Pathological angiogenesis can cause loss of vision and is associated with many diseases of the eye for which there exists no effective treatment. In January 8 Proceedings of the National Academy of Sciences, two papers by teams from The Scripps Research Institute, La Jolla, USA, described the unexpected antiangiogenic activity of a fragment of the human protein tryptophanyl-tRNA synthetase (TrpRS), a molecule also known to be involved in protein synthesis and cell proliferation.

Atsushi Otani and colleagues observed that a recombinant fragment of TrpRS is a potent antagonist of vascular endothelial growth factor-induced angiogenesis in a murine model. The effect was also confirmed in naturally occurring retinal angiogenesis in the neonatal mouse (Proc Natl Acad Sci USA 2002, 99:178-183).

In a second study Wakasugi et al. showed that a natural fragment of TrpRS is angiostatic in a mammalian cell culture system, chick embryos, and two...