FIG. 6.

Decreased retinal angiogenesis in adam15^−/− mice in a mouse ROP model. (A) Wild-type (WT) and adam15^−/− (−/−) mice were subjected to the ROP model, and the ensuing neovascularization in the retina was evaluated as described in Materials and Methods. A significantly decreased angiogenic response was observed in adam15^−/− mice compared to wild-type animals. The bars represent the average value. (B) Western blot analysis of ADAM15 expression in the retinas of mice subjected to the ROP model, analyzed at different time points after the return to room air (top panel). As a control, a Western blot of retinas from age-matched untreated mice is shown in the lower panel. Each lane contains the lysate of one retina. ADAM15 expression is significantly upregulated 1 day after the return to room air (P13). The upregulation persists for at least 4 days and ADAM15 expression in the retina returns to the basal levels by P19. (C) Serial sections of the retinas of wild-type mice subjected to the ROP model stained with ADAM15 or PECAM-1. Prominent expression of ADAM15 is found in the endothelial cells migrating into the vitreous body. The staining pattern of PECAM-1 is very similar to that of ADAM15. Scale bar, 50 μm. (D) Confluent HUVECs were incubated without additional supplement (lanes −), with VEGF (20 ng/ml) (lanes V), or bFGF (20 ng/ml) (lanes F) after 12 h of starvation. Neither addition of VEGF nor addition of bFGF detectably affected the expression level of ADAM15 protein in HUVECs.