Fig. 4

Interferon-responsive microglia functionally impede myelination by mature oligodendrocytes. A Diagram of treatment of neonatal microglia cultures with IFNγ and LPS, or vehicle control, and application of conditioned media to myelinating cultures of oligodendrocytes and neurons. B Representative images of cultures exposed to conditioned media (CM) from vehicle (PBS)-treated microglia or IFNγ and LPS-treated microglia, with myelin indicated by MBP (red), axons indicated by NF (green), and nuclei counterstained with Hoechst (blue). Scale bar, 25 µm. C Percentage of oligodendrocytes (MBP +) which have myelinating processes (grey) versus non-myelinating processes (pink) following treatment with CM from vehicle-treated or IFNγ/LPS-treated microglia, or with IFNγ/LPS directly applied to myelinating cultures. Unpaired 2-tailed Student’s t-test, *P = 0.0428 for non-myelinating processes, and *P = 0.0428 for myelinating processes, for IFNγ/LPS CM versus Veh CM. N = 3 biologically independent repeats. D Percentage of MBP area in myelinating cultures exposed to vehicle (Veh) or IFNγ/LPS-treated microglia CM. Unpaired 2-tailed Student’s t-test, *P = 0.0455. N = 3 biologically independent repeats. E MBP Disruption as measured by sphericity in myelinating cultures exposed to Veh or or IFNγ/LPS treated microglia CM. Unpaired 2-tailed Student’s t-test, ***P = 0.0001. N = 3 biologically independent repeats