BioCentury
ARTICLE | Targets & Mechanisms

Norrin vs. VEGF

November 5, 2009 8:00 AM UTC

Two papers in Celldescribe a new signaling pathway that acts upstream of VEGF to control vascular development in the embryonic retina. The pathway is also present in adults, but the question is whether it's actually active and thus potentially targetable in diseases of retinal neovascularization, including diabetic retinopathy, retinopathy of prematurity and potentially wet age-related macular degeneration.

One study, from a team at The Johns Hopkins University School of Medicine, establishes how a secreted proangiogenic protein called Norrie disease pseudoglioma (NDP; Norrin) interacts with its receptor, frizzled homolog 4 (FZD4), to enable vascular growth during embryonic development.1 The other study, from a team at the Genentech Inc. unit of Roche, identifies an additional protein at the cell surface, tetraspanin 12 (TSPAN12), that helps FZD4 bind to Norrin.2...