Fig. 5: Conditional knockout of Srr in the microglia improved AD pathology in the hippocampi of male 5×FAD mice.
The mouse brains were processed for paraffin-embedded sections, which were subjected to staining with Aβ antibody 6E10. A Representative immunofluorescence images of the hippocampi are depicted. The 6E10 staining (red) was used to visualize Aβ plaques, Iba1 (green) to label activated microglia, and DAPI (blue) to mark cell nuclei. Images were captured with ZeissLSM880 confocal laser microscope system (Zeiss) under a 40× objective. Bar: 500 μm for the first column. The images were magnified in the second column with a scale bar of 100 μm. B In dentate gyri, 5×FAD;Lyz2cre;Srrfl/fl mice (n = 3) exhibited fewer Aβ plaques compared to 5×FAD;Srrfl/fl mice (n = 3). Student’s t test was used to compare the numbers of Aβ plaques in dentate gyri; t[4] = 9.214, p = 0.001. The 5×FAD;Lyz2cre;Srrfl/fl mice showed a significant reduction in the total fluorescence intensity (int.) of Aβ plaques relative to 5×FAD;Srrfl/fl control. Student’s t test was used to compare the total fluorescence intensity (int.) of Aβ plaques; t[4] = 2.789, p = 0.049. The total area of Aβ plaques was less in 5×FAD;Lyz2cre;Srrfl/fl mice than that in 5×FAD;Srrfl/fl control mice. Student’s t test was used for comparison; t[4] = 5.208, p = 0.006. There were no significant differences in the mean fluorescence intensity (int.) or mean area of Aβ plaques between 5×FAD;Lyz2cre;Srrfl/fl mice and 5×FAD;Srrfl/fl control (n = 3). Student’s t test was used to compare the mean fluorescence intensity (int.) with t[4] = 0.769, p = 0.485, and the mean area of Aβ plaques with t[4] = 0.082, p = 0.939. A significantly higher number of Iba1-positive microglia was present in the dentate gyri of 5×FAD;Lyz2cre;Srrfl/fl mice relative to 5×FAD;Srrfl/fl control mice. Student’s t test was used for comparison; t[4] = 6.379, p = 0.003. Error bars denote the variability of the data.
