Fig. 5: Dura mater macrophages play minor role in meningeal vascular regeneration.
From: VEGFR2 signaling drives meningeal vascular regeneration upon head injury
a Representative images of VEGF-A expression by detection of β-galactosidase activity in VEGF-LacZ mice at D3. High expression of VEGF-A is detected in neighboring calvarial bone (yellow arrowheads), F4/80+ macrophages (yellow arrows) in brain, and LYVE1+ macrophages (white arrowheads) in pia mater. Similar findings were observed in n = 3 mice from two independent experiments. Scale bars, 500 µm. b Representative images of VEGF-A in Osterix+ (Osx+) osteogenic progenitor cells/osteoblasts along the endosteal surface of calvarial bone of adult mice at D3 after PTI. No difference in VEGF-A between S3 and D3 is shown. Similar findings were observed in n _= 3 mice from two independent experiments. DM Inter., dura mater interface. Scale bars, 10 µm. c, d Relative mRNA expressions of Vegfa, Vegfc, and Pgf in whole dura mater tissue and VEGF-A protein concentrations in the dura mater (DM) and brain at D3. Each dot indicates a value obtained from one mouse and n = 6 c, n = 4 d mice/group from three independent experiments. Vertical bars indicate mean ± SD. n.s., not significant versus each S3 by two-tailed Mann–Whitney U test. e Heatmap of Vegfa expression based on single-cell RNAseq analysis of CD45+ hematopoietic cells isolated from dura mater and brain at D3. Emergence of infiltrating macrophages with high Vegfa expression is observed after PTI. f Feature plots showing Vegfa expression in various CD45+ hematopoietic cell clusters at D3. Note emergence of infiltrating macrophages showing high Vegfa expression only in brain after PTI (red dotted circle). g, h Representative images and comparisons of vascular regeneration in the dura mater between control mice and CX3CR1-DTR mice (two cases #1 and #2 are shown) at D7. White dotted-lined circles indicate putative injury areas. Scale bars, 500 µm. Each dot indicates a mean value obtained from one mouse and n = 4 (S3), n = 6 (D3) mice/group from two independent experiments. Vertical bars indicate mean ± SD. n.s., not significant versus control by two-tailed Mann–Whitney U test.
