Figure 6.

Effect of retinal microglial depletion on Müller cells and retina astrocytes. A, mRNA expression levels were assessed using NGS and rtPCR. Comparisons were made between TG mice gavaged with corn oil without tamoxifen (TG Control), and animals depleted of microglia with continuous administration of TAM in corn oil for 15 and 30 d. Levels of Müller cell-expressed genes that are typically upregulated in the context of activation (GFAP, S100A6, vimentin) were increased with microglial depletion. (pairwise comparisons made with one-way ANOVA; *indicates comparisons relative to TG control for which p < 0.05, n = 3 male, 8-week-old animals per group). B, Immunolabeling of retinal astrocyte processes for GFAP and Müller cell end-feet processes for glutamine synthetase (GS) in the ganglion cell layer of retinal flat-mounts demonstrated a similar density and organization of processes in microglia-depleted retinas (TG Depleted) relative to controls. C, GS-immunopositive Müller cells, as viewed in retinal sections, have similar morphologies in TG-depleted retinas (with ablated CD11b immunostaining following microglial depletion) compared with TG Control (top). Müller cells also failed to upregulate GFAP expression in their cellular processes following microglial depletion in TG-depleted retinas (with ablated Iba1 immunostaining), similar to that in TG control retinas (bottom). Scale bars, 30 μm.