What prevents our tissues from drowning in their own fluid? Mammals develop a unique vascular network called the lymphatic system, which drains excess fluids from our tissues to prevent swelling of our extremities and helps to maintain our proper osmotic balance. In the January 2004 issue of Nature Immunology, researchers identify a critical factor, vascular endothelial growth factor C (VEGF-C), which is required to develop and maintain this drainage system.
Mice lacking VEGF-C die before birth due to distorted organ swelling. Even adult mice that harbor only one defective Vegfc gene copy still develop swollen paws and defects in immune cell trafficking throughout their bodies. Alitalo and colleagues find that VEGF-C provides the signal to form lymphatic veins, which are distinct from blood veins.
VEGF-C commands the cells that form these vessels to migrate in developing embryonic tissues and coalesce to form the lymphatics. The new results suggest that mutations in VEGFC might be responsible for a human genetic predisposition to lymphedema – a condition marked by gross swelling of the extremities. This work will enlighten our understanding of internal fluid containment and provide animal models to test potential future therapies for the treatment of patients with lymphedema.
University of Helsinki, Finland
Tel: +358 9 1912 5511
Additional Contact For Comment On Paper:
Harvard Medical School
Tel: +1 617 355 7661
Also available online.
(C) Nature Immunology press release.
Message posted by: Trevor M. D'Souza