Fig. 9. TGF-β signaling via microglia-derived TGF-β1 ligand or ALK5-dependent signaling is required for the repopulation of homeostatic microglia after PLX5622 ablation.

A Mouse model for Tgfb1 and Alk5 iKO in microglia and experimental design. B, C Representative images of B control, C Cx3cr1^CreERTgfb1^fl/fl, and D Cx3cr1^CreERAlk5^fl/fl mice showing immunostaining of IBA1, TMEM119, Ki67, P2RY12, CD68, and GFAP. Quantification of microglial morphology by E terminal end number (**p = 0.0044 and p = 0.0053) and F and process length (**p = 0.0022 and p = 0.0014). G Total microglia count (****p < 0.0001). H Quantification of astrocyte reactivity using GFAP immunoreactivity (**p = 0.0057 and p = 0.0032). E–H, n = 6, 3, 4 for each group, one-way ANOVA, two-sided, Tukey’s multiple comparisons). Mean ± SE, each data point represents the average of a single animal. Scale bar = 100 µm. A Created with BioRender.com and released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license. Source data are provided as a source data file.