1. Inflammatory stimuli downregulate macropinocytosis of exosomes in microglia.
Inflammatory stimuli downregulate macropinocytosis of exosomes in microglia. (A) Primary microglia were treated for 24 hours with IFNγ or left untreated. Purified exosomes labelled with the dye PKH67 (green) or 40 kDa FITC-conjugated Dextran were incubated for 2 hours with primary microglia (exosomes from 1×107 Oli-neu cells per well) and internalisation was determined by FACS. (B) Primary microglia were treated for 24 hours with different concentration of LPS and uptake of purified exosomes was determined by microscopy and image analysis. Values represent means ± s.e.m. of three independent experiments (*P<0.05; **P<0.01; ***P<0.001). (C) Microglia were treated for 8–12 hours with IFNγ before adding purified labelled exosomes to the cells for 2 hours. Microglia were fixed, permeabilised and stained for MHCII. Scale bar: 10 μm. Average fluorescence intensities were determined for exosomes (green) and MHC II (red) by image analysis from two independent experiments, as depicted in the graph.
Dirk Fitzner et al. J Cell Sci 2011;124:
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