Figure 6.

Inactivation of Vegfa in Macrophages Inhibits Vascularization of the Nerve Bridge after Nerve Transection

(A) Representative images of longitudinal sections of injured sciatic nerves from Vegfa^fl/fl (control), Vegfa^fl/flLysm^Cre, and Vegfa^fl/flTie2-Cre mice, Day 5 after transection, immunostained to detect ECs (CD31⁺, red) and SCs (p75^NTR+, green). Scale bar, 50 μm.

(B) Quantification of (A) showing the proportion of CD31-positive area per bridge area and shows that the vascularization of the bridge is significantly reduced in mutants animals (n = 5).

(C) Quantification of (A) showing the area of SC influx from the proximal and distal stumps in Vegfa^fl/fl versus Vegfa^fl/flTie2-Cre animals (n = 5).

(D) Representative images of longitudinal sections of injured sciatic nerves from wild-type that have received bone marrow from Vegfa^fl/fl (control) or Vegfa^fl/flTie2-Cre mice immunostained to detect ECs (CD31⁺, red), SCs (p75^NTR+, green), and axons (NF⁺, blue), Day 5 after transection. Scale bar, 100 μm.

(E) Quantification of (D) showing the proportion of CD31-positive area per bridge area (n = 3 for each group).

(F) Representative images of longitudinal sections of injured sciatic nerves of Vegfa^fl/flTie2-Cre mice, Day 5 after transection following injection of PBS or VEGF-A¹⁸⁸ into the bridges at Day 4. Scale bar, 100 μm.

(G and H) Quantification of (F) showing the blood vessel density (G) or area of infiltrating SCs (H) (n = 4). For reconstruction of longitudinal sections shown in (A), (D) and (F), multiple images from the same sample were acquired using the same microscope settings.

Graphs show mean value ± SEM. See also Figure S6.