Fig. 8

dBET6 treatment inhibits STING expression in microglia/macrophages in response to LD. A, C Average expression of known microglia marker genes are used to identify the mouse (A) and human (C) retinal microglia cell cluster. Violin plots of genes previously reported to be enriched in microglia cell populations are plotted (cellmarker2.0, http://yikedaxue.slwshop.cn/). Mouse sc-RNA data are extracted from https://github.com/jiewwwang/Single-cell-retinal-regeneration, and human sc-RNA data can be accessed by GEO#: GSE137537. B, D Dot plot of cGAS-STING signaling genes and BRD4 in retinal microglia. E IHC shows indicated protein expression in mouse retina. Note STING-positive cells were localized to the GCL, IPL and INL in control mice. LD led to infiltration of IBA1-positive macrophages/microglia to the photoreceptors, and most of these infiltrating/reactive mononuclear phagocyte show STING staining (enlarged figure b). Administration of dBET6 reduced IBA1-positive cell in the photoreceptors and STING signal (enlarged figure c). Scale bar: 50 μm. D. IF analysis of retinal flat mounts. Note the evident overlapping of STING and IBA1 in both ramified (resting) and amoeboid-shaped (reactive) microglia/macrophages. Scale bar: 50 μm. E Quantification of STING IF intensity from the retinal flat mounts. For each group, six to ten regions were randomly selected in the whole mounts, the intensity of STING signal was measured by Image J. About 30 cells measured for Vehicle or LD + Vehicle, and ~ 60 cells measured for LD + dBET6. ****: p < 0.0001, One-way ANOVA, Tukey’s test, n = 3 retinas per group