Figure 4.

Angiogenesis in Müller cell–specific sEH knockout mice. (A) sEH expression (red) in cryosections from sEH^fl/fl and sEH^ΔMC littermates. Bars, 50 µm. Endothelial cells were identified using Isolectin B4 (green), and Müller cells by GS (blue) using confocal microscopy. Similar observations were made in 4 additional experiments. (B) sEH activity was assessed by LC-MS/MS in fresh retinas and cultured Müller cells (MCs) from sEH^fl/fl and sEH^ΔMC littermates. Each sample was a pool of 3 retinas, and the analysis was performed on 4 independent samples per genotype (graph shows pooled data from the four analyses). (C) Isolectin B4 staining of retinal whole mounts of P2 and P5 retinas from sEH^fl/fl and sEH^ΔMC mice. Bars, 500 µm. (D and E) Quantification of vessel radial expansion (D), vascularized area, and vessel branch points (E) in sEH^fl/fl and sEH^ΔMC mice at P5 based in data in C. n = 5–7 total mice from 3–4 different experiments. (F) Isolectin B4–stained tip cells and filopodia at P5 assessed by confocal microscopy. Bar, 50 µm. (G and H) Quantification of tip cells (G) and filopodia numbers (H) in P5 retinas based on data in F. n = 6 total mice from 3–4 different experiments. (I) Notch pathway gene expression in retinas from sEH^ΔMC relative to sEH^fl/fl mice was assessed by RT-qPCR. Each sample was a pool of 3 retinas, and the assay was performed on 4 independent samples per genotype. Error bars represent SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001 versus sEH^fl/fl.