FIGURE 8.

Genetic elimination of Tlr4 results in milder light-induced retinal degeneration in Abca4^−/−Rdh8^−/− mice. Tlr4^−/−Abca4^−/−Rdh8^−/− mice were established by cross-breeding Abca4^−/−Rdh8^−/− mice with Tlr4^−/− mice. Abca4^−/−Rdh8^−/− mice from littermates were used as controls. Retinal degeneration was induced by exposing mice to 10,000 lux light for 30 min. A, ONL thickness was measured by OCT (left) and numbers of AF spots were counted by SLO (right) 7 days after light exposure. *, indicates p < 0.05. B, rod and cone photoreceptors were stained by anti-rhodopsin (Rho) Ab (red) and peanut agglutinin lectin (PNA) (green), respectively (upper and middle panels). Middle panels are magnified images of the dashed rectangles in the upper panel. Müller cells and astrocytes were stained by anti-GFAP Ab (lower panels). Bars indicate 50 μm. C, microglial activation was examined by staining with anti-MHC Class II (green) and anti-Iba1 (red) Abs. Nuclei were stained by DAPI (blue). Fewer numbers of activated microglia with double positive staining were counted in Tlr4^−/−Abca4^−/−Rdh8^−/− (tKO) mice relative to Abca4^−/−Rdh8^−/− (dKO) mice. Bars indicate 50 μm. * indicates p < 0.05.