UDP-Induced Phagocytosis and ATP-Stimulated Chemotactic Migration Are Impaired in STIM1^−/− Microglia In Vitro and In Vivo

Figure 4

Retarded peripheral localization of Orai1 in STIM1^−/− microglia upon UDP stimulation. UDP induces movement of Orai1 (green) and STIM1 (red) in WT microglia (a) and STIM1^−/− microglia (b), respectively. Treatment with 100 μM UDP for 40 min increased Orai1 localization at the cell surface throughout the cell border in WT(a) and STIM1^−/− microglia (b). Insets were magnified following separated three (a) or one image (b). Orai1-FITC-intensity profiles in red lined regions were shown in each of the rightmost images. The cell border is indicated by dotted lines. Clustered Orai1 in peripheral regions of WT microglia were indicated by white arrows, and the absence of Orai1 in peripheral regions of STIM1^−/− microglia was indicated by black arrows. (c) Intensity of surface Orai1 in cell periphery was compared with the UDP condition. Intensity of surface Orai1 in cell periphery was determined by the intensity of ROI with 0.65 μm away from the cell edges, using MetaMorph software.

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