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CSF1 over‐expression has pleiotropic effects on microglia in vivo (844.13)
Author(s) -
De Ishani,
Nikodemova Maria,
Steffen Megan,
Sokn Emily,
Watters Jyoti,
Collier Lara
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.844.13
Subject(s) - microglia , in vivo , neurodegeneration , macrophage colony stimulating factor , biology , microbiology and biotechnology , cytokine , neuroinflammation , immunology , macrophage , cancer research , inflammation , medicine , in vitro , pathology , biochemistry , disease
Increased microglial numbers and activated microglial phenotypes are associated with many central nervous system (CNS) disorders including gliomas, neurodegeneration and brain injury. Thus, microglia are being tested as potential drug targets. Macrophage Colony Stimulating Factor (CSF1), an important cytokine for microglia and macrophages, is upregulated in these CNS disorders, but the effects of CSF1 on microglial phenotypes have not been well‐characterized in vivo . To study the effects of CSF1 over‐expression on microglia in the unperturbed CNS in vivo, we generated a transgenic mouse model in which CSF1 is inducibly over‐expressed in the GFAP compartment. We found that CSF1 over‐expression results in increased microglial proliferation, increased microglial numbers and an altered microglial phenotype compared to control mice. Microglia in CSF1 over‐expressing mice do not exhibit gene expression profiles typical of either M1 or M2 polarization, however they are defective in their response to the inflammatory stimulus LPS. Treatment with a small molecule inhibitor of the CSF1 receptor (CSF1R) and related kinases, decreased microglial numbers through apoptosis in both CSF1 over‐expressing and control mice. These results indicate that CSF1 signaling has multiple effects on microglia in vivo , and pharmacological inhibition of this signaling pathway may have efficacy in reversing the pathological levels of microglial accumulation in various CNS diseases by promoting microglial apoptosis. Moreover, our CSF1 over‐expressing genetic model should have utility for studying the impact of CSF1 over‐expression in mouse models of human disease. Grant Funding Source : Goldhirsh Foundation, the University of Wisconsin Graduate School and the NIH