde von einer deutlichen Zunahme einer sekundären Entzündungsreaktion in der weißen und grauen Substanz durch zytotoxische CD8+ und CD4+ T-Lymphozyten begleitet. Wir zeigen hier, dass diese krankheitsbedingten Veränderungen durch eine genetische Deletion von Teilen des adaptiven Immunsystems verbessert bzw. ihr Auftreten hinausgezögert werden können. Entsprechend zeigen wir, dass eine Behandlung mit klinisch etablierten Immunomodulatoren (Fingolimod/FTY720 oder Teriflunomid), die zu der Behandlung der Multiplen Sklerose (MS) eingesetzt werden, den Krankheitsverlauf positiv beeinflusst, wenn sie in einem frühzeitigen (Gabe vor neuronalem Schaden) oder späten (Gabe nach/während neuronalem Schaden) Behandlungsversuch appliziert werden. Diese Arbeit deutet stark darauf hin, dass Immunomodulation eine Therapiemöglichkeit für die noch nicht behandelbare Krankheit SPG11 sein könnte, inklusive der typischen neuropsychologischen Auffälligkeiten. Das wirft die Frage auf, ob sekundäre Entzündungsreaktionen nicht nur einen krankheitsverstärkenden Effekt in SPG11 haben, sondern als ein vereinender Faktor für andere genetisch determinierte Krankheiten des ZNS fungieren können. Dies könnte den Weg dahin ebnen das Fortschreiten anderer unheilbarer, primär genetisch bedingter, neurologischer Erkrankungen durch eine individuelle Behandlung mit auf dem Markt verfügbaren immunomodulatorischen Medikamenten zu verlangsamen. KW - Entzündung KW - Immunmodulation KW - Hereditary spastic paraplegia KW - Hereditäre spastsiche Paraplegie KW - Approved immunomodulators KW - Nervendegeneration KW - Neurodegenerative Erkrankung KW - Entzündungsreaktion KW - Inflammation Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-303368 ER -