Pexidartinib treatment in Alexander disease model mice reduces macrophage numbers and increases glial fibrillary acidic protein levels, yet has minimal impact on other disease phenotypes.
J Neuroinflammation 2021;
18:67. [PMID:
33685480 PMCID:
PMC7941726 DOI:
10.1186/s12974-021-02118-x]
[Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND
Alexander disease (AxD) is a rare neurodegenerative disorder that is caused by dominant mutations in the gene encoding glial fibrillary acidic protein (GFAP), an intermediate filament that is primarily expressed by astrocytes. In AxD, mutant GFAP in combination with increased GFAP expression result in astrocyte dysfunction and the accumulation of Rosenthal fibers. A neuroinflammatory environment consisting primarily of macrophage lineage cells has been observed in AxD patients and mouse models.
METHODS
To examine if macrophage lineage cells could serve as a therapeutic target in AxD, GFAP knock-in mutant AxD model mice were treated with a colony-stimulating factor 1 receptor (CSF1R) inhibitor, pexidartinib. The effects of pexidartinib treatment on disease phenotypes were assessed.
RESULTS
In AxD model mice, pexidartinib administration depleted macrophages in the CNS and caused elevation of GFAP transcript and protein levels with minimal impacts on other phenotypes including body weight, stress response activation, chemokine/cytokine expression, and T cell infiltration.
CONCLUSIONS
Together, these results highlight the complicated role that macrophages can play in neurological diseases and do not support the use of pexidartinib as a therapy for AxD.
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