Fig. 6.

YAP/TAZ are mediators of VEGF-induced angiogenesis ex vivo and in vivo. a–c Pharmacological inhibition of YAP/TAZ reduces angiogenesis ex vivo in a rat aorta model. Sections of aorta were cultured for 7 days in Matrigel with 100 ng ml⁻¹ VEGF and the indicated concentrations of VP. Representative images are shown in a. Sprout area is quantified in b. Scale bar denotes 500  μm. c Immunostaining of aorta sections demonstrates that outgrowths are positive for VE-cadherin. Scale bar denotes 300 μm. Wimasis image analysis software was used to visualize sprouts (n = 3). d Transient knockdown of YAP/TAZ or pharmacological inhibition of YAP/TAZ with VP reduces angiogenesis by HUVECs in vivo in Matrigel plug experiments. Five million cells were injected subcutaneously into mice with Matrigel and 200 ng mL⁻¹ VEGF. VP was administered by intraperitoneal injection every other day. Plugs were excised after 1 week. Representative images are shown in the top two rows. In the bottom panels, angiogenesis in the Matrigel plugs was stained by IHC for the human endothelial cell marker hCD31. Scale bar denotes 500 μm. e YAP/TAZ inhibition reduces endogenous angiogenesis in vivo in Matrigel plug experiments. Matrigel plugs with 200 ng ml⁻¹ VEGF were implanted subcutaneously in mice. VP was administered by intraperitoneal injection every other day. Plugs were excised after 2 weeks. Angiogenesis was assessed by IHC staining for mouse mCD31 endothelial cell marker. Scale bar denotes 500 μm. f–h YAP/TAZ inhibition diminishes angiogenesis in vivo in a mouse retinal model. Mice were injected with 1 mg kg⁻¹ VEGF with or without 100 mg kg⁻¹ VP at postnatal day 3 (P3) and 4 (P4). At P5, retinal blood vasculature was stained. Representative images of the retinal vessel density are shown in f, whereas g shows images of the vascular front. Scale bar denotes 100 μm f or 30 μm g. Number of filopodia (active angiogenesis) is quantified in h. Each data point represents the average of two retinas from a single mouse (n = 4 for control, n = 3 for VP). *p < 0.05 in two-sample unpaired t-test. All data are represented as mean ± SD